KR20040058038A - Chemical conversion coating agent and surface-treated metal - Google Patents

Abstract

PURPOSE: To provide a chemical conversion coating agent which places a less burden on the environment and can apply good chemical conversion treatment to all metals such as iron, zinc and aluminum, and a surface-treated metal obtained using the same. CONSTITUTION: The chemical conversion coating agent comprises at least one kind selected from the group consisting of zirconium, titanium and hafnium; fluorine; and a water-soluble resin, wherein the water-soluble resin has, in at least a part thereof, a constituent unit expressed by chemical formula(1) and/or chemical formula(2), wherein the water-soluble resin is a polyvinylamine resin or a polyallylamine resin, wherein the water-soluble resin has a molecular weight of 500 to 500,000, and a content of the water-soluble resin in the chemical conversion coating agent is 5 to 5,000 ppm, wherein the chemical conversion coating agent further contain 1 to 5,000 ppm of at least one kind of a chemical conversion reaction accelerator selected from the group consisting of nitrite ion, nitro group-containing compounds, hydroxylamine sulfate, persulfate ion, sulfite ion, hyposulfite ion, peroxides, iron (III) ion, citric acid iron compounds, bromate ion, perchlorate ion, chlorate ion, chlorite ion, as well as ascorbic acid, citric acid, tartaric acid, malonic acid, succinic acid and salts thereof, and wherein the at least one kind selected from the group consisting of zirconium, titanium and hafnium has a content of 20 to 10,000 ppm in terms of metal, and the chemical conversion coating agent has a pH of 1.5 to 6.5.

Description

CHEMICAL CONVERSION COATING AGENT AND SURFACE-TREATED METAL}

The present invention relates to a chemical conversion treatment agent and a surface treatment 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. From the viewpoint of improving the adhesion and corrosion resistance of the coating film, chemical conversion treatment is performed. The chromate treatment, which has been used in recent years, has been pointed out that the danger of chromium has been pointed out, requiring the development of a chemical treatment agent containing no chromium. As such chemical conversion treatment, a treatment with zinc phosphate is widely performed (for example, see Japanese Patent Laid-Open No. 10-204649).

However, since the zinc phosphate treatment agent is a highly reactive treatment agent with high metal ion and acid concentrations, economic efficiency and workability in wastewater treatment are not good. In addition, insoluble salts are formed in the water and precipitate due to the metal surface treatment with the zinc phosphate treatment agent. Such deposits are generally called sludge, and the cost of removing and discarding such sludge Generation and the like are problematic. Furthermore, since phosphate ions may burden the environment by eutrophication, it is preferable not to use phosphate ions because they require effort in treating the waste liquid. Moreover, in metal surface treatment with a zinc phosphate treatment agent, it is necessary to perform surface adjustment and there also exists a problem that a process becomes long.

As a metal surface treatment agent other than such a zinc phosphate chemical treatment agent or chromate chemical conversion treatment agent, the metal surface treatment agent which consists of a zirconium compound is known (for example, see Unexamined-Japanese-Patent No. 7-310189). It consists of such a zirconium compound. The metal surface treatment agent has excellent properties compared with the zinc phosphate chemical treatment agent mentioned above in that generation | occurrence | production of sludge is suppressed.

However, the chemical conversion film obtained by the metal surface treatment agent which consists of a zirconium compound has bad adhesiveness with the coating film obtained by cation electrodeposition coating, powder coating, etc., and it is usually performed as a pretreatment process of such coating. In particular, such a zirconium In the metal surface treatment agent which consists of a compound, improvement of adhesiveness and corrosion resistance are performed by using components, such as a phosphate ion, together. However, when phosphate ions are used in combination, the problem of eutrophication as described above occurs. In addition, there was no examination regarding the use of such a treatment with a metal surface treatment agent as a pretreatment method for coating. Moreover, when processing an iron base material with such a metal surface treatment agent, there existed a problem that sufficient coating-film adhesiveness and corrosion resistance after coating were not obtained.

As a zirconium compound containing metal surface treatment agent which improved the above-mentioned problem, development of the metal surface treatment agent which consists of a zirconium compound, vanadium, and resin which do not contain a phosphate ion is performed (for example, Unexamined-Japanese-Patent No. 2002-60699). However, since such a metal surface treatment agent contains vanadium, it is not preferable at the point which causes a danger to a human body, a waste liquid disposal problem, etc ..

In addition, parts of various metal materials such as iron, zinc, and aluminum, such as automobile bodies and parts, may have to be subjected to surface treatment of all metals in a single treatment, and in this case, chemical conversion can be performed without problems. Development of chemical conversion agents is desired.

SUMMARY OF THE INVENTION In view of the present condition, the present invention provides a chemical conversion agent capable of performing a good chemical conversion treatment on all metals such as iron, zinc, aluminum, etc., and a surface-treated metal obtained by using the same. It is for the purpose.

The present invention is at least one member selected from the group consisting of zirconium, titanium and hafnium, a conversion treatment agent of fluorine and a water-soluble resin, wherein the water-soluble resin is at least a part of the following formula (1);

And / or the following formula (2);

It is a water-soluble resin which has a structural unit represented by it, and is a chemical conversion treatment agent characterized by not containing phosphate ion substantially.

It is preferable that the said water-soluble resin is polyvinylamine resin or polyallylamine resin. The said water-soluble resin has a molecular weight of 500-500000, and it is preferable that content of the said water-soluble resin in the said chemical conversion treatment agent is 5-5000 ppm.

The chemical conversion treatment agent further includes nitrite ions; Nitro group-containing compounds; Sulfuric acid hydroxylamine; Persulfate ions; Sulfite ions; Hyposulfite ions; peroxide; Iron (III) ions; Iron citrate compounds; Bromate ions; Perchlorate ions; Chlorate ions; Chlorite ions; Or at least one selected from the group consisting of ascorbic acid, citric acid, tin acid, malonic acid, zucchini acid and salts thereof; It is preferable to contain 1-5000 ppm of chemical conversion reaction accelerators.

The chemical conversion agent preferably has at least one content selected from the group consisting of zirconium, titanium and hafnium as a metal ion concentration of 20 to 10000 ppm and a pH of 1.5 to 6.5.

The present invention also provides a surface-treated metal having a chemical conversion film formed by the chemical conversion treatment agent.

It is preferable that the said chemical conversion film is 0.1-500 mg / m <^2> as a total amount of the metal contained in a chemical conversion treatment agent.

Hereinafter, the present invention will be described in detail.

The present invention is a chemical conversion treatment agent containing at least one selected from the group consisting of zirconium, titanium and hafnium and fluorine, and substantially free of harmful heavy metal ions such as chromium and vanadium or phosphate ions.

In the case where the metal surface is treated with a known chemical conversion treatment agent composed of zirconium or the like, a good treatment film may not be formed depending on the type of metal. Particularly in the case where the iron-based substrate is treated with the chemical conversion treatment agent, There was a problem that the adhesion between the coating film and the metal surface in the case of coating on the film and the corrosion resistance after coating were not sufficiently obtained. The present invention is completed by discovering that the above problem is solved by a chemical conversion agent containing a specific resin component. It is done.

At least one selected from the group consisting of zirconium, titanium, and hafnium contained in the conversion treatment agent is a chemical conversion film-forming component, and a chemical conversion film including at least one selected from the group consisting of zirconium, titanium, and hafnium is formed on the substrate, It can improve corrosion resistance and abrasion resistance, and can further improve adhesiveness with a coating film.

The source of the zirconium is not particularly limited, for example, K ₂ ZrF ₆

Alkali metal fluoro zirconates; Fluorine zirconates such as (NH ₄ ) ₂ ZrF ₆ ; soluble fluorine zirconates such as fluoro zirconate acids such as H ₂ ZrF ₆ , and the like; Zirconium fluoride; Zirconium oxide etc. are mentioned.

The source of the titanium is not particularly limited, and for example, fluoro titanates such as alkali metal fluoro titanate and (NH ₄ ) ₂ TiF ₆ ; Soluble fluoro titanates such as fluoro titanate acid such as H ₂ TiF ₆ and the like; Titanium fluoride; Titanium oxide, and the like.

The source of the hafnium is not particularly limited, and for example, fluorinated hafnate acids such as H ₂ HfF ₆ ; Hafnium fluoride and the like.

The at least one source selected from the group consisting of zirconium, titanium and hafnium is a ^compound having a high film-forming ability and containing at least one member selected from the group consisting of ZrF ₆ ^2- , TiF ₆ ^2- , and HfF ₆ ^2- . This is preferable.

The content of at least one selected from the group consisting of zirconium, titanium and hafnium contained in the chemical conversion treatment agent is preferably in the range of 20 ppm lower limit and 1000 upper ppm upper limit in terms of metal. It is inadequate and it is economically disadvantageous because it cannot exceed further the said upper limit. The said minimum is more preferable 50 ppm, and the upper limit is more preferable 2000 ppm.

Fluorine contained in the chemical conversion treatment agent serves as an etchant for the substrate. The source of the fluorine is not particularly limited, and examples thereof include fluorides such as hydrofluoric acid, ammonium fluoride, boric fluoride, ammonium hydrogen fluoride, sodium fluoride, sodium hydrogen fluoride, and the like. Hexafluorosilicates; specific examples thereof include hydrofluoric acid silicon, zinc hydrofluoric acid, zinc hydrofluoric acid, manganese silicon hydrofluoric acid, magnesium hydrofluoric acid, nickel hydrofluoric acid, iron hydrofluoric acid, calcium hydrofluoric acid, and the like. have.

The water-soluble resin used for the chemical conversion treatment agent of the present invention has at least a part of the following formula (1);

And / or the following formula (2);

It is thought that the chemical conversion film which consists of the said water-soluble resin can improve the adhesiveness of a metal base material and a coating film by the action of the amino group contained in the said water-soluble resin. It is not specifically limited, It can manufacture by a well-known method.

As for the said water-soluble resin, polyvinylamine resin which is a polymer which consists only of a structural unit represented by said Formula (1), and / or polyallylamine resin which is a polymer which consists only of a structural unit represented by said formula (2) is especially preferable. The said polyvinylamine resin and polyallylamine resin are especially preferable at the point which is excellent in the effect of an adhesive improvement. The said polyvinylamine resin is not specifically limited, Commercially available polyvinylamine resin, such as PVAM-0595B (Mitsubishi Chemical Corporation), can be used. The polyallylamine resin is not particularly limited, and for example, commercially available polyallylamine resins such as PAA-01, PAA-10C, PAA-H-10C, PAA-DllHCl (all of which are manufactured by Il Dong Oriental Co., Ltd.) can be used. Moreover, what used polyvinylamine resin and polyallylamine resin together may be sufficient.

The water-soluble resin is modified by a method such as acetylating a part of the amino group of the polyvinylamine resin and / or polyallylamine resin within a range that does not impair the object of the present invention, part of the amino group Or the whole thing neutralized with the acid, the thing bridge | crosslinked by the crosslinking agent in the range which does not affect solubility, etc. can also be used.

It is preferable that the said water-soluble resin has an amino group in the range of the lower limit 0.01 mol and an upper limit 2.3 mol per 100 g of resin. If it is less than 0.1 mol, sufficient effect cannot be obtained and it is not preferable. If it exceeds 2.3 mol, there exists a possibility that a desired effect may not be obtained. The said minimum is more preferable at 0.1 mol.

In the chemical conversion treatment agent of the present invention, the content of the water-soluble resin is preferably in the range of 5 ppm lower limit and 5000 ppm upper limit as solid content. If it is less than 5 ppm, the chemical conversion film which has sufficient coating film adhesiveness cannot be obtained, and it is unpreferable. When it exceeds 5000 ppm, there exists a possibility that it may inhibit film formation. The said lower limit is more preferable 10 ppm, and the said upper limit is more preferable 500 ppm. Do.

It is preferable that the said water-soluble resin is in the range of the lower limit 500 and the upper limit 500000. If it is less than 500, the chemical conversion film which has sufficient coating-film adhesiveness cannot be obtained, and it is unpreferable. When it exceeds 500000, there exists a possibility of inhibiting film formation.

5000 is more preferable and the said minimum is more preferable 70000.

In addition, the chemical conversion treatment agent of the present invention preferably contains a chemical reaction accelerator. The chemical reaction accelerator has an effect of suppressing the stain on the surface of the chemical film obtained by the metal surface treatment agent made of a zirconium compound. Occurs because the amount of deposited film is different depending on the difference in the portions of the base and the edge of the substrate. For example, when treating a metal substrate having an edge portion with a surface treatment agent made of a conventional zirconium compound, the cathode dissolution reaction selectively occurs at the edge portion, so that a cathode reaction is likely to occur, and as a result, a film is deposited near the edge portion. On the other hand, such staining occurs because the anode dissolution reaction hardly occurs in the planar portion and the deposition of the film is suppressed.

According to the zinc phosphate chemical treatment, since the obtained chemical film is a thick film (thick film) type, staining is not a big problem. However, since the chemical film made of a zirconium compound is a thin film type, sufficient amount of film in the flat part which is difficult to chemically treat If it cannot be obtained, it may cause uneven coating, and may cause problems in appearance, corrosion resistance, and the like.

In the present invention, the chemical reaction accelerator is blended with the chemical treatment agent so that the chemical conversion treatment can be performed without causing a difference in chemical conversion treatment between the edge portion and the flat portion.

The chemical reaction accelerator may include nitrite ions; Nitro group-containing compounds; Sulfuric acid hydroxylamine; Persulfate ions; Sulfite ions; Hyposulfite ions; peroxide; Iron (III) ions; Iron citrate compounds; Bromate ions; Perchlorate ions; Chlorate ions; Chlorite ions; Or at least one selected from the group consisting of ascorbic acid, citric acid, tartaric acid, malonic acid, succinic acid and salts thereof, and among them, one having an oxidizing action or an organic acid to efficiently promote the etching reaction is preferable.

By incorporating such a chemical reaction promoter into a chemical conversion treatment agent, it is possible to adjust the bias of the film deposition and to obtain a good chemical film without spots even at the edge portion and the flat portion of the substrate.

The source of the nitrite ion is not particularly limited, and examples thereof include sodium nitrite, potassium nitrite, ammonium nitrite, and the like. The nitro group-containing compound is not particularly limited. For example, nitrobenzene sulfonic acid and nitro guanidine. The source of the persulfate ions is not particularly limited, and examples thereof include Na ₂ S ₂ O ₈ , K ₂ S ₂ O ₈ , and the like. The source of the sulfite ions is not particularly limited. Examples thereof include sodium sulfite, potassium sulfite, ammonium sulfite, and the like. The source of the sulfite ions is not particularly limited. The peroxide is not particularly limited, and examples thereof include hydrogen peroxide, sodium peroxide and potassium peroxide.

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

The source of the chlorate ions is not particularly limited, and for example, sodium chlorate, potassium chlorate, ammonium chlorate, etc. The source of the chlorite ions is not particularly limited, for example, sodium chlorite, nitrite Potassium chlorate, ammonium chlorite, and the like. The ascorbic acid and salts thereof are not particularly limited, and examples thereof include ascorbic acid, sodium ascorbate, potassium ascorbate and ammonium ascorbate. Can be. The citric acid and salts thereof are not particularly limited, and examples thereof include citric acid, sodium citrate, potassium citrate, and ammonium citrate. The said tartaric acid and its salt are not specifically limited, For example, a tartaric acid, ammonium titanate, potassium titanate, sodium titanate, etc. are mentioned. The said malonic acid and its salt are not specifically limited, For example, malonic acid, ammonium malonate, potassium malonate, sodium malonate, etc. are mentioned. The succinic acid and salts thereof are not particularly limited, and examples thereof include amber acid, sodium amber acid, potassium amber acid, ammonium amber acid and the like.

Although the above-mentioned chemical reaction accelerator may be used alone, two or more components may be used as needed.

In the chemical conversion treatment agent of the present invention, the compounding amount of the chemical reaction accelerator is preferably in the range of 1 ppm lower limit and 5000 ppm upper limit. If it is less than 1 ppm, sufficient effect cannot be obtained. The lower limit is more preferably 3 ppm, more preferably 5 ppm. The upper limit is more preferably 2000 ppm and even more preferably 1500 ppm.

It is preferable that the chemical conversion treatment agent of the present invention is substantially free of phosphate ions. Actually containing no phosphate ions means that phosphate ions are not contained to such an extent that they act as a component in the chemical conversion treatment agent and are used in the present invention. Since the chemical conversion agent does not substantially contain phosphate ions, sludge, such as iron phosphate and zinc phosphate, generated when a zinc phosphate treatment agent is used, without substantially using phosphorus which causes environmental burdens. Can be suppressed.

It is preferable that the said chemical conversion treatment agent exists in the range of the minimum of 1.5 and the upper of 6.5. If the lower limit is less than 1.5, the etching is excessive and sufficient film formation is impossible. If the upper limit is more than 6.5, etching is 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. Acidic compounds such as nitric acid and sulfuric acid and alkaline compounds such as sodium hydroxide, potassium hydroxide and ammonia can be used to adjust the pH of the chemical conversion agent. have.

The chemical conversion treatment agent of this invention may use arbitrary components together as needed in addition to the said component. As a component which can be used, zinc ion, magnesium ion, calcium ion, aluminum ion, manganese ion, iron ion, cobalt ion, copper And silicon-containing compounds such as metal ions such as ions, silica, water-soluble silicate compounds, silicate esters, alkyl silicates, and silane coupling agents.

The chemical conversion treatment of the metal by the chemical conversion treatment agent is not particularly limited and can be carried out by bringing the chemical conversion treatment agent into contact with the metal surface under normal processing conditions. In the chemical conversion treatment, the treatment temperature is preferably in the range of the lower limit of 20 ° C and the upper limit of 70 ° C. The lower limit is more preferably 30 ° C and more preferably the upper limit of 50 ° C. It is preferable that the time is 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, for example, the dipping method, Spray method, roll coat method and the like.

Examples of the metal substrate to be treated by the chemical conversion treatment agent of the present invention include iron-based substrates, aluminum-based substrates, and zinc-based substrates. Iron, aluminum, and zinc-based substrates include iron-based substrates made of iron and / or alloys thereof. An aluminum substrate made of aluminum and / or an alloy thereof, and a zinc based substrate made of zinc and / or an alloy thereof. The chemical conversion treatment agent of the present invention includes a plurality of metal substrates of an iron base, an aluminum base, and a zinc base. It can also be used for chemical conversion of the finished coating.

The chemical conversion treatment agent of this invention is preferable at the point which can provide sufficient coating film adhesiveness also with respect to the iron base material which is difficult to obtain sufficient coating film adhesiveness in the chemical conversion treatment agent which consists of normal zirconium etc., For this reason, at least one part is especially iron-based base material. It has excellent properties in that it can also be used for the treatment of the to-be-processed object containing.

The iron-based substrate is not particularly limited, and examples thereof include a cold rolled steel sheet and a hot rolled steel sheet. The aluminum base is not particularly limited, and examples thereof include a 5000 series aluminum alloy and a 6000 series aluminum alloy. The zinc-based substrate is not particularly limited, for example, zinc-plated 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- Zinc- or zinc-based alloy-coated steel sheets such as zinc-based electroplating such as magnesium-plated steel sheets and zinc-manganese-plated steel sheets, hot dip galvanizing and deposition-coated steel sheets, and the like. The substrate can be chemically treated simultaneously.

Chemical conversion coating obtained by the chemical conversion treatment agent of the present invention is preferably the coating amount is in the range of a lower limit to the total amount of metal Ol mg / m ^2, the upper limit 5OO mg / m ² to be contained in the chemical conversion treatment agent is .Ol mg / m is less than ² It is not preferable because a uniform chemical conversion film cannot be obtained. If it exceeds 5OO mg / m ² , no further effect is obtained and it is economically disadvantageous. As for the said minimum, 5 mg / m <^2> is more preferable, and the said upper limit is more preferable 200 mg / m <^2> .

The surface of the metal substrate is preferably subjected to degreasing treatment after degreasing and washing with degreasing before being chemically treated by the chemical conversion agent, and washing with dehydration after chemical conversion.

The degreasing treatment is carried out to remove oil or dirt adhering to the surface of the substrate. The degreasing treatment is usually performed for 30 minutes at a temperature of 30 to 55 ° C. using a degreasing agent such as an unattended and nitrogen-free degreasing washing liquid. Therefore, the preliminary degreasing treatment can be performed before the degreasing treatment.

The degreasing washing treatment after degreasing is performed by spraying one or more times using a large amount of washing water to wash the degreasing agent after the degreasing treatment.

The above-described water washing treatment is performed one or more times so as not to adversely affect the adhesion, corrosion resistance, and the like after the various coatings thereafter. In this case, the final water washing is appropriately performed with pure water. In the treatment, either spray washing or immersion washing may be used, and washing may be performed by combining these methods.

After the above-mentioned chemical | cleaning treatment after chemical conversion, it can dry as needed by a well-known method, and can apply | coat various coatings after that.

In addition, since the chemical conversion treatment using the chemical conversion treatment agent of the present invention does not need to perform surface adjustment treatment or the like, which is required by a method of treating using a zinc phosphate chemical conversion treatment agent, which has been put to practical use in the past, the metal base material in fewer processes. The conversion process can be performed.

The present invention also provides a surface-treated metal having a chemical conversion film formed by the chemical conversion treatment agent. The surface-treated metal of the present invention is also excellent in adhesion between the coating film and the metal when forming coatings such as cationic electrodeposition coating and powder coating on the chemical conversion film. The coating that can be performed on the surface treatment metal of the present invention Although it does not specifically limit, cationic electrodeposition coating, powder coating, etc. are mentioned. Especially, since the chemical conversion treatment agent of this invention can perform favorable treatment with respect to all metals, such as iron, zinc, and aluminum, at least one part is iron type | system | group. It can be used suitably as a pretreatment of the cation electrodeposition coating of the to-be-processed object which consists of a base material. The said cationic electrodeposition coating is not specifically limited, The conventionally well-known cation electrodeposition coating material which consists of an amino-ized epoxy resin, an amino-ized acrylic resin, a sulfonated epoxy resin, etc. can be apply | coated.

The chemical conversion treatment agent of the present invention contains at least one member selected from the group consisting of zirconium, titanium, and hafnium as a film forming component, and in addition, contains a water-soluble resin having a specific structure. The chemical conversion film which was excellent in coating-film adhesiveness can also be formed also about the iron base material with which the pretreatment in place was inadequate.

Since the chemical conversion treatment agent used in the present invention does not substantially contain phosphate ions, the burden on the environment is small and no sludge occurs. Moreover, the chemical conversion treatment using the chemical conversion treatment agent of the present invention requires a surface adjustment process. Since it does not, the chemical conversion treatment of a metal base material can be performed in a lesser process.

Example

In the following Examples, the present invention is described in more detail, but the present invention is not limited only to these Examples.

Example 1

Based on a commercially available cold rolled steel sheet (SPCC-SD, Japan Test Panel Co., Ltd., 70 mm x 150 mm x 0.8 mm), coating pretreatment was performed under the following conditions.

(1) painting pretreatment

Degreasing treatment: It was immersed for 2 minutes at 40 degreeC with 2 weight% "Surf Cleaner-53" (Nippon Paint Co., Ltd. degreaser).

Washing treatment after degreasing: Sprayed with tap water for 30 seconds.

Chemical conversion treatment: A chemical conversion treatment agent having a resin concentration of 100 ppm as a zirconium concentration of 100 ppm and a solid content was prepared using zircon hydrofluoric acid as a film forming component and PVAM-0595B (polyvinylamine resin: molecular weight 70000: Mitsubishi Chemical Corporation) as a resin. pH was adjusted to 4 using sodium hydroxide. The temperature of the chemical conversion treatment agent was adjusted to 40 ° C. and the substrate was immersed for 60 seconds. The amount of coating at the initial stage of treatment was 10 mg / m ² .

After ignition washing with water: sprayed with tap water for 30 seconds. Again, sprayed with ion-exchanged water for 30 seconds.

Drying Treatment: The cold rolled steel sheet after washing with water was dried at 80 ° C. for 5 minutes in an electric drying furnace. In addition, the coating amount was analyzed as the total amount of the metal contained in the chemical conversion treatment agent using "XRF 1700" (Shimazu Corporation, fluorescence X-ray analyzer).

(2) painting

After processing a cold rolled steel sheet of 1 m ² per 1 L of chemical conversion treatment agent, electrodeposition coating was carried out using a `` Powernics 110 '' (Nippon Paint Co., cationic electrodeposition paint) so as to have a dry film thickness of 20 μm, followed by water washing at 170 ° C. for 20 minutes. The test plate was produced by baking by heating.

Evaluation test

(Sludge observation)

After treating a 1 m ² cold rolled steel sheet per 1 L of chemical conversion agent, the haze in the chemical conversion agent was visually observed.

: Not cloudy

×: turbidity

(Second Adhesion Test (SDT))

In the obtained test plate, two longitudinal parallel cuts reaching the bottom were put, and then immersed in a 5% NaCl aqueous solution at 50 ° C. for 480 hours. Then, the cut part was peeled off by tape and the peeling of paint was observed.

◎: no peeling

: Slightly peeled off

X: Peeling width 3 mm or more

The evaluation results are shown in Table 1.

Example 2

A test plate was produced in the same manner as in Example 1 except that the resin concentration was changed to 500 ppm using PAA-01 (polyallylamine resin: molecular weight 1000: Ildong Oriental Co., Ltd.) as the water-soluble resin.

Example 3

A test plate was produced in the same manner as in Example 1 except that PAA-10C (polyallylamine resin: molecular weight 15000: Ildong Oriental Co., Ltd.) was used as the water-soluble resin.

Example 4

A test plate was produced in the same manner as in Example 1 except that the resin concentration was changed to 50 ppm using PAA-H-10C (polyallylamine resin: molecular weight 60000: Ildong Oriental Co., Ltd.) as the water-soluble resin.

Example 5

A test plate was produced in the same manner as in Example 1 except that the resin concentration was changed to 50 ppm using PAA-D11-HC1 (polyallylamine copolymer: molecular weight 70000: Ildong Co., Ltd.) as the water-soluble resin.

Example 6

A test plate was produced in the same manner as in Example 1 except that the resin concentration was changed to 5 ppm using PAA-H-10C as the water-soluble resin.

Example 7

A test plate was produced in the same manner as in Example 1 except that the zirconium concentration was 500 ppm and the resin concentration was changed to 5000 ppm using PAA-01 as the water-soluble resin.

Example 8

A test plate was produced in the same manner as in Example 1 except that the metal substrate was changed to a galvanized steel sheet (GA steel plate, Japanese Test Panel Co., Ltd., 70 mm x 180 mm x 0.8 mm).

Example 9

A test plate was produced in the same manner as in Example 1 except that the metal substrate was changed to 5000 series aluminum (70 mm × 180 mm × 0.8 mm, Japan Test Panel Co., Ltd.).

Example 10

Instead of "Surf Cleaner 53", degreasing treatment was performed using "Surf Cleaner EC92", zircon hydrofluoric acid, PAA-10C, zinc nitrate, commercial silica (Nissan Chemical), and ascorbic acid as chemical reaction accelerators in Table 1 A test plate was prepared in the same manner as in Example 1, except that the compound was blended in the concentration shown and was put into a coating process without drying the metal substrate in a wet (wet) state. The concentrations of zinc nitrate and silica were used as metal ions or silicon. Concentration as a component.

Example 11

Examples 10 and 10 except that zirconic hydrofluoric acid, zinc nitrate, magnesium nitrate, and sodium bromide were blended in the concentrations shown in Table 1 as pH, the pH was adjusted to 5.5, and the metal substrate was blow-dried to be added to the coating process. In the same manner, a test plate was produced.

Comparative Example 1

A test plate was produced in the same manner as in Example 1 except that no water-soluble resin was added.

Comparative Example 2

A test plate was produced in the same manner as in Example 1 except that no zirconic hydrofluoric acid was added.

Comparative Example 3

A test plate was prepared in the same manner as in Example 10 except that zirconic hydrofluoric acid and ammonium ferric citrate were blended in the concentrations shown in Table 1.

Comparative Example 4

After degreasing, washing with water was carried out for 30 seconds at room temperature using surfpine 5N-8M (Nippon Paint Co., Ltd.), and at 35 ° C using Surfdyne SD-6350 (Nippon Paint Co., zinc phosphate chemical treatment agent). A test plate was obtained in the same manner as in Example 1 except that the chemical conversion treatment was performed by performing the dipping treatment for 2 minutes.

TABLE 1

From Table 1, it can confirm that sludge does not generate | occur | produce in the chemical conversion treatment agent of this invention. Furthermore, the chemical conversion treatment agent of the present invention has been shown to form a chemical conversion film having good coating film adhesion on all metal substrates. On the other hand, in the comparative example, it suppresses the generation of sludge and also has excellent adhesion to the cationic electrodeposition coating film. Martian film could not be obtained.

Since the chemical conversion treatment agent of the present invention is substantially free of harmful heavy metal compounds such as chromium and vanadium or phosphate compounds, it is less burdensome to the environment and does not generate sludge. Iron-based substrates, aluminum-based substrates and zinc-based compounds All materials of the base material can be treated well, and a chemical film having excellent stability and coating film adhesion can be formed. In addition, such as automobile bodies and parts, various kinds of iron-based, aluminum-based and zinc-based substrates, etc. It is also excellent in that it can surface-treat the to-be-processed object consisting of a base material.

Claims (7)

At least one selected from the group consisting of zirconium, titanium and hafnium, fluorine and water-soluble resin, wherein the water-soluble resin is at least a part of the following formula (1); And / or the following formula (2); The chemical conversion treatment agent which has a structural unit represented by. The method according to claim 1, The said water-soluble resin is polyvinylamine resin or polyallylamine resin, The chemical conversion treatment agent characterized by the above-mentioned. The method according to claim 1 or 2, The said water-soluble resin has a molecular weight of 500-500,000, and content of the said water-soluble resin in a chemical conversion treatment agent is 5-5000 ppm, The chemical conversion treatment agent characterized by the above-mentioned. The method according to claim 1 or 2, Nitrite ions; Nitro group-containing compounds; Sulfuric acid hydroxylamine; Persulfate ions; Sulfite ions; Hyposulfite ions; peroxide; Iron (III) ions; Iron citrate compounds; Bromate ions; Perchlorate ions; Chlorate ions; Chlorite ions; Or at least one selected from the group consisting of ascorbic acid, citric acid, tin acid, malonic acid, zucchini acid and salts thereof; The chemical conversion treatment agent containing 1-5000 ppm of chemical conversion reaction accelerators further. The method according to claim 1 or 2, A chemical conversion treatment agent characterized in that at least one content selected from the group consisting of zirconium, titanium and hafnium is 20 to 10,000 ppm in terms of metal, and the pH is 1.5 to 6.5. It has a chemical conversion film formed with the chemical conversion treatment agent of Claim 1 or 2, The surface treatment metal characterized by the above-mentioned. The method according to claim 6, The chemical conversion film is a surface-treated metal, characterized in that the coating amount is 0.1 to 50,000 mg / m ² as the total amount of the metal contained in the chemical conversion treatment agent.