JP2006306994A - Water paint composition and method for painting the water paint composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a water paint composition having good storage stability as a paint, followable to substrate cracks, and capable of forming even at normal temperature a paint film excellent in paint film properties such as water resistance, weather resistance, alkali resistance and stain resistance, and to provide a method for painting therewith. <P>SOLUTION: The water paint composition comprises a copolymer water-dispersion (A) dispersed with a copolymer particle group having 350-1,500 nm volume-average particle diameter and <2.0 particle diameter distribution, and a sedimentation preventive (B), wherein the paint film formed from the water paint composition has 50-1,000% elongation at break in a condition of 20°C. The method for painting comprises painting the water paint composition. The volume ratio of the copolymer particle group having <300 nm particle diameter in the copolymer water-dispersion (A) is preferably ≤30%. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention is excellent in coating film properties such as water resistance, weather resistance, stain resistance, and the ability to follow cracks in buildings and the like, and is suitable for maintaining the aesthetics of buildings and the like over a long period of time at room temperature. The present invention relates to an aqueous coating composition that can be formed and a method for applying the aqueous coating composition.

  In recent years, from the viewpoint of environmental protection, in the field of paints, it is desired to switch from organic solvent-based paints to water-based paints. In general, an emulsion or the like in which a resin is dispersed in water is used as a binder component of a water-based paint. In the production of an emulsion, a hydrophilic compound such as an emulsifier or the like is generally used in the resin itself from the viewpoint of production stability or storage stability. Therefore, hydrophilic functional groups and emulsifiers derived from the emulsion are incorporated into the coating film obtained from the water-based paint, and as a result, the film performance such as water resistance and weather resistance is improved in the paint film by the solvent-based paint. It tends to be inferior.

  As a binder component for water-based paints, for example, Patent Document 1 specifies a polymerizable unsaturated monomer having a carbonyl group, a polyvinyl compound, a water-soluble ethylenically unsaturated monomer, and other ethylenically unsaturated monomers. An aqueous copolymer dispersion obtained by emulsion polymerization of a monomer mixture containing a proportion in the presence of an emulsifier and a resin composition for aqueous coatings containing the same are disclosed. The water-based coating composition containing the resin composition can form a coating film having excellent water resistance in the initial stage after painting even at room temperature, but it is water-resistant for a long period of time as when painted outdoors. It was difficult to hold.

  By the way, as a painting method for water-based paints in the building field, a base coat paint that forms an elastic coating film that can follow cracks in the base material is applied, and then a top coat paint that forms a paint film having excellent weather resistance and finish properties is applied. For example, there is a method of applying a single-layer elastic paint that can form a coating film having the characteristics of an undercoat paint and an overcoat paint with a single paint by applying it to a base material with a predetermined coating amount. In recent years, further improvements in water resistance, weather resistance, and contamination resistance have been demanded for top coating materials and single-layer elastic coating materials used in these methods.

  As a measure for improving the performance of the coating film in the water-based paint, there can be mentioned a method of designing the glass transition temperature of the resin in the emulsion in the paint to be high. For example, in Patent Document 2, a specific unsaturated polyurethane resin is used as an emulsifier component at the time of emulsion polymerization in the first stage among multiple stages, and a theoretical glass transition temperature of a copolymer composed of a polymerizable unsaturated monomer is 30 ° C. An aqueous coating composition containing an emulsion polymer and a hydrazine derivative characterized by the above is described. Further, this document describes that a specific amount of a film-forming aid is included in the aqueous coating composition in order to promote the fusion of particles. According to the water-based paint composition, since the urethane component is contained, the formed coating film is tough and excellent in flexibility, and has good stain resistance when exposed to the outdoors. The film is formed by fusing particles of the emulsion polymer, and the glass transition temperature of the copolymer part in the emulsion polymer is high, so that the particles are not sufficiently fused. In some cases, the finished appearance was not sufficient. In addition, when a large amount of film-forming aid is blended in the paint, the formed coating film may not be able to follow the cracks in the substrate over time.

  On the other hand, Patent Document 3 discloses particles obtained by a production method characterized by emulsion polymerization of a vinyl monomer in an aqueous medium in which an electrolyte substance is dissolved while reducing the concentration of the electrolyte substance. A coating composition prepared using a resin emulsion having a wide diameter distribution is described. According to the coating composition, it is excellent in quick-drying and has the characteristics of eliminating pattern thinness during thick film coating, and can be suitably applied to single-layer elastic coatings, etc. The physical properties of the coating called alkalinity are equivalent to those of conventional coatings and have not been improved.

Japanese Patent Laid-Open No. 10-324720 JP 2002-114942 A JP 2001-342201 A

  An object of the present invention is an aqueous coating composition capable of following a crack of a substrate and capable of forming a coating film excellent in coating film properties such as water resistance, weather resistance, alkali resistance, and stain resistance at room temperature, and It is to provide a method for coating the water-based coating composition.

  As a result of diligent studies to solve the above problems, the present inventors include a copolymer aqueous dispersion having a volume average particle size and a particle size distribution within a specific range and an anti-settling agent, and a specific elongation at break. Water-based paint composition capable of forming a coating film having good storage stability and coating workability in paint state, following cracks in the substrate, water resistance, weather resistance, alkali resistance, stain resistance, etc. The present inventors have found that a coating film having excellent coating film physical properties can be formed even at room temperature, and have reached the present invention.

That is, the present invention is 1. Copolymer aqueous dispersion (A) and anti-settling agent (B) in which copolymer particle groups having a volume average particle size in the range of 350 to 1500 nm and a particle size distribution of less than 2.0 are dispersed. An aqueous coating composition comprising: a coating film formed from the aqueous coating composition, wherein the elongation at break in a 20 ° C. atmosphere is within a range of 50 to 1000%;
2. 2. The aqueous coating composition according to 1, wherein the volume fraction of the copolymer particles having a particle diameter in the copolymer aqueous dispersion (A) of less than 300 nm is 30% or less,
3. The aqueous coating composition according to item 1 or 2, wherein the monomer component forming the copolymer particles of the aqueous copolymer dispersion (A) contains a carbonyl group-containing polymerizable unsaturated monomer as a part thereof,
4). The aqueous coating composition according to any one of 1 to 3, wherein the aqueous copolymer dispersion (A) comprises polysiloxane-modified copolymer particles obtained by modifying copolymer particles with polysiloxane.
5. 5. The aqueous coating composition according to any one of items 1 to 4, wherein the glass transition temperature of the resin of the copolymer aqueous dispersion (A) is in the range of −50 to 120 ° C.
6). 6. The copolymer aqueous dispersion (C) obtained by dispersing a copolymer particle group having a volume average particle diameter of 50 nm or more and less than 350 nm, according to any one of items 1 to 5. Water-based paint composition,
7). The ratio of the total volume of the copolymer particle group a having a particle diameter of less than 300 nm to the total volume of the copolymer particle group b having a particle diameter of 300 nm or more and less than 2000 nm is 3/97 to 99 in terms of a / b volume ratio. The water-based coating composition according to item 6, which is within the range of / 1;
8). 8. A coating method for coating the surface to be coated with the water-based coating composition according to any one of items 1 to 7;
9. A coated article obtained by the coating method according to item 8,
About.

  The aqueous coating composition of the present invention has an appropriate elongation at break that can follow cracks in a substrate such as a building, but the copolymer particle group in the copolymer aqueous dispersion is a specific volume average particle. By having a specific particle size distribution, it is possible to form a coating film that is excellent in water resistance, weather resistance, alkali resistance, stain resistance and other coating film properties at room temperature, and In addition, it has an advantage that the storage stability in the paint state and the coating workability are also good.

Copolymer aqueous dispersion (A)
The copolymer aqueous dispersion (A) used in the aqueous coating composition of the present invention has a volume average particle size of 350 to 1500 nm, preferably 450 to 750 nm, and a particle size distribution of less than 2.0. Preferably, copolymer particles in the range of 1.0 to 1.8 are dispersed.

  When the volume average particle diameter of the copolymer particle group in the copolymer aqueous dispersion (A) is less than 350 nm, the water resistance and stain resistance of the coating film formed by the aqueous coating composition of the present invention are insufficient, and 1500 nm. Exceeding this is not preferable because the gloss of the coating film decreases. Moreover, when the particle size distribution is 2.0 or more, the water resistance and alkali resistance of the formed coating film are insufficient, which is not preferable.

  In the present invention, the volume average particle diameter of the copolymer particle group of the copolymer aqueous dispersion (A) is deionized so that the resin solid content of the copolymer aqueous dispersion (A) is 0.05%. The sample diluted with water and adjusted to 20 ° C. is used as a sample, and is obtained by measurement with “SALD-3100” (trade name, manufactured by Shimadzu Corporation, laser diffraction particle size distribution analyzer).

Moreover, the particle size distribution in this specification is a value calculated by the following formula.
Particle size distribution = Volume average particle size / Number average particle size Here, the number average particle size can be obtained by converting the data obtained after measuring the volume average particle size with an arithmetic device provided in the same apparatus. .

  In addition, from the viewpoint of water resistance, alkali resistance, and stain resistance of the coating film formed from the aqueous coating composition of the present invention, copolymer particles having a particle size in the aqueous copolymer dispersion (A) of less than 300 nm are used. It is desirable that the volume ratio of the group is 30% or less, preferably 20% or less.

  Here, the volume ratio (%) of the copolymer particle group having a particle diameter of less than 300 nm in the aqueous copolymer dispersion can be obtained from the measurement result of the volume average particle diameter.

  In the present invention, the copolymer aqueous dispersion (A) may be a copolymer aqueous dispersion obtained by dispersing a group of copolymer particles formed using a monomer component, or the copolymer particles. May further include modified copolymer particles modified with a resin such as polysiloxane.

  Specific examples of the polymerizable unsaturated monomer include, for example, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, and pentyl (meth). Linear or branched alkyl (meth) acrylates such as acrylate, hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, lauryl (meth) acrylate, stearyl (meth) acrylate; cyclohexyl (meth) acrylate, isobornyl ( Alicyclic (meth) acrylates such as meth) acrylate; Aralkyl (meth) acrylates such as benzyl (meth) acrylate; Alkoxy such as 2-methoxyethyl (meth) acrylate and 2-ethoxyethyl (meth) acrylate Alkyl (meth) acrylate; perfluoroalkyl (meth) acrylate, N, N-diethylaminoethyl (meth) acrylate; (meth) acrylamide, (meth) acrylonitrile; vinyl ester compounds such as vinyl acetate and vinyl propionate; styrene, α -Vinyl aromatic compounds such as methylstyrene; allyl (meth) acrylate, ethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, 1,3-butylene glycol di ( (Meth) acrylate, trimethylolpropane tri (meth) acrylate, 1,4-butanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, 1,6-hexanediol di (meth) ) Acrylate, pentaerythritol di (meth) acrylate, pentaerythritol tetra (meth) acrylate, glycerol di (meth) acrylate, 1,1,1-trishydroxymethylethanedi (meth) acrylate, 1,1,1-trishydroxy At least two polymerizable unsaturated groups in one molecule such as methylethane tri (meth) acrylate, 1,1,1-trishydroxymethylpropane tri (meth) acrylate, triallyl isocyanurate, diallyl terephthalate, divinylbenzene (Meth) acrolein, formylstyrene, vinyl alkyl ketones having 4 to 7 carbon atoms (for example, vinyl methyl ketone, vinyl ethyl ketone, vinyl butyl ketone, etc.), acetoacetoxyethyl (meth) acetate Carbonyl group-containing polymerizable unsaturated monomers such as acrylate, acetoacetoxyallyl ester, diacetone (meth) acrylamide; Carboxyl group-containing polymerizable unsaturated monomers such as (meth) acrylic acid, maleic acid, crotonic acid, and β-carboxyethyl acrylate Monomer: Hydroxyalkyl (meth) acrylate such as 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, hydroxybutyl (meth) acrylate, allyl alcohol , Ε-caprolactone modified form of the above hydroxyalkyl (meth) acrylate, hydroxyl group-containing polymerizable unsaturated monomer such as polyoxyethylene chain-containing (meth) acrylate having a hydroxyl group at the molecular end; glycidyl (meth) acrylate , Β-methylglycidyl (meth) acrylate, 3,4-epoxycyclohexylmethyl (meth) acrylate, 3,4-epoxycyclohexylethyl (meth) acrylate, 3,4-epoxycyclohexylpropyl (meth) acrylate, allyl glycidyl ether, etc. Epoxy group-containing polymerizable unsaturated monomers; isocyanato group-containing polymerizable unsaturated monomers such as isocyanatoethyl (meth) acrylate and m-isopropenyl-α, α-dimethylbenzyl isocyanate; vinyltrimethoxysilane, vinyltriethoxysilane Alkoxysilyl group-containing polymerizable unsaturated monomers such as γ-methacryloyloxypropyltrimethoxysilane, γ-methacryloyloxypropyltriethoxysilane; epoxy group-containing polymerizable unsaturated monomers or water Reaction products of group-containing polymerizable unsaturated monomers and unsaturated fatty acids, oxidatively curable groups such as dicyclopentenyloxyethyl (meth) acrylate, dicyclopentenyloxypropyl (meth) acrylate, dicyclopentenyl (meth) acrylate, etc. Examples thereof include a polymerizable unsaturated monomer, and these can be used alone or in combination of two or more.

  In the present invention, the monomer component for forming the copolymer particles of the copolymer aqueous dispersion (A) is a cross-linking functional group as a part thereof from the viewpoint of water resistance, stain resistance, curability and the like of the formed coating film. It is preferred to include a group-containing polymerizable unsaturated monomer.

  Such a crosslinkable reactive group-containing polymerizable unsaturated monomer is a compound containing a crosslinkable reactive group and a polymerizable unsaturated group in the molecule. Examples of the crosslinkable reactive group include a carbonyl group, a hydroxyl group, and an alkoxysilyl group. And can be used alone or in combination of two or more.

  In the present invention, since the finished appearance, water resistance, and alkali resistance of the formed coating film are good, the monomer component that forms the copolymer particles of the copolymer aqueous dispersion (A) is a carbonyl group as a part thereof. It is preferred that it contains a polymerizable unsaturated monomer.

  The carbonyl group-containing polymerizable unsaturated monomer is 0.1 to 10.0% by mass, preferably 0.5%, in the total polymerizable unsaturated monomer used for the production of the copolymer aqueous dispersion (A). It can be used within a range of ˜5.5% by mass.

  In addition, from the viewpoint of the elongation at break of the formed coating film, the monomer component forming the copolymer particles of the aqueous copolymer dispersion (A) is a straight or branched chain having 4 or more carbon atoms as a part thereof. It is preferable to include a polymerizable unsaturated monomer containing an alkyl group.

  Examples of the polymerizable unsaturated monomer containing a linear or branched alkyl group having 4 or more carbon atoms include n-butyl (meth) acrylate, i-butyl (meth) acrylate, and tert-butyl (meth). Acrylate, n-hexyl (meth) acrylate, octyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, nonyl (meth) acrylate, tridecyl (meth) acrylate, lauryl (meth) acrylate, stearyl (meth) acrylate, “iso And stearyl acrylate "(manufactured by Osaka Organic Chemical Co., Ltd.).

  Such a polymerizable unsaturated monomer having a linear or branched alkyl group having 4 or more carbon atoms is 10 in the total polymerizable unsaturated monomer used in the production of the copolymer aqueous dispersion (A). It can be used in the range of mass% or more, preferably 20 to 80 mass%.

  When the monomer component forming the copolymer particles of the copolymer aqueous dispersion (A) contains a carbonyl group-containing polymerizable unsaturated monomer as a part thereof, the aqueous coating composition of the present invention is stored. From the viewpoint of stability and mechanical stability, it is preferable to use a hydroxyl group-containing polymerizable unsaturated monomer and / or a carboxyl group-containing polymerizable unsaturated monomer in combination.

  In addition, the monomer component forming the copolymer particles of the copolymer aqueous dispersion (A) includes the storage stability of the aqueous coating composition of the present invention and the water resistance, stain resistance, weather resistance of the formed coating film, From the viewpoint of coating film physical properties such as alkali resistance, a polyvinyl compound having at least two polymerizable unsaturated groups in one molecule can be included as a part thereof. The polyvinyl compound having at least two polymerizable unsaturated groups in one molecule is 0.01 to 10% in the total polymerizable unsaturated monomer used in the production of the copolymer aqueous dispersion (A). It can be used within a range of 0.0 mass%, preferably 0.05 to 5.0 mass%.

  The copolymer particles in the copolymer aqueous dispersion (A) may be a single-layer type obtained by reacting the entire amount of the monomer components exemplified above, or react in a stepwise manner with monomer components having different compositions. A multi-layered type obtained by, for example, a core-shell type may be used.

  In the case where the copolymer particles in the copolymer aqueous dispersion (A) are of the core-shell type, the blending ratio of the core monomer to the shell monomer is 99 / core monomer mass ratio of core / shell monomer. It is suitable from the point of a coating-film formation property and a contamination | pollution resistance that it exists in the range of 1-10 / 90, Preferably it is 90 / 10-10 / 90.

  In the present invention, the method for producing the copolymer aqueous dispersion (A) is not particularly limited, and examples thereof include a polymerizable unsaturated monomer in an aqueous medium in which an emulsifier and / or a protective colloid is dispersed or dissolved. A seed polymerization method in which an appropriate amount of a polymerizable unsaturated monomer is polymerized in advance in a reactor to form seed particles, and then the remaining polymerizable unsaturated monomer is added to perform polymerization. A method in which a polymerizable unsaturated monomer containing a polymerizable unsaturated monomer containing a hydrophilic group such as a carboxyl group as an essential component in a solvent is subjected to solution polymerization, phase inversion emulsification, and then desolvation is carried out if necessary. Examples thereof include a combination method and a miniemulsion polymerization method, and a seed polymerization method can be preferably used from the viewpoint of production stability.

  For example, when the copolymer particles in the copolymer aqueous dispersion (A) are of the core-shell type, seed particles generated from the core monomer mixture (I) containing the polymerizable unsaturated monomer (a) The remaining monomer mixture for core (I) is dropped into the aqueous dispersion, and the copolymer aqueous dispersion obtained by polymerization is added to the monomer mixture for shell (II) containing the polymerizable unsaturated monomer (b). It can manufacture by dripping and superposing | polymerizing.

  In the case of using an emulsifier in the production of the copolymer aqueous dispersion (A), a conventionally known emulsifier can be used. Examples of applicable emulsifiers include an anionic emulsifier, a nonionic emulsifier, both Examples include ionic emulsifiers.

  Examples of anionic emulsifiers include diammonium dodecyl diphenyl ether disulfonate, sodium dodecyl diphenyl ether disulfonate, calcium dodecyl diphenyl ether disulfonate, alkyl diphenyl ether disulfonate such as sodium alkyl diphenyl ether disulfonate; sodium dodecyl benzene sulfonate, ammonium dodecyl benzene sulfonate, etc. Alkyl benzene sulfonates; alkyl sulfates such as sodium lauryl sulfate and ammonium lauryl sulfate; aliphatic carboxylates such as fatty acid sodiums and potassium oleate; sulfate salts containing polyoxyalkylene units (for example, polyoxyethylene alkyl ethers) Sodium sulfate, polyoxyethylene alkyl ether sulfate Polyoxyethylene alkyl ether sulfate salts such as nium; polyoxyethylene alkyl phenyl ether sulfate salts such as sodium polyoxyethylene alkyl phenyl ether sulfate and polyoxyethylene alkyl phenyl ether ammonium sulfate; polyoxyethylene polycyclic sodium phenyl ether sulfate; Polyoxyethylene polycyclic phenyl ether sulfate salts such as ammonium polyoxyethylene phenyl ether sulfate; etc.); naphthalene sulfonic acid formalin condensate sodium naphthalene sulfonic acid formalin condensate salt, etc .; sodium dialkylsulfosuccinate, monoalkyl succinate And alkyl succinate sulfonates such as disodium sulfonate and the like. These may be used alone or in combination of two or more. It is possible to use Te Align.

  Nonionic emulsifiers include, for example, polyoxyalkylene unit-containing ether compounds (for example, polyoxyalkylene alkyls such as polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene tridecyl ether, polyoxyethylene oleyl ether). Ether compounds; polyoxyalkylene alkyl phenyl ether compounds such as polyoxyethylene octyl phenyl ether and polyoxyethylene nonyl phenyl ether; polyoxyalkylene polycyclic phenyl ether compounds such as polyoxyethylene polycyclic phenyl ether; etc.); polyoxyethylene Polyoxyalkylene alkyl esterification such as monolaurate, polyoxyethylene monostearate, polyoxyethylene monooleate Polyoxyalkylene alkylamine compounds such as polyoxyethylene alkylamine; sorbitan compounds such as sorbitan monolaurate, sorbitan monostearate, sorbitan trioleate, polyoxyethylene sorbitan monolaurate, polyoxyethylene sorbitan monooleate, etc. And can be used alone or in combination of two or more.

  Examples of amphoteric surfactants include dimethylalkylbedines, dimethylalkyllaurylbedines, and alkylglycines.

  Moreover, as the emulsifier, a reactive emulsifier containing a polymerizable unsaturated group and an anionic group or a nonionic group in the molecule can also be used.

  In the present invention, from the viewpoint of the production stability of the aqueous copolymer dispersion (A), the water resistance of the formed coating film, the stain resistance, and the like, the emulsifier is an alkyl diphenyl ether disulfonate, a polyoxyalkylene unit-containing sulfate. It is preferably at least one selected from the group consisting of a salt, an alkyl succinate sulfonate, and a polyoxyalkylene unit-containing ether compound.

  In addition, when a protective colloid is used in the production of the copolymer aqueous dispersion (A), as applicable protective colloid, partially saponified polyvinyl alcohol, carboxyl group-containing acrylic resin, carboxyl group-containing polyester resin, carboxyl group-containing Anionic resins such as polyurethane resins can be mentioned, and these can be used alone or in combination of two or more.

  The amount of the emulsifier or protective colloid used is a copolymer from the viewpoint of the production stability of the aqueous copolymer dispersion (A) and the water resistance of the coating film formed using the aqueous coating composition of the present invention. The range of 0.5 to 10.0% by mass, preferably 1.0 to 5.0% by mass, based on the total monomers used in the production of the aqueous dispersion (A) is suitable.

  The polymerization initiator applicable in the production of the copolymer aqueous dispersion (A) may be any of oil-soluble and water-soluble types, and the oil-soluble polymerization initiator is Examples include organic peroxides such as benzoyl peroxide, octanoyl peroxide, lauroyl peroxide and stearoyl peroxide; azo compounds such as azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile). Examples of water-soluble initiators include cumene hydroperoxide, tert-butyl peroxide, tert-butyl peroxylaurate, tert-butyl peroxyisopropyl carbonate, tert-butyl peroxyacetate, diisopropylbenzene hydro Organic peroxide such as peroxide Azobis (2-methylpropiononitrile), azobis (2-methylbutyronitrile), 4,4′-azobis (4-cyanobutanoic acid), dimethylazobis (2-methylpropionate), azobis [2- Azo compounds such as methyl-N- (2-hydroxyethyl) -propionamide] and azobis {2-methyl-N- [2- (1-hydroxybutyl)]-propionamide}; potassium persulfate, ammonium persulfate, Examples thereof include persulfates such as sodium sulfate. These can be used alone or in combination of two or more. Moreover, you may use together with said polymerization initiators reducing agents, such as sugar, sodium formaldehyde sulfoxylate, and an iron complex; Chain transfer agents, such as mercaptans, as needed.

  The amount of the polymerization initiator used is from the viewpoint of the degree of polymerization of the aqueous copolymer dispersion (A) and the water resistance and stain resistance of the coating film formed using the aqueous coating composition of the present invention. In the range of 0.01 to 5.0% by weight, preferably 0.05 to 1.0% by weight, based on the weight of all polymerizable unsaturated monomers used in the production of the polymer aqueous dispersion (A). Is preferred.

  In the present invention, the aqueous copolymer dispersion (A) contains polysiloxane-modified copolymer particles obtained by modifying copolymer particles formed using the polymerizable unsaturated monomer with polysiloxane. May be.

  The polysiloxane modification of the copolymer particles is performed by copolymer aqueous dispersion (m) in which the copolymer particles are dispersed (the copolymer aqueous dispersion before polysiloxane modification is copolymer water dispersion ( m)), an alkoxysilyl group-containing organosilane (n) is added, and the organosilane (n) is subjected to a condensation polymerization reaction.

  The copolymer particles in the copolymer aqueous dispersion (m) are not particularly limited, but from the viewpoint of reactivity with the organosilanes (n), hydroxyl groups and / or alkoxysilyl groups may be used. It is desirable to contain it.

Examples of the alkoxysilyl group-containing organosilanes (n) include at least one selected from the group consisting of an organosilane represented by the following formula (1) and a hydrolysis condensate of the organosilane.
_{^{(R 1) n -Si- (OR}} 2) 4-n (1)
Wherein R ¹ is the same or different and represents a hydrogen atom or an optionally substituted hydrocarbon group having 1 to 20 carbon atoms, and R ² is the same or different and may be a hydrogen atom or substituted. A good C1-C10 organic group is shown, and n is an integer of 0-3.).

Specific examples of R ¹ include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, t-butyl, n-pentyl, isopentyl, neopentyl, and t-pentyl. Straight chain or branched such as a group, n-hexyl group, n-heptyl group, n-octyl group, isooctyl group, 2,2,4-trimethylpentyl group, n-nonyl group, n-decyl group, n-dodecyl group Alkyl groups; cycloalkyl groups such as cyclopentyl group, cyclohexyl group, 4-ethylcyclohexyl group, cycloheptyl group, norbornyl group and methylcyclohexenyl group; phenyl group, biphenylyl group, naptyl group, anthonyl group, phenanthryl group, etc. Aryl groups such as o-, m-, p-tolyl groups, xylyl groups and ethylphenyl groups; Aralkyl groups such as benzyl group, α- or β-phenylethyl group; Epoxy group-containing groups such as glycidoxy group and epoxycyclohexyl group; (Meth) acryloyl group; Amino groups such as amino group, phenylamino group and dibutylamino group Groups; sulfur-containing groups such as mercapto groups and tetrasulfide groups; alkyl ether groups such as (polyoxyalkylene) alkyl ether groups; anionic groups such as carboxyl groups and sulfonyl groups; halogen atoms such as fluorine and chlorine; It may be partially substituted with a hydroxyl group, an isocyanato group or the like.

Specific examples of R ² include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, t-butyl group, n-pentyl group, isopentyl group, neopentyl group, Examples include a linear or branched alkyl group such as a t-pentyl group, n-hexyl group, n-heptyl group, and n-octyl group, or an aryl group such as a phenyl group, and a methyl group is particularly preferable.

  Specific examples of such alkoxysilyl group-containing organosilanes (n) include tetraalkoxysilanes such as tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane, and tetraphenoxysilane; methyltrimethoxysilane, methyltriethoxysilane, Ethyltrimethoxysilane, ethyltriethoxysilane, n-propyltrimethoxysilane, n-propyltriethoxysilane, i-propyltrimethoxysilane, i-propyltriethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, phenyltri Trialkoxysilanes such as propoxysilane; dimethyldimethoxysilane, dimethyldiethoxysilane, dimethyldipropoxysilane, diethyldimethoxysilane, diethyldipropoxysilane, Dialkoxysilanes such as propoxydimethoxysilane, dipropoxydiethoxysilane, diphenyldimethoxysilane, diphenyldiethoxysilane, diphenyldipropoxysilane; trimethylethoxysilane, trimethylpropoxysilane, triphenylmethoxysilane, triphenylethoxysilane, triphenylpropoxy Monoalkoxysilanes such as silane; Organo having an isocyanato group such as γ-isocyanatopropyltrimethoxysilane, γ-isocyanatopropyltriethoxysilane, γ-isocyanatopropylmethyldimethoxysilane, γ-isocyanatopropylmethyldiethoxysilane Silane; γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, γ-glycidoxypropylmethyl Organosilanes having an epoxy group such as rudimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, 3,4-epoxycyclohexyltrimethoxysilane; N-β- (aminoethyl) aminopropyltrimethoxysilane, N-β -Organosilane having an amino group such as (aminoethyl) aminopropyltriethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane; γ-mercapto Organosilanes having a mercapto group such as propyltrimethoxysilane and γ-mercaptopropyltriethoxysilane; and hydrolyzed condensates thereof may be used, and these may be used alone or in combination of two or more.

  The amount of the organosilanes (n) used is based on 100 parts by mass of the resin solid content of the aqueous copolymer dispersion (m) from the viewpoint of the weather resistance, stain resistance, and production stability of the formed coating film. The range of 0.1 to 200 parts by mass, preferably 5 to 80 parts by mass is appropriate.

  For the polysiloxane modification of the copolymer particles in the copolymer aqueous dispersion (m), the pH of the copolymer aqueous dispersion (m) is 5.0 to 9.0, preferably 6.0 to 8.0. The temperature is 90 ° C. or less, preferably 70 ° C. or less, more preferably 50 ° C. or less, and particularly preferably 30 ° C. to 10 ° C., in the copolymer aqueous dispersion (m). n) is added to absorb the organosilanes (c) in the copolymer particles, and then the reaction temperature is set to 30 ° C. or higher, preferably 50 ° C. or higher, more preferably 60 ° C. to 90 ° C. The reaction can be allowed to proceed.

  In the present invention, the copolymer aqueous dispersion (A), from the viewpoint of particle mechanical stability and toning stability, when the copolymer aqueous dispersion (A) has an acidic group, It is desirable to neutralize this with a neutralizing agent. The neutralizing agent is not particularly limited as long as it can neutralize acidic groups. For example, sodium hydroxide, potassium hydroxide, trimethylamine, dimethylaminoethanol, 2-methyl-2-amino-1-propanol, Examples include triethylamine and aqueous ammonia.

  In the present invention, the glass transition temperature of the resin of the aqueous copolymer dispersion (A) obtained as described above from the viewpoints of elongation at break, water resistance, weather resistance, alkali resistance, and stain resistance of the formed coating film. However, it is desirable to be within the range of −50 to 120 ° C., preferably −30 to 80 ° C.

  In the present specification, the glass transition temperature (° C.) is determined by taking a sample in a measuring cup using a differential scanning calorimeter such as “DSC-50Q type” (manufactured by Shimadzu Corporation) and removing the solvent by vacuum suction. The amount of heat change was measured in the range of −100 ° C. to + 100 ° C. at a rate of temperature increase of 3 ° C./min, and the first baseline change point on the low temperature side is taken as the glass transition temperature.

Anti-settling agent (B)
In the water-based coating composition of the present invention, the copolymer aqueous dispersion is used in terms of storage stability, coating workability, and formation of uneven patterns on the coated surface when coated with a roller having a coarse mesh roller cover. In addition to (A), it further contains an anti-settling agent (B).

  As the anti-settling agent (B), conventionally known ones can be used without limitation, and specific examples thereof include inorganic compounds such as water-soluble alkali silicate, montmorillonite, colloidal alumina; methyl cellulose, hydroxyethyl cellulose, carboxymethyl cellulose. Fibrin derivative compounds such as pluronic polyethers, polyether dialkyl esters, polyether dialkyl ethers, polyether urethane modified products, polyether epoxy modified products, polyacrylic acid soda, polyacrylic acid (meta ) Polyacrylic acid compounds such as acrylic acid ester copolymers; polyvinyl compounds such as polyvinyl alcohol, polyvinylpyrrolidone, polyvinyl alcohol, polyvinyl benzyl alcohol copolymer; sodium alginate Alginate-based compounds; protein derivatives such as sodium caseinate and ammonium caseinate; partial esters of vinyl methyl ether-maleic anhydride copolymer, anhydrous esters of drying oil fatty acid allyl alcohol ester-maleic anhydride, etc. A maleic acid copolymer is mentioned, These can be used individually or in combination of 2 or more types. In the present invention, a polyether-based compound and / or a polyacrylic acid-based compound is used as the anti-settling agent (B) from the viewpoint of storage stability of the aqueous coating composition, coating workability, and uneven pattern formation. Is preferred. The amount of the anti-settling agent can be 0.01 to 20% by mass, preferably 0.05 to 5% by mass, based on the resin solid content contained in the aqueous coating composition.

Copolymer aqueous dispersion (C)
Since the aqueous coating composition of the present invention can impart gloss to the formed coating film while maintaining the water resistance and alkali resistance of the formed coating film, the copolymer aqueous dispersion (A) and the anti-settling agent are used. In addition to (B), it further contains a copolymer aqueous dispersion (C) in which a copolymer particle group having a volume average particle diameter of 50 nm or more and less than 350 nm, particularly 80 to 250 nm is dispersed. Is desirable.

  As the copolymer aqueous dispersion (C), those having good compatibility with the copolymer aqueous dispersion (A) are suitable, and even if the copolymer particles are of a single layer type. Alternatively, a multi-layer type such as a core-shell type may be used.

  There is no restriction | limiting in particular as a polymerizable unsaturated monomer which forms the copolymer particle of the said copolymer aqueous dispersion (C), It selects from the inside listed by description of the said copolymer aqueous dispersion (A) suitably. Can be used.

  In the present invention, the glass transition temperature of the resin of the aqueous copolymer dispersion (C) is −60 ° C. or higher from the viewpoint of the weather resistance and stain resistance of the coating film formed from the aqueous coating composition of the present invention. It is desirable that the temperature be within a range of −40 ° C. to 100 ° C.

  Moreover, it is preferable that the monomer component which forms the copolymer particle of the said copolymer aqueous dispersion (C) contains the polymerizable unsaturated monomer which has a crosslinking functional group as a part.

  The polymerizable unsaturated monomer having a crosslinking reactive group can be appropriately selected from those listed in the description of the copolymer aqueous dispersion (A), and is formed from an aqueous coating composition. From the viewpoint of the water resistance and alkali resistance of the coating film, it is preferable to use a carbonyl group-containing polymerizable unsaturated monomer.

  The carbonyl group-containing polymerizable unsaturated monomer is 0.1 to 10% by mass, preferably 0.5 to 5%, in the total polymerizable unsaturated monomer used for the production of the copolymer aqueous dispersion (C). It can be used within the range of mass%.

  In the case where the monomer component forming the copolymer particles of the copolymer aqueous dispersion (C) contains a carbonyl group-containing polymerizable unsaturated monomer as part thereof, the storage stability of the aqueous coating composition of the present invention and From the viewpoint of mechanical stability, it is desirable to use a hydroxyl group-containing polymerizable unsaturated monomer and / or a carboxyl group-containing polymerizable unsaturated monomer in combination.

  The monomer component forming the copolymer particles of the copolymer aqueous dispersion (C) includes the storage stability of the aqueous coating composition of the present invention and the water resistance, stain resistance, weather resistance of the formed coating film, From the viewpoint of physical properties of the coating film such as alkali resistance, it is desirable that a polyvinyl compound having at least two polymerizable unsaturated groups in one molecule is included as a part thereof.

  The polyvinyl compound having at least two polymerizable unsaturated groups in one molecule can be appropriately selected from those listed in the description of the copolymer aqueous dispersion (A). In the total polymerizable unsaturated monomer used for the production of the polymer aqueous dispersion (C), 0.01 to 10.0% by mass, preferably 0.05 to 5.0% by mass is used. be able to.

  The emulsifier and the polymerization initiator applicable in the production of the copolymer aqueous dispersion (C) may be appropriately selected from those listed in the description of the copolymer aqueous dispersion (A). it can.

  The amount of the emulsifier used is preferably in the range of 0.5 to 20.0% by mass, preferably 1.0 to 10.0% by mass, based on the resin solid content of the copolymer aqueous dispersion (C). The amount of the polymerization initiator used is 0.01 to 5.0% by mass, preferably 0.05 to 1.0% by mass, based on the resin solid content of the aqueous copolymer dispersion (C). The range of is preferable.

  Further, when the copolymer particles in the copolymer aqueous dispersion (C) are, for example, a core-shell type, the blending ratio of the core monomer and the shell monomer is the core monomer / shell monomer mass ratio. In the range of 99/1 to 10/90, preferably in the range of 90/10 to 10/90, it is preferable from the viewpoint of coating film formability and water resistance.

  The manufacturing method of the said copolymer aqueous dispersion (C) is not restrict | limited in particular, A well-known method can be utilized. For example, it can be the same as the method listed in the description of the copolymer aqueous dispersion (A).

  As the blending ratio of the copolymer aqueous dispersion (A) and the copolymer aqueous dispersion (C), the gloss of the coating film formed from the aqueous coating composition, the water resistance, the alkali resistance and the stain resistance are From the point of coexistence, the ratio of the total volume of the copolymer particle group a having a particle diameter of less than 300 nm and the total volume of the copolymer particle group b having a particle diameter of 300 nm or more and less than 2000 nm is expressed as a / b volume ratio. It is desirable to adjust so that it may fall within the range of 3/97 to 99/1, preferably 5/95 to 30/70.

Crosslinking agent In the aqueous coating composition of the present invention, when the resin component in the composition has a crosslinking reactive group, the crosslinking agent that reacts with the crosslinking reactive group, A catalyst for reacting with the crosslinking agent in a complementary manner can be appropriately included.

  Examples of these crosslinking agents include conventionally known ones such as hydrazine derivatives, oxazoline group-containing compounds, carbodiimide group-containing compounds, amino group-containing compounds, isocyanate group-containing compounds, and crosslinking reactive groups contained in resin components. It is possible to select a single compound or a plurality of compounds as appropriate.

  When the crosslinkable group contained in the resin component is, for example, a carbonyl group, it is desirable to contain a hydrazine derivative as a crosslinker.

  Examples of such hydrazine derivatives include succinic acid dihydrazide, malonic acid dihydrazide, succinic acid dihydrazide, glutaric acid dihydrazide, adipic acid dihydrazide, sebacic acid dihydrazide and the like, dihydrazides of saturated aliphatic carboxylic acids having 2 to 18 carbon atoms; maleic acid dihydrazide, Dihydrazides of monoolefinically unsaturated dicarboxylic acids such as fumarate dihydrazide, itaconic acid dihydrazide; phthalic acid, terephthalic acid or isophthalic acid dihydrazide; pyromellitic acid dihydrazide, trihydrazide or tetrahydrazide; nitrilotriacetic acid trihydrazide, citric acid trihydride Hydrazide, 1,2,4-benzenetrihydrazide; ethylenediaminetetraacetic acid tetrahydrazide, 1,4,5,8-naphthoic acid tetrahydrazide; carboxylic acid low Polyhydrazide obtained by reacting a low polymer having an alkyl ester group with hydrazine or hydrazine hydrate (hydrazine hydride), etc .; dihydrazide carbonate, bissemicarbazide; diisocyanate such as hexamethylene diisocyanate, isophorone diisocyanate, and polyisocyanate derived therefrom Polyfunctional semicarbazide obtained by excessively reacting a compound with N, N-substituted hydrazine such as N, N-dimethylhydrazine or the above-mentioned hydrazide; the polyisocyanate compound and polyether polyols, polyethylene glycol monoalkyl ethers, etc. An aqueous polyfunctional semicarbazide obtained by excessively reacting the above-exemplified dihydrazide with an isocyanate group in a reaction product with an active hydrogen compound containing a hydrophilic group; A mixture of soil and water-based polyfunctional semicarbazide; bis-acetyl-di hydrazone, or the like may be suitably used. The compounds described above can be used alone or in combination of two or more.

  The amount of the hydrazine derivative is 0.01 to 5.0% by mass, preferably 0.05 to 2.0% by mass, based on the solid content of the resin in the aqueous coating composition. .

  When the crosslinking reactive group contained in the resin component in the aqueous coating composition is a hydroxyl group, for example, a water-dispersible polyisocyanate compound; an amino group-containing compound such as a melamine resin can be used as the crosslinking agent. .

  Examples of the water-dispersible polyisocyanate compound include those obtained by reacting a nonisocyanate emulsifier with a polyisocyanate compound containing two or more isocyanate groups in one molecule.

  Examples of the polyisocyanate compound include aliphatic diisocyanates such as tetramethylene diisocyanate, pentamethylene diisocyanate, hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, and lysine diisocyanate; alicyclic groups such as 4,4′-methylenebis (cyclohexyl isocyanate) and isophorone diisocyanate. Diisocyanates; aromatic diisocyanates such as xylylene diisocyanate, tolylene diisocyanate, diphenylmethane diisocyanate, polyphenylmethane diisocyanate (hereinafter referred to as polymeric MDI); and similar compounds such as these isocyanurates and burettes. Alternatively, two or more kinds can be mixed and used.

  As the nonionic emulsifier that can be reacted with the polyisocyanate compound, for example, those exemplified as the nonionic emulsifier that can be used in the production of the copolymer aqueous dispersion (A) can be used, and active hydrogen that reacts with an isocyanate group. Those having a group and particularly having an oxyethylene unit as the oxyalkylene unit are preferred.

  If necessary, the water-dispersible polyisocyanate may be reacted with a silane coupling agent having an active hydrogen group at one end and an alkoxysilyl group at one end. Examples of the silane coupling agent include N-β- (aminoethyl) -γ-aminopropyltrimethoxysilane, N-β- (aminoethyl) -γ-aminopropylmethyldimethoxysilane, and γ-aminopropyltriethoxysilane. N-phenyl-γ-aminopropyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane, and the like.

  Examples of commercially available water-dispersible polyisocyanates include “Bayhydr 3100”, “VPLS2319” (trade names, manufactured by Bayer).

  As a compounding quantity of the said water dispersible polyisocyanate, it is 0.5-40.0 mass% with respect to the resin solid content of the copolymer aqueous dispersion containing a hydroxyl group, Preferably it is 2.0-30.0 mass% It is preferable that

  In the present invention, the water-based paint composition can be used as a clear paint or an enamel paint.

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

  Color pigments include white pigments such as titanium dioxide; black pigments such as carbon black, acetylene black, lamp black, bone black, graphite, iron black, and aniline black; yellow iron oxide, titanium yellow, monoazo yellow, and condensed azo yellow. Yellow pigments such as azomethine yellow, bismuth vanadate, benzimidazolone, isoindolinone, isoindoline, quinophthalone, benzidine yellow, permanent yellow; orange pigments such as permanent orange; red iron oxide, naphthol AS azo red, ansanthrone, Red pigments such as anthraquinonyl red, perylene maroon, quinacridone red pigment, diketopyrrolopyrrole, watching red, permanent red; cobalt purple, quinacridone violet, dioxazine bai Purple pigments such as lettuce; Blue pigments such as cobalt blue, phthalocyanine blue, and selenium blue; Green pigments such as phthalocyanine green; and the like. Examples of glitter pigments include aluminum powder, bronze powder, copper powder, and tin powder. Metallic pigments such as iron phosphide; pearl-like pigments such as metal-coated mica powder and mica-like iron oxide. Examples of extender pigments include zinc powder, barita powder, precipitated barium sulfate, barium carbonate, calcium carbonate , Gypsum, clay, silica, white carbon, diatomaceous earth, talc, magnesium carbonate, alumina white, gloss white and the like.

  As the blending amount of the pigment, the pigment is 5 to 5 based on the solid content of the resin in the aqueous coating composition from the viewpoint of the elongation at break of the formed coating film, the base concealing property, the coating surface smoothness, and the uneven pattern forming property. It is desirable that the ratio be within a range of 300% by mass, preferably 20 to 150% by mass, and more preferably 30 to 120% by mass.

  The aqueous coating composition of the present invention comprises a surfactant, an aqueous water repellent, a dispersant, an antifoaming agent, an antiseptic, an antifungal agent, an antifreezing agent, an ultraviolet absorber, a light stabilizer, a film-forming aid, Paint additives such as zinc whiskers, curing accelerators and formaldehyde adsorbents can be blended as required.

  The aqueous coating composition of the present invention is characterized in that the elongation at break of the formed coating film in an atmosphere of 20 ° C. is in the range of 50 to 1000%, preferably 120 to 500%.

  If the elongation at break of the formed coating film is less than 50%, the formed coating film cannot follow the cracks in the substrate and the finished appearance may be deteriorated. On the other hand, if it exceeds 1000%, the toughness of the coating film is insufficient. May be.

  In this specification, the elongation at break is a free coating film (dry film thickness 1000 μm, drying condition 20 ° C., relative humidity 50%, cured for 2 weeks) made of the aqueous coating composition of the present invention as a test piece, JIS A In accordance with 6909-7-29, a tensile tester Autograph AGS-20KNG type (trade name, manufactured by Shimadzu Corporation) was used, and the measurement was performed in a 20 ° C. atmosphere under a tensile speed of 200 mm / min.

Coating method The method of the present invention is a coating method for coating the surface to be coated with the aqueous coating composition of the present invention obtained as described above.

  Examples of coated surfaces include concrete surfaces, mortar surfaces, slate plates, PC plates, ALC plates, cement calcium silicate plates, wood, stone, plastic, metal and other substrate surfaces, and acrylics provided on these substrates. Examples of the coating surface include resin, acrylic urethane resin, polyurethane resin, fluororesin, silicon acrylic resin, vinyl acetate resin, and epoxy resin.

  The coated surface is preferably treated with a sealer in order to suppress the occurrence of suction unevenness and the like.

  As the sealer, an aqueous or organic solvent-based sealer having a resin component such as an epoxy resin-based resin, an acrylic resin-based resin, or a urethane resin-based resin can be used. It is desirable to use a water-based sealer from the viewpoints of adhesion to a coating film by a product and finish.

The coating amount of the aqueous coating composition of the present invention, the formed coating film in terms of stain resistance, 0.1~2kg / m ² / dose, preferably 0.1~1.2kg / m ² / dose range The inside is suitable and can be applied a plurality of times as required.

  As the coating means, for example, a known coating device such as a roller, air spray, airless spray, lysine gun, universal gun, brush, or the like can be used. The drying method may be room temperature drying, but may be forced drying or heat drying. In this specification, the drying condition of less than 40 ° C. is room temperature drying, the drying condition of 40 ° C. or more and less than 80 ° C. is forced drying, and the drying condition of 80 ° C. or more is heat drying.

Hereinafter, the present invention will be described in more detail with reference to examples. “Parts” and “%” indicate “parts by mass” and “% by mass”.

Production of single-layer copolymer aqueous dispersion Synthesis Example 1
38.8 parts of water was charged into a 4 L four-necked flask equipped with a stirrer, a condenser, a temperature sensor, and a nitrogen blowing port, and the temperature was raised to 82 ° C. while stirring to maintain a nitrogen atmosphere. A monomer emulsion having the following composition was prepared in a separate container. Next, 0.3 part of the monomer emulsion and an aqueous initiator solution in which 0.10 part of ammonium persulfate was dissolved in 5.9 parts of deionized water were added to the flask and stirred for 30 minutes to disperse the seed particles in water. A liquid was obtained. Subsequently, the remaining monomer emulsion and an initiator aqueous solution in which 0.20 part of ammonium persulfate was dissolved in 10.8 parts of deionized water were simultaneously stirred for 2 hours while stirring so that the liquid in the flask was 82 ° C. The solution was added dropwise to the flask and aged at 82 ° C. for 1 hour after the completion of the addition. Next, the flask was cooled until the liquid in the flask became 40 ° C. or less, and neutralized with 0.4 part of 25% aqueous ammonia to obtain a copolymer aqueous dispersion (A1) having a solid content of 50%. The volume average particle size of the aqueous dispersion (A1) was 620 nm, the volume ratio of the particle group having a particle size of less than 300 nm to the total particle group was 0%, and the particle size distribution was 1.2. Moreover, resin Tg was 27.5 degreeC.
Monomer emulsion composition Methyl methacrylate 62.0 parts n-Butyl methacrylate 35.0 parts 2-Hydroxyethyl methacrylate 2.5 parts Acrylic acid 0.5 parts Deionized water 40.9 parts "Newcol 271-S" ( Note 1) 2.0 parts "Newcol 704" (Note 2) 1.0 part (Note 1) "Newcol 271-S": Nippon Emulsifier Co., Ltd., trade name, sodium alkyldiphenyl ether disulfonate, active ingredient 47%
(Note 2) “Newcol 704”: manufactured by Nippon Emulsifier Co., Ltd., trade name, polycyclic phenyl ether type nonionic emulsifier, active ingredient 100%.

Synthesis Examples 2-4
In the synthesis example 1, single-layer copolymer aqueous dispersions (A2) to (A4) were produced in the same manner as in the synthesis example 1 except that the monomer emulsion composition was changed to the following Table 1.

Solid content: The ratio of the mass when 2.0 g of a sample is collected and heated at 105 ° C. for 3 hours to the mass before heating.

Production synthesis example 5 of core-shell type copolymer aqueous dispersion
36.0 parts of water was charged into a 4 L four-necked flask equipped with a stirrer, a condenser, a temperature sensor, and a nitrogen blowing port, and the temperature was raised to 82 ° C. while stirring to maintain a nitrogen atmosphere. A core monomer emulsion having the following composition was prepared in a separate container. Next, 0.3 part of the core monomer emulsion and an initiator aqueous solution in which 0.10 part of ammonium persulfate was dissolved in 2.5 parts of deionized water were added to the flask and stirred for 30 minutes. An aqueous dispersion was obtained. Next, while stirring so that the liquid in the flask becomes 82 ° C., the remaining emulsion for core monomer and an aqueous initiator solution in which 0.14 part of ammonium persulfate was dissolved in 7.86 parts of deionized water were simultaneously applied for 2 hours. Then, each was dropped into the flask, and aged at 82 ° C. for 1 hour after the dropping was completed. Subsequently, a monomer emulsion for shell having the following composition and an aqueous initiator solution in which 0.06 part of ammonium persulfate was dissolved in 3.94 parts of deionized water were simultaneously added dropwise over 30 minutes and aged at 82 ° C. for 2 hours. After the flask was cooled until the liquid in the flask became 40 ° C. or lower, 25% ammonia water was neutralized with 0.4 part to obtain a copolymer aqueous dispersion (A5) having a solid content of 50%. The volume average particle size of the aqueous dispersion (A5) was 580 nm, the volume ratio of the particle group having a particle size of less than 300 nm to the total particle group was 0%, and the particle size distribution was 1.1. Moreover, resin Tg was 17.4 degreeC.
Monomer emulsion composition for core Methyl methacrylate 50.0 parts n-Butyl acrylate 18.0 parts 2-Hydroxyethyl methacrylate 2.0 parts Deionized water 32.0 parts "Newcol 271-S" (Note 1) 1 .4 parts "Newcol 704" (Note 2) 0.7 parts
Monomer emulsion composition for shell Methyl methacrylate 6.0 parts n-Butyl acrylate 23.0 parts 2-Hydroxyethyl methacrylate 0.5 parts Acrylic acid 0.5 parts Deionized water 13.7 parts “Newcol 271-S (Note 1) 0.6 part "Newcol 704" (Note 2) 0.3 part.

Synthesis Examples 6-8
Core-shell type copolymer aqueous dispersions (A6) to (A8) were produced in the same manner as in Synthesis Example 5 except that the composition of the monomer emulsion was changed to the following Table 2 in Synthesis Example 5.

(Note 3) “Newcol 707SF”: manufactured by Nippon Emulsifier Co., Ltd., trade name, sodium polyoxyethylene polycyclic phenyl ether sulfate, active ingredient 30%
(Note 4) “Newcol 293”: manufactured by Nippon Emulsifier Co., Ltd., trade name, monoalkyl succinate sulfonic acid disodium salt, active ingredient 40%.

Synthesis of polysiloxane-modified copolymer aqueous dispersion Synthesis Example 9
The aqueous copolymer dispersion (A5) obtained in Synthesis Example 5 was adjusted to a temperature of 25 ° C. and pH = 7.0 with ammonia. Methyltriethoxysilane was added to the resin solid content of 100 parts of the copolymer aqueous dispersion (A5) so as to be 10 parts and stirred at 25 ° C. for 1 hour. Thereafter, the temperature was raised to 70 ° C., and the mixture was stirred for 3 hours to obtain a polysiloxane-modified copolymer aqueous dispersion (A9) having a solid content of 50%. The volume average particle size of the aqueous dispersion (A9) was 600 nm, the volume ratio of the particle group having a particle size of less than 300 nm to the total particle group was 0%, and the particle size distribution was 1.3. Moreover, resin Tg was 17.7 degreeC.

Synthesis Example 10
38.8 parts of water was charged into a 4 L four-necked flask equipped with a stirrer, a condenser, a temperature sensor, and a nitrogen blowing port, and the temperature was raised to 82 ° C. while stirring to maintain a nitrogen atmosphere. A monomer emulsion having the following composition was prepared in a separate container. Next, 5.0 parts of the monomer emulsion and an aqueous initiator solution prepared by dissolving 0.10 parts of ammonium persulfate in 5.9 parts of deionized water are added to the flask and stirred for 30 minutes to obtain an aqueous dispersion of seed particles. Got. Next, the remaining monomer emulsion and an aqueous initiator solution in which 0.20 part of ammonium persulfate was dissolved in 10.8 parts of deionized water were simultaneously stirred for 2 hours while stirring so that the liquid in the flask was 82 ° C. The solution was added dropwise to the flask and aged at 82 ° C. for 1 hour after the completion of the addition. Next, the flask was cooled until the liquid in the flask became 40 ° C. or less, and neutralized with 0.4 part of 25% aqueous ammonia to obtain a copolymer aqueous dispersion (B1) having a solid content of 50%. The volume average particle diameter of the aqueous dispersion (B1) was 180 nm, the volume ratio of the particle group having a particle diameter of less than 300 nm to the total particle group was 97%, and the particle diameter distribution was 1.1. Moreover, resin Tg was 27.5 degreeC.
Monomer emulsion composition Methyl methacrylate 62.0 parts n-Butyl acrylate 35.0 parts 2-Hydroxyethyl methacrylate 2.5 parts Acrylic acid 0.5 parts Deionized water 41.7 parts "Newcol 707SF" (Note 3) ) 2.2 parts.

Synthesis Example 11
In Synthesis Example 10, a copolymer aqueous dispersion (B2) having a solid content of 50% was obtained in the same manner as in Synthesis Example 10 except that the monomer emulsion composition was changed to the following composition. The volume average particle size of the aqueous dispersion was 200 nm, the volume ratio of the particle group having a particle size of less than 300 nm to the total particle group was 94%, and the particle size distribution was 1.2. Moreover, resin Tg was 67.8 degreeC.
Monomer emulsion composition Methyl methacrylate 80.0 parts n-butyl acrylate 14.0 parts Diacetone acrylamide 5.0 parts 2-hydroxyethyl methacrylate 0.5 parts Acrylic acid 0.5 parts Deionized water 41.7 Part “Newcol 707SF” (Note 3) 2.2 parts.

Synthesis Example 12
36 parts of water was charged into a 4 L four-necked flask equipped with a stirrer, a cooling tube, a temperature sensor, and a nitrogen blowing port, and the temperature was raised to 82 ° C. while stirring, and kept in a nitrogen atmosphere. A core monomer emulsion having the following composition was prepared in a separate container. Next, 5 parts of the core monomer emulsion and an aqueous initiator solution in which 0.1 part of ammonium persulfate is dissolved in 2.5 parts of deionized water are added to the flask and stirred for 30 minutes to disperse the seed particles in water. A liquid was obtained. Next, while stirring so that the liquid in the flask becomes 82 ° C., the remaining emulsion for core monomer and an aqueous initiator solution in which 0.14 part of ammonium persulfate was dissolved in 7.86 parts of deionized water were simultaneously applied for 2 hours. Then, each was dropped into the flask and aged at 82 ° C. for 1 hour after the completion of dropping. Subsequently, a monomer emulsion for shell having the following composition and an aqueous initiator solution in which 0.06 part of ammonium persulfate was dissolved in 3.94 parts of deionized water were simultaneously added dropwise over 30 minutes and aged at 82 ° C. for 2 hours. After the flask was cooled until the liquid in the flask became 40 ° C. or lower, 25% aqueous ammonia was neutralized with 0.4 part to obtain a copolymer aqueous dispersion (B3) having a solid content of 50%. The volume average particle size of the aqueous dispersion was 220 nm, the volume ratio of the particle group having a particle size of less than 300 nm to the total particle group was 86%, and the particle size distribution was 1.2. Moreover, resin Tg was 12.4 degreeC.
Monomer emulsion composition for core Methyl methacrylate 10.0 parts Styrene 20.0 parts n-Butyl acrylate 37.5 parts 1,6-hexanediol diacrylate 2.5 parts 2-hydroxyethyl methacrylate 2.0 parts Deionized water 32.0 parts "Newcol 707SF" (Note 3) 5.0 parts
Monomer emulsion for shell Methyl methacrylate 6.0 parts n-butyl acrylate 23.0 parts 2-hydroxyethyl methacrylate 0.5 parts Acrylic acid 0.5 parts Deionized water 14.4 parts “Newcol 707SF” (Note) 3) 2.3 parts.

Synthesis Example 13
In Synthesis Example 12, a copolymer aqueous dispersion (B4) having a solid content of 50% was obtained in the same manner as in Synthesis Example 12 except that the monomer emulsion composition was changed to the following composition. The volume average particle size of the aqueous dispersion was 200 nm, the volume ratio of the particle group having a particle size of less than 300 nm to the total particle group was 95%, and the particle size distribution was 1.2. Moreover, resin Tg was 17.2 degreeC.
Monomer emulsion composition for core Methyl methacrylate 47.0 parts n-butyl acrylate 17.0 parts 1,6-hexanediol diacrylate 3.5 parts 2-hydroxyethyl methacrylate 2.0 parts diacetone acrylamide 5 parts Deionized water 32.0 parts "Newcol 707SF" (Note 3) 5.0 parts
Monomer emulsion composition for shell Methyl methacrylate 4.5 parts n-butyl acrylate 23.0 parts 2-hydroxyethyl methacrylate 0.5 parts diacetone acrylamide 1.5 parts acrylic acid 0.5 parts deionized water 14 4 parts "Newcol 707SF" (Note 3) 2.3 parts.

Synthesis Example 14
A reaction vessel equipped with a thermometer, a stirrer, a reflux condenser and a nitrogen inlet was charged with 20.05 parts of deionized water, and the temperature was raised to 80 ° C. in a nitrogen atmosphere. At 80 ° C., 0.45 part of ammonium persulfate was charged all at once, 20 minutes later, the following monomer emulsion was added dropwise over 4 hours, held for 60 minutes, and then cooled. Using aqueous ammonia and deionized water, the pH was adjusted to 8.1 and the solid content was adjusted to 50% to obtain a copolymer aqueous dispersion (B5). The volume average particle size of the aqueous dispersion was 600 nm, the volume ratio of the particle group having a particle size of less than 300 nm to the total particle group was 22%, and the particle size distribution was 2.2. Moreover, resin Tg was 27.5 degreeC.
Monomer emulsion composition Methyl methacrylate 62.0 parts n-Butyl methacrylate 35.0 parts 2-Hydroxyethyl methacrylate 2.5 parts Acrylic acid 0.5 parts Deionized water 17.5 parts "New Coal 293" ( Note 4) 1.88 parts “Hitenol N-08” (Note 5) 0.25 parts “Neugen EA-170S” (Note 6) 2.13 parts (Note 5) “Hitenol N-08”: Product name , Manufactured by Daiichi Kogyo Seiyaku Co., Ltd., polyoxyalkylene phenyl ether sulfate ammonium (Note 6) “Neugen EA-170S”: trade name, manufactured by Daiichi Kogyo Seiyaku Co., Ltd., polyoxyethylene nonylphenyl ether.

Examples 1-14 and Comparative Examples 1-5
Production of aqueous coating composition Each component shown below was charged in a container in order, and stirring was continued with a disper for 30 minutes until uniform, to obtain a pigment dispersion paste (A). Next, each component shown in Table 3 was sequentially added to 24.3 parts of the pigment-dispersed paste (A) and stirred with a disper until uniform, and each of the aqueous coating compositions (C1) to (C14) and (D1) To (D5) were obtained.
Pigment dispersion paste (A) Composition Water supply 6.0 parts Ethylene glycol 2.0 parts "SN thickener 601" (Note 7) 0.2 parts "SN Dispersant 5468" (Note 8) 0.5 parts "SN Defarmer A63" (Note 9) 0.6 parts Calcium carbonate 5.0 parts "JR-605" (Note 10) 10.0 parts (Note 7) "SN thickener 601": Trade name, manufactured by San Nopco, Polyether-based anti-settling agent (Note 8) “SN Dispersant 5468”: trade name, manufactured by San Nopco, pigment dispersant (Note 9) “SN Defermer A-63”: trade name, manufactured by San Nopco, antifoaming agent (Note 10) “JR-605”: trade name, manufactured by Teika, titanium dioxide, average particle size 250 nm
Comparative Example 6
In the pigment dispersion paste (A), a pigment dispersion paste (B) having the same composition as that of the pigment dispersion paste (A) was prepared except that the anti-settling agent “SN thickener 601” was not included. Subsequently, each component shown in Table 3 was sequentially added to 24.1 parts of the pigment dispersion paste (B) and stirred until it became uniform with a disper to obtain an aqueous coating composition (D6) containing no anti-settling agent.

(Note 11) “VPLS2319”: trade name, manufactured by Bayer, water dispersible polyisocyanate, isocyanate value 18, active ingredient 100%
(Note 12) “Nopcoside SN-135”: trade name, manufactured by San Nopco, antiseptic / antifungal agent (Note 13) “SN thickener 618”: trade name, manufactured by San Nopco, polyacrylic acid anti-settling agent.

Evaluation test 1. Paint and paint test (* 1) Storage stability 1 kg of each aqueous paint composition was put into an inner-coated can with a capacity of 1 L, sealed with nitrogen, and stored at 40 ° C. for 30 days. Then, it returned to room temperature, the state in a container was observed visually, and the following reference | standard evaluated.
○: There is no significant thickening, pigment sedimentation, and resin separation / precipitation.
×: Among the above, there is one that does not correspond.
(* 2) Coating workability "Eco-cation sealer" (manufactured by Kansai Paint Co., Ltd., acrylic emulsion-based cationic aqueous sealer) is applied to a 70 x 150 x 5 mm slate plate arranged vertically, and each aqueous coating composition is applied. After adjusting the viscosity by adding clean water, it was painted with a brush so that the coating amount was about 0.15 Kg / m ² and visually evaluated according to the following criteria.
○: No sagging and good finish Δ: Sagging is partially observed and the finish is inferior ×: Sagging is seen and the finish is extremely inferior

2. Coating film test
Preparation of test coating plate "Eco-cation sealer" (manufactured by Kansai Paint Co., Ltd., acrylic emulsion-based cationic aqueous sealer) is applied to a slate plate of 70 x 150 x 5 mm, and viscosity is adjusted by adding clean water to each aqueous coating composition. After coating, the coating was applied with a brush so that the coating amount was about 0.15 Kg / m ^2, and after 24 hours, the coating was performed again in the same manner. After the coating, each test coating plate was obtained by leaving it in a constant temperature room at 20 ° C. for 2 weeks.

(* 3) Gloss The 60 ° gloss of each test coated plate was measured. The higher the value, the higher the gloss.
(* 4) Water resistance The test coating plate was immersed in clean water, and the state after 10 days was visually observed. The case where there was no abnormality in the coating film was rated as ◯, and the case where swelling was generated was marked as x.
(* 5) Alkali resistance The test coating plate was immersed in a saturated potassium hydroxide aqueous solution at 23 ° C., and the state after 7 days was visually observed. The case where there was no abnormality in the coating film was rated as ◯, and the case where swelling was generated was marked as x.

(* 6) Weather resistance Each test coated plate is immersed in 20 ± 2 ° C. water for 18 hours, cooled at −20 ° C. for 3 hours, and then heated at 50 ° C. for 3 hours. After repeating this operation of 24 hours as one cycle 10 times, the 60 ° gloss of each test coated plate was measured, and the gloss retention rate (%) with respect to the initial 60 ° gloss value was calculated. The higher the value, the better.
(* 7) For each water-borne paint composition, two test coating plates were prepared. One of these was used for exposure, and the other was used for recording. The test coated plate for exposure was attached to an exposed plate at 30 ° south surface in the Kansai Paint Tokyo office, taken out after 6 months, and the color difference ΔE with the test plate for recording was measured. A smaller value means better.
(* 8) “Eco-cation sealer” (acrylic emulsion-based cationic aqueous sealer manufactured by Kansai Paint Co., Ltd.) is applied to a 70 × 150 × 5 mm slate plate, and each aqueous coating composition is applied with a mastic roller. The concavo-convex pattern was applied so that the coating amount was 1.0 kg / m ² . After 24 hours, each water-based coating composition was further diluted with clean water, and then applied with a brush so that the coating amount was about 0.15 Kg / m ² to obtain each test coating plate having a concavo-convex pattern. It observed from the place 1 meter away from the coating board, and evaluated by the following reference | standard.
○: Uneven pattern is clear and easily visible, Δ: Uneven pattern is unclear but visible, x: Uneven pattern is not visible

Claims (9)

Copolymer aqueous dispersion (A) and anti-settling agent (B) in which copolymer particle groups having a volume average particle size in the range of 350 to 1500 nm and a particle size distribution of less than 2.0 are dispersed. An aqueous coating composition comprising: a coating film formed from the aqueous coating composition, wherein the elongation at break in a 20 ° C. atmosphere is in the range of 50 to 1000%. The aqueous coating composition according to claim 1, wherein the volume fraction of the copolymer particles having a particle diameter of less than 300 nm in the aqueous copolymer dispersion (A) is 30% or less. The aqueous coating composition according to claim 1 or 2, wherein the monomer component forming the copolymer particles of the aqueous copolymer dispersion (A) contains a carbonyl group-containing polymerizable unsaturated monomer as a part thereof. The aqueous coating composition according to any one of claims 1 to 3, wherein the aqueous copolymer dispersion (A) comprises polysiloxane-modified copolymer particles obtained by modifying copolymer particles with polysiloxane. The aqueous coating composition according to any one of claims 1 to 4, wherein the glass transition temperature of the resin of the aqueous copolymer dispersion (A) is in the range of -50 to 120 ° C. The copolymer aqueous dispersion (C) in which a copolymer particle group having a volume average particle diameter of 50 nm or more and less than 350 nm is further dispersed, according to any one of claims 1 to 5. Water-based paint composition. The ratio of the total volume of the copolymer particle group a having a particle diameter of less than 300 nm to the total volume of the copolymer particle group b having a particle diameter of 300 nm or more and less than 2000 nm is 3/97 to 99 in terms of a / b volume ratio. The water-based coating composition according to claim 6, which is within the range of / 1. A coating method for coating the surface to be coated with the aqueous coating composition according to any one of claims 1 to 7. A coated article obtained by the coating method according to claim 8.