KR101781771B1 - Zinc or zinc alloy coated steel sheet with surface treatment film, and method of producing same - Google Patents

Abstract

(1) Excellent in inner Dakinability after severe ironing such as continuous high-speed press forming, (2) Excellent in peelability on inner flake plating after severe ironing such as continuous high-speed press forming (3) A zinc plated steel sheet provided with a surface treated coating capable of suppressing the dependence of the deposition amount on the black deformation. The zinc plated steel sheet having the surface treated coating of the present invention has a zinc plated steel sheet, a first coating on the zinc plated steel sheet, and a surface treatment coating containing a second coating on the first coating. The first and second coatings are formed by applying a surface treatment liquid containing a zirconium carbonate compound (A), a phosphoric acid compound (B), a tetraalkoxysilane (C) and a silane coupling agent (D) , And dried by heating. The first coating film contains a large amount of the phosphoric acid compound (B), and the second coating film contains a small amount of the phosphoric acid compound (B).

Description

[0001] DESCRIPTION [0002] ZINC OR ZINC ALLOY COATED STEEL SHEET WITH SURFACE TREATMENT FILM, AND METHOD OF PRODUCING SAME [0002]

The present invention relates to a zinc plated steel sheet in which a surface treated film formed on a surface of a zinc-based plated steel sheet is provided with a surface treated film suitable for use in an environmentally-friendly motor case containing no pollution control substances such as hexavalent chromium .

Conventionally, for the purpose of improving the corrosion resistance (whitening resistance, intrinsic adaptability, etc.), a steel sheet having been subjected to a chromate treatment with a treatment liquid containing chromic acid, dichromic acid or a salt thereof as a main component on the surface of a zinc plated steel sheet has been widely used . However, there is a growing demand for the adoption of a non-polluting surface-treated steel sheet which is not subject to a chromate treatment, that is, a so-called chrome-free treated steel sheet, from recent global environmental problems.

The zinc-plated steel sheet (hereinafter simply referred to as " steel sheet " in the section of the background art) on which such surface-treated coating is formed is often used as parts for automobiles, household appliances, OA equipment and the like. In particular, when used as a component such as a motor case, press molding such as drawing processing is performed. For example, continuous high-speed press forming in which 100 parts or more of a molded product is produced for 1 minute by applying a lubricating oil to the surface of the steel sheet and by using a pre-press press machine or the like may be performed. In a severe press environment such as continuous high-speed press forming, there has been a problem that the surface treatment film is peeled off due to the sliding of the steel plate and the metal, or a part of the zinc plated layer is peeled off. Further, peeling of the surface-treated coating film and the zinc-based coating layer causes metal luster on a part of the surface of the molded product, thereby significantly deteriorating the appearance and deteriorating the corrosion resistance.

Further, the peeled surface treated coating and the zinc-based plated layer are accumulated in the lubricating oil. These extremely fine exfoliations adhere to and remain on the subsequent press-molded article, resulting in darkening of the surface, thereby deteriorating the appearance after press-molding. Particularly, in the step of press molding using quick-drying oil, cleaning is not performed in the final step, but in the case of darkening, it is necessary to form a step of removing darkening, and productivity is deteriorated. In addition, deterioration of inner darkness caused by darkening which was not completely removed was also a problem.

In addition, the zinc plated steel sheet for the motor case is mostly used for uncoated, and the surface appearance is important. For this reason, it is required that the zinc plated steel sheet for the motor case is free from deterioration or discoloration of the surface from the manufacture to the press molding. Therefore, the zinc-plated steel sheet for use in the motor case is also required to have various performances of the plate portion corrosion resistance, black degeneration and anti-stain resistance.

Patent Document 1 discloses a method of forming a surface-treated coating film by a water-based surface treatment liquid containing a water-soluble zirconium compound, a water-dispersible fine particle silica, a silane coupling agent, a vanadic acid compound, a phosphoric acid compound, a nickel compound and an acrylic resin emulsion at a specific ratio , A method of obtaining a zinc-based plated steel sheet excellent in plate corrosion resistance, black weathering and excellent appearance after press molding and corrosion resistance is disclosed.

Patent Document 2 discloses a method of forming a surface-treated coating film by a surface treatment solution containing a lithium silicate, a silane coupling agent, a vanadium compound, a titanium compound, and a wax, and subjecting the substrate to dip coating, A technique of obtaining a steel sheet is described. Patent Document 3 discloses that darkening occurs when a surface treatment film is formed by a surface treatment liquid containing lithium silicate and sodium silicate as main components and further containing a silane coupling agent and a vanadium compound Thereby obtaining a zinc-plated coated steel sheet suppressed.

Japanese Patent Application Laid-Open No. 2008-169470 Japanese Laid-Open Patent Publication No. 2010-37584 Japanese Laid-Open Patent Publication No. 2010-215973

In the conventional press forming, press molding is carried out using a press oil having a high viscosity, and after the working, the press surface is usually degreased and cleaned with an organic solvent. Therefore, even if a darkening material adheres to the surface of the press, there is no problem if it can be cleaned, and it is sufficient to suppress darkening which is not completely cleaned. In recent years, however, as interest in the environment has increased, there has been a demand for omission of cleaning with an organic solvent after press molding using quick-drying oil. In this case, it is required that the surface of the press does not adhere well to the original darkening material. Moreover, since the quick-drying oil has a viscosity lower than that of the conventional press oil, the lubricity is not sufficient and it is more likely to cause darkening than the conventional press oil. Therefore, improvement of inner darkness at a higher level is required. Here, the technique of Patent Document 1 is directed to suppress darkening after press molding, but the inventors of the present invention have found that there is room for improvement from the viewpoint of improvement of the high darkening resistance.

In addition, when a strict machining is carried out such as a reduction in plate thickness with quick-drying oil, a very high surface pressure may be locally applied. In this case, there is a problem that abrasion occurs due to strong sliding of the mold and the steel sheet, a part of the zinc-based plated layer is peeled off on the flake, and the peeled product on the flake breaks the mold or the molded product by the subsequent pressing The inventors of the present invention have newly discovered what is caused. Patent Document 1 poses a problem of darkening accompanied by peeling of a zinc-based plated layer when high-speed continuous press forming is performed with a common press oil (see paragraph [0003]). However, the exfoliating material causing darkening is a very fine granular exfoliant such that it can not be seen even in the form of a grain in the naked eye. The above-mentioned exfoliating on the flakes Regarding water suppression, Patent Document 1 is not considered at all.

The technology of Patent Documents 2 and 3 is a technology in which lithium silicate forms a surface treatment coat from the surface treatment liquid of the main component. When the surface pressure is applied at the time of press forming, the surface treatment film is peeled off to expose the zinc-based plated layer, and the zinc-based coating has a problem in that the zinc-based plated layer and the zinc- Thereby causing a problem that the flake-like exfoliated material is generated from the zinc-based plated layer (the peelability of plating on the inner flake is inferior).

When the degree of change in color tone before and after the blackening greatly depends on the deposition amount of the surface treatment film, if the film thickness of the surface treatment film is non-uniform, the film is discolored due to unevenness of the film thickness after blackening, have. Therefore, even when the surface treated film is formed under the condition that the film thickness unevenness can occur, it is necessary that the black weathering does not depend on the adhesion amount of the surface treated film so that the uneven shape is not conspicuous after the blackening. Hereinafter, in the present specification, this property is referred to as " deposition amount dependence of the inner coat resistance ". In all of the above Patent Documents 1 to 3, no consideration is given to the dependence of the adhesion amount of the blackening resistance.

In the present invention, it is particularly important to use a steel sheet for a component of a motor case, (1) to improve inner darkness after severe ironing such as continuous high-speed press forming, (2) It was noted that the flaking resistance on the inner flake after the severe ironing processing such as molding was improved, and (3) the dependence of the deposition amount of the blackening resistance was suppressed.

That is, the present invention provides a flame retardant resin composition which is excellent in (1) resistance to internal darkening after severe ironing such as continuous high-speed press molding, (2) an inner flake phase after severe ironing such as continuous high- (3) A zinc-plated steel sheet having a surface-treated film capable of suppressing the dependence of the amount of coating on blackness, and a method for producing the same.

As a result of intensive investigations to solve the above problems, the present inventors have found that a zirconium carbonate compound (A) composed of a zirconium carbonate compound (A), a phosphate compound (B) Layered laminated film obtained by sequentially applying and drying two kinds of surface treatment liquids (X) and (Y) having different content ratios, thereby achieving the above-mentioned object, .

That is, the present invention provides the following (1) to (5).

(1) A zinc plated steel sheet,

A zinc plated steel sheet having a surface coating film having a first coating on the zinc plated steel sheet and a surface coating containing a second coating on the first coating,

Wherein the first coating film contains a zirconium carbonate compound (A), a phosphoric acid compound (B), a tetraalkoxy silane (C) and a silane coupling agent (D) having an epoxy group and satisfies the following condition (I) Coating the surface of the zinc plated steel sheet with a first surface treatment liquid (X) prepared so as to be heated and dried,

Wherein the second coating film contains a zirconium carbonate compound (A), a phosphoric acid compound (B), a tetraalkoxy silane (C) and a silane coupling agent (D) having an epoxy group and satisfies the following condition (II) A second surface treatment liquid (Y) prepared so as to be applied to the surface of the first coating film, followed by heating and drying,

Wherein the total coating amount of the first and second coatings is 0.2 to 2.0 g / m < 2 > per one side.

(I) of the solid content mass (B ₁ ) of the phosphate compound (B) in terms of P and the solid mass (A ₁ ) of the zirconium carbonate compound (A) in terms of Zr in the first surface treatment liquid (X) When the ratio (B ₁ / A ₁ ) exceeds 0.30 to not more than 2.20

(II) of the second surface treatment liquid (Y) of the phosphoric acid compound (B) solid content by weight (B ₂₎ and, Zr solid mass (A ₂₎ of the weight of the zirconium carbonate compound (A) of P in terms of (B ₂ / A ₂ ) of not less than 0.05 and not more than 0.46 and the solid content ratio (B ₁ / A ₁ ) of (I) is more than 0.30 but not more than 0.46, the solid content ratio (B ₂ / A ₂ ) (a).

(B ₁ / A ₁ )> (B ₂ / A ₂ ) ... (A)

(2) The phosphoric acid compound (B) is at least one of the first and second surface treatment liquids (X, Y), the inorganic phosphate compound and the organic phosphate compound, (1), wherein the solid content mass (B _in ) and the solid content mass (B _og ) of the organic phosphoric acid compound in terms of P (B _in / B _og ) are 0.1 to 1.5, .

(3) At least one of the first and second surface treatment liquids (X, Y) contains at least one of the hydroxycarboxylic acid (E), the vanadic acid compound (F), and the nickel compound (1) or (2), wherein the surface-treated coating is formed on the surface-treated coating film.

(4) The fluorine resin composition according to any one of (1) to (4), wherein at least one of the first and second surface treatment liquids (X, Y) contains a fluororesin emulsion (H) Coated steel sheet according to any one of (1) to (3), wherein the surface-treated coating is formed.

(III) When the fluororesin emulsion (H) is contained in the first surface treatment liquid (X), the solid mass of the fluororesin emulsion (H) and the total solid mass of the first surface treatment liquid (H ₁ / X ₁ ) of from 0.001 to 0.100

(IV) When the fluororesin emulsion (H) is contained in the second surface treatment liquid (Y), the solid mass of the fluororesin emulsion (H) and the total solid mass of the second surface treatment liquid (H ₂ / Y ₂ ) of from 0.001 to 0.100

(5) The method according to any one of (1) to (4) above, wherein the adhesion amount of the first coating film is 0.1 to 1.5 g / m 2 per one side and the deposition amount of the second coating film is 0.1 to 1.5 g / A zinc plated steel sheet having a surface treated coating formed thereon.

(6) A method for producing a zinc-coated steel sheet, comprising the steps of applying a first surface treatment liquid (X) of any one of the above items (1) to (4) ; A step

A step of applying a second surface treatment liquid (Y) in any one of the above-mentioned (1) to (4) onto the surface of the first coating film and heating and drying to form a second coating film on the surface of the first coating film , And the total deposition amount of the surface-treated coatings composed of the first and second coatings is set to 0.2 to 2.0 g / m < 2 > per one side of the coated surface.

The zinc plated steel sheet on which the surface treated film of the present invention is formed and the zinc plated steel sheet on which the surface treated film obtained by the manufacturing method of the present invention are formed have the following characteristics: (1) the inner darkness after a severe ironing process such as continuous high- (2) excellent flaking resistance on the inner flake after severe ironing such as continuous high-speed press forming, and (3) the dependence of the deposition amount on the blackening resistance can be suppressed.

1 (A) is a surface of a second coating formed by heating and drying a second surface treatment liquid (Y) containing a fluororesin emulsion having an MFT of 40 占 폚 at 100 占 폚. 1 (B) is a surface of a second coating formed by heating and drying a second surface treatment liquid (Y) containing a fluororesin emulsion having an MFT of 40 占 폚 at 30 占 폚.

Hereinafter, embodiments of the present invention will be described in detail.

<Zinc-plated steel plate>

In the present invention, the zinc-base plated steel sheet to be the base may be a steel sheet containing zinc in its plated layer and is not particularly limited, but a hot-dip galvanized steel sheet (GI) or a galvannealed galvanized steel sheet (GA) Zn-Al-Mg coated steel sheet (for example, Zn-6 mass% Al-3 mass% Mg alloy plated steel sheet, Zn-11 mass), zinc-plated steel sheet such as galvanized steel sheet (EG) % Al-3 mass% Mg alloy plated steel plate), Zn-Al plated steel plate (for example, Zn-5 mass% Al alloy plated steel plate, Zn-55 mass% Al alloy plated steel plate).

The zinc plating layer may contain one or more of a small amount of dissimilar metal elements or impurities such as nickel, cobalt, manganese, iron, molybdenum, tungsten, titanium, chromium, aluminum, magnesium, lead, antimony, tin, do. Further, two or more of the same or different zinc plating layers may be plated.

<Zinc-based plated steel sheet having a surface treated film formed>

The zinc plated steel sheet having the surface treated film of the present invention has the zinc plated steel sheet and the surface treated film formed on at least one side of the zinc plated steel sheet. The surface treated film includes a first coating on the zinc plated steel sheet and a second coating on the first coating. The first coating film is obtained by applying a first surface treatment liquid (X) to be described later to the surface of a zinc plated steel sheet, followed by heating and drying. The second coating film is obtained by applying a second surface treatment liquid (Y), which will be described later, to the surface of the first coating film, followed by heating and drying.

&Lt; First surface treatment liquid (X) and second surface treatment liquid (Y) &gt;

The first and second surface treatment liquids (X and Y) are prepared by mixing a zirconium carbonate compound (A), a phosphoric acid compound (B), a tetraalkoxy silane (C), a silane coupling agent (D) having an epoxy group, And at least one of the hydroxycarboxylic acid (E), the vanadic acid compound (F), the nickel compound (G), and the fluororesin emulsion (H) may be contained if necessary.

The first and second surface treatment liquids (X, Y) contain a zirconium carbonate compound (A). When a surface treatment liquid containing a zirconium carbonate compound is used and dried, a surface treated coating film which is not dissolved in water is obtained, so that a steel sheet excellent in flat portion corrosion resistance and anti-scattering property can be obtained. In addition, since the adhesion of the surface treated film is excellent, even if the press forming is carried out, a steel sheet excellent in the anti-darkening property, the flaking resistance on the flaky plating, and the corrosion resistance can be obtained.

As the zirconium carbonate compound (A), for example, salts of sodium, potassium, lithium, ammonium and the like of a zirconium carbonate compound can be used, and one kind or two kinds or more of them can be used. Among them, use of zirconium carbonate ammonium can improve the anti-stain property or is preferable in some respects.

The first and second surface treatment liquids (X, Y) contain a phosphoric acid compound (B). The phosphoric acid compound in the first surface treatment liquid (X), when brought into contact with the zinc-based plated layer, is etched to form a reaction layer composed of zinc and a poorly soluble metal salt on the surface of the steel plate. In addition, zirconium phosphate is produced by the reaction with the zirconium carbonate compound (A). When the phosphoric acid compound in the second surface treatment liquid (Y) comes into contact with the first coating film, zirconium phosphate is produced in the second coating film while forming a reaction layer with the first coating film. By these reaction layers and zirconium phosphate, a steel sheet excellent in inner Dakinability, flaking resistance in plating on an inner flake, and corrosion resistance can be obtained even if strict press forming is performed. In addition, since the phosphate compound is present in the surface treated film in a state in which it is easily dissolved in water, the zinc ions dissolved in the corrosion are captured and insolubilized, so that the conventional flat surface corrosion resistance can be improved.

The phosphoric acid compound (B) is not particularly limited as long as it is soluble in the first and second surface treatment liquids (X, Y), and at least one selected from an inorganic phosphoric acid compound and an organic phosphoric acid compound can be used. Examples of the inorganic phosphoric acid compound include phosphoric acid, primary phosphate, secondary phosphate, tertiary phosphate, condensed phosphate such as pyrrole phosphate, tripolyphosphate and tripolyphosphate, phosphorous acid, phosphite, Phosphate and the like can be used. As the organic phosphoric acid compound, a phosphonic acid or a phosphonic acid salt can be used, and examples thereof include nitrilotrismethylenephosphonic acid, phosphonobutanetricarboxylic acid, ethylenediaminetetramethylenephosphonic acid, methyldiphosphonic acid, methylenephosphine Ethylidene diphosphonic acid, and their ammonium salts and alkali metal salts. With respect to plating flaking on the flakes, it is preferable to use an inorganic phosphoric acid compound from the viewpoint that it is easier to form a less soluble metal salt. In the case of using an organic phosphoric acid compound, It is preferable to use phosphonic acid.

The present invention is characterized in that the first and second surface treatment agents (X, Y) are prepared by mixing the zirconium carbonate compound (A) and the phosphoric acid compound (B) at different specific mixing ratios. By using the surface treatment agents (X, Y) having different blending ratios to form the first and second coatings respectively, and laminating these coatings on the surface of the steel sheet, an effect that is not obtained in the single layer coating can be obtained.

Specifically, the first surface treatment agent (X) has a phosphoric acid-rich composition. By using such a surface treatment agent (X), a more viscous salt is liable to be formed, and even if rigorous press molding is carried out, a first coating film excellent in peelability and corrosion resistance on the flaking plating can be obtained. On the other hand, the second surface treatment agent (Y) has a rich composition of the zirconium carbonate compound. By using such a surface treatment agent (Y), the excess phosphoric acid compound (B) in the first coating film and the zirconium carbonate compound (A) of the second surface treatment agent (Y) , Zirconium phosphate is produced on the surface of the first coating film (near the boundary between the first coating film and the second coating film). In the second coating film, when the barrier property is emphasized in this manner, the dependence of the adhesion amount of the blackening resistance can be sufficiently suppressed.

In the first surface treatment liquid X, the ratio (B ₁ / A ₁ (A ₁ )) of the solid mass (B ₁ ) of the phosphate compound (B) to the solid mass (A ₁ ) in terms of Zr of the zirconium carbonate compound ) Is more than 0.30 and not more than 2.20, preferably 0.50 to 1.30. (B ₁ / A ₁ ) exceeds 2.20, since the phosphoric acid compound (B) is excessive, the weathering resistance and the stain resistance are reduced, and the dependence of the adhesion amount of the blackening resistance is also increased. (B ₁ / A ₁ ) is not more than 0.30, the Zr is excessive and the film is retreated, so that the flat portion corrosion resistance becomes insufficient and the flaking resistance and the corrosion resistance of the flaky finish after the press molding are not sufficiently obtained.

In the second surface treatment agent (Y), the ratio (B ₂ / A (A ₂ )) of the solid content mass (B ₂ ) of the phosphoric acid compound (B) to the solid content mass ₂ ) in the range of more than 0.05 and not more than 0.46, more preferably not less than 0.08 and not more than 0.30, and more preferably not less than 0.10 and not more than 0.20. When the solid content ratio (B ₁ / A ₁ ) of (I) is more than 0.30 but not more than 0.46, the solid content ratio (B ₂ / A ₂ ) needs to satisfy the following formula (a).

(B ₁ / A ₁ )> (B ₂ / A ₂ ) ... (A)

(B ₂ / A ₂ ) exceeds 0.46, or when the formula (a) is not satisfied, the effect of making the surface treated coating two-layered can not be obtained, that is, The adhesion amount dependency of the gender is increased. (B ₂ / A ₂ ) is 0.05 or less, the reactivity with the first coating is lowered due to the insufficient amount of the phosphoric acid compound (B), and the excessive Zr results in poor adhesion to the first coating It is impossible to obtain sufficient flaking resistance on the inner flake after plate forming, plate corrosion resistance, and corrosion resistance after press forming.

Inorganic phosphoric acid compounds are likely to generate metal salts with zinc and zirconium. Further, since the organic phosphoric acid compound has excellent liquid stability (since it has the effect of chelating zinc slightly released from the surface of the zinc-based plated layer into the surface treatment solution and preventing the generation of precipitates), it is preferable to use both of them . In this case, the ratio (B _in / B _og ) of the solid content mass (B _in ) of the inorganic phosphoric acid compound to the solid content mass (B _og ) of the organic phosphoric acid compound in terms of P is preferably 0.1 to 1.5, More preferably 0.3 to 1.3. When the mass ratio is 0.1 or more, it is possible to further improve the peelability of plating on the inner flake at the time of the strict press forming, and when it is 1.5 or less, the black marking and the dirt stain resistance are not lowered. The organic phosphoric acid compound is preferably a phosphonic acid.

The first and second surface treatment liquids (X, Y) contain tetraalkoxysilane (C). Tetraalkoxysilane is a Si compound that is much more dense than colloidal silica and, when dissolved in water, hydrolyzes to generate silanol groups. This silanol group is three-dimensionally crosslinked with a silane coupling agent (D) having an epoxy group described later and a zirconium carbonate compound (A), and a surface treatment film excellent in adhesion with the zinc based plated layer can be obtained very densely. Therefore, it contributes to the improvement of the flat portion corrosion resistance, the black deformation and the dirt stain resistance, and also the anti-darkening and the corrosion resistance after press molding.

The tetraalkoxysilane (C) is not particularly limited as long as it contains four lower alkoxyl groups (for example, methoxy group, ethoxy group and propoxy group) as hydrolyzable groups in one molecule, Actual periods may be all or part of the same, or all may be different. As the tetraalkoxysilane (C), for example, tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane and the like can be given, and at least one of them can be used. Among them, the use of tetraethoxysilane and / or tetramethoxysilane is preferable from the viewpoint of more satisfactorily obtaining the respective effects described above.

The ratio (C / A) of the solid content of tetraalkoxysilane (C) to the solid content in terms of Zr of the zirconium carbonate compound (A) is set to 0.05 to 1.80 in the first and second surface treatment liquids , And more preferably 0.25 to 0.90. When the mass ratio is not less than 0.05, the effects of improving the flatness corrosion resistance, black degeneration, anti-dirtiness, anti-darkening property and corrosion resistance after press molding can be obtained more satisfactorily. When the mass ratio is 1.80 or less, The peelability and the corrosion resistance of plating on the inner flakes after press forming are further improved.

The first and second surface treatment liquids (X, Y) contain a silane coupling agent (D) having an epoxy group. The silane coupling agent having an epoxy group, together with the zirconium carbonate compound (A) and the tetraalkoxysilane (C), is extremely dense and the silanol group generated by the hydrolysis of the silane coupling agent is a zeolite- Contributes to the formation of a surface-treated film having excellent adhesion of the reaction layer made of a metal salt.

The silane coupling agent (D) having an epoxy group is particularly limited as long as it contains a glycidyl group and a lower alkoxyl group (for example, a methoxy group, an ethoxy group and a propoxy group) as a hydrolyzable group in one molecule containing Si For example, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 2- (3,4-epoxycyclohexyl ) Ethyltriethoxysilane, and the like, and at least one of them can be used.

The ratio (D / A) of the solid content of the silane coupling agent (D) to the solid content in terms of Zr of the zirconium carbonate compound (A) is 0.05 to 0.50 in the first and second surface treatment liquids (X, Y) , More preferably 0.10 to 0.35. When the mass ratio is not less than 0.05, the effect of improving the corrosion resistance on the flat portion, the weathering resistance on the black surface, the stain resistance on the surface, and the corrosion resistance after the rigid press molding can be sufficiently obtained. When the mass ratio is 0.50 or less, It is possible to further improve the plating releasability, the hardening resistance and the corrosion resistance on the inner flake after the severe press forming.

The first and second surface treatment liquids (X, Y) may contain a hydroxycarboxylic acid (E). By containing the hydroxycarboxylic acid (E), the phosphoric acid compound (B) can be stably mixed at a high concentration for a long period of time in the surface treatment liquid containing the zirconium carbonate compound (A). That is, phosphoric acid and zirconium carbonate tend to precipitate crystals of zirconium phosphate in an alkali solution and tend to lower the liquid stability. By mixing a predetermined amount of the hydroxycarboxylic acid (E), zirconium carbonate is stabilized So that precipitation of zirconium phosphate can be stably suppressed for a long period of time. As a result, the phosphate compound (B) can be compounded at a high concentration. As a result, the adhesion of the surface treated film can be enhanced as described above. As a result, excellent flake resistance and peeling resistance have. Further, the hydroxycarboxylic acid (E) is considered to make the three-dimensional crosslinked structure of the tetraalkoxysilane (C), the silane coupling agent (D) having an epoxy group and the zirconium carbonate compound (A) It is possible to further improve the peelability of plating on the inner flake after strict press forming, in addition to the plate portion corrosion resistance, the black weathering and the dust scattering.

The hydroxycarboxylic acid (E) includes, for example, lactic acid, tartaric acid, malic acid, and citric acid, and at least one selected from them can be used.

(E ₁ / A) of the solid content mass (E ₁ ) of the hydroxycarboxylic acid (E) to the solid mass (A ₁ ) in terms of Zr of the zirconium carbonate compound (A) ₁ ) is preferably 0.05 to 0.87, more preferably 0.15 to 0.40. (E ₁ / A ₁₎ is more than 0.05, the solution stability of surface treatment liquid (X) in a holding state for a long period of time reliably, a (B ₁ / A ₁₎ specified in the present invention the amount of 0.30 greater than 2.20 or less Of phosphoric acid compound (B) can be compounded. Therefore, in order to obtain the effect of the present invention in the case where (E ₁ / A ₁ ) is less than 0.05, it is preferable to coat and dry within 3 days after preparation of the surface treatment liquid (X). (E ₁ / A ₁ ) is 0.05 or more, the surface treatment liquid X can be stably used for one month or more. (E ₁ / A ₁ ) is more than 0.87, the hydroxycarboxylic acid (E ₁ ) is contained in an excess amount more than the amount required for water stabilization of the Zr in the surface treatment liquid. Therefore, A large amount of components effective for water-storage stabilization of the coating film remains. Therefore, there is a possibility that the surface-treated film-forming property is inferior, and particularly, the stain resistance is reduced.

(E ₂ / A) of the solid content mass (E ₂ ) of the hydroxycarboxylic acid (E) and the solid mass (A ₂ ) in terms of Zr of the zirconium carbonate compound (A) ₂ ) is preferably 0.05 to 0.87, more preferably 0.15 to 0.40. (B ₂ / A ₂ ) defined in the present invention is in the range of 0.05 to 0.46 in a state where the liquid surface stability of the surface treatment liquid (Y) is maintained when the ratio (E ₂ / A ₂ ) (B) may be blended. (E ₂ / A ₂ ) is more than 0.87, the hydroxycarboxylic acid (E ₂ ) is contained in an excess amount more than that required for water stabilization of the Zr in the surface treatment liquid. Therefore, A large amount of components effective for water-storage stabilization of the coating film remains. Therefore, there is a possibility that the surface-treated film-forming property is inferior, and particularly, the stain resistance is reduced.

The first and second surface treatment liquids (X, Y) may contain a vanadic acid compound (F). The vanadinic acid compound is present in a state in which it easily dissolves in water throughout the film, and acts as an inhibitor at the time of zinc corrosion, so that a steel sheet excellent in corrosion resistance can be obtained. Examples of the vanadic acid compound include ammonium metavanadate, sodium metavanadate and vanadium acetylacetonate, and at least one of these may be used.

(F / A) of the solid content of the vanadic acid compound (F) in terms of V and the solid content in terms of Zr of the zirconium carbonate compound (A) among the first and second surface treatment liquids (X, Y) It is preferably 0.02 to 0.30, more preferably 0.03 to 0.20. When the mass ratio is 0.02 or more, the flat portion corrosion resistance and the corrosion resistance after press forming are not lowered, and when the ratio is 0.30 or less, the stain resistance and the black weather resistance are not lowered.

The first and second surface treatment liquids (X, Y) may contain a nickel compound (G). The nickel compound (G) is present as ions in the surface treatment liquid. When the nickel compound (G) is in contact with zinc, part of the nickel compound (G) is displaced on the surface of zinc by ionization tendency It is believed that the surface of the zinc is concentrated on the surface of the zinc to modify the surface of the zinc, thereby preventing the blackening of the zinc. Examples of the nickel compound include nickel nitrate, nickel sulfate, nickel carbonate, nickel chloride and nickel phosphate, and at least one of them can be used.

The ratio (G / A) of the solid content of the nickel compound (G) in terms of Ni to the solid content in terms of Zr of the zirconium carbonate compound (A) 0.16, and more preferably 0.03 to 0.08. When the mass ratio is 0.02 or more, the weathering resistance is not lowered. When the mass ratio is 0.16 or less, the flat portion corrosion resistance and the corrosion resistance after press forming are not lowered.

At least one of the first and second surface treatment liquids (X, Y) may contain a fluororesin emulsion (H). The surface treated film obtained by applying the surface treatment liquid to which the fluororesin emulsion (H) has been added and heating and drying has a surface energy lowered because the fluororesin emulsion is wetted and spread to cover the surface of the film, So that the oil wettability is improved. Thus, when the steel plate is used in the motor case, the lubricating oil is not sufficiently leaked from the bearing portion of the motor, and the lubricating oil is appropriately held in the bearing portion, so that vibration and noise of the motor can be suppressed.

As will be described later, when a large amount of the fluororesin emulsion (H) is added, the organic component derived from the resin becomes excessively large, and the inner darkening property after the press molding is lowered. In the single-layered coating, it is difficult to achieve both of the sufficient surface energy reduction effect and the resistance to intrinsic darkening. However, by distributing the fluororesin emulsion (H) to the first coating and the second coating, sufficient surface energy reduction effect and intrinsic darkness can be achieved . First, when the fluororesin emulsion (H) is contained in the second coating, since the fluororesin can be concentrated on the surface side of the surface treated coating, as compared with the case of using an equivalent amount of the fluororesin emulsion (H) The surface energy reduction effect becomes higher. Therefore, a sufficient oil-wettability can be obtained even after processing with a content that does not deteriorate the inner ductility. When the fluororesin emulsion (H) is contained in the first coating film, occurrence of darkening is suppressed because the first coating film is protected by the second coating film during press working. By press working, fine cracks are generated in the surface treated film, whereby the first film appears from the space between the second coating films and the oil wettability is manifested. In this case, if the surface energy of the second coating film is adjusted to be high, there is no fear that the coating film will overturn the press oil and affect the press at the time of pressing.

The fluororesin emulsion (H) is not particularly limited as long as it is a homopolymer of a fluorinated acrylate monomer or a copolymer of a fluorinated acrylate monomer and an ethylenic monomer such as ethylene, styrene, acrylic acid, methacrylic acid or methacrylic acid ester, If there is compatibility, there is no limitation on the presence or absence of an emulsifier or the like.

When the first surface treatment liquid X contains the fluororesin emulsion H, the solid mass H ₁ of the fluororesin emulsion H and the total solid mass X ₁ of the first surface treatment liquid X (H ₁ / X ₁ ) of from 0.001 to 0.100, preferably from 0.003 to 0.070. Even when the second surface treatment liquid Y contains the fluororesin emulsion H, the solid mass H ₂ of the fluororesin emulsion H and the total solid mass H _{2 of} the second surface treatment liquid Y (Y ₂₎ ratio is required to be a (H ₂ / Y ₂₎ 0.001 ~ 0.100, it is preferable that the 0.003 ~ 0.070. When the mass ratio is less than 0.001, the effect of suppressing the wetting of the oil is lowered. When the mass ratio exceeds 0.100, the effect of suppressing the wetting of the oil is sufficient, but the organic component derived from the resin is too large So that the internal darkening property after the press forming is lowered. When the first surface treatment liquid (X) contains the fluororesin emulsion (H), when the second surface treatment liquid (Y) is coated on the first coating film, the first coating liquid is applied to the second surface treatment liquid Y ) On the surface of the substrate, so that the mass ratio is not more than 0.100.

The fluorine resin emulsion (H) preferably has a minimum film forming temperature (MFT) of 10 to 50 ° C. If the MFT is 10 占 폚 or higher, the inner darkening property after the press molding is not lowered, and the effect of the flaking on the inner flake after press forming can be reliably obtained. When the MFT is 50 DEG C or less, the corrosion resistance after press forming is not lowered.

Further, at the surface of the coating formed by heating and drying the surface treatment liquid (X or Y) at a temperature higher than the MFT of the contained fluorinated resin emulsion (H), the fluororesin emulsion is wetted and diffused. As a result, the oil-wettability is manifested. On the other hand, at the surface of the coating formed by heating and drying the surface treatment liquid (X or Y) at a temperature lower than the MFT of the contained fluororesin emulsion (H), the fluororesin emulsion does not spread well and is not diffused, The coating becomes insufficient. Therefore, the oil-wetting resistance property can not be sufficiently obtained. These phenomena can be confirmed by observing the contrast of the reflected electron image obtained under the condition of the incident voltage of 75 V, which can extract information of only the surface of the sample pole, using a scanning electron microscope (SEM). In this observation condition, the fluororesin component showing the oil-repelling effect is observed with a bright contrast as compared with the surrounding inorganic matrix.

1 (A) is a surface of a second coating formed by heating and drying a second surface treatment liquid (Y) containing a fluororesin emulsion having an MFT of 40 占 폚 at 100 占 폚. The wet fluoropolymer covers most of the coating surface. As a result, excellent oil-wettability can be obtained. On the other hand, FIG. 1 (B) is a surface of a second coating formed by heating and drying the second surface treatment liquid (Y) containing fluororesin emulsion having an MFT of 40 占 폚 at 30 占 폚. In this film, the fluororesin is not wetted to the surface of the film as compared with FIG. 1 (A). Therefore, sufficient oil wetting diffusibility can not be obtained.

Further, in the present invention, even when the first coating film contains a fluorine resin, sufficient oil-wettability can be obtained. The first surface treatment liquid X is heated and dried at a temperature higher than the MFT of the fluororesin emulsion containing the fluororesin emulsion in the first surface treatment liquid X to form the first film. Thereafter, a second coating film is formed on the first coating film. In this case, the surface of the first coating film, which is visible at the bottom of the fine cracks generated in the second coating film at the time of press forming, has a shape similar to that of FIG. 1 (A).

The first and second surface treatment solutions (X, Y) are obtained by mixing the above components in water such as deionized water, distilled water and the like. The solid fraction ratio of the first and second surface treatment liquids (X, Y) may be suitably selected. The pH of the first and second surface treatment liquids (X, Y) is not particularly limited, but in the case of adjusting the pH, ammonia or a salt thereof, the above-mentioned hydroxycarboxylic acid, Any one or more of them may be appropriately used. A water-soluble solvent, a defoaming agent, an antibacterial / antifungal agent, a coloring agent, a wettability improver for uniform coating, a surfactant and the like may be added to the first and second surface treatment liquids (X, Y) May be added. However, it is important that they are added to such an extent as not to impair the quality obtained in the present invention, and it is preferable that the addition amount is less than 5% by mass based on the total solid content of the surface treatment liquid. It is preferable that the first and second surface treatment liquids (X, Y) contain no solids other than the above. Further, in the present invention, since the compositions of the first and second surface treatment liquids (X, Y) are close to each other, even after coating the second surface treatment liquid (Y) There is no adverse effect that the component of the first coating film is eluted into the second coating film.

&Lt; Method of producing zinc plated steel sheet having surface treated coating film &gt;

The method for manufacturing a zinc-plated steel sheet in which the surface-treated coating film of the present invention is formed is characterized in that the first surface treatment liquid (X) is coated on the surface of the zinc-plated steel sheet and heated and dried, And a step of coating the surface of the first surface treatment liquid (Y) on the surface of the first coating, followed by heating and drying to form a second coating film on the surface of the first coating film.

The total deposition amount of the first and second coatings is 0.2 to 2.0 g / m 2 per one side. When the total adhesion amount is less than 0.2 g / m 2, the peelability of plating on the inner flakes after strict press molding can not be sufficiently obtained. On the other hand, if it exceeds 2.0 g / m 2, the inner darkness, .

The deposition amount of the first coating is preferably 0.1 to 1.5 g / m 2 per one side, and the deposition amount of the second coating is also preferably 0.1 to 1.5 g / m 2 per side. If the adhesion amount of the first coating film is 0.1 g / m &lt; 2 &gt; or more, the reaction layer comprising zinc and the hardly soluble metal salt can be sufficiently formed on the surface of the steel sheet, , There is no case where the amount of phosphoric acid is increased and the black pigmentation is lowered. When the adhesion amount of the second coating film is 0.1 g / m 2 or more, the barrier property is sufficient, and the black marking and the dirt stain resistance are further improved. When the coating amount is 1.5 g / m 2 or less, none.

As a method of applying the first and second surface treatment liquids (X, Y), an optimum method may be appropriately selected according to the shape and the like of the zinc plated steel sheet to be treated, and a roll coating method, a bar coating method, Spray coating method and the like. It is also possible to adjust the coating amount, uniformize the appearance, and uniform the film thickness by the air knife method or the roll squeeze method after application.

As a means for performing heat drying, a dryer, a hot air furnace, a high frequency induction heating furnace, an infrared furnace or the like can be used. The heating temperature is not particularly limited, but is preferably from 50 to 250 ° C, more preferably from 60 to 200 ° C, and most preferably from 60 to 180 ° C as the peak metal temperature (PMT). When the temperature is lower than 250 占 폚, cracks are not generated in the surface treated film and the corrosion resistance on the flat portion is not lowered. On the other hand, if the temperature is 50 캜 or higher, the various properties of the present invention are not deteriorated because the bonding between the components of the surface treated film is not insufficient. The optimum heating time is appropriately selected depending on the type of zinc plated steel sheet to be used and the like, preferably 0.1 to 60 seconds, more preferably 1 to 30 seconds from the viewpoint of productivity and the like.

Prior to applying the surface treatment liquid to the zinc plated steel sheet, pretreatment may be carried out on the zinc plated steel sheet for the purpose of removing oil and contamination on the surface of the zinc plated steel sheet, if necessary. The zinc plated steel sheet is often coated with anti-rust oil for rust prevention purposes, and even when oil is not applied by rust-preventive oil, there is oil or contamination adhered during the operation. By performing the above-mentioned pretreatment, the surface of the zinc-based plated layer is cleaned, and it becomes easy to wet uniformly. When there is no oil or contamination on the surface of the galvanized steel sheet and the surface treatment liquid is uniformly wetted, a pre-treatment step is not particularly required. The pretreatment method is not particularly limited, and examples thereof include a method such as hot water washing, solvent washing, and alkali degreasing.

Hereinafter, the effects of the present invention will be described with reference to examples, but the present examples are merely illustrative of the present invention and are not intended to limit the present invention.

Example

(1) Disclosure plate

Various zinc-plated steel sheets shown in Table 1 were used as a release plate. The zinc plated layer is formed on both surfaces of the steel sheet, and the adhesion amount in Table 1 means the adhesion amount of the zinc plated layer per one surface.

[Table 1]

(2) Pretreatment (cleaning)

The surface of the above described plate was treated with Pearlcreen N364S manufactured by Nihon Parkerizing Co., Ltd. to remove oil and contamination on the surface. Next, it was washed with tap water, and it was confirmed that the surface of the publicly known plate was wetted with water. Then, pure water (deionized water) was flowed again, and moisture was dried in an oven at 100 캜 atmosphere.

(3) Preparation of surface treatment liquid

The respective components were mixed in water at a composition (solid content mass ratio) shown in Table 2 to obtain a first surface treatment liquid (X) and a second surface treatment liquid (Y). These surface treatment solutions were immediately used for the test after preparation.

Hereinafter, the compounds used in Table 2 will be described.

&Lt; Zirconium carbonate compound (A)

A1: Zirconium carbonate sodium

A2: Zirconium carbonate ammonium

<Phosphoric acid compound (B)>

B1: phosphoric acid (H ₃ PO ₄₎

B2: ammonium dihydrogen phosphate _{(NH 4 (H 2 PO 4} ))

B3: diphosphonic acid (C ₂ H ₈ P ₂ O ₇ )

&Lt; Tetraalkoxysilane (C) &gt;

C1: tetramethoxysilane

C2: tetraethoxysilane

&Lt; Silane coupling agent having epoxy group (D) &gt;

D1: 3-glycidoxypropyltriethoxysilane

D2: 3-glycidoxypropyltrimethoxysilane

&Lt; Hydroxycarboxylic acid (E) &gt;

E1: malic acid

E2: Tartaric acid

E3: Citric acid

&Lt; Vanadic acid compound (F) &gt;

F1: sodium metavanadate (NaVO ₃₎

F2: ammonium metavanadate (NH ₄ VO ₃₎

&Lt; Nickel compound (G) &gt;

G1: Nickel nitrate hexahydrate (Ni (NO ₃ ) ₂ .6H ₂ O)

G2: nickel sulfate hexahydrate (NiSO ₄ · 6H ₂ O)

&Lt; Fluoro resin emulsion (H) &gt;

As the fluorinated alkyl group-containing acrylate and the acrylic acid alkyl ester copolymer, those having a minimum film-forming temperature (MFT) were used.

H1: MFT 5 DEG C

H2: MFT 14 DEG C

H3: MFT 33 C

H4: MFT 55 C

[Table 2-1]

[Table 2-2]

[Table 2-3]

[Table 2-4]

[Table 2-5]

[Table 2-6]

[Table 2-7]

[Table 2-8]

[Table 2-9]

(4) Processing method

Various kinds of first surface treatment liquids (X) shown in Table 2 were applied to various publicly known plates subjected to pretreatment for each of the steel plates shown in Table 1 (the numbers of the steel plates are shown in the column of "steel plate" in Table 2) Thereafter, the resultant was placed in an oven without washing with water and dried at the peak metal temperature (PMT) shown in the column of "PMT" in Table 2, and the first coating of the amount of coating . Next, various second surface treatment liquids (Y) shown in Table 2 were coated on the surface of the first coating film by a bar coater and thereafter put in an oven without water rinsing, And dried at a final plate temperature to form second coatings on both surfaces of the coating amount (per one surface) shown in Table 2.

(5) Method of evaluation test

The results of the following evaluations (5-1) to (5-9) are shown in Table 2 for the zinc plated steel sheet (hereinafter, simply referred to as "sample") on which the obtained surface treatment film was formed.

(5-1) Corrosion resistance of flat plate

Each sample was subjected to a salt water spray test (SST) in accordance with JIS-Z-2371-2000 in a state of being flat without pressing. The corrosion resistance of the plate portion was evaluated by the area ratio of white rust occurrence after 120 hours. The evaluation criteria are as follows.

(Evaluation standard)

◎: Less than 5% of white rust area

○: area of white rust less than 5% and less than 10%

○ -: Ratio of white rust less than 10% to less than 25%

△: Ratio of white rust area 25% or more and less than 50%

×: area ratio of white rust 50% or more and less than 100%

(5-2) Black degeneration

The color difference ΔL ^* (JIS-Z-8729-A) of the sample surface before and after the holding for 24 hours under the environment of 80 ° C. and 98% RH in the state of a flat plate without pressing is applied to each sample having a uniform film thickness of the surface- The difference in CIE 1976 brightness L ^* in the L ^* , a ^* , and b ^* indications specified in 2004) and visual observation. The evaluation criteria are as follows.

(Evaluation standard)

?: -2.5 &lt;? L ^* ? 1 Furthermore, a uniform appearance without unevenness

?: -3 <? L ^* ? -2.5 Further, a uniform appearance without unevenness

○ -: - 3.5 <ΔL ^* ≤ -3 In addition, uniform appearance without unevenness

?: -4 <? L ^* ? -3.5 Further,

×: ΔL ^* ≤ -4 or appearance unevenness

(5-3) Dependence of Deposition Amount of Black Degeneration

For each sample, a second sample of 1.2 times the deposition amount of Table 2 was prepared for both the first coating and the second coating. With respect to both the samples and the second sample corresponding to each sample, the color difference? L ^* described in (5-2) was measured in the state of a flat plate. DELTA (DELTA L ^* ) was determined from the following equation, and the dependence of the deposition amount on the resistance to lightness was evaluated.

^{Δ (ΔL *) = (ΔL} * of the sample) - (ΔL ^* in the second sample)

(Evaluation standard)

?: -0.5 <? (? L ^* )? 1.0

?: -1.0 <? (? L ^* )? -0.5

? - - - 1.5 <? (? L ^* )? -1.0

?: -2.0 <? (? L ^* )? -1.5

×: Δ (ΔL ^* ) ≦ -2.0

(5-4)

For each sample, 300 占 퐇 of deionized water was dripped on the surface of the sample in the state of a flat plate without being pressed, and the sample was placed in a hot air oven at 100 占 폚 for 10 minutes. After removing the water drop from the oven, Observation was made to evaluate the stain resistance. The evaluation criteria are as follows.

(Evaluation standard)

◎: Water droplet boundary is not confirmed regardless of viewing angle

○: The droplet boundary is slightly observed depending on the viewing angle.

○ -: The droplet boundary is slightly confirmed regardless of the viewing angle.

△: The water droplet boundary clearly confirmed regardless of the viewing angle

X: The droplet boundary clearly exceeds the dropping range.

(5-5) Inner Darkness (appearance after continuous high-speed press molding)

In each of the samples, a multi-stage drawing molding under the following press conditions was carried out in the state that the quick-press oil (oilless press machine G-6231F manufactured by Nihon Kokusaku Co., Ltd.) was oil coated, , And the degree of darkening attached to the surface of the 10th sample was observed with naked eyes and the darkening resistance was evaluated. The evaluation criteria are as follows.

(Press condition)

Molding speed 450 mm / sec, blank diameter 90 mm

First stage: punch diameter 49 mm, clearance of punch and die 1.0 mm

Second stage: punch diameter 39 mm, clearance of punch and die 0.8 mm

Third stage: punch diameter 32 mm, clearance between punch and die 0.8 mm

4th stage: punch diameter φ 27.5 mm, clearance of punch and die 0.8 mm

5th stage: punch diameter 24.4 mm, clearance of punch and die 0.8 mm

(Evaluation standard)

◎: Darkening is not attached to the sample surface immediately after the press.

○: Darkening is attached to the sample surface at an area ratio of 5% or less immediately after the press, but the darkening flows from the surface of the steel plate with time and becomes almost unidentifiable.

○ -: Darkening is attached to the sample surface at an area ratio of 5% or less immediately after the press, and darkening remains on the surface of the steel even after the elapse of time.

△: Darkening is attached to the sample surface at an area ratio of more than 5% and less than 15%, and darkening remains on the surface of the steel even after a lapse of time.

X: Darkening is attached to the sample surface at an area ratio exceeding 15%, and darkening remains on the surface of the steel even after a lapse of time.

(5-6) Plating peelability in flakes (appearance after plane drawing)

In each of the samples, under the conditions of oil application of quick-drying press oil (G-6231F manufactured by Nihon Kokusaku Co., Ltd.) without contamination and peeling residue attached to the mold, Was plunged three times in succession, and then the degree of the plating peeling residue attached to the sample surface was magnified to a loof and observed with naked eyes to evaluate the peeling resistance of the plating. The evaluation criteria are as follows.

(Press condition)

Bead tip diameter 0.5 mm, pressing load 200 kgf, drawing speed 16.7 mm / sec, drawing distance 100 mm

(Evaluation standard of plating peeling residue)

◎: The plating peeling residue does not have metallic luster and has a small amount and is fine granular.

?: The plating peeling residue does not have metallic luster and is a fine granular phase.

○ -: Plated peeling residue has metallic luster and fine granularity.

DELTA: Plating peeling residue has metallic luster and is scaly.

X: Plated peeling residue has a metallic luster, a large amount, and a planer-crumb phase.

(5-7) Corrosion resistance after continuous high-speed press forming

The samples subjected to the multi-stage drawing molding shown in the above ((5-5) Dakingability) were subjected to a salt water spray test according to JIS-Z-2371-2000 for each sample after the quick-drying press oil was dried . The corrosion resistance after continuous high-speed press forming was evaluated by the white rust occurrence area ratio after 16 hours. The evaluation criteria are as follows.

(Evaluation standard)

◎: Less than 5% of white rust area

○: area of white rust less than 5% and less than 10%

○ -: Ratio of white rust less than 10% to less than 25%

△: Ratio of white rust area 25% or more and less than 50%

×: area ratio of white rust 50% or more and less than 100%

(5-8) Oil Wet Diffusion Property (1)

Each sample was stretched at a stretching speed of 10 mm / min and an elongation of 20% using an electronic universal testing machine ("CATY" manufactured by YONEKURA CO., LTD.). ("ALL TIME J 652" manufactured by NOK Clover Co., Ltd.) having a kinematic viscosity of 51 to 69 mm 2 / s at 40 ° C. and a kinematic viscosity of 11.1 to 14.9 mm 2 / s at 100 ° C. were placed in a container, Was placed in the oil for bearing in the vessel and left standing at 85 캜 for 3 days to measure the blurring height of the oil for bearing. The evaluation criteria are as follows.

(Evaluation standard)

◎: Bleeding height less than 0.5 ㎝

○: Bleeding height 0.5 cm or more and less than 1.5 cm

○ -: Bleeding height 1.5 ㎝ or more and less than 3.0 ㎝

?: Spreading height of 3.0 cm or more and less than 4.5 cm

X: Bleeding height 4.5 cm or more

(5-9) Diffusion of oil wetting (2)

Each sample was stretched at a stretching speed of 10 mm / min and an elongation of 20% using an electronic universal testing machine ("CATY" manufactured by YONEKURA CO., LTD.). Thereafter, with each sample heated to 85 캜, the oil for bearing described in (5-8) was dropped onto the surface of the sample, and the mixture was dropped and allowed to stand at 85 캜 for 3 days. Thereafter, the contact angle of each sample was measured by a solid-liquid interface analyzer ("Drop Master 500" manufactured by Kyowa Interface Science Co., Ltd.). The evaluation criteria are as follows.

(Evaluation standard)

◎: Contact angle 40 ° or more

○: Contact angle 30 ° or more and less than 40 °

○ -: Contact angle 20 ° or more and less than 30 °

DELTA: Contact angle 10 DEG or more and less than 20 DEG

×: contact angle less than 10 °

(6) Consideration of evaluation result

As shown in Table 2, in the case of the present invention, severe ironing such as (5-5) inner darkening after severe ironing such as continuous high-speed press forming, and (5-6) continuous high- A zinc plated steel sheet having a surface treated film excellent in all of the flaking resistance on the flaky flakes and the dependency of the amount of blackening on the plating resistance after machining was obtained. In contrast, at least one of (5-6) and (5-3) was not excellent in the comparative example.

Examples of the plating solution containing the hydroxycarboxylic acid (E), the vanadic acid compound (F) and the nickel compound (G) are plate corrosion resistance, black degeneration and anti-dirtiness, And excellent in corrosion resistance after molding. The inventive example containing the fluororesin emulsion (H) was excellent in oil-wettability.

Industrial availability

The present invention is useful when providing a zinc plated steel sheet having a surface treated coating formed thereon for continuous high-speed press forming such as the use of parts such as a motor case.

Claims (6)

A galvanized steel plate,
A zinc plated steel sheet having a surface coating film having a first coating on the zinc plated steel sheet and a surface coating containing a second coating on the first coating,
Wherein the first coating film contains a zirconium carbonate compound (A), a phosphoric acid compound (B), a tetraalkoxy silane (C) and a silane coupling agent (D) having an epoxy group and satisfies the following condition (I) Coating the surface of the zinc plated steel sheet with a first surface treatment liquid (X) prepared so as to be heated and dried,
Wherein the second coating film contains a zirconium carbonate compound (A), a phosphoric acid compound (B), a tetraalkoxy silane (C) and a silane coupling agent (D) having an epoxy group and satisfies the following condition (II) A second surface treatment liquid (Y) prepared so as to be applied to the surface of the first coating film, followed by heating and drying,
Wherein the total coating amount of the first and second coatings is 0.2 to 2.0 g / m &lt; 2 &gt; per one side.
(I) of the solid content mass (B ₁ ) of the phosphate compound (B) in terms of P and the solid mass (A ₁ ) of the zirconium carbonate compound (A) in terms of Zr in the first surface treatment liquid (X) When the ratio (B ₁ / A ₁ ) exceeds 0.30 to not more than 2.20
(II) of the second surface treatment liquid (Y) of the phosphoric acid compound (B) solid content by weight (B ₂₎ and, Zr solid mass (A ₂₎ of the weight of the zirconium carbonate compound (A) of P in terms of (B ₂ / A ₂ ) is more than 0.05 and not more than 0.46 and the solid content mass ratio (B ₁ / A ₁ ) of the above (I) is more than 0.30 but not more than 0.46, the solid mass ratio (B ₂ / A ₂ ) (a).
(B ₁ / A ₁ )> (B ₂ / A ₂ ) ... (A) The method according to claim 1,
Wherein the phosphoric acid compound (B) comprises at least one of the first and second surface treatment liquids (X, Y), the inorganic phosphate compound and the organic phosphoric acid compound, and the solid content mass B _in ) and a ratio (B _in / B _og ) of the solid content mass (B _og ) of the organic phosphoric acid compound in terms of P is 0.1 to 1.5. 3. The method according to claim 1 or 2,
Wherein at least one of the first and second surface treatment liquids (X, Y) contains at least one of a hydroxycarboxylic acid (E), a vanadic acid compound (F), and a nickel compound (G) A zinc plated steel sheet having a treated film formed thereon. 3. The method according to claim 1 or 2,
Wherein at least one of the first and second surface treatment liquids (X, Y) contains a fluororesin emulsion (H) and satisfies the following conditions (III), (IV) or (III) Coated zinc plated steel sheet.
(III) When the fluorine resin emulsion (H) is contained in the first surface treatment liquid (X), the solid mass (H ₁ ) of the fluorine resin emulsion (H) (H ₁ / X ₁ ) of the total solid mass (X ₁ )
(IV) When the second surface treatment liquid (Y) contains the fluororesin emulsion (H), the solids mass (H ₂ ) of the fluororesin emulsion (H) (H ₂ / Y ₂ ) of the total solid mass (Y ₂ ) 3. The method according to claim 1 or 2,
Wherein the coating amount of the first coating is 0.1 to 1.5 g / m 2 per one side and the amount of the second coating is 0.1 to 1.5 g / m 2 per one side. Coating a surface of the zinc plated steel sheet with the first surface treatment liquid (X) according to claim 1 or 2 and heating and drying it to form a first coating film on the surface of the zinc plated steel sheet;
A method for manufacturing a semiconductor device, comprising the steps of applying the second surface treatment liquid (Y) of claim 1 or 2 onto the surface of the first coating film and then heating and drying to form a second coating film on the surface of the first coating film,
Wherein a total deposition amount of the surface treatment film composed of the first and second coating films is set to 0.2 to 2.0 g / m 2 per one side surface.

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