JP4067103B2 - Degreasing and chemical conversion treatment agent and surface-treated metal - Google Patents

Description

The present invention relates to a degreasing and chemical conversion treatment agent and a surface-treated metal.

When cationic electrodeposition coating or powder coating is applied to the surface of a metal material, chemical conversion treatment is usually performed for the purpose of improving properties such as corrosion resistance and coating film adhesion. When such a chemical conversion treatment is performed, if a chemical component such as rust preventive oil, press oil, or cutting oil adheres to the surface of the metal material to be processed, the chemical conversion treatment agent as described above is not uniformly applied. Problems such as rust prevention and deterioration of the film appearance occur. For this reason, a degreasing process is mostly performed before performing a chemical conversion treatment. Furthermore, in the chemical conversion treatment using zinc phosphate, in order to satisfactorily form a chemical conversion film in the metal chemical conversion treatment which is a subsequent step, it is common to perform a surface adjustment treatment. That is, in such a chemical conversion treatment, it is necessary to perform each step of the degreasing step, the water washing step, the surface adjustment step, the chemical conversion treatment step, the water washing step, the pure water washing step, and the coating step in this order.

In such a chemical conversion treatment method, management items increase as the process becomes longer, which is very disadvantageous from the viewpoint of workability. For this reason, the method of performing a degreasing | defatting process and a chemical conversion treatment by the same process by mix | blending a degreasing agent with a chemical conversion treatment agent, and omitting a water washing process simultaneously has been examined. For example, a degreasing and zinc phosphate chemical conversion agent in which polyoxyethylene alkyl ether and mineral oil are blended with a zinc phosphate chemical conversion treatment agent has been developed (see, for example, Patent Document 1).

However, such a chemical conversion treatment method by zinc phosphate treatment could not be omitted up to the surface adjustment step. Moreover, since the surface adjustment process is used, it is necessary to perform bath management or the like in the surface adjustment process, and the management items as the entire process increase. If the surface adjustment step can be omitted, only the degreasing and chemical conversion treatment step, the water washing step, the pure water washing step, and the coating step can be performed, and the process can be greatly shortened and management items can be reduced.

As a metal surface treatment agent other than the zinc phosphate chemical conversion treatment agent, a metal surface treatment agent comprising a zirconium compound is known (for example, see Patent Document 2). Such a metal surface treatment agent comprising a zirconium compound has properties superior to the zinc phosphate chemical conversion treatment agent described above in that a surface adjustment step is not required.

Even if a degreasing agent is blended with such a metal surface treatment agent composed of a zirconium compound and the degreasing and chemical conversion treatments are performed simultaneously, the stability of the chemical conversion film and the adhesion of the coating film decrease due to the action of the degreasing agent. Therefore, it could not be put to practical use as a pretreatment for painting. For this reason, the development of a degreasing and chemical conversion treatment agent that can form a good chemical conversion film without requiring a surface adjustment step is desired.

JP 2000-87254 A JP-A-7-310189

In view of the above, an object of the present invention is to provide a degreasing and chemical conversion treatment agent that does not require a surface adjustment step and can form a chemical conversion film having excellent stability and coating film adhesion. .

The present invention is a degreasing and chemical conversion treatment agent comprising at least one selected from the group consisting of zirconium, titanium and hafnium, fluorine, and a nonionic surfactant, and the nonionic surfactant has an HLB value of 9 to 17 A degreasing and chemical conversion treating agent characterized in that the content is 20 to 300,000 ppm as a solid content.

The degreasing and chemical conversion treating agent further comprises at least one metal ion (A) selected from the group consisting of zinc, manganese, and cobalt ions, alkaline earth metal ions (B), and metal ions of group 3 metals in the periodic table. It is preferable to contain at least one selected from the group consisting of (C), copper ions (D), and silicon-containing compounds (E).

The degreasing and chemical conversion treating agent further comprises nitrite ion, nitro group-containing compound, hydroxylamine sulfate, persulfate ion, sulfite ion, hyposulfite ion, peroxide, iron (III) ion, iron citrate compound, bromine 1-5000 ppm of at least one chemical reaction accelerator selected from the group consisting of acid ions, perchlorate ions, chlorate ions, chlorite ions, ascorbic acid, citric acid, tartaric acid, malonic acid, and succinic acid. Is preferred.

The degreasing and chemical conversion treating agent further contains 5 to 30000 ppm of at least one cation selected from the group consisting of nitrate ion, sulfate ion, hexafluorozirconium ion, hexafluorotitanium ion and fluoride ion on a mass basis. Is preferred.

This invention is also a surface treatment metal characterized by having the chemical conversion film formed with the degreasing and chemical conversion treatment agent mentioned above.
It is preferable that the said chemical film contains 0.1-500 mg / m < ² > of the metal contained in a degreasing and chemical conversion treating agent in a total amount.
Hereinafter, the present invention will be described in detail.

The degreasing and chemical conversion treatment agent of the present invention is a treatment agent capable of performing a degreasing treatment and a chemical conversion treatment by a single treatment. The degreasing treatment is performed to remove oil and dirt adhering to the surface of the base material. When such oil and dirt are present on the base material, a good chemical conversion film cannot be obtained. The degreasing and chemical conversion treating agent of the zinc phosphate treatment system cannot omit the surface conditioning step, but the degreasing and chemical conversion treating agent of the present invention which is a chemical conversion treating agent containing at least one selected from the group consisting of zirconium, titanium and hafnium is In addition, a chemical conversion film excellent in stability and coating film adhesion can be formed at the same time while having a sufficient degreasing action in a very short process without requiring a surface adjustment process.

At least one selected from the group consisting of zirconium, titanium, and hafnium contained in the degreasing and chemical conversion treatment agent of the present invention is a chemical film forming component, and at least one selected from the group consisting of zirconium, titanium, and hafnium is used as the base material. By forming the chemical conversion film containing, it is possible to improve the corrosion resistance and wear resistance of the base material and to further improve the adhesion with the coating film to be formed next.

The zirconium source is not particularly limited, and examples thereof include alkali metal fluorozirconates such as K ₂ ZrF ₆ ; fluorozirconates such as (NH ₄ ) ₂ ZrF ₆ ; fluorozirconate acids such as H ₂ ZrF _6, etc. And soluble fluorozirconate, etc .; zirconium fluoride; zirconium oxide and the like.

The titanium source is not particularly limited. For example, alkali metal fluorotitanate, fluorotitanate such as (NH ₄ ) ₂ TiF ₆ ; soluble fluorotitanate such as fluorotitanate such as H ₂ TiF _6, etc .; titanium fluoride A titanium oxide can be mentioned.

The source of hafnium is not particularly limited, and examples thereof include fluorohafnate acids such as H ₂ HfF ₆ ; hafnium fluoride.
The at least one source selected from the group consisting of zirconium, titanium and hafnium is at least one selected from the group consisting of ZrF ₆ ²⁻ , TiF ₆ ²⁻ , and HfF ₆ ²⁻ due to high film forming ability. The compound which has is preferable.

The total amount of at least one selected from the group consisting of zirconium, titanium and hafnium contained in the degreasing and chemical conversion treatment agent is preferably in the range of a lower limit of 20 ppm and an upper limit of 10,000 ppm in terms of metal. If it is less than the lower limit, the resulting chemical conversion film has insufficient performance. If the upper limit is exceeded, no further effect can be expected, which is economically disadvantageous. The lower limit is more preferably 50 ppm, and the upper limit is more preferably 2000 ppm.

Fluorine contained in the degreasing and chemical conversion treatment agent of the present invention plays a role as an etching agent for the substrate. The fluorine supply source is not particularly limited, and examples thereof include fluorides such as hydrofluoric acid, ammonium fluoride, borofluoric acid, ammonium hydrogen fluoride, sodium fluoride, and sodium hydrogen fluoride. . Examples of the complex fluoride include hexafluorosilicate, and specific examples thereof include hydrofluoric acid, zinc silicofluoride, manganese silicofluoride, magnesium silicofluoride, and hydrosilicofluoride. Examples thereof include nickel, iron silicohydrofluorate, and calcium silicohydrofluoride.

The degreasing and chemical conversion treating agent of the present invention contains a nonionic surfactant having an HLB of 9 to 17. By containing the nonionic surfactant whose HLB is in the range of the lower limit 9 and the upper limit 17, the surface of the base material can be sufficiently degreased and a good chemical conversion film can be formed. The HLB is calculated based on the following general formula (1).
HLB = 20 × (Mw / M) (1)
(Mw: weight of hydrophilic group part, M: molecular weight of surfactant)

If the HLB is less than 9, the degreasing action is insufficient. When the HLB exceeds 17, adsorption to the substrate surface becomes strong, and a good chemical conversion film may not be obtained. The lower limit is preferably 10, and the upper limit is preferably 16.
In addition, when an anionic surfactant is used, the foaming property is strong, which is not preferable in terms of work, and sufficient cleaning performance cannot be obtained under acidic conditions, so that a good chemical conversion film cannot be obtained. If a cationic surfactant is used, sufficient cleaning performance cannot be obtained, and thus a good chemical conversion film may not be obtained.

The nonionic surfactant is not particularly limited. For example, polyoxyethylene alkyl ether, polyalkylene alkyl ether, polyoxyalkylene glycol, fatty acid methyl ester (ethylene oxide addition type), polyoxyalkylamide, alkylamine oxide and the like. Polyoxyethylene alkyl ether is preferable from the viewpoint of environmental problems. It does not specifically limit as said polyoxyethylene alkyl ether, For example, Newcol 1100 (Nippon Emulsifier Co., Ltd. product: HLB13.1) etc. can be used. The nonionic surfactant preferably has a molecular weight of a lower limit of 200 and an upper limit of 1500.

Nonylphenol surfactants and alkylphenol surfactants are known to have excellent detergency among nonionic surfactants, but are desirably surfactants that are not used in consideration of the environment. In the degreasing and chemical conversion treatment agent of the present invention, since the above-described nonionic surfactant can be used to obtain sufficient detergency, the above nonylphenol surfactant and alkylphenol surfactant should not be used. Is preferred.

Although the said nonionic surfactant may be used independently, you may use 2 or more types together as needed. In that case, it is particularly preferable to blend at least one nonionic surfactant having defoaming properties such as higher alcohol (ethylene oxide adduct or alkylene oxide adduct) and silicon-based activator from the viewpoint of workability.

The total amount of the nonionic surfactant is within the range of a lower limit of 20 ppm and an upper limit of 300000 ppm. If it is less than 20 ppm, sufficient degreasing power cannot be obtained, and a good chemical conversion film cannot be obtained. If it exceeds 300,000 ppm, no further effect can be expected, which is economically disadvantageous. The lower limit is preferably 50 ppm, and the upper limit is preferably 100,000 ppm.
When using a nonionic surfactant having an antifoaming property such as the above higher alcohol (ethylene oxide adduct or alkylene oxide adduct) and a silicon-based active agent in combination, the total amount of the nonionic surfactant having an antifoaming property, It is preferable that the lower limit is within a range of 20 ppm and the upper limit is within a range of 100,000 ppm. If it is less than 20 ppm, a sufficient defoaming effect cannot be obtained, which is not preferable. If it exceeds 100000 ppm, the blending amount of the nonionic surfactant excellent in degreasing power may be reduced, and sufficient degreasing treatment may not be performed.

The degreasing and chemical conversion treatment agent of the present invention is further selected from the group consisting of zinc, manganese, and cobalt ions in order to form a chemical conversion film having sufficient adhesion to the iron-based substrate. Selected from the group consisting of at least one metal ion (A), alkaline earth metal ion (B), Periodic Table Group 3 metal ion (C), copper ion (D), and silicon-containing compound (E). It is preferable to contain at least one kind.
The degreasing and chemical conversion treatment agent of the present invention is presumed to reduce the fluorine concentration in the chemical conversion film and improve the performance as the chemical conversion film by blending the components (A) to (E). In addition, it is presumed that the chemical stability of the film increases or the porosity of the film decreases as a result of mixing these elements into the film, resulting in improved performance after coating.

At least one (A) selected from the group consisting of the above zinc ions, manganese ions, and cobalt ions is a metal ion having a divalent or trivalent valence. Among the above ions, zinc ions are preferable. The content of the degreasing and chemical conversion treatment agent is preferably in the range of a lower limit of 1 ppm and an upper limit of 5000 ppm. If it is less than 1 ppm, the corrosion resistance of the resulting chemical conversion film is lowered, which is not preferable. If it exceeds 5000 ppm, further improvement of the effect is not observed, which is economically disadvantageous, and the adhesion after coating may be lowered. The lower limit is preferably 20 ppm, and the upper limit is preferably 2000 ppm.

The alkaline earth metal ion (B) is not particularly limited, and examples thereof include magnesium ions, calcium ions, barium ions, strontium ions, etc. Among them, magnesium ions are preferable. The content of the alkaline earth metal ion is preferably in the range of a lower limit of 1 ppm and an upper limit of 5000 ppm. If it is less than 1 ppm, the corrosion resistance of the resulting chemical conversion film is lowered, which is not preferable. If it exceeds 5000 ppm, further improvement of the effect is not observed, which is economically disadvantageous, and the adhesion after coating may be lowered. The lower limit is more preferably 20 ppm, and the upper limit is more preferably 2000 ppm.

Examples of the third group metal ions (C) in the periodic table include aluminum ions, gallium ions, and indium ions. The content of the Group 3 metal ions in the periodic table is preferably in the range of a lower limit of 1 ppm and an upper limit of 5000 ppm. If it is less than 1 ppm, the corrosion resistance of the resulting chemical conversion film is lowered, which is not preferable. If it exceeds 5000 ppm, no further improvement in the effect is observed, which is economically disadvantageous, and the adhesion after coating may be lowered. The lower limit is more preferably 5 ppm, and the upper limit is more preferably 2000 ppm.

The copper ion (D) content is preferably in the range of a lower limit of 0.5 ppm and an upper limit of 100 ppm. If it is less than 0.5 ppm, the corrosion resistance of the resulting chemical conversion film is lowered, which is not preferable. When it exceeds 100 ppm, there is a possibility that a negative effect is brought about on the zinc-based substrate and the aluminum-based substrate. The lower limit is more preferably 2 ppm, and the upper limit is more preferably 50 ppm. Since the copper ion is particularly effective in stabilizing the chemical conversion film because of displacement plating on the surface of the metal substrate, it is presumed that a high effect can be obtained in a small amount as compared with other components.

The supply source of each of the metal ion components (A), (B), (C), and (D) is not particularly limited. For example, a degreasing and chemical conversion treatment agent such as a nitrate, a sulfate, or a fluoride. Can be blended. Of these, nitrate is preferable because it does not adversely affect the chemical reaction.

The silicon-containing compound (E) is not particularly limited, and examples thereof include silica such as water-dispersible silica, water-soluble silicate compounds such as sodium silicate, potassium silicate, and lithium silicate, silicate esters, diethyl Examples thereof include alkyl silicates such as silicate. Among these, silica is preferable because it has an effect of increasing the barrier property of the chemical conversion film, and water-dispersible silica is more preferable because of its high dispersibility in the degreasing and chemical conversion treatment agent. The water-dispersible silica is not particularly limited, and examples thereof include spherical silica, chain silica, and aluminum-modified silica that are low in impurities such as sodium. The spherical silica is not particularly limited. For example, “Snowtex N”, “Snowtex O”, “Snowtex OXS”, “Snowtex UP”, “Snowtex XS”, “Snowtex AK”, “Snow” Examples include colloidal silica such as Tex OUP, Snowtex C, and Snowtex OL (all manufactured by Nissan Chemical Industries, Ltd.) and fumed silica such as Aerosil (produced by Nippon Aerosil Co., Ltd.). Can do. The chain silica is not particularly limited, and examples thereof include silica sols such as “Snowtex PS-M”, “Snowtex PS-MO”, and “Snowtex PS-SO” (all manufactured by Nissan Chemical Industries, Ltd.) Can be mentioned. Examples of the aluminum-modified silica include commercially available silica sols such as “Adelite AT-20A” (manufactured by Asahi Denka Kogyo Co., Ltd.). Although the said silicon containing compound may be used independently, when using it in combination with the metal ion of (A)-(E) mentioned above, the outstanding effect is exhibited.

The content of the silicon-containing compound (E) is preferably in the range of a lower limit of 1 ppm and an upper limit of 5000 ppm as a silicon component. If it is less than 1 ppm, the corrosion resistance of the resulting chemical conversion film is lowered, which is not preferable. If it exceeds 5000 ppm, further improvement of the effect is not observed, which is economically disadvantageous, and the adhesion after coating may be lowered. The lower limit is more preferably 5 ppm, and the upper limit is more preferably 2000 ppm.

Each of the components (A) to (E) may be used alone, or may be used in combination of two or more components as necessary. When two or more components are used at the same time, the content of each component is preferably within the above range, and the total amount of each component is not particularly limited.
Particularly preferred combinations include a combination of at least one metal ion (A) selected from the group consisting of zinc, manganese, and cobalt ions and an alkaline earth metal ion (B).

When a metal substrate having an edge portion is treated with a zirconium-containing chemical conversion treatment agent, an anodic dissolution reaction occurs selectively at the edge portion and a cathode reaction occurs near the edge portion. As a result, a film is deposited near the edge portion. It becomes easy. On the other hand, since the anodic dissolution reaction hardly occurs in the flat portion of the metal substrate, the deposition of the film is suppressed. For this reason, there is a problem in that the amount of the deposited film is different between the vicinity of the edge portion and the flat portion, and as a result, the appearance of the metal substrate is uneven.

In order to improve the above problems and obtain a good film appearance, the degreasing and chemical conversion treatment agent of the present invention preferably contains a chemical conversion reaction accelerator.
The chemical conversion reaction accelerator is not particularly limited. For example, nitrite ion, nitro group-containing compound, hydroxylamine sulfate, persulfate ion, sulfite ion, hyposulfite ion, peroxide, iron (III) ion, citric acid Examples thereof include iron compounds, bromate ions, perchlorate ions, chlorate ions, chlorite ions, ascorbic acid, citric acid, tartaric acid, malonic acid, succinic acid, and salts thereof.

The supply source of the nitrite ions is not particularly limited, and examples thereof include sodium nitrite, potassium nitrite, and ammonium nitrite. The nitro group-containing compound is not particularly limited, and examples thereof include nitrobenzenesulfonic acid and nitroguanidine. It is not particularly limited as the source of the persulfate ion, for _example, a _{Na 2 S 2 O 8, K} 2 S 2 O 8 or the like. The supply source of the sulfite ion is not particularly limited, and examples thereof include sodium sulfite, potassium sulfite, and ammonium sulfite. The supply source of the hyposulfite ion is not particularly limited, and examples thereof include sodium hyposulfite, potassium hyposulfite, and ammonium hyposulfite. It does not specifically limit as said peroxide, For example, hydrogen peroxide, sodium peroxide, potassium peroxide etc. can be mentioned.

The supply source of the iron (III) ions is not particularly limited, and examples thereof include ferric nitrate, ferric sulfate, and ferric chloride. The iron citrate compound is not particularly limited, and examples thereof include iron ammonium citrate, sodium iron citrate, and potassium iron citrate. The source of bromate ions is not particularly limited, and examples thereof include sodium bromate, potassium bromate, and ammonium bromate. The supply source of the perchlorate ion is not particularly limited, and examples thereof include sodium perchlorate, potassium perchlorate, and ammonium perchlorate.

The supply source of the chlorate ion is not particularly limited, and examples thereof include sodium chlorate, potassium chlorate, and ammonium chlorate. The supply source of the chlorite ion is not particularly limited, and examples thereof include sodium chlorite, potassium chlorite, and ammonium chlorite. Ascorbic acid and its salt are not particularly limited, and examples include ascorbic acid, sodium ascorbate, potassium ascorbate, and ammonium ascorbate. It does not specifically limit as said citric acid and its salt, For example, a citric acid, sodium citrate, potassium citrate, ammonium citrate etc. can be mentioned. The tartaric acid and its salt are not particularly limited, and examples thereof include tartaric acid, ammonium tartrate, potassium tartrate, sodium tartrate and the like. It does not specifically limit as said malonic acid and its salt, For example, malonic acid, ammonium malonate, potassium malonate, sodium malonate, etc. can be mentioned. The succinic acid and its salt are not particularly limited, and examples thereof include succinic acid, sodium succinate, potassium succinate, ammonium succinate and the like.
The chemical conversion reaction accelerator may be used alone or in combination of two or more as necessary.

The content of the chemical conversion reaction accelerator in the degreasing and chemical conversion treatment agent of the present invention is preferably in the range of a lower limit of 1 ppm and an upper limit of 5000 ppm. If it is less than 1 ppm, a sufficient effect cannot be obtained, which is not preferable. If it exceeds 5000 ppm, film formation may be hindered. The lower limit is more preferably 3 ppm, and the upper limit is more preferably 2000 ppm.

In the degreasing and chemical conversion treating agent of the present invention, the content of at least one cation selected from the group consisting of nitrate ion, sulfate ion, hexafluorosilicon ion, tetrafluoroboron ion and fluoride ion has a lower limit of 5 ppm and an upper limit of 30000 ppm. It is preferable to be within the range. If it is less than 5 ppm, the chemical reaction may be inhibited due to insufficient etching, and if it exceeds 30000 ppm, the chemical reaction may be inhibited due to excessive etching.

The nitrate ion, sulfate ion, hexafluorosilicon ion, tetrafluoroboron ion, and fluoride ion are added as counter ions when blending each component such as fluorine, adhesion imparting agent, chemical reaction accelerator, etc. Or may be added as a corresponding acid.

It is preferable that the degreasing and chemical conversion treatment agent of the present invention contains substantially no phosphate ions. The phrase “substantially free of phosphate ions” means that the phosphate ions are not contained so much as to act as a component in the degreasing and chemical conversion treatment agent. Since the degreasing and chemical conversion treatment agent used in the present invention does not substantially contain phosphate ions, it does not substantially use phosphorus that causes environmental impact, and a zinc phosphate treatment agent is used. Generation of sludge such as iron phosphate, zinc phosphate, etc. generated in the steel can be suppressed.

The degreasing and chemical conversion treating agent of the present invention preferably has a pH in a range with a lower limit of 1.5 and an upper limit of 6.5. If it is less than 1.5, the etching becomes excessive and a sufficient film cannot be formed. If it exceeds 6.5, etching becomes insufficient and a good film cannot be obtained. The lower limit is more preferably 2.0, and the upper limit is more preferably 5.5. The lower limit is more preferably 2.5, and the upper limit is more preferably 5.0. In order to adjust the pH, acidic compounds such as nitric acid and sulfuric acid and basic compounds such as sodium hydroxide and potassium hydroxide can be used.

The metal surface treatment with the degreasing and chemical conversion treatment agent of the present invention is not particularly limited, and can be performed by bringing the chemical conversion treatment agent and the metal surface into contact with each other under normal treatment conditions. The treatment temperature in the chemical conversion treatment is preferably within a range of a lower limit of 20 ° C. and an upper limit of 70 ° C. The lower limit is more preferably 30 ° C, and the upper limit is more preferably 50 ° C. The chemical conversion time in the chemical conversion treatment is preferably in the range of a lower limit of 5 seconds and an upper limit of 1200 seconds. The lower limit is more preferably 30 seconds, and the upper limit is more preferably 120 seconds. The chemical conversion treatment method is not particularly limited, and examples thereof include a dipping method, a spray method, and a roll coating method.

After the treatment with the degreasing and chemical conversion treatment agent, it is preferable to perform a post-chemical conversion water washing step. The post-chemical conversion water-washing treatment is performed once or more so as not to adversely affect the adhesion, corrosion resistance, and the like after the subsequent various coatings. In this case, it is appropriate that the final water washing is performed with pure water. In this post-chemical conversion water washing treatment, either spray water washing or immersion water washing may be used, and these methods may be combined for water washing.

The chemical conversion treatment using the degreasing and chemical conversion treatment agent of the present invention is good without performing the surface conditioning treatment required in the method of treatment using a zinc phosphate chemical conversion treatment agent that has been practically used in the past. Therefore, it is possible to carry out the chemical conversion treatment of the metal substrate with fewer steps.

In the chemical conversion treatment using the degreasing and chemical conversion treatment agent of the present invention, a drying step is not always necessary after the post-chemical conversion water washing treatment. Even if the coating is performed while the chemical conversion film is wet without performing the drying step, the obtained performance is not affected. Moreover, when performing a drying process, it is preferable to perform cold air drying, hot air drying, etc. In the case of performing hot air drying, 300 ° C. or less is preferable from the viewpoint of saving thermal energy.

Examples of the metal substrate treated with the degreasing and chemical conversion treatment agent of the present invention include an iron-based substrate, an aluminum-based substrate, and a zinc-based substrate. Iron, aluminum, and zinc-based substrate are iron-based substrates in which the substrate is made of iron and / or an alloy thereof, aluminum substrates in which the substrate is made of aluminum and / or an alloy thereof, and the substrate is made of zinc and / or Or the zinc-type base material consisting of the alloy is meant. The degreasing and chemical conversion treatment agent of the present invention can be used for a chemical conversion treatment of an object to be coated consisting of a plurality of metal substrates among an iron-based substrate, an aluminum-based substrate, and a zinc-based substrate. it can.

The degreasing and chemical conversion treating agent of the present invention is an iron-based substrate that is difficult to obtain sufficient coating film adhesion in a chemical conversion treating agent containing at least one selected from the group consisting of ordinary zirconium, titanium, and hafnium. In view of this, it is preferable in that it can provide sufficient coating film adhesion, and is excellent in that it can be used for processing of an object including an iron-based substrate at least in part. Have the same properties. A surface-treated metal having a chemical conversion film formed by the degreasing and chemical conversion treatment agent of the present invention is also one aspect of the present invention.

It does not specifically limit as said iron-type base material, For example, a cold-rolled steel plate, a hot-rolled steel plate, etc. can be mentioned. It does not specifically limit as said aluminum-type base material, For example, 5000 series aluminum alloy, 6000 series aluminum alloy, etc. can be mentioned. The zinc-based substrate is not particularly limited. For example, galvanized steel sheet, zinc-nickel plated steel sheet, zinc-iron plated steel sheet, zinc-chromium plated steel sheet, zinc-aluminum plated steel sheet, zinc-titanium plated steel sheet, zinc- Examples thereof include zinc-based electroplating such as magnesium-plated steel sheet and zinc-manganese-plated steel sheet, zinc such as hot-dip plating and vapor-deposited steel sheet, or zinc-based alloy-plated steel sheet. By using the degreasing and chemical conversion treatment agent, it is possible to simultaneously perform chemical conversion treatment on iron, aluminum and zinc-based substrates.

Chemical conversion film obtained by degreasing and chemical conversion treatment agent of the present invention, the lower limit 0.1 mg / m 2 in a total amount of metal coating weight is comprised in the degreasing and chemical conversion treatment agent ^is within the range between the upper limit 500 mg / m ² It is preferable. If the coating amount is less than 0.1 mg / m ^2, it is not preferable because a uniform chemical conversion coating cannot be obtained. If it exceeds 500 mg / m ² , it is economically disadvantageous. The lower limit is more preferably 5 mg / m ² , and the upper limit is more preferably 200 mg / m ² .

The coating that can be performed on the surface-treated metal of the present invention is not particularly limited, and conventionally known coating such as cationic electrodeposition coating and powder coating can be performed. Among them, since it is possible to perform a good treatment on all metals such as iron, zinc, and aluminum, it is suitable as a pretreatment for cationic electrodeposition coating of an object to be treated which is at least partially composed of an iron-based substrate. Can be used. The cationic electrodeposition coating is not particularly limited, and a conventionally known cationic electrodeposition coating made of an aminated epoxy resin, an aminated acrylic resin, a sulfoniumated epoxy resin, or the like can be applied.

The degreasing and chemical conversion treatment agent of the present invention contains at least one selected from the group consisting of zirconium, titanium, and hafnium, fluorine, and a nonionic surfactant, so that a surface conditioning step is not required, and degreasing treatment and chemical conversion treatment are performed. It is a degreasing and chemical conversion treatment agent capable of performing treatment simultaneously. Furthermore, by reducing the concentration of fluorine contained in the resulting chemical conversion film and improving the stability of the chemical conversion film, it is possible to improve the stability of the chemical conversion film. Can form a chemical conversion film having excellent coating film adhesion. Moreover, the chemical conversion film nonuniformity can also be improved by adding a chemical conversion reaction accelerator and adjusting the amount of deposition of the chemical conversion film.

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited only to these examples.

Examples 1-9, Comparative Examples 5-7
Commercially cold-rolled steel plate (SPCC-SD, manufactured by Nippon Test Panel, 70 mm × 150 mm × 0.8 mm), galvanized steel plate (GA steel plate, manufactured by Nippon Test Panel, 70 mm × 150 mm × 0.8 mm), 5000 Pre-painting treatment is performed under the following conditions using a base aluminum (70 mm x 150 mm x 0.8 mm, manufactured by Nippon Test Panel Co.) or a base material of 6000 series aluminum (manufactured by Nippon Test Panel, 70 mm x 150 mm x 0.8 mm). did.
(1) Pre-coating degreasing and chemical conversion treatment: polyoxyethylene alkyl ether, polyalkylene alkyl ether, zircon hydrofluoric acid, titanium hydrofluoric acid, nitrate of each metal, silica (manufactured by Nissan Chemical Industries, Nippon Aerosil Kogyo Co., Ltd.) ) Was used to prepare a chemical conversion treatment having the composition shown in Table 1. The pH was adjusted using nitric acid or sodium hydroxide. The coating amount at the initial stage of the treatment was 46 mg / m ² .

Water treatment after chemical conversion: Sprayed with tap water for 30 seconds. Furthermore, it spray-processed for 10 second with ion-exchange water.
Drying treatment: A metal substrate after the water washing treatment was prepared without being dried and entering the next coating step while being wet, or by cold air drying. The coating amount was analyzed as the total amount of metals contained in the chemical conversion treatment agent using “XRF1700” (Shimadzu Corporation X-ray fluorescence analyzer).

(2) After processing 1 m ² of metal base material per liter of coating chemical conversion treatment agent, electrodeposition coating was applied using “Powernics 110” (Cation Electrodeposition Paint manufactured by Nippon Paint Co., Ltd.) to a dry film thickness of 20 μm. After washing with water, baking was performed by heating at 170 ° C. for 20 minutes to prepare a test plate.

Evaluation test <film appearance>
After the chemical conversion film obtained by the chemical conversion treatment agent prepared in each Example and Comparative Example was dried with cold air, the appearance of the film was visually observed.
○: Unevenness ×: Unevenness

<Sludge observation>
After processing 1 m ² metal base material per liter of chemical conversion treatment agent, the turbidity in the chemical conversion treatment agent was visually observed.
○: No turbidity ×: Turbidity

<Secondary adhesion test (SDT)>
Two vertical and parallel cuts reaching the substrate were put in the obtained test plate, and then immersed in a 5% NaCl aqueous solution at 50 ° C. for 480 hours. Thereafter, the cut part was peeled off with tape, and the peeling of the paint was observed.
A: No peeling O: Slight peeling x: Peel width 3 mm or more The evaluation results are shown in Table 3.

Comparative Examples 1-4
After immersion treatment at 40 ° C. for 2 minutes with “Surf Cleaner EC92” (degreasing agent manufactured by Nippon Paint Co., Ltd .: 2 mass%), spray treatment was performed for 30 seconds with tap water. Next, surface adjustment is performed at room temperature for 30 seconds using Surffine 5N-8M (manufactured by Nippon Paint Co., Ltd.), and at 35 ° C. using Surfdyne SD-6350 (a zinc phosphate-based chemical conversion treatment agent manufactured by Nippon Paint Co., Ltd.). After performing chemical conversion treatment by performing immersion treatment for 2 minutes, electrodeposition coating was performed in the same manner as in Examples to obtain a test plate.

From Table 3, it was shown that a good degreasing treatment and a surface-treated metal can be obtained by the degreasing and chemical conversion treating agent of the present invention without performing the surface adjustment step. Furthermore, sludge generation was not observed in the degreasing and chemical conversion treatment agent of the present invention. On the other hand, in the comparative example, it was not possible to obtain a chemical conversion film that suppresses the generation of sludge and has excellent adhesion to the cationic electrodeposition coating film.

According to the present invention, it is possible to obtain a degreasing and chemical conversion treatment agent that can perform a degreasing treatment and a chemical conversion treatment at the same time without performing a surface adjustment step. Furthermore, since the degreasing and chemical conversion treatment agent of the present invention does not substantially contain phosphate ions, the load on the environment is small, and no labor for drainage is required, so that both workability and economy are excellent.

Claims (6)

A degreasing and chemical conversion treatment agent comprising at least one selected from the group consisting of zirconium, titanium and hafnium, fluorine, and a nonionic surfactant,
The nonionic surfactant has a HLB value of 9 to 17 and a content of 20 to 300,000 ppm as a solid content. Furthermore, at least one metal ion (A) selected from the group consisting of zinc, manganese, and cobalt ions,
Alkaline earth metal ions (B),
Periodic Table III metal ions (C),
Copper ions (D), and
The degreasing and chemical conversion treating agent according to claim 1, comprising an adhesion imparting agent which is at least one selected from the group consisting of silicon-containing compounds (E). Furthermore, nitrite ion, nitro group-containing compound, hydroxylamine sulfate, persulfate ion, sulfite ion, hyposulfite ion, peroxide, iron (III) ion, iron citrate compound, bromate ion, perchlorate ion, A chlorate ion, a chlorite ion, and at least one chemical conversion accelerator selected from the group consisting of ascorbic acid, citric acid, tartaric acid, malonic acid, succinic acid and salts thereof are contained in an amount of 1 to 5000 ppm. Or the degreasing and chemical conversion treatment agent of 2 description. Furthermore, 5 to 30,000 ppm of at least one cation selected from the group consisting of nitrate ion, sulfate ion, hexafluorosilicon ion, tetrafluoroboron ion and fluoride ion is contained on the basis of mass. Degreasing and chemical conversion treatment agent. A surface-treated metal having a chemical conversion film formed by the degreasing and chemical conversion treatment agent according to claim 1. The surface-treated metal according to claim 5, wherein the chemical conversion film contains 0.1 to 500 mg / m ^{2 of} a total amount of metals contained in the degreasing and chemical conversion treatment agent.