JP5602081B2 - Surface-treated steel sheet excellent in pest repellency and method for producing the same - Google Patents

Description

  The present invention relates to a surface-treated steel sheet having excellent repellency and corrosion resistance against pests such as living pests, hygiene pests, and unpleasant pests, and a method for producing the same.

  Inside cooking appliances such as gas tables, gas stoves, and IH cooking heaters, and household appliances such as refrigerators, washing machines, and microwave ovens are warm and humid, and thus are favored by insects such as cockroaches. In fact, pests enter these home appliances, causing various safety and hygiene damages.

In order to solve such a problem, it has been proposed to form an organic resin film (repellent film) containing an insect repellent on the surface of a steel sheet used for home appliances. For example, Patent Documents 1 and 2 disclose insect-proof steel sheets in which an aqueous organic resin treatment solution containing a pyrethroid insect repellent is applied to the surface of the steel sheet and dried to form an organic resin film (repellent film). ing. Since the pyrethroid insect repellent is hardly soluble in an aqueous solvent, it is considered that the particles of the pyrethroid insect repellent are dispersed in the organic resin film in the insect repellent steel sheets described in Patent Documents 1 and 2. In addition, in the insect-proof steel plates described in Patent Documents 1 and 2, in order to ensure weldability, the film thickness of the organic resin film is reduced to 0.5 to 4 μm (attachment amount is 0.5 to 4 g / m ² ). ing.

JP 2006-231690 A JP 2009-114169 A

  By using the insect-proof steel plates described in Patent Documents 1 and 2, damage caused by insects such as cockroaches can be prevented. However, the insect-proof steel plates described in Patent Documents 1 and 2 have a problem that the base steel plate is easily corroded.

  As described above, a place where pests such as the inside of home appliances prefer to gather is high temperature and high humidity, so that the base steel sheet is easily corroded. The insect-proof steel plates described in Patent Documents 1 and 2 are manufactured by forming a single thin organic resin film on the surface of a base steel plate. Therefore, when a defect such as a pinhole is present in the organic resin film, corrosive components such as moisture and salt easily reach the base steel plate through the defective portion and corrode the base steel plate. In particular, when the dispersed insect repellent penetrates the organic resin film, the insect repellent itself becomes a defect, and the corrosion resistance is lowered.

  This invention is made | formed in view of this point, and it aims at providing the surface treatment steel plate (insect-proof steel plate) which is excellent not only in the repellent property to a pest but also in corrosion resistance, and its manufacturing method.

  The inventor has found that the above problem can be solved by forming a chemical conversion film containing valve metal and phosphate between the base steel sheet and the organic resin film (repellent film), and completed the present invention. It was.

That is, the present invention relates to the following surface-treated steel sheets.
[1] A plated steel sheet; a chemical conversion film containing a valve metal compound and a phosphate formed on the surface of the plated steel sheet; and a pyrethroid insect repellent formed on the chemical conversion film and having a pyrethroid insect repellent content of 0. A surface-treated steel sheet having 1 to 10% by mass, an organic resin film having a thickness of 0.2 to 5 μm and containing 0.01 to 1% by mass of a hydrophobic organopolysiloxane.
[2] The surface-treated steel sheet according to [1], wherein the valve metal is Ti, Zr, Hf, V, Nb, Ta, Mo, W, or a combination thereof.
[3] The surface-treated steel sheet according to [1] or [2], wherein the chemical conversion treatment film includes a soluble or hardly soluble metal phosphate or composite phosphate.
[4] The surface-treated steel sheet according to any one of [1] to [3], wherein the chemical conversion film further includes an organic acid, an organic resin, or a combination thereof.
[5] The surface-treated steel sheet according to any one of [1] to [4], wherein the organic resin film further includes a lubricant.
[6] The pyrethroid insect repellent is (S) -α-cyano-3-phenoxybenzyl = (Z)-(1R, 3S) -2,2-dimethyl-3- [2- (2,2, The surface-treated steel sheet according to any one of [1] to [5], which is 2-trifluoro-1-trifluoromethylethoxycarbonyl) vinyl] cyclopropanecarboxylate.
[7] The hydrophobic organopolysiloxane is any one of [1] to [6], which is one or a combination of two or more polyoxyethylene-modified organopolysiloxanes having a melting point in the range of 35 to 70 ° C. The surface-treated steel sheet according to claim 1.

Moreover, this invention relates to the manufacturing method of the following surface treatment steel plates.
[8] A step of preparing a plated steel plate, a step of applying a chemical conversion treatment solution containing a valve metal compound and a phosphate to the surface of the plated steel plate, and drying to form a chemical conversion treatment coating, and the chemical conversion treatment coating An organic resin, a pyrethroid insect repellent having a number average particle size of 3 μm or less, and a water-based organic resin treatment solution containing a hydrophobic organopolysiloxane are applied and dried to give a film thickness of 0.2 to Forming an organic resin film having a thickness of 5 μm; the aqueous organic resin treatment liquid is 0.1 to 10 parts by mass of the pyrethroid insect repellent with respect to 100 parts by mass of the solid, and the hydrophobic The manufacturing method of the surface-treated steel plate containing 0.01-1 mass part of organopolysiloxane.
[9] The method for producing a surface-treated steel sheet according to [8], wherein the valve metal is Ti, Zr, Hf, V, Nb, Ta, Mo, W, or a combination thereof.
[10] The method for producing a surface-treated steel sheet according to [8] or [9], wherein the chemical conversion treatment liquid contains a soluble or hardly soluble metal phosphate or composite phosphate.
[11] The method for producing a surface-treated steel sheet according to any one of [8] to [10], wherein the chemical conversion treatment liquid further includes an organic acid, an organic resin, or a combination thereof.
[12] The method for producing a surface-treated steel sheet according to any one of [8] to [11], wherein the aqueous organic resin treatment liquid further includes a lubricant.
[13] The pyrethroid insect repellent is (S) -α-cyano-3-phenoxybenzyl = (Z)-(1R, 3S) -2,2-dimethyl-3- [2- (2,2, The method for producing a surface-treated steel sheet according to any one of [8] to [12], which is 2-trifluoro-1-trifluoromethylethoxycarbonyl) vinyl] cyclopropanecarboxylate.
[14] Any of [8] to [13], wherein the hydrophobic organopolysiloxane is one or a combination of two or more polyoxyethylene-modified organopolysiloxanes having a melting point in the range of 35 to 70 ° C. A method for producing a surface-treated steel sheet according to claim 1.

  ADVANTAGE OF THE INVENTION According to this invention, the surface treatment steel plate which is excellent in both the repellent property with respect to a pest and corrosion resistance can be provided. The surface-treated steel sheet of the present invention is suitable for applications that require both repellency against pests and corrosion resistance. For example, the surface-treated steel sheet of the present invention is suitable for uses such as cooking appliances such as gas tables, gas stoves, and IH cooking heaters, and household appliances such as refrigerators, washing machines, and microwave ovens.

SEM image of the surface of the surface-treated steel sheet of the present invention The schematic diagram which shows the structure of the surface treatment steel plate which concerns on one embodiment of this invention. Schematic diagram showing the configuration of the shelter used to evaluate cockroach repellency Schematic diagram showing shelter placement in the evaluation of cockroach repellency

1. Surface-treated steel sheet The surface-treated steel sheet of the present invention is a surface-treated steel sheet having excellent pest repellent properties, comprising 1) plated steel sheet, 2) chemical conversion film formed on the surface of the plated steel sheet, and 3) chemical conversion film And an organic resin film (repellent film) containing an insect repellent formed thereon. That is, the surface-treated steel sheet of the present invention is manufactured by sequentially forming a chemical conversion film and an organic resin film (repellent film) on the surface of the plated steel sheet.

  Hereinafter, each component of the surface-treated steel sheet of the present invention will be described.

1) Plated steel plate As the base steel plate (original plate), a plated steel plate having excellent corrosion resistance and design properties is used. The kind of plated steel plate is not particularly limited. Examples of plated steel sheets include galvanized steel sheets (electrical Zn plating, hot dip Zn plating), galvanized steel sheets (alloyed hot dip Zn plating alloyed after hot dip Zn plating), zinc alloy galvanized steel sheets (hot Zn-Mg). Plating, hot-dip Zn—Al—Mg plating, hot-dip Zn—Al plating), hot-dip Al-plated steel plate, hot-dip Al—Si-plated steel plate and the like are included.

  The base steel of the plated steel sheet is not particularly limited, and low carbon steel, medium carbon steel, high carbon steel, alloy steel, or the like is used. When workability is required, deep drawing steels such as low carbon Ti-added steel and low carbon Nb-added steel are preferred as the base steel.

2) Chemical conversion coating The chemical conversion coating is formed on the surface of the plated steel sheet and contains a valve metal compound and a phosphate. The chemical conversion treatment film improves the corrosion resistance of the plated steel sheet and improves the adhesion of the organic resin film to the plated steel sheet.

  The chemical conversion coating contains a valve metal compound that improves corrosion resistance and coating adhesion. Examples of the valve metal include Ti, Zr, Hf, V, Nb, Ta, Mo, and W. These may be used alone or in combination of two or more.

  The kind of valve metal compound is not particularly limited. From the viewpoint of imparting corrosion resistance and self-healing properties, the chemical conversion film preferably contains a valve metal oxide or hydroxide and a valve metal fluoride as the valve metal compound.

  Since the valve metal oxide and hydroxide exhibit high insulation resistance, the chemical conversion coating containing the valve metal oxide or hydroxide acts as a resistance against electron movement. Therefore, the chemical conversion treatment film containing the valve metal oxide or hydroxide suppresses the reduction reaction of dissolved oxygen contained in the moisture in the atmosphere, and also suppresses the oxidation reaction of the paired plated steel sheet. As a result, elution (corrosion) of metal components from the plated steel sheet is suppressed.

  The fluoride of the valve metal elutes from the chemical conversion film to the defective part, and is deposited on the surface of the plated steel sheet as a hardly soluble oxide or hydroxide. Therefore, even if a defect occurs in the chemical conversion coating during molding or the like, the chemical conversion coating containing the valve metal fluoride can repair defects in the chemical conversion coating and maintain the corrosion resistance.

  When the chemical conversion coating includes a valve metal oxide or hydroxide and a valve metal fluoride, the ratio of the valve metal oxide or hydroxide to the valve metal fluoride is F atoms relative to O atoms. The ratio (F / O) is preferably 1/100 or more. When the atomic ratio F / O is less than 1/100, sufficient self-repairability cannot be imparted. The O concentration and the F concentration in the chemical conversion coating can be measured by elemental analysis using fluorescent X-rays, ESCA, or the like.

The adhesion amount of the valve metal compound is preferably 1 mg / m ² or more in terms of valve metal from the viewpoint of ensuring corrosion resistance. When the adhesion amount of the valve metal compound is less than 1 mg / m ^{2 in} terms of valve metal, the corrosion resistance may not be sufficiently improved.

  The chemical conversion coating also includes a phosphate that improves corrosion resistance and coating adhesion. The kind of phosphate is not particularly limited. From the viewpoint of imparting corrosion resistance and self-healing properties, the chemical conversion film preferably contains a metal phosphate or a complex phosphate that is soluble or hardly soluble as a phosphate.

  Soluble metal phosphates and composite phosphates elute from the chemical conversion coating to defects and react with the plating components (Zn, Al, etc.) of the plated steel sheet to form insoluble phosphates. It precipitates in. Thus, soluble metal phosphates and complex phosphates complement the self-healing action of valve metal fluorides. Also, when the soluble metal phosphate or complex phosphate is dissociated, the atmosphere is slightly acidified, which accelerates the hydrolysis of the valve metal fluoride and the formation of the valve metal oxide or hydroxide. Is done. Examples of the metal constituting the soluble metal phosphate include alkali metals, alkaline earth metals, and Mn.

  Slightly soluble metal phosphates and composite phosphates are dispersed in the chemical conversion coating to make it difficult to cause defects and improve the strength of the chemical conversion coating. Examples of the metal constituting the hardly soluble metal phosphate include Al, Ti, Zr, Hf, and Zn.

From the viewpoint of ensuring corrosion resistance, the amount of phosphate adhered is preferably in the range of 5 to 100 mg / m ^{2 in} terms of P. When the adhesion amount of phosphate is less than 5 mg / m ^{2 in} terms of P, the corrosion resistance may not be sufficiently improved. On the other hand, when the adhesion amount of phosphate is more than 100 mg / m ^{2 in} terms of P, not only the corrosion resistance action is saturated, but also the amount of soluble components contained in the chemical conversion treatment film increases. Adhesion may be reduced.

  The chemical conversion treatment film may further contain an organic acid or an organic resin. The organic acid and the organic resin improve the adhesion of the organic resin film to the plated steel sheet by bonding a hydroxy group in the chemical structure to a surface of the plated steel sheet or a functional group (for example, a hydroxy group) of the organic resin film. The pyrethroid insect repellent (described later) blended in the organic resin film has low adhesion itself, and therefore decreases the adhesion of the organic resin film when blended. Therefore, it is preferable to add an organic acid or an organic resin to the chemical conversion film from the viewpoint of compensating for the decrease in film adhesion due to the pyrethroid insect repellent. The chemical conversion treatment film may contain only one of an organic acid and an organic resin, or may contain both.

  The type of organic acid is not particularly limited as long as it has a hydroxy group in its chemical structure. Examples of organic acids include tannic acid, tartaric acid, citric acid, malonic acid, lactic acid and the like. Of these, oxycarboxylic acids such as tartaric acid and polyhydric phenols such as tannic acid are particularly preferable because they also complement the self-repairing action of the valve metal fluoride.

  The type of organic resin is not particularly limited as long as it has a hydroxy group in the chemical structure. Examples of the organic resin include urethane resin, acrylic resin, epoxy resin, olefin resin, polyester resin, and fluororesin.

  The addition amount of the organic acid and the organic resin is not particularly limited, but from the viewpoint of sufficiently improving the film adhesion, the molar ratio of the total amount of the organic acid and the organic resin to the metal ion (organic acid and organic resin / metal ion) It is preferable that the amount is 0.02 or more.

3) Organic resin film (repellent film)
The organic resin film is formed on the surface of the chemical conversion film, and includes a pyrethroid insect repellent and a hydrophobic organopolysiloxane. The organic resin film gives the plated steel sheet a repellent effect against pests (insects) and improves the corrosion resistance of the plated steel sheet.

  The kind of organic resin which comprises an organic resin film is not specifically limited. Examples of the organic resin include polyester, urethane resin, acrylic resin, epoxy resin, olefin resin, fluorine resin, and the like. These organic resins may be used alone or in combination of two or more.

  The film thickness of the organic resin film is preferably in the range of 0.2 to 5 μm. When the film thickness of the organic resin film is less than 0.2 μm, the repellent effect against pests and the corrosion resistance cannot be sufficiently provided. On the other hand, when the film thickness of the organic resin film is more than 5 μm, it is not preferable from the viewpoint of production cost because performance improvement accompanying the increase in thickness cannot be expected.

  The organic resin film contains a pyrethroid insect repellent that imparts a repellent effect on pests (insects). The pyrethroid insect repellent is dispersed in the organic resin film in a particulate state, and a part thereof is exposed to the outside on the surface of the organic resin film. Since the pyrethroid insect repellent exhibits a repellent effect by direct contact with pests, at least a part of the pyrethroid insect repellent must be exposed to the outside on the surface of the organic resin film.

  The kind of pyrethroid insect repellent is not particularly limited. Examples of pyrethroid insect repellents include acrinatrin, permethrin, allethrin, D-tetramethrin, resmethrin, framethrin, phenothrin, permethrin, ciphenothrin, brathrin, etofenprox, cyfluthrin and the like. For example, as shown in Examples described later, acrinathrin ((S) -α-cyano-3-phenoxybenzyl = (Z)-(1R, 3S) -2,2-dimethyl-3- [2- (2 , 2,2-trifluoro-1-trifluoromethylethoxycarbonyl) vinyl] cyclopropanecarboxylate) and permethrin (3-phenoxybenzyl = (1RS, 3RS)-(1RS, 3SR) -3- (2,2 -Dichlorovinyl) -2,2-dimethylcyclopropanecarboxylate) can be suitably used.

  The amount of the pyrethroid insect repellent in the organic resin film is preferably in the range of 0.1 to 10% by mass. When the amount of the pyrethroid insect repellent is less than 0.1% by mass, a repellent effect against pests cannot be sufficiently provided. On the other hand, when the amount of the pyrethroid insect repellent exceeds 10% by mass, the corrosion resistance may be reduced. Further, even if the amount of the pyrethroid insect repellent exceeds 10% by mass, the repellent effect against pests is saturated, which is not preferable from the viewpoint of production cost.

  The organic resin film also includes a hydrophobic organopolysiloxane. Hydrophobic organopolysiloxane moves to the surface during film formation (drying process). At this time, the pyrethroid insect repellent also moves to the surface together with the hydrophobic organopolysiloxane and concentrates on the surface layer. That is, the hydrophobic organopolysiloxane promotes surface concentration of the pyrethroid insect repellent. Further, since hydrophobic organopolysiloxane has high hydrophobicity, pits (holes; one type of repelling) are formed around it. As a result, since the pyrethroid insect repellent present inside the organic resin film easily moves to the surface layer, the persistence of the repellent effect against pests is improved.

  FIG. 1 is an SEM image of the surface of the surface-treated steel sheet of the present invention (pyrethroid insect repellent: 5 mass%, organopolysiloxane: 0.2 mass%). 1A is an SEM image with a magnification of 1000 times, FIG. 1B is an SEM image with a magnification of 5000 times, and FIG. 1C is an SEM image with a magnification of 10000 times. As shown in these SEM images, pits are formed on the surface of the organic resin film by forming the organic resin film using an organic resin treatment liquid containing a hydrophobic organopolysiloxane.

The kind of the hydrophobic organopolysiloxane is not particularly limited, and may be linear or branched. For example, the hydrophobic organopolysiloxane may be a polyoxyethylene-modified organopolysiloxane having a melting point of 35 to 70 ° C. represented by the following general formula (1).
R ¹ ₂ R ² SiO— (R ¹ ₂ SiO) _n —SiR ¹ ₂ R ² (1)

In the above formula (1), R ¹ is the same or different substituted or unsubstituted monovalent hydrocarbon group having 1 to 18 carbon atoms. Examples of R ¹ are methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, dodecyl, tridecyl, tetradecyl, hexadecyl, octadecyl Alkyl groups such as cyclohexyl groups; cycloalkyl groups such as cyclohexyl groups; alkenyl groups such as vinyl groups and allyl groups; aryl groups such as phenyl groups and tolyl groups; aralkyl groups such as styryl groups and α-methylstyryl groups; A chloromethyl group, a 3-chloropropyl group, a 3,3,3-trifluoropropyl group, a cyanoethyl group, a 3-aminopropyl group in which part or all of the hydrogen atoms are substituted with a halogen atom, a cyano group, an amino group, or the like N- (β-aminoethyl) -γ-aminopropyl group, and the like. From the economical viewpoint, it is preferable that 80 mol% or more of R ¹ is a methyl group.

R ² is a polyoxyethylene group represented by the following general formula (2).
—R ³ —O (CH ₂ CH ₂ O) _c —R ⁴ (2)

In the above formula (2), R ³ is a divalent hydrocarbon group such as an alkylene group having 2 to 6 carbon atoms. Examples of R ³ include ethylene group, propylene group, butylene group, pentene group, hexene group and the like. R ⁴ is a hydrogen atom or an alkyl group having 1 to 6 carbon atoms. Examples of the alkyl group include methyl group, ethyl group, propyl group, butyl group, pentyl group and the like.

  In said Formula (2), c is 20-100, Preferably it is an integer of 25-50. When c is less than 20, the emulsifying dispersibility of the polyoxyethylene-modified organopolysiloxane of formula (1) is lowered (at this time, it becomes liquid at room temperature). On the other hand, when it exceeds 100, the melting point and the melt viscosity are increased, and workability is lowered.

  In the above formula (1), n is an integer of 1 to 150, preferably 10 to 100. When n is more than 150, the emulsification dispersibility of the polyoxyethylene-modified organopolysiloxane of formula (1) is lowered (at this time, it becomes liquid at room temperature).

  The polyoxyethylene-modified organopolysiloxane of the formula (1) may be used alone or in combination of two or more. In any case, the melting point of the polyoxyethylene-modified organopolysiloxane is 35 to 70 ° C, preferably 40 to 60 ° C.

  The amount of the hydrophobic organopolysiloxane in the organic resin film is preferably in the range of 0.01 to 1% by mass. If the amount of the hydrophobic organopolysiloxane is less than 0.01% by mass, the repellent effect against pests may be sustained only for a short period. On the other hand, when the amount of the hydrophobic organopolysiloxane exceeds 1% by mass, an excessive number of pits are formed in the organic resin film, which may reduce the corrosion resistance.

  The organic resin film may further contain a lubricant for improving processability, in addition to the pyrethroid insect repellent and the hydrophobic organopolysiloxane.

  The type of lubricant is not particularly limited. Examples of the lubricant include organic lubricants (low melting wax or high melting wax) such as fluorine, polyethylene and styrene, inorganic lubricants such as silica, molybdenum disulfide and talc. The low melting point organic wax bleeds on the surface of the film when the organic resin treatment liquid is dried, and exhibits lubricity. On the other hand, the high melting point organic wax and the inorganic lubricant are dispersed inside the organic resin film, but express the lubricity by being distributed in an island shape on the outermost layer.

  The amount of the lubricant in the organic resin film is preferably in the range of 0.5 to 5% by mass. When the amount of the lubricant is less than 0.5% by mass, the workability cannot be sufficiently improved. On the other hand, when the amount of the lubricant exceeds 5% by mass, the coil may be easily deformed or the load may be easily collapsed.

  FIG. 2 is a schematic diagram showing the configuration of the surface-treated steel sheet according to one embodiment of the present invention. As shown in FIG. 2, the surface-treated steel sheet 100 of the present invention includes a plated steel sheet 130 composed of a base steel sheet 110 and a plating layer 120, a chemical conversion film 140 formed on the surface of the plated steel sheet 130, and a chemical conversion film. And an organic resin film (repellent film) 150 formed on 140. A pyrethroid insect repellent 160 is dispersed in the organic resin film 150. Further, pits 170 are formed in the organic resin film 150.

  As explained so far, in the surface-treated steel sheet of the present invention, a chemical conversion film containing valve metal and phosphate is formed between the plated steel sheet (base steel sheet) and the organic resin film (repellent film). Yes.

  In the surface-treated steel sheet of the present invention, a pyrethroid insect repellent is added to the organic resin film. The pyrethroid insect repellent is concentrated on the surface of the organic resin film by hydrophobic organopolysiloxane. Thus, by adding a pyrethroid insect repellent, repellent properties against insect pests (insects) can be imparted, but on the other hand, the adhesion and water resistance of the organic resin film may be reduced. However, in the surface-treated steel sheet of the present invention, since a chemical conversion film is formed between the plated steel sheet and the organic resin film, even if a pyrethroid insect repellent is added to the organic resin film, the film adhesion and corrosion resistance Will not drop.

  In the surface-treated steel sheet of the present invention, hydrophobic organopolysiloxane is added to the organic resin film. Hydrophobic organopolysiloxane promotes surface concentration of pyrethroid insect repellent and forms pits in the organic resin film. By blending the hydrophobic organopolysiloxane in this way, pits are formed in the organic resin film, and the repellency against insects (insects) can be maintained for a long time. The corrosion resistance of the film may be reduced. However, in the surface-treated steel sheet of the present invention, since a chemical conversion film is formed between the plated steel sheet and the organic resin film, even if a pyrethroid insect repellent is added to the organic resin film, the corrosion resistance decreases. There is no.

  As described above, the surface-treated steel sheet of the present invention can maintain the repellent property against pests for a long period of time and is excellent in corrosion resistance.

  The manufacturing method of the surface treatment steel plate of this invention is not specifically limited. For example, the surface-treated steel sheet of the present invention can be manufactured by the following procedure.

2. Manufacturing method of surface-treated steel sheet The manufacturing method of the surface-treated steel sheet according to the present invention is a manufacturing method of a surface-treated steel sheet having excellent pest repellent properties, and includes 1) a first step of preparing a plated steel sheet, and 2) a plated steel sheet. A second step of forming a chemical conversion coating on the surface; and 3) a third step of forming an organic resin coating on the chemical conversion coating.

  Hereafter, each step of the manufacturing method of the surface treatment steel plate of this invention is demonstrated.

1) First Step In the first step, a plated steel plate is prepared as a base steel plate (original plate). As above-mentioned, the kind of plated steel plate is not specifically limited, It can select from a well-known plated steel plate suitably.

2) Second Step In the second step, a chemical conversion treatment liquid containing a valve metal compound and a phosphate is applied to the surface of the plated steel sheet prepared in the first step and dried to form a chemical conversion treatment film. .

  The chemical conversion treatment liquid can be prepared by dissolving or dispersing the aforementioned valve metal compound, phosphate, organic acid, organic resin, or the like in an aqueous solvent.

In order to include a valve metal oxide or hydroxide in the chemical conversion coating, a valve metal salt may be added to the chemical conversion solution. By drying the chemical conversion solution containing the valve metal salt, the valve metal salt becomes an oxide or hydroxide of the valve metal. The valve metal salt is, for example, a halide or oxyacid salt of valve metal. For example, examples of titanium salts include K _n TiF ₆ (K: alkali metal or alkaline earth metal, n: 1 or 2), K ₂ [TiO (COO) ₂ ], (NH ₄ ) ₂ TiF ₆ , TiCl. ₄ , TiOSO ₄ , Ti (SO ₄ ) ₂ , Ti (OH) _{4 and the} like.

In order to include the valve metal fluoride in the chemical conversion film, the valve metal fluoride may be added to the chemical conversion solution as it is, or a valve metal salt and a soluble fluoride (for example, (NH ₄ ) F). ) May be added in combination.

  In order to include a soluble or hardly soluble metal phosphate or composite phosphate in the chemical conversion treatment film, various metal phosphates may be added as they are to the chemical conversion treatment solution, or various metal salts and phosphoric acid, polyphosphoric acid may be added. You may add in combination with an acid or a phosphate.

  The method for applying the chemical conversion liquid is not particularly limited. Examples of the method for the chemical conversion solution include a roll coating method, a spin coating method, a spray method, and the like.

The coating amount of the chemical conversion solution is not particularly limited, but it is preferable to adjust the amount of the valve metal to be 1 mg / m ² or more. As described above, when the adhesion amount of the valve metal is less than 1 mg / m ² , the corrosion resistance and the film adhesion may not be sufficiently improved.

  The chemical conversion solution may be dried at room temperature, but considering continuous operation, it is preferable to keep the temperature at 50 ° C. or higher to shorten the drying time. However, high-temperature heating exceeding 220 ° C. is not preferable because organic components contained in the chemical conversion treatment solution are thermally decomposed and properties such as repellency, lubricity, and corrosion resistance may be deteriorated.

3) Third Step In the third step, a water-based organic resin treatment solution containing an organic resin, a pyrethroid insect repellent and a hydrophobic organopolysiloxane is applied onto the chemical conversion film formed in the second step. And dried to form an organic resin film having a thickness of 0.2 to 5 μm.

  The aqueous organic resin treatment liquid can be prepared by dissolving or dispersing the pyrethroid insect repellent, the hydrophobic organopolysiloxane, the lubricant, and the like in the aqueous emulsion of the organic resin.

  The number average particle diameter of the pyrethroid insect repellent is preferably 3 μm or less, and particularly preferably less than the film thickness of the organic resin film. When the pyrethroid insect repellent is large, the pyrethroid insect repellent penetrates the organic resin film and forms a large defect in the organic resin film, which may reduce the corrosion resistance of the surface-treated steel sheet. The particle size of the pyrethroid insect repellent can be adjusted by a ball mill, a roller mill, a centrifugal pulverizer, a mixer mill, a disk mill, or the like. The number average particle size of the pyrethroid insect repellent can be measured by a laser diffraction / scattering particle size distribution apparatus.

  In order to include the pyrethroid insect repellent in the organic resin film, the pyrethroid insect repellent particles of a predetermined size may be dispersed as they are in an organic resin aqueous emulsion. Since the pyrethroid insect repellent is hardly soluble in an aqueous solvent, the pyrethroid insect repellent is dispersed in the form of particles without being dissolved in the organic resin treatment liquid.

  The addition amount of the pyrethroid insect repellent may be 0.1 to 10 parts by mass with respect to 100 parts by mass of the solid content of the organic resin treatment liquid. Moreover, the addition amount of hydrophobic organopolysiloxane should just be 0.01-1 mass part with respect to 100 mass parts of solid content of an organic resin processing liquid.

  The method for applying the organic resin treatment liquid is not particularly limited. Examples of the method for the organic resin treatment liquid include a roll coating method, a spin coating method, and a spray method.

  The coating amount of the organic resin treatment liquid is preferably adjusted so that the film thickness of the organic resin film is in the range of 0.2 to 5 μm. As described above, when the film thickness of the organic resin film is less than 0.2 μm, there is a possibility that repellency and corrosion resistance against pests cannot be sufficiently provided. On the other hand, when the film thickness of the organic resin film is more than 5 μm, it is not preferable from the viewpoint of production cost because performance improvement accompanying the increase in thickness cannot be expected.

  The organic resin treatment liquid may be dried at room temperature, but considering continuous operation, it is preferable to keep the temperature at 50 ° C. or higher to shorten the drying time. However, high temperature heating exceeding 220 ° C. is not preferable because the organic components contained in the chemical conversion coating film and the organic resin treatment liquid may be thermally decomposed, and characteristics such as repellency, lubricity, and corrosion resistance may be deteriorated. .

  By the above procedure, there is a chemical conversion coating between the plated steel plate (base steel plate) and the organic resin coating (repellent coating), and the pyrethroid insect repellent is dispersed in the organic resin coating. In addition, a surface-treated steel sheet excellent in corrosion resistance can be produced.

  EXAMPLES Hereinafter, although this invention is demonstrated in detail with reference to an Example, this invention is not limited by these Examples.

1. Preparation of surface-treated steel sheet A hot-dip galvanized steel sheet (thickness 0.5 mm, single-sided plating adhesion 45 g / m ² ) was alkali degreased to prepare an original sheet.

  The chemical conversion treatment liquid having the composition shown in Table 1 was applied to the surface of the original plate, accommodated in an electric oven without being washed with water, and dried by heating at a plate temperature of 50 to 200 ° C. to form a chemical conversion treatment film. As the urethane resin, APX-601 (DIC Corporation) was used. As the acrylic resin, Aqualon AN-50 (Daiichi Kogyo Seiyaku Co., Ltd.) was used.

Next, a water-based organic resin treatment liquid having the composition shown in Table 2 was applied to the surface of the chemical conversion-plated steel sheet (liquid film thickness: 2.5 to 25 μm), dried at 120 ° C., and an organic resin film (repellent) Film) was formed. Super Grex 130 (Daiichi Kogyo Seiyaku Co., Ltd.) was used as the water-based emulsion of urethane resin. Aquabrid (Daicel Chemical Industries, Ltd.) was used as the aqueous emulsion of acrylic resin. The number average particle size of the pyrethroid insect repellent (acrinathrin and permethrin) was 3 μm or less. KM-7852 (Shin-Etsu Chemical Co., Ltd.) was used as the organopolysiloxane. CJ-137 (Koyo Chemical Co., Ltd.) was used as the lubricant. SiO ₂ was used a snow-Tex -N (Nissan Chemical Co., Ltd.). Table 3 shows the configuration of the obtained surface-treated steel sheet.

2. Evaluation of surface-treated steel sheet A test piece was cut out from the produced surface-treated steel sheet and subjected to the following evaluation tests.

(1) Evaluation of cockroach repellency This evaluation test was conducted in accordance with the test method of the Japan Environmental Health Center.

  FIG. 3 is a schematic diagram for explaining the configuration of the shelter used in this evaluation test. First, as shown in FIG. 3A, a test piece 200 of 70 mm × 70 mm was cut out. Next, as shown in FIG. 3B, four square members 210 each having a length of 5 mm, a width of 5 mm, and a length of 50 mm were arranged on the test piece 200. Finally, as shown in FIG. 3C, a 70 mm × 70 mm veneer plate 220 was placed on the square member 210 to produce a shelter.

  FIG. 4 is a schematic diagram for illustrating the arrangement of the shelters in this evaluation test. As shown in FIG. 4, two of the above-mentioned shelters were placed in an upper open container 300 made of resin having a width of 260 mm × length of 150 mm × height of 200 mm. One is a shelter using the surface-treated steel sheet to be evaluated as the test piece 200, and the other is a shelter using an untreated hot-dip galvanized steel sheet as the test piece 210 '. Between these two shelters, absorbent cotton 310 and chow 320 containing water were placed. In order to prevent the escape of cockroaches, petrolatum was thinly applied to the upper inner surface of the container 300.

Twenty adult cockroaches were placed in the container 300 shown in FIG. 4, and the number of cockroaches in each shelter was measured after 1 day and 2 months, and the repelling rate was calculated by the following formula. In the following formula, “the number of cockroaches in the treated area” means the number of cockroaches in the shelter using the surface-treated steel sheet to be evaluated, and “the number of cockroaches in the untreated area” means “untreated cockroaches”. It means the number of cockroaches in a shelter using galvanized steel sheet.

Repelling rate (%) = (1−number of cockroaches in treated area / number of cockroaches in untreated area) × 100

  Taking into account variations due to light sources, temperature and humidity differences, individual differences, etc., the same test was performed three times, and the repelling rate was calculated from the total value. When the number of cockroaches in the treated area exceeded the number of cockroaches in the untreated area even once, the repellent rate of the test piece was set to “0%” because no repellent effect was observed.

  For each surface-treated steel sheet, “◎” when the repelling rate is 90% or more, “◯” when 70% or more and less than 90%, “△” when 40% or more and less than 70%, and less than 40%. Was evaluated as “×”, and “◎” and “◯” were accepted.

(2) Evaluation of corrosion resistance A 150 mm x 70 mm test piece was cut out from the produced surface-treated steel sheet, and the end face and the back face of each test piece were sealed. A salt spray test (based on JIS Z2371; 120 hours) was performed using each sealed test piece, and the white rust generation area ratio of the flat portion was evaluated.

  For each surface-treated steel sheet, “◎” when the white rust occurrence area ratio is 5% or less, “◯” when it exceeds 5% and 10% or less, “△” when it exceeds 10% and 40% or less, When it exceeded 40%, it evaluated as "x" and made "◎" and "(circle)" a pass.

(3) Evaluation of film adhesion A test piece of 100 mm × 80 mm was cut out from the produced surface-treated steel sheet and immersed in hot water at 90 ° C. for 24 hours. A cross-cut test (based on JIS K5400) was performed on the test piece pulled up from the hot water, and the film adhesion was evaluated by the residual ratio of the organic resin film.

  For each surface-treated steel sheet, “◎” when the residual ratio of the organic resin film is 90% or more, “◯” when 70% or more and less than 90%, “△” when 40% or more and less than 70%, 40 When it was less than%, it was evaluated as “×”, and “「 ”and“ ◯ ”were regarded as acceptable.

(4) Evaluation of galling resistance A test piece of 300 mm × 30 mm was cut out from the produced surface-treated steel sheet, and burrs on the end face were removed. 1.67 × 10 ⁻³ m / sec). The surface of the test piece after the test was observed, and galling resistance was evaluated by the residual ratio of the organic resin film in the mold sliding portion.

  For each surface-treated steel sheet, “◎” when the residual ratio of the organic resin film is 90% or more, “◯” when 70% or more and less than 90%, “△” when 40% or more and less than 70%, 40 When it was less than%, it was evaluated as “×”, and “「 ”and“ ◯ ”were regarded as acceptable.

(5) Evaluation results Table 4 shows the evaluation results of the respective surface-treated steel sheets (Examples 1 to 12, Comparative Examples 1 to 7).

  As shown in Table 4, the surface-treated steel sheets of Comparative Examples 1 to 3 in which a chemical conversion treatment film containing no valve metal or phosphate was inferior in corrosion resistance and film adhesion.

  Further, the surface-treated steel sheet of Comparative Example 4 in which an organic resin film containing more than 10% by mass of a pyrethroid insect repellent was formed had poor corrosion resistance. On the other hand, the surface-treated steel sheet of Comparative Example 6 on which an organic resin film containing less than 0.1% by mass of a pyrethroid insect repellent was formed had poor insect repellent properties.

  Further, the surface-treated steel sheet of Comparative Example 5 in which an organic resin film not containing organopolysiloxane was formed was inferior in insect repellency. On the other hand, the surface-treated steel sheet of Comparative Example 8 in which an organic resin film containing 2% by mass of organopolysiloxane was formed was inferior in corrosion resistance and galling resistance.

  Further, the surface-treated steel sheet of Comparative Example 7 in which the film thickness of the organic resin film was less than 0.2 μm was inferior in insect repellency, corrosion resistance, and galling resistance.

  On the other hand, the surface-treated steel sheets of Examples 1 to 12 gave good results for all of insect repellency, corrosion resistance, film adhesion, and galling resistance.

  The surface-treated steel sheet of the present invention has excellent repellency and corrosion resistance against pests such as living pests, hygiene pests, and unpleasant pests. For example, cooking appliances such as gas tables, gas stoves, and IH cooking heaters, refrigerators, washing machines, Useful for household appliances such as microwave ovens.

DESCRIPTION OF SYMBOLS 100 Surface treatment steel plate 110 Base material steel plate 120 Plating layer 130 Plated steel plate 140 Chemical conversion treatment film 150 Organic resin film 160 Pyrethroid insect repellent 170 Pit 200 Test piece 210 Square material 220 Plywood 300 Resin container 310 Absorbent cotton 320 containing water Solid feed

Claims (8)

Plated steel sheet,
A chemical conversion film containing a valve metal compound and a phosphate formed on the surface of the plated steel sheet;
Organic having a film thickness of 0.2 to 5 μm formed on the chemical conversion coating and containing 0.1 to 10% by mass of a pyrethroid insect repellent and 0.01 to 1% by mass of a hydrophobic organopolysiloxane. A resin film;
I have a,
The valve metal is Ti, Zr, Hf, V, Nb, Ta, Mo, W or a combination thereof.
The hydrophobic organopolysiloxane is one or a combination of two or more polyoxyethylene-modified organopolysiloxanes having a melting point in the range of 35 to 70 ° C.
Surface treated steel sheet.   The surface-treated steel sheet according to claim 1, wherein the chemical conversion treatment film further includes an organic acid, an organic resin, or a combination thereof.   The surface-treated steel sheet according to claim 1, wherein the organic resin film further contains a lubricant.   The pyrethroid insect repellent is (S) -α-cyano-3-phenoxybenzyl = (Z)-(1R, 3S) -2,2-dimethyl-3- [2- (2,2,2-tri The surface-treated steel sheet according to claim 1, which is (fluoro-1-trifluoromethylethoxycarbonyl) vinyl] cyclopropanecarboxylate. Preparing a plated steel sheet; and
Applying a chemical conversion treatment solution containing a valve metal compound and phosphate to the surface of the plated steel sheet, and drying to form a chemical conversion treatment film; and
On the chemical conversion coating film, an organic resin, a pyrethroid insect repellent having a number average particle size of 3 μm or less, and a water-based organic resin treatment solution containing a hydrophobic organopolysiloxane are applied and dried. Forming a 0.2 to 5 μm organic resin film,
The aqueous organic resin treatment liquid contains 0.1 to 10 parts by mass of the pyrethroid insect repellent and 0.01 to 1 part by mass of the hydrophobic organopolysiloxane with respect to 100 parts by mass of a solid content .
The valve metal is Ti, Zr, Hf, V, Nb, Ta, Mo, W or a combination thereof.
The hydrophobic organopolysiloxane is one or a combination of two or more polyoxyethylene-modified organopolysiloxanes having a melting point in the range of 35 to 70 ° C.
Manufacturing method of surface-treated steel sheet. The said chemical conversion liquid is a manufacturing method of the surface treatment steel plate of Claim 5 which further contains an organic acid, organic resin, or these combination. The method for producing a surface-treated steel sheet according to claim 5 , wherein the aqueous organic resin treatment liquid further contains a lubricant. The pyrethroid insect repellent is (S) -α-cyano-3-phenoxybenzyl = (Z)-(1R, 3S) -2,2-dimethyl-3- [2- (2,2,2-tri The method for producing a surface-treated steel sheet according to claim 5 , which is (fluoro-1-trifluoromethylethoxycarbonyl) vinyl] cyclopropanecarboxylate.