WO2006118218A1

WO2006118218A1 - Method of chemical treatment and chemically treated member

Info

Publication number: WO2006118218A1
Application number: PCT/JP2006/308903
Authority: WO
Inventors: Katsutoshi Ando; Yasuhito Murai; Kazuhiro Makino; Shinya Nishida; Masanobu Futsuhara; Toshiaki Shimakura
Original assignee: Honda Motor Co., Ltd.; Nippon Paint Co., Ltd.
Priority date: 2005-04-28
Filing date: 2006-04-27
Publication date: 2006-11-09
Also published as: CN101163820A; US20090078340A1; GB2440863A; CA2606171A1; GB0722061D0; JPWO2006118218A1

Abstract

A chemical treatment method in which an object to be treated is treated with a chemical treating agent to form a chemical conversion coating, wherein the object to be treated comprises at least one aluminum-plated steel sheet and at least one member selected from the group consisting of cold-rolled steel sheets, zinc-plated steel sheets, and aluminum sheets and the chemical treating agent is one which comprises zirconium, fluorine, and an aminated silane coupling agent and in which the zirconium content is 100-700 ppm in terms of metal amount and the fluorine/zirconium ratio is 3.5-7.0 by mole. According to the method, a sufficient coating amount can be ensured on the surface of a zinc deposit, cold-rolled steel sheet, zinc-plated steel sheet, aluminum-plated steel sheet, or the like and a chemical conversion coating having sufficient base-hiding properties and sufficient adhesion can be formed.

Description

Specification

Chemical conversion treatment method and chemical conversion treatment member

Technical field

TECHNICAL FIELD [0001] The present invention relates to a chemical conversion treatment method, and more particularly to a chemical conversion treatment method suitable for pre-painting treatment of general industrial products, particularly automobile bodies, and a chemical conversion treatment member formed by this chemical conversion treatment method.

Background art

[0002] Conventionally, automobile bodies have been constructed based on bare steel, mild steel such as galvanized steel, and aluminum. The surface treatment technology includes zinc phosphate treatment, and the corrosion resistance and adhesion of coating are ensured by depositing a zinc phosphate film on the surface of the material (see Patent Document 1).

[0003] However, recently, with the reduction in weight of automobile bodies, the materials used for the body have been diversified, and in particular, the application of high-tensile steel sheets has been rapidly increasing. The required properties of steel sheets, such as strength and elongation, vary depending on the body part to be applied. For example, there are various types of strength from 270 MPa class to 1500 MPa class. Of these, generally, a steel plate of 440 MPa or more is called a high-tensile steel plate, and a steel plate of less than 440 MPa is called a mild steel plate.

[0004] With the diversification of such steel sheets, the alloy composition and manufacturing method of the steel sheets differ depending on the required characteristics. In particular, as the amount of Si component increases, the etching properties of the surface of the material worsen, and the conventional zinc phosphate treatment technology causes variations in the depositability of the zinc phosphate coating, making it difficult to ensure the corrosion resistance and adhesion of the coating. . Furthermore, for ultra-high-strength steel sheets with strength exceeding lOOOMPa, the accuracy of molding dimensions is insufficient in the ordinary cold stamp manufacturing method, so heat stamping such as induction hardening is performed after molding, or hot stamping that is heated during molding Since a manufacturing method is used, it becomes more difficult to ensure adhesion and corrosion resistance of the coating film. In particular, in the hot stamping method, when a bare iron material is used, the surface of the material is oxidized by the thermal history, and the corrosion resistance and adhesion of the coating film cannot be obtained. In order to obtain satisfactory corrosion resistance and adhesion, oxidation scale by shot blasting Removal is essential and is economically disadvantageous. Therefore, aluminized steel sheets are being widely used as a method to prevent surface oxidation during hot stamping.

[0005] As a feature of an aluminized steel sheet, when heated at the time of forming, the clinging component diffuses into the iron base and an AlFe alloy is produced. This AlFe alloy is stable and exhibits high corrosion resistance. On the other hand, since a normal zinc phosphate film is not formed at all, sufficient adhesion of the coating film cannot be obtained. This is based on the fact that in order to deposit a crystalline zinc phosphate film, continuous electron supply by material etching is required, but it is difficult to etch because of its stability.

[0006] Therefore, the emergence of an amorphous film deposition-based surface treatment technology that can coat metal products by electron supply by intensive material etching is desired. For example, a surface treatment technique using a gino-recon coating system has been proposed, and it has also been proposed as a surface treatment method for automobile bodies (see Patent Document 2). In addition, with regard to sludge discharge and environmental protection measures, which are the disadvantages of zinc phosphate coatings, a technology that applies ginolecon coatings is being established as a method for surface treatment of automobile bodies, and coating adhesion by adding resin components Attempts have been made to improve the property and impart anti-corrosion properties by adding metal components (see Patent Documents 3 to 5).

Patent Document 1: JP-A-10-204649

Patent Document 2: Japanese Patent Laid-Open No. 2003-334490

Patent Document 3: WO2002 / 103080 pamphlet

Patent Document 4: Japanese Unexamined Patent Application Publication No. 2004-218070

Patent Document 5: Japanese Unexamined Patent Application Publication No. 2004-218075

Disclosure of the invention

Problems to be solved by the invention

[0007] However, with this surface treatment technology based on the zircon film, the amount of the zircon film tends to decrease when an aluminum-plated steel sheet manufactured by the hot stamping method is used, compared to a bare iron-coated zinc-plated steel sheet. There is. For this reason, the conventional zircon film surface treatment technology cannot provide a coating film having sufficient adhesion.

[0008] As described above, it is possible to secure a sufficient coating amount and sufficient substrate concealability and coating for any material such as galvanized, cold-rolled steel, galvanized steel, and aluminized steel. So far, no chemical conversion treatment method has been established that can simultaneously form a chemical conversion treatment film that provides film adhesion. Therefore, it is very useful to establish such a chemical conversion treatment method for automobile bodies and automobile parts composed of these materials.

[0009] The present invention has been made in view of the problems as described above, and its purpose is to provide a sufficient film on the surface of zinc-plated, cold-rolled steel sheet, zinc-plated steel sheet, aluminum-plated steel sheet, and the like. The present invention provides a chemical conversion treatment method capable of simultaneously forming a chemical conversion treatment film capable of securing a sufficient amount and providing sufficient substrate concealability and coating film adhesion, and a chemical conversion treatment member formed by this chemical conversion treatment method. is there.

Means for solving the problem

[0010] As a result of intensive studies in view of the above-mentioned problems, the present inventors have identified the compounding ratio in the chemical conversion treatment agent containing zirconium, fluorine, and an amino group-containing silane coupling agent. The present inventors have found that the problem can be solved and have completed the present invention. More specifically, the present invention provides the following.

[0011] (1) A chemical conversion treatment method for forming a chemical conversion film by treating an object to be treated with a chemical conversion treatment agent, wherein the object to be treated is at least one kind of an aluminum-plated steel sheet, a cold-rolled steel sheet, and a zinc-coated steel sheet. At least one selected from the group consisting of a steel plate and an aluminum plate, and the chemical conversion treatment agent is a chemical conversion treatment agent containing zirconium, fluorine, and an amino group-containing silane coupling agent. , The zirconium content in the chemical conversion treatment agent

The chemical conversion treatment method, wherein the metal conversion is lOOppm or more and 700ppm or less, and the molar ratio of the fluorine to the zirconium is 3.5 or more and 7.0 or less.

[0012] (2) The chemical conversion treatment method according to (1), wherein a content of the amino group-containing silane coupling agent in the chemical conversion treatment agent is 50 ppm or more and 500 ppm or less in terms of solid content concentration.

[0013] (3) The chemical conversion treatment method according to (1) or (2), wherein the chemical conversion treatment agent has a pH of 2.6 to 4.5.

(4) The chemical conversion treatment agent is at least one adhesion and corrosion resistance imparting agent selected from the group consisting of magnesium ions, zinc ions, calcium ions, aluminum ions, gallium ions, indium ions, and copper ions. The chemical conversion treatment method according to any one of (1) to (3) V, where the deviation is a chemical conversion treatment agent further contained. [0015] (5) The object to be processed is an automobile body member and an automobile body (1) to (4

) The chemical conversion processing method described in reg.

[0016] (6) A chemical conversion treatment member having a chemical conversion film formed by the chemical conversion treatment method according to any one of (1) to (5).

The invention's effect

[0017] According to the chemical conversion treatment method of the present invention, a sufficient amount of film can be secured on the surface of galvanized, cold-rolled steel sheet, galvanized steel sheet as well as aluminum-plated steel sheet, In addition, it is possible to provide a chemical conversion treatment method capable of simultaneously forming a chemical conversion treatment film capable of obtaining sufficient substrate hiding properties and coating film adhesion, and a chemical conversion treatment member formed by this chemical conversion treatment method. For this reason, the kind of aluminized steel sheet applicable to an automobile body can be expanded. In addition, it is possible to easily form a film on the edge portion of the substrate, and it is possible to prevent the occurrence of red wrinkles, which has conventionally been a concern for the portion where the iron substrate is exposed, due to plating cracks and scratches during molding.

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, embodiments of the present invention will be described.

[0019] <Chemical conversion treatment agent>

The present invention is a chemical conversion treatment method for forming a chemical conversion film by treating an object to be treated with a chemical conversion treatment agent, wherein the chemical conversion treatment agent contains zirconium, fluorine, and an amino group-containing silane coupling agent. It is a treatment agent.

[0020] [Zirconium component]

Zirconium contained in the chemical conversion treatment agent is a chemical film forming component. By forming a chemical conversion film containing dinoleconium on the object to be treated, the corrosion resistance of the substrate can be improved, and the adhesion to the coating film can be further improved.

[0021] When the surface treatment of the object to be treated is carried out with the chemical conversion treatment agent containing dinoleconium used in the present invention, the metal ions eluted in the chemical conversion treatment agent are dissolved in the ZrF by the dissolution reaction of the metal constituting the treatment object. ² _ Fluorine I is removed by bowing, and the pH of the interface increases.

6

Thus, zirconium hydroxide or oxide is produced. It is considered that this zirconium hydroxide or oxide is deposited on the surface of the object to be treated. For the present invention Since the chemical conversion treatment agent to be used is a reactive chemical conversion treatment agent, it can be used for immersion treatment of an object to be processed having a complicated shape. In addition, since a chemical conversion film firmly adhered to the object to be treated can be obtained by a chemical reaction, it is possible to perform water washing after the treatment.

[0022] The supply source of zirconium is not particularly limited. For example, K ZrF

2 6 alkali metal fluorozirconates, (NH 2) ZrF and other fluorozirconates, H Zr

4 2 6 2

Soluble fluorozirconate such as F and the like, and zirconium fluoride

6

, Zirconium oxide, zirconium nitrate, zirconium carbonate, and the like.

[0023] [Zirconium content]

The content of zirconium contained in the chemical conversion treatment agent used in the present invention is in the range of lOOppm or more and 700ppm or less in terms of metal. If it is less than lOOppm, a sufficient amount of film cannot be obtained on an aluminum-plated steel sheet. On the other hand, if it exceeds 700 ppm, no further effect can be expected, which is economically disadvantageous. Preferably it is 150ppm or more and 550ppm or less.

[0024] [Fluorine component]

Fluorine contained in the chemical conversion treatment agent used in the present invention plays a role as an etching agent for the object to be treated. The source of fluorine is not particularly limited. For example, fluorides such as hydrofluoric acid, ammonium fluoride, boron fluoride, ammonium hydrogen fluoride, sodium fluoride, sodium hydrogen fluoride, etc. Can be mentioned. It is also possible to use a complex fluoride as a supply source, for example, hexafluorosilicate, such as key hydrofluoric acid, key zinc hydrofluoride, key potassium hydrofluoride, key hydrofluoric acid. Examples thereof include magnesium, nickel key hydrofluoride, iron key hydrofluoride, and calcium key hydrofluoride.

[0025] [Content of fluorine component]

The content of fluorine contained in the chemical conversion treatment agent used in the present invention is in a range where the molar ratio of fluorine to zirconium is 3.5 or more and 7.0 or less. If the molar ratio of fluorine to zirconium is less than 3.5, the solution may become unstable and precipitation may occur.On the other hand, if it exceeds 7.0, the etching force will decrease and the film will be sufficiently formed. This is inconvenient because the process is not performed. Preferably, it is 4.5 or more and 6.5 or less, and more preferably 5.0 or more and 6.0 or less. [Amino group-containing silane coupling agent]

The amino group-containing silane coupling agent contained in the chemical conversion treatment agent used in the present invention has at least one alkyl chain in the molecule, and at least one alkyl chain has at least one amino group. In addition, it is a compound which is a functional group bonded to the remaining bond of silicon, an elemental force alkoxy group, or a halogen (mainly chlorine). Since the amino group-containing silane coupling agent acts on both the chemical conversion film and the coating film formed thereafter, the adhesion between them can be improved.

[0027] Such an effect is presumed to be caused by covalently adsorbing on the surface of the silanol force-treated material generated by hydrolysis of the alkoxy group or the surface of the dinoleconium film.

[0028] In addition, since the amino group-containing silane coupling agent contained in the chemical conversion film acts not only on the object to be treated but also on the coating film formed thereafter, it has an action of improving mutual adhesion. Conceivable. The amino group-containing silane coupling agent can exert an effect of improving the adhesion particularly to the coating film by the cationic electrodeposition coating.

[0029] The amino group-containing silane coupling agent is not particularly limited. For example, N-2 (aminoethyl) 3-aminopropylmethyldimethoxysilane, N-2 (aminoethyl) 3— Aminopropyltrimethoxysilane, N-2 (aminoethyl) 3-Aminopropyltriethoxysilane, 3-Aminopropyltrimethoxysilane, 3-Aminopropyltriethoxysilane, 3_ Triethoxysilyl _N_ (1, 3 _Dimethyl monobutylidene) propylamine, N-phenyl _3-aminopropyltrimethoxysilane, N, N-bis [3- (trimethoxysilyl) propyl] ethylenediamine, 3-aminopropyltrichlorosilane, and other known silane cups Examples thereof include a ring agent. In addition, KBM-602, KBM-603, KBE-603, KBM-903, KBE-9103, KBM-573 (manufactured by Shin-Etsu Chemical Co., Ltd.), XS1003 (Chisso shares) are commercially available as amino group-containing silane coupling agents It is also possible to use it as it is. Among these, N_ 2 (aminoethyl) 3-aminopropyltriethoxysilane (APS-L), N-2 (aminoethyl) 3-aminopropyltrimethoxysilane (AP S-L), 3- Minopropyltriethoxysilane (APS-S) and 3-aminopropyltrimethoxysilane are preferred. [0030] [Amino group-containing silane coupling agent content]

The content of the amino group-containing silane coupling agent contained in the chemical conversion treatment agent used in the present invention is preferably in the range of 50 ppm to 500 ppm in terms of solid content. If the content is less than 50 ppm, sufficient film adhesion may not be obtained. On the other hand, if it exceeds 500 ppm, no further effect can be expected, which is economically disadvantageous. More preferably, it is in the range of lOOppm or more and 300ppm or less, more preferably 150ppm or more and 250ppm or less.

[0031] [pH of chemical conversion treatment agent]

The pH of the chemical conversion treatment agent used in the present invention is preferably 2.6 or more and 4.5 or less. If the pH is less than 2.6, etching may be excessive and sufficient film formation may not be possible, or the film may become uneven and adversely affect the appearance of the coating. On the other hand, if it exceeds 4.5, etching is insufficient and a good film cannot be obtained. More preferably, it is in the range of 3.0 to 4.2, and more preferably 3.2 to 4.0.

[0032] The pH of the chemical conversion treatment agent can be adjusted using an acidic compound such as nitric acid or sulfuric acid and a basic compound such as sodium hydroxide, potassium hydroxide or ammonia.

[0033] [Adhesion and corrosion resistance imparting agent]

The chemical conversion treatment agent used in the present invention further includes at least one adhesion selected from the group consisting of iron ions, magnesium ions, zinc ions, calcium ions, aluminum ions, gallium ions, indium ions, and copper ions, and It is preferable to contain a corrosion resistance imparting agent. In the present invention, a chemical conversion film having better adhesion and corrosion resistance can be obtained by including an adhesion and corrosion resistance imparting agent.

[0034] [Content of adhesiveness and corrosion resistance imparting agent]

The content of the adhesion and corrosion resistance imparting agent optionally added to the chemical conversion treatment agent used in the present invention is preferably in the range of 1 ppm to 5000 ppm. If the blending amount is less than lpp m, the effect of imparting sufficient adhesion and corrosion resistance cannot be obtained, which is preferable. On the other hand, if it exceeds 5000 ppm, further improvement of the effect is not observed and it is economically unsatisfactory, and adhesion after coating may be reduced. More preferably, it is in the range of 25 ppm or more and lOOOppm or less. [0035] [Other ingredients]

In addition to the above components, the chemical conversion treatment agent used in the present invention may be used in combination with optional components as necessary. Examples of components that can be used include silica. By adding such components, it is possible to improve the corrosion resistance after painting.

[0036] Further, it is preferable that the chemical conversion treatment agent does not substantially contain phosphate ions. The phrase “substantially free of phosphate ions” means that phosphate ions are not contained so much as to act as a component in the chemical conversion treatment agent. By using a chemical conversion treatment agent that does not substantially contain phosphate ions, there is substantially no use of phosphorus that causes environmental burdens. In addition, phosphorus generated when using a zinc phosphate treatment agent is used. Generation of sludge such as iron oxide and zinc phosphate can be prevented.

[0037] <Chemical conversion treatment method>

The chemical conversion treatment method of the present invention can be carried out by bringing the chemical conversion treatment agent into contact with the surface of the object to be processed under normal processing conditions that are not particularly limited. For example, a dipping method, a spray method, a roll coating method, etc. can be mentioned.

[0038] [Chemical conversion treatment conditions]

The treatment temperature in the chemical conversion treatment is preferably in the range of 20 ° C. or more and 70 ° C. or less. More preferably, it is the range of 30 ° C or more and 50 ° C or less. Below 20 ° C, there is a possibility that sufficient film formation may not be performed, and there are inconveniences such as the need for temperature adjustment in summer, and even if it is above 70 ° C, there is no particular effect economically It is only disadvantageous. In addition, the chemical formation time in the chemical conversion treatment is preferably in the range of 5 seconds to 1100 seconds. More preferably, it is the range of 30 seconds or more and 120 seconds or less. If the time is less than 5 seconds, a sufficient amount of film cannot be obtained, which is inconvenient. If the time exceeds 1100 seconds, the effect cannot be obtained even if the amount of film is further increased.

[0039] The chemical conversion treatment method of the present invention does not require a surface conditioning treatment as compared with a treatment using a zinc phosphate chemical conversion treatment agent that has been put into practical use. For this reason, it is possible to perform the chemical conversion treatment of the object to be processed with fewer steps.

[0040] [Processed object] Examples of the object to be treated used in the chemical conversion treatment method of the present invention include iron-based substrates, aluminum-based substrates, and zinc-based substrates. Iron, aluminum, and zinc-based substrate are iron-based substrates composed of iron and / or alloys thereof, aluminum substrates composed of aluminum and / or alloys thereof, and zinc-based substrates composed of zinc and Z or alloys thereof. Means wood.

[0041] In particular, in the present invention, a sufficient amount of the ginolecon film can be secured even for an aluminum plated steel sheet after hot stamping, which has been a problem in the past. It is possible to obtain sufficient paint adhesion.

[0042] Further, the chemical conversion treatment method of the present invention is simultaneously applied to an object to be processed including a plurality of metal substrates among an iron-based substrate, an aluminum-based substrate, and a zinc-based substrate. be able to. Auto bodies and parts for automobiles are composed of various metallic materials such as iron, zinc, and aluminum, and all these materials must be surface treated in a single treatment. In some cases, according to the chemical conversion treatment method of the present invention, the chemical conversion treatment can be performed on all the materials without any problem once.

[0043] The iron-based substrate used as the workpiece of the present invention is not particularly limited, and examples thereof include cold-rolled steel sheets and hot-rolled steel sheets. In addition, the aluminum base material is not particularly limited, and examples thereof include a 5000 series aluminum alloy, a 6000 series aluminum alloy, an aluminum-plated steel sheet such as an aluminum-based electroplating, melt-bonding, and vapor-deposition plating. Can be mentioned. The zinc-based substrate is not particularly limited, and examples thereof include zinc-plated steel sheets, zinc-nickenore-coated steel sheets, zinc-iron-plated steel sheets, zinc-chrome-plated steel sheets, zinc-aluminum-plated steel sheets, zinc -Zinc-based steel plates such as titanium-plated steel plates, zinc-magnesium-plated steel plates, zinc-manganese-plated steel plates, zinc-plated steel plates, zinc-plated steel plates, etc. In the present invention, the iron, aluminum and zinc base materials can be subjected to chemical conversion treatment simultaneously.

[0044] [Average amount of conversion coating]

The average coating amount of the chemical conversion film obtained by the chemical conversion treatment method of the present invention is preferably in the range of 0.1 mg / m ² or more and 500 mgZm ² or less in terms of the total amount of metals contained in the chemical conversion treatment agent. If it is less than lmg / m ² , a uniform chemical conversion film cannot be obtained and good adhesion is obtained. Les preferred, because you may not get. On the other hand, if it exceeds 500 mg / m ² , no further effect can be obtained, which is economically disadvantageous. More preferably, it is in the range of 5 mg / m ² or more and 150 mg Zm ² or less.

[0045] In particular, in the chemical conversion treatment method of the present invention, the amount of the ginolecon film can be sufficiently secured even for the aluminum-plated steel sheet after hot stamping, which has been a problem in the past, and the aluminum-plated steel sheet In this case, it is possible to obtain sufficient paint adhesion. For this reason, sufficient coating adhesion can be obtained even when a chemical conversion treatment is performed simultaneously on an object to be processed consisting of a plurality of metal substrates including an aluminum-plated steel sheet. According to the chemical conversion treatment method of the present invention, an average coating amount of 10 mg / m ² or more can be ensured even for an aluminized steel sheet.

[0046] [Coating film formed thereafter]

After forming the chemical conversion film by the chemical conversion treatment method of the present invention, the coating film formed on the chemical conversion film is, for example, a conventionally known paint such as a cationic electrodeposition paint, a solvent paint, an aqueous paint, or a powder paint. Mention may be made of the coating film to be formed. For example, as the cationic electrodeposition coating material, a conventionally known cationic electrodeposition coating material made of an aminated epoxy resin, an aminated acrylic resin, a sulfonylated epoxy resin or the like can be mentioned. Among these, in order to further improve the adhesion between the electrodeposition coating film and the chemical conversion film by the action of the amino group-containing silane coupling agent contained in the chemical conversion treatment agent, a functional or reactive function with an amino group is exhibited. Cationic electrodeposition paints made of resin with groups are preferred.

[0047] [Pretreatment of workpiece]

The object to be treated of the present invention is preferably subjected to a water washing treatment after degreasing the surface of the object to be treated before performing the chemical conversion treatment. The degreasing treatment is performed to remove oil and dirt adhering to the surface of the object to be treated, and is usually performed at 30 ° C to 55 ° C with a degreasing agent such as a phosphorus-free and nitrogen-free degreasing cleaning solution. Immersion treatment is performed for several minutes. If desired, a preliminary degreasing process can be performed before the degreasing process. In addition, the water washing treatment after the degreasing treatment is performed by spraying at least once with a large amount of washing water in order to wash the degreasing agent with water.

[0048] [Post-treatment of processed material] The chemical conversion treatment member on which the chemical conversion film is formed by the chemical conversion treatment method of the present invention is preferably subjected to a water washing treatment before forming a coating film to be subsequently applied. The water washing treatment after the chemical conversion treatment is performed at least once in order not to adversely affect the adhesion and corrosion resistance after the various coatings. In this case, it is appropriate that the final washing is performed with pure water. In the water washing treatment after this chemical conversion treatment, washing can be carried out by combining these methods, which may be either spray water washing or immersion water washing. After the chemical conversion treatment and the water washing treatment, it is dried as necessary according to a known method, and then a coating film is formed by various coatings.

Example

[0049] Next, the present invention will be described more specifically with reference to examples and comparative examples, but the present invention is not limited to these examples. The blending amount represents parts by mass unless otherwise specified.

[0050] <Example 1>

Commercially cold-rolled steel plate (SPCC_SD, Nippon Test Panel, 70mm XI 50mm X 0.8 mm), high-tensile steel plate (JSC780T, Nippon Steel Corporation, 70mm X 150mm X 0.8 mm), and aluminum plating A steel plate (USIBOR1500P, manufactured by ARCELOR, 70 mm X 150 mm X 2.3 mm) was prepared as a workpiece.

[0051] [Pretreatment of workpiece before chemical conversion]

[Degreasing]

1. A 6% by mass EC90 (Nippon Paint degreasing agent) was used for immersion at 42 ° C for 2 minutes.

[Washing treatment]

After degreasing, it was immersed and washed in a water washing tank, and then spray washed with tap water for about 30 seconds.

[0052] [Chemical conversion treatment]

Zirconyl nitrate (manufactured by Nippon Light Metal) as the zirconium source and KBE- 903 (APS-S) (aminopropyltriethoxysilane: effective concentration 100%: manufactured by Shin-Etsu Chemical Co., Ltd.) as the amino group-containing silane coupling agent Used, zirconium concentration 500ppm, Fluorine concentration 416ppm (mono); 匕 = 416 X 91. 2/500 X 19. 0 = 4.0), amino group-containing silane coupling agent concentration 100ppm as solid content, magnesium ion 100ppm as adhesion and corrosion resistance imparting agent, And the chemical conversion treatment agent of 500 ppm of zinc ions was prepared. In addition, the pH was adjusted to 2.8 using a 10% aqueous sodium hydroxide solution. The temperature of the chemical conversion treatment agent was adjusted to 40 ° C, and then the workpiece was immersed for 60 seconds.

[0053] [Measurement of coating amount]

About each steel plate, the film amount after chemical conversion treatment was measured. Coating amount, the fluorescent X-ray analysis apparatus XRF- 1700 using (manufactured by Shimadzu Corporation X-ray fluorescence analyzer), the amount of Zr contained in the chemical conversion film (mg / m ²⁾ and Si amount (mg / m ² ) Was measured. The results are shown in Table 1.

[0054] [Rinse treatment after chemical conversion treatment]

Each steel plate subjected to chemical conversion treatment was sprayed with tap water for 30 seconds. Next, a spray treatment for 30 seconds was performed with ion-exchanged water.

[0055] [Electrodeposition coating]

Electrodeposition coating was performed on each steel plate that had been subjected to water treatment after chemical conversion treatment in a wet state by water washing treatment. Electrodeposition coating was performed using PN150 (Cation Electrodeposition Paint manufactured by Nippon Paint Co., Ltd.) so that the dry film thickness was 20 / m. After forming a coating film by electrodeposition coating, each steel plate was washed with water, and then heated at 170 ° C. for 20 minutes for baking to obtain a test plate.

[0056] [Secondary adhesion test (SDT)]

Two longitudinally parallel cuts reaching the substrate were put into the obtained test plate, and immersed in a 5% NaCl aqueous solution at 55 ° C for 240 hours. Thereafter, the cut portion was peeled off with tape, and the state of peeling of the paint was observed. In addition, the following evaluation was performed by the magnitude | size of the largest peeling width. The results are shown in Table 1.

: Within 1mm

U: lmm ~ 2mm

Δ: 2mm to 3mm

X: 3mm or more

[0057] [Composite cycle test (CCT)] A vertical equilibrium cut reaching the substrate was put on the obtained test plate, and then a 5% NaCl aqueous solution was continuously sprayed for 2 hours in a salt spray tester maintained at 35 ° C. Next, after drying for 4 hours under conditions of 60 ° C. and humidity 20-30%, it was kept for 2 hours under humid conditions of 50 ° C. and humidity of 95% or more. The above is one cycle, and 100 cycles were implemented. After 100 cycles, the swollen width from the cut part was measured. The following evaluation was performed according to the size of the maximum swollen width. The results are shown in Table 1.

◎: Within 3mm

U: 3mm ~ 4mm

Δ: 4mm to 5mm

X: 5mm or more

Fluorine concentration is 570 111 (mono: 匕 = 570 91.2 / 500X19.0 = 5.5), and KBM- 603 (APS- L) (N- (2-aminoethyl) 3-amino is used as the amino group-containing silane coupling agent. (Propyltriethoxysilane: Effective concentration 100%: Shin-Etsu Chemical Co., Ltd.) was used, and the solid content concentration lOOppm was used and the pH was adjusted to 3.5. It was. Table 1 shows the evaluation results of the test plates obtained.

Fluorine concentration is 574ppm (mono); 匕 = 574X91.2 / 500X19.0 = 5.5), and KBM_603 (APS_U (N_ (2-aminoethyl) 3-aminopropyltriethoxysilane: amino group-containing silane coupling agent: The test plate was obtained in the same manner as in Example 1 except that the effective concentration 100% (manufactured by Shin-Etsu Chemical Co., Ltd.) was used at a solid concentration of 200 ppm and the pH was adjusted to 3.5. The evaluation results of the test plate are shown in Table 1.

The test plate was prepared in the same manner as in Example 1 except that the concentration of dinoleconium was 200 ppm, the fluorine concentration was 210 ppm (mono); 匕 = 210X91.2 / 20 0X19.0 = 5.0, and the pH was adjusted to 3.5. Got. Table 1 shows the evaluation results of the test plates obtained.

Ginoleconium concentration 200 ppm, fluorine concentration 210 ppm (mono); 匕 = 210X91.2 / 20 0 X 19.0 = 5.0), and the same procedure as in Example 1 was performed except that the pH was adjusted to 3.5 without using an amino group-containing silane coupling agent. Obtained. Table 1 shows the evaluation results of the test plates obtained.

[Example 6]

Fluorine concentration was 626ppm (mono); 匕 = 626 X 91.2 / 500 X 19. 0 = 6.0, and KBM_603 (APS_U (N_ (2-aminoethyl) 3--) as the amino group-containing silane coupling agent (Minopropyltriethoxysilane: effective concentration 100%: Shin-Etsu Chemical Co., Ltd.) solid concentration 250 ppm, zinc ion 500 ppm as adhesion and corrosion resistance imparting agent, pH adjusted to 3.5 Carried out the same operations as in Example 1 to obtain test plates, and Table 1 shows the evaluation results of the obtained test plates.

[0063] <Comparative Example 1>

A test plate was obtained in the same manner as in Example 1 except that the chemical conversion treatment was changed to the zinc phosphate treatment shown below. Table 1 shows the evaluation results of the test plates obtained.

Zinc oxalate treatment]

Surface treatment was performed by immersing each treated object subjected to the degreasing treatment and the water washing treatment with 0.3% of 0 1 (a surface conditioner manufactured by Nippon Paint Co., Ltd.) for 30 seconds at room temperature. Then, immersion treatment was performed at 42 ° C. for 2 minutes using Surfdyne SD-6800 (a zinc phosphate chemical conversion treatment agent manufactured by Nippon Paint Co., Ltd.).

[0064] <Comparative Example 2>

Same as Example 1 except that the concentration of dinoleconium was 100ppm, the fluorine concentration was 250ppm (mono); 匕 = 250 X 91. 2/10 0 X 19. 0 = 12.0), and the pH was adjusted to 3.5 The test plate was obtained by carrying out the above operations. Table 1 shows the evaluation results.

[0065] <Comparative Example 3>

Fluorine concentration is 940ppm (Monole); 匕 = 940 X 91. 2/500 X 19. 0 = 9.00, and KBM_603 (APS_U (N_ (2-aminoethyl) 3) is used as an amino group-containing silane coupling agent. (Minopropyltriethoxysilane: effective concentration 100%: manufactured by Shin-Etsu Chemical Co., Ltd.) solid concentration 250 ppm, and without adjusting adhesion and corrosion resistance, and adjusting pH to 3.5. The same operation as in Example 2 was performed to obtain a test plate, and the evaluation results are shown in Table 1. Show.

[0066] [Table 1]

APS-S: NH ₂ (CH ₂ ) ₃ Si (0C ₂ H ₅ ) ₃

APS-L: NH ₂ (CH ₂ ) ₂ NH (CH ₂ ) ₃ Si (0C ₂ H ₅ ) ₃ Industrial Applicability

[0067] The chemical conversion treatment member obtained by the present invention can secure a sufficient amount of film even on an aluminum-plated steel sheet, and also forms a sufficient chemical conversion treatment film on various objects to be treated at the same time. In addition, since sufficient corrosion resistance can be ensured, the vehicle exterior plate, various parts, container outer surface, coil coating, etc. of the automobile body, motorcycle body, etc. before coating are applied afterwards. It is preferably used in the field to be used.

Claims

The scope of the claims

[1] A chemical conversion treatment method for forming a chemical conversion film by treating a treatment object with a chemical conversion treatment agent, the treatment object comprising at least one kind of an aluminum-plated steel sheet, a cold-rolled steel sheet, and a zinc plated steel sheet And at least one selected from the group consisting of aluminum plates,

The chemical conversion treatment agent is a chemical conversion treatment agent containing zirconium, fluorine, and an amino group-containing silane coupling agent,

The content of the zirconium in the chemical conversion treatment agent is not less than lOOppm and not more than 70 Oppm in terms of metal,

A chemical conversion treatment method wherein the molar ratio of the fluorine to the zirconium is 3.5 or more and 70 or less.

[2] The chemical conversion treatment method according to claim 1, wherein the content of the amino group-containing silane coupling agent in the chemical conversion treatment agent is 50 ppm or more and 500 ppm or less in terms of solid content concentration.

[3] The chemical conversion treatment method according to claim 1 or 2, wherein the chemical conversion treatment agent has a pH of 2.6 to 4.5.

[4] The chemical conversion treatment agent is further added with at least one adhesion and corrosion resistance imparting agent selected from the group consisting of magnesium ions, zinc ions, calcium ions, aluminum ions, gallium ions, indium ions, and copper ions. The chemical conversion treatment method according to claim 1, wherein the chemical conversion treatment agent is contained.

[5] The chemical conversion treatment method according to any one of claims 1 to 4, wherein the object to be treated is an automobile body member or an automobile body.

[6] A chemical conversion treatment member having a chemical conversion film formed by the chemical conversion treatment method according to any one of claims 1 to 5.