JP2010285666A - Aqueous surface treating agent for metal material and surface coated metal material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an aqueous surface treating agent for a metal material, which is free of hexavalent chromium ions and with which a coating film having excellent corrosion resistance, adhesiveness, solvent resistance or the like is formed. <P>SOLUTION: The aqueous surface treating agent for a metal material is obtained by, in water, blending: a water dispersible urethane resin (A) having a glass transition temperature higher than 50°C, a lowest film forming temperature of ≤40°C, and a carboxylic group as a functional group; an organic compound (B) having at least one cross-linking group, selected from an amino compound, an amino resin, a carbodiimide compound, a carbodiimide resin, an epoxy compound, an epoxy resin, a silane compound, an isocyanate compound and a urethane prepolymer having isocyanato group; and at least one metal complex compound (C), selected from zinc, aluminum and titanium. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention is an aqueous surface treatment agent for metal materials used for processed products such as automobile bodies, automobile parts, building materials, home appliance parts, cast products, sheet coils, etc. Further, the present invention relates to a water-based surface treatment agent for metal materials and a surface-coated metal material that not only have corrosion resistance at a processed part, but also newly imparts paint adhesion and solvent resistance that could not be obtained by conventional techniques.

Almost all metal materials as well as galvanized steel materials, when left in the atmosphere, corrode SO ₂ , NO ₂ , flying sea salt particles, etc. in the presence of moisture physically adsorbed from the atmosphere. Corrosion occurs on the surface due to the action of the accelerated adhesion substance. In order to prevent this corrosion, as a conventional corrosion prevention method for metallic materials such as galvanized steel, the chromate film is deposited or applied by bringing the surface of the metallic material into contact with a treatment liquid containing chromium such as chromate chromate. Then, there is a method of forming a chromate film on the surface of the metal material by drying and the like.

  As a specific example of the method, there is a method described in Patent Document 1. In Patent Document 1, for the purpose of improving roll forming property and corrosion resistance, an aqueous treatment liquid in which hexavalent chromium ions are blended in a specific ratio with a specific water solubility or resin and the pH is adjusted to 3 to 10 is disclosed. A treatment method is described which is applied to the surface of an aluminum-zinc alloy-plated steel material. The aluminum-zinc alloy-plated steel material subjected to the surface treatment containing hexavalent chromium ions is excellent in corrosion resistance, in particular, processed portion corrosion resistance. However, since hexavalent chromium ions have a drawback that has a direct adverse effect on the human body, the chromate treatment tends to be avoided in recent years with the growing awareness of environmental conservation. Further, wastewater containing hexavalent chromium ions needs to be subjected to a special treatment stipulated in the Water Pollution Control Law, which causes a considerable increase in costs as a whole. In addition, the metal material subjected to the chromate treatment has a great disadvantage that it cannot be recycled when it becomes a chromium-containing industrial waste, which is a social problem. Further, there is a problem that elution of hexavalent chromium ions from a film containing hexavalent chromium ions, particularly elution of hexavalent chromium ions from a damaged part of the film during processing may occur.

Patent Document 2 discloses an anionic water-dispersible urethane resin, zirconium compound and silane whose glass transition point exceeds 50 ° C. for the purpose of improving the formability, corrosion resistance, chemical resistance, etc. of the aluminum-zinc-based alloy-plated steel material. An aqueous resin composition containing a compound and a coating method have been proposed.
However, although the corrosion resistance of the panel material and the corrosion resistance of processed products assuming that food containers and automobile parts and general office cases are manufactured can be obtained to some extent, it is formed for solvent wiping and solvent simple cleaning by immersion. However, there is a problem that the film is deteriorated due to decomposition or swelling of the coated film or extraction of additives such as a plasticizer in the film. Further, the coating adhesion has a problem that satisfactory performance can be obtained when the film drying temperature is high, but satisfactory performance cannot be obtained when the coating temperature is low.

Patent Document 3 proposes a film-forming composition containing a carboxyl group-containing polyurethane resin, a crosslinking agent, and silica particles for the purpose of improving the corrosion resistance, coating adhesion, and blackening resistance of the metal plate surface.
Corrosion resistance, processed part corrosion resistance, and paint adhesion are good, but if only the organic compound of the epoxy-based crosslinking agent used as the crosslinking agent, the barrier property of the film against the solvent is not sufficient, and satisfactory performance is obtained. Absent.

Patent Document 4 discloses a surface-treated metal in which a coating containing a crosslinked resin matrix and an inorganic rust preventive agent is formed for the purpose of improving corrosion resistance, alkali resistance, solvent resistance, scratch resistance and adhesion on the surface of a metal plate Board technology has been proposed.
Although corrosion resistance, paint adhesion, and solvent resistance can be obtained, performance that satisfies the processed portion corrosion resistance is not obtained. The performance required for the corrosion resistance of the processed part may be temporarily stored outdoors after processing the product, or may be exposed to a real environment for many years in severe cases. Therefore, it is necessary not only to be able to process the product but also to have corrosion resistance that can withstand in an actual environment.

Patent Document 5 discloses a high corrosion resistance underlayer film having a dry film thickness of 0.01 to 1 μm and a fingerprint film having a dry film thickness of 0.2 to 3 μm on a metal steel plate for the purpose of improving corrosion resistance and fingerprint resistance. And a high corrosion-resistant underlayer coating comprising a hydrolyzable titanium compound, a low condensate of hydrolyzable titanium compound, titanium hydroxide and a low condensate of titanium hydroxide. Titanium obtained by mixing at least one titanium compound selected from the group with hydrogen peroxide water, an organic phosphate compound, a water-soluble or water-dispersible organic resin, metavanadate, zirconium fluoride and zirconium carbonate It has been proposed to provide a surface-treated steel sheet characterized by being a film formed from a surface treatment composition for an underlayer film that is contained.
Although corrosion resistance, processed part corrosion resistance, and coating adhesion are good, if only a complex compound of a titanium compound used as a crosslinking agent is used, the barrier property of the film against the solvent is not sufficient, and satisfactory performance cannot be obtained. In addition, since an organic phosphorus compound, zirconium fluoride, or the like is used, the material is etched, and there is a possibility that sludge and impurities are mixed into the treatment agent.

  From the above, by forming a film layer with the aqueous surface treatment agent for metal materials of the present invention, a film excellent in corrosion resistance, processed part corrosion resistance, paint adhesion, and solvent resistance can be formed, and hexavalent chromium ions can be formed. The present condition is that the water-based surface treating agent which does not contain is not obtained.

Japanese Patent No. 2097278 Japanese Patent No. 3874493 JP 2005-199673 A JP 2005-281863 A JP 2006-22370 A

  The present invention is for solving the problems of the prior art, without using etching agents such as metal hydrofluoric acid and metal hydrofluoride compounds, corrosion resistance, processed part corrosion resistance, low temperature Excellent coating adhesion satisfying high solvent resistance that prevents elution, swelling, and decomposition of coating components against any organic solvent of non-polar or polar that can be satisfied even when dried, It is another object of the present invention to provide an aqueous surface treating agent for metal materials and a metal material coated with a film formed using the surface treating agent without containing chromium.

As a result of intensive studies on means for solving the problems of the prior art, the present inventors have found that water-dispersible urethane having specific physical properties on the surface of galvanized steel materials, zinc alloy plated steel materials, aluminum materials, etc. The inventors have found that the above problems can be solved by forming a coating layer containing a resin as a main component, and have completed the present invention.
Water dispersible urethane resin (A) having a glass transition temperature exceeding 50 ° C. and a minimum film forming temperature of 40 ° C. or less and having a carboxyl group as a functional group, amino compound, amino resin, carbodiimide compound, carbodiimide resin, epoxy compound , An epoxy resin, a silane compound, an isocyanate compound and an organic compound (B) having at least one crosslinking group selected from urethane prepolymers having an isocyanato group, at least one metal complex compound selected from zinc, aluminum and titanium ( The present invention relates to a water-based surface treatment agent for metals that contains C) in water.

  Metal materials such as galvanized steel materials, zinc alloy plated steel materials, and aluminum materials obtained by applying the aqueous surface treatment agent for metal materials of the present invention to the surface and drying are corrosion resistance, processed portion corrosion resistance, solvent resistance, and paint adhesion. And overcoming environmental problems. Therefore, the present invention has extremely great industrial utility value.

BEST MODE FOR CARRYING OUT THE INVENTION

  The best mode of the present invention will be specifically described below. The technical scope of the present invention is not limited to the following best modes and examples. Hereinafter, first, the aqueous surface treating agent for metal materials of the present invention will be described.

<< Aqueous surface treatment agent for metal materials >>
The water-based surface treatment agent for metal materials according to the present invention has a glass transition temperature exceeding 50 ° C. and a minimum film-forming temperature of 40 ° C. or less, a water-dispersible urethane resin (A) having a carboxyl group as a functional group, amino Compound, amino resin, carbodiimide compound, carbodiimide resin, epoxy compound, epoxy resin, silane compound, isocyanate compound and organic compound (B) having at least one crosslinking group selected from urethane prepolymer having isocyanate group, zinc, aluminum And at least one metal complex compound (C) selected from titanium and water. Hereinafter, the blending components will be described first.

(Compounding component: Water dispersible urethane resin (A))
The water-dispersible urethane resin (A) blended in the aqueous surface treatment agent for metal materials of the present invention plays a role of imparting or improving corrosion resistance, processed part corrosion resistance, and solvent resistance to the metal material that is the material to be treated. Bear.
The water-dispersible urethane resin (A) blended in the aqueous surface treatment agent for metal material of the present invention has a glass transition temperature (Tg) exceeding 50 ° C. and a minimum film-forming temperature of 40 ° C. or less. The glass transition temperature is a temperature at which the resin changes from a glass state to a rubber state. Basically, when a resin having a high glass transition temperature is used, corrosion resistance and solvent resistance are often excellent. However, when the glass transition temperature is high, there is a problem that the energy cost increases because baking at a temperature considerably higher than the glass transition temperature is required. Moreover, when the glass transition temperature is high, a hard film is often formed, and the corrosion resistance of the processed part is often poor. Therefore, in the water-dispersible urethane resin (A) used in the present invention, the glass transition temperature exceeds 50 ° C., but when the minimum film forming temperature is 40 ° C. or less, the baking temperature exceeds the glass transition temperature. Excellent corrosion resistance, processed part corrosion resistance, solvent resistance, etc. can be exhibited even when the temperature is lower than the glass transition temperature. Further, optionally, the tensile strength as the film physical property of the water-dispersible urethane resin (A) is set to 20 to 90 N / mm ² and the elongation is set to 200 to 700%. A film can be formed.

When the glass transition temperature of the water-dispersible urethane resin (A) is 50 ° C. or lower, when placed in a high-temperature and high-humidity atmosphere, the film softens, so that water vapor easily penetrates and the corrosion resistance tends to decrease. The glass transition temperature of the water dispersible urethane resin (A) is preferably in the range of 80 ° C to 150 ° C, and more preferably in the range of 100 ° C to 130 ° C. If the temperature exceeds 150 ° C, the film becomes too hard, resulting in poor adhesion to the metal material. Also, since the film becomes difficult to follow during processing, the processed film becomes fragile and the corrosion resistance of the processed part decreases. Tend to.
Moreover, when the minimum film-forming temperature of water-dispersible urethane resin (A) exceeds 40 degreeC, the process part corrosion resistance and solvent resistance of the membrane | film | coat formed may fall. The minimum film-forming temperature of the water-dispersible urethane resin (A) is preferably 20 ° C. or less, more preferably 5 ° C. or less, and even more preferably 0 ° C. or less. There is no particular limitation on the lower limit of the minimum film forming temperature.
Here, the minimum film-forming temperature can be controlled, for example, by appropriately selecting the type of film-forming aid and appropriately setting the amount. The glass transition temperature can be controlled by appropriately selecting the type of polyol or isocyanate and appropriately setting the amount. Generally, the glass transition point can be lowered by increasing the amount of polyol or increasing the molecular weight.

  Further, in order to make the water-dispersible urethane resin (A) water-dispersible, the acid of the water-dispersible urethane resin (A) is also used from the viewpoint of the physical properties of the film formed from the water-dispersible urethane resin (A). The value is preferably in the range of 2 to 40, more preferably in the range of 4 to 35, and still more preferably in the range of 4 to 25. When the acid value is in the range of 2 to 40, the adhesion with the metal material is enhanced, and the processed portion corrosion resistance and solvent resistance are further improved. Here, the acid value can be appropriately controlled by adjusting the amount of the carboxylic acid and the reactive derivative (these will be described later) in the solid content of the production raw material composition.

Furthermore, it is preferable that the tensile strength is in the range of ²⁰ to 90 N / mm ² and the elongation is in the range of 200 to 700% as the physical properties of the film formed from the water dispersible urethane resin (A). More preferably, the tensile strength is in the range of 50 to 80 N / mm ² and the elongation is in the range of 250 to 600%. When the tensile strength and the elongation satisfy the above ranges, the film followability and the moldability are further improved. Here, the elongation and tensile strength can be adjusted, for example, by controlling the amount and molecular weight of polyol and isocyanate. For example, if the amount of polyol is increased or the molecular weight is increased, the elongation increases and the tensile strength decreases.

  Although there is no restriction | limiting in particular about the number average molecular weight of water-dispersible urethane resin (A), When it measures by a gel permeation chromatography, it is preferable that it is about 10,000-1,000,000, 50,000- More preferably, it is about 500,000.

  The water-dispersible urethane resin (A) is made from polyisocyanate (particularly diisocyanate), polyol (particularly diol), carboxylic acid having two or more, preferably two hydroxyl groups, or a reactive derivative thereof and polyamine (particularly diamine). As obtained by a general synthesis method. More specifically, although not limitedly interpreted, for example, a urethane prepolymer having an isocyanate group at both ends is produced from a diisocyanate and a diol, and a carboxylic acid having two hydroxyl groups or a reactivity thereof. By reacting the derivative to form a derivative having an isocyanato group at both ends, then adding triethanolamine or the like to form an ionomer (triethanolamine salt), adding it to water to make an emulsion, and further adding a diamine to extend the chain, A water dispersible urethane resin (A) can be obtained.

  Examples of the polyisocyanate used when producing the water-dispersible urethane resin (A) include aliphatic, alicyclic and aromatic polyisocyanates, and any of them can be used. Specifically, for example, tetramethylene diisocyanate, hexamethylene diisocyanate, lysine diisocyanate, hydrogenated xylylene diisocyanate, 1,4-cyclohexylene diisocyanate, 4,4′-dicyclohexylmethane diisocyanate, 2,4′-dicyclohexylmethane diisocyanate, Isophorone diisocyanate, 3,3′-dimethoxy-4,4′-biphenylene diisocyanate, 1,5-naphthalene diisocyanate, 1,5-tetrahydronaphthalene diisocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 4, , 4'-diphenylmethane diisocyanate, 2,4'-diphenylmethane diisocyanate, phenylene diisocyanate, xylylene diisocyanate Tetramethyl xylylene diisocyanate. Among these, tetramethylene diisocyanate, hexamethylene diisocyanate, lysine diisocyanate, hydrogenated xylylene diisocyanate, 1,4-cyclohexylene diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, 2,4'-dicyclohexylmethane diisocyanate, isophorone diisocyanate When an aliphatic or alicyclic polyisocyanate such as the above is used, a film excellent in solvent resistance, corrosion resistance and the like is obtained, which is preferable.

Examples of the polyol species used when producing the water-dispersible urethane resin (A) include polyester polyols and polyether polyols, and any of them can be used. In the present invention, polyester polyols and polyether polyols are particularly preferable.
As the polyester polyol, a polyester polyol obtained by subjecting a glycol component and a dicarboxylic acid or a reactive derivative thereof (an acid anhydride) to a dehydration condensation reaction; a cyclic ester compound such as ε-caprolactone as a polyhydric alcohol initiator And polyester polyols obtained by ring-opening polymerization.

  Examples of the glycol component used for producing the polyol include ethylene glycol, propylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, and 3-methyl-1,5-pentanediol. 1,6-hexanediol, neopentyl glycol, butylethylpropane diol, diethylene glycol, triethylene glycol, tetraethylene glycol, polyethylene glycol (molecular weight 300 to 6,000), dipropylene glycol, tripropylene glycol, bis (hydroxyethoxy) ) Benzene, 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, bisphenol A, hydrogenated bisphenol A, hydroquinone and the like. Moreover, as a glycol component used for manufacture of a polyether polyol, the (di) ethylene glycol type polyether polyol and (di) propylene glycol type polyether polyol obtained by carrying out addition reaction of ethylene oxide and / or propylene oxide to the said glycol are mentioned. Glycerin-based polyether polyol, trimethylolpropane-based polyether polyol, pentaerythritol-based polyether polyol, mono (di, tri) ethanolamine-based polyether polyol, methyldiethanolamine-based polyether polyol, ethylenediamine-based polyether polyol, 3- And polyoxyalkylene polyols such as dimethylaminopropylamine polyether polyol, and the like. It can be used as a mixture of two or more. Among these, (di) ethylene glycol polyether polyol, (di) propylene glycol polyether polyol, glycerin polyether polyol, triethanolamine polyether obtained by addition reaction of ethylene oxide and / or propylene oxide. Polyols are preferred.

  Examples of the dicarboxylic acid and its reactive derivative used in the production of polyester polyol include succinic acid, adipic acid, azelaic acid, sebacic acid, dodecanedicarboxylic acid, fumaric acid, 1,3-cyclopentanedicarboxylic acid, 1,4 -Cyclohexanedicarboxylic acid, terephthalic acid, isophthalic acid, phthalic acid, 1,4-naphthalenedicarboxylic acid, 2,5-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, naphthalic acid, biphenyldicarboxylic acid, 1,2-bis (Phenoxy) ethane-p, p′-dicarboxylic acid and anhydrides of these dicarboxylic acids.

  The carboxylic acid and reactive derivative used in producing the water-dispersible urethane resin (A) having a carboxyl group introduce an acidic group into the water-dispersible urethane resin (A), and water the urethane resin (A). Used for dispersibility. Examples of the carboxylic acid used include dimethylol alkanoic acids such as dimethylolpropionic acid, dimethylolbutanoic acid, dimethylolpentanoic acid, and dimethylolhexanoic acid. Examples of the reactive derivative include hydrolyzable esters such as acid anhydrides. Thus, by making the water dispersible urethane resin (A) self-dispersible and not using an emulsifier or using it as much as possible, a film excellent in corrosion resistance and solvent resistance can be obtained. Of these, dimethylolpropionic acid and dimethylolbutanoic acid are preferred.

  Examples of the polyamine used for producing the urethane resin (A) include hydrazine, ethylenediamine, propylenediamine, 1,6-hexanediamine, tetramethylenediamine, isophoronediamine, xylylenediamine, piperazine, and 1,1′-bicyclohexane. Examples include -4,4'-diamine, diphenylmethanediamine, ethyltolylenediamine, diethylenetriamine, dipropylenetriamine, triethylenetetramine, and tetraethylenepentamine.

  The water-dispersible urethane resin (A) of the present invention may be silane-modified with a hydrolyzable silane compound at the stage of synthesis. There are no particular restrictions on the type of silane compound and the amount of modification when silane modification is performed. As a silane compound, the thing similar to the silane compound included by the below-mentioned organic compound (B) can be used. By modifying with silane, the adhesion of the water-dispersible urethane resin (A) to the metal material is increased, and the solvent resistance and the processed portion corrosion resistance are improved.

  The degree of silane modification is not particularly limited as long as the effect of these modifications is recognized, but usually it is preferably modified so that the Si-OH equivalent is in the range of 150 to 1,000, More preferably, it is modified so as to be in the range of 300 to 800.

  The water-dispersible urethane resin (A) of the present invention has a film forming aid during synthesis in order to enhance the film stability of the film when the resin stability during resin synthesis and the surrounding environment during film formation are under low temperature drying. It is preferable to add an agent. Examples of the film-forming aid include butyl cellosolve, N-methyl-2-pyrrolidone, butyl carbitol acetate, and texanol, and N-methyl-2-pyrrolidone is more preferable.

(Compounding component: organic compound (B) having a crosslinking group)
At least one selected from an amino compound, an amino resin, a carbodiimide compound, a carbodiimide resin, an epoxy compound, an epoxy resin, a silane compound, an isocyanate compound and a urethane prepolymer having an isocyanato group, which is blended in the aqueous surface treatment agent of the present invention. The organic compound (B) having a crosslinking group plays a role of enhancing the corrosion resistance and solvent resistance of the formed film.

  As the amino compound in the organic compound (B), a melamine compound, a guanamine compound, a guanidine compound, or the like can be used. Examples of the melamine compound include melamine, methylolated melamine, methyl ether of methylolated melamine, etc .; examples of the guanamine compound include benzoguanamine; examples of the guanidine compound include 1,3-diphenylguanidine, di-o-tolylguanidine, and guanidine carbonate. As the amine compound, allylamine, aniline, polyaniline, dicyandiamide and the like can also be used. In the above, methylolated melamine has the following structural formula (1), wherein R1 to R6 each independently represents a hydrogen atom or a methylol group, and at least one of R1 to R6 is a methylol group or any two of these compounds The methyl ether of methylolated melamine is a compound in which the hydroxyl group of at least one methylol group of methylolated melamine is O-methylated or a mixture of any two or more of these compounds. Polyaniline is represented by the following structural formula (2).

  The amino resin in the organic compound (B) is a resin obtained by addition-condensing formaldehyde or alcohol with an amine compound such as melamine, benzoguanamine, or urea, and includes urea resin, melamine resin, guanamine resin, and the like.

  The carbodiimide resin in the organic compound (B) is a polymer having a —N═C═N— group in the molecule, and can be produced, for example, by decarboxylation condensation reaction of diisocyanate in the presence of a carbodiimidization catalyst. Here, examples of the carbodiimidization catalyst include tin, magnesium oxide, a combination of potassium ion and 18-crown-6, and the like. As diisocyanate, the diisocyanate in what was illustrated as polyisocyanate used for manufacture of water-dispersible urethane resin (A) can be illustrated.

  The carbodiimide equivalent of the carbodiimide resin (the chemical amount of the carbodiimide resin per carbodiimide group, in other words, the value obtained by dividing the molecular weight of the carbodiimide resin by the number of carbodiimide groups contained in the carbodiimide resin) is not particularly limited. The range is preferably 100 to 1,000, and more preferably 200 to 800.

  Examples of the epoxy compound in the organic compound (B) include bisphenol A diglycidyl ether, orthophthalic acid diglycidyl ester, isophthalic acid diglycidyl ester, terephthalic acid diglycidyl ester, p-oxybenzoic acid diglycidyl ester, and tetrahydrophthal. Acid diglycidyl ester, hexahydrophthalic acid diglycidyl ester, succinic acid diglycidyl ester, adipic acid diglycidyl ester, sebacic acid diglycidyl ester, ethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, 1,4-butanediol di Glycidyl ether, 1,6-hexanediol diglycidyl ether, and polyalkylene glycol diglycidyl ethers, trimellitic acid trig Sidyl ester, triglycidyl isocyanurate, 1,4-glycidyloxybenzene, diglycidyl propylene urea, glycerol triglycidyl ether, trimethylol ethane triglycidyl ether, trimethylolpropane triglycidyl ether, pentaerythritol tetraglycidyl ether, glycerol alkylene oxide addition The triglycidyl ether of a thing can be mentioned. These can be used alone or in combination.

As the epoxy resin in the organic compound (B), an epoxy resin having bisphenol A or F as a unit in the skeleton can be used, but part or all of the glycidyl group of the epoxy resin is silane-modified or phosphoric acid-modified. The epoxy resin made is more preferably used.
As an epoxy resin having bisphenol A or F as a unit in the skeleton, one obtained by repeated dehydrochlorination and addition reaction of epichlorohydrin and bisphenol A or F, and having two or more, preferably two glycidyl groups Examples thereof include those obtained by repeating the addition reaction between the epoxy compound and bisphenol (A, F). As for the epoxy compound shown here, the epoxy compound mentioned above is mentioned.

Silane modification of an epoxy resin having bisphenol A or F as a unit in the skeleton may be performed in the same manner as the modification of the urethane resin (A). There is an effect that the adhesion between the film formed by silane modification and the metal material and the solvent resistance of the epoxy resin itself are improved. Moreover, the phosphoric acid modification | denaturation of the epoxy resin which has bisphenol A or F as a unit in frame | skeleton is performed by making this epoxy resin react with phosphoric acid or its ester. As phosphoric acids, metaphosphoric acid, phosphonic acid, orthophosphoric acid, pyrophosphoric acid and the like can be used. As esters of phosphoric acids, monoesters such as metaphosphoric acid, phosphonic acid, orthophosphoric acid, pyrophosphoric acid, such as monomethyl phosphoric acid, Monooctyl phosphoric acid, monophenyl phosphoric acid and the like can be used. Moreover, since the phosphoric acid modified substance of an epoxy resin produces | generates a more stable resin composition by neutralizing with an amine compound, it is preferable to neutralize. Examples of the amine compound include ammonia; alkanolamines such as dimethanolamine and triethanolamine; alkylamines such as diethylamine and triethylamine; alkylalkanolamines such as dimethylethanolamine. By modifying phosphoric acids, there is an effect of increasing the adhesion between the formed film and the metal material.

  As a silane compound in the organic compound (B), vinyltrichlorosilane, vinyltris (2-methoxyethoxy) silane, vinyltriethoxysilane, vinyltrimethoxysilane, 3-methacryloyloxypropyltrimethoxysilane, 2- (3,4- Epoxycyclohexyl) ethyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, N- (2-aminoethyl) -3- Aminopropyltrimethoxysilane, N- (2-aminoethyl) -3-aminopropylmethyldimethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, N-phenyl-3-aminopropyltrimeth Shishiran, 3-mercaptopropyltrimethoxysilane, 3-chloropropyl trimethoxy silane, and the like ureidopropyltriethoxysilane.

  As an isocyanate compound in an organic compound (B), the polyisocyanate already described about manufacture of water-dispersible urethane resin (A) can be used.

  The urethane prepolymer in which the isocyanato group is protected by adding an alkali metal bisulfite to the isocyanato group in the organic compound (B) is a monomer and prepolymer having isocyanate (particularly diisocyanate) and a polyol (particularly diol) to a certain extent. It is obtained by adding an alkali metal bisulfite (sodium salt, potassium salt, etc.) to the polycondensed intermediate product to protect the isocyanato group. As the polyisocyanate and the polyol, those similar to those used in the production of the water-dispersible urethane resin (A) can be used.

(Compounding component: metal complex compound (C))
At least one metal complex compound (C) selected from zinc, aluminum and titanium to be blended in the aqueous surface treating agent of the present invention is a polar group such as a carboxyl group present in a metal material or a water-dispersible urethane resin. The corrosion resistance and solvent resistance of the formed film are improved by a crosslinking reaction with a specific functional group or the like when present in the organic compound (B). Here, a more preferable metal complex compound is an organometallic complex compound. When such an organometallic complex compound is used, not only a crosslinking effect for bonding a resin and a metal, but also the structure of the organic portion causes a metal chelate effect, so that adhesion to a metal material is enhanced.

  The skeleton of the metal complex compound preferably contains an alkoxide or a hydroxyl group in order to enhance the effect, and more preferably contains both functional groups.

  Examples of zinc in the metal complex compound (C) include zinc stearate, zinc gluconate, zinc picolinate, zinc citrate, and zinc acetylacetonate. Particularly preferred are zinc gluconate and zinc citrate. Examples of aluminum in the metal complex compound (C) include aluminum acetate, aluminum stearate, aluminum ethylate, aluminum isopropylate, aluminum triisopropyloxide, aluminum ethyl acetoacetate diisopropylate, aluminum trisethyl acetoacetate, aluminum. Tris (acetyl acetate), aluminum oxide isopropoxide trimer, etc. are mentioned. Particularly preferred are aluminum triisopoloxide, aluminum trisacetyl acetate and the like. Examples of titanium in the metal complex compound (C) include titanium tetraisopropoxide, titanium tetranormal butoxide, titanium butoxide dimer, titanium tetra-2-ethylhexoxide, titanium diisopropoxybis (acetylacetonate), and titanium tetraacetyl. Acetonate, titanium dioctyloxy bis (octylene glycolate), titanium diisopropoxy bis (ethyl acetoacetate), titanium diisopropoxy bis (triethanolaminate), titanium lactate ammonium salt, titanium lactate, polyhydroxy titanium stea Rate and the like. Particularly preferred are titanium diisopropoxybis (ethyl acetoacetate), titanium diisopropoxybis (triethanolaminate), and the like.

(Compounding component: Silica (D))
Furthermore, you may mix | blend a silica (D) with the water-system surface treating agent which concerns on this invention. Silica (D) is dispersed in the aqueous surface treatment agent of the present invention, and the particle size, shape, and type are not particularly limited. The particle diameter of silica (D) is preferably in the range of 3 to 500 nm, and more preferably in the range of 3 to 150 nm. Silica (D) plays a role of adjusting the tensile strength and forming a dense film, and can further improve the corrosion resistance, the solvent resistance, and the processed portion corrosion resistance. Here, the average particle diameter of silica refers to that measured using a particle size distribution measuring device.

  Furthermore, the water-based surface treatment agent according to the present invention may contain a resin such as a water-soluble or water-dispersible acrylic resin, a water-dispersible polyester resin, a water-dispersible fluororesin, or a water-dispersible polyolefin resin. In addition, to the aqueous surface treatment agent of the present invention, a lubricant (for example, polyolefin wax such as molybdenum disulfide, graphite, polyethylene or polypropylene), a pigment (for example, phthalocyanine, carbon, etc.) within a range not impairing the effects of the present invention. Black, titanium oxide, etc.), antibacterial agents, antifoaming agents, leveling agents, thickeners, components that suppress deterioration of resin components due to heat, and components that suppress deterioration of resin components due to light (antioxidants, ultraviolet absorbers) , Quencher, HALS, etc.).

(Composition composition)
Having described the components of the aqueous surface treatment agent for metal materials, the composition of each component in the aqueous surface treatment agent for metal materials according to the present invention will be described next.

  The blending ratio (A) / (B) of the water-dispersible urethane resin (A) and the organic compound (B) is preferably in the range of 1000/1 to 10/1 as a solid content mass ratio, 200/1 to A range of 15/1 is more preferable. When (A) / (B) is larger than 1000/1, the effect of blending the organic compound (B) tends to be not recognized, and when it is smaller than 10/1, the characteristics of the water-dispersible urethane resin (A) are hindered. The solvent resistance of the surface-treated metal material may be reduced.

  The mixing ratio of the water-dispersible urethane resin (A) and the metal complex compound (C) is in the range of 1,000 / 1 to 10/1 as the mass ratio of the solid content of (A) / the metal atom of (C). It is preferable that the range is 200/1 to 20/1. When the solid content ratio of (A) / (C) solid content is in the range of 1,000 / 1 to 10/1, the corrosion resistance and solvent resistance of the formed film can be improved.

The blending ratio of the water dispersible urethane resin (A) and silica (D) is preferably in the range of 1/1 to 100/1 as the solid content of (A) / solid content mass of silica (D), A range of 3/2 to 100/1 is more preferable. When the solid content ratio of (A) solid content / silica (D) is in the range of 1/1 to 100/1, the processed portion corrosion resistance and solvent resistance of the formed film can be improved.

  Further, the amount of the optional component is added. For example, when a resin such as a water-soluble or water-dispersible acrylic resin, a water-dispersible polyester resin, a water-dispersible fluororesin, or a water-dispersible polyolefin resin is blended, the present invention You may mix | blend in 1-30 mass% as solid content mass ratio with respect to water-dispersible urethane resin (A) in the range which does not impair the effect of this.

  The total solid concentration of the aqueous surface treatment agent of the present invention is not particularly limited as long as the effects of the present invention can be achieved, but it is usually preferably adjusted to a range of 1 to 40% by mass, and 5 to 30% by mass. It is more preferable to adjust to the range of%.

  In addition, description of the essential component which comprises the aqueous surface treating agent of this invention, and an arbitrary component represents the state at the time of a mixing | blending, and even if it reacts between components after a mixing | blending, it does not deviate from the scope of the present invention. .

  The medium used in the aqueous surface treatment agent of the present invention is water, but a small amount (for example, 10% by mass or less of the entire aqueous medium) of alcohol, ketone, cellosolve, lactam or the like is used for the purpose of improving the drying property of the film. An organic solvent may be used in combination.

(Physical properties)
Although there is no restriction | limiting in particular about pH of the aqueous surface treating agent of this invention, It is preferable that it is the range of 5-13, and it is more preferable that it is the range of 7-11. When the pH is less than 5 or greater than 13, the aqueous surface treatment agent tends to thicken or gel, and the stability tends to decrease. When pH adjustment is necessary, an alkaline component such as ammonia, dimethylamine, or triethylamine, or an acidic component such as acetic acid or phosphoric acid can be added.

<< Production Method of Aqueous Surface Treatment Agent for Metal Materials >>
The aqueous surface treatment agent of the present invention is prepared by adding a water-dispersible urethane resin (A), an organic compound (B), a metal complex compound (C), and other components as necessary to water as a dispersion medium, and stirring. Can be manufactured. There is no restriction | limiting in particular in the addition order of each component.

<Usage method of water-based surface treatment agent for metal materials>
The method of using the water-based surface treatment agent for metal materials according to the present invention includes an application step of applying the water-based surface treatment agent to at least one surface of the metal material surface, evaporating the solvent of the applied surface treatment agent, and baking as necessary. Including a drying step. Furthermore, a pretreatment step (for example, a step of cleaning a metal material, a surface adjustment step, and a base treatment step) is optionally included before the coating step. Hereinafter, the method will be described in detail.

  First, the metal material to which the aqueous surface treatment agent of the present invention is applied is not particularly limited, but preferred metal materials include galvanized steel materials, zinc alloy plated steel materials, aluminum materials and the like. Specific examples include galvanized steel materials. The plated steel material may contain a trace amount of elements such as silicon, magnesium, cobalt, and manganese in the plating composition.

  The pretreatment step prior to the treatment with the aqueous surface treatment agent of the present invention is not particularly limited. Usually, an alkaline degreasing agent or a degreasing agent is used to remove oil and dirt adhered to the metal material to be treated before performing this treatment. Washing with an acidic degreasing agent, washing with hot water, washing with solvent, etc., and then adjusting the surface with acid, alkali, etc. as necessary. In cleaning the metal material surface, it is preferable to wash with water after cleaning so that the cleaning agent does not remain on the metal material surface as much as possible. Further, a base treatment may be performed before performing this processing. As for the type of the base treatment, treatment by self-deposition, electrolytic deposition, etc. is preferable in the treatment agent containing Ti, Hf, V, Mg, Mn, Zn, W, Mo, Al, Ni, Co, Ce and Ca ions. .

  The treatment with the aqueous surface treatment agent of the present invention is performed by applying the aqueous surface treatment agent and then drying. There is no particular limitation on the application method, and for example, a normal application method such as a roll coating method, a curtain flow coating method, a spray method, a dipping method, a shower ringer method, an air knife method, a bar coating method, or a brush coating method can be adopted. . Although there is no restriction | limiting in particular also about a process liquid temperature, Since the solvent of this processing agent is water mainly, it is preferable that a process liquid temperature is 0-60 degreeC, and it is more preferable that it is 5-40 degreeC.

  There is no restriction | limiting in particular also about the drying method after apply | coating the aqueous surface treating agent of this invention, You may employ | adopt natural drying or forced drying. In the case of forced drying, drying can be performed using a heating apparatus such as an electric furnace, a hot air furnace, an induction heating furnace, and the temperature of the reached metal material is not particularly limited, but is preferably 30 to 200 ° C., 40 to More preferably, it is 150 ° C. In this case, the drying time is not particularly limited, but is preferably in the range of 1 second to 10 minutes, and more preferably in the range of 5 seconds to 5 minutes.

Preferably dry film mass formed on the surface of the metallic material is in the range of 0.1 to 3 g / ^{m 2,} and more preferably in the range of 0.5 to 3 g / ^{m 2.} When the coating amount is less than 0.1 g / m ² , the metal material is not sufficiently covered, and the corrosion resistance and solvent resistance of the processed part may be deteriorated. On the other hand, if it exceeds 3 g / m ² , the effect is saturated, which is not economical.

(Mechanism of action)
An aqueous surface treating agent that combines a water-dispersible urethane resin, an organic compound, and a metal complex compound is known (Patent Document 2). It has also been conventionally known that each of these components can impart to the film any or more of the properties (one or more) required by the present invention. However, the water-based surface treatment agent according to the present invention is not merely a collection of conventional components with known properties or a simple substitution. That is, the present invention is not limited to utilizing the properties of each component that has been conventionally known, and a new mechanism of action is realized by selecting components having specific structures and properties and combining them. It is improved. Specifically, as described above, a water-dispersible urethane resin having a predetermined property having a carboxyl group is selected as “water-dispersible urethane resin”, and an organic compound having a predetermined structure having a crosslinking group is selected as “organic compound”. When a metal complex compound of zinc, aluminum and titanium is selected from “metal complex compounds”, it is presumed that an excellent film is formed by the following mechanism. The carboxyl group contained in the water-dispersible urethane is dehydrated by heat, easily undergoes a crosslinking reaction, and easily forms a film. However, at low temperature drying, the reactivity is poor and a sufficient crosslinking effect cannot be expected. Therefore, by blending the organic compound (B) having a highly reactive crosslinking group, strong organic crosslinking occurs even at low temperature drying, and a film can be formed. Furthermore, a tough film is formed by metal crosslinking with the metal complex compound (C), and sufficient solvent resistance can be imparted by sufficient corrosion resistance, processed portion corrosion resistance, particularly metal crosslinking effect. In the case where the metal complex compound is an organometallic complex compound, a chelating effect with a metal is also caused, and thus the adhesion with the material is further increased. Due to such a mechanism, the film formed by the aqueous surface treatment agent according to the present invention is a film against corrosion resistance, processed part corrosion resistance, coating adhesion which can be satisfied even at low temperature drying, and non-polar or polar organic solvents. It is understood that it has the property of satisfying high solvent resistance which prevents elution, swelling and decomposition of components.

EXAMPLES Hereinafter, the present invention will be described more specifically together with effects thereof with reference to examples and comparative examples, but the present invention is not limited to these examples.
(1) Manufacture of water-based surface treatment agent The water-based surface treatment agents of Examples 1 to 47 and Comparative Examples 1 to 5 shown in Table 2 were prepared using the components shown below in combinations and proportions shown in Table 2. That is, a water-dispersible urethane resin (A), an organic compound (B), and a metal complex compound (C) are added to deionized water in this order, and finally the solid content concentration is 20% by mass using deionized water. It was adjusted to become.
<Water-dispersible urethane resin (A)>
The water-dispersible urethane resin used has the physical properties shown in Table 1. The carboxyl group contained in the resin is derived from dimethylolpropionic acid.

Measuring method of physical properties of water-dispersible urethane resin (A) and resin film properties (a) Glass transition point (Tg)
Measurement was performed using a dynamic viscoelasticity measuring device (Rheograph Solid S, manufactured by Toyo Seiki Seisakusho Co., Ltd.).
(B) Minimum film-forming temperature (MFT)
Based on JIS-Z2371, the minimum film-forming temperature (MFT) was calculated | required by measuring the temperature which the film formed using the water-dispersible urethane resin (A) aqueous dispersion softens. As a measuring device, a minimum film-forming measuring device (manufactured by Imoto Seisakusho Co., Ltd.) was used.
(C) Acid value
According to JISK2501, the potassium hydroxide required per 1 g of solid content of the water dispersible urethane resin to neutralize the carboxylic acid contained in the water dispersible urethane resin was expressed in mg.

(D) Tensile Strength and Elongation * Resin Film Preparation Method A film having a thickness of 150 μm was formed on a PP film.
Drying conditions: 23 ° C. × RH 65% × 24 hours Heat treatment: 108 ° C. × 2 hours (removing solvent, etc.)
Next, the formed film was peeled off from the PP film, and tensile strength and elongation were measured with a tensile tester.
* Tensile tester (AUTOGRAPH AGS-1KNG, manufactured by Shimadzu Corporation)
Tensile strength: The tensile strength (N / mm ² ) of the maximum point (breaking point) was measured.
Elongation: The elongation (%) of the maximum point (breaking point) was measured.

<Organic compound (B)>
B1 methylolated melamine B2 guanidine carbonate B3 carbodiimide resin (carbodiimide equivalent 450)
B4 Carbodiimide resin (carbodiimide equivalent 590)
B5 Allylamine B6 Urea resin B7 Vinyltrimethoxysilane B8 3-Glycidoxypropyltrimethoxysilane B9 Polyether urethane prepolymer sodium bisulfite adduct B10 Polyester urethane prepolymer sodium bisulfite adduct
<Metal complex compound (C)>
C1 Zinc citrate C2 Zinc acetylacetonate C3 Aluminum tris (acetylacetate)
C4 Titanium lactate C5 Titanium diisopropoxybis (triethanolaminate)
<Silica (D)>
D1 Colloidal silica (grain size 20nm)
D2 Gas phase silica (particle size 150nm)

(2) Pretreatment and surface treatment with aqueous surface treatment agent (a) Test plate GI: hot dip galvanized steel, plate thickness 0.6 mm, single-sided plating adhesion 40 g / m ²
GA: Alloyed hot-dip galvanized steel, thickness 0.8 mm, single-sided plating adhesion 50 g / m ²
(B) Degreasing treatment As a pretreatment of the test plate, a clean surface state was obtained by alkali degreasing. Specifically, Parclean-N364S (manufactured by Nihon Parkerizing Co., Ltd.), a silicate alkaline degreasing agent, is diluted with deionized water to a concentration of 20 g / L, adjusted to a temperature of 60 ° C., and then applied to the surface of the test plate for 10 seconds. Sprayed. Then, after wash | cleaning with a tap water, it squeezed with the draining roll and heat-dried at 50 degreeC for 30 second.
(C) Surface treatment The aqueous surface treatment agents of Examples 1 to 47 and Comparative Examples 1 to 5 prepared above were wet by changing the type of bar coater so that the dry film amounts shown in Table 3 were obtained. The amount of adhesion was controlled and applied to the surface of the test plate after the degreasing treatment. Subsequently, it dried so that it might become the ultimate board temperature shown in Table 3, respectively.

(3) Evaluation test The surface-treated test plate prepared above was subjected to the following test.
(3) -1 Plane portion corrosion resistance Each surface-treated galvanized steel sheet was subjected to a salt spray test defined in JIS-Z2371 for 72 hours. And the white rust generation | occurence | production area rate was measured visually and evaluated. Here, the white rust generation area ratio is a percentage of the area of the white rust generation site to the area of the observation site.
<Evaluation criteria>
◎: White rust occurrence area ratio less than 5% ○: White rust occurrence area ratio 5% or more, less than 10% △: White rust occurrence area ratio 10% or more, less than 50% ×: White rust occurrence area ratio 50% or more

(3) -2 Processed part corrosion resistance Each surface-treated galvanized steel sheet was subjected to 6 mm extrusion using an Erichsen tester, and a salt spray test prescribed in JIS-Z2371 was carried out for 48 hours. And the white rust generation | occurence | production area rate was measured visually and evaluated. Here, the white rust generation area ratio is a percentage of the area of the white rust generation site to the area of the observation site.
<Evaluation criteria>
◎: White rust occurrence area ratio less than 5% ○: White rust occurrence area ratio 5% or more, less than 10% △: White rust occurrence area ratio 10% or more, less than 50% ×: White rust occurrence area ratio 50% or more

(3) -3 Solvent resistance Methyl ethyl ketone (MEK), ethanol, and hexane are soaked in gauze, and the surface of the organic film of the surface-treated test material coated plate is subjected to 20 reciprocating rubbing tests to observe the surface.
<Evaluation criteria>
◎: No change in appearance ○: Some change △: Some change ×: Change

(3) -4 Coating adhesion The coating process was performed using a melamine alkyd paint (Delicon # 700, manufactured by Dainippon Paint Co., Ltd.). The coating was performed by bar coating. After coating, baking was performed at 140 ° C. for 20 minutes, and a film having a thickness of 25 μm was formed after drying. After that, 1 mm square, 100 grids were cut with an NT cutter on each coated metal plate, extruded 5 mm with an Eriksen tester, and then subjected to a peel test with an adhesive tape on the extruded convex part. Evaluation was based on the number of peeled coating films.
<Evaluation criteria>
◎: No peeling ○: Number of peeled 1 or more, less than 10 △: Number of peeled 11 or more, less than 50 x: Number of peeled 51 or more

The evaluation results are shown in Table 3. As a result, the surface treatment test plate having a film formed using the surface treatment agent of the present invention (Examples 1 to 47) was excellent in corrosion resistance, processed part corrosion resistance, solvent resistance, and paint adhesion. showed that.
On the other hand, if any of the water-dispersible urethane resin (A), the organic compound (B), and the metal complex compound (C) is outside the range specified in the products of the present invention such as Comparative Examples 1 to 5, the corrosion resistance and the processing Some of the corrosion resistance, solvent resistance, and paint adhesion were inferior.

Table 1

Table 2

Table 3

Claims (9)

  Water dispersible urethane resin (A) having a glass transition temperature exceeding 50 ° C. and a minimum film forming temperature of 40 ° C. or less and having a carboxyl group as a functional group, amino compound, amino resin, carbodiimide compound, carbodiimide resin, epoxy compound , An epoxy resin, a silane compound, an isocyanate compound, and an organic compound having at least one crosslinking group selected from urethane prepolymers having an isocyanato group (B) at least one metal complex compound selected from zinc, aluminum and titanium (C ) Is a water-based surface treatment agent for metal materials.   The aqueous surface treating agent according to claim 1, wherein at least one metal complex compound (C) selected from zinc, aluminum and titanium is an organometallic complex compound.   The aqueous surface treating agent according to claim 1 or 2, wherein silica (D) is blended. The acid value of the water dispersible urethane resin (A) is in the range of 2 to 40, and further, the tensile properties are 20 to 90 N / mm ² and the elongation is 200 to 700% as the film physical properties of the resin. The aqueous surface treating agent according to any one of claims 1 to 3.   The mixing ratio (A) / (B) of the water-dispersible urethane resin (A) and the organic compound (B) is in a range of 1000/1 to 10/1 as a solid content mass ratio. The aqueous surface treatment agent according to one item.   The compounding ratio of the water-dispersible urethane resin (A) and the metal complex compound (C) is in a range of 1000/1 to 10/1 as a mass ratio of solid content of (A) / metal atom of (C). The aqueous surface treating agent according to any one of 1 to 5.   The water-based surface treatment agent according to any one of claims 1 to 6, wherein the water-dispersible urethane resin (A) is a silane-modified water-dispersible urethane resin. At least one side is coated, the surface-coated metal material to form a coating of 0.1 to 3 g / m ² as dry coating weight of aqueous surface-treating agent a metal material surface according to any one of claims 1 to 7 . The surface-coated metal material according to claim 8, wherein the metal material is a galvanized steel material, a zinc alloy-plated steel material, or an aluminum material.