JP5588885B2 - Aqueous resin composition for architectural paints - Google Patents

Description

  The present invention relates to an aqueous resin composition for architectural paints. More specifically, the present invention relates to an aqueous resin composition for architectural paints and an aqueous architectural paint containing the aqueous resin composition for architectural paints.

  In recent years, building exterior paints have been converted from organic solvent-type paints to water-based paints from the viewpoint of protecting the global environment, and water-based resin compositions are used for these water-based paints. As the aqueous resin composition, for example, an aqueous resin composition containing a resin emulsion and a resin such as an epoxy resin or an amino resin has been proposed (see, for example, Patent Document 1). However, this aqueous resin composition has a drawback that the formed coating film is inferior in gloss and stain resistance.

JP 2004-83644 A

  The present invention has been made in view of the prior art, and is superior in gloss and stain resistance of the coating film to the aqueous resin composition, and further has excellent water resistance, coating film hardness and weather resistance. It is an object to provide a water-based architectural paint for building paints and a water-based architectural paint containing the aqueous resin composition for architectural paints.

The present invention
(1) (A) An aqueous composition obtained by mixing 10 g of emulsion particles, 0.5 g of a water-soluble polymer and 90 g of water is centrifuged at a rotational speed of 40000 min ⁻¹ for 4 hours at a temperature of 25 ° C. A water-soluble polymer satisfying that the amount of the water-soluble polymer present in the separated water layer is 85% by mass or more of the total amount of the water-soluble polymer, and (B) emulsion particles. An aqueous resin composition for building paints, wherein the weight average molecular weight of the functional polymer is 500 to 80000, and the amount of the water-soluble polymer per 100 parts by mass of the emulsion particles is 0.3 to 12 parts by mass;
(2) The water-based resin composition for architectural paints according to (1), wherein the use is a building exterior topcoat,
(3) The aqueous resin composition for architectural paints according to (2), wherein the emulsion particles have a multilayer structure,
(4) The emulsion particles have at least three layers of an outer layer, an intermediate layer and an inner layer, and the glass transition temperature of the polymer constituting the intermediate layer is higher than the glass transition temperature of the polymer constituting the outer layer. (2) or the aqueous resin composition for architectural paints according to (3),
(5) The aqueous resin composition for building paints according to (1), wherein the use is a building material paint,
(6) The aqueous resin composition for architectural paints according to (5), wherein the emulsion particles have a multilayer structure,
(7) The emulsion particles have an inner layer and an outer layer, the glass transition temperature of the inner layer is 80 to 200 ° C, and the glass transition temperature of the outer layer is -10 to 40 ° C, as described in (5) or (6) above Water-based resin composition for building paints,
(8) The difference between the glass transition temperature of the polymer constituting the inner layer and the glass transition temperature of the polymer constituting the outer layer is 50 ° C. or higher, and any one of (5) to (7) Water-based resin composition for architectural paints,
(9) The aqueous resin composition for architectural paints according to any one of (5) to (8), wherein the glass transition temperature of the entire emulsion particles is 0 to 65 ° C.
(10) The mass ratio of the polymer constituting the inner layer to the polymer constituting the outer layer [polymer constituting the inner layer / polymer constituting the outer layer] is 25/75 to 75/25 (5) to (9) The aqueous resin composition for architectural paints according to any one of
(11) The total content of the polymer constituting the inner layer and the polymer constituting the outer layer in the emulsion particles is 50 to 100% by mass according to any one of (5) to (10). Water-based resin composition for building paints,
(12) The content of the carboxyl group-containing monomer in the monomer component used in the polymer constituting the outer layer is the content of the carboxyl group-containing monomer in the monomer component used in the polymer constituting the inner layer. The aqueous resin composition for architectural paints according to any one of (5) to (11), which is higher than the rate,
(13) The aqueous resin composition for architectural paints according to any one of (1) to (12), wherein the water-soluble polymer is at least one selected from the group consisting of polyethylene glycol, polyvinyl pyrrolidone and a surfactant. And (14) The architectural paint comprising the aqueous resin composition for architectural paints according to any one of (1) to (13) and a pigment.

  ADVANTAGE OF THE INVENTION According to this invention, the aqueous resin composition for building paints which forms the coating film which is excellent in the glossiness and stain resistance of a coating film compared with the conventional aqueous resin composition, and has further favorable water resistance, coating film hardness, and a weather resistance. And an architectural paint containing the aqueous resin composition for architectural paints.

The aqueous resin composition for architectural paints of the present invention comprises (A) an aqueous composition obtained by mixing 10 g of emulsion particles, 0.5 g of a water-soluble polymer and 90 g of water at a temperature of 25 ° C. at a rotational speed of 40000 min ^−1. A water-soluble polymer that is centrifuged for a period of time and satisfies the amount of the water-soluble polymer present in the water layer separated by the centrifugal separation being 85% by mass or more of the total amount of the water-soluble polymer, and (B) The emulsion particles are contained, the weight average molecular weight of the water-soluble polymer is 500 to 80000, and the amount of the water-soluble polymer per 100 parts by mass of the emulsion particles is 0.3 to 12 parts by mass.

In the present invention, an aqueous composition formed by mixing 10 g of emulsion particles, 0.5 g of a water-soluble polymer and 90 g of water is centrifuged at a rotational speed of 40000 min ⁻¹ at a temperature of 25 ° C. for 4 hours, and separated by the centrifugation. Satisfaction that the amount of the water-soluble polymer present in the aqueous layer is 85% by mass or more of the total amount of the water-soluble polymer is an indicator that the water-soluble polymer is not adsorbed on the emulsion particles.

  In the present invention, since the water-soluble polymer is used, when the water-soluble polymer is used for an architectural paint, the water-soluble polymer is adsorbed on the emulsion particles when the coating film formed by the architectural paint is dried. Since it is difficult, aggregation of emulsion particles is suppressed, and since the surface of the coating becomes smooth without causing wrinkles and cracks due to shrinkage, it is considered that gloss is imparted to the coating.

  The resin emulsion used in the aqueous resin composition for architectural paints of the present invention can be prepared by emulsion polymerization of monomer components.

  Examples of the monomer component include radical polymerizable monomers such as aromatic monomers and ethylenically unsaturated monomers, and these monomers may be used alone, Two or more types may be used in combination.

  Examples of the aromatic monomer include styrene and derivatives thereof, aralkyl (meth) acrylate, and the like, but the present invention is not limited to such examples. These aromatic monomers may be used alone or in combination of two or more.

  Examples of styrene and derivatives thereof include styrene, α-methyl styrene, o-methyl styrene, m-methyl styrene, p-methyl styrene, o-ethyl styrene, m-ethyl styrene, p-ethyl styrene, o-methoxy styrene. , M-methoxystyrene, p-methoxystyrene, o-ethoxystyrene, m-ethoxystyrene, p-ethoxystyrene, o-fluorostyrene, m-fluorostyrene, p-fluorostyrene, o-chlorostyrene, m-chlorostyrene P-chlorostyrene, o-bromostyrene, m-bromostyrene, p-bromostyrene, o-acetoxystyrene, m-acetoxystyrene, p-acetoxystyrene, o-tert-butoxystyrene, m-tert-butoxystyrene, p-tert-butoki Styrene, o-tert-methylstyrene, m-tert-methylstyrene, p-tert-methylstyrene, but such vinyl toluene and the like, and the present invention is not limited only to those exemplified. These monomers may be used alone or in combination of two or more. Styrene and its derivatives have a functional group such as an alkyl group such as a methyl group or a tert-butyl group, a nitro group, a nitrile group, an alkoxyl group, an acyl group, a sulfone group, a hydroxyl group, or a halogen atom in the benzene ring. Also good. Among styrene and its derivatives, styrene is preferable from the viewpoint of increasing the water resistance of the coating film.

  Examples of the aralkyl (meth) acrylate include aralkyl having 7 to 18 carbon atoms such as benzyl (meth) acrylate, phenylethyl (meth) acrylate, methylbenzyl (meth) acrylate, naphthylmethyl (meth) acrylate and the like. Although (meth) acrylate etc. are mentioned, this invention is not limited only to this illustration. These monomers may be used alone or in combination of two or more.

  In the present specification, “(meth) acrylate” means “acrylate” and / or “methacrylate”, and “(meth) acrylic acid” means “acrylic acid” and / or “methacrylic acid”. To do.

  Examples of the ethylenically unsaturated monomer include alkyl (meth) acrylate, hydroxyl group-containing (meth) acrylate, carboxyl group-containing monomer, oxo group-containing monomer, fluorine atom-containing monomer, and nitrogen atom-containing monomer. Examples include monomers, epoxy group-containing monomers, alkoxyalkyl (meth) acrylates, silane group-containing monomers, carbonyl group-containing monomers, aziridinyl group-containing monomers, and the present invention is only such examples. It is not limited to. These ethylenically unsaturated monomers may be used alone or in combination of two or more.

  Examples of the alkyl (meth) acrylate include methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, tert-butyl (meth) acrylate, sec-butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, n-octyl (meth) acrylate, tridecyl (meth) acrylate, n-lauryl (meth) acrylate, dodecyl (meth) Acrylate, stearyl (meth) acrylate, 2- (acetoacetoxy) ethyl (meth) acrylate, 2-ethylhexyl carbitol (meth) acrylate, isobornyl (meth) acrylate, cyclohexyl (meth) ) Acrylate, 4-methylcyclohexylmethyl (meth) acrylate, tert-butylcyclohexyl (meth) acrylate, and alkyl (meth) acrylate having 1 to 18 carbon atoms in the ester group such as cyclododecyl (meth) acrylate. The present invention is not limited to such examples. These monomers may be used alone or in combination of two or more.

  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 include hydroxyl group-containing (meth) acrylates having 1 to 18 carbon atoms in ester groups such as butyl (meth) acrylate and caprolactone-modified hydroxy (meth) acrylate, but the present invention is not limited to such examples. Absent. These monomers may be used alone or in combination of two or more.

  Examples of the carboxyl group-containing monomer include (meth) acrylic acid, maleic acid, fumaric acid, crotonic acid, itaconic acid, citraconic acid, maleic anhydride, maleic acid monomethyl ester, maleic acid monobutyl ester, and itaconic acid monomethyl. Examples thereof include carboxyl group-containing aliphatic monomers such as esters, itaconic acid monobutyl ester, vinyl benzoic acid, oxalic acid monohydroxyethyl (meth) acrylate, and carboxyl group-terminated caprolactone-modified (meth) acrylate. Is not limited to such examples. These monomers may be used alone or in combination of two or more. Among these carboxyl group-containing monomers, acrylic acid, methacrylic acid and itaconic acid are preferable, and acrylic acid and methacrylic acid are more preferable from the viewpoint of improving the dispersion stability of the emulsion particles.

  Examples of the oxo group-containing monomer include (di) ethylene glycol (methoxy) (meta) such as ethylene glycol (meth) acrylate, ethylene glycol methoxy (meth) acrylate, diethylene glycol (meth) acrylate, and diethylene glycol methoxy (meth) acrylate. ) Acrylate and the like, but the present invention is not limited to such examples. These monomers may be used alone or in combination of two or more.

  Examples of the fluorine atom-containing monomer include trifluoroethyl (meth) acrylate, tetrafluoropropyl (meth) acrylate, octafluoropentyl (meth) acrylate, perfluorobutylethyl (meth) acrylate, perfluoroisononylethyl ( Although fluorine atom containing alkyl (meth) acrylate which has a fluorine atom in ester groups, such as (meth) acrylate and perfluoro octyl ethyl (meth) acrylate, etc. are mentioned, this invention is not limited only to this illustration. These monomers may be used alone or in combination of two or more.

  Examples of the nitrogen atom-containing monomer include (meth) acrylamide, N-monomethyl (meth) acrylamide, N-monoethyl (meth) acrylamide, N, N-dimethyl (meth) acrylamide, and Nn-propyl (meth). Acrylamide, N-isopropyl (meth) acrylamide, methylenebis (meth) acrylamide, N-methylol (meth) acrylamide, N-butoxymethyl (meth) acrylamide, dimethylaminoethyl (meth) acrylamide, N, N-dimethylaminopropylacrylamide, Nitrogen atoms such as acrylamide compounds such as diacetone acrylamide, dimethylaminoethyl (meth) acrylate, diethylaminoethyl (meth) acrylate, ethylene oxide addition (meth) acrylate of morpholine (Meth) acrylate compound, N-vinylpyrrolidone, N-vinylpyridine, N-vinylimidazole, N-vinylpyrrole, N-vinyloxazolidone, N-vinylsuccinimide, N-vinylmethylcarbamate, N, N-methylvinyl Examples include acetamide, (meth) acryloyloxyethyltrimethylammonium chloride, 2-isopropenyl-2-oxazoline, 2-vinyl-2-oxazoline, and (meth) acrylonitrile, but the present invention is limited to such examples. It is not a thing. These monomers may be used alone or in combination of two or more.

  Examples of the epoxy group-containing monomer include glycidyl (meth) acrylate, α-methylglycidyl (meth) acrylate, glycidyl allyl ether, oxocyclohexylmethyl (meth) acrylate, and 3,4-epoxycyclohexylmethyl (meth) acrylate. However, the present invention is not limited to such examples. These monomers may be used alone or in combination of two or more.

  Examples of the alkoxyalkyl (meth) acrylate include methoxyethyl (meth) acrylate, methoxybutyl (meth) acrylate, ethoxybutyl (meth) acrylate, and trimethylolpropane tripropoxy (meth) acrylate. However, the present invention is not limited to such examples. These monomers may be used alone or in combination of two or more.

  Examples of the silane group-containing monomer include vinyltrimethoxysilane, vinyltriethoxysilane, vinyltri (methoxyethoxy) silane, γ- (meth) acryloyloxypropyltrimethoxysilane, 2-styrylethyltrimethoxysilane, vinyltri Examples include chlorosilane, γ- (meth) acryloyloxypropylhydroxysilane, and γ- (meth) acryloyloxypropylmethylhydroxysilane, but the present invention is not limited to such examples. These monomers may be used alone or in combination of two or more.

  Examples of the carbonyl group-containing monomer include acrolein, humylstyrene, vinyl ethyl ketone, (meth) acryloxyalkylpropenal, acetonyl (meth) acrylate, diacetone (meth) acrylate, and 2-hydroxypropyl (meth) acrylate. Examples include acetyl acetate and butanediol-1,4-acrylate acetyl acetate, but the present invention is not limited to such examples. These monomers may be used alone or in combination of two or more.

  Examples of aziridinyl group-containing monomers include (meth) acryloylaziridine and 2-aziridinylethyl (meth) acrylate, but the present invention is not limited to such examples. These monomers may be used alone or in combination of two or more.

  Among the ethylenically unsaturated monomers, from the viewpoint of improving the water resistance of the coating film, (meth) acrylic monomers are preferable, tert-butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, cyclohexyl (Meth) acrylate and glycidyl (meth) acrylate are more preferred.

  Further, in the present invention, from the viewpoint of imparting ultraviolet stability and ultraviolet absorption to the emulsion particles, an ultraviolet stable monomer, an ultraviolet absorbing monomer, and the like are simply used within a range that does not impede the purpose of the present invention. You may make it contain in a mass component.

  Examples of UV-stable monomers include 4- (meth) acryloyloxy-2,2,6,6-tetramethylpiperidine, 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- Crotonoylamino-2,2,6,6-tetramethylpiperidine, 4- (meth) acryloylamino-1,2,2,6,6-pentamethylpiperidine, 4-si No-4- (meth) acryloylamino-2,2,6,6-tetramethylpiperidine, 4-crotonoyloxy-2,2,6,6-tetramethylpiperidine, 1- (meth) acryloyl-4-cyano Examples include -4- (meth) acryloylamino-2,2,6,6-tetramethylpiperidine, 1-crotonoyl-4-crotonoyloxy-2,2,6,6-tetramethylpiperidine, and the like. However, these monomers may be used alone or in combination of two or more.

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

  Examples of the benzotriazole UV-absorbing monomer include 2- [2′-hydroxy-5 ′-(meth) acryloyloxymethylphenyl] -2H-benzotriazole, 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) acryloyloxyhex Ruphenyl] -2H-benzotriazole, 2- [2′-hydroxy-3′-tert-butyl-5 ′-(meth) acryloyloxyethylphenyl] -2H-benzotriazole, 2- [2′-hydroxy-3 ′ -Tert-butyl-5 '-(meth) acryloyloxyethylphenyl] -5-chloro-2H-benzotriazole, 2- [2'-hydroxy-5'-tert-butyl-3'-(meth) acryloyloxyethyl Phenyl] -2H-benzotriazole, 2- [2′-hydroxy-5 ′-(meth) acryloyloxyethylphenyl] -5-chloro-2H-benzotriazole, 2- [2′-hydroxy-5 ′-(meta ) Acrylyloxyethylphenyl] -5-cyano-2H-benzotriazole, 2- [2'-hydride Xyl-5 '-(meth) acryloyloxyethylphenyl] -5-tert-butyl-2H-benzotriazole, 2- [2'-hydroxy-5'-(β- (meth) acryloyloxyethoxy) -3'- tert-butylphenyl] -4-tert-butyl-2H-benzotriazole, and the like, but the present invention is not limited to such examples. These monomers may be used alone or in combination of two or more.

  Examples of the benzophenone-based UV-absorbing monomer include 2-hydroxy-4- (meth) acryloyloxybenzophenone, 2-hydroxy-4- [2-hydroxy-3- (meth) acryloyloxy] propoxybenzophenone, 2- 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 such examples. These monomers may be used alone or in combination of two or more.

  Examples of the method for emulsion polymerization of the monomer component include, for example, an aqueous medium containing a water-soluble organic solvent such as lower alcohol such as methanol and water, an emulsifier dissolved in a medium such as water, and the monomer under stirring. Examples of the method include dropping a component and a polymerization initiator, and a method of dropping a monomer component that has been pre-emulsified with an emulsifier and water into water or an aqueous medium. It is not limited. In addition, what is necessary is just to set the quantity of a medium suitably in consideration of the non volatile matter amount contained in the resin emulsion obtained. The medium may be charged in the reaction vessel in advance or used as a pre-emulsion. The medium may be used when a resin emulsion is produced by emulsion polymerization of monomer components as required.

  When the monomer component is emulsion-polymerized, the monomer component, the emulsifier and the medium may be mixed and then emulsion polymerization may be performed. The emulsion polymerization may be carried out after preparing the emulsion, or the emulsion polymerization may be carried out by mixing at least one of the monomer component, the emulsifier and the medium and the remaining pre-emulsion. The monomer component, the emulsifier, and the medium may be added all at once, dividedly, or continuously dropped.

  When the outer layer is formed on the emulsion particles contained in the resin emulsion obtained above, the monomer component is emulsion-polymerized in the resin emulsion in the same manner as described above to form the outer layer on the emulsion particles. An outer layer can be formed. Moreover, when forming an outer layer further on the emulsion particle | grains in which the said outer layer was formed, an outer layer is further formed on the said emulsion particle | grain by carrying out the emulsion polymerization of the monomer component in a resin emulsion like the above. Can be made. Thus, a resin emulsion containing emulsion particles having a multilayer structure can be prepared by a multistage emulsion polymerization method.

  Examples of the emulsifier include an anionic emulsifier, a nonionic emulsifier, a cationic emulsifier, an amphoteric emulsifier, and a polymer emulsifier. These emulsifiers may be used alone or in combination of two or more.

  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, sodium dodecyl sulfonate and sodium alkyl diphenyl ether disulfonate; ammonium dodecyl benzene sulfonate and sodium dodecyl naphthalene sulfonate. Polyoxyethylene alkyl sulfonate salts; polyoxyethylene alkyl sulfate salts; polyoxyethylene alkyl aryl sulfate salts; dialkyl sulfosuccinates; aryl sulfonic acid-formalin condensates; ammonium laurate, sodium stearate, etc. Fatty acid salt; bis ( (Rioxyethylene polycyclic phenyl ether) methacrylate sulfonate salt, propenyl-alkylsulfosuccinate ester salt, (meth) acrylic acid polyoxyethylene sulfonate salt, (meth) acrylic acid polyoxyethylene phosphonate salt, allyloxymethylalkyloxypoly Sulfuric acid ester having an allyl group, such as sulfonate salt of oxyethylene or a salt thereof; Sulfuric acid ester salt of allyloxymethylalkoxyethyl polyoxyethylene, polyoxyalkylene alkenyl ether ammonium sulfate, and the like. It is not limited to.

  Nonionic emulsifiers include, for example, polyoxyethylene alkyl ether, polyoxyethylene alkyl aryl ether, condensate of polyethylene glycol and polypropylene glycol, sorbitan fatty acid ester, polyoxyethylene sorbitan fatty acid ester, fatty acid monoglyceride, ethylene oxide and aliphatic Condensates with amines, allyloxymethylalkoxyethylhydroxypolyoxyethylene, polyoxyalkylene alkenyl ethers and the like can be mentioned, but the present invention is not limited to such examples.

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

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

  Examples of the polymer emulsifier include poly (meth) acrylates such as sodium polyacrylate; polyvinyl alcohol; polyvinyl pyrrolidone; polyhydroxyalkyl (meth) acrylates such as polyhydroxyethyl acrylate; single polymers constituting these polymers. Although the copolymer etc. which use 1 or more types of a monomer as a copolymerization component are mentioned, this invention is not limited only to this illustration.

  Moreover, as an emulsifier, the emulsifier which has a polymeric group, ie, what is called a reactive emulsifier, is preferable from a viewpoint of improving the water resistance of a coating film, and a non-nonylphenyl type emulsifier is preferable from a viewpoint of environmental protection.

  Examples of reactive emulsifiers include propenyl-alkylsulfosuccinic acid ester salts, (meth) acrylic acid polyoxyethylene sulfonate salts, (meth) acrylic acid polyoxyethylene phosphonate salts, polyoxyethylene alkylpropenyl phenyl ether sulfonate salts, Allyloxymethylalkyloxypolyoxyethylene sulfonate salt, allyloxymethylnonylphenoxyethylhydroxypolyoxyethylene sulfonate salt, allyloxymethylalkoxyethylhydroxypolyoxyethylene sulfate ester, bis (polyoxyethylene polycyclic phenyl ether) methacrylate Sulfonate salts, allyloxymethylalkoxyethylhydroxypolyoxyethylene, polyoxyethylene alkylpropenyl pheny Ethers, such as allyloxymethyl nonyl phenoxyethyl hydroxy polyoxyethylene and the like, and the present invention is not limited only to those exemplified.

  The amount of the emulsifier is preferably 0.01 parts by mass or more, more preferably 0.5 parts by mass or more, and further preferably 1 part by mass or more from the viewpoint of improving polymerization stability per 100 parts by mass of the monomer component. From the viewpoint of improving the water resistance of the coating film, it is preferably 10 parts by mass or less, more preferably 7 parts by mass or less, and still more 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), 2,2-azobis (2-methylpropionamidine); persulfates such as potassium persulfate; hydrogen peroxide , Benzoyl peroxide, parachlorobenzoyl peroxide, lauroyl peroxide, peroxides such as ammonium peroxide, and the like, but the present invention is not limited to such examples. These polymerization initiators may be used alone or in combination of two or more.

  The amount of the polymerization initiator is preferably 0.01 parts by mass or more, more preferably 0 from the viewpoint of increasing the polymerization rate and reducing the residual amount of the unreacted monomer component per 100 parts by mass of the monomer component. 0.05 parts by mass or more, more preferably 0.1 parts by mass or more, and from the viewpoint of improving the water resistance of the coating film, it is preferably 1 part by mass or less, more preferably 0.8 part by mass or less, and still more preferably 0. .5 parts by mass or less.

  The method for adding the polymerization initiator is not particularly limited. Examples of the addition method include batch charging, divided charging, and continuous dripping. From the viewpoint of advancing the completion time of the polymerization reaction, a part of the polymerization initiator may be added before or after the monomer component is added to the reaction system.

  In order to accelerate the decomposition of the polymerization initiator, for example, a reducing agent such as sodium bisulfite and a polymerization initiator decomposition agent such as transition metal salt such as ferrous sulfate are added in an appropriate amount to the reaction system. Also good.

  A chain transfer agent can be used to adjust the weight average molecular weight of the emulsion particles. Examples of the chain transfer agent include 2-ethylhexyl thioglycolate, tert-dodecyl mercaptan, n-octyl mercaptan, n-dodecyl mercaptan, mercaptoacetic acid, mercaptopropionic acid, 2-mercaptoethanol, α-methylstyrene, α-methyl. Although a styrene dimer etc. are mentioned, this invention is not limited only to this illustration. These chain transfer agents may be used alone or in combination of two or more. The amount of the chain transfer agent is preferably 0.01 to 10 parts by mass per 100 parts by mass of the monomer component from the viewpoint of adjusting the weight average molecular weight of the emulsion particles.

  If necessary, additives such as a pH buffer, a chelating agent, and a film-forming aid may be added to the reaction system. Since the amount of the additive varies depending on the type, it cannot be determined unconditionally, but usually, it is preferably about 0.01 to 5 parts by weight, more preferably 0.1 to 100 parts by weight per 100 parts by weight of the monomer component. About 3 parts by mass.

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

  The polymerization temperature for emulsion polymerization of the monomer component is not particularly limited, but is usually preferably 0 to 100 ° C, more preferably 40 to 95 ° C. The polymerization temperature may be constant or may be changed during the polymerization reaction.

  The polymerization time for emulsion polymerization of the monomer component is not particularly limited, and may be appropriately set according to the progress of the polymerization reaction, but is usually about 2 to 8 hours.

  In addition, when carrying out emulsion polymerization of a monomer component, you may make it neutralize part or all of the acidic group which the polymer obtained has with a neutralizing agent. The neutralizing agent may be used after the monomer component is added in the final stage. For example, the neutralizing agent may be used between the first stage polymerization reaction and the second stage polymerization reaction. It may be used at the end of the polymerization reaction.

  Examples of the neutralizing agent include alkali metal and alkaline earth metal hydroxides such as sodium hydroxide; alkali metal and alkaline earth metal carbonates such as calcium carbonate; and organic amines such as ammonia and monomethylamine. Although an alkaline substance is mentioned, this invention is not limited only to this illustration. Among these neutralizing agents, volatile alkaline substances such as ammonia are preferable from the viewpoint of improving the water resistance of the formed coating film.

  Moreover, when carrying out emulsion polymerization of a monomer component, you may use a silane coupling agent in a suitable quantity from a viewpoint of improving the water resistance of the coating film formed. Examples of the silane coupling agent include a silane coupling agent having a polymerizable unsaturated bond such as a (meth) acryloyl group, a vinyl group, an allyl group, and a propenyl group. It is not limited.

  A resin emulsion is obtained by emulsion polymerization of the monomer component as described above. The emulsion particles contained in the resin emulsion may be composed of only one type of polymer prepared by one-stage emulsion polymerization, but it has a multilayer structure prepared by multi-stage emulsion polymerization of monomer components. It is preferable to have a polymer layer from the viewpoint of reconciling the properties of the coating film hardness and the film-forming property that conflict with each other.

  In addition, the emulsion particles have a multilayer polymer layer and are emulsion particles made of an acrylic polymer, so that the low-temperature film-forming property and the coating film hardness and water resistance of the formed coating film are improved. To preferred. In addition, the emulsion particle which has a polymer layer of a multilayer structure and consists of an acrylic polymer has a polymer layer of a multilayer structure, and is a monomer component used for the polymer which forms the polymer layer Means emulsion particles in which (meth) acrylic acid is used as an essential component.

  The aqueous resin composition for architectural paints of the present invention can be suitably used, for example, as an aqueous resin composition for building exterior topcoats and an aqueous resin composition for building materials. In addition, the aqueous resin composition for building exterior topcoats is used, for example, for painting a topcoat outdoors, and the formed coating film is dried at room temperature. Moreover, the water-based resin composition for building materials is used when, for example, coating is performed in a factory such as a factory for manufacturing building materials, and the formed coating film is usually dried by heating.

[Aqueous resin composition for building exterior topcoat]
The emulsion particles used in the aqueous resin composition for building exterior topcoats preferably have a multilayer structure from the viewpoint of improving the low-temperature film-forming property and the coating film hardness and water resistance of the formed coating film. When the emulsion particles have a plurality of polymer layers, the number of the polymer layers is not particularly limited, but is preferably 2 to 5 layers, more preferably 2 to 4 layers, and still more preferably 2 to 3 layers.

  The emulsion particles preferably have a multilayer structure of at least three layers of an outer layer, an intermediate layer, and an inner layer from the viewpoint of improving the water resistance and gloss of the formed coating film and increasing the coating film hardness. Emulsion particles having a multilayer structure can be easily prepared by the multistage emulsion polymerization method described above. For example, emulsion particles having a three-layer structure can be easily prepared by performing pre-stage emulsion polymerization for forming an inner layer, middle-stage emulsion polymerization for forming an intermediate layer, and post-stage emulsion polymerization for forming an outer layer. These emulsion polymerizations are performed in the order of emulsion polymerization for forming the inner layer, emulsion polymerization for forming the intermediate layer, and emulsion polymerization for forming the outer layer.

  When preparing emulsion particles having a multilayer structure, one or more stages of emulsion polymerization may be performed before the emulsion polymerization for forming the inner layer. The emulsion polymerization for forming the inner layer and the intermediate layer may be performed. One-stage or multi-stage emulsion polymerization may be performed between the emulsion polymerization to be formed. Moreover, you may perform one step or multiple steps | paragraphs of emulsion polymerization between the emulsion polymerization which forms the said intermediate | middle layer, and the emulsion polymerization which forms the said outer layer. Furthermore, after the emulsion polymerization for forming the outer layer, one or more stages of emulsion polymerization may be performed.

  In the emulsion particles having a polymer layer having a multilayer structure, at least one layer is derived from at least one monomer selected from the group consisting of cyclohexyl (meth) acrylate, styrene and tert-butyl (meth) acrylate. It is preferable that it is formed with the polymer which has a monomer unit from a viewpoint of raising the coating-film hardness of the coating film formed. The content of the monomer in all monomer components used in the polymer constituting the emulsion particles having the polymer layer having the multilayer structure is preferably from the viewpoint of increasing the coating film hardness of the formed coating film. Is 5% by mass or more, more preferably 10% by mass or more. The said monomer should just be contained in the monomer component used for any one polymer layer which comprises the polymer layer of a multilayer structure, or two or more polymer layers.

  Accordingly, in the emulsion particles having a polymer layer having a multilayer structure, at least one layer contains at least one monomer selected from the group consisting of cyclohexyl (meth) acrylate, styrene and tert-butyl (meth) acrylate. Is formed by emulsion polymerization of the monomer component, and the content of the monomer in all monomer components used in the polymer constituting the emulsion particles is preferably 5% by mass or more, more preferably Is preferably 10% by mass or more from the viewpoint of increasing the coating film hardness of the formed coating film.

  While appropriately setting the glass transition temperature of the emulsion particles themselves having a multilayer structure, the glass transition temperature of the polymer constituting the outer layer constituting the emulsion particles is lowered, and the film thickness and outer layer of the outer layer are reduced. When the composition of the constituent monomer components is appropriately set, the hardness is high and the wear resistance is excellent while maintaining a low-temperature film-forming property equivalent to or higher than that of acrylic polymer emulsion particles having a low hardness. Emulsion particles can be prepared.

  From the viewpoint of low-temperature film-forming properties of the aqueous resin composition of the present invention, coating film hardness of the formed coating film, water resistance and gloss, emulsion particles having at least three layers of an inner layer, an intermediate layer and an outer layer, It is preferable that the glass transition temperature of the constituting polymer is higher than the glass transition temperature of the polymer constituting the outer layer, and the glass transition temperature of the polymer constituting the intermediate layer constitutes the outer layer. More preferably, it is higher than the glass transition temperature of the polymer, and the polymer constituting the intermediate layer is different from the polymer constituting the inner layer. The aqueous paint using the aqueous resin composition containing emulsion particles having at least three layers of the inner layer, the intermediate layer, and the outer layer has a low-temperature film-forming property even if it does not contain a volatile organic solvent (VOC). It has the advantage of forming a coating film excellent in coating film hardness, water resistance and gloss.

  The reason why the aqueous resin composition containing emulsion particles having at least three layers of an inner layer, an intermediate layer and an outer layer is excellent in low-temperature film-forming properties is that the glass transition temperature of the polymer constituting the intermediate layer constitutes the outer layer. This is considered to be based on the fact that the outer layer is easily deformed at a low temperature because it is higher than the glass transition temperature of the polymer. The reason why the coating film hardness of the coating film formed is high is that the glass transition temperature of the polymer constituting the intermediate layer is higher than the glass transition temperature of the polymer constituting the outer layer. It is considered that the hardness of the emulsion particles is maintained by the layer existing inside.

  "The polymer constituting the intermediate layer is different from the polymer constituting the inner layer" means that the composition of the monomer component used as a raw material for these polymers is different, or It means that the structure and molecular weight of the polymer are different. Examples of the polymer constituting the intermediate layer being different from the polymer constituting the inner layer are that the type of monomer used in the monomer is different, the same type of monomer When used, the amount of the monomer used is different, and the molecular weight and structure of the polymer are different.

  In addition, in the emulsion particles having at least three layers of an inner layer, an intermediate layer and an outer layer, the intermediate layer is constituted from the viewpoint of improving the film forming property and improving the gloss of the coating film by forming a smooth coating film. The glass transition temperature of the polymer is preferably higher than the glass transition temperature of the polymer constituting the inner layer.

  In emulsion particles having at least three layers of an inner layer, an intermediate layer, and an outer layer, one or more layers may be formed inside the inner layer, and one or more layers are formed between the intermediate layer and the inner layer. One or more layers may be formed between the outer layer and the intermediate layer, or one or more layers may be formed outside the outer layer. Further, the layers are compatible with each other, and the boundary portion between the layers may not be clear.

In addition, the glass transition temperature of the polymer which comprises the emulsion particle | grains is the glass transition temperature (Tg) of the homopolymer which consists of the monomer contained in the monomer component used as a raw material of the polymer ( From the absolute temperature: K) and the mass fraction of the monomer, the formula (I):
1 / Tg = W ₁ / Tg ₁ + W ₂ / Tg ₂ + W ₃ / Tg ₃ +... + W _n / Tg _n (I)
[Wherein, Tg is the glass transition temperature (K) of the polymer to be obtained, W ₁ , W ₂ , W ₃ ... W _n are the mass fraction of each monomer, Tg ₁ , Tg _2, Tg ₃ ···· Tg _n are respectively the glass transition temperature (K) of a homopolymer composed of a monomer corresponding to the mass fraction of each monomer]
Can be determined based on In addition, the glass transition temperature of a polymer can also be measured by DSC (differential scanning calorimeter), DTA (differential thermal analyzer), and TMA (thermomechanical analyzer).

  In this specification, the glass transition temperature of a polymer means the glass transition temperature calculated | required based on Formula (I). For example, the glass transition temperature of the entire polymer constituting the emulsion particles having a multilayer structure corresponds to the mass fraction of each monomer in all monomer components used in the multi-stage emulsion polymerization. It means the glass transition temperature determined from the glass transition temperature of the homopolymer of the monomer.

  Considering the glass transition temperature of the polymer constituting the emulsion particles, the composition of the monomer component used as the raw material for the polymer constituting the emulsion particles can be determined.

  The glass transition temperature of the homopolymer is, for example, 105 ° C. (378 K) for the homopolymer of methyl methacrylate, −70 ° C. (203 K) for the homopolymer of 2-ethylhexyl acrylate, and 100 ° C. (373 K) for the homopolymer of styrene. ), A homopolymer of cyclohexyl methacrylate at 83 ° C. (356 K), a homopolymer of isobornyl methacrylate at 180 ° C. (453 K), a homopolymer of N-vinylpyrrolidone at 175 ° C. (448 K), a homopolymer of acrylic acid 95 ° C. (368 K) for the coalescence, 130 ° C. (403 K) for the homopolymer of methacrylic acid, 55 ° C. (328 K) for the homopolymer of 2-hydroxyethyl methacrylate, 4-methacryloyloxy-2,2,6,6- Tetramethylpiperidine (HALS) homopolymer is 130 ° C. (4 3K), 94 ° C. is a homopolymer of isobornyl acrylate (367K), which is 107 ° C. is a homopolymer of tert- butyl methacrylate (380K), -56 ℃ is a homopolymer of butyl acrylate (217K).

  The outer layer of the emulsion particles having a multilayer structure functions as a fusion layer when the resin emulsion is dried and the emulsion particles are fused. The glass transition temperature of the polymer constituting the outer layer of the emulsion particles having a multilayer structure is preferably from the viewpoint of increasing the coating film hardness of the formed coating film and improving the stain resistance and abrasion resistance of the coating film. Is −50 ° C. or higher, more preferably −40 ° C. or higher, and preferably 10 ° C. or lower, more preferably 0 ° C. or lower, from the viewpoint of improving the low-temperature film-forming property.

  The glass transition temperature of the polymer constituting the intermediate layer of the emulsion particles having a multilayer structure increases the coating film hardness of the formed coating film, and from the viewpoint of improving the stain resistance and abrasion resistance of the coating film, Preferably it is 50 degreeC or more, More preferably, it is 70 degreeC or more, More preferably, it is 85 degreeC or more, Most preferably, it is 90 degreeC or more, From a viewpoint of improving low temperature film forming property, Preferably it is 150 degreeC or less.

  The glass transition temperature of the polymer constituting the inner layer of the emulsion particles having a multilayer structure is preferably from the viewpoint of increasing the coating film hardness of the formed coating film and improving the stain resistance and abrasion resistance of the coating film. Is −50 ° C. or higher, more preferably −40 ° C. or higher, and preferably 0 ° C. or lower from the viewpoint of improving the low-temperature film-forming property.

  As described above, the glass transition temperature of the polymer constituting the outer layer of the emulsion particles having a multilayer structure, the glass transition temperature of the polymer constituting the intermediate layer, and the glass transition of the polymer constituting the inner layer. When the temperature is adjusted, the low-temperature film-forming property of the aqueous resin composition of the present invention and the coating film hardness of the formed coating film can be made compatible.

  In addition, the glass transition temperature of the entire polymer constituting the emulsion particles having a multilayer structure increases the coating film hardness of the formed coating film, from the viewpoint of improving the stain resistance and abrasion resistance of the coating film, The temperature is preferably −20 ° C. or higher, and preferably 30 ° C. or lower from the viewpoint of improving the low-temperature film-forming property.

  In the emulsion particles having at least three layers of the inner layer, the intermediate layer and the outer layer, the solubility parameter of the polymer constituting the inner layer is smaller than the solubility parameter of the polymer constituting the intermediate layer. It is preferable from the viewpoint of improving the coating film hardness. In this case, the difference between the solubility parameter of the polymer constituting the inner layer and the solubility parameter of the polymer constituting the intermediate layer is 0.1 or more from the viewpoint of improving the coating film hardness of the coating film. It is more preferable.

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

  The solubility parameter of the polymer is described in “POLYMER ENGINEERING AND SCIENCE”, 1974, Vol. 14, no. 2, p. It is the value calculated | required by the method of 147-154. The following outlines the method for determining the solubility parameter.

As the solubility parameter of the homopolymer, the evaporation energy (Δei) and the molar volume (Δvi) of the structural unit forming the homopolymer are obtained by formula (II):
δ = (ΣΔei / ΣΔvi) ^1/2 (II)
(In the formula, Δei represents the evaporation energy of the atom or atomic group of component i, and Δvi represents the molar volume of the atom or atomic group of component i)
Can be determined based on

  The solubility parameter (δ) of the copolymer was obtained by calculating Δei and Δvi of the homopolymer of each monomer constituting the copolymer and multiplying by the mole fraction of those constituent monomers. Using the value, it can be obtained based on the formula (II).

  The solubility parameter of the homopolymer (hereinafter referred to as SP value) is, for example, 9.22 for the homopolymer of 2-ethylhexyl acrylate, 14.04 for the homopolymer of acrylic acid, or 9.24 for the homopolymer of butyl acrylate. 77, 9.45 for the homopolymer of butyl methacrylate, 7.44 for the homopolymer of cyclohexyl methacrylate, 10.20 for the homopolymer of ethyl acrylate, 13.47 for the homopolymer of 2-hydroxyethyl methacrylate, methacryl The homopolymer of acid is 12.54, the homopolymer of methyl methacrylate is 9.93, the homopolymer of styrene is 7.31, and the homopolymer of tert-butyl methacrylate is 9.07.

  The content of the outer layer in the emulsion particles having at least the outer layer, the intermediate layer, and the outer layer is preferably 40% by mass or more, more preferably 50% by mass or more, and further preferably 55% by mass or more, from the viewpoint of improving the low-temperature film-forming property. Particularly preferably, it is 60% by mass or more, and preferably 85% by mass or less, more preferably 80% from the viewpoint of increasing the coating film hardness of the coating film to be formed and improving the stain resistance and wear resistance of the coating film. It is not more than mass%, more preferably not more than 75 mass%, particularly preferably not more than 70 mass%.

  The content of the intermediate layer in the emulsion particles having at least the outer layer, the intermediate layer, and the outer layer is preferably 10 from the viewpoint of increasing the coating film hardness of the formed coating film and improving the stain resistance and abrasion resistance of the coating film. % By mass or more, more preferably 15% by mass or more, more preferably 20% by mass or more, still more preferably 25% by mass or more, and particularly preferably 30% by mass or more, from the viewpoint of improving low-temperature film-forming properties. Is 45% by mass or less, more preferably 42% by mass or less, and still more preferably 40% by mass or less.

  The content of the inner layer in the emulsion particles having the outer layer, the intermediate layer, and the outer layer is preferably 1 mass from the viewpoint of increasing the coating film hardness of the formed coating film and improving the stain resistance and abrasion resistance of the coating film. % Or more, more preferably 2% by mass or more, further preferably 3% by mass or more, and particularly preferably 5% by mass or more. From the viewpoint of improving the low-temperature film-forming property, it is preferably 25% by mass or less, more preferably 12% by mass. It is not more than mass%, more preferably not more than 10 mass%.

  In addition, in this specification, the content rate of each layer in an emulsion particle means the content rate of the monomer used for each layer in all the monomer components used for an emulsion particle.

  In the present invention, the glass transition temperature of the polymer constituting the outer layer is 0 ° C. or less, the content of the outer layer in the emulsion particles having at least the outer layer, the intermediate layer and the outer layer is 40 to 80% by mass, and the emulsion Emulsion particles having a glass transition temperature of −20 to 30 ° C. are preferable because the outer layer has excellent low-temperature film-forming properties and the coating film formed has high coating hardness. Furthermore, this emulsion particle has the advantage that the coating film hardness of the formed coating film is enhanced by the intermediate layer having a high glass transition temperature. In this case, the glass transition temperature of the polymer constituting the intermediate layer may be the same as the glass transition temperature of the polymer constituting the inner layer, but the polymer glass constituting the intermediate layer may be the same. The transition temperature is preferably higher than the glass transition temperature of the polymer constituting the inner layer from the viewpoint of increasing the coating strength of the coating film to be formed. In this case, the glass transition temperature of the polymer constituting the intermediate layer is 10 ° C. or more higher than the glass transition temperature of the polymer constituting the inner layer from the viewpoint of increasing the coating strength of the formed coating film. It is preferably 30 ° C. or higher, more preferably 50 ° C. or higher.

  The glass transition temperature of the polymer composing the intermediate layer is higher than the glass transition temperature of the polymer composing the outer layer and the glass transition temperature of the polymer composing the inner layer. It is preferable from the viewpoint of improving the gloss of the coating film by improving and forming a smooth coating film. In this case, the glass transition temperature of the polymer constituting the intermediate layer constitutes the outer layer from the viewpoint of improving the film forming property and improving the gloss of the coating film by forming a smooth coating film. The glass transition temperature of the polymer and the glass transition temperature of the polymer constituting the inner layer are preferably 10 ° C. or higher, more preferably 30 ° C. or higher, and even more preferably 50 ° C. or higher.

  The upper limit value of the glass transition temperature of the polymer constituting the outer layer is preferably −10 ° C., more preferably −20 ° C., from the viewpoint of improving the low-temperature film-forming property. The content of the outer layer in the emulsion particles is preferably 50% by mass or more from the viewpoint of improving the low-temperature film-forming property.

  The presence of two or more types of polymers having different glass transition temperatures in the emulsion particles having a multilayer structure can be confirmed by measuring the differential scanning calorimetry (DSC) of the dried coating film of the emulsion particles. In addition, the presence of an intermediate layer composed of a polymer having a high glass transition temperature can be confirmed by an atomic force microscope (AFM) in a phase mode. In the Phase mode, the hard layer is depicted as a relatively white contrast.

  From the viewpoint of improving the dispersion stability of the emulsion particles, the average particle diameter of the emulsion particles is preferably 70 nm or more, more preferably 80 nm or more, and further preferably 100 nm or more, from the viewpoint of improving the water resistance of the coating film. Preferably it is 450 nm or less, More preferably, it is 400 nm or less, More preferably, it is 350 nm or less.

  In this specification, the average particle diameter of emulsion particles is determined by diluting a resin emulsion with distilled water, collecting about 10 mL of the obtained diluted solution in a glass cell, and measuring the particle size distribution measuring instrument [particle It means volume average particle diameter measured using Windows-based software [Windows (registered trademark) Based Software] using a product name: NICOM P Model 380, manufactured by Sizing Systems (Particle Sizing Systems).

  The minimum film-forming temperature of the resin emulsion used in the aqueous resin composition for building exterior topcoats is preferably 10 ° C. or less, more preferably 5 ° C. or less, from the viewpoint of reducing the amount of film-forming aid that is an organic compound. More preferably, it is 0 ° C. or lower.

  In the present specification, the minimum film-forming temperature means a boundary temperature between a film-formed part and a non-film-formed part when a resin emulsion is applied in a strip shape on a flat plate having an appropriate temperature gradient. It is defined as “the minimum temperature at which a uniform coating film without cracks is formed”. The minimum film-forming temperature can be measured according to, for example, JIS K6828-2 (2003). More specifically, in the present invention, an MFT tester [manufactured by Tester Sangyo Co., Ltd., product number: TP-801 LT] is used, and a coating film having a thickness of 250 μm when applied onto a stainless steel grooveless flat plate. Is measured with an applicator, and the minimum temperature (° C.) when a uniform coating film without cracks is formed is measured. The presence or absence of cracks in the coating film can be determined visually according to JIS K6828-2.

  In addition, the KOENIG hardness of the coating film formed by drying the aqueous resin composition of the present invention at 23 ° C. for 24 hours is preferably 4 times or more, more preferably 9 from the viewpoint of increasing the coating film hardness. More than once.

  The Koenig hardness is a value when measured using, for example, a pendulum type hardness meter (Erichsen (Germany), Koenig type, product number: 299). More specifically, a coating film is formed by applying an aqueous resin composition on a glass plate with an applicator so that the thickness at the time of application is 250 μm (solid content concentration: about 40 to 60% by mass). After standing for 24 hours at 23 ° C., the obtained coated plate is set on the pendulum type hardness meter, the measurement start angle is set to 6 °, and the pendulum (steel carbide made from tungsten carbide) until the measurement end angle falls below 3 °. Sphere) is measured, and the measured number of reciprocations is taken as the Königs hardness (times). If the coating film has a tack, the pendulum stops on the coating plate, so that the greater the number of reciprocations, the higher the coating film hardness.

  In the present specification, for convenience, the film formed by the aqueous resin composition of the present invention and the film formed by the architectural paint of the present invention are both referred to as a coating film.

[Water-based resin composition for building materials]
The emulsion particles used in the water-based resin composition for building and building material paints preferably have a multilayer polymer layer from the viewpoint of improving the low-temperature film-forming property and the coating film hardness and water resistance of the formed coating film.

  The glass transition temperature of the polymer constituting the inner layer is preferably 80 ° C. or higher, more preferably 85 ° C. or higher from the viewpoint of improving weather resistance, coating film hardness, water resistance and frost damage resistance, and improves frost damage resistance. From the viewpoint of making it preferable, it is preferably 200 ° C. or lower, more preferably 180 ° C. or lower. The glass transition temperature of the polymer constituting the inner layer can be easily adjusted by adjusting the composition of the monomer used for the monomer component forming the inner layer.

  The polymer constituting the inner layer may have a crosslinked structure. The weight average molecular weight of the polymer constituting the inner layer is such that the polymer constituting the inner layer has a crosslinked structure and a case where the polymer does not have a crosslinked structure. From the viewpoint of improving the frost damage resistance, it 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. The upper limit value of the weight average molecular weight of the polymer constituting the inner layer is not particularly limited when it has a crosslinked structure, since it is difficult to measure the weight average molecular weight. From the viewpoint of improving frost damage resistance, it is preferably 5 million or less.

  In this specification, the weight average molecular weight of the polymer is gel permeation chromatography [manufactured by Tosoh Corporation, product number: HLC-8120GPC, column: TSKgel G-5000HXL and TSKgel GMHXL-L used in series. ] Is used to mean the weight average molecular weight (in terms of polystyrene) measured.

  Next, after forming an inner layer, it is preferable to form the outer layer which consists of a polymer whose glass transition temperature is -10-40 degreeC on the surface of the said inner layer.

  When the monomer component forming the outer layer is emulsion-polymerized, the monomer component forming the outer layer is emulsified after the polymerization reaction rate of the polymer constituting the inner layer reaches 90% or more, preferably 95% or more. Polymerization is preferable from the viewpoint of forming a layer separation structure in the emulsion particles.

  In addition, after forming an inner layer, before forming an outer layer, the layer which consists of another polymer may be formed if needed in the range which does not inhibit the objective of this invention. Therefore, in the method for producing an aqueous resin composition of the present invention, after forming the inner layer, before forming the outer layer, the layer made of another polymer, if necessary, as long as the object of the present invention is not hindered. An operation for forming the film may be included.

  As the monomer component forming the outer layer, a monomer component containing a carboxyl group-containing monomer can be used.

  Examples of the carboxyl group-containing monomer include those similar to the carboxyl group-containing monomer used for the monomer component forming the inner layer. The carboxyl group-containing monomers may be used alone or in combination of two or more. Among the carboxyl group-containing monomers, acrylic acid, methacrylic acid and itaconic acid are preferable, and acrylic acid and methacrylic acid are more preferable from the viewpoint of improving the dispersion stability of the emulsion particles.

  The content of the carboxyl group-containing monomer in the monomer component forming the outer layer is preferably 1% by mass or more from the viewpoint of improving the frost damage resistance, and preferably from the viewpoint of improving the weather resistance and water resistance. Is 6% by mass or less.

  Monomers that can be copolymerized with the carboxyl group-containing monomer used for the monomer component forming the outer layer include aromatic monomers and alkyl (meta) used for the monomer component forming the inner layer. ) Acrylate, hydroxyl group-containing (meth) acrylate, oxo group-containing monomer, fluorine atom-containing monomer, nitrogen atom-containing monomer, epoxy group-containing monomer, alkoxyalkyl (meth) acrylate, silane group-containing monomer Body, carbonyl group-containing monomer, aziridinyl group-containing monomer, and the like, but the present invention is not limited to such examples. The monomers copolymerizable with these carboxyl group-containing monomers may be used alone or in combination of two or more.

  The content of the monomer copolymerizable with the carboxyl group-containing monomer in the monomer component forming the outer layer is preferably 94% by mass or more from the viewpoint of improving weather resistance and water resistance, and is resistant to frost damage. From the viewpoint of improving the properties, it is preferably 99% by mass or less.

  The method and polymerization conditions for emulsion polymerization of the monomer component forming the outer layer may be the same as the method and polymerization conditions for emulsion polymerization of the monomer component forming the inner layer.

  The polymer constituting the outer layer may have a crosslinked structure. The weight average molecular weight of the polymer constituting the outer layer is the weather resistance, water resistance, coating film hardness and the case where the polymer constituting the outer layer has either a crosslinked structure or no crosslinked structure. From the viewpoint of improving the frost damage resistance, it 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. The upper limit of the weight average molecular weight of the polymer constituting the outer layer is not particularly limited when it has a crosslinked structure, since it is difficult to measure the weight average molecular weight. From the viewpoint of improving the property and water resistance, it is preferably 5 million or less.

  The glass transition temperature of the polymer constituting the outer layer is preferably 40 ° C. or lower, more preferably 35 ° C. or lower, and further preferably 30 ° C. or lower, from the viewpoint of improving frost damage resistance. The glass transition temperature of the polymer constituting the outer layer is preferably −10 ° C. or higher, more preferably 0 ° C. or higher, and further preferably 10 ° C. or higher, from the viewpoint of improving weather resistance and coating film hardness. The glass transition temperature of the polymer constituting the outer layer can be easily adjusted by adjusting the composition of the monomer used for the monomer component forming the outer layer.

  The difference between the glass transition temperature of the polymer constituting the inner layer and the glass transition temperature of the polymer constituting the outer layer is preferably 50 ° C. or more from the viewpoint of improving the coating film hardness of the formed coating film. The temperature is more preferably 60 ° C. or higher, and preferably 200 ° C. or lower, more preferably 130 ° C. or lower, from the viewpoint of improving the frost damage resistance of the coating film.

  The glass transition temperature of the entire emulsion particles is preferably 0 ° C. or higher, more preferably 10 ° C. or higher, more preferably 20 ° C. or higher, from the viewpoint of improving weather resistance and water resistance, and from the viewpoint of improving frost damage resistance. The temperature is preferably 65 ° C. or lower, more preferably 60 ° C. or lower, and still more preferably 55 ° C. or lower.

  The SP value of the polymer constituting the outer layer is preferably higher than the SP value of the polymer constituting the inner layer from the viewpoint of forming a layer separation structure in the emulsion particles. The difference between the SP value of the polymer constituting the inner layer and the SP value of the polymer constituting the outer layer is preferably large from the viewpoint of forming a layer separation structure in the emulsion particles.

  Further, since the carboxyl group-containing monomer has a high SP value, the content of the carboxyl group-containing monomer in the monomer component used in the polymer constituting the outer layer is the same as that used in the polymer constituting the inner layer. Higher than the content of the carboxyl group-containing monomer in the monomer component is preferable from the viewpoint of clearly separating the inner layer and the outer layer.

  The mass ratio of the polymer constituting the inner layer and the polymer constituting the outer layer [polymer constituting the inner layer / polymer constituting the outer layer] is preferably 25 / from the viewpoint of improving weather resistance and coating film hardness. It is 75 or more, more preferably 35/65 or more, and from the viewpoint of improving water resistance and frost damage resistance, it is preferably 75/25 or less, more preferably 65/35 or less.

  The total content of the polymer constituting the inner layer and the polymer constituting the outer layer in the emulsion particles is 50% by mass or more, preferably 65%, from the viewpoint of improving weather resistance, frost damage resistance and water resistance. The higher the total content of the polymer constituting the inner layer and the polymer constituting the outer layer in the emulsion particles, the higher the upper limit value is 100% by mass.

  The aqueous resin composition for building and building material paints of the present invention contains a resin emulsion containing emulsion particles prepared as described above.

  From the viewpoint of improving weather resistance and frost damage resistance, the minimum film-forming temperature of the resin emulsion used in the aqueous resin composition for building and building material paints of the present invention is preferably −5 ° C. or higher, more preferably 5 ° C. or higher. The temperature is preferably 20 ° C. or higher, and from the viewpoint of improving frost damage resistance, it is preferably 70 ° C. or lower, more preferably 65 ° C. or lower, and further preferably 60 ° C. or lower.

  The content of the carboxyl group-containing monomer in the monomer component used in the polymer constituting the outer layer is determined from the viewpoint of forming a layer separation structure in the emulsion particles, and the monomer used in the polymer constituting the inner layer It is preferably higher than the content of the carboxyl group-containing monomer in the component. Difference between the content of the carboxyl group-containing monomer in the monomer component used in the polymer constituting the outer layer and the content of the carboxyl group-containing monomer in the monomer component used in the polymer constituting the inner layer Is preferably 0.5 points or more, more preferably 1 point or more from the viewpoint of obtaining emulsion particles having an ideal structure in which the inner layer and the outer layer are clearly separated.

  From the above, when producing emulsion particles having an inner layer and an outer layer, the difference between the glass transition temperature of the polymer constituting the inner layer and the glass transition temperature of the polymer constituting the outer layer is 50 ° C. or more. The content of the carboxyl group-containing monomer in the monomer component used in the polymer constituting the outer layer is adjusted so that the carboxyl group-containing monomer in the monomer component used in the polymer constituting the inner layer is The emulsion particles are adjusted by forming an inner layer having a glass transition temperature of 80 to 200 ° C. and then forming an outer layer having a glass transition temperature of −10 to 40 ° C. It is possible to produce an aqueous resin composition for building paints that is excellent in gloss and stain resistance of the coating film, and forms a coating film having good water resistance, coating film hardness and weather resistance. In preferred.

  From the viewpoint of improving the storage stability of the resin emulsion, the average particle diameter of the emulsion particles is preferably 30 nm or more, more preferably 50 nm or more, and further preferably 70 nm or more, from the viewpoint of improving weather resistance and frost damage resistance. , Preferably 250 nm or less, more preferably 200 nm or less.

  Crosslinking property can be imparted to the aqueous resin composition for building and building material paints of the present invention by further containing a crosslinking agent. As a crosslinking agent, a crosslinking reaction may be started at room temperature, or a crosslinking reaction may be initiated by heat. By including a crosslinking agent in the aqueous resin composition of the present invention, water resistance and coating film hardness can be improved.

  Suitable cross-linking agents include, for example, oxazoline group-containing compounds, isocyanate group-containing compounds, aminoplast resins, and the like. These crosslinking agents may be used alone or in combination of two or more. Among these crosslinking agents, an oxazoline group-containing compound is preferable from the viewpoint of improving water resistance and coating film hardness.

As described above, the aqueous resin composition for architectural coatings of the present invention is obtained by mixing an aqueous composition obtained by mixing (A) 10 g of emulsion particles, 0.5 g of a water-soluble polymer and 90 g of water at a rotation speed of 40000 min ⁻¹ . Centrifuge at a temperature of 25 ° C. for 4 hours, and satisfying that the amount of the water-soluble polymer present in the aqueous layer separated by the centrifugation is 85% by mass or more of the total amount of the water-soluble polymer. And (B) emulsion particles, the weight average molecular weight of the water-soluble polymer is 500 to 80000, and the amount of the water-soluble polymer per 100 parts by mass of the emulsion particles is 0.3 to 12 parts by mass. It is characterized by.

  The aqueous resin composition for architectural paints according to the present invention contains the emulsion particles and the specific water-soluble polymer, and thus has excellent gloss and stain resistance, and further has good water resistance, coating film hardness and weather resistance. Can be obtained.

In the aqueous composition obtained by mixing 10 g of the emulsion particles, 0.5 g of the water-soluble polymer and 90 g of water, the amount of the emulsion particles was set to 10 g in order to enable sufficient centrifugation of the aqueous composition. The reason why the amount of the water-soluble polymer is 0.5 g is to reduce the viscosity of the aqueous composition and shorten the time required for centrifugation. In the centrifugation operation, the rotational speed was set to 40000 min ⁻¹ , the centrifugation time was set to 4 hours, and the measurement was performed at a temperature of 25 ° C. in order to sufficiently centrifuge the emulsion particles.

By suppressing aggregation of emulsion particles, a smooth coating film is formed, and from the viewpoint of imparting gloss to the formed coating film, 10 g of emulsion particles, 0.5 g of water-soluble polymer and 90 g of water are mixed. The obtained aqueous composition is centrifuged at a rotational speed of 40000 min ⁻¹ at a temperature of 25 ° C. for 4 hours, and the amount of the water-soluble polymer present in the aqueous layer separated by the centrifugation is the total amount of the water-soluble polymer. Of these, 85% by mass or more, preferably 90% by mass or more, more preferably 95% by mass or more, and particularly preferably the total amount of the water-soluble polymer.

  Suitable water-soluble polymers include, for example, polyethylene glycol, polyvinyl pyrrolidone, surfactants and the like, but the present invention is not limited to such examples. These water-soluble polymers may be used alone or in combination of two or more. Among these water-soluble polymers, polyvinylpyrrolidone is preferable from the viewpoint of increasing the coating film hardness of the formed coating film.

  Polyethylene glycol is a polyether polymer compound having a structure in which ethylene glycol is polymerized. The molecular end of polyethylene glycol may be a hydrogen atom as long as it has water solubility, and one or both ends are, for example, lower alkyl having 1 to 4 carbon atoms such as methyl group, ethyl group, and butyl group. It may be substituted with a group.

  The weight average molecular weight of the water-soluble polymer is 500 or more, preferably 1000 or more, more preferably 3000 or more, from the viewpoint of improving the water resistance of the formed coating film. The viscosity and formation of the aqueous resin composition of the present invention. From the viewpoint of improving the gloss of the coated film, it is 80000 or less, preferably 50000 or less, more preferably 30000 or less.

  In this specification, the weight average molecular weight of the water-soluble polymer is measured by the following gel permeation chromatography (hereinafter referred to as GPC) using a high-speed GPC system “HLC-8320GPC EcoSEC” manufactured by Tosoh Corporation. By performing GPC analysis under conditions, it is determined in terms of polyethylene glycol.

[GPC measurement conditions]
Column: Showa Denko Co., Ltd., trade name: “Shodex SB-G”, “Shodex SB-806”, “Shodex SB-804”, “Shodex SB-803”, “Shodex SB-802.5”
Eluent: 0.1M sodium nitrate in water-acetonitrile solution [volume ratio of purified water to acetonitrile (purified water / acetonitrile): 9/1]
・ Eluent flow rate: 0.8mL / min
・ Injection volume: 100 μL
-Column oven: 40 ° C
・ Detector: Differential refractometer (RI)
Sample concentration: 0.5% by mass

  Examples of the surfactant include anionic surfactants, nonionic surfactants, cationic surfactants, and amphoteric surfactants. These surfactants may be used alone or in two types. You may use the above together. Among these surfactants, anionic surfactants are preferred from the viewpoint of being hardly adsorbed on the emulsion particles and improving the gloss of the formed coating film.

  Examples of the anionic surfactant include alkyl sulfate salts such as ammonium dodecyl sulfate and sodium dodecyl sulfate; alkyl sulfonate salts such as ammonium dodecyl sulfonate, sodium dodecyl sulfonate and sodium alkyl diphenyl ether disulfonate; ammonium dodecyl benzene sulfonate and sodium dodecyl naphthalene. Polyoxyethylene alkyl sulfonate salts; polyoxyethylene alkyl sulfate salts; polyoxyethylene alkyl aryl ether sulfate salts such as polyoxyethylene alkyl phenyl ether sulfate ammonium salts; dialkyl sulfosuccinates; aryl sulfonic acids -Hol Phosphorus condensate; fatty acid salt such as ammonium laurate, sodium stearate; bis (polyoxyethylene polycyclic phenyl ether) methacrylate sulfonate salt, propenyl-alkylsulfosuccinate ester salt, (meth) acrylic acid polyoxyethylene sulfonate salt, ( (Meth) acrylic acid polyoxyethylene phosphonate salt, sulfonate salt of allyloxymethylalkyloxypolyoxyethylene, or a sulfate thereof having an allyl group; sulfate salt of allyloxymethylalkoxyethyl polyoxyethylene, polyoxy Although alkylene alkenyl ether ammonium sulfate etc. are mentioned, this invention is not limited only to this illustration.

  Nonionic surfactants include, for example, polyoxyethylene alkyl ether, polyoxyethylene alkyl aryl ether, condensate of polyethylene glycol and polypropylene glycol, sorbitan fatty acid ester, polyoxyethylene sorbitan fatty acid ester, fatty acid monoglyceride, ethylene oxide and Examples include condensates with aliphatic amines, allyloxymethylalkoxyethylhydroxypolyoxyethylene, polyoxyalkylene alkenyl ethers, and the like, but the present invention is not limited to such examples.

  Examples of the cationic surfactant include alkylammonium salts such as dodecyl ammonium chloride, but the present invention is not limited to such examples.

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

  Among the water-soluble polymers, polyvinylpyrrolidone is preferable from the viewpoint of forming a coating film having excellent water resistance and gloss and high hardness.

  The amount of the water-soluble polymer per 100 parts by mass of the emulsion particles is 0.3 parts by mass or more, preferably 1 part by mass or more, more preferably 2 parts by mass or more from the viewpoint of imparting gloss to the formed coating film. From the viewpoint of improving the water resistance of the formed coating film and increasing the coating film hardness, it is 12 parts by mass or less, preferably 10 parts by mass or less, more preferably 8 parts by mass or less.

  The aqueous resin composition for architectural paints of the present invention contains emulsion particles and a water-soluble polymer, and the water content in the aqueous resin composition for architectural paints of the present invention can be adjusted so that the total amount becomes 100% by mass. .

  The nonvolatile content in the aqueous resin composition for architectural paints 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 from the viewpoint of improving handleability. It is 70 mass% or less, More preferably, it is 60 mass% or less.

In the present specification, the non-volatile content in the aqueous resin composition is determined 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.
[Nonvolatile content in water-based resin composition (mass%)]
= ([Residue mass] ÷ [aqueous resin composition 1 g]) × 100
Means the value obtained based on

  The aqueous resin composition for architectural paints of the present invention can be easily prepared, for example, by mixing a resin emulsion containing the water-soluble polymer and a water-soluble polymer and adding water as necessary.

  The aqueous resin composition of the present invention may contain other resin emulsions other than the resin emulsion as long as the object of the present invention is not impaired. In that case, it is included in the aqueous resin composition. What is necessary is just to adjust so that the average particle diameter of the whole emulsion particle | grains currently may become in the said range.

  In addition, the aqueous resin composition of the present invention includes, for example, an ultraviolet absorber, an ultraviolet inhibitor, a filler, a leveling agent, a dispersant, a thickener, a wetting agent, a plasticizer, and the like within a range that does not hinder the object of the present invention. Additives such as additives, stabilizers, dyes, and antioxidants may be contained in appropriate amounts.

  The aqueous resin composition for architectural paints of the present invention obtained as described above is superior in gloss and stain resistance of the coating film than the conventional aqueous resin composition, and further has better water resistance, coating film hardness and weather resistance. For example, it can be suitably used for building exterior topcoat paints, building construction material paints, and the like.

  The architectural paint of the present invention contains the aqueous resin composition for architectural paints. The architectural paint of the present invention is superior in water paint, gloss resistance and stain resistance to conventional aqueous resin compositions, and further forms a paint film having good water resistance, film hardness and weather resistance. Since the composition is used, it can be suitably used as a coating for building exterior topcoats, a coating for building materials, and the like.

  The architectural paint of this invention may be comprised only with the said water-based resin composition for architectural paints, and may contain the pigment. Examples of the pigment include organic pigments and inorganic pigments, and these may be used alone or in combination of two or more.

  Examples of organic pigments include azo pigments such as benzidine and hansa yellow, azomethine pigments, methine pigments, anthraquinone pigments, phthalocyanine pigments such as phthalocyanine blue, perinone pigments, perylene pigments, diketopyrrolopyrrole pigments, thioindigo pigments, and iminoisoindoline. Pigments, iminoisoindolinone pigments, quinacridone pigments such as quinacridone red and quinacridone violet, flavantron pigments, indanthrone pigments, anthrapyrimidine pigments, carbazole pigments, monoarylide yellow, diaryride yellow, benzimidazolone yellow, tolyl orange , Naphthol orange, quinophthalone pigment, and the like, but the present invention is not limited to such examples. These organic pigments may be used alone or in combination of two or more.

  Examples of inorganic pigments include titanium dioxide, antimony trioxide, zinc white, lithopone, lead white, red iron oxide, black iron oxide, iron oxide, chromium oxide green, carbon black, yellow lead, molybdenum red, ferrocyanide Pigment with flat shape such as ferric (Prussian blue), ultramarine, lead chromate, mica, clay, aluminum powder, talc, aluminum silicate, calcium carbonate, magnesium hydroxide, aluminum hydroxide And extender pigments such as barium sulfate and magnesium carbonate, but the present invention is not limited to such examples. These inorganic pigments may be used alone or in combination of two or more.

  The amount of the pigment is preferably 20 parts by mass or more, more preferably 40 parts by mass or more, and still more preferably 60 parts by mass or more, from the viewpoint of increasing the coating film hardness per 100 parts by mass of the nonvolatile content of the resin emulsion used in the building paint. From the viewpoint of improving the film forming property, it is preferably 200 parts by mass or less.

  The building paint of the present invention may contain an additive as necessary. Examples of additives include aggregates, fillers, leveling agents, dispersants, thickeners, wetting agents, plasticizers, stabilizers, dyes, antioxidants, UV absorbers, UV stabilizers, and the like. The present invention is not limited to such examples.

  The aggregate may be a transparent aggregate or a colored aggregate. Examples of the transparent aggregate include feldspar powder, cinnabar sand, aragonite powder, cold water sand, glass beads, resin beads, and the like, but the present invention is not limited to such examples. Examples of the colored aggregate include marble powder, granite powder, serpentine, fluorite powder, colored cinnabar powder, and colored ceramic powder. However, the present invention is not limited to such examples. Aggregates may be used alone or in combination of two or more.

  The architectural paint of the present invention can be easily prepared by, for example, mixing the above-mentioned aqueous resin composition for architectural paints, and, if necessary, pigments, additives, water and the like.

  In addition, it is preferable that the content rate of the volatile organic compound in the building paint of this invention is 1 mass% or less from a viewpoint of reducing the load with respect to an environment.

  A typical example of a material to which the building paint of the present invention can be applied is an inorganic building material. Examples of the inorganic building material include a ceramic base material and a metal base material. Ceramic base materials are used for applications such as tiles and outer wall materials, for example. Ceramic base materials are the addition of inorganic fillers, fibrous materials, etc. to the hydraulic glue used as the raw material for inorganic hardened bodies, molding the resulting mixture, curing the resulting molded body, and curing it. Obtained by. Examples of the inorganic building material include flexible boards, calcium silicate boards, gypsum slag perlite boards, wood chip cement boards, precast concrete boards, ALC boards, and gypsum boards.

  The architectural paint of the present invention may be applied alone in one layer, or may be applied by recoating two or more layers. When coating is performed by recoating two or more layers, only a part of the layers may be formed by the architectural paint of the present invention, or all the layers may be formed by the architectural paint of the present invention. For overcoating, for example, a first layer (for example, undercoat layer) coating is applied to an object that has been subjected to primer treatment or sealer treatment, and then dried, and then for the second layer (for example, topcoat layer). Although the method of overcoating and drying a paint is mentioned, this invention is not limited by this method. When applying the paint, for example, spray, roller, brush, or iron can be used.

  As described above, in recent years, environmental issues have been emphasized, and not only building interior paints as a countermeasure against sick house syndrome but also exterior paints that do not contain volatile organic compounds (VOC) (VOC-free) paints. Although it is sought, by using the building paint of the present invention, it contains almost no volatile organic compound (VOC), and is superior in gloss and stain resistance of the coating film than the conventional aqueous resin composition, and is even better. A coating film having water resistance, coating film hardness and weather resistance can be formed.

  Next, the present invention will be described in more detail based on examples. However, the present invention is not limited to such examples. In the following, “part” means “part by mass” and “%” means “mass%” unless otherwise specified.

Production Example 1
In a flask equipped with a dropping funnel, a stirrer, a nitrogen introducing tube, a thermometer and a reflux condenser, 460 parts of deionized water and an anionic reactive surfactant as an emulsifier [polyoxyalkyl ether sulfate ammonium salt, Daiichi Kogyo 8 parts of a 25% aqueous solution manufactured by Pharmaceutical Co., Ltd., trade name: Aqualon (registered trademark) KH-10] was charged, and the temperature was raised to 78 ° C. with stirring while gently blowing nitrogen gas.

  After heating, an anionic reactive surfactant [polyoxyalkyl ether sulfate ammonium salt, manufactured by Daiichi Kogyo Seiyaku Co., Ltd., trade name: Aqualon (registered trademark) KH-10] as an emulsifier and a table 15 parts of pre-emulsion (monomer component amount: 10 parts) prepared by mixing the monomer component of the first stage shown in 1 so that the concentration of the monomer component is 67% is charged into the flask at a time. did.

  After the internal temperature of the flask was stabilized at 75 ° C., emulsion polymerization was started by adding 100 parts of a 3% potassium persulfate aqueous solution into the flask. At this time, the temperature in the reaction system was raised to 80 ° C. and maintained at that temperature for 20 minutes to carry out the first stage polymerization reaction.

  After completion of the first stage polymerization reaction, an anionic reactive surfactant [polyoxyalkyl ether sulfate ammonium salt, Daiichi Kogyo Seiyaku Co., Ltd.] as an emulsifier while maintaining the temperature in the reaction system at 80 ° C. Manufactured, trade name: Aqualon (registered trademark) KH-10] pre-emulsion prepared by mixing an aqueous solution of 8% and the second-stage monomer component shown in Table 1 so that the concentration of the monomer component is 67%. 600 parts (monomer component amount: 400 parts) was uniformly dropped over 60 minutes, and then aged at 80 ° C. for 60 minutes to carry out a second-stage polymerization reaction.

  After the completion of the second stage polymerization reaction, an anionic reactive surfactant [polyoxyalkyl ether sulfate ammonium salt, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.] as an emulsifier while maintaining the temperature in the reaction system at 80 ° C. , Trade name: Aqualon (registered trademark) KH-10] 8% aqueous solution and the third-stage monomer component shown in Table 1 were mixed so that the concentration of the monomer component was 67%, 881 parts of pre-emulsion (590 parts as a monomer) was added dropwise over 120 minutes and then aged at 80 ° C. for 120 minutes to carry out a third-stage polymerization reaction.

  The flask was cooled to room temperature, 25% ammonia water was added so that the pH of the contents in the flask was 8.5, and deionized water was added so that the solid content concentration was 50%. The mixture was filtered through a wire mesh having an opening of 100 mesh (JIS mesh) to obtain a resin emulsion. The minimum film-forming temperature of the obtained resin emulsion was 5 ° C. Moreover, the average particle diameter of the emulsion particles contained in the resin emulsion was 150 nm, the nonvolatile content in the resin emulsion was 50%, and the glass transition temperature of the whole emulsion particles was 15.8 ° C.

Production Example 2
In Production Example 1, the composition of the monomer component used in the first stage was changed as shown in Table 1, and the amount of pre-emulsion was 75 parts (monomer component amount: 50 parts). The emulsifier is changed to an anionic reactive surfactant (trade name: Latemul (registered trademark) PD-104, manufactured by Kao Corporation), and the amount of pre-emulsion is changed to 522 parts (monomer component amount: 350 parts). In the same manner as in Production Example 1 except that the amount of pre-emulsion in the third stage was changed to 900 parts (monomer component amount: 600 parts) and the water-soluble polymer shown in Table 1 was used. An emulsion was prepared. The minimum film-forming temperature of the obtained resin emulsion was less than 0 ° C. Moreover, the average particle diameter of the emulsion particles contained in the resin emulsion was 150 nm, the nonvolatile content in the resin emulsion was 50%, and the glass transition temperature of the entire emulsion particles was 0.6 ° C.

Production Example 3
In Production Example 1, the composition of the monomer component used in the first stage was changed as shown in Table 1, and the amount of pre-emulsion was 150 parts (monomer component amount: 100 parts). The composition of the monomer component used was changed as shown in Table 1, the amount of pre-emulsion was changed to 373 parts (monomer component amount: 250 parts), and the monomer component used in the third stage was changed. The composition was changed as shown in Table 1, the amount of pre-emulsion was changed to 970 parts (monomer component amount: 650 parts), and the water-soluble polymer shown in Table 1 was used. A resin emulsion was prepared in the same manner. The obtained emulsion particles had two layers because the compositions of the monomer components in the first and second stages used when preparing the resin emulsion were the same. The minimum film-forming temperature of the obtained resin emulsion was less than 0 ° C. Moreover, the average particle diameter of the emulsion particles contained in the resin emulsion was 150 nm, the nonvolatile content in the resin emulsion was 50%, and the glass transition temperature of the whole emulsion particles was −3.6 ° C.

Production Example 4
In Production Example 1, the composition of the monomer component used in the first stage was changed as shown in Table 1, and the amount of pre-emulsion was 150 parts (monomer component amount: 100 parts). The composition of the monomer component used was changed as shown in Table 1, the pre-emulsion amount was changed to 373 parts (monomer component amount: 250 parts), and the monomer component used in the third stage was changed. The composition was changed as shown in Table 1, the amount of the pre-emulsion in the third stage was changed to 970 parts (monomer component amount: 650 parts), and the water-soluble polymer shown in Table 1 was used, except that A resin emulsion was prepared in the same manner as in Production Example 1. The obtained emulsion particles had one layer because the composition of the monomer components in the first, second and third stages used in preparing the resin emulsion was the same. The minimum film-forming temperature of the obtained resin emulsion was less than 0 ° C. Moreover, the average particle diameter of the emulsion particles contained in the resin emulsion was 150 nm, the nonvolatile content in the resin emulsion was 50%, and the glass transition temperature of the whole emulsion particles was −24.4 ° C.

Each abbreviation shown in Table 1 means the following.
2EHA: 2-ethylhexyl acrylate CHMA: cyclohexyl methacrylate St: styrene MMA: methyl methacrylate t-BMA: tert-butyl methacrylate AA: acrylic acid Tg: glass transition temperature of polymer BA: butyl acrylate HEMA: 2-hydroxyethyl methacrylate HALS: 4-Methacryloyloxy-2,2,6,6-tetramethylpiperidine [Asahi Denka Kogyo Co., Ltd., trade name: ADK STAB (registered trademark) LA-87]

Preparation Example 265.5 parts of deionized water, 10 parts of additive A for paint (BIC Chemie Japan Co., Ltd., trade name: BYK (registered trademark) -154), additive B for paint (BIC Chemie Japan Co., Ltd.) Product name: BYK (registered trademark) -187] 10 parts, paint additive C (BIC Chemie Japan Co., Ltd.), product name: BYK (registered trademark) -024] 1.3 parts and titanium oxide [Ishihara A paste was obtained by mixing 1000 parts by Sangyo Co., Ltd., trade name: Tybak CR-95].

Examples 1-11
Resin by adjusting the amount of the active ingredient of the water-soluble polymer so that the amount per 100 parts of the emulsion particles contained in the resin emulsion obtained in any one of Production Examples 1 to 4 is the amount shown in Table 2. An aqueous resin composition was obtained by adding the water-soluble polymer shown in Table 2 to the emulsion.

In addition, each abbreviation of the water-soluble polymer described in each table means the following.
PEG1: Polyethylene glycol with a weight average molecular weight of 1000 with hydrogen atoms at both ends PEG2: Polyethylene glycol with a weight average molecular weight of 6000 with hydrogen atoms at both ends PEG3: Polyethylene glycol with hydrogen atoms at both ends and a weight average molecular weight of 20000 PEG4: one end is a hydrogen atom, the other end is a methyl group, and the weight average molecular weight is 6000 polyethylene glycol PEG5: both ends are ethyl groups, and the weight average molecular weight is 6000, polyethylene glycol PEG6: one end is Polyethylene glycol PEG 7 having a weight average molecular weight of 6000 which is a hydrogen atom and the other end is a butyl group: Ethylene glycol PEG 8 having both ends of a hydrogen atom and a weight average molecular weight of 62: Both ends have a hydrogen atom and a weight average molecular weight of 100,000 Polyethylene glycol

PVP1: polyvinylpyrrolidone PVP2 having a weight average molecular weight of 20000: polyvinylpyrrolidone PVP3 having a weight average molecular weight of 160000: polyvinylpyrrolidone PVP4 having a weight average molecular weight of 800,000: polyvinylpyrrolidone having a weight average molecular weight of 6000

SUR1: Polyoxyethylene alkyl ether [trade name: Emulgen 1118S-70, manufactured by Kao Corporation]
SUR2: polyoxyethylene alkyl ether [trade name: Emulgen 1135S-70, manufactured by Kao Corporation]
SUR3: Polyoxyethylene alkylphenyl ether sulfate ammonium salt [Daiichi Kogyo Seiyaku Co., Ltd., trade name: Hytenol N-08]

  Next, 86.2 parts of the paste obtained in the above preparation example, 200 parts of the aqueous resin composition obtained in each example or each comparative example, film-forming aid [manufactured by Chisso Corporation, trade name: CS- 12] 4 parts, 0.5 part of 25% aqueous ammonia and paint additive C [BIC Chemie Japan Co., Ltd., trade name: BYK-024] 0.5 parts were mixed, and 25 ° C of the resulting mixture Was measured with a Stormer-type viscometer, and the viscosity was adjusted to 80 KU using a thickener [Rohm and Haas, product name: TT-935], whereby an aqueous coating for topcoat was prepared. Obtained.

Example 12
In Example 10, the same procedure as in Example 10 was performed except that the film-forming aid [manufactured by Chisso Corporation, trade name: CS-12] was not used when preparing the water-based paint for topcoat. An aqueous paint for top coat was obtained.

Examples 13-20 and Comparative Examples 1-9
In Example 1, the topcoat was used in the same manner as in Example 1 except that the resin emulsion described in Table 2 was used and the water-soluble polymer described in Table 2 was used in the amount described in Table 2. A water-based paint was obtained.

Comparative Example 10
A water-soluble resin was prepared in the same manner as in “Production of water-soluble resin” described in paragraph [0065] of JP-A-2004-83644.

  Next, instead of the water-soluble polymer used in Example 13, the water-soluble resin obtained above was used in the same manner as in Example 13 except that the water-soluble resin was used at the same resin solid content as in Example 13. An aqueous paint was obtained.

In each example and each comparative example, an aqueous composition obtained by mixing 10 g of emulsion particles, 0.5 g of a water-soluble polymer and 90 g of water was centrifuged at a rotational speed of 40,000 min ⁻¹ at a temperature of 25 ° C. for 4 hours. The amount of the water-soluble polymer present in the water layer separated by the centrifugal separation is measured, and the ratio of the water-soluble polymer present in the water layer to the total water-soluble polymer used [(the amount of the water-soluble polymer present in the water layer Mass) ÷ (mass of all water-soluble polymers used) × 100] was determined and evaluated based on the following evaluation criteria. The results are shown in “Content” in the column of the water-soluble polymer in Table 2.
(Evaluation criteria)
○: The ratio of the water-soluble polymer present in the aqueous layer to the total water-soluble polymer is 95% by mass or more. Δ: The ratio of the water-soluble polymer present in the aqueous layer to the total water-soluble polymer is 85% by mass or more and less than 95% by mass. : The ratio of the water-soluble polymer in the aqueous layer to the total water-soluble polymer is less than 85% by mass

  Next, as the physical properties of the water-based paint for top coats obtained in each Example and each Comparative Example, the gloss, water resistance, film hardness, stain resistance and weather resistance of the formed coating film are based on the following methods. Measured. The results are shown in Table 2.

[Glossy]
Using a 6 mil applicator on the glass plate, apply the water-based paint for topcoat obtained in each example or each comparative example, and at a temperature of 23 ± 1 ° C. in an atmosphere of 50 ± 10% relative humidity for one day. After drying, the 60 ° specular gloss value was measured with a gloss meter (manufactured by Nippon Denshoku Industries Co., Ltd., product number: VG2000), and evaluated based on the following evaluation criteria.
(Evaluation criteria)
A: Specular gloss value of 80 or more ◯: Specular gloss value of 78 or more and less than 80 Δ: Specular gloss value of 75 or more and less than 78 ×: Specular gloss value of less than 75

〔water resistant〕
Brush the slate plate (manufactured by Nozawa Co., Ltd., trade name: Nozawa Flexible Sheet, JIS A5403 standard product) and sealer [manufactured by Nippon Paint Co., Ltd., trade name: DAN transparent sealer] in an amount of 130 g / m ² . The top coat aqueous paint obtained in each Example or each Comparative Example was applied to a sealer plate that was applied and dried at room temperature for 1 day using a 6 mil applicator, and dried at room temperature for 1 day. The film was immersed in water having a water temperature of 23 ° C., the coating film was observed after 7 days, and evaluated based on the following evaluation criteria.
(Evaluation criteria)
○: No abnormality in the coating film △: Swelling / peeling is observed in the range of less than 5% of the coating film X: Swelling / peeling is observed in the range of 5% or more of the coating film

[Coating hardness]
Using a 6 mil applicator on the glass plate, apply the water-based paint for topcoat obtained in each example or each comparative example, and at a temperature of 23 ± 1 ° C. in an atmosphere of 50 ± 10% relative humidity for one day. After drying, use a König hardness tester (Erichsen (Germany), König type, product number: 299), hardness at a position where wind is not directly applied in a temperature-controlled room at 23 ± 1 ° C and relative humidity 50 ± 10%. Measure the number of reciprocations of the pendulum (tungsten carbide steel balls) until the measurement end angle is less than 3 °, and set the measurement count as the hardness index. . The greater the number of measurements, the better the coating. Based on the measurement results, the hardness was evaluated according to the following evaluation criteria.
(Evaluation criteria)
◎: Number of round trips 15 times or more ○: Number of round trips 5-14 times ×: Number of round trips 4 or less

[Contamination resistance]
Brush the slate plate [manufactured by Nozawa Co., Ltd., trade name: Nozawa Flexible Sheet, JIS A-5403 standard product], and sealer [manufactured by Nippon Paint Co., Ltd., trade name: DAN transparent sealer] in an amount of 130 g / m ^2. Using the 6 mil applicator, the top coat water-based paint obtained in each Example or each Comparative Example was applied to the sealer plate that had been applied and dried at room temperature for 1 day, and dried at room temperature for 7 days. After that, an exposure test was performed outdoors on an elevated surface, and contamination by rain streaks was visually observed, and the contamination resistance was evaluated according to the following evaluation criteria.
(Evaluation criteria)
◎: The period until the rain streak is recognized is 2 months or more ○: The period until the rain streak is recognized is 1 month or more and less than 2 months ×: The period until the rain streak is recognized is less than 1 month

〔Weatherability〕
Brush the slate plate (manufactured by Nozawa Co., Ltd., trade name: Nozawa Flexible Sheet, JIS A5403 standard product) and sealer [manufactured by Nippon Paint Co., Ltd., trade name: DAN transparent sealer] in an amount of 130 g / m ² . After applying and applying the water-based paint for topcoat obtained in each Example or each Comparative Example to a sealer plate that was applied and dried at room temperature for 1 day using a 6 mil applicator and dried at room temperature for 7 days, The time required for the gloss retention (GR) to be less than 80% was measured with a super xenon weather meter (Suga Test Instruments Co., Ltd., product number: SX2-75) under the test conditions according to JIS A6909. The weather resistance was evaluated according to the following evaluation criteria.
(Evaluation criteria)
A: Time required for the gloss retention rate to be less than 80% is 2500 hours or more. B: Time required for the gloss retention rate to be less than 80% is 2000 hours or more and less than 2500 hours. Δ: The gloss retention rate is 80. % Required to be less than 1500% and less than 2000 hours ×: less than 1500 hours required for gloss retention to be less than 80%

  In Table 2, the production example number described in the column of the emulsion type means that the resin emulsion obtained in the production example was used. The amount of the water-soluble polymer indicates an amount (parts) per 100 parts of the emulsion particles. Moreover, in each evaluation, evaluation more than (triangle | delta) becomes a pass standard.

  From the results shown in Table 2, the water-based paints obtained in each of the Examples are superior in the gloss and stain resistance of the coating film as compared with the water-based paint obtained in the conventional Comparative Example 10, and are even better. It turns out that the coating film which has water resistance, coating-film hardness, and a weather resistance is formed. Therefore, it turns out that the water-based paint obtained in each Example can be used suitably as a paint for building exterior topcoats.

Production Example 5
In a flask equipped with a dropping funnel, a stirrer, a nitrogen introduction tube, a thermometer, and a reflux condenser, 810 parts of deionized water was charged. In a dropping funnel, 145 parts of deionized water and an anionic surfactant as an emulsifier [polyoxyethylene alkylphenyl ether sulfate ester, manufactured by Daiichi Kogyo Seiyaku Co., Ltd., trade name: Aqualon (registered trademark) HS-10 A pre-emulsion for dripping consisting of 60 parts of a 25% aqueous solution, 90 parts of 2-ethylhexyl acrylate, 400 parts of methyl methacrylate and 10 parts of acrylic acid, of which 71 parts corresponding to 5% of the total amount of all monomer components was prepared. The mixture was added to the flask, heated to 80 ° C. while gently blowing nitrogen gas, and 14 parts of a 3.5% aqueous solution of ammonium persulfate was added to initiate the polymerization reaction. Thereafter, the remainder of the pre-emulsion for dropping, 43 parts of a 3.5% aqueous solution of ammonium persulfate and 30 parts of a 2.5% aqueous solution of sodium bisulfite were added dropwise uniformly over 120 minutes. After completion of the dropping, the first stage polymerization reaction was carried out by maintaining the temperature at 80 ° C. for 60 minutes.

  After completion of the first stage polymerization reaction, with the temperature in the reaction system maintained at 80 ° C., 145 parts of deionized water, an anionic surfactant [polyoxyethylene alkylphenyl ether sulfate ester salt, Daiichi Kogyo Seiyaku Co., Ltd., trade name: Aqualon (registered trademark) HS-10] 25% aqueous solution 60 parts, 2-ethylhexyl acrylate 100 parts, butyl acrylate 90 parts, methyl methacrylate 300 parts and acrylic acid 10 parts The second stage pre-emulsion, 43 parts of a 3.5% aqueous solution of ammonium persulfate and 30 parts of a 2.5% aqueous solution of sodium hydrogen sulfite were uniformly added dropwise into the flask over 120 minutes. After completion of the dropwise addition, the temperature was maintained at 80 ° C. for 120 minutes, and the pH was adjusted to 8 by adding 25% aqueous ammonia to complete the polymerization reaction.

  The resulting reaction solution was cooled to room temperature, and then filtered through a (JIS mesh) wire mesh having a mesh opening of 300 mesh to obtain a resin emulsion. The average particle diameter of the emulsion particles contained in the obtained resin emulsion was 150 nm.

  The non-volatile content in the resin emulsion obtained above is 43%, the glass transition temperature of the inner layer resin constituting the emulsion particles is 54 ° C., the glass transition temperature of the outer layer is 16 ° C., and the glass of the entire emulsion particles The transition temperature was 34 ° C. The total content of the polymer constituting the inner layer and the polymer constituting the outer layer in the emulsion particles was 100%, and the minimum film-forming temperature of the resin emulsion was 55 ° C.

Production Example 6
In a flask equipped with a dropping funnel, a stirrer, a nitrogen introduction tube, a thermometer, and a reflux condenser, 810 parts of deionized water was charged. In a dropping funnel, 96 parts of deionized water, an anionic surfactant as an emulsifier [polyoxyethylene alkylphenyl ether sulfate ester, manufactured by Daiichi Kogyo Seiyaku Co., Ltd., trade name: Aqualon (registered trademark) HS-10 ], 40 parts of a 25% aqueous solution, 335 parts of methyl methacrylate and 5 parts of acrylic acid are prepared, and 71 parts, which is 5% of the total amount of all the monomer components, is added to the flask. The temperature was raised to 80 ° C. while blowing nitrogen gas, and 14 parts of a 3.5% aqueous solution of ammonium persulfate was added to initiate the polymerization reaction. Thereafter, the remainder of the pre-emulsion for dropping, 29 parts of a 3.5% aqueous solution of ammonium persulfate and 20 parts of a 2.5% aqueous solution of sodium bisulfite were added dropwise uniformly over 90 minutes. After completion of the dropping, the first stage polymerization reaction was carried out by maintaining the temperature at 80 ° C. for 60 minutes.

  After completion of the first stage polymerization reaction, 96 parts of deionized water and an anionic surfactant [polyoxyethylene alkylphenyl ether sulfate ester salt as an emulsifier, with the temperature in the reaction system maintained at 80 ° C. Daiichi Kogyo Seiyaku Co., Ltd., trade name: Aquaron (registered trademark) HS-10] 25% aqueous solution 40 parts, 2-ethylhexyl acrylate 80 parts, butyl acrylate 45 parts, methyl methacrylate 200 parts and acrylic acid 5 parts The second stage pre-emulsion, 29 parts of a 3.5% aqueous solution of ammonium persulfate and 20 parts of a 2.5% aqueous solution of sodium hydrogen sulfite were uniformly added dropwise into the flask over 90 minutes. After completion of the dropwise addition, the polymerization reaction at the second stage was performed by maintaining at 80 ° C. for 60 minutes.

  After completion of the second stage polymerization reaction, with the temperature in the reaction system maintained at 80 ° C., 100 parts of deionized water, an anionic surfactant as an emulsifier [polyoxyethylene alkylphenyl ether sulfate, Daiichi Kogyo Seiyaku Co., Ltd., trade name: Aquaron (registered trademark) HS-10] 25% aqueous solution 40 parts, 2-ethylhexyl acrylate 45 parts, butyl acrylate 85 parts, methyl methacrylate 190 parts and acrylic acid 10 parts The third stage pre-emulsion, 29 parts of a 3.5% aqueous solution of ammonium persulfate, and 20 parts of a 2.5% aqueous solution of sodium hydrogen sulfite were uniformly dropped into the flask over 90 minutes. After completion of the dropwise addition, the temperature was maintained at 80 ° C. for 120 minutes, and the pH was adjusted to 8 by adding 25% aqueous ammonia to complete the polymerization reaction.

  The resulting reaction solution was cooled to room temperature, and then filtered through a (JIS mesh) wire mesh having a mesh opening of 300 mesh to obtain a resin emulsion. The average particle diameter of the emulsion particles contained in the obtained resin emulsion was 150 nm.

  The resin emulsion obtained above has a nonvolatile content of 43%, the glass transition temperature of the inner layer resin constituting the emulsion particles is 105 ° C., the glass transition temperature of the intermediate layer is 16 ° C., and the glass transition temperature of the outer layer is The glass transition temperature of the whole emulsion particle was 54 ° C. The total content of the polymer constituting the inner layer and the polymer constituting the outer layer in the emulsion particles was 67%, and the minimum film-forming temperature of the resin emulsion was 40 ° C.

Production Example 7
In a flask equipped with a dropping funnel, a stirrer, a nitrogen introduction tube, a thermometer, and a reflux condenser, 810 parts of deionized water was charged. In a dropping funnel, 96 parts of deionized water, an anionic surfactant as an emulsifier [polyoxyethylene alkylphenyl ether sulfate ester, manufactured by Daiichi Kogyo Seiyaku Co., Ltd., trade name: Aqualon (registered trademark) HS-10 ], 40 parts of a 25% aqueous solution, 335 parts of cyclohexyl methacrylate and 5 parts of acrylic acid are prepared, and 71 parts, which is 5% of the total amount of all the monomer components, is added into the flask. The temperature was raised to 80 ° C. while blowing nitrogen gas, and 14 parts of a 3.5% aqueous solution of ammonium persulfate was added to initiate the polymerization reaction. Thereafter, the remainder of the pre-emulsion for dropping, 29 parts of a 3.5% aqueous solution of ammonium persulfate and 20 parts of a 2.5% aqueous solution of sodium bisulfite were added dropwise uniformly over 90 minutes. After completion of the dropping, the first stage polymerization reaction was carried out by maintaining the temperature at 80 ° C. for 60 minutes.

  After completion of the first stage polymerization reaction, 96 parts of deionized water and an anionic surfactant [polyoxyethylene alkylphenyl ether sulfate ester salt as an emulsifier, with the temperature in the reaction system maintained at 80 ° C. Daiichi Kogyo Seiyaku Co., Ltd., trade name: Aquaron (registered trademark) HS-10] 25% aqueous solution 40 parts, 2-ethylhexyl acrylate 80 parts, butyl acrylate 45 parts, methyl methacrylate 200 parts and acrylic acid 5 parts The second stage pre-emulsion, 29 parts of a 3.5% aqueous solution of ammonium persulfate and 20 parts of a 2.5% aqueous solution of sodium hydrogen sulfite were uniformly added dropwise into the flask over 90 minutes. After completion of the dropwise addition, the polymerization reaction at the second stage was performed by maintaining at 80 ° C. for 60 minutes.

  After completion of the second stage polymerization reaction, with the temperature in the reaction system maintained at 80 ° C., 100 parts of deionized water, an anionic surfactant as an emulsifier [polyoxyethylene alkylphenyl ether sulfate, Daiichi Kogyo Seiyaku Co., Ltd., trade name: Aquaron (registered trademark) HS-10] 25% aqueous solution 40 parts, 2-ethylhexyl acrylate 45 parts, butyl acrylate 85 parts, methyl methacrylate 190 parts and acrylic acid 10 parts The third stage pre-emulsion, 29 parts of a 3.5% aqueous solution of ammonium persulfate, and 20 parts of a 2.5% aqueous solution of sodium hydrogen sulfite were uniformly dropped into the flask over 90 minutes. After completion of the dropwise addition, the temperature was maintained at 80 ° C. for 120 minutes, and the pH was adjusted to 8 by adding 25% aqueous ammonia to complete the polymerization reaction.

  The resulting reaction solution was cooled to room temperature, and then filtered through a (JIS mesh) wire mesh having a mesh opening of 300 mesh to obtain a resin emulsion. The average particle diameter of the emulsion particles contained in the obtained resin emulsion was 150 nm.

  The non-volatile content in the resin emulsion obtained above is 43%, the glass transition temperature of the inner layer resin constituting the emulsion particles is 83 ° C., the glass transition temperature of the intermediate layer is 16 ° C., and the glass transition temperature of the outer layer is The glass transition temperature of the whole emulsion particle was 48 ° C. The total content of the polymer constituting the inner layer and the polymer constituting the outer layer in the emulsion particles was 67%, and the minimum film-forming temperature of the resin emulsion was 40 ° C.

Examples 21-41 and Comparative Examples 11-19
The amount of the active ingredient of the water-soluble polymer is adjusted so that the amount per 100 parts of the emulsion particles contained in the resin emulsion obtained in any one of Production Examples 5 to 7 is the amount shown in Table 3 or Table 4. Then, an aqueous resin composition was obtained by adding the water-soluble polymer shown in Table 3 or Table 4 to the resin emulsion.

  Next, 86.2 parts of the paste obtained in the above preparation example, 8 parts of black paste [manufactured by Yokohama Kasei Co., Ltd., trade name: UNILANT 88, CONK BLACK], aqueous solution obtained in each example or each comparative example. 200 parts of resin composition, film-forming aid [manufactured by Chisso Corporation, trade name: CS-12] 8 parts, 8 parts of butyl cellosolve, 0.5 part of 25% aqueous ammonia and paint additive C [BIC Chemie Japan ( Co., Ltd., trade name: BYK-024] 0.5 parts was mixed, and the viscosity of the resulting mixture at 25 ° C. was measured with a Stormer viscometer, and a thickener [Rohm and Haas, trade name: By using TT-935], the water-based paint for building materials was obtained by adjusting the viscosity to 80 KU.

  In Comparative Example 14 and Comparative Example 18, the aqueous paint could not be prepared because the viscosity became too high when the aqueous paint was prepared.

In each example and each comparative example, an aqueous composition obtained by mixing 10 g of emulsion particles, 0.5 g of a water-soluble polymer and 90 g of water was centrifuged at a rotational speed of 40,000 min ⁻¹ at a temperature of 25 ° C. for 4 hours. The amount of the water-soluble polymer present in the water layer separated by the centrifugal separation is measured, and the ratio of the water-soluble polymer present in the water layer to the total water-soluble polymer used [(the amount of the water-soluble polymer present in the water layer Mass) ÷ (mass of all water-soluble polymers used) × 100] was determined and evaluated in the same manner as in Example 1. The results are shown in “Content” in the column of the water-soluble polymer in Tables 3 and 4.

Next, 20 g of solvent-based sealer (manufactured by SK Kaken Co., Ltd., trade name: EX sealer) is dried on a slate plate (manufactured by Nippon Test Panel Co., Ltd., 70 mm long × 150 mm wide × 6 mm thick). / M ^2, and air coating at 23 ° C. for 24 hours, and then the water-based paint obtained in each example was applied with a 10 mil applicator and then heated at 100 ° C. with a hot air dryer for 10 minutes. A test plate was obtained by drying.

  Using the test plate obtained above, the glossiness, water resistance, coating film hardness, stain resistance, weather resistance and frost damage resistance were examined as the physical properties of the water-based paint based on the following methods. The results are shown in Table 3 or Table 4.

[Glossy]
The 60 ° specular gloss value of the test plate was measured with a gloss meter (manufactured by JEOL Ltd., product number: VG2000) and evaluated based on the following evaluation criteria.
(Evaluation criteria)
A: Specular gloss value of 85 or more B: Specular gloss value of 80 or more and less than 85 C: Specular gloss value of 75 or more and less than 80 D: Specular gloss value of 70 or more and less than 75 E: Surface gloss value of less than 70

〔water resistant〕
After curing the test plate at 23 ° C. for 24 hours, the L value (L ₀ ) of the test plate was measured with a color difference meter [manufactured by Nippon Denshoku Industries Co., Ltd., trade name: spectroscopic color difference meter SE-2000]. Further, after immersing this test plate in warm water adjusted to 60 ° C. for 240 hours, the test plate was pulled up from the warm water, wiped with Kim Towel (manufactured by Nippon Paper Crecia Co., Ltd.), and within 1 minute with the color difference meter. The L value (L ₁ ) was measured.

Next, the change value of the L value is expressed by the formula:
ΔL = (L ₁ ) − (L ₀ )
And evaluated based on the following evaluation criteria.
(Evaluation criteria)
A: ΔL is less than 2.0 B: ΔL is 2.0 or more and less than 4.0 C: ΔL is 4.0 or more and less than 6.0 D: ΔL is 6.0 or more and less than 10.0 E: ΔL is 10. 0 or more

[Coating hardness]
After moving the test plate into a hot air dryer at 60 ° C. and adjusting the temperature for 1 minute, gauze (manufactured by Comet Sanitary Materials Co., Ltd., Japanese Pharmacopoeia Gauze Type 1), float glass plate [Japan Test Panel, manufactured by Panel Co., Ltd., 70 mm long, 150 mm wide, 2 mm thick] and weights were loaded in that order and left at a temperature of 60 ° C. for 2 hours. At this time, the load was adjusted to be 280 g / cm ² .

Next, after the test plate was cooled to room temperature, the gauze on the test plate was slowly peeled off, the state of the coating film was visually observed, and evaluated based on the following evaluation criteria.
(Evaluation criteria)
A: No abnormality (no gauze marks)
B: Slight gauze trace C: Shallow gauze trace D: Deep gauze trace E: Gauze remaining

[Contamination resistance]
Half of the test plate was immersed in carbon black powder and left in a hot air dryer at 50 ° C. for 2 hours, and then the test plate was pulled up and cooled to room temperature. Next, after the carbon black powder adhering to the surface of the test plate was lightly swept off with a brush, the state of the coating film was visually observed and evaluated based on the following evaluation criteria.
(Evaluation criteria)
A: No contamination B: Contamination enough to be swept away with a brush C: Contamination so that carbon black powder remains slightly C: Contamination enough to show that carbon black powder remains clearly D: Carbon black powder Almost the entire surface of the coating is contaminated

〔Weatherability〕
The test plate was cured in an atmosphere at 23 ° C. for 24 hours. After curing, the side and back of the test plate are sealed with aluminum tape, and the color difference (L ₀ , a ₀ , b ₀ ) of the surface of the test plate to which the clear paint is applied is measured by a color difference meter [Nippon Denshoku Industries Co., Ltd. Manufactured, trade name: spectroscopic color difference meter SE-2000], and further subjected to a weather resistance test for 1000 hours under the following weather resistance test conditions, and the surface of the test plate on which the clear coating was applied with the color difference meter The color difference (L ₁ , a ₁ , b ₁ ) is measured, and the change value (ΔE) of the E value is expressed by the formula:
ΔE = [(L ₁ −L ₀ ) ² + (a ₁ −a ₀ ) ² + (b ₁ −b ₂ ) ² ] ^1/2
And evaluated based on the following evaluation criteria.

(Test conditions for weather resistance test)
Testing machine: Metal weather [Daipura 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 in an atmosphere of 35% relative humidity and 98% relative humidity Shower: 30 seconds each before and after wetting

(Evaluation criteria)
A: ΔE is less than 2.0 B: ΔE is 2.0 or more and less than 3.0 C: ΔE is 3.0 or more and less than 4.0 D: ΔE is 4.0 or more and less than 6.0 E: ΔE is 6. 0 or more

[Frost resistance]
After the test plate was cured for 24 hours in an atmosphere at 23 ° C., the side surface and the back surface of the test plate were sealed with a two-part curable solvent-based resin, and a frost damage resistance test was performed with a freeze-thaw tester. The freezing and thawing conditions at that time were air freezing (-20 ° C. for 2 hours) and water thawing (20 ° C. for 2 hours). The frost damage resistance was evaluated based on the following evaluation criteria by visually observing with a magnifying glass and measuring the cycle until the test plate cracked.
(Evaluation criteria)
A: No crack at 400 cycles B: Cracks occurred at 300 cycles or more and less than 400 cycles C: Cracks occurred at 200 cycles or more and less than 300 cycles D: Cracks occurred at 100 cycles or more and less than 200 cycles E: Cracks at less than 100 cycles Occurs

Examples 42-53 and Comparative Examples 20-25
The amount of the active ingredient of the water-soluble polymer is adjusted so that the amount per 100 parts of the emulsion particles contained in the resin emulsion obtained in any one of Production Examples 5 to 7 is the amount shown in Table 3 or Table 4. Then, an aqueous resin composition was obtained by adding the water-soluble polymer shown in Table 3 or Table 4 to the resin emulsion.

  Next, 86.2 parts of the paste obtained in the above preparation example, 200 parts of the aqueous resin composition obtained in each example or each comparative example, film-forming aid [manufactured by Chisso Corporation, trade name: CS- 12] 8 parts, 8 parts of butyl cellosolve, 0.5 part of 25% aqueous ammonia and additive C for coating material [BIC Chemie Japan Co., Ltd., trade name: BYK-024] 0.5 parts were mixed and obtained. By measuring the viscosity of the mixture at 25 ° C. with a Stormer-type viscometer and adjusting the viscosity to 80 KU using a thickener (Rohm and Haas, trade name: TT-935), A paint was obtained.

On the other hand, 200 parts of acrylic resin emulsion [made by Nippon Shokubai Co., Ltd., trade name: U Double E-771SI] is mixed with 8 parts of a film-forming aid [made by Chisso Corporation, trade name: CS-12] and 8 parts of butyl cellosolve. Then, water and an antifoaming agent (manufactured by San Nopco Co., Ltd., trade name: SN deformer 777) were added to the resulting mixture to adjust the nonvolatile content to 30%. Thereafter, a thickener [manufactured by Nippon Shokubai Co., Ltd., trade name] was used so that the viscosity at the time of measurement at 25 ° C. was 65 ± 1 KU using a Krebs unit viscometer (manufactured by Brookfield, product number: KU-1). : Acreset WR-503A] was added to the mixture. This mixture was stirred with a homodisper at 1500 min ^-1 for 30 minutes to obtain a clear paint. The resulting clear paint was allowed to stand for 1 day and then used.

Next, 20 g of solvent-based sealer (manufactured by SK Kaken Co., Ltd., trade name: EX sealer) is dried on a slate plate (manufactured by Nippon Test Panel Co., Ltd., 70 mm long × 150 mm wide × 6 mm thick). After coating with air spray so that it becomes / m ² and drying at a temperature of 23 ° C. for 24 hours, the building material paint obtained in each example is applied with a 10 mil applicator, and 10 ° C. with a hot air dryer at 100 ° C. Let dry for minutes. The clear coating obtained above was further applied to the coated surface of the test plate with a 5 mil applicator and dried with a hot air dryer at 100 ° C. for 10 minutes to obtain a test plate.

  Using the test plate obtained above, the physical properties of the building material paint were examined in the same manner as in Example 21. The results are shown in Tables 3 and 4.

  In Table 3 and Table 4, the production example number described in the column of the type of emulsion means that the resin emulsion obtained in the production example was used. The amount of the water-soluble polymer indicates an amount (parts) per 100 parts of the emulsion particles. Further, in each evaluation, if there is at least one evaluation of D or less, it is rejected.

  From the results shown in Tables 3 and 4, the water-based paints obtained in each example were superior in the gloss and stain resistance of the coating film, as compared with the water-based paints obtained in each comparative example. It can be seen that a coating film having excellent water resistance, coating film hardness, weather resistance, water resistance and frost damage resistance is formed. Therefore, it turns out that the water-based paint obtained by each Example can be used suitably as a building construction material paint.

  From the above results, it can be seen that the building paint of the present invention can be suitably used as, for example, a paint for exterior building top coats, a paint for building materials.

Claims (7)

(A) An aqueous composition obtained by mixing 10 g of emulsion particles, 0.5 g of a water-soluble polymer and 90 g of water was centrifuged at a rotational speed of 40000 min ⁻¹ at a temperature of 25 ° C. for 4 hours, and separated by the centrifugation. A water-soluble polymer satisfying that the amount of the water-soluble polymer present in the water layer is 85% by mass or more of the total amount of the water-soluble polymer, and (B) emulsion particles. a weight average molecular weight of 500 to 80,000, I architectural coatings aqueous resin composition der amount of the water-soluble polymer per 100 parts by weight of the emulsion particles is 0.3 to 12 parts by weight, polyvinyl as the water-soluble polymer Pyrrolidone is used, the emulsion particles have an inner layer and an outer layer, and the glass transition temperature of the polymer constituting the inner layer is 80 to 200 ° C. There, the glass transition temperature of the polymer constituting the outer layer is -10 to 40 ° C., architectural coatings aqueous resin composition having a glass transition temperature of the entire emulsion particles are characterized by 20 to 65 ° C. der Rukoto. The aqueous resin composition for building paints according to claim 1 , wherein the difference between the glass transition temperature of the polymer constituting the inner layer and the glass transition temperature of the polymer constituting the outer layer is 50 ° C or higher. Mass ratio of the polymer constituting the polymer and the outer layer constituting the inner layer [polymer constituting the polymer / outer layer constituting the inner layer] is as defined in claim 1 or 2 which is 25 / 75-75 / 25 An aqueous resin composition for architectural paints. The aqueous resin composition for architectural paints according to any one of claims 1 to 3 , wherein the total content of the polymer constituting the inner layer and the polymer constituting the outer layer in the emulsion particles is 50 to 100% by mass. object. The content of the carboxyl group-containing monomer in the monomer component used in the polymer constituting the outer layer is greater than the content of the carboxyl group-containing monomer in the monomer component used in the polymer constituting the inner layer. The aqueous resin composition for architectural paints according to any one of claims 1 to 4 , which is high. The water-based resin composition for building paints according to any one of claims 1 to 5 , wherein the use is a building material paint . An architectural paint comprising the aqueous resin composition for architectural paints according to any one of claims 1 to 6 and a pigment.