JP5578757B2 - Surface treatment agent and steel plate - Google Patents

Description

  The present invention relates to a surface treatment agent used when surface-treating a galvanized steel sheet and a steel sheet surface-treated with the surface treatment agent.

  A zinc-based plated steel sheet forms a film on the surface in order to improve corrosion resistance. For example, chromate treatment is applied to a zinc-based plated steel sheet to form a chromate film on the surface of the zinc-based plated steel sheet. However, since chromate treatment uses chromate (hexavalent chromium), which is a harmful chromium compound, it causes environmental pollution and affects the health of humans involved in production. For this reason, the surface treating agent which can form a membrane | film | coat without using a harmful chromium compound is desired.

  In addition, when processing steel sheets into various metal products such as household electrical appliances and automobile parts, first, the steel sheets coated with oil such as lubricating oil are subjected to forming processing such as press forming to be processed into the desired shape. To do. Thereafter, degreasing such as alkaline degreasing is performed to remove oil applied to the surface of the steel sheet. The steel sheet is required not to deteriorate in corrosion resistance even when such degreasing is performed.

  Patent Document 1 describes a conventional technique for a surface treatment agent for surface-treating a galvanized steel sheet. The surface treatment agent of Patent Document 1 is a surface treatment agent that contains a water-soluble polyvalent metal phosphate compound, a chelating agent, and a corrosion inhibitor and does not contain a chromium compound. Specifically, the component contained in the surface treatment agent is one or a mixture of two selected from polyvalent metal phosphate compounds selected from primary aluminum phosphate and primary magnesium phosphate. The chelating agent is one or a mixture of two selected from phosphonic acid chelating agents and oxycarboxylic acid chelating agents. The corrosion inhibitor is one or a mixture of two kinds of an imidazoline compound, a thiocarbonyl group-containing compound and a quinoline derivative obtained by quaternizing an imidazoline compound with a quaternizing agent.

  This surface treatment agent is not a dehydration condensation reaction between phosphate groups of a polyvalent metal phosphate compound, but is applied to at least one surface of a zinc-based plated steel sheet and then baked. A film having a network (network) structure is formed by a chelate formation reaction between the compound and the chelating agent, so that a uniform and dense film is formed at a low baking temperature. Therefore, this surface treatment agent can form a coating film having excellent corrosion resistance on a galvanized steel sheet at a low baking temperature without using a chromium compound, and can obtain a steel sheet having excellent corrosion resistance. it can.

  However, since the coating composed mainly of a phosphate compound formed from this surface treatment agent has low corrosion resistance against alkali (alkali resistance), if the steel sheet surface-treated with this surface treatment agent is subjected to alkaline degreasing, the corrosion resistance Will fall. When the steel sheet surface-treated with this surface treatment agent is used as it is, it can exhibit excellent corrosion resistance. However, when the steel sheet is molded and used, the corrosion resistance is reduced by alkaline degreasing, so it is excellent. Corrosion resistance cannot be demonstrated.

  As another conventional technique, a technique similar to the technique of Patent Document 1 is described in Patent Document 2. The surface treatment agent of Patent Document 2 includes a water-soluble polyvalent metal phosphate compound, a chelating agent, and a corrosion inhibitor, and the corrosion inhibitor is a vanadate compound or a polyamine compound having a specific structure. .

JP 2002-155375 A JP 2005-126739 A

  According to Patent Literature 2, a surface on which a coating having excellent corrosion resistance can be formed on a zinc-based plated steel sheet at a low baking temperature by applying and baking to at least one surface of the zinc-based plated steel sheet It is a processing agent. Furthermore, by using a specific alkaline degreasing agent and controlling degreasing conditions such as temperature and time, a steel sheet having excellent corrosion resistance can be obtained even after alkaline degreasing.

  However, when processing steel sheets into various metal products such as household electric products and automobile parts, there are a wide variety of alkaline degreasing agents used for degreasing, and various degreasing conditions. Therefore, depending on the alkaline degreasing agent and the degreasing conditions, when alkaline degreasing is performed, the corrosion resistance of the steel sheet is lowered.

  In addition, when a forming process, particularly a bending process, is performed on the steel sheet, the steel sheet and the mold often rub against each other, so that the steel sheet is often scratched (die galling). The steel sheet is required to have resistance to scratching, so-called mold galling resistance. However, the steel sheet surface-treated with the surface treatment agent does not have a high mold galling resistance because the mechanical strength of the coating formed on the surface is not high.

  The object of the present invention is to be able to be baked at a low baking temperature without using a chromium compound, and to form a film having excellent corrosion resistance even after degreasing on the surface of a galvanized steel sheet. It is to provide a surface treatment agent capable of imparting galling resistance to a zinc-based plated steel sheet and a steel sheet surface-treated with the surface treatment agent.

The present invention is a surface treatment agent that does not contain a resin (excluding a resin component as a solid lubricant or a silane coupling agent) and a chromium compound used for the surface treatment of a zinc-based plated steel sheet,
Against aluminum primary phosphate 100 parts by weight of water-soluble, hexafluoro titanic acid and / or hexafluoro titanate comprises less than 1000 parts by weight more than 10 parts by weight, and hexafluorotitanate and / or hexafluorotitanate treatment agent concentration of salt is not less than 20% 2.0% or more, the ammonium metavanadate and / or vanadate potassium comprises 50 parts by weight or less than 1 part by weight, the phosphonic acid chelating agent as a chelating agent 100 It is a surface treatment agent excellent in corrosion resistance and alkali galling resistance after alkaline degreasing, characterized by containing from 250 parts by weight to 250 parts by weight.

Further, the present invention is a surface treatment agent that does not contain a resin (excluding a resin component as a solid lubricant or a silane coupling agent) and a chromium compound, which is used for the surface treatment of a zinc-based plated steel sheet,
Contains more than 10 parts by weight and less than 1000 parts by weight of hexafluorotitanic acid and / or hexafluorotitanate with respect to 100 parts by weight of water-soluble primary aluminum phosphate, and hexafluorotitanic acid and / or hexafluorotitanium The concentration of the acid salt in the treatment agent is 2.0% or more and 20% or less, contains 1 part by weight or more and 50 parts by weight or less of ammonium metavanadate and / or potassium vanadate, and 100 weights of phosphonic acid chelating agent as a chelating agent A surface excellent in corrosion resistance and mold galling resistance after alkaline degreasing, characterized by containing 0.001 part by weight or more and 1 part by weight or less of pyridinium and / or thiocyanate as a corrosion inhibitor. It is a processing agent.
The present invention, ho Suhon acid chelating agent, characterized in that it is a 1-hydroxyethylidene-1,1-diphosphonic acid.

Moreover, this invention is characterized by including a solid lubricant.
Moreover, this invention is characterized by including a silane coupling agent.

  In the present invention, the hexafluorotitanate is ammonium hexafluorotitanate.

Further, the present invention is a steel sheet in which a film is formed on the surface of a zinc-based plated steel sheet,
The film is a steel plate formed by applying and baking the surface treatment agent on at least one surface of the zinc-based plated steel plate.

Further, the invention is characterized in that the coating amount of the film is 100 mg / m ² or more and 1000 mg / m ² or less.

According to the present invention, the surface treatment agent does not contain a resin (excluding a resin component as a solid lubricant or a silane coupling agent) and a chromium compound, which are used for the surface treatment of a zinc-based plated steel sheet. The surface treatment agent for aluminum primary phosphate 100 parts by weight of water-soluble, hexafluoro titanic acid and / or hexafluoro titanate comprises less than 1000 parts by weight more than 10 parts by weight, and hexafluorotitanate and / or 20% or less treating agent concentration is 2.0% or more hexafluoro titanate, ammonium metavanadate and / or vanadate potassium comprises 50 parts by weight or less than 1 part by weight, phosphonic as a chelating agent 100 parts by weight or more and 250 parts by weight or less of an acid-based chelating agent is included.

  This surface treatment agent is baked at a low baking temperature, for example, 50 ° C. or higher and 200 ° C. or lower without using a chromium compound by applying and baking it on at least one surface of a zinc-based plated steel sheet. A dense film is formed. This uniform and dense film has excellent corrosion resistance even after degreasing and has high mechanical strength. Therefore, this surface treatment agent can form a film having excellent corrosion resistance even after degreasing on the surface of the galvanized steel sheet, and can further impart excellent anti-galling resistance to the galvanized steel sheet. it can. The reason why a uniform and dense film is formed by this surface treatment agent is not clear, but the following mechanism can be estimated.

When a film is formed only with primary aluminum phosphate (hereinafter sometimes referred to as a polyvalent metal phosphate compound ) , the film is formed by a dehydration condensation reaction, so that baking at a high temperature of 300 ° C. or higher is required. Become. However, when baking is performed at such a high temperature, the resulting film becomes crystalline, making it difficult to form a uniform and dense film.

This surface treatment agent contains 100 parts by weight or more and 250 parts by weight or less of a phosphonic acid chelating agent as a chelating agent, so that the polyvalent metal phosphorus is not a dehydration condensation reaction between the phosphate groups of the polyvalent metal phosphate compound. A film having a network structure is formed by a chelate formation reaction between the acid salt compound and the chelating agent. Since this film formation does not involve a dehydration condensation reaction, a uniform and dense film can be formed at a low baking temperature. Therefore, this surface treating agent can form a film having excellent corrosion resistance on a zinc-based plated steel sheet at a low baking temperature.

Further, the surface treatment agent, hexafluorotitanate and / or the hexafluoro titanate unrealized less than 1000 parts by weight more than 10 parts by weight, and hexafluorotitanate and / or treatment agent of hexafluoro titanate When the concentration is 2.0% or more and 20% or less, the phosphate groups of the polyvalent metal phosphate compound can be bonded with titanium interposed therebetween. Since this bond formation does not involve a dehydration condensation reaction, a film can be formed at a low baking temperature. This film has a high alkali resistance and a high mechanical strength by forming a bond with titanium interposed. Therefore, this surface treatment agent can form a coating film having excellent corrosion resistance even after degreasing at a low baking temperature on the surface of the galvanized steel sheet, and further exhibits excellent anti-galling resistance on the galvanized steel sheet. Can be granted.

This surface treatment agent is baked at a low baking temperature without using a chromium compound, and a uniform and dense film is formed. This uniform and dense film has excellent corrosion resistance even after degreasing and has high mechanical strength. Therefore, this surface treatment agent can form a film having excellent corrosion resistance even after degreasing on the surface of the galvanized steel sheet, and can further impart excellent anti-galling resistance to the galvanized steel sheet. it can.
Further, according to the present invention, a surface treatment agent that does not contain a resin (excluding a resin component as a solid lubricant or a silane coupling agent) and a chromium compound, which is used for the surface treatment of a zinc-based plated steel sheet, The hexafluorotitanic acid and / or hexafluorotitanate containing more than 10 parts by weight and less than 1000 parts by weight with respect to 100 parts by weight of the primary aluminum phosphate The concentration in the treating agent is 2.0% or more and 20% or less, contains 1 to 50 parts by weight of ammonium metavanadate and / or potassium vanadate, and contains 100 parts by weight or more of a phosphonic acid chelating agent as a chelating agent. 250 parts by weight or less, and pyridinium and / or thiocyanate as a corrosion inhibitor .001 parts by weight or more, including 1 part by weight or less.
When a surface treatment agent containing a polyvalent metal phosphate compound is applied to the surface of a zinc-based plated steel sheet, the zinc-based plating is dissolved by the polyvalent metal phosphate compound, and the phosphoric acid of the polyvalent metal phosphate compound is dissolved. Zinc phosphate is produced by the dissolved zinc ions, so that chelation reaction and titanium-mediated bond formation are inhibited. Since this surface treatment agent contains a corrosion inhibitor, it is possible to suppress dissolution of zinc-based plating by the polyvalent metal phosphate compound, and since it is not inhibited by zinc phosphate, a more uniform and dense film Can be formed.

  Moreover, according to this invention, it is preferable that a solid lubricant is included. This surface treatment agent can impart lubricity to the film to be produced by including a solid lubricant. Therefore, when processing the steel sheet on which the film is formed into various metal products such as household electric products and automobile parts, excellent workability and slidability can be ensured.

  Moreover, according to this invention, it is preferable that a silane coupling agent is included. This surface treatment agent can improve the secondary adhesion between the coating formed on the zinc-based plated steel sheet and the top coating applied on the coating by including a silane coupling agent.

Also, by using a polyvalent metal phosphate compound, it is possible to form a coating having excellent corrosion resistance without the surface of the galvanized steel sheet using harmful chromium compounds.

  According to the invention, the hexafluorotitanate is preferably ammonium hexafluorotitanate. By doing so, the titanium of ammonium hexafluorotitanate can combine the phosphate groups of a polyvalent metal phosphate compound more. Therefore, a film having higher alkali resistance and mechanical strength is formed.

Also, by using at least one of ammonium metavanadate and potassium vanadate, it is possible to further suppress the corrosion of the coating, more alkali resistance is high film is formed.

  According to the invention, the chelating agent is preferably a phosphonic acid chelating agent. By doing so, the phosphoric acid group of the phosphonic acid chelating agent and the phosphoric acid group of the polyvalent metal phosphate compound are combined to form a chelate, so that a more uniform and dense film can be formed. it can.

  According to the invention, the phosphonic acid chelating agent is preferably 1-hydroxyethylidene-1,1-diphosphonic acid. By doing so, the phosphoric acid group of the phosphonic acid chelating agent and the phosphoric acid group of the polyvalent metal phosphate compound are combined to form a chelate, so that a more uniform and dense film can be formed. it can.

  Moreover, according to this invention, it is a steel plate by which the membrane | film | coat was formed on the surface of a zinc-plated steel plate. Since this film is formed by applying and baking the above-mentioned surface treatment agent on at least one surface of a zinc-based plated steel sheet, it is a film having higher alkali resistance and mechanical strength. Therefore, this steel plate has excellent corrosion resistance and excellent mold galling resistance even after degreasing.

According to the present invention, the adhesion amount of the coating is 100 mg / ^{m 2} or more 1000 mg / ^{m 2} or less. This steel sheet has excellent corrosion resistance and excellent mold galling resistance even after degreasing. Moreover, this steel plate has high adhesiveness with a zinc-plated steel plate and a membrane | film | coat.

Surface treatment agent which is an embodiment of the present invention is to provide aluminum primary phosphate 100 parts by weight of water-soluble in an aqueous medium, 10 parts by weight of hexafluorotitanate and / or hexafluoro titanate beyond containing less than 1000 parts by weight, and is a treatment agent concentration of hexafluorotitanate and / or hexafluoro titanate is 20% or less 2.0% or more, ammonium metavanadate and / or potassium vanadate (hereinafter, 1 to 50 parts by weight, and a phosphonic acid chelating agent as a chelating agent is contained in an amount of 100 to 250 parts by weight. Since this surface treatment agent does not contain harmful chromium compounds, problems such as environmental pollution due to the use of conventional chromium compounds do not occur. The aqueous medium may be water alone or a mixed solvent of water and a water-soluble organic solvent, but is preferably water alone.

  This surface treatment agent is baked at a low baking temperature, for example, 50 ° C. or more and 200 ° C. or less by applying and baking on at least one surface of a zinc-based plated steel sheet, thereby forming a uniform and dense film. This uniform and dense film has excellent corrosion resistance even after degreasing and has high mechanical strength. Therefore, this surface treatment agent can form a film having excellent corrosion resistance even after degreasing on the surface of the galvanized steel sheet, and can further impart excellent anti-galling resistance to the galvanized steel sheet. it can. The reason why a uniform and dense film is formed by this surface treatment agent is not clear, but the following mechanism can be estimated.

  When the film is formed only with the polyvalent metal phosphate compound, the film is formed by a dehydration condensation reaction, so that baking at a high temperature of 300 ° C. or higher is required. However, when baking is performed at such a high temperature, the resulting film becomes crystalline, making it difficult to form a uniform and dense film.

  Since this surface treatment agent contains a chelating agent, it is not a dehydration condensation reaction between the phosphate groups of the polyvalent metal phosphate compound, but a chelate-forming reaction between the polyvalent metal phosphate compound and the chelating agent. A film having a (network) structure is formed. Since this film formation does not involve a dehydration condensation reaction, a uniform and dense film can be formed at a low baking temperature. Therefore, this surface treating agent can form a film having excellent corrosion resistance on a zinc-based plated steel sheet at a low baking temperature.

  Furthermore, this surface treating agent contains at least one of hexafluorotitanic acid and hexafluorotitanate, whereby the phosphate groups of the polyvalent metal phosphate compound are bonded with titanium (phosphorus). Acid group-titanium-phosphate group). Since this bond formation does not involve a dehydration condensation reaction, a film can be formed at a low baking temperature. This film has a high alkali resistance and a high mechanical strength by forming a bond with titanium interposed. Therefore, this surface treatment agent can form a coating film having excellent corrosion resistance even after degreasing at a low baking temperature on the surface of the galvanized steel sheet, and further exhibits excellent anti-galling resistance on the galvanized steel sheet. Can be granted.

  Moreover, this surface treating agent is carry | supported by the membrane | film | coat formed on the galvanized steel plate by containing a vanadium compound. As a result, even in an environment where the film is corroded, such as alkaline degreasing, the vanadium compound is eluted from the film and suppresses the corrosion of the film, so that the alkali resistance is increased, so that excellent corrosion resistance is obtained even after degreasing. The film which has can be formed.

Aluminum primary phosphate is contained in the surface treatment agent, Ri component der composed mainly (base) to form a film can be formed by applying and baking the solution on the galvanized steel sheet. Primary phosphate aluminum can may be those produced industrial manner. Also, aluminum primary phosphate, the molar ratio of Al / P is not preferable those 0.7 / 3 to 1.2 / 3.

  The concentration of the polyvalent metal phosphate compound in the surface treatment agent is preferably 1% by weight or more and 50% by weight or less. When the amount is less than 1% by weight, hydrolysis may occur and precipitation may occur. When the amount exceeds 50% by weight, the polyvalent metal phosphate compound exceeds the solubility of the polyvalent metal phosphate compound, and the surface treatment agent is used. May cause problems with stability.

  The surface treatment agent contains at least one of hexafluorotitanic acid (titanium hydrofluoric acid) and hexafluorotitanate (salt of titanium hydrofluoric acid). Examples of compounds that form hexafluorotitanate include sodium, potassium, lithium, and ammonium. Specific compounds include sodium hexafluorotitanate (sodium titanium fluoride) and potassium hexafluorotitanate (titanium fluoride). Potassium fluoride), lithium hexafluorotitanate (lithium titanium fluoride), ammonium hexafluorotitanate (titanium ammonium fluoride), and the like. Of these, the hexafluorotitanate is preferably ammonium hexafluorotitanate. More preferably, a mixture of hexafluorotitanic acid and ammonium hexafluorotitanate is used.

The hexafluorotitanic acid and hexafluorotitanate in the surface treatment agent are preferably contained in an amount of more than 10 parts by weight and less than 1000 parts by weight with respect to 100 parts by weight of the primary aluminum phosphate . If it is less than 10 parts by weight, a uniform and dense film having excellent corrosion resistance cannot be formed even after alkaline degreasing, and the formed film has low mechanical strength and excellent mold resistance. The galling property cannot be exhibited. In addition, even if the amount exceeds 1000 parts by weight, the amount of titanium that does not participate in bonding increases too much, and even after alkaline degreasing, a uniform and dense film having excellent corrosion resistance cannot be formed. Strength is lowered.

  The vanadium compound in the surface treatment agent is preferably contained in an amount of 1 to 50 parts by weight with respect to 100 parts by weight of the polyvalent metal phosphate compound. If the amount is less than 1 part by weight, sufficient corrosion resistance cannot be obtained. If the amount exceeds 50 parts by weight, the vanadium compound may precipitate, causing a problem in the stability of the surface treatment agent.

  Specific examples of the phosphonic acid-based chelating agent include aminotrimethylenephosphonic acid, 1-hydroxyalkylidene-1,1-diphosphonic acid, ethylenediaminetetramethylenephosphonic acid, hexamethylenediaminetetramethylenephosphonic acid, diethylenetriaminepentamethylenephosphonic acid, Or the salt can be mentioned. In particular, when preparing the treatment liquid, 1-hydroxyalkylidene-1,1-diphosphonic acid is preferable from the viewpoint of solubility of the phosphate compound in an aqueous solution. More preferred is 1-hydroxyethylidene-1,1-diphosphonic acid.

Specific examples of the oxycarboxylic acid chelating agent include oxalic acid, citric acid, malic acid, gluconic acid, malonic acid and the like.
These chelating agents may be used alone or in combination of two or more.

The chelating agent in the surface treatment agent for aluminum primary phosphate 100 parts by weight, but preferably contains 10 parts by weight or more 1000 parts by weight, containing less 250 parts by weight or more to 100 parts by weight in this embodiment . If it is less than 10 parts by weight, sufficient corrosion resistance cannot be obtained, and if it exceeds 1000 parts by weight, the formed film may become sticky.

  The surface treatment agent preferably contains a solid lubricant. This surface treatment agent can impart lubricity to the film to be produced by including a solid lubricant. Therefore, when processing the steel sheet on which the film is formed into various metal products such as household electric products and automobile parts, excellent workability and slidability can be ensured. Examples of the solid lubricant include wax, fluororesin particles, and metal soap, but wax is preferable. Many waxes have a relatively low melting point (melting point of 130 ° C. or lower). The workability and slidability when processing a steel sheet with a film formed into various metal products are particularly significant in the temperature range from the room temperature to the melting point of the lubricant.

  Examples of the wax include polyethylene wax, carnauba wax, paraffin wax, and Teflon (registered trademark) (R) wax. Among these listed waxes, since the polyvalent metal phosphate compound contained in the surface treatment agent is water-soluble, a wax having good dispersibility or solubility in water is preferable. Polyethylene wax is particularly preferred.

  The solid lubricant in the surface treatment agent is preferably contained in an amount of 1 to 100 parts by weight with respect to 100 parts by weight of the polyvalent metal phosphate compound. If it is less than 1 part by weight, the effect of the solid lubricant that can ensure excellent workability and slidability when processing the steel sheet with the film formed into various metal products cannot be sufficiently exhibited. If it exceeds 100 parts by weight, the corrosion resistance of the film may not be sufficiently obtained.

  The surface treatment agent preferably contains a silane coupling agent. This surface treatment agent can improve the secondary adhesion between the coating formed on the zinc-based plated steel sheet and the top coating applied on the coating by including a silane coupling agent.

  Examples of the silane coupling agent include vinyltrimethoxysilane, vinyltriethoxysilane, N- (2-aminoethyl) -3-aminopropylmethyldimethoxysilane, and N- (2-aminoethyl) -3-aminopropylmethyl. Examples include trimethoxysilane, 3-aminopropyltriethoxysilane, 3-glycidoxypropyltrimethoxysilane, and 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane. Xylpropyltrimethoxysilane is preferred.

  The silane coupling agent in the surface treatment agent is preferably contained in an amount of 0.1 to 100 parts by weight with respect to 100 parts by weight of the polyvalent metal phosphate compound. If it is less than 0.1 part by weight, the effect of the silane coupling agent that can improve the secondary adhesion between the film formed on the zinc-based plated steel sheet and the top coating applied on the film should be sufficiently exhibited. When the amount exceeds 100 parts by weight, there may be a problem in the stability of the surface treatment agent.

  The surface treatment agent preferably contains a corrosion inhibitor. When a surface treatment agent containing a polyvalent metal phosphate compound is applied to the surface of a zinc-based plated steel sheet, the zinc-based plating is dissolved by the polyvalent metal phosphate compound, and the phosphoric acid of the polyvalent metal phosphate compound is dissolved. Zinc phosphate is produced by the dissolved zinc ions, so that chelation reaction and titanium-mediated bond formation are inhibited. Since this surface treatment agent contains a corrosion inhibitor, it is possible to suppress dissolution of zinc-based plating by the polyvalent metal phosphate compound, and since it is not inhibited by zinc phosphate, a more uniform and dense film Can be formed. Therefore, the corrosion inhibitor can increase the corrosion resistance of the coating.

  Corrosion inhibitors include imidazolium compounds, quinoline compounds, thiocarbonyl compounds, thiazole compounds, mercapto compounds, sulfide compounds, thiocarbamates, pyridinium compounds, thiocyanates obtained by quaternizing imidazoline compounds with quaternizing agents. Among the acid salts and isothiocyanates, at least one kind or two or more kinds can be mentioned. Further, there are many cases where a synergistic effect is obtained by mixing, and it is preferable to use a mixture of these compounds.

  The corrosion inhibitor in the surface treatment agent is preferably contained in an amount of 0.001 to 1 part by weight with respect to 100 parts by weight of the polyvalent metal phosphate compound. If it is less than 0.001 part by weight, the effect of the corrosion inhibitor capable of enhancing the corrosion resistance of the film cannot be sufficiently exhibited, and if it exceeds 1 part by weight, the formed film may be sticky. Moreover, since the effect of a corrosion inhibitor is saturated, it is not economical.

  Specific examples of the imidazolium compound obtained by quaternizing an imidazoline compound with a quaternizing agent include, for example, 2-alkyl (C12-C18) -1-alkyl (C1-C16) -1-acylalkyl (C11- C17) Imidazolium chloride, 2-alkyl (C12-C18) -1-alkyl (C1-C16) -1-acylalkyl (C11-C17) imidazolium bromide, 2-alkyl (C12-C18) -1-alkyl ( C1-C16) -1-acylalkyl (C11-C17) imidazolium iodide, 2-alkyl (C12-C18) -1-alkyl (C1-C16) -1-acylalkyl (C11-C17) imidazolium fluoride 2-alkyl (C12-C18) -1-alkyl (C1-C16) -1 Acylalkyl (C11-C17) imidazolium ethoxysulfate, 1,3-dibenzyl-2-methylimidazolium chloride, 1,3-dibenzyl-2-methylimidazolium bromide, 1,3-dibenzyl-2-methylimidazolium io Dide, 1,3-dibenzyl-2-methylimidazolium fluoride, 1,3-dibenzyl-2-methylimidazolium ethoxysulfate, 1-dodecyl-2-methyl-3-carboxymethylimidazolium chloride, 1-dodecyl- 2-methyl-3-carboxymethylimidazolium bromide, 1-dodecyl-2-methyl-3-carboxymethylimidazolium iodide, 1-dodecyl-2-methyl-3-carboxymethylimidazolium fluoride, 1-dodecyl 2-methyl-3-carboxymethylimidazolium ethoxysulfate, 1-benzyl-2-alkyl (C1-C4) -3-carboxymethylimidazolium chloride, 1-benzyl-2-alkyl (C1-C4) -3-carboxy Methyl imidazolium bromide, 1-benzyl-2-alkyl (C1-C4) -3-carboxymethylimidazolium iodide, 1-benzyl-2-alkyl (C1-C4) -3-carboxymethylimidazolium fluoride, 1 -Benzyl-2-alkyl (C1-C4) -3-carboxymethylimidazolium ethoxysulfate, 1-cyanoethyl-2-alkyl (C1-C4) -4-alkyl (C1-C4) -carboxymethylimidazolium chloride, 1 -Cyanoethyl-2-al (C1-C4) -4-alkyl (C1-C4) -carboxymethylimidazolium bromide, 1-cyanoethyl-2-alkyl (C1-C4) -4-alkyl (C1-C4) -carboxymethylimidazolium iodide 1-cyanoethyl-2-alkyl (C1-C4) -4-alkyl (C1-C4) -carboxymethylimidazolium fluoride, 1-cyanoethyl-2-alkyl (C1-C4) -4-alkyl (C1-C4) ) -Carboxymethylimidazolium ethoxy sulfate, 1-cyanoethyl-2-n-undecyl-3-carboxymethylimidazolium chloride, 1-cyanoethyl-2-n-undecyl-3-carboxymethylimidazolium bromide, 1-cyanoethyl-2 -N-undecyl-3-carbo Ximethylimidazolium iodide, 1-cyanoethyl-2-n-undecyl-3-carboxymethylimidazolium fluoride, 1-cyanoethyl-2-n-undecyl-3-carboxymethylimidazolium ethoxysulfate, 1-cyanoethyl-2 And -n-undecyl-3-carboxymethylimidazolium chloride. The brackets shown in the enumerated compounds indicate the number of carbon atoms constituting the alkyl group. The imidazolium compounds obtained by quaternizing these imidazoline compounds with a quaternizing agent may be used singly or in combination of two or more.

  Specific examples of the quinoline compound include 3-bromoquinoline, 2-hydroxyquinoline, 6-chloro-2-methylquinoline, 7-chloro-2-methylquinoline, 8-chloro-2-methylquinoline, 2- Chloromethylquinoline, 2-methyl-8-hydroxyquinoline, 2-hydroxyquinoline, 6-hydroxyquinoline, 8-hydroxyquinoline, 6-methoxy-2-methylquinoline, 2-methylquinoline, 4-methylquinoline, 5-nitro Quinoline, 8-nitroquinoline, 2-quinolinecarboxylic acid, 4-quinolinealdehyde, 4-quinolinecarboxylic acid, 8-quinolinecarboxylic acid, 8-quinolinesulfonyl chloride, alkyl (C12) isoquinolinium bromide, alkyl (C12) Quinolinium chloride, 5-aminoisoquinoline 5-hydroxy isoquinoline, 1-isoquinoline carboxylic acid, 5 etc. isoquinoline sulfonic acid can be exemplified. Such quinoline compounds may be used alone or in combination of two or more.

  Specific examples of the thiocarbonyl compound include thiourea, thiosemicarbazide, phenylthiourea, tolylthiourea, N-methylthiourea, dimethylthiourea, diethylthiourea, dibutylthiourea, tetramethylthiourea, methylisothiourea, benzylisothiourea, di Examples include phenylthiourea, diisopropylthiourea, and ethylenethiourea. Such thiocarbonyl compounds may be used alone or in combination of two or more.

  Specific examples of thiazole compounds include mercaptobenzothiazole, 2,5-dimercapto-1,3,4-thiadiazole, 2-mercaptobenzothiazole, 2- (thiocyanomethylthio) benzothiazole, 3- (2-benzo And thiazylthio) propionic acid and (2-benzothiazylthio) acetic acid. Such thiazole compounds may be used alone or in combination of two or more.

  Specific examples of the mercapto compound include isobutyl mercaptan, butyl mercaptan, octyl mercaptan, 2-mercaptoimidazoline and the like. Such mercapto compounds may be used alone or in combination of two or more.

  Specific examples of the sulfide compound include mercaptobenzothiazyl sulfide, tetramethyl thiuram monosulfide, tetramethyl thiuram disulfide, tetraethyl thiuram disulfide, tetrabutyl thiuram disulfide, dipentamethylene thiuram tetrasulfide and the like. Such sulfide compounds may be used alone or in combination of two or more.

  Specific examples of the thiocarbamate include pentamethylenedithiocarbamate piperidine salt, pipecolyl dithiocarbamate pipecoline, dimethyldithiocarbamate, sodium diethyldithiocarbamate, and dibutyldithiocarbamate. Such sulfide compounds may be used alone or in combination of two or more.

  Specific examples of the pyridinium compound include alkylpicolinium chloride, alkylpyridinium chloride, alkylpyridinium bromide, alkylpicolinium bromide, alkylpyridinium iodide, alkylpicolinium iodide, and N- (p-chlorobenzyl) -pyridinium chloride. And N- (p-chlorobenzyl) pyrrolium chloride. Such sulfide compounds may be used alone or in combination of two or more.

  Specific examples of thiocyanate include ammonium thiocyanate, calcium thiocyanate, potassium thiocyanate, and benzyl thiocyanate. Such sulfide compounds may be used alone or in combination of two or more.

  Specific examples of isothiocyanates include phenyl isothiocyanate, benzyl isothiocyanate, 3,4-difluorophenyl isothiocyanate, 2-chlorophenyl isothiocyanate, cyclohexyl isothiocyanate, and 3-acetylaminophenyl isothiocyanate. Can do. Such sulfide compounds may be used alone or in combination of two or more.

  Moreover, you may mix | blend other additives, such as a rust preventive agent, an antifoamer, and surfactant, with a surface treating agent as needed.

The zinc-based plated steel sheet to which the surface treatment agent is applied is not particularly limited as long as it is a steel sheet that has been subjected to zinc-containing plating by a known plating method. Examples of the plating method include hot dipping, electroplating, and vapor phase plating. Examples of galvanized steel sheets include electrogalvanized steel sheets, electrogalvanized nickel-plated steel sheets, hot-dip galvanized steel sheets, hot-dip zinc-aluminum alloy-plated steel sheets, hot-dip zinc-aluminum-magnesium alloy-plated steel sheets, and alloyed hot-dip galvanized steel sheets. A steel plate etc. can be mentioned. Examples of the hot dip zinc-aluminum alloy plated steel sheet include a hot dip Zn-55% Al alloy and a hot dip Zn-5% Al alloy plated steel sheet. But not coating weight also specifically limited, at a coverage per surface, the electroplated steel sheet ^{5g / m 2 ~70g / m 2} , the hot dip plated steel sheet of about ^30g / ^{m 2 ~250g} / m 2 is typical.

  By applying and baking the surface treatment agent on at least one surface of the galvanized steel sheet, a steel sheet having a film formed on the surface of the galvanized steel sheet is obtained. Since this steel sheet has a coating with higher alkali resistance and mechanical strength formed on its surface, it has excellent corrosion resistance and excellent mold galling resistance even after degreasing.

The adhesion amount of the film is preferably 100 mg / m ² or more and 1000 mg / m ² or less. If the adhesion amount is less than 100 mg / m ² , sufficient corrosion resistance cannot be obtained. In addition, when the adhesion amount exceeds 1000 mg / m ² , the improvement in corrosion resistance is saturated and the adhesion of the film may be lowered, and a part of the film is easily scraped off by the mold, and the resistance to mold galling. Decreases.

  The surface treatment liquid can be applied by a known application method generally used in the industry, and is not particularly limited, and examples thereof include a roll coater and spray coating. The baking can be performed by a known baking method, and is not particularly limited. For example, the baking can be performed by a baking method such as a hot air method, an infrared method, and an induction heating method. Moreover, baking temperature can be performed at 50 to 200 degreeC. If the baking temperature is less than 50 ° C., baking will be insufficient, and a film cannot be formed. If the baking temperature exceeds 200 ° C., the corrosion resistance of the film cannot be improved, and the production efficiency will deteriorate.

  The steel sheet on which such a film is formed can be formed into metal products such as household electric products and automobile parts. In the molding process, lubricating oil is generally used, followed by degreasing treatment with an alkaline degreasing solution. This steel sheet is less likely to be scratched during forming, and further, since the film is not affected by the degreasing treatment with an alkaline degreasing solution, it can continue to exhibit excellent corrosion resistance even after degreasing.

  EXAMPLES Hereinafter, although an Example demonstrates this invention concretely, this invention is not limited by this. In Examples and Comparative Examples, “%” represents “% by weight”, and the balance is water. Moreover, a weight part represents the weight part with respect to 100 weight part of polyvalent metal phosphate.

Example 1
As a polyvalent metal phosphate compound, 4.0% of primary aluminum phosphate and 3.0% of titanium hydrofluoric acid are applied on one side of an electrogalvanized steel sheet (plating adhesion amount per side: 20 g / m ² ). % (75 parts by weight), 1.0% (25 parts by weight) titanium titanium fluoride, 0.3% (7.5 parts by weight) ammonium metavanadate as a vanadium compound, and a phosphonic acid chelate as a chelating agent An aqueous solution containing 5.5% (137.5 parts by weight) of 1-hydroxyethylidene-1,1-diphosphonic acid as an agent is applied with a spin coater and baked at 100 ° C., and a coating amount of 500 mg / m ² And a test piece was prepared.

( Reference Example 1 )
As a polyvalent metal phosphate compound, 4.0% of primary aluminum phosphate and 0.3% of titanium hydrofluoric acid were applied on one side of the electrogalvanized steel sheet (plating adhesion amount per side: 20 g / m ² ). % (7.5 parts by weight), ammonium titanium fluoride 0.1% (2.5 parts by weight), vanadium compound, ammonium metavanadate 0.3% (7.5 parts by weight), and chelating agent, An aqueous solution containing phosphonic acid-based chelating agent 1-hydroxyethylidene-1,1-diphosphonic acid 0.4% (10 parts by weight) was applied with a spin coater and baked at 100 ° C., and the adhesion amount was 1000 mg / m ^2. A test piece was prepared.

( Reference Example 2 )
As a polyvalent metal phosphate compound, 4.0% of primary aluminum phosphate and 30% of titanium hydrofluoric acid (on a plated surface of an electrogalvanized steel sheet (plating amount per side: 20 g / m ² )) 750 parts by weight), 10% (250 parts by weight) ammonium titanium fluoride, 0.3% (7.5 parts by weight) ammonium metavanadate as a vanadium compound, and 1- An aqueous solution containing 40% (1000 parts by weight) of hydroxyethylidene-1,1-diphosphonic acid was applied with a spin coater and baked at 100 ° C. to form a film with an adhesion amount of 800 mg / m ² to prepare a test piece. did.

(Example 2 )
As a polyvalent metal phosphate compound, 20% primary aluminum phosphate and 15% titanium hydrofluoric acid (75 wt.%) Are formed on one side of the electrogalvanized steel sheet (plating adhesion amount per side: 20 g / m ² ). Part), titanium fluoride ammonium 5.0% (25 parts by weight), vanadium compound, ammonium metavanadate 0.2% (1 part by weight), and chelating agent, phosphonic acid chelating agent 1-hydroxyethylidene An aqueous solution containing 20% (100 parts by weight) of -1,1-diphosphonic acid was applied with a spin coater and baked at 100 ° C. to form a film with an adhesion amount of 300 mg / m ² to prepare a test piece.

(Example 3 )
As a polyvalent metal phosphate compound, 2.0% of primary aluminum phosphate and titanium hydrofluoric acid were added to the plated surface of one side of an electrogalvanized steel sheet (plating adhesion amount per side: 20 g / m ² ). 5% (75 parts by weight), ammonium titanium fluoride 0.5% (25 parts by weight), vanadium compound, potassium vanadate 1.0% (50 parts by weight), and chelating agent, phosphonic acid chelating agent An aqueous solution containing 5.0% (250 parts by weight) of 1-hydroxyethylidene-1,1-diphosphonic acid was applied with a spin coater and baked at 100 ° C. to form a film having an adhesion amount of 600 mg / m ^2. A test piece was prepared.

(Example 4 )
As a polyvalent metal phosphate compound, 4.0% primary aluminum phosphate and 4.0% titanium hydrofluoric acid were applied to one side of the electrogalvanized steel sheet (plating adhesion amount per side: 20 g / m ² ). % (100 parts by weight), as a vanadium compound, 0.3% (7.5 parts by weight) ammonium metavanadate, and as a chelating agent, 1-hydroxyethylidene-1,1-diphosphonic acid 5 as a phosphonic acid chelating agent An aqueous solution containing 5% (137.5 parts by weight) was applied by a spin coater and baked at 100 ° C. to form a film having an adhesion amount of 500 mg / m ² to prepare a test piece.

(Example 5 )
As a polyvalent metal phosphate compound, 4.0% of primary aluminum phosphate and 3.0% of titanium hydrofluoric acid are applied on one side of an electrogalvanized steel sheet (plating adhesion amount per side: 20 g / m ² ). % (75 parts by weight), 1.0% (25 parts by weight) titanium titanium fluoride, 0.3% (7.5 parts by weight) ammonium metavanadate as a vanadium compound, and a phosphonic acid chelate as a chelating agent 1-hydroxyethylidene-1,1-diphosphonic acid 5.5% (137.5 parts by weight) and 3.7 × 10 ⁻⁵ % ammonium thiocyanate (9.25 × 10 ⁻⁴ ) as a corrosion inhibitor. and parts by weight), an aqueous solution containing an alkyl picolinium chloride ^{3.0 × 10 -6% (7.5 ×} 10 -5 parts by weight) was applied by a spin coater and baked at 100 ° C., the amount of deposition is 10 forming a coating of mg / ^{m 2,} to prepare a test piece.

(Example 6 )
As a polyvalent metal phosphate compound, 20% primary aluminum phosphate and 15% titanium hydrofluoric acid (75 wt.%) Are formed on one side of the electrogalvanized steel sheet (plating adhesion amount per side: 20 g / m ² ). Part), titanium fluoride ammonium 5.0% (25 parts by weight), vanadium compound, ammonium metavanadate 0.2% (1 part by weight), and chelating agent, phosphonic acid chelating agent 1-hydroxyethylidene -1,1-diphosphonic acid 20% (100 parts by weight), as a corrosion inhibitor, ammonium thiocyanate 3.7 × 10 ⁻² % (1.85 × 10 ⁻¹ part by weight), and alkylpicolinium chloride 3 An aqueous solution containing 0.0 × 10 ⁻³ % (1.5 × 10 ⁻² parts by weight) was applied with a spin coater and baked at 100 ° C., and the adhesion amount was 200 mg / m ² . A film was formed to prepare a test piece.

(Example 7 )
As a polyvalent metal phosphate compound, 4.0% of primary aluminum phosphate and 3.0% of titanium hydrofluoric acid are applied on one side of an electrogalvanized steel sheet (plating adhesion amount per side: 20 g / m ² ). % (75 parts by weight), 1.0% (25 parts by weight) titanium titanium fluoride, 0.3% (7.5 parts by weight) ammonium metavanadate as a vanadium compound, and a phosphonic acid chelate as a chelating agent 1-hydroxyethylidene-1,1-diphosphonic acid of the agent 5.5% (137.5 parts by weight), polyethylene wax 1.3% (32.5 parts by weight) as a solid lubricant, and as a corrosion inhibitor, ammonium thiocyanate 3.7 × 10 ^{- 5}
% (9.25 × 10 ⁻⁴ parts by weight) and an alkylpicolinium chloride 3.0 × 10 ⁻⁶ % (7.5 × 10 ⁻⁵ parts by weight) were applied with a spin coater at 100 ° C. And a film having an adhesion amount of 400 mg / m ² was formed to prepare a test piece.

(Example 8 )
As a polyvalent metal phosphate compound, 4.0% of primary aluminum phosphate and 3.0% of titanium hydrofluoric acid are applied on one side of an electrogalvanized steel sheet (plating adhesion amount per side: 20 g / m ² ). % (75 parts by weight), 1.0% (25 parts by weight) titanium titanium fluoride, 0.3% (7.5 parts by weight) ammonium metavanadate as a vanadium compound, and a phosphonic acid chelate as a chelating agent 1-hydroxyethylidene-1,1-diphosphonic acid 5.5% (137.5 parts by weight), silane coupling agent (Silas Ace S510 manufactured by Chisso) 0.6% (15 parts by weight), and corrosion inhibition agents as, 3.7 × 10 ^-5% ammonium thiocyanate and (9.25 × 10 ^-4 parts by weight), alkyl picolinium chloride ^{3.0 × 10 -6% (7.5 ×} 10 -5 double The aqueous solution containing portion) and coated with a spin coater and baked at 100 ° C., the amount of deposition to form a coating of 700 mg / m ^2, to prepare a test piece.

(Comparative Example 1)
An aqueous solution containing 20% primary aluminum phosphate as a polyvalent metal phosphate compound was applied to one plated surface of an electrogalvanized steel sheet (plating adhesion amount per side: 20 g / m ² ) with a spin coater, 100 A test piece was produced by baking at a temperature of 500 ° C. to form a film having an adhesion amount of 500 mg / m ² .

(Comparative Example 2)
As a polyvalent metal phosphate compound, 20% primary aluminum phosphate and a phosphonic acid chelating agent as a chelating agent on one surface of an electrogalvanized steel sheet (plating adhesion amount per side: 20 g / m ² ) An aqueous solution containing 15% (75 parts by weight) of 1-hydroxyethylidene-1,1-diphosphonic acid was applied with a spin coater and baked at 100 ° C. to form a film having an adhesion amount of 500 mg / m ^2. A piece was made.

(Comparative Example 3)
On one side of the electrogalvanized steel sheet (plating amount per side: 20 g / m ² ), 20% primary aluminum phosphate as the polyvalent metal phosphate compound, and ammonium metavanadate as the vanadium compound. An aqueous solution containing 75% (3.75 parts by weight) and 8.75% (43.75 parts by weight) of 1-hydroxyethylidene-1,1-diphosphonic acid phosphonic acid chelating agent as a chelating agent Then, the film was baked at 100 ° C. to form a film having an adhesion amount of 500 mg / m ² to prepare a test piece.

(Comparative Example 4)
As a polyvalent metal phosphate compound, 20% of primary aluminum phosphate and 16.7% of titanium hydrofluoric acid are applied on one side of the electrogalvanized steel sheet (plating adhesion amount per side: 20 g / m ² ). 83.5 parts by weight), 16.7% (83.5 parts by weight) of ammonium titanium fluoride, and 23.3% of 1-hydroxyethylidene-1,1-diphosphonic acid phosphonic acid chelating agent as a chelating agent ( 116.5 parts by weight) was applied with a spin coater and baked at 100 ° C. to form a film with an adhesion amount of 500 mg / m ² to prepare a test piece.

(Comparative Example 5)
As a polyvalent metal phosphate compound, 4.0% of primary aluminum phosphate and 3.0% of titanium hydrofluoric acid are applied on one side of an electrogalvanized steel sheet (plating adhesion amount per side: 20 g / m ² ). % (75 parts by weight), 1.0% (25 parts by weight) titanium titanium fluoride, 0.3% (7.5 parts by weight) ammonium metavanadate as a vanadium compound, and a phosphonic acid chelate as a chelating agent An aqueous solution containing 0.2% (5 parts by weight) of 1-hydroxyethylidene-1,1-diphosphonic acid as an agent is applied with a spin coater and baked at 100 ° C. to form a film having an adhesion amount of 500 mg / m ^2. Thus, a test piece was produced.

(Comparative Example 6)
As a polyvalent metal phosphate compound, 4.0% of primary aluminum phosphate and 3.0% of titanium hydrofluoric acid are applied on one side of an electrogalvanized steel sheet (plating adhesion amount per side: 20 g / m ² ). % (75 parts by weight), 1.0% (25 parts by weight) titanium titanium fluoride, 0.3% (7.5 parts by weight) ammonium metavanadate as a vanadium compound, and a phosphonic acid chelate as a chelating agent An aqueous solution containing 48.0% (1200 parts by weight) of 1-hydroxyethylidene-1,1-diphosphonic acid as an agent is applied by a spin coater and baked at 100 ° C. to form a film having an adhesion amount of 500 mg / m ^2. Thus, a test piece was produced.

(Comparative Example 7)
As a polyvalent metal phosphate compound, 4.0% of primary aluminum phosphate and 3.0% of titanium hydrofluoric acid are applied on one side of an electrogalvanized steel sheet (plating adhesion amount per side: 20 g / m ² ). % (75 parts by weight), ammonium titanium fluoride 1.0% (25 parts by weight), ammonium metavanadate 0.02% (0.5 parts by weight) as a vanadium compound, and phosphonic acid chelate as a chelating agent An aqueous solution containing 5.5% (137.5 parts by weight) of 1-hydroxyethylidene-1,1-diphosphonic acid as an agent is applied with a spin coater and baked at 100 ° C., and a coating amount of 500 mg / m ² And a test piece was prepared.

(Comparative Example 8)
As a polyvalent metal phosphate compound, 4.0% of primary aluminum phosphate and 3.0% of titanium hydrofluoric acid are applied on one side of an electrogalvanized steel sheet (plating adhesion amount per side: 20 g / m ² ). % (75 parts by weight), 1.0% (25 parts by weight) ammonium titanium fluoride, 3.0% (75 parts by weight) ammonium metavanadate as a vanadium compound, and a phosphonic acid chelating agent as a chelating agent An aqueous solution containing 5.5% (137.5 parts by weight) of 1-hydroxyethylidene-1,1-diphosphonic acid is applied with a spin coater and baked at 100 ° C. to form a film having an adhesion amount of 500 mg / m ^2. Thus, a test piece was produced.

(Comparative Example 9)
As a polyvalent metal phosphate compound, 4.0% of primary aluminum phosphate and 0.15 of titanium hydrofluoric acid are applied on one side of an electrogalvanized steel sheet (plating adhesion amount per side: 20 g / m ² ). % (3.75 parts by weight), ammonium titanium fluoride 0.05% (1.25 parts by weight), vanadium compound, ammonium metavanadate 0.3% (7.5 parts by weight), and chelating agent, An aqueous solution containing 5.5% (137.5 parts by weight) of 1-hydroxyethylidene-1,1-diphosphonic acid, a phosphonic acid chelating agent, was applied with a spin coater and baked at 100 ° C. A film of m2 was formed to prepare a test piece.

(Comparative Example 10)
As a polyvalent metal phosphate compound, 4.0% primary aluminum phosphate and 41.0% titanium hydrofluoric acid are applied on one side of the electrogalvanized steel sheet (plating adhesion amount per side: 20 g / m 2). (1025 parts by weight), 12.5% (312.5 parts by weight) of ammonium titanium fluoride, 0.3% (7.5 parts by weight) of ammonium metavanadate as a vanadium compound, and phosphonic acid as a chelating agent An aqueous solution containing 5.5% (137.5 parts by weight) of the chelating agent 1-hydroxyethylidene-1,1-diphosphonic acid is applied with a spin coater and baked at 100 ° C., and the coating amount is 500 mg / m 2 And a test piece was prepared.

In order to evaluate the corrosion resistance and the corrosion resistance after alkaline degreasing, the test pieces obtained in the above Examples , Reference Examples and Comparative Examples were tested in the following manner. These test results are shown together in Table 1 together with the composition of the surface treatment liquid and the amount of adhesion. Symbols such as “◎”, “◯”, “Δ”, and “x” described in the description of the evaluation items are symbols indicating evaluation results used in Table 1. “◎” indicates very good, “○” indicates excellent, “△” indicates that it is practical, “×” and “XX” indicate that it is practical “Xx” indicates that the utility is lower than “x”. In addition, “◎” and “◯” are acceptable.

(Corrosion resistance evaluation)
Each test piece is exposed to a salt spray environment using a salt spray device conforming to JIS Z-2371 under the conditions of a salt water concentration of 5%, a bath temperature of 35 ° C., and a spray pressure of 200 psi (about 14.1 kg / cm 2). The area ratio of white rust generated on the surface after 72 hours was measured.

Evaluation was performed in the following five stages.
A: White rust area ratio 0%
○: White rust area ratio higher than 0% and lower than 5% △: White rust area ratio higher than 5% and lower than 10% ×: White rust area ratio higher than 10% and lower than 50% XX: White rust area ratio 50% or higher

(Evaluation of corrosion resistance after alkaline degreasing 1)
Each test piece was immersed in an alkaline degreasing solution (manufactured by Nihon Parkerizing Co., Ltd., FC4480 (pH about 10)) for 30 seconds, washed with water, and then dried and used under the same conditions as above. The corrosion resistance after spraying with salt water was evaluated. Evaluation was performed according to the same evaluation criteria as described above.

(Evaluation of corrosion resistance after alkaline degreasing 2)
Each test piece was immersed in an alkaline degreasing solution at 60 ° C. (manufactured by Nihon Parkerizing Co., Ltd., N364S (pH about 12)) for 120 seconds, washed with water, dried, and then dried under the same conditions as described above. The corrosion resistance after spraying with salt water was evaluated. Evaluation was performed according to the same evaluation criteria as described above.

(Evaluation of mold galling resistance)
Each test piece (plate thickness 0.8 mm) was cut into a size of 30 mm × 150 mm, and formed into a U shape with a clearance of −10% of the plate thickness (die and punch shoulder R = 5 mm). The appearance (the part subjected to sliding by the mold) was visually evaluated.

Evaluation was performed in the following four stages.
A: The galling is not noticeable.
○: Scratch is slightly noticeable.
Δ: Scratch is conspicuous.
X: The galling is very conspicuous.

(Slidability evaluation)
With each test piece in contact with the mold plate (made of the same material as the mold) with a Bowden test machine, the test piece was reciprocated 30 times while applying a load of 1 kg · f, 30 The evaluation was based on the average value of the dynamic friction coefficient of the forward path and the dynamic friction coefficient of the return path during the second round-trip.

Evaluation was performed in the following four stages.
◎: Less than 0.2 ○: 0.2 to less than 0.35 Δ: 0.35 to less than 0.45 ×: 0.45 or more

(Secondary adhesion evaluation)
About 30 μm of Glymine (alkydmelamine paint) manufactured by Shinto Paint Co., Ltd. was applied to each test piece and baked at 130 ° C. Thereafter, the surface of a test piece obtained by dipping in 80 ° C. warm water for 2 hours and drying was cut in a grid pattern to perform a tape peeling test.

Evaluation was performed in the following four stages.
A: Peeling area 0 to less than 2% B: Peeling area 2 to less than 5% Δ: Peeling area 5 to less than 20% ×: Peeling area 20% or more

As shown in Table 1, in Examples 1 to 8 in which the zinc-based plated steel sheet was treated using the surface treating agent according to the present invention, the corrosion resistance, the corrosion resistance after alkaline degreasing, and the mold galling resistance have good performance. I understood it. Moreover, in Example 7 using the surface treating agent containing polyethylene wax which is a solid lubricant, the performance with good slidability was maintained while maintaining good performances of corrosion resistance, corrosion resistance after alkaline degreasing, and mold galling resistance. I found out that Moreover, in Example 8 using the surface treating agent containing a silane coupling agent, the secondary adhesiveness is also a good performance in a state where the corrosion resistance, the corrosion resistance after alkali degreasing, and the mold galling resistance are maintained. I understood it.

The surface treating agent used in Example 1 has an optimal composition. The surface treatment agent used in Reference Example 1 has relatively less hexafluorotitanic acid and its salts and chelating agents than the surface treatment agent used in Example 1, and the formed film becomes weaker, resulting in corrosion resistance and mold resistance. The galling property was lower than that in Example 1, but the adhesion amount was large, and the corrosion resistance, the corrosion resistance after alkaline degreasing, and the galling resistance showed good performance. The surface treatment agent used in Reference Example 2 has relatively more hexafluorotitanic acid and its salts and chelating agents than the surface treatment agent used in Example 1, and the formed film becomes weaker, resulting in corrosion resistance and mold galling. Although the property was lower than that of Example 1, the adhesion amount was large, and the corrosion resistance, the corrosion resistance after alkaline degreasing, and the mold galling resistance showed good performance. Since the surface treatment agent used in Example 2 contained fewer vanadium compounds than the surface treatment agent used in Example 1, the corrosion resistance was lower than that in Example 1. Further, since the vanadium compound does not participate in the formation of the film, the mold galling property did not decrease. The surface treatment agent used in Example 3 has more vanadium compounds than the surface treatment agent used in Example 1, and a polyvalent metal phosphate compound, hexafluorotitanic acid and its salt, which are components that form a film, Since the chelating agent was relatively reduced, the corrosion resistance was slightly reduced as compared with Example 1, but the mold galling property was not so low. The surface treating agent used in Example 4 does not contain a salt of hexafluorotitanic acid, but is only hexafluorotitanic acid. The combined use of hexafluorotitanic acid and its salt tends to improve the corrosion resistance. Hexafluorotitanic acid alone has a slight decrease in corrosion resistance compared to Example 1, but does not affect mold galling resistance. . The surface treating agent used in Example 5 was obtained by adding a corrosion inhibitor to the surface treating agent used in Example 1, and the same performance as in Example 1 was obtained. Moreover, since the amount of adhesion is smaller than that of Example 1 and the performance is equivalent, the performance is substantially higher than that of the surface treatment agent used in Example 1. Surface treatment agent used in Example 6 is obtained by adding a corrosion inhibitor to the surface treatment agent used in Example 2, the same performance as in Example 2 was obtained. Moreover, since the amount of adhesion is smaller than that of Example 2 and the performance is equivalent, it is substantially higher than that of Example 2 . The surface treatment agent used in Example 7 is obtained by adding polyethylene wax to the surface treatment agent used in Example 5 . The surface treatment agent used in Example 7 showed comparable performance in terms of corrosion resistance, corrosion resistance after alkaline degreasing, and mold galling resistance, as compared with Example 5, and good sliding properties. The surface treatment agent used in Example 8 is obtained by adding a silane coupling agent to the surface treatment agent used in Example 5 . The surface treatment agent used in Example 8 was comparable in performance to corrosion resistance, corrosion resistance after alkaline degreasing, and anti-galling resistance as compared with Example 5, and good in secondary adhesion with the top coating. there were.

  On the other hand, the surface treating agent used in Comparative Example 1 contains only a polyvalent metal phosphate compound. In this case, corrosion resistance and corrosion resistance after alkaline degreasing were inferior.

  The surface treatment agent used in Comparative Example 2 contains only a polyvalent metal phosphate compound and a chelating agent. In Comparative Example 2 using such a surface treatment agent, although the corrosion resistance and mold galling resistance were improved as compared with Comparative Example 1, the corrosion resistance after alkaline degreasing was inferior.

  The surface treatment agent used in Comparative Example 3 contains only a polyvalent metal phosphate compound, a chelating agent, and a vanadium compound. In Comparative Example 3 using such a surface treating agent, although the corrosion resistance and mold galling resistance were improved as compared with Comparative Example 1, they were insufficient and the corrosion resistance after alkaline degreasing was inferior.

  The surface treatment agent used in Comparative Example 4 contains only a polyvalent metal phosphate compound, a chelating agent, hexafluorotitanic acid and its salt. In Comparative Example 4 using such a surface treatment agent, improvement in mold galling resistance was observed as compared with Comparative Examples 2 and 3. However, the corrosion resistance and corrosion resistance after alkaline degreasing were insufficient.

Each surface treating agent used in Comparative Examples 5 to 10 includes all of a polyvalent metal phosphate compound, a chelating agent, hexafluorotitanic acid and a salt thereof, and a vanadium compound, and any of those contents is in a preferred range. Deviate from. In Comparative Examples 5 to 10 using such a surface treating agent, the corrosion resistance, the corrosion resistance after alkaline degreasing, and the anti-scoring property were insufficient as compared with Examples 1 to 6 and Reference Examples 1 and 2 . .

  From the above, according to the present invention, the surface treatment agent does not contain harmful substances such as chromium compounds, and further, corrosion resistance of the zinc-based plated steel sheet, corrosion resistance after alkaline degreasing, mold galling resistance, slidability, secondary Adhesion can be remarkably improved. Therefore, the surface treatment agent of the present invention can be used as a treatment agent in place of the conventional chromate treatment which is harmful and has a problem of environmental pollution.

Claims (8)

A surface treatment agent that does not contain a resin (excluding a resin component as a solid lubricant or a silane coupling agent) and a chromium compound, which is used for the surface treatment of a galvanized steel sheet,
Against aluminum primary phosphate 100 parts by weight of water-soluble, hexafluoro titanic acid and / or hexafluoro titanate comprises less than 1000 parts by weight more than 10 parts by weight, and hexafluorotitanate and / or hexafluorotitanate treatment agent concentration of salt is not less than 20% 2.0% or more, the ammonium metavanadate and / or vanadate potassium comprises 50 parts by weight or less than 1 part by weight, the phosphonic acid chelating agent as a chelating agent 100 A surface treatment agent excellent in corrosion resistance and alkali resistance against alkali degreasing, characterized by containing from 250 parts by weight to 250 parts by weight. A surface treatment agent that does not contain a resin (excluding a resin component as a solid lubricant or a silane coupling agent) and a chromium compound, which is used for the surface treatment of a galvanized steel sheet,
Contains more than 10 parts by weight and less than 1000 parts by weight of hexafluorotitanic acid and / or hexafluorotitanate with respect to 100 parts by weight of water-soluble primary aluminum phosphate, and hexafluorotitanic acid and / or hexafluorotitanium The concentration of the acid salt in the treatment agent is 2.0% or more and 20% or less, contains 1 part by weight or more and 50 parts by weight or less of ammonium metavanadate and / or potassium vanadate, and 100 weights of phosphonic acid chelating agent as a chelating agent A surface excellent in corrosion resistance and mold galling resistance after alkaline degreasing, characterized by containing 0.001 part by weight or more and 1 part by weight or less of pyridinium and / or thiocyanate as a corrosion inhibitor. Processing agent. The surface treatment agent having excellent corrosion resistance and anti-galling property after alkaline degreasing according to claim 1 or 2, wherein the phosphonic acid chelating agent is 1-hydroxyethylidene-1,1-diphosphonic acid. The surface treating agent excellent in corrosion resistance after alkali degreasing and mold galling resistance according to any one of claims 1 to 3 , comprising a solid lubricant. A surface treatment agent excellent in corrosion resistance and mold galling resistance after alkali degreasing according to any one of claims 1 to 4 , comprising a silane coupling agent. The surface treatment agent having excellent corrosion resistance and anti-galling property after alkali degreasing according to any one of claims 1 to 5 , wherein the hexafluorotitanate is ammonium hexafluorotitanate. A steel sheet with a coating formed on the surface of a zinc-based plated steel sheet,
The film is formed by applying and baking the surface treatment agent according to any one of claims 1 to 6 on at least one surface of the zinc-based plated steel sheet. Steel sheet with excellent corrosion resistance and mold galling resistance. The steel sheet excellent in corrosion resistance and alkali galling resistance after alkali degreasing according to claim 7 , wherein the coating amount of the film is 100 mg / m ² or more and 1000 mg / m ² or less.