JP2006321911A - Aqueous resin composition for metal surface treating agent - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an aqueous resin composition for metal surface treating agents, using together with neither chromium-based compound nor various antirust pigment but excellent in corrosion resistance. <P>SOLUTION: The aqueous resin composition for metal surface treating agents comprises a carboxy-containing aqueous urethane resin (I) and an aqueous vinyl modified epoxy ester resin (II), wherein, preferably, the carboxy-containing aqueous urethane resin (I) is a polyesterurethane resin obtained from a polyester polyol (A) composed of acid components comprising an aromatic dicarboxylic acid and an aliphatic dicarboxylic acid and having ≥50 wt.% aromatic dicarboxylic acid content based on the acid components, an isocyanate compound (B) and a chain extender (C) containing a glycol component (A-3) having carboxy in a molecule. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention particularly relates to an aqueous resin composition for a metal surface treatment agent that is excellent in corrosion resistance of a film having a film thickness.

  Conventionally, various types of water-based resins have been used as vehicles for metal surface treatment agents, but they have been put to practical use in combination with chromium-based compounds or various anti-rust pigments. In many cases, the mixing stability is a problem.

  In addition, an emulsion-type baking type rust preventive mainly composed of a polymer having a coating film forming ability, which is at least one selected from the group of water-based urethane resins and water-based epoxy ester resins, has been proposed (for example, However, in the present invention, an aqueous urethane resin and an aqueous vinyl-modified epoxy ester resin are essential components, and in Patent Document 1, other components used in combination have a large particle size, metal This is inconvenient for the coating amount (film thickness) as a surface treatment agent.

JP 2000-160064 A

  The problem to be solved by the present invention is to provide an aqueous resin composition for a metal surface treatment agent that is excellent in corrosion resistance without the use of a chromium-based compound or various antirust pigments.

  As a result of intensive studies on the above problems, the present inventors have found that an aqueous resin composition for a metal surface treatment agent comprising an aqueous urethane resin (I) and an aqueous vinyl-modified epoxy ester resin (II) as essential components has excellent corrosion resistance. The present invention has been completed. Further, a metal surface treatment comprising a resin composition comprising water-based urethane resin (I) and water-based vinyl-modified epoxy ester resin (II) as essential components, a metal dryer, a compound containing a hydrolyzable silyl group or silanol group. It has been found that the aqueous resin composition for an agent is excellent in corrosion resistance.

  That is, the present invention provides an aqueous resin composition for a metal surface treatment agent, which contains a carboxyl group-containing aqueous urethane resin (I) and an aqueous vinyl-modified epoxy ester resin (II).

  According to the aqueous resin composition for a metal surface treatment agent of the present invention, an aqueous resin composition for a metal surface treatment agent having excellent corrosion resistance can be obtained without using various rust preventive pigments in combination.

  The carboxyl group-containing aqueous urethane resin (I) used in the present invention is a polyester urethane resin obtained from a polyester polyol as an active hydrogen-containing compound, a chain extender such as a glycol component, and a polyisocyanate compound. An aqueous polyester polyurethane resin composition, wherein a carboxyl group is neutralized with ammonia or an organic amine and dispersed or dissolved in an aqueous medium.

  The carboxyl group-containing aqueous urethane resin (I) used in the present invention comprises a polyester polyol (A) composed of an acid component (A-1) and a glycol component (A-2) not containing a carboxyl group, a polyisocyanate compound ( It is a resin obtained from B) and a chain extender (C) containing a glycol component (A-3) having a carboxyl group in the molecule.

  The acid component (A-1) preferably contains an aromatic dicarboxylic acid, and an aliphatic dicarboxylic acid may be used in combination, but 50% by weight of the total amount of the acid component (A-1) is aromatic. It is preferably a group dicarboxylic acid. The aliphatic dicarboxylic acid includes both a linear aliphatic dicarboxylic acid and a cyclic aliphatic dicarboxylic acid, and is hereinafter referred to as an aliphatic (cyclic) dicarboxylic acid.

  The carboxyl group-containing aqueous urethane resin (I) preferably contains a carboxyl group having an acid value of 5 to 60 mgKOH / g, and part or all of the carboxyl group is neutralized with a base. From the viewpoint of being dispersed or dissolved in an aqueous medium.

  In the polyester polyol (A) used in the present invention, 50% by weight of the total amount of the acid component (A-1) is aromatic in order to impart excellent adhesion and water resistance to the high molecular weight product obtained thereby. A dicarboxylic acid is preferred. It is essential that the aromatic dicarboxylic acid in the acid component (A-1) is contained in an amount of 50% by weight or more because the water resistance of the film is not significantly lowered. In this range, the flexibility and adhesion of the coating tend to be improved by reducing the aromatic dicarboxylic acid.

  As the method for producing the carboxyl group-containing aqueous urethane resin (I), a product obtained by forcibly dispersing a polyurethane resin in an aqueous medium with an external emulsifier is not preferable because it contains an emulsifier. It can be produced by various methods in the absence of an emulsifier. For example, a polyester polyol (A) is optionally added to a chain extender (C) in an organic solvent inert to the isocyanate and hydrophilic. In addition, it is produced by reacting with the polyisocyanate compound (B) and urethanizing, and then neutralizing with ammonia or an organic amine to form an aqueous solution (solvent is removed under reduced pressure if necessary). In addition, in the reaction with the polyisocyanate compound (B), an isocyanate-terminated prepolymer is obtained by making the equivalent of the isocyanate group excessive with respect to the active hydrogen atom, and at the same time the chain is extended in water. It can also be obtained by adding aqueous solution. However, the term “water-based” as used herein means that the resin is stably dissolved or dispersed in water.

In order to prevent gelation in the urethanization reaction, reaction terminators such as alcohols such as methanol, ethanol and isopropyl alcohol; glycols such as ethylene glycol and 1,3-butanediol can also be used.
Therefore, the use ratio of the active hydrogen-containing compound and the polyisocyanate compound (B) in the aqueous urethane resin (I) is not limited.

  Examples of the aromatic dicarboxylic acid as the acid component (A-1) used in the present invention include terephthalic acid, isophthalic acid, phthalic acid, 1,4-naphthalenedicarboxylic acid, 2,5-naphthalenedicarboxylic acid, 2,6- Aromatic dicarboxylic acids such as naphthalenedicarboxylic acid, naphthalic acid, biphenyldicarboxylic acid, 1,2-bis (phenoxy) ethane-P, P′-dicarboxylic acid and their anhydrides or ester-forming derivatives, p-hydroxybenzoic acid And aromatic hydroxycarboxylic acids such as p- (2-hydroxyethoxy) benzoic acid and ester-forming derivatives thereof.

  Examples of the aliphatic (cyclic) dicarboxylic acid include succinic acid, adipic acid, azelaic acid, sebacic acid, maleic anhydride, fumaric acid and other aliphatic dicarboxylic acids, 1,3-diclopentane dicarboxylic acid, 1,4- Aliphatic dicarboxylic acids such as dichlorohexanedicarboxylic acid and their anhydrides or ester-forming derivatives.

  The glycol component (A-2) not containing a carboxyl group used in the present invention is a compound having two hydroxyl groups, such as ethylene glycol, propylene glycol, 1,3-propanediol, 1,4-butanediol, , 5-pentanediol, 1,6-hexanediol, neopentyl glycol, diethylene glycol, triethylene glycol, polyethylene glycol, dipropylene glycol and other aliphatic diols; 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, etc. Alicyclic diol, bisphenol A, hydroquinone, and their alkylene oxide adducts.

  In this invention, you may use together the glycol component (A-3) which has a carboxyl group in a molecule | numerator. Examples of these include glycols having a carboxyl group in the molecule such as 2,2-dimethylolpropionic acid, 2,2-dimethylolbutyric acid, 2,2-dimethylolvaleric acid, and the like.

  Use of a polyfunctional component is not hindered as long as the water dispersibility of the obtained polyester polyurethane resin and the adhesion of the polyester polyurethane resin composition are not impaired. Such polyfunctional components include polycarboxylic acids such as trimellitic acid, pyromellitic acid, dichlorohexanetricarboxylic acid, and anhydrides or ester-forming derivatives thereof, polyols such as glycerin, trimethylolethane, trimethylolpropane, and pentaerythritol. Is mentioned.

  The average molecular weight of the polyester polyol (A) used in the present invention is preferably 800 to 4000. If the molecular weight is 800 or more, the isocyanate content in the polyester polyurethane obtained from the polyester polyol does not become excessive. Further, the flexibility of the coating of the polyester polyurethane resin composition does not decrease and become brittle, and the adhesion and adhesion to various adherends are not significantly decreased. If the molecular weight is 4000 or less, the resulting aqueous polyester polyurethane resin has good solubility and stability over time, and more preferably 1000 to 3000.

  The polyisocyanate compound (B) used in the present invention includes 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, m-phenylene diisocyanate, p-phenylene diisocyanate, 4,4′-. Diphenylmethane diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate, xylylene diisocyanate, lysine diisocyanate, isophorone diisocyanate, trimethylhexamethylene diisocyanate, 1,4-cyclohexylene diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, 3,3'- Dimethyl-4,4′-biphenylene diisocyanate, 3,3′-dimethoxy-4,4′-biphenylene diisocyanate, 3,3′-dichloro-4,4 ′ Biff Eni diisocyanate, 1,5-naphthalene diisocyanate, 1,5-tetrahydronaphthalene diisocyanate.

  Examples of the chain extender (C) used in the present invention include a glycol component (A-2) that does not include the compound having a carboxyl group, a glycol component (A-3) that has a carboxyl group in the molecule, or ethylenediamine. Diamines such as propylene diamine, hexamethylene diamine, phenylene diamine, tolylene diamine, diphenyl diamine, diamino diphenyl methane, diamino siloxyhexyl methane, piperazine, isophorone diamine and the like, hydrazine, water and the like.

  The aqueous urethane resin (I) to be obtained is preferably reacted with such an amount that the carboxyl group content falls within the range of 5 to 60 mgKOH / g as the acid value. If the acid value is 5 or more, the water resistance of the aqueous urethane resin film is remarkably improved without lowering the stability of the resin itself, which is preferable. Moreover, if an acid value is 60 or less, it is preferable from the adhesiveness to various to-be-adhered bodies improving, without reducing the water resistance of a film | membrane, especially the adhesive strength at the time of water immersion.

  The molecular weight of the aqueous urethane resin (I) thus obtained is preferably 8,000 to 100,000. Most preferably, it is 10,000-50,000.

  Examples of the base for neutralizing the carboxyl group used in the present invention include sodium hydroxide, potassium hydroxide, lithium hydroxide, ammonia, trimethylamine, triethylamine, triisopropylamine, tribitylamine, triethanolamine, methyldiethanolamine, dimethylethanolamine, Examples include organic amines such as diethylethanolamine, but in order to improve the water resistance of the dried film, highly volatile compounds that are easily dissociated by heat are preferred, especially ammonia, trimethylamine, triethylamine, dimethylethanolamine, etc. Is preferred.

  Examples of the organic solvent that is inert and hydrophilic to the isocyanate used in the present invention include ethers such as tetrahydrofuran and dioxane, esters such as ethyl acetate, ketones such as acetone, methyl ethyl ketone, and cyclohexanone, dimethyl Examples thereof include amides such as formamide and N-methylpyrrolidone. Since the polyester polyurethane is usually removed by distillation under reduced pressure, it is preferable to use a solvent having a boiling point lower than that of water.

  The aqueous vinyl-modified epoxy ester resin (II) used in the present invention is obtained by esterifying an epoxy resin, an unsaturated fatty acid, an unsaturated dibasic acid and / or a polyhydric alcohol as necessary, and then an ethylenically unsaturated monomer. The product is obtained by graft polymerization, and some or all of the contained carboxyl groups are neutralized with a base and dissolved or dispersed in an aqueous medium.

As a method for producing the aqueous vinyl-modified epoxy ester resin (II) used in the present invention, esterification of an epoxy resin, an unsaturated fatty acid, and optionally an unsaturated dibasic acid and / or a polyhydric alcohol is usually performed. The process is carried out, for example, by heating at 180-220 ° C. for 8-14 hours in the presence of an inert gas. The acid value of the epoxy ester resin is defined by the solid content acid value of the aqueous vinyl-modified epoxy ester resin (II) described later.
The method of graft polymerization of an ethylenically unsaturated monomer to the obtained epoxy ester resin involves diluting the epoxy ester resin in a water-soluble organic solvent, and then performing graft polymerization using a polymerization initiator by a usual method. Just do it. The polymerization reaction may be carried out, for example, at 60 to 140 ° C. under an inert gas by dropping ethylenically unsaturated monomers or charging them all at once. The vinyl-modified epoxy ester resin thus obtained is neutralized with the above base, and water is added if necessary to obtain the aqueous vinyl-modified epoxy ester resin (II) used in the present invention.

  Examples of the neutralizing agent that can be used in the production of the aqueous vinyl-modified epoxy ester resin (II) used in the present invention include bases used in the production of the aqueous urethane resin (I). Is preferably after graft polymerization.

  The use ratio of the epoxy ester resin and the ethylenically unsaturated monomer of the aqueous vinyl-modified epoxy ester resin (II) is preferably 95/5 to 50/50 in solid content ratio.

  Further, the solid content acid value of the aqueous vinyl-modified epoxy ester resin (II) is preferably 10 to 60 mgKOH / g.

  Examples of the epoxy resin used in the present invention include aromatic epoxy resins such as bisphenol A type epoxy resins, bisphenol F type epoxy resins, novolac type epoxy resins, and aliphatic ether type epoxy resins such as polyethylene glycol diglycidyl ether and polypropylene glycol. Diglycidyl ether; ester-based epoxy resins such as diglycidyl phthalate. Examples of commercially available products include “Epicoat 828”, “Epicoat 1001”, “Epicoat 1004”, “Epicoat 1007”, “Epicoat 1009”, “Epicoat 1010”, “Epicoat 4004P”, and “Epicoat 4007P” manufactured by Shell Chemical Co., Ltd. ”,“ Epicoat 4010P ”,“ Epicoat 152 ”,“ Epicoat 154 ”,“ EPICLON 850 ”,“ EPICLON 1055 ”,“ EPICLON 3050 ”,“ EPICLON 7050 ”,“ EPICLON 830 ”,“ EPICLON-670 ”, manufactured by Dainippon Ink & Chemicals, Inc. "EPICLON-N-775" etc. are mentioned. Of these, aromatic epoxy resins are preferred. The usage-amount of an epoxy resin is a factor which controls the corrosion resistance of the metal surface treating agent of this invention, and 30 weight% or more of epoxy ester resin solid content is preferable.

Examples of unsaturated fatty acids include fatty acids obtained from drying oils such as paulownia oil, soybean oil, linseed oil, dehydrated castor oil, and safflower oil, and versatic acids obtained by synthesis. As the usage-amount of unsaturated fatty acid, 20 weight% or more of epoxy ester resin solid content is preferable.
Examples of the unsaturated dibasic acid include (anhydrous) maleic acid, fumaric acid, itaconic acid and the like.

  Examples of the polyhydric alcohol include glycol component (A-2) not containing the above-mentioned compound having a carboxyl group, glycerin, trimethylolethane, trimethylolpropane, pentaerythritol and the like. Furthermore, polycarboxylic acids such as trimellitic acid, pyromellitic acid, dichlorohexanetricarboxylic acid, and anhydrides thereof can be used as the acid component.

Examples of the water-soluble organic solvent include methanol, ethanol, n-propanol,
Isopropanol, n-butanol, sec-butanol, tert-butanol, isobutanol, methyl cellosolve, ethyl cellosolve, propyl cellosolve, butyl cellosolve, ethyl carbitol, butyl carbitol, methyl cellosolve acetate, ethyl cellosolve acetate, other dioxane, dimethylformamide, Examples include diacetone alcohol and N-methylpyrrolidone. These may be used alone or in combination of two or more, and water and the organic solvent may be used in combination as necessary.

Examples of the ethylenically unsaturated monomer include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, pentyl (meth) acrylate, and (meth) acrylic. (Meth) acrylic acid ester exemplified by hexyl acid, heptyl (meth) acrylate, octyl (meth) acrylate, octadecyl (meth) acrylate, etc., styrene, α-methylstyrene, vinyltoluene, chlorostyrene, 2, Ethylenically unsaturated aromatic monomers exemplified by 4-dibromostyrene, unsaturated nitriles such as (meth) acrylonitrile, (meth) acrylic acid, crotonic acid, maleic acid and anhydrides thereof, fumaric acid, itacon Ethylenically unsaturated carboxylic acids such as acids, as well as unsaturated dicarboxylic acid monoalkyl esters such as maleic Vinyl esters such as monomethyl acid, monoethyl fumarate, mono-n-butyl itaconate, vinyl acetate, vinyl propionate, vinylidene halides such as vinylidene chloride, vinylidene bromide, 2-hydroxyethyl acrylate, acrylic acid-2 -Hydroxyalkyl esters of ethylenically unsaturated carboxylic acids such as hydroxypropyl, 2-hydroxyethyl methacrylate, glycidyl esters of ethylenically unsaturated carboxylic acids such as glycidyl (meth) acrylate and (meth) acrylamide, N Examples include radically polymerizable compounds such as methylol (meth) acrylamide, N-butoxymethyl acrylamide, and diacetnan acrylamide.

  Examples of the polymerization initiator include diacyl peroxides such as benzoyl peroxide, lauroyl peroxide, decanoyl peroxide, dialkyl peroxides such as t-butylcumyl peroxide, dicumyl peroxide, and t-butylperoxy. Peroxyesters such as laurate, t-butylperoxybenzoate, hydroperoxides such as cumene hydroperoxide, paramentane hydroperoxide, t-butyl hydroperoxide, azobises such as azobisisobutyronitrile And a mixture of one or more of these can be used.

  The use ratio of the water-based urethane resin (I) and the water-based vinyl-modified epoxy ester resin (II) is (I) / (II) = 30/70 to 90/10, preferably 40/60 to 90/10, as a solid content ratio. It is.

  As the metal dryer of the present invention, salts of naphthenic acid such as manganese, cobalt, zirconium, nickel, iron, and lead, octylic acid, etc. can be used, and zirconium octylate, manganese naphthenate, cobalt octylate alone, or the like Mixtures are preferred. The amount used varies depending on the amount used of the aqueous vinyl-modified epoxy ester resin (II) and the type of metal dryer used. For example, the solid content of the aqueous urethane resin (I) and the aqueous vinyl-modified epoxy ester resin (II) From 0.1 to 5 parts by weight of solid content can be used with respect to a total amount of 100 parts by weight. More preferably, it is 0.2 to 3 parts by weight. In addition, for the metal surface treatment agent of the present invention, it is preferable to use an aqueous metal dryer, for example, Dicknate 3111, Dicknate 1000W (both manufactured by Dainippon Ink & Chemicals, Inc.) and the like.

  As the amount of the hydrolyzable silyl group or silanol group-containing compound (B) used in the present invention, from the viewpoint of curability, performance after curing, and storage stability, aqueous urethane resin (I) and aqueous vinyl modified It is preferable to use in the range of 0.1 to 10 parts by weight with respect to 100 parts by weight of the total solid content of the epoxy ester resin (II). More preferably, it is 0.3 to 5 parts by weight. The compound (B) containing a silanol group and / or hydrolyzable silyl group used in the present invention includes a polyfunctional silane compound, a silane coupling agent, a hydrolyzable silyl group or a silanol group-containing ethylenic heavy compound. Typical examples include coalescence and silicone resin.

The hydrolyzable silyl group used in the present invention is, for example, an atomic group containing a silicon atom to which an alkoxy group, a substituted alkoxy group, a phenoxy group, a halogen atom, an isopropenyloxy group, an acyloxy group, iminooxy, or the like is bonded, A compound that is easily hydrolyzed to generate a silanol group, and examples of the hydrolyzable silyl group or the compound containing a silanol group include polyfunctional silane compounds, methyltrimethoxysilane, phenyltrimethoxysilane, Various trifunctional silane compounds such as methyltriethoxysilane, phenyltriethoxysilane or isobutyltrimethoxysilane; dimethyldimethoxysilane, dimethyldiethoxysilane, diethyldimethoxysilane, diethyldiethoxysilane or diphenyldimethoxysilane Various bifunctional silane compounds; various halosilanes such as methyltrichlorosilane, phenyltrichlorosilane, ethyltrichlorosilane, dimethyldichlorosilane or diphenyldichlorosilane; or various bifunctional or 3 as described above Examples thereof include low-molecular weight silanol compounds which can be obtained by almost completely hydrolyzing a functional silane compound. As the coupling agent, a silane coupling agent having an organic functional group and a hydrolyzable group in one molecule, that is, as the organic functional group, a hydrolyzable group such as a vinyl group, a (meth) acryl group, an epoxy group, a mercapto group, etc. Examples thereof include silane coupling agents having a methoxy group, an ethoxy group, an isopropoxy group, and the like. Furthermore, as the compound (B) having a silanol group and / or hydrolyzable silyl group used in the present invention, an epoxy group and a compound having a hydrolyzable silyl group and / or a silanol group are particularly preferred. Ring agent, for example, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, or γ-glycidoxypropyltriisopropenyl Examples include oxysilane.
Various additives can be added to the aqueous resin composition for a metal surface treatment agent of the present invention as necessary.

Examples of the additive that can be added to the aqueous resin composition for a metal surface treatment agent of the present invention include, for example, inorganic pigments, organic pigments, colorants and fillers such as dyes, rust preventives, dispersants, and antioxidants. , Reducing agents, ultraviolet absorbers, thickeners, surfactants, antifoaming agents, bactericides, preservatives, crosslinking agents, antiblocking agents, water / oil repellents, organic solvents, etc. The selection, addition amount, order of addition, etc. of the agent may be appropriately determined in consideration of the manufacturing conditions, workability, stability, processing suitability, coating amount, etc. of the steel sheet treating agent.
Examples of inorganic pigments include aluminum hydroxide, magnesium hydroxide, magnesium carbonate, barium sulfate, light / heavy calcium carbonate, light calcium carbonate, talc, clay, silica, carbon black, graphite, titanium oxide, sepiolite, halogenated Examples thereof include silver (Cl, Br, I), ultramarine blue, cobalt blue, metal complex, and the like. Other inorganic additives may be added, and these may be used in combination.

  Examples of organic pigments include phthalocyanine pigments, triarylcarbonyl pigments, indigo, indanthrone pigments, organic silver salts, and other organic metal salts. Other inorganic additives may be added, and these may be used in combination. May be. Examples of the dye include anthraquinone dyes, azomethine dyes, indoaniline dyes, and azo dyes.

  Antirust agents include various metal salts, organometallic compounds, fine-particle silica, calcium ion-exchangeable amorphous silica such as Shieldex manufactured by Fuji Silysia Chemical Co., Ltd., zinc phosphate, surface treated with metal compounds In addition to phosphates such as aluminum tripolyphosphate, metal phosphites such as zinc, calcium, magnesium and aluminum, metal molybdates such as zinc, calcium, magnesium and aluminum, triazoles as organic compounds, Examples include thiols, thiazoles, thiadiazoles, thiurams, and the like.

  Examples of the dispersant include sodium hexametaphosphate, sodium tripolyphosphate, sodium pyrophosphate, potassium pyrophosphate, polycarboxylic acid, sodium bisnaphthalene sulfonate, polyacrylic acid, acrylic acid copolymer, and maleic acid copolymer. Polymer, maleic acid monoester copolymer, acryloylpropane sulfonic acid copolymer, alginic acid, pectic acid, methylcellulose, carboxymethylcellulose, hydroxyethylcellulose, hydroxyethylmethylcellulose, carboxymethyl starch, etc. good.

Examples of the antioxidant include phenol-based, amine-based, hindered phenol-based, hindered amine-based, sulfur-based, phosphorus-based, and acrylate-based, and a plurality of them may be used in combination. Examples of the reducing agent include sodium sulfite, sodium hydrogen sulfite, ferrous sulfate, glucose, formaldehyde, L-ascorbic acid, sodium sulfoxylate, O-polyphenol, and bisphenols, and a plurality thereof may be used in combination. Examples of the ultraviolet absorber include amine, hindered amine, benzotriazole, benzophenone, cyanoacrylate, benzoate, oxalinide, formamidine, triazine, carbazide, etc. May be. Examples of the thickener include organic thickeners such as sodium polyacrylate, ammonium polyacrylate, carboxyl methyl cellulose, hydroxyl ethyl cellulose, methyl cellulose, hydroxyl propoxyl methyl cellulose, poval, polyacrylamide, polyethylene oxide, starch, etc. Inorganic thickeners such as bentonite can be mentioned. Of these, any polyacrylic acid, acrylic acid copolymer, maleic acid copolymer, maleic acid monoester copolymer can be used alone or in combination. Polymers, acryloylpropane sulfonic acid copolymers, sodium and ammonium salts such as alginic acid and pectic acid, methylcellulose, carboxymethylcellulose, hydroxyethylcellulose, hydroxyethylmethylcellulose, hydroxy In addition to organic thickeners such as lepropoxylmethylcellulose, carboxymethyl starch, poval, polyacrylamide, polyethylene oxide, and starch, inorganic thickeners such as bentonite are included. Among these, single or multiple types are used in combination. May be. Examples of the surfactant include nonionic surfactants such as alkyl allyl ethers, alkyl ethers, alkyl esters, alkyl amines, sorbitan derivatives, fatty acid salts, higher alcohol sulfates, aliphatic amines / aliphatics. Amide sulfates, fatty alcohol phosphates, dibasic fatty acid ester sulfonates, alkyl allyl sulfonates, formalin condensed naphthalene sulfonates, and other anionic active agents, cationic active agents, betaine, alanine, imidazoline Amphoteric activators and the like, and a combination of anions and cations, or a plurality of them may be used in combination. Examples of the antifoaming agent include silicone, mineral oil, alcohol, and ethylene oxide-propylene oxide. Examples of preservatives and fungicides include phenolic, organotin, quaternary ammonium, dithiocarbamate, thiadiazine, triazine, iodopropazyl, N-halomethylthio, thiazoline, and imidazole. Can be mentioned. Examples of the anti-blocking agent and water / oil repellent include carnauba wax, silicon wax, fluorine wax, rosin wax, polyethylene wax, paraffin wax, stearyl stearate, ammonium stearate, zinc stearate, fluorine And system active agents.
Examples of the cross-linking agent include melamine resin, urea resin, phenol resin, block isocyanate, and epoxy.

  Examples of organic solvents include film forming aids such as alkylene glycol derivatives or dialkyl esters of aliphatic dicarboxylic acids for the purpose of improving film forming properties, and various emulsions, dispersions, water-soluble resins and the like as required, such as acrylic resins. Emulsion, acrylic styrene resin emulsion, styrene resin emulsion, synthetic rubber latex, urethane resin emulsion, polyester resin emulsion, epoxy resin emulsion, phenol resin emulsion, fluororesin emulsion, vinyl chloride resin emulsion, vinylidene chloride resin emulsion, hybrid resin emulsions of these Water-soluble alkyd resins, water-soluble acrylic resins, water-soluble polyester resins and the like can be added.

The aqueous resin composition for a metal surface treatment agent of the present invention can be used as a metal surface treatment agent such as a surface treatment agent or a primer by appropriately adding the various additives described above. The coating amount at that time is 0.5 to 30 g / m ^{2, and} various coating methods such as roll coater coating, spray coating, curtain coater coating, bar coater coating, die coater coating, brush coating, etc. Is used.

  Hereinafter, the present invention will be described with reference to examples. All parts and% in the examples are based on weight.

  Synthesis example 1

  830 parts of terephthalic acid, 830 parts of isophthalic acid, 562 parts of 1,4-butanediol, 631 parts of diethylene glycol, and 0.5 part of dibutyltin oxide in the presence of an inert gas over 5 hours from 160 ° C to 230 ° C The temperature was raised and the mixture was heated at 230 ° C. for about 8 hours until the acid value became 1 or less to obtain a polyester polyol (A-1) having an acid value of 0.1 and a hydroxyl value of 86.1.

  1300 parts of polyester polyol (A-1) was dehydrated at 120 ° C. under reduced pressure, cooled to 80 ° C. and sufficiently dissolved with 1082 parts of methyl ethyl ketone, 67 parts of 2,2｀-dimethylolpropionic acid was added, 256 parts of diisocyanate was added and reacted at 70 ° C. for 8 hours. After completion of the reaction, the mixture was cooled to 40 ° C., neutralized by adding 57 parts of triethylamine, and then water-solubilized by adding 5350 parts of ion-exchanged water. Furthermore, after removing methyl ethyl ketone from the obtained reaction product at 65 ° C. under reduced pressure, the pH and nonvolatile content were adjusted to obtain an aqueous urethane resin (I-1) having a nonvolatile content of 25% and a pH of 7.1. .

Synthesis example 2
While introducing nitrogen gas in a reactor equipped with a thermometer, nitrogen gas inlet tube, and stirrer, 664 parts of terephthalic acid, 631 parts of isophthalic acid, 472 parts of 1,4-butanediol, 447 parts of neopentyl glycol and dibutyltin After 0.5 parts of oxide was charged and esterified at 180 to 230 ° C. for 5 hours, a polycondensation reaction was performed at 230 ° C. for 6 hours until an acid value <1. Next, the mixture was cooled to 120 ° C., 321 parts of adipic acid and 268 parts of dimethylolpropionic acid were added, the temperature was raised again to 170 ° C. and reacted at this temperature for 20 hours, and a polyester polyol having an acid value of 46.5 and a hydroxyl value of 59.8 ( A-2) was obtained. Polyester polyol A 1880 parts (A-2) was dehydrated at 120 ° C. under reduced pressure, and then cooled to 80 ° C., then 1412 parts of methyl ethyl ketone was added and sufficiently stirred and dissolved, and then 238 parts of 4,4′-diphenylmethane diisocyanate was added and 70 ° C. For 8 hours. After completion of the reaction, the reaction mixture was cooled to 40 ° C. and neutralized by adding 202 parts of 10% aqueous ammonia, and then water-solubilized by adding 6860 parts of ion-exchanged water. After removing methyl ethyl ketone from the obtained reaction product at 65 ° C. under reduced pressure, pH and nonvolatile content were adjusted to obtain an aqueous urethane resin (I-2) having a nonvolatile content of 25% and pH 7.0.
Synthesis example 3

  200 parts of safflower oil fatty acid, Epicote 1001, 200 parts and 5 parts of fumaric acid were heated in the presence of an inert gas at 200 ° C. for 8 hours to obtain an epoxy ester resin having a solid content acid value of 20. 70 parts of butyl cellosolve is added to 100 parts, and 2 parts of benzoyl peroxide, 20 parts of ethyl methacrylate, 23 parts of vinyl toluene and 7 parts of methacrylic acid are added dropwise over 2 hours at 100 ° C. After maintaining the temperature, the mixture was cooled, neutralized with 13 parts of triethylamine, and 69 parts of ion-exchanged water was added to obtain an aqueous vinyl-modified epoxy ester resin (II-1) having a non-volatile content of 50% and a pH of 8.4.

Synthesis example 4
Heat 470 parts linseed oil fatty acid and 50 parts dehydrated castor oil fatty acid to 140 ° C. under inert gas, add Epicoat 1001, 450 parts, and after homogenizing the system and becoming transparent, add 0.5 parts dimethylbenzylamine. In addition, the temperature was raised to 180 ° C. and held for 1 hour, cooled to 120 ° C., 20 parts of phthalic anhydride was added, the temperature was raised to 230 ° C. over 3 hours, and maintained at 230 ° C. until the acid value reached 15. After cooling to 80 ° C., 500 parts of butyl cellosolve and 500 parts of ethyl cellosolve were added to obtain an epoxy ester resin having a nonvolatile content of 50%. 1200 parts of this epoxy ester resin was heated to 130 ° C. under inert gas, and 225 parts of styrene, 53 parts of lauryl methacrylate, 72 parts of methyl methacrylate, 41 parts of acrylic acid and perbutyl Z (t-butyl peroxybenzoate) 25 parts of Nippon Oil & Fats Co., Ltd.) was added dropwise over 3 hours, further maintained at 130 for 6 hours, cooled, neutralized with 48 parts of triethylamine, 31 parts of ion-exchanged water was added, and the non-volatile content was 60%. An aqueous vinyl-modified epoxy ester resin (II-2) having a pH of 8.5 was obtained.

Test Example (1) Test Material A degreased 55% aluminum / zinc-based plated steel sheet (0.5 mm thickness) was used.
(2) Method for producing surface-treated steel sheet The resin compositions produced in Examples and Comparative Examples are diluted as necessary to adjust the coating film amount, and the film amount is 10 g / m ² with a bar coater. Thus, it apply | coated to the test material and baked for 20 second in 250 degreeC oven.
(3) Evaluation of film performance (rust prevention) Salt spraying was performed according to JIS-K-5400, and the rusting state after 240 hours was observed.

◯: Almost no rusting, Δ: Partial rusting, x Remarkably rusting (T-bend workability) When bent 180 °, the minimum number of sandwiched plates where cracks do not occur was measured.
(Adhesiveness) It was performed according to the cross-cut tape method described in 8.2 of JIS-K-5400 (gap spacing 1 mm).
Table 1 shows the test results.

Dicknate 3111; Metal dryer Non-volatile content 30%
SH6040; gamma-glycidoxypropyltrimethoxysilane (Toray Dow Corning Silicone Co., Ltd.)

Claims (7)

An aqueous resin composition for a metal surface treatment agent comprising a carboxyl group-containing aqueous urethane resin (I) and an aqueous vinyl-modified epoxy ester resin (II), wherein the carboxyl group-containing aqueous urethane resin (I) is an acid component ( Polyester polyol (A) and polyisocyanate compound (B) composed of AI) and a glycol component (A-2) containing no carboxyl group in the molecule, and a glycol component having a carboxyl group in the molecule (A- The aqueous resin composition for metal surface treatment agents according to claim 1, which is a polyester urethane resin obtained by reacting the chain extender (C) containing 3). The acid component (A-1) comprises an aromatic dicarboxylic acid and an aliphatic dicarboxylic acid, and the content of the aromatic dicarboxylic acid is 50% by weight or more of the acid component (A-1). The aqueous resin composition for metal surface treating agents as described. The aqueous resin composition for a metal surface treatment agent according to claim 1, wherein the aqueous vinyl-modified epoxy ester resin (II) contains an acid group, and part or all of the acid group is neutralized with a base. The aqueous resin composition for metal surface treatment agents according to claim 1, 2, or 3, wherein the aqueous urethane resin (I) and the aqueous vinyl-modified epoxy ester resin (II) are produced in the absence of an emulsifier. The mixing ratio (I) / (II) of the aqueous urethane resin (I) and the aqueous vinyl-modified epoxy ester resin (II) is 10/90 to 90/10 (solid content ratio). An aqueous resin composition for a metal surface treatment agent according to Item. The aqueous resin composition for a metal surface treatment agent according to any one of claims 1 to 5, comprising a metal dryer. The aqueous resin composition for metal surface treatment agents according to any one of claims 1 to 6, comprising a compound containing a silanol group and / or a hydrolyzable silyl group.