JP5194481B2 - Water-based resin dispersion for elastic paint, method for producing the same, and water-based elastic architectural paint - Google Patents

Description

  The present invention relates to an aqueous resin dispersion for elastic paints and an aqueous elastic architectural paint capable of forming a tough and elastic coating film. Specifically, the water-based elastic building paint for covering the surface of an alkaline substrate such as ceramic building materials such as concrete, mortar, slate board, ALC board (lightweight cellular concrete panel), siding board, etc. used in buildings and structures, and the like The present invention relates to an aqueous resin dispersion constituting a paint. More specifically, the present invention relates to an elastic paint capable of forming an elastic coating film having excellent adhesion to an aqueous sealer layer coated on an alkali base material, and an aqueous resin dispersion for elastic paint constituting the paint.

  Water-based resin dispersions obtained by emulsion polymerization of ethylenically unsaturated monomers include various coating agents such as water-based paints, water-based pressure-sensitive adhesives / adhesives, fiber processing agents such as nonwoven fabric binders, paper-processing binders, and water-based inks. It is used for such purposes. In recent years, water-based products have been rapidly developed for environmental reasons, and various water-based products are being expanded in building paints that have conventionally used solvent-based resins. For architectural coatings, depending on the intended functionality and application, thick coating type paints that require flexibility called elastic coatings, sealer coatings for base preparation, and gloss application There are various types of paint such as flat paint for top coat.

  Elastic coatings for surface coating of alkali substrates such as ceramic building materials such as concrete, mortar, slate plates, ALC plates (lightweight cellular concrete panels) can be broadly classified into single layer type elastic coatings and multilayer type elastic coatings. Single-layer elastic coatings are not overcoated with topcoat coatings, so their growth has been remarkable in recent years due to the shortening of construction period and cost. In addition, since the multi-layer type elastic paint is used by overcoating the top coat paint on the elastic coating film, those coated objects are water resistant, waterproof, glossy, Excellent physical properties such as weather resistance and stain resistance. In any type of elastic paint, crack followability and low temperature performance are particularly required in terms of performance as a paint. In addition, the crack followability mentioned here is considered to be an index indicating the degree of cracks occurring in the coating film with respect to relatively large cracks occurring in the casing, and the adhesion strength between the base and the coating film and the elasticity of the coating film. It is a performance that reflects (strength, elongation, etc.) in a composite manner. As one of the test methods, there are a tensile test and a fatigue resistance test defined in JIS-A-6909 (finishing coating material for building) and JIS-A-6021 (waterproofing material for architectural coating).

  In the case of a single-layer type elastic paint, durability, weather resistance, stain resistance, etc. are required as a top coat paint to be applied to the upper layer in the case of a multi-layer type elastic paint. On the other hand, the multilayer elastic coating material requires further crack followability, low temperature performance, water resistance, waterproofness, adhesion to the top coat, and the like. In any elastic paint, adhesion to a sealer layer applied to an alkali base material is required. In order to satisfy these requirements, various elastic paints have been proposed in which various fillers are blended into an emulsion obtained by emulsion polymerization of an ethylenically unsaturated monomer.

  For example, Patent Document 1 discloses an elastic paint obtained by blending an inorganic filler with a copolymer emulsion obtained by emulsion polymerization of a monomer mixture containing acrylonitrile as an essential component. The coating film formed from the elastic coating described in Patent Document 1 is tough and rich in elasticity, is excellent in terms of water resistance, alkali resistance, etc., and can sufficiently follow cracks in the ground.

  In addition, the paint disclosed in Patent Document 2 is intended to solve the problems of blocking resistance and stain resistance that the paint disclosed in Patent Document 1 has. Patent Document 2.

  The copolymer emulsion disclosed in Patent Document 3 is an emulsion having a multilayer structure having different Tg by multi-stage emulsion polymerization, has high elasticity, has little tack, and is resistant to contamination, adhesion to the ground, and weather resistance. It is described that it can be used for an elastic paint capable of forming a film having excellent properties.

  Furthermore, the emulsion for a low-contamination type single-layer elastic coating disclosed in Patent Document 4 is an emulsion obtained by emulsion polymerization using a specific monomer and a polymerizable surfactant, and is hardly contaminated by raindrops. In addition, an emulsion for a single-layer elastic paint having sufficient initial water resistance that does not cause a coating film to flow out due to rainfall after construction is disclosed. Specifically, an emulsion for a paint having both the hydrophilicity of the coating film and the water resistance at the initial drying stage and having high gloss, elongation, strength and adhesion is disclosed.

However, the coating film formed from the elastic paint or the elastic paint using an emulsion described in Patent Documents 1 to 4 does not have sufficient adhesion to the sealer layer formed on the alkali base material. This was particularly noticeable when an aqueous type paint was used as the sealer paint for forming the sealer layer.
Japanese Patent Laid-Open No. 53-030635 Japanese Patent Laid-Open No. 01-004662 JP-A-6-179726 Japanese Patent Laid-Open No. 10-46099

An object of the present invention is to provide an aqueous elastic architectural paint containing an aqueous resin dispersion for an elastic paint, which can be used for a paint capable of forming an elastic coating film which is tough and rich in elasticity and has excellent adhesion to a sealer layer. With the goal.

In the present invention, an anionic surfactant (A) and a nonionic surfactant (B) are used to emulsify an ethylenically unsaturated monomer (C) with a polymerization initiator (D) in an aqueous medium. A water-based resin dispersion for an elastic coating obtained by polymerization,
The anionic surfactant (A) is an activator represented by the following general formula (1), and
The nonionic surfactant (B) has an HLB value of 13.5 to 18.5, and
The Tg of the resin relates to an aqueous resin dispersion for elastic paints having a temperature of −50 to 0 ° C.

General formula (1)
R ¹ —O — (— CH ₂ CH ₂ O—) _n —SO ₃ M
[R ¹ is a C _{7 to} C ₁₇ alkyl group, n is an integer of 0 to 4, M is Na or NH ₄ or NH (R ² OH) ₃ , where R ² is a C _{1 to} C ₄ Alkylene group]

  Further, the present invention provides the above water-based resin for elastic coatings, wherein the ethylenically unsaturated monomer (C) contains 1 to 20% by weight of (meth) acrylonitrile with respect to the whole monomer (C). Concerning the dispersion.

  Furthermore, the present invention relates to the above-mentioned aqueous resin dispersion for elastic paint, wherein the polymerization initiator (D) is a peroxide polymerization initiator and is emulsion-polymerized using a reducing agent (E) in combination.

  Furthermore, this invention relates to the water-based elastic building paint which comprises the said water-based resin dispersion for elastic paints.

  Furthermore, this invention relates to the said water-based elastic architectural coating characterized by coating on the coating film of the water-based sealer (S) coated on the alkali base material.

  Furthermore, this invention relates to the to-be-coated article formed by apply | coating the said water-based elastic building paint on the coating film of the water-based sealer (S) coated on the alkali base material.

Furthermore, the present invention uses an anionic surfactant (A) and a nonionic surfactant (B) to bring an ethylenically unsaturated monomer (C) into an aqueous medium by a polymerization initiator (D). A method for producing an aqueous resin dispersion for an elastic coating that undergoes emulsion polymerization,
The anionic surfactant (A) is an activator represented by the following general formula (1), and
The nonionic surfactant (B) has an HLB value of 13.5 to 18.5, and
The present invention relates to a method for producing a water-based resin dispersion for elastic paint, wherein the Tg of the resin is -50 to 0 ° C.

General formula (1)
R ¹ —O — (— CH ₂ CH ₂ O—) _n —SO ₃ M
[R ¹ is a C _{7 to} C ₁₇ alkyl group, n is an integer of 0 to 4, M is Na or NH ₄ or NH (R ² OH) ₃ , where R ² is a C _{1 to} C ₄ Alkylene group]

  Further, the present invention provides the above water-based resin for elastic coatings, wherein the ethylenically unsaturated monomer (C) contains 1 to 20% by weight of (meth) acrylonitrile with respect to the whole monomer (C). The present invention relates to a method for producing a dispersion.

  Furthermore, the present invention provides the above-mentioned aqueous resin dispersion for elastic coating, wherein the polymerization initiator (D) is a peroxide polymerization initiator and is emulsion-polymerized in combination with a reducing agent (E). It relates to the manufacturing method.

  The aqueous resin dispersion for elastic coatings of the present invention can be used for aqueous elastic architectural coatings that can form an elastic coating film that is tough and rich in elasticity, and has excellent adhesion to the sealer layer. Furthermore, it is possible to provide a water-based elastic architectural paint excellent in weather resistance, water resistance, alkali resistance and stain resistance.

  The term “elastic coating” as used in the present invention means that even if a crack occurs in a building base material such as concrete, the coating film stretches and contracts well, covers the base crack and protects the inside, and also affects the temperature rise and fall. A paint that has a function that is difficult to be affected. Elastic coatings are used in multi-layer and single-layer coating systems as described above. In either case, generally, a base material is first applied to a base material for building adjustment such as concrete. An undercoat paint, also called a primer, is applied and an elastic paint is applied over the undercoat sealer.

  As the elastic coating material, an aqueous resin dispersion mainly containing a hydrophobic monomer capable of forming a relatively soft homopolymer having a glass transition temperature of −20 ° C. or less is used.

  The aqueous resin dispersion for elastic coatings of the present invention uses an anionic surfactant (A) and a nonionic surfactant (B) to remove an ethylenically unsaturated monomer (C) in an aqueous medium. It is obtained by emulsion polymerization with a polymerization initiator (D).

  The present invention uses an anionic surfactant (A) represented by the following general formula (1) and a nonionic surfactant (B) having an HLB value of 13.5 to 18.5, and a resin. It was found that the adhesiveness to the sealer layer was remarkably improved by setting the Tg of -50 to 0 ° C.

General formula (1)
R ¹ —O — (— CH ₂ CH ₂ O—) _n —SO ₃ M
[R ¹ is a C _{7 to} C ₁₇ alkyl group, n is an integer of 0 to 4, M is Na or NH ₄ or NH (R ² OH) ₃ , where R ² is a C _{1 to} C ₄ Alkylene group]

When the carbon atom of R ^{1 in} the general formula (1) is 6 or less, or 18 or more, the emulsion stability of the ethylenically unsaturated monomer (C), the polymerization stability, and further with the sealer layer Problems arise in adhesion. In addition, when n is 5 or more, there is a problem in adhesion to the sealer layer, and resistance such as water resistance tends to be inferior.

  Examples of the anionic surfactant (A) include sodium lauryl sulfate, ammonium lauryl sulfate, triethanolamine lauryl sulfate, polyoxyethylene sodium lauryl sulfate [where n = 1 to 4 in the above general formula (1)], polyoxy And ethylene lauryl sulfate triethanolamine [where n = 1 to 4 in the above general formula (1)] and the like.

  Moreover, as a commercial item of anionic surfactant (A), for example, Emar 10, Emar 2FG, Emar TD, Latem AD-25, Emar D-4-D, Emar E-27C, Emar 20C, Emar 20T ( As mentioned above, New Coal 1703-SFD (made by Nippon Emulsifier Co., Ltd.), Monogen Y-100, Hightenol 227L, Hightenol 325L (Daiichi Kogyo Seiyaku Co., Ltd.), etc. are mentioned.

  As other anionic surfactants, dodecylbenzene sulfonate, polyoxyethylene alkylphenyl ether sulfate, polyoxyethylene polycyclic phenyl ether sulfate and the like can be used in combination.

  Furthermore, the present invention is characterized in that an active agent having an HLB value of 13.5 to 18.5 is used as the nonionic surfactant (B). More preferably, the HLB value is 15 to 18.5, and further preferably 16 to 18.5. If the HLB value is less than 13.5, the ability to emulsify the ethylenically unsaturated monomer is poor, and aggregates may be produced during emulsion polymerization. On the other hand, if the HLB value exceeds 18.5, the adhesion to the sealer layer is deteriorated and the water resistance is also lowered. Here, the value obtained by the Davis calculation method is used as the value of “HLB” in this specification. The method of calculating Davis is detailed in, for example, ["Introduction to New Surfactants": Takehiko Fujimoto Publication: Sanyo Chemical Industries, Ltd. (1992)].

  Examples of the nonionic surfactant (B) include polyoxyethylene alkyl ether, polyoxyethylene alkyl phenyl ether, polyoxyethylene polycyclic phenyl ether, polyoxyethylene styrenated phenyl ether, and polyoxyethylene distyrenylated phenyl ether. , Polyoxyethylene polyoxypropylene alkyl ether, and the like. Among them, nonionic surfactants having an HLB value of 13.5 to 18.5 are commercially available products such as Emulgen 1108 (HLB = 13. 5), Emulgen A-90 (HLB = 14.5), Emulgen 1118S-70 (HLB = 16.4), Emulgen 1135S-70 (HLB = 17.9), Emulgen A-500 (HLB = 18.0) Emulgen 950 (HLB = 18. ), Emulgen 1150S-60 (HLB = 18.5), [above, manufactured by Kao Corporation], Neugen EA-167 (HLB = 14.8), Neugen EA-177 (HLB = 15.6), Neugen EA- 197 (HLB = 17.5) [above, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.], Lionol TDM-200 (HLB = 14.8), Lionol TD-150 (HLB = 15.4) [above, manufactured by Lion Corporation ], New Coal 2320 (HLB = 16.4), New Coal 2327 (HLB = 17.2) [above, manufactured by Nippon Emulsifier Co., Ltd.] and the like.

  Further, an anionic or nonionic reactive surfactant may be used in combination. For example, as a commercially available product, Latemul PD-104, Latemuru PD-420 (above, manufactured by Kao Corporation), Eleminor JS-2, (Sanyo Chemical Industries Co., Ltd.), Aqualon KH-10, Aqualon RN-20 (above, Daiichi Kogyo Seiyaku Co., Ltd.), Adeka Soap SR-10, Adeka Soap SE-10N, Adeka Soap ER-10, Adeka Soap ER-20 (above, made by Adeka Co., Ltd.), Antox MS-60 (Nippon Emulsifier Co., Ltd.).

  In the present invention, by using the anionic surfactant (A) and the nonionic surfactant (B) in combination, an aqueous resin dispersion for an elastic coating having excellent adhesion to the sealer layer can be obtained.

  Next, the ethylenically unsaturated monomer (C) used in the present invention will be described. Although there is no restriction | limiting in particular in the ethylenically unsaturated monomer (C) used for this invention, Tg (glass transition temperature) of resin formed by superposing | polymerizing a monomer (C) is -50-0 degreeC. It is necessary to choose to be. More preferably, it is −50 to −20 ° C. When Tg is less than −50 ° C., the toughness and strength of the coating film are deteriorated, and the tackiness is further increased, resulting in a problem of contamination resistance. Moreover, when it exceeds 0 degreeC, the softness | flexibility of the coating film obtained will lose | eliminate, the stretchability and elongation of a coating film will be bad, and the performance as resin for elastic paints cannot be exhibited. The Tg (glass transition temperature) of the polymer referred to in the present invention was a value calculated by the following Fox equation. In addition, in the case of emulsion polymerization, polyfunctional ethylenically unsaturated monomers having two or more polymerization sites are excluded from this calculation because a homopolymer cannot be obtained and the actual amount used is small. To do.

1 / Tg = W1 / Tg1 + W2 / Tg2 +... + Wn / Tgn
W1 to Wn indicate the weight fraction of the monomer used, and Tg1 to Tgn indicate the glass transition temperature (unit: absolute temperature “K”) of each homopolymer.

The Tg of the main homopolymer used for the calculation is exemplified below.
2-ethylhexyl acrylate: -55 ° C (218K)
Butyl acrylate: -45 ° C (228K)
Lauryl methacrylate: -65 ° C (208K)
Acrylic acid: 106 ° C (378K)
Methacrylic acid: 130 ° C (403K)
Acrylonitrile: 96 ° C (369K)
Methyl methacrylate: 105 ° C (378K)
Styrene: 100 ° C (373K)
Acrylic amide: 153 ° C (426K)

  Resin obtained by polymerizing ethylenically unsaturated monomer (C) is appropriately combined with monomers (C) that can form various Tg homopolymers to form resins with Tg of -50 to 0 ° C. I can do it.

  In the present invention, it is preferable to use (meth) acrylonitrile as one of the ethylenically unsaturated monomers (C) from the viewpoint of the toughness of the coating film and the low temperature performance. (Meth) acrylonitrile is preferably contained in the monomer (C) in an amount of 1 to 20% by weight, more preferably 3 to 10% by weight. If it is less than 1% by weight, the development of elasticity and coating strength may not be observed. If it exceeds 20% by weight, the monomer reaction rate on the synthetic surface, the elongation on the performance side, and the low-temperature performance may deteriorate. is there. Moreover, acrylonitrile is preferable to methacrylonitrile. This is because the glass transition temperature of the homopolymer of methacrylonitrile is 120 ° C., which is higher than that of acrylonitrile, and the constituent components and ratio of the monomer (C) are restricted.

Other ethylenically unsaturated monomers (C) include methyl acrylate, ethyl acrylate, isopropyl acrylate, n-butyl acrylate, isobutyl acrylate, n-hexyl acrylate, 2-ethylhexyl acrylate, acrylic Alkyl acrylates such as n-octyl acid, isobornyl acrylate and cyclohexyl acrylate;
Methyl methacrylate, ethyl methacrylate, propyl methacrylate, n-butyl methacrylate, tert-butyl methacrylate, isobutyl methacrylate, n-hexyl methacrylate, 2-ethylhexyl methacrylate, n-octyl methacrylate, methacrylic acid Alkyl methacrylates such as lauryl, isobornyl methacrylate, cyclohexyl methacrylate;
Vinyl ester monomers such as vinyl acetate and vinyl propionate;
Styrene monomers such as styrene and vinyltoluene;
Furthermore, carboxyl group-containing monomers such as acrylic acid, methacrylic acid, itaconic acid, maleic acid, fumaric acid, crotonic acid, hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxybutyl acrylate, hydroxyethyl methacrylate, hydroxymethacrylate Functional group monomers that contribute to the stabilization of emulsion resins, such as hydroxyl group-containing monomers such as propyl and hydroxybutyl methacrylate, amide group-containing monomers such as acrylamide and methacrylamide, and methylol group-containing monomers typified by N-methylolacrylamide Examples include hydrophilic monomers that are called.

In addition to these, epoxy group-containing monomers such as glycidyl acrylate and glycidyl methacrylate;
Polyfunctional ethylenically unsaturated monomers such as ethylene glycol dimethacrylate, diallyl phthalate, divinylbenzene;
γ-methacryloxypropylmethyldimethoxysilane, γ-methacryloxypropylmethyldiethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-methacryloxypropyltriethoxysilane, γ-acryloxypropylmethyldimethoxysilane, γ-acryloxy Silicon-containing monomers such as propylmethyldiethoxysilane, γ-acryloxypropyltrimethoxysilane, γ-acryloxypropyltriethoxysilane;
Carbonyl group-containing monomers such as diacetone acrylic amide and acetoacetoxyethyl methacrylate;
Etc. In the present invention, one or more of these monomers can be selected.

  Examples of the polymerization initiator (D) of the present invention include inorganic peroxide polymerization initiators such as ammonium persulfate, potassium persulfate, and sodium persulfate, hydrogen peroxide, t-butyl hydroperoxide, cumene hydroperoxide, and the like. Organic peroxide polymerization initiators, 2,2′-azobis [2-methyl-N- (2-hydroxyethyl) propionamide], 2,2′-azobis (2-amidinopropane) dihydrochloride, etc. An azo polymerization initiator can be used. In the case of a thermal decomposition type polymerization method using these initiators alone or a peroxide polymerization initiator, a reducing agent (E) such as sodium bisulfite, sodium thiosulfate, sodium sorbate, ascorbic acid, tartaric acid, etc. Although any of the redox type polymerization methods used in combination may be used, the present invention preferably uses a redox type in which a peroxide polymerization initiator and a reducing agent (E) are used in combination. The combination of the peroxide polymerization initiator and the reducing agent (E) tends to improve the adhesion of the sealer layer and the like. These polymerization initiator (D) and reducing agent (E) are generally used in an amount of 0.1 to 5.0% by weight based on the ethylenically unsaturated monomer (C). A necessary amount of these may be used collectively at the start of polymerization, or may be divided and added every arbitrary time. Further, ferrous sulfate, copper sulfate, ferrous chloride, copper chloride or the like may be used as a polymerization initiation accelerator.

  Further, if necessary, sodium acetate, sodium citrate, sodium bicarbonate, etc. as buffering agents, polyvinyl alcohol, water-soluble cellulose derivatives, etc. as protective colloids, octyl mercaptan, thioglycolic acid 2 as chain transfer agents -An appropriate amount of mercaptans such as ethylhexyl, stearyl mercaptan, lauryl mercaptan, t-dodecyl mercaptan can be used.

  An antifoaming agent, a leveling agent, a preservative, a pH adjusting agent, a viscosity adjusting agent, and the like can be blended in the aqueous resin dispersion obtained in the present invention as necessary.

  The aqueous resin dispersion for elastic paints obtained in the present invention is useful for aqueous elastic architectural paints. Next, the water-based elastic architectural paint of the present invention will be described. The aqueous elastic building paint of the present invention contains the above-described aqueous resin dispersion of the present invention, and can contain an inorganic filler in addition to the aqueous resin dispersion. Examples of inorganic fillers include color pigments such as titanium oxide, zinc oxide, carbon black, molybdenum red, and petrol, extender pigments such as calcium carbonate, clay, talc, kaolin, and barium sulfate. Titanium oxide is a color pigment. And at least one selected from the group consisting of calcium carbonate as extender pigments and clay. These inorganic fillers are preferably contained in an amount of 0.1 to 200 parts by weight, more preferably 50 to 150 parts by weight, based on 100 parts by weight of the aqueous resin dispersion.

  As other additives, commonly used wetting agents, dispersants, antifreeze agents, thickeners, viscosity modifiers, preservatives, antifungal agents, antifoaming agents, pH adjusters, and the like can be used as necessary. Furthermore, you may use together a well-known ultraviolet absorber and light stabilizer in the range which does not have a bad influence on performance.

  The water-based elastic architectural paint of the present invention is characterized in that it is coated on a coating film of a water-based sealer (S) coated on an alkali base material. By coating on the coating film of the aqueous sealer (S), it is possible to obtain a coating film with excellent alkali resistance and weather resistance, and particularly excellent adhesion with the sealer layer. Durability can be obtained.

  In general, when a paint is applied directly to an alkali base material, problems such as peeling and alteration of the coating film are likely to occur, the original physical properties of the paint cannot be exhibited, and inconveniences such as having to apply the paint more than necessary are likely to occur. . Further, when the base material of the coating base is brittle, or when the base coating film is deteriorated or choked, it is necessary to adjust the base in advance so that these problems do not occur. Furthermore, since the alkali base material contains an alkali component, there is a risk that the alkali component elutes to the outside of the substrate with time and corrodes the top coat film or the like.

  Aqueous sealer (S) has the ability to penetrate the porous alkali base material and the surface strength of the base material by infiltrating the porous brittle base material or the base material with weak surface strength to dry solidify or harden. The coating film is excellent in properties to be improved, and the coating film has properties such as water resistance, moisture resistance, alkali resistance, adhesion to a substrate, adhesion to a coating film of an overcoat or an old coating film, and the like. Such primer is called sealer, primer, surfacer, etc., organic solvent solution of one-component synthetic resin such as acrylic resin, vinyl chloride, chlorinated rubber, solvent-based two-component such as epoxy resin, urethane resin, etc. Those made of a reaction curable resin or the like are mainly used. In recent years, the use of an aqueous sealer (S) has been desired due to environmental problems.

  As the aqueous sealer (S), an aqueous resin dispersion obtained by emulsion polymerization using a monomer having a functional group that causes a crosslinking reaction such as a glycidyl group and a carboxyl group, a hydrazide group and a carbonyl group, an epoxy group and an amino group, An aqueous resin dispersion emulsion-polymerized with an ethylenically unsaturated monomer having a specific organosilane group in the molecule as an essential component, and emulsion polymerization in the presence of a reactive emulsifier having an ethylenically unsaturated group in the molecule. Examples thereof include an aqueous resin dispersion obtained, and a paint containing an aqueous resin dispersion obtained by emulsion polymerization of a monomer having a chlorine atom in the molecule.

  Examples of the alkali base material include ceramic building materials such as concrete, mortar, slate board, ALC board (lightweight cellular concrete panel), siding board, and flexible board.

The aqueous elastic architectural paint of the present invention is applied by a method such as spray coating, roller coating, or brush coating. The coating film thickness has an optimum film thickness depending on the purpose of use. For example, in the case of a relatively thick coating material such as multi-layer elasticity, the wet coating amount: 0.3 to 2.4 kg / m ² (dry coating) (Film thickness: 100 to 2000 microns). In the case of on-site paint, the drying after coating needs to be able to form a film in a wide range from an ambient temperature of around 5 ° C. in a cold region or in winter to around 40 ° C. in summer.

Furthermore, the present invention is an article to be coated in which an aqueous sealer (S) is first applied to an alkali base material to form a sealer layer, and then the above-described aqueous elastic building paint is applied to form an elastic layer. It is preferable to further apply a top coat paint to the article to be coated of the present invention. As a painting method, methods such as spray painting, roller painting, and brush painting are generally used. Among the topcoat coating films, in the case of a relatively thin flat coating film, 0.1 to 0.4 kg / m ² (dry film thickness: 50 to 300 microns) is a general coating amount. The article to be coated thus obtained is excellent in water resistance, waterproofness, weather resistance, stain resistance and the like, and is useful for architectural purposes.

  EXAMPLES Hereinafter, although an Example demonstrates this invention concretely, it is not limited to these. In the examples, “part” represents “part by weight” and “%” represents “% by weight”.

Example 1
A reaction vessel equipped with a stirrer, thermometer, dropping funnel and reflux condenser and charged with nitrogen gas was charged with ion-exchanged water (initial charge: 251 parts). Ethylenically unsaturated monomer (2-ethylhexyl acrylate: 750 parts, acrylic acid: 20 parts, acrylonitrile: 70 parts, methyl methacrylate: 160 parts), anionic surfactant [Emar 10 (10% aqueous solution, Kao) Company Ltd., the general formula (1) in _{^{R 1 = C 12, n =}} 0, M = Na): 150 parts, a nonionic surfactant [Noigen EA-177 (25% aqueous solution, manufactured by Dai-ichi Kogyo Seiyaku Co., HLB value = 15.6): 100 parts], ion-exchanged water (dropped portion: 147 parts) was charged into a dropping tank, mixed, stirred and emulsified to obtain an emulsified pre-emulsion. The Tg of the resin that can be formed from the monomer is −30 ° C. 1% (14 parts) of this emulsified pre-emulsion was charged into the reaction vessel as an initial divided portion. After raising the internal temperature of the reaction vessel to 70 ° C., 10% each of a polymerization initiator (ammonium persulfate 5% aqueous solution: 80 parts and sodium bisulfite 5% aqueous solution: 40 parts) was added to initiate the reaction. . The dripping of the remaining 99% of the emulsified pre-emulsion was started 5 minutes after the start of the reaction. The internal temperature was kept at 70 ° C., and the solution was continuously added dropwise over 4 hours, and further reacted at that temperature for 2 hours. The polymerization initiator (remaining 90%) was also added dropwise simultaneously with the addition of the emulsified pre-emulsion. After confirming that the reaction rate was 99% or more, the pH was adjusted with aqueous ammonia (20 parts) after cooling. Filtration through a 150 mesh filter cloth gave an aqueous resin dispersion having a nonvolatile content of 58.0%, a viscosity (BH type rotational viscometer, No4 rotor 20 rpm): 3000 mPa · s, and a particle size: 290 nm.

Example 2
A reaction vessel equipped with a stirrer, thermometer, dropping funnel and reflux condenser and charged with nitrogen gas was charged with ion-exchanged water (initial charge: 251 parts). Ethylenically unsaturated monomer (2-ethylhexyl acrylate: 750 parts, acrylic acid: 20 parts, acrylonitrile: 70 parts, methyl methacrylate: 160 parts), anionic surfactant [Latemul AD-25 (10% aqueous solution) Manufactured by Kao Corporation, R ¹ = C ₁₂ in general formula (1), n = 0, M = NH ₄ ): 150 parts], nonionic surfactant [Emulgen 1118S-70 (25% active ingredient aqueous solution, Kao Corporation) Manufactured, HLB value = 16.4): 100 parts], ion-exchanged water (dropped portion: 147 parts) was charged into a dropping tank, mixed, stirred and emulsified to obtain an emulsified pre-emulsion. The Tg of the resin that can be formed from the monomer is −30 ° C. 1% (14 parts) of this emulsified pre-emulsion was charged into the reaction vessel as an initial divided portion. After raising the internal temperature of the reaction vessel to 70 ° C., 10% each of a polymerization initiator (ammonium persulfate 5% aqueous solution: 80 parts and sodium bisulfite 5% aqueous solution: 40 parts) was added to initiate the reaction. . The dripping of the remaining 99% of the emulsified pre-emulsion was started 5 minutes after the start of the reaction. The internal temperature was kept at 70 ° C., and the solution was continuously added dropwise over 4 hours, and further reacted at that temperature for 2 hours. The polymerization initiator (remaining 90%) was also added dropwise simultaneously with the addition of the emulsified pre-emulsion. After confirming that the reaction rate was 99% or more, the pH was adjusted with aqueous ammonia (20 parts) after cooling. Filtration through a 150 mesh filter cloth gave an aqueous resin dispersion having a nonvolatile content of 57.9%, a viscosity (BH type rotational viscometer, No4 rotor 20 rpm): 2600 mPa · s, and a particle size: 340 nm.

Example 3
A reaction vessel equipped with a stirrer, thermometer, dropping funnel and reflux condenser and charged with nitrogen gas was charged with ion-exchanged water (initial charge: 251 parts). Ethylenically unsaturated monomer (2-ethylhexyl acrylate: 750 parts, acrylic acid: 20 parts, acrylonitrile: 70 parts, methyl methacrylate: 160 parts), anionic surfactant [Latemul AD-25 (10% aqueous solution) Manufactured by Kao Corporation, R ¹ = C ₁₂ in general formula (1), n = 0, M = NH ₄ ): 150 parts): Nonionic surfactant [Newcol 2327 (25% aqueous solution, manufactured by Nippon Emulsifier Co., Ltd., HLB value = 17.2: 100 parts], ion-exchanged water (dropped portion: 147 parts) was charged into a dropping tank, mixed, stirred and emulsified to obtain an emulsified pre-emulsion. Tg is −30 ° C. 1% portion (14 parts) of this emulsified pre-emulsion was charged into the reaction vessel as an initial divided portion, and after raising the internal temperature of the reaction vessel to 70 ° C., a polymerization initiator ( Persulfuric acid 10% each of ammonium 5% aqueous solution: 80 parts and sodium bisulfite 5% aqueous solution: 40 parts) were added to start the reaction, and dropping of the remaining 99% of the emulsified pre-emulsion was started 5 minutes after the start of the reaction. The inner temperature was kept at 70 ° C. and continuously dropped over 4 hours, and the reaction was further continued for 2 hours at that temperature, and the polymerization initiator (remaining 90%) was continuously dropped simultaneously with the dropping of the emulsified pre-emulsion. After confirming that it was 99% or more, pH was adjusted with aqueous ammonia (20 parts) after cooling, filtered through a 150 mesh filter cloth, non-volatile content: 58.1%, viscosity (BH rotational viscometer, No. 4 rotor 20 rpm): 3500 mPa · s, particle size: 300 nm aqueous resin dispersion was obtained.

Example 4
A reaction vessel equipped with a stirrer, a thermometer, a dropping funnel and a reflux condenser and charged with nitrogen gas was charged with ion-exchanged water (initial charge: 298 parts). Ethylenically unsaturated monomer (2-ethylhexyl acrylate: 750 parts, acrylic acid: 20 parts, acrylonitrile: 70 parts, methyl methacrylate: 160 parts), anionic surfactant [Emar E-27C (20% aqueous solution) Manufactured by Kao Corporation, R ¹ = C ₁₂ in general formula (1), n = 2, M = Na): 75 parts], nonionic surfactant [Neugen EA-177 (25% aqueous solution, Daiichi Kogyo Seiyaku Co., Ltd.) Manufactured, HLB value = 15.6): 100 parts], ion-exchanged water (dropped portion: 175 parts) was charged into a dropping tank, mixed, stirred and emulsified to obtain an emulsified pre-emulsion. The Tg of the resin that can be formed from the monomer is −30 ° C. 1% (14 parts) of this emulsified pre-emulsion was charged into the reaction vessel as an initial divided portion. After raising the internal temperature of the reaction vessel to 70 ° C., 10% each of a polymerization initiator (ammonium persulfate 5% aqueous solution: 80 parts and sodium bisulfite 5% aqueous solution: 40 parts) was added to initiate the reaction. . The dripping of the remaining 99% of the emulsified pre-emulsion was started 5 minutes after the start of the reaction. The internal temperature was kept at 70 ° C., and the solution was continuously added dropwise over 4 hours, and further reacted at that temperature for 2 hours. The polymerization initiator (remaining 90%) was also added dropwise simultaneously with the addition of the emulsified pre-emulsion. After confirming that the reaction rate was 99% or more, the pH was adjusted with aqueous ammonia (20 parts) after cooling. Filtration through a 150-mesh filter cloth gave an aqueous resin dispersion having a nonvolatile content of 58.1%, a viscosity (BH type rotational viscometer, No4 rotor 20 rpm): 2400 mPa · s, and a particle size: 330 nm.

Example 5
A reaction vessel equipped with a stirrer, a thermometer, a dropping funnel and a reflux condenser and charged with nitrogen gas was charged with ion-exchanged water (initial charge: 298 parts). Ethylenically unsaturated monomer (2-ethylhexyl acrylate: 750 parts, acrylic acid: 20 parts, acrylonitrile: 30 parts, methyl methacrylate: 200 parts), anionic surfactant [Emar 20T (20% aqueous solution, Kao) company Ltd., R ¹ = C ₁₂ in the general formula (1), n = 3, M = NH (C 2 H 4 OH) 3): 75 parts, a nonionic surfactant [Emulgen A-500 (25% aqueous solution , Manufactured by Kao Corporation, HLB value = 18.0): 100 parts], ion-exchanged water (dropped portion: 175 parts) was charged into a dropping tank, mixed, stirred and emulsified to obtain an emulsified pre-emulsion. The Tg of the resin that can be formed from the monomer is -29 ° C. 1% (14 parts) of this emulsified pre-emulsion was charged into the reaction vessel as an initial divided portion. After raising the internal temperature of the reaction vessel to 70 ° C., 10% each of a polymerization initiator (ammonium persulfate 5% aqueous solution: 80 parts and sodium bisulfite 5% aqueous solution: 40 parts) was added to initiate the reaction. . The dripping of the remaining 99% of the emulsified pre-emulsion was started 5 minutes after the start of the reaction. The internal temperature was kept at 70 ° C., and the solution was continuously added dropwise over 4 hours, and further reacted at that temperature for 2 hours. The polymerization initiator (remaining 90%) was also added dropwise simultaneously with the addition of the emulsified pre-emulsion. After confirming that the reaction rate was 99% or more, the pH was adjusted with aqueous ammonia (20 parts) after cooling. Filtration through a 150-mesh filter cloth gave an aqueous resin dispersion having a nonvolatile content of 58.2%, a viscosity (BH type rotational viscometer, No4 rotor 20 rpm): 1700 mPa · s, and a particle size: 360 nm.

Example 6
A reaction vessel equipped with a stirrer, thermometer, dropping funnel and reflux condenser and charged with nitrogen gas was charged with ion-exchanged water (initial charge: 251 parts). Ethylenically unsaturated monomer (2-ethylhexyl acrylate: 750 parts, acrylic acid: 20 parts, acrylonitrile: 50 parts, methyl methacrylate: 180 parts), anionic surfactant [Emar 10 (10% aqueous solution, Kao) Company Ltd., the general formula (1) in _{^{R 1 = C 12, n =}} 0, M = Na): 150 parts, a nonionic surfactant [Emulgen 1118S-70 (25% aqueous solution, manufactured by Kao Corp. HLB value = 16 4): 100 parts], ion-exchanged water (dropped portion: 147 parts) was charged into a dropping tank, mixed and stirred to emulsify, and an emulsified pre-emulsion was obtained. The Tg of the resin that can be formed from the monomer is -29 ° C. 1% (14 parts) of this emulsified pre-emulsion was charged into the reaction vessel as an initial divided portion. After raising the internal temperature of the reaction vessel to 70 ° C., 10% each of a polymerization initiator (ammonium persulfate 5% aqueous solution: 80 parts and sodium bisulfite 5% aqueous solution: 40 parts) was added to initiate the reaction. . The dripping of the remaining 99% of the emulsified pre-emulsion was started 5 minutes after the start of the reaction. The internal temperature was kept at 70 ° C., and the solution was continuously added dropwise over 4 hours, and further reacted at that temperature for 2 hours. The polymerization initiator (remaining 90%) was also added dropwise simultaneously with the addition of the emulsified pre-emulsion. After confirming that the reaction rate was 99% or more, the pH was adjusted with aqueous ammonia (20 parts) after cooling. Filtration through a 150 mesh filter cloth gave an aqueous resin dispersion having a nonvolatile content of 58.3%, a viscosity (BH type rotational viscometer, No4 rotor 20 rpm): 3100 mPa · s, and a particle size of 310 nm.

Example 7
A reaction vessel equipped with a stirrer, thermometer, dropping funnel and reflux condenser and charged with nitrogen gas was charged with ion-exchanged water (initial charge: 251 parts). Ethylenically unsaturated monomer (2-ethylhexyl acrylate: 750 parts, acrylic acid: 20 parts, acrylonitrile: 70 parts, methyl methacrylate: 160 parts), anionic surfactant [Emar 10 (10% aqueous solution, Kao) Company Ltd., the general formula (1) in _{^{R 1 = C 12, n =}} 0, M = Na): 150 parts, a nonionic surfactant [Newcol 2327 (25% aqueous solution, Nippon emulsifier Co. HLB value = 17 .2): 100 parts], ion-exchanged water (dropped portion: 147 parts) was charged into a dropping tank, mixed and stirred to emulsify to obtain an emulsified pre-emulsion. The Tg of the resin that can be formed from the monomer is −30 ° C. 1% (14 parts) of this emulsified pre-emulsion was charged into the reaction vessel as an initial divided portion. After raising the internal temperature of the reaction vessel to 70 ° C., 10% each of a polymerization initiator (ammonium persulfate 5% aqueous solution: 80 parts and sodium bisulfite 5% aqueous solution: 40 parts) was added to initiate the reaction. . The dripping of the remaining 99% of the emulsified pre-emulsion was started 5 minutes after the start of the reaction. The internal temperature was kept at 70 ° C., and the solution was continuously added dropwise over 4 hours, and further reacted at that temperature for 2 hours. The polymerization initiator (remaining 90%) was also added dropwise simultaneously with the addition of the emulsified pre-emulsion. After confirming that the reaction rate was 99% or more, the pH was adjusted with aqueous ammonia (20 parts) after cooling. Filtration through a 150 mesh filter cloth gave an aqueous resin dispersion having a non-volatile content of 57.6%, a viscosity (BH type rotational viscometer, No4 rotor 20 rpm): 2900 mPa · s, and a particle size of 270 nm.

Example 8
A reaction vessel equipped with a stirrer, thermometer, dropping funnel and reflux condenser and charged with nitrogen gas was charged with ion-exchanged water (initial charge: 251 parts). Ethylenically unsaturated monomer (2-ethylhexyl acrylate: 750 parts, acrylic acid: 20 parts, acrylonitrile: 100 parts, methyl methacrylate: 130 parts), anionic surfactant [Emar 10 (10% aqueous solution, Kao) Company Ltd., the general formula (1) in _{^{R 1 = C 12, n =}} 0, M = Na): 150 parts, a nonionic surfactant [Emulgen A-500 (25% aqueous solution, manufactured by Kao Corporation, HLB value = 18.0): 100 parts], ion-exchanged water (dropped portion: 147 parts) was charged into a dropping tank, mixed, stirred and emulsified to obtain an emulsified pre-emulsion. The Tg of the resin that can be formed from the monomer is −30 ° C. 1% (14 parts) of this emulsified pre-emulsion was charged into the reaction vessel as an initial divided portion. After raising the internal temperature of the reaction vessel to 70 ° C., 10% each of a polymerization initiator (ammonium persulfate 5% aqueous solution: 80 parts and sodium bisulfite 5% aqueous solution: 40 parts) was added to initiate the reaction. . The dripping of the remaining 99% of the emulsified pre-emulsion was started 5 minutes after the start of the reaction. The internal temperature was kept at 70 ° C., and the solution was continuously added dropwise over 4 hours, and further reacted at that temperature for 2 hours. The polymerization initiator (remaining 90%) was also added dropwise simultaneously with the addition of the emulsified pre-emulsion. After confirming that the reaction rate was 99% or more, the pH was adjusted with aqueous ammonia (20 parts) after cooling. Filtration through a 150 mesh filter cloth gave an aqueous resin dispersion having a nonvolatile content of 57.8%, a viscosity (BH type rotational viscometer, No4 rotor 20 rpm): 2800 mPa · s, and a particle size of 320 nm.

Example 9
A reaction vessel equipped with a stirrer, thermometer, dropping funnel and reflux condenser and charged with nitrogen gas was charged with ion-exchanged water (initial charge: 251 parts). Ethylenically unsaturated monomer (butyl acrylate: 750 parts, acrylic acid: 20 parts, acrylonitrile: 70 parts, methyl methacrylate: 160 parts), anionic surfactant [Latemul AD-25 (10% aqueous solution, Kao) Company Ltd., R ¹ = C ₁₂ in the general formula 1, n = 0, M = NH 4): 150 parts, a nonionic surfactant [Emulgen A-500 (25% aqueous solution, manufactured by Kao Corporation, HLB value = 18 0.0): 100 parts], ion-exchanged water (dropped portion: 147 parts) was charged into a dropping tank, mixed and stirred to emulsify to obtain an emulsified pre-emulsion. The Tg of the resin that can be formed from the monomer is −20 ° C. 1% (15 parts) of this emulsified pre-emulsion was charged into the reaction vessel as an initial divided portion. After raising the internal temperature of the reaction vessel to 70 ° C., 10% each of a polymerization initiator (ammonium persulfate 5% aqueous solution: 80 parts and sodium bisulfite 5% aqueous solution: 40 parts) was added to initiate the reaction. . The dripping of the remaining 99% of the emulsified pre-emulsion was started 5 minutes after the start of the reaction. The internal temperature was kept at 70 ° C., and the solution was continuously added dropwise over 4 hours, and further reacted at that temperature for 2 hours. The polymerization initiator (remaining 90%) was also added dropwise simultaneously with the addition of the emulsified pre-emulsion. After confirming that the reaction rate was 99% or more, the pH was adjusted with aqueous ammonia (20 parts) after cooling. Filtration through a 150 mesh filter cloth gave an aqueous resin dispersion having a nonvolatile content of 57.9%, a viscosity (BH type rotational viscometer, No4 rotor 20 rpm): 5300 mPa · s, and a particle size: 250 nm.

Example 10
A reaction vessel equipped with a stirrer, thermometer, dropping funnel and reflux condenser and charged with nitrogen gas was charged with ion-exchanged water (initial charge: 251 parts). Ethylenically unsaturated monomer (2-ethylhexyl acrylate: 898 parts, methacrylic acid: 30 parts, acrylonitrile: 50 parts, methyl methacrylate: 22 parts), anionic surfactant [Emar 10 (10% aqueous solution, Kao) Company Ltd., the general formula (1) in _{^{R 1 = C 12, n =}} 0, M = Na): 150 parts, a nonionic surfactant [Emulgen 1118S-70 (effective component 25% aqueous solution, manufactured by Kao Corp., HLB Value = 16.4): 100 parts], ion-exchanged water (dropped portion: 147 parts) was charged into a dropping tank, mixed, stirred and emulsified to obtain an emulsified pre-emulsion. The Tg of the resin that can be formed from the monomer is -45 ° C. 1% (14 parts) of this emulsified pre-emulsion was charged into the reaction vessel as an initial divided portion. After raising the internal temperature of the reaction vessel to 70 ° C., 10% each of a polymerization initiator (ammonium persulfate 5% aqueous solution: 80 parts and sodium bisulfite 5% aqueous solution: 40 parts) was added to initiate the reaction. . The dripping of the remaining 99% of the emulsified pre-emulsion was started 5 minutes after the start of the reaction. The internal temperature was kept at 70 ° C., and the solution was continuously added dropwise over 4 hours, and further reacted at that temperature for 2 hours. The polymerization initiator (remaining 90%) was also added dropwise simultaneously with the addition of the emulsified pre-emulsion. After confirming that the reaction rate was 99% or more, the pH was adjusted with aqueous ammonia (20 parts) after cooling. Filtration through a 150-mesh filter cloth gave an aqueous resin dispersion having a nonvolatile content of 58.0%, a viscosity (BH type rotational viscometer, No4 rotor 20 rpm): 2700 mPa · s, and a particle size of 320 nm.

Example 11
A reaction vessel equipped with a stirrer, thermometer, dropping funnel and reflux condenser and charged with nitrogen gas was charged with ion-exchanged water (initial charge: 251 parts). Ethylenically unsaturated monomer (2-ethylhexyl acrylate: 897 parts, methacrylic acid: 30 parts, acrylonitrile: 50 parts, styrene: 23 parts), anionic surfactant [Latemul AD-25 (10% aqueous solution, Kao) Company Ltd., R ¹ = C in formula _{(1) 12, n = 0} , M = NH 4): 150 parts, a nonionic surfactant [Emulgen A-500 (25% aqueous solution, manufactured by Kao Corporation, HLB value = 18.0): 100 parts], ion-exchanged water (dropped portion: 147 parts) was charged into a dropping tank, mixed, stirred and emulsified to obtain an emulsified pre-emulsion. The Tg of the resin that can be formed from the monomer is -45 ° C. 1% (14 parts) of this emulsified pre-emulsion was charged into the reaction vessel as an initial divided portion. After raising the internal temperature of the reaction vessel to 70 ° C., 10% each of a polymerization initiator (ammonium persulfate 5% aqueous solution: 80 parts and sodium bisulfite 5% aqueous solution: 40 parts) was added to initiate the reaction. . The dripping of the remaining 99% of the emulsified pre-emulsion was started 5 minutes after the start of the reaction. The internal temperature was kept at 70 ° C., and the solution was continuously added dropwise over 4 hours, and further reacted at that temperature for 2 hours. The polymerization initiator (remaining 90%) was also added dropwise simultaneously with the addition of the emulsified pre-emulsion. After confirming that the reaction rate was 99% or more, the pH was adjusted with aqueous ammonia (20 parts) after cooling. Filtration through a 150 mesh filter cloth gave an aqueous resin dispersion having a nonvolatile content of 58.3%, a viscosity (BH type rotational viscometer, No3 rotor 20 rpm): 3800 mPa · s, and a particle size: 270 nm.

Example 12
A reaction vessel equipped with a stirrer, thermometer, dropping funnel and reflux condenser and charged with nitrogen gas was charged with ion-exchanged water (initial charge: 308 parts). Ethylenically unsaturated monomer (butyl acrylate: 663 parts, methacrylic acid: 20 parts, acrylonitrile: 50 parts, methyl methacrylate: 217 parts, styrene: 50 parts), anionic surfactant [Emar 10 (10% Aqueous solution, manufactured by Kao Corporation, R ¹ = C ₁₂ in general formula (1), n = 0, M = Na): 150 parts], nonionic surfactant [Emulgen 1118S-70 (25% active ingredient aqueous solution, Kao Corporation) Manufactured, HLB value = 16.4): 100 parts], ion-exchanged water (dropped portion: 147 parts) was charged into a dropping tank, mixed, stirred and emulsified to obtain an emulsified pre-emulsion. The Tg of the resin that can be formed from the monomer is −10 ° C. 1% (14 parts) of this emulsified pre-emulsion was charged into the reaction vessel as an initial divided portion. After raising the internal temperature of the reaction vessel to 70 ° C., 10% each of a polymerization initiator (ammonium persulfate 5% aqueous solution: 80 parts and sodium bisulfite 5% aqueous solution: 40 parts) was added to initiate the reaction. . The dripping of the remaining 99% of the emulsified pre-emulsion was started 5 minutes after the start of the reaction. The internal temperature was kept at 70 ° C., and the solution was continuously added dropwise over 4 hours, and further reacted at that temperature for 2 hours. The polymerization initiator (remaining 90%) was also added dropwise simultaneously with the addition of the emulsified pre-emulsion. After confirming that the reaction rate was 99% or more, the pH was adjusted with aqueous ammonia (15 parts) after cooling. Filtration through a 150 mesh filter cloth gave an aqueous resin dispersion having a nonvolatile content of 57.6%, a viscosity (BH type rotational viscometer, No4 rotor 20 rpm): 2500 mPa · s, and a particle size of 300 nm.

Comparative Example 1
A reaction vessel equipped with a stirrer, a thermometer, a dropping funnel and a reflux condenser and charged with nitrogen gas was charged with ion-exchanged water (initial charge: 298 parts). Ethylenically unsaturated monomer (2-ethylhexyl acrylate: 750 parts, acrylic acid: 20 parts, acrylonitrile: 70 parts, methyl methacrylate: 160 parts), anionic surfactant [eleminol NHS-20 (20% aqueous solution) Sanyo Chemical Industries, R ¹ = C ₁₂ , n = 10, M = NH ₄ ) in the general formula (1): 75 parts], nonionic surfactant [Emulgen 1118S-70 (25% active ingredient aqueous solution, Kao) Manufactured by HLB Co., Ltd., HLB value = 16.4): 100 parts], ion-exchanged water (dropped portion: 175 parts) was charged into a dropping tank, mixed, stirred and emulsified to obtain an emulsion pre-emulsion. The Tg of the resin that can be formed from the monomer is −30 ° C. 1% (14 parts) of this emulsified pre-emulsion was charged into the reaction vessel as an initial divided portion. After raising the internal temperature of the reaction vessel to 70 ° C., 10% each of a polymerization initiator (ammonium persulfate 5% aqueous solution: 80 parts and sodium bisulfite 5% aqueous solution: 40 parts) was added to initiate the reaction. . The dripping of the remaining 99% of the emulsified pre-emulsion was started 5 minutes after the start of the reaction. The internal temperature was kept at 70 ° C., and the solution was continuously added dropwise over 4 hours, and further reacted at that temperature for 2 hours. The polymerization initiator (remaining 90%) was also added dropwise simultaneously with the addition of the emulsified pre-emulsion. After confirming that the reaction rate was 99% or more, the pH was adjusted with aqueous ammonia (20 parts) after cooling. Filtration through a 150 mesh filter cloth gave an aqueous resin dispersion having a nonvolatile content of 58.0%, a viscosity (BH type rotational viscometer, No4 rotor 20 rpm): 3200 mPa · s, and a particle size: 290 nm.

Comparative Example 2
A reaction vessel equipped with a stirrer, a thermometer, a dropping funnel and a reflux condenser and charged with nitrogen gas was charged with ion-exchanged water (initial charge: 298 parts). Ethylenically unsaturated monomer (2-ethylhexyl acrylate: 750 parts, acrylic acid: 20 parts, acrylonitrile: 70 parts, methyl methacrylate: 160 parts), anionic surfactant [Newcol 2320-SN (20% aqueous solution, Nippon emulsifier Co., R ¹ = C ₁₂ ~ ₁₃ in the general formula (1), n = 20, M = Na): 75 parts, a nonionic surfactant [Emulgen 1118S-70 (25% aqueous solution, manufactured by Kao Manufactured by HLB Co., Ltd., HLB value = 16.4): 100 parts], ion-exchanged water (dropped portion: 175 parts) was charged into a dropping tank, mixed, stirred and emulsified to obtain an emulsion pre-emulsion. The Tg of the resin that can be formed from the monomer is −30 ° C. 1% (14 parts) of this emulsified pre-emulsion was charged into the reaction vessel as an initial divided portion. After raising the internal temperature of the reaction vessel to 70 ° C., 10% each of a polymerization initiator (ammonium persulfate 5% aqueous solution: 80 parts and sodium bisulfite 5% aqueous solution: 40 parts) was added to initiate the reaction. . The dripping of the remaining 99% of the emulsified pre-emulsion was started 5 minutes after the start of the reaction. The internal temperature was kept at 70 ° C., and the solution was continuously added dropwise over 4 hours, and further reacted at that temperature for 2 hours. The polymerization initiator (remaining 90%) was also added dropwise simultaneously with the addition of the emulsified pre-emulsion. After confirming that the reaction rate was 99% or more, the pH was adjusted with aqueous ammonia (20 parts) after cooling. Filtration through a 150 mesh filter cloth gave an aqueous resin dispersion having a nonvolatile content of 57.7%, a viscosity (BH type rotational viscometer, No4 rotor 20 rpm): 2300 mPa · s, and a particle size of 310 nm.

Comparative Example 3
A reaction vessel equipped with a stirrer, thermometer, dropping funnel and reflux condenser and charged with nitrogen gas was charged with ion-exchanged water (initial charge: 251 parts). Ethylenically unsaturated monomer (butyl acrylate: 755 parts, acrylic acid: 20 parts, acrylonitrile: 70 parts, methyl methacrylate: 155 parts), anionic surfactant [Emar 10 (10% aqueous solution, manufactured by Kao Corporation) , R ¹ = C ₁₂ in general formula (1), n = 0, M = Na): 150 parts], nonionic surfactant [Emulgen A-60 (25% aqueous solution, manufactured by Kao Corporation, HLB value = 12. 8): 100 parts], ion-exchanged water (dropped portion: 147 parts) was charged into a dropping tank, mixed and stirred to emulsify, and an emulsified pre-emulsion was obtained. The Tg of the resin that can be formed from the monomer is −30 ° C. 1% (14 parts) of this emulsified pre-emulsion was charged into the reaction vessel as an initial divided portion. After raising the internal temperature of the reaction vessel to 70 ° C., 10% each of a polymerization initiator (ammonium persulfate 5% aqueous solution: 80 parts and sodium bisulfite 5% aqueous solution: 40 parts) was added to initiate the reaction. . The dripping of the remaining 99% of the emulsified pre-emulsion was started 5 minutes after the start of the reaction. The internal temperature was kept at 70 ° C., and the solution was continuously added dropwise over 4 hours, and further reacted at that temperature for 2 hours. The polymerization initiator (remaining 90%) was also added dropwise simultaneously with the addition of the emulsified pre-emulsion. After confirming that the reaction rate was 99% or more, the pH was adjusted with aqueous ammonia (15 parts) after cooling. Filtration was performed with a 150 mesh filter cloth to obtain an aqueous resin dispersion having a nonvolatile content of 57.9%, a viscosity (BH type rotational viscometer, No4 rotor 20 rpm): 2000 mPa · s, and a particle size: 330 nm.

Comparative Example 4
A reaction vessel equipped with a stirrer, thermometer, dropping funnel and reflux condenser and charged with nitrogen gas was charged with ion-exchanged water (initial charge: 251 parts). Ethylenically unsaturated monomer (butyl acrylate: 755 parts, acrylic acid: 20 parts, acrylonitrile: 70 parts, methyl methacrylate: 155 parts), anionic surfactant [Emar 10 (10% aqueous solution, manufactured by Kao Corporation) , R ¹ = C ₁₂ in general formula (1), n = 0, M = Na): 150 parts], nonionic surfactant [New Coal 516 (25% aqueous solution, manufactured by Nippon Emulsifier Co., Ltd., HLB value = 18. 8): 100 parts], ion-exchanged water (dropped portion: 147 parts) was charged into a dropping tank, mixed and stirred to emulsify, and an emulsified pre-emulsion was obtained. The Tg of the resin that can be formed from the monomer is −30 ° C. 1% (14 parts) of this emulsified pre-emulsion was charged into the reaction vessel as an initial divided portion. After raising the internal temperature of the reaction vessel to 70 ° C., 10% each of a polymerization initiator (ammonium persulfate 5% aqueous solution: 80 parts and sodium bisulfite 5% aqueous solution: 40 parts) was added to initiate the reaction. . The dripping of the remaining 99% of the emulsified pre-emulsion was started 5 minutes after the start of the reaction. The internal temperature was kept at 70 ° C., and the solution was continuously added dropwise over 4 hours, and further reacted at that temperature for 2 hours. The polymerization initiator (remaining 90%) was also added dropwise simultaneously with the addition of the emulsified pre-emulsion. After confirming that the reaction rate was 99% or more, the pH was adjusted with aqueous ammonia (20 parts) after cooling. Filtration was performed with a 150 mesh filter cloth to obtain an aqueous resin dispersion having a nonvolatile content of 57.9%, a viscosity (BH type rotational viscometer, No4 rotor 20 rpm): 2000 mPa · s, and a particle size: 330 nm.

Comparative Example 5
A reaction vessel equipped with a stirrer, thermometer, dropping funnel and reflux condenser and charged with nitrogen gas was charged with ion-exchanged water (initial charge: 308 parts). Ethylenically unsaturated monomer (2-ethylhexyl acrylate: 666 parts, lauryl methacrylate: 300 parts, acrylic acid: 20 parts, acrylonitrile: 14 parts), anionic surfactant [Emar 10 (10% aqueous solution, Manufactured by Kao Corporation, R ¹ = C ₁₂ in general formula (1), n = 0, M = Na): 150 parts], nonionic surfactant [Emulgen 1118S-70 (25% aqueous solution, manufactured by Kao Corporation, HLB value) = 16.4): 100 parts], ion-exchanged water (dropped portion: 147 parts) was charged into a dropping tank, mixed, stirred and emulsified to obtain an emulsified pre-emulsion. The Tg of the resin that can be formed from the monomer is -55 ° C. 1% (14 parts) of this emulsified pre-emulsion was charged into the reaction vessel as an initial divided portion. After raising the internal temperature of the reaction vessel to 70 ° C., 10% each of a polymerization initiator (ammonium persulfate 5% aqueous solution: 80 parts and sodium bisulfite 5% aqueous solution: 40 parts) was added to initiate the reaction. . The dropping of the remaining 99% of the emulsified pre-emulsion was started 5 minutes after the start of the reaction. The internal temperature was kept at 70 ° C., and the solution was continuously added dropwise over 4 hours, and further reacted at that temperature for 2 hours. The polymerization initiator (remaining 90%) was also added dropwise simultaneously with the addition of the emulsified pre-emulsion. After confirming that the reaction rate was 99% or more, the pH was adjusted with aqueous ammonia (15 parts) after cooling. Filtration through a 150 mesh filter cloth gave an aqueous resin dispersion having a nonvolatile content of 58.1%, a viscosity (BH type rotational viscometer, No4 rotor 20 rpm): 2200 mPa · s, and a particle size of 350 nm.

Comparative Example 6
A reaction vessel equipped with a stirrer, thermometer, dropping funnel and reflux condenser and charged with nitrogen gas was charged with ion-exchanged water (initial charge: 251 parts). Ethylenically unsaturated monomer (2-ethylhexyl acrylate: 488 parts, methacrylic acid: 20 parts, acrylonitrile: 50 parts, methyl methacrylate: 392 parts, styrene: 50 parts), anionic surfactant [Emar 10 ( 10% aqueous solution, manufactured by Kao Corporation, R ¹ = C ₁₂ in general formula (1), n = 0, M = Na): 150 parts], nonionic surfactant [Emulgen 1118S-70 (25% aqueous solution, Kao Corporation) Manufactured, HLB value = 16.4): 100 parts], ion-exchanged water (dropped portion: 147 parts) was charged into a dropping tank, mixed, stirred and emulsified to obtain an emulsified pre-emulsion. The Tg of the resin that can be formed from the monomer is 5 ° C. 1% (14 parts) of this emulsified pre-emulsion was charged into the reaction vessel as an initial divided portion. After raising the internal temperature of the reaction vessel to 70 ° C., 15% of each of a polymerization initiator (ammonium persulfate 5% aqueous solution: 80 parts and sodium bisulfite 5% aqueous solution: 40 parts) was added to initiate the reaction. . The dripping of the remaining 99% of the emulsified pre-emulsion was started 5 minutes after the start of the reaction. The internal temperature was kept at 70 ° C., and the solution was continuously added dropwise over 4 hours, and further reacted at that temperature for 2 hours. The polymerization initiator (remaining 90%) was also added dropwise simultaneously with the addition of the emulsified pre-emulsion. After confirming that the reaction rate was 99% or more, the pH was adjusted with aqueous ammonia (20 parts) after cooling. Filtration through a 150 mesh filter cloth gave an aqueous resin dispersion having a nonvolatile content of 58.3%, a viscosity (BH type rotational viscometer, No4 rotor 20 rpm): 3300 mPa · s, and a particle size of 300 nm.

Using the aqueous resin dispersions of Examples 1 to 12 and Comparative Examples 1 to 6, they were blended as follows and mixed and stirred with a disper to obtain an aqueous elastic building paint.
Aqueous dispersion for elastic paint: 233 parts Calcium carbonate (NS # 100, manufactured by Nitto Flour Chemical Co., Ltd.): 190 parts Titanium oxide (Taipeku CR97, manufactured by Ishihara Sangyo Co., Ltd.): 10 parts Dispersant (Primal 850 Nippon Acrylic) (Made by Co., Ltd.): 3 parts Antifoaming agent (SN Deformer 1070, made by San Nopco): 5 parts 25% ammonia water: 1 part Zinc oxide: 1 part Thickener (Primal ASE-60 Nippon Acrylic Chemical Co., Ltd.) ) Made): 1 part

  The obtained water-based elastic architectural paint was evaluated as follows. Table 1 shows the results of the examples and Table 2 shows the results of the comparative examples.

<Evaluation method>
(1) Adhesiveness with sealer layer A commercially available flexible slate plate coated with a commercially available aqueous sealer was coated with a water-based elastic building paint so as to have a thickness of about 0.1 mm (dry thickness), and dried at room temperature for 1 day. The elastic coating film was cut into 1 mm square grids (100), and the adhesion with the sealer layer was evaluated by a grid test where the cellophane tape was peeled off. (As evaluated below, the number of grids that did not peel off was evaluated.)
100/100-80/100: ○
79/100 to 60/100: Δ
59/100 or less: x

(2) Tensile performance of coating film (elongation at break)
A water-based elastic building paint was applied to the release paper to a thickness of about 1 mm (dry thickness) and dried at room temperature for 7 days. In accordance with JIS-A-6021, the elongation at break of the isolated coating film at 23 ° C. was determined.

(3) Water resistance A commercially available flexible slate plate coated with a commercially available water-based sealer was coated with a water-based elastic architectural paint so as to have a thickness of about 0.1 mm (dry thickness) and dried at room temperature for 1 day. The flexible slate plate was immersed in warm water at 50 ° C. for 2 hours, and water resistance was evaluated from blistering and peeling. The case where no change was visually observed was indicated as “◯”, and the case where blistering or peeling was observed was indicated as “X”.

Emar 10, Latemul AD-25, Emar E-27C, Emar 20T, Emulgen 1118S-70, Emulgen A-500: New Coal 2327, New Coal 516 manufactured by Kao Corporation Neugen EA-177 manufactured by Nippon Emulsifier Co., Ltd. ELEMINOL NHS-20 manufactured by Sanyo Chemical Industries

  As shown in Table 1, the aqueous dispersions for elastic coatings of Examples 1 to 12 using specific anionic and nonionic surfactants and having a Tg of the resin in a certain range are adhesive to the sealer layer. , Tensile performance (elongation rate) and water resistance were all good, whereas Comparative Examples 1 to 6 were obtained in which any of the above physical properties was poor and all were good. There wasn't.

Claims (7)

An aqueous elastic building paint comprising an aqueous resin dispersion for an elastic coating, coated on a coating film of an aqueous sealer (S) coated on an alkali base material,
Aqueous resin dispersion for elastic paints (excluding formaldehyde condensates of melamine sulfonate and resins having side chains represented by the following general formula (I) and general formula (II))
Is an emulsion polymerization of an ethylenically unsaturated monomer (C) with an initiator (D) in an aqueous medium using an anionic surfactant (A) and a nonionic surfactant (B). The anionic surfactant (A) is an activator represented by the following general formula (1), and the nonionic surfactant (B) has an HLB value of 13.5 to 18.5. ,And,
A water-based elastic architectural paint having a Tg of -50 to 0 ° C.
General formula (1)
R ¹ —O — (— CH ₂ CH ₂ O—) _n —SO ₃ M
[R ¹ is a C _{7 to} C ₁₇ alkyl group, n is an integer of 0 to 4, M is Na or NH ₄ or NH (R ² OH) ₃ , where R ² is a C _{1 to} C ₄ Alkylene group]
Formula (I)

(In the formula, Y ¹ represents a single bond, a methylene group, —COO—R ¹ — or —CONH—R ² —,
Here, R ¹ and R ² each represent an alkylene group having 1 to 6 carbon atoms , and Y ² represents hydrogen or CN)
Formula (II)

(Wherein R ³ represents an alkylene group having 1 to 6 carbon atoms , and Y ³ represents hydrogen or an alkyl group having 1 to 6 carbon atoms )   The water-based elastic building paint according to claim 1, wherein the ethylenically unsaturated monomer (C) contains (meth) acrylonitrile in an amount of 1 to 20% by weight based on the whole monomer (C).   The water-based elastic architectural paint according to claim 1 or 2, wherein the polymerization initiator (D) is a peroxide-based polymerization initiator and is emulsion-polymerized using the reducing agent (E) in combination.   A coated object obtained by coating the aqueous elastic architectural paint according to any one of claims 1 to 3 on a coating film of an aqueous sealer (S) coated on an alkali base material. A method for producing a water-based elastic architectural paint, which is coated on a coating film of a water-based sealer (S) coated on an alkali base material,
Elastic paint for emulsion polymerization of ethylenically unsaturated monomer (C) with polymerization initiator (D) in aqueous medium using anionic surfactant (A) and nonionic surfactant (B) Aqueous resin dispersions for elastic paints, including aqueous resin dispersions (excluding formaldehyde condensates of melamine sulfonate and resins having side chains represented by the following general formula (I) and general formula (II)) A method for producing a water-based elastic architectural paint.
An anionic surfactant (A) is an active agent represented by the following general formula (1) Nonionic surfactant (B) has an HLB value of 13.5 to 18.5.
Tg of resin is −50 to 0 ° C.
General formula (1)
R ¹ —O — (— CH ₂ CH ₂ O—) _n —SO ₃ M
[R ¹ is a C _{7 to} C ₁₇ alkyl group, n is an integer of 0 to 4, M is Na or NH ₄ or NH (R ² OH) ₃ , where R ² is a C _{1 to} C ₄ Alkylene group]
Formula (I)

(In the formula, Y ¹ represents a single bond, a methylene group, —COO—R ¹ — or —CONH—R ² —,
Here, R ¹ and R ² each represent an alkylene group having 1 to 6 carbon atoms , and Y ² represents hydrogen or CN)
Formula (II)

(Wherein R ³ represents an alkylene group having 1 to 6 carbon atoms , and Y ³ represents hydrogen or an alkyl group having 1 to 6 carbon atoms )   The ethylenically unsaturated monomer (C) contains 1 to 20% by weight of (meth) acrylonitrile based on the total amount of the monomer (C). Method. The water-based elastic building paint according to claim 5 or 6, wherein the polymerization initiator (D) is a peroxide polymerization initiator and is emulsion-polymerized in combination with the reducing agent (E). Method.