JP5876175B2 - Sealer coating composition - Google Patents

Description

  The present invention relates to a sealer coating composition. More specifically, for example, the present invention relates to a coating composition for a sealer useful for a sealer used for an inorganic building material such as a ceramic building material, and an inorganic building material to which the coating composition is applied. The coating composition for a sealer of the present invention can be suitably used, for example, for an undercoat material called a sealer that is applied to the front or back surface of an inorganic building material. The sealer coating composition of the present invention can be suitably used, for example, for factory coating, that is, when coating inorganic building materials on a line in the factory.

  In recent years, from the viewpoint of environmental protection, an aqueous undercoat paint composition containing an emulsion resin (see, for example, Patent Document 1), and an aqueous two-component undercoat paint composition mainly composed of a resin emulsion (see, for example, Patent Document 2). Has been proposed. In these undercoat coating compositions, since film formation is performed by fusing resin particles, it is necessary to use a large amount of a film-forming aid when the glass transition temperature of the resin is high. However, when the amount of the film-forming aid increases, if the coating film to be formed is insufficiently dried, the remaining film-forming aid reduces the blocking resistance, so that the coating film tends to be damaged, The protection of things will be insufficient, and the beauty will be impaired.

  As an aqueous coating composition with improved blocking resistance, an aqueous resin composition in which particles having a multilayer structure are dispersed has been proposed (for example, see Patent Document 3). However, since this aqueous resin composition needs to have a high glass transition temperature of the shell portion of the particles in order to impart blocking resistance, it has the disadvantage of being inferior in film forming property and water permeability of the coating film. is there.

  Therefore, in order to improve the blocking resistance, it is conceivable to use a water-soluble polymer having a high glass transition temperature and a low molecular weight, or increasing the pigment content. However, when a water-soluble polymer having a high glass transition temperature and a low molecular weight is used, there is a disadvantage that it is inferior in frost damage resistance and the like. There is a drawback that the water resistance is lowered.

JP 2001-335735 A Japanese Patent Laid-Open No. 2001-262053 Japanese Patent Laid-Open No. 2002-12816

  The present invention has been made in view of the prior art, and provides a sealer coating composition excellent in blocking resistance and film-forming properties, and an inorganic building material coated with the sealer coating composition. Let it be an issue.

The present invention
(1) resin emulsions containing emulsion particles having a plurality of resin layers obtained by the monomer components is a multistage emulsion polymerization, a sealer coating composition containing Pigment and rheology control agents, said emulsion A resin layer in which an inner layer of particles is obtained by emulsion polymerization of a monomer component containing 90 to 100% by weight of an aromatic monomer and 0 to 10% by weight of a monomer other than the aromatic monomer. And the rheology control agent is a urethane-associative rheology control agent, and the amount of the pigment per 100 parts by weight of the nonvolatile content of the resin emulsion is 140 to 400 parts by weight, and ( 2) It is related with the inorganic building material by which the coating composition for sealers as described in said (1) is applied.

  ADVANTAGE OF THE INVENTION According to this invention, the coating composition for sealers excellent in blocking resistance and film forming property is provided.

  As described above, the coating composition for a sealer of the present invention contains a resin emulsion containing emulsion particles having a glass transition temperature of 0 to 60 ° C., a pigment, and a rheology control agent, and the nonvolatile content of the resin emulsion is 100% by weight. The amount of the pigment per part is 100 to 400 parts by weight, and the amount of the active ingredient of the rheology control agent is 0.1 to 10 parts by weight. The resin emulsion can be prepared by emulsion polymerization of monomer components.

  The content of the aromatic monomer in all monomer components used as a raw material for the resin emulsion is 70% by weight or more from the viewpoint of improving the water permeability of the coating film. It is preferable that the content of other monomers is 30% by weight or less, and from the viewpoint of improving the film-forming property, the content of the aromatic monomer is 85% by weight or less. The content of the monomer other than the monomer is preferably 15% by weight or more.

  Examples of the aromatic monomer include styrene, α-methylstyrene, p-methylstyrene, tert-methylstyrene, chlorostyrene, aralkyl (meth) acrylate, vinyltoluene, and the like. It is not limited to illustration only. Examples of the aralkyl (meth) acrylate include aralkyl having 7 to 18 carbon atoms such as benzyl (meth) acrylate, phenylethyl (meth) acrylate, methylbenzyl (meth) acrylate, naphthylmethyl (meth) acrylate and the like. Although (meth) acrylate etc. are mentioned, this invention is not limited only to this illustration. These aromatic monomers may be used alone or in combination of two or more. Among these aromatic monomers, styrene is preferable from the viewpoint of improving the water resistance of the coating film.

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

  Examples of the 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). Acrylate, 2-ethylhexyl (meth) acrylate, tridecyl (meth) acrylate, cyclohexyl (meth) acrylate, n-octyl (meth) acrylate, n-lauryl (meth) acrylate, 2- (acetoacetoxy) ethyl (meth) acrylate, etc. The alkyl group having 1 to 18 carbon atoms in the ester group may be an alkyl (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 hydroxyl group-containing (meth) acrylate include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, and 4-hydroxy Examples include hydroxyl group-containing (meth) acrylates having 1 to 18 carbon atoms in the 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 (meth) acrylic acid, maleic acid, fumaric acid, crotonic acid, itaconic acid, maleic anhydride, and other carboxyl group-containing aliphatic monomers. The invention is not limited to such examples. These monomers may be used alone or in combination of two or more. Among these carboxyl group-containing monomers, acrylic acid, methacrylic acid and itaconic acid are preferable, and acrylic acid and methacrylic acid are more preferable from the viewpoint of improving the dispersion stability of the emulsion particles.

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

  Examples of the fluorine atom-containing monomer include 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. Although (meth) acrylate etc. are mentioned, this invention is not limited only to this illustration. These monomers may be used alone or in combination of two or more.

  Examples of the nitrogen atom-containing monomer include acrylamide compounds such as (meth) acrylamide, N, N-dimethylaminopropyl acrylamide and diacetone acrylamide, and nitrogen such as dimethylaminoethyl (meth) acrylate and diethylaminoethyl (meth) acrylate. Although an atom containing (meth) acrylate compound, N-vinylpyrrolidone, etc. are mentioned, this invention is not limited only to this illustration. These monomers may be used alone or in combination of two or more.

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

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

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

  The emulsion particles contained in the resin emulsion may be composed of only one type of resin prepared by one-stage emulsion polymerization, but a plurality of resin layers prepared by multi-stage emulsion polymerization of monomer components It is preferable from the viewpoint of making the properties of the coating film hardness and the film-forming property conflict with each other. When the emulsion particles have a plurality of resin layers, the number of the resin layers is not particularly limited, but is preferably 2 to 5 layers, more preferably 2 to 4 layers, and further preferably 2 to 3 layers.

  When the emulsion particles have a plurality of resin layers, any one of the plurality of resin layers has an aromatic monomer of 80 to 100% by weight, preferably 85 to 100% by weight, more preferably 90 to 100% by weight. It is obtained by emulsion polymerization of a monomer component containing 0 to 20% by weight, preferably 0 to 15% by weight, more preferably 0 to 10% by weight of a monomer other than the aromatic monomer. It is desirable that the resin layer to be contained is included from the viewpoint of improving the water permeability of the coating film. This resin layer may be contained in any of the plurality of resin layers, but is preferably present in the inner layer of the emulsion particles from the viewpoint of improving the film forming property. Examples of the monomer other than the aromatic monomer include the aforementioned ethylenically unsaturated monomer. The ethylenically unsaturated monomer can be suitably used in the present invention. Specific examples of monomers other than aromatic monomers include alkyl (meth) acrylates, hydroxyl group-containing (meth) acrylates, carboxyl group-containing monomers, oxo group-containing monomers, fluorine atom-containing monomers. , A nitrogen atom-containing monomer, an epoxy group-containing monomer, and the like, but the present invention is not limited to such examples. These monomers may be used alone or in combination of two or more.

  In any of the plurality of resin layers constituting the emulsion particles, from the viewpoint of improving the film forming property and the water resistance of the coating film, the carboxyl group-containing monomer is 10 to 25% by weight and the carboxyl group-containing monomer. It is preferable that the resin layer obtained by carrying out emulsion polymerization of the monomer component containing 75 to 90 weight% of monomers other than is contained. In this case, from the viewpoint of improving the film forming property, the content of the carboxyl group-containing monomer in the monomer component is 10% by weight or more, and the content of monomers other than the carboxyl group-containing monomer Is preferably 90% by weight or less. Further, from the viewpoint of improving the water permeability of the coating film, the content of the carboxyl group-containing monomer in this monomer component is 25% by weight or less, preferably 20% by weight or less, more preferably 15% by weight or less. In addition, it is desirable that the content of the monomer other than the carboxyl group-containing monomer is 75% by weight or more, preferably 80% by weight or more, and more preferably 85% by weight or more. This resin layer may be contained in any of the plurality of resin layers, but is preferably present in the outer layer of the emulsion particles from the viewpoint of improving the film forming property.

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

  A suitable resin emulsion is obtained by emulsion polymerization of monomer component A containing 80 to 100% by weight of an aromatic monomer and 0 to 20% by weight of a monomer other than the aromatic monomer. A monomer component B containing an inner layer comprising the resulting polymer (I), 10 to 25% by weight of a carboxyl group-containing monomer and 75 to 90% by weight of a monomer other than the carboxyl group-containing monomer A resin emulsion containing emulsion particles having an outer layer made of polymer (II) obtained by emulsion polymerization can be mentioned.

  In the present invention, a layer other than the inner layer and the outer layer may be formed in the emulsion particles as long as the object of the present invention is not impaired.

  The polymer (I) forming the inner layer is, for example, a monomer component containing 80 to 100% by weight of an aromatic monomer and 0 to 20% by weight of a monomer other than the aromatic monomer. It is obtained by emulsion polymerization of A.

  The content of the aromatic monomer in the monomer component A is preferably 80 to 100% by weight, more preferably 85 to 100% by weight from the viewpoint of improving blocking resistance and water permeability of the coating film. is there. Therefore, the monomer component A may be comprised only with the aromatic monomer. Among the aromatic monomers, as described above, styrene is preferable from the viewpoint of improving the water resistance of the coating film. The monomer component A may contain a monomer other than the aromatic monomer, preferably in the range of 0 to 20% by weight, more preferably in the range of 0 to 15% by weight. What was mentioned above is illustrated as monomers other than an aromatic monomer.

  Examples of the method for emulsion polymerization of monomer component A include, for example, an aqueous medium containing a water-soluble organic solvent such as lower alcohol such as methanol and water, an emulsifier dissolved in a medium such as water, and a single amount under stirring. Examples thereof include a method of dropping a body component A and a polymerization initiator, a method of dropping a monomer component previously emulsified with an emulsifier and water, into water or an aqueous medium, and the like. It is not limited to only. In addition, what is necessary is just to set the quantity of a medium suitably in consideration of the non volatile matter amount contained in the resin emulsion obtained.

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

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

  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 Although the condensation product with an amine etc. are mentioned, this invention is not limited only to this illustration.

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

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

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

  Further, as the emulsifier, an emulsifier having a polymerizable group, that is, a so-called reactive emulsifier is preferable from the viewpoint of improving the water permeability of the coating film, and a non-nonylphenyl emulsifier is preferable from the viewpoint of environmental protection.

  As the reactive emulsifier, for example, propenyl-alkylsulfosuccinic acid ester salt, (meth) acrylic acid polyoxyethylene sulfonate salt, (meth) acrylic acid polyoxyethylene phosphonate salt [for example, manufactured by Sanyo Chemical Industries, Ltd., Product name: Eleminol RS-30, etc.], polyoxyethylene alkylpropenyl phenyl ether sulfonate salt [for example, product name: Aqualon HS-10, manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.], allyloxymethylalkyloxypolyoxyethylene Sulfonate salt [for example, product name: Aqualon KH-10 manufactured by Daiichi Kogyo Seiyaku Co., Ltd.], sulfonate salt of allyloxymethylnonylphenoxyethylhydroxypolyoxyethylene [for example, product name: ADEKA manufactured by ADEKA Corporation Rear soap SE-10 etc.), Ryloxymethylalkoxyethylhydroxypolyoxyethylene sulfate ester salt (for example, manufactured by ADEKA, trade name: Adekaria soap SR-10, SR-30, etc.), bis (polyoxyethylene polycyclic phenyl ether) methacrylated sulfonate Salts (for example, Nippon Emulsifier Co., Ltd., trade name: Antox MS-60, etc.), allyloxymethylalkoxyethylhydroxypolyoxyethylene [eg, ADEKA Corporation, trade name: Adeka Soap ER-20, etc. ], Polyoxyethylene alkylpropenyl phenyl ether [for example, manufactured by Daiichi Kogyo Seiyaku Co., Ltd., trade name: Aqualon RN-20, etc.], allyloxymethylnonylphenoxyethyl hydroxypolyoxyethylene [for example, manufactured by ADEKA Corporation, Product Name: Adekaria Soap E-10, etc.) and the like, the present invention is not limited only to those exemplified.

  The amount of the emulsifier is preferably 0.5 parts by weight or more, more preferably 1 part by weight or more, further preferably 2 parts by weight or more, particularly preferably from the viewpoint of improving the polymerization stability per 100 parts by weight of the monomer component A. Is 3 parts by weight or more, and from the viewpoint of improving the water permeability of the coating film, it is preferably 10 parts by weight or less, more preferably 7 parts by weight or less, still more preferably 6 parts by weight or less, and even more preferably 5 parts by weight. The amount is particularly preferably 4 parts by weight or less.

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

  The amount of the polymerization initiator is preferably 0.05 parts by weight or more, more preferably from the viewpoint of increasing the polymerization rate and reducing the residual amount of the unreacted monomer component A per 100 parts by weight of the monomer component A. From the viewpoint of improving the water permeability of the coating film, it is preferably 1 part by weight or less, and more preferably 0.5 part by weight or less.

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

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

  In addition, if necessary, additives such as chain transfer agents such as compounds having a thiol group such as tert-dodecyl mercaptan, pH buffering agents, chelating agents, film forming aids may be added to the reaction system. Good. Since the amount of the additive varies depending on the type of the additive, it cannot be determined unconditionally, but is usually preferably 0.01 to 5 parts by weight, more preferably 0.1 to 3 parts per 100 parts by weight of the monomer component A. Parts by weight.

  Although the atmosphere at the time of carrying out emulsion polymerization of the monomer component A is not specifically limited, It is preferable that it is inert gas, such as nitrogen gas, from a viewpoint of improving the efficiency of a polymerization initiator.

  Although the polymerization temperature at the time of carrying out emulsion polymerization of the monomer component A does not have limitation, Usually, Preferably it is 50-100 degreeC, More preferably, it is 60-95 degreeC. The polymerization temperature may be constant or may be changed during the polymerization reaction.

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

  By polymerizing the monomer component A as described above, the polymer (I) forming the inner layer is obtained in the form of emulsion particles.

  The polymer (I) may have a crosslinked structure. From the viewpoint of improving the water resistance of the coating film, the weight average molecular weight of the polymer (I) is either the case where the polymer (I) has a crosslinked structure or the case where the polymer (I) does not have a crosslinked structure. Preferably it is 100,000 or more, More preferably, it is 300,000 or more, More preferably, it is 550,000 or more, Most preferably, it is 600,000 or more. The upper limit of the weight average molecular weight of the polymer (I) is not particularly limited when it has a crosslinked structure, and it is difficult to measure the weight average molecular weight. From the viewpoint of improving the viscosity, it is preferably 5 million or less.

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

  Next, after forming an inner layer made of the polymer (I), a monomer containing 10 to 25% by weight of a carboxyl group-containing monomer and 75 to 90% by weight of a monomer other than the carboxyl group-containing monomer. By subjecting the monomer component B to emulsion polymerization, an outer layer made of the polymer (II) is formed.

  In addition, from the viewpoint of improving adhesion and preventing shrinkage wrinkles of the coating film, the content of the carboxyl group-containing monomer in the monomer component B is 10% by weight or more, and other than the carboxyl group-containing monomer The monomer content is preferably 90% by weight or less, and from the viewpoint of improving the water permeability and frost resistance of the coating film, the content of the carboxyl group-containing monomer in the monomer component B is 25% by weight. It is below, and it is preferable that monomers other than the said carboxyl group-containing monomer are 75 weight% or more.

  Examples of the monomer other than the carboxyl group-containing monomer include, for example, the above-described aromatic monomer, alkyl (meth) acrylate, hydroxyl group-containing (meth) acrylate, oxo group-containing monomer, fluorine atom-containing monomer Body, nitrogen atom-containing monomer, epoxy group-containing monomer, and the like, but the present invention is not limited to such examples. Monomers other than these carboxyl group-containing monomers may be used alone or in combination of two or more.

  When the monomer component B is emulsion-polymerized, the polymerization reaction rate of the polymer (I) reaches 90% or more, preferably 95% or more, and then the monomer component B is emulsion-polymerized. This is preferable from the viewpoint of forming a layer separation structure in the particles.

  In addition, after forming the inner layer made of the polymer (I) and before forming the outer layer made of the polymer (II), it is made of another polymer, if necessary, as long as the object of the present invention is not hindered. A layer may be formed. Therefore, in the method for producing a coating composition for a sealer of the present invention, the object of the present invention is inhibited after the inner layer made of the polymer (I) is formed and before the outer layer made of the polymer (II) is formed. An operation for forming a layer made of another polymer may be included as necessary within the range not performed.

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

  By emulsion polymerization of the monomer component B as described above, emulsion particles in which the polymer (II) forming the outer layer is formed on the surface of the inner layer can be obtained. In addition, on the surface of the outer layer made of the polymer (II), a surface layer made of another polymer may be further formed as necessary within the range not hindering the object of the present invention.

  The polymer (II) may have a crosslinked structure. The weight average molecular weight of the polymer (II) is preferably 100,000 or more from the viewpoint of improving the water resistance of the coating film, regardless of whether the polymer (II) has a crosslinked structure or not. More preferably, it is 300,000 or more, More preferably, it is 550,000 or more, Most preferably, it is 600,000 or more. The upper limit of the weight average molecular weight of the polymer (II) is not particularly limited because it is difficult to measure the weight average molecular weight of the polymer (II) when it has a crosslinked structure. From the viewpoint of improving the viscosity, it is preferably 5 million or less.

  The glass transition temperature of the polymer (II) is preferably 40 ° C. or lower, more preferably 30 ° C. or lower, from the viewpoint of improving the film forming property. In addition, the glass transition temperature of the polymer (II) is preferably −20 ° C. or higher, more preferably 0 ° C. or higher, from the viewpoint of improving blocking resistance. The glass transition temperature of the polymer (II) can be easily adjusted by adjusting the composition of the monomer used for the monomer component.

In the present specification, the glass transition temperature of the polymer is expressed by the following formula: the glass transition temperature of the homopolymer of the monomer used in the monomer component constituting the polymer.
1 / Tg = Σ (Wm / Tgm) / 100
[Wm represents the content (% by weight) of monomer m in the monomer component constituting the polymer, and Tgm represents the glass transition temperature (absolute temperature: K) of the homopolymer of monomer m. ]
The temperature calculated | required based on the Formula of Fox (Fox) represented by these.

  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 − for a homopolymer of butyl acrylate. 56 ° C., 95 ° C. for acrylic acid homopolymer, and 130 ° C. for methacrylic acid homopolymer.

  The glass transition temperature of the polymer is a value obtained based on the Fox equation, but the measured value of the glass transition temperature of the polymer was obtained based on the Fox equation. The value is preferably the same. The actual measured value of the glass transition temperature of the polymer can be obtained, for example, by measuring the differential scanning calorific value.

  Examples of the differential scanning calorimeter measuring device include Seiko Instruments Inc., product number: DSC220C. Further, 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 the differential scanning calorific value (DSC) curve, a method of performing a smoothing process, and a method of obtaining a target peak temperature There is no limitation in particular. For example, when the measuring device is used, the drawing may be performed from data obtained by using the measuring 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., product number: EXSTAR6000], but the present invention is not limited to such examples. In addition, the peak temperature obtained in this way may include an error due to plotting of about 5 ° C. up and down.

  Any of the plurality of resin layers constituting the emulsion particles includes a resin layer made of a polymer having a glass transition temperature of 75 to 120 ° C. from the viewpoint of increasing the coating film hardness and improving the film forming property. It is preferable. The glass transition temperature of this polymer is preferably 75 ° C. or higher, more preferably 80 ° C. or higher, further preferably 90 ° C. or higher, particularly preferably 95 ° C. or higher, from the viewpoint of increasing the coating film hardness. From the viewpoint of improving, it is preferably 120 ° C. or lower, more preferably 115 ° C. or lower, and further preferably 110 ° C. or lower. The resin layer is preferably formed in the inner layer of the emulsion particles from the viewpoint of improving both the film-forming property and the hardness of the coating film.

  In addition, the glass transition temperature of the emulsion particles themselves is 0 ° C. or higher, preferably 10 ° C. or higher, more preferably 20 ° C. or higher, and further preferably 30 ° C. or higher from the viewpoint of increasing the coating film hardness, thereby improving the film forming property. From the viewpoint of making it, 60 ° C. or lower, preferably 55 ° C. or lower, more preferably 50 ° C. or lower.

  The solubility parameter (hereinafter also referred to as SP value) of the polymer (II) is preferably higher than the SP value of the polymer (I) from the viewpoint of forming a layer separation structure in the emulsion particles. Moreover, it is preferable that the difference of SP value of polymer (I) and SP value of polymer (II) is large from a viewpoint of forming a layer-separated structure within emulsion particles. The inner layer is composed of a polymer (I) in which a large amount of styrene having a low SP value is used and a polymer (II) in which a carboxyl group-containing monomer having a high SP value is used in a large amount. This is preferable because the emulsion particles have an ideal structure in which the outer layer and the outer layer are clearly separated.

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

  The weight ratio of the polymer (I) to the polymer (II) [polymer (I) / polymer (II)] is 25/75 or more from the viewpoint of improving the blocking resistance and the water permeability of the coating film. The ratio is preferably 35/65 or more, and 75/25 or less, preferably 65/35 or less from the viewpoint of improving the frost damage resistance.

  The total content of the polymer (I) and the polymer (II) in the emulsion particles is 50% by weight, preferably from the viewpoint of improving blocking resistance, water permeability of the coating film, frost damage resistance and adhesion. It is 65% by weight or more, and the higher the total content of the polymer (I) and the polymer (II) in the emulsion particles, the better. The upper limit is 100% by weight.

  In the present invention, the content of styrene in all monomer components used as a raw material for the polymer constituting the emulsion particles is preferably 70% by weight from the viewpoint of improving the water resistance of the coating film. From the viewpoint of improving the film forming property, it is preferably 85% by weight or less.

  From the viewpoint of improving the storage stability of the emulsion particles, the average particle diameter of the emulsion particles is preferably 30 nm or more, more preferably 50 nm or more, further preferably 70 nm or more, and particularly preferably 100 nm or more. From the viewpoint of improving the properties, it is preferably 400 nm or less, more preferably 300 nm or less, still more preferably 250 nm or less, and particularly preferably 200 nm or less.

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

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

In the present specification, the nonvolatile content in the resin emulsion is determined by weighing 1 g of the resin emulsion and drying it with a hot air dryer at a temperature of 110 ° C. for 1 hour.
[Non-volatile content in resin emulsion (mass%)]
= ([Residue mass] / [resin emulsion 1 g]) × 100
Means the value obtained based on

  The minimum film forming temperature of the resin emulsion for sealer used in the sealer coating composition of the present invention is preferably −10 ° C. or higher, more preferably 5 ° C. or higher, more preferably 20 ° C. or higher, from the viewpoint of increasing the coating film hardness. From the viewpoint of improving film formability, it is preferably 90 ° C. or lower, more preferably 75 ° C. or lower, and further preferably 60 ° C. or lower.

  In this specification, the minimum film-forming temperature of the resin emulsion is such that the resin emulsion is coated on a glass plate placed on a thermal gradient tester with an applicator so that the thickness is 0.2 mm and dried. It means the temperature when a crack occurs.

  The nonvolatile content of the resin emulsion in the sealer coating composition of the present invention is preferably 20% by weight or more from the viewpoint of improving the film forming property, the water permeability of the coating film and the frost damage resistance, and is resistant to blocking. From the viewpoint of improving the properties, it is preferably 50% by weight or less, more preferably 50% by weight or less, still more preferably 34% by weight or less, and particularly preferably 28% by weight or less.

  Examples of the pigment used in the sealer coating composition of the present invention include an organic pigment and an inorganic pigment, and these may be used alone or in combination of two or more.

  Examples of organic pigments include azo pigments, azomethine pigments, methine pigments, anthraquinone pigments, phthalocyanine pigments, perinone pigments, perylene pigments, diketopyrrolopyrrole pigments, thioindigo pigments, iminoisoindoline pigments, iminoisoindolinone pigments, and quinacridone red. And quinacridone pigments such as quinacridone violet, flavanthrone pigment, indanthrone pigment, anthrapyrimidine pigment, carbazole pigment, monoarylide yellow, diarylide yellow, benzoimidazolone yellow, tolyl orange, naphthol orange, quinophthalone pigment, etc. However, the present invention is not limited to such examples. These organic pigments may be used alone or in combination of two or more.

  Examples of inorganic pigments include titanium dioxide, red iron oxide, black iron oxide, iron oxide, chromium oxide green, carbon black, ferric ferrocyanide (Prussian blue), ultramarine, lead chromate, and mica. (Mica), clay, aluminum powder, pigment having a flat shape such as talc, aluminum silicate, and extender pigments such as calcium carbonate, magnesium hydroxide, aluminum hydroxide, barium sulfate, magnesium carbonate, etc. Is not limited to such examples. These inorganic pigments may be used alone or in combination of two or more.

  Among the pigments, extender pigments are preferable from the viewpoint of economy, and among them, calcium carbonate is more preferable.

  The amount of the pigment per 100 parts by weight of the non-volatile content of the resin emulsion is 100 parts by weight or more, preferably 140 parts by weight or more, more preferably 190 parts by weight or more, further preferably 260 parts by weight or more, from the viewpoint of increasing the coating film hardness. From the viewpoint of improving the film forming property, it is 400 parts by weight or less.

  The sealer coating composition of the present invention has one major feature in that it contains a rheology control agent. In the sealer coating composition of the present invention, a rheology control agent is used together with a resin emulsion and a high content of pigment, and the interaction between these components is improved, so that it has stable thixotropic viscosity and Newtonian viscosity. A sealer coating composition is obtained.

  Accordingly, when spraying the sealer coating composition on a substrate having an uneven surface, the coating composition for sealer is subjected to a high shearing force to lower the viscosity, so that atomization is promoted and applied to the substrate. Since the viscosity is restored, it is difficult for the sealer coating composition to accumulate in the recesses, so that a coating film without smears is formed.

  Further, since the rheology control agent imparts a Newtonian viscosity to the sealer coating composition, when the sealer coating composition is applied to a base material by a roll coater, the coating amount can be secured. At the same time, it is possible to form a coating film having a uniform film thickness without spots due to high leveling properties.

The thixotropic viscosity and the Newtonian viscosity can be represented by a ratio of a viscosity at a high shear force and a viscosity at a low shear force. Thixotropic viscosity and Newtonian viscosity, B type viscometer [e.g., Tokyo Keiki Co., Ltd., etc.] and the viscosity of the sealer coating composition at 25 ° C. with a viscosity in the rotational speed 6min ^-1 when the ratio of the viscosity at speed 60min ^-1 (viscosity at viscosity / rotational speed 60min ^-1 in rotational speed 6min ^-1) is 3.5 to 7, sealer coating composition has thixotropic viscosity When the ratio is 1 to 2.5, the sealer coating composition has a Newtonian viscosity.

  As the rheology control agent, an agent that increases or decreases the viscosity of the system in which the rheology control agent is used is used. Examples of the rheology control agent include inorganic rheology control agents such as silicates such as water-soluble aluminum silicate, montmorillonite, organic montmorillonite, colloidal alumina; and cellulose derivative rheology control agents such as carboxymethylcellulose, methylcellulose, and hydroxyethylcellulose. A protein rheology control agent such as casein, sodium caseinate, and ammonium caseinate; an alginate rheology control agent such as sodium alginate; a polyvinyl rheology control agent such as polyvinyl alcohol, polyvinyl pyrrolidone, and polyvinyl-benzyl ether copolymer; Sodium acrylate, alkali-soluble poly (meth) acrylic acid- (meth) acrylic Polyacrylic rheology control agents such as acid ester copolymers; polyether rheology control agents such as pluronic polyethers, polyether dialkyl esters, polyether dialkyl ethers, polyether urethane-associated group modified products, and polyether epoxy modified products ; Maleic anhydride copolymer based rheology control agent such as partial ester of vinyl methyl ether-maleic anhydride copolymer, half ester of reaction product of drying oil fatty acid allyl alcohol ester and maleic anhydride; acetylene glycol, xanthan gum, xanthan gum However, the present invention is not limited to such examples. These rheology control agents may be used alone or in combination of two or more.

  Among the rheology control agents, polyacrylic acid type rheology control agents are preferable from the viewpoint of imparting thixotropic viscosity to the coating composition for sealers, and alkali soluble type is particularly preferred for imparting viscosity when sprayed. Rheology control agents are more preferred. Alkali-soluble rheology control agents can be easily obtained commercially, for example, Acryset WR-507, Acreset WR-650 [above, manufactured by Nippon Shokubai Co., Ltd., trade name], etc. However, the present invention is not limited to such examples. These rheology control agents may be used alone or in combination of two or more.

  Of the above rheology control agents, polyether rheology control agents are preferred from the viewpoint of imparting Newtonian viscosity to the sealer coating composition, and urethane association is particularly desirable for imparting viscosity when coating with a roll coater. A type rheology control agent is more preferred. Urethane associative rheology control agents can be easily obtained commercially, for example, Adecanol UH-420, Adecanol UH-438, Adecanol UH-450VF [above, trade name, manufactured by ADEKA Corporation] However, the present invention is not limited to such examples. These rheology control agents may be used alone or in combination of two or more.

  From the above viewpoint, the rheology control agent suitable in the present invention includes an alkali-soluble rheology control agent and a urethane-associated rheology control agent, and these may be used alone or in combination of two or more. May be.

  The amount of the active ingredient of the rheology control agent per 100 parts by weight of the non-volatile content of the resin emulsion is 0.1 parts by weight or more, preferably from the viewpoint of imparting stable thixotropic viscosity and Newtonian viscosity to the sealer coating composition. It is 0.5 parts by weight or more, and from the viewpoint of improving the water permeability of the coating film, it is 10 parts by weight or less.

  The sealer coating composition of the present invention can be easily prepared by mixing a resin emulsion, a pigment, and a rheology control agent.

  Since the coating composition for sealers of the present invention obtained as described above is excellent in blocking resistance and film-forming properties, it is useful for sealers for inorganic building materials such as ceramic building materials.

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

  Such an inorganic building material generally has a property of being easily deteriorated because water is easily permeable to the inside thereof. Therefore, an undercoat material called a sealer is generally applied to the front and back surfaces of the inorganic building material. A top coating is usually applied to the surface of the inorganic building material in order to impart a desired design. Among these, the sealer coating composition of the present invention can be suitably used as an undercoat material. The inorganic building material of the present invention is obtained by applying the sealer coating composition.

  EXAMPLES Next, although this invention is demonstrated further in detail based on an Example, this invention is not limited only to this Example. In the following examples, “part” means “part by weight” and “%” means “% by weight” unless otherwise specified.

Production Example 1
In a flask equipped with a dropping funnel, a stirrer, a nitrogen introduction tube, a thermometer, and a reflux condenser, 820 parts of deionized water was charged.

  In a dropping funnel, 145 parts of deionized water, 120 parts of a 25% aqueous solution of an emulsifier [Daiichi Kogyo Seiyaku Co., Ltd., trade name: Aqualon HS-10], 60 parts of 2-ethylhexyl acrylate, 120 parts of butyl acrylate, methyl methacrylate A pre-emulsion for dripping consisting of 300 parts, 500 parts of styrene and 20 parts of acrylic acid was prepared.

  Of the obtained pre-emulsion for dripping, 71 parts corresponding to 5% of the total amount of the monomer components were added to the flask, the temperature was raised to 80 ° C. while gently blowing nitrogen gas, and 3.5% ammonium persulfate was added. 14 parts of the aqueous solution was added into the flask, and emulsion polymerization was started.

  Next, the remainder of the pre-emulsion for dropping, 86 parts of a 3.5% aqueous ammonium persulfate solution and 60 parts of a 2.5% aqueous sodium hydrogen sulfite solution were dropped into the flask over 240 minutes. After completion of dropping, the temperature was maintained at 80 ° C. for 120 minutes.

  Thereafter, 25% aqueous ammonia was added, and pH (measured at 23 ° C. using Horiba, Ltd., product number: F-23, the same shall apply hereinafter) was adjusted to 8 to complete the emulsion polymerization reaction. The resulting reaction mixture was cooled to room temperature and then filtered through a 300 mesh (JIS mesh, hereinafter the same) wire mesh to obtain a resin emulsion for a sealer.

  Table 1 shows the composition of the monomer components used in the sealer resin emulsion and the properties of the sealer resin emulsion.

Production Example 2
In a flask equipped with a dropping funnel, a stirrer, a nitrogen introduction tube, a thermometer, and a reflux condenser, 820 parts of deionized water was charged.

  In a dropping funnel, 145 parts of deionized water, 60 parts of a 25% aqueous solution of an emulsifier [Daiichi Kogyo Seiyaku Co., Ltd., trade name: Aqualon HS-10], 100 parts of 2-ethylhexyl acrylate, 10 parts of methyl methacrylate, 380 styrene A pre-emulsion for dripping consisting of 10 parts of acrylic acid and 10 parts of acrylic acid was prepared.

  Of the obtained pre-emulsion for dripping, 71 parts corresponding to 5% of the total amount of the monomer components were added to the flask, the temperature was raised to 80 ° C. while gently blowing nitrogen gas, and a 3.5% ammonium persulfate aqueous solution was added. 14 parts were added into the flask to initiate emulsion polymerization.

  Next, the remainder of the dropping pre-emulsion, 43 parts of a 3.5% aqueous solution of ammonium persulfate and 30 parts of a 2.5% aqueous solution of sodium hydrogen sulfite were dropped into the flask over 120 minutes. After completion of dropping, the temperature was maintained at 80 ° C. for 60 minutes.

  Thereafter, 145 parts of deionized water, 60 parts of a 25% aqueous solution of an emulsifier [Daiichi Kogyo Seiyaku Co., Ltd., trade name: Aqualon HS-10], 100 parts of 2-ethylhexyl acrylate, 30 parts of butyl acrylate, 350 parts of styrene, and A second pre-emulsion comprising 20 parts of acrylic acid, 43 parts of a 3.5% aqueous solution of ammonium persulfate and 30 parts of a 2.5% aqueous solution of sodium hydrogen sulfite were dropped into the flask over 120 minutes. After completion of the dropping, the temperature was maintained at 80 ° C. for 120 minutes, 25% aqueous ammonia was added, the pH was adjusted to 8, and the emulsion polymerization reaction was terminated. The obtained reaction mixture was cooled to room temperature and then filtered through a 300 mesh wire mesh to obtain a resin emulsion for a sealer.

  Table 1 shows the composition of the monomer components used in the sealer resin emulsion and the properties of the sealer resin emulsion.

Production Examples 3-5
In Production Example 2, a resin emulsion for a sealer was obtained in the same manner as in Production Example 2 except that the monomer components were changed as shown in Table 1. Table 1 shows the composition of the monomer components used in the obtained sealer resin emulsion and the properties of the sealer resin emulsion.

Production Example 6
In a flask equipped with a dropping funnel, a stirrer, a nitrogen introduction tube, a thermometer, and a reflux condenser, 800 parts of deionized water was charged.

  In a dropping funnel, 100 parts of deionized water, 40 parts of a 25% aqueous solution of an emulsifier [Daiichi Kogyo Seiyaku Co., Ltd., trade name: Aqualon HS-10], 5 parts of 2-ethylhexyl acrylate, 330 parts of styrene, and acrylic acid 5 A pre-emulsion for dripping consisting of parts was prepared.

  Of the obtained pre-emulsion for dripping, 71 parts corresponding to 5% of the total amount of the monomer components were added to the flask, the temperature was raised to 80 ° C. while gently blowing nitrogen gas, and 3.5% ammonium persulfate was added. 14 parts of an aqueous solution was added into the flask to initiate polymerization.

  Next, the remainder of the dropping pre-emulsion, 29 parts of a 3.5% aqueous ammonium persulfate solution and 20 parts of a 2.5% aqueous sodium hydrogen sulfite solution were dropped into the flask over 90 minutes. After completion of dropping, the temperature was maintained at 80 ° C. for 60 minutes.

  Thereafter, from 96 parts of deionized water, 40 parts of a 25% aqueous solution of emulsifier [Daiichi Kogyo Seiyaku Co., Ltd., trade name: Aqualon HS-10], 100 parts of 2-ethylhexyl acrylate, 225 parts of styrene and 5 parts of acrylic acid The second stage pre-emulsion, 29 parts of a 3.5% ammonium persulfate aqueous solution and 20 parts of a 2.5% sodium hydrogen sulfite aqueous solution were dropped into the flask over 90 minutes. After completion of dropping, the temperature was maintained at 80 ° C. for 60 minutes.

  Next, 96 parts of deionized water, 40 parts of a 25% aqueous solution of an emulsifier [Daiichi Kogyo Seiyaku Co., Ltd., trade name: Aqualon HS-10], 70 parts of 2-ethylhexyl acrylate, 50 parts of butyl acrylate, 170 parts of styrene A third pre-emulsion comprising 40 parts of acrylic acid, 29 parts of a 3.5% aqueous ammonium persulfate solution and 20 parts of a 2.5% aqueous sodium hydrogen sulfite solution were added dropwise to the flask over 90 minutes. After completion of the dropping, the temperature is maintained at 80 ° C. for 120 minutes, 25% aqueous ammonia is added, and the pH (measured at 23 ° C. using Horiba, Ltd., product number: F-23, the same applies below) is set to 8. The emulsion polymerization reaction was completed by adjusting. The obtained reaction mixture was cooled to room temperature and then filtered through a 300 mesh wire mesh to obtain a resin emulsion for a sealer.

  Table 1 shows the composition of the monomer components used in the sealer resin emulsion and the properties of the sealer resin emulsion.

Comparative production example 1
In Production Example 1, a resin emulsion for a sealer was obtained in the same manner as in Production Example 1 except that the monomer components were changed as shown in Table 1. Table 1 shows the composition of the monomer components used in the obtained sealer resin emulsion and the properties of the sealer resin emulsion.

Comparative production example 2
In Production Example 2, a resin emulsion for a sealer was obtained in the same manner as in Production Example 2 except that the monomer components were changed as shown in Table 1. Table 1 shows the composition of the monomer components used in the obtained sealer resin emulsion and the properties of the sealer resin emulsion.

The abbreviations listed in Table 1 mean the following.
[Meanings of abbreviations in Table 1]
St: Styrene MMA: Methyl methacrylate 2EHA: 2-ethylhexyl acrylate BA: Butyl acrylate AA: Acrylic acid MAA: Methacrylic acid

Moreover, the term of Table 1 means the following.
[St amount in layer 1]
Styrene content in monomer component used as raw material for layer 1 (%)
[Amount of carboxylic acid in layer 3]
Carboxyl group-containing monomer content in monomer component used as raw material for layer 3 (%)
[Total St amount]
Styrene content (%) in all monomer components used as raw materials for the polymer constituting the emulsion particles
(Layer composition ratio)
Weight ratio of each layer constituting the emulsion particles (showing the ratio of layer 1 / layer 2 / layer 3 in order from the left)
[Tg of each layer]
Glass transition temperature (° C.) of each layer constituting the emulsion particles (showing glass transition temperatures of layer 1 / layer 2 / layer 3 in order from the left)
[Total Tg]
Glass transition temperature of emulsion particles (℃)
[MFT]
Minimum film forming temperature of sealer resin emulsion (℃)
[Non-volatile content]
Nonvolatile content in resin emulsion (% by mass)
[Average particle size]
Average particle diameter of emulsion particles (nm)

  In Table 1, Layers 1 to 3 indicate the polymerization order. Moreover, in the monomer component in Table 1, “-” means that the monomer is not used.

Preparation Example Dispersant [Kao Co., Ltd., trade name: Demol EP] 60 parts, Dispersant [Daiichi Kogyo Seiyaku Co., Ltd., trade name: DISCOAT N-14] 50 parts, Wetting agent [Kao Corporation Product name: Emulgen LS-106] 10 parts, deionized water 210 parts, titanium oxide [manufactured by Ishihara Sangyo Co., Ltd., product number: CR-97] 200 parts, calcium carbonate [manufactured by Takehara Chemical Industry Co., Ltd.] 600 parts of light calcium carbonate], 200 parts of talc [manufactured by Nippon Talc Co., Ltd., product number: MICROACE S-3], 10 parts of antifoaming agent [manufactured by San Nopco Co., Ltd., trade name: Nopco 8034L] and glass beads (diameter: 1 mm) A white pigment paste having a non-volatile content of 75% by mass after mixing with 200 parts under stirring with a disper followed by aging by stirring for 60 minutes at a rotational speed of 3000 min ⁻¹ , filtering through a 100 mesh wire net. The Obtained. The non-volatile content in the pigment paste was determined by the same method as the non-volatile content in the resin emulsion.

Example 1
While dispersing 82 parts of the resin emulsion obtained in Production Example 1 with a homodisper at a rotational speed of 1500 min ⁻¹ , 2,2,4-trimethyl-1,3-pentanediol monoisobutyrate [Tisso Co., Ltd., product number: CS-12] and butyl cellosolve are mixed in an equal weight, and a mixed solution is added to the resin emulsion so that the film forming temperature is 0 to 5 ° C. Obtained.

  To the obtained mixture, 87 parts of the pigment paste obtained above was added, and an appropriate amount of dilution water and an appropriate amount of antifoaming agent (silicone antifoaming agent, Sannopco Corp.) were added so that the nonvolatile content was 40% by mass. Product name: SN deformer 777] was added to obtain a resin composition for a sealer.

Next, 1.4 parts of an alkali-soluble rheology control agent [manufactured by Nippon Shokubai Co., Ltd., trade name: Acre Reset WR-507, amount of active ingredient: 30%] was added to the obtained resin composition for sealer. The mixture was then stirred at a rotational speed of 1500 min ⁻¹ for 30 minutes to obtain a sealer coating composition. This sealer coating composition was allowed to stand for more than 1 day at room temperature.

Example 2
In Example 1, except that the resin emulsion obtained in Production Example 2 was used as the resin emulsion, the amount of the pigment paste was changed to 57 parts, and the amount of the rheology control agent was changed to 1.2 parts. A sealer coating composition was obtained in the same manner as in Example 1.

Example 3
In Example 1, the resin composition obtained in Production Example 2 was used as the resin emulsion, and the coating composition for sealer was prepared in the same manner as in Example 1 except that the amount of the rheology control agent was changed to 1.9 parts. Obtained.

Example 4
In Example 2, as a rheology control agent, except that 1.4 parts of urethane-associated rheology control agent (manufactured by ADEKA, trade name: Adecanol UH-420, amount of active ingredient: 30%) was used. A sealer coating composition was obtained in the same manner as in Example 2.

Example 5
In Example 3, as a rheology control agent, except that 2.0 parts of a urethane-associative rheology control agent [manufactured by ADEKA, trade name: Adecanol UH-420, amount of active ingredient: 30%] was used. A sealer coating composition was obtained in the same manner as in Example 3.

Example 6
In Example 1, except that the resin emulsion obtained in Production Example 3 was used as the resin emulsion, the amount of the pigment paste was changed to 71 parts, and the amount of the rheology control agent was changed to 1.8 parts. A sealer coating composition was obtained in the same manner as in Example 1.

Example 7
In Example 6, the resin composition obtained in Production Example 4 was used as the resin emulsion, and the sealer coating composition was prepared in the same manner as in Example 6 except that the amount of the rheology control agent was changed to 1.9 parts. Obtained.

Example 8
In Example 2, the resin emulsion obtained in Production Example 5 was used as the resin emulsion, and the sealer coating composition was prepared in the same manner as in Example 2 except that the amount of the rheology control agent was changed to 2.0 parts. Obtained.

Example 9
In Example 1, the resin composition obtained in Production Example 5 was used as the resin emulsion, and the sealer coating composition was prepared in the same manner as in Example 1 except that the amount of the rheology control agent was changed to 2.5 parts. Obtained.

Example 10
In Example 4, the resin emulsion obtained in Production Example 5 was used as the resin emulsion, and the sealer coating composition was prepared in the same manner as in Example 4 except that the amount of the rheology control agent was changed to 1.6 parts. Obtained.

Example 11
In Example 5, the resin emulsion obtained in Production Example 5 was used as the resin emulsion, and the sealer coating composition was prepared in the same manner as in Example 5 except that the amount of the rheology control agent was changed to 2.1 parts. Obtained.

Example 12
In Example 1, the resin composition obtained in Production Example 6 was used as the resin emulsion, and the sealer coating composition was prepared in the same manner as in Example 1 except that the amount of the rheology control agent was changed to 2.6 parts. Obtained.

Example 13
In Example 2, except that 11.8 parts of an aqueous solution of 3% hydroxyethyl cellulose (indicated as HEC in Table 2) (product number: SP-850) manufactured by Daicel Chemical Industries, Ltd. was used as the rheology control agent. A sealer coating composition was obtained in the same manner as in Example 2.

Comparative Example 1
In Example 6, the resin emulsion obtained in Comparative Production Example 1 was used as the resin emulsion, and the amount of the rheology control agent was changed to 1.5 parts. Got.

Comparative Example 2
In Example 6, the resin emulsion obtained in Comparative Production Example 2 was used as the resin emulsion, and the amount of the rheology control agent was changed to 1.6 parts. Got.

Comparative Example 3
A sealer coating composition was obtained in the same manner as in Example 2, except that in Example 2, the amount of the pigment paste was changed to 31 parts and the amount of the rheology control agent was changed to 0.8 parts.

Comparative Example 4
A sealer coating composition was obtained in the same manner as in Example 4 except that the amount of pigment paste was changed to 31 parts and the amount of rheology control agent was changed to 0.9 parts in Example 4.

Comparative Example 5
In Example 4, a sealer coating composition was obtained in the same manner as in Example 4 except that the rheology control agent was not used.

Experimental Example Next, the physical properties of the coating composition for sealers obtained in each Example or each Comparative Example were examined based on the following methods. The results are shown in Table 2.

  When an alkali-soluble rheology control agent is used as the rheology control agent, a test plate is prepared based on the following test plate preparation method 1, and when a urethane-associative rheology control agent is used. A test plate was prepared based on the following test plate preparation method 2.

[Method 1 for preparing test plate]
A sealer coating composition using an alkali-soluble rheology control agent is airless spray [manufactured by Anest Iwata Co., Ltd., product number: EX-700] with a slate plate [manufactured by Japan Test Panel Co., Ltd., 300 mm × 300 mm × 12 mm] The coating was applied at a thickness of 100 g / m ^{2 and} dried at 100 ° C. for 10 minutes with a hot air dryer to obtain a test plate.

[Method 2 for preparing test plate]
A coating composition for a sealer using a urethane-associative rheology control agent is applied to a slate plate (manufactured by Nippon Test Panel Co., Ltd., 300 mm × 300 mm × 12 mm thickness) with a roll coater (manufactured by Seiwa Sangyo Co., Ltd.). A test plate was obtained by applying at / m ^{2 and} drying with a hot air dryer at 100 ° C. for 10 minutes.

<Viscosity>
BM-type viscometer by [Tokyo Keiki Co., Ltd.], at 25 ° C., the viscosity was measured for rheology control agent in the viscosity of the rheology control agent and the rotational speed 60min ^-1 in rotational speed 6min ^-1.

<Viscosity>
As the viscosity of the sealer coating composition, the formula:
[Thixotropic Index (TI)]
= [Viscosity of rheology control agent at a rotational speed of 6 min ^-1 ]
÷ [Rheology control agent viscosity at a rotational speed of 60 min ^-1 ]
Based on the above, a thixotropic index (TI) was obtained.

<Sprayability>
The sealer coating composition using the alkali-soluble rheology control agent was evaluated according to the following evaluation criteria based on the thixotropic index (TI) determined above.
〔Evaluation criteria〕
◎: TI is 5.5 or more and less than 6.0 ○: TI is 5.0 or more and less than 5.5 Δ: TI is 4.0 or more and less than 5.0 ×: TI is less than 4

<Roll coater>
The sealer coating composition using the urethane-associative rheology control agent was evaluated according to the following evaluation criteria based on the thixotropic index (TI) determined above.
〔Evaluation criteria〕
◎: TI is 1.0 or more and less than 1.5 ○: TI is 1.5 or more and less than 2.0 Δ: TI is 2.0 or more and less than 3.0 ×: TI is 3.0 or more

<Water resistance>
A funnel (diameter: 10 cm) is placed on the coating film formed on the test plate, and the contact portion of both is sealed with a silicone bath bond (manufactured by Konishi Co., Ltd.), and the “funnel method” prescribed in JIS K5400 is used. Based on the following evaluation criteria, the water loss after 24 hours was measured based on the following evaluation criteria.
(Evaluation criteria)
A: Less than 0.03 mL / cm ² ○: 0.03 mL / cm ² or more, less than 0.05 mL / cm ² Δ: 0.05 mL / cm ² or more, less than 0.10 mL / cm ² ×: 0.10 mL / cm ² or more

<Blocking resistance>
After two test plates (7 × 15 cm) were left in an atmosphere at 60 ° C. for 1 hour, the surfaces of the test pieces on which the coating film was formed were overlapped, and a load of 300 g / cm ² was applied thereon. In this state, the test plate was allowed to stand at a temperature of 60 ° C. for 24 hours, and then each test plate was separated. The state of the coating film surface was visually observed and evaluated based on the following evaluation criteria.
(Evaluation criteria)
◎: No change ○: Only slight gloss change on the coating film surface △: There are a few peeling points of the coating film ×: There are many peeling points of the coating film

<Frost resistance>
After sealing the side surface of the test plate and the back surface on which the coating film is not formed with a silicone-based bath bond (manufactured by Konishi Co., Ltd.), it is frozen for 2 hours by cooling to −20 ° C. in the air using a freeze-thaw tester. Then, the operation of immersing in water at 20 ° C. for 2 hours is set as one cycle, and the operation is performed 300 cycles while observing the occurrence of cracks on the coating film surface using a magnifying glass with a magnification of 30 times every 100 cycles. Evaluation was made based on the following evaluation criteria.
(Evaluation criteria)
◎: No problem even at 300 cycles ○: No problem at 200 cycles, but cracks occurred at 300 cycles Δ: No problems at 100 cycles, but cracks occurred at 200 cycles ×: Cracks occurred at 100 cycles

<Pigment content>
The pigment content is calculated using the formula:
[Pigment content (%)]
= ([Pigment weight] / [resin non-volatile content weight + pigment weight]) × 100
Based on.

  The production example number described in Table 2 means that the resin emulsion obtained by the production example number is used. “Comparative 1” and “Comparative 2” mean that the resin emulsions obtained in Comparative Production Example 1 and Comparative Production Example 2 are used, respectively. The amount of the active ingredient of the rheology control agent means the amount of the active ingredient of the rheology control agent per 100 parts of the nonvolatile content of the resin emulsion used in the sealer coating composition.

  A sealer coating composition having at least one “x” in physical properties is not suitable for use in a sealer coating.

  From the results shown in Table 2, each of the sealer coating compositions obtained in each example was excellent in sprayability or roll coater properties, and was excellent in water permeability, blocking resistance and frost damage resistance. It can be seen that a film is formed.

  The coating composition for a sealer of the present invention is expected to be used as an aqueous one-pack type, for example, a coating composition for a building material sealer for ceramics, a sealer coating, and the like.

Claims (2)

Resin emulsions containing emulsion particles having a plurality of resin layers obtained by the monomer component by multistage emulsion polymerization, a sealer coating composition containing Pigment and rheology control agents, the inner layer of the emulsion particles Is a resin layer obtained by emulsion polymerization of a monomer component containing 90 to 100% by weight of an aromatic monomer and 0 to 10% by weight of a monomer other than the aromatic monomer, A sealer coating composition, wherein the rheology control agent is a urethane-associative rheology control agent, and the amount of pigment per 100 parts by weight of the nonvolatile content of the resin emulsion is 140 to 400 parts by weight.   An inorganic building material obtained by applying the sealer coating composition according to claim 1.