JP5201830B2 - Two-part aqueous paint composition - Google Patents

Description

  The present invention relates to a two-part aqueous coating composition, and more specifically, for example, various coatings on, for example, interiors and exteriors of buildings, automobiles, household appliances, plastics, and the contact angle with water of the obtained coating film is 70 ° or less. The present invention relates to a two-component aqueous coating composition that can form such a hydrophilic surface.

  The coating composition that forms a hydrophilic surface is useful for suppressing the occurrence of dirt caused by automobile exhaust gas or the like, which is particularly demanded in exterior coatings for buildings (hereinafter referred to as “stain resistance”). It is known. In a solvent-based paint using an organic solvent, a hydrophilic surface is formed by blending tetraalkoxysilane and / or a hydrolysis condensate thereof (hereinafter, these compounds may be simply referred to as “silicates”), It has been disclosed that stain resistance can be improved, and it is used as a low-contamination paint (see, for example, Patent Document 1). However, these silicates cause a hydrolytic condensation reaction upon contact with water, and have low compatibility or dispersibility with water and a polymer that is a coating film forming component. When added to water-based paints, which are rarely contained, rapid reaction, low compatibility or dispersibility causes extreme changes in paint viscosity, deterioration of paint film appearance, and dispersion of paint film surface hydrophilicity. Cheap.

For the purpose of imparting compatibility or dispersibility of such silicates to water-based paints, for example, by introducing a hydrophilic polyoxyalkylene chain into the silicate itself to improve the dispersibility in water, An aqueous paint decontaminating agent to be used is disclosed (for example, see Patent Document 2), and a resin composition for an aqueous paint to be added after an aqueous emulsified silicate is previously added using an emulsifier is disclosed (for example, Patent Document 3). A resin composition for water-based paints which is added after partially hydrolyzing silicates with an acid or a base to form an aqueous sol (see, for example, Patent Document 4). However, in Patent Document 2 and Patent Document 3, a polyoxyalkylene chain or an emulsifier, which is a hydrophilic component, is inevitably accompanied, and the water resistance of the coating film due to these becomes a problem. Moreover, in patent document 4, stability becomes a problem, such as the aqueous sol obtained gelatinizes over time.
WO94 / 06870 Publication WO99 / 05228 Japanese Patent Application Laid-Open No. 8-259892 JP-A-9-221611

  In view of the above problems, the present invention provides a water-based coating composition capable of forming a hydrophilic surface using a coating film surface hydrophilizing agent containing a water-based coating and tetraalkoxysilane and / or a hydrolysis condensate thereof. An object of the present invention is to provide a two-component aqueous coating composition that stably exhibits coating viscosity, coating film appearance, coating film surface hydrophilicity and a coating method thereof without accompanying a hydrophilic component that lowers the film performance.

  As a result of intensive studies to solve these problems, the present inventors have found that a coating surface hydrophilizing agent containing tetraalkoxysilane and / or a hydrolysis condensate thereof and an acidic phosphorus compound is used for promoting dispersion. It was found that the paint viscosity, coating film appearance, and coating film hydrophilicity could be stably exhibited without the need to use the polyoxyalkylene chain-containing compound.

  That is, the present invention comprises (1) an aqueous paint and (2) a coating surface hydrophilizing agent, and (1) the aqueous paint comprises a water-soluble resin and / or an aqueous emulsion as a coating film-forming component, 2) A two-part aqueous coating composition characterized in that the coating surface hydrophilizing agent contains tetraalkoxysilane and / or its hydrolysis condensate (A) and acidic phosphorus compound (B) (Claim 1). .

  In a preferred embodiment of the present invention, the acidic phosphorus compound (B) is an acidic phosphate ester, phosphonic acid or acidic phosphonic acid ester having a hydrocarbon group selected from an alkyl group having 12 or less carbon atoms, an alkylene group or an aralkyl group. The two-component water-based coating composition according to claim 1, which is at least one selected from the group consisting of the following groups (claim 2).

  A preferred embodiment of the present invention is the two-component water-based coating composition according to claim 1 or 2, wherein the tetraalkoxysilane and / or its hydrolysis condensate (A) contains an alkyl group having 2 or more carbon atoms. Item 3).

  A preferred embodiment of the present invention is the two-component coating composition according to any one of claims 1 to 3, wherein the (1) water-based coating further contains a hydrolyzable silyl group-containing acrylic polymer. ).

  The present invention provides the method for coating a two-component coating composition according to claims 1 to 4, wherein the (2) coating surface hydrophilizing agent is added to the (1) water-based coating, and the mixture is coated after coating. It is.

  In the present invention, a tetraalkoxysilane and / or a hydrolysis condensate thereof (A) and an acidic phosphorus compound (B) are mixed in advance, and this is an aqueous solution containing a water-soluble resin and / or an aqueous emulsion as a film-forming component. It is a coating composition formed by adding to a coating material.

  The water-based coating composition of the present invention can be produced with low cost and simple operation. According to the aqueous coating composition of the present invention, it is possible to disperse silicates well in an aqueous coating without using a polyoxyalkylene chain-containing compound or an emulsifier as a hydrophilic component that lowers the water resistance of the coating film. it can. Moreover, the formed coating film has high gloss and improves water resistance.

Hereinafter, the present invention will be described in detail.
Water-based paint (1) The water-based paint constituting the water-based paint composition of the present invention is not particularly limited as long as it is a paint containing a water-soluble resin and / or an aqueous emulsion as a film-forming component. Examples of the resin include acrylic resins, urethane resins, fluororesins, melamine resins, silicone resins, epoxy resins, polyester resins, and polyether resins. Among these resins, acrylic resin, urethane resin, fluororesin, etc. are preferable in terms of weatherability and chemical resistance of the resulting coating film and the wide range of resin design, and coating film surface hydrophilicity. An acrylic resin is preferable from the viewpoint of low cost.

  The acrylic resin can be synthesized using a vinyl monomer, and the vinyl monomer (a-1) used for polymer synthesis is not particularly limited. For example, methyl (meth) acrylate, ethyl C1-C20 alkyl (meth) acrylates such as (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, t-butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate; cyclohexyl ( C4-C20 cycloalkyl (meth) acrylate such as (meth) acrylate, isobornyl (meth) acrylate, dicyclopentanyl (meth) acrylate; allyl (meth) acrylate, benzyl (meth) acrylate, dicyclopentenyl (meth) ) Aralkyl having 3 to 20 carbon atoms such as acrylate ) Acrylate; epoxy group-containing vinyl monomers such as glycidyl (meth) acrylate and oxycyclohexylinyl (meth) acrylate; acrylic acid, methacrylic acid, maleic acid, maleic anhydride, itaconic acid, itaconic anhydride, crotonic acid, Α, β-ethylenically unsaturated carboxylic acids such as fumaric acid and citraconic acid, or salts thereof (alkali metal salts, ammonium salts, amine salts, etc.); acid anhydrides such as maleic anhydride or those having 1 to 1 carbon atoms 20 half esters with linear or branched alcohols or salts thereof (alkali metal salts, ammonium salts, amine salts, etc.); styrene sulfonic acid, vinyl sulfonic acid, 2- (meth) acryloxyethyl sulfonic acid, 2 -Polymerizable carbon such as (meth) acryloxyethyl phosphate- Acids having an elementary double bond, or salts thereof (alkali metal salts, ammonium salts, amine salts, etc.); N, N-dimethylaminoethyl (meth) acrylate, N, N-dimethylaminopropyl (meth) acrylate, An amino group-containing vinyl monomer such as N, N-diethylaminoethyl (meth) acrylate or a salt thereof (hydrochloride, acetate, etc.); a quaternary amino group such as trimethylaminoethyl (meth) acrylate hydrochloride; Vinyl monomers having; (meth) acrylamide, α-ethyl (meth) acrylamide, N-butoxymethyl (meth) acrylamide, N, N-dimethyl (meth) acrylamide, N-methyl (meth) acrylamide, acryloylmorpholine, etc. (Meth) acrylamide or their salts (hydrochloride, acetate) Nitrogen-containing vinyl monomers such as N-vinylpyrrolidone, N-vinylpyridine, N-vinylimidazole, etc .; 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, glycerin mono (meth) acrylate , 2-hydroxyethyl vinyl ether, N-methylol (meth) acrylamide, hydroxystyrene-containing vinyl monomers such as hydroxystyrene; PixelFA-1, PlaceFA-4, Placel FM-1, Placel FM-4 (above, manufactured by Daicel Chemical Co., Ltd.) Polylactone or polyester having a polymerizable carbon-carbon double bond at the end, such as Blemmer PP series, Blemmer PE series, Blemmer PEP series (manufactured by NOF Corporation), MA-30, MA-50, Polymerizable carbon-carbon such as A-100, MA-150, RA-1120, RA-2614, RMA-564, RMA-568, RMA-1114, MPG130-MA (manufactured by Nippon Emulsifier Co., Ltd.) Polyoxyalkylene terminated with a heavy bond; Phosphoric ester of hydroxyalkyl ester of α, β-ethylenically unsaturated carboxylic acid; Vinyl compound such as (meth) acrylate containing urethane bond or siloxane bond; Toa Gosei Chemical Co., Ltd. ) Macromonomers such as AS-6, AN-6, AA-6, AB-6, AK-5; vinyl esters such as vinyl acetate, vinyl propionate, vinyl versatate, diallyl phthalate, and allyl compounds Nitrile group-containing vinyl monomers such as (meth) acrylonitrile; styrene, α-me Aromatic hydrocarbon vinyl monomers such as styrene, chlorostyrene, 4-hydroxystyrene, vinyltoluene; other vinyl monomers such as vinyl methyl ether, vinyl chloride, vinylidene chloride, chloroprene, propylene, butadiene, etc. One or a mixture of two or more selected from the group can be used.

  In addition, a hydrolyzable silyl group-containing monomer (a-2) having one or more polymerizable carbon-carbon double bonds and one or more hydrolyzable silyl groups in one molecule can be used. Crosslinking reactivity by a siloxane bond can be imparted.

  This crosslinking reactivity can be promoted by the acidic phosphorus compound (B) contained in (2) the coating surface hydrophilizing agent, and the use of (a-2) improves the water resistance and weather resistance of the resulting coating. It is preferable because it improves and works advantageously in the expression of hydrophilicity on the coating film surface. Specific examples of (a-2) include vinyltrimethoxysilane, vinyltriethoxysilane, vinyltri (n-propoxy) silane, vinyltriisopropoxysilane, vinyltributoxysilane, vinyltris (β-methoxyethoxy) silane, allyl Triethoxysilane, trimethoxysilylpropylallylamine, γ- (meth) acryloxypropyltrimethoxysilane, γ- (meth) acryloxypropyltriethoxysilane, γ- (meth) acryloxypropyltriisopropoxysilane, γ- ( (Meth) acryloxypropyltris (β-methoxyethoxy) silane, γ- (meth) acryloxypropylmethyldimethoxysilane, γ- (meth) acryloxypropylmethyldiethoxysilane, γ- (meth) acryloxypropyldimethylmeth Sisilane, γ- (meth) acryloxypropyldimethylethoxysilane, N-vinylbenzyl-γ-aminopropyltrimethoxysilane, 2-styrylethyltrimethoxysilane, 3- (N-styrylmethyl-2-aminoethylamino) propyl Examples include trimethoxysilane, (meth) acryloxyethyldimethyl (3-trimethoxysilylpropyl) ammonium chloride, vinyltriacetoxysilane, vinyltrichlorosilane, and the like, and one or more selected from these groups Mixtures can be used. Among these, an alkoxysilyl group-containing monomer is particularly preferable from the viewpoint of stability.

  The amount of (a-2) used is preferably 0.01 to 50% by weight in a total of 100% by weight of the monomer mixture. If (a-2) is less than 0.01%, the effect of improving the physical properties of the coating film due to siloxane crosslinking may be insufficient, and if it exceeds 50% by weight, the water-soluble resin and / or aqueous emulsion becomes unstable. There is a case. More preferably, it is 0.5 to 20% by weight.

  Moreover, the vinyl-type monomer (a-3) containing a carbonyl group can also be used, and crosslinking reactivity can be provided by using together the compound which has a hydrazine and a hydrazyl group. Specific examples of (a-3) include, for example, acrolein, diacetone acrylamide, formyl styrene, preferably vinyl alkyl ketone having 4 to 7 carbon atoms (for example, vinyl methyl ketone, vinyl ethyl ketone, vinyl Isobutyl ketone, etc.), diacetone acrylate, acetonyl acrylate, diacetone methacrylate, 2-hydroxypropyl acrylate-acetyl acetate, butanediol-1,4-acrylate-acetyl acetate, etc., and one kind selected from these groups Alternatively, a mixture of two or more types can be used. The amount of (a-3) used is 0.1 to 30% by weight, preferably 3 to 10% by weight, in a total of 100% by weight of the monomer mixture.

  By using a carbonyl group-containing polymer, it can be reacted with a compound having hydrazine and a hydrazyl group. As the compound having hydrazine and a hydrazyl group, a hydrazine derivative containing at least two hydrazine residues in one molecule is preferable, and a dicarboxylic acid and hydrazine having 2 to 10, more preferably 4 to 6 carbon atoms. Dicarboxylic acid dihydrazide (eg, oxalic acid dihydrazide, malonic acid dihydrazide, succinic acid dihydrazide, glutaric acid dihydrazide, adipic acid dihydrazide, sebacic acid dihydrazide, maleic acid dihydrazide, fumaric acid dihydrazide, itaconic acid dihydride, etc.) An aliphatic water-soluble dihydrazine having 2 to 4 carbon atoms (for example, ethylene-1,2-dihydrazine, propylene-1,3-dihydrazine, butylene-1,4-dihydrazine, etc.). . The amount of these hydrazine and hydrazyl group-containing compounds is preferably such that the amount of hydrazine and hydrazyl group is 0.2 to 2 molar equivalents relative to the carbonyl group in the polymer.

  Also, for example, polyethylene glycol di (meth) acrylate, ethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, tri If a monomer having two or more polymerizable carbon-carbon double bonds such as methylolpropane tri (meth) acrylate and triallyl cyanurate is used, water resistance and coating strength can be improved. Such a monomer having two or more polymerizable carbon-carbon double bonds can be used as long as the film formability is not hindered, and in an aqueous emulsion, it is water resistant by being used in the core of polymer particles. It is also possible to ensure a balance between coating film strength and film formability.

  The kind of the vinyl monomer may be selected according to the desired physical properties of the obtained acrylic resin, for example, to improve the solubility of the water-soluble resin in water or the stability of the aqueous emulsion. Is an acid having a polymerizable carbon-carbon double bond such as the α, β-ethylenically unsaturated carboxylic acid or sulfonic acid group-containing monomer of the above (a-1) or a salt thereof (alkali metal salt) Amino group-containing vinyl monomers, or salts thereof (hydrochlorides, acetates, etc.); vinyl monomers having quaternary amino groups; hydroxyl group-containing vinyl monomers; Polyoxyalkylene having a polymerizable carbon-carbon double bond at the end; (meth) acrylamide, or a salt thereof (hydrochloride, acetate, etc.), N-vinylpyrrolidone, N-vinylpyridine, etc. It is preferable to use a hydrophilic monomer such as a water-soluble nitrogen-containing vinyl monomer. The amount of these hydrophilic monomers used is 5 to 70% by weight in the case of a water-soluble resin and 0.1 to 30% by weight in the case of an aqueous emulsion in a total of 100% by weight of the monomer mixture. It is preferable. In the case of an aqueous emulsion, when the amount used is less than 0.1% by weight, the mechanical stability of the emulsion and the gloss of the coating film formed from the resulting coating composition tend to decrease, and 30 When the amount exceeds wt%, the water resistance and weather resistance of the coating film tend to decrease.

  Among the above hydrophilic monomers, when a polyoxyalkylene having a polymerizable carbon-carbon double bond at the terminal was used, a hydrolyzable silyl group-containing vinyl monomer (a-2) was used. In some cases, it is also preferable from the standpoint that retention of the hydrolyzable silyl group in the acrylic resin, that is, storage stability is possible. When an aqueous emulsion of an acrylic resin using a combination of polyoxyalkylene terminated with a polymerizable carbon-carbon double bond and (a-2) is used in the coating composition of the present invention, crosslinking by a siloxane bond In addition to the weather resistance, water resistance, and hydrolyzable silyl group storage stability due to formation, it is particularly preferred in that the appearance and surface hydrophilicity of the coating film are improved. As such a polyoxyalkylene having a polymerizable carbon-carbon double bond at the terminal, polyalkylene glycol mono (meth) acrylate or an alkyl ether or ester (a-4) thereof is preferable in view of polymerizability. Further, those having a polyoxyethylene structure are preferred from the viewpoint of solubility of water-soluble resin in water or stability of aqueous emulsion.

  The method for producing the water-soluble resin of acrylic resin is not particularly limited as long as it is a method for obtaining an aqueous medium solution of a copolymer from the above monomers, and includes bulk polymerization, solution polymerization, suspension polymerization, emulsion polymerization and the like. A known polymerization method can be appropriately selected. For example, in the case of solution polymerization using a radical polymerization initiator, the solvent to be used is not particularly limited as long as it can dissolve or disperse the copolymer to be formed, and an azo compound or an organic solvent usually used in the solvent is not limited. The above monomer may be polymerized in the presence of a radical polymerization initiator such as an oxide. In this polymerization, the molecular weight may be adjusted using a chain transfer agent such as a mercaptan that is usually used. In making the aqueous solution, it may be mixed with the aqueous medium while being dissolved in the solvent, or after isolating the copolymer by evaporating or reprecipitation of the solvent, it may be added as a solution to the aqueous medium. Upon solubilization, the copolymer may be mixed with an aqueous medium while being dissolved in an organic solvent, or the solvent may be stripped after mixing with the aqueous medium, or the solvent may be distilled off or reprecipitated. The polymer may be recovered and then added to the aqueous medium. In the method of mixing with an aqueous medium while being dissolved in a solvent, if a water-soluble organic solvent such as alcohol, polyalkylene glycol, polyalkylene glycol monoalkyl ether is used as the solvent to be used, mixing is easy and a uniform solution can be obtained. Since it is obtained, it is preferable. In addition, when an acid having a polymerizable carbon-carbon double bond is used as the hydrophilic monomer, the acidic group is neutralized with a basic compound such as an alkali metal hydroxide or an amine. If it is converted into a salt and then mixed with an aqueous medium, it is preferable because mixing is easy and a uniform solution can be obtained.

  The method for producing an aqueous emulsion of acrylic resin is not particularly limited as long as it is a method for obtaining an aqueous medium dispersion of a copolymer from the above monomers, and batch polymerization and reaction for batch polymerization of monomer emulsions. After the production of a polymer by a known emulsion polymerization method such as monomer dropping polymerization for sequentially introducing monomers into the system, emulsion monomer dropping polymerization for sequentially introducing an emulsion of monomers into the reaction system, solution polymerization, A method for dispersing in an aqueous medium can be appropriately selected. In particular, an emulsion polymerization method using monomer dropping polymerization or emulsion monomer dropping polymerization is suitable for ensuring stability during production. In addition, if a so-called seed polymerization method is used in which a seed polymer dispersion is formed in advance in the reaction system, followed by monomer dropping polymerization and emulsion monomer dropping polymerization, the particle size of the aqueous emulsion can be easily controlled. To preferred. In addition, so-called soap-free polymerization in which monomer-drop polymerization is performed using the above water-soluble acrylic resin as a dispersant is also possible.

  The emulsifier used in the emulsion polymerization is not particularly limited as long as it is a commonly used one, and examples thereof include anionic, cationic, and nonionic surfactants. Anionic surfactants include fatty acid salts such as sodium stearate; sulfonates such as sodium lauryl sulfonate, sodium dodecylbenzene sulfonate and sodium isooctyl benzene sulfonate; sulfate esters such as sodium lauryl sulfate; Newcol- 723SF, Newcol-707SN, Newcol-707SF, Newcol-740SF, Newcol-560SN (manufactured by Nippon Emulsifier Co., Ltd.), polyoxyalkylene alkylphenyl ether, polyoxyalkylene alkylphenyl ether, polyoxyalkylene polycyclic phenyl ether or An anionic emulsifier containing a polyoxyalkylene chain which is a sulfate ester salt of a polyoxyalkylene styrenated alkylphenyl ether; Such as Rusuruho succinate, and the like. Examples of the cationic surfactant include alkylimidazole, alkylammonium and salts thereof, and alkylammonium hydroxide. Nonionic surfactants include Newcol-723, Newcol-707 (manufactured by Nippon Emulsifier Co., Ltd.), polyoxyalkylene alkylphenyl ethers such as polyoxyethylene lauryl ether and polyoxyethylene nonylphenyl ether, and polyoxyalkylenes. Polyoxyalkylene alkyl ethers which are alkyl phenyl ethers, polyoxyalkylene polycyclic phenyl ethers or polyoxyalkylene styrenated alkyl phenyl ethers; polyoxyalkylene alkyl esters such as polyoxyethylene oleates; glycerin, sorbitan and their ethylene oxides Polyhydric alcohol fatty acid esters such as adducts; Pluronic F68, Pluronic L71, Pluronic L61 (above Adeka) Polyoxypropylene such as - polyoxyethylene block copolymers; etc. L-77, L-7001, L-7604 (all manufactured by Nippon Unicar Co.) polyoxyalkylene-modified silicones and the like.

  Moreover, when a surfactant having a carbon-carbon double bond such as a (meth) acryloxy group, an allyl group or an isopropenyl group, a so-called reactive emulsifier is used as an emulsifier, the defoaming property of the water-based paint, the water resistance of the coating film It is preferable because improvement of the above can be achieved. Specific examples of such reactive emulsifiers include ADEKA rear soap SE-10N, SR-10, SR-20, PP70, NE-10, NE-20, NE-30, NE-40, ER-10, ER-20. , ER-30, ER-40 (manufactured by Adeka Co., Ltd.), Aqualon HS-10, HS-20, BC-05, BC-10, BC-20, KH-10, RN-20, RN-30, RN-40 (manufactured by Daiichi Kogyo Seiyaku Co., Ltd.), Eleminol JS-2, RS-30 (manufactured by Sanyo Chemical Co., Ltd.), Latemuru S-180, S-180A (manufactured by Kao Corporation), Antox-MS-60, Antox-MS-2N, RMA-653 (manufactured by Nippon Emulsifier Co., Ltd.).

  The amount of the emulsifier used is 0.5 to 15 parts by weight, preferably 1 to 7 parts by weight, based on 100 parts by weight of the total amount of monomers.

  What is necessary is just to use what is normally used as a polymerization initiator used for emulsion polymerization. Specifically, persulfates such as potassium persulfate and ammonium persulfate; hydrogen peroxide solution; t-butyl hydroperoxide, benzoyl peroxide, cumene hydroperoxide, p-menthane hydroperoxide, dibutyl peroxide, diisopropyl Organic peroxides such as peroxydicarbonate, t-butyl peroxyoctate, cumylperoxyneodecanoate, cumylperoxyoctoate; azo such as azobisamidinopropane hydrochloride, azobisisobutyronitrile System compounds. Furthermore, it is preferable to use a redox catalyst from the viewpoint of the stability of polymerization. Specifically, for example, potassium persulfate, ammonium persulfate and sodium sulfite, Rongalite, hydrogen peroxide and ascorbic acid, A combination of an organic peroxide such as t-butyl hydroperoxide, benzoyl peroxide, cumene hydroperoxide, or p-menthane hydroperoxide with acidic sodium sulfite, Rongalite, or the like is used. In particular, a combination of an organic peroxide and a reducing agent is preferable. In order to stably obtain the catalytic activity, a compound containing a divalent iron ion such as iron sulfate and a chelating agent such as disodium ethylenediaminetetraacetate may be used in combination. The usage-amount of an initiator is 0.01-10 weight part with respect to 100 weight part of total monomers, Preferably it is 0.05-5 weight part.

  Moreover, a pH adjuster can also be added at the time of emulsion polymerization. In particular, when a hydrolyzable silyl group-containing vinyl monomer (a-2) is used, a pH adjuster is used to suppress hydrolysis and condensation of the hydrolyzable silyl group during polymerization, and the pH of the reaction system Is preferably controlled to 5 to 9, more preferably 6 to 8. Examples of pH adjusters include general pH buffers, bases such as alkali metals, alkaline earth metals, organic amine hydroxides or carboxylic acids, hydrochloric acid, carbonic acid, boric acid, phosphoric acid salts, and the like. A combination of these may be used. Specifically, sodium hydroxide, sodium acetate, sodium formate, sodium bicarbonate, sodium carbonate, sodium borate, monosodium phosphate, disodium phosphate, trisodium phosphate, potassium hydroxide, potassium acetate, potassium formate, Examples thereof include potassium hydrogen carbonate, potassium carbonate, and ammonium acetate. The usage-amount of a pH adjuster is 0.001-3 weight part with respect to the aqueous medium to contain.

  Moreover, you may adjust molecular weight using a chain transfer agent as needed. As the chain transfer agent, those usually used may be used, but mercaptans are preferable from the viewpoint of easy adjustment. Mercaptans include alkyl mercaptans such as n-dodecyl mercaptan, t-dodecyl mercaptan and n-butyl mercaptan; alkanol mercaptans such as mercaptoglycerin; mercaptoacetic acid alkyl ester; mercaptopropionic acid alkyl ester; γ-mercaptopropyltrimethoxysilane, Examples thereof include mercaptoalkyl group-containing silane compounds such as γ-mercaptopropyltriethoxysilane and γ-mercaptopropylmethyldimethoxysilane. The amount of mercaptans used is 0.001 to 20 parts by weight, preferably 0.01 to 2 parts by weight, based on 100 parts by weight of the total amount of monomers. When the amount is less than 0.001 part by weight, the molecular weight adjusting effect tends to be insufficient, and when the amount exceeds 20 parts by weight, the progress of polymerization tends to be inhibited.

  Emulsion polymerization is usually performed at a temperature of 10 to 90 ° C. In particular, when the hydrolyzable silyl group-containing vinyl monomer (a-2) is used, the polymerization temperature is preferably 70 ° C. or lower in order to suppress hydrolysis and condensation of the hydrolyzable silyl group during polymerization. It is more preferable that the temperature be not higher than ° C.

  The solid content concentration of the aqueous emulsion at the completion of the polymerization is preferably in the range of 20 to 70% by weight. If the solid content concentration exceeds 70% by weight, the viscosity of the system during the polymerization will rise significantly, making it difficult to remove the heat generated by the polymerization reaction and taking a long time to remove from the polymerization machine. Tend to occur. On the other hand, when the solid content concentration is less than 20% by weight, no problem occurs in the aspect of the polymerization operation, but the amount of resin generated by one polymerization operation is small. In terms of application requirements, if the concentration is less than 20% by weight, the film thickness of the coating film becomes thin, resulting in performance deterioration or disadvantages in terms of coating workability.

  The aqueous emulsion of acrylic resin by the above production method is a dispersion of acrylic resin fine particles having an average particle size of about 0.02 to 1.0 microns in an aqueous medium, resulting in excellent film formation. Have the ability.

  Aqueous emulsions of acrylic resins are preferred because the design and preparation of the resin and paint are easy, but in the paint composition comprising (1) the aqueous paint and (2) the coating surface hydrophilizing agent of the present invention, For example, what has a composition as described in the following (i)-(v) is especially preferable at the point of a coating-film physical property.

  (I) Use of hydrolyzable silyl group-containing monomer (a-2): As mentioned above, hydrolysis reaction of hydrolyzable silyl group and crosslinking reaction by condensation are contained in (2) coating surface hydrophilizing agent The acidic phosphorus compound (B) is preferable because it can be promoted, improves the water resistance and weather resistance of the resulting coating film, and works favorably in the expression of coating film surface hydrophilicity.

  (Ii) Use of polyalkylene glycol mono (meth) acrylate or an alkyl ether or ester (a-4) thereof as a hydrophilic monomer: It is preferable in that the appearance of the coating film and the surface hydrophilicity are further improved. The details of this effect are not clear, but the improvement in the dispersibility of the coating film surface hydrophilizing agent in the paint by the aqueous emulsion using (a-4) improves the appearance and surface hydrophilicity of the coating film. It is estimated that it works favorably.

  (Iii) Use of (a-2) and polyalkylene glycol mono (meth) acrylates or their alkyl ethers or esters (a-4) as hydrophilic monomers: as described above, by crosslinking with siloxane bonds In addition to weather resistance and water resistance, it is preferable in terms of further improving the storage stability of the hydrolyzable silyl group, the appearance of the coating film, and the surface hydrophilicity. Although the details of this action are not clear, the retention of the reactivity by improving the storage stability of the hydrolyzable silyl group favors the expression of the coating film surface hydrophilicity by the reaction of the coating film surface hydrophilizing agent (2). At the same time, it is presumed that the improvement in dispersibility of the coating film surface hydrophilizing agent in (2) the coating film surface hydrophilizing agent by (a-4) works favorably on the appearance of the coating film and the surface hydrophilicity.

  (Iv) (a-2), (a-4) and (meth) acrylate (a-5) having an alkyl group having 4 or more carbon atoms or a cycloalkyl group having 6 or more carbon atoms in a total of 100 monomer mixtures Use of 50% by weight or more in% by weight: coating film surface hydrophilicity estimated to be related to weatherability, water resistance, storage stability of hydrolyzable silyl groups, and storage stability of hydrolyzable silyl groups It is also preferable in terms of expression of sex. Although this detail is not clear, it is presumed that the water absorption of the resulting acrylic resin is reduced.

  (V) Using (a-2) and (a-4) and adjusting the molecular weight using a chain transfer agent: by reducing the molecular weight of the resulting acrylic resin, weather resistance, water resistance, appearance of the coating film In view of further improving the surface hydrophilicity. Although the details are not clear, the molecular chain of the acrylic resin is easy to move, the reactivity of the hydrolyzable silyl group in the resin and (2) the coating surface hydrophilizing agent, and the fusion between the emulsion particles. Is estimated to be improved.

The urethane resin is not particularly limited as long as it has a urethane or urea bond in the main chain structure, and either a self-emulsifying type or a forced emulsifying type can be used. As a method for producing a self-emulsifying urethane resin aqueous emulsion, for example, a urethane prepolymer having an isocyanate group at a terminal, a chain extender and a chain extender having a group exhibiting ionicity are reacted and dispersed in water. can get. The urethane prepolymer having an isocyanate group at the terminal is, for example, a polymer containing an isocyanate compound having two or more isocyanate groups in one molecule and two or more hydroxyl groups, amino groups or other active hydrogen groups in one molecule. It is made to react. Examples of the isocyanate compound having two or more isocyanate groups in one molecule include tolylene diisocyanate (TDI), 4,4′-diphenylmethane diisocyanate (MDI), xylene diisocyanate (XDI), hexamethylene diisocyanate (HDI), and isophorone diisocyanate. (IPDI), aliphatic, aromatic and alicyclic diisocyanate compounds such as lysine diisocyanate, 4,4'-methylenebis (cyclohexyl isocyanate), methylcyclohexane-2,4-diisocyanate, trimethylhexane diisocyanate; isocyanurate-modified HDI And isocyanurate-bonded or biuret-bond-modified products of diisocyanate compounds such as: Special polyisocyanates such as polymeric MDI. Polymers containing two or more hydroxyl groups and amino groups such as amino groups in one molecule include polyoxyalkylene polymers such as polypropylene glycol and polytetramethylene glycol; polybasic acids such as adipic acid and Polycondensation polyester polymer by polycondensation of polyhydric alcohols such as butanediol and neopentyl glycol; Ring-opening polymerization polyester polymer by ring-opening polymerization of ε-caprolactone and β-methyl-δ-valerolactone; Examples thereof include acrylic polymers copolymerized with hydroxyl group-containing vinyl monomers such as (meth) acrylate; polycarbonate polymers such as polyhexylene carbonate diol; polyolefin polymers such as polybutadiene diol and hydrogenated polybutadiene diol. Examples of the chain extender include glycols such as ethylene glycol and butanediol; diamines such as ethylenediamine, propylenediamine, isophoronediamine, xylylenediamine, and piperazine. Examples of the chain extender having a group that expresses ionicity include polyhydroxycarboxylic acids such as 2,2′-bis (hydroxymethyl) propionic acid; polyhydroxysulfonic acid; aminosulfonic acid and the like.
Examples of the fluororesin include trifluoroethyl (meth) acrylate, pentafluoropropyl (meth) acrylate, perfluorocyclohexyl (meth) acrylate, 2,2,3,3-tetrafluoropropyl methacrylate, β- (perfluorooctyl). ) Ethyl (meth) acrylate, vinyl fluoride, vinylidene fluoride, tetrafluoroethylene, hexafluoropropylene, pentafluoropropylene, tetrafluoropropylene, trifluoropropylene, chlorotrifluoroethylene, bromotrifluoroethylene, chlorodifluoroethylene, dichloro The copolymer is not particularly limited as long as it is a copolymer using a fluorine-containing vinyl monomer such as difluoroethylene. An example of a method for producing a water-soluble resin of a fluororesin is a fluoroethylene copolymer containing a hydroxyl group and / or a carboxyl group (Japanese Patent Laid-Open No. 62-143915). In addition, as a method for producing an aqueous emulsion of a fluororesin, for example, a fluoroolefin copolymer (JP-A-7-53911, JP-A-7-62289), in the presence of a fluororesin aqueous dispersion (meta) Fluorine-containing resin / (meth) acrylic resin composite aqueous dispersion obtained by emulsion polymerization of acrylate (JP-A-9-157314), fluorine-containing aqueous resin dispersion made of fluoroalkyl (meth) acrylate copolymer, and the like (Japanese Examined Patent Publication No. 34-8838).

  The (1) water-based paint of the present invention can be obtained by blending the above-mentioned water-soluble resin and / or water-based emulsion as it is or an additive used in a normal water-based paint composition. Additives used in ordinary aqueous paint compositions include, for example, pigments (eg, white pigments such as titanium dioxide, calcium carbonate, barium carbonate, kaolin, and colored pigments such as carbon black, bengara, and cyanine blue), freezing Inhibitors (for example, ethylene glycol, propylene glycol, etc.), plasticizers, solvents, dispersants, wetting agents, thickeners, antifoaming agents, antiseptics, anti-settling agents, leveling agents, UV absorbers, light stabilizers, etc. Is given.

  Among the above additives, titanium dioxide is useful as a pigment because of its hiding properties, and titanium dioxide whose surface is treated with alumina, zirconia or silica is particularly preferable in terms of coating film gloss and weather resistance. The solvent may be one generally used as a film forming aid, for example, alcohols such as methanol, ethanol, n-propyl alcohol, i-propyl alcohol, n-butanol, i-butanol, pentanol and hexanol. ; Methyl cellosolve, ethyl cellosolve, butyl cellosolve, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, ethylene glycol mono-2-ethylhexyl ether, propylene glycol monoethyl ether, propylene glycol mono-n-butyl ether, propylene glycol monoisobutyl ether, dipropylene glycol Monoethyl ether, dipropylene glycol mono-n-butyl ether, dipropylene glycol monoisobutyl ether Ethers such as tripropylene glycol monoethyl ether, tripropylene glycol mono-n-butyl ether, tripropylene glycol monoisobutyl ether; butyl cellosolve acetate, diethylene glycol monobutyl ether acetate, dipropylene glycol monobutyl ether acetate, tripropylene glycol mono-n Organic solvents such as butyl ether acetate, tripropylene glycol monoisobutyl ether acetate, 2,2,4-trimethylpentanediol-1,3-monoisobutyrate, glycol ether esters such as CS-12 (manufactured by Chisso) One type or two or more types selected from these groups can be used. Among these, CS-12 and ethylene glycol mono-2-ethylhexyl ether are preferable in terms of the stability of the paint and the gloss of the coating film.

  In order to obtain the dispersibility of the pigment, it is common to use a dispersant in the enamel paint in which the pigment is dispersed and colored. Various types of dispersants for water-based paints are known, but compounds having a hydrophilic group are generally used for adsorption to the pigment surface and stabilization of dispersion in an aqueous medium. . For example, a maleic acid copolymer or a salt of a modified product thereof as a anionic dispersant, a polyphosphate, a salt of a sulfonic acid group-containing polymer, a quaternary ammonium group-containing polymer as a cationic dispersant, Furthermore, a compound in which a nonionic hydrophilic group such as a polyoxyalkylene chain is combined to improve dispersion stability is also known. Among these, when a dispersant having a nonionic hydrophilic group is used, it is preferable in terms of the appearance of the coating film and the surface hydrophilicity. Although this detail is not clear, it is presumed that (2) the coating film surface hydrophilizing agent in the enamel paint works favorably for improving dispersibility. Examples of the dispersant having a nonionic hydrophilic group include Disperbyk190, Disperbyk192 (above, manufactured by Big Chemie Co., Ltd.) and the like.

In addition, as the antifoaming agent, mineral oil, silicone, polyether, acrylic, etc. are known, but the mineral oil system that does not have a polyorganosiloxane structure in terms of the appearance and surface hydrophilicity of the coating film, Polyether type and acrylic type are preferred.
Coating surface hydrophilizing agent (2) The coating surface hydrophilizing agent that forms the aqueous coating composition of the present invention contains tetraalkoxysilane and / or its hydrolysis condensate (A) and acidic phosphorus compound (B). It does not contain water. The coating surface hydrophilizing agent is a polyoxyalkylene chain-containing compound that leads to a decrease in the durability of the coating, particularly water resistance, and a hydrophilic group and a reactive functional group described in JP-A-2005-15676 in the same molecule. (1) It exhibits dispersibility in water-based paints, and can stably exhibit paint viscosity, paint film appearance, and paint film hydrophilicity.

  The tetraalkoxysilane and / or its hydrolysis condensate (A) that forms the coating surface hydrophilizing agent is a tetraalkoxysilane having an alkoxy group having 1 to 20 carbon atoms and / or its hydrolysis condensate. The thing which does not have an alkylene structure is mentioned. As the alkoxy group contained in (A), those having different numbers of carbon atoms and branched alkoxy groups in the same molecule may be used, and one kind may be used alone, or two or more kinds may be used in combination. Examples of such tetraalkoxysilane and / or its hydrolysis condensate include, for example, tetramethoxysilane, tetraethoxysilane, tetra-n-propoxysilane, tetra-i-propoxysilane, tetra-n-butoxysilane, tetra- An i-butoxysilane, tetra-t-butoxysilane and one or more partial hydrolyzed condensates thereof, and further an alkoxy group formed by transesterification of these tetraalkoxysilane and / or hydrolyzed condensate thereof. Substituted ones are listed.

  The higher the degree of condensation of (A), the lower the compatibility with the aqueous paint, which is advantageous for the expression of hydrophilicity of the paint film surface by improving the migration to the paint film surface. It leads to deterioration of the appearance. It is generally known that the number of carbon atoms and branching of the alkoxy group contained in (A) greatly affect the reactivity of the hydrolysis condensation reaction, and that the lower the number of carbon atoms and the less the branching, the higher the reactivity. However, as described above, rapid reaction leads to deterioration of the coating film appearance and variation in coating film surface hydrophilicity. Regarding the reactivity of the alkoxy group, for example, a methoxy group or an ethoxy group (carbon number 1 or 2) and a propoxy group or butoxy group (carbon number 3 or 4) are contained in one molecule (A), or each Adjustment is possible by using together (A) having an alkoxy group. As a preferred structure of (A), the degree of condensation is about 1 to 20, more preferably 3 to 15, and the number of carbon atoms of the alkoxy group is 1 to 4, in terms of the number average value for all alkoxy groups in (A). Preferably it is 1.5-2.8.

Examples of the acidic phosphorus compound (B) that forms the coating surface hydrophilizing agent include phosphorus-containing acidic compounds that do not have a polyoxyalkylene structure. Examples of such acidic phosphorus compounds include phosphoric acid, acidic phosphoric acid ester, phosphonic acid or acidic phosphonic acid ester represented by formula (1), acidic phosphoric acid group-containing polymers, condensates thereof, and these moieties. Examples include neutralized salts and completely neutralized salts.


Q
‖
R ¹ _m (R ² Q) _n P (QH) _3-mn (1)


In the above formula (1), R ¹ and R ² are monovalent organic groups, and Q is an oxygen or sulfur atom. m and n are 0 to 2 and m + n is 2 or less. R ¹ or R ² may be the same or different when m or n is 2. R ¹ and R ² are selected from an alkyl group having 12 or less carbon atoms, an alkylene group, or an aralkyl group, and a preferable lower limit value of the carbon number is 4, more preferably 6, more preferably 8, and a preferable upper limit value is 12, More preferably, it is 10, Most preferably, it is C8-C10.

  Examples of such acidic phosphorus compounds include inorganic phosphate compounds such as phosphoric acid, metaphosphoric acid, and pyrophosphoric acid; monopropyl phosphate, mono-isopropyl phosphate, monobutyl phosphate, mono- (2-ethylhexyl) phosphate, monooctyl Phosphate, monodecyl phosphate, monoisodecyl phosphate, monolauryl phosphate, mono- (methacryloxyethyl) phosphate, mono- (acryloxyethyl) phosphate dimethyl phosphate, diethyl phosphate, dipropyl phosphate, di-isopropyl phosphate, dibutyl phosphate, Di- (2-ethylhexyl) phosphate, di- (2-ethylhexyl) dithiophosphate, dioctyl phosphate, didecyl phosphate, diiso Acid phosphates such as sylphosphate, dilauryl phosphate, di- (methacryloxyethyl) phosphate, di- (acryloxyethyl) phosphate; phosphones such as phenylphosphonic acid, 2-ethylhexylphosphonic acid mono (2-ethylhexyl) ester Acid or acidic phosphonic acid ester; reaction product of phosphoric acid or acidic phosphoric acid ester and polyvalent epoxide such as bisphenol A type epoxy resin, copolymer of mono- (methacryloxyethyl) phosphate and other vinyl monomers, etc. Examples thereof include an acidic phosphate group-containing polymer. In addition, as a basic compound for forming a neutralized salt, alkali metal hydroxides or carbonates such as lithium, sodium, potassium, cesium; alkaline earth metal hydroxides such as calcium, magnesium, barium , Oxides or carbonates; transition metal salts such as aluminum, zinc, titanium; ammonia; trimethylamine, diethylamine, triethylamine, propylamine, tripropylamine, dibutylamine, amylamine, 1-aminooctane, 2-aminoethanol, 2- Dimethylaminoethanol, ethylaminoethanol, 2-diethylaminoethanol, 1-amino-2-propanol, 2-amino-1-propanol, 3-amino-1-propanol, 1-dimethylamino-2-propanol, 3-dimethylamino 1-propanol, 2-propyl-aminoethanol, diethanolamine, ethoxy propylamine, aminobenzyl alcohol, morpholine, N- methylmorpholine, and organic amines DBU and the like.

  (2) The coating surface hydrophilizing agent may be prepared by mixing (A) and (B), and a container equipped with a normal stirring device may be used. From the viewpoint of suppressing the quality change such as increase in viscosity due to moisture (2) obtained, mixing under conditions in which the influence of moisture is blocked, such as in a closed container or under a dry nitrogen stream, is preferable. The temperature at the time of mixing is not particularly limited as long as there is no problem in the stability such as coloring of the obtained (2), but heating is performed when the miscibility of both (A) and (B) is low. In some cases, it is preferable in view of the appearance and surface hydrophilicity of the resulting coating film. In addition, water is intentionally added during preparation to hydrolyze and condense (A), and the degree of condensation in (A) is adjusted. Similarly, alcohols are added and the alkoxy group in (A) is converted by an exchange reaction. It is also possible to do so. It is also possible to carry out the neutralization reaction with the basic compound (B) after mixing (A) and (B).

  The ratios of (A) and (B) are not particularly limited, but (1) the water-based paint used, the desired coating film properties and pot life (after mixing (1) and (2), the paint cannot be applied) It may be selected so that the time until Generally, the weight ratio (A) / (B) is 1/99 to 99.95 / 0.05, preferably 50/50 to 99/1.

  (2) The coating surface hydrophilizing agent is usually a solvent, a filler, an antifoaming agent, a thickener, a dispersant, etc., as long as the effects of the present invention other than (A) and (B) are not impaired Additives used in these paints can be used in combination.

  Although the coating method of the two-component aqueous coating composition of the present invention is not particularly limited, as described above, after preparing (1) the aqueous coating and (2) the coating surface hydrophilizing agent, It is preferable that 1) the water-based paint and (2) the coating film surface hydrophilizing agent are mixed, and the mixture obtained by stirring and uniforming is applied to the object. There is no limitation in particular as a to-be-coated object, It can use for a building interior and exterior, a motor vehicle, household appliances, a plastics, etc.

  The two-component aqueous coating composition of the present invention is not particularly limited, but is suitable for architectural interior / exterior coatings, automotive coatings, home appliance coatings, plastic coatings, and the like.

  Hereinafter, the present invention will be described based on examples, but the present invention is not limited thereto.

(Manufacturing method of coating surface hydrophilizing agent: Production Examples 1 to 6 and Comparative Production Example 1-2)
The components shown in Table 1 were charged into a container equipped with a stirrer, a reflux condenser, a nitrogen gas inlet tube and a dropping funnel while stirring in the order of (A) and (B). After completion of the addition, the mixture was stirred for 30 minutes, and Production Examples 1 to 6 and Comparative Production Example 1-2 were performed to obtain each (2) coating surface hydrophilizing agent. The obtained coating film surface hydrophilizing agent was put in a transparent container, and it was confirmed by visual observation that there was no separation / sedimentation.

No separation / sedimentation: ○
Separation / sedimentation: ×

シリケート４０（多摩化学工業（株）製）：テトラエトキシシランの部分加水分解縮合物（シリカ残量比率４０％）
ＭＳ５８Ｂ３０（三菱化学（株）製）：同一分子中にメチル基７０％、ｎ−ブチル基３０％含有するシリケート（シリカ残量比率５８％）
ＡＰ−３（大八化学工業（株）製）：イソプロピルアシッドホスフェート
ＡＰ−８（大八化学工業（株）製）：２−エチルヘキシルアシッドホスフェート
ＤＰ−８Ｒ（大八化学工業（株）製）：ジ−２−エチルヘキシルホスフェート
ＪＡＭＰ−８（城北化学工業（株）製）：モノｎ−オクチルホスフェート
ＭＰ−１０（大八化学工業（株）製）：モノイソデシルホスフェート
（アルコキシシリル基含有アクリル樹脂エマルジョンの合成例１）
撹拌機、還流冷却器、窒素ガス導入管および滴下ロートを備えた反応容器に、脱イオン水２００重量部、Ｎｅｗｃｏｌ−７０７ＳＦ（日本乳化剤（株）製：有効成分３０％）０．１６重量部、炭酸水素ナトリウム０．０５重量部を仕込み、窒素ガスを導入しつつ５０℃に昇温した。昇温後、表２（Ｅ−１）のコア部に示すモノマーの混合物のうち１２重量部、ｔ−ブチルハイドロパーオキサイド０．１４重量部、ロンガリット０．４重量部を添加し、３０分間初期重合を行った。上記モノマー混合物の残り２６８重量部にアクアロンＢＣ０５１５（第一工業製薬（株）製：有効成分１５％）９．７重量部、アクアロンＲＮ２０２５（第一工業製薬（株）製：有効成分２０％）２．７重量部および脱イオン水６６重量部を加え乳化したモノマー乳化液とｔ−ブチルハイドロパーオキサイド０．２０重量部を１４５分かけて等速追加した。追加終了後、１時間後重合を行った。さらに、表２（Ｅ−１）のシェル部に示すモノマー混合物１２０重量部にアクアロンＢＣ０５１５ ６．０重量部、アクアロンＲＮ２０２５ １．６重量部および脱イオン水２７重量部を加え乳化したモノマー乳化液とｔ−ブチルハイドロパーオキサイド０．１５重量部を６５分かけて等速追加した。追加終了後、１時間後重合を行った。得られた合成樹脂エマルジョンに炭酸水素ナトリウム２．０重量部を添加後、脱イオン水で固形部５０％に調整した（Ｅ−１）。

Silicate 40 (manufactured by Tama Chemical Co., Ltd.): Tetraethoxysilane partially hydrolyzed condensate (silica residual ratio 40%)
MS58B30 (manufactured by Mitsubishi Chemical Corporation): silicate containing 70% methyl group and 30% n-butyl group in the same molecule (silica residual ratio 58%)
AP-3 (manufactured by Daihachi Chemical Industry Co., Ltd.): isopropyl acid phosphate AP-8 (manufactured by Daihachi Chemical Industry Co., Ltd.): 2-ethylhexyl acid phosphate DP-8R (manufactured by Daihachi Chemical Industry Co., Ltd.): Di-2-ethylhexyl phosphate JAMP-8 (manufactured by Johoku Chemical Industry Co., Ltd.): Mono n-octyl phosphate MP-10 (manufactured by Daihachi Chemical Industry Co., Ltd.): monoisodecyl phosphate (alkoxysilyl group-containing acrylic resin emulsion) Synthesis Example 1)
In a reaction vessel equipped with a stirrer, a reflux condenser, a nitrogen gas inlet tube and a dropping funnel, 200 parts by weight of deionized water, 0.16 parts by weight of Newcol-707SF (manufactured by Nippon Emulsifier Co., Ltd .: 30% active ingredient), Sodium hydrogen carbonate 0.05 part by weight was charged, and the temperature was raised to 50 ° C. while introducing nitrogen gas. After the temperature increase, 12 parts by weight of the monomer mixture shown in the core part of Table 2 (E-1), 0.14 parts by weight of t-butyl hydroperoxide, and 0.4 parts by weight of Rongalite were added, and the initial time was 30 minutes. Polymerization was performed. The remaining 268 parts by weight of the monomer mixture is 9.7 parts by weight of Aqualon BC0515 (Daiichi Kogyo Seiyaku Co., Ltd .: active ingredient 15%), Aqualon RN2025 (Daiichi Kogyo Seiyaku Co., Ltd .: active ingredient 20%) 2 .7 parts by weight and 66 parts by weight of deionized water and emulsified monomer emulsion and 0.20 parts by weight of t-butyl hydroperoxide were added at a constant rate over 145 minutes. Polymerization was performed after 1 hour after the addition was completed. Furthermore, a monomer emulsion obtained by emulsifying by adding 6.0 parts by weight of Aqualon BC0515, 1.6 parts by weight of Aqualon RN2025 and 27 parts by weight of deionized water to 120 parts by weight of the monomer mixture shown in the shell part of Table 2 (E-1), 0.15 parts by weight of t-butyl hydroperoxide was added at a constant rate over 65 minutes. Polymerization was performed after 1 hour after the addition was completed. After adding 2.0 parts by weight of sodium hydrogen carbonate to the resulting synthetic resin emulsion, the solid part was adjusted to 50% with deionized water (E-1).

(Synthesis example of cross-linked acrylic emulsion)
Polymerization was conducted in the same manner as in Synthesis Example 1 except that Table 2 (E-2) was used as the monomer. Furthermore, 6.2 parts by weight of adipic acid dihydrazide was added to the resultant synthetic resin emulsion to obtain a cross-linked acrylic emulsion (E-2).

(Synthesis example of acrylic emulsion containing polyoxyalkylene chain)
Polymerization was performed in the same manner as in Synthesis Example 1 except that Table 2 (E-3) was used as the monomer (E-3).

(Synthesis example of carboxyl group-containing acrylic emulsion)
Polymerization was carried out in the same manner as in Synthesis Example 1 except that Table 2 (E-4) was used as the monomer (E-4).

（白顔料ペーストの製造方法）
表３の示す処方にガラスビーズを加え、サンドミルを用いて１０００回転で１時間分散し、白顔料ペースト（Ｗ）を調製した。

(Manufacturing method of white pigment paste)
Glass beads were added to the formulation shown in Table 3 and dispersed at 1000 rpm for 1 hour using a sand mill to prepare a white pigment paste (W).

（水性塗料の製造）
合成した樹脂エマルション（Ｅ−１〜４）、市販のウレタン樹脂エマルション、市販のふっ素樹脂エマルション、作製した白顔料ペースト（Ｗ）、およびその他の塗料添加剤を用いて、表４に示す配合で水性塗料を調製した。

(Manufacture of water-based paint)
Using the synthesized resin emulsions (E-1 to 4), commercially available urethane resin emulsions, commercially available fluorine resin emulsions, prepared white pigment paste (W), and other paint additives, the composition shown in Table 4 is aqueous. A paint was prepared.

（アルコキシシリル基含有アクリル樹脂塗料）（ＡＳ−１）。
（架橋型アクリル樹脂塗料）（ＣＡ−１）。
（ウレタン変性アクリル樹脂塗料）（ＡＵ−１）。
（ポリオキシアルキレン鎖含有アクリル樹脂塗料）（Ａ−１）。
（カルボキシル基含有アクリル樹脂塗料）（Ａ−２）。
（スチレン−アクリル樹脂塗料）（ＳＡ−１）。
（ふっ素樹脂塗料）（Ｆ−１）。
スーパーフレックス４１０（第一工業製薬（株）製）：ウレタン樹脂エマルション、固形分４０％。
ゼッフルＳＥ−３１０（ダイキン工業（株）製）：フッ素樹脂エマルション、固形分５０％。
ボンコートＥＣ−８５６（大日本インキ化学工業（株）製）：スチレンアクリルエマルション、固形分５０％。

(Alkoxysilyl group-containing acrylic resin paint) (AS-1).
(Crosslinked acrylic resin paint) (CA-1).
(Urethane-modified acrylic resin paint) (AU-1).
(Polyoxyalkylene chain-containing acrylic resin paint) (A-1).
(Carboxyl group-containing acrylic resin paint) (A-2).
(Styrene-acrylic resin paint) (SA-1).
(Fluororesin paint) (F-1).
Superflex 410 (Daiichi Kogyo Seiyaku Co., Ltd.): urethane resin emulsion, solid content 40%.
Zeffle SE-310 (manufactured by Daikin Industries, Ltd.): fluororesin emulsion, solid content 50%.
Boncoat EC-856 (Dainippon Ink Chemical Co., Ltd.): Styrene acrylic emulsion, solid content 50%.

(Examples 1-12 and Comparative Examples 1-2)
In the said manufacture examples 1-6 and the comparative manufacture examples 1-2 in the produced water-based paint (AS-1, CA-1, AU-1, A-1, A-2, SA-1, and F-1). The prepared coating surface hydrophilizing agents are mixed as shown below in the amounts shown in Tables 5 to 7 to prepare a coating composition or form a coating film. Each physical property (gloss, coating film contact angle, gelation) Property). The physical property evaluation results are shown in Tables 5-7.
(Evaluation of the physical properties)
-The glossy water-based paint and the coating surface hydrophilizing agent were mixed, and after 30 minutes, they were coated on a glass plate with a 6 mil applicator and cured at room temperature for 14 days. The gloss value of the specimen at an incident angle of 60 ° was measured with a gloss meter Multi-Gloss 268 (manufactured by Minolta Co., Ltd.). For the gloss value, the average value of the values measured three times was calculated.

-Measurement of water contact angle of coating film The prepared water-based paint and the coating film surface hydrophilizing agent were mixed, and after 30 minutes, coated on a glass plate with a 6 mil applicator and cured at room temperature for 14 days. Thereafter, the test specimen was immersed in water for 7 days, and after being pulled up, dried at room temperature for 16 hours or more, and then contacted statically with water using a contact angle measuring machine (Kyowa Interface Science Co., Ltd .: CA-S150 type). The corner was measured.

Gelling property The prepared water-based paint and the coating surface hydrophilizing agent were allowed to stand in a thermostatic chamber at 23 ° C. overnight and mixed, and then placed in a sealed container and allowed to stand in a thermostatic chamber at 23 ° C. Thereafter, it was visually determined whether or not coating was possible 24 hours after mixing the aqueous paint and the coating surface hydrophilizing agent.
A: Gelation (no fluidity)
○: Thickening and thixotropy (feels unpaintable)
X: Fluidity (feels paintable)

表５から明らかなように、実施例１〜６においては酸性リン化合物、シリケート類の種類を変化させたが、いずれも高い光沢及び塗膜表面の親水化を示した。また、ゲル化性についても混合後２４時間後にはいずれも塗装不可能になった。表６から明らかなように、実施例７〜１２においては水性塗料の種類を変更したが、いずれも高い光沢及び塗膜表面の親水化を示した。表から明らかなように、本発明の実施例１〜１２では塗膜表面親水化剤に、塗膜の耐水性を低下させる親水成分たるポリオキシアルキレン鎖含有化合物や乳化剤を使用していないことから、耐水性改善効果が期待出来る。また、水性塗料と塗膜表面親水化剤を混合後十分な可使時間を有しているが、翌日になると粘度が大幅に上昇し、接触角低下能が低下する前に使用不能となるようゲル化性が付与されている。
一方、表７に示されるように、シリケート４０単独の塗膜表面親水化剤を使用した比較例１では、塗膜表面の親水化を発現しなかった。さらに、光沢も低かった。また、同一分子中にメチル基７０％、ｎ−ブチル基３０％含有するシリケートであるＭＳ５８Ｂ３０単独の塗膜表面親水化剤を使用した比較例２では、塗膜表面の親水化は発現されるものの、光沢は極めて低かった。

As is clear from Table 5, in Examples 1 to 6, the types of acidic phosphorus compounds and silicates were changed, but both showed high gloss and hydrophilicity on the coating surface. Moreover, as for the gelation property, all became unpaintable 24 hours after mixing. As is clear from Table 6, in Examples 7 to 12, the type of water-based paint was changed, but all showed high gloss and hydrophilicity of the coating film surface. As is clear from the table, in Examples 1 to 12 of the present invention, the coating film surface hydrophilizing agent does not use a polyoxyalkylene chain-containing compound or an emulsifier, which is a hydrophilic component that reduces the water resistance of the coating film. The water resistance improvement effect can be expected. In addition, it has sufficient pot life after mixing the water-based paint and the coating surface hydrophilizing agent, but the next day, the viscosity increases significantly, so that it becomes unusable before the contact angle reduction ability decreases. Gelling properties are imparted.
On the other hand, as shown in Table 7, in Comparative Example 1 using the coating surface hydrophilizing agent of silicate 40 alone, the coating surface was not hydrophilized. Furthermore, the gloss was also low. In Comparative Example 2 using a coating surface hydrophilizing agent of MS58B30 alone, which is a silicate containing 70% methyl group and 30% n-butyl group in the same molecule, the coating surface becomes hydrophilic. The gloss was extremely low.

Claims (5)

It consists of (1) a water-based paint and (2) a coating surface hydrophilizing agent,
(1) The water-based paint is a paint having a water-soluble resin and / or an aqueous emulsion as a film-forming component,
(2) The coating surface hydrophilizing agent contains a tetraalkoxysilane and / or its hydrolysis condensate (A) and an acidic phosphorus compound (B), a polyoxyalkylene chain-containing compound, a hydrophilic group and a reactive functional group Does not contain any compound having at least one group in the same molecule ,
The acidic phosphorus compound (B) is at least one selected from the group consisting of an acidic phosphate ester, phosphonic acid or acidic phosphonic acid ester having a hydrocarbon group selected from an alkyl group having 12 or less carbon atoms, an alkylene group or an aralkyl group. A two-component water-based coating composition characterized by being a seed . The two-component water-based coating composition according to claim 1, wherein the tetraalkoxysilane and / or its hydrolysis condensate (A) contains an alkyl group having 2 or more carbon atoms. The two-component aqueous coating composition according to claim 1 or 2 , wherein the (1) aqueous coating contains a hydrolyzable silyl group-containing acrylic polymer. The two-component water-based paint composition according to any one of claims 1 to 3 , wherein the (2) paint film surface hydrophilizing agent is added to the (1) water-based paint, and the resultant is mixed and then applied to an object to be coated. Painting method. Acidic phosphate ester, phosphonic acid or acidic phosphonic acid ester having tetraalkoxysilane and / or its hydrolysis condensate (A) and a hydrocarbon group selected from an alkyl group, alkylene group or aralkyl group having 12 or less carbon atoms An acidic phosphorus compound (B), which is at least one selected from the group consisting of the above, is mixed in advance (wherein the polyoxyalkylene chain-containing compound and one or more hydrophilic groups and reactive functional groups each in the same molecule) Neither of these compounds is mixed), and this is added to a water-based paint containing a water-soluble resin and / or an aqueous emulsion as a film-forming component.