JPH0819532B2 - Zinc phosphate treatment method for metal surface - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for treating a surface of a coating metal with zinc phosphate and a metal material obtained by the method, more specifically, an iron-based surface, a zinc-based surface, an aluminum-based surface or Suitable for electrodeposition coating, especially cation type electrodeposition coating on a metal surface that has these surfaces in combination at the same time, coating adhesion,
The present invention relates to a treatment method for forming a zinc phosphate coating having excellent corrosion resistance, particularly hot salt water resistance and scab resistance.

2. Description of the Related Art The zinc phosphate film chemical conversion treatment has long been performed as a metal pretreatment for coating, and a spray method, a dipping method, or a combination thereof has been adopted as the treatment method. The spray method is advantageous in terms of equipment cost, production efficiency, etc., but on the other hand, it has the drawback that unprocessed parts are generated on complicated articles such as bags and that film formation defects due to spray rebound easily occur. There is.

Further, the dipping method has a drawback that the equipment becomes large, but on the other hand, it has an advantage that a uniform film can be formed even on a complex article having a bag structure portion or the like even on a portion where the film is not formed by the spray treatment.

In the case of zinc phosphate film formation by the normal dipping method, the zinc ion concentration of the treatment liquid is as high as 2 to 4 g /, and the treatment conditions can be formed only at high temperature (60 to 90 ° C) and long time (3 to 10 minutes). Moreover, the obtained film has a high film amount (3 to 5 g / m ² ),
In addition, the quality of the coating is poor, and it is considered unsuitable as a coating substrate, especially as an electrodeposition coating substrate because of poor adhesion, corrosion resistance and coating appearance. Also, in recent years, automobile departments, etc. are required to have sufficient rust preventive power under corrosive environment, and therefore the electrodeposition paint is changing from anion type to cation type. Since a large amount of force is applied to the zinc phosphate coating, the strength of the zinc phosphate coating itself under the cationic electrodeposition coating must also be high. It was said that a groundwork suitable for coating was not obtained.

Under such circumstances, recently, in JP-A-55-107784, by controlling the concentration of the film formation accelerator such as zinc ion, phosphate ion and nitrite ion in the treatment bath, a low temperature and short time dipping method was used. It is possible to obtain a zinc phosphate coating with a low coating amount, uniform and dense adhesion, and excellent corrosion resistance.
A method for forming a film that can be sufficiently used as an electrodeposition coating base has been proposed, and the sudden immersion method has come into the limelight. That is, in the above-mentioned Japanese Patent Laid-Open Publication No. Sho-in, the zinc ion is controlled to 0.5 to 1.5 g /, the phosphate ion is controlled to 5 to 30 g /, and the nitrite ion is controlled to 0.01 to 0.2 g /, and the acidic phosphorus containing these as main components is controlled. 40-70 on the metal surface with zinc oxide treatment liquid
Immersion treatment at ℃ for 15 to 120 seconds, and then spray treatment at the same treatment liquid for the purpose of removing sludge at the treatment temperature for 2 to 60 seconds, a low coating amount of 1.5 to 3 g / m ² and a uniform and dense electrode. It forms a base suitable for coating. After that, mainly in the automobile industry, a steel material having zinc or alloyed zinc plating on only one surface began to be used as a body material for the purpose of further improving the corrosion resistance after painting, and there is no problem on the iron-based surface in the immersion treatment with the treatment bath. In addition, there is a problem that the salt water spray resistance after cationic electrodeposition coating is insufficient for zinc-based surfaces, or the secondary adhesion after intermediate coating and top coating is significantly inferior to that of iron-based surfaces. In order to cope with this problem, for example, as disclosed in JP-A-57-152472, manganese ions of 0.6 to 3 g / and / or nickel are added to a bath containing a zinc ion, a phosphate ion and a film formation accelerator concentration controlled. Technology to contain 0.1 to 4g / ion, or technology to add 0.05g / min or more fluoride ion together with manganese ion for the purpose of lowering the treatment temperature (Japanese Patent Publication 61)
-36588) has been developed.

In this way, it is possible to provide a chemical conversion coating suitable for electrodeposition coating by the zinc phosphate treatment by the dipping method, even on an iron-based surface or on a metal surface having both an iron-based surface and a zinc-based surface. It is now possible not only for building materials and small articles, but also for a wide range of automobile bodies, automobile parts, iron,
The dipping method has established a firm base for the zinc phosphate chemical conversion treatment mainly for improving the corrosion resistance of articles having zinc and their alloy surfaces.

However, in recent years, the required quality for corrosion resistance of automobile bodies has become higher and higher. For example, when the exterior surface is scratched and salt water and wet / wet weather conditions are repeatedly applied, the rust (scab) -like rust (scab Corrosion) prevention and higher resistance to hot salt water are strongly desired, and the current zinc phosphate treatment methods are no longer able to meet such requirements.

On the other hand, for steel furniture and the like, spray treatment is still the mainstream, but zinc steel sheets are being introduced in this field for the purpose of improving rust prevention, and these are not always satisfactory in terms of adhesion and corrosion resistance. It has not been. Further, it is desired to improve the scab resistance and hot salt water resistance by pretreatment.

Aluminum materials are also widely used in various fields such as automobiles and building materials, and there is a demand for zinc phosphate treatment on the surface of iron or zinc materials containing aluminum materials. However, when iron materials including aluminum materials are treated in the previously proposed acidic zinc phosphate treatment bath for iron or zinc materials, aluminum ions accumulate in the treatment bath, and if the amount exceeds a certain amount, iron materials On the other hand, it is known that the formation becomes poor. That is, in the treatment liquid containing no fluorine ion, Al ³⁺
5ppm or more, 100ppm or more for treatment liquid containing HBF _4, and H ₂ SiF
It has been found that even in a treatment bath containing ₆ at a concentration of 300 ppm or more, poor formation of iron material occurs. Therefore, in order to reduce Al ³⁺ in the treatment liquid, a method of adding acidic potassium fluoride and sodium acid fluoride to the treatment liquid and precipitating Al ³⁺ as K ₂ NaAlF ₆ or Na ₃ AlF ₆ is disclosed in JP-A-57 -70281 has been proposed, but if such aluminum precipitates adhere to the coating film, it will cause cationic electrodeposition coating failure, resulting in lack of uniformity of the film and poor secondary adhesion of the coating film. Therefore, in this method, it is necessary to remove the precipitate having a floating suspension property from the treatment liquid, which not only complicates the work but also has insufficient effect. It has also been proposed to control the treatment ratio of aluminum and iron to 3/7 or less and maintain the Al ³⁺ ion concentration in the fluorozinc phosphate treatment solution at 70 ppm or less (Japanese Patent Laid-Open No. 61-104089). However, it is difficult to maintain the Al ³⁺ ion concentration at 70 ppm or less simply by reducing the treatment rate of the aluminum material.

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention Therefore, there is provided a zinc phosphate treatment method for an iron-based surface, a zinc-based surface, an aluminum-based surface, or a metal surface having a combination of these surfaces, which has corrosion resistance suitable for painting and electrodeposition coating Not only can a chemical conversion film be provided, but the scab resistance of the iron surface and the hot salt water resistance of the iron surface and zinc surface are improved significantly,
A treatment that can provide a highly corrosion-resistant coating even on the surface of iron or zinc containing aluminum, and further improves the secondary adhesion when intermediate coating or top coating is applied to the electrodeposition coated plate. There is a need for a method and it is an object of the present invention to meet such challenges.

Means for Solving the Problems The present inventors have the above-mentioned object of treating a metal surface with an acidic zinc phosphate treatment aqueous solution containing 0.01 to 20.0 g / of a soluble tungsten compound as tungsten. And a tungstate such as sodium tungstate or ammonium tungstate is used as the soluble tungsten compound, and the silicotungstic acid and / or the silicotungstate compound is particularly effective. The present invention found that the effect of silicotungstic acid and / or silicotungstate compound can be particularly prominently exhibited in a specific concentration range of each metal ion of zinc, nickel, manganese, and fluorine ion. Completed the method.

In the present invention, it is most effective when targeting a metal surface having an iron-based surface or an iron-based surface and a zinc-based surface, but not limited to this, a zinc-based surface alone, an aluminum-based surface alone, or a combination of these surfaces. It goes without saying that the metal surface that it has can be treated for the same purpose. That is, the present invention is directed to the treatment of any of the metal surfaces described above.

A practically advantageous specific example of the treatment method of the present invention is as follows. First, heat the metal surface with alkaline absorbent cotton.
Spray and / or soak for 2 minutes at 30-60 ° C to degrease, then wash with tap water, and then in the case of soaking, spray and / or soak with a surface conditioner for 10 to 30 seconds at room temperature, then above. It may be immersed and / or sprayed for 15 seconds or more at a temperature of 30 to 70 ° C. with the acidic zinc phosphate-treated aqueous solution of the present invention, and then washed with tap water and deionized water.

When the present application is used in the dipping treatment, zinc ion which is the main component of the treatment liquid of the present invention is 0.1 to 2.0 g / preferably 0.3 to
1.5g / is enough. If it is less than 0.1 g / g, a uniform zinc phosphate film is not formed on the metal surface, and a partly blue-colored film with a lot of scale is formed. If it exceeds 2.0 g /, a uniform zinc phosphate film is formed, but the film on the surface is likely to be a film that is easily dissolved in alkali, and particularly the film is easily dissolved by the alkaline atmosphere exposed during cationic electrodeposition. As a result, the hot salt water resistance generally decreases, and especially in the case of an iron-based surface, the scab resistance deteriorates, and desired performance cannot be obtained, so it is unsuitable as an electrodeposition coating, especially as a cationic electrodeposition coating base. . Phosphate ion is 5-40 g / preferably 10-
30 g /. If it is less than 5 g /, a non-uniform coating is likely to be formed, and if it exceeds 40 g /, the effects of the present invention cannot be expected, and the amount of chemicals used is large, which is economically disadvantageous. Soluble tungsten compound is 0.01-2 as tungsten
0.0 g /, preferably 0.05-10.0 g / more preferably 0.1
It is ~ 3.0g /. If it is less than 0.01 g / z, the zinc phosphate coating is not sufficiently modified, and the scab resistance and hot salt water resistance are not improved. Further, in the treatment of aluminum material, the effect of suppressing the elution of aluminum becomes insufficient. On the other hand, if it exceeds 20 g /, the amount of tungsten is more than that contributing to the film reaction, the effect of the present invention or more cannot be expected, and sludge increases, which is not preferable.

Nitrite ion as a film formation accelerator 0.01-0.5 g /
, Preferably 0.01 to 0.4 g /, m-nitrobenzenesulfonate ion 0.05 to 5 g /, preferably 0.1 to 4 g /,
And hydrogen peroxide (H ₂ O ₂ 100% conversion) of 0.5 to 10 g /, preferably 1 to 8 g /.
If the amount of these accelerators does not reach the specified amount, sufficient film formation cannot be achieved on the iron-based surface, resulting in yellow rust, and if the amount exceeds the specified amount, a blue-colored non-uniform film is easily formed on the iron-based surface. As a supply source of these main components, for example, zinc ions may be zinc oxide, zinc carbonate, zinc nitrate, etc., and phosphate ions may be phosphoric acid, zinc phosphate, manganese phosphate, etc.,
Soluble tungsten compounds include tungstates such as sodium tungstate and ammonium tungstate, borotungstic acid, phosphotungstic acid, phosphotungsten compounds, and especially silicotungstic acid and silicotungstate compounds are preferably used. The acid may be a commercially available product, and the soluble silicotungstate compound may be selected from soluble compounds such as alkali metal salts, ammonium salts, and alkaline earth metal salts of silicotungstic acid. It is particularly desirable to use silicotungstic acid or silicotungstate in a treatment liquid for treating the surface of an aluminum material or an iron or zinc material containing an aluminum material.

The film formation accelerator is sodium nitrite, ammonium nitrite, m
-Sodium nitrobenzene sulfonate, hydrogen peroxide solution, etc. may be used.

In the case of spray treatment, the conversion of the zinc phosphate coating for the coating base to the metal surface is made good, and in addition, the consumption of nitrite is reduced to 1/2 or less compared to the conventional treatment liquid, and by-product sludge For the purpose of further reducing the generated amount to 1/3 to 1/4, the phosphate ion concentration in the treatment liquid during chemical conversion treatment is at least 5 g /, nitrite ion 0.0.
2 to 0.5 g /, zinc ion concentration of at least 0.3 g /,
The molar ratio of phosphate ion to nitrate ion is 1: 0.7 to 1.
3, and phosphate ion: zinc ion molar ratio of 1: 0.1
Maintaining at 16 or less and treating in the range where the pH of the treatment liquid is 3.3 to 3.8, for example, is proposed and noted in JP-B-55-5590. According to the present invention, by adding a soluble tungsten compound as tungsten in a concentration range of at least 0.01 to 20 g / in accordance with the present invention, a zinc phosphatization solution for spraying is also expected to have scab resistance and hot salt water resistance. It is possible to remarkably improve the adhesion, especially the adhesion of the zinc-based surface.

When the treatment liquid of the present invention contains manganese ions, nickel ions, and fluorine ions in a specific concentration range in addition to the above main components, the effects of the soluble tungsten compound can be exerted in a mutually complementary manner. In particular, when iron or zinc material containing aluminum material is targeted, silicotungstic acid or silicotungstate is selected as the soluble tungsten compound as described above,
It is desirable to contain a specific concentration of fluorine ions.
Fluorine ion is in the range of 0.05 to 4 g /, preferably 0.1 to 2 g /. If it is less than 0.05 g /, it will adversely affect the chemical conversion of iron materials. Further, in the case of a metal surface containing an aluminum material, the upper limit concentration of remaining aluminum in the treatment bath becomes low, which is not desirable. Further, when the fluorine ion concentration exceeds 4 g /, the effect of improving the hot salt water resistance tends to be reduced. Fluorine ions are hydrofluoric acid, borofluoric acid, silicofluoric acid,
It can be supplied with those metal salts, but when supplied with borofluoric acid or a salt of borofluoric acid, the allowable upper limit concentration of aluminum ions is 100 ppm, and when supplied with hydrosilicofluoric acid or its salt, 300 ppm Since it has been confirmed that, in the aluminum material treatment bath, it is most preferable that the fluorine ion is supplied by hydrosilicofluoric acid or its metal salt, although it is not essential.

Manganese ion is in the range of 0.1 to 3 g /, preferably 0.
It is in the range of 6 to 3 g /. If it is less than 0.1 g /, the adhesion of the zinc-based surface and the effect of improving hot salt water resistance will be insufficient, and
If it exceeds 3 g /, the effect of improving the corrosion resistance becomes insufficient. Nickel ion is in the range of 0.1 to 4 g /, preferably 0.1 to 2
It is in the range of g /. If the amount is less than 0.1 g /, the effect of improving the corrosion resistance due to the combined use with the soluble tungsten compound will be insufficient, and if it exceeds 4 g / the effect of improving the corrosion resistance will tend to be reduced. Examples of sources of these components include manganese ions such as manganese carbonate, manganese nitrate, manganese chloride, and manganese phosphate, and nickel ions such as nickel carbonate, nickel nitrate, nickel chloride, nickel phosphate, and nickel hydroxide. , Fluoride ion is hydrofluoric acid,
Borofluoric acid, hydrosilicofluoric acid, their metal salts, etc. may be used, nitrate ions may be sodium nitrate, ammonium nitrate, zinc nitrate, manganese nitrate, nickel nitrate, etc., and chlorate ions may be sodium chlorate, ammonium chloride. Etc.

The treatment temperature with the treatment liquid of the present invention is 30 to 70 ° C., preferably
It may be 35-60 ° C. If the temperature is too low, the chemical conversion of the film is poor, and long-time treatment is required. If the temperature is too high, the balance of the treatment liquid is easily lost due to decomposition of the film formation accelerator and precipitation of the treatment liquid, and it is difficult to obtain a good film.

The treatment time may be 15 seconds or longer, preferably 30 to 120 seconds. If the time is too short, a film having desired crystals cannot be formed sufficiently. When treating an article having a complicated shape such as an automobile body, it is preferable to combine the immersion treatment and the spray treatment for practical use. In that case,
For example, first, the immersion treatment may be performed for 15 seconds or longer, preferably 30 to 120 seconds, and then the spray treatment may be performed for 2 seconds or longer, preferably 5 to 45 seconds. In order to wash off the sludge attached during the dipping treatment, it is preferable that the spraying treatment be performed for as long as possible. Therefore, the treatment according to the present invention also includes treatment modes such as a dipping treatment, a spraying treatment and a combination thereof.

The present invention also relates to a concentration treating agent which provides a treating liquid having the above-mentioned constitution. In this concentrated treatment agent, the zinc ion source and the phosphate ion source are in ion form by weight, the soluble tungsten compound source is by weight as tungsten, and the weight ratio is zinc ion: phosphate ion: Soluble Tungsten Compound (as W) = 1: 2.5-4
It is composed of two liquids, a liquid (A) and a liquid (B) which is an accelerator liquid, which are prepared by mixing them so as to have a composition of 00: 0.005-200. The liquid is easily prepared. Incidentally, the liquid (A) can be added with an ion supply source other than the main component, that is, a manganese ion, nickel ion, fluorine ion, nitrate ion, chlorate ion supply source or the like. However, the chlorate ion source may be added to the solution (B) instead of the solution (A), and particularly when the manganese ion source is added to the solution (A), the chlorate ion source is added to the solution (B). Preferably.
Incidentally, the soluble tungsten compound supply source may be added to the liquid (B) so that the weight ratio of tungsten is such that the zinc ion: tungsten compound = 1: 0.005 to 200.

It should be noted that when tungstates such as sodium tungstate and ammonium tungstate are used, it is recognized that the film obtained by the treatment method of the present invention surely contains tungsten.

According to the present invention having the above constitution, not only the iron-based surface but also the zinc surface, the aluminum surface, or the metal surface having a combination thereof at the same time is applied to the coating base, especially the electrodeposition even after the initial and continuous treatments. It is suitable as a cationic electrodeposition coating substrate, especially as a cationic electrodeposition coating substrate, and is capable of forming a film having particularly excellent corrosion resistance, particularly scab resistance, warm water resistance, and good adhesion.

 Hereinafter, the present invention will be described with reference to examples.

<< Examples 1 to 7, 10 to 12, and Comparative Examples 1 to 7 >> (1) Metals to be treated: (a) Hot-dip galvannealed alloy: hot-dip galvanized steel sheet (b) Electric zinc: hot-dip galvanized steel sheet ( C) Alloyed electro-zinc: Alloyed electro-galvanized steel sheet (d) Cold rolled steel sheet (2) Acidic zinc phosphate treatment aqueous solution: Use 17 kinds of composition having the composition shown in Table 1 (3) Treatment step The metal surfaces of the seeds ((1) to (4) of (1)) are simultaneously treated according to the following steps. (4) Treatment conditions (a) Degreasing: Use an alkaline degreasing agent ("Surf Cleaner SD250" 2% by weight concentration manufactured by Nippon Paint Co., Ltd.)
Immerse at 0 ° C. for 2 minutes.

(B) Washing with water: Using tap water, wash at room temperature for 15 seconds.

(C) Surface adjustment: A surface adjusting agent ("Surffine 5N-5" manufactured by Nippon Paint Co., Ltd., 0.1% by weight concentration) is used, and immersion treatment is performed at room temperature for 15 seconds.

(D) Formation: Using the above acidic zinc phosphate-treated aqueous solution, dip treatment is performed for 120 seconds at the temperature (52 ° C. or 40 ° C.) shown in Table 1.

(E) Washing with water: Using tap water, wash at room temperature for 15 seconds.

(F) Washing with pure water: Using ion-exchanged water, soak for 15 seconds at room temperature.

(G) Drying: Dry with hot air at 100 ° C for 10 minutes. The appearance and the weight of the chemical conversion film of the chemical conversion treatment plate thus obtained are measured.

(H) Coating: Cationic type electrodeposition coating (manufactured by Nippon Paint Co., Ltd., "Power Top U-80 Gray") is baked to give a dried film thickness of 20.
Painted to μ (voltage 180V, energization time 3 minutes), 180
Bake at ℃ for 30 minutes. A part of the obtained electrodeposition coated plate is subjected to a hot salt water immersion test. The remaining electrodeposition coated plate is spray-coated with an intermediate coating paint ("Olga TO4811 Gray" from Nippon Paint Co., Ltd., melamine alkyd resin type) to a dry film thickness of 30μ, and baked at 140 ° C for 20 minutes. Next, a top coat paint (“Olga TO630 Dover White” manufactured by Nippon Paint Co., Ltd., melamine alkyd resin type) is spray-coated to a dry film thickness of 40 μm, baked at 140 ° C. for 20 minutes, and a total of 3 coats and 3 baking plates are applied. To get This is subjected to an adhesion test and a scab test.

<< Examples 8 and 9 and Comparative Examples 8 and 9 >> (1) Metals to be treated: (a) Alloyed hot-dip zinc: Alloyed hot-dip galvanized steel sheet (b) Electro-zinc: Electro-galvanized steel sheet (c) Alloyed Electrogalvanized: Alloyed electrogalvanized steel sheet (d) Cold rolled steel sheet (2) Acidic zinc phosphate treatment aqueous solution: Use four types having the composition shown in Table 1 (3) Treatment step The above four types ((1 ) (A) to (d)) metal surfaces are treated simultaneously according to the following steps (4) Treatment conditions (a) Degreasing: Using an alkaline degreasing agent ("Surf Cleaner S102" manufactured by Nippon Paint Co., 2 wt% concentration),
Spray for 2 minutes at 50 ° C.

(B) Washing with water: Using tap water, wash at room temperature for 15 seconds.

(C) Formation: Using the above acidic zinc phosphate-treated aqueous solution, perform a spray treatment at a spray pressure of 0.7 kg / cm ² and 55 ° C. for 120 seconds.

(D) Washing with water: Using tap water, wash at room temperature for 15 seconds.

(E) Pure water washing: Ion-exchanged water is used for immersion treatment at room temperature for 15 seconds.

(F) Drying: Dry with hot air at 100 ° C for 10 minutes. The appearance and the weight of the chemical conversion film of the chemical conversion treatment plate thus obtained are measured.

(G) Coating: Cationic type electrodeposition coating (“Power Top U-80 Gray” manufactured by Nippon Paint Co., Ltd.) was applied to a dry film thickness of 20 μm (voltage 180 V, energization time 3 minutes), and 180 ° C. for 3 minutes.
Bake for 0 minutes. A part of the obtained electrodeposition coated plate is subjected to a hot salt water immersion test. The remaining electrodeposition coated plate is spray-coated with an intermediate coating paint ("Olga TO4811 Gray" from Nippon Paint Co., Ltd., melamine alkyd resin type) to a dry film thickness of 30μ, and baked at 140 ° C for 20 minutes. Next, a top coat paint (“Olga TO630 Dover White” manufactured by Nippon Paint Co., Ltd., melamine alkyd resin type) is spray-coated to a dry film thickness of 40 μm, baked at 140 ° C. for 20 minutes, and a total of 3 coats and 3 baking plates are applied. To get This is subjected to an adhesion test and a scup test.

Test results: Various tests were carried out on the various test plates obtained in the above Examples and Comparative Examples, and the results are shown in Table 2. The test methods are shown below.

(A) Hot salt water immersion test 5% of the electrodeposition coated plate was cut with a sharp cutter.
After immersing in saline at 55 ° C for 480 hours, the adhesive tape is adhered to the cut part and then peeled off, and the maximum peeled width of the coating film is measured.

(B) Adhesion test: The coated plate was immersed in deionized water at 40 ° C for 20 days, and then 1 mm interval and 2 mm interval goggles (100 pieces) were formed with a sharp cutter and adhered to each surface. After adhering the tapes, these are peeled off, and the number of crepe coats remaining on the coated plate is counted.

(C) Scab test The coated plate is cut with a sharp cutter, and then this coated plate is subjected to a 5% salt spray test (JIS-Z-2371, 24 hours).
→ Wet test (humidity 40 ° C, relative humidity 85%, 120 hours) → Left indoor (24 hours) As one cycle, 10 cycles of corrosion test (hereinafter referred to as scab test) were performed. The maximum corrosion width of the coated surface after the test was examined.

As the tungsten compound in the above-mentioned examples, ammonium tungstate was used in Examples 1 to 8 and sodium tungstate was used in Example 9 and silicotungstic acid was used in Examples 11 and 12.

Examples 13, 14 Comparative Examples 10, 11, 12 (1) Object to be treated (a) Alloyed hot-dip galvanized steel sheet (b) Cold rolled steel sheet (c) Aluminum alloy sheet (Al / Mg alloy system) (2) Acidic Four types of zinc phosphate-treated aqueous solutions having the compositions shown in Table 3 were used.

(3) Treatment step The three types of ((1) (a) to (c)) metal surfaces are treated at the same time at the rates of 80, 10, 10% of the treated area respectively according to the following steps.

Degreasing → Washing with water → Surface preparation → Chemical conversion (dip) → Washing with water → Washing with pure water → Drying → Painting (4) Treatment conditions (a) Degreasing: Alkaline degreasing agent (Nippon Paint's "Surf Cleaner SD250", 2% by weight concentration) ) Was used for immersion treatment at 40 ° C. for 2 minutes.

[Bath management]

Alkalinity (10 ml was sampled, and bromphenol blue was used as an indicator to maintain 0.1 ml of 0.1N HCl for neutralization). Surf cleaner SD250 was used as the replenishing agent.

(C) Surface adjustment Using a surface adjustment agent ("Surffine 5N-5" manufactured by Nippon Paint Co., Ltd., 0.1% by weight concentration), at room temperature, 1
Immerse for 5 seconds.

[Bath management] Maintain alkalinity (same as above).

As a replenishing agent, Surffine 5N-5 (d) formation: The above acidic zinc phosphate-treated aqueous solution was used, and immersion treatment was performed at 40 ° C. for 2 minutes.

[Bath management]

Concentration of each ionic composition and free acidity in the above acidic zinc phosphate treated aqueous solution (10 ml was sampled, 0.1 ml of 0.1 N NaOH required for neutralization using bromphenol blue as an indicator)
To maintain. Supplemental agents are Zn, PO ₄ , Mn, Ni, W, F and NO _3.
In order to maintain the respective ion concentrations of the above, a replenishing concentrated treatment agent A containing zinc white, phosphoric acid, manganese nitrate, nickel carbonate, silicotungstic acid, silicofluoric acid (or borofluoric acid) and nitric acid, and NO ₂ In order to maintain the ion concentration of the above, a supplementary concentrated treatment agent B containing sodium nitrite was used. Further, in Comparative Example 12, in order to maintain the Al concentration of the zinc phosphate-treated aqueous solution at 50 ppm or less, an aluminum precipitation additive C containing potassium acid fluoride and sodium acid fluoride in a 2: 1 molar weight ratio, respectively. used.

(E) (f) Test results similar to those in Example 1 In Example 13, the equilibrium concentration of aluminum ions in the zinc phosphate-treated aqueous solution was 160 ppm. Indicated.

In Comparative Example 10, the aluminum ion concentration exceeded 300 ppm and reached 400 ppm, the chemical conversion of the cold-rolled steel sheet deteriorated (yellow rust occurred), and the coating quality deteriorated.

In Example 14, the equilibrium concentration of aluminum ions was 80 ppm.
However, all three types of treated objects showed good coating base suitability.

In Comparative Example 11, the aluminum ion concentration exceeded 100 ppm and reached 200 ppm, and the film forming property of the cold rolled steel sheet deteriorated (yellow rust occurred). Comparative Example 12 has an aluminum ion concentration of 50 pp
Although it was maintained below m, the tendency for aluminum precipitates to deposit on the object to be treated increased, and the suitability for the coating base deteriorated. (Less uniformity of cationic electrodeposition coating) The following embodiments are included in the present invention.

(1) The method according to claim 1, wherein the treatment method is immersion treatment.

(2) Soluble tungsten compounds are sodium tungstate, ammonium tungstate, borotungstic acid, phosphotungstic acid, phosphotungstic acid salt, silicotungstic acid, silicotungstic acid alkali metal salt, ammonium silicotungstic acid salt, and alkaline earth silicotungstic acid salt. The method according to claim 1, which is at least one selected from the group consisting of metal salts.

(3) Film formation accelerator is nitrite ion 0.01-0.5g /
, M-nitrobenzene sulfonate ion 0.05-5g /
The method according to claim 1, which is at least one selected from hydrogen peroxide and 0.5 to 10 g / hydrogen peroxide.

(4) The acidic zinc phosphate-treated aqueous solution contains manganese ions of 0.
1 to 3 g /, fluorine ion 0.05 to 4 g /, nickel ion
The method according to claim 1, comprising 0.1 to 4 g / at least one kind.

(5) Acidic zinc phosphate treated aqueous solution is 0.1 to 15g of nitrate ion
4. The method according to claim 1 or claim 3, which contains 0.05 to less than 2.0 g / of chlorate ions.

(6) The method according to claim 1, wherein the treatment temperature is 30 to 70 ° C.

(7) The method according to claim 1, wherein the dipping treatment is a combination of dipping treatment for 15 seconds or more and then spraying treatment.

(8) The method according to claim 1, wherein the metal surface has an iron-based surface, a zinc-based surface, or an iron-based surface and a zinc-based surface at the same time.

(9) The metal surface has an aluminum-based surface or an aluminum-based surface and an iron-based surface, and a zinc-based surface at the same time.
2.0g /, phosphate ion 5-40g /, fluoride ion 0.05
4. The method according to claim 1, which comprises .about.4 g / tungsten silicotungstic acid and / or silicotungstate as tungsten as 0.01 to 20 g / and a film formation accelerator as a main component.

(10) A component (A) containing a zinc ion source, a phosphate ion source and a tungsten ion source (as W) in a weight ratio of 1: 2.5 to 400: 0.005 to 200, and a film formation accelerator (B).
A two-pack type concentrated treatment agent for adjusting the acidic zinc phosphate treatment aqueous solution according to claim 1 by dilution.

(11) The two-pack type concentrated treatment agent according to the above item 8, wherein W is added to (B).

(12) A metal material having a tungsten-containing zinc phosphate coating obtained by the method according to claim 1.

(13) Zinc ion 0.1-2.0g /, phosphate ion 5-40g /
, Soluble tungsten compounds as tungsten.
A metal material having a tungsten-containing zinc phosphate coating obtained by treatment with an acidic zinc phosphate treatment aqueous solution containing 01 to 20.0 g / and a film formation accelerator as a main component.

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Koetsu Endo 19-17 Ikedanaka-cho, Neyagawa-shi, Osaka Japan Paint Co., Ltd. (72) Inventor Akio Tokuyama 19-17 Ikedanaka-cho, Neyagawa-shi, Osaka Japan Paint Incorporated (72) Inventor Tamotsu Nakata 19-17 Ikedanaka-cho, Neyagawa, Osaka Japan Paint Co., Ltd. (56) Reference JP-A-52-130444 (JP, A) JP-A-51-54010 ( JP, A) JP 55-131176 (JP, A) JP 61-36588 (JP, B2) JP 60-17827 (JP, B2) JP 55-5590 (JP, B2)

Claims (2)

[Claims] 1. A method for treating a metal surface with zinc phosphate, which comprises treating the metal surface with an acidic zinc phosphate treatment aqueous solution containing 0.01 to 20.0 g of a soluble tungsten compound as tungsten. 2. Acidic zinc phosphate containing zinc ion of 0.1 to 2.0 g /, phosphate ion of 5 to 40.0 g /, a soluble tungsten compound as tungsten of 0.01 to 20.0 g /, and a film formation accelerator as a main component. The method according to claim 1, wherein the method is performed with a treatment aqueous solution.