JP6624863B2 - Resin emulsion for paint - Google Patents

Description

  The present invention relates to a resin emulsion for paint. More specifically, the present invention is, for example, a resin emulsion for paints that can be suitably used as an overcoat paint called a top coat that is applied to the surface of building interiors and exteriors, ceramic building materials, and the like. The present invention relates to a production method thereof, and a topcoat containing the resin emulsion for a paint.

  In recent years, in order to avoid environmental problems due to the release of volatile organic compounds into the atmosphere, water-based paints containing water-dispersible resins such as water-soluble resins and emulsions have been used. However, water-based paints have a technical problem that they are generally inferior in water resistance, weather resistance, etc. as compared with organic solvent-based paints due to using water as a solvent.

  As an aqueous coating composition excellent in weather resistance and water resistance, an aqueous coating composition in which multi-layer particles having a core portion and a shell portion made of an acrylic polymer having a specific glass transition temperature are dispersed in water (for example, Patent Reference 1) has been proposed.

  However, although the aqueous coating composition has some weather resistance and water resistance, further improvement in weather resistance and water resistance is desired.

  As a coating resin composition for forming a coating film having excellent weather resistance, water resistance and extensibility, it contains a resin emulsion obtained by emulsion-polymerizing a monomer component, and contains emulsion particles contained in the resin emulsion. There has been proposed a coating resin composition in which the content of an acid group-containing monomer in a monomer component used as a raw material is 0.3% by mass or less (for example, see Patent Document 2). Since the resin composition for coatings has excellent weather resistance, water resistance and elongation, it can be suitably used, for example, as a top coating.

  However, in recent years, there has been a demand for the development of resin emulsions for coatings that form coating films that are entirely excellent in weather resistance, freezing and fluidity retention, extensibility, low-temperature film-forming stability, and heat deformation resistance.

JP 2002-138123 A JP 2014-031456 A

  The present invention has been made in view of the above prior art, and is a coating resin which forms a coating film having excellent overall weather resistance, freezing and fluidity retention, extensibility, low temperature film forming stability and heat deformation resistance. An object of the present invention is to provide an emulsion, a method for producing the emulsion, and a top coat containing the resin emulsion for a paint.

The present invention
(1) interior of the building, a top coat resin emulsion used in the sheath or the surface of the ceramic building materials in buildings, the inner layer, the intermediate layer and the outer layer contains an emulsion particles having at least three layers layer resin The inner layer is formed of a polymer obtained by polymerizing a monomer component for forming an inner layer containing 80 to 100% by mass of a styrene monomer and 0 to 20% by mass of a monomer other than the styrene monomer. The polymer constituting the intermediate layer has a glass transition temperature of −45 to 0 ° C., a mass ratio of the inner layer to the intermediate layer (inner layer / intermediate layer) of 10/90 to 90/10, and the emulsion particles total content of 30 to 90% by mass of the inner layer and the intermediate layer in is, the outer layer forming monomer components for forming the outer layer, the number of carbon atoms in the ester is C1-8 alkyl (meth ) Acrylate 80 A monomer component containing 100% by mass, 0 to 5% by mass of (meth) acrylic acid, and 0 to 15% by mass of an ultraviolet-stable monomer, and the glass transition temperature of the polymer constituting the outer layer is -35 to 35%. coating resin emulsion according to claim 40 ° C. der Rukoto,
(2) The content of the styrene monomer in all monomer components used as a raw material of the polymer constituting the emulsion particles is 10 to 50% by mass, and The resin emulsion for coating according to the above (1), wherein the content of the monomer is 50 to 90% by mass,
(3) The resin emulsion for a coating according to (1) or (2), wherein the content of the ultraviolet light-stable monomer in the monomer component for forming an outer layer is 2 to 15% by mass .
(4) a monomer component for forming an intermediate layer for forming an intermediate layer, wherein the ester has 80 to 100% by mass of an alkyl (meth) acrylate having 1 to 8 carbon atoms, and 0 to 15% by mass of styrene; The resin emulsion for a coating according to any one of the above (1) to (3), which is a monomer component containing 0 to 5% by mass of (meth) acrylic acid,
(5) The monomer other than the styrene-based monomer used for the inner layer-forming monomer component is formed from an alkyl (meth) acrylate and a (meth) acrylic acid in which the ester has 1 to 8 carbon atoms. The resin emulsion for paint according to any one of the above (1) to (4), which is at least one kind of monomer selected from the group consisting of:
(6) An overcoat paint comprising the resin emulsion for a paint as described in any of (1) to ( 5 ) above,
( 7 ) A method for producing a resin emulsion for a topcoat paint used on the interior of a building, the exterior of a building, or the surface of a ceramic building material , wherein the resin emulsion comprises at least three resin layers of an inner layer, an intermediate layer, and an outer layer. Containing emulsion particles having a styrene-based monomer of 80 to 100% by mass and a monomer component for forming an inner layer containing 0 to 20% by mass of a monomer other than the styrene-based monomer to form an inner layer. The inner layer is formed such that the mass ratio of the inner layer and the intermediate layer (inner layer / intermediate layer) is 10/90 to 90/10, and the total content of the inner layer and the intermediate layer in the emulsion particles is 30 to 90% by mass. after the glass transition temperature to form an intermediate layer which is -45～0 ° C. above carbon atoms carbon atoms in the ester as monomer component for the outer layer forming for forming the outer layer in forming the outer layer The outer layer is constituted by using a monomer component containing 80 to 100% by mass of alkyl (meth) acrylate, 0 to 8% by mass, 0 to 5% by mass of (meth) acrylic acid, and 0 to 15% by mass of a UV-stable monomer. method for producing a coating resin emulsion which is characterized that you adjust the glass transition temperature -35～40 ° C. of the polymer to be related.

  ADVANTAGE OF THE INVENTION According to this invention, the resin emulsion for paints which forms the coating film excellent in weather resistance, freeze-flow retention property, elongation, low-temperature film-forming stability, and heat-resistant deformation property comprehensively is provided. Further, according to the invention of the present application, there is provided a topcoat paint which forms a coating film which is totally excellent in weather resistance, freezing and fluidity retention, extensibility, low-temperature film-forming stability and heat deformation resistance.

  In general, when a resin layer obtained by polymerizing a monomer component containing a styrene-based monomer at a content of 50% by weight or more to emulsion particles contained in a resin emulsion used for a top coat is used. The coating film formed is inferior in weather resistance and film forming property as described in JP-A-7-70513 and the like, and is hard and brittle. It is considered unfavorable to include a styrene monomer in a content of 50% by weight or more in the resulting monomer component.

  On the other hand, in the present invention, a polymer composed of a monomer component containing a styrene-based monomer at a content of more than 50% by mass and not less than 80% by mass is used for the resin layer of the emulsion particles. Nevertheless, it is possible to form a coating film which is totally excellent in weather resistance, freeze-flow retention, elongation, low-temperature film-forming stability, and heat deformation resistance. As described above, in the resin emulsion of the present invention, a polymer composed of a monomer component containing a styrene-based monomer at a content of more than 50% by mass and not less than 80% by mass is used for the resin layer of the emulsion particles. It is possible to form a coating film that is totally excellent in weather resistance, freezing and fluidity retention, extensibility, low-temperature film formation stability and heat deformation resistance. is there.

  As described above, the coating resin emulsion of the present invention contains emulsion particles having at least three resin layers of an inner layer, an intermediate layer, and an outer layer.

  The resin emulsion for paint of the present invention is obtained by polymerizing a monomer component whose inner layer contains 80 to 100% by mass of a styrene monomer and 0 to 20% by mass of a monomer other than the styrene monomer. The glass transition temperature of the polymer formed of the polymer and constituting the intermediate layer is −45 to 0 ° C., and the mass ratio between the inner layer and the intermediate layer (inner layer / intermediate layer) is 10/90 to 90/10. The total content of the inner layer and the intermediate layer in the emulsion particles is 30 to 90% by mass.

  In the present invention, layers other than the inner layer, the intermediate layer, and the outer layer may be formed on the emulsion particles as long as the object of the present invention is not hindered. Therefore, in the present invention, for example, an inner layer may be further formed inside the inner layer, another resin layer may be formed between the inner layer and the intermediate layer, and between the intermediate layer and the outer layer. May be formed with another resin layer, or an outer layer may be further formed outside the outer layer.

  The polymer forming the inner layer is emulsion polymerized with an inner layer forming monomer component containing 80 to 100% by mass of a styrene-based monomer and 0 to 20% by mass of a monomer other than the styrene-based monomer. Obtained by:

  The content of the styrene-based monomer in the monomer component for forming the inner layer is from the viewpoint of forming a coating film that is totally excellent in weather resistance, freezing and fluidity retention, extensibility, low-temperature film formation stability and heat deformation resistance. From 80 to 100% by mass, preferably 85 to 100% by mass, more preferably 90 to 100% by mass. Therefore, the monomer component for forming the inner layer may be composed of only the styrene monomer. In addition, the monomer component for forming the inner layer forms a coating film having excellent weather resistance, freezing and fluidity retention, extensibility, low-temperature film formation stability, and heat deformation resistance. Preferably, a monomer other than the styrene monomer may be contained in the range of 0 to 15% by mass, more preferably 0 to 10% by mass.

  The styrene monomer means a monomer having a styrene skeleton. Examples of the styrene-based monomer include, for example, styrene, α-methylstyrene, p-methylstyrene, tert-butylstyrene, chlorostyrene, vinyltoluene, and the like, but the present invention is limited to only such examples. is not. These monomers may be used alone or in combination of two or more. Styrene monomers have a benzene ring having an alkyl group such as a methyl group and a tert-butyl group, a nitro group, a nitrile group, an alkoxyl group, an acyl group, a sulfone group, a hydroxyl group, and a functional group such as a halogen atom. You may. Of the styrene monomers, styrene is preferred from the viewpoint of improving the weather resistance of the coating film.

  Examples of the monomer other than the styrene-based monomer include an ethylenically unsaturated monomer other than the styrene-based monomer.

  Examples of the ethylenically unsaturated monomer other than the styrene monomer include, for example, an aromatic monomer other than the styrene monomer and an ethylenically unsaturated monomer other than the aromatic monomer. These monomers may be used alone or in combination of two or more.

  Examples of the aromatic monomer other than the styrene monomer include aralkyl (meth) acrylate. Examples of the aralkyl (meth) acrylate include aralkyl having an aralkyl group having 7 to 18 carbon atoms, such as benzyl (meth) acrylate, phenylethyl (meth) acrylate, methylbenzyl (meth) acrylate, and naphthylmethyl (meth) acrylate. Examples include (meth) acrylate, but the present invention is not limited to only such examples. These monomers may be used alone or in combination of two or more.

  In this specification, “(meth) acrylate” means “acrylate” or “methacrylate”, and “(meth) acryl” means “acryl” or “methacryl”.

  Examples of the ethylenically unsaturated monomer other than the aromatic monomer include, for example, an ethylenically unsaturated aliphatic monomer, an ethylenically unsaturated alicyclic structure-containing monomer, and the like. However, the present invention is not limited to only such an example.

  Specific examples of the ethylenically unsaturated monomer other than the aromatic monomer include, for example, alkyl (meth) acrylate, hydroxyl group-containing (meth) acrylate, carboxyl group-containing monomer, carbonyl group-containing monomer, and oxo group. Examples include a group-containing monomer, a fluorine atom-containing monomer, a nitrogen atom-containing monomer, and an epoxy group-containing monomer, but the present invention is not limited only to such examples. These monomers may be used alone or in combination of two or more.

  Examples of the alkyl (meth) acrylate include methyl (meth) acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, tert-butyl (meth) acrylate, and sec-butyl (meth). Alkyl having 1 to 18 carbon atoms in an ester group such as acrylate, 2-ethylhexyl (meth) acrylate, tridecyl (meth) acrylate, cyclohexyl (meth) acrylate, n-octyl (meth) acrylate, and n-lauryl (meth) acrylate. Examples include (meth) acrylate, but the present invention is not limited to only such examples. These monomers may be used alone or in combination of two or more. Among these alkyl (meth) acrylates, from the viewpoint of forming a coating film that is totally excellent in weather resistance, freeze fluidity retention, extensibility, low-temperature film-forming stability and heat deformation resistance, the carbon number of the ester group is high. Is preferably an alkyl (meth) acrylate having 1 to 8;

  Examples of the hydroxyl group-containing (meth) acrylate include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, and 4-hydroxy. Examples thereof include a hydroxyl group-containing (meth) acrylate having 1 to 18 carbon atoms in an ester group such as butyl (meth) acrylate, but the present invention is not limited to such examples. These monomers may be used alone or in combination of two or more.

  Examples of the carboxyl group-containing monomer include carboxyl group-containing aliphatic monomers such as (meth) acrylic acid, maleic acid, fumaric acid, crotonic acid, itaconic acid, and maleic anhydride. The invention is not limited to only such examples. These monomers may be used alone or in combination of two or more. Among these carboxyl group-containing monomers, acrylic acid, methacrylic acid and itaconic acid are preferable, and acrylic acid and methacrylic acid are more preferable from the viewpoint of improving the dispersion stability of the emulsion particles.

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

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

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

  Examples of the nitrogen atom-containing monomer include, for example, acrylamide compounds such as (meth) acrylamide, N, N-dimethylaminopropylacrylamide, diacetone acrylamide, and nitrogen such as dimethylaminoethyl (meth) acrylate and diethylaminoethyl (meth) acrylate. Examples include an atom-containing (meth) acrylate compound, N-vinylpyrrolidone, and the like, but the present invention is not limited to only such examples. These monomers may be used alone or in combination of two or more.

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

  Accordingly, examples of the monomer other than the styrene monomer include, for example, an aromatic monomer other than the styrene monomer, an alkyl (meth) acrylate, a hydroxyl group-containing (meth) acrylate, and a carboxyl group-containing monomer. , An oxo group-containing monomer, a fluorine atom-containing monomer, a nitrogen atom-containing monomer, an epoxy group-containing monomer, and the like. These monomers may be used alone or in combination of two. The above may be used in combination.

  Among monomers other than styrene-based monomers, from the viewpoint of forming a coating film that is totally excellent in weather resistance, freezing and fluidity retention, extensibility, low-temperature film formation stability and heat deformation resistance, styrene-based Ethylenically unsaturated monomers other than monomers are preferred, alkyl (meth) acrylate and (meth) acrylic acid are more preferred, and alkyl (meth) acrylate and (meth) acrylate having 1 to 8 carbon atoms in the ester. ) Acrylic acid is more preferred, and methyl (meth) acrylate, tert-butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate and (meth) acrylic acid are even more preferred.

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

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

  Examples of the anionic emulsifier include alkyl sulfate salts such as ammonium dodecyl sulfate and sodium dodecyl sulfate; alkyl sulfonate salts such as ammonium dodecyl sulfonate and sodium dodecyl sulfonate; alkyl aryl sulfonate salts such as ammonium dodecyl benzene sulfonate and sodium dodecyl naphthalene sulfonate; Polyoxyethylene alkyl sulfate salts; polyoxyethylene alkyl aryl sulfate salts; dialkyl sulfosuccinate salts; aryl sulfonic acid-formaldehyde condensates; fatty acid salts such as ammonium laurate and sodium stearylate; It is not limited only to the illustration.

  Nonionic emulsifiers include, for example, polyoxyethylene alkyl ether, polyoxyethylene alkyl aryl ether, condensate of polyethylene glycol and polypropylene glycol, sorbitan fatty acid ester, polyoxyethylene sorbitan fatty acid ester, fatty acid monoglyceride, ethylene oxide and aliphatic Examples thereof include condensation products with amines, but the present invention is not limited only to such examples.

  Examples of the cationic emulsifier include an alkyl ammonium salt such as dodecyl ammonium chloride and the like, but the present invention is not limited only to such an example.

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

  Examples of the polymer emulsifier include poly (meth) acrylates such as sodium polyacrylate; polyvinyl alcohol; polyvinylpyrrolidone; polyhydroxyalkyl (meth) acrylates such as polyhydroxyethyl acrylate; Examples include copolymers having at least one of the monomers as a copolymer component, but the present invention is not limited to only such examples.

  As an emulsifier, an emulsifier having a polymerizable group, that is, a so-called reactive emulsifier, from the viewpoint of forming a coating film excellent in weather resistance, freezing fluidity retention, extensibility, low-temperature film-forming stability, and heat deformation resistance. Is preferable, and a non-nonylphenyl type emulsifier is preferable from the viewpoint of environmental protection.

  As the reactive emulsifier, for example, a propenyl-alkyl sulfosuccinate salt, a (meth) acrylic acid polyoxyethylene sulfonate salt, a (meth) acrylic acid polyoxyethylene phosphonate salt [for example, manufactured by Sanyo Chemical Industries, Ltd .; Trade name: Eleminol RS-30, etc.), polyoxyethylene alkylpropenyl phenyl ether sulfonate salt (eg, manufactured by Daiichi Kogyo Seiyaku Co., Ltd., trade name: Aqualon HS-10, etc.), and allyloxymethyl alkyloxy polyoxyethylene Sulfonate salt (eg, manufactured by Daiichi Kogyo Seiyaku Co., Ltd., trade name: Aqualon KH-10 etc.), sulfonate salt of allyloxymethylnonylphenoxyethylhydroxypolyoxyethylene [eg, manufactured by ADEKA Corporation, trade name: Adeka Rear soap SE-10 Allyloxymethylalkoxyethyl hydroxy polyoxyethylene sulfate [eg, manufactured by ADEKA, trade name: Adecaria Soap SR-10, SR-30, etc.], bis (polyoxyethylene polycyclic phenyl ether) Methacrylated sulfonate salt (eg, manufactured by Nippon Emulsifier Co., Ltd., trade name: Antox MS-60, etc.), allyloxymethylalkoxyethylhydroxypolyoxyethylene [eg, manufactured by ADEKA Corporation, trade name: Adecaria Soap ER -20, etc.), polyoxyethylene alkylpropenyl phenyl ether [eg, manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd., trade name: Aqualon RN-20, etc.], allyloxymethyl nonylphenoxyethyl hydroxy polyoxyethylene [eg, Co., Ltd.] Made by ADEKA Name: Adeka such REASOAP NE-10) but the like, the present invention is not limited only to those exemplified.

  The amount of the emulsifier per 100 parts by mass of the inner layer forming monomer component is preferably 0.5 parts by mass or more, more preferably 1 part by mass or more, and still more preferably 2 parts by mass or more, from the viewpoint of improving polymerization stability. And still more preferably 3 parts by mass or more, and preferably 10 parts by mass from the viewpoint of forming a coating film which is totally excellent in weather resistance, freezing fluidity retention, extensibility, low-temperature film-forming stability and heat deformation resistance. Parts by mass, more preferably 8 parts by mass or less, still more preferably 6 parts by mass or less, still more preferably 5 parts by mass or less.

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

  The amount of the polymerization initiator per 100 parts by mass of the inner layer forming monomer component is preferably 0.05 part by mass, from the viewpoint of increasing the polymerization rate and reducing the remaining amount of the unreacted inner layer forming monomer component. As described above, the amount is more preferably 0.1 part by mass or more, and preferably 1 part by mass or less, more preferably 0.5 part by mass or less from the viewpoint of improving the water resistance of the coating film.

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

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

  In the reaction system, if necessary, for example, an additive such as a chain transfer agent such as a compound having a thiol group such as tert-dodecyl mercaptan, a pH buffer, a chelating agent, and a film-forming auxiliary may be added. Good. Since the amount of the additive varies depending on the type thereof, it cannot be determined unconditionally, but is usually preferably 0.01 to 5 parts by mass, more preferably 0.1 to 5 parts by mass, per 100 parts by mass of the inner layer forming monomer component. 1 to 3 parts by mass.

  The atmosphere in which the inner layer forming monomer component is emulsion-polymerized is not particularly limited, but is preferably an inert gas such as a nitrogen gas or an argon gas from the viewpoint of increasing the efficiency of the polymerization initiator.

  The polymerization temperature at the time of emulsion polymerization of the monomer component for forming the inner layer is not particularly limited, but is usually preferably 50 to 100 ° C, more preferably 60 to 95 ° C. The polymerization temperature may be constant or may be changed during the polymerization reaction.

  The polymerization time for emulsion-polymerizing the inner layer-forming monomer component is not particularly limited and may be appropriately set according to the progress of the polymerization reaction, and is usually about 2 to 9 hours.

  By emulsion-polymerizing the monomer component for forming the inner layer as described above, the polymer for forming the inner layer is obtained in the form of emulsion particles.

  The polymer forming the inner layer may have a crosslinked structure. The weight-average molecular weight of the polymer forming the inner layer is determined in terms of improving the water permeability of the coating film, regardless of whether the polymer forming the inner layer has a crosslinked structure or not. Therefore, it is preferably 100,000 or more, more preferably 300,000 or more, further preferably 550,000 or more, and particularly preferably 600,000 or more. The upper limit of the weight average molecular weight of the polymer forming the inner layer is not particularly limited because it is difficult to measure the weight average molecular weight when the polymer has a crosslinked structure. From the viewpoint of improving the properties, the content is preferably 5,000,000 or less.

  In the present specification, the weight average molecular weight is determined by gel permeation chromatography [manufactured by Tosoh Corporation, product number: HLC-8120GPC, column: TSKgel G-5000HXL and TSKgel GMHXL-L are used in series]. Means the weight average molecular weight (in terms of polystyrene) measured by the above method.

  Next, after forming emulsion particles made of a polymer constituting the inner layer, an intermediate layer is formed on the surface of the emulsion particles. The intermediate layer can be formed on the surface of the emulsion particles composed of the polymer constituting the inner layer by emulsion-polymerizing the monomer component for forming the intermediate layer in the presence of the emulsion particles.

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

  In addition, after forming the inner layer and before forming the intermediate layer, a layer made of another polymer may be formed as needed, as long as the object of the present invention is not hindered. Therefore, in the coating resin emulsion of the present invention, after forming the inner layer, before forming the intermediate layer, if necessary, a layer made of another polymer is formed as long as the object of the present invention is not hindered. An operation for causing the operation to be performed may be included.

  As the monomer component for forming the intermediate layer, those exemplified for the monomer component for forming the inner layer can be used. Examples of the monomer component for forming an intermediate layer include an aromatic monomer, a monomer having an alicyclic structure, an alkyl (meth) acrylate, a hydroxyl-containing (meth) acrylate, a carboxyl-containing monomer, and oxo. Group-containing monomer, fluorine atom-containing monomer, nitrogen atom-containing monomer, epoxy group-containing monomer, alkoxyalkyl (meth) acrylate, silane group-containing monomer, carbonyl group-containing monomer, aziridinyl group Although the contained monomer etc. are mentioned, this invention is not limited only to such an illustration. These monomers may be used alone or in combination of two or more.

  Examples of the aromatic monomer include styrene monomers such as styrene, α-methylstyrene, p-methylstyrene, tert-butylstyrene, chlorostyrene, and vinyltoluene; benzyl (meth) acrylate, phenyl Examples thereof include aralkyl (meth) acrylates having an aralkyl group having 7 to 18 carbon atoms, such as ethyl (meth) acrylate, methylbenzyl (meth) acrylate, and naphthylmethyl (meth) acrylate. However, the present invention is not limited to this.

  Among the monomer components for forming the intermediate layer, from the viewpoint of forming a coating film having excellent weather resistance, freezing and fluidity retention, extensibility, low-temperature film formation stability and heat deformation resistance, ethylenically unsaturated. Monomers are preferable, alkyl (meth) acrylate, styrene and (meth) acrylic acid are more preferable, and alkyl (meth) acrylate, styrene and (meth) acrylic acid having 1 to 8 carbon atoms in the ester are further preferable. Preferably, methyl (meth) acrylate, tert-butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, styrene and (meth) acrylic acid are even more preferred.

  As a suitable intermediate layer forming monomer component from the viewpoint of forming a coating film excellent in weather resistance, freeze fluidity retention, extensibility, low-temperature film-forming stability and heat deformation resistance, for example, esters of Examples include a monomer component containing 80 to 100% by mass of an alkyl (meth) acrylate having 1 to 8 carbon atoms, 0 to 15% by mass of styrene, and 0 to 5% by mass of (meth) acrylic acid.

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

  Emulsion polymerization of the monomer component for forming the intermediate layer as described above can provide emulsion particles in which the polymer forming the intermediate layer is formed on the surface of the inner layer. Note that a layer made of another polymer may be formed on the surface of the intermediate layer, if necessary, as long as the object of the present invention is not hindered.

  The polymer forming the intermediate layer may have a crosslinked structure. The weight-average molecular weight of the polymer forming the intermediate layer is water-resistant, water-permeable and heat-resistant, regardless of whether the polymer forming the intermediate layer has a cross-linked structure or not. From the viewpoint of forming a coating film having excellent deformability, it is preferably 100,000 or more, more preferably 300,000 or more, further preferably 550,000 or more, and still more preferably 600,000 or more. The upper limit of the weight-average molecular weight of the polymer forming the intermediate layer is not particularly limited because it is difficult to measure the weight-average molecular weight when the polymer has a cross-linked structure. From the viewpoint of forming a coating film having excellent film formability and extensibility, the amount is preferably 5,000,000 or less.

  The glass transition temperature of the polymer forming the intermediate layer is -45 ° C or higher, preferably -40 ° C or higher, from the viewpoint of improving the weather resistance and heat deformation resistance of the coating film, and the low-temperature film-forming stability of the coating film. From the viewpoint of improving extensibility, the temperature is 0 ° C. or lower, preferably −5 ° C. or lower. The glass transition temperature of the polymer forming the intermediate layer can be easily adjusted by adjusting the composition of the monomer used for the monomer component for forming the intermediate layer.

In the present specification, the glass transition temperature of the polymer is calculated by using the glass transition temperature of the homopolymer of the monomer used for the monomer component constituting the polymer as follows:
1 / Tg = Σ (Wm / Tgm) / 100
[Wherein, Wm represents the content (% by weight) of the monomer m in the monomer components constituting the polymer, and Tgm represents the glass transition temperature (absolute temperature: K) of the homopolymer of the monomer m. ]
Means the temperature determined based on the Fox equation represented by

  The glass transition temperature of the polymer is, for example, 100 ° C. for a homopolymer of styrene, 105 ° C. for a homopolymer of methyl methacrylate, −70 ° C. for a homopolymer of 2-ethylhexyl acrylate, and 95% for a homopolymer of acrylic acid. C., 130 ° C. for a methacrylic acid homopolymer and 130 ° C. for a 4-methacryloyloxy-1,2,2,6,6-pentamethylpiperidine homopolymer.

  The glass transition temperature of the polymer is a value determined based on the Fox equation, and the measured value of the glass transition temperature of the polymer is determined based on the Fox equation. It is preferably the same as the value. The measured value of the glass transition temperature of the polymer can be determined, for example, by measuring its differential scanning calorimetry.

  In the present specification, the glass transition temperature of a polymer means a glass transition temperature determined based on the above formula unless otherwise specified. For monomers whose glass transition temperature is unknown, such as special monomers and polyfunctional monomers, the total amount of the monomers whose glass transition temperature is unknown in the monomer component is 10% by mass. In the following cases, the glass transition temperature is determined using only the monomer whose glass transition temperature is known. When the total amount of the monomers whose glass transition temperature is unknown in the monomer component exceeds 10% by mass, the glass transition temperature of the polymer is determined by differential scanning calorimetry (DSC), differential calorimetry (DTA), It is determined by thermomechanical analysis (TMA) or the like.

  As a differential scanning calorimeter measuring device, for example, Seiko Instruments Co., Ltd., product number: DSC220C and the like can be mentioned. When measuring the differential scanning calorific value, a method of drawing a differential scanning calorific value (DSC) curve, a method of obtaining a first derivative curve from a differential scanning caloric value (DSC) curve, a method of performing a smoothing process, and a method of determining a target peak temperature There is no particular limitation on the like. For example, when the measurement device is used, the drawing may be performed from data obtained by using the measurement device. At that time, analysis software capable of performing mathematical processing can be used. Examples of the analysis software include analysis software (manufactured by Seiko Instruments Inc., part number: EXSTAR6000), but the present invention is not limited to only such examples. Note that the peak temperature obtained in this manner may include an error due to drawing about 5 ° C. above and below.

  The mass ratio between the inner layer and the intermediate layer (inner layer / intermediate layer) is adjusted to be 10/90 to 90/10. The mass ratio between the inner layer and the intermediate layer (inner layer / intermediate layer) is determined from the viewpoint of forming a coating film that is totally excellent in weather resistance, freezing and fluidity retention, extensibility, low-temperature film formation stability and heat deformation resistance. 10/90 or more, preferably 20/80 or more, more preferably 30/70 or more, even more preferably 40/60 or more, weather resistance, freezing and fluidity retention, extensibility, low-temperature film-forming stability and heat deformation. It is 90/10 or less, preferably 80/20 or less, more preferably 70/30 or less, from the viewpoint of forming a coating film having excellent overall properties.

  The total content of the inner layer and the intermediate layer in the emulsion particles is 30% by mass from the viewpoint of forming a coating film having excellent weather resistance, freezing fluidity retention, extensibility, low-temperature film-forming stability and heat deformation resistance. % Or more, preferably 35% by mass or more, more preferably 40% by mass or more, and still more preferably 45% by mass or more, and is comprehensive in weather resistance, freezing and fluidity retention, extensibility, low-temperature film formation stability and heat deformation resistance. From the viewpoint of forming an excellent coating film, the content is 90% by mass or less, preferably 85% by mass or less, more preferably 80% by mass or less.

  Next, after forming emulsion particles having an intermediate layer, an outer layer is formed on the surface of the emulsion particles. The outer layer can be formed on the surface of the emulsion particles by emulsion-polymerizing the monomer component for forming the outer layer in the presence of the emulsion particles having the intermediate layer.

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

  In addition, after forming the intermediate layer and before forming the outer layer, a layer made of another polymer may be formed as needed, as long as the object of the present invention is not hindered. Therefore, in the coating resin emulsion of the present invention, after forming the intermediate layer, before forming the outer layer, if necessary, as long as the object of the present invention is not impaired, forming a layer made of another polymer An operation for causing the operation to be performed may be included.

  Examples of the outer layer-forming monomer component include, in addition to those exemplified as the intermediate layer-forming monomer component, an ultraviolet absorbing monomer, an ultraviolet stable monomer, and the like. However, the present invention is not limited to this. These monomers may be used alone or in combination of two or more.

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

  Examples of the benzotriazole-based UV-absorbing monomer include 2- [2'-hydroxy-5 '-(meth) acryloyloxymethylphenyl] -2H-benzotriazole and 2- [2'-hydroxy-5'- (Meth) acryloyloxyethylphenyl] -2H-benzotriazole, 2- [2′-hydroxy-5 ′-(meth) acryloyloxymethylphenyl] -5-tert-butyl-2H-benzotriazole, 2- [2 ′ -Hydroxy-5 '-(meth) acryloylaminomethyl-5'-tert-octylphenyl] -2H-benzotriazole, 2- [2'-hydroxy-5'-(meth) acryloyloxypropylphenyl] -2H-benzo Triazole, 2- [2'-hydroxy-5 '-(meth) acryloyloxyhexyl Phenyl] -2H-benzotriazole, 2- [2'-hydroxy-3'-tert-butyl-5 '-(meth) acryloyloxyethylphenyl] -2H-benzotriazole, 2- [2'-hydroxy-3' -Tert-butyl-5 '-(meth) acryloyloxyethylphenyl] -5-chloro-2H-benzotriazole, 2- [2'-hydroxy-5'-tert-butyl-3'-(meth) acryloyloxyethyl Phenyl] -2H-benzotriazole, 2- [2'-hydroxy-5 '-(meth) acryloyloxyethylphenyl] -5-chloro-2H-benzotriazole, 2- [2'-hydroxy-5'-(meta ) Acryloyloxyethylphenyl] -5-cyano-2H-benzotriazole, 2- [2′-hydrido) Xy-5 '-(meth) acryloyloxyethylphenyl] -5-tert-butyl-2H-benzotriazole, 2- [2'-hydroxy-5'-(β- (meth) acryloyloxyethoxy) -3'- tert-butylphenyl] -4-tert-butyl-2H-benzotriazole, and the like, but the present invention is not limited to only such examples. These benzotriazole-based UV-absorbing monomers may be used alone or in combination of two or more.

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

  Examples of the UV-stable monomer include 4- (meth) acryloyloxy-2,2,6,6-tetramethylpiperidine and 4- (meth) acryloylamino-2,2,6,6-tetramethylpiperidine 4- (meth) acryloyloxy-1,2,2,6,6-pentamethylpiperidine, 4- (meth) acryloyl-1-methoxy-2,2,6,6-tetramethylpiperidine, 4-cyano- 4- (meth) acryloyloxy-2,2,6,6-tetramethylpiperidine, 1- (meth) acryloyl-4- (meth) acryloylamino-2,2,6,6-tetramethylpiperidine, 4-croto Noylamino-2,2,6,6-tetramethylpiperidine, 4- (meth) acryloylamino-1,2,2,6,6-pentamethylpiperidine, 4-sia -4- (meth) acryloylamino-2,2,6,6-tetramethylpiperidine, 4-crotonoyloxy-2,2,6,6-tetramethylpiperidine, 1- (meth) acryloyl-4-cyano- Examples thereof include 4- (meth) acryloylamino-2,2,6,6-tetramethylpiperidine, 1-crotonoyl-4-crotonoyloxy-2,2,6,6-tetramethylpiperidine, and the present invention However, the present invention is not limited to only such an example. These UV-stable monomers may be used alone or in combination of two or more.

  More specifically, the outer layer-forming monomer component includes, for example, an aromatic monomer, a monomer having an alicyclic structure, an alkyl (meth) acrylate, a hydroxyl group-containing (meth) acrylate, and a carboxyl group-containing monomer. Monomer, oxo group-containing monomer, fluorine atom-containing monomer, nitrogen atom-containing monomer, epoxy group-containing monomer, alkoxyalkyl (meth) acrylate, silane group-containing monomer, carbonyl group-containing monomer Examples include monomers, aziridinyl group-containing monomers, UV-absorbing monomers, and UV-stable monomers, but the present invention is not limited to these examples. These monomers may be used alone or in combination of two or more.

  Among the monomer components for forming the outer layer, from the viewpoint of forming a coating film having excellent weather resistance, freezing and fluidity retention, extensibility, low-temperature film-forming stability and heat deformation resistance, ethylenically unsaturated monomer is preferred. Monomers, UV-absorbing monomers and UV-stable monomers are preferred, alkyl (meth) acrylates, (meth) acrylic acids, UV-absorbing monomers and UV-stable monomers are more preferred, Alkyl (meth) acrylates having 1 to 8 carbon atoms, (meth) acrylic acid and UV-stable monomers are more preferred, and methyl (meth) acrylate, tert-butyl (meth) acrylate, 2-ethylhexyl ( Even more preferred are (meth) acrylates, (meth) acrylic acids and UV-stable monomers. These monomers may be used alone or in combination of two or more.

  Suitable outer layer forming monomer components from the viewpoint of forming a coating film having excellent overall weather resistance, freezing and fluidity retention, extensibility, low-temperature film-forming stability and heat deformation resistance include, for example, ester carbon A monomer component containing 80 to 100% by mass of an alkyl (meth) acrylate having 1 to 8 carbon atoms, 0 to 5% by mass of (meth) acrylic acid and 0 to 15% by mass of a UV-stable monomer; Is mentioned.

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

  By emulsion-polymerizing the monomer component for forming the outer layer as described above, emulsion particles in which the polymer forming the outer layer is formed on the surface of the intermediate layer can be obtained. In addition, a resin layer made of another polymer may be formed on the surface of the outer layer, if necessary, as long as the object of the present invention is not hindered.

  The polymer forming the outer layer may have a crosslinked structure. The weight-average molecular weight of the polymer forming the outer layer is determined whether the polymer forming the outer layer has a cross-linked structure or has no cross-linked structure, regardless of whether the polymer has water resistance, water permeability and heat deformation resistance. From the viewpoint of forming an excellent coating film, it is preferably 100,000 or more, more preferably 300,000 or more, further preferably 550,000 or more, and still more preferably 600,000 or more. The upper limit of the weight average molecular weight of the polymer forming the outer layer is not particularly limited because it is difficult to measure the weight average molecular weight when the polymer has a crosslinked structure. From the viewpoint of forming a coating film having excellent film properties and extensibility, the content is preferably 5,000,000 or less.

  The glass transition temperature of the polymer forming the outer layer is preferably -35 from the viewpoint of forming a coating film which is totally excellent in weather resistance, freezing fluidity retention, extensibility, low-temperature film formation stability and heat deformation resistance. ° C or more, more preferably -25 ° C or more, still more preferably -15 ° C or more, and still more preferably 5 ° C or more, and is excellent in weather resistance, freeze-flow retention, extensibility, low-temperature film-forming stability and heat deformation resistance. From the viewpoint of forming an overall excellent coating film, the temperature is preferably 40 ° C or lower, more preferably 35 ° C or lower.

  The glass transition temperature of the polymer forming the outer layer can be easily adjusted by adjusting the composition of the monomer used for the monomer component for forming the outer layer.

  The content of the outer layer in the emulsion particles is preferably 10% by mass or more, and more preferably 10% by mass or more, from the viewpoint of forming a coating film excellent in weather resistance, freezing fluidity retention, extensibility, low-temperature film-forming stability and heat deformation resistance. It is 15% by mass or more, more preferably 20% by mass or more, 70% by mass or less, preferably 65% by mass or less, more preferably 60% by mass or less, and further preferably 55% by mass or less.

  The glass transition temperature of the whole emulsion particles is preferably 0 ° C. or higher, from the viewpoint of forming a coating film having excellent weather resistance, freezing fluidity retention, elongation, low-temperature film-forming stability and heat deformation resistance. It is preferably at least 5 ° C, more preferably at least 10 ° C, preferably at most 50 ° C, more preferably at most 45 ° C, even more preferably at most 40 ° C.

  The content of styrene-based monomer in all monomer components used as the raw material of the polymer that constitutes the emulsion particles depends on the weather resistance, freezing fluidity retention, extensibility, low-temperature film-forming stability and heat resistance. From the viewpoint of forming a coating film having excellent overall deformability, the content is preferably 10% by mass or more, more preferably 15% by mass or more, and still more preferably 20% by mass or more. From the viewpoint of forming a coating film having excellent overall properties, low-temperature film-forming stability and heat deformation resistance, the content is preferably 50% by mass or less, more preferably 45% by mass or less. Further, the content of monomers other than the styrene-based monomer in all the monomer components used as a raw material of the polymer constituting the emulsion particles is weather resistance, freezing fluidity retention, extensibility, It is preferably at least 50% by mass, more preferably at least 55% by mass from the viewpoint of forming a coating film having excellent low-temperature film-forming stability and heat deformation resistance, and has weather resistance, freezing fluidity retention, and elongation. From the viewpoint of forming a coating film having excellent overall low-temperature film formation stability and heat deformation resistance, the content is preferably 90% by mass or less, more preferably 85% by mass or less, and further preferably 80% by mass or less.

  The resin emulsion for paint of the present invention contains the emulsion particles prepared as described above.

  The content of the non-volatile components in the resin emulsion for a coating material of the present invention is preferably 30% by mass or more, more preferably 40% by mass or more, from the viewpoint of improving the productivity, and preferably from the viewpoint of improving the handleability. 70 mass% or less, more preferably 60 mass% or less.

In the present specification, the content of non-volatile components in the resin emulsion for coating is determined by weighing 1 g of the resin emulsion for coating and drying it at a temperature of 110 ° C. for 1 hour with a hot-air drier to obtain a residue as a non-volatile component. ,formula:
[Content of nonvolatile components in resin emulsion for paints (% by mass)]
= ([Mass of residue] ÷ [resin emulsion for paint 1 g]) × 100
Means the value obtained based on

  From the viewpoint of improving the storage stability of the emulsion particles, the average particle size of the emulsion particles is preferably 30 nm or more, more preferably 50 nm or more, and still more preferably 70 nm or more. From the viewpoint of forming an excellent coating film, the thickness is preferably 250 nm or less, more preferably 200 nm or less. Emulsion particles prepared by the above method usually have the average particle size.

  In the present specification, the average particle size of the emulsion particles is measured using a particle size distribution analyzer (Particle Sizing Systems, Inc., product name: NICOMP Model 380) by a dynamic light scattering method. Mean volume average particle size.

  The minimum film-forming temperature of the resin emulsion for paints of the present invention is preferably -5 ° C or higher, more preferably 5 ° C or higher, and still more preferably 20 ° C or higher, from the viewpoint of increasing the hardness of the coating film. From the viewpoint of performing the heating, the temperature is preferably 70 ° C. or lower, more preferably 65 ° C. or lower, and further preferably 60 ° C. or lower.

  In this specification, the minimum film-forming temperature of the resin emulsion for coating is determined by coating the resin emulsion for coating with an applicator on a glass plate placed on a thermal gradient tester so that the thickness becomes 0.2 mm. Temperature at which cracks occur.

  The resin emulsion for paint of the present invention may contain other resin emulsions other than the resin emulsion for paint as long as the object of the present invention is not hindered.

  The resin emulsion for paint of the present invention obtained as described above has at least three resin layers of an inner layer, an intermediate layer and an outer layer, and the inner layer is composed of 80 to 100% by mass of the styrene monomer and the styrene monomer. Is formed of a polymer obtained by polymerizing a monomer component containing 0 to 20% by mass of a monomer other than the monomer, and a glass transition temperature of the polymer constituting the intermediate layer is −45 to 0 ° C. Since the mass ratio between the inner layer and the intermediate layer (inner layer / intermediate layer) is 10/90 to 90/10 and the total content of the inner layer and the intermediate layer in the emulsion particles is 30 to 90% by mass, It forms a coating film that is totally superior in heat resistance, freezing fluidity retention, extensibility, low temperature film forming stability and heat deformation resistance, so it can be applied to the interior and exterior of buildings, surfaces of ceramic building materials, etc. The top coat is called Ri paint (water-based paint) can be suitably used, for example.

  The resin emulsion for paints of the present invention may be, for example, an ultraviolet absorber, an ultraviolet stabilizer, a filler, a leveling agent, a dispersant, a thickener, a wetting agent, a plasticizer, or a stabilizer within a range in which the object of the present invention is not hindered. Additives such as agents, pigments, dyes, and antioxidants may be included in appropriate amounts.

  The resin emulsion for a paint of the present invention can be used as it is as a top coat as it is. However, if necessary, it can be used as a top coat by mixing with other components.

  The overcoat paint contains the resin emulsion for paint. The top coating composition of the present invention may be composed of only the resin emulsion for the coating composition, and within a range in which the object of the present invention is not impaired, for example, a film forming aid, a plasticizer, a foam inhibitor, a pigment, and a thickener. Even if it contains one or more of agents, matting agents, dispersants, wetting agents, ultraviolet absorbers, ultraviolet stabilizers, fillers, leveling agents, stabilizers, pigments, dyes, antioxidants, etc. Good. Examples of the overcoat paint include an enamel paint and a clear paint.

  When the resin emulsion for a paint of the present invention is used in an aqueous paint, crosslinking properties can be imparted by including a crosslinking agent. The crosslinking agent may be one that starts a crosslinking reaction at room temperature or one that starts a crosslinking reaction by heat. By including a crosslinking agent in the resin emulsion for coating of the present invention, the water resistance and the water resistance can be improved.

  Suitable crosslinking agents include, for example, oxazoline group-containing compounds, hydrazine compounds, isocyanate group-containing compounds, aminoplast polymers, and the like. These crosslinking agents may be used alone or in combination of two or more. Among these crosslinking agents, oxazoline group-containing compounds are preferred from the viewpoint of forming a coating film having excellent water resistance and water permeability.

  The oxazoline group-containing compound is a compound having two or more oxazoline groups in a molecule capable of reacting with a carboxyl group as a functional group of a carboxyl group-containing monomer used as a monomer component.

  Examples of the oxazoline group-containing compound include, for example, 2,2′-bis (2-oxazoline), 2,2′-methylene-bis (2-oxazoline), 2,2′-ethylene-bis (2-oxazoline), , 2'-trimethylene-bis (2-oxazoline), 2,2'-tetramethylene-bis (2-oxazoline), 2,2'-hexamethylene-bis (2-oxazoline), 2,2'-octamethylene -Bis (2-oxazoline), 2,2'-ethylene-bis (4,4'-dimethyl-2-oxazoline), 2,2'-p-phenylene-bis (2-oxazoline), 2,2'- m-phenylene-bis (2-oxazoline), 2,2'-m-phenylene-bis (4,4'-dimethyl-2-oxazoline), bis (2-oxazolinylcyclohexane) sulfite , Bis (2-oxazolinyl sulfonyl norbornane) sulfide, but like oxazoline ring-containing polymer, the present invention is not limited only to those exemplified. These oxazoline group-containing compounds may be used alone or in combination of two or more. Among the oxazoline group-containing compounds, from the viewpoint of improving reactivity, a water-soluble oxazoline group-containing compound is preferable, and a water-soluble oxazoline ring-containing polymer is more preferable.

  The oxazoline ring-containing polymer can be easily prepared by polymerizing a monomer component containing an addition-polymerizable oxazoline and a monomer copolymerizable with the addition-polymerizable oxazoline as necessary. Can be.

  Examples of the addition-polymerizable oxazoline include 2-vinyl-2-oxazoline, 2-vinyl-4-methyl-2-oxazoline, 2-vinyl-5-methyl-2-oxazoline, 2-isopropenyl-2-oxazoline, Examples thereof include 2-isopropenyl-4-methyl-2-oxazoline, 2-isopropenyl-5-methyl-2-oxazoline, and 2-isopropenyl-5-ethyl-2-oxazoline. It is not limited to only. These addition-polymerizable oxazolines may be used alone or in combination of two or more. Among these addition-polymerizable oxazolines, 2-isopropenyl-2-oxazoline is preferable because it is easily available.

  Examples of monomers copolymerizable with the addition-polymerizable oxazoline include methyl (meth) acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, and tert-butyl (meth) acrylate. , Cyclohexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, methoxypolyethylene glycol (meth) acrylate, lauryl (meth) acrylate, stearyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2- Hydroxypropyl (meth) acrylate, monoester of (meth) acrylic acid and polyethylene glycol, 2-aminoethyl (meth) acrylate and salts thereof, caprolactone-modified (meth) acrylic acid, methacryloyl (Meth) acrylates such as 2,2,6,6-tetramethylpiperidine and methacryloyloxy-1,2,2,6,6-pentamethylpiperidine; sodium (meth) acrylate, (meth) acryl (Meth) acrylates such as potassium acrylate and ammonium (meth) acrylate; unsaturated nitriles such as (meth) acrylonitrile; (meth) acrylamide, N-methylol (meth) acrylamide, N- (2-hydroxyethyl) ( Unsaturated amides such as meth) acrylamide; vinyl esters such as vinyl acetate and vinyl propionate; vinyl ethers such as methyl vinyl ether and ethyl vinyl ether; α-olefins such as ethylene and propylene; halogens such as vinyl chloride, vinylidene chloride and vinyl fluoride. Contains α, β-unsaturated Aliphatic hydrocarbon compounds; α, β-unsaturated aromatic hydrocarbon compounds such as styrene, α-methylstyrene, and sodium styrenesulfonate; and the like, but the present invention is not limited to only these examples. . These monomers copolymerizable with the addition-polymerizable oxazoline may be used alone or in combination of two or more.

  The oxazoline group-containing compound is easily commercially available, for example, as trade names: Epocross WS-500, Epocross WS-700, Epocross K-2010, Epocross K-2020, Epocross K-2030, manufactured by Nippon Shokubai Co., Ltd. can do. Among these, water-soluble oxazoline group-containing compounds such as Nippon Shokubai Co., Ltd., trade name: Epocross WS-500 and Epocross WS-700 are preferable from the viewpoint of improving the reactivity.

  Examples of hydrazine compounds include, for example, adipic dihydrazide, sebacic dihydrazide, maleic dihydrazide, fumaric dihydrazide, oxalic dihydrazide, malonic dihydrazide, succinic dihydrazide, glutaric dihydrazide, isophthalic dihydrazide, carboxylic acid, and the like. However, the present invention is limited to only such examples, and does not include sodium. Of these, adipic dihydrazide is preferred.

  The isocyanate group-containing compound is a compound containing an isocyanate group capable of reacting with a hydroxyl group as a functional group of a hydroxyl group-containing monomer used as a monomer component.

  Examples of the isocyanate group-containing compound include a water-dispersed (block) polyisocyanate. In addition, (block) polyisocyanate means a polyisocyanate and / or a blocked polyisocyanate.

  Examples of the water-dispersible polyisocyanate include, for example, those obtained by dispersing a polyisocyanate having a hydrophilic property imparted by a polyethylene oxide chain in water with an anionic dispersant or a nonionic dispersant.

  Examples of the polyisocyanate include diisocyanates such as hexamethylene diisocyanate and isophorone diisocyanate; and derivatives (modified products) of polyisocyanates such as trimethylolpropane adducts, burettes, and isocyanurates of these diisocyanates. The present invention is not limited only to such an example. These polyisocyanates may be used alone or in combination of two or more.

  Water-dispersible polyisocyanates are, for example, manufactured by Tosoh Corporation, trade names: Aquanate (registered trademark) 100, Aquanate (registered trademark) 110, Aquanate (registered trademark) 200, Aquanate 210, etc .; Sumika Bayer Urethane Co., Ltd., trade names: Bihidul TPLS-2032, SUB-isocyanate L801, etc .; Mitsui Chemicals, Inc., trade names: Takenate (registered trademark) WD-720, Takenate (registered trademark) WD-725, Takenate ( (Registered trademark) WD-220, etc .; commercially available from Dainichi Seika Kogyo Co., Ltd., trade name: Rezamin D-56, etc.

  The water-dispersed blocked polyisocyanate is obtained by blocking an isocyanate group of the water-dispersed polyisocyanate with a blocking agent. Examples of the blocking agent include diethyl malonate, ethyl acetoacetate, ε-caprolactam, butanone oxime, cyclohexanone oxime, 1,2,4-triazole, dimethyl-1,2,4-triazole, and 3,5-dimethylpyrazole. , Imidazole and the like, but the present invention is not limited only to such examples. These blocking agents may be used alone or in combination of two or more. Among these blocking agents, those that cleave at a temperature of 160 ° C. or lower, preferably 150 ° C. or lower are desirable. Suitable blocking agents include, for example, butanone oxime, cyclohexanone oxime, 3,5-dimethylpyrazole, and the like. Of these, butanone oxime is more preferred.

  The water-dispersed block polyisocyanate is, for example, trade names: Takenate (registered trademark) WB-720, Takenate (registered trademark) WB-730, Takenate (registered trademark) WB-920, etc., manufactured by Mitsui Chemicals, Inc .; Bayer Urethane Co., Ltd., trade names: Bayhidule BL116, Bayhidur BL5140, Bayhidur BL5235, Bayhidur TPLS2186, Desmodur VPLS2310, and the like can be easily obtained commercially.

  The aminoplast polymer is an addition condensation product of a compound having an amino group such as melamine and guanamine with formaldehyde, and is also called an amino polymer.

  As aminoplast polymers, for example, dimethylol melamine, trimethylol melamine, tetramethylol melamine, pentamethylol melamine, hexamethylol melamine, fully alkylated methylated melamine, fully alkylated butylated melamine, fully alkylated isobutylated melamine, Melamine polymers such as fully alkylated mixed etherified melamine, methylol-based methylated melamine, imino-based methylated melamine, methylol-based mixed-etherified melamine, imino-based mixed-etherified melamine, etc .; Butylated benzoguanamine, methyl / ethyl Examples include guanamine polymers such as mixed alkylated benzoguanamine, methyl / butyl mixed alkylated benzoguanamine, and butylated glycoluril, but the present invention is not limited to only such examples. Not intended to be. These aminoplast polymers may be used alone or in combination of two or more.

  The aminoplast polymer is commercially easily available as, for example, Cytec Industries, trade name: Cymel 232, Cymel 235, Cymel 254, Cymel 303, Cymel 325, Cymel 370, Cymel 771, Cymel 1170, etc. Can be.

  The amount of the aminoplast polymer is usually the weight ratio of the solid content of the polymer contained in the emulsion particles to the solid content of the aminoplast polymer [solid content of the polymer / solid content of the aminoplast polymer]. It is preferable to adjust so as to be 60/40 to 99/1.

  In the present invention, besides the above-mentioned cross-linking agent, for example, a cross-linking agent such as a carbodiimide compound; a polyvalent metal compound represented by a zirconium compound, a zinc compound, a titanium compound, an aluminum compound, etc. It can be used as long as it is not inhibited.

  If necessary, a pigment can be contained in the overcoat paint. Examples of the pigment include an organic pigment and an inorganic pigment, and these may be used alone or in combination of two or more.

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

  Examples of the inorganic pigment include titanium dioxide, antimony trioxide, zinc white, lithopone, lead white, red iron oxide, black iron oxide, iron oxide, chrome oxide green, carbon black, graphite, molybdenum red, and ferrocyanide. Pigments having a flat shape such as diiron (Prussian blue), ultramarine, lead chromate, mica (mica), clay, aluminum powder, talc, aluminum silicate, calcium carbonate, magnesium hydroxide, aluminum hydroxide , Barium sulfate, magnesium carbonate, and the like, but the present invention is not limited to only such examples. These inorganic pigments may be used alone or in combination of two or more.

  The amount of the pigment per 100 parts by mass of the non-volatile content of the resin emulsion for coating is preferably 20 parts by mass or more, more preferably 40 parts by mass or more, from the viewpoint of forming a coating film excellent in weather resistance and heat deformation resistance. The amount is preferably 190 parts by mass or less from the viewpoint of forming a coating film having excellent low-temperature film-forming stability and extensibility.

  Since the top coat contains the resin emulsion for a paint of the present invention, it can be suitably used, for example, for ceramic building materials.

  The topcoat paint can be suitably used, for example, when applying on-site coating to the interior and outer layers of buildings, outer walls, and the like, and can also be suitably used for inorganic building materials such as ceramic building materials. Examples of the ceramic building materials include tiles and outer wall materials. Ceramic building materials are obtained by adding an inorganic filler, a fibrous material, etc. to a hydraulic adhesive material that is a raw material of an inorganic cured product, molding the resulting mixture, curing the obtained molded product, and curing it. can get. Examples of the inorganic building materials constituting the exterior of the building include a flexible board, a calcium silicate board, a gypsum slag perlite board, a wood chip cement board, a precast concrete board, an ALC board, and a gypsum board.

  The top coating may be applied alone in one layer, or may be applied in two or more layers. When coating is performed by applying two or more layers, only a part of the layers may be formed with the aqueous coating composition of the present invention, or all the layers may be formed with the top coating composition of the present invention. The overcoating is performed, for example, by applying a coating for a first layer (for example, an undercoat layer) to a substrate that has been subjected to a primer treatment, a sealer treatment, or the like, drying it, and then applying a coating for a second layer (for example, an overcoat layer) Examples include a method of overcoating and drying the paint, but the present invention is not limited by such a method. Examples of the method of applying the topcoat include, for example, a brush, a bar coater, an applicator, an air spray, an airless spray, a roll coater, a coating method using a flow coater, and the like, but the present invention is limited to only such examples. Not something.

  When the top coat is applied to the front and back surfaces of the building material, the building material may be heated as necessary from the viewpoint of efficiently producing a building material having a coating film on both surfaces.

Next, the present invention will be described in more detail based on examples, but the present invention is not limited to only these examples. In the following examples, unless otherwise specified, “parts”
Means "parts by mass" and "%" means "% by mass". The third embodiment is treated as a reference example.

Preparation Example 1
223 parts of deionized water, 60 parts of dispersant [trade name: Demol EP, manufactured by Kao Corporation], 50 parts of dispersant [trade name: Discoat N-14, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.], wetting agent [Kao Co., Ltd., trade name: Emulgen LS-106] 10 parts, propylene glycol 50 parts, titanium oxide [Ishihara Sangyo Co., Ltd., trade name: Taipe CR-95] 1000 parts, and glass beads (diameter: 1 mm) ) 200 parts were dispersed with a homodisper at a rotation speed of 3000 min ^{-1 for} 60 minutes, and then filtered through a 100 mesh (JIS mesh, hereinafter the same) wire mesh to prepare a white paste.

Example 1
764 parts of deionized water was charged into a flask equipped with a dropping funnel, a stirrer, a nitrogen gas inlet tube, a thermometer, and a reflux condenser. In a dropping funnel, 189 parts of deionized water, 40 parts of a 25% aqueous solution of an emulsifier (trade name: Aqualon BC-10, manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.), 450 parts of styrene, 45 parts of 2-ethylhexyl acrylate, and acrylic acid 2. Prepare a pre-emulsion for dropping consisting of 5 parts and 2.5 parts of methacrylic acid, add 73 parts corresponding to 5% of the total amount of all monomer components to the flask, and slowly blow nitrogen gas to 80 ° C. The temperature was raised, and 10 parts of a 5% aqueous solution of ammonium persulfate was added into the flask to initiate polymerization. Thereafter, the remainder of the dropping pre-emulsion and 15 parts of a 5% aqueous ammonium persulfate solution were uniformly dropped into the flask over 120 minutes.

  After completion of the dropwise addition, the content of the flask was maintained at 80 ° C. for 60 minutes, and subsequently, 94.5 parts of deionized water and a 25% aqueous solution of an emulsifier [ADEKA Corporation, trade name: Adecaria Soap SR-10] 20 , A second stage pre-emulsion comprising 100 parts of methyl methacrylate and 150 parts of 2-ethylhexyl acrylate is prepared, and the obtained pre-emulsion for dropping is uniformly mixed with 7.5 parts of a 5% aqueous ammonium persulfate solution in a flask for 60 minutes. It was dropped into.

  After completion of the dropwise addition, the content of the flask was maintained at 80 ° C. for 60 minutes, and subsequently, 94.5 parts of deionized water and a 25% aqueous solution of an emulsifier [ADEKA Corporation, trade name: Adecaria Soap SR-10] 20 Part, methyl methacrylate 120 parts, 2-ethylhexyl acrylate 100 parts and 4-methacryloyloxy-2,2,6,6-tetramethylpiperidine 30 parts of a pre-emulsion for dripping was prepared, and the obtained drop-emulsion was prepared. The pre-emulsion was dropped uniformly into the flask over a period of 60 minutes together with 7.5 parts of a 5% aqueous ammonium persulfate solution.

  After the completion of the dropwise addition, the content of the flask was maintained at 80 ° C. for 60 minutes, and the pH was adjusted to 8 by adding 25% aqueous ammonia to terminate the polymerization. The obtained reaction liquid was cooled to room temperature (about 25 ° C.), and then filtered through a 300-mesh wire net to prepare a resin emulsion for coating. The non-volatile content in this resin emulsion for coatings was 45%.

  The emulsion particles contained in the resin emulsion for paint obtained above have a three-layer structure, the content of styrene in the monomer component constituting the inner layer is 90%, and the content of the polymer constituting the intermediate layer is 90%. The glass transition temperature is −24 ° C., the mass ratio between the inner layer and the outer layer is 67/33, the total content of the inner layer and the outer layer in the emulsion particles is 75%, and all the monomers constituting the emulsion particles Is 45%, the glass transition temperature of the polymer constituting the outer layer is 10 ° C., the glass transition temperature of the polymer constituting the inner layer is 74 ° C., and the glass transition temperature of the whole emulsion particles. Was 27 ° C.

12 parts of 2,2,4-trimethyl-1,3-pentanediol monoisobutyrate [manufactured by JNC Co., Ltd., part number: CS-12] as a film-forming aid in 100 parts of the resin emulsion for coating obtained above. Was added and the mixture was stirred with a homodisper at a rotation speed of 1500 min ^{-1 for} 30 minutes, and then 30 parts of the white paste obtained in Preparation Example 1 and a defoaming agent [manufactured by San Nopco Co., Ltd., trade name: SN deformer 777] 0 .5 parts, and a thickening agent [manufactured by ADEKA Corporation, so that the viscosity when measured at 25 ° C using a Krebs unit viscometer (manufactured by Brookfield, product number: KU-1) is 80 KU. Trade name: ADECANOL UH-420] was added thereto, and the mixture was stirred for 30 minutes in that state to prepare a top coat.

Example 2
764 parts of deionized water was charged into a flask equipped with a dropping funnel, a stirrer, a nitrogen gas inlet tube, a thermometer, and a reflux condenser. A dropping pre-emulsion consisting of 94.5 parts of deionized water, 20 parts of a 25% aqueous solution of an emulsifier (trade name: Aqualon BC-10, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) and 250 parts of styrene was prepared in a dropping funnel. Among them, 73 parts corresponding to 5% of the total amount of all the monomer components were added to the flask, the temperature was raised to 80 ° C. while gently blowing nitrogen gas, and 10 parts of a 5% aqueous ammonium persulfate solution was added to the flask, followed by polymerization. Started. Thereafter, the remainder of the pre-emulsion for dropping and 7.5 parts of a 5% aqueous ammonium persulfate solution were uniformly dropped into the flask over 60 minutes.

  After completion of the dropwise addition, the content of the flask was maintained at 80 ° C. for 60 minutes, followed by 189 parts of deionized water, 40 parts of a 25% aqueous solution of an emulsifier [ADEKA Corporation, trade name: Adecaria Soap SR-10], and A second stage pre-emulsion comprising 50 parts of styrene, 195 parts of methyl methacrylate, 250 parts of 2-ethylhexyl acrylate and 5 parts of methacrylic acid was prepared, and the obtained pre-emulsion for dripping was added together with 15 parts of a 5% aqueous ammonium persulfate solution to 120 parts. The mixture was dropped uniformly into the flask over a period of minutes.

  After completion of the dropwise addition, the content in the flask was maintained at 80 ° C. for 60 minutes. Subsequently, 94.5 parts of deionized water and a 25% aqueous solution of an emulsifier [ADEKA Corporation, trade name: Adecaria Soap SR-10] were used. A third stage pre-emulsion comprising 20 parts, 175 parts of methyl methacrylate, 70 parts of 2-ethylhexyl acrylate and 5 parts of 4-methacryloyloxy-2,2,6,6-tetramethylpiperidine was prepared, and the obtained drop was prepared. The pre-emulsion for use together with 7.5 parts of a 5% ammonium persulfate aqueous solution was uniformly dropped into the flask over 60 minutes.

  After the completion of the dropwise addition, the content of the flask was maintained at 80 ° C. for 60 minutes, the pH was adjusted to 8 by adding 25% aqueous ammonia, and the polymerization was terminated. The obtained reaction solution was cooled to room temperature (about 25 ° C.), and then filtered through a 300-mesh wire net to prepare a resin emulsion for coating. The non-volatile content in this resin emulsion for coatings was 45%.

  The emulsion particles contained in the resin emulsion for coating obtained above have a three-layer structure, the content of styrene in the monomer component constituting the inner layer is 100%, and the content of the polymer constituting the intermediate layer is 100%. The glass transition temperature is −9 ° C., the mass ratio between the inner layer and the outer layer is 50/50, and the total content of the inner layer and the outer layer in the emulsion particles is 50%. Is 30%, the glass transition temperature of the polymer constituting the outer layer is 32 ° C., the glass transition temperature of the polymer constituting the inner layer is 100 ° C., and the glass transition temperature of the whole emulsion particles. Was 23 ° C.

12 parts of 2,2,4-trimethyl-1,3-pentanediol monoisobutyrate [manufactured by JNC Co., Ltd., product number: CS-12] as a film-forming aid in 100 parts of the resin emulsion for coating obtained above. Was added and the mixture was stirred with a homodisper at a rotation speed of 1500 min ^{-1 for} 30 minutes, and then 30 parts of the white paste obtained in Preparation Example 1 and a defoaming agent [manufactured by San Nopco Co., Ltd., trade name: SN deformer 777] 0 .5 parts, and a thickening agent [manufactured by ADEKA Corporation, so that the viscosity when measured at 25 ° C using a Krebs unit viscometer (manufactured by Brookfield, product number: KU-1) is 80 KU. Trade name: ADECANOL UH-420] was added thereto, and the mixture was stirred for 30 minutes in that state to prepare a top coat.

Example 3
764 parts of deionized water was charged into a flask equipped with a dropping funnel, a stirrer, a nitrogen gas inlet tube, a thermometer, and a reflux condenser. In a dropping funnel, 126 parts of deionized water, 27 parts of a 25% aqueous solution of an emulsifier (trade name: Aqualon BC-10, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.), 300 parts of styrene, 30 parts of 2-ethylhexyl acrylate, and 3 parts of methacrylic acid A pre-emulsion for dropping was prepared, and 73 parts, 5% of the total amount of all monomer components, was added to the flask, and the temperature was raised to 80 ° C. while gently blowing nitrogen gas. Then, 10 parts of a 5% aqueous solution of ammonium persulfate was added to the flask to initiate polymerization. Thereafter, the remainder of the dropping pre-emulsion and 10 parts of a 5% aqueous ammonium persulfate solution were uniformly dropped into the flask over 90 minutes.

  After completion of the dropwise addition, the content of the flask was maintained at 80 ° C. for 60 minutes, followed by 126 parts of deionized water, 27 parts of a 25% aqueous solution of an emulsifier [ADEKA Corporation, trade name: Adecaria Soap SR-10], A second stage pre-emulsion comprising 100 parts of methyl methacrylate, 230 parts of 2-ethylhexyl acrylate and 3 parts of methacrylic acid was prepared, and the obtained pre-emulsion for dropping was uniformly mixed with 10 parts of a 5% aqueous ammonium persulfate solution for 90 minutes. It was dropped into the flask.

  After completion of the dropwise addition, the content of the flask was maintained at 80 ° C. for 60 minutes, followed by 126 parts of deionized water, 27 parts of a 25% aqueous solution of an emulsifier [ADEKA Corporation, trade name: Adecaria Soap SR-10], A pre-emulsion for dropping comprising 240 parts of methyl methacrylate, 90 parts of 2-ethylhexyl acrylate and 4 parts of methacrylic acid was prepared, and the obtained pre-emulsion for dropping was uniformly placed in a flask together with 10 parts of a 5% aqueous ammonium persulfate solution for 90 minutes. It was dropped.

  After the completion of the dropwise addition, the content in the flask was maintained at 80 ° C. for 60 minutes, the pH was adjusted to 8 by adding 25% aqueous ammonia, and the polymerization was terminated. The obtained reaction solution was cooled to room temperature (about 25 ° C.), and then filtered through a 300-mesh wire net to prepare a resin emulsion for coating. The non-volatile content in this resin emulsion for coatings was 45%.

  The emulsion particles contained in the resin emulsion for paint obtained above have a three-layer structure, the content of styrene in the monomer component constituting the inner layer is 90%, and the content of the polymer constituting the intermediate layer is 90%. The glass transition temperature was −36 ° C., the mass ratio between the inner layer and the outer layer was 50/50, and the total content of the inner layer and the outer layer in the emulsion particles was 66.7%. The styrene content in the monomer is 30%, the glass transition temperature of the polymer constituting the outer layer is 34 ° C., the glass transition temperature of the polymer constituting the inner layer is 100 ° C., and the glass of the whole emulsion particles is The transition temperature was 22 ° C.

12 parts of 2,2,4-trimethyl-1,3-pentanediol monoisobutyrate [manufactured by JNC Co., Ltd., part number: CS-12] as a film-forming aid in 100 parts of the resin emulsion for coating obtained above. Was added and the mixture was stirred with a homodisper at a rotation speed of 1500 min ^{-1 for} 30 minutes, and then 30 parts of the white paste obtained in Preparation Example 1 and a defoaming agent [manufactured by San Nopco Co., Ltd., trade name: SN deformer 777] 0 .5 parts, and a thickening agent [manufactured by ADEKA Corporation, so that the viscosity when measured at 25 ° C using a Krebs unit viscometer (manufactured by Brookfield, product number: KU-1) is 80 KU. Trade name: ADECANOL UH-420] was added thereto, and the mixture was stirred for 30 minutes in that state to prepare a top coat.

Comparative Example 1
764 parts of deionized water was charged into a flask equipped with a dropping funnel, a stirrer, a nitrogen gas inlet tube, a thermometer, and a reflux condenser. In a dropping funnel, 189 parts of deionized water, 40 parts of a 25% aqueous solution of an emulsifier (trade name: Aqualon BC-10, manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.), 450 parts of styrene, 45 parts of 2-ethylhexyl acrylate, and acrylic acid 2. Prepare a pre-emulsion for dropping consisting of 5 parts and 2.5 parts of methacrylic acid, add 73 parts corresponding to 5% of the total amount of all monomer components to the flask, and slowly blow nitrogen gas to 80 ° C. The temperature was raised, and 10 parts of a 5% aqueous solution of ammonium persulfate was added into the flask to initiate polymerization. Thereafter, the remainder of the dropping pre-emulsion and 15 parts of a 5% aqueous ammonium persulfate solution were uniformly dropped into the flask over 120 minutes.

  After completion of the dropwise addition, the contents of the flask were maintained at 80 ° C. for 60 minutes. Subsequently, 189 parts of deionized water, 40 parts of a 25% aqueous solution of an emulsifier [ADEKA Corporation, trade name: Adecaria Soap SR-10], 40 parts of methyl, A second stage pre-emulsion comprising 275 parts of methacrylate, 195 parts of 2-ethylhexyl acrylate and 30 parts of 4-methacryloyloxy-2,2,6,6-tetramethylpiperidine was prepared, and the obtained pre-emulsion for dripping was prepared. The mixture was dropped uniformly into the flask over 15 minutes together with 15 parts of a 5% ammonium persulfate aqueous solution.

  After the completion of the dropwise addition, the content of the flask was maintained at 80 ° C. for 60 minutes, the pH was adjusted to 8 by adding 25% aqueous ammonia, and the polymerization was terminated. The obtained reaction solution was cooled to room temperature (about 25 ° C.), and then filtered through a 300-mesh wire net to prepare a resin emulsion for coating. The non-volatile content in this resin emulsion for coatings was 45%.

  The emulsion particles contained in the resin emulsion for paint obtained above have a two-layer structure, the content of styrene in the monomer component constituting the inner layer is 90%, and the mass ratio between the inner layer and the outer layer is 50/50, the total content of the inner layer and the outer layer in the emulsion particles was 100%, the styrene content in all the monomers constituting the emulsion particles was 45%, and the content of the polymer constituting the outer layer was 45%. The glass transition temperature was 10 ° C, the glass transition temperature of the polymer constituting the inner layer was 74 ° C, and the glass transition temperature of the whole emulsion particles was 39 ° C.

12 parts of 2,2,4-trimethyl-1,3-pentanediol monoisobutyrate [manufactured by JNC Co., Ltd., part number: CS-12] as a film-forming aid in 100 parts of the resin emulsion for coating obtained above. Was added and the mixture was stirred with a homodisper at a rotation speed of 1500 min ^{-1 for} 30 minutes, and then 30 parts of the white paste obtained in Preparation Example 1 and a defoaming agent [manufactured by San Nopco Co., Ltd., trade name: SN deformer 777] 0 .5 parts, and a thickening agent [manufactured by ADEKA Corporation, so that the viscosity when measured at 25 ° C using a Krebs unit viscometer (manufactured by Brookfield, product number: KU-1) is 80 KU. Trade name: ADECANOL UH-420] was added thereto, and the mixture was stirred for 30 minutes in that state to prepare a top coat.

Comparative Example 2
764 parts of deionized water was charged into a flask equipped with a dropping funnel, a stirrer, a nitrogen gas inlet tube, a thermometer, and a reflux condenser. In a dropping funnel, 189 parts of deionized water, 40 parts of a 25% aqueous solution of an emulsifier (trade name: Aqualon BC-10, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.), 250 parts of styrene, 200 parts of methyl methacrylate, 45 parts of 2-ethylhexyl acrylate , 2.5 parts of acrylic acid and 2.5 parts of methacrylic acid to prepare a dropping pre-emulsion, of which 73 parts, which is 5% of the total amount of all monomer components, was added to the flask, and nitrogen gas was slowly added. The temperature was raised to 80 ° C. while blowing, and 10 parts of a 5% ammonium persulfate aqueous solution was added into the flask to initiate polymerization. Thereafter, the remainder of the dropping pre-emulsion and 15 parts of a 5% aqueous ammonium persulfate solution were uniformly dropped into the flask over 120 minutes.

  After completion of the dropwise addition, the content of the flask was maintained at 80 ° C. for 60 minutes, and subsequently, 94.5 parts of deionized water and a 25% aqueous solution of an emulsifier [ADEKA Corporation, trade name: Adecaria Soap SR-10] 20 , 80 parts of styrene, 20 parts of methyl methacrylate, and 150 parts of 2-ethylhexyl acrylate to prepare a second stage pre-emulsion for dripping, and the obtained pre-emulsion for dripping together with 7.5 parts of a 5% aqueous ammonium persulfate solution for 60 minutes. , And was dripped into the flask uniformly.

  After completion of the dropwise addition, the contents of the flask were maintained at 80 ° C. for 60 minutes, and subsequently, 94.5 parts of deionized water and a 25% aqueous solution of emulsifier [ADEKA Corporation, trade name: Adecaria Soap SR-10] in 20% were added. Styrene, 120 parts of styrene, 100 parts of 2-ethylhexyl acrylate and 30 parts of 4-methacryloyloxy-2,2,6,6-tetramethylpiperidine to prepare a third-stage dropping pre-emulsion. The emulsion was uniformly dropped into the flask with 7.5 parts of a 5% aqueous solution of ammonium persulfate over 60 minutes.

  After the completion of the dropwise addition, the content of the flask was maintained at 80 ° C. for 60 minutes, the pH was adjusted to 8 by adding 25% aqueous ammonia, and the polymerization was terminated. The obtained reaction solution was cooled to room temperature (about 25 ° C.), and then filtered through a 300-mesh wire net to prepare a resin emulsion for coating. The non-volatile content in this resin emulsion for coatings was 45%.

  The emulsion particles contained in the resin emulsion for paint obtained above have a three-layer structure, the content of styrene in the monomer component constituting the inner layer is 50%, and the content of the polymer constituting the intermediate layer is 50%. The glass transition temperature is −24 ° C., the mass ratio between the inner layer and the outer layer is 67/33, the total content of the inner layer and the outer layer in the emulsion particles is 75%, and all the monomers constituting the emulsion particles Is 45%, the glass transition temperature of the polymer constituting the outer layer is 10 ° C., the glass transition temperature of the polymer constituting the inner layer is 76 ° C., and the glass transition temperature of the whole emulsion particles. Was 27 ° C.

12 parts of 2,2,4-trimethyl-1,3-pentanediol monoisobutyrate [manufactured by JNC Co., Ltd., part number: CS-12] as a film-forming aid in 100 parts of the resin emulsion for coating obtained above. Was added and the mixture was stirred with a homodisper at a rotation speed of 1500 min ^{-1 for} 30 minutes, and then 30 parts of the white paste obtained in Preparation Example 1 and a defoaming agent [manufactured by San Nopco Co., Ltd., trade name: SN deformer 777] 0 .5 parts, and a thickening agent [manufactured by ADEKA Corporation, so that the viscosity when measured at 25 ° C using a Krebs unit viscometer (manufactured by Brookfield, product number: KU-1) is 80 KU. Trade name: ADECANOL UH-420] was added thereto, and the mixture was stirred for 30 minutes in that state to prepare a top coat.

Comparative Example 3
764 parts of deionized water was charged into a flask equipped with a dropping funnel, a stirrer, a nitrogen gas inlet tube, a thermometer, and a reflux condenser. A dropping pre-emulsion consisting of 94.5 parts of deionized water, 20 parts of a 25% aqueous solution of an emulsifier (trade name: Aqualon BC-10, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) and 250 parts of styrene was prepared in a dropping funnel. Among them, 73 parts corresponding to 5% of the total amount of all the monomer components were added to the flask, the temperature was raised to 80 ° C. while gently blowing nitrogen gas, and 10 parts of a 5% aqueous ammonium persulfate solution was added to the flask, followed by polymerization. Started. Thereafter, the remainder of the pre-emulsion for dropping and 7.5 parts of a 5% aqueous ammonium persulfate solution were uniformly dropped into the flask over 60 minutes.

  After completion of the dropwise addition, the content of the flask was maintained at 80 ° C. for 60 minutes, and subsequently, 189 parts of deionized water, 40 parts of a 25% aqueous solution of an emulsifier [ADEKA Corporation, trade name: Adecaria Soap SR-10], A second stage pre-emulsion comprising 50 parts of styrene, 445 parts of 2-ethylhexyl acrylate and 5 parts of methacrylic acid was prepared, and the obtained pre-emulsion for dropping was uniformly mixed with 15 parts of a 5% ammonium persulfate aqueous solution for 120 minutes in a flask. It was dropped into.

  After completion of the dropwise addition, the content of the flask was maintained at 80 ° C. for 60 minutes, and subsequently, 94.5 parts of deionized water and a 25% aqueous solution of an emulsifier [ADEKA Corporation, trade name: Adecaria Soap SR-10] 20 175 parts of methyl methacrylate, 70 parts of 2-ethylhexyl acrylate and 5 parts of 4-methacryloyloxy-2,2,6,6-tetramethylpiperidine to prepare a third-stage dropping pre-emulsion. The pre-emulsion was dropped uniformly into the flask over a period of 60 minutes together with 7.5 parts of a 5% aqueous ammonium persulfate solution.

  After the completion of the dropwise addition, the content of the flask was maintained at 80 ° C. for 60 minutes, the pH was adjusted to 8 by adding 25% aqueous ammonia, and the polymerization was terminated. The obtained reaction solution was cooled to room temperature (about 25 ° C.), and then filtered through a 300-mesh wire net to prepare a resin emulsion for coating. The non-volatile content in this resin emulsion for coatings was 45%.

  The emulsion particles contained in the resin emulsion for coating obtained above have a three-layer structure, the content of styrene in the monomer component constituting the inner layer is 100%, and the content of the polymer constituting the intermediate layer is 100%. The glass transition temperature is −59 ° C., the mass ratio between the inner layer and the outer layer is 50/50, and the total content of the inner layer and the outer layer in the emulsion particles is 50%. Is 30%, the glass transition temperature of the polymer constituting the outer layer is 32 ° C., the glass transition temperature of the polymer constituting the inner layer is 100 ° C., and the glass transition temperature of the whole emulsion particles. Was -12 ° C.

12 parts of 2,2,4-trimethyl-1,3-pentanediol monoisobutyrate [manufactured by JNC Co., Ltd., product number: CS-12] as a film-forming aid in 100 parts of the resin emulsion for coating obtained above. Was added and the mixture was stirred with a homodisper at a rotation speed of 1500 min ^{-1 for} 30 minutes, and then 30 parts of the white paste obtained in Preparation Example 1 and a defoaming agent [manufactured by San Nopco Co., Ltd., trade name: SN deformer 777] 0 .5 parts, and a thickening agent [manufactured by ADEKA Corporation, so that the viscosity when measured at 25 ° C using a Krebs unit viscometer (manufactured by Brookfield, product number: KU-1) is 80 KU. Trade name: ADECANOL UH-420] was added thereto, and the mixture was stirred for 30 minutes in that state to prepare a top coat.

  Next, using the top coat obtained in each example or each comparative example, each physical property was examined based on the following methods. Table 1 shows the results. In addition, the thing which has one evaluation of x is rejected.

(1) Weather resistance A slate plate (manufactured by Nippon Test Panel Co., Ltd., length: 70 mm, width: 150 mm, thickness: 6 mm) is air-sprayed with a sealer (manufactured by SK Chemical Co., Ltd., trade name: EX sealer). It was applied uniformly at a coating amount of 150 g / m ² and dried in air at 23 ° C. for one week.

Next, a top coat is applied with a 10 mil applicator and dried in air at 23 ° C. for one week, and then the side and the back of the slate plate coated with the top coat are sealed with aluminum tape, and the top coat is applied. 60 ° specular gloss of the finished surface was measured with a gloss meter (manufactured by Nippon Denshoku Industries Co., Ltd., product number: VG2000), and further subjected to a weather resistance test for 500 hours under the following conditions. Measure the gloss of the painted surface of the formula:
[Gloss retention rate (%)]
= [[Gloss after weather resistance test] / [gloss before weather resistance test]] x 100
And weather resistance was evaluated based on the following evaluation criteria.

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

(Evaluation criteria)
：: Gloss retention of 80% or more ○: Gloss retention of 60% or more and less than 80% ×: Gloss retention of less than 60%

(2) Freeze-flowability 100 parts of the resin emulsion were placed in a 200-mL metal can (manufactured by Zentomo Metals Co., Ltd., primer round can), allowed to stand in the air at -3 ° C for 1 day, and then left at 23 ° C. The operation of standing in the air for one day was defined as one cycle, and after the operation was performed three cycles, the freezing and fluidity retention of the resin emulsion was evaluated based on the following evaluation criteria.
(Evaluation criteria)
◎: no change in fluidity ○: change in fluidity is observed, but there is fluidity ×: no fluidity

(3) Extensibility A top coat is applied to a polypropylene plate (length: 70 mm, width: 150 mm, thickness: 2 mm) with a 20 mil applicator, dried at room temperature (about 25 ° C.) for 24 hours, and then formed coating film (Length: about 1 cm, width: about 7 cm, thickness: 150 μm) was peeled from the polypropylene plate.

Next, after the peeled coating film was temperature-controlled for 3 hours in a constant temperature box at a temperature of 0 ° C., a short side of the coating film was subjected to a tensile tester [manufactured by Shimadzu Corporation, trade name: Autograph AGS] -100D] and pulled under the conditions of an initial mark line distance of 50 mm and a pulling speed of 200 mm / min.
[Elongation (%)] = [(Elongation at break−50 mm) ÷ (50 mm)] × 100
The elongation rate of the coating film was examined based on the following, and the extensibility was evaluated based on the following evaluation criteria.
(Evaluation criteria)
◎: Elongation rate of 30% or more ：: Elongation rate of 20% or more and less than 30% X: Elongation rate of less than 20%

(4) Low-temperature film-forming stability A straight plate (manufactured by Nippon Test Panel, length: 7 cm, width: 15 cm, thickness: 6 mm) and a sealer (manufactured by SK Chemical Co., Ltd., trade name: EX sealer) applied to the air spray. To a uniform amount of 150 g / m ² , and dried in air at 23 ° C. for one week.

  A sample prepared by adding 10 parts of water to 100 parts of the top coat paint was applied to the coating surface of the sealer of the slate plate using a 10 mil applicator, and dried for 24 hours in a thermostat controlled at 5 ° C. I let it.

Next, the slate plate was immersed in water at normal temperature for 24 hours, pulled out of the water, and dried at room temperature (about 25 ° C.) for 24 hours. Thereafter, the state of the coating film on the slate plate was magnified 10 times with a loupe and visually observed, and the low-temperature film-forming stability was evaluated based on the following evaluation criteria.
(Evaluation criteria)
◎: No cracks ：: Small cracks (less than 5 mm in length) are observed in the coating film.
X: Large cracks (length 5 mm or more) are observed in the coating film.

(5) Heat-resistant deformation resistance 150 g of a sealer (manufactured by Nippon Test Panel, length: 7 cm, width: 15 cm, thickness: 6 mm) with a sealer (trade name: EX Sealer, manufactured by SK Chemicals Co., Ltd.) by air spray / M ² , and dried in air at 23 ° C. for one week.

  A sample prepared by adding 10 parts of water to 100 parts of the topcoat paint was applied to the sealer application surface of the slate plate using a 10 mil thick applicator, and dried in air at 23 ° C. for 24 hours.

Next, a gauze (length: 7 cm, width: 7 cm) is placed on the surface of the formed coating film, and a 250 g weight is placed on the gauze, and is placed in air at room temperature (about 25 ° C.) for 2 hours. After the standing, the surface of the coating film was visually observed, and the heat deformation resistance was evaluated based on the following evaluation criteria.
(Evaluation criteria)
◎: No gauze residue on surface of coating film ○: Shallow gauze residue on surface of coating film X: Deep gauze residue on surface of coating film

(6) Comprehensive evaluation In the evaluation of each physical property, ◎ is set to 20 points, ○ is set to 10 points, and × is set to 0 point, and the total points of each physical property are added up (maximum score: 100 points, lowest score: 0). Points) were obtained and used as an index for comprehensive evaluation. Table 1 shows the results.

  From the results shown in Table 1, all of the resin emulsions for paints and the topcoat paints obtained in each Example were comprehensive in terms of weather resistance, freezing and fluidity retention, elongation, low-temperature film formation stability and heat deformation resistance. It can be seen that a coating film excellent in quality was formed.

  The resin emulsion for paint of the present invention is used as an aqueous one-pack type, for example, for an overcoat paint called a top coat applied to the surface of an interior and an outer layer of a building, an exterior, a ceramic building material and the like. There is expected.

Claims (7)

Interior of the building, a top coat resin emulsion used in the sheath or the surface of the ceramic building materials in buildings, containing an inner layer, the emulsion particles having at least three layers the resin layer of the intermediate and outer layers, said inner layer Is formed from a polymer obtained by polymerizing a monomer component for forming an inner layer containing 80 to 100% by mass of a styrene-based monomer and 0 to 20% by mass of a monomer other than the styrene-based monomer, The glass transition temperature of the polymer constituting the intermediate layer is −45 to 0 ° C., the mass ratio between the inner layer and the intermediate layer (inner layer / intermediate layer) is 10/90 to 90/10, the total content of the intermediate layer is Ri 30 to 90% by mass, the outer layer forming monomer components for forming the outer layer, the alkyl (meth) acrylate 80 carbon atoms in the ester is 1 to 8 carbon atoms -10 It is a monomer component containing 0 to 5% by mass of (meth) acrylic acid and 0 to 15% by mass of a UV-stable monomer, and the polymer constituting the outer layer has a glass transition temperature of -35 to 40. ℃ coating resin emulsion according to claim der Rukoto.   The content of the styrene-based monomer in all monomer components used as a raw material of the polymer constituting the emulsion particles is 10 to 50% by mass, and the content of a monomer other than the styrene-based monomer is contained. The resin emulsion for paint according to claim 1, wherein the ratio is 50 to 90% by mass. The resin emulsion for paint according to claim 1 or 2, wherein the content of the ultraviolet light-stable monomer in the monomer component for forming the outer layer is 2 to 15% by mass . The monomer component for forming an intermediate layer for forming the intermediate layer is such that the ester has 80 to 100% by mass of an alkyl (meth) acrylate having 1 to 8 carbon atoms, 0 to 15% by mass of styrene, and (meth) The resin emulsion for paint according to any one of claims 1 to 3, which is a monomer component containing 0 to 5% by mass of acrylic acid. The monomer other than the styrene-based monomer used for the inner layer forming monomer component is selected from the group consisting of alkyl (meth) acrylate and (meth) acrylic acid in which the ester has 1 to 8 carbon atoms. The coating resin emulsion according to any one of claims 1 to 4, which is at least one selected monomer. A topcoat paint comprising the resin emulsion for a paint according to any one of claims 1 to 5 . What is claimed is: 1. A method for producing a resin emulsion for a topcoat paint used on the interior of a building, the exterior of a building, or the surface of a ceramic building material , wherein the resin emulsion has at least three resin layers of an inner layer, an intermediate layer and an outer layer. And forming an inner layer by polymerizing a monomer component for forming an inner layer containing 80 to 100% by mass of a styrene-based monomer and 0 to 20% by mass of a monomer other than the styrene-based monomer, Glass on the inner layer such that the mass ratio between the inner layer and the intermediate layer (inner layer / intermediate layer) is 10/90 to 90/10, and the total content of the inner layer and the intermediate layer in the emulsion particles is 30 to 90% by mass. after the transition temperature to form an intermediate layer which is -45~0 ℃, the carbon number of the ester as monomer component for the outer layer forming for forming the outer layer in forming the outer layer with 1 to 8 carbon atoms Constituting the outer layer using a monomer component containing 80 to 100% by mass of an alkyl (meth) acrylate, 0 to 5% by mass of (meth) acrylic acid and 0 to 15% by mass of a UV-stable monomer the method for producing coating resin emulsion a glass transition temperature which is characterized that you adjust -35~40 ℃.