JP4844128B2 - High corrosion resistance surface-treated steel sheet and manufacturing method thereof - Google Patents

Description

  The present invention is a surface-treated steel sheet that is most suitable for applications such as automobiles, home appliances, and building materials, and in particular, an environment-adaptive surface-treated steel sheet that does not use chromium at all in the production of the surface-treated steel sheet and in the surface-treated film, and a method for producing the same. It is about.

  Conventionally, steel sheets for home appliances, steel sheets for building materials, and steel sheets for automobiles have been used for the purpose of improving corrosion resistance (white rust resistance, red rust resistance) on the surface of galvanized steel sheets or aluminum galvanized steel sheets. Steel plates subjected to chromate treatment with a treatment liquid containing chromic acid or a salt thereof as a main component are widely used. This chromate treatment is an economical treatment method that is excellent in corrosion resistance and can be performed relatively easily.

  Chromate treatment uses hexavalent chromium, a pollution-controlling substance, but this hexavalent chromium is treated in a closed system in the treatment process, completely reduced and recovered, and not released into nature. Since the elution of chromium from the chromate film can be made almost zero by the sealing action of the organic film, the environment and the human body are not substantially contaminated by hexavalent chromium. However, due to recent global environmental problems, there is a growing trend to voluntarily reduce the use of heavy metals including hexavalent chromium. In addition, in order not to pollute the environment when the shredder dust of discarded products is dumped, there has been a movement to minimize or reduce the amount of heavy metals contained in the product.

For this reason, in order to prevent the occurrence of white rust in galvanized steel sheets, many treatment techniques that do not rely on chromate treatment, so-called chromium-free techniques, have been proposed. For example, there is a method of forming a thin film by a method such as immersion, coating, or electrolytic treatment using an inorganic compound, an organic compound, an organic polymer material, or a solution combining these.
Specifically, the following methods can be cited as conventional techniques.
(1) A method of forming a film by immersing or applying a treatment liquid in a treatment liquid containing a polyhydric phenol carboxylic acid such as tannic acid and a silane coupling agent (for example, Patent Document 1, Patent Document 2, etc.)
(2) A method of forming a film using a treatment liquid in which a polyhydric phenol carboxylic acid such as tannic acid or a phosphoric acid compound is blended in an organic resin (for example, Patent Document 3 to Patent Document 6)
(3) A method of forming a film in which an organic resin and a silane coupling agent are blended (for example, Patent Document 7 to Patent Document 13)
(4) An organic composite coating comprising a phosphoric acid and / or phosphoric acid compound film (lower layer) containing an oxide, a tetravalent vanadium compound, etc., and a resin film (upper layer) containing a specific antirust additive component Technology to form (for example, Patent Document 14)

JP 7-216268 A Japanese Patent No. 2968959 JP-A-8-325760 JP 2000-34578 A JP 2000-199076 A JP 2000-248380 A JP-A-11-106945 JP 2000-319787 A JP 2000-248384 A Japanese Patent Laid-Open No. 2000-177871 JP 2000-199076 A JP 2000-281946 A Japanese Patent Laid-Open No. 2000-14443 JP 2005-154811 A

As the method of (1) above, there is a method of treating with an aqueous solution containing a polyhydric phenol carboxylic acid and a silane coupling agent, and further metal ions, and one of them is a method shown in Patent Document 1 or the like. . However, this treatment method can provide good adhesion, but cannot provide sufficient corrosion resistance.
As the above method (2), for example, Patent Document 3 discloses a method in which treatment is performed with a treatment liquid in which a polyhydric phenol carboxylic acid, an organic resin, and metal ions are blended. Further, Patent Document 4 discloses a method of dipping in a treatment liquid to which an organic resin and a phosphoric acid compound are added or applying a treatment liquid and then drying. However, although the protective film formed by these treatment liquids contributes to the improvement of the corrosion resistance to some extent, the high degree of corrosion resistance as in the case of the chromate treatment cannot be obtained.

  As the method (3), for example, Patent Document 8 and Patent Document 9 disclose a method having a film containing an organic resin and a silane coupling agent, and further a thiocarbonyl compound, a phosphate compound, and a vanadium compound. However, the corrosion resistance is not sufficient because the organic resin is polyurethane or acrylic olefin resin. Patent Document 11 discloses a film having an acid-modified epoxy resin film. Patent Document 10 discloses a resin containing a hydroxyl group, carboxyl group, glycidyl group, or phosphate group-containing monomer as a copolymer component. Although the thing which has the film | membrane which mix | blended the agent and the phosphoric acid compound is each disclosed, corrosion resistance is not enough also about these. Patent Document 7 discloses a film having a film in which an etching agent such as a polyvinylphenol derivative, a silane coupling agent, and phosphoric acid is blended. However, sufficient corrosion resistance cannot be obtained. Patent Document 12 discloses a film having an organic resin blended with an etching agent, and Patent Document 13 discloses a film having a film blended with an organic resin and a silane coupling agent. There is no description and the corrosion resistance is insufficient.

The technique (4) above contains a specific antirust additive component (self-repairing substance) in the upper layer, and replaces hexavalent Cr in the film formed at the interface with the galvanization, that is, the lower film. Since the tetravalent vanadium compound functions as a self-repairing substance, a certain degree of corrosion resistance can be obtained. However, since the barrier property of the lower layer inorganic film is insufficient, its corrosion resistance is not always sufficient.
Accordingly, an object of the present invention is to provide a surface-treated steel sheet that solves such problems of the prior art and does not contain chromium in the film and that provides excellent corrosion resistance.

  As a result of intensive studies by the present inventors in order to solve the above-described problems, a tetravalent vanadium compound, a phosphoric acid compound, and a silane were formed on the surface of a zinc-based plated steel sheet or an aluminum-based plated steel sheet as a first layer film. A film made of a surface treatment composition containing a coupling agent and at least one metal compound selected from Al, Mg, and Mn is formed, and a specific organic polymer resin is formed as a second layer film thereon. It has been found that a surface-treated steel sheet having very excellent corrosion resistance can be obtained by forming an organic film as a resin.

The present invention has been made based on such findings, and the features thereof are as follows.
[1] At least one selected from the group consisting of a vanadium compound having a valence of 4, a phosphoric acid compound, a silane coupling agent, and Al, Mg, and Mn on the surface of a zinc-based plated steel sheet or an aluminum-based plated steel sheet It is a film having a film thickness of 0.01 to 1.0 μm formed by applying a surface treatment composition containing a seed metal compound (but not containing an organic resin) and drying. The amount of vanadium compound having a valence is 0.1-200 mg / m ^{2 in} terms of V, the amount of phosphate compound is 0.1-200 mg / m ^{2 in} terms of P, and the amount of silane coupling agent is Si is ^{1.0~400mg / m 2 0.1~180mg / m 2} , Al, Mg, the amount of deposition of at least one metal compound selected from among Mn of Al, the sum of Mg and Mn converted at conversion table An active hydrogen-containing compound (C) having a surface-treated film on which the main component of the resin composition is a film-forming organic resin (A) and a hydrazine derivative (C) in which some or all of the compounds have active hydrogen A highly corrosion-resistant surface-treated steel sheet characterized by having an upper film having a film thickness of 0.5 to 2.0 μm formed by applying and drying a coating composition comprising a reaction product with B).

[2] In the highly corrosion-resistant surface-treated steel sheet according to [1] , the coating composition for the upper film further includes a non-chromium rust preventive additive in a solid content ratio with respect to 100 mass parts of the solid content of the resin composition. A highly corrosion-resistant surface-treated steel sheet characterized by containing 0.1 to 50 parts by mass.

[3] The highly corrosion-resistant surface-treated steel sheet according to [2] , wherein the non-chromium rust preventive additive is at least one selected from the following (a) to (e): Treated steel sheet.
(A) silicon oxide (b) calcium compound (c) poorly soluble phosphate compound (d) molybdate compound (e) one or more selected from triazoles, thiols, thiadiazoles, thiazoles, thiurams , Organic compounds containing S atoms
[4] In the highly corrosion-resistant surface-treated steel sheet according to any one of [1] to [3] , the surface treatment composition for the surface treatment film is at least one silane coupling agent having a glycidyl group as a reactive functional group. A highly corrosion-resistant surface-treated steel sheet, characterized by comprising:
[5] In the highly corrosion-resistant surface-treated steel sheet according to any one of [1] to [4] , the coating composition for the upper layer film further contains a solid lubricant with respect to 100 parts by mass of the solid content of the resin composition. A highly corrosion-resistant surface-treated steel sheet characterized by containing 1 to 30 parts by mass in minutes.
[6] In the highly corrosion-resistant surface-treated steel sheet according to any one of [1] to [5], the surface treatment composition for the surface treatment film contains at least vanadium sulfate as a vanadium compound having a tetravalent valence. A highly corrosion-resistant surface-treated steel sheet characterized by containing.

[7] At least one selected from the group consisting of a vanadium compound having a tetravalent valence, a phosphoric acid compound, a silane coupling agent, and Al, Mg, and Mn on the surface of a zinc-based plated steel sheet or an aluminum-based plated steel sheet A surface treatment composition containing a seed metal compound (but not containing an organic resin) has a tetravalent vanadium compound adhesion amount of 0.1 to 200 mg / m ^{2 in} terms of V, a phosphoric acid compound the adhesion amount 0.1 to 200 mg / ^{m 2} at P terms, the adhesion amount of the silane coupling agent is 0.1~180mg ^/ m 2, Al in terms of Si, Mg, at least one selected from among Mn Coating is performed so that the adhesion amount of the metal compound is 1.0 to 400 mg / m ^{2 in} total in terms of Al, Mg and Mn, and drying is performed at a final plate temperature of 30 to 200 ° C. 0 A surface-treated film having a thickness of .about.1.0 .mu.m is formed, and the main component of the resin composition is a film-forming organic resin (A) and a hydrazine derivative (C) in which some or all of the compounds have active hydrogen. By applying a coating composition composed of a reaction product with the active hydrogen-containing compound (B) and drying at a temperature of the ultimate plate temperature of 30 to 200 ° C., the film thickness is 0.5 to 2.0 μm. A method for producing a highly corrosion-resistant surface-treated steel sheet, characterized in that is formed.

  The surface-treated steel sheet of the present invention has a very excellent flat plate and post-processing corrosion resistance despite the fact that it does not contain chromium in the film, and also has excellent weldability and paintability. For this reason, the surface-treated steel sheet of the present invention is particularly useful for automobile applications.

The details of the present invention and the reasons for limitation will be described below.
Examples of the zinc-based plated steel sheet used as the base of the surface-treated steel sheet of the present invention include a galvanized steel sheet, a Zn-Ni alloy-plated steel sheet, a Zn-Fe alloy-plated steel sheet (electroplated steel sheet, galvannealed steel sheet), Zn-Cr. Alloy-plated steel sheet, Zn-Mn alloy-plated steel sheet, Zn-Co 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 plating Steel plate (for example, Zn-5% Al alloy-plated steel plate, Zn-55% Al alloy-plated steel plate), Zn-Mg alloy-plated steel plate, Zn-Al-Mg alloy-plated steel plate (for example, Zn-6% Al-3% Mg) Alloy-plated steel sheets, Zn-11% Al-3% Mg alloy-plated steel sheets), and metal oxides, polymers, etc. are dispersed in the plating film of these plated steel sheets Zinc-based composite-plated steel sheet (for example, Zn-SiO ₂ dispersion plating steel plate) was the like can be used.

In addition, among the above-described plating, a multi-layer plated steel sheet in which two or more layers of the same type or different types are plated can also be used.
Moreover, as an aluminum system plated steel plate used as the base of the surface treatment steel plate of this invention, an aluminum plating steel plate, an Al-Si alloy plating steel plate, etc. can be used.
Moreover, as a plated steel plate, the steel plate surface may be previously plated with lightness such as Ni, and various plating as described above may be performed thereon.
As a plating method, any feasible method among an electrolytic method (electrolysis in an aqueous solution or electrolysis in a non-aqueous solvent), a melting method, and a gas phase method can be adopted.
Furthermore, in order to prevent blackening of the plating, about 1 to 2000 ppm of one or more trace elements of Ni, Co, Fe are deposited in the plating film, or one of Ni, Co, Fe is deposited on the surface of the plating film. These elements may be deposited by performing a surface conditioning treatment with an alkaline aqueous solution or an acidic aqueous solution containing the above.

Next, the surface treatment film formed as the first layer film and the surface treatment composition for forming this film on the surface of the zinc-based plated steel sheet or the aluminum-based plated steel sheet will be described.
This surface treatment film is a surface treatment composition containing a vanadium compound having a valence of 4, a phosphate compound, a silane coupling agent, and at least one metal compound selected from Al, Mg, and Mn. It is formed by applying an object and drying. In addition, the surface treatment composition can contain the above-mentioned components as main components, but can further contain additives (mainly antirust additives, etc.) as main components.

Examples of the tetravalent vanadium compound to be blended in the surface treatment composition include vanadium oxide, hydroxide, sulfide, sulfate, carbonate, halide, nitride, fluoride, carbide, cyanide (thiocyanide). And salts thereof. Thus, there is no special restriction | limiting in the supply source of vanadium, Among these, 1 type can be used individually or in mixture of 2 or more types. In particular, among tetravalent vanadium compounds, it is desirable to use a sulfate capable of exhibiting the most excellent corrosion resistance.
The adhesion amount of the tetravalent vanadium compound in the surface treatment film is 0.1 to 200 mg / m ^{2 in} terms of V. When the adhesion amount is less than 0.1 mg / m ² , the effect of adding a tetravalent vanadium compound is not sufficient. Moreover, if the adhesion amount is 200 mg / m ² or less, there is no problem economically and the electrodeposition coating property is also good. From this point of view, more preferred coating weight is 0.5~150mg / m ^2, particularly preferably 1 to 100 mg / m ^2.

The phosphoric acid compound blended in the surface treatment composition is a soluble compound. Examples of the soluble phosphoric acid compound include phosphoric acid, primary phosphate, secondary phosphate, tertiary phosphate, and pyrroline. Acid, pyrophosphate, tripolyphosphate, condensed phosphate such as tripolyphosphate, phosphorous acid, phosphite, hypophosphorous acid, hypophosphite, etc. Or a mixture of two or more.
The adhesion amount of the phosphoric acid compound in the surface treatment film is 0.1 to 200 mg / m ^{2 in} terms of P. When the adhesion amount is less than 0.1 mg / m ² , the effect of blending the phosphoric acid compound is not sufficient. On the other hand, if the adhesion amount is 200 mg / m ² or less, sufficient water resistance can be maintained. From this point of view, more preferred coating weight is 0.5~150mg / m ^2, particularly preferably 1 to 100 mg / m ^2.

As a silane coupling agent to be blended in the surface treatment composition, vinyl methoxy silane, vinyl ethoxy silane, vinyl trichloro silane, vinyl trimethoxy silane, vinyl triethoxy silane, β- (3,4 epoxy cyclohexyl) ethyl trimethoxy silane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, γ-glycidoxypropyltriethoxysilane, N-β (aminoethyl) γ-aminopropylmethyldimethoxysilane, N-β ( Aminoethyl) γ-aminopropyltrimethoxysilane, N-β (aminoethyl) γ-aminopropyltrimethoxysilane, γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ-methacryloxypropylmethyldimethoxy Run, γ-methacryloxypropyltrimethoxysilane, γ-methacryloxypropylmethyldiethoxysilane, γ-methacryloxypropyltriethoxysilane, γ-mercaptopropylmethyldimethoxysilane, γ-mercaptopropyltrimethoxysilane, p-styryltri Methoxysilane, γ-acryloxypropyltrimethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, γ-ureidopropyltriethoxysilane, γ-chloropropyltrimethoxysilane, bis (triethoxysilylpropyl) tetrasulfide, γ-isocyanatopropyltriethoxysilane, γ-triethoxysilyl-N- (1,3-dimethyl-butylidene) propylamine, N- (vinylbenzylamine) -β-aminoethyl-γ-amino B pills trimethoxysilane, etc. can be mentioned, these silane coupling agents may be used alone or in admixture of two or more kinds of them. Among the silane coupling agents, a silane coupling agent having a glycidyl group as a reactive functional group is particularly preferable.
The adhesion amount of the silane coupling agent in the surface treatment film is 0.1 to 180 mg / m ^{2 in} terms of Si. When the adhesion amount is less than 0.1 mg / m ² , the effect of blending the silane coupling agent is not sufficient. On the other hand, if the adhesion amount is 180 mg / m ² or less, the silane coupling agent is not saturated and the corrosion resistance can be maintained. From such a viewpoint, the more preferable adhesion amount is 0.5 to 140 mg / m ² , and particularly preferably 1 to 90 mg / m ² .

Regarding one or more metal compounds selected from Al, Mg, Mn (Al compound, Mg compound, Mn compound) to be blended in the surface treatment composition, the form existing in the film is not particularly limited, and metal Or a compound such as an oxide, hydroxide, hydrated oxide, phosphoric acid compound, fluoride, or coordination compound, or a composite compound. There is no particular limitation on the ionicity and solubility of these compounds, hydroxides, hydrated oxides, phosphate compounds, coordination compounds, and the like. As a method for introducing a metal compound into the film, Mg, Mn, Al phosphates, sulfates, nitrates, fluorides, chlorides, etc. (one of these may be used alone or two or more may be mixed) ) What is necessary is just to make it contain in a surface treatment composition.
The adhesion amount of the metal compound in the surface treatment film is 1.0 to 400 mg / m ^{2 in} total in terms of Mg, Mn and Al. When the adhesion amount is less than 1.0 mg / m ² , the effect of blending the metal compound is not sufficient. On the other hand, if the adhesion amount is 400 mg / m ² or less, good corrosion resistance and coating appearance can be maintained. From such a viewpoint, the more preferable adhesion amount is 5 to 300 mg / m ² , and particularly preferably 10 to 200 mg / m ² .

The surface of the plated steel sheet is coated with a surface treatment composition containing a tetravalent vanadium compound, a phosphate compound, a silane coupling agent, and one or more metal compounds selected from Al, Mg, and Mn. The reason why the corrosion resistance can be improved by forming is not necessarily clear, but is presumed to be due to the following mechanism.
Among the vanadium compounds, a general pentavalent vanadium compound is reduced by its oxidation action, and a film such as an oxide or hydroxide is formed on the surface of the plating layer. The formed film is composed of 2, 3, and tetravalent compounds depending on the difference in local pH increase during film formation (difference in local pH increase due to hydrogen ion consumption during vanadium compound reduction). It is considered to be mixed. That is, the form of the reduced product stably present varies depending on the pH, and forms a bivalent, trivalent and tetravalent vanadium compound film. However, some of the formed vanadium compound films in which 2, 3, and 4 valences are mixed cannot exhibit a sufficient barrier effect to suppress corrosion, and that portion becomes a starting point of corrosion. On the other hand, unlike the pentavalent vanadium compound, the tetravalent vanadium compound used in the present invention has no oxidizing action, so that the divalent or trivalent vanadium compound is hardly formed, and most of the film is formed of the tetravalent vanadium compound. The The reason why the tetravalent compound has a sufficient barrier effect is that the tetravalent vanadyl (IV) ion: VO ₂ ⁺ and its complex ion (for example, [VO (SO ₄ ) ₂ ] ²⁻ ) This is presumably for forming a particularly dense film on the plating surface.

  In the present invention, the corrosion resistance can be drastically improved by adding a phosphate compound in combination with a tetravalent vanadium compound. The reason is considered as follows. Since the effect of improving the corrosion resistance by the treatment liquid (surface treatment composition) containing the phosphoric acid compound can be obtained regardless of the surface state of the plated steel sheet, the interface between the treatment liquid containing the phosphoric acid compound and the plating metal This is considered to be caused by an increase in the reaction, that is, the etching reaction on the plating surface. Then, an interfacial reaction layer containing vanadium and phosphorus is formed on the surface of the plating layer activated by this etching reaction to form a film that is firmly adhered to the plating metal. As a result, it is considered that excellent corrosion resistance can be exhibited because the rust preventive component is hardly eluted even in a humid environment and the barrier effect can be maintained.

Furthermore, in the present invention, by adding a silane coupling agent and a specific acid component in combination, the acid component contained in the surface treatment composition activates the plating film surface by etching, and the silane coupling agent is activated. It is considered that extremely excellent adhesion can be obtained between the plated metal and the surface treatment film by chemically bonding with the plated metal. In other words, compared with the case where a silane coupling agent is added alone, the adhesion between the plating metal and the film-forming resin ( the organic resin in the upper layer film) is significantly improved. Corrosion resistance is considered to be obtained. Furthermore, by using a silane coupling agent having a glycidyl group as a reactive functional group, a denser film is formed by an intermolecular addition reaction between a silanol group and a glycidyl group, and particularly excellent corrosion resistance is obtained. Conceivable.
Further, by adding one or more metal compounds selected from Al, Mg, and Mn, in addition to the above-described advanced barrier effect, an excellent self-repair effect is obtained. This is because when a defect occurs in the film, OH ions are generated by the cathode reaction and the interface becomes alkaline, so that the metal compound is precipitated as Me (OH) _{2 and the} defect is formed as a dense and poorly soluble product. This is to block and suppress the corrosion reaction.
The surface-treated film in the present invention is considered to exhibit very high corrosion resistance by combining the antirust effect obtained by the interaction of the four components as described above.

The film thickness of the surface-treated film in the present invention after heating and drying is 0.01 to 1.0 μm, preferably 0.1 to 0.8 μm. When the dry film thickness is 0.01 μm or more, sufficient corrosion resistance is obtained, and when it is 1.0 μm or less, the conductivity and workability can be sufficiently maintained. In such a film thickness, as described above, the adhesion amount of each constituent component is a vanadium compound having a tetravalent valence: 0.1 to 200 mg / m ^{2 in} terms of V, phosphate compound: P 0.1 to 200 mg / m ^{2 in} terms of conversion, silane coupling agent: 0.1 to 180 mg / m ^{2 in} terms of Si, at least one metal compound selected from Al, Mg and Mn: Al, Mg and Mn It is necessary to satisfy 1.0 to 400 mg / m ^{2 in} total in terms of conversion.

  Further, in the surface treatment composition, in order to further improve the corrosion resistance, oxide fine particles (for example, aluminum oxide, silicon oxide, zirconium oxide, titanium oxide, cerium oxide, antimony oxide, etc.), phosphate (for example, Zinc phosphate, aluminum dihydrogen phosphate, zinc phosphite, etc.), molybdate, phosphomolybdate (eg, aluminum phosphomolybdate), vanadate, fluoride (eg, zirconium fluoride, fluoride) Titanium, aluminum fluoride, magnesium fluoride, hexafluorozirconic acid, hexafluorotitanic acid, etc.), organic phosphoric acid and its salts (for example, phytic acid, phytate, phosphonic acid, phosphonate and their metal salts, Alkali metal salts), organic inhibitors (eg hydrazine derivatives, Lumpur compounds, such as dithiocarbamate) organic compound (e.g., polyethylene glycol) one or more compounds may be further added selected from among such.

The amount of the additive is 1 to 200 parts by weight, preferably 1 to 100 parts by weight, based on 100 parts by weight of the inorganic solid in the surface treatment composition. If the compounding amount of the additive is 1 part by mass or more, the effect of improving the corrosion resistance is sufficiently obtained. On the other hand, if it is 200 parts by mass or less, a good film appearance is maintained and the corrosion resistance is not lowered.
Further, in the surface treatment composition, as other additives, organic coloring pigments (for example, condensed polycyclic organic pigments, phthalocyanine organic pigments, etc.), coloring dyes (for example, organic solvent azo dyes, water-soluble azo dyes) Metal dyes, etc.), inorganic pigments (eg, titanium oxide, etc.), chelating agents (eg, thiols, etc.), conductive pigments (eg, metal powders such as zinc, aluminum, nickel, etc., iron phosphide, antimony-doped tin oxide, etc.) ), Melamine / cyanuric acid adducts and the like can also be added.

Next, an upper layer film (organic film) formed as a second layer film on the surface treatment film and a coating composition for forming this film will be described.
This upper layer film is a reaction product of the active ingredient-containing compound (B) in which the main component of the resin composition is a film-forming organic resin (A) and a hydrazine derivative (C) in which some or all of the compounds have active hydrogen. It is a film having a film thickness of 0.5 to 2.0 μm formed by applying a coating composition composed of a product and drying. This upper layer film also contains no chromium.

  As the kind of the film-forming organic resin (A), a part or all of the compounds react with the active hydrogen-containing compound (B) made of the hydrazine derivative (C) having active hydrogen, so that the film-forming organic resin contains active hydrogen. There is no particular limitation as long as the compound (B) can be bonded by a reaction such as addition or condensation and can form a film appropriately. Examples of the film-forming organic resin (A) include epoxy resins, modified epoxy resins, polyurethane resins, polyester resins, alkyd resins, acrylic copolymer resins, polybutadiene resins, phenol resins, and adducts of these resins or A condensate etc. can be mentioned, One of these can be used individually or in mixture of 2 or more types.

  The film-forming organic resin (A) is particularly preferably an epoxy group-containing resin (D) containing an epoxy group in the resin from the viewpoints of reactivity, easiness of reaction, anticorrosion, and the like. As the epoxy group-containing resin (D), a part or all of the compounds react with the active hydrogen-containing compound (B) composed of the hydrazine derivative (C) having active hydrogen to form an active hydrogen-containing compound in the film-forming organic resin. There is no special limitation as long as (B) is a resin that can be bonded by a reaction such as addition or condensation and can form a film appropriately. For example, an acrylic resin copolymerized with an epoxy resin, a modified epoxy resin, or an epoxy group-containing monomer. Examples thereof include copolymer resins, polybutadiene resins having an epoxy group, polyurethane resins having an epoxy group, and adducts or condensates of these resins. One of these epoxy group-containing resins may be used alone or in combination of two or more. It can be used by mixing.

  Of these epoxy group-containing resins (D), epoxy resins and modified epoxy resins are particularly preferred from the viewpoints of adhesion to the plating surface and corrosion resistance. Among them, thermosetting epoxy resins and modified epoxy resins that have excellent barrier properties against corrosion factors such as oxygen are the most suitable, and in particular, the coating amount to obtain high conductivity and spot weldability. It is particularly advantageous when the level is low.

  The epoxy resin may be formed by reacting a polyphenol such as bisphenol A, bisphenol F, or novolac type phenol with an epihalohydrin such as epichlorohydrin to introduce a glycidyl group, or further adding a polyphenol to the glycidyl group introduction reaction product. An aromatic epoxy resin obtained by reacting with an aromatic epoxy resin, an aliphatic epoxy resin, an alicyclic epoxy resin, and the like. These may be used alone or in admixture of two or more. Can do. These epoxy resins preferably have a number average molecular weight of 1500 or more, particularly when film formation at low temperatures is required.

Examples of the modified epoxy resin include a resin obtained by reacting various modifiers with an epoxy group or a hydroxyl group in the epoxy resin, such as an epoxy ester resin, acrylic acid or methacrylic acid obtained by reacting a dry oil fatty acid. An epoxy acrylate resin modified with a polymerizable unsaturated monomer component containing styrene, a urethane-modified epoxy resin reacted with an isocyanate compound, and the like can be exemplified.
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 comprising an acrylic ester or a methacrylic ester, a solution polymerization method, Examples thereof include resins synthesized by an emulsion polymerization method or a suspension polymerization method.

Examples of the polymerizable unsaturated monomer component include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, n-, iso- or tert-butyl (meth) acrylate, hexyl (meth) acrylate, C1-24 alkyl ester of acrylic acid or methacrylic acid such as 2-ethylhexyl (meth) acrylate, decyl (meth) acrylate, lauryl (meth) acrylate; acrylic acid, methacrylic acid, styrene, vinyltoluene, acrylamide, acrylonitrile, N- Examples thereof include methylol (meth) acrylamide, C1-4 alkyl etherified product of N-methylol (meth) acrylamide; N, N-diethylaminoethyl methacrylate and the like.
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. .
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.

このようなビスフェノールＡ型エポキシ樹脂の製造法は当業界において広く知られている。また、上記化学構造式において、ｑは０〜５０、好ましくは１〜４０、特に好ましくは２〜２０である。
なお、皮膜形成有機樹脂（Ａ）は、有機溶剤溶解型、有機溶剤分散型、水溶解型、水分散型のいずれであってもよい。 Particularly preferable as the epoxy resin is a resin having a chemical structure represented by the following formula, which is a reaction product of bisphenol A and epihalohydrin, and this epoxy resin is particularly preferable because of its excellent corrosion resistance.

A method for producing such a bisphenol A type epoxy resin is widely known in the art. Moreover, in the said chemical structural formula, q is 0-50, Preferably it is 1-40, Most preferably, it is 2-20.
The film-forming organic resin (A) may be any of an organic solvent dissolution type, an organic solvent dispersion type, a water dissolution type, and a water dispersion type.

The present invention aims to provide a hydrazine derivative in the molecule of the film-forming organic resin (A). Therefore, at least part (preferably all) of the active hydrogen-containing compound (B) is hydrazine having active hydrogen. It must be a derivative (C).
In the case where the film-forming organic resin (A) is an epoxy group-containing resin, examples of the active hydrogen-containing compound (B) that reacts with the epoxy group include those shown below. In this case as well, at least a part (preferably all) of the active hydrogen-containing compound (B) needs to be a hydrazine derivative having active hydrogen.
・ Hydrazine derivatives with active hydrogen ・ Primary or secondary amine compounds with active hydrogen ・ Organic acids such as ammonia and carboxylic acids ・ Halogen halides such as hydrogen chloride ・ Alcohols and thiols ・ Having active hydrogen Quaternary chlorinating agent which is a mixture of hydrazine derivative or tertiary amine and acid

Examples of the hydrazine derivative (C) having active hydrogen include the following.
(1) Carbohydrazide, propionic acid hydrazide, salicylic acid hydrazide, adipic acid dihydrazide, sebacic acid dihydrazide, dodecanoic acid dihydrazide, isophthalic acid dihydrazide, thiocarbohydrazide, 4,4'-oxybisbenzenesulfonylhydrazide, benzophenone hydrazone, aminopolyacrylamide Hydrazide compounds such as;
(2) pyrazole compounds such as pyrazole, 3,5-dimethylpyrazole, 3-methyl-5-pyrazolone, 3-amino-5-methylpyrazole;
(3) 1,2,4-triazole, 3-amino-1,2,4-triazole, 4-amino-1,2,4-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- Triazole compounds such as methyl-8-hydroxytriazolopyridazine, 6-phenyl-8-hydroxytriazolopyridazine, 5-hydroxy-7-methyl-1,3,8-triazaindolizine;

(4) tetrazole compounds such as 5-phenyl-1,2,3,4-tetrazole and 5-mercapto-1-phenyl-1,2,3,4-tetrazole;
(5) thiadiazole compounds such as 5-amino-2-mercapto-1,3,4-thiadiazole and 2,5-dimercapto-1,3,4-thiadiazole;
(6) Maleic hydrazide, 6-methyl-3-pyridazone, 4,5-dichloro-3-pyridazone, 4,5-dibromo-3-pyridazone, 6-methyl-4,5-dihydro-3-pyridazone, etc. Pyridazine compounds Among these, pyrazole compounds and triazole compounds having a 5-membered or 6-membered ring structure and having a nitrogen atom in the ring structure are particularly suitable.
These hydrazine derivatives can be used individually by 1 type or in mixture of 2 or more types.

Typical examples of the amine compound having active hydrogen that can be used as part of the active hydrogen-containing compound (B) include the following.
(A) a 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; A compound modified with aldimine, ketimine, oxazoline or imidazoline by heat reaction with aldehyde or carboxylic acid at a temperature of about 100 to 230 ° C., for example;
(B) secondary monoamines such as diethylamine, diethanolamine, di-n- or -iso-propanolamine, N-methylethanolamine, N-ethylethanolamine;
(C) a secondary amine-containing compound obtained by adding a monoalkanolamine such as monoethanolamine and a dialkyl (meth) acrylamide by a Michael addition reaction;
(D) a compound obtained by modifying a primary amino group of an alkanolamine such as monoethanolamine, neopentanolamine, 2-aminopropanol, 3-aminopropanol, 2-hydroxy-2 '(aminopropoxy) ethyl ether to ketimine;

The quaternary chlorinating agent that can be used as a part of the active hydrogen-containing compound (B) is a hydrazine derivative or a tertiary amine that does not have active hydrogen and is not reactive with an epoxy group by itself. In order to be able to react with the acid. The quaternary chlorinating agent reacts with an epoxy group in the presence of water as necessary to form a quaternary salt with the epoxy group-containing resin.
The acid used to obtain the quaternary chlorinating agent may be any of organic acids such as acetic acid and lactic acid, and inorganic acids such as hydrochloric acid. Examples of the hydrazine derivative having no active hydrogen used for obtaining a quaternary chlorinating agent include 3,6-dichloropyridazine, and examples of the tertiary amine include dimethylethanolamine, triethylamine, Examples include trimethylamine, triisopropylamine, and methyldiethanolamine.

The reaction product of the film-forming organic resin (A) and the active hydrogen-containing compound (B) composed of a hydrazine derivative (C) in which a part or all of the compounds have active hydrogen is the film-forming organic resin (A) and active hydrogen. It is obtained by reacting the containing compound (B) at 10 to 300 ° C., preferably 50 to 150 ° C. for about 1 to 8 hours.
This reaction may be performed by adding an organic solvent, and the type of the organic solvent to be used is not particularly limited. For example, ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, dibutyl ketone, cyclohexanone; ethanol, butanol, 2-ethylhexyl alcohol, benzyl alcohol, ethylene glycol, ethylene glycol monoisopropyl ether, ethylene glycol monobutyl ether, ethylene glycol monohexyl ether , Propylene glycol, propylene glycol monomethyl ether, diethylene glycol, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether and other alcohols and ethers containing hydroxyl groups; ethyl acetate, butyl acetate, ethylene glycol monobutyl ether acetate and other esters; toluene, xylene Aromatic hydrocarbons such as Illustration can, it is possible to use one or more of these. Of these, ketone-based or ether-based solvents are particularly preferred from the standpoints of solubility with an epoxy resin and film-forming properties.

The blending ratio between the film-forming organic resin (A) and the active hydrogen-containing compound (B) composed of a hydrazine derivative (C) in which some or all of the compounds have active hydrogen is a solid content ratio. ) The active hydrogen-containing compound (B) is preferably 0.5 to 20 parts by mass, particularly preferably 1.0 to 10 parts by mass with respect to 100 parts by mass.
When the film-forming organic resin (A) is an epoxy group-containing resin (D), the blending ratio of the epoxy group-containing resin (D) and the active hydrogen-containing compound (B) is the active hydrogen-containing compound (B ) And the number of epoxy groups in the epoxy group-containing resin (D) [number of active hydrogen groups / number of epoxy groups] is 0.01 to 10, more preferably 0.1 to 8, and still more preferably. It is appropriate to set it to 0.2-4 from points, such as corrosion resistance.

  The proportion of the hydrazine derivative (C) having active hydrogen in the active hydrogen-containing compound (B) is 10 to 100 mol%, more preferably 30 to 100 mol%, and still more preferably 40 to 100 mol%. Is appropriate. If the ratio of the hydrazine derivative (C) having active hydrogen is less than 10 mol%, the organic film cannot be provided with a sufficient rust prevention function, and the resulting rust prevention effect is obtained by simply mixing the film-forming organic resin and the hydrazine derivative. It is no different from the case of using it.

In the present invention, in order to form a dense barrier film, it is desirable to mix a curing agent in the resin composition and heat cure the organic film (upper layer film).
As a curing method for forming a resin composition film, (1) a curing method using a urethanization reaction between an isocyanate and a hydroxyl group in a base resin, and (2) 1 selected from melamine, urea and benzoguanamine An etherification reaction between an alkyl etherified amino resin obtained by reacting a monohydric alcohol having 1 to 5 carbon atoms with a part or all of a methylol compound obtained by reacting formaldehyde with a seed or more and a hydroxyl group in a base resin. The curing method to be used is suitable, and among these, it is particularly preferable to use a urethanization reaction between isocyanate and a hydroxyl group in the base resin as a main reaction.

The polyisocyanate compound used in the curing method (1) above is composed of an aliphatic, alicyclic (including heterocyclic) or aromatic isocyanate compound having at least two isocyanate groups in one molecule, or many of these compounds. It is a compound that has been partially reacted with a monohydric alcohol. Examples of such polyisocyanate compounds include the following.
(I) m- or p-phenylene diisocyanate, 2,4- or 2,6-tolylene diisocyanate, o- or p-xylylene diisocyanate, hexamethylene diisocyanate, dimer acid diisocyanate, isophorone diisocyanate (ii) above (i) Or a mixture thereof and a polyhydric alcohol (dihydric alcohols such as ethylene glycol and propylene glycol; trihydric alcohols such as glycerin and trimethylolpropane; tetrahydric alcohols such as pentaerythritol; sorbitol, dipentaerythritol, etc. A compound of at least two isocyanates in one molecule. These polyisocyanate compounds may be used alone or in combination of two or more. It can be.

Moreover, as a protective agent (blocking agent) of a polyisocyanate compound, for example,
(1) Aliphatic monoalcohols such as methanol, ethanol, propanol, butanol, octyl alcohol (2) Ethylene glycol and / or diethylene glycol monoethers such as methyl, ethyl, propyl (n-, iso), butyl ( n-, iso, sec) monoethers (3) phenols, aromatic alcohols such as cresol (4) oximes such as acetooxime, methyl ethyl ketone oxime, etc., and one or more of these and the polyisocyanate By reacting with the compound, a polyisocyanate compound that is stably protected at least at room temperature can be obtained.

Such a polyisocyanate compound (E) is (A) / (E) = 95/5 to 55/45 (weight ratio of non-volatile content) with respect to the film-forming organic resin (A) as a curing agent, preferably ( It is suitable to mix | blend in the ratio of A) / (E) = 90 / 10-65 / 35. The polyisocyanate compound has water absorption, and if it is blended in excess of (A) / (E) = 55/45, the adhesion of the upper film is deteriorated. Furthermore, when top coating is performed on the upper layer film, the unreacted polyisocyanate compound moves into the coating film, which causes inhibition of curing of the coating film and poor adhesion. 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, but it is desirable to use a known curing accelerating catalyst in order to further increase the low temperature crosslinking property. Examples of the curing accelerating catalyst include N-ethylmorpholine, dibutyltin dilaurate, cobalt naphthenate, stannous chloride, zinc naphthenate, and bismuth nitrate.
For example, when an epoxy group-containing resin is used for the film-forming organic resin (A), a known acrylic, alkyd, polyester, or the like is mixed with the epoxy group-containing resin for the purpose of improving some physical properties such as adhesion. It can also be used.

The upper film (coating composition) may contain a non-chromium rust preventive additive as necessary for the purpose of improving the corrosion resistance. By including such a non-chromium-based anticorrosive additive in the upper layer film, more excellent anticorrosion performance can be obtained.
In particular, it is preferable to use one or more selected from the following (a) to (e) as the non-chromium-based rust preventive additive.
(A) silicon oxide (b) calcium compound (c) poorly soluble phosphate compound (d) molybdate compound (e) one or more selected from triazoles, thiols, thiadiazoles, thiazoles, thiurams , Organic compounds containing S atoms

The details and anticorrosion mechanism of the non-chromium rust preventive additives (a) to (e) are as follows.
First, as the component (a), colloidal silica or dry silica, which is fine particle silica, can be used. From the viewpoint of corrosion resistance, calcium ion-exchanged silica in which calcium is bonded to the surface is used. Is desirable.
As colloidal silica, for example, SNOWTEX O, 20, 30, 40, C, S (all trade names) manufactured by Nissan Chemical Co., Ltd. can be used, and as fumed silica, Nippon Aerosil ( AEROSIL made by
R971, R812, R811, R974, R202, R805, 130, 200, 300, 300CF (all are trade names) can be used. As calcium ion exchange silica, WRGrace & Co. SHIELDEX C303, SHIELDEX AC3, SHIELDEX AC5 (all are trade names) manufactured by SHIELDEX, SHIELDEX manufactured by Fuji Silysia Chemical Co., Ltd.
SY710 (both are trade names) can be used. These silicas contribute to the production of dense and stable zinc corrosion products in a corrosive environment, and the corrosion products are formed densely on the plating surface, thereby suppressing the promotion of corrosion.

In addition, the above components (b) and (c) exhibit particularly excellent anticorrosion performance (self-repairing property) due to precipitation.
The calcium compound as the component (b) may be any of calcium oxide, calcium hydroxide, and calcium salt, and one or more of these can be used. In addition, there are no particular restrictions on the type of calcium salt. In addition to simple salts containing only calcium as a cation such as calcium silicate, calcium carbonate, and calcium phosphate, calcium and calcium such as calcium phosphate / zinc, calcium phosphate / magnesium, etc. Double salts containing other cations may be used. In the component (b), base metal is preferentially dissolved in the corrosive environment over zinc and aluminum, which are plating metals, and this seals the defective part as a dense and poorly soluble product with OH ⁻ produced by the cathode reaction. And suppress the corrosion reaction. Moreover, when it mix | blends with the above silicas, a calcium ion adsorb | sucks to the surface and neutralizes a surface charge electrically and aggregates. As a result, a dense and sparingly soluble protective film is formed to block the corrosion and suppress the corrosion reaction.

  Moreover, as a poorly soluble phosphoric acid compound which is said (c), a hardly soluble phosphate can be used. This sparingly soluble phosphate includes all types of salts such as simple salts and double salts. Moreover, there is no limitation in the metal cation which comprises it, and any metal cation, such as poorly soluble zinc phosphate, magnesium phosphate, calcium phosphate, aluminum phosphate, may be sufficient. Further, there is no limitation on the skeleton or the degree of condensation of phosphate ions, and any of normal salt, dihydrogen salt, monohydrogen salt or phosphite may be used. In addition, orthophosphate may be polyphosphate other than orthophosphate. Includes all condensed phosphates such as salts. By using this poorly soluble phosphorus compound, the plating metal zinc or aluminum eluted by corrosion reacts with the phosphate ions dissociated by hydrolysis to form a dense and sparingly soluble protective film. The corrosion starting point is blocked, and the corrosion reaction is suppressed.

  In addition, as the molybdate compound (d), for example, molybdate can be used. The molybdate is not limited in its skeleton and degree of condensation, and examples thereof include orthomolybdate, paramolybdate, and metamolybdate. Moreover, all salts, such as a single salt and a double salt, are included, and phosphoric acid molybdate etc. are mentioned as a double salt. Molybdate compounds exhibit self-repairing properties due to the passivating effect. That is, by forming a dense oxide on the plating film surface together with dissolved oxygen in a corrosive environment, the corrosion starting point is blocked and the corrosion reaction is suppressed.

  Moreover, as an organic compound of said (e), the following can be mentioned, for example. That is, as triazoles, 1,2,4-triazole, 3-amino-1,2,4-triazole, 3-mercapto-1,2,4-triazole, 5-amino-3-mercapto-1,2 1,4-triazole, 1H-benzotriazole, etc., and as thiols, 1,3,5-triazine-2,4,6-trithiol, 2-mercaptobenzimidazole, etc., and as thiadiazoles, 5- Amino-2-mercapto-1,3,4-thiadiazole, 2,5-dimercapto-1,3,4-thiadiazole and the like, and as thiazoles, 2-N, N-diethylthiobenzothiazole, 2-mercapto Examples include benzothiazoles, and examples of thiurams include tetraethylthiuram disulfide. It is. These organic compounds exhibit self-repairing properties due to the adsorption effect. That is, zinc and aluminum eluted by corrosion are adsorbed on polar groups containing sulfur contained in these organic compounds to form an inert film, thereby blocking the corrosion starting point and suppressing the corrosion reaction.

The compounding amount of the non-chromium rust preventive additive is 0.1 to 50 parts by mass, preferably 0.5 to 30 parts by mass, relative to 100 parts by mass of the solid content of the resin composition for film formation. The part is appropriate. If the blending amount of this non-chromium rust preventive additive is less than 0.1 parts by mass, the effect of improving corrosion resistance after alkali degreasing cannot be sufficiently obtained. On the other hand, if it exceeds 50 parts by mass, paintability, workability, and welding This is not preferable because the corrosion resistance is deteriorated as well as the property.
Two or more rust preventive additives (a) to (e) may be added in combination. In this case, since the inherent anticorrosive action is combined, higher corrosion resistance can be obtained. In particular, calcium ion-exchanged silica is used as the component (a), and one or more of the components (c), (d), (e), particularly preferably the components (c) to (e). When all are added in combination, particularly excellent corrosion resistance is obtained.

  In addition to the above rust preventive additive components, other oxide fine particles (for example, aluminum oxide, zirconium oxide, titanium oxide, cerium oxide, antimony oxide, etc.) may be used in the upper layer film (coating composition) as a corrosion inhibitor. ), Phosphomolybdate (eg, aluminum phosphomolybdate), organophosphoric acid and its salts (eg, phytic acid, phytate, phosphonic acid, phosphonate, and metal salts thereof, alkali metal salts, alkalis) 1 type or 2 types or more, such as an earth metal salt etc.) and organic inhibitors (for example, a hydrazine derivative, a thiol compound, a dithiocarbamate etc.) can be added.

In the upper layer film (coating composition), if necessary, a solid lubricant can be blended for the purpose of improving the workability of the film.
Examples of the solid lubricant applicable to the present invention include the following, and one or more of these can be used.
(1) Polyolefin wax, paraffin wax: For example, polyethylene wax, synthetic paraffin, natural paraffin, micro wax, chlorinated hydrocarbon, etc. (2) Fluorine resin fine particles: For example, polyfluoroethylene resin (polytetrafluoroethylene resin, etc.) In addition to these, fatty acid amide compounds (for example, stearic acid amide, palmitic acid amide, methylene bisstearamide, ethylene bisstearamide, oleic acid amide, esyl) Acid amides, alkylene bis fatty acid amides), metal soaps (eg, calcium stearate, lead stearate, calcium laurate, calcium palmitate, etc.), metal sulfides (eg, molybdenum disulfide, tungsten disulfide) ), Graphite, fluorinated graphite, boron nitride, polyalkylene glycol, alkali metal sulfate or the like may be used.

Among the above solid lubricants, polyethylene wax and fluororesin fine particles (in particular, polytetrafluoroethylene resin fine particles) are preferable.
As polyethylene wax, for example, Celite dust 9615A, Celite dust 3715, Celite dust 3620, Celite dust 3910 (all trade names) manufactured by Hoechst, Sanwa Chemical Co., Ltd. sun wax 131-P, Sun wax 161-P (all (Trade name), Chemipearl W-100, Chemipearl W-200, Chemipearl W-500, Chemipearl W-800, Chemipearl W-950 (all trade names) manufactured by Mitsui Petrochemical Co., Ltd. can be used.

The fluororesin fine particles are most preferably tetrafluoroethylene fine particles. For example, Lubron L-2 and Lubron L-5 (both trade names) manufactured by Daikin Industries, Ltd., MP1100 manufactured by Mitsui DuPont Co., Ltd. , MP1200 (all trade names), full-on dispersion AD1, full-on dispersion AD2, full-on L141J, full-on L150J, full-on L155J (all trade names) manufactured by Asahi IC Fluoropolymers Co., Ltd. are suitable.
Among these, a particularly excellent lubricating effect can be expected by the combined use of polyolefin wax and tetrafluoroethylene fine particles.
The blending amount of the solid lubricant in the upper layer film is 1 to 30 parts by mass, preferably 1 to 10 parts by mass with respect to 100 parts by mass of the solid content of the resin composition for film formation. It is desirable. If the blending amount of the solid lubricant is less than 1 part by mass, the lubricating effect is poor. On the other hand, if the blending amount exceeds 30 parts by mass, the paintability is lowered, which is not preferable.

  The upper layer film (coating composition) of the surface-treated steel sheet of the present invention comprises 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 main product is a reaction product (resin composition) with a curing agent, a non-chromium rust preventive additive, a solid lubricant, etc., if necessary. Organic coloring pigments (for example, condensed polycyclic organic pigments, phthalocyanine organic pigments), coloring dyes (for example, organic solvent-soluble azo dyes, water-soluble azo metal dyes, etc.), inorganic pigments (for example, titanium oxide) Etc.), chelating agents (for example, thiols), conductive pigments (for example, metal powders such as zinc, aluminum, nickel, iron phosphide, antimony-doped tin oxide), coupling agents ( In example, a silane coupling agent, titanium coupling agent) may be added to one or more of melamine-cyanuric acid adduct.

In addition, the coating composition for forming a film containing the main component and the additive component usually contains a solvent (an 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 the reaction product of the film-forming organic resin (A) and the active hydrogen-containing compound (B), and can be prepared as a coating composition. The various organic solvents exemplified above can be used.
The neutralizing agent is blended as necessary to neutralize the film-forming organic resin (A) to make it water-based. 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 a neutralizing agent.
The dry film thickness of the upper layer film is 0.5 to 2.0 μm, preferably 0.5 to 1.5 μm. If the film thickness of the upper layer film is 0.5 μm or more, sufficient corrosion resistance is obtained, while if the film thickness is 2.0 μm or less, good weldability and electrodeposition coating properties can be maintained.
Further, from the viewpoint of weldability and electrodeposition coating properties, the total film thickness of the surface treatment film of the first layer and the upper film of the second layer is preferably 2.0 μm or less.

Next, the manufacturing method of the surface treatment steel plate of this invention is demonstrated.
In order to form a surface treatment film on the surface of a zinc-based plated steel sheet or an aluminum-based plated steel sheet, a surface treatment composition (treatment liquid) having the above-described composition is applied to the surface of the plated steel sheet so that the dry film thickness is in the above range. And heat-dried without washing with water.
As a method of coating the surface treatment composition on the surface of the plated steel sheet, any of an application method, a dipping method, and a spray method may be used. As a coating treatment method, any method such as a roll coater (3-roll method, 2-roll method, etc.), a squeeze coater, or a die coater may be used. In addition, after the coating process or dipping process using a squeeze coater or the like, or the spray process, the coating amount can be adjusted, the appearance can be made uniform, and the film thickness can be made uniform by an air knife method or a roll drawing method.

After coating the surface treatment composition, drying is performed without washing with water. As the heating and drying means, a dryer, a hot air furnace, a high frequency induction heating furnace, an infrared furnace or the like can be used. It is desirable that the heat drying is carried out in the range of 30 to 200 ° C., preferably 40 to 140 ° C., at the ultimate plate temperature. If the heating and drying temperature is 30 ° C. or higher, the moisture in the film can be sufficiently dried, resulting in good corrosion resistance. In addition, by setting the heating and drying temperature to 200 ° C. or lower, not only can economical heating and drying be performed, but also high corrosion resistance can be maintained because no defects occur in the film.
An upper layer film (organic resin film) is formed as the second layer film on the upper layer of the surface treatment film formed as described above. The coating composition for the second layer film is applied to the surface-treated film surface so as to have the above-described film thickness, and dried by heating. Application | coating of a coating composition should just be performed according to the method used for formation of the surface treatment film mentioned above.

After application of the coating composition, drying is usually performed without washing with water, but a washing process may be performed after application of the coating composition. For the heat drying treatment, a dryer, a hot air furnace, a high-frequency induction heating furnace, an infrared furnace, or the like can be used. It is desirable that the heat drying is carried out in the range of 30 to 200 ° C., preferably 40 to 140 ° C., at the ultimate plate temperature. If the heating and drying temperature is 30 ° C. or higher, the solvent in the film can be sufficiently dried, resulting in good corrosion resistance. Further, by the heat drying temperature and 200 ° C. or less, not only it allows economical heating drying, Ru can maintain high corrosion resistance for a defect does not occur in the film.

Therefore, the manufacturing method of the surface treatment steel plate of this invention and its preferable embodiment are as follows.
[1] At least one selected from the group consisting of a vanadium compound having a valence of 4, a phosphoric acid compound, a silane coupling agent, and Al, Mg, and Mn on the surface of a zinc-based plated steel sheet or an aluminum-based plated steel sheet A surface treatment composition containing a seed metal compound (but not containing an organic resin) has a tetravalent vanadium compound adhesion amount of 0.1 to 200 mg / m ^{2 in} terms of V, a phosphoric acid compound the adhesion amount 0.1 to 200 mg / ^{m 2} at P terms, the adhesion amount of the silane coupling agent is 0.1~180mg ^/ m 2, Al in terms of Si, Mg, at least one selected from among Mn Coating is performed so that the adhesion amount of the metal compound is 1.0 to 400 mg / m ^{2 in} total in terms of Al, Mg and Mn, and drying is performed at a final plate temperature of 30 to 200 ° C. 0 A surface-treated film having a thickness of .about.1.0 .mu.m is formed, and the main component of the resin composition is a film-forming organic resin (A) and a hydrazine derivative (C) in which some or all of the compounds have active hydrogen. By applying a coating composition composed of a reaction product with the active hydrogen-containing compound (B) and drying at a temperature of the ultimate plate temperature of 30 to 200 ° C., the film thickness is 0.5 to 2.0 μm. A method for producing a highly corrosion-resistant surface-treated steel sheet, characterized in that is formed.

[2] In the production method of [1 ] above, the coating composition for the upper layer film further contains a non-chromium rust preventive additive in a ratio of 0.1 to 100 parts by mass of the solid content of the resin composition. 1-50 mass parts contains, The manufacturing method of the highly corrosion-resistant surface treatment steel plate characterized by the above-mentioned.

[3] In the production method of [2] , the non-chromium-based antirust additive is one or more antirust additives selected from the following (a) to (e): A method for producing a corrosion-resistant surface-treated steel sheet.
(A) silicon oxide (b) calcium compound (c) poorly soluble phosphate compound (d) molybdate compound (e) one or more selected from triazoles, thiols, thiadiazoles, thiazoles, thiurams , Organic compounds containing S atoms
[4] In the production method according to any one of [1] to [3] , the surface treatment composition for a surface treatment film contains at least one silane coupling agent having a glycidyl group as a reactive functional group. A method for producing a highly corrosion-resistant surface-treated steel sheet.
[5] In the production method according to any one of [1] to [4 ] above, the coating composition for the upper film further comprises a solid lubricant in a solid content ratio of 100 parts by mass of the solid content of the resin composition. The manufacturing method of the highly corrosion-resistant surface-treated steel plate characterized by containing 1-30 mass parts.

The surface treatment composition for forming the first layer (surface treatment film) includes vanadium compounds shown in Table 2, phosphoric acid compounds shown in Table 3, silane coupling agents shown in Table 4, metal compounds shown in Table 5, and Table 6. Additives shown in the above were appropriately blended, and the mixture was stirred for a predetermined time using a paint disperser (sand grinder) to prepare a surface treatment composition.
As the coating composition for forming the second layer (upper layer film), the resin composition shown in Table 7 was used, and the non-chromium rust preventive additive shown in Table 8 and the solid lubricant shown in Table 9 were appropriately used. The mixture was blended and stirred for a predetermined time using a paint disperser (sand grinder) to prepare a paint composition.

The base resin (reaction product) of the resin composition shown in Table 7 was synthesized as follows.
<Synthesis Example 1>
EP828 (manufactured by Yuka Shell Epoxy Co., Epoxy Equivalent 187) 1870 parts, bisphenol A 912 parts, tetraethylammonium bromide 2 parts, methyl isobutyl ketone 300 parts are charged into a four-necked flask and heated to 140 ° C. and reacted for 4 hours. An epoxy resin having an epoxy equivalent of 1391 and a solid content of 90% was obtained. To this product, 1500 parts of ethylene glycol monobutyl ether was added and 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 epoxy group disappeared. After reacting for 6 hours, 205 parts of methyl isobutyl ketone was added while cooling to obtain a pyrazole-modified epoxy resin having a solid content of 60%. This is designated as resin composition (1). 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 heated to 120 ° C. to completely dissolve the epoxy resin in 1 hour. This was cooled to 100 ° C., 168 parts of 3-amino-1,2,4-triazole (molecular weight 84) was added, and the mixture was allowed to react for 6 hours until the epoxy group disappeared. A triazole-modified epoxy resin having a solid content of 60% was obtained. This is designated as resin composition (2). This resin composition (2) 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 3>
222 parts of isophorone diisocyanate (isocyanate equivalent 111) and 34 parts of methyl isobutyl ketone were charged into a four-necked flask and maintained at 30 to 40 ° C., and 87 parts of methyl ethyl ketoxime (molecular weight 87) was added dropwise over 3 hours. By maintaining the time, a partially blocked isocyanate having an isocyanate equivalent of 309 and a solid content of 90% was obtained.
Subsequently, 1428 parts of EP828 (manufactured by Yuka Shell Epoxy Co., Ltd., epoxy equivalent 187), 684 parts of bisphenol A, 1 part of tetraethylammonium bromide and 241 parts of methyl isobutyl ketone were charged into a four-necked flask and heated to 140 ° C. for 4 hours. Reaction was performed 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 then cooled to 100 ° C., and 202 parts of 3-mercapto-1,2,4-triazole (molecular weight 101) was added and reacted for 6 hours until the epoxy group disappeared. Thereafter, 230 parts of the partially blocked isocyanate having a solid content of 90% was added and reacted at 100 ° C. for 3 hours to confirm that the isocyanate group had disappeared. Further, 461 parts of ethylene glycol monobutyl ether was added to obtain a triazole-modified epoxy resin having a solid content of 60%. This is designated as 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>
EP828 (manufactured by Yuka Shell Epoxy Co., Epoxy Equivalent 187) 1870 parts, bisphenol A 912 parts, tetraethylammonium bromide 2 parts, methyl isobutyl ketone 300 parts are charged into a four-necked flask and heated to 140 ° C. and reacted for 4 hours. An epoxy resin having an epoxy equivalent of 1391 and a solid content of 90% was obtained. To this was added 1500 parts of ethylene glycol monobutyl ether, cooled to 100 ° C., added with 258 parts of dibutylamine (molecular weight 129), reacted for 6 hours until the epoxy group disappeared, and then cooled with methyl isobutyl. 225 parts of ketone was added to obtain an epoxyamine adduct having a solid content of 60%. This is designated as 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 plated steel sheet shown in Table 1, which is a plated steel sheet for home appliances, building materials, and automobile parts based on cold-rolled steel sheets, was used as a processing original sheet. In addition, the thing of predetermined | prescribed board thickness was employ | adopted for the board thickness of the steel plate according to the objective of evaluation. After the surface of this plated steel sheet was subjected to alkali degreasing treatment, washed with water and dried, the surface treatment composition for forming the first layer was applied with a roll coater and dried by heating at various temperatures. The film thickness of the film was adjusted by the solid content (heating residue) of the surface treatment composition or coating conditions (rolling force of the roll, rotation speed, etc.).
Next, the coating composition for forming the second layer was applied by a roll coater and dried by heating at various temperatures. The film thickness of the film was adjusted by the solid content (heating residue) of the coating composition or application conditions (rolling force of roll, rotation speed, etc.).

Tables 10 to 19 show the results of evaluating the film composition and quality performance (corrosion resistance, post-processing corrosion resistance, weldability, electrodeposition coating property) of the obtained surface-treated steel sheet. The quality performance was evaluated as follows.
(1) Corrosion resistance About each sample, the following combined cycle test (CCT) was given, and it evaluated by the white rust generation | occurrence | production area rate and red rust generation | occurrence | production area rate after progress of 36 cycles.
Salt spray (based on JIS-Z-2371): 4 hours ↓
Dry (60 ° C): 2 hours ↓
Wet (50 ° C., 95% RH): 2 hours The evaluation criteria are as follows.
◎: White rust generation area ratio less than 10% ○: White rust generation area ratio of 10% or more and less than 30% ○-: White rust generation area ratio of 30% or more and no red rust generation △: Red rust generation, red rust generation area ratio Less than 10% ×: Red rust generation area ratio 10% or more

(2) Corrosion resistance after processing For each sample, deformation and sliding were added with a draw bead under the following conditions, and this sample was used at 45 ° C. for 2 minutes using “FC-4460” manufactured by Nippon Parkerizing Co., Ltd. After degreasing under the conditions, the CCT performed in “(1) Corrosion resistance” was performed, and the white rust generation area ratio and red rust generation area ratio after 24 cycles were evaluated.
Pressing load: 800kgf
Drawing speed: 1000mm / min
Bead shoulder R: Male side 5mmR, Female side 5mmR
Pushing depth: 7mm
Oil used: Preton R-352L
The evaluation criteria are as follows.
◎: White rust generation area rate less than 10% ○: White rust generation area rate of 10% or more and less than 30% ○-: White rust generation area rate of 30% or more, no red rust generation △: Red rust generation, red rust generation area Rate of less than 10% ×: Red rust generation area rate of 10% or more

(3) Weldability With respect to each sample, a welding test with continuous spotting was performed under the conditions of using electrode: CF-type Cr—Cu electrode, applied pressure: 200 kgf, energizing time: 10 cycles / 50 Hz, welding current: 10 kA, and continuously hitting. The score was evaluated. The evaluation criteria are as follows.
◎: 2000 points or more ○: 1000 points or more, less than 2000 points △: 500 points or more, less than 1000 points ×: Less than 500 points (4) Electrodeposition paintability Cationic electrodeposition paint (manufactured by Kansai Paint Co., Ltd.) After coating “GT-10”) to a film thickness of 30 μm, baking was performed at 130 ° C. for 30 minutes. The coated sample was immersed in boiling water for 2 hours, immediately cut in a grid pattern (10 × 10, 1 mm interval), attached and peeled with an adhesive tape, and the peeled area ratio of the coating film was measured. The evaluation criteria are as follows.
◎: No peeling ○: Peeling area rate less than 5% △: Peeling area rate of 5% or more and less than 20%

In addition, * 1 to * 12 described in Tables 10 to 19 indicate the following contents.
* 1: No. described in Table 1. (Plated steel plate)
* 2: No. in Table 2 (Vanadium compounds)
* 3: No. described in Table 3 (Phosphate compound)
* 4: No. in Table 4 (Silane coupling agent)
* 5: No. in Table 5 (Metal compound )
* 7: No. in Table 6 (Additive)
* 8: parts by weight with respect to the inorganic solid content of 100 parts by weight of the surface treatment composition * 9: No. described in Table 7 (Resin composition)
* 10: No. in Table 8 (Anti-rust additive)
* 11: No. in Table 9 (Solid lubricant)
* 12: Mass parts of solid content (for components other than organic resins, mass parts relative to 100 mass parts of solid content of organic resin)

Claims (7)

At least one metal selected from the group consisting of a vanadium compound having a valence of 4, a phosphate compound, a silane coupling agent, and Al, Mg, and Mn on the surface of a zinc-based plated steel sheet or an aluminum-based plated steel sheet It is a film having a film thickness of 0.01 to 1.0 μm formed by applying and drying a surface treatment composition containing a compound (but not containing an organic resin), and having a tetravalent valence. The vanadium compound adhesion amount is 0.1 to 200 mg / m ^{2 in} terms of V, the phosphate compound adhesion amount is 0.1 to 200 mg / m ^{2 in} terms of P, and the silane coupling agent adhesion amount is 0 in terms of Si. ^{.1~180mg / m 2, Al, Mg} , surface treatment the adhesion amount of at least one metal compound selected from among Mn of 1.0~400mg / ^{m 2} in total of Al, Mg and Mn in terms of An active hydrogen-containing compound (B) comprising a film, the main component of the resin composition being a film-forming organic resin (A) and a hydrazine derivative (C) in which a part or all of the compounds have active hydrogen. A highly corrosion-resistant surface-treated steel sheet characterized by having an upper film having a film thickness of 0.5 to 2.0 μm formed by applying and drying a coating composition comprising a reaction product of The coating composition for the upper layer film further comprises 0.1 to 50 parts by mass of a non-chromium rust preventive additive in a solid content ratio of 100 parts by mass of the solid content of the resin composition. The highly corrosion-resistant surface-treated steel sheet according to claim 1 . The highly corrosion-resistant surface-treated steel sheet according to claim 2 , wherein the non-chromium rust preventive additive is at least one selected from the following (a) to (e).
(A) silicon oxide (b) calcium compound (c) poorly soluble phosphate compound (d) molybdate compound (e) one or more selected from triazoles, thiols, thiadiazoles, thiazoles, thiurams , Organic compounds containing S atoms The surface treatment composition for surface treatment film contains at least 1 sort (s) of the silane coupling agent which has a glycidyl group as a reactive functional group, The highly corrosion-resistant surface in any one of Claims 1-3 characterized by the above-mentioned. Treated steel sheet. The coating composition for the upper layer coating, further according to claim 1-4, characterized in that it contains 1 to 30 parts by weight at a ratio of solids relative to 100 parts by weight of the solid content of the solid lubricant resin composition The high corrosion resistance surface-treated steel sheet according to any one of the above. The surface treatment composition for a surface treatment film contains at least a sulfate of vanadium as a vanadium compound having a tetravalent valence. 6. The highly corrosion-resistant surface treatment according to claim 1, steel sheet. At least one metal selected from the group consisting of a vanadium compound having a valence of 4, a phosphate compound, a silane coupling agent, and Al, Mg, and Mn on the surface of a zinc-based plated steel sheet or an aluminum-based plated steel sheet The surface treatment composition containing a compound (but not containing an organic resin) has an adhesion amount of a vanadium compound having a tetravalent valence of 0.1 to 200 mg / m ^{2 in} terms of V, and an adhesion amount of a phosphate compound. Of 0.1 to 200 mg / m ^{2 in} terms of P, the adhesion amount of the silane coupling agent is 0.1 to 180 mg / m ^{2 in} terms of Si, at least one metal compound selected from Al, Mg, and Mn The coating thickness is 0.01 to 1 by applying the coating amount so that the total amount in terms of Al, Mg and Mn is 1.0 to 400 mg / m ² and drying at a final plate temperature of 30 to 200 ° C. A surface treatment film having a thickness of 0.0 μm is formed, and the active layer is composed of a hydrazine derivative (C) in which the main component of the resin composition is a film-forming organic resin (A) and a part or all of the compounds have active hydrogen. A coating composition comprising a reaction product with the containing compound (B) is applied, and dried at a temperature of the ultimate plate temperature of 30 to 200 ° C., thereby forming an upper film with a film thickness of 0.5 to 2.0 μm. A method for producing a highly corrosion-resistant surface-treated steel sheet.