JP5001829B2 - Aqueous resin dispersion, aqueous resin composition, and method for producing aqueous resin composition - Google Patents

Description

  The present invention relates to an aqueous resin dispersion, an aqueous resin composition, and a method for producing the same. More specifically, it can be used as a paint, a coating agent, an optical component, an electronic material, a medical test agent, and the like, but the most effective usage is for matte paint of enamel and clear.

  Matting agent compositions such as matting paints often contain inorganic or organic particles in the composition, and water-based ones may be used for the coating of building material surfaces for the purpose of high design. Many.

  Conventionally, as particles used in matting agent compositions, inorganic particles, especially silica-based powders, have been the mainstream and widely used for low cost. There was also a problem in weathering and frost damage.

  On the other hand, as a method of blending organic resin particles, there is an aqueous resin composition obtained by adding a hydrophilic organic solvent to an aqueous dispersion of resin particles obtained by a suspension polymerization method in water ( For example, see Patent Document 1.)

However, the aqueous resin composition obtained by such a method can suppress the formation of a hard cake, but settles easily and separates, and this forms a hard cake. There was a drawback that it was insufficient.
JP 2000-313720 A

  Accordingly, an object of the present invention is to provide a novel aqueous resin dispersion.

  Another object of the present invention is to provide an aqueous resin composition excellent in weather resistance and a method for producing the same.

  Still another object of the present invention is to provide an aqueous resin composition having low water absorption and excellent film transparency and excellent weather resistance and frost damage resistance, and a method for producing the same.

  Another object of the present invention is to form a network between particles by adding a thickener to the suspension polymerization aqueous dispersion, and suppress the contact between the particles, thereby suppressing the formation of a hard cake and obtained. It is an object of the present invention to provide an economical aqueous resin composition in which an aqueous dispersion does not settle for several days and a method for producing the same.

  The above objects are achieved by the following (1) to (2).

  (1) Monomer component containing (a) (meth) acrylic acid ester, (b) polyfunctional crosslinkable monomer, and (c) unsaturated monomer having UV-stable group and / or UV-absorbing group An aqueous resin dispersion containing resin particles having an average particle diameter of 1 to 100 μm formed by suspension polymerization.

  (2) The aqueous resin dispersion according to claim 1, wherein (a) the (meth) acrylic acid ester is a (meth) acrylic acid ester having a cycloalkyl group and / or a tertiary butyl group.

  Since this invention has the above structures, the obtained aqueous resin dispersion and aqueous resin composition can form a film excellent in transparency, weather resistance, and frost damage resistance. Further, by adding a thickener to the suspension polymerization aqueous dispersion, a network is formed between the particles, the contact between the particles is suppressed, the generation of hard cake is suppressed, and the obtained aqueous dispersion is kept for several days. This is an economically excellent aqueous resin composition that does not settle over time.

Examples of the (A) (a) (meth) acrylic acid ester used as a monomer in the present invention include the following.
Specific examples of (a) (meth) acrylic acid ester include, for example, methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, (meth) acrylic acid-2-ethylhexyl, and the like. (Meth) acrylic acid and (meth) acrylic acid esters which are esters of C1-C18 (including aliphatic, alicyclic, and aromatic) alcohols; (meth) acrylic acid-2-hydroxyethyl, (meta ) (Meth) acrylic acid esters having a hydroxy group such as 2-hydroxypropyl acrylate, monoester of (meth) acrylic acid and polypropylene glycol, and the like.

  Preferred are (meth) acrylic acids having a cycloalkyl group and (meth) acrylic acids having a t-butyl group, and more preferred are (meth) acrylic acids having a cycloalkyl group.

  The cycloalkyl group structure in the polymerizable unsaturated monomer having a cycloalkyl group includes a cyclobutyl structure, a cyclopentyl structure, a cyclohexyl structure, a cyclohexyl structure, a cyclooctyl structure, a cyclononyl structure, a cyclodecyl structure, a cycloundecyl structure, a cyclo A dodecyl structure, a cyclotridecyl structure, a cyclotetradecyl structure, a cyclopentadecyl structure, a cyclohexadecyl structure, a cycloheptadecyl structure, a cyclooctadecyl structure, and the like are preferable.

  Examples of the polymerizable unsaturated monomer having a cycloalkyl group include cyclohexyl (meth) acrylate, methylcyclohexyl (meth) acrylate, tert-butylcyclohexyl (meth) acrylate, cyclooctyl (meth) acrylate, and cyclododecyl (meth). Acrylate, isobornyl methacrylate (manufactured by Kyoeisha Chemical Co., Ltd., trade name: Light Ester IB-X), isobornyl acrylate (manufactured by Hitachi Chemical Co., Ltd., trade name: FA-544A; trade name: Kyoeisha Chemical Co., Ltd., trade name: Light acrylate) IB-XA), dicyclopentanyl methacrylate (manufactured by Hitachi Chemical Co., Ltd., trade name: FA-513M), dicyclopentanyl acrylate (manufactured by Hitachi Chemical Co., Ltd., trade name: FA-513A), 4-methylolcyclohexylmethyl Acrylate (Hitachi Adult Industries, Ltd., trade name: CHDMMA), 4- methylcyclohexyl methyl (meth) acrylate, cyclohexylmethyl (meth) acrylate and the like preferred, these can be used alone or in combination. Among these, cyclohexyl (meth) acrylate, 4-methylcyclohexylmethyl (meth) acrylate, and cyclohexylmethyl (meth) acrylate are more preferable.

  Examples of (meth) acrylic acids having a t-butyl group include t-butyl methacrylate and t-butyl acrylate.

  The amount used is not particularly limited in the first, second, fourth and fifth inventions, but is preferably 5 to 99% by mass, more preferably 30 to 99% by mass. Moreover, in 3rd and 6th invention, it is 50-99 mass%, Preferably it is 60-95 mass%, More preferably, it is 70-90 mass%.

  (A) (b) Polyfunctional crosslinkable monomers include (meth) acrylic acid and ethylene glycol, propylene glycol, 1,3-butylene glycol, diethylene glycol, polyethylene glycol, polypropylene glycol, trimethylolpropane, pentaerythritol, di Examples include esters with polyhydric alcohols such as pentaerythritol; polyfunctional vinyl compounds such as divinylbenzene; (meth) acrylic acid such as allyl (meth) acrylate and allyl esters. The amount used is not particularly limited in the first, second and fourth inventions, but is preferably 0.1 to 20% by mass, more preferably 5 to 15% by mass.

  (A) (c) As an unsaturated monomer having an ultraviolet stabilizing group and / or an ultraviolet absorbing group, for example, 2,4-dihydroxybenzophenone, or 2,2 ′, 4-trihydroxybenzophenone and glycidyl (meth) 2-hydroxy-4- [3- (meth) acryloxy-2-hydroxypropoxy] benzophenone obtained by reacting acrylate, 2,2′-dihydroxy-4- [3- (meth) acryloxy-2-hydroxy Benzophenone monomers such as propoxy] benzophenone, and 2- [2′-hydroxy-5 ′-(methacryloyloxymethyl) phenyl] -2H-benzotriazole, 2- [2′-hydroxy-5 ′-(methacryloyl) Oxyethyl) phenyl] -2H-benzotriazole, 2- [2′-hydroxy-5′- Methacryloyloxypropyl] phenyl] -2H-benzotriazole, 2- [2′-hydroxy-5 ′-(methacryloyloxyhexyl] phenyl] -2H-benzotriazole, 2- [2′-hydroxy-3′-t-butyl -5 '-(methacryloyloxyethyl] phenyl] -2-benzotriazole, 2- [2'-hydroxy-5'-t-butyl-3'-(methacryloyloxyethyl] phenyl] -2H-benzotriazole, 2- [2′-hydroxy-5 ′-(methacryloyloxyethyl) phenyl] -5-chloro-2H-benzotriazole, 2- [2′-hydroxy-5 ′-(methacryloyloxyethyl) phenyl] -5-methoxy-2H -Benzotriazole, 2- [2'-hydroxy-5 '-(methacryloyloxyethyl) fe L] -5-cyano-2H-benzotriazole, 2- [2'-hydroxy-5 '-(methacryloyloxyethyl) phenyl] -5-t-butyl-2H-benzotriazole, 2- [2'-hydroxy- Monomers having ultraviolet absorbing ability such as benzotriazole monomers such as 5 ′-(methacryloyloxyethyl) phenyl] -5-t-butyl-2H-benzotriazole; 4- (meth) acryloyloxy-2 , 2,6,6-tetramethylpiperidine, 4- (meth) acryloylamino-2,2,6,6-tetramethylpiperidine, 4- (meth) acryloyloxy-1,2,2,6,6-penta Methylpiperidine, 4- (meth) acryloylamino-1,2,2,6,6-pentamethylpiperidine, 4-cyano-4- (meth) acryloyloxy -2,2,6,6-tetramethylpiperidine, 1- (meth) acryloyl-4- (meth) acryloamino-2,2,6,6-tetramethylpiperidine, 4-crotoyloxy-2,2,6 Piperidine series such as 1,6-tetramethylpiperidine, 4-crotoylamino-2,2,6,6-tetramethylpiperidine, 1-crotoyl-4-crotoyloxy-2,2,6,6-tetramethylpiperidine And other monomers having ultraviolet stabilizing ability, such as polymerizable monomers.

  The amount of such UV-stable group and / or UV-absorbing group used is not particularly limited, but is preferably 0.1 to 10% by mass, more preferably 0.5 to 5% by mass. This improves the weather resistance of the aqueous resin composition obtained.

  The sum of (a), (b) and (c) in the monomer mixture is 100% by mass.

  In the first, second, fourth and fifth inventions of the present application, (d) other monomers are not essential, but may be blended. The amount used is not particularly limited, but is preferably 0 to 94.8% by mass.

As such (A) (d) and other monomers, any monomers can be used as long as they can be copolymerized with the monomers. As main polymerizable monomers,
(Meth) acrylic acid such as methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, (meth) acrylic acid-2-ethylhexyl, and C1 to C18 (aliphatic, alicyclic, (Meth) acrylic acid esters which are esters of alcohols (including aromatics); (meth) acrylic acid-2-hydroxyethyl, (meth) acrylic acid, (meth) acrylic acid-2-2 hydroxypropyl, (meth) ) (Meth) acrylic acid esters having hydroxy groups such as monoesters of acrylic acid and polypropylene glycol, ethylenically unsaturated monocarboxylic acids such as acrylic acid, methacrylic acid and crotonic acid; unsaturated of fumaric acid and itaconic acid Polyvalent carboxylic acids; ethylenically unsaturated polyvalent monocarboxylic acids such as monoethyl maleate and monoethyl itaconate Polymerizable monomer having a carboxyl group of a partial ester compound. Polymerizable monomer having an epoxy group such as glycidyl (meth) acrylate, 2-methylglycidyl (meth) acrylate, and allyl glycidyl ether. Methacryloylaziridine , Polymerizable monomers having an aziridinyl group such as (meth) acrylic acid-2-aziridinylethyl; polymerizable monomers having an oxazoline group such as 2-isopropenyl-2-oxazoline and 2-vinyl-oxazoline -(Meth) acrylamide derivatives such as (meth) acrylamide, N-monoethyl (meth) acrylamide, N-monomethyl (meth) acrylamide, N, N-dimethyl (meth) acrylamide, etc.-Dimethylaminoethyl (meth) acrylate, dimethyl Aminoethyl (meth) acrylamide, vinyl Basic polymerizable monomers such as gin, vinylimidazole and vinylpyrrolidone ・ Crosslinkable (meth) acrylamides such as N-methylol (meth) acrylamide and N-ptoxymethyl (meth) acrylamide ・ Styrene, vinyltoluene, α-methyl Styrene derivatives such as styrene and chloromethylstyrene; polymerizable monomers having a cyano group such as (meth) acrylonitrile; ethyl (meth) acrylic acid-2-sulfonate and salts thereof; sulfones such as vinylsulfonic acid and salts thereof Polymerizable monomers having an acid group, unsaturated monomers having an organosilicon group such as vinyltrimethoxysilane, γ- (meth) acryloxypropyltrimethoxysilane, allyltriethoxysilane, trimethoxysilylpropylallylamine, Vinyl acetate such as vinyl acetate and vinyl propionate Examples thereof include halogenated monomers such as tellurium, vinyl fluoride, vinylidene fluoride, vinyl chloride and vinylidene chloride, conjugated dienes such as butadiene and isoprene, and olefins such as ethylene, propylene and pentenes. These exemplary polymerizable monomers may be used alone or in combination of two or more.

  As the polymerization initiator used in the suspension polymerization, an oil-soluble initiator is used. For example, lauroyl peroxide, benzoyl peroxide, t-butylperoxy-2-ethyl ketanoate, 1,1 -Peroxide initiators such as di-t-butylperoxy-2-methylcyclohexane, 2,2'-azobisisobutyronitrile, 2,2'-azobis-2,4-dimethylvaleronitrile, etc. And azo initiators. The amount of these initiators used is preferably 0.01 to 5 parts by mass with respect to 100 parts by mass of the monomer mixture.

  Examples of the dispersion stabilizer used in the suspension polymerization include polyvinyl alcohol, polyvinyl pyrrolidone, poly (meth) acrylic acid or a salt thereof, celluloses such as carboxycellulose, methylcellulose, and methylhydroxycellulose, and water-soluble polymers such as gelatin. ; Inorganic powder such as barium sulfate, calcium sulfate, calcium carbonate, magnesium carbonate, calcium phosphate; anionic surfactant, nonionic surfactant, cationic surfactant, amphoteric surfactant, polymer surfactant, etc. In addition, any of the above surfactants, as well as reactive surfactants having one or more polymerizable carbon-carbon unsaturated bonds in the molecule can be used. These may be one type or two or more types, and the amount of these dispersion stabilizers used is preferably 0.01 to 10 parts by mass, more preferably 0.1 to 5 parts per 100 parts by mass of the monomer mixture. Part by mass.

  The aqueous resin dispersion (A) containing resin particles having an average particle diameter of 1 to 100 μm is a monomer mixture or a monomer composed of the monomers (a), (b), (c) and, if necessary, (d). The monomer mixture comprising the monomers (a), (b) and, if necessary, (d) can be obtained by subjecting the monomer mixture to suspension polymerization in an aqueous medium in the presence of a dispersion stabilizer and a polymerization initiator. The reaction temperature is usually 50 to 100 ° C, preferably 60 to 90 ° C. The reaction temperature may be constant or may be changed during the reaction. The polymerization time is not particularly limited and can be appropriately selected according to the progress of the reaction. It is usually 1 to 10 hours, preferably 2 to 5 hours from the start to the end of the polymerization.

  Although the average particle diameter in the said aqueous resin dispersion (A) is 1-100 micrometers, Preferably it is 5-60 micrometers, More preferably, it is 10-50 micrometers. That is, if it is less than 1 μm, the matting effect is insufficient, and if it exceeds 100 μm, the storage stability of the aqueous resin dispersion obtained by suspension polymerization is significantly lowered. Moreover, solid content concentration in this aqueous resin dispersion (A) is 5-50 mass%, Preferably it is 10-30 mass%.

  The usage form of the aqueous resin dispersion (A) containing resin particles having an average particle diameter of 1 to 100 μm is not particularly limited. However, from the viewpoint of economy and workability, a method of using the aqueous dispersion as it is is preferable.

  The aqueous resin dispersion (B) containing resin particles having an average particle diameter of 0.01 to 1 μm is any of the monomer (d) and, if necessary, the monomers (a), (b), and (c). It can be obtained by carrying out emulsion polymerization by a conventional method in the presence of an emulsifier and a polymerization initiator in an aqueous medium in the form of a monomer or a monomer mixture comprising one or a mixture of two or more. The reaction temperature is usually 50 to 90 ° C, preferably 60 to 85 ° C. The reaction temperature may be constant or may be changed during the reaction. The polymerization time is not particularly limited and can be appropriately selected according to the progress of the reaction. It is usually 1 to 10 hours, preferably 1 to 5 hours from the start to the end of the polymerization.

  The average particle size in the aqueous resin dispersion (B) is 0.01 to 1 μm, preferably 0.04 to 0.5 μm, and more preferably 0.08 to 0.2 μm. Moreover, solid content concentration in this aqueous resin dispersion (B) is 5-70 mass%, Preferably it is 30-60 mass%.

  The monomer used in the production of the aqueous resin dispersion (B) can be any monomer as long as it is a polymerizable monomer, but preferably a) an unsaturated monomer having a cycloalkyl group. 5 to 99% by mass, (c) 0.1 to 10% by mass of an unsaturated monomer having an ultraviolet stabilizing group and / or an ultraviolet absorbing group, more preferably a) an unsaturated monomer having a cycloalkyl group 30 to 70% by mass, (c) 0.5 to 5% by mass of an unsaturated monomer having an ultraviolet stabilizing group and / or an ultraviolet absorbing group. The calculated Tg of the emulsion is preferably -20 to 90 ° C, more preferably 0 to 60 ° C. Here, Tg (K) is given by the following equation.

  The glass transition temperature of the homopolymer of each monomer constituting the polymer composed of n types of monomers is TgI (K), and the weight distribution of each monomer is WI. However,

  In any of the methods for producing an aqueous resin dispersion, the aqueous medium to be used is usually water, and a hydrophilic solvent such as a lower alcohol or a ketone can be used in combination as necessary. The amount of the aqueous medium used is used such that the solid content of the obtained aqueous resin dispersion falls within the above-mentioned predetermined range with respect to the amount of the above-mentioned total polymerizable monomer component used.

  There are no particular limitations on the emulsifier, and for example, all surfactants such as anionic surfactants, nonionic surfactants, cationic surfactants, amphoteric surfactants, and polymeric surfactants should be used. Can do. Furthermore, a reactive surfactant having one or more polymerizable carbon-carbon unsaturated bonds in the molecule can be used.

  Specific examples of the anionic surfactant include alkali metal alkyl sulfates such as sodium dodecyl sulfate and potassium dodecyl sulfate; ammonium alkyl sulfates such as ammonium dodecyl sulfate; sodium dodecyl polyglycol ether sulfate; sodium sulforicinoate Alkyl sulfonates such as alkali metal salts of sulfonated paraffins and ammonium salts of sulfonated paraffins; fatty acid salts such as sodium laurate, triethanolamine oleate, triethanolamine abiate; sodium dodecylbenzenesulfonate, alkali phenol hydroxyethylene Alkyl aryl sulfonates such as alkali metal sulfates; High alkyl naphthalene sulfones Salts; naphthalenesulfonic acid-formalin condensate; dialkyl sulfosuccinate, polyoxyethylene alkyl sulfate salts, polyoxyethylene alkylaryl sulfate salts and the like.

  Specific examples of the nonionic surfactant include polyoxyethylene alkyl ether; polyoxyethylene alkyl aryl ether; sorbitan fatty acid ester; polyoxyethylene sorbitan fatty acid ester; fatty acid monoglyceride such as monolaurate of glycerol; An oxyethyleneoxypropylene copolymer; a condensation product of ethylene oxide and an aliphatic amine, amide or acid can be used.

  Specific examples of the polymer surfactant include polyvinyl alcohol; sodium poly (meth) acrylate, potassium poly (meth) acrylate, ammonium poly (meth) acrylate, polyhydroxyethyl (meth) acrylate; Polyhydroxypropyl (meth) acrylate; or a copolymer of two or more kinds of polymerizable monomers which are constituent units of these polymers, or a copolymer with other monomers. Moreover, since a phase transfer catalyst such as crown ethers exhibits surface activity, it may be used as a surfactant.

  Specific examples of the reactive surfactant include sodium propenyl-2-ethylhexylbenzenesulfosuccinate, sulfate of polyoxyethylene (meth) acrylate, polyoxyethylene alkylpropenyl ether ammonium sulfate, (meth) Acrylic acid polyoxyethylene ester phosphate ester, bis (polyoxyethylene polycyclic phenyl ether) methacrylate sulfate ammonium salt, polyoxyethylene alkylaryl sulfate salt structure, propenyl group, isopropenyl group, allyl Group, acrylate group, methacrylate group and other anionic reactive surfactants; polyoxyethylene alkylbenzene ether (meth) acrylic acid ester, polyoxyethylene Alkyl ether (meth) acrylic acid ester has the structure of polyoxyethylene alkyl aryl ether, and an isopropenyl group, a nonionic reactive surfactant such as those having a polymerizable aryl group and the like. The use of surfactants as these emulsifiers may be used alone or in combination of two or more, but considering the water resistance of the dried coating film from the aqueous resin dispersion A reactive surfactant is preferred.

  The use amount of the emulsifier is not particularly limited, but is preferably 0.3 to 5% by mass, more preferably 0.5 to 3% by mass, based on the use amount of the total polymerizable monomer component. . When the amount of the emulsifier used is too large, the water resistance of the coating film is lowered. When the amount is too small, the polymerization stability of the resin particles is significantly lowered. Since the particle size of the resin is greatly influenced by the type of emulsifier, the amount used must be selected appropriately within the above range depending on the emulsifier used.

  The polymerization initiator is not particularly limited. Specifically, for example, 2,2′-azobisisobutyronitrile, 2,2′-azobis (2-amidinopropane) · dihydrochloride, 4 Water-soluble azo compounds such as 4,4'-azobis (4-cyanopentanoic acid); persulfates such as potassium persulfate; peroxides such as hydrogen peroxide, peracetic acid, benzoyl peroxide, di-t-butyl peroxide Thing; etc. are mentioned.

  The amount of the polymerization initiator used is not particularly limited, but is preferably 0.1 to 3% by weight, more preferably 0.5 to 2% by weight, based on the amount of all polymerizable monomer components used. It is. When the amount of the polymerization initiator used is too large, the water resistance of the coating film is lowered. When the amount is too small, the polymerization rate is slowed and unreacted monomers are likely to remain. The polymerization initiator may be used alone or in combination of two or more. In order to increase the polymerization rate, a reducing agent such as sodium hydrogen sulfite or a metal salt such as ferrous sulfate may be used in combination with the polymerization initiator as necessary.

  The method for adding the polymerization initiator is not particularly limited, and may be any method such as batch charging, split charging, and continuous dropping. In order to speed up the completion of the polymerization, a part of the polymerization initiator may be specially added before and after the completion of the dropwise addition of all the monomer components.

  In addition to the polymerization initiator during polymerization, a chain transfer agent can be added as necessary. For example, a compound having a thiol group such as t-dodecyl mercaptan, α-methylstyrene dimer, or the like is added. Can do.

  The neutralizing agent used when neutralizing the acidic group is not particularly limited, and various conventionally known neutralizing agents can be used. Specifically, for example, alkali metal compounds such as sodium hydroxide and potassium hydroxide; alkaline earth metal compounds such as calcium hydroxide and calcium carbonate; ammonia; monomethylamine, dimethylamine, trimethylamine, monoethylamine, diethylamine, triethylamine And water-soluble organic amines such as monopropylamine, dimethylpropylamine, monoethanolamine, diethanolamine, triethanolamine, ethylenediamine, and diethylenetriamine. Among these neutralizing agents, low boiling point amines such as ammonia, monomethylamine, dimethylamine, and trimethylamine are scattered at room temperature or under heating, so that the water resistance of a cured coating film in a paint containing an aqueous resin dispersion is reduced. It is preferable because it can prevent the decrease, and ammonia is more preferable. Only one type of the exemplified neutralizing agent may be used, or two or more types may be used in combination.

  In the fourth and fifth inventions, the thickener (C) is added to the aqueous resin dispersion (A) containing resin particles having an average particle diameter of 1 to 100 μm, and then the average particle diameter is 0.01 to This is a method for producing an aqueous resin composition by mixing an aqueous resin dispersion containing 1 μm resin particles.

  The thickener (C) is not particularly limited, and examples thereof include the following.

1) Water-soluble polymer Specific examples of the water-soluble polymer used as a thickener include, for example, methylcellulose, cellulose ethers (for example, hydroxypropylmethylsesulose), polyethylene oxide, polypropylene oxide, polyethylene glycol, poly Examples include acrylamide and polyvinyl alcohol.

(2) Associative thickeners Associative thickeners used as thickeners are generally grafted with a hydrophobic pendant group such as a higher alkyl group at the end or in the middle of the hydrophilic polymer main chain. It is a thing. The expression mechanism of the thickening action of the associative thickener is known to be due to the associative property by the secondary binding force (for example, hydrophobic binding force) of the hydrophobic pendant group. Specific examples of the associative thickener used as the thickener include, for example, polyethylene glycol associative thickeners and acrylic associative thickeners. One aspect of the polyethylene glycol-based associative thickener is one in which hydrophobic pendant groups are bonded to both ends of polyethylene glycol.

(3) Acrylic associative thickener An acrylic associative thickener is obtained by grafting a hydrophobic pendant group such as a higher alkyl group on the end or in the middle of a hydrophilic acrylic polymer main chain. Specific examples of the acrylic associative thickener include, for example, an acrylic monomer and an associative monomer having a hydrophobic pendant group such as a higher alkyl group (eg, having a hydrophobic pendant group such as an alkyl group or an aralkyl group). And a reactive surfactant, which is an ethylenically unsaturated monomer that can be copolymerized with an acrylic monomer). Specifically, the thickener shown in JP 2001-240633 A is preferable.

  The addition amount of the thickener (C) is 0.05 to 2 parts by mass, preferably 0.002 per 100 parts by mass of the aqueous resin dispersion (B) containing resin particles having an average particle diameter of 0.01 to 1 μm. 1 to 1.5 parts by mass, more preferably 0.1 to 0.7 parts by mass. That is, if the amount of the thickener (C) is less than 0.05 parts by mass, the thickening effect cannot be exhibited, while if it exceeds 2 parts by mass, the water resistance decreases.

  In all the present inventions, the addition amount of the aqueous resin dispersion (A) containing resin particles having an average particle diameter of 1 to 100 μm is an aqueous resin dispersion containing resin particles having an average particle diameter of 0.01 to 1 μm. It is 1-30 mass parts per 100 mass parts of solid content of a body (B), Preferably it is 5-25 mass parts. That is, if the amount of the aqueous resin dispersion (A) is less than 1 part by mass, the matting effect is insufficient, while if it exceeds 30 parts by mass, the storage stability becomes insufficient.

  The aqueous resin composition of the present invention may be one using only the aqueous resin dispersion as it is, or may contain various additives as necessary. Examples of additives include pigments, film forming aids, fillers (fillers), toners, wetting agents, antistatic agents, pigment dispersants, plasticizers, antioxidants, flow control agents, viscosity modifiers, and the like. It is done. Further, other water-soluble resins or water-dispersible resins may be added and mixed for use. Examples of these resins include styrene acrylic, acrylic, urethane, silicon, acrylic silicon, acrylic urethane, fluorine, and acrylic fluorine.

  Among the additives, in particular, as pigments, white pigments such as titanium oxide, calcium oxide, antimony trioxide, zinc white, lithopone, lead white, carbon black, yellow lead, molybdenum red, bengara, yellow iron oxide And inorganic pigments such as colored pigments such as yellow flower; organic pigments such as azo compounds such as benzidine and Hansa Yellow, and phthalocyanines such as phthalocyanine blue. These may use only 1 type and can also use 2 or more types together. Among these examples, it is preferable to use a pigment having good weather resistance so as not to lower the weather resistance of the resulting coating film. For example, when using titanium oxide, which is a white pigment, it is preferable to use rutile type titanium oxide rather than anatase type titanium oxide. Furthermore, when using rutile-type titanium oxide, it is more preferable to use chlorine-based titanium oxide than sulfuric acid-based titanium oxide in order to develop long-term weather resistance.

  Next, the present invention will be described in more detail with reference to examples. “Parts” and “%” described below represent “parts by mass” and “% by mass” unless otherwise specified.

  In a reaction vessel, 0.5 part of a 25% aqueous solution of polyvinyl alcohol (manufactured by Kuraray Co., Ltd.) PVA-CST) and polyoxyethylene oleyl ether sulfate ammonium salt (Daiichi Kogyo Seiyaku Co., Ltd. Hightenol 18E) Was dissolved in 154.5 parts deionized water. In this, 88 parts of cyclohexyl methacrylate, 4-methacryloyloxy-2,2,6,6-tetramethylpiperidine (Adeka Corporation LA-87: hereinafter referred to as piperidine A); 2 parts, trimethylolpropane tri 10 parts of methacrylate (TMPTMA: manufactured by Nippon Shokubai Co., Ltd.) and 1 part of lauroyl peroxide were added, and the mixed monomer mixture solution was added and stirred with a stirrer. As a result of visual observation with an optical microscope, a monomer dispersion having a particle size of about 10 μm was obtained. This dispersion was charged into a 2 liter Separa flask, 254 parts of deionized water was further added, and the temperature was raised to 75 ° C. while stirring in a nitrogen atmosphere. After the initiation of polymerization, the solution was heated to 85 ° C. and then aged at 85 ° C. for 3 hours to obtain an aqueous resin dispersion. The average particle diameter of the obtained aqueous resin dispersion was about 9 μm as a result of measurement with a Coulter counter.

Suspension polymerization production example 2
This was carried out in the same manner as in Suspension Polymerization Production Example 1 except that the unsaturated monomer composition was changed to 60 parts of cyclohexyl methacrylate, 10 parts of TMPTMA, 2 parts of piperidine (A) and 28 parts of methyl methacrylate (MMA). As a result of measuring the average particle size of the obtained aqueous resin dispersion with a Coulter counter, it was about 10 μm.

Suspension polymerization production example 3
The unsaturated monomer composition is 40 parts cyclohexyl methacrylate, 10 parts TMPTMA, 2 parts piperidine (A), 2- [2′-hydroxy-5 ′-(methacryloyloxyethyl) phenyl] -2H-benzotriazole (hereinafter referred to as benzotriazole). (B)) The same procedure as in Suspension Polymerization Production Example 1 except that 1 part and 47 parts of methyl methacrylate (MMA) were used.

  The average particle diameter of the obtained aqueous resin dispersion was about 9 μm as a result of measurement with a Coulter counter.

Suspension polymerization production example 4
This was carried out in the same manner as in Suspension Polymerization Production Example 1 except that the unsaturated monomer composition was 93 parts of cyclohexyl methacrylate, 5 parts of TMPTMA and 2 parts of piperidine (A).

  As a result of measuring the average particle size of the obtained aqueous resin dispersion with a Coulter counter, it was about 10 μm.

Suspension polymerization production example 5
This was carried out in the same manner as in Suspension Polymerization Production Example 1 except that the unsaturated monomer composition was 83 parts of cyclohexyl methacrylate, 15 parts of TMPTMA and 2 parts of piperidine (A).

  As a result of measuring the average particle size of the obtained aqueous resin dispersion with a Coulter counter, it was about 10 μm.

Suspension polymerization production example 6
This was carried out in the same manner as in Suspension Polymerization Production Example 1 except that the unsaturated monomer composition was changed to 70 parts cyclohexyl methacrylate, 10 parts TMPTMA, and 20 parts MMA.

  The average particle size of the obtained aqueous resin dispersion was about 11 μm as a result of measurement with a Coulter counter.

Suspension polymerization production example 7
This was carried out in the same manner as in Suspension Polymerization Production Example 1 except that the unsaturated monomer composition was 90 parts of cyclohexyl methacrylate and 10 parts of TMPTMA.

  The average particle diameter of the obtained aqueous resin dispersion was about 9 μm as a result of measurement with a Coulter counter.

Suspension polymerization production example 8
The same procedure as in Suspension Polymerization Production Example 1 was conducted except that the unsaturated monomer composition TMPTMA was 10 parts and MMA 90 parts. As a result of measuring the average particle size of the obtained aqueous resin dispersion with a Coulter counter, it was about 12 μm.

Suspension polymerization production example 9
Except that the unsaturated monomer composition was 80 parts of cyclohexyl methacrylate, 18 parts of TMPTMA, and the emulsifier was 1 part of polyoxyalkylene alkylphenyl ether sulfate ammonium salt (Daiichi Kogyo Seiyaku Co., Ltd. “Hitenol N-08”). The suspension polymerization was carried out in the same manner as in Production Example 1. The average particle diameter of the obtained aqueous resin dispersion was 10 μm as measured with a Coulter counter.

Suspension polymerization production example 10
Except that the unsaturated monomer composition was 80 parts of cyclohexyl methacrylate, 18 parts of TMPTMA, and the emulsifier was 1 part of polyoxyethylene alkylpropenyl phenyl ether sulfate ammonium salt (Daiichi Kogyo Co., Ltd. “Aqualon BC-10”), This was carried out in the same manner as in Suspension polymerization production example 1. The average particle diameter of the obtained aqueous resin dispersion was 11 μm as measured with a Coulter counter.

Suspension polymerization production example 11
1. Unsaturated monomer composition 80 parts cyclohexyl methacrylate, 18 parts TMPTMA and emulsifier bis (polyoxyethylene polycyclic phenyl ether) methacrylate ammonium sulfate (“Antox MS-60” manufactured by Japan Emulsifier Co., Ltd.) 1 The procedure was the same as in Suspension Polymerization Production Example 1 except that the ratio was changed to part. The average particle diameter of the obtained aqueous resin dispersion was 11 μm as measured with a Coulter counter.

Suspension polymerization production example 12
This was carried out in the same manner as in Suspension Polymerization Production Example 1 except that the unsaturated monomer composition was 83 parts of cyclohexyl methacrylate, 15 parts of TMPTMA and 0.3 part of Hytenol 18E as the emulsifier. The average particle diameter of the obtained aqueous resin dispersion was 12 μm as measured with a Coulter counter.

Suspension polymerization production example 13
This was carried out in the same manner as in Suspension Polymerization Production Example 1 except that the unsaturated monomer composition was 83 parts of cyclohexyl methacrylate, 15 parts of TMPTMA, and 0.5 parts of Hightenol 18E as the emulsifier. The average particle diameter of the obtained aqueous resin dispersion was 12 μm as measured with a Coulter counter.

Suspension polymerization production example 14
This was carried out in the same manner as in Suspension Polymerization Production Example 1 except that the unsaturated monomer composition was 83 parts of cyclohexyl methacrylate, 15 parts of TMPTMA, and 1.5 parts of PVA-CST and 1.5 parts of Hightenol 18E were used as the emulsifier. . The average particle diameter of the obtained aqueous resin dispersion was 9 μm as measured with a Coulter counter.

Suspension polymerization production example 15
This was carried out in the same manner as in Suspension Polymerization Production Example 1 except that the unsaturated monomer composition was 83 parts of cyclohexyl methacrylate, 15 parts of TMPTMA and 0.5 parts of LPO as an emulsifier. The average particle diameter of the obtained aqueous resin dispersion was 10 μm as measured with a Coulter counter.

Suspension polymerization production example 16
This was carried out in the same manner as in Suspension Polymerization Production Example 1 except that the unsaturated monomer composition was 83 parts of cyclohexyl methacrylate, 15 parts of TMPTMA, and the initiator was 2 parts of LPO. The average particle diameter of the obtained aqueous resin dispersion was 10 μm as measured with a Coulter counter.

  The above suspension polymerization production examples 1 to 16 are summarized in Table 1.

Acrylic emulsion production example 1
963.0 parts by mass of pure water was charged into a flask equipped with a dropping funnel, a stirrer, a nitrogen introduction tube, a thermometer, and a reflux condenser, and the temperature was raised to 75 ° C. with stirring while gently blowing nitrogen gas. On the other hand, 529.0 parts by mass of methyl methacrylate (MMA), 361.0 parts by mass of 2-ethylhexyl acrylate (hereinafter referred to as 2EHA) and 100.0 parts by mass of styrene (hereinafter referred to as St) and acrylic acid (hereinafter referred to as AA) 80 parts by mass of a 25% aqueous solution of Aqualon BC-10, polyoxyethylene alkylphenyl ether (nonionic reactive emulsifier Aqualon RN-20, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) 40 parts by mass of a 25% aqueous solution of nonionic reactive emulsifier manufactured by Pharmaceutical Co., Ltd. and 230 parts by mass of pure water were added to obtain a pre-emulsion mixture. 10% by mass of this pre-emulsion mixture was added to the flask and maintained at 75 ° C., and then 60.0 parts by mass of 5% aqueous ammonium persulfate solution was added to initiate polymerization. After maintaining the inside of the reaction system at 80 ° C. for 10 minutes, the remaining pre-emulsion mixture was uniformly added dropwise over 180 minutes. After the completion of dropping, the dropping tank was washed with 20 parts by mass of pure water, and the washing solution was added to the flask. During the dropwise addition, the inside of the reaction system was maintained at 80 ° C., and after completion of the dropwise addition, the mixture was aged with stirring at 80 ° C. for 60 minutes to complete the polymerization. Thereafter, cooling was performed, and 9.3 g of 25% aqueous ammonia was added at 50 ° C. or lower in the reaction system. After stirring for 10 minutes or more, the mixture was cooled to room temperature and filtered through a 100 mesh wire net to obtain a polymer dispersion. The average particle size of the obtained acrylic emulsion was about 150 nm as measured with a light scattering particle size measuring device.

Acrylic emulsion production example 2
A flask equipped with a dropping funnel, a stirrer, a nitrogen introducing tube, a thermometer, and a reflux condenser was charged with 943.0 parts by mass of pure water, and heated to 75 ° C. with stirring while gently blowing nitrogen gas. On the other hand, in a monomer mixed solution composed of 200.0 parts by mass of CHMA, 102.6 parts by mass of MMA, 137.4 parts by mass of 2EHA, 50.0 parts by mass of n-butyl methacrylate (hereinafter referred to as n-BMA) and AA 10.0, 40 parts by mass of 25% aqueous solution of Aqualon BC-10 (anionic reactive emulsifier manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) and 25% aqueous solution of Aqualon RN-20 (nonionic reactive emulsifier manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) 20 parts by mass and 115 parts by mass of pure water were added to obtain a pre-emulsion mixture 1. 20% by mass of this pre-emulsion mixture 1 was added to the flask and maintained at 75 ° C., and then 60.0 parts by mass of 5% aqueous ammonium persulfate solution was added to initiate polymerization. After the inside of the reaction system was kept at 80 ° C. for 10 minutes, the remaining pre-emulsion mixture was uniformly added dropwise over 90 minutes. After the completion of dropping, the dropping tank was washed with 20 parts by mass of pure water, and the washing solution was added to the flask. During the dropping, the inside of the reaction system was maintained at 80 ° C., and further maintained at 80 ° C. for 30 minutes after the completion of dropping, and 4.3 parts by mass of 25% ammonia water was added to complete the first stage polymerization after neutralization. .

  Next, while maintaining the reaction system at 80 ° C., 200.0 parts by mass of CHMA, 102.6 parts by mass of MMA, 137.4 parts by mass of EHA, 50.0 parts by mass of n-BMA, 50.0 parts by mass of piperidine (A) prepared in the same manner as Pre-emulsion 1 10.0, a pre-emulsion mixture 2 consisting of 40 parts by mass of a 25% aqueous solution of Aqualon BC-10, 20 parts by mass of a 25% aqueous solution of Aqualon RN-20, and 115 parts by mass of pure water is uniformly applied at 80 ° C. for 90 minutes. It was dripped. After the completion of dropping, the dropping tank was washed with 20 parts by mass of pure water, and the washing solution was added to the flask. Further, aging was performed at 80 ° C. for 60 minutes to complete the second stage polymerization. Thereafter, the reaction system is cooled, 5.0 parts by mass of 25% aqueous ammonia is added at 50 ° C. or lower, stirred for 10 minutes or longer, cooled to room temperature, filtered through a 100-mesh wire mesh, Obtained. The average particle size of the obtained acrylic emulsion was about 130 nm as measured with a light scattering particle size measuring device.

  Table 2 summarizes the acrylic emulsion production examples 1 and 2 described above.

Example 1
To 29.0 parts of the aqueous resin dispersion obtained in Suspension Polymerization Production Example 1, 0.3 part of 25% aqueous ammonia solution and 2.9 parts of thickener WR-600 (nonvolatile content: 5.0%) were added. . Viscosity 1260 mPa · s. 100.0 parts of the acrylic emulsion polymerized in acrylic emulsion production example 1 and butyl cellosolve / CS-12 (2,2,4-trimethyl-1,3-pentanediol monoisobutyrate: Chisso Co., Ltd. as a film forming aid. (Manufactured by the company) = 1/1 mixed liquid 5.1 parts, foam suppressor (SN deformer 777: manufactured by San Nopco) 0.2 dilution water was added to obtain a clear coating composition. The specifications were a non-volatile content of 37.0%, a viscosity of 650 mPa · s, and a pH of 8.5.

Example 2
Same as Example 1 except that Suspension Polymerization Production Example 2 was used instead of Suspension Polymerization Production Example 1. The specifications were a non-volatile content of 36.9%, a viscosity of 650 mPa · s, and a pH of 8.5.

Example 3
Similar to Example 1 except that Suspension Polymerization Production Example 3 was used instead of Suspension Polymerization Production Example 1. The specifications were a non-volatile content of 37.1%, a viscosity of 670 mPa · s, and a pH of 8.6.

Example 4
Similar to Example 1 except that Suspension Polymerization Production Example 4 was used instead of Suspension Polymerization Production Example 1. The specifications were a non-volatile content of 37.1%, a viscosity of 700 mPa · s, and a pH of 8.4.

Example 5
Similar to Example 1 except that Suspension Polymerization Production Example 5 was used instead of Suspension Polymerization Production Example 1. The specifications were a non-volatile content of 36.8%, a viscosity of 680 mPa · s, and a pH of 8.5.

Example 6
Similar to Example 1 except that Suspension Polymerization Production Example 6 was used instead of Suspension Polymerization Production Example 1. The specifications were a non-volatile content of 37.0%, a viscosity of 670 mPa · s, and a pH of 8.5.

Example 7
Similar to Example 1 except that Suspension Polymerization Production Example 7 was used instead of Suspension Polymerization Production Example 1. The specifications were a non-volatile content of 37.3%, a viscosity of 720 mPa · s, and a pH of 8.3.

Example 8
The same as Example 1 except that the acrylic emulsion production example 2 was used instead of the acrylic emulsion production example 1. The specifications were a non-volatile content of 37.1%, a viscosity of 650 mPa · s, and a pH of 8.5.

Example 9
The same as Example 1 except that the suspension polymerization production example 2 was used instead of the suspension polymerization production example 1, and the acrylic emulsion production example 2 was used instead of the acrylic emulsion production example 1. The specifications were a non-volatile content of 37.0%, a viscosity of 650 mPa · s, and a pH of 8.6.

Example 10
The same as Example 1 except that the suspension polymerization production example 3 was used instead of the suspension polymerization production example 1, and the acrylic emulsion production example 2 was used instead of the acrylic emulsion production example 1. The specifications were a non-volatile content of 36.7%, a viscosity of 710 mPa · s, and a pH of 8.7.

Example 11
The same as Example 1 except that the suspension polymerization production example 4 was used instead of the suspension polymerization production example 1, and the acrylic emulsion production example 2 was used instead of the acrylic emulsion production example 1. The specifications were a non-volatile content of 37.3%, a viscosity of 700 mPa · s, and a pH of 8.5.

Example 12
The same as Example 1 except that the suspension polymerization production example 5 was used instead of the suspension polymerization production example 1, and the acrylic emulsion production example 2 was used instead of the acrylic emulsion production example 1. The specifications were a non-volatile content of 36.8%, a viscosity of 650 mPa · s, and a pH of 8.6.

Example 13
The same as Example 1 except that the suspension polymerization production example 6 was used instead of the suspension polymerization production example 1, and the acrylic emulsion production example 2 was used instead of the acrylic emulsion production example 1. The specifications were a non-volatile content of 36.9%, a viscosity of 680 mPa · s, and a pH of 8.4.

Example 14
The same as Example 1 except that the suspension polymerization production example 7 was used instead of the suspension polymerization production example 1, and the acrylic emulsion production example 2 was used instead of the acrylic emulsion production example 1. The specifications were a non-volatile content of 37.0%, a viscosity of 700 mPa · s, and a pH of 8.6.

Example 15
Similar to Example 1 except that Suspension Polymerization Production Example 9 was used instead of Suspension Polymerization Production Example 1. The specifications were a non-volatile content of 37.0%, a viscosity of 700 mPa · s, and a pH of 8.5.

Example 16
Similar to Example 1 except that Suspension Polymerization Production Example 10 was used instead of Suspension Polymerization Production Example 1. The specifications were a non-volatile content of 37.0%, a viscosity of 690 mPa · s, and a pH of 8.6.

Example 17
Similar to Example 1 except that Suspension Polymerization Production Example 11 was used instead of Suspension Polymerization Production Example 1. The specifications were a non-volatile content of 37.3%, a viscosity of 690 mPa · s, and a pH of 8.5.

Example 18
Similar to Example 1 except that Suspension Polymerization Production Example 12 was used instead of Suspension Polymerization Production Example 1. The specifications were a non-volatile content of 36.7%, a viscosity of 670 mPa · s, and a pH of 8.7.

Example 19
Similar to Example 1 except that Suspension Polymerization Production Example 13 was used instead of Suspension Polymerization Production Example 1. The specifications were a non-volatile content of 37.0%, a viscosity of 690 mPa · s, and a pH of 8.5.

Example 20
Similar to Example 1 except that Suspension Polymerization Production Example 14 was used instead of Suspension Polymerization Production Example 1. The specifications were a non-volatile content of 37.1%, a viscosity of 700 mPa · s, and a pH of 8.4.

Example 21
Similar to Example 1 except that Suspension Polymerization Production Example 15 was used instead of Suspension Polymerization Production Example 1. The specifications were a non-volatile content of 37.0%, a viscosity of 700 mPa · s, and a pH of 8.5.

Example 22
Similar to Example 1 except that Suspension Polymerization Production Example 16 was used instead of Suspension Polymerization Production Example 1. The specifications were a non-volatile content of 37.3%, a viscosity of 670 mPa · s, and a pH of 8.6.

Example 23
Similar to Example 1 except that Suspension Polymerization Production Example 9 was used instead of Suspension Polymerization Production Example 1 and Acrylic Silicon Emulsion Production Example 2 was used instead of Acrylic Emulsion Production Example 1. The specifications were a non-volatile content of 36.7%, a viscosity of 700 mPa · s, and a pH of 8.5.

Example 24
The same as Example 1, except that Suspension Polymerization Production Example 10 was used instead of Suspension Polymerization Production Example 1, and Acrylic Silicon Emulsion Production Example 2 was used instead of Acrylic Emulsion Production Example 1. The specifications were a non-volatile content of 37.1%, a viscosity of 690 mPa · s, and a pH of 8.4.

Example 25
The same as Example 1 except that the suspension polymerization production example 11 was used instead of the suspension polymerization production example 1, and the acrylic silicone emulsion production example 2 was used instead of the acrylic emulsion production example 1. The specifications were a non-volatile content of 36.8%, a viscosity of 670 mPa · s, and a pH of 8.7.

Example 26
The same as Example 1 except that Suspension Polymerization Production Example 12 was used instead of Suspension Polymerization Production Example 1, and Acrylic Silicon Emulsion Production Example 2 was used instead of Acrylic Emulsion Production Example 1. The specifications were a non-volatile content of 36.9%, a viscosity of 670 mPa · s, and a pH of 8.7.

Example 27
The same as Example 1 except that Suspension Polymerization Production Example 13 was used instead of Suspension Polymerization Production Example 1, and Acrylic Silicon Emulsion Production Example 2 was used instead of Acrylic Emulsion Production Example 1. The specifications were a non-volatile content of 36.8%, a viscosity of 680 mPa · s, and a pH of 8.5.

Example 28
Similar to Example 1 except that Suspension Polymerization Production Example 14 was used instead of Suspension Polymerization Production Example 1, and Acrylic Silicon Emulsion Production Example 2 was used instead of Acrylic Emulsion Production Example 1. The specifications were a non-volatile content of 37.2%, a viscosity of 700 mPa · s, and a pH of 8.5.

Example 29
Similar to Example 1 except that Suspension Polymerization Production Example 15 was used instead of Suspension Polymerization Production Example 1, and Acrylic Silicon Emulsion Production Example 2 was used instead of Acrylic Emulsion Production Example 1. The specifications were a non-volatile content of 36.3%, a viscosity of 700 mPa · s, and a pH of 8.6.

Example 30
Similar to Example 1 except that Suspension Polymerization Production Example 16 was used instead of Suspension Polymerization Production Example 1, and Acrylic Silicon Emulsion Production Example 2 was used instead of Acrylic Emulsion Production Example 1. The specifications were a non-volatile content of 37.3%, a viscosity of 710 mPa · s, and a pH of 8.6.

Comparative Example 1
Similar to Example 1 except that Suspension Polymerization Production Example 8 was used instead of Suspension Polymerization Production Example 1. The specifications were a non-volatile content of 37.0%, a viscosity of 650 mPa · s, and a pH of 8.5.

Comparative Example 2
Instead of suspension polymerization preparation example 1, suspension polymerization preparation example 8 is used. Moreover, it is the same as that of Example 1 except having used acrylic emulsion manufacture example 2 instead of acrylic emulsion manufacture example 1. The specifications were a non-volatile content of 36.8%, a viscosity of 680 mPa · s, and a pH of 8.5.

Comparative Example 3
4.4 parts of silica powder p-526 (manufactured by Mizusawa Chemical) 100.0 parts of the acrylic emulsion obtained in acrylic emulsion production example 1 and thickener WR-600 (nonvolatile content: 5.0%) 2.9 Part, 0.2 part of foam suppressor (SN deformer 777; manufactured by San Nopco), 1.0 part of dispersant (SN Dispersant 5027: manufactured by San Nopco) and dilution water were added to obtain a clear coating composition. The specifications were a nonvolatile content of 37.3%, a viscosity of 920 mPa · s, and a pH of 8.2.

Comparative Example 4
Similar to Comparative Example 3 except that Acrylic Emulsion Production Example 2 was used instead of Acrylic Emulsion Production Example 1. The specifications were a non-volatile content of 37.2%, a viscosity of 900 mPa · s, and a pH of 8.1.

  The physical properties of Examples 1 to 30 and Comparative Examples 1 to 4 are as shown in Table 3 and Table 4.

Example 31
To 100 parts of the aqueous dispersion obtained in Suspension Polymerization Production Example 1, 1 part of 25% aqueous ammonia solution and 10 parts of thickener RW-600 (nonvolatile content: 5.0%) were added (viscosity 1260 mPa · s), The time to settling was observed at room temperature. After sedimentation, the sediment was stirred with a stir bar to confirm the presence or absence of hard cake (redispersibility).

Comparative Example 5
To 100 parts of the aqueous dispersion obtained in Production Example 1 of suspension polymerization, 5.1 parts of a butyl cellosolve / CS-12 = 1/1 mixed solution was added as a film forming aid (viscosity 15 mPa · s), and until sedimentation at room temperature. Was observed. After sedimentation, the sediment was stirred with a stir bar to check for the presence of a hard cake.

  Production Example 1 Time until sedimentation of 100 parts of an aqueous dispersion (viscosity: 10 mPa · s) was observed. After sedimentation, the sediment was stirred with a stir bar to check for the presence of a hard cake.

Test method <Non-volatile content>
About 1 g of the obtained water dispersion and coating composition are weighed. The temperature was dried at 105 ° C. for 1 hour with a hot air dryer, and the ratio of the weight before drying was expressed in weight%, with the remaining amount of drying being a non-volatile content.

<PH>
The value at 25 ° C. was measured with a pH meter (“F-23” manufactured by Horiba, Ltd.).

<Viscosity>
It measured at 30 rpm and 25 degreeC with the BM type | mold viscosity meter (made by Tokyo Keiki Co., Ltd.). The rotor to be used was selected according to the viscosity.

<Average particle size>
Measurement of average particle diameter of suspension polymer The measurement was performed with a Coulter counter (Beckman Coulter, model: Coulter Multisizer II).

-Average particle size measurement of acrylic emulsion Light scattering particle size measurement device (manufactured by US Particulate Sizing Systems, model: NICOM 380)
<Glossy appearance>
The obtained coating composition is applied to a black acrylic plate (manufactured by Taisuke Corporation) using a 4 mil applicator. After setting for 5 minutes at room temperature, the gloss (gloss) of the coated plate dried for 10 minutes in a hot air dryer at 100 ° C. was measured with a gloss meter (60 ° Gloss).

GL25 or less ... ○, GL26 or more ... ×
<Transparency>
The transparency of the coated plate produced by the same method as the appearance matte property was measured with a color difference meter.

L value 10 or less ... ○, L value 11 or more ... ×
<Water absorption rate>
A release paper was affixed on a glass plate, and a mold frame with a thickness of one gum tape (thickness of about 300 μm) was formed thereon. The obtained coating composition is poured into the mold and cast. After setting for 5 minutes, it was dried in a hot air dryer at 100 ° C. for 10 minutes to prepare a test film. The test film was allowed to stand at room temperature for 24 hours, then cut to 4 cm × 4 cm, and the weight (WO) was measured. Then, it was immersed in room temperature water, and after 1 week, it was taken out, wiped off the surface water, and the weight (W1) of the film was measured immediately. Further, the test film was dried in a hot air dryer at 150 ° C. for 1 hour, and its weight (W2) was measured. And the coating-film water absorption rate was computed by the following formula.

<Hot water resistance test>
The coated plate produced by the same method as the above-described matte appearance is left at room temperature for 24 hours, then immersed in 60 ° C. warm water, pulled up after 1 week, and dried at room temperature for 1 day. . The appearance of the painted board after drying is compared with an untested board (initial board).

<Weather resistance (M-WOM)>
After applying a solvent-based sealer on a slate plate to a dry ²⁰ μm / m ² and drying at room temperature for 1 day, a base coat paint having the following composition was applied with a 4 mil applicator and set for 5 minutes, then 100 ° C. For 10 minutes in a hot air dryer. After leaving at room temperature for 1 day, the obtained coating composition was applied with a 4 mil applicator, set for 5 minutes, and then dried for 10 minutes in a hot air dryer at 100 ° C. to prepare a coated plate. A super-accelerated weather resistance test was conducted using a coated plate that had passed one day after production.

(Super accelerated weather resistance test: M-WOM condition)
The painted plate prepared above is set in a die plastic metal weather testing machine manufactured by Daipura Wintes Co., Ltd., irradiation 6 hours (temperature 63 ° C.-humidity 50%), shower 10 seconds, condensation 2 hours (temperature 30 ° C.-humidity 95%) As described above, the test was repeated for 700 hours with 10 seconds of shower as one cycle.

1000 hr coating film no abnormalities ... ◎, 700 hr coating film no abnormalities ... ○, coating color change ... △, cracking in coating film ... ×
(Composition of paint for base coat)
◎ Acrylic emulsion (Acre Reset EX-35: manufactured by Nippon Shokubai): 300 parts by weight
◎ White paste (the following adjustment paste): 135 parts by weight
Dispersant (Demol EP: manufactured by Kao): 60 parts by weight
(Discoat N-14: manufactured by Daiichi Kogyo Seiyaku Co., Ltd.): 50 parts by weight,
-Wetting agent (Emulgen 909: manufactured by Kao): 10 parts by weight,
-Ethylene glycol: 60 parts by weight,
-Deionized water: 210 parts by weight
-Titanium oxide (CR-95: Ishihara Sangyo): 1000 parts by weight,
-Antifoaming agent (Nopco 8034L: manufactured by San Nopco): 10 parts by weight,
・ Glass beads: 500 parts by weight
The above was blended under homodisper 3000 rpm stirring. Add everything and stir for 60 minutes to adjust.

◎ Film forming aid (butyl cellosolve): 15 parts by weight
◎ (CS-12: manufactured by Chisso Corporation): 15 parts by weight,
◎ Black paste (Unirant 88: Yokohama Chemical): 10 parts by weight,
◎ Foam suppressant (Nopco 8034L: San Nopco): 1.5 parts by weight

Claims (1)

  (A) 60 to 95% by mass of cyclohexyl (meth) acrylate and / or tert-butyl (meth) acrylate, (b) ester of (meth) acrylic acid and polyhydric alcohol, polyfunctional vinyl compound and (meth) acrylic Ultraviolet rays containing at least one polyfunctional crosslinking monomer selected from the group consisting of allyl esters of acids and (c) 0.1 to 10% by mass of a benzophenone monomer and / or a piperidine monomer A monomer component containing an unsaturated monomer having a stable group and / or an ultraviolet absorbing group (however, (a) + (b) + (c) is 100% by mass) is obtained by suspension polymerization. An aqueous resin dispersion containing resin particles having an average particle diameter of 1 to 100 μm.