JP2006052295A - Method for producing aqueous resin dispersion - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for stably producing an aqueous resin dispersion by carrying out emulsion polymerization of a polymerizable unsaturated monomer (A) by using a fatty acid-modified polyurethane resin (B) as a polymer emulsifying agent and to provide an aqueous resin composition and a water-based coating composition readily curable even at normal temperature in spite of a one package type and forming a cured film having excellent transparency, gloss and finishing properties (luster and a build feeling) and excellent performances such as water, weather and corrosion resistances and durability. <P>SOLUTION: The method for producing the aqueous resin dispersion comprises carrying out the emulsion polymerization of the polymerizable unsaturated monomer (A) in the presence of water and the emulsifying agent. In the method for producing the aqueous resin dispersion, the fatty acid-modified polyurethane resin (B) prepared by reacting a polyol (b) containing a fatty acid ester (b1) containing ≥2 hydroxy groups in one molecule with a polyisocyanate compound (c) and a carboxyl group-containing diol (d) is used as the emulsifying agent. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a method for producing an aqueous resin dispersion.

  In recent years, in the fields of paints, inks, adhesives, etc., from the viewpoint of resource saving, environmental hygiene, non-pollution, non-hazardous materials, etc., conversion from organic solvent type compositions to aqueous type compositions has been promoted. . For example, examples of the vehicle used in the aqueous coating composition include resins such as alkyd resins, acrylic resins, polyester resins, polyurethane resins, and epoxy resins. In these aqueous coating compositions, the alkyd resin can introduce an oxidative curing group into the resin skeleton by using an unsaturated fatty acid as a raw material, and the aqueous coating composition using the alkyd resin can be cured at one room temperature. In addition, due to its oiliness, anti-corrosion properties can be expected when applied to a metal surface, but its soft nature delays drying of the coating and generally has a weak weather resistance. On the other hand, the acrylic resin is inferior in anticorrosion property although it is excellent in quick drying property and weather resistance. As an aqueous resin material having the characteristics of these two types of resins, many graft resins and the like for bonding alkyd resins and acrylic resins by chemical reaction have been developed and proposed. For example, Patent Documents 1 to 3 disclose that a fatty acid-modified monomer obtained by reacting an unsaturated fatty acid having a non-conjugated double bond with a glycidyl ester of an α, β-ethylenically unsaturated acid and α, β-ethylene. Water-soluble or water-dispersed product of resin by copolymerizing unsaturated monomer such as unsaturated carboxylic acid in organic solvent, neutralizing carboxyl group in the resulting resin with basic substance and diluting with water A method of manufacturing is disclosed. However, the hydrophilic resin produced by this method requires solution of the produced polymer in an organic solvent in order to go through solution polymerization, and it is generally difficult to increase the molecular weight. In order to make a polymer water-soluble or water-dispersed, a large amount of a monomer or emulsifier having a hydrophilic group such as a carboxyl group or a hydroxyl group must be used, and as a result, a polymer is formed. There is a problem that the coating film has insufficient water resistance.

  Patent Document 4 discloses a fatty acid-modified monomer obtained by reacting a dry oil fatty acid or semi-dry oil fatty acid with an α, β-ethylenically unsaturated acid glycidyl ester using a surfactant and / or a polymer protective colloid. It is disclosed that an oxidative polymerization type aqueous emulsion is produced by emulsion polymerization of a monomer mixture containing a radically polymerizable monomer.

  On the other hand, attempts have been made to incorporate oxidatively curable groups derived from unsaturated fatty acids into polyurethane. For example, Patent Documents 5 and 6 propose aqueous polyurethane dispersions for wood. The aqueous polyurethane dispersion described in the publication is a polyurethane that can be oxidatively cured at a low temperature, but by introducing an (unsaturated) fatty acid, plasticization is remarkable and quick-drying is insufficient. There are disadvantages such as insufficient weather resistance.

  Therefore, in order to solve the above-mentioned problems, Patent Document 7 proposes compounding with an acrylic component, but the polyurethane-alkyd resin used in the acrylate-modified polyurethane-alkyd resin described in the publication has a branched structure. Since the skeleton has a wide molecular weight distribution, the low molecular weight component contained causes problems such as softening the coating film, and the high molecular weight portion reduces the finish.

JP 50-126723 A JP-A-56-5863 JP-A-60-212469 JP 59-8773 A JP 2000-226428 A JP 7-166130 A JP 2001-501995 gazette

  An object of the present invention is to provide a method for stably producing an aqueous resin dispersion by emulsion polymerization of a polymerizable unsaturated monomer (A) using a fatty acid-modified polyurethane resin (B) as a polymer emulsifier. Although it is a one-pack type, it can be cured easily at room temperature, and it has excellent transparency, gloss, finish (gloss, feeling of flesh), water resistance, weather resistance, durability, and corrosion resistance. Another object of the present invention is to provide an aqueous resin composition and an aqueous coating composition capable of forming a cured film.

  The present invention relates to a method for producing an aqueous resin dispersion in which a polymerizable unsaturated monomer (A) is emulsion-polymerized in the presence of water and an emulsifier, and the emulsifier contains two or more hydroxyl groups in one molecule. An aqueous solution comprising a fatty acid-modified polyurethane resin (B) obtained by a reaction with a polyol (b) containing a fatty acid ester (b1), a polyisocyanate compound (c), and a carboxyl group-containing diol (d). The present invention relates to a method for producing a resin dispersion, and also relates to an aqueous resin composition comprising the aqueous resin dispersion and an aqueous coating composition comprising the aqueous resin composition.

  According to the present invention, it is possible to obtain a cured film that is not only excellent in water resistance and finish, but also excellent in quick drying and weather resistance.

  As the polymerizable unsaturated monomer (A) used in the present invention, a conventionally known monomer can be used without particular limitation. Usually, at least one, preferably one polymerizable unsaturated group in the molecule, for example, Compounds containing vinyl groups, (meth) acryloyl groups and the like are included.

Specific examples of the polymerizable unsaturated monomer (A) include, for example, methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, i-propyl (meth) acrylate, n-butyl (meth) ) Acrylate, i-butyl (meth) acrylate, tert-butyl (meth) acrylate, n-hexyl (meth) acrylate, octyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, nonyl (meth) acrylate, tridecyl (meth) ) Acrylate, lauryl (meth) acrylate, stearyl (meth) acrylate, isostearyl (meth) acrylate, cyclohexyl (meth) acrylate, methyl cyclohexyl (meth) acrylate, t-butyl cyclohexyl (meth) acrylate, An alkyl or cycloalkyl (meth) acrylate such as clododecyl (meth) acrylate; a polymerizable unsaturated compound having an isobornyl group such as isobornyl (meth) acrylate; a polymerizable unsaturated having an adamantyl group such as adamantyl (meth) acrylate Compound: Vinyl aromatic compound such as styrene, α-methylstyrene, vinyltoluene; vinyltrimethoxysilane, vinyltriethoxysilane, vinyltris (2-methoxyethoxy) silane, γ- (meth) acryloyloxypropyltrimethoxysilane, γ -Polymerizable unsaturated compounds having an alkoxysilyl group such as (meth) acryloyloxypropyltriethoxysilane; such as perfluorobutylethyl (meth) acrylate and perfluorooctylethyl (meth) acrylate Perfluoroalkyl (meth) acrylate; polymerizable unsaturated compound having a fluorinated alkyl group such as fluoroolefin; polymerizable unsaturated compound having a photopolymerizable functional group such as maleimide group; N-vinylpyrrolidone, ethylene, butadiene, Vinyl compounds such as chloroprene, vinyl propionate and vinyl acetate; compounds having a carboxyl group such as (meth) acrylic acid, maleic acid, crotonic acid and β-carboxyethyl acrylate; (meth) acrylonitrile, (meth) acrylamide, dimethylamino Nitrogen-containing polymerizable unsaturated compounds such as propyl (meth) acrylamide, dimethylaminoethyl (meth) acrylate, adducts of glycidyl (meth) acrylate and amines; 2-hydroxyethyl (meth) acrylate, 2-hydroxy Propyl Meth) acrylate - DOO, 3-hydroxypropyl (meth) acrylate, _C 2 -C ₈ hydroxyalkyl (meth) acrylate (meth) acrylic acid such as hydroxybutyl (meth) acrylate, allyl alcohol - le, the _C 2 -C (Meth) acrylate having a hydroxyl group such as an ε-caprolactone modified form of ₈ -hydroxyalkyl (meth) acrylate; a polymerizable unsaturated compound having a hydroxyl group such as (meth) acrylate having a polyoxyethylene chain having a molecular terminal hydroxyl group; (Meth) acrylate having a polyoxyethylene chain whose molecular terminal is an alkoxy group; 2-acrylamido-2-methylpropanesulfonic acid, allylsulfonic acid, styrenesulfonic acid sodium salt, sulfoethyl methacrylate, and sodium and ammonium salts thereof A polymerizable unsaturated compound having a sulfonic acid group: 2-hydroxy-4- (3-methacryloyloxy-2-hydroxypropoxy) benzophenone, 2-hydroxy-4- (3-acryloyloxy-2-hydroxypropoxy) benzophenone, Hydroxybenzophenones such as 2,2'-dihydroxy-4- (3-methacryloyloxy-2-hydroxypropoxy) benzophenone and 2,2'-dihydroxy-4- (3-acryloyloxy-2-hydroxypropoxy) benzophenone and glycidyl An addition reaction product with (meth) acrylate, or a polymerizable unsaturated compound having an ultraviolet-absorbing functional group such as 2- (2′-hydroxy-5′-methacryloyloxyethylphenyl) -2H-benzotriazole; (Meta) acryloil Ci-1,2,2,6,6-pentamethylpiperidine, 4- (meth) acryloyloxy-2,2,6,6-tetramethylpiperidine, 4-cyano-4- (meth) acryloylamino-2, 2,6,6-tetramethylpiperidine, 1- (meth) acryloyl-4- (meth) acryloylamino-2,2,6,6-tetramethylpiperidine, 1- (meth) acryloyl-4-cyano-4- (Meth) acryloylamino-2,2,6,6-tetramethylpiperidine, 4-crotonoyloxy-2,2,6,6-tetramethylpiperidine, 4-crotonoylamino-2,2,6,6- UV-stable polymerizable unsaturated compounds such as tetramethylpiperidine, 1-crotonoyl-4-crotonoyloxy-2,2,6,6-tetramethylpiperidine; Carbonyl groups such as vinylacetone, diacetone acrylamide, diacetone methacrylamide, acetoacetoxyethyl methacrylate, formyl styrene, vinyl alkyl ketones having 4 to 7 carbon atoms (for example, vinyl methyl ketone, vinyl ethyl ketone, vinyl butyl ketone) Polymerizable unsaturated compounds having the following: allyl (meth) acrylate, ethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate 1,3-butylene glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, 1,4-butanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate 1,6-hexanediol (meta ) Acrylate, pentaerythritol di (meth) acrylate, pentaerythritol tetra (meth) acrylate, glycerol di (meth) acrylate, 1,1,1-trishydroxymethylethane (Meth) acrylate, 1,1,1-trishydroxymethylethane tri (meth) acrylate, 1,1,1-trishydroxymethylpropane tri (meth) acrylate, triallyl isocyanurate, Examples thereof include polyvinyl compounds having at least two polymerizable unsaturated groups in one molecule such as diallyl terephthalate and divinylbenzene, and these are used alone depending on the performance desired for the obtained aqueous resin dispersion. Or in combination of two or more.

  Among these, in the present invention, the polymerizable unsaturated monomer (A) contains the hydroxyl group-containing polymerizable unsaturated monomer (a1) as at least a part of its components. From the viewpoint of crosslinkability with a curing agent such as an isocyanate-based or melamine-based curing agent, and the atomized monomer emulsion in the polymerization stage or the aqueous resin dispersion in the storage stage. This is preferable from the viewpoint of ensuring the stability of the particles.

Examples of the hydroxyl group-containing polymerizable unsaturated monomer (a1) include compounds having one hydroxyl group and one polymerizable unsaturated group in one molecule. Specifically, for example, 2-hydroxyethyl (meth) acrylate - DOO, 2-hydroxypropyl (meth) acrylate - DOO, 3-hydroxypropyl (meth) acrylate, _C 2 -C ₈ hydroxyalkyl (meth) acrylate (meth) acrylic acid such as hydroxybutyl (meth) acrylate, (Meth) acrylate having a hydroxyl group such as allylic alcohol, ε-caprolactone modified product of the above C ₂ -C ₈ hydroxyalkyl (meth) acrylate; (meth) acrylate having a polyoxyethylene chain having a hydroxyl group at the molecular end, etc. These can be used alone or in combination of two or more.

  As the at least part of the polymerizable unsaturated monomer (A), one containing a hydroxyl group-containing polymerizable unsaturated monomer (a1) is used, and an isocyanate-based curing agent or a melamine-based curing is added to the obtained aqueous resin dispersion. By adding an agent or the like, crosslinking between the hydroxyl group derived from the hydroxyl group-containing polymerizable unsaturated monomer (a1) and the curing agent can be promoted, and the curability of the coating film can be further improved and weather resistance can be improved. It is possible to prepare a coating composition that forms a coating film having excellent physical properties such as water resistance.

  The hydroxyl group-containing polymerizable unsaturated monomer (a1) is generally used in a range of 0.5 to 30% by weight, preferably 1 to 20% by weight, based on the total weight of the monomer (A). Is suitable.

  In the present invention, the polymerizable unsaturated monomer (A) contains the carbonyl group-containing polymerizable unsaturated monomer (a2) as at least a part of its components. In the case of using as such, it is preferable from the viewpoint of crosslinkability with a hydrazine derivative described later.

  The carbonyl group-containing polymerizable unsaturated monomer (a2) includes a compound having one carbonyl group and one polymerizable unsaturated bond in one molecule. Specific examples thereof include acrolein and diacetone acrylamide. , Diacetone methacrylamide, acetoacetoxyethyl methacrylate, formylstyrene, vinyl alkyl ketones having 4 to 7 carbon atoms (for example, vinyl methyl ketone, vinyl ethyl ketone, vinyl butyl ketone) and the like. Or it can use in combination of 2 or more types. Of these, diacetone (meth) acrylamide is particularly preferred.

  Using at least a part of the polymerizable unsaturated monomer (A) that contains the carbonyl group-containing polymerizable unsaturated monomer (a2) and blending the obtained aqueous resin dispersion with a hydrazine derivative described later. As a result, in addition to the oxidative curing by the fatty acid component, auxiliary crosslinking between the carbonyl group derived from the carbonyl group-containing polymerizable unsaturated monomer (a2) and the hydrazine derivative can be advanced, and the drying property of the coating film is further improved. The coating composition which forms the coating film excellent also in physical properties, such as weather resistance and water resistance, can be prepared.

  Such a carbonyl group-containing polymerizable unsaturated monomer (a2) is generally used in the range of 0.5 to 35% by weight, preferably 2 to 20% by weight, based on the total weight of the monomer (A). Is suitable.

  Furthermore, in the present invention, the polymerizable unsaturated monomer (A) contains the fatty acid-modified polymerizable unsaturated monomer (a3) as at least a part of its components, which is compatible with the fatty acid-modified polyurethane resin (B). From the point of view, it is preferable from the viewpoint of giving a feeling of meatiness to the finish of the coating film formed using the produced aqueous resin dispersion particles.

  The fatty acid-modified polymerizable unsaturated monomer (a3) usually includes a polymerizable unsaturated monomer having a polymerizable unsaturated group at the terminal of a fatty acid-derived hydrocarbon chain. Here, examples of the polymerizable unsaturated group include a vinyl group and a (meth) acryloyl group, and a (meth) acryloyl group is particularly preferable.

  Examples of the fatty acid-modified polymerizable unsaturated monomer (a3) obtained by reacting a fatty acid (s1) with an epoxy group-containing polymerizable unsaturated monomer (s2) or a hydroxyl group-containing polymerizable unsaturated monomer (s3) Can be mentioned.

Examples of the fatty acid (s1) include those having a structure in which a carboxyl group is bonded to the end of a hydrocarbon chain, and examples include a dry oil fatty acid, a semi-dry oil fatty acid, and a non-dry oil fatty acid. 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 epoxy group-containing polymerizable unsaturated monomer (s2) that can be reacted with the fatty acid (s1) to produce the fatty acid-modified polymerizable unsaturated monomer (a3) is one epoxy group and one in one molecule. Specifically, for example, glycidyl (meth) acrylate, β-methyl glycidyl (meth) acrylate, 3,4-epoxycyclohexylmethyl (meth) acrylate, 3,4- Examples thereof include epoxycyclohexylethyl (meth) acrylate, 3,4-epoxycyclohexylpropyl (meth) acrylate, and allyl glycidyl ether. These can be used alone or in combination of two or more.

  In the fatty acid (s1) and the epoxy group-containing polymerizable unsaturated monomer (s2), the equivalent ratio of the carboxyl group in the fatty acid (s1) and the epoxy group in the epoxy group-containing monomer (s2) is 0.75: 1 to 1. The reaction can be carried out in such a ratio that it is in the range of 1.25: 1, preferably 0.8: 1 to 1.2: 1.

  The reaction between the fatty acid (s1) and the epoxy group-containing polymerizable unsaturated monomer (s2) is usually carried out in the presence of a polymerization inhibitor without causing any problems in the reaction such as gelation. The reaction can be carried out under conditions that allow the group and the epoxy group in the epoxy group-containing polymerizable unsaturated monomer to react smoothly, and is usually heated at a temperature of about 100 to about 180 ° C. for about 0.5 to about 10 hours. Is suitable.

  In this reaction, an esterification reaction catalyst such as a tertiary amine such as N, N-dimethylaminoethanol, a quaternary ammonium salt such as tetraethylammonium bromide or tetrabutylammonium bromide can be used. An inert organic solvent may be used.

  Examples of the polymerization inhibitor include hydroxy compounds such as hydroquinone, hydroquinone monomethyl ether, pyrocatechol and p-tert-butylcatechol; nitrobenzene, nitrobenzoic acid, o-, m- or p-dinitrobenzene, 2,4- Nitro compounds such as dinitrotoluene, 2,4-dinitrophenol, trinitrobenzene, and picric acid; quinone compounds such as p-benzoquinone, dichlorobenzoquinone, chloranil, anthraquinone, and phenanthroquinone; nitrosobenzene, nitroso-β-naphthol, and the like Examples thereof include radical polymerization inhibitors known per se, such as nitroso compounds, and these can be used alone or in combination of two or more.

The fatty acid-modified polymerizable monomer (a3) can also be obtained by esterifying the fatty acid (s1) with a hydroxyl group-containing polymerizable unsaturated monomer (s3). The hydroxyl group-containing polymerizable unsaturated monomer (s3) includes a compound having one hydroxyl group and one polymerizable unsaturated group in one molecule. Specifically, for example, 2-hydroxyethyl (meta ) acrylate - DOO, 2-hydroxypropyl (meth) acrylate - DOO, 3-hydroxypropyl (meth) acrylate, _C 2 -C ₈ hydroxyalkyl (meth) acrylate (meth) acrylic acid such as hydroxybutyl (meth) acrylate , Allyl alcohol, (meth) acrylate having a hydroxyl group such as a modified ε-caprolactone of the above C ₂ -C ₈ hydroxyalkyl (meth) acrylate; (meth) acrylate having a polyoxyethylene chain having a hydroxyl group at the molecular end, etc. These may be used alone or in combination of two or more. Kill.

  The fatty acid (s1) and the hydroxyl group-containing polymerizable unsaturated monomer (s3) usually have an equivalent ratio of 0.4: 1 to the carboxyl group in the fatty acid (s1) to the hydroxyl group in the hydroxyl group-containing monomer (s3). The reaction can be carried out in such a ratio that it is in the range of 1.25: 1, preferably 0.5: 1 to 1.2: 1.

  The reaction between the fatty acid (s1) and the hydroxyl group-containing polymerizable unsaturated monomer (s3) is usually carried out in the fatty acid (s1) component in the presence of a polymerization inhibitor without causing problems such as gelation. In the presence of an esterification catalyst at a temperature of about 100 to about 180 ° C. in the presence of an esterification catalyst. It is suitable to carry out by heating for 5 to about 10 hours. Examples of the esterification catalyst include sulfuric acid, aluminum sulfate, potassium hydrogen sulfate, alkyl-substituted benzene, hydrochloric acid, methyl sulfate, phosphoric acid and the like. These catalysts usually contain the fatty acid (s1) to be reacted and a hydroxyl group. It can be used in the range of about 0.001 to about 2.0% by weight, based on the total amount of polymerizable unsaturated monomer (s3). Furthermore, an organic solvent inert to the reaction can also be used.

  Examples of the polymerization inhibitor include hydroxy compounds such as hydroquinone, hydroquinone monomethyl ether, pyrocatechol and p-tert-butylcatechol; nitrobenzene, nitrobenzoic acid, o-, m- or p-dinitrobenzene, 2,4- Nitro compounds such as dinitrotoluene, 2,4-dinitrophenol, trinitrobenzene, and picric acid; quinone compounds such as p-benzoquinone, dichlorobenzoquinone, chloranil, anthraquinone, and phenanthroquinone; nitrosobenzene, nitroso-β-naphthol, and the like Examples thereof include radical polymerization inhibitors known per se, such as nitroso compounds, and these can be used alone or in combination of two or more.

  In the present invention, the fatty acid-modified polyurethane resin (B) is used as a polymer emulsifier, and includes a polyol (b) containing a fatty acid ester (b1) containing two or more hydroxyl groups in one molecule, a polyisocyanate compound ( c) and a reaction with the carboxyl group-containing diol (d).

  The fatty acid ester (b1) contains two or more hydroxyl groups in one molecule and usually has a structural unit derived from a fatty acid via an ester bond, particularly from low molecular weight to high molecular weight. Without limitation, it can be appropriately selected depending on the use of the aqueous resin dispersion obtained by the method of the present invention.

  For example, glycerin monofatty acid ester can be used as fatty acid ester (b1). Examples of the glycerin monofatty acid ester include glycerin monolaurate, glycerin monooleate, and glycerin monostearate, 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. And the like obtained by the above. Moreover, the reaction product of a glycidol and a fatty acid may be sufficient. The glycerin monofatty acid ester is a weather-resistant, anti-corrosive, water-resistant, such as an undercoat paint applied to an architectural exterior top coat or a metal building material, or a one-coat finish paint applied to a metal surface. When used in applications requiring quick drying properties, finish properties, etc., it can be suitably selected as the fatty acid ester (b1).

  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 (b1), a reaction product of an epoxy resin containing two or more epoxy groups in one molecule and a fatty acid can be used. The reaction product of the epoxy resin and the fatty acid has a secondary hydroxyl group, and the aqueous resin dispersion of the present invention is applied to an undercoat paint applied to a building exterior top coat paint or a metal building material, or other metal surfaces. When used in applications that require weather resistance, corrosion resistance, water resistance, quick drying, finish, etc., such as a one-coat finish paint, it can be suitably selected as the fatty acid ester (b1). In particular, when a bisphenol A glycidyl ether type epoxy resin is used as an epoxy resin, it is suitable for use as an undercoat paint 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 at least one modifier selected from alkylphenol and fatty acid; epoxy group-introduced alkylphenol or alkylphenol novolak resin obtained by reacting alkylphenol or alkylphenol novolac resin with epichlorohydrin; dibasic acid Examples thereof include a modified epoxy resin, an epoxy resin modified with a dibasic acid and a carboxyl group-containing phenol. It is preferred that the epoxy resin has a weight average molecular weight in the range of about 200 to about 3,000, preferably in the range of about 300 to about 2,000. The weight average molecular weight is a value when the weight average molecular weight measured by gel permeation chromatography is converted on the basis of the weight average molecular weight of polystyrene using tetrahydrofuran as a solvent. “HLC8120GPC” (trade name, manufactured by Tosoh Corporation) can be used for the gel permeation chromatography apparatus, and columns used for gel permeation chromatography include “TSKgel G-4000H × L” and “TSKgel G-”. 3000H × L ”,“ TSKgel G-2500H × L ”,“ TSKgel G-2000H × L ”(all are trade names, manufactured by Tosoh Corporation), and the like.

  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 epoxy group / carboxyl group reaction catalysts include quaternary salt catalysts such as tetraethylammonium bromide, tetrabutylammonium bromide, tetraethylammonium chloride, tetrabutylphosphonium bromide, triphenylbenzylphosphonium chloride; triethylamine, tributylamine And the like. The reaction temperature is suitably about 120 to 150 ° C.

  As the fatty acid ester (b1), 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 when the aqueous resin dispersion of the present invention is used in applications where water resistance, finish, etc. are required, such as a 1-coat finish paint applied to a metal surface, It can be suitably selected as the fatty acid ester (b1).

  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 Hexahydrophthalic acid, hexahydroisophthalic acid, hexahydroterephthalic acid, tetrahydrophthalic acid, hexahydrotrimellitic acid, methylhexahydrophthalic acid, malic acid, citric acid and other polycarboxylic acids and their anhydrides These can be used alone or in combination of two or more. It can be.

  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, undecanoic acid glycidyl ester, lauric acid glycidyl ester, myristic acid glycidyl ester, Glycidyl esters such as glycidyl palmitate, glycidyl stearate, and Cardura E10 (manufactured by Japan Epoxy Resin, Neodecanoic acid monoglycidyl ester); butyl glycidyl ester Ether, phenyl glycidyl ether, glycidyl ethers such as decyl glycidyl ether; styrene oxide, AOEX24 (manufactured by Daicel Chemical Industries, alpha-olefin monoepoxide mixture) include alpha-olefin monoepoxide such like. The hydrocarbon group having 4 or more carbon atoms may have, for example, a substituent such as a hydroxyl group. Specifically, as a 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.

  The polyol (b) contains the fatty acid ester (b1), and has at least two hydroxyl groups in one molecule other than the fatty acid ester (b1) as necessary, for example, low molecular weight glycols, 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, hydrogenated bisphenol A, cyclohexanedimethanol, bisphenol A polyethylene glycol ether, bisphenol A polypropylene glycol ether, and the like. These may be used alone or in combination 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 content of the fatty acid ester (b1) in the polyol (b) is 5% by weight or more, preferably 10% by weight or more, and more preferably 20% by weight or more in terms of curability, water resistance and finish. To preferred.

  The polyisocyanate compound (c) 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-cyclohex Alicyclic diisocyanates such as diisocyanates; bullet type adducts and isocyanurate cycloadducts of these diisocyanates; 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 phenyl isocyanate); bullet type adducts of these diisocyanate compounds, isocyanurate cycloadducts; 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 Trial Urethane adducts obtained by reacting a polyisocyanate compound in an excess ratio of the isocyanate groups to the hydroxyl groups of the polyols; burette type adducts, isocyanurate ring adducts, etc. of these urethanized adducts Can do.

  Examples of the carboxyl group-containing diol (d) 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 fatty acid-modified polyurethane resin (B) used in the present invention may have a radically polymerizable unsaturated group at the terminal as necessary. For the purpose of introducing the radically polymerizable unsaturated group, the above ( It can be produced by reacting the b), (c) and (d) components with the hydroxyl group-containing polymerizable unsaturated monomer (e). Examples of the hydroxyl group-containing polymerizable unsaturated monomer (e) include compounds having one hydroxyl group and one polymerizable unsaturated group in one molecule. Specifically, for example, 2-hydroxyethyl (meth) acrylate - DOO, 2-hydroxypropyl (meth) acrylate - DOO, 3-hydroxypropyl (meth) acrylate, _C 2 -C ₈ hydroxyalkyl (meth) acrylate (meth) acrylic acid such as hydroxybutyl (meth) acrylate, (Meth) acrylate having a hydroxyl group such as allylic alcohol, ε-caprolactone modified product of the above C ₂ -C ₈ hydroxyalkyl (meth) acrylate; (meth) acrylate having a polyoxyethylene chain having a hydroxyl group at the molecular end, etc. These may be used alone or in combination of two or more.

  The production of the fatty acid-modified polyurethane resin (B) is not particularly limited, and a conventionally known method can be adopted. For example, the above-described components (b), (c) and (d), and (e) are reacted at once. You may make it react, and you may make it react in multistage. The production of the fatty acid-modified polyurethane resin (B) may be carried out in an organic solvent inert to the isocyanate group, but from the point of eliminating the introduction of the solvent, in the above-mentioned polymerizable unsaturated monomer (A), It is preferable to produce the fatty acid-modified polyurethane resin (B) using a monomer inert to an isocyanate group as a diluent component. The proportions of the components (b), (c) and (d) and the component (e) can be varied, but the equivalent ratio of isocyanate groups to hydroxyl groups in all components is generally 1: 1 to 1: 3. Preferably, the ratio is 1: 1 to 1: 2.5. If the ratio is less than 1: 1, the terminal end becomes isocyanate, which is not preferable for this purpose. If the ratio is more than 1: 3, an excessive hydroxyl component that does not react increases, and stability during the production of the aqueous resin dispersion is decreased. Moreover, you may mix | blend monohydric alcohol as needed in order to block an excess isocyanate group. Furthermore, when using (e) component, it is appropriate for the usage-amount to be 0.01-1 with respect to 1 equivalent of isocyanate groups, Preferably it is the range of 0.02-0.8 equivalent.

  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 according to Asuka. It may be used. Also, hydroquinone, hydroquinone monomethyl ether, p-benzoquinone, etc. are used in order to prevent polymerization of the polymerizable unsaturated monomer (A) used as component (e) or in some cases as a diluting component during the urethanization reaction. can do.

  The fatty acid-modified polyurethane resin (B) produced in this way has an acid value of 5 to 100 mgKOH / g, preferably 10 to 80 mgKOH / g, so that the stability of the aqueous resin dispersion, the water resistance of the formed coating, etc. From the point of view, it is preferable.

  The fatty acid-modified polyurethane resin (B) obtained as described above preferably has an oil length in the range of 5 to 50%, more preferably 10 to 45%. From the point of view, it is preferable. Oil length here is the weight percentage of the fatty acid contained in the solid content of the fatty acid-modified polyurethane resin (B).

  The fatty acid-modified polyurethane resin (B) is dispersed in water. Water dispersion can be carried out by a conventionally known method without any particular limitation. For example, a neutralizing agent, a surfactant, etc. are added to the above-mentioned fatty acid-modified polyurethane resin (B) as necessary, and stirring is performed while gradually adding water. And can be mixed and dispersed. 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. In addition to the polyurethane resin (B), the neutralizing agent may neutralize the carboxyl group, or may be added to water as a dispersion medium and neutralized simultaneously with the dispersion. Further, when the polyurethane resin (B) is used as an emulsifier during the production of the aqueous resin dispersion, it may be mixed and neutralized simultaneously in the pre-emulsion. The amount used is preferably 0.5 to 2.0, more preferably 0.7 to 1.3 equivalents per equivalent of carboxyl group.

  In the method of the present invention, the aforementioned polymerizable unsaturated monomer (A) is emulsion polymerized in the presence of the fatty acid-modified polyurethane resin (B) and water. As the emulsifier, a known anionic surfactant, nonionic surfactant, or the like can be appropriately used in combination with the fatty acid-modified polyurethane resin (B) as necessary, and one or more of the emulsifiers can be used. Emulsion polymerization can be carried out using a polymerization initiator in the presence. Examples of the polymerization initiator include azo initiators such as azoisovaleronitrile, 4,4′-azobis-4-cyanovaleric acid, peroxides such as ammonium persulfate, potassium persulfate, and t-butyl hydroperoxide. Etc. can be used. In addition, the polymerization initiator may be combined with a reducing agent such as sugar, sodium formaldehyde sulfoxylate, iron complex, or the like as necessary to form a redox polymerization system. The emulsion polymerization reaction temperature is preferably about 30 to 95 ° C.

  Further, in order to improve the mechanical stability of the particles of the obtained aqueous resin dispersion, when the aqueous resin dispersion has an acidic group, it may be neutralized with a neutralizing agent as described above. desirable. The neutralizing agent is desirably used in such an amount that the pH of the aqueous resin dispersion after neutralization is about 6.5 to 9.0.

  In the present invention, the ratio of the fatty acid-modified polyurethane resin (B) and the polymerizable unsaturated monomer (A) used is 10:90 to 95: 5, preferably 20:80 to 90:10 in terms of solid content weight ratio. Within the range, it is preferable from the viewpoints of stability during emulsion polymerization, quick drying, and coating film performance.

  In the production of the aqueous resin dispersion of the present invention, emulsion polymerization may be performed in multiple stages using the above-mentioned polymerizable unsaturated monomer (A) in the presence of water and an emulsifier, and at least one of them is emulsified. Polymerization can also be carried out using the fatty acid-modified polyurethane resin (B) as a polymer emulsifier. Specifically, as the multi-stage emulsion polymerization, first, the monomer mixture forming the inner layer component is subjected to the first stage emulsion polymerization using a polymerization initiator in the presence of an emulsifier to obtain a polymer aqueous dispersion. Then, in the aqueous dispersion, the monomer mixture for forming the outer layer component is subjected to emulsion polymerization in the second and subsequent steps in the same manner using an emulsifier and a polymerization initiator, thereby forming a multilayer structure. An aqueous dispersion of the emulsion polymer can be obtained. In this way, in the multi-stage, the polyurethane resin (B) can be blended as a polymer emulsifier in any stage of emulsion polymerization, but the last stage of emulsion polymerization from the viewpoint of freedom of synthesis. It is preferable to mix with.

  The aqueous resin dispersion of the present invention obtained as described above preferably has a solid concentration in the range of 20 to 60% by weight from the viewpoint of stability of the emulsion during emulsion polymerization, and the average particle size of the emulsion is In general, the thickness is preferably about 50 to 500 nm.

  The aqueous resin dispersion produced according to the method of the present invention generally has an oil length in the range of 5 to 70%, preferably 7.5 to 60%, more preferably 10 to 50%. If the oil length is less than 7.5%, the oxidative curability of the film is insufficient. On the other hand, if it exceeds 60%, the film becomes hard and brittle with the passage of time, and the weather resistance, alkali resistance, etc. of the formed film The performance may be inferior. The oil length here is the weight percentage of fatty acid contained in the solid content of the aqueous resin dispersion.

  The aqueous resin composition provided by the present invention comprises the aqueous resin dispersion obtained as described above.

  The aqueous resin composition may further comprise a hydrazine derivative. Specific examples of the hydrazine derivative include saturated dicarboxylic acid dihydrazides having 2 to 18 carbon atoms such as oxalic acid dihydrazide, malonic acid dihydrazide, glutaric acid dihydrazide, succinic acid dihydrazide, adipic acid dihydrazide, sebacic acid dihydrazide and the like. Monoolefinic unsaturated dicarboxylic acid dihydrazide such as maleic acid dihydrazide, fumaric acid dihydrazide, itaconic acid dihydrazide; phthalic acid dihydrazide, terephthalic acid dihydrazide or isophthalic acid dihydrazide; pyromellitic acid dihydrazide, trihydrazide or tetrahydrazide; nitrilotrihydride Citric acid trihydrazide, 1,2,4-benzenetrihydrazide, ethylenediaminetetraacetic acid tetrahydrazide, 1,4,5,8-naphthoic acid Polyhydrazide obtained by reacting a low polymer having a carboxylic acid lower alkyl ester group with hydrazine or a hydrazine hydrate (hydrazine hydride); a hydrazide group-containing compound such as carbonic dihydrazide; bissemicarbazide; hexamethylene diisocyanate Polyfunctional semicarbazide obtained by excessively reacting N, N-substituted hydrazine such as N, N-dimethylhydrazine or the above-mentioned hydrazide with a diisocyanate such as chlorobenzene or isophorone diisocyanate or a polyisocyanate compound derived therefrom, and the polyisocyanate compound Dihydrazide as exemplified above for the isocyanate group in the reaction product of an active hydrogen compound containing a hydrophilic group such as a polyether and a polyol or a polyethylene glycol monoalkyl ether Excessively reacted with the resulting aqueous polyfunctional semicarbazide; compound having a semicarbazide group, such as a mixture of polyfunctional semicarbazide and aqueous polyfunctional semicarbazide; compound having a hydrazone group such as bis-acetyl-di hydrazone and the like.

  Since the aqueous resin composition contains the hydrazine derivative, the coating film formed therefrom adsorbs harmful substances in the air, such as formaldehyde, and is therefore useful for removing these harmful substances. When the resin dispersion has a carbonyl group, it can act as a crosslinking agent for auxiliary crosslinking.

  In general, the blending amount of the hydrazine derivative is desirably in the range of 0.01 to 10% by weight, particularly 0.1 to 8% by weight, based on the resin solid content of the aqueous resin dispersion.

  In addition, when the aqueous resin dispersion has a crosslinkable functional group such as a hydroxyl group, the aqueous resin composition includes a curing agent having a crosslinkable functional group capable of reacting with the functional group, such as an isocyanate-based curing agent or a melamine type. A curing agent or the like can be contained.

  The aqueous resin composition may further comprise a metal dryer, UV absorber, UV stabilizer, wetting agent, antifoaming agent, plasticizer, film-forming aid, organic solvent, thickener, preservative, Additives such as fungicides, pH adjusters, curing catalysts, and surface adjusters can be appropriately selected and contained in combination.

  Thus, the water-based resin composition is used for coatings such as for building, automotive outer panels, automotive parts, coating materials such as printing inks, additives for coatings, bonding agents for nonwovens, adhesives, fillers, It can be used for various applications such as molding materials and resists.

  The present invention also provides an aqueous coating composition comprising the above aqueous resin composition.

  The aqueous coating composition can be used as a clear coating or as an enamel coating.

  When used as an enamel paint, color pigments, glitter pigments, extender pigments, rust preventive pigments and the like known in the paint field can be blended as the pigment component.

  In addition to the above components, the water-based paint composition is a water-soluble or emulsion-type acrylic resin, alkyd resin, silicone resin, fluororesin, epoxy resin, urethane resin, polyester resin and other modifying resins, pigment dispersant, Surfactant, dispersant, defoamer, thickener, film-forming aid, preservative, antifungal agent, antifreeze agent, pH adjuster, flash last inhibitor, aldehyde scavenger, layered viscosity mineral, powdery Alternatively, additives such as fine pollutant activated carbon, photocatalytic acid value titanium, and a low contamination agent such as polyalkylene glycol-modified alkyl silicate can be contained alone or in combination of two or more.

  The water-based paint composition can be applied to a new base material surface or an old coating surface, and the base material is not particularly limited. For example, concrete, mortar, slate plate, PC plate, ALC Inorganic base materials such as plates, cement calcium silicate plates, concrete blocks, wood, stones, etc .; organic base materials such as plastics; metals such as iron and aluminum, etc. Examples of the coating film include an acrylic resin system, an acrylic urethane resin system, a polyurethane resin system, a fluororesin system, a silicon acrylic resin system, a vinyl acetate resin system, an epoxy resin system, and an alkyd resin. An aqueous or solvent-type undercoat material may be applied to these coated surfaces. If necessary, after applying the undercoat material, the aqueous coating composition can be applied as a topcoat material. Further, after applying the aqueous coating composition of the present invention as an undercoat, it is also possible to apply a known aqueous overcoat.

  When the aqueous coating composition of the present invention is applied to a metal surface such as an iron substrate, the aqueous coating composition contains a phosphoric acid pigment in a range of 1 to 10%, preferably 2 to 8% in terms of PVC. It is desirable to do.

  It is desirable that the phosphoric acid pigment be easily dispersible in the presence of a polymer surfactant from the viewpoint of corrosion resistance and gloss. Specific examples of the phosphate pigment include, for example, zinc phosphate, phosphorous zinc silicate, aluminum zinc phosphate, calcium zinc phosphate, calcium phosphate, aluminum pyrophosphate, calcium pyrophosphate, aluminum dihydrogen triphosphate, metaphosphoric acid Examples thereof include aluminum, calcium metaphosphate, zinc phosphomolybdate, and aluminum phosphomolybdate.

  The aqueous coating composition of the present invention can further contain at least one basic compound selected from the group consisting of nitrites, phytates, tannates, and polyamine compounds. Examples of the nitrite include sodium nitrite, calcium nitrite, strontium nitrite, barium nitrite, and ammonium nitrite.Examples of the phytate include sodium phytate and potassium phytate. Examples of the tannate include sodium tannate and potassium tannate. Examples of the polyamine compound include N- (2-hydroxyethyl) ethylenediaminetriacetic acid (HEDTA), ethylenediaminetetraacetic acid (EDTA), Diethylenetriaminepentaacetic acid (DTPA), propylenediaminetetraacetic acid (PDTA), iminodiacetic acid, nitrilotriacetic acid (NTA), diethylenetriaminepentamethylenephosphonic acid (DTPMP), and their alkali metal salts, monoalkylamines Polyamines, intercalation compounds and the like formed by intercalating the like layered phosphate and quaternary ammonium ion such as dihydrogen tripolyphosphate aluminum. These can be used alone or in combination of two or more.

  By adding these basic compounds, it is possible to prevent the rust of the metal surface from bleeding to the coating surface and generating spot rust when the aqueous coating composition is directly applied to the metal surface. The amount of the basic compound added is suitably in the range of 0.02 to 2% by weight, preferably 0.05 to 1% by weight, based on the weight of the aqueous coating composition.

The aqueous coating composition of the present invention can be applied by a method such as air spray coating, airless spray coating, electrostatic coating, brush coating, roller coating, lysing gun, universal gun, etc., and as a drying method, Any of heat drying, forced drying, and room temperature drying may be used. In this specification, the drying condition of less than 40 ° C. is normal temperature drying, the drying condition of 40 ° C. or more and less than 80 ° C. is forced drying, and the drying condition of 80 ° C. or more is heat drying. As a coating amount of the aqueous coating composition of this invention, it can be in the range of 50-300 g / m < ² >, for example.

  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.

Production example 1 of fatty acid-modified monomer
The following components were put into a reaction vessel and reacted at a reaction temperature of 140 ° C. with stirring to obtain a fatty acid-modified monomer (a3-1). The reaction between the epoxy group and the carboxyl group was monitored by measuring the amount of the remaining carboxyl group, and the reaction was continued until the acid value was 5 or less.

Safflower oil fatty acid 560 parts Glycidyl methacrylate 284 parts Hydroquinone 0.65 parts

Production Example 2
The following components were placed in a reaction vessel and heated to 120 ° C. with stirring.

Soybean fatty acid 560 parts Hydroquinone 0.45 parts Methyl sulfate 0.65 parts Toluene 36 parts

  Then, the mixture of the component shown below was dripped at the said reaction container over 2 hours.

Hydroxyethyl methacrylate 325 parts Hydroquinone 0.45 parts Methyl sulfate 1.4 parts Toluene 58.5 parts

  After completion of the dropwise addition, the temperature was raised to 150 ° C., and the reaction was continued for about 5 hours until the acid value became 8.7 or less while removing the condensed water. Thereafter, toluene was removed under reduced pressure until the heating residue was 95% or more to produce a fatty acid-modified monomer (a3-2).

Production Example 3 of Fatty Acid Ester
The following components were put into a reaction vessel, heated to 150 ° C. with stirring, and reacted to an acid value of 1 mgKOH / g or less to obtain a fatty acid ester (b1-1).

"Epicoat 828EL" (Note 1) 598 parts linseed oil fatty acid 905 parts tetraethylammonium bromide 1.5 parts

(Note 1) Epicoat 828EL: Product name, liquid epoxy resin, manufactured by Japan Epoxy Resin Co., Ltd.

Production Example 4
The following components were put into a reaction vessel, heated to 150 ° C. with stirring, and reacted to an acid value of 1 mgKOH / g or less to obtain a fatty acid ester (b1-2).

292 parts of adipic acid "Cardura E10P" (Note 2) 480 parts Tetraethylammonium bromide 1.25 parts

(* 2) Cardura E10P: Japan Epoxy Resin, trade name, glycidyl thiodecanoate.

Production Example 1 of aqueous resin dispersion
The following components were charged in a reaction vessel and heated to 80 ° C.

“Emulsy MU” (Note 3) 11.35 parts Plaxel PLC205 (Note 4) 10.30 parts dimethylolbutanoic acid 3.88 parts hydroquinone 0.0126 parts n-butyl methacrylate 22.5 parts i-butyl methacrylate 17.5 Part Dibutyltin dilaurate 0.0189 part

  Next, 21.58 parts of isophorone diisocyanate was dropped into this over 1 hour, and the mixture was reacted until the NCO value was 18.7 (NCO value-1). Thereafter, 2.88 parts of n-butanol and 0.0126 part of hydroquinone were added and reacted until the NCO value was 1 or less (NCO value-2). After completion of the reaction, the reaction mixture was cooled and when the temperature reached 40 ° C., 0.0126 part of hydroquinone and 10 parts of 2-ethylhexyl methacrylate were charged into the reaction vessel to obtain a monomer-diluted fatty acid-modified polyurethane resin solution.

  In a beaker, 100 parts of the monomer-diluted fatty acid-modified polyurethane resin solution obtained above and 1.64 parts of dimethylaminoethanol were charged and mixed well, and 128 parts of water was gradually added and stirred to replace the aqueous system. A dispersion was obtained.

  This dispersion was transferred to a flask and heated to 80 ° C. A solution prepared by mixing and dissolving 0.5 part of 4,4′azobis-4-cyanovaleric acid, 10 parts of water and 0.31 part of dimethylaminoethanol was dropped into the flask over 1 hour to maintain the temperature. The polymerization reaction was carried out. Thereafter, the temperature was maintained at 80 ° C. for 2 hours, and the reaction was proceeded, followed by cooling to obtain an aqueous resin dispersion (I-1) having an average particle size of 228 nm and a solid content of 42%.

(Note 3) Emergy MU: manufactured by Riken Vitamin Co., Ltd., distilled mono fatty acid glyceride (monoester content 93% or more, iodine value 108-120)
(Note 4) Plaxel PLC205: Daicel Chemical Industries, trade name, polycaprolactone diol

Example 2
The following components were charged in a reaction vessel and heated to 80 ° C.

Fatty acid ester (b1-1) 22.54 parts Plaxel PLC205 (Note 4) 4.63 parts Dimethylol butanoic acid 3.77 parts Hydroquinone 0.0126 parts n-butyl methacrylate 22.5 parts i-butyl methacrylate 15.0 parts Dibutyltin dilaurate 0.0189 parts

  Next, 16.17 parts of isophorone diisocyanate was added dropwise over 1 hour, and the mixture was reacted to an NCO value of 14.5 (NCO value -1). Thereafter, 0.862 part of n-butanol and 0.0126 part of hydroquinone were added and reacted until an NCO value of 8.6 (NCO value of 2), and 4.53 parts of 2-hydroxyethyl acrylate was added. The reaction was carried out to a value of 1 or less (NCO value -3). After completion of the reaction, the reaction mixture was cooled and when the temperature reached 40 ° C., 0.0126 part of hydroquinone and 10 parts of 2-ethylhexyl methacrylate were charged into the reaction vessel to obtain a monomer-diluted fatty acid-modified polyurethane resin solution.

  In a beaker, 100 parts of the monomer-diluted fatty acid-modified polyurethane resin solution obtained above and 1.59 parts of dimethylaminoethanol were charged and mixed well, and 128 parts of water was gradually added and stirred to replace the aqueous system. A dispersion was obtained.

  This dispersion was transferred to a flask and heated to 80 ° C. A solution prepared by mixing and dissolving 0.5 part of 4,4′azobis-4-cyanovaleric acid, 10 parts of water and 0.31 part of dimethylaminoethanol was dropped into the flask over 1 hour to maintain the temperature. The polymerization reaction was carried out. Thereafter, the temperature was maintained at 80 ° C. for 2 hours, and the reaction was proceeded, followed by cooling to obtain an aqueous resin dispersion (I-2) having an average particle diameter of 247 nm and a solid content of 42%.

Example 3
The following components were charged in a reaction vessel and heated to 80 ° C.

Fatty acid ester (b1-2) 15.58 parts PLACCEL PLC205 (Note 4) 8.35 parts dimethylolbutanoic acid 3.81 parts hydroquinone 0.0126 parts n-butyl methacrylate 22.5 parts i-butyl methacrylate 15.0 parts Dibutyltin dilaurate 0.0189 parts

  Next, 18.41 parts of isophorone diisocyanate was added dropwise over 1 hour, and the mixture was reacted until the NCO value was 16.7 (NCO value-1). Then, 6.35 parts of 2-hydroxyethyl acrylate and 0.0126 parts of hydroquinone were added and reacted until the NCO value was 1 or less (NCO value -3). After completion of the reaction, the reaction mixture was cooled and when the temperature reached 40 ° C., 0.0126 part of hydroquinone and 10 parts of 2-ethylhexyl methacrylate were charged into the reaction vessel to obtain a monomer-diluted fatty acid-modified polyurethane resin solution.

  In a beaker, 100 parts of the monomer-diluted fatty acid-modified polyurethane resin solution obtained above and 1.61 parts of dimethylaminoethanol were charged and mixed well, and 128 parts of water was gradually added and stirred to replace the aqueous system. A dispersion was obtained.

  This dispersion was transferred to a flask and heated to 80 ° C. A solution prepared by mixing and dissolving 0.5 part of 4,4′azobis-4-cyanovaleric acid, 10 parts of water and 0.31 part of dimethylaminoethanol was dropped into the flask over 1 hour to maintain the temperature. The polymerization reaction was carried out. Thereafter, the temperature was maintained at 80 ° C. for 2 hours, and the reaction was proceeded, followed by cooling to obtain an aqueous resin dispersion (I-2) having an average particle diameter of 215 nm and a solid content of 42%.

Examples 4 and 6 and Comparative Example 1
According to the method of Example 1, aqueous resin dispersions (I-4), (I-6) and (I-8) were obtained in the same manner as in Example 1 except that the composition was changed as shown in Table 1. )

Examples 5 and 7
According to the method of Example 2, aqueous resin dispersions (I-5) and (I-7) were obtained in the same manner as in Example 2 except that the formulation was changed as shown in Table 1.

Production Examples 8 to 17 and Comparative Example 2 of aqueous resin composition
An aqueous resin composition was obtained according to the composition shown in Table 2 below. Each aqueous resin composition was subjected to the following performance test and evaluated. The results are shown in Table 2.

(Note 5) Water-dispersible polyisocyanate: In a flask, 55 parts of methoxypolyethylene glycol having a number average molecular weight of 550 and 504 parts of “Takenate D170HN” (Mitsui Takeda, hexamethylene diisocyanate trimer) were placed. A polyisocyanate capable of being dispersed in water was prepared by reacting at a temperature of NCO up to 218.

(Note 6) Water-dispersible blocked polyisocyanate: 275 parts of one-end methoxypolyethylene glycol having a number average molecular weight of 550 and 504 parts of “Takenate D170HN” were placed in a flask and reacted at 70 ° C. to give an NCO value of 135. Then, 50 parts of methyl isobutyl ketone was added, the temperature was raised to 120 ° C., 219 parts of methyl ethyl ketoxime was then added dropwise over 1 hour, and the reaction was allowed to proceed to an NCO value of 1 or less. After completion of the reaction, 60 parts of propylene glycol monomethyl ether was added and diluted to prepare a water-dispersible block polyisocyanate having a solid content of 90%.

(Note 7) “Cymel 325”: Cytec Industries, trade name, methylated melamine resin with a solid content of 80% (Note 8) “DICnate 1000W”: Dainippon Ink, trade name, metal dryer, Co content 3 .6%
(Note 9) “TEXANOL”: manufactured by Eastman Chemical Co., Ltd., trade name, 2,2,4-trimethyl-1,3-pentanediol monoisobutyrate, film-forming aid

Evaluation test method (* 1) Water resistance: Each aqueous resin composition is spray-coated on a steel plate so that the dry film thickness is 40 μm, and dried and heated under each film forming condition shown in Table 2. Created.

  The obtained test plate was immersed in a constant temperature water bath at room temperature of 20 ° C. for 7 days, and the state of the coating film was visually observed.

◎: No abnormality ○: Slight swelling and discoloration, but in good condition △: Swelling and discoloration, difficult to use ×: Significant swelling and discoloration

(* 2) Curability: After each aqueous resin composition was applied to a glass plate with a doctor blade so as to have a dry film thickness of 40 μm, and dried and heated under the respective film forming conditions in Table 2. The dried film was peeled off from the glass plate and cut into a size of 4 × 4 cm to obtain a test piece.

The obtained test piece was immersed in acetone for 6 hours under reflux conditions. The coating film extraction residue was calculated as follows from the coating film weight before and after extraction.
Paint film extraction residue (%) = (weight of film after extraction / weight of film before extraction) × 100 (%)

(* 3) Corrosion resistance: Each test plate was prepared in the same manner as the water resistance (* 1), and the obtained test plate was cross-cut with a knife so as to reach the substrate, and this was applied to JIS Z-2371. According to the above, a salt spray resistance test was conducted for 240 hours, and evaluation was made according to the following criteria based on rust and blister width from knife scratches.

○: The maximum width of rust and blisters is less than 2 mm from the cut part (one side)
Δ: The maximum width of rust and blisters is 2 mm or more and less than 3 mm (one side) from the cut portion, and blisters are observed on the entire coating surface. ×: The maximum width of rust and blisters is 3 mm or more from the cut portion and the coating surface. It shows that blisters are observed throughout.

(* 4) Finishing property: Each test plate was prepared in the same manner as in the water resistance (* 1), and the gloss and feeling of flesh of the coated surface were visually evaluated.

○: Very good, Δ: Somewhat good, ×: Bad

Claims (16)

A method for producing an aqueous resin dispersion in which a polymerizable unsaturated monomer (A) is emulsion-polymerized in the presence of water and an emulsifier, wherein the emulsifier is a fatty acid ester (b1) containing two or more hydroxyl groups in one molecule. ) -Containing polyol (b), polyisocyanate compound (c), and fatty acid-modified polyurethane resin (B) obtained by reaction with carboxyl group-containing diol (d) Production method. The method for producing an aqueous resin dispersion according to claim 1, wherein the polymerizable unsaturated monomer (A) contains a hydroxyl group-containing polymerizable unsaturated monomer as at least a part of its components. The method for producing an aqueous resin dispersion according to claim 1, wherein the polymerizable unsaturated monomer (A) contains a carbonyl group-containing polymerizable unsaturated monomer as at least a part of its components. The method for producing an aqueous resin dispersion according to claim 1, wherein the polymerizable unsaturated monomer (A) contains a fatty acid-modified polymerizable unsaturated monomer as at least a part of its components. The method for producing an aqueous resin dispersion according to claim 1, wherein the fatty acid ester (b1) is a glycerin monofatty acid ester. The method for producing an aqueous resin dispersion according to claim 1, wherein the fatty acid ester (b1) is a reaction product of an epoxy resin containing two or more epoxy groups in one molecule and a fatty acid. The method for producing an aqueous resin dispersion according to claim 1, wherein the fatty acid ester (b1) is a reaction product of a compound containing two or more carboxyl groups in one molecule and a monoepoxy compound having a long-chain hydrocarbon group. . The fatty acid-modified polyurethane resin (B) is obtained by further reacting the hydroxyl group-containing ethylenically unsaturated monomer (e) with the polyol (b), the polyisocyanate compound (c) and the carboxyl group-containing diol (d). The method for producing an aqueous resin dispersion according to claim 1. The method for producing an aqueous resin dispersion according to claim 1, wherein the fatty acid-modified polyurethane resin (B) has an acid value of 5 to 100. An aqueous resin dispersion produced by the method according to any one of 1 to 9. An aqueous resin composition comprising the aqueous resin dispersion described in Item 10. Item 12. The aqueous resin composition according to Item 11, further comprising a hydrazine derivative. Item 12. The aqueous resin composition according to Item 11, further comprising an isocyanate curing agent and / or a melamine curing agent. An aqueous coating composition comprising the aqueous resin composition according to any one of 11 to 13. 15. A method for forming a coating film, which comprises coating the surface to be coated with the aqueous coating composition described in item 14. A coated article formed by the method according to item 15.