JP2008255466A - Metal surface treatment composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a metal surface treatment composition of a pollution-free type having adhesiveness, workability, and corrosion resistance equivalent to those of chromate treatment and phosphate treatment. <P>SOLUTION: The metal surface treatment composition is characterized by containing: an aqueous dispersion (A) of a polyurethane resin obtained by reaction of an epoxy prepolymer (I) having an amino group obtained by reaction of a polyepoxy compound (a) and an amine compound (b) and a urethane prepolymer (II) having an isocyanate group at a terminal obtained by reaction of a compound (d) having two or more active hydrogen groups in one molecule including a carboxyl group-containing diol (c) with poly isocyanate compound (e); a silica particle (B); and at least one kind of a compound (C) selected from metal hydrofluoric acid, metal hydrofluoric acid salt, vanadium compound, molybdenum compound, and tungsten compound. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention is a pollution-free metal surface treatment composition capable of obtaining a film excellent in processability, corrosion resistance, top coatability, etc., in place of conventional chromate treatment and phosphate treatment, and the metal surface treatment The present invention relates to a metal plate using the composition.

  Conventionally, chromate treatment and phosphate treatment are generally performed to improve the corrosion resistance of metal surfaces. However, in recent years, the toxicity of chromium has become a social problem. The surface treatment method using chromate is a problem of scattering of chromate fume in the treatment process, a large amount of cost for wastewater treatment equipment, and further problems due to elution of chromic acid from the chemical conversion treatment film, etc. There is. Hexavalent chromium compounds are extremely harmful substances as many public institutions, including IARC (International Agency for Research on Cancer Review), have designated as carcinogenic substances for the human body.

  Also, in phosphate treatment, zinc phosphate and iron phosphate surface treatments are usually performed, but in order to provide corrosion resistance, chrome treatment is usually performed after phosphating for rinsing with chromic acid. In addition to the above problems, there are problems such as a reaction accelerator in the phosphate treatment agent, wastewater treatment of metal ions, and sludge treatment by elution of metal ions from the metal to be treated.

  As a treatment method other than the chromate treatment and the zinc phosphate treatment, (1) a surface treatment method (see Patent Document 1) of heating at a temperature of 150 to 550 ° C. after treatment with an aqueous solution containing aluminum biphosphate. (2) A method of treating with an aqueous solution containing tannic acid (see Patent Document 2) has been proposed, and (3) A method of treating with sodium nitrite, sodium borate, imidazole, aromatic carboxylic acid, surfactant, etc. Or the processing method which combined these is performed.

  However, in the method (1), when a paint is applied thereon, the adhesion of the paint is not sufficient, the method (2) is inferior in corrosion resistance, and the methods (3) are both high temperatures. There is a problem that the corrosion resistance is inferior when exposed to a humid atmosphere.

  In addition, as a zinc-based steel sheet having a thin film with a film thickness of several μm or less, Patent Document 3, Patent Document 4, Patent Document 5 and the like use a zinc-based plated steel sheet as a base material, and form a chromate film on this. Further, a rust-proof steel sheet having an organic composite silicate film formed thereon as an uppermost layer is known, and this has excellent workability and corrosion resistance. However, since this rust-proof steel plate has a chromate film, there was a problem of health and safety due to chromate ions as described above. Moreover, the steel plate obtained by removing the chromate film from the rust-proof steel plate still has insufficient corrosion resistance.

Japanese Patent Publication No.53-28857 JP-A-51-71233 JP 58-224174 A JP 60-50179 A Japanese Patent Laid-Open No. 60-50180

  An object of the present invention is to provide a pollution-free surface treatment composition having adhesion, workability and corrosion resistance comparable to chromate treatment and phosphate treatment.

  As a result of intensive studies to solve the above-mentioned problems, the present inventors have used an aqueous dispersion (A) of a specific polyurethane resin, to which silica particles (B), metal hydrofluoric acid, metal hydrogen fluoride are used. By combining at least one compound (C) selected from acid salts, vanadium compounds, molybdenum compounds and tungsten compounds, it is possible to form a film having rust preventive power comparable to chromate treatment and phosphate treatment. The present inventors have found that a metal surface treatment composition that can be obtained is obtained, and have completed the present invention.

That is, the present invention
(A) An active hydrogen group is contained in one molecule containing an epoxy prepolymer (I) having an amino group obtained by a reaction between a polyepoxy compound (a) and an amine compound (b) and a carboxyl group-containing diol (c). An aqueous dispersion of a polyurethane resin obtained by a reaction with a urethane prepolymer (II) having an isocyanate group at a terminal obtained by a reaction between a compound (d) containing two or more and a polyisocyanate compound (e);
(B) silica particles, and (C) at least one compound selected from metal hydrofluoric acid, metal hydrofluorate, vanadium compound, molybdenum compound, and tungsten compound,
It is related with the metal surface treatment composition characterized by containing.

  Moreover, this invention relates to the metal plate formed by apply | coating the said metal surface treatment composition to a steel plate, and forming a film.

  According to the metal surface treatment composition of the present invention, even without rinsing with chromic acid, it has a corrosion resistance equivalent to or better than that of conventional zinc phosphate treatment, and further forms a film with excellent adhesion and workability. It is extremely useful as a pollution-free metal surface treatment composition.

  The metal surface treatment composition of the present invention includes an epoxy prepolymer (I) having an amino group obtained by a reaction between a polyepoxy compound (a) and an amine compound (b), and a carboxyl group-containing diol (c). Of a polyurethane resin obtained by a reaction with a urethane prepolymer (II) having an isocyanate group at a terminal obtained by a reaction between a compound (d) containing two or more active hydrogen groups in the molecule and a polyisocyanate compound (e) An aqueous dispersion (A), silica particles (B), and at least one compound (C) selected from metal hydrofluoric acid, metal hydrofluoride, vanadium compound, molybdenum compound and tungsten compound. It will be.

Aqueous dispersion of polyurethane resin (A)
A polyurethane resin is obtained by reaction of epoxy prepolymer (I) and urethane prepolymer (II).

  Epoxy prepolymer (I) has an amino group, and is obtained by reaction of polyepoxy compound (a) and amine compound (b).

  The polyepoxy compound (a) is a compound having two or more epoxy groups in one molecule. For example, glycidyl ether type epoxy resins such as bisphenol A and bisphenol F, hydrogenated bisphenol A type epoxy resins, and glycidyl ester type epoxies. Resin, alicyclic epoxy resin, polyglycol type epoxy resin; modified epoxy resin obtained by modifying these epoxy resins with at least one modifier selected from alkylphenol and fatty acid; alkylphenol or alkylphenol novolac type resin and epichlorohydrin Epoxy group-introduced alkylphenol or alkylphenol novolak type resin obtained by reaction; dibasic acid-modified epoxy resin, dibasic acid and epoxy resin modified with carboxyl group-containing phenol Can.

  The amine compound (b) is a compound having a primary amino group, for example, an aliphatic amine such as propylamine, isopropylamine, butylamine, amylamine, hexylamine, octylamine, decylamine, undecylamine, dodecylamine; And aromatic amines such as aniline, o-toluidine, m-toluidine and p-toluidine; cycloaliphatic amines such as cyclobutylamine, cyclopentylamine and cyclohexylamine.

  Moreover, as an amine compound (b), it is preferable to use an alkanolamine from the point of the corrosion resistance and sclerosis | hardenability of a formed film. Examples of the alkanolamine include monoethanolamine and monoisopropanolamine.

  As the amine compound (b), aminosilane can be used from the viewpoint of improving the water resistance of the formed film. The aminosilane contains an amino group and an alkoxysilyl group in one molecule, and specific examples thereof include, for example, γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ-aminopropylmethyldisilane. Examples include ethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, N-β- (aminoethyl) aminopropyltrimethoxysilane, and N-β- (aminoethyl) aminopropyltriethoxysilane.

  Furthermore, when the polyoxyalkylene chain is added to the side chain of the epoxy prepolymer (I), a polyoxyalkylene amine can be used as the amine compound (b). The polyoxyalkyleneamine is not particularly limited as long as it is a compound having a primary amino group and further having a polyoxyalkylene chain, and various compounds can be used. Examples of the polyoxyalkylene chain include a polyoxyethylene chain, a polyoxypropylene chain, a block chain of polyoxyethylene and polyoxypropylene, and the like. The polyoxyalkylene chain preferably has a molecular weight in the range of 100 to 10,000, particularly 200 to 8,000.

  Representative examples of the polyoxyalkyleneamine include, for example, the following general formula (1)

（式中、Ｒ¹は水酸基又は炭素数１〜４のアルコキシ基を表し、Ｒ²は水素原子又はメチル基を表し、ｍは２〜２２０、好ましくは５〜１８０の整数であり、ｎは２〜３の整数、好ましくは２である。ここでｍ個のオキシアルキレン単位（Ｃ_ｎＨ_2ｎＯ）は同じであっても又は互に異なっていてもよい。）で示される化合物を挙げることができる。アミン化合物（ｂ）成分の少なくとも一部又は全部としてポリオキシアルキレンアミンを用いることは、本発明の金属表面処理組成物の貯蔵安定性の点で好ましい。

(Wherein R ¹ represents a hydroxyl group or an alkoxy group having 1 to 4 carbon atoms, R ² represents a hydrogen atom or a methyl group, m is an integer of 2 to 220, preferably 5 to 180, and n is 2) An integer of ˜3, preferably 2. Here, m oxyalkylene units (C _n H _2n O) may be the same or different from each other). it can. The use of polyoxyalkyleneamine as at least a part or all of the amine compound (b) component is preferable from the viewpoint of storage stability of the metal surface treatment composition of the present invention.

  These amine compounds (b) can be used alone or in combination of two or more.

  The production of the epoxy prepolymer (I) is not particularly limited, and a conventionally known method can be adopted, and it is usually performed by heating at 50 to 250 ° C. for 1 to 24 hours. The proportions of the components (a) and (b) can be variously changed, but the equivalent ratio of the epoxy group in the component (a) and the amino group in the component (b) is generally 1: 0.5 to 1 : 2, preferably 1: 0.5 to 1: 0.9.

The epoxy prepolymer (I) thus produced has a number average molecular weight of 500 to 10000, preferably 1000 to 8000, from the viewpoint of viscosity control during synthesis, corrosion resistance of the formed film, and the like. Here, the number average molecular weight is a calculated value, and is calculated by the following formula when the number of moles of the component (a) is M, the molecular weight is m, the number of moles of the component (b) is N, and the molecular weight is n. It is what is done.
Number average molecular weight = {M × m / | MN −} + {N × n / | MN−}
(Here, | M−N | represents the absolute value of M−N.)

  The urethane prepolymer (II) has an isocyanate group at the terminal, a compound (d) containing two or more active hydrogen groups in one molecule containing the carboxyl group-containing diol (c), a polyisocyanate compound (e), It is obtained by the reaction of

  Examples of the carboxyl group-containing diol (c) include 2,2-dimethylolpropionic acid, 2,2-dimethylolbutanoic acid, 2,2-dimethylolbutyric acid, 2,2-dimethylolvaleric acid, and polyester obtained by condensing them. Examples include polyols and polyether polyols. These can be used in combination with hydroxycarboxylic acids such as 12-hydroxystearic acid, paraoxybenzoic acid, 2,2-dimethyl-3-hydroxypropionic acid, and salicylic acid.

  The compounding quantity of carboxyl group-containing diol (c) is not specifically limited. From the viewpoint of water dispersibility and corrosion resistance, the content in the urethane prepolymer (II) is preferably 1 to 25% by weight, more preferably 2 to 15% by weight.

  The compound (d) contains the carboxyl group-containing diol (c), and further has at least two active hydrogen groups in one molecule other than the (c) as necessary. For example, a low molecular weight glycol , High molecular weight glycols, polyester polyols, polycarbonate polyols and the like may be used alone, or low molecular weight glycols may be used in combination with polyester polyols and high molecular weight glycols.

  Examples of the low molecular weight glycols include ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propylene glycol, 1,3-butylene glycol, tetramethylene glycol, hexamethylene glycol, decamethylene glycol, octanediol, and tricyclodecanedi. There are methylol, cyclohexanedimethanol, hydrogenated bisphenol A, etc., and these may be used alone or in admixture of two or more.

  Examples of the high molecular weight glycols include polyethylene glycol, polypropylene glycol, polytetramethylene glycol, and polycarbonate glycol. Polyester polyols include those obtained by reacting a glycol component with a dicarboxylic acid component. It can manufacture easily by this, and it can manufacture not only by esterification but also by transesterification. Moreover, the polyester diol obtained by ring-opening reaction of cyclic ester compounds, such as (epsilon) -caprolactone, and these cocondensation polyesters can also be included.

  The compound (d) preferably contains a bisphenol skeleton-containing diol compound (f) as at least a part of its components from the viewpoint of improving the corrosion resistance of the formed film.

  Examples of the bisphenol skeleton-containing diol compound (f) include ethylene oxide and / or propylene oxide adducts of bisphenols. Examples of bisphenols include bisphenol A, bisphenol F, and bisphenol S.

  When the bisphenol skeleton-containing diol compound (f) is used, the content ratio in the compound (d) is 10 to 98% by weight, preferably 50 to 95% by weight.

  In addition, the compound (d) is a fatty acid ester (g) containing two or more active hydrogen groups in one molecule as at least a part of its components from the viewpoint of improving the drying property, curability, water resistance and the like of the formed film. ) Can be included.

  The fatty acid ester (g) usually has a structural unit derived from a fatty acid via an ester bond, and is not particularly limited from a low molecular weight one to a high molecular weight one. It is possible to select appropriately according to the use and the like.

  For example, glycerin monofatty acid ester can be used as the fatty acid ester (g). Examples of the glycerin monofatty acid ester include glycerin monolaurate, glycerin monooleate, glycerin monostearate and the like, and further esterification reaction between glycerin and a fatty acid having 10 or more carbon atoms, and transesterification reaction between fats and oils and glycerin. The thing obtained by etc. is mentioned. Moreover, the reaction product of a glycidol and a fatty acid may be sufficient. The glycerin monofatty acid ester can be suitably selected as the fatty acid ester (g) when the metal surface treatment composition of the present invention is used in applications requiring water resistance, quick drying properties, finish properties, and the like.

  Examples of the fatty acid include those having a structure in which a carboxyl group is bonded to the end of a hydrocarbon chain, and examples include dry oil fatty acids, semi-dry oil fatty acids, and non-dry oil fatty acids. Dry oil fatty acids and semi-dry oil fatty acids are not strictly distinguishable. Usually, dry oil fatty acids are unsaturated fatty acids having an iodine value of 130 or more, and semi-dry oil fatty acids have an iodine value of 100 or more and less than 130. Of unsaturated fatty acids. On the other hand, non-drying oil fatty acids are usually fatty acids having an iodine value of less than 100.

  Examples of the dry oil fatty acid and the semidry oil fatty acid include fish oil fatty acid, dehydrated castor oil fatty acid, safflower oil fatty acid, linseed oil fatty acid, soybean oil fatty acid, sesame oil fatty acid, poppy oil fatty acid, eno oil fatty acid, hemp oil fatty acid, grape Nuclear oil fatty acid, corn oil fatty acid, tall oil fatty acid, sunflower oil fatty acid, cottonseed oil fatty acid, walnut oil fatty acid, rubber seed oil fatty acid, hydienoic acid fatty acid, etc., and non-drying oil fatty acid include, for example, coconut oil fatty acid , Hydrogenated coconut oil fatty acid, palm oil fatty acid and the like. These can be used alone or in combination of two or more. Furthermore, these fatty acids can be used in combination with caproic acid, capric acid, lauric acid, myristic acid, palmitic acid, stearic acid and the like.

  The reaction between glycerin and the fatty acid is such that the equivalent ratio of the hydroxyl group in glycerin to the carboxyl group in the fatty acid is from 1: 0.17 to 1: 0.5, preferably from 1: 0.23 to 1: 0.43. It is suitable to mix by mixing at a ratio within the range, and usually by heating at a temperature of about 100 to about 180 ° C. for about 0.5 to about 10 hours in the presence of an esterification catalyst. Examples of the esterification catalyst include sulfuric acid, aluminum sulfate, potassium hydrogen sulfate, alkyl-substituted benzene, hydrochloric acid, methyl sulfate, and phosphoric acid. On the other hand, the reaction between fats and oils (fatty acid triglyceride) and glycerin is usually preferably carried out by a method known per se in the presence of a transesterification catalyst such as zinc acetate, lisurge, dibutyltin oxide, calcium naphthenate and the like. it can.

  As the fatty acid ester (g), a reaction product of an epoxy resin containing two or more epoxy groups in one molecule and a fatty acid can be used. When the reaction product of the epoxy resin and the fatty acid has a secondary hydroxyl group, and the metal surface treatment composition of the present invention is used in applications where water resistance, quick drying, finish, etc. are required, It can be suitably selected as the fatty acid ester (g). In particular, when a glycidyl ether type epoxy resin of bisphenol A is used as the epoxy resin, it is suitable for applications requiring high corrosion resistance.

  Examples of the epoxy resin include glycidyl ether type epoxy resins such as bisphenol A and bisphenol F, hydrogenated bisphenol A type epoxy resins, glycidyl ester type epoxy resins, alicyclic epoxy resins, and polyglycol type epoxy resins; Modified epoxy resin obtained by modifying a resin with a modifier such as alkylphenol; Epoxy group-introduced alkylphenol or alkylphenol novolak resin obtained by reacting alkylphenol or alkylphenol novolak type resin with epichlorohydrin; Dibasic acid modified epoxy resin, dibasic acid And an epoxy resin modified with a carboxyl group-containing phenol.

  As said fatty acid, it can select from the thing listed by description of the said glycerol mono fatty acid ester suitably, and can use it.

  In the reaction between the epoxy resin and the fatty acid, the equivalent ratio of the epoxy group in the epoxy resin to the carboxyl group in the fatty acid is 1: 0.6 to 1: 1.4, preferably 1: 0.8 to 1: 1. .2 in a ratio within the range of, for example, usually in the presence of an epoxy group / carboxyl group reaction catalyst for about 1 to 10 hours. Examples of the epoxy group / carboxyl group reaction catalyst include quaternary salt catalysts such as tetraethylammonium bromide, tetrabutylammonium bromide, tetraethylammonium chloride, tetrabutylphosphonium bromide, and triphenylbenzylphosphonium chloride; triethylamine, tributylamine And the like. The reaction temperature is suitably about 120 to 150 ° C.

  As the fatty acid ester (g), a reaction product of a compound containing two or more carboxyl groups in one molecule and a monoepoxy compound containing a long-chain hydrocarbon group can be used. The reaction product has a secondary hydroxyl group and can be suitably selected as the fatty acid ester (g) when used in applications where water resistance, finish, etc. are required.

  Examples of the compound containing two or more carboxyl groups in one molecule include, for example, phthalic acid, isophthalic acid, terephthalic acid, succinic acid, adipic acid, azelaic acid, sebacic acid, naphthalenedicarboxylic acid, 4,4-diphenyl Dicarboxylic acid, diphenylmethane-4,4'-dicarboxylic acid, het acid, maleic acid, fumaric acid, itaconic acid, trimellitic acid, pyromellitic acid, cyclohexane-1,3-dicarboxylic acid, cyclohexane-1,4-dicarboxylic acid Polyhydric carboxylic acids such as hexahydrophthalic acid, hexahydroisophthalic acid, hexahydroterephthalic acid, tetrahydrophthalic acid, hexahydrotrimellitic acid, methylhexahydrophthalic acid, malic acid, citric acid and their acid anhydrides. These are used alone or in combination of two or more. Rukoto can.

  The above-mentioned monoepoxy compound containing a long-chain hydrocarbon group is a monoepoxide compound having a chain or cyclic hydrocarbon group having 4 or more carbon atoms, preferably 6 to 20 carbon atoms. , Pivalic acid glycidyl ester, hexanoic acid glycidyl ester, cyclohexanecarboxylic acid glycidyl ester, 2-ethylhexanoic acid glycidyl ester, isononanoic acid glycidyl ester, decanoic acid glycidyl ester, undecanoic acid glycidyl ester, lauric acid glycidyl ester, myristic acid glycidyl ester, Glycidyl esters such as palmitic acid glycidyl ester, stearic acid glycidyl ester, and Cardura E10 (manufactured by Japan Epoxy Resin Co., Ltd., neodecanoic acid monoglycidyl ester); Le, phenyl glycidyl ether, glycidyl ethers such as decyl glycidyl ether; styrene oxide, AOEX24 (manufactured by Daicel Chemical Industries, alpha-olefin monoepoxide mixture) alpha-olefin monoepoxide, etc., and the like. The hydrocarbon group having 4 or more carbon atoms may have, for example, a substituent such as a hydroxyl group. Specifically, as the monoepoxide compound having a hydrocarbon group having such a substituent, for example, 1,2-epoxyoctanol, hydroxyoctyl glycidyl ether, and the like. These can be used alone or in combination of two or more.

  In the reaction of the carboxyl group-containing compound and the monoepoxy compound, the equivalent ratio of the carboxyl group in the former to the epoxy group in the latter is 1: 0.6 to 1: 1.4, preferably 1: 0.8 to What is necessary is just to make it heat-react for about 1 to 10 hours normally, for example in the presence of an epoxy group / carboxyl group reaction catalyst. The epoxy group / carboxyl group reaction catalyst can be appropriately selected from the above.

  As the fatty acid ester (g), a reaction product of a cyclic carbonate compound and a fatty acid amine can be used. Since the reaction product has a urethane bond, it has excellent hydrolyzability during storage and can be suitably selected as the fatty acid ester (g).

  The cyclic carbonate compound contains at least one cyclic carbonate group per molecule and is usually a compound containing a 5- or 6-membered cyclic carbonate group. Examples of the 5-membered cyclic carbonate include glycerin carbonate (1,3-dioxolan-2-one-4-methanol), 1,3-dioxolan-2-one-4-propanol, 1,3-dioxolan-2-one- Reaction products of polyhydric alcohols such as butanol and 1,3-dioxolan-2-one-pentanol and carbonates; ethylene carbonate, propylene carbonate; diglycidyl ethers and bisphenol type epoxies of phenols such as bisphenol A and bisphenol F Examples include a reaction product of a resin and carbon dioxide gas. Of these, glycerin carbonate can be suitably used from the viewpoint of ease of synthesis. As the cyclic carbonate compound, those having a bisphenol skeleton can be suitably used from the viewpoint of improving the corrosion resistance of the formed film.

  Fatty acid amines contain an amino group and a fatty acid residue in one molecule. For example, oleic acid, linoleic acid, stearic acid, palmitic acid, myristic acid, beef tallow, fish oil, coconut oil, soybean oil, olive oil, linseed Examples are those obtained by amine-modifying at least one selected from oil, cottonseed oil, rapeseed oil and hydrogenated oils obtained by hydrogenating these oils with alkylenediamine such as ethylenediamine or polyoxyalkylenediamine. it can. Among these, those derived from unsaturated fatty acids can be preferably used from the viewpoint of the drying property and curability of the formed film.

  The cyclic carbonate compound and the fatty acid amine have a molar ratio of the cyclic carbonate group in the cyclic carbonate compound to the amino group in the fatty acid amine of 1: 0.8 to 1: 1.2, preferably 1: 0. It is desirable to make it react so that it may become the range of 95-1: 1.05. This reaction is usually performed at a temperature of 25 to 250 ° C, preferably 50 to 160 ° C.

  When the fatty acid ester (g) is used, the content in the compound (d) is 1 to 95% by weight, preferably 20 to 70% by weight, from the viewpoint of curability, water resistance and finish. It is.

  In the present invention, when the side chain of the urethane prepolymer (II) has a polyoxyalkylene chain, the above compound (d) has a polyoxyalkylene chain as a side chain as at least a part of its component. Is preferably included.

  The polyol having a polyoxyalkylene chain as a side chain is a compound having two or more hydroxyl groups in one molecule and further having a polyoxyalkylene chain, and the side chain when incorporated into a urethane prepolymer. Various compounds can be used without particular limitation as long as a polyoxyalkylene chain can be introduced into the portion. Examples of the polyoxyalkylene chain include a polyoxyethylene chain, a polyoxypropylene chain, a block chain of polyoxyethylene and polyoxypropylene, and the like. The polyoxyalkylene chain preferably has a molecular weight in the range of 100 to 10,000, particularly 200 to 8,000.

  Specific examples of the polyol having a polyoxyalkylene chain as a side chain include, for example, a reaction product of an acrylate having a polyoxyalkylene chain and a dialkanolamine, a reaction product of glycerol carbonate and a polyoxyalkyleneamine, and the like. Further, it may be a reaction product of glycidol and polyoxyalkyleneamine.

  As an acrylate having a polyoxyalkylene chain, for example, the following formula (2)

（式中、Ｒ^３は炭素数１〜４のアルキル基を表し、ｍは２〜２２０、好ましくは５〜１８０の整数であり、ｎは２〜３の整数、好ましくは２である、ここでｍ個のオキシアルキレン単位（Ｃ_ｎＨ_2ｎＯ）は同じであっても又は互に異なっていてもよい。）で示される化合物を挙げることができる。その具体例としては、例えば、メトキシポリエチレングリコールアクリレート、エトキシポリエチレングリコールアクリレートなどを挙げることができる。

Wherein R ³ represents an alkyl group having 1 to 4 carbon atoms, m is an integer of 2 to 220, preferably 5 to 180, and n is an integer of 2 to 3, preferably 2. and m oxyalkylene units (C _n H _2n O may be the same or different from each other). Specific examples thereof include methoxy polyethylene glycol acrylate and ethoxy polyethylene glycol acrylate.

  Examples of dialkanolamines include diethanolamine and dipropanolamine.

  The acrylate having a polyoxyalkylene chain and the dialkanolamine have a molar ratio of acrylate to amino group of 1: 0.8 to 1: 1.2, preferably 1: 0.95 to 1: 1.05. It is desirable to make it react so that. This reaction is usually performed at a temperature of 25 to 250 ° C, preferably 50 to 160 ° C.

  As said polyoxyalkylene amine, the thing similar to the polyoxyalkylene amine demonstrated in the above-mentioned amine compound (b) can be selected suitably, and can be used. Glycerin carbonate and polyoxyalkyleneamine have a molar ratio of cyclic carbonate group in glycerin carbonate to amino group in polyoxyalkyleneamine of 1: 0.8 to 1: 1.2, preferably 1: 0.95. It is desirable to make it react so that it may become the range of -1: 1.05. This reaction is usually performed at a temperature of 25 to 250 ° C, preferably 50 to 160 ° C.

  The use of a polyol having a polyoxyalkylene chain as a side chain as at least a part of the compound (d) is preferable from the viewpoint of storage stability of the metal surface treatment composition of the present invention.

  The polyisocyanate compound (e) contains two or more isocyanate groups in one molecule. Specific examples thereof include aliphatic groups such as hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, dimer acid diisocyanate, and lysine diisocyanate. Polyisocyanates; burette type adducts, isocyanurate cycloadducts of these polyisocyanates; isophorone diisocyanate, 4,4'-methylenebis (cyclohexyl isocyanate), methylcyclohexane-2,4- (or -2,6-) Diisocyanate, 1,3- (or 1,4-) di (isocyanatomethyl) cyclohexane, 1,4-cyclohexane diisocyanate, 1,3-cyclopentane diisocyanate, 1,2-cyclohexa Alicyclic diisocyanates such as diisocyanates; bullet type adducts of these diisocyanates, isocyanurate cycloadducts; xylylene diisocyanate, metaxylylene diisocyanate, tetramethyl xylylene diisocyanate, tolylene diisocyanate, 4,4 '-Diphenylmethane diisocyanate, 1,5-naphthalene diisocyanate, 1,4-naphthalene diisocyanate, 4,4'-toluidine diisocyanate, 4,4'-diphenyl ether isocyanate, (m- or p-) phenylene diisocyanate, 4 , 4′-biphenylene diisocyanate, 3,3′-dimethyl-4,4′-biphenylene diisocyanate, bis (4-isocyanatophenyl) sulfone, isopropylidenebis (4-phenyl) Aromatic diisocyanate compounds such as diisocyanate; bullet type adducts and isocyanurate cycloadducts of these diisocyanate compounds; triphenylmethane-4,4 ′, 4 ″ -triisocyanate, 1,3, Three or more isocyanate groups in one molecule such as 5-triisocyanatobenzene, 2,4,6-triisocyanatotoluene, 4,4′-dimethyldiphenylmethane-2,2 ′, 5,5′-tetraisocyanate Polyisocyanates having these: burette-type adducts, isocyanurate cycloadducts of these polyisocyanates; ethylene glycol, propylene glycol, 1,4-butylene glycol, dimethylolpropionic acid, polyalkylene glycol, trimethylolpropane, hexane Polio such as triol Urethane adducts obtained by reacting a polyisocyanate compound in an excess ratio of isocyanate groups to the hydroxyl groups of the ure; burette type adducts, isocyanurate ring adducts, etc. of these urethanized adducts. it can.

  Moreover, the said compound (e) may be polyisocyanate which has the polyoxyalkylene chain used as a side chain. The polyisocyanate having a polyoxyalkylene chain as a side chain is not particularly limited as long as it is a compound having two or more isocyanate groups in one molecule and further having a polyoxyalkylene chain. Various compounds can be used. Use of a polyisocyanate having a polyoxyalkylene chain serving as a side chain as at least a part of the component (e) is preferable from the viewpoint of storage stability of the metal surface treatment composition of the present invention.

  Production of the urethane prepolymer (II) is not particularly limited, and a conventionally known method can be employed. For example, the above-described components (d) and (e) may be reacted at once, or may be reacted in a multistage manner. You may let them. The proportions of the above components (d) and (e) can be varied, but the equivalent ratio of isocyanate groups to hydroxyl groups in all components is generally 1: 0.9 to 1: 0.5, preferably 1: It is desirable that the ratio is 0.9 to 1: 0.7. The reaction is usually carried out at a temperature of 40 to 180 ° C, preferably 60 to 130 ° C. In order to promote this reaction, amine catalysts such as triethylamine, N-ethylmorpholine, and triethylenediamine used in ordinary urethanization reactions, and tin catalysts such as dibutyltin dilaurate and dioctyltin dilaurate are used as necessary. It may be used.

The urethane prepolymer (II) thus prepared has an acid value of 10 to 100 mgKOH / g, preferably 13 to 60 mgKOH / g, more preferably 17 to 56 mgKOH / g, and a number average molecular weight of 1000 to 6000, preferably 1500. ˜5000 is preferable from the viewpoints of viscosity control during synthesis, corrosion resistance of the formed film, and the like. Here, the number average molecular weight is a calculated value, and is calculated by the following formula when the number of moles of the component (d) is O, the molecular weight is o, the number of moles of the component (e) is P, and the molecular weight is p. It is what is done.
Number average molecular weight = {O * o / | OP |} + {P * p / | OP |}
(Here, | O-P | represents the absolute value of OP).

  In the aqueous dispersion (A) of the polyurethane resin used in the present invention, the polyurethane resin obtained by the reaction between the epoxy prepolymer (I) and the urethane prepolymer (II) is dispersed in water in an aqueous medium. Is.

  The reaction between the epoxy prepolymer (I) and the urethane prepolymer (II) is not particularly limited, and a conventionally known method can be employed. Usually, the reaction is performed by heating at 20 to 80 ° C. for 0.1 to 10 hours. Is called. The ratio of both can be varied, but the equivalent ratio of the amino group in the epoxy prepolymer (I) to the isocyanate group in the urethane prepolymer (II) is 0.01: 1 to 0.9: 1, It is desirable to select it so that it is preferably 0.2: 1 to 0.8: 1.

  The polyurethane resin obtained as described above is dispersed in an aqueous medium. Examples of the aqueous medium include water or a water-organic solvent mixed solution obtained by dissolving water or an organic solvent such as a water-soluble organic solvent. Water dispersion can be carried out by a conventionally known method without any particular limitation. For example, a neutralizing agent, a surfactant or the like is added to the polyurethane resin as necessary, and the mixture is stirred and dispersed while gradually adding water. be able to. The neutralizing agent is not particularly limited as long as it can neutralize the carboxyl group. For example, sodium hydroxide, potassium hydroxide, trimethylamine, dimethylaminoethanol, 2-methyl-2-aminopropanol, triethylamine, ammonium, etc. Is mentioned. The neutralizing agent may neutralize the carboxyl group in addition to the polyurethane resin, or may be neutralized simultaneously with the dispersion by adding it to water as a dispersion medium. Examples of the surfactant include nonionic surfactants such as polyoxyethylene nonylphenyl ether and polyoxyethylene-oxypropylene block copolymer, and anionic surfactants such as sodium lauryl sulfate and sodium dodecylbenzenesulfonate. It is done.

  The polyurethane resin can be increased in molecular weight by further reacting with a chain extender if necessary. Examples of the chain extender include ethylenediamine, 1,2-propanediamine, 1,6-hexamethylenediamine, piperazine, 2,5-dimethylpiperazine, isophoronediamine, 4,4′-dicyclohexylmethanediamine, and 3,3′-. Diamines such as dimethyl-4,4′-dicyclohexylmethanediamine, 1,4-cyclohexanediamine, polyoxyethylenediamine, polyoxypropylenediamine, amine-terminated polyoxyethylene-polyoxypropylene copolymer; diethylenetriamine, dipropylenetriamine, tri Polyamines such as ethylenetetramine and tetraethylenepentamine; hydroxyethylhydrazine, hydroxyethyldiethylenetriamine, 2-[(2-aminoethyl) amino] ethanol, 3-aminopropanedio Compounds having an amino group and a hydroxyl group, such as Le; hydrazines, acid hydrazides, and the like. These may be used singly or in combination.

  The polyurethane resin has an acid value of 10 to 100 mgKOH / g, preferably 10 to 50 mgKOH / g, more preferably 12 to 45 mgKOH / g, an amine value of 0 to 50 mgKOH / g, preferably 3 to 35 mgKOH / g, and a hydroxyl value of 20 ˜200 mg KOH / g, preferably 30 to 150 mg KOH / g, is suitable from the viewpoints of adhesion of the formed film, corrosion resistance, and the like.

Silica particles (B)
The silica particles as the component (B) in the metal surface treatment composition of the present invention contribute to keeping the formed film weakly alkaline, and are effective for improving the corrosion resistance of the steel sheet. Effective to remove. As the silica particles (B), both colloidal silica (water dispersion type) and fumed silica (vapor phase silica) can be used. Examples of commercially available colloidal silica include Snowtex C, Snowtex N, Snowtex O (all manufactured by Nissan Chemical Co., Ltd.), Adelite AT-20A, and AT-20N (all manufactured by Asahi Denka Kogyo Co., Ltd.). Examples of commercially available fumed silica include hydrophobic silica AEROSIL R-811, hydrophilic silica AEROSIL 200V (both manufactured by Nippon Aerosil Co., Ltd.) and the like. These may be used alone or in combination of two or more. Can be used. The average particle size (primary particle size) of the silica particles is 5 to 100 nm, preferably 10 to 50 nm from the viewpoint of the stability of the dispersion.

The amount of silica particles (B) added is not particularly limited. Preferably in the range of 1 to 50 parts by weight SiO ₂ relative to 100 parts by weight of a solid content of the aqueous dispersion of the polyurethane resin (A), the more preferably in the range of 5 to 30 parts by weight. The lower limit of these ranges is significant in terms of adhesion to the film and corrosion resistance. Further, the upper limit of these ranges is significant in terms of film hardness, film elongation, and press workability.

Compound (C)
The compound which is the component (C) of the metal surface treatment composition of the present invention is at least one compound selected from metal hydrofluoric acid, metal hydrofluoride, vanadium compound, molybdenum compound and tungsten compound. These compounds are effective in improving curability, adhesion to a steel sheet, water resistance of the film, alkali resistance and corrosion resistance.

  Examples of the metal hydrofluoric acid and the metal hydrofluoride include zirconium hydrofluoric acid, titanium hydrofluoric acid, silicohydrofluoric acid, zirconium fluoride, titanium fluoride, and silicon fluoride. Is mentioned. Examples of the metal hydrofluoric acid salt that can be used include sodium, potassium, lithium, and ammonium. Among them, ammonium is preferable, and specific examples include zirconium ammonium fluoride.

  Examples of the vanadium compound include vanadium oxide, lithium orthovanadate, sodium orthovanadate, lithium metavanadate, potassium metavanadate, sodium metavanadate, ammonium metavanadate, sodium pyrovanadate, vanadyl chloride, and vanadyl sulfate.

  Examples of molybdenum compounds include molybdenum oxide, molybdic acid, lithium molybdate, sodium molybdate, potassium molybdate, ammonium heptamolybdate, calcium molybdate, magnesium molybdate, strontium molybdate, barium molybdate, phosphomolybdic acid, Examples thereof include sodium phosphomolybdate and zinc phosphomolybdate.

  Examples of the tungsten compound include tungsten oxide, tungstic acid, lithium tungstate, sodium tungstate, potassium tungstate, sodium metatungstate, sodium paratungstate, ammonium pentatungstate, ammonium heptungstate, sodium phosphotungstate, Examples thereof include barium borotungstate.

  These compounds (C) can be used alone or in combination of two or more. Further, in terms of moisture resistance and corrosion resistance, it is preferable to combine metal hydrofluoric acid or metal hydrofluoride with at least one selected from vanadium compounds, molybdenum compounds, or tungsten compounds.

  The amount of compound (C) added is not particularly limited. Preferably, it is in the range of 0.3 to 20 parts by weight, more preferably in the range of 0.5 to 15 parts by weight, particularly preferably 1 to 1 part by weight based on 100 parts by weight of the solid content of the polyurethane resin aqueous dispersion (A). The range is 10 parts by weight. The lower limits of these ranges are significant in terms of adhesion and corrosion resistance. Further, the upper limit of these ranges is significant in terms of paint stability.

  The metal surface treatment composition of the present invention essentially comprises the above components (A) to (C), and can further contain the following (D) to (F).

Silane coupling agent (D)
The metal surface treatment composition of the present invention may contain a silane coupling agent (D). A silane coupling agent (D) can improve adhesiveness with a steel plate more.

  Examples of the silane coupling agent include γ- (2-aminoethyl) aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, N-β (aminoethyl) γ-aminopropyltrimethoxysilane, N-β ( Aminoethyl) Amino group-containing silane coupling agent such as γ-aminopropylmethyldimethoxysilane; Glycidyl group-containing silane coupling agent such as γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldimethoxysilane; -Mercapto group-containing silane coupling agent such as mercaptopropyltrimethoxysilane; Vinyl group-containing silane coupling agent such as vinyltriethoxysilane, vinyltrimethoxysilane, vinyltris (methoxyethoxy) silane; γ- (meth) acryloyloxypropi Examples include (meth) acryloyl group-containing silane coupling agents such as trimethoxysilane, γ- (meth) acryloyloxypropyltriethoxysilane, and γ- (meth) acryloyloxypropyldimethoxymethylsilane, which are used alone or in combination. More than one species can be used in combination.

  The addition amount of the silane coupling agent (D) is not particularly limited. Preferably, it is in the range of 0.3 to 25 parts by weight, more preferably in the range of 1 to 10 parts by weight with respect to 100 parts by weight of the solid content of the aqueous polyurethane resin dispersion (A). The lower limit of these ranges is significant in terms of adhesion. Further, the upper limit of these ranges is significant in terms of paint stability.

Lubricating agent (E)
The metal surface treatment composition of the present invention may contain a lubrication function-imparting agent (E). The lubrication function-imparting agent (E) may be any one that imparts lubricity to the resulting film. Specifically, for example, fluororesin fine powder (for example, tetrafluoroethylene resin, tetrafluoroethylene-hexafluoropropylene copolymer resin, tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer resin, tetrafluoroethylene- Fine particles of ethylene copolymer resin, ethylene trifluoride chloride resin, vinylidene fluoride resin, etc.), polyolefin wax (eg, polyethylene wax, polypropylene wax, etc.), polyolefin and fluororesin are mixed in one particle Lubricants, graphite, boron nitride, carbon fluoride and the like, which can be used alone or in combination of two or more.

  The average particle size of the lubricating function-imparting agent (E) is preferably 0.3 to 5.0 μm, more preferably 0.5 to 3.0 μm. When the average particle size of the lubrication function-imparting agent becomes smaller, the effect of improving the lubricity tends to decrease, and when the average particle size becomes too large, the protruding portion from the film increases, and the lubrication function-imparting agent in continuous processing. Peels off, and the problem of being easily attached to the mold arises.

  Also, in continuous high-speed machining with heat generation, the surface temperature rises due to frictional heat, so it becomes a liquid with a low melting point lubricating function imparting agent, which is not fixed to the film but adheres to and accumulates on the mold and damages the metal surface. It is not preferable. For high-speed machining with heat generation, it is suitable to use polyolefin wax with a softening point of 100 ° C or higher, preferably 130-150 ° C. Even at high temperatures, the wax is uniformly fixed to the film and effectively lubricates without damaging the surface of the steel sheet. Function can be demonstrated. Lubricating function-imparting agent (E) can be used in combination of two or more types from the viewpoint of coating workability, lubricity, etc., for example, a combination of the polyolefin wax and fluororesin powder is preferred. As mentioned.

  The addition amount of the lubricating function-imparting agent (E) is not particularly limited. Preferably, it is in the range of 2 to 50 parts by weight, more preferably in the range of 5 to 30 parts by weight, based on 100 parts by weight of the solid content of the aqueous polyurethane resin dispersion (A). The lower limit of these ranges is significant in terms of improving lubricity. The upper limit of these ranges is significant in terms of the gloss value of the film, transparency, surface smoothness, film elongation and adhesion, adhesion, press workability, and adhesion to the top coat film.

Curing agent (F)
The metal surface treatment composition of the present invention may contain a curing agent (F). By adding the curing agent (F), a dense barrier film can be formed and the corrosion resistance and hardness can be further improved.

  The curing agent (F) is not particularly limited, and examples thereof include a blocked polyisocyanate compound, an amino resin, an oxazoline group-containing compound, and a resol type phenol resin.

  The blocked polyisocyanate compound is a compound obtained by blocking free isocyanate groups of a polyisocyanate compound with a blocking agent.

  The polyisocyanate compound before blocking is one containing two or more isocyanate groups in one molecule, and examples thereof include the same as the polyisocyanate compound (e).

  Examples of the blocking agent for blocking the isocyanate group include phenols such as phenol, cresol, and xylenol; ε-caprolactam; lactams such as δ-valerolactam, γ-butyrolactam, and β-propiolactam; methanol, ethanol, n- Or i-propyl alcohol, n-, i- or t-butyl alcohol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, propylene glycol monomethyl ether, benzyl alcohol, etc. Alcohols: formamidoxime, acetaldoxime, acetoxime, methyl ethyl ketoxime, diacetyl monoo Shim, benzophenone oxime, cyclohexane oxime, etc. oxime; dimethyl malonate, diethyl malonate, ethyl acetoacetate, methyl acetoacetate, can be suitably used blocking agent such as active methylene of acetylacetone.

  By mixing the polyisocyanate compound and the blocking agent, free isocyanate groups of the polyisocyanate compound can be easily blocked. These blocked polyisocyanate compounds can be used alone or in combination of two or more.

  Examples of amino resins include methylolated amino resins obtained by reacting amino components such as melamine, urea, benzoguanamine, acetoguanamine, steroguanamine, spiroguanamine, and dicyandiamide with aldehydes. Examples of the aldehyde used in the above reaction include formaldehyde, paraformaldehyde, acetaldehyde, and benzaldehyde. Further, those obtained by etherifying the above methylolated amino resin with an appropriate alcohol can also be used. Examples of alcohols used for etherification include methyl alcohol, ethyl alcohol, n-propyl alcohol, i-propyl alcohol, and n-butyl. Alcohol, i-butyl alcohol, 2-ethylbutanol, 2-ethylhexanol, etc. are mentioned. These amino resins are usually called melamine resin, urea resin, benzoguanamine resin, acetoguanamine resin, steroguanamine resin, spiroguanamine resin, dicyandiamide resin, etc., derived from the name of the amino component of the raw material. These amino resins can be used alone or in combination of two or more.

  Among the amino resins, melamine resin and benzoguanamine resin are preferable from the viewpoint of curability.

  Examples of the oxazoline group-containing compound include 2,2′-bis (2-oxazoline), 2,2′-methylene-bis (2-oxazoline), 2,2′-ethylene-bis (2-oxazoline), 2 2,2'-trimethylene-bis (2-oxazoline), 2,2'-tetramethylene-bis (2-oxazoline), 2,2'-hexamethylene-bis (2-oxazoline), 2,2'-octamethylene -Bis (2-oxazoline), 2,2'-decamethylene-bis (2-oxazoline), 2,2'-p-phenylene-bis (2-oxazoline), 2,2'-m-phenylene-bis (2 -Oxazoline), 2,2'-o-phenylene-bis (2-oxazoline), 2,2'-cyclohexylene-bis (2-oxazoline), 2,2'-diphenylene-bis ( -Oxazoline), 2,2'-bis (4-methyl-2-oxazoline), 2,2'-bis (4,4'-dimethyl-2-oxazoline), 2,2'-bis (4-ethyl- 2-oxazoline), 2,2'-bis (4,4'-diethyl-2-oxazoline), 2,2'-bis (4-propyl-2-oxazoline), 2,2'-bis (4-butyl) -2-oxazoline), 2,2'-bis (4-phenyl-2-oxazoline), 2,2'-bis (4-cyclohexyl-2-oxazoline), 2,2'-bis (4-benzyl-2) -Oxazoline), 2,2'-m-phenylene-bis (4-methyl-2-oxazoline), 2,2'-m-phenylene-bis (4,4'-dimethyl-2-oxazoline), bis- ( 2-Oxazolinylcyclohexane) sulfur , Bis - (2-oxazolinyl sulfonyl norbornane) sulfide, and the like.

  Also, 2-vinyl-2-oxazoline, 2-vinyl-4-methyl-2-oxazoline, 2-vinyl-5-methyl-2-oxazoline, 2-isopropenyl-2-oxazoline, 2-isopropenyl-4- Homopolymers and copolymers of oxazoline group-containing unsaturated monomers such as methyl-2-oxazoline and 2-isopropenyl-5-methyl-2-oxazoline can also be mentioned as oxazoline group-containing compounds.

  Furthermore, polymers containing an oxazoline group such as Epocros WS-500, Epocros WS-700, and Epocros K2020E manufactured by Nippon Shokubai Co., Ltd. can also be mentioned. These oxazoline group-containing compounds can be used alone or in combination of two or more.

  As a resol type phenol resin, a phenol component and formaldehydes are heated in the presence of a reaction catalyst to cause a condensation reaction by introducing a methylol group, and a part of the methylol group of the methylolated phenol resin obtained with an alcohol is an alkyl ether. It is made up of.

  In the production of a resol-type phenol resin, a bifunctional phenol compound, a trifunctional phenol compound, a tetrafunctional or higher functional phenol compound, or the like can be used as the phenol component that is a starting material.

  Examples of the bifunctional phenol compound used in the production of the resol type phenol resin include 2 such as o-cresol, p-cresol, p-tert-butylphenol, p-ethylphenol, 2,3-xylenol, and 2,5-xylenol. A functional phenol etc. can be mentioned, As a trifunctional phenol compound, a phenol, m-cresol, m-ethylphenol, 3, 5- xylenol, m-methoxyphenol etc. are mentioned, As a tetrafunctional phenol compound May include bisphenol A, bisphenol F, and the like. Among these, it is preferable from the viewpoint of adhesion and corrosion resistance to use a trifunctional or higher functional phenol compound, particularly phenol and / or bisphenol A. These phenol compounds can be used alone or in admixture of two or more.

  Examples of formaldehydes used in the production of the resol type phenol resin include formaldehyde, paraformaldehyde, trioxane and the like, and these can be used alone or in combination of two or more.

  As the alcohol used for alkyl etherifying a part of the methylol group of the methylolated phenol resin, a monohydric alcohol having 1 to 8 carbon atoms, preferably 1 to 4 carbon atoms, can be suitably used. Suitable monohydric alcohols include methanol, ethanol, n-propanol, n-butanol, isobutanol and the like.

  The resol type phenol resin preferably has a number average molecular weight in the range of 200 to 2,000, and more preferably in the range of 300 to 1,200. The average number of methylol groups per benzene nucleus is preferably in the range of 0.3 to 3.0, more preferably in the range of 0.5 to 3.0, and 0.7 to 3.0. A range is further preferred. By using the above-mentioned resol type phenol resin, it is possible to form a film having excellent adhesion and workability.

  The compounding quantity of a hardening | curing agent (F) is not specifically limited. The solid content is preferably in the range of 1 to 50 parts by weight, more preferably in the range of 3 to 20 parts by weight with respect to 100 parts by weight of the solid content of the aqueous polyurethane resin dispersion (A). The lower limits of these ranges are significant in terms of adhesion and corrosion resistance. Further, the upper limit of these ranges is significant in terms of workability.

  The addition method of the hardening | curing agent (F) to the metal surface treatment composition of this invention is not specifically limited, It can add by a conventionally well-known method. For example, in the case of a water-soluble curing agent, it can be added directly to an aqueous medium. Further, in the case of a hardly water-soluble or water-insoluble curing agent, an addition method of mixing the polyurethane resin with the polyurethane resin before dispersing the polyurethane resin in the aqueous medium in the production of the aqueous dispersion (A) of the polyurethane resin can be taken. .

  The aqueous dispersion (A) of the polyurethane resin is sufficiently crosslinked by the addition of the curing agent as described above, but a known curing accelerating catalyst can be used to further increase the low temperature crosslinking property. Examples of the curing accelerating catalyst include N-ethylmorpholine, dibutyltin dilaurate, cobalt naphthenate, stannous chloride, zinc naphthenate, and bismuth nitrate.

  For the metal surface treatment composition of the present invention, if necessary, for example, in addition to the above-described components, thickeners, repellency inhibitors, antifoaming agents, surfactants, oxidizing agents, antibacterial agents, rust prevention An agent (tannic acid, phytic acid, benzotriazole, etc.), a color pigment, an extender pigment, a rust preventive pigment, a conductive pigment, and the like can be contained.

  Moreover, you may add hydrophilic solvents, such as methanol, ethanol, isopropanol, an ethylene glycol type, a propylene glycol type, to the metal surface treatment composition of this invention as needed.

Metal plate metal surface treatment composition of the present invention, it is possible to omit the conventional chromate treatment step, cold-rolled steel sheet or aluminum sheet untreated, or galvanized steel sheet untreated, the plated steel sheet of aluminum-plated steel sheets, etc. By directly applying and drying, a metal plate excellent in corrosion resistance and press workability can be obtained. In addition, even if the metal surface treatment composition of the present invention is applied to a chromate-treated steel plate, there is no problem in performance, and a metal plate with better corrosion resistance can be obtained, so that it can be used as necessary. it can.

  Examples of the galvanized steel sheet include an electrogalvanized steel sheet, a hot dip galvanized steel sheet, a nickel-zinc alloy plated steel sheet, and a zinc-aluminum alloy plated steel sheet. As the zinc-aluminum plated steel sheet, in the case of zinc base, 5% Al-Zn series, 8% Al-Zn series, 15% Al-Zn series, etc., and as the aluminum base, 55% Al-Zn series, 75, etc. % Al—Zn-based materials are known, but the metal surface treatment composition of the present invention is applicable not only to these materials but also to composite plated steel sheets whose plating layers are mainly composed of aluminum and zinc. For example, an Al—Zn alloy to which Mg, Mn, Si, Ti, Ni, Co, Pb, Sn, Cr, rare metals (La, Ce, Y, Nb, etc.), etc. are added is also applicable.

The metal surface treatment composition of the present invention is used by being applied to the steel sheet, and the coating amount is preferably in the range of 0.3 to 6.0 g / m ² in terms of dry film weight, 0.5 to 4.0 g. / M ² is more preferable. When the film is thinned, the corrosion resistance, black discoloration resistance and lubricity are lowered. When the film is thickened, the corrosion resistance is improved but the press workability is lowered, and the cost is increased.

Further, it if you want to grant a proper weld metal surface treatment composition of the present invention in the steel sheet coated to a dry coating weight of 1.5 g / ^{m 2} or less, particularly about 0.3 to 1.0 g / ^{m 2} Is desirable. When the coating amount is large, dust is likely to be generated during spot welding, and the welding strength is insufficient.

  In forming the film by applying the composition of the present invention to a steel sheet, the viscosity of the composition is appropriately adjusted to about 5 to 30 centipoise depending on the coating amount with a diluent such as water, and then roll coater coating, spray coating, dipping It is preferable to dry for 5 to 60 seconds within a range of 50 to 180 ° C. within the maximum temperature (PMT) of the steel sheet after coating so as to have a predetermined film weight by a generally known method such as coating. By coating and drying the coating composition in this manner, a steel sheet having excellent corrosion resistance, press workability, etc. is produced.

  Hereinafter, the present invention will be described in more detail with reference to examples. “Part” and “%” indicate “part by weight” and “% by weight” unless otherwise specified.

Synthesis Example 1 (Synthesis of aqueous polyurethane resin dispersion III-1)
Preparation of epoxy prepolymer (I-1) A four-necked flask equipped with a thermometer, a stirrer, and a reflux condenser was replaced with nitrogen, and bisphenol A type epoxy resin (manufactured by Japan Epoxy Resin Co., Ltd .: jER-1001, Epoxy equivalent 450 g / eq) (180 g) was dissolved in propylene glycol monopropyl ether (49.6 g), and 2-aminoethanol (18.3 g) was added thereto, and the mixture was held at 85 ° C. for 3 hours. The reaction was continued until the amino group content (Note 1) reached about 1.50 to 1.55 mmol / g. Thereafter, methyl ethyl ketone (148.7 g) was added to obtain an epoxy prepolymer (I-1) solution. The resulting epoxy prepolymer (I-1) solution had a solid content concentration of 50.0%, and the number average molecular weight of the prepolymer was 1983.

(Note 1) Epoxy group and amino group content: Followed by the following measurement method.
The sample (g) is weighed in an Erlenmeyer flask, and 40 ml of methyl ethyl ketone is added to dissolve it. If difficult to dissolve, heat to 50 ° C to dissolve. Next, 10 ml of CTAB (cetyltrimethylammonium bromide) solution is added with a total pipette to make it uniform. Subsequently, 0.2 ml of screen indicator is accurately added, titrated with an N / 10 perchloric acid-acetic acid solution, and the end point is reached when pink lasts for about 30 seconds with the last drop. The amino group content is calculated from the following calculated value. The CTAB solution was dissolved by adding 200 ml of acetic acid to 20 g of CTAB, and further adjusted to a uniform solution by adding 200 ml of methyl ethyl ketone. The screen indicator was 1.5 g of thymol blue in a solution of 0.3 g of alphazulin in 100 ml of glacial acetic acid. Was prepared by mixing a solution prepared by dissolving the solution in 500 ml of methanol.
Calculation formula: E = (AB) × 0.1 × F / (S × 0.01 × W)
Where E: epoxy group and amino group content (mmol / g)
A: Amount of N / 10 perchloric acid-acetic acid solution used in this test (ml)
B: Amount of N / 10 perchloric acid-acetic acid solution used in the blank test (ml)
Factor of F: N / 10 perchloric acid-acetic acid solution
S: Sample heating residue (%)
W: Amount of sample (g)

Preparation of urethane prepolymer (II-1) A four-necked flask equipped with a thermometer, a stirrer, and a reflux condenser was replaced with nitrogen, and among them, “Bisol 3PN” (Note 2) (212.3 g), “Bisol 6PN "(Note 3) (305.9 g) and dimethylolpropionic acid (61.1 g) were dissolved in N-methylpyrrolidone (154.2 g), and hexamethylene diisocyanate (191.7 g) was added dropwise over 30 minutes. The reaction was carried out at 60 ° C. for 1.5 hours. Thereafter, the temperature was raised to 80 ° C. and reacted for 2 hours, isophorone diisocyanate (168.7 g) was added, and further reacted at 80 ° C. for 3 hours until the NCO value (Note 4) reached about 25 to 37. Thereafter, methyl ethyl ketone (418 g) was added to obtain a urethane prepolymer (II-1) solution. The resulting urethane prepolymer (II-1) solution had a solid content concentration of 62.2%, a number average molecular weight of the prepolymer of 2473, and an acid value of 27.2 mgKOH / g.

(Note 2) Bisol 3PN: trade name, manufactured by Toho Chemical Co., Ltd., propylene oxide modified bisphenol A (propylene oxide modified amount = 3 mol)
(Note 3) Bisol 6PN: trade name, manufactured by Toho Chemical Co., Ltd., propylene oxide modified bisphenol A (propylene oxide modified amount = 6 mol)
(Note 4) NCO value: The amount of isocyanate group (mg) contained in 1 g of urethane prepolymer, which was tracked by the following measuring method.
Sample (g) is correctly weighed into an Erlenmeyer flask, 10 ml of dioxane is added, the dissolved sample is heated to 50 ° C., 10 ml of N / 5 dibutylamine-dioxane solution that has been correctly weighed is added, and the mixture is stirred for 2 minutes. React butylamine. Next, add 2-3 drops of bromophenol blue-ethyl alcohol solution and titrate with N / 10 hydrochloric acid solution, and the end point is when the color changes from blue to yellow-green.
Formula N = {0.1 × 42 × (AB) × f} / (0.01 × S × W)
Here, N: NCO value (mg of NCO contained in 1 g of sample)
A: Used to neutralize blank N / 5 dibutylamine-dioxane solution
Amount of N / 10 hydrochloric acid solution (ml)
B: Amount of N / 10 hydrochloric acid solution used for titration of sample (ml)
f: Factor of N / 10 hydrochloric acid solution
S: Sample heating residue (%)
W: Amount of sample (g)
42: Molecular weight of NCO

Preparation of aqueous polyurethane resin dispersion (III-1) Using a device similar to the above, a 62.2% urethane prepolymer (II-1) solution (1511 g) was kept at 50 ° C. in a stirred state. A 50% epoxy prepolymer (I-1) solution (753.6 g) was added and stirred for 1 hour. It was then cooled to 40 ° C., neutralized with triethylamine (36.8 g), and deionized water (2392.6 g) was added and dispersed. Into this, diethylenetriamine (9.1 g) diluted with deionized water (91.3 g) was added dropwise over 30 minutes and held at 50 ° C. for 2 hours. Thereafter, methyl ethyl ketone was distilled off under reduced pressure at 60 ° C. to obtain an aqueous dispersion (III-1) of polyurethane resin. The solid content concentration of this aqueous dispersion was 35.0%, the acid value of the polyurethane resin was 19.4 mgKOH / g, the amine value was 8.1 mgKOH / g, and the hydroxyl value was 59.1 mgKOH / g.

Synthesis Example 2 (Synthesis of aqueous polyurethane resin dispersion III-2)
Preparation of epoxy prepolymer (I-2) A four-necked flask equipped with a thermometer, a stirrer, and a reflux condenser was replaced with nitrogen, and bisphenol A type epoxy resin (manufactured by Japan Epoxy Resin Co., Ltd .: jER-1004, Epoxy equivalent 875 g / eq) (660 g) was dissolved in propylene glycol monopropyl ether (174.2 g), 2-aminoethanol (36.6 g) was added to this, and the mixture was kept at 85 ° C. for 3 hours, containing amino groups The reaction was continued until the amount (Note 1) reached about 0.860 to 0.865 mmol / g. Thereafter, methyl ethyl ketone (522.5 g) was added to obtain an epoxy prepolymer (I-2) solution. The resulting epoxy prepolymer (I-2) solution had a solid content concentration of 50.0%, and the number average molecular weight of the prepolymer was 3,483.

Preparation of urethane prepolymer (II-2) A four-necked flask equipped with a thermometer, a stirrer, and a reflux condenser was replaced with nitrogen, among which "Bisol 3PN" (Note 2) (508.7 g), "Bisol 6PN "(Note 3) (733.1 g) and dimethylolpropionic acid (194.3 g) were dissolved in N-methylpyrrolidone (388.2 g), and hexamethylene diisocyanate (504.6 g) was added dropwise over 30 minutes. The reaction was carried out at 60 ° C. for 1.5 hours. Thereafter, the temperature was raised to 80 ° C. and the reaction was carried out for 2 hours, isophorone diisocyanate (444.0 g) was added, and the mixture was further reacted at 80 ° C. for 3 hours until the NCO value (Note 4) reached about 25 to 37. Thereafter, methyl ethyl ketone (1100 g) was added to obtain a urethane prepolymer (II-2) solution. The resulting urethane prepolymer (II-2) solution had a solid content concentration of 61.6%, a number average molecular weight of the prepolymer of 2384, and an acid value of 34.1 mgKOH / g.

Preparation of aqueous polyurethane resin dispersion (III-2) Using a device similar to the above, a 61.6% urethane prepolymer (II-2) solution (1200.6 g) was maintained at 50 ° C. in a stirred state. A 50% epoxy prepolymer (I-2) solution (1079.8 g) was added thereto and stirred for 1 hour. It was then cooled to 40 ° C., neutralized with triethylamine (36.3 g), and deionized water (2401.4 g) was added and dispersed. Into this, diethylenetriamine (7.45 g) diluted with deionized water (74.5 g) was added dropwise over 30 minutes and held at 50 ° C. for 2 hours. Thereafter, methyl ethyl ketone was distilled off under reduced pressure at 60 ° C. to obtain an aqueous dispersion (III-2) of polyurethane resin. The solid content concentration of this aqueous dispersion was 35.0%, the acid value of the polyurethane resin was 19.7 mgKOH / g, the amine value was 6.8 mgKOH / g, and the hydroxyl value was 83.7 mgKOH / g.

Synthesis Example 3 (Synthesis of aqueous polyurethane resin dispersion III-3)
Preparation of epoxy prepolymer (I-3) A four-necked flask equipped with a thermometer, a stirrer, and a reflux condenser was replaced with nitrogen, and bisphenol A type epoxy resin (manufactured by Japan Epoxy Resin Co., Ltd .: jER-1007, Epoxy equivalent 1750 g / eq) (696.0 g) was dissolved in propylene glycol monopropyl ether (179.5 g), 2-aminoethanol (22.0 g) was added thereto, and the mixture was maintained at 85 ° C. for 3 hours. The reaction was continued until the group content (Note 1) reached about 0.50 to 0.505 mmol / g. Thereafter, methyl ethyl ketone (538.5 g) was added to obtain an epoxy prepolymer (I-3) solution. The resulting epoxy prepolymer (I-3) solution had a solid content concentration of 50.0%, and the number average molecular weight of the prepolymer was 5983.

Preparation of urethane prepolymer (II-3) A four-necked flask equipped with a thermometer, a stirrer, and a reflux condenser was replaced with nitrogen, among which "Bisol 3PN" (Note 2) (438.9 g), "Bisol 6PN "(Note 3) (632.5 g) and dimethylolpropionic acid (241.2 g) were dissolved in N-methylpyrrolidone (363.4 g), and hexamethylene diisocyanate (504.6 g) was added dropwise over 30 minutes. The reaction was carried out at 60 ° C. for 1.5 hours. Thereafter, the temperature was raised to 80 ° C. and the reaction was carried out for 2 hours, isophorone diisocyanate (444.0 g) was added, and the mixture was further reacted at 80 ° C. for 3 hours until the NCO value (Note 4) reached about 25 to 37. Thereafter, methyl ethyl ketone (1100 g) was added to obtain a urethane prepolymer (II-3) solution. The obtained urethane prepolymer (II-3) solution had a solid content concentration of 60.7%, a number average molecular weight of 2261, and an acid value of 44.7 mgKOH / g.

Preparation of aqueous polyurethane resin dispersion (III-3) Using a device similar to the above, a 60.7% urethane prepolymer (II-3) solution (353.8 g) was maintained at 50 ° C. with stirring, A 50% epoxy prepolymer (I-3) solution (568.4 g) was added to the solution and stirred for 1 hour. It was then cooled to 40 ° C., neutralized with triethylamine (13.8 g), and deionized water (956.7 g) was added and dispersed. Into this, diethylenetriamine (2.28 g) diluted with deionized water (22.8 g) was added dropwise over 30 minutes and held at 50 ° C. for 2 hours. Then, methyl ethyl ketone was distilled off under reduced pressure at 60 ° C. to obtain an aqueous dispersion (III-3) of polyurethane resin. The solid content concentration of this aqueous dispersion was 35.0%, the acid value of the polyurethane resin was 19.2 mgKOH / g, the amine value was 5.3 mgKOH / g, and the hydroxyl value was 135 mgKOH / g.

Synthesis Example 4 (Synthesis of aqueous polyurethane resin dispersion III-4)
Preparation of epoxy prepolymer (I-4) A four-necked flask equipped with a thermometer, a stirrer, and a reflux condenser was replaced with nitrogen. eq) (192 g) was dissolved in propylene glycol monopropyl ether (52.6 g), and 2-aminoethanol (18.3 g) was added thereto, and the mixture was held at 85 ° C. for 3 hours to obtain an amino group content (Note 1). ) Until about 1.50 to 1.55 mmol / g. Thereafter, methyl ethyl ketone (157.8 g) was added to obtain an epoxy prepolymer (I-4) solution. The resulting epoxy prepolymer (I-4) solution had a solid content concentration of 50.0%, and the number average molecular weight of the prepolymer was 2103.

Preparation of urethane prepolymer (II-4) A four-necked flask equipped with a thermometer, a stirrer, and a reflux condenser was replaced with nitrogen, among which "Bisol 3PN" (Note 2) (212.3g), "Bisol 6PN "(Note 3) (305.9 g) and dimethylolpropionic acid (61.1 g) were dissolved in N-methylpyrrolidone (154.2 g), and hexamethylene diisocyanate (191.7 g) was added dropwise over 30 minutes. The reaction was carried out at 60 ° C. for 1.5 hours. Thereafter, the temperature was raised to 80 ° C. and reacted for 2 hours, isophorone diisocyanate (168.7 g) was added, and further reacted at 80 ° C. for 3 hours until the NCO value (Note 4) reached about 25 to 37. Thereafter, methyl ethyl ketone (418 g) was added to obtain a urethane prepolymer (II-4) solution. The resulting urethane prepolymer (II-4) solution had a solid content concentration of 62.2%, a number average molecular weight of the prepolymer of 2473, and an acid value of 27.2 mgKOH / g.

Preparation of aqueous polyurethane resin dispersion (III-4) Using a device similar to the above, a 62.2% urethane prepolymer (II-4) solution (1511 g) was kept at 50 ° C. in a stirred state. A 50% epoxy prepolymer (I-4) solution (799.2 g) was added and stirred for 1 hour. It was then cooled to 40 ° C., neutralized with triethylamine (36.8 g), and deionized water (2396.5 g) was added and dispersed. Into this, diethylenetriamine (9.1 g) diluted with deionized water (91.3 g) was added dropwise over 30 minutes and held at 50 ° C. for 2 hours. Thereafter, methyl ethyl ketone was distilled off under reduced pressure at 60 ° C. to obtain an aqueous dispersion (III-4) of polyurethane resin. The solid content concentration of this aqueous dispersion was 35.0%, the acid value of the polyurethane resin was 19.4 mgKOH / g, the amine value was 8.1 mgKOH / g, and the hydroxyl value was 59.1 mgKOH / g.

Synthesis Example 5 (Synthesis of polyurethane resin aqueous dispersion III-5)
Preparation of epoxy prepolymer (I-5) A four-necked flask equipped with a thermometer, a stirrer, and a reflux condenser was replaced with nitrogen, and bisphenol A type epoxy resin (manufactured by Japan Epoxy Resin Co., Ltd .: jER-1001, Epoxy equivalent 450 g / eq) (180 g) was dissolved in propylene glycol monopropyl ether (82.1 g), 3-aminopropyltriethoxysilane (66.4 g) was added thereto, and the mixture was held at 85 ° C. for 3 hours. The reaction was continued until the amino group content (Note 1) was about 1.21 to 1.22 mmol / g. Thereafter, methyl ethyl ketone (164.3 g) was added to obtain an epoxy prepolymer (I-5) solution. The resulting epoxy prepolymer (I-5) solution had a solid content concentration of 50.0%, and the number average molecular weight of the prepolymer was 2464.

Preparation of urethane prepolymer (II-5) A four-necked flask equipped with a thermometer, a stirrer, and a reflux condenser was replaced with nitrogen, among which “Bisol 3PN” (Note 2) (323.2 g), “Bisol 6PN "(Note 3) (465.8 g) and dimethylolpropionic acid (104.5 g) were dissolved in N-methylpyrrolidone (239.2 g), and hexamethylene diisocyanate (302.8 g) was added dropwise over 30 minutes. The reaction was carried out at 60 ° C. for 1.5 hours. Thereafter, the temperature was raised to 80 ° C. and the reaction was carried out for 2 hours, isophorone diisocyanate (266.4 g) was added, and the mixture was further reacted at 80 ° C. for 3 hours until the NCO value (Note 4) reached about 25 to 37. Thereafter, methyl ethyl ketone (660 g) was added to obtain a urethane prepolymer (II-5) solution. The obtained urethane prepolymer (II-5) solution had a solid content concentration of 61.9%, a number average molecular weight of the prepolymer of 2438, and an acid value of 29.9 mgKOH / g.

Preparation of aqueous polyurethane resin dispersion (III-5) Using a device similar to the above, a 61.9% urethane prepolymer (II-5) solution (236.2 g) was kept at 50 ° C. with stirring. A 50% epoxy prepolymer (I-5) solution (147.9 g) was added thereto, followed by stirring for 1 hour. It was then cooled to 40 ° C., neutralized with triethylamine (6.3 g), and deionized water (408.2 g) was added and dispersed. Into this, diethylenetriamine (1.44 g) diluted with deionized water (14.4 g) was added dropwise over 30 minutes and held at 50 ° C. for 2 hours. Thereafter, methyl ethyl ketone was distilled off under reduced pressure at 60 ° C. to obtain an aqueous dispersion (III-5) of polyurethane resin. The solid content concentration of this aqueous dispersion was 35.0%, the acid value of the polyurethane resin was 19.9 mgKOH / g, the amine value was 7.6 mgKOH / g, and the hydroxyl value was 66.1 mgKOH / g.

Synthesis Example 6 (Synthesis of polyurethane resin aqueous dispersion III-6)
Preparation of epoxy prepolymer (I-6) A four-necked flask equipped with a thermometer, a stirrer, and a reflux condenser was replaced with nitrogen, in which an epoxy equivalent of 450 g / eq of bisphenol A type epoxy resin (126 g), Dissolved in propylene glycol monopropyl ether (54.91 g), “Jephamine M-2070” (trade name, manufactured by Huntsman, compound contained in the structure represented by the general formula (1), R ¹ is a methoxy group After adding a block chain of polyoxyethylene and polyoxypropylene, number average molecular weight of about 2000) (140 g) and reacting at 90 ° C. for 3 hours, 2-aminoethanol (8.55 g) was added at 90 ° C. The reaction was continued for 3 hours until the epoxy group and amino group content (Note 1) reached about 0.762 to 0.767 mmol / g. Thereafter, methyl ethyl ketone (219.6 g) was added to obtain an epoxy prepolymer (I-6) solution. The resulting epoxy prepolymer (I-6) solution had a solid content concentration of 50%, and the number average molecular weight of the prepolymer was 3922.

Preparation of urethane prepolymer (II-6) A four-necked flask equipped with a thermometer, a stirrer, and a reflux condenser was replaced with nitrogen, among which "Bisol 3PN" (Note 2) (49.9), "Bisol 6PN "(Note 3) (71.9 g) and dimethylolpropionic acid (20.1 g) were dissolved in N-methylpyrrolidone (47.3 g), and hexamethylene diisocyanate (50.5 g) was added dropwise over 30 minutes. The reaction was carried out at 60 ° C. for 1.5 hours. Thereafter, the temperature was raised to 80 ° C. and the reaction was carried out for 2 hours. Isophorone diisocyanate (44.4 g) was added, and further reacted at 80 ° C. for 3 hours until the NCO value (Note 4) reached about 34 to 38. Thereafter, methyl ethyl ketone (110.5 g) was added to obtain a urethane prepolymer (II-6) solution. The solid content concentration of the obtained urethane prepolymer (II-6) solution was 60.0%, the number average molecular weight of the prepolymer was 2367, and the acid value of the prepolymer was 35.5 mgKOH / g.

Preparation of aqueous polyurethane resin dispersion (III-6) Using a device similar to the above, a 60.0% urethane prepolymer (II-6) solution (394.5 g) was kept at 50 ° C. with stirring, A 50% epoxy prepolymer (I-6) solution (392.2 g) was added thereto and stirred for 1 hour. The mixture was then cooled to 40 ° C., neutralized with triethylamine (12.1 g), deionized water (1009.9 g) was added and dispersed, and then the temperature was raised to 70 ° C. and held for 1 hour. Thereafter, methyl ethyl ketone was distilled off under reduced pressure at 60 ° C. to obtain an aqueous dispersion (III-6) of a polyurethane resin. The solid content concentration of this aqueous dispersion was 30.0%, the acid value of the polyurethane resin was 19.4 mgKOH / g, and the hydroxyl value was 58.8 mgKOH / g.

Synthesis Example 7 (Synthesis of polyurethane resin aqueous dispersion III-7)
Preparation of aqueous polyurethane resin dispersion (III-7) A four-necked flask equipped with a thermometer, a stirrer, and a reflux condenser was replaced with nitrogen, and UHCARB100 (Note 5) (360 g), dimethylolpropionic acid ( 40.0 g) is dissolved in N-methylpyrrolidone (130.2 g), dicyclohexylmethane-4,4′-diisocyanate (251.5 g) is added, and the mixture is stirred at 85 ° C. for 3 hours. Thereafter, the mixture was cooled to 50 ° C., acetone (170.8 g) was added, neutralized with triethylamine (29.4 g), and deionized water (1296.0 g) was added and dispersed. The ethylenediamine (5.4g) diluted with deionized water (54.0g) was dripped in it over 30 minutes, and it hold | maintained at 40 degreeC for 2 hours. Thereafter, acetone was distilled off under reduced pressure at 50 ° C. to obtain an aqueous dispersion (III-6) of polyurethane resin. The solid content concentration of this aqueous dispersion was 30.0%, and the acid value of the polyurethane resin was 25.8 mgKOH / g.
(Note 5) UHCARB100: trade name, manufactured by Ube Industries, polycarbonate diol, number average molecular weight of about 1000

Synthesis Example 7 (Synthesis of resol type phenol resin)
188 parts of phenol and 324 parts of a 37% aqueous formaldehyde solution were placed in a flask and heated to 50 ° C. to uniformly dissolve the contents. Next, zinc acetate was added and mixed to adjust the pH in the system to 5.0, and then heated to 90 ° C. and reacted for 5 hours. Next, the mixture was cooled to 50 ° C., 32% calcium hydroxide dispersion was slowly added to adjust the pH to 8.5, and the reaction was carried out at 50 ° C. for 4 hours. After completion of the reaction, the pH was adjusted to 4.5 with 20% hydrochloric acid, and then the resin was extracted with a mixed solvent of xylene / n-butanol / cyclohexane = 1/2/1 (weight ratio) to obtain a catalyst, neutralized salt Then, azeotropic dehydration was performed under reduced pressure to obtain a light yellow and transparent resol type phenolic resin solution having a solid content of 60%. The obtained resin (solid content) had a number average molecular weight of about 320 and an average number of methylol groups of 1.3 and an average number of alkoxymethyl groups of 0.2 per benzene nucleus.

Synthesis Example 8 (Synthesis of resol type phenol resin)
100 parts of bisphenol A, 178 parts of 37% formaldehyde aqueous solution and 1 part of sodium hydroxide were charged into a flask, reacted at 60 ° C. for 3 hours, and dehydrated at 50 ° C. for 1 hour under reduced pressure. Then, 100 parts of n-butanol and 3 parts of phosphoric acid were added and reacted at 110 to 120 ° C. for 2 hours. After completion of the reaction, the resulting solution was filtered to remove the sodium phosphate produced, thereby obtaining a resol type phenol resin solution having a solid content of about 50%. The obtained resin (solid content) had a number average molecular weight of 880 and an average number of methylol groups of 0.4 and an average number of alkoxymethyl groups of 1.0 per benzene nucleus.

Examples 1-18, Comparative Examples 1-3
Production of Metal Surface Treatment Composition A metal surface treatment composition shown in Table 1 below was obtained using each polyurethane resin aqueous dispersion obtained above. In addition, the mixing | blending in Table 1 was displayed with the solid content weight ratio in the metal surface treatment composition which is aqueous solution. Each metal surface treatment composition was diluted to 20% solid content with deionized water and subjected to the following test. In addition, the addition method of the hardening | curing agent (F) of Examples 8-10, 12 and 13 is the synthesis | combination of the polyurethane resin before adding deionized water in the synthesis | combination of the aqueous dispersion (III-1) of a polyurethane resin. (F) was mixed and stirred for 5 minutes, followed by adding deionized water.

（注６）スノーテックスＣ：商品名、日産化学社製、コロイダルシリカ、粒子径１０〜２０ｎｍ、ＳｉＯ_２含有量２０％
（注７）シリコーンＫＢＭ−９０３：商品名、信越化学工業社製、γ−アミノプロピルトリメトキシシラン
（注８）ケミパールＷ−７００：商品名、三井化学社製、高密度タイプポリエチレンワックス
（注９）サイメル３０３：商品名、日本サイテックインダストリーズ社製、アルキルエーテル化メラミン樹脂
（注１０）サイメル２５０：商品名、日本サイテックインダストリーズ社製、アルキルエーテル化メラミン樹脂
（注１１）デュラネートＭＦ−Ｋ６０Ｘ：商品名、旭化成ケミカルズ社製、ブロック化ポリイソシアネート化合物
（注１２）エポクロスＷＳ−７００：商品名、日本触媒社製、オキサゾリン基含有アクリルポリマー

(Note 6) Snowtex C: trade name, manufactured by Nissan Chemical Industries, colloidal silica, particle size 10-20 nm, SiO ₂ content 20%
(Note 7) Silicone KBM-903: trade name, manufactured by Shin-Etsu Chemical Co., Ltd., γ-aminopropyltrimethoxysilane (Note 8) Chemipearl W-700: trade name, manufactured by Mitsui Chemicals, high density type polyethylene wax (Note 9) ) Cymel 303: trade name, manufactured by Nippon Cytec Industries, Inc., alkyl etherified melamine resin (Note 10) , Manufactured by Asahi Kasei Chemicals, blocked polyisocyanate compound (Note 12) Epocros WS-700: trade name, manufactured by Nippon Shokubai Co., Ltd., oxazoline group-containing acrylic polymer

Preparation of test plate and evaluation of coating film performance Each of the metal surface treatment compositions of Examples 1 to 18 and Comparative Examples 1 to 3 obtained in Table 1 was electrogalvanized steel sheet (trade name: gin coat, plate thickness) of 70 mm × 150 mm. 0.6 mm, plating coverage 20 g / m ² ) Using a bar coater, the coating weight is 1.2 g / m ² and dried under the conditions shown in Table 1 to prepare each test plate. did. Each of the obtained test plates was subjected to the following various performance tests. The obtained results are shown in Table 1.

Test method Moisture resistance: After leaving the test plate at a temperature of 40 ° C. in a 95% humidity environment for 120 hours, a test before and after the test using a color difference meter “SM color computer MODEL SM-5” (manufactured by Suga Test Instruments Co., Ltd.) The color difference (ΔE) of the plate was measured and evaluated according to the following criteria.
◎: ΔE is less than 2 ○: ΔE is 2 or more and less than 5 Δ: ΔE is 5 or more and less than 10 ×: ΔE is 10 or more

Alkali resistance: before and after testing using a color difference meter “SM color computer MODEL SM-5” (manufactured by Suga Test Instruments Co., Ltd.) The color difference (ΔE) of the test plate was measured and evaluated according to the following criteria.
◎: ΔE is less than 2 ○: ΔE is 2 or more and less than 5 Δ: ΔE is 5 or more and less than 10 ×: ΔE is 10 or more

Corrosion resistance: After the back surface and cut portion of the test plate were sealed with a rust preventive paint, a salt spray test was performed according to JIS Z-2371. The test time is 120 hours for the untreated (i) test plate, and 72 hours for the test plate after the alkali treatment (ii) and the test plate after 4T bending (iii).
The treatments and processing methods (i) to (iii) are as follows.
(I) No treatment: The test plate was subjected to the test without undergoing the following treatment, processing, etc. (ii) Alkali treatment: The test plate was immersed in a 5% aqueous sodium hydroxide solution at 35 ° C. for 2 minutes and then washed with water. Dry (iii) 4T folding: Bending with the test plate surface facing outside, sandwiching four plates of the same thickness as the test plate inside, and bending the test plate 180 degrees in a vise The degree of occurrence of white rust was evaluated according to the following criteria. In addition, about the test plate after 4T bending process, the process part was evaluated.
◎: Generation of white rust and blistering is less than 5% of coating area ○: Generation of white rust and blistering is 5% to less than 10% of coating film area △: Generation of white rust and blistering Is 10% or more of the paint film area and less than 30% x: generation of white rust, blistering, etc. is 30% or more

Adhesiveness of top coat film: Magcron # 1000 (trade name, manufactured by Kansai Paint Co., Ltd.) which is a thermosetting acrylic paint on a test plate on which a coating film of each metal surface treatment composition is formed has a cured film thickness of 25 μm. Then, it was baked at 150 ° C. for 20 minutes to prepare a top coat plate. The prepared top coat plate was immersed in boiling water for 2 hours, and then the swelling of the flat portion and the extent of the peeled area were visually evaluated according to the following criteria.
A: No blistering and peeling area less than 3% B: Little blistering and peeling area less than 3% Or no blistering and peeling area of 3% or more and less than 10% Δ: Blowing slightly and peeling area is 3 % Or more and less than 10% x: Many blisters or peeling area is 10% or more

Claims (8)

(A) An active hydrogen group is contained in one molecule containing an epoxy prepolymer (I) having an amino group obtained by a reaction between a polyepoxy compound (a) and an amine compound (b) and a carboxyl group-containing diol (c). An aqueous dispersion of a polyurethane resin obtained by a reaction with a urethane prepolymer (II) having an isocyanate group at a terminal obtained by a reaction between a compound (d) containing two or more and a polyisocyanate compound (e);
(B) silica particles, and (C) at least one compound selected from metal hydrofluoric acid, metal hydrofluorate, vanadium compound, molybdenum compound, and tungsten compound,
A metal surface treatment composition comprising: The metal surface treatment composition according to claim 1, wherein the amine compound (b) contains an alkanolamine. The metal surface treatment composition according to claim 1 or 2, wherein the compound (d) contains a bisphenol skeleton-containing diol compound (f) as at least a part of its components. The polyurethane resin has an acid value of 10 to 100 mgKOH / g and an amine value of 0 to 50 mgK.
It is OH / g and the hydroxyl value of 20-200 mgKOH / g, The metal surface treatment composition of any one of Claims 1-3. The metal surface treatment composition of any one of Claims 1-4 containing a silane coupling agent (D). The metal surface treatment composition according to any one of claims 1 to 5, comprising a lubricating function imparting agent (E). The metal surface treatment composition according to any one of claims 1 to 6, comprising a curing agent (F). A metal plate formed by coating a steel sheet with the metal surface treatment composition according to any one of claims 1 to 7 in a dry film weight of 0.3 to 6.0 g / m ² .