JP2000017451A - Protective film-formed steel sheet, its production and composition for forming protective film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain excellent performance in a steel sheet without using sexivalent chromium by treating a galvanized steel sheet with a soln. contg. at least one kind selected from the groups composed of Mo, W, V, Nb, Ta, Ti, Zr, Ce, Sr and trivalent chromium and contg. no sexivalent chromium. SOLUTION: On a steel applied with galvanizing or galvannealing or subjected to alloying treatment after the plating, a protective film is formed. The composition for forming this protective film contains a feeding source of at least one kind among Mo, W, V, Nb, Ta, Ti, Zr, Ce, Sr and trivalent chromium and a feeding source of oxidizing substance such as the oxyacid and oxysalt of phosphorous or their anhydrides and peroxide, chloric acid or the like arbitrarily. The steel is brought to contact with this composition, is thereafter subjected to washing or no washing and is dried, and a protective film is formed. The steel after the formation of the protective film is, if required, further brought to contact with a soln. contg. a silicon compd., a resin, inorganic colloid or the like and can be applied with an organic or inorganic overcoat or the one of the combined material thereof.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the surface treatment of widely used steel materials such as steel plates and steel pipes, and more particularly to an alternative treatment to chromate treatment for harmfulness of hexavalent chromium, which has recently become a problem.

[0002]

2. Description of the Related Art Conventionally, various chromate treatments have been invented, put into practical use, and used as surface treatments of steel materials subjected to zinc or zinc alloy plating or alloying treatment after plating. A method of adding silica sol or trivalent chromium to a chromate treatment solution as a conventional chromate (for example, Japanese Patent Publication No. Sho 42-14050, Japanese Patent Publication No. Sho 52-2851)
With improved adhesion and corrosion resistance (for example, Tokiko Sho 61
-585552). In recent years, interest in pollution problems has been increasing with the deterioration of the global environment, and the harmfulness of hexavalent chromium used for conventional chromate treatment has been highlighted. Hexavalent chromium has many problems such as allergy, reproductive toxicity, and carcinogenicity, and the need for surface treatment that does not use hexavalent chromium has increased.However, recent patents for steel materials have been found to reduce the elution of hexavalent chromium. Mainstream.

[0003]

An object of the present invention is to form a protective film on the surface of a steel material such as a steel plate or a steel pipe which is widely used, without using harmful hexavalent chromium and equivalent to the conventional chromate treatment. Outstanding performance (uniform and good appearance, corrosion resistance, paint base, fingerprint resistance, blackening resistance, etc.)
To form a film having

[0004]

As a result of intensive studies made by the present inventors, it has been found that a method using a composition containing a specific metal as one of the main components can solve the problems in the prior art. That is, a) Mo, W, V, Nb, Ta,
A composition comprising one or more sources of Ti, Zr, Ce, Sr and trivalent chromium, oxyacids of phosphorous, oxyacid salts or anhydrides thereof, and optionally a source of an oxidizing substance; b) a composition comprising 0.001-600 g / L trivalent chromium ion and 0.001-600 g / L chlorine, fluorine, sulfate, nitrate, peroxide, chlorate or acetate ion; Or c) 0.001
After contact with a composition containing 600 g / L of iron, cobalt, nickel, magnesium, calcium or aluminum, one or more of organic acids or inorganic acids, and optionally fluorine, rinsing may be performed or not. It has been found that a film having characteristics such as a beautiful appearance, excellent corrosion resistance, and excellent paint baseability can be produced without using hexavalent chromium by a drying method. Further, before or after drying, a silicon compound, a resin, an inorganic colloid, an organic carboxylic acid, a thiazole, a triazole, an amine compound, caustic, ammonia, an oxygen acid of phosphorus,
PVA, nonionic polymer, polyol, cellulose,
It has been found that a protective film with further improved corrosion resistance can be obtained by contacting with a liquid containing polyacrylic acid, an acid amide compound, a fatty acid ester, a thiol compound, a tannic acid or a compound having a mercapto group. After forming a film by various methods, by further overcoating an organic or inorganic and a composite rust preventive film thereof, the metal protection method of the present invention becomes a very high level metal protection method. Further, the film obtained by the present invention has excellent heat and corrosion resistance,
It has been found that this is a solution to the problem of a decrease in corrosion resistance due to heat treatment, which was a drawback of the conventional chromate film. In addition to the above, not only the case where this treatment is performed by immersion but also the case of coating, the economical advantage that the conventional treatment equipment can be used as it is is also a feature of this method.

The details of the present invention are as follows.
The composition of the present invention includes: 1) Mo, W, V, Nb, Ta, Ti, Zr, Ce, S
Composition comprising a source of r or trivalent chromium metal cation or an oxymetal anion thereof and a phosphorus oxyacid, oxyacid salt or anhydride thereof and an optional oxidizing substance source 2) 0.001-600 g / L trivalent chromium ion and 0.001-600 g / L chlorine, fluorine, sulfate ion, nitrate ion, peroxide, chloric acid, acetate ion, formate ion, succinic acid A composition containing at least one selected from ions and glycolate ions, and 3) one or more selected from 0.001 to 600 g / L of iron, cobalt, nickel, magnesium, calcium and aluminum, and an organic acid or an inorganic acid And a composition containing fluorine as an optional component.

The exact behavior of each component in the composition of 1) is unknown, but various components such as molybdate ion, tungstate ion, vanadate ion, niobate ion, tantalate ion and trivalent chromium ion are known. The metal source and the oxyacids, oxyacids or their anhydrides of phosphorus are presumed to be the constituents of the skeleton of the film, and the oxidizing substances are the oxyacids or oxyacids of phosphoric acid in solutions of these anhydrides. It is presumed that, while suppressing ionization of the solution and ensuring the stability of the solution, the zinc surface is appropriately etched to contribute to the formation of a smooth film. Molybdate ion, tungstate ion,
The total amount of metal sources such as vanadate, niobate, tantalate or trivalent chromium ions is 0.001 to 600 g / L, preferably 0.5 to 200 g / L. If the amount is less than this, it is difficult to form a good film, and the film is not formed, or the required function cannot be obtained. Although a film is formed even with a liquid having a higher concentration than this, there are problems such as a decrease in the uniformity of the film appearance and a non-uniform coating adhesion (painting base property). These sources include ammonium vanadate, sodium tungstate, chromium acetate, chromium nitrate, and the like, and are not particularly limited. The oxyacid, oxyacid salt of phosphorus or anhydride thereof must contain 0.01 to 800 g / L, preferably 1 to 400 g / L. If the amount is less than this, it is difficult to form a good film, and the film is not formed, or the required function cannot be obtained. In addition, although a film is formed even with a liquid with a higher concentration, the uniformity of the film appearance is deteriorated and the coating adhesion (painting base property) is reduced.
There are problems such as non-uniformity. Phosphorus oxyacid as well as orthophosphoric acid, diphosphorous acid, hypophosphorous acid, pyrophosphoric acid,
Tripolyphosphoric acid or perphosphoric acid can be used. As the oxidizing substance, peroxide, chloric acid, bromic acid, nitric acid, peroxoic acid, and the like can be used. If these metal salts are used, the metal and the oxidizing substance can be supplied simultaneously. These are added in an amount of 0.001 to 500 g / L, preferably 1 to 500 g / L.
L is contained. If the amount is smaller than this, the stability of the liquid is reduced, and the film formation rate becomes unstable. I do. In any case, the film may not be formed. The pH is preferably 0.1 to 6.5, more preferably 1.0 to 4.0.
If it is lower than this, it is difficult to form a uniform film, and if it is higher, the corrosion resistance tends to be slightly lowered. The chemical used for adjusting the pH may be an acid such as nitric acid or sulfuric acid if it is high, or an alkali such as ammonia or sodium hydroxide if it is low. Among these compositions, the combination with the better performing composition is 0.00
1 to 600 g / L trivalent chromium ion and 0.001 to
A combination composition containing 500 g / L of nitrate ions and 0.1 to 800 g / L of phosphate ions.

There are no particular restrictions on the processing conditions for film formation, and the conditions for performing a general reactive chromate treatment (liquid temperature: 15 to 5)
(0 ° C., processing time: several seconds to 10 seconds or less), and application by a spray, a roll coater, a bar coater, a spin coater, or the like. Further, the processing can be performed under the condition of a processing time of 240 seconds, and has a wide condition range. When the reactive chromate is treated, it is usually dried through a rinsing step after the treatment. However, the present invention has such features that the rinsing step can be omitted and has a wide range of treatment conditions. The present invention can also be treated by electrolysis, and the conditions for forming a film by electrolysis are as follows: current density is 100 A / dm ² or less, preferably 0.5 to 20 A / dm ² , and energization time is 1200 seconds or less, preferably 2 to 15 seconds. It is. Even when the current density is low, a film is formed. However, in the present invention, since the film is formed without electrolysis, it is difficult to discriminate between the film formation by the electrolysis and the film formation by the reaction, and the lower limit of the current density cannot be defined. When it is high, appearance defects called burns or burns occur in the high current density portion. Although a film is formed even when the electrolysis time is short, in the present invention, a film is formed without electrolysis, and it is difficult to determine the formation of a film by electrolysis and the formation of a film by a reaction, and the lower limit of the electrolysis time cannot be defined. When it is long, a matte appearance defect sometimes occurs. Excessive processing time also significantly reduces productivity.

The behavior of each component in the composition 2) is 1).
It is estimated that the trivalent chromium ion of 0.001 to 600 g / L, preferably 0.5 to 200 g / L functions similarly to the trivalent chromium ion of 1).
Chlorine, fluorine, sulfate ions, acetate ions, etc. in an amount of from 1 to 600 g / L, preferably from 1 to 150 g / L. The method of supplying trivalent chromium is not particularly specified, and if it is supplied with a salt such as chromium chloride or chromium acetate, components other than trivalent chromium can be supplied, which is convenient. Further, in this composition, a silicon compound, phosphoric acid, or Ti, Fe, Mo, Mg, Co, Ni
Addition of a metal such as is effective for improving and stabilizing corrosion resistance, and the amount of each is 0.01 to 200 g /
L is a guide. The production method using this composition is 1)
Is the same as

The composition of 3) is 0.001 to 500 g / L.
Contains iron, cobalt, nickel, magnesium, calcium, aluminum, one or more organic acids or inorganic acids, and optionally fluorine. Acids include hydrochloric acid, sulfuric acid,
Nitric acid, hydrogen peroxide, phosphoric acid and formic acid, acetic acid, succinic acid,
Carboxylic acids such as diglycolic acid are preferred. The appropriate concentration of each concentration is 0.001 to 300 g / L, preferably 0.5 to 200 g / L. If the concentration is less than this, film formation is not performed smoothly, and chemical conversion defects such as unevenness and spots occur. If the amount is larger than this, not only is the economic loss large, but also problems such as formation failure due to excessive etching occur. The addition of a silicon compound to the composition is effective for improving the appearance and corrosion resistance, and the standard for the addition is 0.01 to 400 g / L. The method using this composition can be applied to both dipping and coating as in 1).

These compositions may further contain one or more of alkaline earth metals, inorganic colloids, silane coupling agents and organic carboxylic acids. Silica sol, alumina sol, titanium sol, zirconia sol and the like can be used as the inorganic colloid, and vinyltriethoxysilane, γ-methacryloxypropyltrimethoxysilane and the like can be used as the silane coupling agent. Although it is unlikely that the alkaline earth metal precipitates on the film, the corrosion resistance is improved by the addition, so it is presumed that there is an effect of densifying the film. Inorganic colloids, silane coupling agents, and the like do not necessarily need to be added due to cost and the like. However, after coating or coating after the treatment of the present invention, they act to improve adhesion and as a result improve corrosion resistance.

In addition, after dipping the composition, before or after the drying step, silicon compound, resin, inorganic colloid, organic carboxylic acid, thiazole, triazole, amine compound, caustic alkali, ammonia, oxygenic acid of phosphorus, PVA, nonionic Contact with a solution containing a conductive polymer, polyol, cellulose, polyacrylic acid, acid amide compound, fatty acid ester, thiol compound, tannic acid, and a compound having a mercapto group, a protective film with further improved corrosion resistance can be obtained. found. Examples of the silicon compound include sodium silicate, potassium silicate, lithium silicate, ammonium silicate, colloidal silica having a particle diameter of 500 nm or less, and a silane coupling agent. The carboxylic acid is not limited to monocarboxylic acids such as acetic acid and formic acid, and polyvalent carboxylic acids can be used, and tartaric acid, citric acid, ascorbic acid, glutaric acid, gluconic acid and the like are suitable. Examples of the amine compound include monoamines such as monoethanolamine and triethanolamine, diamines such as dimethylaminopropylenediamine, and polyamines such as triamine and higher, cyclic amines such as imidazole, and their reactants and polymers. 2-amino-2-ethyl-1,3-propanediol, 3- (2-aminoethylamino) propylamine, allylamine, isobutylamine, ethylaminoethylamine, ethylenediamine, xylenediamine, diisobutylamine, diethylaminoethylamine, diethylaminopropylamine , Diethylenetriamine, dicyclohexylamine, dibenzylamine, dibutylaminopropylamine, dimethylaminoethylamine, tetramethylethylenedia Emissions, trimethylamine, methylamine, methyl iminobispropylamine, triethylenetetramine, amino alcohols, amino pyridine,
N-aminopropyl-2-pipecholine, 1-amino-4
-Methylpiperazine, triethylamine hydrochloride, quinoline, N, N-dimethylpiperazinetetramethylpentamine, trimethylaminoethylpiperazine, N-methyl-
2-pyrrolidone, N-methylpiperidine, N-methylpyrrolidine, picoline, pipecoline 3,5-lutidine,
3,5-Lupetidine, polyethyleneimine, diethylaniline octadecylamine acetate, and the like. As the acid amide, alkyl sulfosuccinic acid amide salt,
Alkenyl succinic amides and the like can be mentioned, and fatty acid esters include fatty acid methyltaurine salts and sorbitan fatty acid esters, and compounds having a mercapto group include thioglycolate. In addition to these, phosphate ester salts, cetyltrimethylammonium bromide, polyoxyethylene alkylamine and the like can also be mentioned. Suitable amounts of these are 0.001 to 500 g / L, preferably 1 to 500 g / L.
It is 150 g / L.

The metal protection method of the present invention can be a very high level of metal protection by overcoating an organic or inorganic and composite rust preventive film after forming the film by various methods. The overcoating may be performed immediately after the surface treatment according to the present invention, but is also effective after the processing such as pressing or bending. The method of overcoating is not particularly limited, and coating, dip coating, electrostatic coating, electrodeposition coating,
Various methods such as powder coating are possible, and the paint and the resin type are not particularly limited, and can be applied to water-based or non-water-based ones.

According to the present invention, harmful hexavalent chromium is not used, and processing equipment and processing conditions are substantially the same as those of conventional chromate.
It is possible to form a protective film equal to or more than a conventional chromate on a steel material such as a steel plate or a steel pipe which has been subjected to zinc or zinc alloy plating or alloying treatment after plating by a treatment method. As a result, not only general users who are concerned about elution of hexavalent chromium from processed products, but also the health effects of chromate manufacturers and chromate processors who have been exposed to the hazards of chromate and the effects on wild animals The problem can be solved. Prior to the present invention, a chromate treatment method and a phosphate treatment method are known, both of which use harmful hexavalent chromium.

Further, it has been found that the film obtained according to the present invention is excellent in heat resistance and corrosion resistance, and solves the problem of deterioration in corrosion resistance due to heat treatment, which was a drawback of the conventional chromate film.

[0015]

The present invention will be described below with reference to examples. After performing an appropriate pretreatment such as nitric acid immersion, each of the following treatments was performed. The appearance was evaluated visually, and the corrosion resistance was evaluated by a salt spray test (JISZ2731). Fingerprint resistance was evaluated by ΔE after application of white petrolatum. The blackening resistance was evaluated by ΔL before and after the test after storing for 10 days in a wet state at a humidity of 90% and a temperature of 60 ° C. The paint adhesion was evaluated by the remaining area after the cross-cut cellophane tape peeling test of the test piece prepared by immersing in the silicon compound or the resin-containing coating agent in the examples, and was not immersed in the silicon compound or the resin-containing coating agent. The test specimens were evaluated after applying an acrylic clear coating (trade name: GX-235T: manufactured by Nippon Surface Chemical Co., Ltd.) for evaluation. Table 1 shows the evaluation results.
Shown in

[0016]Example 1  Electrogalvanized steel sheet (200 × 300mm)
35g / L, 75% phosphoric acid 40g / L, 67.5% nitrate
The pH was adjusted to 2.2 with ammonia containing 20 g / L of acid.
The specimen was immersed in the treatment liquid for 5 seconds to prepare a test piece.Example 2 Electrogalvanized steel sheet (200 × 300mm)
50g / L, 75% phosphoric acid 35g / L, 67.5% nitrate
The pH was adjusted to 1.7 with ammonia containing 30 g / L of acid.
After immersion in treatment solution for 8 seconds, sodium silicate 90g / L, hydroxylation
Immersion in an aqueous solution containing 25 g / L of sodium for 15 seconds
A test piece was prepared. 200 ° C for 2 hours
Was performed.Example 3  Electrogalvanized steel sheet (300 × 400mm)
30g / L, 75% phosphoric acid 28g / L, 67.5% nitrate
The pH was adjusted to 2.3 with ammonia containing 20 g / L of acid.
After dipping in the treatment solution for 7 seconds, the resin-containing coating agent (product
5G018: manufactured by Nippon Surface Chemical Co., Ltd.) for 10 seconds
A test piece was prepared. 200 ° C for 2 hours
Was performed.Example 4 Hot-dip galvanized steel sheet (200 x 300 mm)
Sodium butyrate 55 g / L, phosphorous acid 25 g / L, 60
Aqueous solution containing 25 g / L nitric acid with ammonia at pH 2.
After immersion in the treatment solution adjusted to 0 for 10 seconds, 5G018 (day
(Manufactured by Surface Chemical Co., Ltd.) and dried.Example 5 Zinc-nickel alloy plated steel sheet (200 × 300mm)
With 25 g / L of chromium nitrate at pH 1.6,
Mon 1 g / L, hypophosphorous acid 20 g / L, 60% nitric acid 18
g / L for 10 seconds, and then dipped in 5G018 (day
The product was immersed and dried in Honshu Kagaku Co., Ltd.
Was.

Example 6 An electrogalvanized steel sheet (100 × 200 mm) was prepared by using ammonium molybdate 15 g / L, chromium nitrate 30 g / L,
Aqueous solution containing 20 g / L phosphoric acid, 20 g / L nitric acid, and 20 g / L colloidal silica with ammonia
After performing cathodic electrolysis with a treatment solution adjusted to H2.5 at a current density of 3 A / dm ² and an electrolysis time of 9 seconds, 5G018 was further added.
(Manufactured by Nippon Surface Chemical Co., Ltd.), and the dried product was used as a test piece. Example 7 A bar coater was prepared by treating a galvanized steel sheet (200 × 300 mm) containing 15 g / L of chromium nitrate, 15 g / L of 75% phosphoric acid, and 15 g / L of 67.5% nitric acid and adjusting the pH to 2.4 with ammonia using a bar coater. Was applied to prepare a test piece. Example 8 A treatment liquid containing 38 g / L of chromium sulfate and 40 g / L of 75% phosphoric acid and adjusted to pH 1.8 with ammonia using a spin coater was applied to an alloyed hot-dip galvanized steel sheet (200 × 300 mm). 38 g / L of colloidal silica,
A test piece was immersed in an aqueous solution containing 5 g / L of sodium hydroxide and dried. Example 9 Alloyed hot-dip galvanized steel sheet (200 × 300 mm)
35 g / L of chromium sulfate of H2.5, 1.9 g / L of hydrochloric acid,
The specimen was immersed in a treatment solution containing 1 g / L of 60% sulfuric acid for 8 seconds to prepare a test piece.

Example 10 An alloyed hot-dip galvanized steel sheet (200 × 300 mm) was p
H2.2 chromium sulfate 10 g / L, hydrochloric acid 1.5 g / L,
After immersion for 7 seconds in a treatment solution containing 1 g / L of 60% sulfuric acid and 1 g / L of nitric acid, a treatment solution containing 120 g / L of colloidal silica, 2 g / L of potassium hydroxide, and 5 g / L of sodium hydroxide at 50 ° C.
A test piece was prepared by immersion for -15 seconds. Example 11 An electrogalvanized steel sheet (100 × 200 mm) having a pH of 1.
5, a treatment solution containing 30 g / L of chromium sulfate and 50 g / L of phosphoric acid was applied using a spin coater, and then 95 g / L of colloidal silica, 2 g / L of potassium hydroxide, and 4 g of potassium soda.
/ L was immersed in a treatment liquid containing 50 L for 15 seconds to prepare a test piece. Example 12 A treatment solution prepared by adjusting an aqueous solution containing 4 g / L of chromium chloride, 6 g / L of ammonium fluoride, and 2 g / L of 75% sulfuric acid to pH 2.0 with ammonia was applied to a hot-dip galvanized sheet (100 × 200 mm). A test piece was prepared. Example 13 Zinc-nickel alloy plated steel sheet (200 × 300 mm)
PH 1.6 chromium acetate 6 g / L, hydrofluoric acid 0.5 g /
L, 5 g / L of phosphoric acid, and 2 g / L of sulfuric acid were spray-applied, immersed in 5G018, and then dried to prepare test pieces. Example 14 An electrogalvanized steel sheet was treated with aluminum sulfate at 7.5 g / L,
A test piece was immersed in a pH 3.0 aqueous solution containing 10 g / L of phosphoric acid and 4.5 g / L of 67.5% nitric acid for 8 seconds.

Example 15 8.5 g of aluminum nitrate was added to a galvannealed steel sheet.
/ L, No. 3 sodium silicate 90g / L, 62.5% nitric acid 5g
/ L of an aqueous solution having a pH of 2.2 was spray-coated to obtain test pieces. Example 16 An electrogalvanized steel sheet was coated with aluminum sulfate at 7 g / L,
Phosphoric acid 12g / L, hydrochloric acid 2g / L, 67.5% nitric acid 3g
/ L for 20 seconds in an aqueous solution of pH 2.8 containing
It was immersed in 5G018 to prepare a test piece. Example 17 Aluminum sulfate 1 having a pH of 3.0 was applied to a galvanized steel sheet.
5 g / L, No. 3 sodium silicate 17 g / L, hydrofluoric acid 5 g / L
L, phosphoric acid 2 g / L, acetic acid 2 g / L, 67.5% nitric acid 5
g / L of the treatment liquid with a bar coater, potassium silicate 80 g / L, potassium hydroxide 7 g / L, cataloid S
A test piece was prepared by immersion in a treatment solution containing 20 g / L of I-30 (manufactured by Catalyst Chemicals, Inc.) for 10 seconds. Example 18 Chromium nitrate 7 g / L, nitric acid 5 g /
L and a treatment solution containing 1 g / L sulfuric acid and adjusted to pH 3.0 were spray-coated to prepare test pieces. Example 19 11 g / L of chromium chloride and 11 of nitric acid were added to a hot-dip galvanized steel sheet.
A treatment solution adjusted to pH 2.2 containing g / L and phosphoric acid 10 g / L was applied with a bar coater, and then immersed in 5G018 to prepare a test piece.

[0020]Example 20 Electrogalvanized steel sheet was prepared by iron sulfate 7g / L, phosphoric acid 15g / L
L, pH containing hydrochloric acid 1 g / L, 67.5% nitric acid 2 g / L
After immersion for 8 seconds in 2.6 aqueous solution, immersion in 5G018
A test piece was prepared.Example 21 Hot-dip galvanized steel sheet is iron sulfate 15g / L, magnesium nitrate
20 g / L, sulfuric acid 1 g / L, 75% phosphoric acid 25 g / L
L, aqueous solution containing 62.5% nitric acid 1 g / L with ammonia
Current density 5 A / d with treatment solution adjusted to pH 2.1
m^Two, Electrolysis for 10 seconds to make a test piece
Was.Example 22 15g of aluminum sulfate
L, magnesium nitrate 65 g / L, sulfuric acid 1 g / L, 75
Water containing 15 g / L of 15% phosphoric acid and 1 g / L of 62.5% nitric acid
Current is applied to the treatment solution adjusted to pH 2.5 with ammonia.
Density 6A / dm ^TwoAfter performing electrolysis for 10 seconds of electrolysis time,
After dipping in 5G018, it was dried to prepare a test piece.Example 23 Electrogalvanized steel sheet (200 × 300mm)
25g / L, 75% phosphoric acid 37g / L, 67.5% nitrate
The pH was adjusted to 2.2 with ammonia containing 17 g / L of acid.
The specimen was immersed in the treatment liquid for 38 seconds to prepare a test piece.Example 24 Alloyed hot-dip galvanized steel sheet (200 x 300 mm)
H2.6 chromium sulfate 37 g / L, hydrochloric acid 2.5 g / L,
Immersed in a treatment solution containing 0.4 g / L of 75% sulfuric acid for 45 seconds
Test pieces were prepared.Example 25 Zinc-nickel alloy plated steel sheet (200 × 300mm)
To pH 2.3 chromium sulfate 26 g / L, hydrochloric acid 2 g / L,
Current density 5A in processing solution containing 1.4g / L of 75% sulfuric acid
/ Dm^TwoAfter electrolysis for 8 seconds, potassium silicate 60g
/ L, caustic potash 7g / L, cataloid SI-30 (catalyst
(Manufactured by Kasei Co., Ltd.) for 10 seconds in a processing solution containing 35 g / L.
To prepare a test piece.

[0021]

[Table 1]

Note in Table 1) Appearance ：: Uniform and almost non-uniformity to a degree that does not matter even if there is unevenness, Δ: A degree to which slight unevenness is noticeable and cannot be ignored, and X: There is obvious unevenness Corrosion resistance ◎ : 5% white rust occurrence time 360 hours or more, ○: 5% white rust occurrence time 120 hours or more, Δ: 5% white rust occurrence time 48 hours or more, ×: 5% white rust occurrence time less than 48 hours Fingerprint resistance ○: ΔE ≦ 1, Δ: 1 <ΔE <4, ×: ΔE ≧ 4 Blackening resistance ○: ΔL <1.5, Δ: 1.5 ≦ ΔL <5, ×: △ L ≧ 5

Continued on the front page (72) Inventor Mitsuomi Katori 1136 Hagizono, Chigasaki-shi, Kanagawa F-term in Japan Surface Chemical Co., Ltd. BB10 CA13 CA15 CA18 CA19 CA23 CA24 CA25 CA26 CA27 CA28 CA29 CA30 CA31 CA32 CA33 CA34 CA35 CA36 CA37 CA38 CA41 DA11 DA12 EB02 EB05 EB08 EB11 4K027 AA02 AA05 AA22 AB05 AB09 AB28 AB42 AC82 4K044 AA02 BC02 BA10 BA11 BA02 CA16 CA18 CA53

Claims (15)

[Claims] 1. A steel material which has been subjected to zinc or zinc alloy plating or alloying treatment after plating, further comprising Mo, W,
A steel material that has been surface-treated with a treatment solution containing at least one selected from the group consisting of V, Nb, Ta, Ti, Zr, Ce, Sr, and trivalent chromium and containing no hexavalent chromium. 2. A composition for forming a protective film on a steel material subjected to zinc or zinc alloy plating or alloying treatment after plating, comprising: A) Mo, W, V, Nb, Ta, Ti, Zr, Ce, S
at least one source selected from the group consisting of r and trivalent chromium; B) a phosphorus oxyacid, oxyacid salt or anhydride thereof; and C) optionally a source of an oxidizing substance. Composition. 3. A composition for forming a protective film on a steel material subjected to zinc or zinc alloy plating or alloying treatment after plating, comprising: A) trivalent chromium ions of 0.001 to 600 g / L;
And B) at least one selected from the group consisting of 0.001 to 600 g / L of chlorine, fluorine, sulfate, nitrate, peroxide, chlorate, acetate, formate, succinate and glycolate. A composition containing a seed. 4. A composition for forming a protective film on steel which has been subjected to zinc or zinc alloy plating or alloying treatment after plating, comprising: A) 0.001 to 600 g / L of trivalent chromium ions; A composition containing B) 0.001 to 500 g / L nitrate ion and C) 0.01 to 800 g / L phosphate ion. 5. The steel material subjected to zinc or zinc alloy plating or alloying treatment after plating contains at least one selected from the group consisting of iron, cobalt, nickel, magnesium, calcium and aluminum and does not contain hexavalent chromium. A steel material surface-treated with the composition. 6. A composition for forming a protective film on a steel material which has been subjected to zinc or zinc alloy plating or alloying treatment after plating, comprising: A) 0.001 to 600 g / L of iron, cobalt, nickel; A composition containing at least one metal selected from the group consisting of magnesium, calcium, and aluminum; B) at least one acid selected from the group consisting of organic acids or inorganic acids; and C) fluorine as an optional component. 7. The source of the oxidizing substance is peroxide, chloric acid, bromic acid, nitric acid, or a salt thereof, and the oxyacid of the phosphorus is orthophosphoric acid, condensed phosphoric acid, phosphorous acid or 3. The composition according to claim 2, which is hypophosphorous acid. 8. The composition according to claim 6, wherein said metal is iron, aluminum or magnesium, and said acid is hydrochloric acid, sulfuric acid, nitric acid, hydrogen peroxide, phosphoric acid or carboxylic acid. 9. The composition according to claim 8, wherein said carboxylic acid is formic acid, acetic acid, succinic acid or diglycolic acid. 10. The composition according to claim 1, further comprising an alkaline earth metal,
Silicon compound, alumina sol, silane coupling agent,
The composition according to claim 2, 3, 4, 6, 6, 7, 8 or 9, comprising at least one selected from the group consisting of organic carboxylic acids. 11. A steel material which has been subjected to zinc or zinc alloy plating or alloying treatment after plating.
A method for forming a protective film, comprising: contacting the composition according to 7, 8, 9 or 10 with a rinsing step or drying without performing the rinsing step. 12. Before or after the drying, the steel material is further subjected to silicon compound, resin, inorganic colloid, silane coupling agent, organic carboxylic acid, thiazole, triazole,
Selected from the group consisting of amine compounds, caustic alkalis, ammonia, oxyacids of phosphorus, PVA, nonionic polymers, polyols, cellulose, polyacrylic acid, acid amide compounds, fatty acid esters, thiol compounds, tannic acids and mercapto groups. The method according to claim 11, wherein the solution is contacted with a solution having at least one of the following. 13. The steel material according to claim 1 or 5, or a steel material produced by the method according to claim 11 or 12, further overcoated with an organic or inorganic material or a composite thereof. 14. The method according to claim 14, wherein the silicon compound is sodium silicate,
The composition according to claim 10, which is potassium silicate, lithium silicate, or colloidal silica having a particle size of 500 nm or less. 15. The method according to claim 15, wherein the silicon compound is sodium silicate.
The method according to claim 12, which is potassium silicate, lithium silicate, or colloidal silica having a particle size of 500 nm or less.