JP2011105905A - Aqueous curable coating composition and method for producing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an aqueous curable coating composition exhibiting high ultraviolet shielding properties of a coating film when being applied for reducing damage of coated matter (substrate) and satisfying optical transparency and surface protection protecting a base material, antifouling property, and weatherability and the like at the same time. <P>SOLUTION: In the aqueous curable coating composition, a composite resin (ABC) obtained by binding a polysiloxane segment (B) of a composite resin (AB), which is formed by chemically bonding a polymer segment (A) having neutralized acid groups to the polysiloxane segment (B), and a polysiloxane segment (C) resulting from an alkyltrialkoxysilane condensate (c) having 1C-3C alkyl groups through a silicon-oxygen linkage is dissolved/dispersed in an aqueous medium. The aqueous curable coating composition includes an ultraviolet absorber (D). A method for producing the aqueous curable coating composition is also provided. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an aqueous curable coating composition from which a coating film excellent in ultraviolet shielding properties can be obtained, and has excellent crack resistance after coating film formation, excellent weather resistance, and excellent curing resistance. Since it provides a coating film, it is suitable for coating materials for various substrates constituting solar cells.

  In recent years, solar power generation has been expected as a next-generation energy source from the viewpoint of global warming countermeasures. The solar power industry is rapidly expanding at a rate of 30-40% in the country, and significant growth is expected to continue in the future. On the other hand, in relation to solar power generation members, for example, plastic base materials such as PET that constitute solar cells are yellowed or deteriorated by exposure to ultraviolet rays, surface protective members are contaminated with dust and dirt, and power generation efficiency is increased. There is a problem that durability is poor unless it is protected by a coating, a film, etc., mainly for outdoor use.

  Among the above-mentioned problems, for the purpose of giving a transparent coating film with low base protection and haze, an aqueous coating composition in which a benzotriazole ultraviolet absorber is added to an aqueous fluorine atom-containing resin composition is mentioned. (For example, refer to Patent Document 1). Although it is described that the aqueous coating composition has good storage stability and that the resulting coating film has a haze of 6 or less at a film thickness of 15 μm, the resulting coating film is shielded from ultraviolet rays. In addition, there is no description or suggestion about ultraviolet shielding retention rate, stain resistance, weather resistance, chemical resistance, solvent resistance, etc., and there is no description about the degree of ultraviolet shielding.

JP 2002-201420

  The problem to be solved by the present invention is that the coated film has a high ultraviolet shielding property when applied, and as a result, the damage to the object to be coated (underlying) is low, and the light transmitting property that protects the substrate An object of the present invention is to provide an aqueous curable coating composition that simultaneously satisfies surface protection, stain resistance, weather resistance, and the like.

  As a result of intensive studies to solve the above problems, the present inventor has obtained a composite resin in which a polymer segment (A) having a neutralized acid group and a polysiloxane segment (B) are chemically bonded. The polysiloxane segment (B) of (AB) and the polysiloxane segment (C) derived from the condensate (c) of alkyltrialkoxysilane having an alkyl group having 1 to 3 carbon atoms are bonded via a silicon-oxygen bond. Aqueous curable coating composition containing an aqueous product of composite resin (ABC) formed by dissolving or dispersing composite resin (ABC) in an aqueous medium and an ultraviolet absorber (D) The present inventors have found a solution and have completed the present invention.

  That is, the present invention relates to a polysiloxane segment (B) of a composite resin (AB) formed by chemically bonding a polymer segment (A) having a neutralized acid group and a polysiloxane segment (B), and an alkyl group. A composite resin (ABC) in which a polysiloxane segment (C) derived from a condensate (c) of an alkyltrialkoxysilane having 1 to 3 carbon atoms is bonded via a silicon-oxygen bond is present in an aqueous medium. An aqueous curable coating composition dissolved or dispersed, wherein the aqueous curable coating composition contains an ultraviolet absorber (D), and the aqueous curable coating composition A method for producing an adhesive coating composition is provided.

  The aqueous curable coating composition of the present invention is excellent in ultraviolet ray shielding properties, excellent in crack resistance after coating film formation, excellent in weather resistance, and forms a cured coating film excellent in stain resistance. Utilizing the characteristics, it can be used for various applications including, for example, exterior paints for protecting the base and base material, and members of solar power generation.

  Below, the water-based curable coating composition which concerns on this invention, and its manufacturing method are demonstrated concretely. The composite resin (ABC), which is a component of the aqueous composition of the present invention, is derived from a polymer segment (A), a polysiloxane segment (B), and a condensate of alkyltrialkoxysilane having 1 to 3 carbon atoms in the alkyl group. Polysiloxane segments (C), each segment having a structure with bonds of “(A)-(B)-(C)”. The aqueous composition is a composition in which the composite resin is dissolved or dispersed in an aqueous medium and contains an ultraviolet absorber (D).

  The composite resin (ABC) used in the present invention is a polysiloxane segment of a composite resin (AB) in which a polymer segment (A) having a neutralized acid group and a polysiloxane segment (B) are chemically bonded. A composite resin in which (B) and a polysiloxane segment (C) derived from a condensate (c) of an alkyltrialkoxysilane having 1 to 3 carbon atoms of an alkyl group are bonded via a silicon-oxygen bond For example, a composite resin having a graft structure chemically bonded to a side chain of the polymer segment (A) having a neutralized acid group of the polysiloxane segment (B), or the polymer segment (A) The polysiloxane segment (B) of the composite resin having a block structure in which the polysiloxane segment (B) is chemically bonded to the terminal of the alkyl group, and the alkyl group having 1 to 3 carbon atoms Alkyl condensate of trialkoxysilane and (c) derived from a polysiloxane segment (C) silicon - composite resins having a chemically bonded structure through an oxygen bond.

  The chemical bond between the polymer segment (A) and the polysiloxane segment (B) included in the composite resin (ABC) is not particularly limited. For example, the following structural formula (S-1) or Examples include the bonding mode of the following structural formula (S-2). Among them, the use of a composite resin having the bonding mode of the structural formula (S-1) can form a coating film excellent in weather resistance. preferable. [However, the carbon atom in the structural formula (S-1) constitutes a part of the polymer segment (A), and the silicon atom and the oxygen atom constitute a part of the polysiloxane segment (B). ]

[However, the carbon atom in the structural formula (S-2) constitutes a part of the polymer segment (A), and the silicon atom constitutes a part of the polysiloxane segment (B). ]

  The polymer segment (A) constituting the composite resin (ABC) may be a polymer segment having a neutralized acid group in order to disperse or dissolve the composite resin (ABC) in an aqueous medium. Essentially, among them, the above structural formula (S-1) is easily hydrolyzed and condensed with a hydroxyl group bonded to a silicon atom or a hydrolyzable group bonded to a silicon atom of the polysiloxane segment (B) or its synthesis raw material. As a result of chemical bonding in the bonding mode, a hydroxyl group bonded to a silicon atom and / or a hydrolyzable group bonded to a silicon atom together with a neutralized acid group (hereinafter referred to as “hydroxyl group and / or hydrolysis of a silicon atom bond”). It is preferably a polymer segment derived from the polymer (a) having an abbreviated “functional group”. Examples of the polymer (a) include vinyl polymers such as acrylic polymers, fluoroolefin polymers, vinyl ester polymers, aromatic vinyl polymers, and polyolefin polymers, polyurethane polymers, and polyester polymers. , Polyether polymers, and the like. Among them, vinyl polymers and polyurethane polymers are preferable, and acrylic polymers are more preferable.

  Examples of the acid group in the polymer (a) include a carboxyl group, a phosphoric acid group, an acidic phosphoric acid ester group, a phosphorous acid group, a sulfonic acid group, and a sulfinic acid group. Among these, a composite resin (ABC) A carboxyl group is preferred because it is easily introduced into the skeleton.

  Examples of the basic compound used for neutralizing the acid group include organic amines such as methylamine, dimethylamine, trimethylamine, ethylamine, diethylamine, triethylamine, 2-aminoethanol, and 2-dimethylaminoethanol. ; Inorganic basic compounds such as ammonia, sodium hydroxide and potassium hydroxide; quaternary ammonium hydroxides such as tetramethylammonium hydroxide, tetra-n-butylammonium hydroxide and trimethylbenzylammonium hydroxide can be used. Of these, organic amines and ammonia (ammonia water may be used) are preferably used.

  From the viewpoint of maintaining good storage stability of an aqueous dispersion or aqueous solution in which the composite resin (ABC) is dispersed or dissolved in an aqueous medium, the neutralized acid group in the polymer (a). It is preferably present at a rate of 0.1 to 20% by weight, more preferably at a rate of 0.2 to 10% by weight, based on 100% by weight of the composite resin (ABC). preferable.

  Moreover, as a hydrolysable group couple | bonded with the silicon atom in the said polymer (a), if it is a functional group which can produce | generate the hydroxyl group (silanol group) couple | bonded with the silicon atom by being hydrolyzed, Well, for example, halogen atom bonded to silicon atom, alkoxy group bonded to silicon atom, acyloxy group bonded to silicon atom, phenoxy group bonded to silicon atom, mercapto group bonded to silicon atom, amino bonded to silicon atom Group, an amide group bonded to a silicon atom, an aminooxy group bonded to a silicon atom, an iminooxy group bonded to a silicon atom, an alkenyloxy group bonded to a silicon atom, and the hydrolysis reaction can proceed easily. In addition, since a by-product after the reaction can be easily removed, an alkoxy group bonded to a silicon atom is preferable.

  The polymer segment (A) may have other functional groups other than neutralized acid groups, silicon atom-bonded hydroxyl groups, and / or hydrolyzable groups, as long as the effects of the present invention are not impaired. Good. Examples of such other functional groups include unneutralized carboxyl groups, blocked carboxyl groups, carboxylic anhydride groups, hydroxyl groups, blocked hydroxyl groups, cyclocarbonate groups, epoxy groups, carbonyl groups, and primary amide groups. Secondary amide group, carbamate group, polyethylene glycol group, polypropylene glycol group, group shown by following structural formula (S-3), etc. are mentioned.

  Examples of the polysiloxane segment (B) constituting the composite resin (ABC) include a segment derived from a polysiloxane having a silicon atom-bonded hydroxyl group and / or a hydrolyzable group. Examples of the hydrolyzable group bonded to the silicon atom include those similar to the hydrolyzable group bonded to the silicon atom described in the polymer segment (A), and preferred ones are also the same.

  As said polysiloxane segment (B), what has a structure shown by the following general formula (S-4) or (S-5) especially is preferable. Since the polysiloxane segment having the structure represented by the following general formula (S-4) or (S-5) has a three-dimensional network-like polysiloxane structure, the resulting coating film has solvent resistance and weather resistance. It has excellent properties.

[In the general formulas (S-4) and (S-5), R ¹ is an organic group having 4 to 12 carbon atoms bonded to a silicon atom, and R ² and R ³ are each independently a silicon atom. A bonded methyl group or an ethyl group bonded to a silicon atom. R ¹ is preferably a hydrocarbon group having 4 to 12 carbon atoms bonded to a silicon atom, and more preferably a phenyl group or an alkyl group having 4 carbon atoms. R ² and R ³ are each preferably a methyl group bonded to a silicon atom or an ethyl group bonded to a silicon atom, and more preferably a methyl group bonded to a silicon atom. ]

  The polysiloxane segment having the structure represented by the general formula (S-4) or (S-5) is an organoalkoxysilane, preferably an organic group having 4 to 12 carbon atoms bonded to a silicon atom (hereinafter, “ A monoorganotrialkoxysilane having a silicon atom-bonded organic group having 4 to 12 carbon atoms ”) and / or a methyl group bonded to a silicon atom and / or an ethyl group bonded to a silicon atom (hereinafter referred to as an“ organic group ”). And a segment derived from polysiloxane obtained by hydrolytic condensation of a diorganodialkoxysilane having two of “a silicon atom-bonded methyl group and / or ethyl group”. These polysiloxane segments consist of two organic atom-bonded organic groups having 4 to 12 carbon atoms, silicon atom-bonded hydroxyl groups and / or hydrolyzable groups, and / or silicon atom-bonded methyl groups and / or ethyl groups. And a silicon atom-bonded hydroxyl group and / or hydrolyzable group, and may have any structure of linear, branched, and cyclic.

  Examples of the organic group having 4 to 12 carbon atoms bonded to the silicon atom include an alkyl group, a cycloalkyl group, an aryl group, and an aralkyl group each having 4 to 12 carbon atoms bonded to the silicon atom. In addition, these organic groups may have a substituent.

  Such an organic group having 4 to 12 carbon atoms bonded to a silicon atom is preferably a hydrocarbon group bonded to a silicon atom, for example, an n-butyl group, an iso-butyl group, or an n-hexyl bonded to a silicon atom. Group, n-octyl group, n-dodecyl group, alkyl group such as cyclohexylmethyl group; cycloalkyl group such as cyclohexyl group, 4-methylcyclohexyl group; aryl group such as phenyl group, 4-methylphenyl group; benzyl group, etc. Among them, a phenyl group bonded to a silicon atom or an alkyl group having 4 carbon atoms bonded to a silicon atom is more preferable.

  The polysiloxane segment (C) constituting the composite resin (ABC) is a segment derived from a condensate (c) of an alkyltrialkoxysilane having 1 to 3 carbon atoms in the alkyl group, and the alkyl group used here The alkyltrialkoxysilane condensate (c) having 1 to 3 carbon atoms has a hydroxyl group bonded to a silicon atom and / or an alkoxy group bonded to a silicon atom.

The alkyltrialkoxysilane condensate (c) preferably has a structure represented by the following general formula (S-6). Since the polysiloxane segment derived from the alkyltrialkoxysilane condensate having the structure represented by the following general formula (S-6) has a three-dimensional network polysiloxane structure, the resulting coating film is solvent resistant. It has excellent properties and weather resistance. [However, R ⁴ in the general formula (S-6) is an alkyl group having 1 to 3 carbon atoms. ]

  The composite resin (ABC) is derived from the polysiloxane segment (B) and alkyltrialkoxysilane condensate (c) in the composite resin (ABC) because a coating film excellent in weather resistance can be obtained. The polysiloxane segment (C) and the total amount (B + C) are preferably 15 to 85 parts by weight, and more preferably 20 to 50 parts by weight.

  In addition, as the composite resin (ABC), since a coating film having excellent weather resistance and crack resistance is obtained, the polyalkylenesilane-derived polycondensate (c) derived from the alkyltrialkoxysilane in the composite resin (ABC) is obtained. The amount of the siloxane segment (C) is preferably 5 to 50 parts by weight, and more preferably 10 to 30 parts by weight.

  Although the said composite resin (ABC) can be manufactured with various methods, it is preferable to manufacture in the process which consists of following (I)-(II) especially.

Step (I) A polymer (a ′) having both an acid group and a silicon atom-bonded hydroxyl group and / or hydrolyzable group, an organoalkoxysilane (b) and / or a hydrolysis condensate thereof (b-1) Is a composite resin (A′B) obtained by chemically condensing the polymer segment (A ′) derived from the polymer (a ′) and the polysiloxane segment (B) derived from the organoalkoxysilane (b). )

As the step (II), the following two types of routes can be mentioned.
(II-1) In step (I), the resulting composite resin (A′B) and the alkyltrialkoxysilane condensate (c) having 1 to 3 carbon atoms in the alkyl group are hydrolyzed and condensed to form a composite. The polysiloxane segment (B) of the resin (A′B) and the polysiloxane segment (C) derived from the condensate (c) of the alkyltrialkoxysilane having 1 to 3 carbon atoms of the alkyl group have silicon-oxygen bonds. A composite resin (A′BC) bonded via a base, and then neutralizing an acid group in the composite resin (A′BC) with a basic compound to obtain a composite resin (ABC).
(II-2) After neutralizing the acid group in the composite resin (A′B) obtained in the step (I) with a basic compound to obtain a composite resin (AB), the alkyl group has 1 to 1 carbon atoms. The condensation product (c) of 3 alkyltrialkoxysilane is hydrolyzed and condensed to produce a polysiloxane segment (B) of the composite resin (AB) and an alkyltrialkoxysilane having 1 to 3 carbon atoms in the alkyl group. (C) A step of obtaining a composite resin (ABC) in which the derived polysiloxane segment (C) is bonded via a silicon-oxygen bond.

  In addition, the said basic compound is a thing similar to what neutralizes the acid group in the above-mentioned polymer (a).

  The hydrolysis-condensation reaction in the production process can be progressed by various methods, but a method in which the reaction is advanced by supplying water and a catalyst during the production process is simple and preferable.

  The hydrolysis condensation reaction refers to a condensation reaction in which part of the hydrolyzable group is hydrolyzed under the influence of water or the like to form a hydroxyl group, and then proceeds between the hydroxyl group or hydrolyzable group.

  The polymer (a ′) is a polymer having both an acid group and a silicon atom-bonded hydroxyl group and / or a hydrolyzable group, and the neutralized acid except that the acid group is not neutralized. This is exactly the same as the polymer (a) having both a group and a silicon atom-bonded hydroxyl group and / or hydrolyzable group.

  When a vinyl polymer is used as the polymer (a ′), the vinyl polymer may be, for example, an acid group-containing vinyl monomer, a hydroxyl group-containing vinyl monomer bonded to a silicon atom, and / or a silicon atom. The polymer can be produced by polymerizing a hydrolyzable group-containing vinyl monomer bonded to, and if necessary, another vinyl monomer.

  Examples of the acid group-containing vinyl monomer include various vinyl monomers containing an acid group such as a carboxyl group, a phosphoric acid group, an acidic phosphoric acid ester group, a phosphorous acid group, a sulfonic acid group, and a sulfinic acid group. Of these, a vinyl monomer containing a carboxyl group (which may be a carboxylic anhydride group) is preferred.

  Examples of the carboxyl group-containing vinyl monomer include (meth) acrylic acid, 2-carboxyethyl (meth) acrylate, crotonic acid, itaconic acid, maleic acid, fumaric acid and other unsaturated carboxylic acids; maleic anhydride, Unsaturated polycarboxylic acid anhydrides such as itaconic anhydride; unsaturated monocarboxylic acid anhydrides such as acrylic acid anhydride and methacrylic anhydride; unsaturated carboxylic acid such as acrylic acid and methacrylic acid; acetic acid and propion Acid, mixed acid anhydride with saturated carboxylic acid such as benzoic acid; monomethyl itaconate, mono-n-butyl itaconate, monomethyl maleate, mono-n-butyl maleate, monomethyl fumarate, mono-n-fumarate Various monoesters (half-esters) of saturated dicarboxylic acids such as butyl and saturated monohydric alcohols; Monovinyl esters of saturated dicarboxylic acids such as monovinyl dipinate and monovinyl succinate; bonded to carbon atoms with anhydrides of saturated polycarboxylic acids such as succinic anhydride, glutaric anhydride, phthalic anhydride and trimellitic anhydride Addition reaction products with vinyl monomers containing hydroxyl groups; and various monomers obtained by addition reaction of the carboxyl group-containing monomers with lactones, among others. Unsaturated carboxylic acids such as (meth) acrylic acid are preferred because they can be easily introduced into the vinyl polymer.

  The carboxyl group may be blocked. Examples of the vinyl monomer having a blocked carboxyl group include trimethylsilyl (meth) acrylate, dimethyl-tert-butylsilyl (meth) acrylate, and trimethylsilylcroto. Silyl ester group-containing vinyl monomers such as nates; hemiacetal ester groups such as 1-ethoxyethyl (meth) acrylate, 2-methoxy-2- (meth) acryloyloxypropane, 2- (meth) acryloyloxytetrahydrofuran Or hemiketal ester group-containing monomers; tert-butyl ester group-containing monomers such as tert-butyl (meth) acrylate and tert-butyl crotonate.

  Examples of the hydroxyl group-containing vinyl monomer bonded to the silicon atom include trihydroxyvinylsilane, ethoxydihydroxyvinylsilane, diethoxyhydroxyvinylsilane, dichlorohydroxyvinylsilane, 3- (meth) acryloyloxypropyltrihydroxysilane, 3 -(Meth) acryloyloxypropylmethyldihydroxysilane and the like.

As the hydrolyzable group-containing vinyl monomer bonded to the silicon atom, for example, a vinyl monomer having a hydrolyzable group represented by the following general formula (S-7) can be used. [In the general formula (S-7), R ⁵ represents a monovalent organic group such as an alkyl group, an aryl group or an aralkyl group, and R ⁶ represents a halogen atom, an alkoxy group, an acyloxy group, a phenoxy group or an aryloxy group. , A mercapto group, an amino group, an amide group, an aminooxy group, an iminooxy group, or an alkenyloxy group, and b is an integer of 0-2. ]

  Examples of the vinyl monomer having a hydrolyzable group represented by the general formula (S-7) include vinyltrimethoxysilane, vinyltriethoxysilane, vinylmethyldimethoxysilane, vinyltri (2-methoxyethoxy) silane, and vinyl. Triacetoxysilane, vinyltrichlorosilane, 2-trimethoxysilylethyl vinyl ether, 3- (meth) acryloyloxypropyltrimethoxysilane, 3- (meth) acryloyloxypropyltriethoxysilane, 3- (meth) acryloyloxypropylmethyldimethoxy Silane, 3- (meth) acryloyloxypropyltrichlorosilane, and the like. Among them, the hydrolysis reaction can easily proceed, and by-products after the reaction can be easily removed. Silane, 3 (Meth) acryloyloxy propyl trimethoxy silane is preferred.

  Examples of the other vinyl monomers include methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, tert- Alkyl (meth) acrylates having an alkyl group having 1 to 22 carbon atoms such as butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, lauryl (meth) acrylate; benzyl (meth) acrylate, 2-phenylethyl (meta ) Aralkyl (meth) acrylates such as acrylate; Cycloalkyl (meth) acrylates such as cyclohexyl (meth) acrylate and isobornyl (meth) acrylate; 2-methoxyethyl (meth) acrylate, 4-methoxybutyl (meth) acrylic Ω-alkoxyalkyl (meth) acrylates such as carbonates; aromatic vinyl monomers such as styrene, p-tert-butylstyrene, α-methylstyrene, vinyltoluene; vinyl acetate, vinyl propionate, pivalic acid Carboxylic acid vinyl esters such as vinyl and vinyl benzoate; alkyl esters of crotonic acid such as methyl crotonate and ethyl crotonate; Unsaturation such as dimethyl malate, di-n-butyl malate, dimethyl fumarate and dimethyl itaconate Dialkyl esters of dibasic acids; α-olefins such as ethylene and propylene; fluoroolefins such as vinylidene fluoride, tetrafluoroethylene, hexafluoropropylene and chlorotrifluoroethylene; alkyls such as ethyl vinyl ether and n-butyl vinyl ether Nyl ethers; Cycloalkyl vinyl ethers such as cyclopentyl vinyl ether and cyclohexyl vinyl ether; Tertiary amides such as N, N-dimethyl (meth) acrylamide, N- (meth) acryloylmorpholine, N- (meth) acryloylpyrrolidine and N-vinylpyrrolidone Group-containing monomers;

Hydroxyalkyl (meth) acrylates such as 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate and 4-hydroxybutyl (meth) acrylate; hydroxyl groups such as 2-hydroxyethyl vinyl ether and 4-hydroxybutyl vinyl ether -Containing vinyl ethers; hydroxyl group-containing allyl ethers such as 2-hydroxyethyl allyl ether and 2-hydroxybutyl allyl ether; vinyl monomers containing hydroxyl groups bonded to these carbon atoms and lactones such as ε-caprolactone; Addition reaction product of

2-dimethylaminoethyl (meth) acrylate, 2-diethylaminoethyl (meth) acrylate, 2-di-n-propylaminoethyl (meth) acrylate, 3-dimethylaminopropyl (meth) acrylate, 4-dimethylaminobutyl (meth) ) Tertiary amino group-containing (meth) acrylic acid esters such as acrylate and N- [2- (meth) acryloyloxy] ethylmorpholine; tertiary amino group-containing vinylpyridine, N-vinylcarbazole, N-vinylquinoline, etc. Aromatic vinyl monomers: N- (2-dimethylamino) ethyl (meth) acrylamide, N- (2-diethylamino) ethyl (meth) acrylamide, N- (2-di-n-propylamino) ethyl ( Tertiary amino group-containing (meth) acrylamides such as (meth) acrylamide; Tertiary amino group-containing crotonic acid amides such as-(2-dimethylamino) ethylcrotonic acid amide, N- (4-dimethylamino) butylcrotonic acid amide; 2-dimethylaminoethyl vinyl ether, 2-diethylaminoethyl vinyl ether, 4 -Tertiary amino group-containing vinyl ethers such as dimethylaminobutyl vinyl ether.

  The vinyl monomer can be appropriately selected in kind and amount within a range not impairing the effects of the present invention, depending on the properties imparted to the aqueous curable coating composition of the present invention.

  The polymer (a ′) is selected from the group consisting of an anionic group, a cationic group and a nonionic group for the purpose of improving the solubility or dispersibility of the composite resin (ABC) in an aqueous medium. Those having at least one hydrophilic group can be used.

  Examples of the vinyl polymer usable as the polymer (a ′) include acid group-containing vinyl monomers, hydroxyl group-containing vinyl monomers bonded to silicon atoms, and / or hydrolyzable bonded to silicon atoms. It can be produced by polymerizing a group-containing vinyl monomer and, if necessary, another vinyl monomer by a polymerization method such as a bulk radical polymerization method, a solution radical polymerization method or a non-aqueous dispersion radical polymerization method. Especially, since it is easy to manufacture, it is preferable to apply a so-called solution radical polymerization method in which a vinyl polymer is manufactured by radical polymerization of the vinyl monomer in an organic solvent.

  When the vinyl monomer is polymerized by the radical polymerization method, a polymerization initiator can be used as necessary. Examples of such a polymerization initiator include 2,2′-azobis (isobutyronitrile), 2,2′-azobis (2,4-dimethylvaleronitrile), 2,2′-azobis (2-methylbutyronitrile). Azo compounds such as nitrile); tert-butyl peroxypivalate, tert-butyl peroxybenzoate, tert-butyl peroxy-2-ethylhexanoate, di-tert-butyl peroxide, cumene hydroperoxide, diisopropyl And peroxides such as peroxycarbonate.

  Examples of the organic solvent include aliphatic or alicyclic hydrocarbons such as n-hexane, n-heptane, n-octane, cyclohexane, and cyclopentane; aromatic hydrocarbons such as toluene, xylene, and ethylbenzene. Alcohols such as methanol, ethanol, n-butanol, ethylene glycol monomethyl ether, propylene glycol monomethyl ether; ethyl acetate, n-butyl acetate, n-amyl acetate, ethylene glycol monomethyl ether acetate, propylene glycol monomethyl ether acetate Esters such as acetone; ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, methyl n-amyl ketone, cyclohexanone; diethylene glycol dimethyl ether, diethylene glycol dibutyl ether Polyalkylene glycol dialkyl ethers such as 1, ethers such as 1,2-dimethoxyethane, tetrahydrofuran, and dioxane; N-methylpyrrolidone, dimethylformamide, dimethylacetamide, ethylene carbonate, and the like. These may be used alone or in combination of two or more. Can be used in combination.

  The polymer (a ′) preferably has a number average molecular weight in the range of 500 to 200,000, more preferably in the range of 700 to 100,000, and in the range of 1,000 to 50,000. Particularly preferred are those having By using the polymer (a ′) having a number average molecular weight within such a range, it is possible to prevent thickening and gelation when producing the composite resin (ABC), and to provide a coating film excellent in durability. Can be formed.

  Next, the organoalkoxysilane (b) and / or the hydrolysis condensate (b-1) thereof used for constituting the polysiloxane segment (B) in the production step (I) will be described.

  The organoalkoxysilane (b) is not particularly limited, but among them, since it can form a coating film excellent in stability and durability of the composite resin (ABC), it has 4 to 12 carbon atoms. A monoorganotrialkoxysilane having an organic group and a diorganodialkoxysilane having two methyl groups and / or ethyl groups are preferred.

  The hydrolyzed condensate (b-1) of the organoalkoxysilane (b) is not particularly limited as long as it is a hydrolyzed condensate of the organoalkoxysilane (b). A product obtained by hydrolytic condensation of a monoorganotrialkoxysilane having -12 organic groups and / or a diorganodialkoxysilane having two silicon-bonded methyl and / or ethyl groups is preferred.

  Examples of the monoorganotrialkoxysilane having a silicon atom-bonded organic group having 4 to 12 carbon atoms include iso-butyltrimethoxysilane, cyclohexyltrimethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, 3- ( And (meth) acryloyloxypropyltrimethoxysilane, 3- (meth) acryloyloxypropyltriethoxysilane, and the like.

  Examples of the diorganodialkoxysilane having two silicon atom-bonded methyl groups and / or ethyl groups include dimethyldimethoxysilane, dimethyldiethoxysilane, dimethyldi-n-butoxysilane, dimethyldiacetoxysilane, and diethyldimethoxy. Silane, diethyl diacetoxysilane, etc. are mentioned.

  Among these organoalkoxysilanes (b), the hydrolysis reaction can easily proceed and the by-products after the reaction can be easily removed. Therefore, iso-butyltrimethoxysilane, phenyltrimethoxysilane, and dimethyldimethoxysilane are used. preferable. These organoalkoxysilanes (b) may be used alone or in combination of two or more.

  In addition, in the said manufacturing process (I), although it is also possible enough to use the hydrolysis-condensation product (b-1) of organoalkoxysilane (b) independently, it is the composite resin (A'B) by hydrolysis condensation. Since it is easy to produce, it is preferable to use an organoalkoxysilane (b) alone or a combination of an organoalkoxysilane (b) and its hydrolysis condensate (b-1), and use an organoalkoxysilane (b) alone. Is particularly preferred. Here, the single use of the organoalkoxysilane (b) is to use only the organoalkoxysilane (b), and includes the case where two or more organoalkoxysilanes (b) are used in combination.

  The hydrolysis condensation reaction in the production step (I) can proceed by various methods, but there is a method in which the reaction is advanced by supplying water and a catalyst during the production step (I). Simple and preferred.

  Examples of the catalyst include inorganic acids such as hydrochloric acid, sulfuric acid, and phosphoric acid; organic acids such as p-toluenesulfonic acid, monoisopropyl phosphate, and acetic acid; inorganic bases such as sodium hydroxide and potassium hydroxide; tetraisopropyl titanate, tetra Titanate esters such as butyl titanate; 1,8-diazabicyclo [5.4.0] undecene-7 (DBU), 1,5-diazabicyclo [4.3.0] nonene-5 (DBN), 1,4 -Compounds containing basic nitrogen atoms such as diazabicyclo [2.2.2] octane (DABCO), tri-n-butylamine, dimethylbenzylamine, monoethanolamine, imidazole, 1-methylimidazole; tetramethylammonium salts Quaternary anions such as tetrabutylammonium salt and dilauryldimethylammonium salt Quaternary ammonium salts which are chlorides, bromides, carboxylates, hydroxides, etc. as counter anions; dibutyltin diacetate, dibutyltin dioctoate, dibutyltin dilaurate, dibutyltin diacetylacetonate, tin octylate, Tin carboxylates such as tin stearate can be used alone or in combination of two or more.

  The catalyst is preferably used in an amount of 0.0001 to 10 parts by weight with respect to 100 parts by weight of the organoalkoxysilane (b) and / or its hydrolysis condensate (b-1). It is more preferable to use in the range of ˜3 parts by weight, and it is particularly preferable to use in the range of 0.001 to 1 part by weight.

  The water used when the hydrolysis condensation reaction proceeds is based on 1 mol of the hydrolyzable group and hydroxyl group of the organoalkoxysilane (b) and / or the hydrolysis condensate (b-1) thereof. 0.05 mol or more is appropriate, preferably 0.1 mol or more, particularly preferably 0.5 to 3.0 mol.

  The catalyst and water may be supplied collectively or sequentially, or a mixture of the catalyst and water previously supplied may be supplied.

  The reaction temperature of the hydrolysis condensation reaction is suitably in the range of 0 to 150 ° C, and preferably in the range of 20 to 100 ° C. The reaction can be carried out under any conditions of normal pressure, increased pressure, or reduced pressure.

  Alcohol and water, which are by-products that can be generated in the hydrolysis-condensation reaction, may be removed by a method such as distillation when the stability of the resulting aqueous curable coating composition is reduced.

  Next, the alkyltrialkoxysilane condensate (c) having 1 to 3 carbon atoms in the alkyl group used for constituting the polysiloxane segment (C) in the production step (II) will be described in detail.

  Examples of the alkyltrialkoxysilane having 1 to 3 carbon atoms in the alkyl group include, for example, methyltrimethoxysilane, methyltriethoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, n-propyltrimethoxysilane, and iso-propyl. Trimethoxysilane and the like can be mentioned. Among them, methyltrimethoxysilane and ethyltrimethoxysilane are preferable because the hydrolysis reaction can easily proceed and by-products after the reaction can be easily removed. These alkyltrialkoxysilanes may be used alone or in combination of two or more.

  There are no particular limitations on the method for obtaining the condensate (c) from the alkyltrialkoxysilane, and various methods may be mentioned. A method for allowing the hydrolysis and condensation reaction to proceed by supplying water and a catalyst is simple. preferable.

  About the water and catalyst used in that case, it can be used on the same conditions as the hydrolysis-condensation reaction in the said manufacturing process (I).

  Moreover, in the said manufacturing process (II), in addition to the condensate (c) of alkyl trialkoxysilane whose alkyl group has 1 to 3 carbon atoms, other silane compounds and hydrolysis condensates thereof may be used in combination. it can.

  Examples of the other silane compounds include tetrafunctional alkoxysilane compounds such as tetramethoxysilane, tetraethoxysilane, and tetra n-propoxysilane; hydrolysis condensates of the tetrafunctional alkoxysilane compounds, and the like. These can be used in combination as long as the effects of the present invention are not impaired.

  When the tetrafunctional alkoxysilane compound or a hydrolysis condensate thereof is used in combination, the tetrafunctional alkoxy is used with respect to 100 mol% of all silicon atoms constituting the polysiloxane segment (B) and the polysiloxane segment (C). It is preferable to use together in the range which the silicon atom which a silane compound and its hydrolysis condensate does not exceed 20 mol%.

  Furthermore, the condensate (c) of the alkyltrialkoxysilane having 1 to 3 carbon atoms of the alkyl group is substituted with a metal alkoxide compound other than a silicon atom such as boron, titanium, zirconium or aluminum, and the effect of the present invention is impaired. Can be used in combination as long as there is no range. For example, the above-mentioned metal alkoxide compound should be used in combination within a range not exceeding 25 mol% with respect to 100 mol% of all silicon atoms constituting the polysiloxane segment (B) and the polysiloxane segment (C). Can do.

The aqueous curable coating composition of the present invention comprises an aqueous product of a composite resin (ABC) obtained by dispersing or dissolving the composite resin (ABC) in an aqueous medium, preferably an aqueous dispersion of the composite resin (ABC) And an ultraviolet absorber (D).

  As its production method, it can be produced by various methods. In particular, after producing the composite resin (ABC) by the production steps (I) to (II), it is dissolved or dispersed in an aqueous medium in the step (III). Thus, after obtaining an aqueous dispersion of the composite resin (ABC), it can be produced in the step (IV) of dispersing the ultraviolet absorbent (D) in the aqueous dispersion.

  The ultraviolet absorber (D) may be added to the aqueous dispersion and mixed as it is, or added and mixed after being dissolved or dispersed in water, an organic solvent or the like. May be.

  Examples of the aqueous medium used in the present invention include water, organic solvents miscible with water, and mixtures thereof. Examples of the organic solvent miscible with water include alcohols such as methanol, ethanol, n- and isopropanol; ketones such as acetone and methyl ethyl ketone; polyalkylene glycols such as ethylene glycol, diethylene glycol and propylene glycol; Alkyl ethers; lactams such as N-methyl-2-pyrrolidone, and the like. In the present invention, only water may be used, a mixture of water and an organic solvent miscible with water may be used, or only an organic solvent miscible with water may be used. From the viewpoint of safety and load on the environment, water alone or a mixture of water and an organic solvent miscible with water is preferable, and only water is particularly preferable.

  As the ultraviolet absorber (D) used in the present invention, when added to the coating film, the ultraviolet shielding property of the coating film is good and the stability of the composite resin (ABC) is not deteriorated. Although not particularly limited, for example, metal oxides such as titanium oxide, zinc oxide, tin oxide, cerium oxide, benzotriazole-based UV absorber, triazine-based UV absorber, indole-based UV absorber, benzophenone-based UV absorber And azomethine-based ultraviolet absorbers.

  Examples of the benzotriazole UV absorber include 2- (2′-hydroxy-5′-methylphenyl) benzotriazole, 2,2′-methylenebis [6- (2H-benzotriazol-2-yl) -1, 4-dihydroxybenzene], 2,2′-methylenebis [6- (2H-benzotriazol-2-yl) -4- (hydroxymethyl) phenol], 2,2′-methylenebis [6- (2H-benzotriazole- 2-yl) -4- (2-hydroxyethyl) phenol and the like.

Examples of the triazine ultraviolet absorber include 2- (4,6-diphenyl-1,3,5-triazin-2-yl) -5-hexyloxyphenol, 2- (4,6-diphenyl-1,3, 5-triazin-2-yl) -5-methyloxyphenol, 2- (4,6-diphenyl-1,3,5-triazin-2-yl) -5-ethyloxyphenol, 2- (4,6- Diphenyl-1,3,5-triazin-2-yl) -5-propyloxyphenol, 2- (4,6-diphenyl-1,3,5-triazin-2-yl) -5-butyloxyphenol, etc. Is exemplified. Further examples include 2- (4,6-bis (2,4-dimethylphenyl) -1,3,5-triazin-2-yl) -5-hexyloxyphenol.

Examples of the indole ultraviolet absorber include 5-indoleol, 4-aminoindole, 4-methoxyindole and the like.

Examples of the benzophenone-based ultraviolet absorber include 2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2,2′-dihydroxy-4-methoxybenzophenone, 2-hydroxy-4-methoxy-2′-carboxybenzophenone. 2-hydroxy-4-methoxy-5-sulfobenzophenone trihydrate, 2,2'-dihydroxy-4,4'-dimethoxybenzophenone, 2-hydroxy-4-octoxybenzophenone, 2-hydroxy-4-octa Decyloxybenzophenone, sodium 2,2'-dihydroxy-4,4'-dimethoxy-5-sulfobenzophenone, 2,2 ', 4,4'-tetrahydroxybenzophenone, 4-dodecyloxy-2-hydroxybenzophenone, 5-chloro -2-hydroxy Benzophenone, resorcinol monobenzoate, 2,4-dibenzoyl resorcinol, 4,6-dibenzoyl resorcinol, hydroxydodecylbenzophenone, 2,2'-dihydroxy-4 (3-methacryloxy-2- Hydroxypropoxy) benzophenone and the like.

  Although there is no restriction | limiting in particular in the usage-amount of a ultraviolet absorber (D), A ultraviolet absorber is 0.1-50 weight part with respect to 100 weight part of composite resins, Preferably it is 0.5-10 weight part, Preferably Is preferably in the range of 0.5 to 2 parts by weight.

  Next, you may use together a hardening | curing agent (E) with the water-based curable coating composition of this invention as needed. The curing agent (E) may be a compound having a functional group that reacts with the acid group and / or the hydroxyl group bonded to the silicon atom of the composite resin (ABC), and can be appropriately selected and used. Examples of the functional group that reacts with a hydroxyl group bonded to an acid group and / or a silicon atom include a functional group that reacts with a carboxyl group such as an isocyanate group or a blocked isocyanate group but also reacts with a hydroxyl group bonded to a silicon atom; an epoxy group Functional groups that react with carboxyl groups such as cyclocarbonate groups, amide groups, hydroxyl groups, oxazoline groups, carbodiimide groups, hydrazino groups; and hydroxyl groups bonded to silicon atoms such as N-hydroxymethylamino groups and N-alkoxymethylamino groups; Functional groups that react but also react with carboxyl groups; hydroxyl groups bonded to silicon atoms, hydrolyzable groups bonded to silicon atoms, functional groups that react with hydroxyl groups bonded to silicon atoms such as carboxyl groups, and the like.

  Specific examples of the curing agent (E) include a compound having a silicon atom-bonded hydroxyl group and / or a hydrolyzable group, a compound having an isocyanate group and a silicon atom-bonded hydroxyl group and / or a hydrolyzable group, an epoxy group, Compounds having a silicon atom-bonded hydroxyl group and / or hydrolyzable group, polyisocyanate compound, block polyisocyanate compound, polyepoxy compound, polycyclocarbonate compound, amino resin, primary or secondary amide group-containing compound, polycarboxy compound , Polyhydroxy compounds, polyoxazoline compounds, polycarbodiimide compounds, polyhydrazide compounds, and the like. Among them, compounds having silicon atom-bonded hydroxyl groups and / or hydrolyzable groups, epoxy groups and silicon atom-bonded hydroxyl groups and / or Or a compound having a hydrolyzable group, Cyanate compound, blocked polyisocyanate compound, polyepoxy compound, a polyoxazoline compound is preferable. These can be used alone or in combination of two or more.

  Examples of the epoxy group and a hydroxyl group having a silicon atom bond and / or a hydrolyzable compound include 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, and 3-glycidoxypropyltrimethyl. Ethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, etc., their hydrolysis condensates, vinyl groups having epoxy groups and hydrolyzable silyl groups And copolymers.

  Examples of the polyisocyanate compound include aromatic diisocyanates such as tolylene diisocyanate and diphenylmethane-4,4′-diisocyanate; meta-xylylene diisocyanate, α, α, α ′, α′-tetramethyl-meta-xylyl Aralkyl diisocyanates such as range isocyanate; hexamethylene diisocyanate, lysine diisocyanate, 1,3-bisisocyanate methylcyclohexane, 2-methyl-1,3-diisocyanate cyclohexane, 2-methyl-1,5-diisocyanate cyclohexane Aliphatic or cycloaliphatic diisocyanates such as isophorone diisocyanate:

Various prepolymers having an isocyanate group, obtained by addition reaction of the polyisocyanate compound with polyhydric alcohols; prepolymers having an isocyanurate ring obtained by cyclization and trimerization of the polyisocyanate compound A polyisocyanate having a biuret structure obtained by reacting the polyisocyanate compound with water; 2-isocyanatoethyl (meth) acrylate, 3-isopropenyl-α, α-dimethylbenzyl isocyanate, (meth) Examples thereof include vinyl copolymers containing isocyanate groups obtained from vinyl monomers containing as an essential component a vinyl monomer having an isocyanate group such as acryloyl isocyanate.

  Examples of the block polyisocyanate compound include those obtained by blocking the polyisocyanate compound with various blocking agents. Examples of the blocking agent include alcohols such as methanol, ethanol, and lactic acid esters; phenolic hydroxyl group-containing compounds such as phenol and salicylic acid ester; amides such as ε-caprolactam and 2-pyrrolidone; acetone oxime, methyl ethyl ketoxime, and the like And active methylene compounds such as methyl acetoacetate, ethyl acetoacetate, and acetylacetone.

  Examples of the polyepoxy compound include polyglycidyl ethers of aliphatic or alicyclic polyols such as ethylene glycol, hexanediol, neopentyl glycol, trimethylolpropane, pentaerythritol, sorbitol, and hydrogenated bisphenol A; bisphenol A Polyglycidyl ethers of aromatic diols such as bisphenol S and bisphenol F; polyglycidyl ethers of polyether polyols such as polyethylene glycol, polypropylene glycol and polytetramethylene glycol; tris (2-hydroxyethyl) isocyanurate Polyglycidyl ethers; polyglycidyl esters of aliphatic or aromatic polycarboxylic acids such as adipic acid, butanetetracarboxylic acid, phthalic acid, terephthalic acid; Bisepoxides of hydrocarbon dienes such as crooctadiene and vinylcyclohexene; Alicyclic rings such as bis (3,4-epoxycyclohexylmethyl) adipate and 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexylcarboxylate Formula polyepoxy compounds; vinyl copolymers containing two or more epoxy groups.

  Examples of the polyoxazoline compound include 2,2′-p-phenylene-bis- (1,3-oxazoline), 2,2′-tetramethylene-bis- (1,3-oxazoline), and 2,2 ′. -Low molecular weight poly (1,3-oxazoline) compounds such as octamethylene-bis- (2-oxazoline); 1,3-oxazoline group-containing vinyl monomers such as 2-isopropenyl-1,3-oxazoline And a vinyl polymer containing a 1,3-oxazoline group obtained by copolymerizing a homopolymer of the above and a vinyl monomer copolymerizable therewith.

  Examples of the polyhydrazide compound include dihydrazide compounds of organic acids such as oxalic acid dihydrazide, malonic acid dihydrazide, and succinic acid dihydrazide.

  Examples of the amino resin include alkylol groups obtained by reacting amino group-containing compounds such as melamine, benzoguanamine, acetoguanamine, urea, and glycouril with aldehyde compounds (or aldehyde supply substances) such as formaldehyde and acetaldehyde. Examples of the amino resin having an alkylol group include alkoxyalkyl group-containing amino resins obtained by reacting the amino resin having an alkylol group with a lower alcohol such as methanol, ethanol, n-butanol, and iso-butanol.

  As the usage-amount of the said hardening | curing agent (E), a hardening | curing agent (E) is a compound which has a hydroxyl group and / or hydrolyzable group of a silicon atom bond, a block polyisocyanate compound, an amino resin, and a polycarboxy compound, for example. In this case, the solid content of the curing agent (E) is preferably in the range of 0.1 to 200 parts by weight, and 0.5 to 150 parts by weight with respect to 100 parts by weight of the composite resin (ABC). More preferably, it is in the range of 1 part by weight, and particularly preferably in the range of 1 to 100 parts by weight.

  Further, for example, the curing agent (E) is a compound having an epoxy group and a silicon atom-bonded hydroxyl group and / or a hydrolyzable group, a polyepoxy compound, a polycyclocarbonate compound, a primary or secondary amide group-containing compound, poly When it is a compound having a group that reacts with a carboxyl group such as a hydroxy compound, a polyoxazoline compound, a polycarbodiimide compound, a polyhydrazide compound, and the composite resin (ABC) is a composite resin containing a carboxyl group, Groups (epoxy group, cyclocarbonate group, amide group, hydroxyl group, oxazoline group carbodiimide group, hydrazino group) that react with the carboxyl group in the curing agent (E) with respect to 1 equivalent of the carboxyl group in the composite resin (ABC). Etc.) is preferably in the range of 0.2 to 5.0 equivalents, 0 5 to 3.0, more preferably in the range of equivalents, and particularly preferably in the range of 0.7 to 2.0 equivalents.

  Further, for example, the curing agent (E) is a compound having a isocyanate group and a silicon atom-bonded hydroxyl group and / or a hydrolyzable group, or a polyisocyanate compound, and the composite resin (ABC) is a silicon atom-bonded hydroxyl group. And / or in the case of a composite resin having a hydrolyzable group, in the curing agent (E) with respect to 1 equivalent of a hydroxyl group and / or hydrolyzable group of a silicon atom bond in the composite resin (ABC). The amount of isocyanate group is preferably in the range of 0.1 to 10 equivalents, more preferably in the range of 0.3 to 5.0 equivalents, and in the range of 0.5 to 2.0 equivalents. It is particularly preferred.

  Among the curing agents (E), those that are not easily separated when mixed with an aqueous dispersion in which the composite resin (ABC) is dissolved or dispersed are preferable. For example, the hardener (E) is dispersed or dissolved in the aqueous medium. Those having a possible level of hydrophilicity, uniformly dispersed or dissolved in the aqueous dispersion, and cannot be dispersed or dissolved alone in the aqueous medium, but are mixed with the aqueous dispersion when mixed with the aqueous dispersion ( (ABC) Intrusion, fusion, adsorption, etc. to the particles occur, and the particles are integrated. Examples of those that are uniformly dispersed or dissolved in the aqueous dispersion include, for example, an aqueous polyisocyanate compound “Bernock DNW-5000” manufactured by DIC Corporation (polyisocyanate compound having an isocyanate group content of 13.5% by weight). Aqueous dispersion, non-volatile content 80% by weight), Daiichi Kogyo Seiyaku Co., Ltd. blocked polyisocyanate “Elastolon BN-77” (aqueous self-emulsified blocked polyisocyanate compound, solid content 31% by weight), Nippon Shokubai 1,3-oxazoline group-containing water-soluble resin “Epocross WS-500” (an aqueous solution of 1,3-oxazoline group-containing water-soluble resin having an equivalent of 220 g / eq of oxazoline group, content: 40% by weight) Moreover, as what integrates with composite resin (ABC) particle | grains at the time of mixing with the said aqueous dispersion, for example, 3 Glycidoxypropyltrimethoxysilane (3GPTMS), polymethoxysiloxane “MKC silicate MS51” manufactured by Mitsubishi Chemical Corporation, epoxy compound “Denacol EX-614B” manufactured by Nagase ChemteX Corporation (epoxy having an epoxy equivalent of 173 g / eq) Compound) and the like.

  In the case where the functional group other than an acid group or a hydroxyl group of silicon atom bond and / or a hydrolyzable group, which may be contained in the polymer segment (A), is cross-linked, the aforementioned compound or resin is used. Can be preferably used.

  The aqueous curable coating composition of the present invention can contain a thermosetting resin as necessary. Examples of such thermosetting resins include vinyl resins, polyester resins, polyurethane resins, epoxy resins, epoxy ester resins, acrylic resins, phenol resins, petroleum resins, ketone resins, silicon resins, or modified resins thereof.

  In the aqueous curable coating composition of the present invention, for example, for the purpose of adjusting the visible light reflectance, a resin in which various particles are dispersed can be used as a coating layer as necessary. Examples of such particles (fillers) include particles of titanium oxide, silicon oxide (silica), tin oxide, calcium carbonate, indium tin oxide, antimony oxide, and the like. The diameter of such particles is preferably in the range of 0.1 to 1000 nm. Examples of resins for dispersing such particles include polyester, cellulose derivatives, polyvinyl chloride, polystyrene, polyvinyl acetate, polybutene, poly (meth) acrylic acid and its ester compounds, polyvinyl alcohol, polyvinyl formal, polyvinyl butyral, polyamide, An ethylene-vinyl acetate copolymer, an ethylene-acrylic acid copolymer, a urethane resin, an epoxy resin, a silicone resin, a fluorine resin, or the like can be used. The compounding ratio of the particles and the resin is not particularly limited, but is preferably in the range of 0.1 to 15 parts by weight with respect to 100 parts by weight of the resin. The thickness of the coating layer in which such various particles are dispersed is usually 0.1 to 100 μm, preferably 0.5 to 50 μm, and particularly preferably 0.3 to 30 μm.

  The aqueous curable coating composition of the present invention may further include an inorganic pigment, an organic pigment, an extender pigment, a dye, a wax, a surfactant, a stabilizer, a flow regulator, an antifoaming agent, a leveling agent, a rheology, if necessary. Various additives such as a control agent, a light stabilizer, an antioxidant, or a plasticizer can be used.

  The film thickness of the coating film formed using the aqueous curable coating composition of the present invention is not particularly limited, but is preferably 0.1 to 100 μm, more preferably 0.3 to 50 μm. It is particularly preferable that the thickness is 0.3 to 30 μm. If it is the film thickness in the said range, the crack which may arise in a cured coating film can be suppressed, and the cured coating film which has the outstanding weather resistance and stain resistance can be formed.

  Examples of the method for applying the aqueous curable coating composition of the present invention to a substrate include spin coating, roller coating, spray coating, dip coating, flow coater coating, roll coater coating, brush coating, and the like. It is possible to apply various coating methods such as the method.

  After applying the aqueous curable coating composition of the present invention by the coating method, it may be a method of curing at room temperature for about 1 to 10 days, but is heated at a temperature range of 50 to 250 ° C. for about 1 second to 2 hours. Is preferred.

  Examples of the substrate on which the coating agent comprising the aqueous curable coating composition of the present invention can be applied include metals, inorganic building materials, glass, paper, wood, plastic substrates, and the like.

Examples of the plastic base material include ABS (acrylonitrile-butadiene-styrene) resin, PC (polycarbonate) resin as materials employed in plastic molded products such as mobile phones, home appliances, automobile interior and exterior materials, and OA equipment. ABS / PC resin, PS (polystyrene) resin, acrylic resin, polypropylene resin, polyethylene resin and the like can be mentioned. As the plastic substrate, polyethylene terephthalate, polyester, polyethylene, polypropylene, TAC (triacetyl cellulose), polycarbonate, polychlorinated A substrate made of vinyl or the like can be used. The various base materials described above may be coated in advance, or the coating agent of the present invention may be directly applied to the surface of the base material to form a coating film.

  Next, the present invention will be specifically described with reference to examples and comparative examples. In the examples, all parts and% are based on weight except for the specular reflectance (gloss value) and gloss retention.

Synthesis Example 1 [Preparation example of condensate (c-1) of methyltrimethoxysilane]
Into a reaction vessel equipped with a stirrer, a thermometer, a dropping funnel, a condenser tube and a nitrogen gas inlet, 1421 parts of methyltrimethoxysilane (MTMS) was charged and heated to 60 ° C. Subsequently, a mixture of 0.17 part of “A-3” (iso-propyl acid phosphate manufactured by Sakai Chemical Co., Ltd.) and 207 parts of deionized water was added dropwise over 5 minutes. After completion of the dropwise addition, the temperature in the reaction vessel was raised to 80 ° C. and stirred for 4 hours to conduct a hydrolysis condensation reaction. Then, the obtained condensate is reduced under a reduced pressure of 300 to 10 mmHg (the reduced pressure condition at the start of the distillation of methanol is 300 mmHg, and finally reduced to 10 mmHg. The same applies hereinafter), 40 to 40. By removing the produced methanol and water within a temperature range of 60 ° C., a methyltrimethoxysilane condensate (c-) having a number average molecular weight of 1,000 and an active ingredient of 70.0% in the reaction solution is obtained. 1) 1,000 parts were obtained. In addition, the active ingredient in the reaction solution is a condensation reaction based on the theoretical yield (parts by weight) when all methoxy groups of silane monomers such as methyltrimethoxysilane (MTMS) and ethyltrimethoxysilane (ETMS) undergo a condensation reaction. Calculated by the value obtained by dividing by the subsequent actual yield (parts by weight) [theoretical yield when all the methoxy groups of the silane monomer have undergone the condensation reaction (parts by weight) / actual yield after the condensation reaction (parts by weight)] ( The same applies hereinafter.)

Synthesis Example 2 [Preparation Example of Aqueous Dispersion of Composite Resin (ABC-1)]
In a reaction vessel similar to Synthesis Example 1, 50 parts of propylene glycol monopropyl ether (PnP), 80 parts of isopropyl alcohol (IPA), 26 parts of phenyltrimethoxysilane (PTMS) and 15 parts of dimethyldimethoxysilane (DMDMS) were charged. The temperature was raised to 80 ° C. Next, 96 parts of methyl methacrylate (MMA), 99 parts of cyclohexyl methacrylate (CHMA), 96 parts of butyl acrylate (BA), 13 parts of acrylic acid (AA), 16 parts of 3-methacryloyloxypropyltrimethoxysilane (MPTS) at the same temperature A mixture containing 16 parts of IPA and 16 parts of tert-butylperoxy-2-ethylhexanoate (TBPEH) was dropped into the reaction vessel over 4 hours, and after completion of the addition, the mixture was further reacted at the same temperature for 2 hours. After obtaining a polymer (a′-1) having a number average molecular weight of 19,000 having both a carboxyl group and a hydrolyzable group bonded to a silicon atom, 0.4 part of “A-3” and deionized water 11 parts of the mixture was added dropwise over 5 minutes, and the mixture was further stirred at the same temperature for 10 hours to carry out a hydrolysis condensation reaction. The composite resin (A'B-1) which consists of a polymer segment which has a hydrolyzable group couple | bonded together with, and a polysiloxane segment derived from PTMS and DMDMS was obtained. Next, 14 parts of TEA was added to neutralize the carboxyl group in the composite resin (A′B-1) to obtain a composite resin (AB-1), and then a condensate of methyltrimethoxysilane (c-1) 81 Part, and further, 550 parts of deionized water are added, and the polysiloxane segment (C-) derived from the condensate (c-1) of the composite resin (AB-1) and methyltrimethoxysilane by hydrolysis condensation is added. The composite resin (ABC-1) to which 1) was bound was produced and the composite resin (ABC-1) was dispersed in an aqueous medium to obtain an aqueous dispersion of the composite resin (ABC-1).

  Next, the obtained aqueous dispersion was distilled under reduced pressure of 300 to 10 mmHg for 2 hours at 40 to 60 ° C. to remove IPA, generated methanol and water, and the non-volatile content was 40.0%. 1,000 parts of an aqueous dispersion of the composite resin (ABC-1) was obtained.

  The storage stability of the obtained aqueous dispersion of composite resin (ABC-1) was evaluated as follows. The storage stability of the aqueous dispersion of composite resin (ABC-1) was 1.0, which was good.

  Storage stability: The viscosity (initial viscosity) of the aqueous dispersion of the obtained composite resin (ABC) and the viscosity after standing for 30 days in an environment at 50 ° C. (viscosity with time) were measured, and the viscosity with time was determined as the initial viscosity. The value divided by (viscosity with time / initial viscosity) was evaluated. If it is about 1.0-3.0, it can be used as a paint.

Synthesis Example 3 [Preparation Example of Aqueous Dispersion of Composite Resin (ABC-2)]
In a reaction vessel similar to Synthesis Example 1, 36 parts of PnP, 80 parts of IPA, 32 parts of PTMS, and 19 parts of DMDMS were charged, and the temperature was raised to 80 ° C. Next, a mixture containing 99 parts of MMA, 86 parts of butyl methacrylate (BMA), 67 parts of BA, 16 parts of AA, 5 parts of MPTS, 14 parts of PnP, and 14 parts of TBPEH at the same temperature was dropped into the reaction vessel over 4 hours, and after completion of the dropping. Further, after reacting at the same temperature for 2 hours to obtain a polymer (a′-2) having a number average molecular weight of 18,000 having both a carboxyl group and a hydrolyzable group bonded to a silicon atom, “A-3 ”A mixture of 0.9 parts and 24 parts of deionized water was added dropwise over 5 minutes, and the mixture was further stirred for 10 hours at the same temperature to conduct a hydrolytic condensation reaction. As a result, a composite resin (A′B-2) comprising a polymer segment having both a polysiloxane segment derived from PTMS and DMDMS was obtained. Next, 18 parts of TEA was added to neutralize the carboxyl group in the composite resin (A′B-2) to obtain a composite resin (AB-2), and then a methyltrimethoxysilane condensate (c-1) 124. And then 550 parts of deionized water, and a polysiloxane segment (C-) derived from the condensation product (c-1) of the composite resin (AB-2) and methyltrimethoxysilane by hydrolysis condensation. The composite resin (ABC-2) to which 1) was bound was produced and the composite resin (ABC-2) was dispersed in an aqueous medium to obtain an aqueous dispersion of the composite resin (ABC-2).

  Next, the obtained aqueous dispersion was distilled under reduced pressure of 300 to 10 mmHg for 2 hours at 40 to 60 ° C. to remove IPA, generated methanol and water, and the non-volatile content was 40.0%. 1,000 parts of an aqueous dispersion of the composite resin (ABC-2) was obtained.

  When the storage stability of the obtained aqueous dispersion of composite resin (ABC-2) was evaluated in the same manner as in Synthesis Example 2, it was 1.0, which was favorable.

Synthesis Example 4 [Preparation Example of Aqueous Dispersion of Composite Resin (ABC-3)]
In a reaction vessel similar to Synthesis Example 1, 60 parts of PnP, 50 parts of IPA, 54 parts of PTMS, and 32 parts of DMDMS were charged and heated to 80 ° C. Next, a mixture containing 40 parts of MMA, 84 parts of BMA, 51 parts of 2-ethylhexyl methacrylate (EHMA), 19 parts of AA, 6 parts of MPTS, 10 parts of PnP and 10 parts of TBPEH at the same temperature was dropped into the reaction vessel over 4 hours. After completion of the reaction, the mixture was further reacted at the same temperature for 2 hours to obtain a polymer (a′-3) having a number average molecular weight of 17,000 having both a carboxyl group and a hydrolyzable group bonded to a silicon atom. -3 "A mixture of 0.9 parts and 24 parts of deionized water was added dropwise over 5 minutes, and the mixture was further stirred for 10 hours at the same temperature to carry out a hydrolysis condensation reaction, thereby hydrolyzing the carboxyl groups and silicon atoms. A composite resin (A′B-3) comprising a polymer segment having a functional group and a polysiloxane segment derived from PTMS and DMDMS was obtained. Next, 21 parts of TEA was added to neutralize the carboxyl group in the composite resin (A′B-3) to obtain a composite resin (AB-3), and then a condensate of methyltrimethoxysilane (c-1) 207 And 570 parts of deionized water, and a polysiloxane segment (C-) derived from the condensation product (c-1) of the composite resin (AB-3) and methyltrimethoxysilane by hydrolysis condensation. The composite resin (ABC-3) to which 1) was bonded was produced and the composite resin (ABC-3) was dispersed in an aqueous medium to obtain an aqueous dispersion of the composite resin (ABC-3).

  Next, the obtained aqueous dispersion was distilled under reduced pressure of 300 to 10 mmHg for 2 hours at 40 to 60 ° C. to remove IPA, generated methanol and water, and the non-volatile content was 40.0%. 1,000 parts of an aqueous dispersion of the composite resin (ABC-3) was obtained.

  When the storage stability of the obtained aqueous dispersion of composite resin (ABC-3) was evaluated in the same manner as in Synthesis Example 2, it was 1.0, which was favorable.

Synthesis Example 5 [Preparation example of aqueous dispersion of composite resin (ABC-4)]
In a reaction vessel similar to Synthesis Example 1, 126 parts of PnP, 59 parts of PTMS, and 62 parts of DMDMS were charged, and the temperature was raised to 80 ° C. Subsequently, a mixture containing 21 parts of MMA, 20 parts of BMA, 14 parts of BA, 13 parts of AA, 2 parts of MPTS, 3.5 parts of PnP, and 3.5 parts of TBPEH at the same temperature was dropped into the reaction vessel over 4 hours. Furthermore, after reacting at the same temperature for 2 hours to obtain a polymer (a′-4) having a number average molecular weight of 10,100 having both a carboxyl group and a hydrolyzable group bonded to a silicon atom, “A-3” A mixture of 0.016 parts and 45 parts of deionized water was added dropwise over 5 minutes, and the mixture was further stirred at the same temperature for 1 hour to conduct a hydrolysis and condensation reaction, so that both a carboxyl group and a hydrolyzable group bonded to a silicon atom were combined. A composite resin (A′B-4) comprising a polymer segment having polysiloxane segments derived from PTMS and DMDMS was obtained. Next, 290 parts of a condensate (c-1) of methyltrimethoxysilane was added, 59 parts of deionized water was further added, and the mixture was stirred at the same temperature for 16 hours, followed by hydrolysis condensation reaction, and the composite resin. A reaction solution containing a composite resin (A′BC-4) in which a polysiloxane segment (C-1) derived from a condensate (c-1) of (A′B-4) and methyltrimethoxysilane was bonded was obtained. .

  Next, the obtained reaction liquid was distilled under a reduced pressure of 300 to 10 mmHg for 2 hours under conditions of 40 to 60 ° C. to remove generated methanol and water, and then 15 parts of TEA was added to add a composite resin (A 'BC-4) is neutralized to a composite resin (ABC-4) by neutralizing the carboxyl group, and then dispersed in an aqueous medium by adding 497 parts of deionized water. 1,000 parts of an aqueous dispersion of% composite resin (ABC-4) was obtained.

  When the storage stability of the obtained aqueous dispersion of composite resin (ABC-4) was evaluated in the same manner as in Synthesis Example 2, it was 1.0, which was favorable.

Comparative Synthesis Example 1 [Preparation Example of Aqueous Dispersion for Comparative Composite Resin (ABC-5)]
In the same reaction vessel as in Synthesis Example 1, 50 parts of PnP, 80 parts of IPA, 24 parts of PTMS and 14 parts of DMDMS were charged, and the temperature was raised to 80 ° C. Next, a mixture containing 70 parts of MMA, 141 parts of BMA, 113 parts of BMA, 11 parts of AA, 18 parts of MPTS, 18 parts of IPA and 18 parts of TBPEH at the same temperature is dropped into the reaction vessel over 4 hours. After reacting for 2 hours to obtain a polymer (a'-5) having a number average molecular weight of 20,000 having both a carboxyl group and a hydrolyzable group bonded to a silicon atom, 0.4 part of "A-3" A polymer having both a carboxyl group and a hydrolyzable group bonded to a silicon atom by adding a mixture of 11 parts of deionized water dropwise over 5 minutes and further stirring at the same temperature for 10 hours to carry out a hydrolytic condensation reaction. A composite resin (A′B-5) composed of a segment and a polysiloxane segment derived from PTMS and DMDMS was obtained. Next, 12 parts of TEA was added to neutralize the carboxyl group in the composite resin (A′B-5) to obtain a composite resin (AB-5), and then a condensate (c-1) 34 of methyltrimethoxysilane. And 550 parts of deionized water, and a polysiloxane segment (C-) derived from the condensation product (c-1) of the composite resin (AB-5) and methyltrimethoxysilane by hydrolysis condensation. The composite resin (ABC-5) to which 1) was bonded was produced and the composite resin (ABC-5) was dispersed in an aqueous medium to obtain an aqueous dispersion of the composite resin (ABC-5).

  Next, the obtained aqueous dispersion was distilled under reduced pressure of 300 to 10 mmHg for 2 hours at 40 to 60 ° C. to remove IPA, generated methanol and water, and the non-volatile content was 40.0%. 1,000 parts of an aqueous dispersion of the composite resin (ABC-5) was obtained.

  When the storage stability of the obtained aqueous dispersion of composite resin (ABC-5) was evaluated in the same manner as in Synthesis Example 2, it was 1.0, which was favorable.

Comparative Synthesis Example 2 [Preparation Example of Aqueous Dispersion of Comparative Composite Resin (ABC-6)]
In a reaction vessel similar to Synthesis Example 1, 149 parts of PnP, 154 parts of PTMS, and 94 parts of DMDMS were charged, and the temperature was raised to 80 ° C. Subsequently, a mixture containing 7 parts of MMA, 13 parts of BMA, 7 parts of BA, 7 parts of AA, 1 part of MPTS, 1 part of PnP, and 1.4 parts of TBPEH at the same temperature was dropped into the reaction vessel over 4 hours. After reacting at a temperature for 2 hours to obtain a polymer (a′-6) having a number average molecular weight of 9,900 having both a carboxyl group and a hydrolyzable group bonded to a silicon atom, “A-3” 0. A mixture of 03 parts and 70 parts of deionized water was added dropwise over 5 minutes, and the mixture was further stirred for 1 hour at the same temperature to carry out a hydrolytic condensation reaction, whereby a heavy group having both a carboxyl group and a hydrolyzable group bonded to a silicon atom. A composite resin (A′B-6) composed of a coalesced segment and a polysiloxane segment derived from PTMS and DMDMS was obtained. Subsequently, 224 parts of methyltrimethoxysilane condensate (c-1) was added, 38 parts of deionized water was further added, and the mixture was stirred at the same temperature for 16 hours, followed by hydrolysis condensation reaction, and the composite resin. A reaction solution containing a composite resin (A′BC-6) in which a polysiloxane segment (C-1) derived from a condensate (c-1) of (A′B-6) and methyltrimethoxysilane was bonded was obtained. .

  Next, the obtained reaction solution was distilled under reduced pressure of 300 to 10 mmHg for 2 hours under the conditions of 40 to 60 ° C. to remove the generated methanol and water, and then 8 parts of TEA was added to add composite resin (A 'BC-6) is neutralized to a composite resin (ABC-6) by neutralizing the carboxyl group, and then dispersed in an aqueous medium by adding 500 parts of deionized water. 1,000 parts of an aqueous dispersion of% composite resin (ABC-6) was obtained.

  When the storage stability of the aqueous dispersion of the obtained composite resin (ABC-6) was evaluated in the same manner as in Synthesis Example 2, it was 1.0, which was favorable.

  The contents of Synthesis Examples 1 to 5 and Comparative Synthesis Examples 1 and 2 are summarized in Tables 1 to 3 below.

Footnotes “MTMS” in Tables 1 to 3: methyltrimethoxysilane “PTMS”: phenyltrimethoxysilane “DMDMS”: dimethyldimethoxysilane “MMA”: methyl methacrylate “CHMA”: cyclohexyl methacrylate “BMA”: butyl methacrylate “BA”: butyl acrylate “EHMA”: 2-ethylhexyl methacrylate “AA”: acrylic acid “MPTS”: 3-methacryloyloxypropyltrimethoxysilane “TBPEH”: tert-butylperoxy-2-ethylhexanoate

  Various physical properties of the coating film composed of the aqueous dispersion of the composite resins (ABC-1) to (ABC-6) described above were evaluated according to the following evaluation methods.

  Moreover, the aqueous dispersion of composite resins (ABC-1) to (ABC-6) obtained above and an ultraviolet absorbent (manufactured by BASF Japan Ltd .: TINUVIN477-DW (hydroxyphenyltriazine-based ultraviolet absorber dispersed in water) Agent, active ingredient 20%), TINUVIN 928 (benzotriazole ultraviolet absorber, powder), Big Chemie Japan Co., Ltd .: NANOBYK-3820 (zinc oxide dispersed in water, active ingredient 40%), ALDRICH: 5 -Indoleol) and the above-mentioned hardening | curing agent as needed were mixed according to the compounding composition of the following Tables 4-8, and the water-based curable coating composition was obtained. A coating film was formed using the obtained aqueous curable coating composition, and various physical properties of the coating film were evaluated according to the following evaluation methods.

In the following evaluation, the aqueous curable coating composition was applied on a glass plate (JIS3202R) manufactured by Engineering Test Service so that the thickness of the cured coating film was 20 μm, and was dried in an environment of 120 ° C. for 20 minutes. Evaluation was performed using the obtained cured coating film.

Appearance of coating film: State of coating film immediately after preparation of the obtained cured coating film and sunshine weather meter for 3000 hours [manufactured by Suga Test Instruments Co., Ltd., black panel temperature 63 ° C., wetting cycle = 18 minutes / 120 minutes The state of the coating film after the middle exposure was visually observed and judged according to the following evaluation criteria.
○: No crack on the coating surface.
Δ: A crack is observed on a part of the coating surface.
X: The crack has generate | occur | produced on the whole coating-film surface.

Adhesion: Measured based on JIS K-5600 cross cut test method. A 1 mm wide cut is made on the cured coating with a cutter, the number of grids is 100, cellophane tape is applied so as to cover all grids, and they are peeled off quickly and left to adhere. Judgment was made by counting the number of. The evaluation criteria are as follows.
○: No peeling.
Δ: The area of peeling is 1 to 64% of the total grid area.
X: The area of peeling is 65% or more of the total grid area.

Solvent resistance: The cured coating film was rubbed 20 times back and forth with a felt soaked with methyl ethyl ketone and ethanol. The state of the coating film before rubbing and after rubbing was judged by finger touch and visual observation. The evaluation criteria are as follows.
○: Softening and gloss reduction are not recognized.
(Triangle | delta): Some softening or gloss reduction is recognized.
X: Significant softening or gloss reduction is observed.

Chemical resistance: Pour 2.0 ml each of 5% aqueous sulfuric acid solution into a glass cup, place it on the coating surface at a temperature of 25 ° C. and expose it for 24 hours. Evaluation was made by visual inspection. The evaluation criteria are as follows.
○: Etching is not recognized.
(Triangle | delta): Some etching or gloss reduction is recognized.
X: Significant etching or gloss reduction is observed.

  Weather resistance: The cured coating film was subjected to an exposure test for 3000 hours using a sunshine weather meter (manufactured by Suga Test Instruments Co., Ltd., black panel temperature 63 ° C., wetting cycle = 18 minutes / 120 minutes).

  Here, the specular gloss reflectance of the surface coating film of the test plate before and after the exposure test was measured using HG-268 manufactured by Suga Test Instruments Co., Ltd., and the gloss retention was determined based on the following formula. .

  [100 × (specular reflectance of coating film after exposure test) / specular reflectance of coating film before exposure test]] The larger the gloss retention value, the better the weather resistance, approximately 80% The above is preferable.

  Contamination resistance: The cured coating film was exposed to DIC Corporation Sakai Factory in Takaishi City, Osaka Prefecture for 3 months. The color difference (ΔE) between the unwashed coating film after the exposure test and the coating film before the exposure test was evaluated using CM-3500d manufactured by Konica Minolta Sensing Co., Ltd. The smaller the color difference (ΔE), the better the stain resistance.

  Ultraviolet ray shielding rate: UV-visible spectrophotometer “V-570” manufactured by JASCO Corporation was used to measure the ultraviolet transmittance (%) of a glass plate (JIS R3202) as a blank, and the curing at 360 nm. The ultraviolet transmittance (%) of the coating film was measured, and the ultraviolet shielding ratio [100- (UV transmittance (%) of the cured coating film at 360 nm)] was determined. It shows that an ultraviolet shielding factor is so favorable that the value of a shielding factor is large.

  UV shielding retention rate: The cured coating film was subjected to an actual exposure test for 3 months outdoors, and the UV shielding rate (%) of the coating film before exposure of the coating film after exposure (%). Retention rate (UV shielding retention rate:%) [100 × (UV shielding rate of coating after exposure) / (UV shielding rate of coating before exposure)]. In addition, it shows that a ultraviolet-ray shielding retention rate is so favorable that the value of a retention rate is large.

Abbreviations for each composition described in Tables 4 to 8 will be described.
“GPTMS”; 3-glycidoxypropyltrimethoxysilane “477-DW”; TINUVIN 477-DW (manufactured by BASF Japan Ltd .: hydroxyphenyltriazine UV absorber)
“928”; TINUVIN 928 (manufactured by BASF Japan Ltd .: benzotriazole UV absorber)
“3820”; NANOBYK-3820 (manufactured by Big Chemie Japan Co., Ltd .: zinc oxide dispersed in water, active ingredient 40%)

Claims (8)

The polysiloxane segment (B) of the composite resin (AB) in which the polymer segment (A) having a neutralized acid group and the polysiloxane segment (B) are chemically bonded, and the alkyl group has 1 carbon atom. Aqueous curing in which a composite resin (ABC) in which a polysiloxane segment (C) derived from a condensate (c) of 3 to 3 is bonded via a silicon-oxygen bond is dissolved or dispersed in an aqueous medium An aqueous curable coating composition comprising an ultraviolet absorber (D) in the aqueous curable coating composition. The aqueous curable coating composition according to claim 1, wherein the composite resin (ABC) is a composite resin containing 15 to 85% by weight of the polysiloxane segment (B) and the polysiloxane segment (C) in total. . The aqueous curable coating composition according to claim 2, wherein the composite resin (ABC) is a composite resin containing 5 to 50% by weight of the polysiloxane segment (C). In the composite resin (ABC), the polymer segment (A) and the polysiloxane segment (B) are represented by the following structural formula (S-1).

[However, the carbon atom in the structural formula (S-1) constitutes a part of the polymer segment (A), and the silicon atom and the oxygen atom constitute a part of the polysiloxane segment (B). ]
The aqueous curable coating composition according to claim 1, 2 or 3, which is a composite resin bonded through a bond represented by: The aqueous curable coating composition according to claim 4, wherein the polymer segment (A) is a segment derived from a vinyl polymer. The aqueous curable coating material according to claim 1, 2 or 3, wherein the alkyltrialkoxysilane condensate (c) is a condensate obtained by hydrolytic condensation of methyltrimethoxysilane and / or methyltriethoxysilane. Composition. The ultraviolet absorber (D) is selected from the group consisting of titanium oxide, zinc oxide, tin oxide, cerium oxide, benzotriazole ultraviolet absorber, triazine ultraviolet absorber, indole ultraviolet absorber, and azomethine ultraviolet absorber. The aqueous curable coating composition according to claim 1, which is one or more selected compounds. A method for producing an aqueous composite resin composition comprising the following steps (I) to (IV):
(I) By polymerizing a vinyl monomer containing at least one selected from the group consisting of a hydrolyzable silyl group-containing vinyl monomer and a silanol group-containing vinyl monomer under an organic solvent, a step of obtaining an organic solvent solution of a2),
(II) A resin in which polysiloxane (a3) is bonded to vinyl polymer (a2) by reacting vinyl polymer (a2) with a silane compound under an organic solvent solution of vinyl polymer (a2). A step of obtaining an organic solvent solution of (C),
(III) a step of neutralizing the hydrophilic group of the resin after completion of the step (I) or after completion of the step (II), and dissolving or dispersing the neutralized product in an aqueous medium;
(IV) A step of dispersing an ultraviolet absorber in the aqueous dispersion.