JP2006036990A - Aqueous resin composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an aqueous resin composition forming a coated film showing a good finished appearance and excellent in weather resistance, waterproof property and low temperature physical properties, even at a normal temperature. <P>SOLUTION: This aqueous resin composition is characterized by containing (A) an aqueous fatty acid-modified resin dispersion produced by finely dispersing (I) a monomer mixture containing (a) a fatty acid-modified polymerizable unsaturated monomer and (b) another polymerizable unsaturated monomer in an aqueous medium so as to form ≤500 nm mean particle diameter, and polymerizing the monomer emulsion, and (B) an aqueous urethane resin, and having within (10/90)-(99/1) range blending ratio of the resin (A) to resin (B) in their solid portion weight ratio. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an aqueous resin composition that is excellent in drying properties and capable of forming a coating film having gloss with a feeling of flesh and an aqueous coating composition comprising the composition.

  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. . 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. From its oiliness, anticorrosion when applied to a metal surface can be expected, but the stability of the fatty acid ester portion is poor, it is difficult to ensure storage stability, even in the coating film, light stability, In some cases, the alkali resistance was insufficient. 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 Document 1 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 oxidation polymerization type aqueous emulsion is produced by emulsion polymerization of a radically polymerizable monomer mixture.

  By the way, the formation mechanism of the emulsion polymer is that the monomer diffuses in the water from the large monomer droplets in the aqueous phase, and the polymerization proceeds in the micelles made by the surfactant to produce polymer particles (polymerized small particles). It consists of to do. In this case, the monomer used for the polymerization must be supplied by diffusing water from the monomer droplets to the polymer particles under the conditions for polymerization.

  In general, there is a large particle size difference between monomer droplets and polymer particles growing from micelles. This means that there is a large difference between the total surface area of the monomer droplets and the total surface area of the polymer particles, so that the initiator radical and the monomer diffusing in water penetrate the larger surface area, that is, the polymer particles, The polymerization then proceeds. In the emulsion polymerization method, polymer particles grow while the particle diameter gradually increases.

  In the case of emulsion polymerization of a radically polymerizable monomer mixture containing the above fatty acid-modified monomer, the fatty acid-modified monomer having extremely poor solubility in water is left in the monomer droplets in the polymerization stage, and polymerization proceeds in the monomer droplets. Polymer particles containing a large amount of fatty acid-modified monomer units are formed, while monomers other than the fatty acid-modified monomer diffuse in water from the monomer droplets into the micelles, where the polymer contains many monomer units other than the fatty acid-modified monomer units. Since the particles are generated, there is a high possibility that the nonuniform distribution of the hydrophilic polymer particles and the hydrophobic polymer particles is extremely generated in the polymer particles in the finally obtained emulsion. Therefore, in the coating film formed from such an oxidation polymerization type aqueous emulsion, the hydrophobic polymer particles become nuclei and cause repelling, or the surface floats and remains sticky on the surface. Therefore, there is a problem that a transparent film cannot be formed and the finished appearance of the coating film is remarkably deteriorated.

  As a measure for overcoming the above problems, Patent Document 2 proposes an aqueous copolymer containing a copolymer that is a polymerization product of a vinyl monomer and a hydrophobic ester or a partial ester, and a method for producing the same. . In this publication, it is proposed to add a hydrophobic ester from a dry oil acid and a polyol to the monomer droplets in order to suppress the formation of second generation particles other than the monomer droplets during the polymerization. The water-based copolymer described in the publication forms a transparent film that does not contain a volatile coalescing aid. However, particularly in the initial stage after application, the drying property is slow, and the adhesive film remains practically sticky. There are drawbacks such as the weather resistance and water resistance of the formed coating film, and the low-temperature properties are not sufficient.

JP 59-8773 A JP 2000-319525 A

  The main object of the present invention is to provide an aqueous resin composition which exhibits a good finished appearance and can form a coating film excellent in weather resistance, water resistance and low-temperature physical properties even at room temperature.

  The present inventors have now completed the present invention with an aqueous resin composition containing an aqueous fatty acid-modified resin dispersion and an aqueous urethane resin produced by a specific production method at a specific ratio.

Thus, the present invention
1. (A) A monomer mixture (I) containing a fatty acid-modified polymerizable unsaturated monomer (a) and other polymerizable unsaturated monomer (b) is finely dispersed in an aqueous medium so that the average particle size is 500 nm or less, It contains an aqueous fatty acid-modified resin dispersion produced by polymerizing the resulting monomer emulsion and (B) an aqueous urethane resin, and the blending ratio of the resin (A) and the resin (B) is 10 in terms of solid content by weight. An aqueous resin composition characterized by being in the range of / 90 to 99/1,
2. 2. The aqueous resin composition according to 1, wherein the aqueous urethane resin has a carbonyl group or a hydrazine group,
3. 3. The aqueous resin composition according to item 1 or 2, further comprising a hydrazine derivative,
An aqueous coating composition containing the aqueous resin composition according to any one of 4.1 to 3,
5. A method for forming a coating film, characterized by applying the aqueous coating composition described in item 4 to a surface to be coated,
A coated article obtained by the method for forming a coating film according to 6.5;
About.

  According to the aqueous resin composition of the present invention, it is excellent in storage stability, film-forming property, etc., and can be easily cured even in a one-pack type at room temperature, and the formed coating film is transparent, glossy, finished. It has a remarkable effect that it has excellent properties (feeling of fleshiness) and is excellent in properties such as low-temperature physical properties, water resistance, durability, corrosion resistance, and weather resistance.

Fatty acid-modified polymerizable unsaturated monomer (a)
The fatty acid-modified polymerizable unsaturated monomer (a) used in the present invention can stably produce the aqueous fatty acid-modified resin dispersion (A) and is formed using the finally obtained aqueous resin composition. In the case of imparting a fleshiness to the coating film and imparting oxidative curability to the composition of the present invention, an oxidative curing group can be introduced into the aqueous fatty acid-modified resin dispersion (A) particles, A polymerizable unsaturated monomer having a polymerizable unsaturated group at the end of a hydrocarbon chain derived from a fatty acid is included. 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 (a) are those obtained by reacting a fatty acid (a1) with an epoxy group-containing polymerizable unsaturated monomer (a2) or a hydroxyl group-containing polymerizable unsaturated monomer (a3). Can be mentioned.

  Examples of the fatty acid (a1) include those having a structure in which a carboxyl group is bonded to the end of a hydrocarbon chain, and examples thereof 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, but usually dry oil fatty acids are unsaturated fatty acids that are iodinated 130 or more, and semi-dry oil fatty acids are iodinated 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.

  In the present invention, from the viewpoint of the initial water resistance of the formed coating film, it is desirable to have oxidative curability, and a dry oil fatty acid and / or a semi-dry oil fatty acid is preferred as the fatty acid.

  The epoxy group-containing polymerizable unsaturated monomer (a2) that can be reacted with the fatty acid (a1) to produce the fatty acid-modified polymerizable unsaturated monomer (a) 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.

  The fatty acid (a1) and the epoxy group-containing polymerizable unsaturated monomer (a2) have an equivalent ratio of a carboxyl group in the fatty acid (a1) and an epoxy group in the epoxy group-containing monomer (a2) of 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 (a1) and the epoxy group-containing polymerizable unsaturated monomer (a2) is usually carried out in the presence of a polymerization inhibitor without causing a problem such as gelation in the fatty acid component. 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, picric acid; quinone compounds such as p-benzoquinone, dichlorobenzoquinone, chloranil, anthraquinone, phenanthroquinone; nitrosobenzene, nitroso-β-naphthol, etc. 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 (a) can also be obtained by esterifying the fatty acid (a1) with the hydroxyl group-containing polymerizable unsaturated monomer (a3). Examples of the hydroxyl group-containing polymerizable unsaturated monomer (a3) include a compound having one hydroxyl group and one polymerizable unsaturated group in one molecule. Specifically, for example, 2-hydroxyethyl (meta C2-C8 hydroxyalkyl (meth) acrylate of (meth) acrylic acid such as acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, hydroxybutyl (meth) acrylate, allyl alcohol -(Meth) acrylate having a hydroxyl group, such as an ε-caprolactone modified product of the above C2-C8 hydroxyalkyl (meth) acrylate; (meth) acrylate having a polyoxyethylene chain having a hydroxyl group at the molecular end, and the like. These can be used alone or in combination of two or more. .

  The fatty acid (a1) and the hydroxyl group-containing polymerizable unsaturated monomer (a3) usually have an equivalent ratio of 0.4: 1 to the carboxyl group in the fatty acid (a1) to the hydroxyl group in the hydroxyl group-containing monomer (a3). 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 (a1) and the hydroxyl group-containing polymerizable unsaturated monomer (a3) is usually carried out in the fatty acid (a1) component in the presence of a polymerization inhibitor without causing a reaction problem 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 (a1) 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 the polymerizable unsaturated monomer (a3). 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.

Other polymerizable unsaturated monomers (b)
In the aqueous fatty acid-modified resin dispersion (A) in the present invention, the other polymerizable unsaturated monomer (b) is a polymerizable unsaturated monomer copolymerizable with the fatty acid-modified polymerizable unsaturated monomer (a), Examples of the compound include one or more, preferably one polymerizable unsaturated group in the molecule. Examples of the polymerizable unsaturated group include a vinyl group and a (meth) acryloyl group. Specific examples of the other polymerizable unsaturated monomer (b) include 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 (meta ) Acrylate, 2-ethylhexyl (meth) acrylate, nonyl (meth) acrylate, tridecyl (meth) acrylate, lauryl (meth) acrylate, stearyl (meth) acrylate, “isostearyl acrylate” (manufactured by Osaka Organic Chemical Co., Ltd.), cyclohexyl ( (Meta) acrylate Alkyl or cycloalkyl (meth) acrylate such as methylcyclohexyl (meth) acrylate, t-butylcyclohexyl (meth) acrylate, cyclododecyl (meth) acrylate, etc .; having isobornyl group such as isobornyl (meth) acrylate Polymerizable unsaturated monomer; polymerizable unsaturated monomer having an adamantyl group such as adamantyl (meth) acrylate; glycidyl (meth) acrylate, β-methylglycidyl (meth) acrylate, 3,4-epoxycyclohexylmethyl (meth) acrylate, Epoxy group-containing polymerizable unsaturated monomers such as 3,4-epoxycyclohexylethyl (meth) acrylate, 3,4-epoxycyclohexylpropyl (meth) acrylate, and allyl glycidyl ether; styrene, α-methyl Aromatic vinyl monomers such as styrene and vinyltoluene; vinyltrimethoxysilane, vinyltriethoxysilane, vinyltris (2-methoxyethoxy) silane, γ- (meth) acryloyloxypropyltrimethoxysilane, γ- (meth) acryloyloxypropyl Alkoxysilyl group-containing polymerizable unsaturated monomer such as triethoxysilane; siloxane macromonomer such as polydimethylsiloxane macromonomer; perfluoroalkyl such as perfluorobutylethyl (meth) acrylate and perfluorooctylethyl (meth) acrylate (meta ) Acrylate; polymerizable unsaturated monomer containing alkyl fluorine group such as fluoroolefin; polymerizable unsaturated monomer having photopolymerizable functional group such as maleimide group; N-vinylpyrrolidone; Vinyl compounds such as tylene, butadiene, chloroprene, vinyl propionate and vinyl acetate; carboxyl group-containing polymerizable unsaturated monomers such as (meth) acrylic acid, fumaric acid, itaconic acid, maleic acid, crotonic acid and β-carboxyethyl acrylate Unsaturated carboxylic acid anhydrides such as maleic anhydride and itaconic anhydride; (meth) acrylonitrile, (meth) acrylamide, dimethylaminopropyl (meth) acrylamide, dimethylaminoethyl (meth) acrylate, and glycidyl (meth) acrylate Nitrogen-containing polymerizable unsaturated monomers such as adducts with amines; 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, hydroxybutyl ( Meta) Acu Alkyl (meth) acrylates containing 2 to 8 carbon atoms of (meth) acrylic acid such as relate, allyl alcohol, and ε-caprolactone modified products of the above hydroxy (meth) acrylates having 2 to 8 carbon atoms, etc. (Meth) acrylate having a hydroxyl group; hydroxyl group-containing polymerizable unsaturated monomer such as (meth) acrylate having a polyoxyethylene chain having a hydroxyl group at the molecular end: having a polyoxyethylene chain having an alkoxy group at the molecular end (meth) Acrylate; 2-acrylamido-2-methylpropane sulfonic acid, allyl sulfonic acid, styrene sulfonic acid sodium salt, sulfoethyl methacrylate and sulfonic acid group-containing polymerizable unsaturated monomers such as sodium salt and ammonium salt thereof; 2-hydroxy-4 -(3-Methacryloyloxy- -Hydroxypropoxy) benzophenone, 2-hydroxy-4- (3-acryloyloxy-2-hydroxypropoxy) benzophenone, 2,2'-dihydroxy-4- (3-methacryloyloxy-2-hydroxypropoxy) benzophenone, 2,2 Addition of hydroxybenzophenones such as 2,4-dihydroxybenzophenone and 2,2 ', 4-trihydroxybenzophenone and glycidyl (meth) acrylate such as' -dihydroxy-4- (3-acryloxy-2-hydroxypropoxy) benzophenone A reaction product or a polymerizable unsaturated monomer having an ultraviolet-absorbing functional group such as 2- (2′-hydroxy-5′-methacryloyloxyethylphenyl) -2H-benzotriazole; 4- (meth) acryloyloxy-1 , 2, , 6,6-pentamethylpiperidine, 4- (meth) acryloyloxy-2,2,6,6-tetramethylpiperidine, 4-cyano-4- (meth) acryloylamino-2,2,6,6-tetra Methylpiperidine, 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-tetramethylpiperidine, 1-crotonoyl A polymerizable unsaturated monomer having a UV-stable functional group such as -4-crotonoyloxy-2,2,6,6-tetramethylpiperidine; Contains carbonyl groups such as in, diacetone acrylamide, diacetone methacrylamide, acetoacetoxyethyl methacrylate, formyl styrene, vinyl alkyl ketone having 4 to 7 carbon atoms (eg vinyl methyl ketone, vinyl ethyl ketone, vinyl butyl ketone) Polymerizable unsaturated monomer: 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 (meth) 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, diallyl A polyvinyl compound having at least two polymerizable unsaturated groups in one molecule, such as terephthalate and divinylbenzene, and the like, and the like. used.

  The ratio of the monomer (a) and the monomer (b) used is not particularly limited, and can be appropriately selected according to the performance and application desired for the intended aqueous resin composition. In general, the coating film formed using the aqueous resin composition has a feeling of fleshiness and weather resistance, and the monomer (a) is generally 5 based on the total amount of the monomer (a) and the monomer (b). -50% by weight, preferably 10-40% by weight, more preferably 10-35% by weight, and monomer (b) 50-95% by weight, preferably 60-90% by weight, more preferably 65-95%. It can be in the range of 90% by weight.

  As said other polymerizable unsaturated monomer (b), the theoretical glass transition temperature of the (co) polymer of all monomers (b) to be used is in the range of 0 to 100 ° C., preferably 10 to 80 ° C. It is desirable to choose.

  In the present invention, the glass transition temperature (absolute temperature) is a value calculated by the following formula.

1 / Tg = W1 / T1 + W2 / T2 + ... Wn / Tn
In the formula, W1, W2... Wn is% by weight of each monomer [= (blending amount of each monomer / total monomer weight) × 100], and T1, T2... Tn are the glass transition temperatures (absolutely) of the homopolymer of each monomer. Temperature). The glass transition temperature of the homopolymer of each monomer is a value according to Polymer Hand Book (Second Edition, edited by J. Brandrup / EHImmergut), and the glass transition temperature of a monomer not described in this document is the homopolymer of the monomer. The polymer is synthesized so that the weight average molecular weight is about 50,000, and the value when the glass transition temperature is measured by differential scanning thermal analysis is used.

  By making the theoretical glass transition temperature of the (co) polymer of all the monomers (b) used to be within the above range, the film-forming property of the coating film formed using the aqueous resin composition, weather resistance, It is possible to achieve both coating film properties such as water resistance.

  The other polymerizable unsaturated monomer (b) is an acid group-containing polymerizable unsaturated monomer (b1) based on the total weight of the monomer (a) and the monomer (b). %, Preferably 0.5% by weight or more and less than 3% by weight.

  Examples of the acid group-containing polymerizable unsaturated monomer (b1) include carboxyl group-containing polymerizable unsaturated monomers such as (meth) acrylic acid, maleic acid, crotonic acid, and β-carboxyethyl acrylate; 2-acrylamide-2- Examples include methylpropane sulfonic acid, allyl sulfonic acid, styrene sulfonic acid sodium salt, sulfoethyl methacrylate and sulfonic acid group-containing polymerizable unsaturated monomers such as sodium salt and ammonium salt thereof, and particularly acrylic acid, methacrylic acid A carboxyl group-containing polymerizable unsaturated monomer such as crotonic acid is preferred.

  Stabilization of aqueous fatty acid-modified resin dispersion (A) particles obtained in an aqueous medium by using acid group-containing polymerizable unsaturated monomer (b1) as at least a part of other polymerizable unsaturated monomer (b) Property and mechanical stability can be ensured, and when the aqueous resin composition containing the same is applied to an enamel paint, the toning property of the paint can be improved.

  In addition, the other polymerizable unsaturated monomer (b) contains, as at least a part thereof, a polymerizable unsaturated monomer containing a linear, branched or cyclic, saturated or unsaturated hydrocarbon group having 4 or more carbon atoms. Monomer (b2) is included in the range of 30 to 90% by weight, preferably 35 to 85% by weight, more preferably 45 to 80% by weight, based on the total weight of monomer (a) and monomer (b). It is desirable that

  Examples of the polymerizable unsaturated monomer (b2) containing a linear, branched or cyclic, saturated or unsaturated hydrocarbon group having 4 or more carbon atoms include n-butyl (meth) acrylate and 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 acrylate” (manufactured by Osaka Organic Chemical Co., Ltd.), cyclohexyl (meth) acrylate, methylcyclohexyl (meth) acrylate, t-butylcyclohexyl (meth) acrylate, Cyclododecyl (meth) acrylate, etc. Alkyl or cycloalkyl (meth) acrylate; polymerizable unsaturated compound having an isobornyl group such as isobornyl (meth) acrylate; polymerizable unsaturated compound having an adamantyl group such as adamantyl (meth) acrylate; styrene, α-methylstyrene, And vinyl aromatic compounds such as vinyl toluene. By using the polymerizable unsaturated monomer (b2) having a hydrocarbon group having 4 or more carbon atoms, the water resistance of the coating film formed using the aqueous resin composition can be improved.

  In addition, the other polymerizable unsaturated monomer (b) includes, as at least a part thereof, a polymerizable unsaturated monomer (b3) containing a linear or branched hydrocarbon group having 6 or more carbon atoms. It is desirable to contain 1 to 30% by weight, preferably 5 to 20% by weight, more preferably 6 to 18% by weight, based on the total weight of (a) and monomer (b).

  Examples of the polymerizable unsaturated monomer (b3) containing a linear or branched hydrocarbon group having 6 or more carbon atoms include n-hexyl (meth) acrylate, octyl (meth) acrylate, 2-ethylhexyl ( And (meth) acrylate, nonyl (meth) acrylate, tridecyl (meth) acrylate, lauryl (meth) acrylate, stearyl (meth) acrylate, “isostearyl acrylate” (manufactured by Osaka Organic Chemical Co., Ltd.), etc. Or in combination of two or more.

  By using the polymerizable unsaturated monomer (b3) containing a linear or branched hydrocarbon group having 6 or more carbon atoms as at least a part of the other polymerizable unsaturated monomer (b), aqueous Maintaining the polymerization stability of the monomer emulsion when the other polymerizable unsaturated monomer (b) is atomized together with the fatty acid-modified polymerizable unsaturated monomer (a) in the production of the fatty acid-modified resin dispersion (A). Moreover, the water resistance of the coating film formed using the aqueous resin composition can be improved.

  The other polymerizable unsaturated monomer (b) contains an acid group-containing polymerizable unsaturated monomer (b1) and a linear, branched or cyclic, saturated or unsaturated hydrocarbon group having 4 or more carbon atoms. A polymerizable unsaturated monomer (b2), and a fatty acid-modified polymerizable unsaturated monomer (a), and another polymerizable unsaturated monomer (b7) other than the monomer (b1) and the monomer (b2). , Based on the total weight of monomer (a) and monomer (b), monomer (a) is 5 to 50% by weight, preferably 10 to 40% by weight, more preferably 10 to 35% by weight, monomer (b1) 0.1 to 5% by weight, preferably 0.5 to 4.5% by weight, more preferably 0.5 to 3% by weight, and monomer (b2) 45 to 80% by weight, preferably 50 to 75% by weight. , More preferably 55 70% by weight, and 0 to 49.9% by weight of other polymerizable unsaturated monomer (b7), preferably 0 to 39.5% by weight, more preferably 0 to 34.5% by weight, where carbon The polymerizable unsaturated monomer (b2) containing a hydrocarbon group having a number of 4 or more is a polymerizable unsaturated monomer (b3) containing a linear or branched hydrocarbon group having a carbon number of 6 or more, It is desirable to contain in the range of 1 to 30% by weight, preferably 5 to 20% by weight, more preferably 6 to 18% by weight, based on the total weight of the monomer (a) and the monomer (b).

  By copolymerizing the above-mentioned specific proportion of the fatty acid-modified polymerizable unsaturated monomer (a) and other polymerizable unsaturated monomer (b), the aqueous fatty acid-modified resin dispersion (A) can be stably produced, Moreover, the coating film formed using the aqueous resin composition has a sense of transparency and a feeling of fleshiness, and can improve performance such as water resistance.

  Further, the other polymerizable unsaturated monomer (b) preferably contains the cycloalkyl group-containing polymerizable unsaturated monomer (b4) as at least a part thereof. As the cycloalkyl group-containing polymerizable unsaturated monomer (b4), a compound having one cycloalkyl group having 6 or more carbon atoms and one polymerizable unsaturated bond in one molecule is suitable. Examples thereof include cyclohexyl (meth) acrylate, methylcyclohexyl (meth) acrylate, t-butylcyclohexyl (meth) acrylate, cyclododecyl (meth) acrylate, and the like. These can be used in combination. Of these, cyclohexyl (meth) acrylate is preferred.

  A coating formed using an aqueous resin composition by using at least a part of the other polymerizable unsaturated monomer (b) comprising the cycloalkyl group-containing polymerizable unsaturated monomer (b4). The weather resistance of the film can be improved, and the water resistance and stain resistance can also be improved. The content in the case of improving the weather resistance is 1 to 70% by weight, preferably 10 to 60% by weight, more preferably 25 to 25% based on the total weight of the monomer (a) and the monomer (b). A range of 45% by weight is preferred.

  Further, the other polymerizable unsaturated monomer (b) desirably contains an aromatic vinyl monomer (b5) as at least a part thereof. As an aromatic vinyl monomer (b5), vinyl aromatic compounds, such as styrene, (alpha) -methylstyrene, vinyl toluene, can be mentioned, for example, These can be used individually or in combination of 2 or more types. By using such an aromatic vinyl monomer (b5), the copolymerizability of the monomer (a) and the monomer (b) can be increased, the amount of unreacted monomers can be minimized, and water-resistant coating such as water resistance can be formed. The physical properties of the film can be improved.

  The aromatic vinyl monomer (b5) is generally 1 to 50% by weight, preferably 5 to 45% by weight, more preferably 12 to 35% by weight, based on the total weight of the monomer (a) and the monomer (b). It is preferable to use within the range of%.

  In the case of imparting weather resistance to the coating film formed using the aqueous resin composition of the present invention, the other polymerizable unsaturated monomer (b) is a cycloalkyl group-containing polymerizable unsaturated monomer (b4). And an aromatic vinyl monomer (b5), and a polymerizable unsaturated monomer (b8) other than the monomer (a), the monomer (b4) and the monomer (b5), and the monomer (a) and the monomer (b ) Based on the total weight of the monomer (a), 5 to 50% by weight, preferably 10 to 40% by weight, more preferably 10 to 35% by weight, and monomer (b4) 1 to 70% by weight, preferably 10 to 60 wt%, more preferably 25 to 45 wt%, monomer (b5) 1 to 50 wt%, preferably 5 to 45 wt%, more preferably 12 to 35 wt%, and other weights 0-93 wt% of sexual unsaturated monomer (b8), preferably 0-75 wt%, still more preferably contains 0-47 wt%.

  By coating the above-mentioned specific proportion of the fatty acid-modified polymerizable unsaturated monomer (a) and other polymerizable unsaturated monomer (b), the coating film formed using the aqueous resin composition is transparent and has a fleshiness It has a feeling and can be excellent in water resistance, weather resistance and the like.

  Further, the other polymerizable unsaturated monomer (b) preferably contains the carbonyl group-containing polymerizable unsaturated monomer (b6) as at least a part thereof.

  The carbonyl group-containing polymerizable unsaturated monomer (b6) includes a compound having one carbonyl group and one polymerizable unsaturated bond in one molecule, and specifically includes, for example, acrolein, 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.

  By using at least a part of the other polymerizable unsaturated monomer (b) containing the carbonyl group-containing polymerizable unsaturated monomer (b6) and blending a hydrazine derivative described later, a carbonyl group and hydrazine It is possible to proceed with crosslinking with the derivative, to further improve the drying property of the coating film, and to prepare a coating composition that forms a coating film having excellent physical properties such as weather resistance and water resistance. it can.

  Such carbonyl group-containing polymerizable unsaturated monomer (b6) is generally in the range of 0.5 to 35% by weight, preferably 2 to 20% by weight, based on the total weight of monomer (a) and monomer (b). Suitable for use within.

  The other polymerizable unsaturated monomer (b) comprises a hydroxyl group-containing (meth) acrylate in order to ensure the stability of the particles in the polymerization stage or storage stage in the aqueous fatty acid-modified resin dispersion (A). You can also Examples of the hydroxyl group-containing (meth) acrylate include those exemplified above, and the use ratio thereof is generally 1 to 50% by weight, preferably based on the total amount of the monomer (a) and the monomer (b), preferably It can be in the range of 1 to 30% by weight, more preferably 1 to 10% by weight.

Aqueous fatty acid-modified resin dispersion (A)
In the present invention, the monomer mixture (I) contains the fatty acid-modified polymerizable unsaturated monomer (a) and the other polymerizable unsaturated monomer (b) as essential components, and is further substantially polymerizable. A compound not containing a saturated group can also be contained, whereby the aqueous fatty acid-modified resin dispersion (A) particles can also encapsulate the compound.

  Examples of such a compound that does not substantially contain a polymerizable unsaturated group include, for example, UV absorbers, UV stabilizers and additives for coating materials such as metal dryers; curing agents such as isocyanate compounds, blocked isocyanate compounds, and melamines; acrylic resins And resins such as polyester resins, polyurethane resins, alkyd resins, polyorganosiloxanes; colorants such as pigments and dyes.

  When the monomer mixture (I) is finely dispersed in an aqueous medium, an emulsifier may be used in combination as necessary. As the emulsifier, an anionic emulsifier and a nonionic emulsifier are suitable. Examples of the anionic emulsifier include sodium salts and ammonium salts such as alkylsulfonic acid, alkylbenzenesulfonic acid, and alkylphosphoric acid. Nonionic emulsifiers include, for example, polyoxyethylene oleyl ether, polyoxyethylene stearyl ether, polyoxyethylene lauryl ether, polyoxyethylene tridecyl ether, polyoxyethylene phenyl ether, polyoxyethylene nonylphenyl ether, polyoxyethylene octyl Phenyl ether, polyoxyethylene monolaurate, polyoxyethylene monostearate, polyoxyethylene monooleate, sorbitan monolaurate, sorbitan monos Areto, sorbitan monostearate, sorbitan trioleate, polyoxyethylene sorbitan monolaurate, and the like.

  Also, a polyoxyalkylene group-containing anionic emulsifier having an anionic group and a polyoxyalkylene group such as a polyoxyethylene group or a polyoxypropylene group in one molecule, or the anionic group and polymerizable unsaturated in one molecule Reactive anionic emulsifiers having groups may be used.

  The emulsifier can be used in the range of 0.1 to 15% by weight, preferably 0.5 to 12% by weight, based on the total amount of all monomers used.

  The monomer mixture (I) may contain a chain transfer agent for the purpose of adjusting the molecular weight of the resulting aqueous fatty acid-modified resin dispersion (A). Examples of the chain transfer agent include compounds having a mercapto group. Specifically, for example, lauryl mercaptan, t-dodecyl mercaptan, octyl mercaptan, 2-ethylhexyl thioglycolate, 2-methyl-5-tert- Examples thereof include butylthiophenol, mercaptoethanol, thioglycerol, mercaptoacetic acid (thioglycolic acid), mercaptopropionate, and n-octyl-3-mercaptopropionate. In general, the chain transfer agent is preferably used in an amount of 0.05 to 10% by weight, particularly 0.1 to 5% by weight, based on the total amount of all monomers.

  The aqueous fatty acid-modified resin dispersion (A) in the present invention can be stably produced by the fatty acid-modified polymerizable unsaturated monomer (a) and the like, which can suppress the diffusion of the monomer (b) in the polymerization stage. However, if necessary, a hydrophobic organic solvent generally used in miniemulsion polymerization such as a long chain saturated hydrocarbon solvent such as hexadecane or a long chain alcohol solvent such as hexadecanol in the monomer mixture (I). May be blended.

  The monomer mixture (I) described above is a monomer dispersion which is a particle dispersion containing the fatty acid-modified polymerizable unsaturated monomer (a) and the other polymerizable unsaturated monomer (b) by being finely dispersed in an aqueous medium. (Hereinafter sometimes abbreviated as “monomer emulsion”).

  The concentration of the monomer mixture (I) in the aqueous medium is generally 10 to 70 from the viewpoint of atomization suitability of the monomer emulsion to be formed, stability in the polymerization stage, practicality when applied to an aqueous paint, and the like. It is suitable within the range of wt%, preferably 20-60 wt%.

  Examples of the aqueous medium include water or a water-organic solvent mixed solution obtained by mixing water with an organic solvent such as a water-soluble organic solvent.

  The fine dispersion of the monomer mixture (I) in the aqueous medium can be usually performed using a disperser having high energy shearing ability. Examples of the disperser that can be used in this case include a high-pressure emulsifier, an ultrasonic emulsifier, a high-pressure colloid mill, and a high-pressure homogenizer. These dispersers can usually be operated under a high pressure of about 10 to 1000 MPa, preferably about 50 to 300 MPa. In addition, the monomer mixture (I) may be pre-emulsified with a disper or the like in advance before being dispersed by the machine.

  The average particle diameter of the dispersed particles in the monomer emulsion obtained by finely dispersing the monomer mixture (I) in the aqueous medium by the above method is 500 nm or less from the viewpoint of the transparency of the formed coating film, water resistance, and the like. The range of 80 to 400 nm is preferable, and the range of 100 to 300 nm is more preferable. When the average particle diameter exceeds 500 nm, the finish and storage stability of the formed coating film are inferior and the practicality is lowered, which is not preferable.

  In this specification, the average particle size is “SALD-3100” (trade name, manufactured by Shimadzu Corporation, laser diffraction particle size distribution analyzer), and the sample is diluted with deionized water to 20 ° C. The average particle size of the emulsion or resin dispersion of the atomized monomer mixture (I) is measured at 30 minutes after the production, respectively.

  In the polymerization of the monomer emulsion thus obtained, for example, in accordance with the mini-emulsion polymerization method, all the monomer emulsion after fine dispersion is charged into a reactor equipped with a stirrer, a polymerization initiator is added, and the mixture is heated while stirring. Can be performed.

  The polymerization initiator may be either oil-soluble or water-soluble, and examples of the oil-soluble polymerization initiator include benzoyl peroxide, octanoyl peroxide, lauroyl peroxide, stearoyl peroxide. Organic peroxides such as oxides; azo compounds such as azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile); and water-soluble initiators such as cumene hydroperoxide , Organic peroxides such as tert-butyl peroxide, tert-butyl peroxylaurate, tert-butyl peroxyisopropyl carbonate, tert-butyl peroxyacetate, diisopropylbenzene hydroperoxide; azobis (2-methylpropiononitrile) A Bis (2-methylbutyronitrile), 4,4′-azobis (4-cyanobutanoic acid), dimethylazobis (2-methylpropionate), azobis [2-methyl-N- (2-hydroxyethyl)- Azo compounds such as propionamide] and azobis {2-methyl-N- [2- (1-hydroxybutyl)]-propionamide}; and persulfates such as potassium persulfate, ammonium persulfate, and sodium persulfate. . These can be used alone or in combination of two or more. Further, if necessary, a reducing agent such as sugar, sodium formaldehyde sulfoxylate, or iron complex may be used in combination with the polymerization initiator to form a redox polymerization system.

  In general, the polymerization initiator is preferably used in an amount of 0.1 to 5% by weight, particularly 0.2 to 3% by weight, based on the total weight of the monomer (a) and the monomer (b). The method for adding the polymerization initiator is not particularly limited, and can be appropriately selected according to the type and amount thereof. For example, it may be previously contained in the monomer mixture (I) or the aqueous medium, or may be added all at once during the polymerization, or may be dropped.

  In the present invention, in order to improve the mechanical stability of the particles of the resulting aqueous fatty acid-modified resin dispersion (A), when the aqueous fatty acid-modified resin dispersion (A) has an acidic group, It is desirable to neutralize with a neutralizing agent. The neutralizing agent is not particularly limited as long as it can neutralize acidic groups. For example, sodium hydroxide, potassium hydroxide, trimethylamine, dimethylaminoethanol, 2-methyl-2-amino-1-propanol, Examples thereof include triethylamine and aqueous ammonia, and these neutralizing agents are desirably used in such an amount that the pH of the aqueous resin dispersion after neutralization is about 6.5 to 9.0.

  The aqueous fatty acid-modified resin dispersion (A) is generally 10,000 to 500,000, particularly 3 to 200,000 from the viewpoint of the weather resistance, water resistance and finish of the coating film formed using the aqueous resin composition. It is desirable to have a weight average molecular weight within the range of Here, the weight average molecular weight is a value obtained by converting the molecular weight measured by gel permeation chromatography based on the molecular weight of polystyrene using tetrahydrofuran as a solvent. Columns used for the gel permeation chromatography include “TSKgel G-4000H × L”, “TSKgel G-3000H × L”, “TSKgel G-2500H × L”, “TSKgel G-2000H × L” (all Tosoh Corporation).

  In the aqueous fatty acid-modified resin dispersion (A), the average particle size of the dispersed resin can be within the range of 500 nm or less, particularly 100 to 300 nm, as the average particle size of the dispersed resin.

  The aqueous fatty acid-modified resin dispersion (A) obtained by the above production method can be stably produced, and the coating film formed using the aqueous resin composition containing the resin dispersion (A) has excellent film-forming properties. It can have good finish and water resistance.

Aqueous polyurethane resin (B)
In the present invention, the conventionally known water-based polyurethane resin (B) can be used without limitation, and a urethane prepolymer obtained by reacting a polyisocyanate, a polyol and a polyol having a carboxyl group is dispersed in an aqueous medium. The resin obtained by making it can be mentioned.

  Examples of the polyisocyanate include 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 4,4′-diphenylmethane diisocyanate, m-phenylene diisocyanate, xylylene diisocyanate, tetramethylene diisocyanate, lysine 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'- Examples include dichloro-4,4′-biphenylene diisocyanate, 1,5-naphthalene diisocyanate, 1,5-tetrahydronaphthalene diisocyanate, and isophorone diisocyanate.

  Examples of the polyol include low molecular weight glycols and high molecular weight glycols, and these may be used alone or in combination of two or more.

  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, tricyclo Examples include decane dimethylol, hydrogenated bisphenol A, cyclohexane dimethanol, and 1,6 hexanediol.

  Examples of the high molecular weight glycols include polyether polyols such as polyethylene glycol, polypropylene glycol, and polytetramethylene glycol; compounds obtained by reacting glycol components with dicarboxylic acid components, and ring opening of cyclic ester compounds such as ε-caprolactone. Examples include polyester diols obtained by the reaction and polyester polyols such as co-condensed polyesters; polycarbonate polyols;

  Examples of the polyol having a carboxyl group include 2,2-dimethylolpropionic acid, 2,2-dimethylolbutyric acid, 2,2-dimethylolvaleric acid, and polyester polyol or polyether polyol obtained by condensing this. The polyol having a carboxyl group may be used in combination with a hydroxycarboxylic acid such as 12-hydroxystearic acid, paraoxybenzoic acid, and salicylic acid.

  The blending ratio of the above components is not particularly limited, but it is desirable to blend so that, for example, the equivalent ratio of isocyanate group / hydroxyl group is in the range of 1.1 to 1.9. The synthesis reaction of the urethane prepolymer can be performed based on a conventionally known method.

  When the urethane prepolymer is dispersed in an aqueous medium, a chain extender, a neutralizing agent, and an emulsifier can be blended in addition to the urethane prepolymer, if necessary.

  As the chain extender, a compound having at least two active hydrogen atoms per molecule is suitable. For example, ethylenediamine, 1,2-propanediamine, 1,6-hexamethylenediamine, piperazine, 2-methylpiperazine, 2 , 5-dimethylpiperazine, isophoronediamine, 4,4'-dicyclohexylmethanediamine, 1,4-cyclohexanediamine and other diamines; diethylenetriamine, dipropylenetriamine, triethylenetetramine and other polyamines, trimethylolpropane, neopentyl glycol Polyols such as glycerin; hydrazines such as hydrazine, ethylene-1,2-dihydrazine, propylene-1,3-dihydrazine and butylene-1,4-dihydrazine.

  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-amino-1-propanol , Triethylamine, ammonia and the like. The neutralizing agent may be neutralized in advance with the carboxyl group in addition to the urethane prepolymer, or may be neutralized simultaneously with the dispersion by adding to the aqueous medium. The neutralizing agent is preferably used at a ratio of usually 0.5 to 2.0 equivalents, preferably 0.7 to 1.3 equivalents with respect to 1 equivalent of the carboxyl group.

  As the emulsifier, those similar to those listed in the description of the aqueous fatty acid-modified resin dispersion (A) can be used.

  The aqueous polyurethane resin (B) obtained as described above may be desolvated by a method known per se as necessary.

  In the present invention, the aqueous urethane resin (B) is desirably a resin having a crosslinkable functional group in the molecule from the viewpoint of the anticorrosive property of the coating film formed using the aqueous resin composition of the present invention. Examples of the functional group include a carbonyl group, a hydrazine group, a hydroxyl group, and an amino group. Among them, a hydrazine group and a carbonyl group are preferable.

  The aqueous polyurethane resin having a hydrazine group can be obtained, for example, by dispersing the prepolymer in an aqueous medium together with hydrazines as chain extenders. When the aqueous polyurethane resin (B) has a hydrazine group, the low-temperature physical properties and anticorrosion properties of the formed coating film are improved, and when the aqueous fatty acid-modified resin dispersion (A) has a carbonyl group, the carbonyl group It reacts with the group at the time of film formation, and can introduce a crosslinked structure into the formed coating film.

  Examples of the aqueous polyurethane resin having a carbonyl group that can be used as the aqueous polyurethane resin (B) in the present invention include a urethane prepolymer obtained by reacting a polyisocyanate, a polyol, a polyol having a carboxyl group, and an alcohol having a carbonyl group. It can be obtained by dispersing the polymer in an aqueous medium.

  As the above-mentioned polyisocyanate, polyol and polyol having a carboxyl group, those described above can be used in the same manner.

  On the other hand, examples of the alcohol having a carbonyl group include diacetone alcohol and 4-hydroxy-2butanone hydroxyacetone.

  The carbonyl group content contained in the aqueous polyurethane resin having a carbonyl group obtained as described above is generally 0.005 to 0.3 mol, preferably 0.01 to 0.2 mol per 100 g of resin solids. It is preferably within the molar range.

  When the aqueous polyurethane resin (B) has a carbonyl group, the corrosion resistance of the formed coating film is improved, and when the aqueous resin composition contains a hydrazine derivative described later, it reacts with the hydrazine group during film formation. A crosslinked structure can be introduced into the formed coating film.

Aqueous resin composition The aqueous resin composition of the present invention contains the aqueous fatty acid-modified resin dispersion (A) and the aqueous polyurethane resin (B) as base resin components, and the blending ratio thereof is strictly limited. However, the aqueous fatty acid-modified resin dispersion (A) and the aqueous polyurethane resin (B) are solids of resin (A) / resin (B). The weight ratio can generally be within the range of 10/90 to 99/1, and preferably within the range of 30/70 to 90/10. When the solid content weight ratio of the resin (A) / resin (B) is less than 10/90, the finish, weather resistance, and water resistance of the formed coating film may be inferior, and it is easy to sag when coating. The coating workability may be insufficient, for example, and if it exceeds 99/1, it may be difficult to ensure the toughness of the formed coating film, particularly the flexibility (elongation rate) at low temperatures. .

  In addition to this, the aqueous resin composition of the present invention preferably further contains a hydrazine derivative. Specific examples of the derivatives include saturated carboxylic 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; Citric acid trihydrazide, 1,2,4-benzenetrihydrazide, ethylenediaminetetraacetic acid tetrahydrazide, 1,4,5,8-naphthoic acid tetrahydride A polyhydrazide obtained by reacting a low polymer having a carboxylic acid lower alkyl ester group with hydrazine or a hydrazine hydrate (hydrazine hydride); a compound having a hydrazide group such as dihydrazide carbonate; a bissemicarbazide; hexamethylene diisocyanate or isophorone A polyfunctional semicarbazide obtained by excessively reacting a diisocyanate such as diisocyanate and a polyisocyanate compound derived therefrom with an N, N-substituted hydrazine such as N, N-dimethylhydrazine or the hydrazide exemplified above; The dihydrazide exemplified above is excessively reacted with an isocyanate group in a reaction product of a polyether and an active hydrogen compound containing a hydrophilic group such as polyols or polyethylene glycol monoalkyl ethers. Resulting aqueous polyfunctional semicarbazide; compound having a semicarbazide group, such as a mixture of polyfunctional semicarbazide and aqueous polyfunctional semicarbazide, compounds and the like having a hydrazone group such as bis-acetyl-di hydrazone.

  By containing the hydrazine derivative, the formed coating film is useful because it is capable of adsorbing and removing harmful substances in the air, such as formaldehyde, and the aqueous fatty acid-modified resin dispersion (A) and / or the aqueous urethane resin. When (B) has a carbonyl group, it can act as a crosslinking agent for crosslinking.

  The amount of the hydrazine derivative is 0.001 to 10% by weight, particularly 0.02 to 5% by weight, based on the total resin solid content of the aqueous fatty acid-modified resin dispersion (A) and the aqueous urethane resin (B). % Is desirable.

  The aqueous resin composition can also contain a metal dryer as a catalyst for promoting oxidative curing. Examples of the metal dryer include a salt of at least one metal selected from the group consisting of aluminum, calcium, cerium, cobalt, iron, lithium, magnesium, manganese, zinc, and zirconium, and an acid. Examples include capric acid, caprylic acid, isodecanoic acid, linolenic acid, naphthenic acid, neodecanoic acid, octenoic acid, oleic acid, palmitic acid, resin acid, ricinoleic acid, soybean oil fatty acid, stearic acid, tall oil fatty acid and the like. It is done.

  The blending amount of the metal dryer is 0.001 to 10% by weight, particularly 0.02 to 5% by weight, based on the total resin solid content of the aqueous fatty acid-modified resin dispersion (A) and the aqueous urethane resin (B). % Is desirable.

  The aqueous resin composition may be water-soluble or emulsion-type acrylic resin, alkyd resin, silicone resin, fluororesin, epoxy resin, polyester resin, amino resin, or other water-soluble or water-soluble polyethylene glycol, polyvinyl alcohol, or the like. Polymers; natural resins such as shellac and rosin; modified resins such as; curing agents such as isocyanate compounds, block polyisocyanate compounds and melamine resins; wetting agents, antifoaming agents, plasticizers, film-forming aids, organic solvents , Thickeners, preservatives, fungicides, pH adjusters, curing catalysts, surface adjusters, and the like can be selected and combined as appropriate.

  Thus, the water-based resin composition is used for coatings such as for building, automobile outer panels, automobile parts, automobile repair, PCM, coating materials such as printing inks, additives for paints, and bonding agents for nonwovens. , Adhesives, fillers, molding materials, resists and the like.

Aqueous paint composition The aqueous paint composition of the present invention comprises the above-described aqueous resin composition.

  When the aqueous resin composition is applied to an aqueous coating composition, it can be applied to either a clear coating or an enamel coating.

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

  The aqueous coating composition preferably contains at least one compound selected from the group consisting of nitrites, phytates, tannates, phosphates and polyamine compounds. Examples of the nitrite include sodium nitrite, calcium nitrite, strontium nitrite, barium nitrite, ammonium nitrite and the like, and 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), and diethylenetriamine. Pentaacetic acid (DTPA), propylenediaminetetraacetic acid (PDTA), iminodiacetic acid, nitrilotriacetic acid (NTA), diethylenetriaminepentamethylenephosphonic acid (DTPMP), and alkali metal salts thereof; monoalkylamines and Riamin, 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.

  The compounding amount of the above compound is 0.001 to 10% by weight, particularly 0.02 to 5% by weight, based on the total resin solid content of the aqueous fatty acid-modified resin dispersion (A) and the aqueous urethane resin (B). The range of is desirable.

  In the above aqueous coating composition, in addition to the above components, pigment dispersant, surfactant, surface conditioner, plasticizer, anti-settling agent, antistatic agent, antibacterial agent, fragrance, ultraviolet absorber, ultraviolet stabilizer, curing Catalysts, dispersants, antifoaming agents, thickeners, film-forming aids, antiseptics, antifungal agents, antifreezing agents, pH adjusters, flash last deterrents, aldehyde scavengers, lamellar viscosity minerals, powders or fine particles Additives such as activated carbon and photocatalytic titanium oxide can be appropriately selected and combined.

  The aqueous coating composition can be applied using a method such as roller, air spray, airless spray, lysine gun, universal gun, brush, electrostatic coating, and the like. Moreover, as a drying method, any of heat drying, forced drying, and normal temperature drying may be sufficient. 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.

  Hereinafter, the present invention will be described more specifically with reference to examples. “Parts” and “%” are “parts by weight” and “% by weight”.

Production of fatty acid-modified polymerizable unsaturated monomer Production Example 1
The following components were put into a reaction vessel and reacted at a reaction temperature of 140 ° C. for 5 hours while stirring to obtain a fatty acid-modified polymerizable unsaturated monomer (a-1).
Safflower oil fatty acid 280 parts Glycidyl methacrylate 142 parts.

Production Example 2
A fatty acid-modified polymerizable unsaturated monomer (a-2) was obtained in the same manner as in Production Example 1 except that the components to be reacted were changed to the following.
Flaxseed oil fatty acid 280 parts Glycidyl methacrylate 142 parts.

Production Example 3
Manufacture of aqueous fatty acid-modified resin dispersion The following components are put into a glass beaker and stirred at 2000 rpm for 15 minutes with a disper to prepare a pre-emulsified liquid. A monomer emulsion having an average particle diameter of 190 nm of dispersed particles was obtained by high-pressure treatment at 100 MPa with a high-pressure emulsifier that collides each other.
Monomer emulsion composition Fatty acid-modified polymerizable unsaturated monomer (a-1) 30.15 parts Styrene 15 parts 2-hydroxyethyl methacrylate 4.5 parts i-butyl methacrylate 20.35 parts t-butyl methacrylate 20 parts 2-ethylhexyl acrylate 8 parts methacrylic acid 2 parts n-octyl-3-mercaptopropionate 0.3 part “Newcol 707SF” (Note 1) 10 parts deionized water 85 parts The above monomer emulsion is then transferred to a flask and deionized. Dilute with water to a solids concentration of 45%. Thereafter, the temperature was raised to 85 ° C., and an initiator aqueous solution in which 2 parts of “VA-086” (Note 2) was dissolved in 10 parts of deionized water was added to the flask, and stirred for 3 hours while maintaining the temperature. Thereafter, an initiator aqueous solution in which 0.5 part of “VA-086” (Note 2) was dissolved in 10 parts of deionized water was added to the flask, stirred for 1 hour while maintaining the temperature, and then cooled to 40 ° C. The pH was adjusted to 8.0 with dimethylaminoethanol to obtain an aqueous resin dispersion (I-1) having a solid content concentration of 40% and an average particle diameter of the dispersion resin of 185 nm.
(Note 1) “Newcol 707SF”: trade name, manufactured by Nippon Emulsifier Co., Ltd., an anionic emulsifier having a polyoxyethylene chain, 30% active ingredient,
(Note 2) “VA-086”: trade name, manufactured by Wako Pure Chemical Industries, 2,2′-azobis [2-methyl-N- (2-hydroxyethyl) -propionamide].

Production Examples 4-6
Aqueous fatty acid-modified resin dispersions (I-2) to (I-4) were obtained in the same manner as in Production Example 3 except that the composition of the monomer emulsion was changed as shown in Table 1.

Production Example 7
A flask containing 36 parts of deionized water and 0.36 part of “Newcol 707SF” was heated to 80 ° C. after purging with nitrogen. While maintaining the internal solution at 80 ° C., 0.1 part of ammonium persulfate was added, and then a monomer emulsion having the following composition was added dropwise over 3 hours.
Deionized water 52.4 parts Styrene 15 parts Methyl methacrylate 40 parts n-Butyl acrylate 40 parts Methacrylic acid 2 parts Diacetone acrylamide 3 parts "Newcol 707SF" 10 parts Ammonium persulfate 0.2 parts 30 minutes after completion of dropping, 0 for 30 minutes A solution of 1 part ammonium persulfate in 1 part deionized water was added dropwise and kept at 80 ° C. for a further 2 hours. The pH was adjusted to 8.0 with dimethylaminoethanol to obtain an aqueous resin dispersion (I-5) having a solid content concentration of 50%, a weight average molecular weight of 150,000, a glass transition temperature of 20.0 ° C. and an average particle diameter of 185 nm. It was.

Production of water-based urethane resin Production Example 8
In a 2 liter four-necked flask, 268.3 parts of methyl ethyl ketone, 260 parts of polypropylene glycol (molecular weight 2000), 26.5 parts of dimethylolpropionic acid, and 116 parts of isophorone diisocyanate are placed, and dry nitrogen is sealed while stirring. The temperature was raised to 1, and the temperature was maintained for 1 hour, and then the reaction was further performed at 80 ° C. for 6 hours. Then, it cooled to 30 degreeC and obtained the urethane prepolymer solution. While stirring this urethane prepolymer solution in an aqueous amine solution prepared by dissolving 7.8 parts of an 80% hydrazine aqueous solution and 21 parts of triethylamine in 764 parts of deionized water in a 2-liter four-necked flask in advance, gradually A poured product was obtained. The temperature is raised to 50 ° C., the solvent is removed by reducing the pressure, the concentration is adjusted by adding deionized water, and it has a translucent hydrazine group having a solid content of 35.4%, pH 8.4 and an acid value of 34 An aqueous urethane resin (B-1) was obtained.

Production Example 9
In a 2-liter four-necked flask, put 396 parts of methyl ethyl ketone, 333.3 parts of polypropylene glycol (molecular weight 2000), 67 parts of dimethylolpropionic acid, 19.7 parts of 1,6 hexanediol, and 296 parts of isophorone diisocyanate while stirring. After encapsulating dry nitrogen, the temperature was raised to 70 ° C., and the temperature was maintained for 1 hour, and the reaction was further performed at 80 ° C. for 2 hours. Thereafter, 19.3 parts of diacetone alcohol was added dropwise over 30 minutes, and the reaction was further performed at 80 ° C. for 4 hours. Then, it cooled to 30 degreeC and obtained the urethane prepolymer solution. This urethane prepolymer solution was gradually poured into an amine aqueous solution in which 11.8 parts of triethylamine and 10 parts of piperazine were dissolved in 868 parts of deionized water in a 2 liter four-necked flask in advance while stirring. I got a thing. The temperature is raised to 50 ° C., the solvent is removed by reducing the pressure, and the concentration is adjusted by adding deionized water. An aqueous urethane resin (B-2) was obtained.

Production Examples 1 to 7 and Comparative Examples 1 to 2 of aqueous coating composition
Each component shown in the composition (A) shown in Table 2 was sequentially charged into a container, and stirring was continued with a disper for 30 minutes until it became uniform to obtain each pigment paste. Thereafter, each aqueous resin dispersion described in Table 2 was charged into each pigment paste, and further each component shown in the composition (B) described in Table 2 was added in order to obtain each aqueous coating composition. Subsequently, each water-based coating composition was evaluated according to the following criteria. The results are shown in Table 2.

(Note 3) “Suraoff 72N”: trade name, manufactured by Takeda Pharmaceutical Co., Ltd., preservative (Note 4) “Nopco Santo K”: trade name, manufactured by San Nopco, pigment dispersant (Note 5) “Adecanol UH-438 ": Brand name, manufactured by Adeka Corporation, thickener (Note 6)" Titanium white JR-600A ": Brand name, manufactured by Teika Corporation, titanium white, specific gravity 4.1
(Note 7) “SN deformer 380”: trade name, manufactured by San Nopco, defoaming agent (Note 8) “Resamine D-6300”: trade name, manufactured by Dainichi Seika Kogyo Co., Ltd., urethane dispersion (carbonyl group and hydrazine group) 30% solids)
(Note 9) “DICnate 1000W”: trade name, manufactured by Dainippon Ink, metal dryer, Co content 3.6%
(Note 10) “TEXANOL”: trade name, manufactured by Eastman Chemical Co., Ltd., 2,2,4-trimethyl-1,3-pentanediol monoisobutyrate, film-forming aid.

(* 1) After each curable aqueous coating composition was applied to a release paper to a film thickness of 20 μm and dried for 1 week, the free coating film was placed in an acetone solvent at 20 ° C. and extracted for 24 hours. The remaining rate (%) of the coating film was examined. Higher values indicate better curability.
(* 2) Feeling of meat Each water-based paint composition was applied to a glass plate using a 6 mil doctor blade, and dried under conditions of an air temperature of 20 ° C. and a relative humidity of 60% to obtain test coating plates. The appearance of the coating film was visually evaluated after 1 day.
○: Excellent meat feeling.
Δ: Poor feeling of meat
(* 3) Gloss 60 degree gloss of the test coated plate obtained in the same manner as in (2) above was measured. The larger the value, the better the gloss.
(* 4) Water resistance The steel plate (150 × 70 × 0.8 mm) specified in JIS K 5410 is degreased with xylene, and then each aqueous coating composition is diluted to about 70 KU with clean water to make a brush. The coating amount was 150 g / m ² and the coating was dried for one week under conditions of an air temperature of 20 ° C. and a relative humidity of 60% to obtain each test coated plate. Each test coating plate was subjected to a water resistance test (96 hours immersion) according to JIS K 5400 8.19. Each coated surface after the test was evaluated according to the following criteria.
○: There is no cracking or peeling, and the gloss retention is 70% or more.
(Triangle | delta): At least 1 generate | occur | produces among crack, peeling, or gloss retention less than 70%.
(* 5) Initial water resistance A steel plate (150 × 70 × 0.8 mm) specified in JIS K 5410 is degreased with xylene, and each water-based coating composition is diluted to about 70 KU with clean water and then brushed. The coating amount was 150 g / m ² and dried for 1 hour under conditions of an air temperature of 20 ° C. and a relative humidity of 60% to obtain each test coated plate. Each test plate was submerged for 10 minutes, and the appearance of the coating film was visually evaluated.
○: Slight shine or swelling is observed but there is no practical problem.
(Triangle | delta): A bulge is large or many are seen, or one part coating film elution is seen.
×: Elution of the coating film is remarkable (* 6) A steel plate (150 × 70 × 0.8 mm) defined in JIS K 5410 is used as an anticorrosive material and degreased with xylene. The mixture was diluted to about 70 KU with clean water and applied with a brush so that the application amount was 100 g / m ² . Further, after the first drying, the second coating was performed in the same manner as the first coating, and each test coating plate was prepared by drying for 7 days under the conditions of an air temperature of 20 ° C. and a relative humidity of 60%. Each test coating plate was subjected to 36 cycles of a combined cycle anti-corrosion test specified in JIS K 5621, and the coating surface was evaluated according to the following criteria.
○: No rust is observed in the coating film,
Δ: The coating film is minute but rust is observed,
X: Rust is recognized on the entire surface of the coating film.
(* 7) Each test coated plate prepared in the same manner as for the accelerated weather resistance and corrosion resistance test was irradiated for 1000 hours in accordance with the accelerated weather resistance test of 9.8.1 (Sunshine carbon arc lamp type) of JIS K 5400. Then, each coated plate surface was evaluated by 9.6 chalking degree of JIS K 5400. The lower the score, the more chalking is progressing.
(* 8) Elongation at low temperature “Ares Rubber Tile Rough” (manufactured by Kansai Paint Co., Ltd., main component for thickening for exterior) was applied on a plate with a 2 mm blade, and after 24 hours, each paint was 100 g / m Painted with a brush to be ² . Two more hours later, the same paint was applied again. Thereafter, it was cured in accordance with the standard of JIS A 6909, and punched with a No. 2 dumbbell was used as a test piece, and an elongation test was performed at -10 ° C.

Claims (6)

(A) A monomer mixture (I) containing a fatty acid-modified polymerizable unsaturated monomer (a) and other polymerizable unsaturated monomer (b) is finely dispersed in an aqueous medium so that the average particle size is 500 nm or less, It contains an aqueous fatty acid-modified resin dispersion produced by polymerizing the resulting monomer emulsion and (B) an aqueous urethane resin, and the blending ratio of the resin (A) and the resin (B) is 10 in terms of solid content by weight. A water-based resin composition characterized by being in the range of / 90 to 99/1. The aqueous resin composition according to claim 1, wherein the aqueous urethane resin has a carbonyl group or a hydrazine group. The aqueous resin composition according to claim 1 or 2, further comprising a hydrazine derivative. An aqueous coating composition comprising the aqueous resin composition according to any one of claims 1 to 3. A coating film forming method, wherein the water-based coating composition according to claim 4 is applied to a surface to be coated. The coated article obtained by the coating-film formation method of Claim 5.