JP6712888B2 - Aqueous resin composition for paint - Google Patents

Description

The present invention relates to an aqueous resin composition for paint. More specifically, the present invention is a water-based resin composition for coating material, which can be suitably used for surface finishing of a base material made of a material such as metal, glass, porcelain, concrete, siding board, and resin, for the coating material. The present invention relates to a gloss coating material containing an aqueous resin composition and a substrate having a coating film made of the gloss coating material. The aqueous resin composition for coatings of the present invention has a high gel fraction, is excellent in storage stability at high temperatures, and is excellent in gloss, extensibility, weather resistance and long-term hydrophilicity of the coating, and thus, for example, It can be suitably used for applications such as ceramic building materials, automobiles, buildings, and civil engineering structures, and in particular for building exteriors and top coats for ceramic building materials.

Weather resistance, warm water whitening resistance, frost damage resistance and blocking resistance are good, as a water-based resin composition for coatings forming a film excellent in stain resistance, a resin emulsion and a water-soluble polymer obtained by emulsion polymerization and A water-based resin composition for a coating composition, which comprises a resin emulsion and a water-soluble polymer capable of forming a crosslinked structure, has been proposed (see, for example, Patent Document 1).

The water-based resin composition for coating forms a film having good weather resistance, warm water whitening resistance, frost damage resistance, and blocking resistance. However, in recent years, development of a water-based resin composition for coating having a high gel fraction, excellent storage stability at high temperatures, and comprehensively excellent film gloss, extensibility, weather resistance and long-term hydrophilicity has been awaited. There is.

International publication 2008/102816 pamphlet

The present invention has been made in view of the above-mentioned prior art, has a high gel fraction, is excellent in storage stability at high temperatures, and is excellent in overall gloss, extensibility, weather resistance and long-term hydrophilicity of a coating. An object is to provide an aqueous resin composition for paints. Further, the present invention contains the above aqueous resin composition for paints, has a high gel fraction, is excellent in storage stability at high temperatures, and is excellent in gloss, extensibility, weather resistance and long-term hydrophilicity of a coating film. It is an object of the present invention to provide a glossy paint. Furthermore, the present invention is to provide a substrate having a coating film formed from the above-mentioned gloss coating material, the substrate having a coating film that is comprehensively excellent in gloss, extensibility, weather resistance and long-term hydrophilicity. And

The present invention is
(1) An aqueous resin composition for coating material, which comprises emulsion particles, a water-soluble polymer and a cross-linking agent, wherein a monomer component used as a raw material for the emulsion particles is 0.1 to 10 mass of a carbonyl group-containing monomer. %, the water-soluble polymer has a weight average molecular weight of 1,000 to 50,000, and the crosslinking agent is an oxazoline-based crosslinking agent, a hydrazine-based crosslinking agent, a blocked isocyanate-based crosslinking agent, an aziridine-based crosslinking agent and a carbodiimide-based crosslinking agent. An aqueous resin composition for paints, which comprises two or more kinds of cross-linking agents selected from the group consisting of agents
(2) A gloss coating material comprising the aqueous resin composition for coating material according to (1) above, and (3) a substrate having a coating film comprising the gloss coating material according to (2) above.

In addition, in this specification, "(meth)acrylate" means "acrylate" or "methacrylate", and "(meth)acryl" means "acryl" or "methacryl."

According to the present invention, a high gel fraction, excellent storage stability at high temperature, coating coating aqueous resin composition excellent in gloss, stretchability, weather resistance and long-term hydrophilicity, gel fraction High-quality, excellent storage stability at high temperature, comprehensively excellent gloss, extensibility, weather resistance and long-term hydrophilicity of coating, and comprehensively gloss, extensibility, weatherability and long-term hydrophilicity Substrates having excellent coatings are provided.

As described above, the coating aqueous resin composition of the present invention is a coating aqueous resin composition containing emulsion particles, a water-soluble polymer and a crosslinking agent, and the monomer component used as a raw material of the emulsion particles is The water-soluble polymer has a weight average molecular weight of 1,000 to 50,000, and contains carbonyl group-containing monomer in an amount of 0.1 to 10% by mass, and the crosslinking agent is an oxazoline-based crosslinking agent, a hydrazine-based crosslinking agent, or a blocked isocyanate. It is characterized in that it is two or more kinds of crosslinking agents selected from the group consisting of a crosslinking agent, an aziridine crosslinking agent and a carbodiimide crosslinking agent.

In the present invention, the monomer component used as a raw material for emulsion particles contains 0.1 to 10% by mass of a carbonyl group-containing monomer.

In the present invention, the carbonyl group-containing monomer is a monomer having a group represented by the formula: ═C═O, in which one of the two bonds of the carbonyl group has a hydrogen atom. Alternatively, it means a monomer to which an alkyl group is bonded and a group having a polymerizable unsaturated double bond at the terminal such as a vinyl group is bonded to the other bond.

As the carbonyl group-containing monomer, for example, acrylolein, methacrolein, horomylstyrene, vinyl ethyl ketone, acryloxyalkylpropenal, methacryloxyalkylpropenal, acetonyl acrylate, acetonyl methacrylate, diacetone acrylate, die Acetone methacrylate, diacetone acrylamide, diacetone methacrylamide, 2-hydroxypropyl acrylate acetyl acetate, 2-hydroxypropyl methacrylate acetyl acetate, butanediol-1,4-acrylate acetyl acetate, 2-(acetoacetoxy)ethyl acrylate, 2- Examples thereof include (acetoacetoxy)ethyl methacrylate, but the present invention is not limited to such examples. These carbonyl group-containing monomers may be used alone or in combination of two or more.

The content of the carbonyl group-containing monomer in the monomer component used as the raw material of the emulsion particles is 0.1 from the viewpoint of improving the gel fraction and forming a coating film excellent in weather resistance and long-term hydrophilicity. Mass% or more, preferably 0.2 mass% or more, more preferably 0.3 mass% or more, further preferably 0.5 mass% or more, to improve the extensibility and weather resistance of the coating film and at high temperature. From the viewpoint of obtaining an aqueous resin composition for coating having excellent storage stability, it is 10% by mass or less, preferably 8% by mass or less, and more preferably 5% by mass or less.

As the monomer used in the monomer component, in addition to the carbonyl group-containing monomer, for example, a carboxyl group-containing monomer, an alkyl (meth) acrylate, a monomer having an alicyclic structure, a hydroxyl group-containing ( (Meth)acrylate, aromatic monomer, silicon atom-containing monomer, fluorine atom-containing monomer, nitrogen atom-containing monomer, epoxy group-containing monomer, UV absorbing monomer, UV stable monomer Examples thereof include, but are not limited to, such examples. These monomers may be used alone or in combination of two or more kinds.

Examples of the carboxyl group-containing monomer include, for example, carboxyl group-containing aliphatic monomers such as acrylic acid, methacrylic acid, maleic acid, fumaric acid, and crotonic acid, but the present invention is limited to such examples. It is not limited. These monomers may be used alone or in combination of two or more kinds.

The content of the carboxyl group-containing monomer in the monomer component used as the raw material of the emulsion particles is improved from the viewpoint of obtaining an aqueous resin composition for coating which improves the extensibility of the coating film and has excellent storage stability at high temperatures. Therefore, it is preferably 10% by mass or less, more preferably 8% by mass or less, further preferably 5% by mass or less, and the lower limit thereof is 0% by mass.

Examples of the alkyl (meth)acrylate include methyl (meth)acrylate, ethyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, tert-butyl (meth)acrylate, sec-butyl (meth). Acrylate, 2-ethylhexyl (meth)acrylate, tridecyl (meth)acrylate, n-octyl (meth)acrylate, alkyl (meth)acrylate having 1 to 18 carbon atoms of the ester group such as n-lauryl (meth)acrylate, etc. However, the present invention is not limited to only these examples. These monomers may be used alone or in combination of two or more kinds. Among these alkyl (meth)acrylates, a water-based resin composition for coatings having a high gel fraction, excellent storage stability at high temperatures, and comprehensively excellent film gloss, extensibility, weather resistance and long-term hydrophilicity. From the viewpoint of obtaining a product, the alkyl group such as methyl (meth)acrylate, n-butyl (meth)acrylate, tert-butyl (meth)acrylate, and 2-ethylhexyl (meth)acrylate has 1 to 12 carbon atoms, preferably 1 carbon atom. Alkyl (meth)acrylates of ~8 are preferred.

In the monomer having an alicyclic structure, the alicyclic structure is preferably a cycloalkyl group having 4 to 20 carbon atoms, and more preferably a cycloalkyl group having 4 to 10 carbon atoms. Examples of the monomer having an alicyclic structure include cycloalkyl (meth)acrylate and cycloalkylalkyl (meth)acrylate, and these monomers may be used alone or in combination of two or more. You may use together. Moreover, these monomers may have a substituent. Examples of the substituent include an alkyl group such as a methyl group and a tert-butyl group, a nitro group, a nitrile group, an alkoxyl group, an acyl group, a sulfone group, a hydroxyl group, and a halogen atom. It is not limited to the examples.

As the cycloalkyl (meth)acrylate, for example, a cycloalkyl (meth)acrylate in which the cycloalkyl group such as isobornyl (meth)acrylate and cyclohexyl (meth)acrylate has preferably 4 to 20, and more preferably 4 to 10 carbon atoms. However, the present invention is not limited to such examples. These cycloalkyl (meth)acrylates may be used alone or in combination of two or more. The cycloalkylalkyl (meth)acrylate includes, for example, cyclohexylmethyl (meth)acrylate, cyclohexylethyl (meth)acrylate, cyclohexylpropyl (meth)acrylate, 4-methylcyclohexylmethyl (meth)acrylate, and the like, having the number of carbon atoms of the cycloalkyl group. Is preferably 4 to 20, and more preferably 4 to 10, and examples thereof include a cycloalkylalkyl (meth)acrylate in which the alkyl group has 1 to 4 carbon atoms. These cycloalkylalkyl (meth)acrylates include Each may be used alone or in combination of two or more.

Among the monomers having an alicyclic structure, a cycloalkyl (meth)acrylate having a cycloalkyl group having 4 to 20 carbon atoms is preferable, and a cycloalkyl (meth) having a cycloalkyl group having 4 to 10 carbon atoms is preferable. Acrylate is more preferred, and isobornyl (meth)acrylate and cyclohexyl (meth)acrylate are even more preferred.

Examples of the hydroxyl group-containing (meth)acrylate include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, and 4-hydroxy. Examples thereof include a hydroxyl group-containing (meth)acrylate having an ester group having 1 to 18 carbon atoms such as butyl (meth)acrylate and glycerin mono (meth)acrylate, but the present invention is not limited to these examples. .. These monomers may be used alone or in combination of two or more kinds. Among these hydroxyl group-containing (meth)acrylates, a water-based resin for coatings that has a high gel fraction, excellent storage stability at high temperatures, and comprehensively excellent film gloss, extensibility, weather resistance and long-term hydrophilicity. From the viewpoint of obtaining the composition, 2-hydroxyethyl (meth)acrylate and glycerin mono(meth)acrylate are preferable.

Examples of the aromatic monomer include styrene, α-methylstyrene, p-methylstyrene, tert-methylstyrene, chlorostyrene, aralkyl(meth)acrylate, vinyltoluene, etc. It is not limited to the examples. Examples of the aralkyl (meth)acrylate include aralkyl having an aralkyl group having 7 to 18 carbon atoms such as benzyl (meth)acrylate, phenylethyl (meth)acrylate, methylbenzyl (meth)acrylate, and naphthylmethyl (meth)acrylate. Examples thereof include (meth)acrylates, but the present invention is not limited to these examples. These aromatic monomers may be used alone or in combination of two or more. Among these aromatic monomers, styrene is preferable.

Examples of the silicon atom-containing monomer include vinyltrichlorosilane, vinyltris(β-methoxyethoxy)silane, vinyltrimethoxysilane, vinyltriethoxysilane, γ-(meth)acryloyloxypropyltrimethoxysilane, and trimethylsiloxyethyl( Examples thereof include, but are not limited to, such examples. These monomers may be used alone or in combination of two or more kinds.

Examples of the fluorine atom-containing monomer include fluorine atom-containing alkyl having an ester group of 2 to 6 carbon atoms, such as trifluoroethyl (meth)acrylate, tetrafluoropropyl (meth)acrylate and octafluoropentyl (meth)acrylate. Examples thereof include (meth)acrylates, but the present invention is not limited to these examples. These monomers may be used alone or in combination of two or more kinds.

Examples of the nitrogen atom-containing monomer include (meth)acrylamide, (meth)acrylamide compounds such as N,N-dimethylaminopropyl (meth)acrylamide, dimethylaminoethyl (meth)acrylate, and diethylaminoethyl (meth)acrylate. Nitrogen atom-containing (meth)acrylate compounds and the like are listed, but the present invention is not limited to these examples. These monomers may be used alone or in combination of two or more kinds.

Examples of the epoxy group-containing monomer include epoxy group-containing (meth)acrylates such as glycidyl (meth)acrylate, but the present invention is not limited to these examples. These monomers may be used alone or in combination of two or more kinds.

Examples of the ultraviolet absorbing monomer include a benzotriazole-based ultraviolet absorbing monomer and a benzophenone-based ultraviolet absorbing monomer, but the present invention is not limited to such examples. These monomers may be used alone or in combination of two or more kinds.

Examples of the benzotriazole-based UV absorbing monomer include 2-[2'-hydroxy-5'-(meth)acryloyloxymethylphenyl]-2H-benzotriazole and 2-[2'-hydroxy-5'-. (Meth)acryloyloxyethylphenyl]-2H-benzotriazole, 2-[2'-hydroxy-5'-(meth)acryloyloxymethylphenyl]-5-tert-butyl-2H-benzotriazole, 2-[2' -Hydroxy-5'-(meth)acryloylaminomethyl-5'-tert-octylphenyl]-2H-benzotriazole, 2-[2'-hydroxy-5'-(meth)acryloyloxypropylphenyl]-2H-benzo Triazole, 2-[2'-hydroxy-5'-(meth)acryloyloxyhexylphenyl]-2H-benzotriazole, 2-[2'-hydroxy-3'-tert-butyl-5'-(meth)acryloyloxy Ethylphenyl]-2H-benzotriazole, 2-[2'-hydroxy-3'-tert-butyl-5'-(meth)acryloyloxyethylphenyl]-5-chloro-2H-benzotriazole, 2-[2'. -Hydroxy-5'-tert-butyl-3'-(meth)acryloyloxyethylphenyl]-2H-benzotriazole, 2-[2'-hydroxy-5'-(meth)acryloyloxyethylphenyl]-5-chloro -2H-benzotriazole, 2-[2'-hydroxy-5'-(meth)acryloyloxyethylphenyl]-5-cyano-2H-benzotriazole, 2-[2'-hydroxy-5'-(meth)acryloyl Oxyethylphenyl]-5-tert-butyl-2H-benzotriazole, 2-[2'-hydroxy-5'-(β-(meth)acryloyloxyethoxy)-3'-tert-butylphenyl]-4-tert -Butyl-2H-benzotriazole and the like can be mentioned, but the present invention is not limited to such examples. These benzotriazole-based UV absorbing monomers may be used alone or in combination of two or more kinds.

Examples of the benzophenone-based UV absorbing monomer include 2-hydroxy-4-(meth)acryloyloxybenzophenone, 2-hydroxy-4-[2-hydroxy-3-(meth)acryloyloxy]propoxybenzophenone, and 2-hydroxy-4-[2-hydroxy-3-(meth)acryloyloxy]propoxybenzophenone. Hydroxy-4-[2-(meth)acryloyloxy]ethoxybenzophenone, 2-hydroxy-4-[3-(meth)acryloyloxy-2-hydroxypropoxy]benzophenone, 2-hydroxy-3-tert-butyl-4- Examples include [2-(meth)acryloyloxy]butoxybenzophenone, but the present invention is not limited to these examples. These benzophenone-based UV absorbing monomers may be used alone or in combination of two or more.

Examples of the UV stable monomer include 4-(meth)acryloyloxy-2,2,6,6-tetramethylpiperidine and 4-(meth)acryloylamino-2,2,6,6-tetramethylpiperidine. , 4-(meth)acryloyloxy-1,2,2,6,6-pentamethylpiperidine, 4-(meth)acryloyl-1-methoxy-2,2,6,6-tetramethylpiperidine, 4-cyano- 4-(meth)acryloyloxy-2,2,6,6-tetramethylpiperidine, 1-(meth)acryloyl-4-(meth)acryloylamino-2,2,6,6-tetramethylpiperidine, 4-croto Noylamino-2,2,6,6-tetramethylpiperidine, 4-(meth)acryloylamino-1,2,2,6,6-pentamethylpiperidine, 4-cyano-4-(meth)acryloylamino-2 , 2,6,6-Tetramethylpiperidine, 4-crotonoyloxy-2,2,6,6-tetramethylpiperidine, 1-(meth)acryloyl-4-cyano-4-(meth)acryloylamino-2, 2,6,6-tetramethylpiperidine, 1-crotonoyl-4-crotonoyloxy-2,2,6,6-tetramethylpiperidine and the like can be mentioned, but the present invention is not limited to these examples. Absent. These UV stable monomers may be used alone or in combination of two or more kinds.

The emulsion particles may have either a single-layer structure or a multi-layer structure, but have a high gel fraction, are excellent in storage stability at high temperatures, and have gloss, extensibility, weather resistance and From the viewpoint of obtaining a water-based resin composition for coatings that is generally superior in long-term hydrophilicity, it preferably has a multilayer structure, more preferably 2 to 4 layers, and even more preferably 2 or 3 layers. ..

Hereinafter, a case where the emulsion particles have an inner layer and an outer layer will be described, but the present invention is not limited to such an embodiment, and may have a layer structure of two or more layers.

Examples of the monomer component used as a raw material for the polymer forming the inner layer (hereinafter referred to as monomer component A) include, for example, carbonyl group-containing monomer, carboxyl group-containing monomer, alkyl (meth)acrylate, Monomers having alicyclic structure, hydroxyl group-containing (meth)acrylate, aromatic monomers, silicon atom-containing monomers, fluorine atom-containing monomers, nitrogen atom-containing monomers, epoxy group-containing monomers However, the present invention is not limited to these examples. These monomers may be used alone or in combination of two or more kinds.

As the monomer component A, an aqueous resin composition for coating having a high gel fraction, excellent storage stability at high temperatures, and comprehensively excellent film gloss, extensibility, weather resistance and long-term hydrophilicity is obtained. From the viewpoint, it is preferable that an alkyl (meth)acrylate and a monomer having an alicyclic structure are contained.

The content of the alkyl (meth)acrylate in the monomer component A is high in gel fraction, excellent in storage stability at high temperature, and excellent in gloss, extensibility, weather resistance and long-term hydrophilicity of the coating film. From the viewpoint of obtaining a water-based resin composition for coatings, it is preferably 10 to 85% by mass, more preferably 15 to 70% by mass.

The content of the monomer having an alicyclic structure in the monomer component A has a high gel fraction, is excellent in storage stability at high temperatures, and is comprehensive in the gloss, extensibility, weather resistance and long-term hydrophilicity of the coating. From the viewpoint of obtaining an excellent water-based resin composition for coatings, it is preferably 5 to 60% by mass, more preferably 10 to 55% by mass.

The content of the hydroxyl group-containing (meth)acrylate in the monomer component A is high in gel fraction, excellent in storage stability at high temperature, and excellent in gloss, extensibility, weather resistance and long-term hydrophilicity of the coating film. From the viewpoint of obtaining the aqueous resin composition for coating composition, the content is preferably 0 to 20% by mass, more preferably 0.5 to 15% by mass, and further preferably 1 to 15% by mass.

The content of the carboxyl group-containing monomer in the monomer component A is high in gel fraction, excellent in storage stability at high temperature, and excellent in gloss, extensibility, weather resistance and long-term hydrophilicity of the coating as a whole. From the viewpoint of obtaining the water-based resin composition for coating materials, it is preferably 0 to 10% by mass, more preferably 0.5 to 10% by mass, and further preferably 1 to 5% by mass.

The content of the aromatic monomer in the monomer component A is high in gel fraction, excellent in storage stability at high temperature, and excellent in gloss, extensibility, weather resistance and long-term hydrophilicity of the coating film. From the viewpoint of obtaining a water-based resin composition for coatings, it is preferably 5 to 30 mass%, more preferably 5 to 25 mass%.

As a method for emulsion-polymerizing the monomer component A, for example, an emulsifier is dissolved in an aqueous medium containing a water-soluble organic solvent such as a lower alcohol such as methanol and water, and a medium such as water, and the mixture is heated and stirred under simple conditions. Examples include a method of dropping the monomer component A and the polymerization initiator, and a method of dropping the monomer component A previously emulsified with an emulsifier and water into water or an aqueous medium. The method is not limited only. The amount of the medium may be appropriately set in consideration of the amount of non-volatile components contained in the obtained resin emulsion.

Examples of emulsifiers include anionic emulsifiers, nonionic emulsifiers, cationic emulsifiers, amphoteric emulsifiers, and polymeric emulsifiers. These emulsifiers may be used alone or in combination of two or more kinds.

Examples of the anionic emulsifier include alkyl sulfate salts such as ammonium dodecyl sulfate and sodium dodecyl sulfate; alkyl sulfonate salts such as ammonium dodecyl sulfonate and sodium dodecyl sulfonate; alkyl aryl sulfonate salts such as ammonium dodecyl benzene sulfonate and sodium dodecyl naphthalene sulfonate; The polyoxyethylene alkyl sulfate salt; the polyoxyethylene alkyl aryl sulfate salt; the dialkyl sulfosuccinate salt; the aryl sulfonic acid-formalin condensate; the fatty acid salts such as ammonium laurate and sodium stearate. It is not limited to the examples.

Examples of nonionic emulsifiers include polyoxyethylene alkyl ethers, polyoxyethylene alkylaryl ethers, condensation products of polyethylene glycol and polypropylene glycol, sorbitan fatty acid esters, polyoxyethylene sorbitan fatty acid esters, fatty acid monoglycerides, ethylene oxide and aliphatic compounds. Examples thereof include condensates with amines, but the present invention is not limited to these examples.

Examples of the cationic emulsifier include alkylammonium salts such as dodecylammonium chloride, but the present invention is not limited to these examples.

Examples of the amphoteric emulsifiers include betaine ester type emulsifiers, but the present invention is not limited to these examples.

Examples of the polymeric emulsifier include poly(meth)acrylic acid salts such as sodium polyacrylate; polyvinyl alcohol; polyvinylpyrrolidone; polyhydroxyalkyl (meth)acrylates such as polyhydroxyethyl acrylate; Examples thereof include polymers having one or more kinds of monomers as copolymerization components, but the present invention is not limited to these examples.

Further, as the emulsifier, a gel fraction having a high gel fraction, excellent in storage stability at high temperature, and gloss of the film, extensibility, weather resistance and a viewpoint of obtaining an aqueous resin composition for coating comprehensively excellent in long-term hydrophilicity Therefore, an emulsifier having a reactive group, that is, a so-called reactive emulsifier is preferable, and a non-nonylphenyl type emulsifier is preferable from the viewpoint of environmental protection.

As the reactive emulsifier, for example, propenyl-alkyl sulfosuccinic acid ester salt, (meth)acrylic acid polyoxyethylene sulfonate salt, (meth)acrylic acid polyoxyethylene phosphonate salt [eg, Sanyo Chemical Industry Co., Ltd., Trade name: Eleminol RS-30, etc.], polyoxyethylene alkylpropenyl phenyl ether sulfonate salt [for example, manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd., trade name: Aqualon HS-10, etc.], allyloxymethylalkyloxypolyoxyethylene Sulfonate salt [for example, manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd., trade name: Aqualon KH-10, etc.], Sulfonate salt of allyloxymethylnonylphenoxyethylhydroxypolyoxyethylene [for example, manufactured by ADEKA Co., Ltd., trade name: ADEKA Riasoap SE-10 etc.], allyloxymethylalkoxyethyl hydroxypolyoxyethylene sulfate ester salt [eg, manufactured by ADEKA, trade name: ADEKA Riasorp SR-10, SR-30 etc.], bis(polyoxyethylene Polycyclic phenyl ether) methacrylated sulfonate salt (for example, manufactured by Nippon Emulsifier Co., Ltd., trade name: Antox MS-60 etc.), allyloxymethylalkoxyethyl hydroxypolyoxyethylene [for example, manufactured by ADEKA Co., Ltd., trade name : ADEKA REASOAP ER-20, etc.], polyoxyethylene alkylpropenyl phenyl ether [eg, Dai-ichi Kogyo Seiyaku Co., Ltd., trade name: Aqualon RN-20, etc.], allyloxymethylnonylphenoxyethyl hydroxypolyoxyethylene [ Examples thereof include ADEKA Corporation, trade name: ADEKA RIASOAP NE-10, etc., but the present invention is not limited to such examples.

The amount of the emulsifier per 100 parts by mass of the monomer component A is preferably 0.5 parts by mass or more, more preferably 1 part by mass or more from the viewpoint of improving the homopolymerization stability, and improves the water permeation resistance of the coating. From the viewpoint of controlling the amount, it is preferably 10 parts by mass or less, more preferably 7 parts by mass or less, and further preferably 5 parts by mass or less.

Examples of the polymerization initiator include azobisisobutyronitrile, 2,2-azobis(2-methylbutyronitrile), 2,2-azobis(2,4-dimethylvaleronitrile), 2,2-azobis( Azo compounds such as 2-diaminopropane) hydrochloride, 4,4-azobis(4-cyanovaleric acid) and 2,2-azobis(2-methylpropionamidine); persulfates such as potassium persulfate; hydrogen peroxide Examples thereof include benzoyl peroxide, parachlorobenzoyl peroxide, lauroyl peroxide, and peroxides such as ammonium peroxide, but the present invention is not limited to these examples. These polymerization initiators may be used alone or in combination of two or more kinds.

The amount of the polymerization initiator per 100 parts by mass of the monomer component A is preferably 0.05 parts by mass or more, more preferably from the viewpoint of increasing the polymerization rate and reducing the residual amount of the unreacted monomer component A. The amount is 0.1 parts by mass or more, and preferably 1 part by mass or less, more preferably 0.5 parts by mass or less, from the viewpoint of improving the water permeation resistance of the formed film.

The method of adding the polymerization initiator is not particularly limited. Examples of the addition method include batch charging, divided charging, continuous dropping and the like. From the viewpoint of accelerating the end time of the polymerization reaction, a part of the polymerization initiator may be added to the flask before or after the addition of the monomer component A into the reaction system.

In order to accelerate the decomposition of the polymerization initiator, for example, a reducing agent such as sodium hydrogen sulfite, a decomposition agent for the polymerization initiator such as a transition metal salt such as ferrous sulfate is added to the reaction system in an appropriate amount. Good.

In addition, in the reaction system, if necessary, for example, a chain transfer agent such as a compound having a thiol group such as tert-dodecyl mercaptan, a pH buffer, a chelating agent, an additive such as a film-forming auxiliary agent is added to the flask. You may. The amount of the additive per 100 parts by mass of the monomer component A cannot be unconditionally determined because it depends on the kind thereof, but it is usually preferably 0.01 to 5 parts by mass, more preferably 0.1 to 3 parts by mass. It is a mass part.

The atmosphere for emulsion-polymerizing the monomer component A is not particularly limited, but is preferably an inert gas such as nitrogen gas from the viewpoint of increasing the efficiency of the polymerization initiator.

The polymerization temperature for emulsion-polymerizing the monomer component A is not particularly limited, but is usually preferably 50 to 100°C, more preferably 60 to 95°C. The polymerization temperature may be constant or may be changed during the polymerization reaction.

The polymerization time for emulsion-polymerizing the monomer component A is not particularly limited and may be appropriately set depending on the progress of the polymerization reaction, but is usually about 2 to 9 hours.

By emulsion-polymerizing the monomer component A as described above, emulsion particles forming the inner layer are obtained.

The polymer forming the emulsion particles may have a crosslinked structure. The weight average molecular weight of the polymer is preferably 100,000 or more, more preferably 300,000 or more, further preferably 550,000 or more, and still more preferably 600,000 or more, from the viewpoint of improving the water resistance of the coating film. The upper limit of the weight average molecular weight of the polymer is not particularly limited because it is difficult to measure the weight average molecular weight when it has a crosslinked structure, but when it does not have a crosslinked structure, it improves the film-forming property. From the viewpoint, it is preferably 5 million or less.

In the present specification, the weight average molecular weight of the polymer is determined by gel permeation chromatography [manufactured by Hitachi High-Tech Fielding Co., product number: LaChrom L-7000, column: manufactured by Tosoh Co., Ltd. TSKgel α-M]. The weight average molecular weight (in terms of polyethylene glycol) was measured by using two in series].

Next, in a reaction solution obtained by emulsion-polymerizing the monomer component A, a monomer component used as a raw material of the polymer forming the outer layer (hereinafter, referred to as a monomer component B) is emulsion-polymerized, An outer layer can be formed.

When emulsion-polymerizing the monomer component B, the polymerization reaction rate of the polymer obtained by emulsion-polymerizing the monomer component A reaches 90% or more, preferably 95% or more, and then the monomer Emulsion polymerization of the component B is preferable from the viewpoint of forming a layer separation structure within the emulsion particles.

In addition, after forming the inner layer by polymerizing the monomer component A and before forming the outer layer, an intermediate layer made of another polymer is formed, if necessary, within a range not impairing the object of the present invention. It may have been done. Therefore, in the present invention, after the emulsion polymerization of the monomer component A to form the inner layer and before the emulsion polymerization of the monomer component B to form the outer layer, within a range that does not impair the object of the present invention. Other layers may be formed.

In the present invention, a high gel fraction, excellent storage stability at high temperature, gloss of the film, extensibility, weather resistance and from the viewpoint of obtaining a coating aqueous resin composition excellent in long-term hydrophilicity, It is preferable that the monomer component B contains a carbonyl group-containing monomer.

Among the carbonyl group-containing monomers, an aqueous resin composition for coatings having a high gel fraction, excellent storage stability at high temperatures, and comprehensively excellent film gloss, extensibility, weather resistance and long-term hydrophilicity. From the viewpoint of obtaining acryloline, methacrolein, horomylstyrene, vinyl ethyl ketone, acryloxyalkylpropenal, methacryloxyalkylpropenal, acetonyl acrylate, acetonyl methacrylate, diacetone acrylate, diacetone methacrylate, diacetone acrylamide. And diacetone methacrylamide are preferred, acrylolein, methacrolein, homyl styrene, acetonyl acrylate, acetonyl methacrylate, diacetone acrylate, diacetone methacrylate, diacetone acrylamide and diacetone methacrylamide are more preferred, and acrylolein, methacrolein. Rhein, acetonyl acrylate, acetonyl methacrylate, diacetone acrylate, diacetone methacrylate, diacetone acrylamide and diacetone methacrylamide are more preferable, and diacetone acrylate, diacetone methacrylate, diacetone acrylamide and diacetone methacrylamide are even more preferable. ..

The content of the carbonyl group-containing monomer in the monomer component B is high in gel fraction, excellent in storage stability at high temperature, and comprehensively excellent in gloss, extensibility, weather resistance and long-term hydrophilicity of the coating. From the viewpoint of obtaining a water-based resin composition for a coating composition, the content is preferably 0.2% by mass or more, more preferably 0.5% by mass or more, still more preferably 1% by mass or more, and has a high gel fraction and high temperature. From the viewpoint of obtaining a water-based resin composition for a coating which is excellent in storage stability and has comprehensively excellent film gloss, extensibility, weather resistance and long-term hydrophilicity, preferably 20% by mass or less, more preferably 15% by mass or less. , And more preferably 10% by mass or less.

Examples of the monomer other than the carbonyl group-containing monomer in the monomer component B (hereinafter referred to as other monomer B) include, for example, alkyl (meth)acrylate, alicyclic structure-containing monomer, and hydroxyl group-containing (Meth)acrylate, aromatic monomer, carboxyl group-containing monomer, silicon atom-containing monomer, fluorine atom-containing monomer, nitrogen atom-containing monomer, epoxy group-containing monomer, UV absorption Examples thereof include monomers and UV-stable monomers, but the present invention is not limited to these examples. These monomers may be used alone or in combination of two or more kinds.

The content of the other monomer B in the monomer component B is high in gel fraction, excellent in storage stability at high temperature, and excellent in gloss, extensibility, weather resistance and long-term hydrophilicity of the coating as a whole. From the viewpoint of obtaining a water-based resin composition for coatings, it is preferably 80% by mass or more, more preferably 85% by mass or more, further preferably 90% by mass or more, and has a high gel fraction and high storage stability at high temperatures. From the viewpoint of obtaining a water-based resin composition for coating which is excellent and has excellent gloss, extensibility, weather resistance and long-term hydrophilicity of the coating, it is preferably 99.8 mass% or less, more preferably 99.5 mass% or less. , And more preferably 99% by mass or less.

The monomer component B has a high gel fraction, is excellent in storage stability at high temperatures, and has a viewpoint of obtaining an aqueous resin composition for coating which is excellent in gloss, extensibility, weather resistance and long-term hydrophilicity of the coating. Therefore, it is preferable to contain an alkyl (meth)acrylate and a monomer having an alicyclic structure.

The content of the alkyl (meth)acrylate in the monomer component B is high in gel fraction, excellent in storage stability at high temperature, and excellent in gloss, extensibility, weather resistance and long-term hydrophilicity of the coating film. From the viewpoint of obtaining a water-based resin composition for coatings, it is preferably 35 to 70% by mass, more preferably 40 to 65% by mass.

The content of the monomer having an alicyclic structure in the monomer component B is high in gel fraction, excellent in storage stability at high temperature, and comprehensive in gloss, extensibility, weather resistance and long-term hydrophilicity of the coating. From the viewpoint of obtaining an excellent aqueous resin composition for coatings, the content is preferably 3 to 35% by mass, more preferably 5 to 30% by mass.

The content of the silicon atom-containing monomer in the monomer component B is high in gel fraction, excellent in storage stability at high temperature, and excellent in gloss, extensibility, weather resistance and long-term hydrophilicity of the coating as a whole. From the viewpoint of obtaining an aqueous resin composition for coating materials, the content is preferably 0 to 10% by mass, more preferably 0 to 5% by mass.

The content of the UV stable monomer in the monomer component B is high in gel fraction, excellent in storage stability at high temperature, and excellent in gloss, extensibility, weather resistance and long-term hydrophilicity of the coating as a whole. From the viewpoint of obtaining an aqueous resin composition for coating materials, the content is preferably 0 to 5% by mass, more preferably 0 to 3% by mass.

The content of the hydroxyl group-containing (meth)acrylate in the monomer component B is high in gel fraction, excellent in storage stability at high temperature, and excellent in gloss, extensibility, weather resistance and long-term hydrophilicity of the coating film. From the viewpoint of obtaining a water-based resin composition for coating materials, it is preferably 0 to 30% by mass, more preferably 3 to 25% by mass.

The emulsion polymerization method and the polymerization conditions for the monomer component B may be the same as the emulsion polymerization method and the polymerization conditions for the monomer A.

By emulsion-polymerizing the monomer component B as described above, it is possible to obtain emulsion particles in which the polymer forming the outer layer is formed on the surface of the inner layer. If necessary, a surface layer made of another polymer may be further formed on the surface of the outer layer of the emulsion particles, as long as the object of the present invention is not impaired.

The polymer obtained by emulsion-polymerizing the monomer component B may have a crosslinked structure. The weight average molecular weight of the polymer is preferably 100,000 or more, more preferably 300,000 or more, further preferably 550,000 or more, and particularly preferably 600,000 or more, from the viewpoint of improving the water resistance of the coating film. The upper limit of the weight average molecular weight of the polymer is not particularly limited because it is difficult to measure the weight average molecular weight when it has a crosslinked structure, but when it does not have a crosslinked structure, it improves the film-forming property. From the viewpoint, it is preferably 5 million or less.

The glass transition temperature of either the polymer that constitutes the inner layer or the polymer that constitutes the outer layer has a high gel fraction, excellent storage stability at high temperatures, and gloss and extensibility of the film. From the viewpoint of obtaining a water-based resin composition for a coating that is generally excellent in weather resistance and long-term hydrophilicity, it is preferably 30° C. or higher, more preferably 35° C. or higher, and has excellent storage stability at high temperatures and From the viewpoint of obtaining a water-based resin composition for coating which is excellent in gloss, extensibility, weather resistance and long-term hydrophilicity, the temperature is preferably 180°C or lower, more preferably 150°C or lower, and further preferably 110°C or lower.

The glass transition temperature of either the polymer that constitutes the inner layer or the polymer that constitutes the outer layer has a high gel fraction, excellent storage stability at high temperatures, and gloss and extensibility of the film. From the viewpoint of obtaining a water-based resin composition for coating that is excellent in weather resistance and long-term hydrophilicity, it is preferably -70°C or higher, more preferably -60°C or higher, and has a high gel fraction and high temperature. From the viewpoint of obtaining a water-based resin composition for coating which is excellent in storage stability, and is generally excellent in coating gloss, extensibility, weather resistance and long-term hydrophilicity, preferably 20°C or lower, more preferably 0°C or lower, and It is preferably -10°C or lower, and more preferably -20°C or lower.

Further, the glass transition temperature of the emulsion particles as a whole has a high gel fraction, is excellent in storage stability at high temperatures, and is a coating aqueous resin composition having excellent overall gloss, extensibility, weather resistance and long-term hydrophilicity. From the viewpoint of obtaining a product, it is preferably −5° C. or higher, more preferably 0° C. or higher, has a high gel fraction, is excellent in storage stability at high temperatures, and has gloss, extensibility, weather resistance and long-term hydrophilicity of the coating. From the standpoint of obtaining a water-based resin composition for coating that is excellent overall, the temperature is preferably 40° C. or lower, more preferably 30° C. or lower, and further preferably 20° C. or lower.

In the present specification, the glass transition temperature of the polymer is represented by the formula (I): by using the glass transition temperature of the homopolymer of the monomer used in the monomer component constituting the polymer.
1/Tg=Σ(Wm/Tgm)/100 (I)
[In the formula, Wm represents the content rate (mass %) of the monomer m in the monomer component constituting the polymer, and Tgm represents the glass transition temperature (absolute temperature: K) of the homopolymer of the monomer m. ]
It means the temperature determined based on the Fox equation.

In the present specification, the glass transition temperature of the polymer constituting the emulsion particles means the glass transition temperature determined based on the formula (I), unless otherwise specified. For example, the glass transition temperature of the entire polymer constituting the emulsion particles having a multilayer structure, the mass fraction of each monomer in all the monomer components used in the multi-stage emulsion polymerization and the corresponding single fraction. It means the glass transition temperature obtained from the glass transition temperature of a homopolymer of a monomer. Incidentally, for monomers whose glass transition temperature is unknown, such as special monomers and polyfunctional monomers, the total amount of monomers whose glass transition temperature is unknown in the monomer component is the mass fraction. In the case of 10% by mass or less, the glass transition temperature can be determined by using only the monomer whose glass transition temperature is known. When the total amount of monomers whose glass transition temperature in the monomer component is unknown exceeds 10 mass% in terms of mass fraction, the glass transition temperature of the polymer is measured by differential scanning calorimetry (DSC), differential calorimetric analysis. (DTA), thermomechanical analysis (TMA), etc.

The glass transition temperature of the polymer can be easily adjusted by adjusting the composition of the monomer components. The composition of the monomer component used as the raw material of the polymer forming the emulsion particles can be determined in consideration of the glass transition temperature of the polymer forming the emulsion particles.

The glass transition temperature of the polymer is, for example, −70° C. for a homopolymer of 2-ethylhexyl acrylate, −56° C. for a homopolymer of n-butyl acrylate, 20° C. for a homopolymer of n-butyl methacrylate, methyl methacrylate. Of the homopolymer of styrene, the homopolymer of cyclohexyl methacrylate is 83° C., the homopolymer of tert-butyl methacrylate is 107° C., the homopolymer of styrene is 100° C., the homopolymer of acrylic acid is 95° C. The acid homopolymer is 130° C., the 2-hydroxyethyl methacrylate homopolymer is 55° C., the diacetone acrylamide homopolymer is 77° C., and the γ-methacryloxypropyltrimethoxysilane homopolymer is 70° C. -Methacryloyloxy-1,2,2,6,6-pentamethylpiperidine homopolymer is about 130°C and glycerin monomethacrylate homopolymer is 55°C.

The solubility parameter of the polymer constituting the outer layer (hereinafter, also referred to as SP value) is higher than the SP value of the polymer constituting the inner layer, which means that the gel fraction is high and the polymer is stored at high temperature. It is preferable from the viewpoint of obtaining a water-based resin composition for coating which is excellent in stability, and has comprehensively excellent gloss, extensibility, weather resistance and long-term hydrophilicity of the coating. The difference (absolute value) between the SP value of the polymer forming the inner layer and the SP value of the polymer forming the outer layer is preferably large from the viewpoint of forming a layer separation structure in the emulsion particles. ..

The SP value is a value defined by the regular solution theory introduced by Hildebrand, and is also a measure of the solubility of a binary solution. In general, substances having similar SP values tend to easily mix with each other. Therefore, the SP value is also a standard for determining the ease of mixing the solute and the solvent.

The mass ratio of the polymer forming the inner layer and the polymer forming the outer layer (polymer forming the inner layer/polymer forming the outer layer) has a high gel fraction and is high at high temperature. From the viewpoint of obtaining a water-based resin composition for coatings which is excellent in storage stability, and has excellent overall film gloss, extensibility, weather resistance and long-term hydrophilicity, preferably 10/90 or more, more preferably 15/85. It is above, from the viewpoint of obtaining a water-based resin composition for coating having a high gel fraction, excellent storage stability at high temperatures, and gloss of the coating, extensibility, weather resistance and long-term hydrophilicity, which are comprehensively superior, Is 60/40 or less.

Further, the total content of the polymer forming the inner layer and the polymer forming the outer layer in the emulsion particles has a high gel fraction, is excellent in storage stability at high temperatures, and has gloss and extensibility of the film. From the viewpoint of obtaining a water-based resin composition for coating that is excellent in weather resistance and long-term hydrophilicity, the content is preferably 40% by mass or more, and the polymer constituting the inner layer and the polymer constituting the outer layer. It is preferable that the total content of and is higher, and the upper limit value is 100% by mass.

The average particle size of the emulsion particles is preferably 50 nm or more, more preferably 100 nm or more from the viewpoint of improving the mechanical stability of the emulsion particles themselves, and preferably 300 nm or less from the viewpoint of improving the water resistance of the coating. More preferably, it is 200 nm or less.

In addition, in this specification, the average particle diameter of emulsion particles is measured using a particle size distribution measuring device [Particle Sizing Systems (manufactured by Particle Sizing Systems), product name: NICOMP Model 380) by a dynamic light scattering method. It means the volume average particle diameter.

The nonvolatile content in the resin emulsion is preferably 30% by mass or more, more preferably 40% by mass or more from the viewpoint of improving productivity, and preferably 70% by mass or less, more preferably from the viewpoint of improving handleability. It is 60 mass% or less.

The nonvolatile content in the resin emulsion was calculated by weighing 1 g of the resin emulsion and drying it with a hot air dryer at a temperature of 110° C. for 1 hour, and the resulting residue was used as the nonvolatile content.
[Nonvolatile content (mass %) in resin emulsion]
= ([Mass of residue]/[resin emulsion 1 g]) x 100
Means the value obtained based on.

The minimum film-forming temperature of the resin emulsion is preferably 10°C or lower, more preferably 0°C or lower, from the viewpoint of improving the film-forming property. The minimum film forming temperature of the resin emulsion of the present invention can be adjusted, for example, by adjusting the glass transition temperature of the entire emulsion particles or the glass transition temperature of the outer layer.

In the present specification, the minimum film-forming temperature of the resin emulsion is determined by applying the resin emulsion on a glass plate placed on a thermal gradient tester with an applicator so that the thickness becomes 0.2 mm, and cracking It means the temperature at which it occurs.

By using the emulsion particles obtained as described above in the aqueous resin composition, the gel fraction is high, the storage stability at high temperature is excellent, and the gloss, extensibility, weather resistance and long-term hydrophilicity of the coating are comprehensive. An excellent coating can be formed.

In the present invention, the monomer component (hereinafter referred to as monomer component C) used as a raw material of the water-soluble polymer has a high gel fraction, is excellent in storage stability at high temperatures, and has gloss and extensibility of the coating film. From the viewpoint of obtaining a water-based resin composition for coating that is excellent in weather resistance and long-term hydrophilicity, it is preferable to contain a carbonyl group-containing monomer.

As described above, since the water-soluble polymer is used together with the emulsion particles, the gel fraction is high, the storage stability at high temperature is excellent, and the gloss, extensibility, weather resistance and long-term hydrophilicity of the coating are comprehensively obtained. An excellent aqueous resin composition for paint can be obtained.

Among the carbonyl group-containing monomers, an aqueous resin composition for coatings having a high gel fraction, excellent storage stability at high temperatures, and comprehensively excellent film gloss, extensibility, weather resistance and long-term hydrophilicity. From the viewpoint of obtaining acryloline, methacrolein, horomylstyrene, vinyl ethyl ketone, acryloxyalkylpropenal, methacryloxyalkylpropenal, acetonyl acrylate, acetonyl methacrylate, diacetone acrylate, diacetone methacrylate, diacetone acrylamide. And diacetone methacrylamide are preferred, acrylolein, methacrolein, homyl styrene, acetonyl acrylate, acetonyl methacrylate, diacetone acrylate, diacetone methacrylate, diacetone acrylamide and diacetone methacrylamide are more preferred, and acrylolein, methacrolein. Rhein, acetonyl acrylate, acetonyl methacrylate, diacetone acrylate, diacetone methacrylate, diacetone acrylamide and diacetone methacrylamide are more preferable, and diacetone acrylate, diacetone methacrylate, diacetone acrylamide and diacetone methacrylamide are even more preferable. ..

The content of the carbonyl group-containing monomer in the monomer component C is high in gel fraction, excellent in storage stability at high temperature, and comprehensively excellent in gloss, extensibility, weather resistance and long-term hydrophilicity of the coating. From the viewpoint of obtaining a water-based resin composition for coatings, the content is preferably 1% by mass or more, more preferably 2% by mass or more, and further preferably 3% by mass or more, and the gel fraction is high and the storage stability at high temperature is high. From the viewpoint of obtaining a water-based resin composition for coating which is excellent in terms of coating gloss, extensibility, weather resistance and long-term hydrophilicity, it is preferably 30% by mass or less, more preferably 25% by mass or less, and further preferably It is 20 mass% or less.

As the monomer other than the carbonyl group-containing monomer in the monomer component C, a monomer that gives a water-soluble polymer is used. A water-soluble monomer can be used as a monomer that gives a water-soluble polymer.

Examples of the water-soluble monomer include N-vinylpyrrolidone, N-vinylcaprolactam, (meth)acrylic acid, maleic acid, fumaric acid, itaconic acid and the like, but the present invention is limited to these examples. is not. These water-soluble monomers may be used alone or in combination of two or more. Among the water-soluble monomers, from the viewpoint of obtaining a water-based resin composition for coating, which has a high gel fraction, is excellent in storage stability at high temperatures, and is excellent in coating gloss, extensibility, weather resistance and long-term hydrophilicity. Therefore, N-vinylpyrrolidone and N-vinylcaprolactam are preferable, and N-vinylpyrrolidone is more preferable.

The content of the water-soluble monomer in the monomer component C is high for gel content, excellent in storage stability at high temperature, and for coatings that have excellent overall gloss, extensibility, weather resistance and long-term hydrophilicity. From the viewpoint of obtaining an aqueous resin composition, it is preferably 70% by mass or more, more preferably 75% by mass or more, further preferably 80% by mass or more, a high gel fraction, excellent storage stability at high temperature, and a film. From the viewpoint of obtaining a water-based resin composition for coating which is excellent in gloss, extensibility, weather resistance and long-term hydrophilicity, it is 99% by mass or less, preferably 98% by mass or less, and more preferably 97% by mass or less. ..

In addition, the monomer component C may contain another monomer C within a range that does not impair the object of the present invention. Examples of the other monomer C include, for example, alkyl (meth)acrylate, alicyclic structure-containing monomer, hydroxyl group-containing (meth)acrylate, aromatic monomer, silicon atom-containing monomer, and fluorine atom-containing monomer. Body, nitrogen atom-containing monomer, epoxy group-containing monomer, UV absorbing monomer, UV stable monomer and the like, but the present invention is not limited to these examples. The content of the other monomer C in the monomer component C cannot be unconditionally determined because it varies depending on the type of the other monomer, but from the viewpoint of maintaining the water solubility of the water-soluble polymer, it is usually It is preferably 10% by mass or less.

The water-soluble polymer may be a random copolymer of a carbonyl group-containing monomer, a water-soluble monomer and optionally another monomer C, a block copolymer, or a graft copolymer. Among these, the water-soluble polymer is a water-based resin composition for coatings having a high gel fraction, excellent storage stability at high temperatures, and comprehensively excellent film gloss, extensibility, weather resistance and long-term hydrophilicity. From the viewpoint of obtaining

The water-soluble polymer can be prepared by a polymerization method such as a solution polymerization method, an emulsion polymerization method, a suspension polymerization method or a precipitation polymerization method. Among these polymerization methods, the solution polymerization method is preferable, and the solution polymerization method using water as a solvent is more preferable.

A solvent is used when the water-soluble polymer is prepared by the solution polymerization method. Examples of the solvent include water, alcohols, ethers, ketones, esters, amides, sulfoxides, hydrocarbon compounds, and the like, but the present invention is not limited to these examples. Suitable solvents include, for example, water, methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, tert-butyl alcohol, methyl cellosolve, ethyl cellosolve, butyl cellosolve, acetone, methyl ethyl ketone, tetrahydrofuran, 1,4-dioxane, 1 , 3-dioxolane, toluene, ethyl acetate and the like, but the present invention is not limited to these examples. These solvents may be used alone or in combination of two or more.

If necessary, the solvent may contain an appropriate amount of an organic amine compound, ammonia, an alkali metal hydroxide and the like.

The polymerization temperature for preparing the water-soluble polymer is not particularly limited, but is usually preferably 0 to 100°C, and more preferably 50 to 80°C. The pressure during the polymerization reaction may be normal pressure, reduced pressure, or increased pressure. The atmosphere during the polymerization reaction is preferably an inert gas such as nitrogen gas, argon gas or carbon dioxide gas.

When the water-soluble polymer is prepared by polymerizing the monomer component C, and after the monomer component for a trunk polymer containing the water-soluble monomer is polymerized, the monomer component C is added to the obtained trunk polymer. In any case of preparing the water-soluble polymer by graft copolymerization, a polymerization initiator can be used during the polymerization.

Examples of the polymerization initiator include persulfates such as ammonium persulfate, sodium persulfate and potassium persulfate; hydrogen peroxide; ketone peroxides such as methyl ethyl ketone peroxide and cyclohexanone peroxide; tert-butyl hydroperoxide, cumene hydro Hydroper such as peroxide, diisopropylbenzene hydroperoxide, p-menthane hydroperoxide, 2,5-dimethylhexane-2,5-dihydroperoxide, 1,1,3,3-tetramethylbutyl hydroperoxide Oxide; Ditert-butyl peroxide, tert-butyl cumyl peroxide, dicumyl peroxide, dialkyl peroxide such as α,α′-bis(tert-butylperoxy)p-diisopropylhexyne; tert-butylperoxy Acetate, tert-butylperoxylaurate, tert-butylperoxybenzoate, ditert-butylperoxyisophthalate, 2,5-dimethyl-2,5-di(benzoylperoxy)hexane, tert-butylperoxyisopropyl Peroxyesters such as carbonates; peroxyketals such as n-butyl-4,4-bis(tert-butylperoxy)valeate and 2,2-bis(tert-butylperoxy)butane; such as dibenzoyl peroxide Examples thereof include diacyl peroxide, but the present invention is not limited to such examples. These polymerization initiators may be used alone or in combination of two or more kinds. The amount of the polymerization initiator per 100 parts by mass of the monomer component used for the polymerization is not particularly limited, but it is usually preferably 0.01 to 10 parts by mass. The polymerization initiator may be charged all at once at the start of the polymerization reaction, or may be added sequentially during the polymerization reaction.

The polymerization initiator may be used in combination with an appropriate amount of reducing agent. Examples of the reducing agent include iron(II) salts, sodium dithionite, sodium hydrogen sulfite, sodium sulfite, sodium thiosulfate, sodium formaldehyde sulfoxylate, and ascorbic acid, but the present invention is only such examples. It is not limited to.

The monomer component C is polymerized as described above, or the monomer component for a trunk polymer containing a water-soluble monomer is polymerized, and then the monomer component C is graft-copolymerized on the obtained trunk polymer. By doing so, a water-soluble polymer can be prepared.

The water-soluble polymer has a high weight-average molecular weight, a high gel fraction, excellent storage stability at high temperatures, and a coating aqueous resin composition that is excellent in overall gloss, extensibility, weather resistance and long-term hydrophilicity. From the viewpoint of obtaining, it is 1000 or more, more preferably 3000 or more, and further preferably 5000 or more, and has a high gel fraction, excellent storage stability at high temperatures, and excellent gloss, extensibility, weather resistance and long-term hydrophilicity. From the viewpoint of obtaining a comprehensively excellent water-based resin composition for coatings, it is 50,000 or less, preferably 40,000 or less, more preferably 30,000 or less.

The mass ratio of emulsion particles to water-soluble polymer [emulsion particles/water-soluble polymer (nonvolatile content)] is high in gel fraction, excellent in storage stability at high temperature, gloss of film, extensibility, weather resistance and long-term From the viewpoint of obtaining a water-based resin composition for coatings having excellent overall hydrophilicity, it is preferably 60/40 to 99/1, more preferably 70/30 to 99/1, and further preferably 75/25. To 99/1, more preferably 80/20 to 98/2, and particularly preferably 90/10 to 97/3.

The aqueous resin composition for paints of the present invention has a high gel fraction, is excellent in storage stability at high temperatures, and is excellent in coating gloss, extensibility, weather resistance and long-term hydrophilicity. From the viewpoint of obtaining the aqueous resin composition, a crosslinking agent is contained.

As the cross-linking agent, two or more kinds of cross-linking agents selected from the group consisting of an oxazoline-based cross-linking agent, a hydrazine-based cross-linking agent, a blocked isocyanate-based cross-linking agent, an aziridine-based cross-linking agent and a carbodiimide-based cross-linking agent are used.

Examples of the oxazoline-based crosslinking agent include 2,2′-bis(2-oxazoline), 1,2-bis(2-oxazolin-2-yl)ethane, and 1,4-bis(2-oxazolin-2-yl). ) Butane, 1,8-bis(2-oxazolin-2-yl)butane, 1,4-bis(2-oxazolin-2-yl)cyclohexane, 1,2-bis(2-oxazolin-2-yl)benzene , 1,3-bis(2-oxazolin-2-yl)benzene, 2-vinyl-2-oxazoline, 2-vinyl-4-methyl-2-oxazoline, 2-vinyl-5-methyl-2-oxazoline, 2 -Isopropenyl-2-oxazoline, 2-isopropenyl-4-methyl-2-oxazoline, 2-isopropenyl-5-ethyl-2-oxazoline and the like can be mentioned, but the present invention is limited only to such examples. Not a thing. These oxazoline crosslinking agents may be used alone or in combination.

The oxazoline-based cross-linking agent is commercially available, and examples thereof include Epocros (registered trademark) WS-300, Epocros (registered trademark) WS-500, and Epocros (registered trademark) WS-700. , Epocros (registered trademark) K-2010E, Epocros (registered trademark) K-2020E, Epocros (registered trademark) K-2030E, and the like, but the present invention is not limited thereto.

Examples of the hydrazine-based crosslinking agent include oxalic acid dihydrazide, malonic acid dihydrazide, succinic acid dihydrazide, glutaric acid dihydrazide, adipic acid dihydrazide, sebacic acid dihydrazide, maleic acid dihydrazide, fumaric acid dihydrazide, and itaconic acid dihydrazide. And aliphatic water-soluble dihydrazine having 2 to 4 carbon atoms such as dicarboxylic acid dihydrazide of 10, ethylene-1,2-dihydrazine, propylene-1,3-dihydrazine and butylene-1,4-dihydrazine. However, the present invention is not limited to such examples. These hydrazine-based crosslinking agents may be used alone or in combination. Among these hydrazine-based cross-linking agents, high gel fraction, excellent storage stability at high temperature, gloss of coating, elongation, weather resistance and long-term hydrophilic aqueous resin composition for coatings From the viewpoint of obtaining, dicarboxylic acid dihydrazide having 4 to 6 carbon atoms such as adipic acid dihydrazide, sebacic acid dihydrazide, maleic acid dihydrazide, fumaric acid dihydrazide, itaconic acid dihydrazide, succinic acid dihydrazide and glutaric acid dihydrazide is preferable.

The blocked isocyanate cross-linking agent is, for example, one obtained by blocking an isocyanate group contained in an isocyanate compound such as hexamethylene diisocyanate or isophorone diisocyanate. Examples of the isocyanate group blocking agent include active methylene compounds such as diethyl malonate, dimethyl malonate, ethyl acetoacetate and methyl acetoacetate, oxime compounds such as cyclohexanone oxime, benzophenone oxime and acetoxime, ε-caprolactam, γ-butyrolactam. Examples thereof include lactam compounds such as aniline, diphenylamine, ethyleneimine, polyethyleneimine, and the like, but the present invention is not limited to these examples.

Blocked isocyanates are commercially available, and examples thereof include Showa Denko KK and trade name: Karenz MOI-BM. However, the present invention is limited to such examples. It is not limited.

Examples of the aziridine crosslinking agent include N,N'-toluene-2,4-bis(1-aziridinecarboxide), N,N'-diphenylmethane-4,4'-bis(1-aziridinecarboxide), N,N′-hexamethylene-1,6-bis(1-aziridinecarboxamide), triethylenemelamine, bisisoprotaroyl-1-(2-methylaziridine), tri-1-aziridinylphosphine oxide, tetra Examples thereof include methylolmethane-triβ-aziridinylpropionate and trimethylolpropane-triβ-aziridinylpropionate, but the present invention is not limited to these examples.

The aziridine-based cross-linking agent is one that can be easily obtained commercially, and examples thereof include Nippon Shokubai Co., Ltd., trade name: Chemitite PZ-33, and the like. It is not limited to only.

Examples of the carbodiimide-based crosslinking agent include polymers having a carbodiimide group (-N=C=N-).

The carbodiimide-based cross-linking agent can be easily obtained commercially, and examples thereof include Nisshinbo Chemical Co., Ltd., trade name: carbodilite V-02, and the like. It is not limited to only.

As a suitable combination of the cross-linking agent, an aqueous resin composition for coating having a high gel fraction, excellent storage stability at high temperature, and comprehensively excellent film gloss, extensibility, weather resistance and long-term hydrophilicity. From the viewpoint of obtaining, a combination of an oxazoline-based crosslinking agent and a hydrazine-based crosslinking agent, a combination of a carbodiimide-based crosslinking agent and a hydrazine-based crosslinking agent, a combination of an aziridine-based crosslinking agent and a hydrazine-based crosslinking agent, and the like can be mentioned. Among these, high gel fraction, excellent storage stability at high temperatures, gloss of the coating, elongation, from the viewpoint of obtaining a coating aqueous resin composition excellent in weather resistance and long-term hydrophilicity, A combination of an oxazoline-based crosslinking agent and a hydrazine-based crosslinking agent is preferable. When the oxazoline-based cross-linking agent and the hydrazine-based cross-linking agent are used in combination, the mass ratio of the oxazoline-based cross-linking agent and the hydrazine-based cross-linking agent (oxazoline-based cross-linking agent/hydrazine-based cross-linking agent) is high, and the gel fraction is high. From the viewpoint of obtaining a water-based resin composition for a coating which is excellent in storage stability and is comprehensively excellent in gloss, extensibility, weather resistance and long-term hydrophilicity of the coating, preferably 30/70 to 70/30, more preferably 40. /60 to 60/40.

The mass ratio of emulsion particles and water-soluble resin to crosslinking agent [emulsion particles and water-soluble resin/crosslinking agent (nonvolatile content)] has a high gel fraction, excellent storage stability at high temperatures, and gloss and elongation of the film. From the viewpoint of obtaining a water-based resin composition for coatings which is excellent in overall durability, weather resistance and long-term hydrophilicity, it is preferably 80/20 to 99.9/0.1, more preferably 90/10 to 99.7/. 0.3, more preferably 92/8 to 99.5/0.5, and even more preferably 94/6 to 99.3/0.7.

The aqueous resin composition for coating material of the present invention can be easily prepared by mixing emulsion particles, a water-soluble polymer and a crosslinking agent in appropriate amounts. The emulsion particles can be usually used in the state of a resin emulsion obtained when the emulsion particles are prepared.

Further, the aqueous resin composition for coating material of the present invention includes, for example, a film forming aid, a defoaming agent, a pH buffering agent, a chelating agent, a pigment, a dye, an ultraviolet absorber within a range that does not impair the object of the present invention. , UV stabilizers, fillers, leveling agents, dispersants, thickeners, wetting agents, plasticizers, stabilizers, antioxidants, matting agents, antifreezing agents, colloidal silica and other additives are contained in appropriate amounts. May be

The nonvolatile content of the aqueous resin composition for coating material of the present invention is preferably 30% by mass or more, more preferably 40% by mass or more from the viewpoint of improving productivity, and preferably 70% from the viewpoint of improving handleability. It is not more than 60% by mass, more preferably not more than 60% by mass. The non-volatile content in the aqueous resin composition for paints of the present invention can be adjusted, for example, by adjusting the water content in the aqueous resin composition for paints of the present invention.

In the present specification, the nonvolatile content in the aqueous resin composition is calculated by weighing 1 g of the aqueous resin composition and drying it with a hot air dryer at a temperature of 110° C. for 1 hour, and the obtained residue is used as a nonvolatile content, and the formula:
[Nonvolatile Content (Amount%) in Aqueous Resin Composition]
=([mass of residue]/[aqueous resin composition 1 g])*100
Means the value obtained based on.

The aqueous resin composition for paints of the present invention can be used as it is or by adding the above-mentioned additives, for example, as a gloss paint.

The aqueous resin composition for coating material of the present invention can be suitably used for surface finishing of a base material made of a material such as metal, glass, porcelain, concrete, siding board, and resin. The aqueous resin composition for coating material of the present invention can be suitably used for the exterior of buildings and the top coat of ceramic building materials, among others.

Examples of ceramic-based building materials include roof tiles and outer wall materials. Ceramic-based building materials are made by adding inorganic fillers, fibrous materials, etc. to a hydraulic glue that is a raw material for an inorganic cured product, molding the resulting mixture, curing the resulting molded product, and curing it. can get. Examples of the inorganic building material that constitutes the exterior of the building include flexible boards, calcium silicate boards, gypsum slag perlite boards, wood chip cement boards, precast concrete boards, ALC boards, and gypsum boards.

The surface of such a building material is usually coated with an overcoating agent (water-based paint) in order to impart a desired design. The aqueous resin composition for paints of the present invention can be suitably used for this topcoat (water-based paint).

In addition, the aqueous resin composition for coating material of the present invention may contain other resin components and emulsion particles as long as the object of the present invention is not impaired.

The water-based resin composition for paints of the present invention and the gloss paint containing the water-based resin composition for paints may be applied as a single layer, or may be applied by coating two or more layers. Good. In the case of coating by coating two or more layers, only a part of the layers may be formed by the aqueous resin composition for coating of the present invention, and all layers may be formed by the aqueous resin composition for coating of the present invention. May be formed of. Overcoating can be performed, for example, by applying the coating material for the first layer (for example, undercoat layer) to an object that has been subjected to primer treatment, sealer treatment, etc. and drying it, and then for the second layer (for example, topcoat layer). Examples include a method of overcoating with a coating material and drying, but the present invention is not limited to such a method. When applying the paint, for example, a spray, a roller, a brush, or a trowel can be used.

The aqueous resin composition for coatings of the present invention obtained as described above has a high gel fraction, is excellent in storage stability at high temperatures, and has gloss of the film, extensibility, weather resistance and long-term hydrophilicity comprehensively. Since it is excellent, it can be suitably used, for example, as a topcoat (water-based gloss coating) called a topcoat that is applied to the exterior of buildings or the surface of ceramic building materials.

Next, the present invention will be described in more detail based on examples, but the present invention is not limited to these examples. In the following examples, "part" means "part by mass".

Production Example A1
582 parts of deionized water was charged into a flask equipped with a dropping funnel, a stirrer, a nitrogen introduction tube, a thermometer and a reflux condenser. To the dropping funnel, 163 parts of deionized water, 80 parts of a 25% aqueous solution of an emulsifier [manufactured by ADEKA, trade name: ADEKA rear soap SR-10], 53 parts of 2-ethylhexyl acrylate, 240 parts of cyclohexyl methacrylate, 90 parts of styrene, A first-stage dropping pre-emulsion consisting of 5 parts of hydroxyethyl methacrylate, 17 parts of tert-butyl methacrylate, 85 parts of methyl methacrylate and 10 parts of butyl acrylate was prepared, and 74 parts of the pre-emulsion was added to the flask and gently added. The temperature was raised to 80° C. while blowing nitrogen gas into the flask, and 10 parts of a 5% potassium persulfate aqueous solution was added to the flask to start the polymerization reaction. Then, the rest of the dropping pre-emulsion, 10 parts of a 5% aqueous solution of potassium persulfate and 20 parts of a 2.5% aqueous solution of sodium hydrogen sulfite were uniformly added dropwise into the flask over 120 minutes. After the dropping was completed, the contents of the flask were maintained at 80° C. for 60 minutes, and 5 parts of 25% aqueous ammonia was added.

Next, 163 parts of deionized water, 80 parts of a 25% aqueous solution of an emulsifier [manufactured by ADEKA, trade name: ADEKA REASORP SR-10], 2-ethylhexyl acrylate 140 parts, butyl acrylate 180 parts, cyclohexyl methacrylate 140 parts. , Γ-methacryloyloxypropyltrimethoxysilane 10 parts, hydroxyethyl methacrylate 5 parts, 1,2,2,6,6-pentamethylpiperidyl methacrylate 10 parts, glycerin monomethacrylate 10 parts and diacetone acrylamide 5 parts The pre-emulsion for eye-dropping, 10 parts of a 5% aqueous solution of potassium persulfate and 10 parts of a 2.5% aqueous solution of sodium hydrogen sulfite were uniformly added dropwise into the flask over 120 minutes. After the dropping was completed, the content of the flask was maintained at 80° C. for 60 minutes, 25% aqueous ammonia was added, and the pH was adjusted to 9 to terminate the polymerization reaction.

The obtained reaction liquid was cooled to room temperature and then filtered through a 300-mesh (JIS mesh, the same applies hereinafter) wire mesh to obtain an aqueous resin dispersion having a nonvolatile content of 49 mass %. The emulsion particles contained in the obtained aqueous resin dispersion have a two-layer structure having an average particle diameter of 150 nm, the glass transition temperature of the inner layer is 59°C, the glass transition temperature of the outer layer is -27°C, and the emulsion particles are The overall glass transition temperature was 10°C.

Production Example A2
573 parts of deionized water was charged into a flask equipped with a dropping funnel, a stirrer, a nitrogen introducing tube, a thermometer and a reflux condenser. To the dropping funnel, 163 parts of deionized water, 80 parts of 25% aqueous solution of an emulsifier [manufactured by ADEKA, trade name: ADEKA REASOAP SR-10], 58 parts of 2-ethylhexyl acrylate, 250 parts of cyclohexyl methacrylate, 100 parts of styrene, A first-stage dropping pre-emulsion consisting of 60 parts of methyl methacrylate, 12 parts of tert-butyl methacrylate, 10 parts of acrylic acid and 10 parts of hydroxyethyl methacrylate was prepared, and 74 parts of the pre-emulsion was added to the flask and gently The temperature was raised to 80° C. while blowing nitrogen gas into the flask, and 20 parts of a 5% potassium persulfate aqueous solution was added to the flask to start the polymerization reaction. Thereafter, the rest of the dropping pre-emulsion, 10 parts of a 5% aqueous solution of potassium persulfate and 10 parts of a 2.5% aqueous solution of sodium hydrogen sulfite were uniformly added dropwise into the flask over 120 minutes. After the dropping was completed, the contents of the flask were maintained at 80° C. for 60 minutes.

Next, 163 parts of deionized water, 80 parts of a 25% aqueous solution of an emulsifier [manufactured by ADEKA, trade name: ADEKA REASORP SR-10], 2-ethylhexyl acrylate 140 parts, cyclohexyl methacrylate 125 parts, γ-methacryloyloxy. Two-stage consisting of 10 parts of propyltrimethoxysilane, 5 parts of hydroxyethyl methacrylate, 20 parts of diacetone acrylamide, 10 parts of glycerin monomethacrylate, 180 parts of butyl acrylate and 10 parts of 1,2,2,6,6-pentamethylpiperidyl methacrylate. The pre-emulsion for eye-dropping, 10 parts of a 5% aqueous solution of potassium persulfate and 10 parts of a 2.5% aqueous solution of sodium hydrogen sulfite were uniformly added dropwise into the flask over 120 minutes. After the dropping was completed, the content of the flask was maintained at 80° C. for 60 minutes, 25% aqueous ammonia was added, and the pH was adjusted to 9 to terminate the polymerization reaction.

The obtained reaction liquid was cooled to room temperature and then filtered through a 300-mesh wire net to obtain an aqueous resin dispersion having a nonvolatile content of 49 mass %. The emulsion particles contained in the obtained aqueous resin dispersion have a two-layer structure having an average particle diameter of 150 nm, the glass transition temperature of the inner layer is 60°C, the glass transition temperature of the outer layer is -27°C, and the emulsion particles are The overall glass transition temperature was 10°C.

Production Example A3
573 parts of deionized water was charged into a flask equipped with a dropping funnel, a stirrer, a nitrogen introducing tube, a thermometer and a reflux condenser. To the dropping funnel, 163 parts of deionized water, 80 parts of 25% aqueous solution of an emulsifier [manufactured by ADEKA, trade name: ADEKA REASOAP SR-10], 58 parts of 2-ethylhexyl acrylate, 250 parts of cyclohexyl methacrylate, 100 parts of styrene, A first-stage dropping pre-emulsion consisting of 55 parts of methyl methacrylate, 12 parts of tert-butyl methacrylate, 15 parts of acrylic acid, 10 parts of hydroxyethyl methacrylate and 100 parts of styrene was prepared, and 74 parts of the pre-emulsion were placed in a flask. Then, the temperature was raised to 80° C. while slowly blowing nitrogen gas, and 20 parts of a 5% potassium persulfate aqueous solution was added to the flask to start the polymerization reaction. Thereafter, the rest of the dropping pre-emulsion, 10 parts of a 5% aqueous solution of potassium persulfate and 10 parts of a 2.5% aqueous solution of sodium hydrogen sulfite were uniformly added dropwise into the flask over 120 minutes. After the dropping was completed, the contents of the flask were maintained at 80° C. for 60 minutes, and 5 parts of 25% aqueous ammonia was added.

Next, 163 parts of deionized water, 80 parts of a 25% aqueous solution of an emulsifier [manufactured by ADEKA, trade name: ADEKA REASORP SR-10], 170 parts of 2-ethylhexyl acrylate, 130 parts of butyl acrylate, 125 parts of cyclohexyl methacrylate. Second stage consisting of 10 parts of γ-methacryloyloxypropyltrimethoxysilane, 5 parts of hydroxyethyl methacrylate, 10 parts of methacrylic acid, 10 parts of 1,2,2,6,6-pentamethylpiperidyl methacrylate and 50 parts of diacetone acrylamide. The pre-emulsion for dropping, 10 parts of a 5% aqueous solution of potassium persulfate and 10 parts of a 2.5% aqueous solution of sodium hydrogen sulfite were uniformly added dropwise into the flask over 120 minutes. After the dropping was completed, the content of the flask was maintained at 80° C. for 60 minutes, 25% aqueous ammonia was added, and the pH was adjusted to 9 to terminate the polymerization reaction.

The obtained reaction liquid was cooled to room temperature and then filtered through a 300-mesh wire net to obtain an aqueous resin dispersion having a nonvolatile content of 49 mass %. The emulsion particles contained in the obtained aqueous resin dispersion have a two-layer structure having an average particle diameter of 150 nm, the glass transition temperature of the inner layer is 59°C, the glass transition temperature of the outer layer is -24°C, and the emulsion particles The overall glass transition temperature was 12°C.

Production Example A4
573 parts of deionized water was charged into a flask equipped with a dropping funnel, a stirrer, a nitrogen introduction tube, a thermometer and a reflux condenser. To the dropping funnel, 163 parts of deionized water, 80 parts of a 25% aqueous solution of an emulsifier [manufactured by ADEKA, trade name: ADEKA REASOAP SR-10], 63 parts of 2-ethylhexyl acrylate, 250 parts of cyclohexyl methacrylate, 105 parts of styrene, A first-stage dropping pre-emulsion composed of 60 parts of methyl methacrylate, 12 parts of tert-butyl methacrylate and 10 parts of hydroxyethyl methacrylate was prepared, and 74 parts of the pre-emulsion was added to the flask, and nitrogen gas was slowly blown into the flask. While heating up to 80° C., 20 parts of a 5% potassium persulfate aqueous solution was added to the flask to start the polymerization reaction. Thereafter, the rest of the dropping pre-emulsion, 10 parts of a 5% aqueous solution of potassium persulfate and 10 parts of a 2.5% aqueous solution of sodium hydrogen sulfite were uniformly added dropwise into the flask over 120 minutes. After the dropping was completed, the contents of the flask were maintained at 80° C. for 60 minutes, and 5 parts of 25% aqueous ammonia was added.

Next, 163 parts of deionized water, 80 parts of a 25% aqueous solution of an emulsifier [manufactured by ADEKA, trade name: ADEKA REASORP SR-10], 2-ethylhexyl acrylate 170 parts, butyl acrylate 150 parts, cyclohexyl methacrylate 145 parts. A second-stage pre-emulsion for dripping consisting of 10 parts of γ-methacryloyloxypropyltrimethoxysilane, 5 parts of hydroxyethyl methacrylate, 10 parts of 1,2,2,6,6-pentamethylpiperidyl methacrylate and 10 parts of glycerin monomethacrylate. 10 parts of 5% potassium persulfate aqueous solution and 10 parts of 2.5% sodium bisulfite aqueous solution were uniformly added dropwise into the flask over 120 minutes. After the dropping was completed, the content of the flask was maintained at 80° C. for 60 minutes, 25% aqueous ammonia was added, and the pH was adjusted to 9 to terminate the polymerization reaction.

The obtained reaction liquid was cooled to room temperature and then filtered through a 300-mesh wire net to obtain an aqueous resin dispersion having a nonvolatile content of 49 mass %. The emulsion particles contained in the obtained aqueous resin dispersion have a two-layer structure with an average particle diameter of 150 nm, the inner layer has a glass transition temperature of 57°C, and the outer layer has a glass transition temperature of -28°C. The overall glass transition temperature was 9°C.

Production Example A5
573 parts of deionized water was charged into a flask equipped with a dropping funnel, a stirrer, a nitrogen introducing tube, a thermometer and a reflux condenser. To the dropping funnel, 163 parts of deionized water, 80 parts of a 25% aqueous solution of an emulsifier [manufactured by ADEKA, trade name: Adecaria Soap SR-10], 53 parts of 2-ethylhexyl acrylate, 250 parts of cyclohexyl methacrylate, 105 parts of styrene, Prepare a first-stage dropping pre-emulsion consisting of 60 parts of methyl methacrylate, 12 parts of tert-butyl methacrylate, 10 parts of hydroxyethyl methacrylate and 10 parts of acrylic acid, and add 74 parts of the pre-emulsion to the flask, and gently The temperature was raised to 80° C. while blowing nitrogen gas into the flask, and 20 parts of a 5% potassium persulfate aqueous solution was added to the flask to start the polymerization reaction. Thereafter, the rest of the dropping pre-emulsion, 10 parts of a 5% aqueous solution of potassium persulfate and 10 parts of a 2.5% aqueous solution of sodium hydrogen sulfite were uniformly added dropwise into the flask over 120 minutes. After the dropping was completed, the contents of the flask were maintained at 80° C. for 60 minutes, and 5 parts of 25% aqueous ammonia was added.

Next, 163 parts of deionized water, 80 parts of a 25% aqueous solution of an emulsifier [manufactured by ADEKA, trade name: ADEKA rear soap SR-10], 235 parts of 2-ethylhexyl acrylate, 30 parts of cyclohexyl methacrylate, γ-methacryloyloxy. Pre-emulsion for the second step consisting of 10 parts of propyltrimethoxysilane, 5 parts of hydroxyethyl methacrylate, 10 parts of 1,2,2,6,6-pentamethylpiperidyl methacrylate, 10 parts of glycerin monomethacrylate and 200 parts of diacetone acrylamide. Then, 10 parts of a 5% potassium persulfate aqueous solution and 10 parts of a 2.5% sodium bisulfite aqueous solution were uniformly added dropwise into the flask over 120 minutes. After the dropping was completed, the content of the flask was maintained at 80° C. for 60 minutes, 25% aqueous ammonia was added, and the pH was adjusted to 9 to terminate the polymerization reaction.

The obtained reaction liquid was cooled to room temperature and then filtered through a 300-mesh wire net to obtain an aqueous resin dispersion having a nonvolatile content of 49 mass %. The emulsion particles contained in the obtained aqueous resin dispersion have a two-layer structure having an average particle diameter of 150 nm, the glass transition temperature of the inner layer is 62°C, the glass transition temperature of the outer layer is -15°C, and the emulsion particles The overall glass transition temperature was 19°C.

Production Example B1 (base resin of B4)
A polymerization vessel equipped with a cooling pipe, a nitrogen introduction line and a thermometer was charged with 750 parts of deionized water, and nitrogen gas was introduced into the polymerization vessel to create a nitrogen gas atmosphere in the polymerization vessel. While stirring the content in the polymerization container at room temperature, 1.7 parts of a 0.1% copper sulfate aqueous solution was added. To the dropping funnel A, 97 parts of deionized water and 1053 parts of N-vinylpyrrolidone were added in a polymerization container to prepare a premix. To the dropping funnel B, 50 parts of deionized water and 64 parts of 35% hydrogen peroxide solution were added. To the dropping funnel C, 50 parts of deionized water and 10 parts of 25% aqueous ammonia solution were added. The contents of the dropping funnel A, the dropping funnel B and the dropping funnel C were uniformly dropped into the polymerization container over 3 hours to start the polymerization reaction. After the internal temperature of the polymerization container rose due to the heat of polymerization, the contents in the polymerization container were stirred at 60° C. for 3 hours.

Next, the dropping funnel A, the dropping funnel B, and the dropping funnel C were washed with 10 parts of deionized water, and the obtained washing liquid was added into the polymerization container. Further, 2.2 parts of 25% aqueous ammonia solution and 10 parts of 30% aqueous hydrogen peroxide solution were added to the polymerization container, and the contents in the polymerization container were stirred at 60° C. for an additional 1 hour to give polymer solution B1. Obtained. The nonvolatile content of the obtained polymer solution B1 was 50.0% by mass, and the weight average molecular weight of the polymer contained in the polymer solution was 3,000.

Production Example B2 (base resin of B5)
A polymerization vessel equipped with a cooling pipe, a nitrogen introduction line and a thermometer was charged with 602 parts of deionized water, and nitrogen gas was introduced to make the inside of the polymerization vessel a nitrogen gas atmosphere. At room temperature, 1.7 parts of 0.02% copper sulfate aqueous solution was added while stirring the contents in the polymerization vessel. A premix was prepared by adding 186.6 parts of deionized water and 1053 parts of N-vinylpyrrolidone to the dropping funnel A. To the dropping funnel B, 74 parts of deionized water and 21.3 parts of 35% hydrogen peroxide solution were added. To the dropping funnel C, 69 parts of deionized water and 3.3 parts of 25% aqueous ammonia solution were added. The contents of the dropping funnel A, the dropping funnel B and the dropping funnel C were uniformly dropped into the polymerization container over 3 hours to start the polymerization reaction. After the internal temperature of the polymerization container was increased by the heat of polymerization, the contents in the polymerization container were stirred at 60° C. for 3 hours.

Next, the dropping funnel A, the dropping funnel B, and the dropping funnel C were washed with 30 parts of deionized water, and the obtained washing liquid was added into the polymerization container. Further, 2.2 parts of 25% aqueous ammonia solution and 10 parts of 30% aqueous hydrogen peroxide were added to the polymerization vessel, and the contents in the polymerization vessel were stirred at 60° C. for 1 hour to give polymer solution B2. Obtained. The nonvolatile content of the obtained polymer solution B2 was 50.0% by mass, and the weight average molecular weight of the polymer contained in the polymer solution was 25,000.

Production Example B3 (base resin of B7)
290 parts of deionized water was charged into a polymerization vessel equipped with a cooling pipe, a nitrogen introduction line and a thermometer, and nitrogen gas was introduced to make the inside of the polymerization vessel a nitrogen gas atmosphere. At room temperature, 1.7 parts of a 0.02% copper sulfate aqueous solution was added while stirring the contents in the polymerization vessel. To the dropping funnel A, 187 parts of deionized water and 1053 parts of N-vinylpyrrolidone were added to prepare a premix. To the dropping funnel B, 81 parts of deionized water and 10.6 parts of 35% hydrogen peroxide solution were added. 70 parts of deionized water and 1.7 parts of 25% aqueous ammonia solution were added to the dropping funnel C. The contents of the dropping funnel A, the dropping funnel B and the dropping funnel C were uniformly dropped into the polymerization container over 3 hours to start the polymerization reaction. After the internal temperature of the polymerization container was increased by the heat of polymerization, the contents in the polymerization container were stirred at 60° C. for 3 hours.

Next, the dropping funnel A, the dropping funnel B, and the dropping funnel C were washed with 320 parts of deionized water, and the obtained washing liquid was added into the polymerization container. Further, 2.2 parts of a 25% aqueous ammonia solution and 10 parts of a 30% aqueous hydrogen peroxide solution were added to the polymerization vessel, and then the content in the polymerization vessel was stirred at 60° C. for 1 hour to obtain a polymer solution B3. Obtained. The nonvolatile content of the obtained polymer solution B3 was 50.0% by mass, and the weight average molecular weight of the polymer contained in the polymer solution was 100,000.

Production Example B4
100 parts of deionized water and 900 parts of deionized water of the polymer solution B1 obtained in Production Example B1 were added into a polymerization vessel equipped with a cooling pipe, a nitrogen introduction line and a thermometer, and nitrogen gas was introduced into the polymerization vessel. By introducing, a nitrogen gas atmosphere was created. While stirring the contents in the polymerization container at room temperature, the temperature was raised to 85° C., and when the temperature became constant, 100 parts of diacetone acrylamide, 10 parts of acrylic acid, 10 parts of hydroxyethyl methacrylate, 50 parts of deionized water. An aqueous solution obtained by mixing 4.7 parts of a 25% aqueous ammonia solution with 20% was added to the polymerization vessel over 120 minutes, and an aqueous solution of 1.5 parts of ammonium persulfate dissolved in 48.5 parts of deionized water was over 120 minutes. It was added to the polymerization vessel. After the dropping was completed, 20 parts of deionized water was added to the polymerization vessel and stirred at 80° C. for 1 hour to complete the polymerization reaction. The nonvolatile content of the obtained polymer solution was 47.1% by mass, and the weight average molecular weight of the polymer contained in the polymer solution was 5,000.

Production Example B5
100 parts of deionized water and 900 parts of the polymer solution B2 obtained in Production Example B2 was added to the polymerization container equipped with a cooling pipe, a nitrogen introduction line and a thermometer, and nitrogen gas was added to the polymerization container. By introducing, a nitrogen gas atmosphere was created. 3. While stirring the contents in the polymerization container at room temperature to 85° C., when the temperature became constant, 100 parts of diacetone acrylamide, 10 parts of acrylic acid, 50 parts of deionized water and 25% aqueous ammonia solution were used. An aqueous solution prepared by mixing 7 parts was added into the polymerization container over 120 minutes, and an aqueous solution in which 1.5 parts of ammonium persulfate was dissolved in 48.5 parts of deionized water was added over 120 minutes into the polymerization container. After the dropping was completed, 200 parts of deionized water was added into the polymerization vessel and stirred at 80° C. for 1 hour to complete the reaction. The nonvolatile content of the obtained polymer solution was 40.1%, and the weight average molecular weight of the polymer contained in the polymer solution was 30,000.

Production Example B6
100 parts of deionized water, 900 parts of the polymer solution B3 obtained in Production Example B3 was added to a polymerization vessel equipped with a cooling pipe, a nitrogen introduction line and a thermometer, and nitrogen gas was added to the polymerization vessel. By introducing, a nitrogen gas atmosphere was created. 3. While stirring the contents in the polymerization container at room temperature to 85° C., when the temperature became constant, 100 parts of diacetone acrylamide, 10 parts of acrylic acid, 50 parts of deionized water and 25% aqueous ammonia solution were used. An aqueous solution prepared by mixing 7 parts was added into the polymerization container over 120 minutes, and an aqueous solution in which 1.5 parts of ammonium persulfate was dissolved in 48.5 parts of deionized water was added over 120 minutes into the polymerization container. After the dropping was completed, 300 parts of deionized water was added into the polymerization vessel and stirred at 80° C. for 1 hour to complete the reaction. The nonvolatile content of the obtained polymer solution was 37.1%, and the weight average molecular weight contained in the polymer solution was 180,000.

Example 1
The water-soluble resin B4 obtained in Production Example B4 was added to the (meth)acrylic emulsion A1 obtained in Production Example A1 so that the mass ratio (A1/B4) of both solids was 9/1. An aqueous resin composition for paints was obtained by adding 6 parts of a cross-linking agent [manufactured by Nippon Shokubai Co., Ltd., trade name: Epocros WS-500] and 8 parts of a cross-linking agent (adipic acid dihydrazide) to 100 parts of the obtained mixture. It was

Example 2
The water-soluble resin B4 obtained in Production Example B4 was added to the (meth)acrylic emulsion A2 obtained in Production Example A2 so that the mass ratio (A2/B4) of both solids was 9/1. An aqueous resin composition for paints was obtained by adding 2 parts of a crosslinking agent [manufactured by Nippon Shokubai Co., Ltd., trade name: Epocros WS-500] and 3 parts of a crosslinking agent (adipic acid dihydrazide) to 100 parts of the obtained mixture. It was

Example 3
The water-soluble resin B4 obtained in Production Example B4 was added to the (meth)acrylic emulsion A3 obtained in Production Example A3 so that the mass ratio (A3/B4) of both solids was 9/1. An aqueous resin composition for paints was obtained by adding 2 parts of a cross-linking agent [manufactured by Nippon Shokubai Co., Ltd., trade name: Epocros WS-500] and 2 parts of a cross-linking agent (adipic acid dihydrazide) to 100 parts of the obtained mixture. It was

Example 4
The water-soluble resin B4 obtained in Production Example B5 was added to the (meth)acrylic emulsion A2 obtained in Production Example A2 so that the mass ratio (A2/B5) of both solids was 9/1. An aqueous resin composition for paints was obtained by adding 2 parts of a cross-linking agent [manufactured by Nippon Shokubai Co., Ltd., trade name: Epocros WS-500] and 2 parts of a cross-linking agent (adipic acid dihydrazide) to 100 parts of the obtained mixture. It was

Example 5
The water-soluble resin B4 obtained in Production Example B4 was added to the (meth)acrylic emulsion A2 obtained in Production Example A2 so that the mass ratio (A2/B4) of both solids was 9/1. An aqueous resin composition for paints was obtained by adding 5 parts of a cross-linking agent [Nisshinbo Chemical Co., Ltd., trade name: Carbodilite V-02] and 5 parts of a cross-linking agent (adipic acid dihydrazide) to 100 parts of the obtained mixture. It was

Example 6
The water-soluble resin B4 obtained in Production Example B4 was added to the (meth)acrylic emulsion A2 obtained in Production Example A2 so that the mass ratio (A2/B4) of both solids was 9/1. An aqueous resin composition for paints was obtained by adding 1 part of a cross-linking agent [manufactured by Nippon Shokubai Co., Ltd., trade name: Chemitite PZ-33] and 5 parts of a cross-linking agent (adipic acid dihydrazide) to 100 parts of the obtained mixture. It was

Example 7
The water-soluble resin B4 obtained in Production Example B4 was added to the (meth)acrylic emulsion A2 obtained in Production Example A2 so that the mass ratio (A2/B4) of both solids was 9/1. An aqueous resin composition for paints was obtained by adding 8 parts of a cross-linking agent [Showa Denko KK, trade name: Karenz MOI-BM] and 5 parts of a cross-linking agent (adipic acid dihydrazide) to 100 parts of the obtained mixture. It was

Comparative Example 1
To the (meth)acrylic emulsion A2 obtained in Production Example A2, the water-soluble resin B6 obtained in Production Example B6 was added so that the mass ratio (A2/B6) of both solids was 9/1. An aqueous resin composition for paints was obtained by adding 2 parts of a crosslinking agent [manufactured by Nippon Shokubai Co., Ltd., trade name: Epocros WS-500] and 3 parts of a crosslinking agent (adipic acid dihydrazide) to 100 parts of the obtained mixture. It was

Comparative example 2
To the (meth)acrylic emulsion A2 obtained in Production Example A2, the water-soluble resin B4 obtained in Production Example B4 was added so that the mass ratio (A1/B4) of both solids was 9/1. An aqueous resin composition for paints was obtained by adding 2 parts of a cross-linking agent [manufactured by Nippon Shokubai Co., Ltd., trade name: Epocros WS-500] to 100 parts of the obtained mixture.

Comparative Example 3
To the (meth)acrylic emulsion A4 obtained in Production Example A4, the water-soluble resin B4 obtained in Production Example B4 was added so that the mass ratio (A4/B4) of both solids was 9/1. An aqueous resin composition for paints was obtained by adding 2 parts of a crosslinking agent [manufactured by Nippon Shokubai Co., Ltd., trade name: Epocros WS-500] and 3 parts of a crosslinking agent (adipic acid dihydrazide) to 100 parts of the obtained mixture. It was

Comparative Example 4
To the (meth)acrylic emulsion A5 obtained in Production Example A5, the water-soluble resin B4 obtained in Production Example B4 was added so that the mass ratio (A5/B4) of both solids was 9/1. An aqueous resin composition for paints was obtained by adding 2 parts of a crosslinking agent [manufactured by Nippon Shokubai Co., Ltd., trade name: Epocros WS-500] and 3 parts of a crosslinking agent (adipic acid dihydrazide) to 100 parts of the obtained mixture. It was

Comparative Example 5
The water-soluble resin B4 obtained in Production Example B4 was added to the (meth)acrylic emulsion A2 obtained in Production Example A2 so that the mass ratio (A2/B4) of both solids was 9/1. An aqueous resin composition for paints was obtained by adding 15 parts of a cross-linking agent [Showa Denko KK, trade name: Karenz MOI-BM] to 100 parts of the obtained mixture.

Comparative Example 6
The water-soluble resin B4 obtained in Production Example B4 was added to the (meth)acrylic emulsion A2 obtained in Production Example A2 so that the mass ratio (A2/B4) of both solids was 9/1. An aqueous resin composition for coating materials was obtained by adding 15 parts of a crosslinking agent [manufactured by Nippon Shokubai Co., Ltd., trade name: Chemitite PZ-33] to 100 parts of the obtained mixture.

Next, the physical properties of the aqueous resin composition for coating material obtained above were examined based on the following methods. The results are shown in Table 1.

[Gloss of coating]
(1) Preparation of sample for evaluation 2,2,4-trimethyl-1,3-pentanediol isobutyrate [manufactured by JNC Corporation, product number: CS-12] as a film forming aid in 100 parts of the aqueous resin composition for coating material ] And 10 parts of a mixed solution obtained by mixing butyl cellosolve in equal masses, and after stirring for 10 minutes with a homodisper at a rotation speed of 1500 min ⁻¹ , an antifoaming agent [manufactured by San Nopco Ltd., trade name : Nopco 8034L] 0.5 part was added, and a thickener was added so that the viscosity was 60 KU when measured at 25° C. using a Krebs unit viscometer (Brookfield, product number: KU-1). A product of Nippon Shokubai Co., Ltd., trade name: Acreset WR-503A] was added, and a sample was prepared by stirring for 30 minutes in that state.

(2) Preparation and test of coating film for evaluation Slate plate [manufactured by Nippon Test Panel Co., Ltd., length: 70 mm, width: 150 mm, thickness: 6 m
m] with a sealer [trade name: EX sealer manufactured by SK Kaken Co., Ltd.] by air spray for 15
A coating amount of 0 g/m ² was applied uniformly, and the coating was dried at 23° C. for 1 week.

Next, the sample was applied with a 10 mil applicator and dried at room temperature for 1 day. The 60° specular gloss of the surface coated with the sample is measured with a gloss meter [manufactured by Nippon Denshoku Industries Co., Ltd., product number: VG2000
] It measured with.

(Evaluation criteria)
⊚: Gloss of 70 or more ○: Gloss of 60 or more and less than 70 Δ: Gloss of 30 or more and less than 60 ×: Gloss of less than 30

[Extensibility of coating]
(1) Preparation of sample for evaluation 2,2,4-trimethyl-1,3-pentanediol isobutyrate [manufactured by JNC Corp., product number: CS-] as a film forming aid in 100 parts of the aqueous resin composition for coating material 12] and 10 parts of a mixed solution obtained by mixing butyl cellosolve in equal mass, and after stirring for 10 minutes with a homodisper at a rotation speed of 1500 min ⁻¹ , a defoaming agent [manufactured by San Nopco Ltd., product Name: Nopco 8034L] 0.5 part was added, and a thickener was added so that the viscosity was 60 KU when measured at 25° C. using a Krebs unit viscometer (manufactured by Brookfield, product number: KU-1). A sample was prepared by adding [Accurit WR-503A, manufactured by Nippon Shokubai Co., Ltd.] and stirring in that state for 30 minutes.

(2) Production and Test of Evaluation Film A polypropylene resin plate (length: 70 mm, width: 150 mm, thickness: 2 mm) was coated with the sample obtained above using a 20 mil applicator and dried at room temperature for 24 hours. After that, the formed coating film (length: 1 cm, width: 7 cm) was peeled from the base material and put in a thermostatic chamber adjusted to 0° C. for 3 hours, and then a tensile tester (manufactured by Shimadzu Corporation) Name: Autograph AGS-100D] was used to perform a tensile test under the conditions of an initial gauge distance of 50 mm and a tensile speed of 200 mm/min, and the elongation rate of the film was calculated by the formula:
[Extension rate of coating (%)]={[elongation at break −50 mm]÷[50 mm]}×100
And the extensibility of the coating film was evaluated based on the following evaluation criteria.

(Evaluation criteria)
◯: The elongation of the coating is 30% or more Δ: The elongation of the coating is 20% or more and less than 30% ×: The elongation of the coating is less than 20%

(Gel fraction)
(1) Preparation of sample for evaluation 2,2,4-trimethyl-1,3-pentanediol isobutyrate [manufactured by JNC Corporation, product number: CS-12] as a film forming aid in 100 parts of the aqueous resin composition for coating material ] And 10 parts by weight of a mixed solution obtained by mixing butyl cellosolve in equal amounts, and after stirring for 10 minutes with a homodisper at a rotation speed of 1500 min ⁻¹ , a defoaming agent [manufactured by San Nopco Ltd., trade name : Nopco 8034L] 0.5 part was added, and a thickener was added so that the viscosity was 60 KU when measured at 25° C. using a Krebs unit viscometer (Brookfield, product number: KU-1). A product of Nippon Shokubai Co., Ltd., trade name: Acreset WR-503A] was added, and a sample was prepared by stirring for 30 minutes in that state.

(2) Preparation and Test of Evaluation Film A polypropylene resin plate (length: 70 mm, width: 150 mm, thickness: 2 mm) was coated with the sample obtained above using a 20 mil applicator and dried at room temperature for 24 hours. Then, two films formed (length: 4 cm, width: 4 cm) were peeled from the base material to obtain a film. One of the obtained films was immersed in tetrahydrofuran for 24 hours, the film was taken out after the immersion, the mass was measured after drying at 150°C for 2 hours, and the other film was dried at 150°C for 2 hours. The gel fraction is calculated by the following formula:
[Gel fraction (%)]
={[mass of film after immersion drying]/[mass of film after drying at 150° C. for 2 hours]}×100
And the gel fraction was evaluated based on the following evaluation criteria.

(Evaluation criteria)
◎: Gel fraction 70% or more ○: Gel fraction 60% or more and less than 70% △: Gel fraction 50% or more and less than 60% ×: Gel fraction less than 50%

[Storage stability at high temperature]
(1) Preparation of sample for evaluation 2,2,4-trimethyl-1,3-pentanediol isobutyrate [manufactured by JNC Corp., product number: CS-12] as a film forming aid in 100 parts of the aqueous resin composition for paint ] And 10 parts by weight of a mixed solution obtained by mixing butyl cellosolve in equal amounts, and after stirring for 10 minutes with a homodisper at a rotation speed of 1500 min ⁻¹ , 30 parts of a white paste and an antifoaming agent [San Nopco (stock ), trade name: Nopco 8034L] 0.5 part was added, and the viscosity was 80 KU when measured at 25° C. using a Krebs unit viscometer (Brookfield, product number: KU-1). A sample was prepared by adding a thickener [trade name: Acryset WR-503A, manufactured by Nippon Shokubai Co., Ltd.] and stirring in that state for 30 minutes.

The white paste was 210 parts of deionized water, 60 parts of a dispersant (manufactured by Kao Corporation, trade name: DEMOL EP), 60 parts of a dispersant (manufactured by Daiichi Kogyo Seiyaku Co., Ltd., trade name: DISCOAT N-14). ] 50 parts, wetting agent [Kao Corporation, trade name: Emulgen LS-106] 10 parts, propylene glycol 60 parts, titanium oxide [Ishihara Sangyo Co., Ltd., product number: CR-95] 1000 parts and glass beads It was prepared by dispersing 200 parts (diameter: 1 mm) with a homodisper at a rotation speed of 3000 min ^{−1 for} 60 minutes.

(2) Test After putting the sample obtained above into a closed container and curing it at room temperature for 1 day, an initial stage at 25° C. at a rotation speed of 60 rpm was measured using a BM viscometer (TVB-10M manufactured by Toki Sangyo). The viscosity was measured.

Next, after curing the sample at 50° C. for 1 month in a closed container, a BM viscometer (manufactured by Toki Sangyo Co., Ltd., product number: TVB-10M) was used at a rotation speed of 60 rpm. The viscosity after curing at 25°C was measured.

Based on the initial viscosity and the post-curing viscosity, the rate of change in viscosity is expressed by the formula:
[Viscosity change rate (%)]={[viscosity after curing]−[initial viscosity]}×100
The storage stability at high temperature was evaluated based on the following evaluation criteria.
(Evaluation criteria)
◎: Viscosity change rate is less than 10% ○: Viscosity change rate is 10% or more and less than 20% △: Viscosity change rate is 20% or more and less than 30% ×: Viscosity change rate is 30% or more

〔Weatherability〕
(1) Preparation of sample for evaluation 2,2,4-trimethyl-1,3-pentanediol isobutyrate [manufactured by JNC Corp., product number: CS-] as a film forming aid in 100 parts of the aqueous resin composition for coating material 12] and 10 parts of a mixed solution obtained by mixing butyl cellosolve in an equal mass, and after stirring for 10 minutes with a homodisper at a rotation speed of 1500 min ⁻¹ , 30 parts of a white paste and an antifoaming agent [San Nopco ( Co., Ltd., trade name: Nopco 8034L] 0.5 part was added so that the viscosity would be 80 KU when measured at 25° C. using a Krebs unit viscometer (Brookfield, product number: KU-1). A sample was prepared by adding a thickener [product name: Axlyset WR-503A, manufactured by Nippon Shokubai Co., Ltd.] to the mixture and stirring for 30 minutes in that state.

The white paste was 210 parts of deionized water, 60 parts of a dispersant (manufactured by Kao Corporation, trade name: DEMOL EP), 60 parts of a dispersant (manufactured by Daiichi Kogyo Seiyaku Co., Ltd., trade name: DISCOAT N-14). ] 50 parts, wetting agent [Kao Corporation, trade name: Emulgen LS-106] 10 parts, propylene glycol 60 parts, titanium oxide [Ishihara Sangyo Co., Ltd., product number: CR-95] 1000 parts and glass beads It was prepared by dispersing 200 parts (diameter: 1 mm) with a homodisper at a rotation speed of 3000 min ^{−1 for} 60 minutes.

(2) Preparation and test of coating for evaluation Slate plate (manufactured by Nippon Test Panel Co., Ltd., length: 70 mm, width: 150 mm, thickness: 6 mm) is a sealer (manufactured by SK Kaken Co., Ltd., trade name: EX sealer) ] Was uniformly applied with an air spray at a coating amount of 150 g/m ² , and dried at 23° C. for 1 week.

Next, the sample was applied on the slate film with a 10 mil applicator and dried at 23° C. for 1 week, and then the side surface and the back surface of the slate plate on which the sample was applied were sealed with aluminum tape to apply the sample. The 60° specular gloss of the slate surface was measured with a gloss meter [manufactured by Nippon Denshoku Industries Co., Ltd., product number: VG2000], and a weather resistance test was performed for 1000 hours under the following conditions. Measure the gloss of the painted surface and formula:
[Gloss retention (%)]=[[Gloss after weather resistance test]/[Gloss before weather resistance test]]×100
The gloss retention rate was calculated based on the above, and the weather resistance was evaluated based on the following evaluation criteria.

(Test conditions for weather resistance test)
・Testing machine: Metal weather [Daipla Wintes Co., Ltd., product number: KU-R4]
・Irradiation: Irradiation for 4 hours in an atmosphere with a temperature of 65°C and a relative humidity of 50% (irradiation intensity: 80 mW/cm ² ).
・Wet: 4 hours exposure in an atmosphere with a temperature of 35°C and a relative humidity of 98% ・Shower: Shower for 30 seconds before and after wetting

(Evaluation criteria)
⊚: Gloss retention is 90% or more O: Gloss retention is 80% or more and less than 90% Δ: Gloss retention is 60% or more and less than 80% ×: Gloss retention is less than 60% or cannot be measured

[Long-term hydrophilicity]
(1) Preparation of sample for evaluation 2,2,4-trimethyl-1,3-pentanediol isobutyrate [manufactured by JNC Corp., product number: CS-] as a film forming aid in 100 parts of the aqueous resin composition for coating material 12] and 10 parts of a mixed solution obtained by mixing butyl cellosolve in an equal mass, and after stirring for 10 minutes with a homodisper at a rotation speed of 1500 min ⁻¹ , 30 parts of a white paste and an antifoaming agent [San Nopco ( Co., Ltd., trade name: Nopco 8034L] 0.5 part is added, and the viscosity is 80 KU when measured at 25° C. using a Krebs unit viscometer (manufactured by Pluckfield, product number: KU-1). As described above, a thickener [manufactured by Nippon Shokubai Co., Ltd., trade name: Acryset WR-503A] was added, and the sample was prepared by stirring for 30 minutes in that state.

The white paste was 210 parts of deionized water, 60 parts of a dispersant (manufactured by Kao Corporation, trade name: DEMOL EP), 60 parts of a dispersant (manufactured by Daiichi Kogyo Seiyaku Co., Ltd., trade name: DISCOAT N-14). ] 50 parts, wetting agent [Kao Corporation, trade name: Emulgen LS-106] 10 parts, propylene glycol 60 parts, titanium oxide [Ishihara Sangyo Co., Ltd., product number: CR-95] 1000 parts and glass beads It was prepared by dispersing 200 parts (diameter: 1 mm) with a homodisper at a rotation speed of 3000 min ^{−1 for} 60 minutes.

(2) Preparation and test of coating for evaluation Slate plate (manufactured by Nippon Test Panel Co., Ltd., length: 70 mm, width: 150 mm, thickness: 6 mm) is a sealer (manufactured by SK Kaken Co., Ltd., trade name: EX sealer) ] Was uniformly applied by air spray at a coating amount of 150 g/m ² , and dried at 23° C. for 1 week.

Next, the sample obtained above was applied onto the coating of the slate plate with a 10 mi1 applicator, and dried at 23° C. for 1 week.

(Test method)
A test plate is sprinkled with water for 60 seconds and then dried at room temperature for 1 day, and a series of operations is taken as one cycle to perform a 5-cycle test. The contact angle of the coating surface with water is measured by a contact angle meter [Kyowa Interface Science Co., Ltd.]. , Product number: CA-X], and the long-term hydrophilicity was evaluated based on the following evaluation criteria.

(Evaluation criteria)
⊚: Contact angle with water is less than 50° ○: Contact angle with water is 50° or more and less than 60° Δ: Contact angle with water is 60° or more and less than 70° ×: Contact angle with water is 70° or more Or impossible to measure

〔Comprehensive evaluation〕
In the evaluation of each physical property, ⊚ was evaluated as 20 points, ◯ was evaluated as 10 points, Δ was evaluated as 5 points, and x was evaluated as -10 points, and the total score was obtained by summing the respective scores. .. In addition, if there is even one evaluation of x, it fails.

From the results shown in Table 1, the aqueous resin composition for coating obtained in each Example has a high gel fraction and high temperature at high temperature as compared with the aqueous resin composition for coating obtained in each Comparative Example. It can be seen that the storage stability is excellent, and the gloss, extensibility, weather resistance and long-term hydrophilicity of the coating are comprehensively excellent.

The resin composition for paints of the present invention can be suitably used for surface finishing of a base material made of a material such as metal, glass, porcelain, concrete, siding board, and resin. Therefore, the aqueous resin composition for coating material of the present invention, for example, is suitable for use in ceramic building materials, automobiles, buildings, civil engineering structures, and the like, in particular, the exterior of buildings and the top coat of ceramic building materials. You can

Claims (4)

Emulsion particles having an inner layer and an outer layer, the polymer constituting the inner layer has a glass transition temperature of 30 to 180° C., and the polymer constituting the outer layer has a glass transition temperature of −70 to 20° C. , a coating aqueous resin composition containing a water-soluble polymer and the crosslinking agent, the monomer component used as a raw material of the emulsion particles contains a monomer 0.1 to 10 mass% containing carbonyl groups, wherein The monomer component used as a raw material of the polymer forming the inner layer is a monomer component containing an alkyl (meth)acrylate and a monomer having an alicyclic structure, and is used as a raw material of the polymer forming the outer layer. The monomer component used is a carbonyl group-containing monomer selected from the group consisting of diacetone acrylate, diacetone methacrylate, diacetone acrylamide, and diacetone methacrylamide, an alkyl (meth)acrylate, and a unit amount having an alicyclic structure. The monomer component containing the body, the water-soluble polymer has a weight average molecular weight of 1000 to 50,000, the monomer component used as a raw material of the water-soluble polymer is diacetone acrylate, diacetone methacrylate, A carbonyl group-containing monomer selected from the group consisting of diacetone acrylamide and diacetone methacrylamide, and a group consisting of N-vinylpyrrolidone, N-vinylcaprolactam, (meth)acrylic acid, maleic acid, fumaric acid and itaconic acid A monomer component containing a water-soluble monomer selected from the above , wherein the crosslinking agent is an oxazoline-based crosslinking agent, a hydrazine-based crosslinking agent, a blocked isocyanate-based crosslinking agent, an aziridine-based crosslinking agent and a carbodiimide-based crosslinking agent. An aqueous resin composition for paints, which is selected from two or more kinds of crosslinking agents containing a hydrazine-based crosslinking agent as an essential component . An aqueous resin composition for coating material, comprising emulsion particles, a water-soluble polymer and a cross-linking agent, wherein a monomer component used as a raw material for the emulsion particles comprises a carbonyl group-containing monomer , an alkyl (meth)acrylate and an alicyclic ring. Containing a monomer having a structure, the content of the carbonyl group-containing monomer is 0.1 to 10% by mass , and the carbonyl group-containing monomer is diacetone acrylate, diacetone methacrylate, diacetone acrylamide and die A monomer component which is a carbonyl group-containing monomer selected from the group consisting of acetone methacrylamide, wherein the water-soluble polymer has a weight average molecular weight of 1,000 to 50,000 and is used as a raw material for the water-soluble polymer. The monomer component is a carbonyl group-containing monomer selected from the group consisting of diacetone acrylate, diacetone methacrylate, diacetone acrylamide and diacetone methacrylamide, and a monomer component containing N-vinylpyrrolidone, The cross-linking agent is selected from the group consisting of an oxazoline-based cross-linking agent, a hydrazine-based cross-linking agent, a blocked isocyanate-based cross-linking agent, an aziridine-based cross-linking agent and a carbodiimide-based cross-linking agent, and two or more kinds containing a hydrazine-based cross-linking agent as an essential component . crosslinker der is, paints aqueous resin composition having a glass transition temperature of the entire emulsion particles are characterized by a -5 to 40 ° C.. A luster paint comprising the aqueous resin composition for paint according to claim 1 or 2 . A base material having a coating film made of the gloss paint according to claim 3 .