JP2000160353A - Organic coated steel sheet excellent in corrosion resistance - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an organic coated steel sheet having excellent corrosion resistance even if a chromate film is not applied to the chemical conversion film constituting the base and moreover capable of achieving excellent chromium elution resistance as well as corrosion resistance in the case a chromate film is applied to the chemical conversion film. SOLUTION: On the surface of a galvanized steel sheet or an aluminum plated steel sheet, a chemical conversion film is applied, and, on the surface of the chemical conversion film, an organic film of 0.1 to 5 μm film thickness contg., as a 1st component, a reaction product of a film forming organic resin (A) and an active hydrogen-contg. compd. (B) in which a part or the whole of the compd. is composed of a hydrazine derivative (C) having active hydrogen an, as a 2nd component, zinc phosphate and/or aluminum phosphate in which the content of zinc phosphate and/or aluminum phosphate is controlled to 1 to 100 pts.wt. (solid content) based on 100 pts.wt. (solid content) of the reaction product is applied.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an organic coated steel sheet which is most suitable for use in automobiles, home appliances, building materials, etc. In order to adapt to environmental issues such as volatilization and elution of harmful substances from products, excellent corrosion resistance can be obtained without applying a chromate coating to the underlying chemical conversion coating, and a chromate coating is applied to the chemical conversion coating. The present invention relates to an environment-adaptive surface-treated steel sheet that, when applied, has not only corrosion resistance but also excellent chromium elution resistance.

[0002]

2. Description of the Related Art Steel sheets for home appliances, steel sheets for building materials, steel sheets for automobiles, etc. are used to improve the corrosion resistance (white rust resistance, red rust resistance) on the surface of a zinc-based or aluminum-based steel sheet. A steel sheet which has been subjected to chromate treatment with a treatment liquid containing chromic acid, dichromic acid or salts thereof as a main component is widely used. This chromate treatment is an economical treatment method that has excellent corrosion resistance and can be performed relatively easily. The corrosion prevention mechanism of the chromate film is 3
It is thought to be due to the barrier effect of the hydrated oxide of chromium (VI) and the self-healing effect of hexavalent chromium.

[0003] Chromate treatment methods include a reaction type, an electrolytic type and a coating type. Among these, the coating-type chromate treatment has recently been applied to surface-treated steel sheets because excellent corrosion resistance can be obtained by controlling the ratio of hexavalent chromium to trivalent chromium in the treatment solution or by adding silica. Its usage as well is growing rapidly. In the case of a reaction type or electrolytic type chromate treatment, a sealing treatment may be performed with a treatment liquid containing hexavalent chromium immediately after the chromate treatment in order to supplement the corrosion resistance of the chromate film.

However, since hexavalent chromium is a pollution control substance, it is necessary to suppress elution of hexavalent chromium from the chromate film. For example, when rust-preventive oil and press oil adhered during press working of a coating-type chromate-treated steel sheet are alkali-degreased, it is necessary to suppress elution of hexavalent chromium into the alkali degreasing solution. Similar considerations are also required in the chromium sealing treatment performed on the surface of the reaction type chromate treated steel sheet or the electrolytic type chromate treated steel sheet for the purpose of improving corrosion resistance. For this reason, there is an increasing need for a chromate treatment in which hexavalent chromium is not eluted from the chromate film.

[0005] For these reasons, various studies have been made to suppress the elution of chromium during the alkaline degreasing of the coating type chromate-treated film and to improve the corrosion resistance. One of the methods is to use trivalent chromium /
A method of increasing the reduction ratio of hexavalent chromium is known, but increasing the reduction ratio in the treatment liquid lowers the corrosion resistance, so there is a limit to the increase in the reduction ratio. In addition to this method, the following method is disclosed.

(A) The drying temperature of the chromate treatment is set to 150 to 250 ° C. at the plate temperature, and after the resin is applied,
(B) A method of suppressing the elution of chromium ions by adding a reducing agent to the upper aqueous resin film (Japanese Patent Laid-Open No. 7-1).
(No. 80069) (c) A method of suppressing the elution of chromium ions by adding polyethylene oxyol into the upper epoxy ester resin film (Japanese Patent Application Laid-Open No. 7-243055)

On the other hand, from the viewpoint that the chromate treatment itself may adversely affect the human body and the environment, a number of pollution-free treatment techniques not based on the chromate treatment have been proposed. Among them, several methods using an organic compound or an organic resin have been proposed, and for example, the following methods can be mentioned.

(1) A method using tannic acid (for example,
(2) A method of using a thermosetting paint in which an epoxy resin, an amino resin and tannic acid are mixed (for example, JP-A-63-971).
No. 0581) (3) A method using a mixed composition of an aqueous resin and a polyhydric phenol carboxylic acid (for example, JP-A-8-325760)
Using the chelating power of tannic acid, such as

(4) A surface treatment method of applying an aqueous solution of a hydrazine derivative to the surface of a tin or zinc iron plate (for example,
JP-B-53-27694, JP-B-56-10386
(5) A method using a rust inhibitor containing an amine addition salt obtained by adding an amine to a mixture of acyl sarcosine and benzotriazole (for example, JP-A-58-130284)
(6) A method using a treating agent in which a heterocyclic compound such as a benzothiazole compound and tannic acid are mixed (for example, JP-A-57-198267)

[0010]

However, the prior arts (a) to (c) for the purpose of suppressing the elution of chromium include:
There are the following problems. First, the above method (a)
Since some hexavalent chromium ions permeate through the upper organic resin film, there is a limit to the suppression of chromium elution. Also,
The above method (b) aims at reducing hexavalent chromium in the chromate film to trivalent chromium.
There is a problem that not only the suppression of chromium elution is limited but also the corrosion resistance is reduced. Further, the above method (c) is expected to form a complex of hexavalent chromium with polyethyleneoxyol, but has a problem that the corrosion resistance is reduced as in the method (b).

The prior arts (1) to (6) which do not use the chromate treatment also have the following problems. First, all of the above methods (1) to (4) have a problem in terms of corrosion resistance and the like. That is, the method (1) is insufficient in corrosion resistance and cannot provide a uniform appearance after the treatment. In addition, the method (2) is particularly suitable for directly forming a thin film (0.1 to 5) on a zinc-based or aluminum-based plating surface.
The purpose of the present invention is not to form a rust-preventive film having a thickness of 1 μm). Therefore, a sufficient anticorrosion effect cannot be obtained even when applied in a thin film on a zinc-based or aluminum-based plating surface. Similarly, the method (3) is also insufficient in corrosion resistance.

Further, the method (4) is not applied to a zinc-based or aluminum-based plated steel sheet, and even if applied to a zinc-based or aluminum-based plated steel sheet, the obtained film has a network structure. It does not have sufficient barrier properties due to lack of corrosion resistance, and therefore has insufficient corrosion resistance. In addition, Japanese Patent Publication No. 53-23772
And JP-B-56-10386, in which a water-soluble polymer compound (polyvinyl alcohol, maleic acid ester copolymer, acrylic acid ester copolymer, etc.) is mixed with an aqueous solution of a hydrazine derivative in order to improve the uniformity of the film. However, a simple mixture of an aqueous hydrazine derivative solution and a water-soluble polymer compound does not provide sufficient corrosion resistance.

Further, the methods (5) and (6) are not aimed at forming a rust-preventive film on the surface of a zinc-based or aluminum-based plated steel sheet in a short time.
Even if the treating agent is applied to the surface of the plated steel sheet, excellent corrosion resistance cannot be obtained because there is no barrier to corrosion factors such as oxygen and water. As for the method (6), mixing with a resin (an epoxy resin, an acrylic resin, a urethane resin, a nitrocellulose resin, a vinyl chloride resin, etc.) as an additive is described, but a complex such as a benzothiazole compound is used. A simple mixture of a ring compound and a resin does not provide sufficient corrosion resistance.

In any of the above-mentioned methods (1) to (6), practical conditions such as performing alkali degreasing at a pH of about 9 to 11 by spraying or the like in order to remove oil applied to the surface by press working or the like. However, there is a problem that the film is peeled or damaged by alkali degreasing, and the corrosion resistance cannot be maintained. Therefore, these methods are not suitable for practical use as a method for forming a rust preventive film.

Accordingly, an object of the present invention is to solve such problems of the prior art, to obtain excellent corrosion resistance without applying a chromate film to a chemical conversion film as a base, and to provide a chromate film to a chemical conversion film. An object of the present invention is to provide an organic-coated steel sheet which can provide not only corrosion resistance but also excellent chromium elution resistance when a coating is applied.

[0016]

Means for Solving the Problems As a result of intensive studies by the present inventors to solve the above problems, the present inventors have found that a chemical conversion treatment film formed on the surface of a zinc-based steel sheet or an aluminum-based steel sheet, Along with forming a specific chelate-forming resin film, by adding an appropriate amount of a specific rust inhibitor to the chelate-forming resin film, excellent corrosion resistance can be obtained without using a chromate treatment as a chemical conversion treatment, When the chromate treatment was used as the chemical conversion treatment, it was found that, in comparison with the conventional chromate-treated steel sheet, significantly superior corrosion resistance was obtained, and that the specific chelate-forming resin film provided excellent chromium elution resistance. Was.

[0017]

SUMMARY OF THE INVENTION The present invention has been made based on such a finding, and the characteristic configuration thereof is as follows. [1] A hydrazine derivative (C) having a chemical conversion coating on the surface of a galvanized steel sheet or an aluminum-plated steel sheet, on which a film-forming organic resin (A) and some or all of the compounds have active hydrogen And a reaction product of the active hydrogen-containing compound (B) and zinc phosphate and / or aluminum phosphate (a), wherein the content of the zinc phosphate and / or aluminum phosphate (a) is as described above. An organically coated steel sheet having excellent corrosion resistance, comprising an organic film having a thickness of 0.1 to 5 μm, which is 1 to 100 parts by weight (solid content) based on 100 parts by weight (solid content) of a reaction product. .

[2] A hydrazine derivative having a chemical conversion coating on the surface of a zinc-based plated steel sheet or an aluminum-based plated steel sheet, and a film-forming organic resin (A) and a part or all of the compound having active hydrogen thereon. (C) a reaction product with an active hydrogen-containing compound (B), zinc phosphate and / or aluminum phosphate (a), and a calcium compound (b), wherein the zinc phosphate and / or phosphorus The total content of aluminum acid (a) and the calcium compound (b) is 1 to 100 parts by weight (solid content) based on 100 parts by weight (solid content) of the reaction product, and zinc phosphate and / or Or, the weight ratio (a) / (b) of the content (solid content) of aluminum phosphate (a) and calcium compound (b) is 1/99 to 99/1, and the film thickness is 0.1 to 5 μm. Organic skin Excellent organic coated steel sheet in corrosion resistance characterized by having a.

[3] A hydrazine derivative having a chemical conversion coating on the surface of a zinc-based plated steel sheet or an aluminum-based plated steel sheet, and on which a film-forming organic resin (A) and some or all of the compounds have active hydrogen A reaction product of (C) with an active hydrogen-containing compound (B), zinc phosphate and / or aluminum phosphate (a), and a solid lubricant (c); The content of aluminum phosphate (a) is 100
1 to 100 parts by weight (solids) based on parts by weight (solids), and the content of the solid lubricant (c) is 1 to 80 parts by weight based on 100 parts by weight (solids) of the reaction product (solids). An organic-coated steel sheet having excellent corrosion resistance, comprising an organic film having a thickness of 0.1 to 5 μm as a solid component.

[4] A hydrazine derivative having a chemical conversion coating on the surface of a zinc-based plated steel sheet or an aluminum-based plated steel sheet, and on which a film-forming organic resin (A) and some or all of the compounds have active hydrogen (C) a reaction product with an active hydrogen-containing compound (B), zinc phosphate and / or aluminum phosphate (a), a calcium compound (b), and a solid lubricant (c), The total content of the zinc phosphate and / or aluminum phosphate (a) and the calcium compound (b) is 1 to 100 parts by weight (solid content) based on 100 parts by weight (solid content) of the reaction product. And the weight ratio (a) / (b) of the content (solid content) of zinc phosphate and / or aluminum phosphate (a) to calcium compound (b) is 1/99 to 99.
/ 1, the content of the solid lubricant (c) is 1 to 80 parts by weight (solid content) based on 100 parts by weight (solid content) of the reaction product, and the film thickness is 0.1 to 5 μm. Organic coated steel sheet with excellent corrosion resistance characterized by having an organic coating of

[5] The organic coated steel sheet according to any one of [1] to [4] above, wherein the film-forming organic resin (A) is an epoxy group-containing resin (D). Coated steel sheet. [6] The organic-coated steel sheet according to any one of [1] to [5],
An organically coated steel sheet having excellent corrosion resistance, wherein the hydrazine derivative (C) having active hydrogen is a pyrazole compound having active hydrogen and / or a triazole compound having active hydrogen.

[7] The organic-coated steel sheet according to any one of [1] to [6] above, wherein the hydrazine derivative (C) having active hydrogen
Is contained in the active hydrogen-containing compound (B) in an amount of 10 to 100 mol%. [8] In the organic-coated steel sheet according to any one of the above [5] to [7],
An organic-coated steel sheet having excellent corrosion resistance, wherein the epoxy group-containing resin (D) is an epoxy resin represented by the following formula (1).

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The basic features of the organic coated steel sheet of the present invention are as follows:
A chemical conversion coating is formed on the surface of a galvanized steel sheet or an aluminum-plated steel sheet, and an active layer consisting of a film-forming organic resin (A) and a hydrazine derivative (C) in which some or all of the compounds have active hydrogen is formed thereon. By reacting with the hydrogen-containing compound (B), the hydrazine derivative (C) is used as a chelating group in the film-forming resin (A).
, A chelate-forming resin as a reaction product is used as a base resin, zinc phosphate and / or aluminum phosphate (a) are blended as a rust preventive additive, and a calcium compound (b) is further added, if necessary. ) Is formed.

Although the mechanism of anticorrosion by the organic film composed of such a specific reaction product is not necessarily clear, the mechanism can be estimated as follows. In other words, by adding a hydrazine derivative to a film-forming organic resin instead of a simple low molecular weight chelating agent, (1) a dense organic polymer film has an effect of blocking corrosion factors such as oxygen and chloride ions. (2) that the hydrazine derivative can firmly bind to the surface of the first layer film to form a stable passivation layer; and (3) free hydrazine derivative in the film traps zinc ions eluted by the corrosion reaction. In order to form a stable insoluble chelate compound layer, the formation of an ion conductive layer at the interface is suppressed and the progress of corrosion is suppressed. It is considered that a high corrosion resistance is obtained.

When such an organic film is formed on the chromate film, the barrier effect of the organic film itself not only suppresses the elution of hexavalent chromium from the chromate film, but also reduces the hydrazine content of the organic resin. It is considered that since the derivative captures hexavalent chromium eluted from the chromate film, excellent chromium elution resistance is obtained.

As a result of the above, 6 was used as the underlayer chemical conversion treatment film.
Even when a chemical conversion coating containing no valent chromium (for example, a phosphate coating) is used, excellent corrosion resistance comparable to a chromate coating can be obtained, and when a chromate coating is used as the chemical conversion coating, It is considered that since this and the anti-corrosion effect of the organic film are compounded, corrosion resistance is obtained, but excellent chromium elution resistance is obtained, which is far superior to conventional chromate-treated steel sheets.

When an epoxy group-containing resin is used as the film-forming organic resin (A), a dense barrier film is formed by the reaction between the epoxy group-containing resin and the crosslinking agent. It has an excellent ability to suppress permeation of corrosion factors such as corrosion factors, and a hydroxyl group in a molecule provides an excellent bonding force with a substrate, so that particularly excellent corrosion resistance is obtained. Further, a hydrazine derivative (C) having active hydrogen
By using a pyrazole compound having active hydrogen and / or a triazole compound having active hydrogen, more excellent corrosion resistance can be obtained.

By simply mixing a hydrazine derivative with a film-forming organic resin as in the prior art, the effect of improving corrosion inhibition is hardly recognized. The reason is that hydrazine derivatives that are not incorporated into the molecules of the film-forming organic resin form a chelate compound with zinc eluted under a corrosive environment, but the chelate compound does not form a dense barrier layer due to its low molecular weight. It is thought that it is. On the other hand, by incorporating the hydrazine derivative into the molecules of the film-forming organic resin as in the present invention, a significantly excellent corrosion inhibiting effect can be obtained.

Further, in the organic coated steel sheet of the present invention, particularly excellent properties can be obtained by blending zinc phosphate and / or aluminum phosphate (a) in an appropriate amount in the organic film composed of the above specific reaction product. Corrosion prevention performance (self-healing action at a film defect portion) can be obtained. The anticorrosion mechanism obtained by blending zinc phosphate and / or aluminum phosphate (a) into this specific organic film is considered to proceed in the following reaction steps.

[First step]: In a corrosive environment,
Zinc and aluminum, which are plating metals, elute. [Second Step]: Zinc phosphate and / or aluminum phosphate undergo a hydrolysis reaction and dissociate into phosphate ions. [Third Step]: The eluted zinc ions and aluminum ions undergo a complexing reaction with phosphate ions to form a dense and hardly soluble protective film, which closes the film defect portion,
Suppress corrosion reaction.

Although a certain degree of anticorrosion effect can be obtained even when zinc phosphate and / or aluminum phosphate is blended in a general organic film, phosphoric acid is contained in an organic film composed of a specific chelate-modified resin as in the present invention. It is considered that by adding zinc and / or aluminum phosphate, the corrosion inhibiting effect of both is compounded, and thereby an extremely excellent anticorrosion effect is exhibited.

Further, in the organic coated steel sheet of the present invention, zinc phosphate and / or aluminum phosphate (a) and calcium compound (b) are added to the organic film composed of the above-mentioned specific reaction product. Thereby, a further effect of improving corrosion resistance can be obtained. The reason is considered as follows. As described above, the self-healing effect of zinc phosphate and / or aluminum phosphate is triggered by the elution of the plating metal (first step). Cannot be completely suppressed. On the other hand, by using a calcium compound which is a metal lower than zinc and aluminum, the preferential elution of calcium instead of the plating metal acts as a trigger as described above, thereby corroding without depending on the elution of the plating metal. The reaction can be suppressed. By such a mechanism, it is considered that a composite rust-preventing effect can be obtained by using a combination of zinc phosphate and / or aluminum phosphate and a calcium compound.

[0033]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The details of the present invention and the reasons for limiting the same will be described below. The zinc-coated steel sheet serving as a base of the organic coated steel sheet of the present invention includes a zinc-coated steel sheet, Zn-Ni
Alloy plated steel sheet, Zn-Fe alloy plated steel sheet (electroplated steel sheet and galvannealed steel sheet), Zn-Cr
Alloy plated steel sheet, Zn-Mn alloy plated steel sheet, Zn-C
o alloy plated steel sheet, Zn-Co-Cr alloy plated steel sheet,
Zn-Cr-Ni alloy plated steel sheet, Zn-Cr-Fe alloy plated steel sheet, Zn-Al alloy plated steel sheet (for example, Z
n-5% Al alloy plated steel sheet, Zn-55% Al alloy plated steel sheet), Zn-Mg alloy plated steel sheet, Zn-Al-
Mg-plated steel sheets, and zinc-based composite plated steel sheets (eg, Zn—SiO ₂ dispersed plated steel sheets) in which metal oxides, polymers, and the like are dispersed in the plating films of these plated steel sheets can be used.

A multi-layer plated steel sheet obtained by plating two or more layers of the same type or different types among the above platings can also be used. In addition, as the aluminum-plated steel sheet serving as the base of the organic-coated steel sheet of the present invention, an aluminum-plated steel sheet, an Al—Si alloy-plated steel sheet, or the like can be used. Further, the plated steel sheet may be one in which thin steel plating such as Ni is previously applied to the surface of the steel sheet and various platings as described above are applied thereon. As a plating method, any practicable method can be adopted among an electrolysis method (electrolysis in an aqueous solution or electrolysis in a non-aqueous solvent), a melting method, and a gas phase method.

In order to prevent the occurrence of film defects and unevenness when a two-layer film as described later is formed on the surface of the plating film, if necessary, the surface of the plating film is previously subjected to alkali degreasing, solvent degreasing, A treatment such as a conditioning treatment (an alkaline surface conditioning treatment or an acidic surface conditioning treatment) can be performed. Further, in order to prevent blackening (a kind of oxidation phenomenon on the plating surface) in the use environment of the organic coated steel sheet, if necessary, an iron group metal ion (Ni
Surface treatment with an acidic or alkaline aqueous solution containing ions, Co ions, and Fe ions) can also be performed. When an electrogalvanized steel sheet is used as a base steel sheet, an iron group metal ion (Ni ion, Co ion, Fe ion) is added to the electroplating bath for the purpose of preventing blackening.
And these metals can be contained in the plating film in an amount of 1 ppm or more. In this case, there is no particular upper limit on the iron group metal concentration in the plating film.

Next, the chemical conversion coating formed on the surface of the zinc-based plated steel sheet or the aluminum-based plated steel sheet will be described. This chemical conversion coating is formed for the purpose of suppressing the activity of the plated steel sheet and improving the corrosion resistance and adhesion, and the type thereof is not particularly limited, and the chemical conversion coating containing no hexavalent chromium and the chromate coating Either may be used.

Examples of the chemical conversion coating containing no hexavalent chromium include: (1) a phosphate coating; (2) a passivation coating such as a molybdate or tungstate coating; a phosphoric acid / molybdate coating; 3) Alkali silicate treated film composed of alkali metal oxide such as lithium oxide and silicon oxide (4) Composite oxide film composed of trivalent chromium (5) Inorganic film such as oxide film composed of titanium oxide and zirconium oxide Can be applied.

In addition to the above inorganic coatings, for example, (6) a thin organic resin coating (0.1 to 2 μm) or an organic composite silicate coating (7) a chelate-forming organic coating such as tannic acid, phytic acid, and phosphonic acid (8) A composite film in which an organic resin is blended in the inorganic film of any of the above (1), (2) and (3) can be applied. Of the above, a hardly soluble film containing silicon oxide (eg, an alkali silicate film) is most desirable from the viewpoint of suppressing zinc white rust.

An organic resin can be incorporated into the chemical conversion coating for the purpose of improving workability and corrosion resistance. As the organic resin, an epoxy resin, a urethane resin, an acrylic resin, an acrylic-ethylene copolymer, an acrylic-styrene copolymer, an alkyd resin, a polyester resin, an ethylene resin, or the like can be used.
These can be supplied as a water-soluble resin and / or a water-dispersible resin. Furthermore, in addition to these water-dispersible resins,
It is effective to use a water-soluble epoxy resin, a water-soluble phenol resin, a water-soluble butadiene rubber (SBR, NBR, MBR), a melamine resin, a blocked isocyanate, an oxazoline compound or the like as a crosslinking agent.

In addition, the above-mentioned chemical conversion coating film may further include a polyphosphate, an additive for further improving the corrosion resistance.
Phosphates (eg, zinc phosphate, aluminum dihydrogen phosphate, zinc phosphite, etc.), molybdates, phosphomolybdates (eg, aluminum phosphomolybdate), organic phosphoric acids and salts thereof (eg, phytic acid) Phytate, phosphonic acid, phosphonate and their metal salts, alkali metal salts), organic inhibitors (eg, hydrazine derivatives, thiol compounds, dithiocarbamates, etc.), organic compounds (polyethylene glycol), etc. May be added.

Further, as other additives, organic coloring pigments (for example, condensed polycyclic organic pigments, phthalocyanine organic pigments, etc.), coloring dyes (for example, organic solvent-soluble azo dyes, water-soluble azo metal dyes, etc.) ), Inorganic pigments (titanium oxide), chelating agents (thiols, etc.), conductive pigments (eg, metal powders such as zinc, aluminum, nickel, iron phosphide, antimony-doped tin oxide, etc.), coupling agents (eg, Silane coupling agents, titanium coupling agents, etc.), melamine / cyanuric acid adducts, and the like.

For the purpose of preventing blackening (a kind of oxidation phenomenon on the plating surface) in the use environment of the organic coated steel sheet, these chemical conversion treatment films are coated with iron group metal ions (Ni ion, C ion).
o ions, Fe ions), preferably Ni ions. In this case, the desired effect can be obtained if the concentration of the iron group metal ion is 1/10000 mol or more with respect to 1 mol of the (β) alkaline earth metal ion in the treatment composition. Although the upper limit of the concentration of the iron group metal ion is not particularly defined, it is set to such an extent that the increase in the concentration does not affect the corrosion resistance. The thickness of these chemical conversion coatings is 3 μm or less. This is because when the film thickness exceeds 3 μm, workability and conductivity are reduced. The lower limit is not particularly defined, but may be a film thickness at which the effect of improving corrosion resistance is recognized.

Next, a case where a chromate film is applied as the chemical conversion film will be described. The chromate film may be any of a reaction type chromate treatment film, an electrolytic type chromate treatment film, and a coating type chromate treatment film.
The coating type chromate treatment film is mainly composed of a partially reduced aqueous solution of chromic acid,
Can be obtained by applying a chromate treatment solution to which one or more components selected from the above components are added, applying the chromate treatment solution to a plated steel sheet, and drying without washing with water.

Water-soluble or water-dispersible organic resins such as acrylic resins and polyester resins Colloids of oxides such as silica, alumina, titania, zirconia, and zinc oxide and / or powders such as molybdic acid, tungstic acid, and vanadic acid Acids and / or salts thereof Phosphoric acids such as phosphoric acid and polyphosphoric acid Zirconium fluorides, fluorides such as silicon fluorides, titanium fluorides, and phosphate fluorides Metal ions such as zinc ions, nickel ions, cobalt ions, and iron ions Phosphorylation Conductive fine powder such as iron and antimony-doped tin oxide Hydrogen fluoride Silane coupling agent

In this coating type chromate treatment, 6
It is effective to increase the reduction ratio in the chromate treatment liquid in order to suppress the content of valent Cr. In particular, it is effective to use a chromate treatment solution in which the proportion of hexavalent chromium in the treatment solution is reduced and the ratio (solid content) of hexavalent Cr / total Cr is 0.1 or less, preferably 0.01 or less. It is. As a method of adjusting such a chromate treatment solution, an excess oxalic acid and / or oxycarboxylic acid is added as a reducing agent to an aqueous solution of chromic anhydride to increase the reduction rate, and the reduction product is obtained by increasing the pH. It is effective to lower the pH with phosphoric acid or the like to prevent precipitation of trivalent Cr, whereby a chromate film containing trivalent Cr as a main component can be stably obtained. In the application type chromate treatment, the treatment liquid is usually applied by a roll coater method, but after applying by a dipping method or a spray method, it is also possible to adjust the application amount by an air knife method or a roll drawing method.

The electrolytic chromate treatment film contains, for example, a partially reduced aqueous solution of chromic acid and sulfuric acid as main components and, if necessary, metal ions (for example, Zn, Ni, Co, Fe, M).
g, ions of Mn, Al, Ca, etc.), oxide colloids and / or fine powder (silica, alumina, titania, zirconia, magnesia, zinc oxide, tin oxide, antimony oxide, etc.) chloride ion, fluorine ion, nitric acid Ions, phosphate ions and other anions Zirconium fluoride, silicon fluoride, titanium fluoride, boron borofluoride, fluoride such as phosphate fluoride One or more selected from organic compounds such as polyethylene glycol and aqueous acrylic resin Is added, pH 1
It can be obtained by subjecting a plated steel sheet to cathodic electrolysis at a temperature of 30 to 70 ° C. and an amount of electricity of 0.5 to 40 C / dm ² using a chromate treatment solution adjusted to ５5.

The reactive type chromate film contains, for example, chromic anhydride and sulfuric acid as main components, and the content of trivalent Cr in all Cr is 50% by weight or less, preferably 20 to 35% by weight. A chromate treatment solution to which an appropriate amount of metal ions (for example, Zn ions, Co ions, Ni ions, Fe ions, etc.) or other mineral acids (for example, phosphoric acid, hydrochloric acid, hydrofluoric acid, etc.) is added, It can be obtained by treating a plated steel sheet with a chromate treatment solution.

The adhesion amount of these chromate films is 1 to 1000 mg / m ^{2 in} terms of chromium metal, preferably 5 to 1000 mg / m ² .
200 mg / m ² , particularly preferably 10 to 100 mg / m ²
and m ^2. When the amount is less than 1 mg / m ² , the corrosion resistance is insufficient. On the other hand, when the amount is more than 1000 mg / m ² , problems such as formation of cracks in the chromate film and deterioration of weldability occur.

Next, the organic film formed on the chemical conversion film will be described. In the present invention, the organic film formed on the chemical conversion film is an active hydrogen-containing compound (B) comprising a film-forming organic resin (A) and a hydrazine derivative (C) in which some or all of the compounds have active hydrogen. And a zinc phosphate and / or aluminum phosphate (a), and a calcium compound (b) and a solid lubricant (c), if necessary, having a film thickness of 0.1 to 5 μm organic film.

As the type of the film-forming organic resin (A),
Some or all of the compounds react with an active hydrogen-containing compound (B) composed of a hydrazine derivative (C) having active hydrogen, and the active hydrogen-containing compound (B) is added to the film-forming organic resin by a reaction such as addition or condensation. There is no particular limitation as long as the resin can be bonded and a film can be appropriately formed. As the film-forming organic resin (A), for example, epoxy resin,
Modified epoxy resins, polyurethane resins, polyester resins, alkyd resins, acrylic copolymer resins, polybutadiene resins, phenolic resins, and adducts or condensates of these resins can be mentioned. They can be used alone or in combination of two or more.

Further, as the film-forming organic resin (A),
The epoxy group-containing resin (D) having an epoxy group in the resin is particularly preferred from the viewpoints of reactivity, easiness of reaction, corrosion resistance and the like. As the epoxy group-containing resin (D), some or all of the compounds react with an active hydrogen-containing compound (B) composed of a hydrazine derivative (C) having an active hydrogen to give a film-forming organic resin an active hydrogen-containing compound. There is no particular limitation as long as (B) is a resin that can be bonded by a reaction such as addition or condensation and that can appropriately form a film. Examples thereof include an epoxy resin, a modified epoxy resin, and an acrylic copolymer copolymerized with an epoxy group-containing monomer. Copolymer resins, polybutadiene resins having an epoxy group, polyurethane resins having an epoxy group, adducts or condensates of these resins, and the like. One of these epoxy group-containing resins may be used alone or in combination with two or more. These can be mixed and used. Among these epoxy group-containing resins (D), epoxy resins and modified epoxy resins are particularly preferred from the viewpoint of adhesion to the plating surface and corrosion resistance.

The epoxy resin is prepared by introducing a glycidyl group by reacting a polyphenol such as bisphenol A, bisphenol F or novolak type phenol with an epihalohydrin such as epichlorohydrin, or by adding a glycidyl group-introduced reaction product. Further, aromatic epoxy resins obtained by increasing the molecular weight by reacting polyphenols, furthermore, aliphatic epoxy resins, alicyclic epoxy resins, and the like, may be used alone or in combination of two or more. Can be used.
It is preferable that these epoxy resins have a number average molecular weight of 1500 or more especially when a film-forming property at a low temperature is required.

Examples of the modified epoxy resin include resins obtained by reacting various modifiers with an epoxy group or a hydroxyl group in the epoxy resin, such as an epoxy ester resin obtained by reacting a drying oil fatty acid, acrylic acid or Examples thereof include an epoxy acrylate resin modified with a polymerizable unsaturated monomer component containing methacrylic acid and the like, and a urethane-modified epoxy resin reacted with an isocyanate compound.

As the acrylic copolymer resin copolymerized with the epoxy group-containing monomer, an unsaturated monomer having an epoxy group and a polymerizable unsaturated monomer component essentially containing an acrylate ester or a methacrylate ester may be used as a solution. Resins synthesized by a polymerization method, an emulsion polymerization method, a suspension polymerization method, or the like can be given.

The polymerizable unsaturated monomer component includes
For example, methyl (meth) acrylate, ethyl (meth)
Acrylate, propyl (meth) acrylate, n-,
C1-24 alkyl esters of acrylic or methacrylic acid such as iso- or tert-butyl (meth) acrylate, hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, decyl (meth) acrylate, lauryl (meth) acrylate; Acrylic acid, methacrylic acid, styrene, vinyltoluene, acrylamide, acrylonitrile, N-methylol (meth) acrylamide, a C1-4 alkyl etherified product of N-methylol (meth) acrylamide; N, N-diethylaminoethyl methacrylate and the like. it can.

The unsaturated monomer having an epoxy group is not particularly limited as long as it has an epoxy group and a polymerizable unsaturated group, such as glycidyl methacrylate, glycidyl acrylate, and 3,4-epoxycyclohexylmethyl (meth) acrylate. There are no restrictions. The acrylic copolymer resin copolymerized with the epoxy group-containing monomer may be a resin modified with a polyester resin, an epoxy resin, a phenol resin, or the like.

Particularly preferred as the epoxy resin is a resin having a chemical structure represented by the following formula (1), which is a reaction product of bisphenol A and epihalohydrin. This epoxy resin is particularly excellent in corrosion resistance. preferable.

Embedded image Methods for producing such bisphenol A type epoxy resins are widely known in the art. In the above chemical structural formula, q is 0 to 50, preferably 1 to 40, particularly preferably 2 to 20. The film-forming organic resin (A) may be any of an organic solvent-soluble type, an organic solvent-dispersed type, a water-soluble type, and a water-dispersed type.

The purpose of the present invention is to provide a hydrazine derivative in the molecule of the film-forming organic resin (A), so that at least a part (preferably all) of the active hydrogen-containing compound (B) contains active hydrogen. Hydrazine derivative (C) having the following formula:

When the film-forming organic resin (A) is an epoxy group-containing resin, examples of the active hydrogen-containing compound (B) which reacts with the epoxy group include the following compounds. You can use more than species,
Also in this case, at least a part (preferably all) of the active hydrogen-containing compound (B) needs to be a hydrazine derivative having active hydrogen.・ Hydrazine derivative having active hydrogen ・ Primary or secondary amine compound having active hydrogen ・ Organic acid such as ammonia or carboxylic acid ・ Halogen halide such as hydrogen chloride ・ Alcohols, thiols ・ Has active hydrogen Quaternary chlorinating agents which are hydrazine derivatives or mixtures of tertiary amines and acids

Examples of the hydrazine derivative (C) having an active hydrogen include the following. Carbohydrazide, propionic hydrazide, salicylic hydrazide, adipic dihydrazide, sebacic dihydrazide, dodecanoic dihydrazide, isophthalic dihydrazide, thiocarbohydrazide, 4,4'-oxybisbenzenesulfonyl hydrazide, benzophenone hydrazide, aminopolyacrylamide such as benzophenone hydrazide Compounds; pyrazole compounds such as pyrazole, 3,5-dimethylpyrazole, 3-methyl-5-pyrazolone, 3-amino-5-methylpyrazole;

1,2,4-triazole, 3-amino-1,2,4-triazole, 4-amino-1,2,2
4-triazole, 3-mercapto-1,2,4-triazole, 5-amino-3-mercapto-1,2,4-
Triazole, 2,3-dihydro-3-oxo-1,
2,4-triazole, 1H-benzotriazole, 1
-Hydroxybenzotriazole (monohydrate), 6-methyl-8-hydroxytriazolopyridazine, 6-phenyl-8-hydroxytriazolopyridazine, 5-hydroxy-7-methyl-1,3,8-triazaind Triazole compounds such as lysine;

5-phenyl-1,2,3,4-tetrazole, 5-mercapto-1-phenyl-1,2,2,
Tetrazole compounds such as 3,4-tetrazole; thiadiazole compounds such as 5-amino-2-mercapto-1,3,4-thiadiazole and 2,5-dimercapto-1,3,4-thiadiazole; maleic hydrazide; Pyridazine compounds such as methyl-3-pyridazone, 4,5-dichloro-3-pyridazone, 4,5-dibromo-3-pyridazone, 6-methyl-4,5-dihydro-3-pyridazone

Of these, a five-membered ring or a six-membered ring
Pyrazole compounds and triazole compounds having a membered ring structure and having a nitrogen atom in the ring structure are particularly preferred. These hydrazine derivatives can be used alone or in combination of two or more.

Representative examples of the amine compound having an active hydrogen which can be used as a part of the active hydrogen-containing compound (B) include, for example, the following. The primary amino group of an amine compound containing one secondary amino group and one or more primary amino groups such as diethylenetriamine, hydroxyethylaminoethylamine, ethylaminoethylamine, and methylaminopropylamine can be converted to ketone, aldehyde or carboxyl. Acid and eg 1
A compound denatured to aldimine, ketimine, oxazoline or imidazoline by a heating reaction at a temperature of about 00 to 230 ° C;

[0065] Diethylamine, diethanolamine, di-n- or -iso-propanolamine, N
A secondary monoamine such as methylethanolamine or N-ethylethanolamine; a secondary amine-containing compound obtained by adding a monoalkanolamine such as monoethanolamine and a dialkyl (meth) acrylamide by a Michael addition reaction. Monoethanolamine, neopentanolamine,
2-aminopropanol, 3-aminopropanol, 2
A compound in which the primary amino group of an alkanolamine such as -hydroxy-2 '(aminopropoxy) ethyl ether is modified to ketimine;

The quaternary chlorinating agents that can be used as a part of the active hydrogen-containing compound (B) include hydrazine derivatives having no active hydrogen and tertiary amines, which themselves have no reactivity with epoxy groups. Is a mixture with an acid so that it can react with an epoxy group. The quaternary chlorinating agent reacts with an epoxy group in the presence of water if necessary, to form a quaternary salt with the epoxy group-containing resin.

The acids used to obtain the quaternary chlorinating agents are:
Any of organic acids such as acetic acid and lactic acid and inorganic acids such as hydrochloric acid may be used. Examples of the hydrazine derivative having no active hydrogen used to obtain a quaternary chlorinating agent include, for example, 3,
Examples of 6-dichloropyridazine and the like and tertiary amines include, for example, dimethylethanolamine, triethylamine, trimethylamine, triisopropylamine, methyldiethanolamine and the like.

The reaction product between the film-forming organic resin (A) and the active hydrogen-containing compound (B) comprising a hydrazine derivative (C) in which some or all of the compounds have active hydrogen is converted to the film-forming organic resin (A) And the active hydrogen-containing compound (B) at 10 to 300 ° C, preferably 50 to 150 ° C, for about 1 to 8
It is obtained by reacting for about an hour.

This reaction may be carried out by adding an organic solvent, and the type of the organic solvent used is not particularly limited. For example, ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, dibutyl ketone and cyclohexanone; ethanol, butanol, 2-ethylhexyl alcohol, benzyl alcohol, ethylene glycol, ethylene glycol monoisopropyl ether, ethylene glycol monobutyl ether, ethylene glycol monohexyl ether Alcohols and ethers having a hydroxyl group such as propylene glycol, propylene glycol monomethyl ether, diethylene glycol, diethylene glycol monoethyl ether, and diethylene glycol monobutyl ether; esters such as ethyl acetate, butyl acetate, and ethylene glycol monobutyl ether acetate; toluene, xylene Such as aromatic hydrocarbons. It can be used one or two or more thereof. Among these, ketone-based or ether-based solvents are particularly preferable from the viewpoints of solubility with an epoxy resin, coatability, and the like.

The compounding ratio of the film-forming organic resin (A) and the active hydrogen-containing compound (B) composed of the hydrazine derivative (C) in which some or all of the compounds have active hydrogen is determined by the ratio of the solid content to the film-forming organic resin. With respect to 100 parts by weight of resin (A), 0.5 to 20 parts by weight of active hydrogen-containing compound (B),
Particularly preferably, the content is 1.0 to 10 parts by weight.

When the film-forming organic resin (A) is an epoxy group-containing resin (D), the mixing ratio of the epoxy group-containing resin (D) and the active hydrogen-containing compound (B) is The ratio of the number of active hydrogen groups in the compound (B) to the number of epoxy groups in the epoxy group-containing resin (D) [the number of active hydrogen groups / the number of epoxy groups] is 0.01 to 10, more preferably 0.1 to 8, It is more preferably 0.2 to 4 from the viewpoint of corrosion resistance and the like.

The ratio of the hydrazine derivative (C) having active hydrogen in the active hydrogen-containing compound (B) is 1%.
Suitably, it is 0 to 100 mol%, more preferably 30 to 100 mol%, further preferably 40 to 100 mol%. If the ratio of the hydrazine derivative (C) having active hydrogen is less than 10 mol%, a sufficient rust-preventing function cannot be imparted to the organic film, and the obtained rust-preventive effect is obtained by simply mixing the hydrazine derivative with the film-forming organic resin. There is no big difference from the case of using.

In the present invention, in order to form a dense barrier film, it is desirable that a curing agent is added to the resin composition and the organic film is cured by heating. As the curing method for forming the resin composition film, (1) a curing method utilizing a urethanization reaction between an isocyanate and a hydroxyl group in the base resin, and (2) one selected from melamine, urea and benzoguanamine. At least one or more methylol compounds obtained by reacting formaldehyde with at least one of
A curing method using an etherification reaction between an alkyl etherified amino resin obtained by reacting a monohydric alcohol with a hydroxyl group in the base resin is suitable. It is particularly preferred that the urethanation reaction be the main reaction.

The polyisocyanate compound used in the curing method (1) is an aliphatic, alicyclic (including heterocyclic) or aromatic isocyanate compound having at least two isocyanate groups in one molecule, or a compound thereof. A compound obtained by partially reacting a compound with a polyhydric alcohol. Examples of such a polyisocyanate compound include the following. m- or p-phenylenediisocyanate, 2,
4- or 2,6-tolylene diisocyanate, o- or p-xylylene diisocyanate, hexamethylene diisocyanate, dimer diisocyanate, isophorone diisocyanate

The above compound alone or a mixture thereof and a polyhydric alcohol (a dihydric alcohol such as ethylene glycol and propylene glycol; a trihydric alcohol such as glycerin and trimethylolpropane; a tetrahydric alcohol such as pentaerythritol; Compounds having at least two isocyanates remaining in one molecule. These polyisocyanate compounds may be used alone or in combination of two or more. Can be used.

Examples of the protective agent (blocking agent) for the polyisocyanate compound include aliphatic monoalcohols such as methanol, ethanol, propanol, butanol and octyl alcohol. Monoethers of ethylene glycol and / or diethylene glycol, for example. Methyl, ethyl, propyl (n-, iso), butyl (n-, iso, se)
c) monoether phenols, aromatic alcohols such as cresol, acetoximes, oximes such as methyl ethyl ketone oxime, and the like. One or more of these can be reacted with the polyisocyanate compound at least at room temperature. Thus, a protected polyisocyanate compound can be obtained.

Such a polyisocyanate compound (E) is used as a curing agent with respect to the film-forming organic resin (A) with respect to (A) / (E) = 95/5 to 55/45 (weight ratio of nonvolatile components); Preferably (A) / (E) = 90/10
It is appropriate to mix them in a ratio of 65/35. The polyisocyanate compound has water absorption, which is referred to as (A) /
(E) If it exceeds 55/45, the adhesion of the organic film is deteriorated. Furthermore, when an overcoat is applied on the organic film, the unreacted polyisocyanate compound moves into the coating film, and causes curing inhibition and poor adhesion of the coating film. From such a viewpoint, the blending amount of the polyisocyanate compound (E) is preferably (A) / (E) = 55/45 or less.

The film-forming organic resin (A) is sufficiently crosslinked by the addition of the crosslinking agent (curing agent) as described above.
In order to further increase the low-temperature crosslinking property, it is desirable to use a known curing acceleration catalyst. As the curing promoting catalyst, for example, N-ethylmorpholine, dibutyltin dilaurate, cobalt naphthenate, stannous chloride, zinc naphthenate, bismuth nitrate and the like can be used. For example, when an epoxy group-containing resin is used as the film-forming organic resin (A), a known acrylic, alkyd,
A resin such as polyester can be used as a mixture.

In the present invention, zinc phosphate and / or aluminum phosphate (a) may be added to the organic film as a rust preventive additive.
Is blended. Zinc phosphate and aluminum phosphate blended in the organic film are not particularly limited in terms of phosphate ion skeleton and degree of condensation, and may be any of normal salt, dihydrogen salt, monohydrogen salt or phosphite. Often, normal salts include all condensed phosphates, such as polyphosphates, in addition to orthophosphates. For example, LF Bowsei ZP-DL manufactured by Kikuchi Color Co., Ltd. can be used as zinc phosphate, and K-WHITE manufactured by Teika Co., Ltd. can be used as aluminum phosphate.

These zinc phosphate and aluminum phosphate are dissociated into phosphate ions by hydrolysis in a corrosive environment, and form a protective film by causing a complexing reaction with the eluted metal. In the present invention, the anticorrosion mechanism when zinc phosphate and / or aluminum phosphate (a) is added to the organic film is as described above. In particular, in the present invention, a specific chelate forming resin which is a film forming organic resin is used. Resin and zinc phosphate and / or aluminum phosphate (a)
Is combined with the above, the effect of suppressing the corrosion in the anode reaction section by the chelate-forming resin, zinc phosphate and / or
Alternatively, an extremely excellent anticorrosion effect is exhibited by combining with the corrosion inhibition effect of aluminum phosphate (a).

The amount of zinc phosphate and / or aluminum phosphate (a) in the organic resin film is determined by the amount of the reaction product (the film forming organic resin (A), 1 to 100 parts by weight (solid content), preferably 100 parts by weight (solid content), based on 100 parts by weight (solid content) of a reaction product with the active hydrogen-containing compound (B) composed of a hydrazine derivative (C) having an active hydrogen. Is 5 to 80
Parts by weight (solid content), more preferably 10 to 50 parts by weight (solid content). If the amount of zinc phosphate and / or aluminum phosphate (a) is less than 1 part by weight, the effect of improving corrosion resistance after alkali degreasing is small. On the other hand, if the amount exceeds 100 parts by weight, the corrosion resistance is undesirably reduced.

In the present invention, particularly excellent corrosion resistance can be obtained by adding a calcium compound (b) together with zinc phosphate and / or aluminum phosphate (a) to the organic film. That is, zinc phosphate and / or
Alternatively, by adding aluminum phosphate (a) and calcium compound (b) in combination, a particularly excellent anticorrosion effect can be obtained by the composite rust prevention mechanism of both as described above.

The calcium compound (b) may be any of calcium oxide, calcium hydroxide and calcium salt, and one or more of these can be used. In addition, the type of calcium salt is not particularly limited, and other than a single salt containing only calcium as a cation such as calcium silicate, calcium carbonate, calcium phosphate,
Double salts containing cations other than calcium and calcium, such as calcium / zinc phosphate and calcium / magnesium phosphate, may be used.

The calcium compound elutes preferentially over the plating metal in a corrosive environment, and causes a complexing reaction with phosphate ions without triggering the elution of the plating metal to form a dense and hardly soluble protective film. It is thought to form and suppress the corrosion reaction.

When zinc phosphate and / or aluminum phosphate (a) and calcium compound (b) are added in combination to the organic film, the amount of the compound is determined by the reaction product (film formation) which is a resin composition for film formation. With respect to 100 parts by weight (solid content) of an organic resin (A) and a reaction product of an active hydrogen-containing compound (B) composed of a hydrazine derivative (C) in which some or all of the compounds have active hydrogen, phosphoric acid 1 to 100 parts by weight (solid content), preferably 5 to 80 parts by weight (solid content) in total of zinc and / or aluminum phosphate (a) and calcium compound (b), and phosphorus The weight ratio (a) / (b) of the compounding amount (solid content) of zinc acid and / or aluminum phosphate (a) and calcium compound (b) is 99/1 to 1/99, preferably 95/5 to 40. / 60, The preferably 90/10
６０60/40.

If the total amount of zinc phosphate and / or aluminum phosphate (a) and calcium compound (b) is less than 1 part by weight, the effect of improving corrosion resistance after alkali degreasing is small. On the other hand, if the total amount exceeds 100 parts by weight, the corrosion resistance is undesirably reduced. Further, the weight ratio (a) / weight of the compounding amount (solid content) of zinc phosphate and / or aluminum phosphate (a) and calcium compound (b)
If (b) is less than 1/99, the corrosion resistance is poor, while if the weight ratio (a) / (b) exceeds 99/1, zinc phosphate and / or aluminum phosphate (a) and the calcium compound (b) The effect of the composite addition cannot be sufficiently obtained.

In the organic film, in addition to the above-mentioned rust preventive additives, fine particles of oxides (for example, silicon oxide, aluminum oxide, zirconium oxide, titanium oxide, cerium oxide, antimony oxide, etc.) may be used as corrosion inhibitors. , Molybdate, phosphomolybdate (eg, aluminum phosphomolybdate), organic phosphoric acid and its salts (eg, phytic acid, phytate, phosphonic acid, phosphonate, and metal salts thereof, alkali metals) Salts, alkaline earth metal salts, etc.), organic inhibitors (eg, hydrazine derivatives, thiol compounds, dithiocarbamates, etc.)
Etc. can be added.

A solid lubricant (c) can be added to the organic film, if necessary, for the purpose of improving the processability of the film. Examples of the solid lubricant applicable to the present invention include the following. (1) Polyolefin wax, paraffin wax:
For example, polyethylene wax, synthetic paraffin, natural paraffin, microwax, chlorinated hydrocarbon, etc. (2) Fluororesin fine particles: For example, polyfluoroethylene resin (polytetrafluoroethylene resin, etc.), polyvinyl fluoride resin, polyvinylidene fluoride Resin, etc.

In addition, fatty acid amide compounds (eg, stearic acid amide, palmitic acid amide,
Methylenebisstearamide, ethylenebisstearamide, oleic amide, esylamide, alkylenebisfatty acid amide, etc., metal soaps (eg, calcium stearate, lead stearate, calcium laurate, calcium palmitate, etc.), metals Sulfide (molybdenum disulfide, tungsten disulfide), graphite,
Graphite fluoride, boron nitride, polyalkylene glycol,
You may use alkali metal sulfate etc.

Among the above solid lubricants, polyethylene wax, fluorine resin fine particles (among others, poly 4
Fluorinated ethylene resin fine particles) are preferred. Examples of the polyethylene wax include Seridust 9615A, Seridust 3715, Seridust 3 manufactured by Hoechst Inc.
620, Seridust 3910, Sunwax 131-P and Sunwax 161-P manufactured by Sanyo Chemical Co., Ltd., Chemipearl W-100, Chemipearl W-200, Chemipearl W-500, Chemipearl W-500, Chemipearl manufactured by Mitsui Petrochemical Co., Ltd.
W-800, Chemipearl W-950 and the like can be used.

As the fluororesin fine particles, tetrafluoroethylene fine particles are most preferable. For example, Lubron L-2 and Lubron L-L manufactured by Daikin Industries, Ltd.
5. MP1100, MP12 manufactured by Mitsui DuPont
00, Fluon Dispersion AD1, Fluon Dispersion AD2, Fluon L141J, Fluon L15 manufactured by Asahi ICI Fluoropolymers Co., Ltd.
0J, Fullon L155J and the like are preferable. Among these, a particularly excellent lubricating effect can be expected by using a combination of polyolefin wax and fine particles of tetrafluoroethylene.

The amount of the solid lubricant (c) in the organic film is determined by the amount of the reaction product (the film-forming organic resin (A) and some or all of the compound is active hydrogen). 100 parts by weight (solid content) of a reaction product with an active hydrogen-containing compound (B) comprising a hydrazine derivative (C)
1 to 80 parts by weight (solid content), preferably 3 to
40 parts by weight (solid content). If the amount of the solid lubricant (c) is less than 1 part by weight, the lubricating effect is poor. On the other hand, if the amount is more than 80 parts by weight, the coatability is undesirably reduced.

The organic film of the organic coated steel sheet of the present invention is usually an active hydrogen-containing compound (B) comprising a film-forming organic resin (A) and a hydrazine derivative (C) in which some or all of the compounds have active hydrogen. The reaction product (resin composition) with zinc oxide and / or aluminum phosphate (a) is blended as a main component, and if necessary,
A calcium compound (b), a solid lubricant (c), a curing agent, and the like are added. If necessary, an organic coloring pigment (for example, a condensed polycyclic organic pigment, a phthalocyanine organic pigment, etc.) may be added as an additive. ), Coloring dyes (eg, organic solvent-soluble azo dyes, water-soluble azo metal dyes, etc.), inorganic pigments (eg, titanium oxide), chelating agents (eg, thiol, etc.), and conductive pigments (eg, zinc, aluminum) , Metal powders such as nickel, iron phosphide, antimony-doped tin oxide, etc.), coupling agents (eg, silane coupling agents, titanium coupling agents, etc.), melamine
Cyanuric acid adducts and the like can be added.

The coating composition for forming a film containing the above-mentioned main components and additional components usually contains a solvent (organic solvent and / or water), and if necessary, a neutralizing agent or the like is added. . The organic solvent is not particularly limited as long as it can dissolve or disperse a reaction product of the film-forming organic resin (A) and the active hydrogen-containing compound (B), and can be adjusted as a coating composition. Various organic solvents exemplified above can be used. The neutralizing agent is added as necessary to neutralize the film-forming organic resin (A) to make it aqueous, and when the film-forming organic resin (A) is a cationic resin, Acids such as acetic acid, lactic acid and formic acid can be used as neutralizing agents.

The above-mentioned organic film is formed on the chemical conversion film formed on the surface of the zinc-based steel sheet or the aluminum-based steel sheet. The dry thickness of the organic film is 0.1 to 5 μm, preferably 0.3 to 3 μm, and more preferably 0.5 to 2 μm. When the thickness of the organic film is less than 0.1 μm, the corrosion resistance is insufficient. On the other hand, when the thickness exceeds 5 μm, the conductivity and the workability deteriorate.

Next, a method for producing the organic coated steel sheet of the present invention will be described. The organic-coated steel sheet of the present invention is obtained by subjecting the surface of a zinc-based plated steel sheet or an aluminum-based plated steel sheet to a chemical conversion treatment, and thereafter, the above-mentioned film-forming organic resin (A) and a part or all of the compounds have active hydrogen thereon. A reaction product (preferably as a main component) with an active hydrogen-containing compound (B) composed of a hydrazine derivative (C),
Manufacture by applying a coating composition containing zinc phosphate and / or aluminum phosphate (a) and optionally adding a calcium compound (b), a solid lubricant (c), etc., and drying by heating. Is done. The surface of the plated steel sheet may be subjected to an alkali degreasing treatment as required before applying the treatment liquid, and may be subjected to a pretreatment such as a surface conditioning treatment in order to improve adhesion and corrosion resistance.

In the case of forming a chemical conversion treatment film containing no hexavalent chromium as the chemical conversion treatment film, the treatment solution may be coated on the surface of the plated steel sheet by any of a coating method, an immersion method, and a spray method. Any coating means such as a roll coater (three-roll type, two-roll type, etc.), a squeeze coater, a die coater, etc. may be used. In addition, after the coating, dipping, and spraying with a squeeze coater or the like, it is also possible to adjust the coating amount, make the appearance uniform, and make the film thickness uniform by an air knife method or a roll drawing method.

After coating the treatment liquid as described above, washing with water if necessary, and then drying by heating. The method of heating and drying the coated treatment liquid is arbitrary, and for example, a means such as a dryer, a hot air oven, a high-frequency induction heating oven, and an infrared oven can be used. The heating and drying treatment is performed at a temperature of 40 to 350 ° C., preferably 80 to 200 ° C.
C., more preferably 80 to 160.degree. If the heating and drying temperature is lower than 40 ° C., a large amount of water remains in the film, and the corrosion resistance becomes insufficient. On the other hand, when the heating and drying temperature exceeds 350 ° C., not only is it uneconomical, but also the coating tends to have defects and the corrosion resistance is reduced.

On the other hand, when the chemical conversion film is a chromate film, any one of the above-mentioned coating type, electrolytic type, and reaction type chromate treatments is performed, and if necessary, washed with water.
Heat and dry. The treatment liquid may be coated on the surface of the plated steel sheet by any of an application method, an immersion method, and a spray method.
Any application means such as a roll method, a two-roll method, a squeeze coater, and a die coater may be used. In addition, after the coating, dipping, and spraying with a squeeze coater or the like, it is also possible to adjust the coating amount, make the appearance uniform, and make the film thickness uniform by an air knife method or a roll drawing method.

The method of heating and drying after the chromate treatment is arbitrary, and for example, means such as a dryer, a hot air oven, a high frequency induction heating oven, and an infrared oven can be used. This heat drying treatment is performed at a temperature of 40 to 150 ° C.,
It is preferable to carry out in the range of 0 to 140 ° C. If the heating and drying temperature is lower than 40 ° C., a large amount of water remains in the film, and the corrosion resistance becomes insufficient. On the other hand, when the heating and drying temperature exceeds 150 ° C., not only is it uneconomical, but also defects such as cracks tend to occur in the coating, and the corrosion resistance is reduced.

After a chemical conversion coating is formed on the surface of a zinc-coated steel sheet or an aluminum-coated steel sheet as described above, a coating composition for forming an organic coating is applied to the upper layer. As a method for applying the coating composition, any method such as an application method, a dipping method, and a spray method can be adopted. As a coating method, any method such as a roll coater (three-roll system, two-roll system, etc.), a squeeze coater, a die coater, and the like may be used. In addition, after the coating, dipping, or spraying with a squeeze coater or the like, it is also possible to adjust the coating amount, uniform the appearance, and uniform the film thickness by an air knife method or a roll drawing method.

After application of the coating composition, drying by heating is usually carried out without washing with water, but a washing step may be carried out after application of the coating composition. For the heating and drying treatment, a dryer, a hot blast furnace, a high-frequency induction heating furnace, an infrared furnace, or the like can be used. Heat treatment is 50-350 ° C at ultimate plate temperature,
It is desirable to carry out the reaction in the range of preferably 80 ° C to 250 ° C. If the heating temperature is lower than 50 ° C., a large amount of water in the film remains, and the corrosion resistance becomes insufficient. The heating temperature is 350 ° C
When it exceeds, it is not only uneconomical, but also there is a possibility that a defect occurs in the film and the corrosion resistance is reduced.

The present invention includes a steel sheet having the above-mentioned organic film on both sides or one side. Therefore, examples of the form of the steel sheet of the present invention include the following. (1) One side: Plating film-Chemical conversion film-Organic film, One surface: Plating film (2) One surface: Plating film-Chemical conversion film-Organic film, One surface: Plating film-Chemical conversion film (3) Both surfaces: Plating film- Chemical conversion coating-organic coating (4) One side: plating coating-chemical conversion coating-organic coating, one side: plating coating-organic coating

[0104]

[Example] Resin composition (reaction product) for forming an organic film
Was synthesized as follows. [Synthesis Example 1] 1870 parts of EP828 (manufactured by Yuka Shell Epoxy, epoxy equivalent: 187) and bisphenol A91
Two parts, 2 parts of tetraethylammonium bromide and 300 parts of methyl isobutyl ketone were charged into a four-necked flask, heated to 140 ° C., and reacted for 4 hours to obtain an epoxy resin having an epoxy equivalent of 1,391 and a solid content of 90%. Add ethylene glycol monobutyl ether 150
After adding 0 parts, the mixture was cooled to 100 ° C., 96 parts of 3,5-dimethylpyrazole (molecular weight: 96) and 129 parts of dibutylamine (molecular weight: 129) were added, and the mixture was reacted for 6 hours until the epoxy group disappeared. While cooling, 205 parts of methyl isobutyl ketone was added to obtain a pyrazole-modified epoxy resin having a solid content of 60%. This is a resin composition (1)
And This resin composition (1) is a reaction product of a film-forming organic resin (A) and an active hydrogen-containing compound containing 50 mol% of a hydrazine derivative (C) having active hydrogen.

[Synthesis Example 2] 4000 parts of EP1007 (manufactured by Yuka Shell Epoxy Co., Ltd., epoxy equivalent: 2000) and 2239 parts of ethylene glycol monobutyl ether were charged into a four-necked flask, and the temperature was raised to 120 ° C and completely completed in 1 hour. The epoxy resin was dissolved. This was cooled to 100 ° C., and 3-amino-1,2,4-triazole (molecular weight: 8
After adding 168 parts of 4) and reacting for 6 hours until the epoxy group disappeared, 540 parts of methyl isobutyl ketone was added with cooling to obtain a modified triazole epoxy resin having a solid content of 60%. This is designated as a resin composition (2). This resin composition (2) comprises a film-forming organic resin (A) and 100 mol of a hydrazine derivative (C) having active hydrogen.
% Of the active hydrogen-containing compound.

[Synthesis Example 3] A four-necked flask was charged with 222 parts of isophorone diisocyanate (isocyanate equivalent weight: 111) and 34 parts of methyl isobutyl ketone.
Keeping at 0 ° C, methyl ethyl ketoxime (molecular weight 87) 8
After dropping 7 parts over 3 hours, the mixture was kept at 40 ° C. for 2 hours to obtain a partially blocked isocyanate having an isocyanate equivalent of 309 and a solid content of 90%.

Subsequently, 1496 parts of EP828 (manufactured by Yuka Shell Epoxy, epoxy equivalent: 187), 684 parts of bisphenol A, tetraethylammonium bromide 1
Parts, 241 parts of methyl isobutyl ketone were charged into a four-necked flask, heated to 140 ° C. and reacted for 4 hours to obtain an epoxy resin having an epoxy equivalent of 1090 and a solid content of 90%. To this, 1000 parts of methyl isobutyl ketone was added, and the mixture was cooled to 100 ° C. to give 3-mercapto-1,
After adding 202 parts of 2,4-triazole (molecular weight 101) and reacting for 6 hours until the epoxy group disappears, 230 parts of the above partially blocked isocyanate having a solid content of 230% was added.
The mixture was reacted at 100 ° C. for 3 hours, and it was confirmed that the isocyanate group had disappeared. Further, 461 parts of ethylene glycol monobutyl ether was added to obtain a modified triazole epoxy resin having a solid content of 60%. This is referred to as a resin composition (3). This resin composition (3) is a reaction product of a film-forming organic resin (A) and an active hydrogen-containing compound containing 100 mol% of a hydrazine derivative (C) having active hydrogen.

[Synthesis Example 4] A four-necked flask was charged with 1,870 parts of EP828 (manufactured by Yuka Shell Epoxy, epoxy equivalent: 187), 912 parts of bisphenol A, 2 parts of tetraethylammonium bromide, and 300 parts of methyl isobutyl ketone, and heated to 140 ° C. Raise the temperature and let it react for 4 hours.
An epoxy resin having an epoxy equivalent of 1391 and a solid content of 90% was obtained. After adding 1500 parts of ethylene glycol monobutyl ether, the mixture was cooled to 100 ° C., 258 parts of dibutylamine (molecular weight: 129) was added, and the mixture was reacted for 6 hours until the epoxy group disappeared. Add 225 parts of ketone, 60% solids
Was obtained. This is referred to as a resin composition (4). This resin composition (4) is a reaction product of a film-forming organic resin (A) and an active hydrogen-containing compound that does not contain a hydrazine derivative (C) having active hydrogen.

The resin compositions (1) to (4) synthesized as described above were mixed with a curing agent to prepare resin compositions (paint compositions) shown in Table 3. These paint compositions are appropriately mixed with zinc phosphate and / or aluminum phosphate shown in Table 4, a calcium compound shown in Table 5, and a solid lubricant shown in Table 6, and a paint dispersing machine (sand grinder).
To obtain a desired coating composition.

Example 1 To obtain an organic-coated steel sheet for home appliances, building materials, and automobile parts, various types of zinc-based plating or aluminum-based cold-rolled steel sheets having a thickness of 0.8 mm and a surface roughness Ra of 1.0 μm were obtained. Using the plated steel sheet shown in Table 1 as a treated base sheet, the surface of this plated steel sheet was subjected to alkali degreasing treatment, washing and drying, and then subjected to a chemical conversion treatment with a treatment solution and treatment conditions shown in Table 2 to form a chemical conversion treatment film. Formed. Next, the coating compositions shown in Table 3 were applied by a roll coater and dried by heating to form a second layer coating (organic coating), thereby producing organic-coated steel sheets of the present invention and comparative examples.
The thickness of the second layer film is determined by the solid content of the coating composition (residual residue after heating).
Alternatively, it was adjusted according to the coating conditions (roll rolling force, rotation speed, etc.).

The obtained organic coated steel sheets were evaluated for quality performance (coating appearance, white rust resistance, white rust resistance after alkali degreasing, paint adhesion, workability). The results are shown in Tables 7 to 2 together with the composition of the chemical conversion coating and the organic coating.
It is shown in FIG. The evaluation of the quality performance of the organic coated steel sheet was performed as follows.

(1) Coating Appearance For each sample, the uniformity of the coating appearance (with or without unevenness) was visually evaluated. The evaluation criteria are as follows. ：: uniform appearance without any unevenness △: appearance with some unevenness ×: appearance with unevenness

(2) White rust resistance For each sample, salt spray test (JIS-Z-23)
71) was carried out, and evaluated by the area ratio of white rust occurrence after a predetermined time. The evaluation criteria are as follows. ◎: No white rust generated ○ +: White rust generation area ratio less than 5% ○: White rust generation area ratio 5% or more and less than 10% ○-: White rust generation area ratio 10% or more and less than 25% △: White rust Generated area rate 25% or more, less than 50% ×: White rust generated area rate 50% or more

(3) White rust resistance after alkali degreasing For each sample, an alkali treatment liquid CLN-364S manufactured by Nippon Parkerizing Co., Ltd. (60 ° C., spray 2
Min), and then a salt spray test (JIS)
-Z-2371), and evaluated by a white rust area ratio after a predetermined time. ◎: No white rust generated ○ +: White rust generation area ratio less than 5% ○: White rust generation area ratio 5% or more and less than 10% ○-: White rust generation area ratio 10% or more and less than 25% △: White rust Generated area rate 25% or more, less than 50% ×: White rust generated area rate 50% or more

(4) Coating Adhesion For each sample, a melamine-based baking coating (film thickness 30
μm), immersed in boiling water for 2 hours, immediately cut in a grid (10 × 10 grids at 1 mm intervals), adhered and peeled with an adhesive tape, and peeled area of the coating film Rate was evaluated. The evaluation criteria are as follows. ：: No peeling ○: Peeling area rate less than 5% △: Peeling area rate 5% or more, less than 20% ×: Peeling area rate 20% or more

(5) Workability Deep drawing was performed with a blank diameter of φ120 mm and a die diameter of φ50 mm (oil-free condition), and evaluated by the molding height until cracks occurred. The evaluation criteria are as follows. ◎: Draw-out ○: Molding height 30 mm or more △: Molding height 20 mm or more, less than 30 mm ×: Molding height less than 20 mm

[0117]

[Table 1]

[0118]

[Table 2]

[0119]

[Table 3]

[0120]

[Table 4]

[0121]

[Table 5]

[0122]

[Table 6]

[0123]

[Table 7]

[0124]

[Table 8]

[0125]

[Table 9]

[0126]

[Table 10]

[0127]

[Table 11]

[0128]

[Table 12]

[0129]

[Table 13]

[0130]

[Table 14]

[0131]

[Table 15]

[0132]

[Table 16]

[0133]

[Table 17]

[0134]

[Table 18]

[0135]

[Table 19]

[0136]

[Table 20]

[0137]

[Table 21]

[0138]

[Table 22]

Example 2 Various zinc-based plating or aluminum-based cold-rolled steel sheets having a thickness of 0.8 mm and a surface roughness Ra of 1.0 μm were obtained in order to obtain organic-coated steel sheets for home appliances, building materials, and automobile parts. Using the plated steel sheet shown in Table 1 as a processing base sheet, the surface of this plated steel sheet is subjected to alkali degreasing treatment, washing and drying, and then any of the following coating chromate treatment, electrolytic chromate treatment, and reaction chromate treatment. To form a chromate film. Next, the coating composition shown in Table 3 was applied by a roll coater and dried by heating to form a second layer coating (organic coating).
Was formed to produce organic-coated steel sheets of the present invention and comparative examples. The thickness of the second layer film was adjusted according to the solid content of the coating composition (residual residue after heating) or the application conditions (roll rolling force, rotation speed, etc.).

Reaction type chromate treatment Chromic anhydride: 30 g / l, phosphoric acid: 10 g / l, Na
Using a treatment liquid containing 0.5 g / l of F and 4 g / l of K ₂ TiF _{6, the} mixture was sprayed at a bath temperature of 40 ° C., and then washed with water and dried. The amount of chromium deposited was adjusted by changing the treatment time and the free acidity.

Electrolytic Chromate Treatment Cathodic electrolysis treatment was carried out using a treatment solution of chromic anhydride: 30 g / l, sulfuric acid: 0.2 g / l, and bath temperature of 40 ° C., followed by washing and drying. The amount of chromium deposited was adjusted by controlling the amount of electricity in the electrolytic treatment.

Coating-type chromate treatment (a) Chromic anhydride aqueous solution: 100 g / l of a reducing agent (starch) was added to adjust to a temperature of 80 ° C. and left for 2 hours to partially reduce chromic anhydride. An aqueous solution of hexavalent Cr / 3 trivalent Cr: 3/2 was prepared. Next, a silica sol was added to this aqueous solution so that silica / total Cr: 6/1, and further, a zinc phosphate aqueous solution obtained by dissolving zinc oxide and phosphoric acid was added to PO ₄ ion / total Cr: A chromate treatment solution was prepared by adding １ ／, divalent Zn / 6 hexavalent Cr: 3/20. This chromate treatment solution was diluted to a predetermined concentration, applied to the surface of various plated steel sheets by a roll coater, and dried by heating at a sheet temperature of 70 to 250 ° C. without washing with water. The amount of chromium adhered was adjusted by changing the concentration of the processing solution and the coating conditions.

Coating type chromate treatment (b) A reducing agent (oxalic acid saturated aqueous solution: 1 L) and phosphoric acid: 100 ml were gradually added to chromic anhydride aqueous solution: 20 g / l (1 L), and the mixture was allowed to stand at room temperature for 24 hours. Chromic acid was reduced to prepare a chromate treatment solution having hexavalent Cr / total Cr <0.1, pH = 1. This chromate treatment solution was diluted to a predetermined concentration, applied to the surface of various plated steel sheets by a roll coater, and dried by heating at a sheet temperature of 70 to 250 ° C. without washing with water. The amount of chromium adhered was adjusted by changing the concentration of the processing solution and the coating conditions.

The obtained organic coated steel sheets were evaluated for quality performance (chromium elution resistance, white rust resistance, white rust resistance after alkali degreasing, paint adhesion, workability). The results are shown in Tables 23 to 50 together with the composition of the chromate-treated film and the organic film. The evaluation of the quality performance of the organic coated steel sheet was performed as follows.

(1) Chromium elution resistance (chromium fixation rate) Each sample was subjected to a degreasing treatment under standard conditions using a degreasing agent Parclean N364S manufactured by Nippon Parkerizing Co., Ltd., and the fixation rate of chromium before and after degreasing was measured. did.
Chromium fixation rate = {(chromium adhesion before degreasing-chromium adhesion after degreasing) / chromium adhesion before degreasing} × 100
(%). The evaluation criteria are as follows. ：: Chromium fixing rate 100% ○: Chromium fixing rate 90% or more and less than 100% △: Chromium fixing rate 80% or more and less than 90% ×: Chromium fixing rate less than 80%

(2) White rust resistance Same as Example 1 (3) White rust resistance after alkali degreasing Same as Example 1 (4) Paint adhesion Same as Example 1 (5) Workability Example 1 the same as

[0147]

[Table 23]

[0148]

[Table 24]

[0149]

[Table 25]

[0150]

[Table 26]

[0151]

[Table 27]

[0152]

[Table 28]

[0153]

[Table 29]

[0154]

[Table 30]

[0155]

[Table 31]

[0156]

[Table 32]

[0157]

[Table 33]

[0158]

[Table 34]

[0159]

[Table 35]

[0160]

[Table 36]

[0161]

[Table 37]

[0162]

[Table 38]

[0163]

[Table 39]

[0164]

[Table 40]

[0165]

[Table 41]

[0166]

[Table 42]

[0167]

[Table 43]

[0168]

[Table 44]

[0169]

[Table 45]

[0170]

[Table 46]

[0171]

[Table 47]

[0172]

[Table 48]

[0173]

[Table 49]

[0174]

[Table 50]

As a conventional reaction type chromate treated steel sheet,
Chromic anhydride: 30 g / l, phosphoric acid: 10 g / l, Na
F: 0.5 g / l, K ₂ TiF ₆ : Spray treatment at a bath temperature of 40 ° C. using a treatment solution containing 4 g / l, followed by washing and drying to obtain the chromium deposition amount (in terms of chromium metal). Manufactured a chromate-treated steel sheet of 20 mg / m ² . When this was subjected to a salt spray test under the same conditions as in this example, white rust was generated in about 24 hours. Therefore,
From these results and the results of this example, it can be seen that the organic-coated steel sheet of the present invention can provide much better corrosion resistance than the conventional chromate-treated steel sheet.

[0176]

As described above, the organic coated steel sheet of the present invention can be used even if a chemical conversion coating containing no hexavalent chromium (for example, a phosphate coating) is used as the base chemical conversion coating. Excellent corrosion resistance comparable to the coating is obtained, and when the chromate coating is used as the chemical conversion coating, the corrosion resistance is significantly improved compared to the conventional chromate-treated steel sheet, and the excellent chromium elution resistance is also obtained. Property is obtained. Therefore, the organically coated steel sheet of the present invention has high utility as an environment-adaptive surface-treated steel sheet for applications such as building materials, home appliances, and automobiles.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C23C 22/50 C23C 22/50 28/00 28/00 C (72) Inventor Naoto Yoshimi Marunouchi, Chiyoda-ku, Tokyo 1-2-1, Nihon Kokan Co., Ltd. (72) Inventor Satoshi Ando 1-2-1, Marunouchi, Chiyoda-ku, Tokyo Nihon Kokan Co., Ltd. (72) Inventor Masaaki Yamashita 1, Marunouchi, Chiyoda-ku, Tokyo No. 1-2 F-term in Nihon Kokan Co., Ltd. (Reference) 4D075 CA33 DA03 DB05 DB07 DC10 EB32 EB33 EB56 EC08 EC54 4K026 AA02 AA07 AA09 BA02 BA03 BA06 BA08 BB08 CA19 CA20 CA28 CA29 CA37 DA02 EB02 EB05 4K027 AA05 AB42 AB 4K044 AA02 BA10 BA15 BA17 BA21 BB03 BB04 BC02 CA11 CA16 CA18 CA27 CA64

Claims (8)

[Claims] Claims: 1. A zinc-coated steel sheet or an aluminum-coated steel sheet has a chemical conversion coating on the surface thereof.
A reaction product of a film-forming organic resin (A) and an active hydrogen-containing compound (B) comprising a hydrazine derivative (C) in which some or all of the compounds have active hydrogen, and zinc phosphate and / or aluminum phosphate ( a) and the content of the zinc phosphate and / or aluminum phosphate (a) is 1 to 100 parts by weight (solid content) of the reaction product.
0.1 to 5 parts by weight (solid content)
An organic coated steel sheet having excellent corrosion resistance, characterized by having an organic coating of m. 2. A zinc-coated steel sheet or an aluminum-coated steel sheet having a chemical conversion coating on the surface thereof,
A reaction product of a film-forming organic resin (A) and an active hydrogen-containing compound (B) comprising a hydrazine derivative (C) in which some or all of the compounds have active hydrogen, and zinc phosphate and / or aluminum phosphate ( a) and a calcium compound (b), wherein the zinc phosphate and / or aluminum phosphate (a) and the calcium compound (b)
Is 1 to 100 parts by weight (solid content) based on 100 parts by weight (solid content) of the reaction product, and zinc and / or aluminum phosphate (a) and a calcium compound (b) (A) / (b) having a weight ratio (a) / (b) of 1/99 to 99/1 and an organic film having a film thickness of 0.1 to 5 μm is excellent in corrosion resistance. Organic coated steel sheet. 3. A zinc-coated steel sheet or an aluminum-coated steel sheet having a chemical conversion coating on the surface thereof,
A reaction product of a film-forming organic resin (A) and an active hydrogen-containing compound (B) comprising a hydrazine derivative (C) in which some or all of the compounds have active hydrogen, and zinc phosphate and / or aluminum phosphate ( a) and a solid lubricant (c), wherein the content of the zinc phosphate and / or the aluminum phosphate (a) is 1 to 100 parts by weight based on 100 parts by weight (solid content) of the reaction product. (Solid content),
When the content of the solid lubricant (c) is 100
An organic coated steel sheet having excellent corrosion resistance, comprising an organic film having a thickness of 0.1 to 5 μm, which is 1 to 80 parts by weight (solid content) with respect to part by weight (solid content). 4. A chemical conversion coating on the surface of a galvanized steel sheet or an aluminum-plated steel sheet.
A reaction product of a film-forming organic resin (A) and an active hydrogen-containing compound (B) comprising a hydrazine derivative (C) in which some or all of the compounds have active hydrogen, and zinc phosphate and / or aluminum phosphate ( a), a calcium compound (b), and a solid lubricant (c), wherein the total content of the zinc phosphate and / or aluminum phosphate (a) and the calcium compound (b) is the reaction product 1 to 100 parts by weight (solid content) with respect to 100 parts by weight (solid content) of the product, and the content (solid content) of zinc phosphate and / or aluminum phosphate (a) and calcium compound (b) Weight ratio (a) / (b) is 1/99 to 99 /
1, the content of the solid lubricant (c) is 1 to 80 parts by weight (solid content) with respect to 100 parts by weight (solid content) of the reaction product, and the film thickness is 0.1 to 5 μm. Organic coated steel sheet with excellent corrosion resistance characterized by having an organic film. 5. The film-forming organic resin (A) is an epoxy group-containing resin (D).
Or an organic-coated steel sheet excellent in corrosion resistance according to 4. 6. The hydrazine derivative (C) having an active hydrogen is a pyrazole compound having an active hydrogen and / or
6. The organic-coated steel sheet having excellent corrosion resistance according to claim 1, which is a triazole compound having active hydrogen. 7. The active hydrogen-containing compound (B) contains 10 to 100 mol% of the hydrazine derivative (C) having an active hydrogen.
7. The organic coated steel sheet having excellent corrosion resistance according to 5 or 6. 8. The organic coated steel sheet having excellent corrosion resistance according to claim 5, wherein the epoxy group-containing resin (D) is an epoxy resin represented by the following formula (1). Embedded image