WO2016171281A1

WO2016171281A1 - Surface treatment agent for metal material and metal material

Info

Publication number: WO2016171281A1
Application number: PCT/JP2016/062884
Authority: WO
Inventors: 太志倉員; 雅矢宮崎; 康彦永嶋
Original assignee: 日本パーカライジング株式会社
Priority date: 2015-04-24
Filing date: 2016-04-25
Publication date: 2016-10-27
Also published as: KR20170141748A; CN107532304B; JPWO2016171281A1; CN107532304A; KR102130197B1; JP6539728B2

Abstract

[Problem] To provide: a surface treatment agent for a metal material that is capable of forming a corrosion-resistant film and has excellent liquid stability; and a metal material with a metal surface treatment film formed by said surface treatment agent. [Solution] Said problem is solved by a surface treatment agent for a metal material characterized: in containing an alkali metal salt (component a) and a nitrate (component b) of zirconium carbonate, and one or more organic polymers (component c) selected from urethane resins, epoxy resins, acrylic resins, phenol resins, polyester resins, polyvinyl resins, polyolefin resins and natural polymers; and the pH being greater than 7 and not more than 12.

Description

Surface treatment agent for metal material and metal material

The present invention relates to a surface treatment agent for a metal material and a metal material having a metal surface treatment film formed by the surface treatment agent.

As a surface treatment agent capable of forming a corrosion-resistant film, those containing ammonium zirconium carbonate have been conventionally developed (see, for example, Patent Documents 1 and 2).

JP-A-1-149865 JP 2007-204847 A

However, the surface treatment agent containing ammonium zirconium carbonate may increase in viscosity and decrease in liquid stability with time. Accordingly, the present invention provides a surface treatment agent for metal materials that can form a corrosion-resistant film and has excellent liquid stability, and a metal material having a metal surface treatment film formed by the surface treatment agent. The purpose is to do.

As a result of intensive studies to solve the above problems, the present inventor has a surface treatment agent in which an alkali metal salt of zirconium carbonate and a nitrate are blended and the pH is adjusted to more than 7 to 12 or less, and the liquid stability is excellent. The inventors have found that a film having corrosion resistance can be formed, and have completed the present invention.

That is, the present invention
(1) Surface treatment agent for metal materials containing an alkali metal salt of zirconium carbonate (component a) and nitrate (component b) and having a pH of more than 7 and 12 or less (excluding those containing fluorine);
(2) In addition, one or more organic polymers (component c) selected from urethane resins, epoxy resins, acrylic resins, phenol resins, polyester resins, polyvinyl resins, polyolefin resins and natural polymers. Containing a surface treatment agent for a metal material according to the above (1);
(3) The surface treatment agent for a metal material according to the above (1) or (2), wherein the pH is 7.5 or more and 12 or less;
(4) A metal material having a surface treatment film formed by bringing the surface treatment agent for metal material according to any one of (1) to (3) above into contact with the surface of the metal material and then drying it;
Etc.

ADVANTAGE OF THE INVENTION According to this invention, the metal material which can form the film which has corrosion resistance and was excellent in liquid stability, and the metal material which has the metal surface treatment film formed with this surface treatment agent are provided. can do.

Hereinafter, the surface treatment agent for metal materials according to the present invention (hereinafter simply referred to as “surface treatment agent”) and the metal material will be described in detail.

The surface treatment agent according to the present invention is in the form of an aqueous solution or an aqueous dispersion at the time of use, and the straight type used as it is and the high concentration type diluted with water at the time of use are included in the concept of the surface treatment agent of the present invention. Hereinafter, a straight type surface treatment agent will be described as an example.

The surface treatment agent contains an alkali metal salt of zirconium carbonate (component a) and nitrate (component b), does not contain fluorine, and has a pH in the range of more than 7 and 12 or less. However, it is not particularly limited, and may include an organic polymer and / or a known additive for a surface treatment agent. However, a surface treatment agent not containing chromium or vanadium is preferable from the viewpoint of environmental measures. Moreover, the surface treating agent which does not contain cobalt, cerium, and silicon is preferable. In the present specification and claims, “does not include” and “excludes including” are not intended to exclude trace amounts, but preferably not included at all. Hereinafter, each component will be described.

Component a is an alkali metal salt of zirconium carbonate. Examples of the alkali metal in this salt include Li, Na, K and the like. In addition, the alkali metal salt of zirconium carbonate to be blended in the surface treatment agent of the present invention may be used alone or in combination of two or more.

Next, component b is nitrate. Here, examples of the counter cation of nitric acid include monovalent or divalent metal ions, alkali metal ions, alkaline earth metal ions, and the like. Specific examples of component b include, but are not limited to, sodium nitrate, potassium nitrate, lithium nitrate, ammonium nitrate, nickel nitrate, zirconium nitrate, magnesium nitrate, calcium nitrate, and aluminum nitrate. . In addition, although 1 type may be used for the nitrate mixed with the surface treating agent of this invention, you may use it in combination of 2 or more type.

The ratio of the total mass (Ma) of Zr in the alkali metal salt of zirconium carbonate (component a) and the total mass (Mb) of nitrate ions in the nitrate (component b) contained in the surface treatment agent [mass ratio = Mb / Ma] is preferably 0.01 to 1.60, more preferably 0.01 to 1.00, particularly preferably 0.04 to 0.94, and 0.04 to Most preferred is 0.7.

In the above description, the surface treatment agent comprising only the component a and the component b in addition to the solvent has been described. However, as described above, a known surface treatment agent may be used even if an organic polymer is further blended. Even if the additive for further use is mix | blended, the organic polymer and the additive for surface treatment agents further blended may be used.

The organic polymer (component c) is not particularly limited as long as it is a resin used for film formation. For example, urethane resin, epoxy resin, acrylic resin, phenol resin, polyester resin, polyvinyl resin, polyolefin Well-known materials such as resin and natural polymer can be used, and can be appropriately selected according to the required performance. These organic polymers may have one or more functional groups of an anionic group, a cationic group, and a nonionic group, but those that can stably exist in the surface treatment agent of the present invention are preferable. . The surface treatment agent containing a solvent and an organic polymer may be in the form of a solution or a dispersion such as an emulsion or a dispersion.

As the urethane resin, a urethane resin that is a polycondensation product of a polyol such as polyether polyol or polycarbonate polyol and a polyisocyanate such as an aliphatic polyisocyanate compound, an alicyclic polyisocyanate compound and / or an aromatic polyisocyanate compound. And a polyurethane obtained by using a polyol having a polyoxyethylene chain such as polyethylene glycol or polypropylene glycol as a part of the polyol described above. Such polyurethane can be water-soluble or water-dispersed by increasing the introduction ratio of the polyoxyethylene chain described above. In addition, the surface treating agent which concerns on this invention does not need to contain the polyester polyurethane resin which has a structural unit derived from a polyester polyol in a molecule | numerator.

In addition, a urethane prepolymer having isocyanate groups at both ends is produced from polyisocyanate and polyol, and this is reacted with a carboxylic acid having two or more hydroxyl groups or a reactive derivative thereof, and a derivative having isocyanate groups at both ends. Next, triethanolamine or the like is added to form an ionomer (triethanolamine salt), and the ionomer is added to water to form an emulsion or dispersion, and if necessary, a diamine is added to perform chain extension. By carrying out like this, the water dispersible urethane resin which has anionic property can be obtained.

The above-described carboxylic acid and reactive derivative used in producing the water-dispersible urethane resin having an anionic property are used to introduce an acidic group into the urethane resin and facilitate the dispersion of the urethane resin in water. Examples of the carboxylic acid used include dimethylol alkanoic acid such as dimethylolpropionic acid, dimethylolbutanoic acid, dimethylolpentanoic acid, and dimethylolhexanoic acid. Examples of the reactive derivative include hydrolyzable esters such as acid anhydrides.

As an epoxy resin, an epoxy compound having two or more glycidyl groups, or an epoxy compound having a bisphenol structure such as bisphenol A or bisphenol F as a unit in the skeleton is reacted with a diamine such as ethylenediamine, and then cationized. Examples thereof include a cationic amine-modified epoxy resin obtained or a nonionic epoxy resin obtained by adding a polyalkylene oxide to a side chain (for example, a hydroxyl group) of an epoxy compound having two or more glycidyl groups.

In addition, the epoxy resin may be an epoxy resin in which a part or all of the glycidyl group in the epoxy resin having a bisphenol structure such as bisphenol A or bisphenol F as a unit in the skeleton is phosphoric acid-modified.

As an epoxy resin having a bisphenol structure such as bisphenol A or bisphenol F as a unit in the skeleton, after dehydrochlorination reaction of epichlorohydrin and bisphenol A or bisphenol F, an epoxy compound obtained by the reaction and a diamine And those obtained by repeating the addition reaction of an epoxy compound having two or more, preferably two glycidyl groups, and bisphenol (A, F).

Examples of epoxy compounds include bisphenol (A, F) diglycidyl ether, orthophthalic acid diglycidyl ester, isophthalic acid diglycidyl ester, terephthalic acid diglycidyl ester, p-oxybenzoic acid diglycidyl ester, and tetrahydrophthalic acid diglyceride. Glycidyl ester, hexahydrophthalic acid diglycidyl ester, succinic diglycidyl ester, adipic acid diglycidyl ester, sebacic acid diglycidyl ester, ethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, 1,4-butanediol diglycidyl ether 1,6-hexanediol diglycidyl ether, sorbitol polyglycidyl ether, polyalkylene glycol diglycidyl ether, Mellitic acid triglycidyl ester, triglycidyl isocyanurate, 1,4-glycidyloxybenzene, diglycidylpropylene urea, glycerol triglycidyl ether, trimethylolethane triglycidyl ether, trimethylolpropane triglycidyl ether, pentaerythritol tetraglycidyl ether, glycerol Examples thereof include triglycidyl ether of an alkylene oxide adduct. These may be used alone or in combination of two or more.

Examples of the acrylic resin include homopolymers or copolymers of acrylic monomers, and copolymers of acrylic monomers and addition polymerizable monomers that can be copolymerized with the acrylic monomers. As long as such an acrylic resin can be stably present in the surface treatment agent, the polymerization form is not particularly limited.

Acrylic monomers include, for example, methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, n-hexyl methacrylate, 2-ethylhexyl acrylate, acrylic acid, methacrylic acid, 2-hydroxyethyl Examples thereof include acrylate, hydroxypropyl acrylate, 2-hydroxyethyl methacrylate, hydroxypropyl methacrylate, glycidyl acrylate, glycidyl methacrylate, sulfoethyl acrylate, and polyethylene glycol methacrylate. Examples of the addition polymerizable monomer that can be copolymerized with the acrylic monomer include maleic acid, itaconic acid, acrylamide, N-methylol acrylamide, diacetone acrylamide, styrene, acrylonitrile, and vinyl sulfonic acid.

Examples of the polyester resin include maleic acid, fumaric acid, itaconic acid, succinic acid, glutaric acid, suberic acid, adipic acid, azelaic acid, sebacic acid, dimer acid, trimer acid, isophthalic acid, terephthalic acid, trimellitic acid, Polybasic acids such as trimesic acid, pyromellitic acid, naphthalene dicarboxylic acid, and polyols such as ethylene glycol, diethylene glycol, trimethylolpropane, neopentyl glycol, 1,4-CHDM (cyclohexanedimethanol), 1,6-hexanediol A polyester polyol obtained by condensing a polybasic acid with a polymer polyol such as a polymer polyol, polycaprolactone polyol, polycarbonate diol, polybutadiene polyol, neopentyl glycol, or methylpentadiol. Condensation resin and Lumpur condensed; and the like. In addition, the condensation products (having unreacted carboxyl groups) of monomers such as trimellitic acid and pyromellitic acid having 3 or more carboxyl groups and various polyols are neutralized with alkali to solubilize or disperse in water. Water-based resins, or water-based resins in which the polybasic acid is reacted with a sulfonic acid such as sulfophthalic acid to solubilize or water-disperse a condensate of a monomer having a sulfonic acid group introduced and various polyols are also used. be able to.

Examples of the polyvinyl resin include polyvinyl acetate, a partially saponified product or a completely saponified product of polyvinyl acetate, and polyvinylpyrrolidone.

The polyvinyl resin includes a saponified polymer obtained by copolymerizing a monomer copolymerizable with vinyl acetate. Furthermore, polyvinyl resins include modified polymers in which anionic groups such as carboxylic acid, sulfonic acid, and phosphoric acid are introduced into copolymerized or saponified polymers, diacetone acrylamide groups, acetoacetyl groups, mercapto groups, and the like. And modified polymers into which functional groups having cross-linking reactivity such as groups are introduced.

Examples of monomers copolymerizable with vinyl acetate include unsaturated carboxylic acids such as maleic acid, fumaric acid, crotonic acid, itaconic acid, (meth) acrylic acid, and esters thereof; ethylene, propylene, and the like. α-olefin; olefin sulfonic acid which may have a carboxyl group, such as (meth) acryl sulfonic acid, ethylene sulfonic acid, sulfonic acid malate; (meth) acrylic sulfonic acid soda, ethylene sulfonic acid soda, sulfonic acid soda Olefin sulfonic acid alkali salts which may have a carboxyl group and / or an alkoxycarbonyl group, such as (meth) acrylate, sulfonic acid soda (monoalkylmalate), disulfonic acid soda alkylmalate; N-methylolacrylamide; Acrylamide alkyl sulfonic acid Amide group-containing monomers such as potassium salt; N- vinylpyrrolidone, N- pyrrolidone group-containing monomers such as vinyl pyrrolidone derivatives; and the like.

Examples of the phenol resin include polycondensates of phenols (phenol, naphthol, bisphenol, etc.) and formaldehyde, which are low molecular weight water-soluble resins or emulsion resins. Among these, a resol type phenol resin having a methylol group having a self-condensation property is preferable.

Examples of natural polymers include cellulose, starch, dextrin, inulin, xanthan gum, tamarind gum, tannic acid, and lignin sulfonic acid.

Examples of the polyolefin resin include polypropylene; polyethylene; propylene or a copolymer of ethylene and α-olefin; etc., modified polyolefin obtained by modifying the polyolefin with an unsaturated carboxylic acid (for example, acrylic acid or methacrylic acid), ethylene, Examples thereof include a resin such as a copolymer with acrylic acid (methacrylic acid). These resins may be further copolymerized with a small amount of another ethylenically unsaturated monomer. Examples of means for dissolving or dispersing these polyolefin resins in water include means for neutralizing carboxyl groups contained in the polyolefin resin with ammonia or amines.

The number average molecular weight of the organic polymer is preferably 1,000 to 1,000,000. Moreover, this polymer resin may have a crosslinkable functional group as long as the effects of the present invention are not impaired. The number average molecular weight can be measured by a GPC method (Gel Permeation Chromatography). More specifically, the difference in refractive index is measured with a GPC apparatus (HLC-8220; manufactured by Tosoh Corporation) equipped with a differential refractometer (RI) detector, and can be calculated in terms of polystyrene (hereinafter referred to as “polystyrene conversion”). the same.).

The organic polymer (component c) contained in the surface treatment agent is a solid content conversion ratio with respect to the total solid content in the surface treatment agent, and is preferably 95% or less as an upper limit, and 90% or less. Is more preferable. On the other hand, the lower limit is preferably 5% or more, and more preferably 10% or more. By containing the organic polymer (component c) in the surface treatment agent in this ratio range, it is possible to improve the film-forming property and form a dense surface-treated film to improve the corrosion resistance. it can.

Examples of additives for surface treatment agents include known additives such as antifoaming agents, leveling agents, stabilizers, rust inhibitors, antibacterial agents, antifungal agents, wetting agents, and thickeners. Of these, one or more of these can be used. Specifically, in addition to the solvent, the component a, and the component b (component c as necessary), an antifoaming agent, a leveling agent, a stabilizer, an antirust agent, an antibacterial agent, an antifungal agent, a wetting agent, or a thickening agent. Anti-foaming agent and leveling agent, antifoaming agent and stabilizer, antifoaming agent and rust preventive agent other than surface treatment agent mixed with agent or solvent and component a and component b (component c as necessary) Agent, antifoaming agent and wetting agent, leveling agent and stabilizer, leveling agent and rust inhibitor, leveling agent and wetting agent, stabilizer and rust inhibitor, stabilizer and wetting agent, rust inhibitor and wetting agent , An antibacterial agent and an antifungal agent, or a surface treatment agent containing a stabilizer, an antibacterial agent and an antifungal agent.

As the antifoaming agent, for example, mineral oil-based antifoaming agents, fatty acid-based antifoaming agents, silicone-based antifoaming agents and the like can be used. In addition, you may mix | blend both in a surface treating agent. Examples of the leveling agent include known compounds such as nonionic or cationic surfactants, polyacetylene glycol polyethylene oxide or polypropylene oxide adducts, and acetylene glycol compounds. As the stabilizer, for example, known chelating agents such as ethanolamines, tartaric acid, citric acid, lactic acid, gluconic acid, glycolic acid and salts thereof may be used, and these may be used alone. Two or more kinds may be used in combination. Examples of the ethanolamines include, but are not limited to, monoethanolamine, diethanolamine, triethanolamine, and the like. As the thickener, for example, sodium salt, potassium salt, or ammonium salt such as hydroxyethyl cellulose or carboxymethyl cellulose; polyethylene glycol; polyvinyl pyrrolidone; copolymer of vinyl pyrrolidone and vinyl acetate; Can be used. The surface treatment agent may or may not contain a hindered amine that is a radical scavenger. Here, the hindered amines mean a compound having a structure in which a carbon atom is bonded to a nitrogen atom of a piperidine ring directly or via an oxygen atom.

When the pH of the surface treatment agent is 7 or less, the oxidizing power of nitrate ions becomes strong, and when the surface treatment agent is brought into contact with the metal material, the oxide film obtained on the surface of the metal material becomes thick, and the surface treatment film and the metal Adhesion between the material surfaces decreases, and corrosion resistance decreases. Moreover, when the pH of the surface treatment agent is more than 12, the oxidizing power of nitrate ions becomes weak, and when the surface treatment agent is brought into contact with a metal material, a dense oxide film cannot be obtained on the surface of the metal material, resulting in corrosion resistance. descend. Therefore, the pH of the surface treatment agent according to the present invention is set to more than 7 and 12 or less. In addition, the pH of a preferable surface treatment agent is 7.5 or more and 12 or less, and the pH of a more preferable surface treatment agent is 8 or more and 11 or less. In addition, pH prescribed | regulated by this specification and a claim points out the value measured at 25 degreeC.

(Method for preparing surface treatment agent)
The method for producing the surface treatment agent according to the present invention is not particularly limited. For example, an alkali metal salt of zirconium carbonate (component a), a nitrate (component b), a solvent, and, if necessary, an organic polymer (component c) and / or other additives such as a mixing mixer It can be prepared by mixing thoroughly with a stirrer.

The solvent is not particularly limited, but an aqueous solvent is preferable. The aqueous solvent means a solvent containing 50% by mass or more of water based on the mass of all the solvents. The “solvent” does not mean a narrowly-defined solvent that dissolves all components, but a concept that includes a dispersion medium that may be in a dispersed state for some components. Examples of the solvent other than water contained in the aqueous solvent include alkane solvents such as hexane and pentane; aromatic solvents such as benzene and toluene; alcohol solvents such as ethanol, 1-butanol and ethyl cellosolve; tetrahydrofuran, dioxane Ether solvents such as ethyl acetate, butoxyethyl acetate, etc .; amide solvents such as dimethylformamide and N-methylpyrrolidone; sulfone solvents such as dimethyl sulfoxide; phosphate amides such as hexamethylphosphate triamide Solvent; and the like. These solvents other than water may be used alone or in combination of two or more. In addition, you may use only water as a solvent.

(Metal material)
Next, the manufacturing method of the metal material which concerns on this invention is demonstrated. The method includes a step of bringing the surface treatment agent into contact with the surface of the metal material (contact step) and a step of drying the surface of the metal material brought into contact with the surface treatment agent (drying step). In general, in the method, a degreasing step and a water washing step are performed before the contact step. Moreover, the said method may perform the process of making a well-known top coat paint contact in order to form a top coat film (film | membrane) on the film | membrane formed with a surface treating agent after the said drying process.

As a method of bringing the surface treatment agent into contact, a conventional method can be applied, and for example, roll coating, curtain flow coating, air spray, airless spray, dipping, bar coating, brush coating, and the like can be performed.

The surface of the metal material in contact with the surface treatment agent can be dried by a conventional method such as heat drying or air drying. The drying temperature is not particularly limited as long as the surface of the metal material can be dried. However, the maximum temperature (PMT) of the metal material is preferably within the range of 40 to 200 ° C, and within the range of 60 to 150 ° C. Is more preferred. By drying within the range of 60 ° C. to 150 ° C., the adhesion between the film formed by the surface treatment agent and the metal material or top coat film can be improved.

The target metal materials are cold-rolled steel sheet, hot-rolled steel sheet, hot-dip galvanized steel sheet, electrogalvanized steel sheet, hot-dip galvanized steel sheet, aluminum-plated steel sheet, aluminum-zinc alloy-plated steel sheet, tin-zinc alloy plating Steel materials such as steel plates, zinc-nickel alloy plated steel plates, stainless steel plates; aluminum materials; aluminum alloy materials; copper materials; copper alloy materials; titanium materials; titanium alloy materials; magnesium materials; Applicable to plating material. Among these, an aluminum material or an aluminum alloy material is preferable. In addition, the metal material with which the surface treatment agent according to the present invention is brought into contact may be a mixture of a plurality of types of materials. These metal materials may be subjected to ordinary treatments such as washing with water and alkaline degreasing before the surface treatment with the surface treatment agent.

Next, the metal material on which a film is formed by the surface treatment will be described. First, the film mass of the formed film is preferably in the range of 0.01 to 1 g / m ² (dry mass). Adhesiveness can be improved when the film mass is within this numerical range. A more preferable range is in the range of 0.02 g / m ² to 0.5 g / m ² .

Next, the utilization method (use) of the metal material on which the film by the surface treatment agent is formed will be described. First, various metal products can be obtained by processing the metal material into a desired shape. Examples of the metal products include anti-fingerprint galvanized steel sheets for home appliances, pre-coated steel sheets for houses for construction, aluminum fin materials for air conditioners, and various metal parts for automobiles. In addition, the top coat film provided on the film is not particularly limited. For example, as the top coat film, an electrodeposition coating film, a solvent coating film, a powder coating film, and a special film, for example, a hydrophilic film layer, a lubricating organic film A layer, an antibacterial and antibacterial film, and the like.

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples. The present invention is not limited by the following examples.

[Metal material]
The metal material used as the substrate is shown below.
Aluminum plate (A1050P; JIS H 4000-2014)
Cold rolled steel sheet (SPCC-SD; JIS G 3141-2011)
Hot dip galvanized steel sheet [GI: Zinc adhesion amount 60 g / m ² per side (double-sided plating); JIS G 3302-2012]

[Surface treatment agent]
As shown in Tables 1 to 3, each surface treating agent used for preparing test materials of Examples 1 to 31 and Comparative Examples 1 to 9, 11 to 18, and 20 to 24 was prepared. Water was used as the solvent. The pH was adjusted using ammonia or acetic acid. The “component C concentration” in each table indicates the non-volatile content concentration (mass%) of component C relative to the total solid mass in the surface treatment agent. Moreover, each symbol shown in the column of “Component A”, “Component B”, and “Component C” in each table represents the following substances. “MB / MA” in each table indicates a mass ratio of the total mass (MA) of Zr in Component A and the total mass (MB) of anions in Component B, which is blended in the surface treatment agent. In addition, the solid content concentration of each surface treatment agent was appropriately adjusted so that the amount of the film formed by the surface treatment agent was 50 mg / m ² .

[Component A]
A1: Sodium zirconium carbonate A2: Lithium zirconium carbonate A3: Potassium zirconium carbonate A4: Ammonium zirconium carbonate

[Component B]
B1: Sodium nitrate B2: Potassium nitrate B3: Ammonium nitrate B4: Sodium sulfate B5: Sodium phosphate

[Component C (organic polymer)]
(Component C1: Urethane resin-anionic)
100 parts by mass of polyester polyol (adipic acid / 3-methyl-1,5-pentanediol, number average molecular weight: 1000, number of functional groups: 2, hydroxyl value: 112.2), 3 parts by mass of trimethylolpropane, dimethylolpropionic acid 25 parts by mass and 85 parts by mass of isophorone diisocyanate were reacted in MEK (methyl ethyl ketone) to obtain a urethane prepolymer. After 9.4 parts by mass of triethylamine was mixed with this reaction product, it was dispersed in water and elongated with ethylenediamine. Thereafter, methyl ethyl ketone was distilled off to obtain an aqueous urethane resin dispersion containing 30% by mass of nonvolatile components. The acid value of the carboxyl group-containing polyurethane in the obtained urethane resin aqueous dispersion was 49 (KOHmg / g).

(Component C2: Epoxy resin-anionic)
To a mixture of 85 g of orthophosphoric acid and 140 g of propylene glycol monomethyl ether, 425 g of a bisphenol A type epoxy resin having an epoxy equivalent of 250 was gradually added and reacted at 80 ° C. for 2 hours. After completion of the reaction, 150 g of a 29% by mass aqueous ammonia solution was gradually added at 50 ° C. or lower, and further 1150 g of water was added to form a phosphoric acid-modified epoxy resin having an acid value of 35 (KOH mg / g) and a solid concentration of 25% by mass. An ammonia neutralized product was obtained.

(Component C3: Acrylic resin-nonionic)
The monomer composition is “methyl methacrylate (molecular weight: 100) 20 parts by mass, butyl acrylate (molecular weight: 128) 40 parts by mass, 2-hydroxypropyl methacrylate (molecular weight: 144) 10 parts by mass, styrene (molecular weight: 104) 10 parts by mass. Part and 20 parts by mass of N, N-dimethylaminopropyl methacrylate (molecular weight: 175) ”. The synthesis of component C3 was performed as follows. Reactive emulsifier “Adeka Resorb NE-20” (manufactured by ADEKA Co., Ltd.) and nonionic emulsifier “Emulgen 840S” (manufactured by Kao Co., Ltd.) were mixed at a ratio of 6: 4 to 100 parts of 10% by weight emulsifier aqueous solution (S-1). The above monomers were mixed and emulsified at 5000 rpm for 10 minutes using a homogenizer to obtain a monomer emulsion (ER). Next, while maintaining the temperature at 40 to 50 ° C., a 5 mass% aqueous solution of ammonium persulfate (50 parts) and a monomer emulsion (ER) were dropped into 150 parts of the emulsifier aqueous solution (S-1) over about 2 hours. Thereafter, the temperature was raised to 60 ° C. and stirred for about 1 hour. Then, it cooled to room temperature, stirring, and obtained the acrylic resin emulsion solution.

(Component C4: Polyester resin-anionic)
An alcohol component composed of ethylene glycol (90 mol%) and trimethylolpropane (10 mol%), isophthalic acid (40 mol%), terephthalic acid (41 mol%), sodium dimethyl-5-sulfonate (2 mol%) and tri An anionic polyester resin (solid content (NVC.) 30%) by a condensation reaction with an acid component consisting of merit acid (17 mol%) was synthesized as follows. Under a nitrogen atmosphere, a mixture of 1 mol of total acid component, 2 mol of total alcohol component and catalyst (calcium acetate 0.25 g, N-butyl titanate 0.1 g) was heated to 180 ° C. to melt. Then, it heated at 200 degreeC and stirred for about 2 hours, and esterification or transesterification was performed. Further, the mixture was heated to 260 ° C., and after about 15 minutes, the pressure in the system was reduced to 0.5 mmHg and reacted for about 3 hours (polycondensation reaction). After completion of the reaction, the reaction was allowed to cool in a nitrogen atmosphere. To the reaction product was added aqueous ammonia (the amount of water was 25% solids) to adjust the pH to 6-7, and the mixture was heated and stirred at 100 ° C. for 2 hours to obtain an aqueous emulsion polyester resin.

(Component C5: Polyvinyl alcohol-nonionic)
An acetoacetylated polyvinyl alcohol having a saponification degree of 99%, a viscosity of 12 mPa · S, an acetoacetylation degree of 9.8%, and a number average molecular weight of 50,000 was used.

[Production of test materials]
Each substrate was degreased by spraying a 3% aqueous solution of fine cleaner 359E (an alkaline degreasing agent manufactured by Nippon Parkerizing Co., Ltd.) at 65 ° C. for 1 minute, and then washed with water to wash the surface. Then, in order to evaporate the water | moisture content on the surface of a base material, it heat-dried at 80 degreeC for 1 minute. Each surface treatment agent is applied to the surface of the degreased and cleaned substrate by a bar coating method using a # 3SUS Meyer bar, and dried at 115 ° C. for 30 seconds in a hot air circulation type drying furnace to form a surface of the substrate. A surface treatment film was formed. Then, using a # 5SUS Meyer bar, a paint containing an acrylic-modified epoxy resin was applied by a bar coating method so as to have a coating amount of 1.7 g / m ^2, and was heated at 255 ° C. for 20 seconds in a hot air circulation drying oven. It dried and produced each test material. The test materials of Comparative Examples 10, 19 and 25 shown in Tables 1 to 3 were prepared by degreasing each substrate, washing with water and drying by heating as described above (not yet). Processing board).

[Performance evaluation]
The liquid stability of each surface treatment agent and the corrosion resistance of each test material were evaluated as follows. The results are shown in Tables 1 to 3.
(Liquid stability evaluation)
300 g of the drug was put into a 1300 ml tall beaker (opening area: 0.31 cm ² ), and stirring was continued under an open condition while maintaining the liquid temperature at 70 ° C. In order to maintain the solid content concentration during stirring, pure water was replenished every 30 minutes, the time until thickening was measured, and the liquid stability was evaluated according to the following evaluation criteria.
<Evaluation criteria>
○: 5 hours or more, ×: less than 5 hours

(Corrosion resistance)
When the metal material is an aluminum plate, after cross-cutting each test material, an acetic acid acidic salt spray test was performed using an aqueous solution of 5 wt% sodium chloride adjusted to pH 3.0 to 3.1 with acetic acid. It was carried out at 35 ° C. for 300 hours. Thereafter, the film was exposed for 96 hours in a constant temperature and humidity environment of 80 ° C. and 70%, and the maximum length of the generated thread rust was measured to evaluate the corrosion resistance according to the following evaluation criteria.
<Evaluation criteria>
6 points: Maximum thread rust length 0 mm, 5 points: Maximum thread rust length 0 mm to 1 mm or less, 4 points: Maximum thread rust length 1 mm to 2 mm or less, 3 points: Maximum thread rust length 2 mm to 3 mm or less 2 points: Maximum yarn rust length 3 mm to 6 mm or less, 1 point: Maximum yarn rust length 6 mm to 10 mm or less

When the metal material is a cold-rolled steel sheet, after cross-cutting each specimen, a salt spray test with a 5 wt% sodium chloride solution is performed at 35 ° C, and the maximum rust width on one side of the cut part reaches 3 mm The time until this was measured, and the corrosion resistance was evaluated according to the following evaluation criteria.
<Evaluation criteria>
6 points: 480 hours or more, 5 points: 400 hours or more and less than 480 hours, 4 points: 320 hours or more and less than 400 hours, 3 points: 240 hours or more and less than 320 hours, 2 points: 120 hours or more and less than 240 hours, 1 point: 0 hours or more and less than 120 hours

When the metal material is a hot-dip galvanized steel sheet, after cross-cutting each test material, a salt spray test with a 5 wt% sodium chloride solution is performed at 35 ° C, and the maximum rust width on one side of the cut part reaches 3 mm The time until this was measured, and the corrosion resistance was evaluated according to the following evaluation criteria.
<Evaluation criteria>
6 points: 720 hours or more, 5 points: 640 hours or more and less than 720 hours, 4 points: 560 hours or more and less than 640 hours, 3 points: 480 hours or more and less than 560 hours, 2 points: 240 hours or more and less than 480 hours, 1 point: 0 hours or more and less than 240 hours

It was confirmed that the test materials of Examples 1 to 17 in Table 1, Examples 18 to 26 in Table 2, and Examples 27 to 31 in Table 3 were very excellent in corrosion resistance. Further, the surface treatment agent used for preparing the test materials of Examples 1 to 17 in Table 1, Examples 18 to 26 in Table 2, and Examples 27 to 31 in Table 3 was 72 in the liquid stability evaluation. It was confirmed that the liquid stability was very excellent without increasing the viscosity over time.

Claims

A surface treatment agent for metal materials (excluding those containing fluorine) characterized by containing an alkali metal salt of zirconium carbonate (component a) and nitrate (component b) and having a pH of more than 7 and 12 or less.
Furthermore, it contains one or more organic polymers (component c) selected from urethane resins, epoxy resins, acrylic resins, phenol resins, polyester resins, polyvinyl resins, polyolefin resins and natural polymers, The surface treating agent for metal materials according to claim 1.
The surface treatment agent for a metal material according to claim 1 or 2, wherein the pH is 7.5 or more and 12 or less.
A metal material having a surface treatment film formed by bringing the surface treatment agent for a metal material according to any one of claims 1 to 3 into contact with the surface of the metal material and then drying it.