JPH0813154A - Zinc-containing metal-plated steel sheet composite having excellent paintability, and method for producing the same - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a zinc-containing metal plated steel sheet composite having excellent coating performance and a method for producing the same. [Constitution] The surface of the zinc-containing metal plated steel sheet contains zinc and phosphorus at a weight ratio of zinc / phosphorus = 2.504: 1 to 3.166: 1, and further Fe, Co, Ni, Ca, Mg, M
A zinc phosphate composite coating (0.3 to 3.0 g / m ² ) containing 0.06 to 9.0% by weight of one or more of n is formed by an electrolytic method or a chemical conversion treatment, and fine A phosphate conversion film having a different crystal size is formed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a zinc-containing metal-plated steel sheet composite having excellent coating properties, particularly coating adhesion in electrodeposition coating properties, and excellent corrosion resistance after coating, and a method for producing the same. is there.

[0002]

2. Description of the Related Art Conventionally, as steel plates for automobile bodies, steel plates plated with zinc-containing metal (hereinafter referred to as zinc-containing metal-plated steel plates) have been widely used in order to suppress pitting corrosion and red rust generation. There is. In particular, in recent years, in order to further enhance the rust preventive power, the weight of the zinc-containing metal plating layer has been increased so as to increase the weight.

However, the conventional zinc-containing metal-plated steel sheet coated after the phosphate treatment has a drawback that the coating film is likely to swell in a wet environment. As a conventional means for solving this problem, Japanese Patent Publication No. 5-5905 discloses that a nickel-iron alloy having a specific composition is deposited on a surface of a zinc-containing alloy material or a plating film of an aluminum-containing alloy by a specific amount by cathodic electrolysis. A plated steel sheet that has been obtained by the above method and is excellent in chemical conversion treatment such as phosphate treatment has been introduced, but since this method is an electrolytic method, the required equipment is expensive and electricity is used for manufacturing. In order to
It has the drawback of high manufacturing costs.

On the other hand, JP-A-2-228482 discloses that a metal surface is treated with an acidic zinc phosphate treatment aqueous solution containing colloidal particles having an isoelectric point of 3 or less and a dispersed particle diameter of 0.1 μm or less. , A method of forming a zinc phosphate film having excellent coating performance is shown. However, in this method, since the processing time is long, the manufacturing cost is high,
It has the drawback of reduced productivity.

In view of the current state of the art as described above, a zinc-containing metal-plated steel sheet composite having excellent coatability, excellent corrosion resistance and coating adhesion after coating, and a low cost and highly efficient production thereof There is a strong demand for development of a method for producing a zinc-containing metal-plated steel sheet composite having excellent paintability.

[0006]

DISCLOSURE OF THE INVENTION The present invention provides a zinc-containing metal-plated steel sheet composite having excellent coatability and excellent corrosion resistance and coating adhesion after coating, and high efficiency,
It is intended to provide a manufacturing method at low cost.

[0007]

The zinc-containing metal-plated steel sheet composite having excellent coatability of the present invention is formed on the surface of a base body made of a zinc-containing metal-plated steel sheet, and the weight ratio of zinc and phosphorus is (zinc / phosphorus). Phosphorus) 2.504: 1 to 3.166:
1, and a zinc phosphate composite coating containing at least one metal selected from iron, cobalt, nickel, calcium, magnesium and manganese at a content of 0.06 to 9.0% by weight, and It is characterized in that it has a phosphate chemical conversion film formed on the zinc phosphate composite film and having a fine crystal size.

In the zinc-containing metal plated steel sheet composite of the present invention, the zinc phosphate composite coating contains at least one metal selected from nickel and manganese in an amount of 1.0 to 9.
The content is preferably 0% by weight.

In the zinc-containing metal-plated steel sheet composite of the present invention, the amount of the zinc phosphate composite coating deposited is 0.3 to 3.
It is preferably 0 g / m ² .

In the zinc-containing metal plated steel sheet composite of the present invention, it is preferable that the phosphate conversion coating has a fine crystal size of 1 to 12 μm.

In order to produce the zinc-containing metal-plated steel sheet composite of the present invention, the method for producing a zinc-containing metal-plated steel sheet composite having excellent coatability according to the present invention comprises: Components (1) to (4): (1) Phosphate ion 5 to 30 g / liter (2) Nitrate ion 1.0 to 15 g / liter (3) Zinc ion 0.1 to 8.0 g / liter (4) Iron Ion, nickel ion, manganese ion, cobalt ion, calcium ion, and magnesium ion, and at least one kind of metal ion 0.1 to 8.0 g / liter is contained, and the zinc ion, other than the above The zinc phosphate composite film is formed by performing cathodic electrolysis treatment with an electrolytic plating solution having a weight ratio to all metal ions of 1:10 to 10: 1. It is characterized in that a phosphate chemical conversion treatment is applied to the composite coating to form the phosphate chemical conversion coating having the fine crystal size.

In the method of the present invention, it is preferable that the cathodic electrolysis treatment is performed at a current density of 0.2 to 30 A / dm ² .

The method for producing a zinc-containing metal-plated steel sheet composite excellent in coatability of the present invention comprises the steps of producing a zinc-containing metal-plated steel sheet composite of the present invention on the surface of a zinc-containing metal-plated steel sheet. The following components (1) to (4): (1) Phosphate ion 10 to 30 g / liter (2) Nitrate ion 1.0 to 15 g / liter (3) Zinc ion 0.1 to 8.0 g / liter (4) At least one metal ion selected from iron ion, nickel ion, manganese ion, cobalt ion, calcium ion, and magnesium ion 0.1 to 8.0 g / liter is contained, and the zinc ion, other than the above The weight ratio to all metal ions is 1:10 to 10: 1 and is a small amount selected from peroxides, fluoride ions, complex fluoride ions, and nitrite ions. A chemical conversion treatment liquid further containing at least one type of reaction accelerator is contacted to form the zinc phosphate composite coating, and the zinc phosphate composite coating is subjected to phosphate chemical conversion treatment to form the fine powder. It is characterized by forming a phosphate conversion film having a crystal size.

In the above-mentioned method of the present invention, the reaction accelerator is contained in the chemical conversion treatment solution in an amount of 0.01 to 8.0 g / liter (however, in the case of fluoride ion and complex fluoride ion, converted to the amount of fluorine ion. It is preferably contained at a concentration of

In the above method of the present invention, it is preferable that the phosphate conversion coating has a fine crystal size of 1 to 12 μm.

In the method of the present invention, the surface of the zinc-containing metal-plated steel sheet is previously treated with a treatment liquid containing (a) at least one metal selected from nickel ions and cobalt ions, and the surface is treated. To the above, an activation treatment for adhering the at least one metal at a metal attachment amount of 0.2 to 50 mg / m ² , (b) an activation treatment for treating with a titanium colloid aqueous solution, or (c) an etching treatment liquid It is preferable to carry out an activation treatment for removing the metal oxide.

[0017]

In the zinc-containing metal-plated steel sheet composite of the present invention, the zinc-containing metal-plated steel sheet used as the substrate is zinc, or zinc and other elements such as nickel,
It is a steel plate plated with an alloy of one or more selected from iron, aluminum, manganese, chromium, lead, antimony, and the like. The plating method is not particularly limited,
Hot dip galvanizing method, alloying hot dip galvanizing method, electrogalvanizing method, and electrogalvanizing alloy (Zn-Ni, Zn-F
e, Zn-Mn or Zn-Cr alloy) plating method, hot-dip Zn-Al plating method, vapor deposition plating method and the like.

The zinc phosphate composite coating of the present invention will be described in detail. Zinc and phosphorus are the main constituents of the composite coating, and their weight ratio (zinc / phosphorus) is 2.50.
4: 1 to 3.166: 1, and the iron in this coating,
0.06 to 9.0 of one or more metals selected from cobalt, nickel, calcium, magnesium and manganese.
It is contained at a content rate of% by weight.

It is considered that a part of zinc is present in the above composite coating in a form in which it is replaced with another divalent or higher valent metal. When the weight ratio of zinc and phosphorus exceeds 3.166: 1 and the content of one or more metals selected from iron, cobalt, nickel, calcium, magnesium and manganese is less than 0.06% by weight. However, the composite obtained by further subjecting it to a phosphate conversion treatment has insufficient electrodeposition coatability and coating performance after topcoating. On the other hand, when the weight ratio of zinc to phosphorus is less than 2.504: 1, and the content of one or more metals selected from iron, cobalt, nickel, calcium, magnesium and manganese exceeds 9.0% by weight. In this case, although the coating performance of the composite obtained by further subjecting it to a phosphate treatment is good, the performance is saturated and the production cost becomes high, which is economically disadvantageous.

The metal other than zinc in the zinc phosphate composite coating is selected from iron, cobalt, nickel, calcium, magnesium and manganese, and its content is 0.06 to 9.0.
When the content is controlled within the range of weight%, the composite obtained by further subjecting it to a phosphate treatment has good coating performance after electrodeposition coating or after top coating. Among the above metal groups, at least one selected from nickel and manganese is preferably contained in an amount of 1.0 to 9.0% by weight, and more preferably in an amount of 1.5 to 8.0% by weight of nickel. preferable.

The amount of the composite coating deposited is not particularly limited, but the composite coating is formed on the substrate made of the zinc-containing metal-plated steel sheet in an amount of 0.3 to 3.0 g / m ² . It is preferable. The adhered amount (coating weight) is 0.
If the amount is less than 3 g / m ² , the zinc phosphate composite film is destroyed during press molding of the resulting composite, and the composite treated with a phosphate is further electrodeposited or the coating after topcoating. Poor performance. Further, if the amount of the composite coating adhered exceeds 3.0 g / m ² , etching is less likely to occur during the phosphate treatment applied thereon, and it becomes impossible to sufficiently deposit the phosphate coating, which is not preferable. .

The zinc phosphate composite film is further subjected to a phosphate treatment, but the composition of the phosphate treatment solution used at this time is not particularly limited, and the material of the steel sheet, the plating layer,
It can be appropriately set according to the composition of the composite film, the thickness, the application of the product, and the like. Further, there is no limitation on the processing temperature, processing time, processing method, coating weight, etc.

In the present invention, when the phosphate conversion treatment is applied to the zinc phosphate composite coating having the above-mentioned constitution, the phosphate conversion treatment is directly performed on the zinc-containing metal plated steel sheet without such a composite coating. Compared with the case where the treatment is applied, the crystal size of the obtained phosphate chemical conversion film is clearly miniaturized, so that the electrodeposition coating performance of the obtained composite and the coating performance after topcoating are remarkably improved. There is a feature called. The special characteristics of such a zinc phosphate composite coating and its use were first discovered in the present invention and succeeded in its use. In the present invention, the crystal size of the phosphate chemical conversion coating formed on the zinc phosphate composite coating is preferably 1 to 12 μm, more preferably 2 to 7 μm, and even more preferably 3 to 6 μm.

It is preferable to form the zinc phosphate composite coating in the present invention in the shortest possible time, and it is important to reduce the manufacturing cost accordingly. Specifically, it is preferable to efficiently form the zinc phosphate composite coating in a short time of 1 to 20 seconds.

There is no particular limitation on the method for forming the zinc phosphate composite coating within such a short time, and a clean zinc-containing metal-plated steel sheet is used as a substrate, and zinc phosphate or nickel phosphate is formed on the surface thereof. , A method of coating an orthophosphate such as manganese phosphate, calcium phosphate, iron phosphate, magnesium phosphate, cobalt phosphate by a plasma spraying method, a vacuum deposition method, a sputtering method, etc.,
These methods have the disadvantage that they are expensive to install and are therefore economically disadvantageous.

As a preferred method for economically forming the zinc phosphate composite coating in the present invention with a simple device, at least 5 to 30 g / liter of phosphate ions, 10 to 15 g / liter of nitrate ions and 0.1 to 10 zinc ions are used. 1-8.
0 g / liter, and 0.1 to 8 g / liter in total of at least one selected from iron ions, cobalt ions, nickel ions, calcium ions, magnesium ions, and manganese ions as other metal ions. In addition, the weight ratio of zinc ion to all other metal ions (zinc ion / all other metal ions) is 1:10 to 1
It can be formed by chemical conversion treatment using a 0: 1 aqueous solution or electrolytic treatment.

The source of metal ions contained in the aqueous solution is not particularly limited, but specific examples are as follows.
Oxides, hydroxides, carbonates and the like of the metal, such as zinc oxide, iron oxide, cobalt oxide, nickel oxide, calcium oxide, magnesium oxide, manganese oxide, zinc hydroxide, iron hydroxide, cobalt hydroxide, water Nickel oxide,
Calcium hydroxide, magnesium hydroxide, manganese hydroxide, zinc carbonate, cobalt carbonate, nickel carbonate, calcium carbonate, magnesium carbonate, manganese carbonate and the like can be used. These metal compounds may be dissolved in inorganic acids such as phosphoric acid, nitric acid, sulfuric acid, hydrochloric acid, hydrofluoric acid and silicofluoric acid, and organic acids such as formic acid, acetic acid and citric acid and supplied to the treatment bath. In addition, nitrates, sulfates, chlorides of the metal,
Soluble salts such as fluoride, silicofluoride, acetate, formate and citrate may be used as the source.

As the method for forming the zinc phosphate composite coating film for producing the zinc-containing metal-plated steel sheet composite of the present invention, the treatment aqueous solution is used as an electrolytic solution, and the zinc-containing metal-plated steel sheet base material is used as a cathode for electrolysis. A method of treating by reaction, and adding a reaction accelerator to the treatment aqueous solution,
A method of treating by a chemical conversion reaction regardless of electrolysis is used.

In the method of the present invention, when the electrolytic reaction method is used to form the zinc phosphate composite film, the current density required for the electrolytic reaction method is not particularly limited, and the concentration and components of each component in the treatment liquid used for electrolysis are not particularly limited. It can be appropriately selected depending on the ratio, the electrolytic treatment temperature, and the like. Generally targeted short time (1 to 20 seconds)
In order to achieve the formation of a composite film, the current density should be 0.2-
It is preferable to control within the range of 30 A / dm ² . If the current density is less than 0.2 A / dm ² , it may be difficult to form the desired zinc phosphate composite coating within the target short time, and if it exceeds 30 A / dm ² , the current efficiency is increased. May decrease and become economically disadvantageous.

There are no particular restrictions on the components that can be contained in the electrolytic treatment solution, but a means for improving the efficiency of the zinc phosphate composite film forming reaction is provided in order to increase the economic efficiency of the zinc phosphate composite film forming reaction. You may use together. There is no limitation on the means for increasing the reaction efficiency, but as a specific example, the ratio of the total acidity / free acidity of the electrolytic treatment liquid is adjusted so that the electrolytic treatment liquid can be used for the zinc-containing metal-plated steel substrate. There is a method to control the etching power. The total acidity / free acidity can be adjusted by adjusting with an ordinary acid such as phosphoric acid or nitric acid or an alkali such as sodium carbonate or sodium hydroxide. Generally, the total acidity / free acidity ratio is preferably 8: 1 to 30: 1.

When the zinc phosphate composite film is formed by the chemical conversion treatment in the method of the present invention, a reaction accelerator is added to the treatment solution as one means for achieving the target short time (1 to 20 seconds). It is useful to add.
As the reaction accelerator, a generally known oxidizing agent and / or etching agent can be used. Specific examples of particularly preferable reaction accelerators may include an inorganic peroxide, an oxidizing agent such as hydrogen peroxide and nitrite ion, an etching agent such as fluoride ion, and a complex fluoride ion. . The addition amount of these reaction accelerators is not particularly limited and can be appropriately determined according to the target processing time. Generally, the concentration of the reaction accelerator in the chemical conversion treatment solution is
It is preferably 0.01 to 8.0 g / liter.
However, when a fluoride ion or a complex fluoride ion is used, its concentration is calculated in terms of the amount of fluorine ion.

Also in the method of the present invention using any one of the cathodic electrolytic treatment reaction, the chemical conversion treatment reaction and the like, if the concentration of phosphate ion in the treatment liquid is less than 5 g / liter, short-time treatment becomes difficult, and If it exceeds 30 g / liter, short-time treatment can be achieved, but wasteful chemicals are consumed, which is economically disadvantageous. The nitrate ion concentration is 1.
When it is less than 0 g / liter, it becomes difficult to achieve short-time treatment, and when it exceeds 1.5 g / liter,
It is economically disadvantageous because the effect of short-time treatment reaches saturation and the consumption of the drug increases.

As described above, in the treatment aqueous solution used in the method of the present invention, 0.1 to 8.0 g / liter of zinc ions and a total amount of 0.1 to 8.0 g / liter of divalent or higher valences of at least 1 are used. Includes one or more selected from other metal ions of the species: iron ion, cobalt ion, nickel ion, calcium ion, magnesium ion, and manganese ion. Further, the weight ratio of zinc ions to all other metal ions is 1:10 to 10: 1. If the total concentration of the other metal ions is less than 0.1 g / liter, short-time treatment becomes difficult, and if it exceeds 8 g / liter, it is preferable for short-time treatment but wasteful chemicals are consumed, which is economically disadvantageous. become.

The weight ratio of zinc to other metal ions is 1:10.
If it is less than the above, the composite obtained by further treating the composite film with a phosphate will reach the saturation of the electrodeposition coating performance or the coating performance after the top coating, and the manufacturing cost will increase, which is economically disadvantageous. . Also, the weight ratio of zinc to other metal ions is 1
When it exceeds 0: 1, the content of one or more metals selected from iron, cobalt, nickel, calcium, magnesium and manganese contained in the formed zinc phosphate composite film becomes too small, and this composite It is not preferable because the composite obtained by further treating the coating with a phosphate has poor electrodeposition coating performance or coating performance after topcoat coating.

As a particularly preferable method for achieving the shortening of the composite film forming treatment, which is one of the purposes of the present invention, a clean zinc-containing metal-plated steel sheet surface is previously subjected to an activation treatment. After that, the treatment liquid having the above composition is preferably maintained at a temperature of 30 to 70 ° C. to treat the surface of the zinc-containing metal-plated steel sheet. If the temperature of the treatment aqueous solution is lower than 30 ° C, the formation rate of the zinc phosphate composite coating becomes slow and the treatment for a short time becomes difficult. On the other hand, even if the temperature exceeds 70 ° C., the effect of the present invention or more cannot be obtained and it is economically wasteful.

The activation treatment method is not particularly limited, but specific examples include (a) treatment with a treatment liquid containing nickel ions or cobalt ions or both, and nickel or cobalt or the same. A treatment for depositing 0.2 to 50 mg / m ^{2 in} terms of both metals,
(D) Treatment of contacting with an aqueous titanium colloid solution, or (iii) treatment of etching the upper layer of the metal oxide formed on the surface of the zinc-containing metal-plated steel sheet.

The activation method (a) will be further described. In this treatment method (a), the surface of a substrate made of a zinc-containing metal-plated steel sheet is treated with a treatment liquid containing nickel ions or cobalt ions, or both, and nickel, cobalt, or both of them are converted to 0 in terms of metal. The amount is from ^{2 to} 50 mg / m ² . If this adhesion amount is less than 0.2 mg / m ^{2 in} terms of metal, activation of the surface of the plated steel sheet is insufficient and it becomes difficult to shorten the treatment time. Also, the adhesion amount is 50
Even if it exceeds mg / m ² , the obtained effect reaches saturation and is not economical.

The source of nickel ions or cobalt ions that can be used in the activation treatment liquid of (a) above is not particularly limited, but water-soluble nickel salts such as nickel sulfate, nickel nitrate, nickel chloride, and nickel fluorosilicate. , Water-soluble cobalt salts such as cobalt sulfate, cobalt nitrate, cobalt chloride, and cobalt silicofluoride, either alone or in part 2
Any combination of two or more species can be used.

In the titanium colloid treatment liquid which can be used in the activation treatment method (b), the source of titanium ions in the treatment liquid is not particularly limited, but examples thereof include titanium sulfate, titanyl sulfate, titanium oxide, and titanium phosphate. It is preferable to use each of these alone or in appropriate combination of two or more thereof.

The etching agent that can be used in the activation treatment method (c) is not particularly limited, but sulfuric acid, nitric acid, phosphoric acid,
Inorganic acids such as hydrofluoric acid, silicofluoric acid and pyrophosphoric acid, organic acids such as citric acid, tartaric acid, acetic acid, oxalic acid and gluconic acid, and chelating compounds such as EDTA and NTA are used, and zinc-containing metal plated steel sheets are used. The upper layer of the metal oxide formed on the surface can be removed by etching.

By applying the activation treatment method (a), (b) or (c) to a clean zinc-containing metal-plated steel sheet surface, and then treating the surface with the treatment liquid for forming the composite coating. , 0.3 to 3.0 g / m ² of the zinc phosphate composite coating can be efficiently formed in a shorter time.

Among various surface treatments of steel materials, zinc phosphate chemical conversion treatment has a long history and is still widely used as a base treatment for coating. The effect of the zinc phosphate chemical conversion coating as a coating base is considered to be due to the physical shape of this composite coating, exhibiting an excellent anchoring effect on the coating and improving the adhesion to the coating. ing. Specific metals other than zinc, that is,
The presence of a metal having a valence of 2 or more, such as iron, cobalt, nickel, calcium, magnesium and manganese, in the form in which a part of zinc in the coating is substituted, improves the alkali resistance of the composite coating. In particular, in a corrosive environment, that is, with respect to a pH increase due to the consumption of H ⁺ at the interface of the coating, the above-mentioned divalent or higher metals show an excellent effect in improving the corrosion resistance of the composite coating.

The action and effect of the zinc phosphate composite coating according to the present invention on the zinc-containing metal-plated steel sheet are basically considered to be the same as the above actions. Rather than the coating performance of a composite obtained by directly subjecting an ordinary zinc-containing metal-plated steel sheet to a phosphate treatment, a composite obtained by further subjecting a zinc phosphate composite coating to a phosphate treatment according to the present invention. The reason why the electrodeposition coating performance of the body or the coating performance after top coating is excellent is that the crystal size of the deposited phosphate film is miniaturized, so that the adhesion of the coating film, the corrosion resistance after coating, etc. It is believed that the coating performance of

That is, by reducing the crystal size in the phosphate chemical conversion coating, the specific surface area of the crystal particles in the phosphate coating is increased, the anchor effect for the coating is improved, and the adhesion of the coating is improved. Coating performance is improved. Further, it is considered that the finer crystal size reduces the pinholes between the phosphate film crystals and exerts the barrier effect even in a corrosive environment, so that the coating performance is further improved.

[0045]

EXAMPLES The present invention will be described in detail with reference to the following examples, but the scope of the present invention is not particularly limited by these examples.

1. Zinc-containing metal-plated steel sheet substrate (a) Commercially available 0.8 mm thick double-sided alloyed hot-dip galvanized steel sheet (GA material: basis weight 60 g / m ² ), (b) Double-sided electrogalvanized steel sheet (EG material: basis weight) 20 g / m ² ),
Was used as the substrate.

2. Zinc phosphate composite film forming treatment 2.1. Cleaning of Substrate Surface A treatment liquid containing fine cleaner L4480 (manufactured by Nippon Parkerizing Co., Ltd.), which is a sodium phosphate-based alkaline degreasing agent, at a drug concentration of 18 g / liter was applied to the above substrate at a treatment temperature of 45 ° C. for a treatment time. The surface of the substrate was cleaned by spraying it under the condition of 120 seconds for degreasing, and then washing the alkaline content remaining on the substrate surface with tap water.

2.2. Activation Treatment [Activation Treatment I] A substrate containing titanium colloid,
A treatment liquid prepared by diluting a commercial product, PREPAREN Z (manufactured by Nippon Parkerizing Co., Ltd.) in water at a concentration of 1.5 g / liter was spray-treated under the conditions of treatment temperature: room temperature and treatment time: 2 seconds. did.

[Activation treatment II] The substrate is provided with nickel sulfate:
Using an aqueous solution of 20 g / liter, treatment temperature: 60
Nickel was attached to the surface by spraying under conditions of ℃ and treatment time: 2 seconds, and then washed with water.

[Activation Treatment III] Nitric acid (67.
5%) was diluted with an aqueous solution having a concentration of 29.6 g / liter to carry out immersion treatment at room temperature for a treatment time of 3 seconds to etch the upper layer of the metal oxide on the surface and wash with water.

[Activation Treatment IV] Cobalt sulfate:
Treatment temperature: 6 using an aqueous solution containing 30 g / liter
Cobalt was adhered to the surface by spraying under conditions of 0 ° C. and treatment time: 2 seconds, and then washed with water.

2.3. Example of treatment liquid for forming zinc phosphate composite film [Treatment liquid A] 20 g / liter of phosphoric acid as PO ₄
Zinc oxide was used as a zinc ion source in an aqueous solution containing nitric acid as NO ₃ at 3 g / liter and hydrofluoric acid as fluorine ion at 1.5 g / liter, and zinc ion was 1.3 g / liter, basic nickel carbonate. Is used as a nickel ion supply source, nickel ions are added at 0.5 g / liter, and manganese carbonate is used as a manganese ion supply source at a concentration of 0.5 g / liter as manganese ions. The ratio was adjusted to 21: 1, sodium nitrite was further used as a supply source, and a chemical conversion treatment liquid containing 0.3 g / liter of nitrite ion was prepared.

[Treatment liquid B] 20 g of phosphoric acid as PO ₄
Per liter, nitric acid as NO ₃ at 3 g / liter, and hydrofluoric acid at 1.5 g / liter as fluoride ions, zinc oxide is used as a zinc ion source, zinc oxide at 2.0 g / liter, and a base. Nickel carbonate is used as a nickel ion source, nickel ions are added at a concentration of 2.5 g / liter, the total acidity / free acidity ratio is adjusted to 17: 1 with sodium carbonate, and sodium nitrite is further supplied as a source. A chemical conversion treatment liquid containing 0.3 g / liter of nitrite ion was prepared.

[Treatment liquid C] 6 g / phosphoric acid as PO ₄
Zinc oxide was used as a zinc ion source and zinc ion was added at a concentration of 2.0 g / liter to an aqueous solution containing liter and nitric acid as NO ₃ at 1 g / liter, and nickel nitrate was used as a nickel ion source. ,
Nickel ions were added at a concentration of 0.5 g / liter to prepare a cathodic electrolytic treatment solution.

[Treatment liquid D] 30 g of phosphoric acid as PO ₄
/ Liter, nitric acid as NO ₃ at 8 g / liter, hydrosilicofluoric acid as fluoride ion at 2.5 g / liter, zinc oxide was used as a zinc ion source, and zinc ion at 1.3 g / liter, Manganese nitrate was used as a manganese ion supply source, 0.5 g / liter as manganese ion, and calcium carbonate was used as a calcium ion supply source.
A chemical conversion treatment in which the concentration of total acidity / free acidity was adjusted to 9: 1 with sodium carbonate and sodium nitrite was used as a supply source and 0.7 g / liter as nitrite ion was added. A liquid was prepared.

[Treatment liquid E] 5 g / phosphoric acid as PO ₄
In an aqueous solution containing liter and nitric acid as NO ₃ at 2 g / liter, zinc oxide was used as a zinc ion source, zinc ion was 1.0 g / liter, cobalt nitrate was used as a cobalt ion source, and cobalt ion was 0.5 g. / Liter, using ferrous sulfate as a supply source,
Iron ions were added at a concentration of 0.1 g / liter to prepare a cathodic electrolytic treatment liquid.

[Comparative liquid F] 20 g of phosphoric acid as PO ₄
/ Liter, nitric acid as NO ₃ at 3 g / liter and hydrofluoric acid as fluoride ion at 1.5 g / liter as an aqueous solution, zinc oxide is used as a zinc ion source, and zinc ion has a concentration of 1.3 g / liter. The total acidity / free acidity ratio is adjusted to 2 with sodium carbonate.
The chemical conversion treatment liquid was adjusted to 1: 1 and further containing sodium nitrite as a supply source to contain 0.3 g / liter of nitrite ion.

[Comparative Solution G] Phosphoric acid as PO ₄ 5 g /
Zinc oxide was used as a zinc ion supply source and was added at a concentration of 1.0 g / liter as zinc ions to an aqueous solution containing liter and nitric acid as NO ₃ at 2 g / liter to prepare a cathodic electrolytic treatment solution.

[Comparative liquid H] ₄ g / phosphoric acid as PO ₄
Lithium, nitric acid as NO ₃ 16g / l, hydrofluoric acid as an aqueous solution containing 1.5g / l as a fluoride ion, zinc oxide was used as a zinc ion supply source, and zinc ion 1.3g / l, nickel nitrate Is added as a nickel ion at a concentration of 0.04 g / liter, the total acidity / free acidity ratio is adjusted to 21: 1 with sodium carbonate, and sodium nitrite is used as a supply source. A chemical conversion treatment liquid containing 0.3 g / liter of nitrate ions was prepared.

Example 1 In the above 2.1. The GA material cleaned by the method described in the item 1) was used as a substrate, which was subjected to [Activation Treatment I], and then heated to a temperature of 45 ° C. [Treatment Solution A].
It was immersed in the solution for 1 second, washed successively with water and dried to form a zinc phosphate composite coating having the composition and the adhesion amount shown in Table 1. Further, on the zinc phosphate composite coating, the following steps
And a zinc-containing metal-plated steel sheet composite was produced.

Phosphate Chemical Treatment Degreasing Step A sodium phosphate-containing alkaline degreasing agent (trade name: Fine Cleaner L4480, manufactured by Nippon Parkerizing Co., Ltd.) was used to degrease the surface of the composite under the following conditions. <Conditions> Drug concentration: 18 g / liter, treatment temperature: 45 ° C., treatment time: 120 seconds, spray treatment

Water Washing Step The alkaline content remaining on the surface of the composite by the degreasing treatment was washed with tap water to clean the surface. <Conditions> Treatment temperature: normal temperature, treatment time: 20 seconds, spray treatment

Surface Conditioning Step A surface conditioner containing a slightly alkaline titanium colloid (trademark: PREPAREN-ZTH, manufactured by Nippon Parkerizing Co., Ltd.) was used. <Conditions> Drug concentration: 1.5 g / liter, processing temperature: normal temperature, processing time: 20 seconds, spray processing

Chemical conversion treatment A phosphate treatment agent (trademark: Palbond-L3080, manufactured by Nippon Parkerizing Co., Ltd.) was used. <Conditions> Drug concentration: 48 g / liter, treatment temperature: 43 ° C., treatment time: 120 seconds, dip treatment Free acidity: 1 point (10 ml of the treatment liquid was sampled, and 0.1N of the indicator bromphenol blue was used.
Value when titrated with NaOH (ml) Total acidity: 23 points (10 ml of the treatment liquid was sampled and 0.1N N was used with the indicator phenolphthalein.
Value titrated with aOH (ml)) Reaction accelerator concentration: 3 points (saccharometer method)

Water Washing Step The chemical conversion treatment liquid remaining on the surface of the composite by the above chemical conversion treatment was washed with tap water to clean the surface. <Conditions> Treatment temperature: normal temperature, treatment time: 20 seconds, spray treatment

Deionized water washing Contaminant ions in the water remaining on the surface of the complex were washed with deionized water. <Conditions> Treatment temperature: normal temperature, treatment time: 20 seconds, spray treatment

Drying Hot air drying was carried out to remove surface moisture. <Conditions> Processing temperature: 100 ° C., processing time: 120 seconds,

Example 2 The same treatment as in Example 1 was carried out except that the EG material was used in place of the GA material in Example 1, and the zinc phosphate composite having the composition and the deposition amount shown in Table 1 was used. A film was formed. Next, the same phosphate treatment as in Example 1 was applied to this composite film to produce a zinc-containing metal-plated steel plate composite.

Example 3 In the above 2.1. The GA material cleaned by the method described in the item 1 is used as a substrate, and this is subjected to activation treatment II,
Next, this base material is added to the treatment liquid B heated to a temperature of 45 ° C.
Immersion for 2 seconds, washing with water, and drying were sequentially performed to form a zinc phosphate composite film having the composition and the amount of adhesion shown in Table 1. Next, the same phosphate chemical conversion treatment as in Example 1 was applied to this composite film to produce a zinc-containing metal-plated steel plate composite.

Example 4 The same treatment as in Example 3 was carried out except that the EG material was used as the substrate instead of the GA material in Example 3, and the zinc phosphate having the composition and the deposition amount shown in Table 1 was used. A composite film was formed. Next, the same phosphate chemical conversion treatment as in Example 1 was applied to this composite film to produce a zinc-containing metal plated steel plate composite.

Example 5 In the above 2.1. Using the GA material cleaned by the method described in the item 1) as a substrate and using it as a cathode,
Using a carbon plate as an anode, in a treatment liquid C heated to a temperature of 40 ° C., a cathodic electrolysis treatment was performed for 2 seconds under a condition of a current density of 9 A / dm ² , and this was washed with water and dried in order. A zinc phosphate composite film having the composition and the adhesion amount shown in 1 was formed. Next, the same phosphate chemical conversion treatment as in Example 1 was applied to this composite film to produce a zinc-containing metal-plated steel plate composite.

Example 6 In Example 5, EG was used as a substrate instead of the GA material.
The same cathodic electrolysis treatment as in Example 5 was performed, except that the material was used, to form a zinc phosphate composite coating having the composition and the deposition amount shown in Table 1. Next, the same phosphate chemical conversion treatment as in Example 1 was applied to this composite film to produce a zinc-containing metal plated steel plate composite.

Example 7 In the above 2.1. Using the GA material cleaned by the method described in the item 1) as a substrate, subjecting it to the activation treatment III, and then immersing it in the treatment liquid D heated to a temperature of 50 ° C. for 1 second, It was washed with water and dried to form a zinc phosphate composite film having the composition and the adhesion amount shown in Table 1. Next, the same phosphate chemical conversion treatment as in Example 1 was applied to this composite film to produce a zinc-containing metal-plated steel plate composite.

Example 8 The same treatment as in Example 7 was carried out except that an EG material was used as the substrate instead of the GA material described in Example 7, and Table 1 was used.
A zinc phosphate composite film having the composition and the amount shown in Fig. 3 was formed. Next, the same phosphate chemical conversion treatment as in Example 1 was applied to this composite film to produce a zinc-containing metal-plated steel plate composite.

Example 9 In the above 2.1. G cleaned by the method described in paragraph
Material A is used as a substrate and this is used as a cathode, a carbon plate is used as an anode, and a cathodic electrolysis treatment for 6 seconds at a current density of 6 A / dm ² is performed in treatment liquid E heated to 50 ° C., followed by washing with water. Then, it was dried to form a zinc phosphate composite film having the composition and the adhesion amount shown in Table 1. Next, this was subjected to the same phosphate chemical conversion treatment as in Example 1 to produce a zinc-containing metal-plated steel plate composite.

Example 10 In place of the GA material described in Example 9, an EG material was used as the substrate, and the same cathodic electrolysis treatment as in Example 9 was performed except for the above,
A zinc phosphate composite film having the composition and the adhesion amount shown in Table 1 was formed. This composite coating was subjected to the same phosphate chemical conversion treatment as in Example 1 to produce a zinc-containing metal plated steel sheet composite.

Example 11 In the above 2.1. Using the GA material cleaned by the method described in the item 1 as a substrate, the substrate is immersed in the treatment liquid A heated to a temperature of 50 ° C. for 3 seconds, washed with water, and dried,
A zinc phosphate composite film having the composition and the adhesion amount shown in Table 1 was formed. Next, the same phosphate chemical conversion treatment as in Example 1 was applied to this composite film to produce a zinc-containing metal-plated steel plate composite.

Example 12 The same treatment as in Example 11 was carried out except that the EG material was used as the substrate instead of the GA material in Example 11, and the composition and the adhesion amount shown in Table 1 were obtained. And a zinc phosphate composite film was formed. The same phosphate conversion treatment as in Example 1 was applied to this composite film to produce a zinc-containing metal plated steel plate composite.

Example 13 In the above 2.1. In the treatment liquid C heated to a temperature of 35 ° C., the GA material cleaned by the method described in the item 1 is used as a substrate and as a cathode, and a carbon plate is used as an anode.
A cathodic electrolysis treatment was carried out for 9 seconds at a current density of 3 A / dm ² , followed by washing with water and drying in order to form a zinc phosphate composite coating having the composition and the deposition amount shown in Table 1. Next, the same phosphate chemical conversion treatment as in Example 1 was applied to this composite film to produce a zinc-containing metal-plated steel plate composite.

Example 14 The same cathodic electrolysis treatment as in Example 13 was performed except that the EG material was used as the substrate instead of the GA material in Example 13, and the composition and the adhesion amount shown in Table 1 were used. A zinc phosphate composite film was formed. Next, this composite coating was subjected to the same phosphate chemical conversion treatment as in Example 1 to produce a zinc-containing metal plated steel sheet composite.

Example 15 Prior to the above 2.1. G cleaned by the method described in paragraph
Material A is used as a substrate and a cathode, a carbon plate is used as an anode, and in a treatment liquid E heated to a temperature of 45 ° C., a current density of 15 A / dm ² is subjected to cathodic electrolysis treatment for 2 seconds, followed by washing with water and drying. Were sequentially performed to form a zinc phosphate composite film having the composition and the amount of adhesion shown in Table 1. Next, the same phosphate chemical conversion treatment as in Example 1 was applied to this composite film to produce a zinc-containing metal-plated steel plate composite.

Example 16 The same cathodic electrolysis treatment as in Example 15 was performed except that the EG material was used as the substrate instead of the GA material described in Example 15, and the composition and adhesion shown in Table 1 were obtained. An amount of zinc phosphate composite coating was formed. Next, the same phosphate chemical conversion treatment as in Example 1 was applied to this composite film to produce a zinc-containing metal plated steel plate composite.

Example 17 The above 2.1. The GA material cleaned by the method described in the item 1 is used as a substrate, which is subjected to activation treatment IV,
Next, it was immersed in the treatment liquid A heated to a temperature of 45 ° C. for 1 second, washed with water and dried in order to form a zinc phosphate composite coating having the composition and the amount of adhesion shown in Table 1. The same phosphate conversion treatment as in Example 1 was applied to this composite film to produce a zinc-containing metal plated steel plate composite.

Example 18 The same chemical conversion treatment as in Example 17 was applied except that the EG material was used as the base material in place of the GA material described in Example 17, and the composition and the amount of adhesion shown in Table 1 were used. And a zinc phosphate composite film was formed. The same phosphate conversion treatment as in Example 1 was applied to this composite film to produce a zinc-containing metal plated steel plate composite.

Comparative Example 1 The above 2.1. The GA material cleaned by the method described in the above item 1 is used as a substrate, and this is subjected to activation treatment I,
Next, it was dipped in Comparative Solution F heated to a temperature of 50 ° C. for 3 seconds, washed successively with water and dried to form a zinc phosphate film having the composition and the amount of adhesion shown in Table 1. The same phosphate chemical conversion treatment as in Example 1 was applied to this coating to produce a zinc-containing metal plated steel sheet composite.

Comparative Example 2 The above 2.1. The GA material cleaned by the method described in the item 1 is used as a substrate and as a cathode, and a carbon plate is used as an anode. In a comparative solution G heated to a temperature of 45 ° C., the current density is 15 A / dm ² A cathodic electrolysis treatment was performed for 2 seconds, followed by washing with water and drying in order to form a zinc phosphate film having the composition and the amount of adhesion shown in Table 1. The same phosphate chemical conversion treatment as in Example 1 was applied to this coating to produce a zinc-containing metal plated steel sheet composite.

Comparative Example 3 In the above 2.1. The GA material cleaned by the method described in the item 1) is used as a substrate, subjected to activation treatment III, and then immersed for 6 seconds in the comparative solution H heated to a temperature of 45 ° C., washed with water and dried. The steps were sequentially performed to form a zinc phosphate composite film having the composition and the adhesion amount shown in Table 1. The same phosphate conversion treatment as in Example 1 was applied to this composite film to produce a zinc-containing metal plated steel plate composite.

Comparative Example 4 The same chemical conversion treatment as in Comparative Example 1 was performed except that the EG material was used as the substrate instead of the GA material described in Comparative Example 1,
A zinc phosphate film having the composition and the adhesion amount shown in Table 1 was formed. Next, the same phosphate chemical conversion treatment as in Example 1 was applied to this coating to produce a zinc-containing metal plated steel sheet composite.

Comparative Example 5 In place of the GA material described in Comparative Example 2, an EG material was used as the base. This EG material was subjected to the same electrolytic treatment as in Comparative Example 2 to form a zinc phosphate film having the composition and the amount of adhesion shown in Table 1. Next, the same phosphate chemical conversion treatment as in Example 1 was applied to this coating to produce a zinc-containing metal plated steel sheet composite.

Comparative Example 6 In the above 2.1. The GA material cleaned by the method described in the section 1 above was directly subjected to the same phosphate chemical conversion treatment as in Example 1.

Comparative Example 7 In the above 2.1. The EG material cleaned by the method described in the above section was directly subjected to the same phosphate chemical conversion treatment as in Example 1.

The zinc-containing metal-plated steel sheet composites prepared in the above Examples and Comparative Examples were subjected to the following characteristic tests.

3.1. Film characteristics 3.1.1. Weight of zinc phosphate composite coating The weight of the zinc phosphate composite coating was measured by the method described below. (1) The weight of the test piece (W1: g) by a precision balance in advance
The test piece was immersed in a deionized aqueous solution containing 20 g / liter of ammonium dichromate and 490 g / liter of 25% ammonia water at room temperature for 15 minutes to remove the zinc phosphate composite film. . (2) The test piece was washed with water to remove the remaining ammonium dichromate aqueous solution and dried. (3) Again, using a precision balance, the weight of the test piece (W2: g)
Was measured and the coating weight per unit area was calculated from the weight difference (W1-W2). (4) Further, zinc ion and iron ion dissolved in the ammonium dichromate aqueous solution used for measuring the film weight were quantified by atomic absorption spectrometry, and the amount of zinc and iron contained per unit area of the composite film were calculated. .

3.1.2. Zinc Phosphate Composite Coating Composition Ratio Each of the components other than zinc and iron in the zinc phosphate composite coating was measured by a fluorescent X-ray method (mg / m ² ), and the content in the coating weight at that time was calculated.

3.1.3. Crystal size of the film after the phosphate treatment The secondary electron beam image was observed to observe the crystal size of the film.

3.2. Coating performance test 3.2.1. Preparation of test pieces The zinc-containing metal-plated steel sheet composites prepared in Examples 1 to 18 and Comparative Examples 1 to 7 were coated by the following steps to prepare test pieces.

A) Electrodeposition coating Cationic electrodeposition coating for automobiles (trademark: manufactured by Kansai Paint Co., Ltd.)
EL-2000). <Conditions> Processing temperature: 30 ° C., set voltage: 200 V, normal time: 3
Min, film thickness: 20 μm

B) Baking Baking was carried out by hot air drying. <Conditions> Treatment temperature: 170 ° C., treatment time: 20 minutes

C) Intermediate coating The intermediate coating for automobiles manufactured by Kansai Paint Co., Ltd. (Trademark: TP-)
37). <Conditions> Treatment temperature: normal temperature, spray treatment, film thickness: 40 μm

D) Baking Baking was carried out by hot air drying. <Conditions> Treatment temperature: 140 ° C., treatment time: 30 minutes

E) Topcoat paint Topcoat paint for automobiles manufactured by Kansai Paint Co., Ltd. (Trademark: NEO 6)
000). <Conditions> Treatment temperature: normal temperature, spray treatment, film thickness: 40 μm

F) Baking Baking was performed by hot air drying. <Conditions> Treatment temperature: 140 ° C., treatment time: 30 minutes

3.2.2. Corrosion resistance test after electrodeposition coating The test piece after electrodeposition coating was cross-cut with an NT cutter, and the test piece was immersed in a 5% NaCl solution at 55 ° C for 10 days. The swollen portion generated in the cross cut portion was peeled off with cellophane tape, and the maximum swollen width (mm) on one side was measured.

3.2.3. Water-resistant secondary adhesion test after topcoat coating After topcoat coating, dip it in deionized water at 40 ° C for 10 days, cut a 1 mm square grid with an NT cutter on this test piece, and subject it to a peeling treatment with cellophane tape. The number of peeled pieces was measured.

Table 1 shows the composition of the treatment liquid, the concentration, and the treatment conditions used for the activation treatment and the treatment for forming the zinc phosphate composite film used in the above-mentioned Examples and Comparative Examples.

[Table 1]

Table 2 shows the types of test steel materials, the types of activation treatments, the types of zinc phosphate composite coating forming treatment liquids, the temperatures, the treatment methods, and the treatment times in the above Examples and Comparative Examples.

[Table 2]

Table 3 shows the composition of the zinc phosphate composite coatings obtained in the above Examples and Comparative Examples, the crystal size of the zinc phosphate chemical conversion coatings, and the coating performance test results.

[Table 3]

As is clear from the results shown in Table 3,
The plated steel sheet composites obtained in Examples 1 to 18 of the present invention showed good results in both the corrosion resistance test after electrodeposition coating and the water resistance secondary adhesion test after top coating. However, in Comparative Examples 1 to 7, none of the tests were good, and the results of the water resistant secondary adhesion test after topcoating were considerably poorer than the results of the examples.

[0109]

INDUSTRIAL APPLICABILITY The present invention provides a zinc phosphate composite coating, which has been problematic in the past, in deterioration of coating performance such as corrosion resistance after coating of zinc-containing metal plated steel sheet in a wet environment and adhesion of coating. By forming a fine chemical conversion film formed by the phosphating chemical conversion treatment on it, it becomes possible to reinforce the coating performance which was insufficient by the phosphating treatment alone, and high quality It has become possible to efficiently manufacture a zinc-containing metal plated steel sheet composite at low cost. The zinc phosphate composite film has high versatility and is useful in a wide range of industrial fields even in consideration of recyclability.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Internal reference number FI technical display location C25D 11/36 (72) Inventor Shuntaro Sudo 1 Toyota-cho, Toyota-shi, Aichi Toyota Motor Co., Ltd. (72) Inventor Atsushi Tanaka 1 Toyota Town, Toyota City, Aichi Prefecture, Toyota Motor Co., Ltd. (72) Inventor Shigeru Chikada, 1 Toyota Town, Toyota City, Aichi Prefecture, Toyota Motor Corporation (72) Inventor, Hiroshi Kawaguchi Aichi 1 Toyota Town, Toyota City, Japan Toyota Motor Co., Ltd.

Claims (10)

[Claims] 1. A substrate made of a zinc-containing metal-plated steel sheet, formed on the surface thereof, containing zinc and phosphorus in a weight ratio (zinc / phosphorus) of 2.504: 1 to 3.166: 1, and iron, 0.06 of one or more metals selected from cobalt, nickel, calcium, magnesium and manganese
A coating characterized by having a zinc phosphate composite coating contained at a content of ˜9.0 wt% and a phosphate conversion coating having a fine crystal size formed on the zinc phosphate composite coating. Zinc-containing metal plated steel sheet composite with excellent properties. 2. The zinc phosphate composite coating contains 1.0 or more of at least one metal selected from nickel and manganese.
The zinc-containing metal-plated steel plate composite according to claim 1, wherein the zinc-containing metal-plated steel plate composite is contained in an amount of ˜9.0 wt%. 3. The amount of the zinc phosphate composite film deposited is 0.
The zinc-containing metal-plated steel plate composite according to claim 1, having a weight ratio of 3 to 3.0 g / m ² . 4. The zinc-containing metal plated steel sheet composite according to claim 1, wherein the phosphate conversion coating has a refined crystal size of 1 to 12 μm. 5. In order to produce the zinc-containing metal-plated steel sheet composite according to claim 1, the following components (1) to (4): (1) phosphate ion 5 on the surface of the zinc-containing metal-plated steel sheet. -30 g / liter (2) Nitrate ion 1.0-15 g / liter (3) Zinc ion 0.1-8.0 g / liter (4) Iron ion, nickel ion, manganese ion, cobalt ion, calcium ion, and magnesium Containing at least one metal ion selected from ions 0.1 to 8.0 g / liter, and the weight ratio of the zinc ions to all the other metal ions is 0.1: 1 to 10: 1. Is subjected to cathodic electrolysis with an electrolytic plating solution to form the zinc phosphate composite coating, and the phosphate conversion treatment is applied to the zinc phosphate composite coating to obtain the fine crystal size. Phosphorus and forming an acid chloride conversion coating method excellent zinc-containing metal-plated steel sheet complex paintability with. 6. The cathode electrolysis treatment is 0.2 to 30 A /
The method for producing a zinc-containing metal-plated steel plate composite according to claim 5, which is performed at a current density of dm ² . 7. The following components (1) to (4): (1) Phosphate ion 10 on the surface of the zinc-containing metal-plated steel sheet for producing the zinc-containing metal-plated steel sheet composite according to claim 1. -30 g / liter (2) Nitrate ion 1.0-15 g / liter (3) Zinc ion 0.1-8.0 g / liter (4) Iron ion, nickel ion, manganese ion, cobalt ion, calcium ion, and magnesium At least one metal ion selected from the group of 0.1 to 8.0 g / liter, and the weight ratio of the zinc ion to all the other metal ions is 1:10 to 10: 1. ,And,
A chemical conversion treatment liquid further containing a reaction accelerator composed of at least one selected from peroxide, fluoride ion, complex fluoride ion, and nitrite ion is contacted to form the zinc phosphate composite film. The zinc phosphate composite coating is subjected to a phosphate conversion treatment to form a phosphate conversion coating having the fine crystal size.
A method for producing a zinc-containing metal-plated steel sheet composite having excellent paintability. 8. The concentration of the reaction accelerator in the chemical conversion treatment solution is 0.01 to 8.0 g / liter (however, in the case of fluoride ion and complex fluoride ion, converted to the amount of fluoride ion). The method for producing a zinc-containing metal-plated steel sheet composite according to claim 7, which is contained in. 9. The zinc-containing metal plated steel sheet composite according to claim 5, wherein the phosphate conversion coating has a refined crystal size of 1 to 12 μm. 10. The surface of the zinc-containing metal-plated steel sheet is previously treated with a treatment liquid containing (a) at least one metal selected from nickel ions and cobalt ions, and the above-mentioned 0.2 to 50 mg of one metal
An activation treatment for depositing a metal deposition amount of / m ² , an activation treatment for treating with (b) a titanium colloid aqueous solution, or (d) an activation treatment for removing a metal oxide with an etching treatment liquid. The method according to 5 or 7.