JP4099726B2 - Water-based coating composition, organic-inorganic composite coating film and method for producing the same - Google Patents

Description

  The present invention relates to an aqueous coating composition containing an organic component and an inorganic component, an organic-inorganic composite coating film obtained using the same, and a method for producing the same.

  In the fields of coating materials and molding materials, there is an increasing need to simultaneously realize handling properties such as flexibility and molding processability and durability such as hardness, heat resistance, and weather resistance. An organic-inorganic composite of an organic polymer and an inorganic polymer is known as a material that can simultaneously exhibit various properties that are usually difficult to achieve at the same time. This organic-inorganic composite is considered to be capable of simultaneously exhibiting the flexibility, moldability, etc., which are characteristics of organic polymers, and the hardness, heat resistance, weather resistance, etc., which are characteristics of inorganic polymers. Various studies have been made on silicone-modified resins obtained by modifying an organic polymer with a silicone resin that is an inorganic polymer. However, it is difficult for such silicone-modified resins to increase the content of silicone. For this reason, silicone-based properties such as heat resistance and hardness cannot be fully exhibited, and usable silicone resins There were restrictions on the type of the product, and the price was high.

  Therefore, as an alternative to the silicone-modified resin as described above, there is a method utilizing a sol-gel method based on hydrolysis condensation reaction of alkoxysilane. Specifically, it is a method in which hydrolysis and polycondensation of alkoxysilane proceed simultaneously in the presence of an organic polymer, thereby compounding the organic polymer and the inorganic polymer.

  As such a method, for example, a method of obtaining an organic-inorganic composite coating film by applying an alcohol sol solution containing polyurethane and hydrolyzable alkoxysilane to a substrate and drying it has been proposed (for example, , See Patent Document 1). This is because when the coating is dried after drying, the alkoxysilane becomes silica fine particles due to moisture in the air and the like, and the silanol groups on the particle surface and polyurethane are combined to form hydrogen bonds or ester bonds. A coating film in which silica fine particles are uniformly dispersed in a polyurethane matrix is obtained. However, this method uses alcohol, which is an organic solvent, so there is a problem that the load on the environment is large, and because it uses moisture in the air, it can be obtained depending on the usage environment (temperature and humidity). There is a possibility that blurring may occur in the performance of the composite (coating film) to be produced, and there is a problem in practical use.

  In addition, by using a composition containing a polyurethane having a hydroxyl group and / or an amino group and a hydrolyzable alkoxysilane, a coating film which is an organic-inorganic composite having excellent heat resistance and retaining the flexibility of polyurethane is obtained. (For example, refer to Patent Document 2). This is intended to improve the heat resistance of the coating film as a whole without compromising the flexibility of the soft segment by combining silica with the hard segment domain in the polyurethane. It was clear that it was not a coating film, and when a large amount of silica component was contained, phase separation was likely to occur, and a composite (coating film) excellent in wear resistance could not be obtained.

  Further, it has been reported that a transparent, uniform, hard and water-resistant organic-inorganic composite coating can be obtained by using a composition containing a water admixture of an organic compound having a hydroxyl group, a polyalkoxysilane, and a catalyst. (For example, see Patent Document 3). However, the composition has poor storage stability because the hydrolysis and condensation reaction of the polyalkoxysilane continues to proceed during storage, and the resulting coating film has a level that satisfies the pencil hardness (about 2H to 6H). It is not a coating film worthy of the abrasion resistance required as an organic-inorganic composite coating film. Furthermore, it has been shown that when a curing agent such as aminoplast resin is not used in combination, whitening is likely to occur in a hot water test at 90 ° C. for 1 hour, but the storage stability of the coating composition can be improved by using the curing agent. Sex is even worse. That is, the coating composition does not have both storage stability and sufficient performance of the resulting coating film, and further improvements are required.

JP-A-6-136321 JP 2001-64346 A JP-A-8-319457

  In view of the above circumstances, the problem to be solved by the present invention is to provide an organic-inorganic composite coating film having various physical properties such as water resistance, transparency, and abrasion resistance at a high level at the same time, and a method for producing the same. An object of the present invention is to provide an aqueous coating composition having good storage stability.

  In order to solve the above-mentioned problems, the present inventors have conducted intensive studies, and in the presence of a cationic polyurethane resin having a specific structure, by performing a sol-gel reaction of a metal alkoxide on a nanoscale. It has been found that a composite of an organic component and an inorganic component can be achieved, and a coating film made of the composite has the above performance, and the present invention has been completed.

  That is, the present invention relates to the following general formula [I]

〔式（Ｉ）中、Ｒ_１は脂肪族環式構造を含んでいてもよいアルキレン鎖、２価フェノール類の残基、又はポリオキシアルキレン鎖であり、Ｒ_２及びＲ_３は、互いに独立して脂肪族環式構造を含んでいてもよいアルキル基であり、Ｒ_４は水素原子又は４級化反応により導入された４級化剤の残基であり、Ｘ⁻はアニオン性の対イオンである。〕
で示される構造単位を含有するカチオン性ポリウレタン樹脂（Ａ）の水性分散体と、金属アルコキシド又はその縮合物（Ｂ）と、酸触媒（Ｃ）とを含有することを特徴とする水性塗料組成物を提供するものである。

[In Formula (I), R ₁ is an alkylene chain which may contain an aliphatic cyclic structure, a residue of a dihydric phenol, or a polyoxyalkylene chain, and R ₂ and R ₃ are independent of each other. An alkyl group which may contain an aliphatic cyclic structure, R ₄ is a hydrogen atom or a residue of a quaternizing agent introduced by a quaternization reaction, X ⁻ is an anionic counter ion is there. ]
An aqueous coating composition comprising an aqueous dispersion of a cationic polyurethane resin (A) containing a structural unit represented by formula (I), a metal alkoxide or a condensate thereof (B), and an acid catalyst (C). Is to provide.

  Furthermore, the present invention provides the following general formula [I] in a matrix comprising a metal oxide.

〔式（Ｉ）中、Ｒ_１は脂肪族環式構造を含んでいてもよいアルキレン鎖、２価フェノール類の残基、又はポリオキシアルキレン鎖であり、Ｒ_２及びＲ_３は、互いに独立して脂肪族環式構造を含んでいてもよいアルキル基であり、Ｒ_４は水素原子又は４級化反応により導入された４級化剤の残基であり、Ｘ⁻はアニオン性の対イオンである。〕
で示される構造単位を含有するカチオン性ポリウレタン樹脂の粒子が分散していることを特徴とする有機無機複合塗膜、及び簡便な方法で該有機無機複合塗膜を製造する方法を提供するものである。

[In Formula (I), R ₁ is an alkylene chain which may contain an aliphatic cyclic structure, a residue of a dihydric phenol, or a polyoxyalkylene chain, and R ₂ and R ₃ are independent of each other. An alkyl group which may contain an aliphatic cyclic structure, R ₄ is a hydrogen atom or a residue of a quaternizing agent introduced by a quaternization reaction, X ⁻ is an anionic counter ion is there. ]
An organic-inorganic composite coating film characterized in that particles of a cationic polyurethane resin containing a structural unit represented by formula (1) are dispersed, and a method for producing the organic-inorganic composite coating film by a simple method. is there.

  ADVANTAGE OF THE INVENTION According to this invention, the aqueous coating composition containing the organic component and inorganic component with favorable storage stability can be provided. The coating film obtained using the water-based coating composition is an organic-inorganic composite coating film having a high balance of high abrasion resistance, water resistance and transparency, and its production method is simple. The coating film can be used for various applications such as automobiles, building materials, woodworking, and plastic hard coats.

  The water-based coating composition of the present invention has the following general formula [I]

〔式（Ｉ）中、Ｒ_１は脂肪族環式構造を含んでいてもよいアルキレン鎖、２価フェノール類の残基、又はポリオキシアルキレン鎖であり、Ｒ_２及びＲ_３は、互いに独立して脂肪族環式構造を含んでいてもよいアルキル基であり、Ｒ_４は水素原子又は４級化反応により導入された４級化剤の残基であり、Ｘ⁻はアニオン性の対イオンである。〕
で示される構造単位を含有するカチオン性ポリウレタン樹脂（Ａ）の水性分散体と、金属アルコキシド又はその縮合物（Ｂ）と、酸触媒（Ｃ）とを含有することを特徴とする。

[In Formula (I), R ₁ is an alkylene chain which may contain an aliphatic cyclic structure, a residue of a dihydric phenol, or a polyoxyalkylene chain, and R ₂ and R ₃ are independent of each other. An alkyl group which may contain an aliphatic cyclic structure, R ₄ is a hydrogen atom or a residue of a quaternizing agent introduced by a quaternization reaction, X ⁻ is an anionic counter ion is there. ]
An aqueous dispersion of a cationic polyurethane resin (A) containing a structural unit represented by formula (A), a metal alkoxide or a condensate (B) thereof, and an acid catalyst (C)

  Recent studies have shown that many diatom and sponge creatures in nature (so-called biosilica) protect their cells with a composite membrane of silica and organic matter. In particular, in the composite membrane of biosilica, it was suggested that the function of the membrane is expressed by combining silica with a cationic polymer or a cationic protein (WEGG Muller Ed., Silicon). Biomineralization: Biology-Biotechnology-Molecular Biology-Biotechnology, 2003, Springer). Although the function of the cationic polymer or the cationic protein has not been fully elucidated yet, basically, the catalytic effect in the silica condensation, the induction of the spatial dimension in the silica sol formation and sol fusion (that is, to form a hybrid membrane with a fixed shape) It is considered to have an adhesive effect between a polymer and silica in forming a nano-level hybrid structure.

  In creating organic-inorganic composite coatings, the design concept based on an understanding of the mechanism of biosilica is considered to be extremely important. In particular, many cationic proteins complexed with biosilica have the characteristic of being insoluble in water even if they have a hydrophilic surface. The present inventors paid attention to this point, and devised to associate it with resin particles having a cationic surface. That is, in the present invention, by using an aqueous dispersion of a cationic polyurethane resin (A) having a specific structure as the cationic polymer, the metal alkoxide or its condensate (B) is present in the presence of the cationic polyurethane resin. By performing a sol-gel reaction with an acid catalyst (C), a fine particle composed of a cationic polyurethane resin as an organic component and a metal oxide matrix obtained from a metal alkoxide or a condensate thereof as an inorganic component, This is based on the finding that it can be combined.

  In the aqueous coating composition of the present invention, the initial hydrolysis of the metal alkoxide or its condensate (B) is promoted by the acid catalyst (C), but the subsequent condensation reaction is suppressed by the cationic polyurethane resin (A). The entire system is governed by ionic interactions between the hydroxy groups on the surface of the metal sol and the cations on the surface of the resin fine particles of the aqueous dispersion of the cationic polyurethane resin (A). As a result, the growth of the sol stops at a certain size, the anion sol is concentrated on the surface of the fine particles of the aqueous dispersion of the cationic polyurethane resin (A), and an aqueous dispersion having good stability can be obtained. By coating this aqueous dispersion, a gelled film having a metal oxide as a continuous phase is formed. In the continuous phase, the resin fine particles made of the cationic polyurethane resin (A) are not aggregated one by one. It is possible to obtain a coating film having a nano-order repeating structure in which is uniformly dispersed and compounded. In the coating film thus obtained, the combined effect of the organic component and the inorganic component is maximized, and the physical properties of the coating film such as wear resistance and water resistance are greatly improved. Such a structure and the effect derived from the structure cannot be obtained by using an aqueous anionic resin dispersion or an aqueous nonionic resin dispersion.

Hereinafter, materials used in the present invention will be described in detail.
[Cationic polyurethane resin (A)]
The cationic polyurethane resin (A) of the present invention has a structural unit represented by the above general formula [I] and forms an aqueous dispersion stably dispersed in an aqueous medium. The aqueous medium is not particularly limited as long as it is a homogeneous solvent system mainly containing water. Examples of such solvent systems include a solvent system in which an alcohol-based water-soluble organic solvent such as methanol, ethanol, isopropanol, and butanol is mixed with water, and an ether-based water-soluble organic solvent such as tetrahydrofuran and butyl cellosolve in water. And the solvent system used. The most preferred aqueous medium is an isopropanol / water mixed solvent system. The amount of such a water-soluble organic solvent added is preferably 50% by mass or less with respect to the amount of water contained in the entire aqueous coating composition.

  The cationic polyurethane resin (A) is dispersed in an aqueous medium, and the average particle diameter of the dispersed resin particles is from the point of having both wear resistance and transparency of the resulting composite coating film. It is preferable that it is 0.005 micrometer-1 micrometer, More preferably, it is 0.01-0.4 micrometer.

  The content of the cationic functional group in the general formula [I] is not particularly limited as long as the cationic polyurethane resin (A) can be formed in a stable dispersion without being dissolved in an aqueous medium. It is not limited. Accordingly, the cationic polyurethane resin (A) has a preferable cationic functional group content depending on the structure other than the general formula [I] such as molecular weight and branching degree. (A) If it contains 0.01-1 equivalent / kg as a cation equivalent in solid content, it can be set as an aqueous dispersion, and especially the dispersibility to the aqueous medium of cationic polyurethane resin (A) and From the point which is excellent in the balance with the water resistance of the coating film obtained, it is preferable to contain 0.02-0.8 equivalent / kg, and it is especially preferable to contain 0.03-0.6 equivalent / kg. preferable.

  As the number average molecular weight (Mn) calculated by polystyrene conversion by gel permeation chromatography (GPC) of the cationic polyurethane resin (A), the cationic polyurethane resin (A) is stable without being dissolved in an aqueous medium. It is not particularly limited as long as the dispersion can be formed, and is usually in the range of 1,000 to 5,000,000, and preferably in the range of 5,000 to 1,000,000.

  The cationic polyurethane resin (A) can be produced by using various compounds, and a production method using an industrially easily available and inexpensive raw material is represented by the following general formula [IV]. A tertiary amino group-containing polyol (a) obtained by reacting a compound (a-1) having two epoxy groups in one molecule with a secondary amine (a-2) is a polyisocyanate (g) described later. The method of reacting with is most useful.

（式［ＩＶ］中、Ｒ_１は、脂肪族環式構造を含んでいてもよいアルキレン鎖、２価フェノール類の残基、又はポリオキシアルキレン鎖である。）

(In the formula [IV], R ₁ is an alkylene chain that may contain an aliphatic cyclic structure, a residue of a dihydric phenol, or a polyoxyalkylene chain.)

  The tertiary amino group-containing polyol (a) introduces a neutral salt of a tertiary amino group for imparting water dispersibility to the polyurethane resin or a cationic group such as a quaternary amino group into the side chain of the polyurethane resin skeleton. It is a compound used for

  The tertiary amino group-containing polyol (a) is a precursor for generating a cationic group by neutralizing the tertiary amino group contained in the molecule with an acid or quaternizing with a quaternizing agent. is there.

  The tertiary amino group-containing polyol (a) includes, for example, a compound (a-1) having two epoxy groups in one molecule and a secondary amine (a-2), which is NH with respect to 1 equivalent of epoxy group. It can be easily obtained by blending so as to be 1 equivalent of a group and performing a ring-opening addition reaction at room temperature or under heating without using a catalyst.

  As the compound (a-1) having two epoxy groups in one molecule represented by the general formula [IV], the following compounds may be used alone or in combination of two or more.

Examples of the raw material for obtaining an alkylene chain that may contain an aliphatic cyclic structure as R ₁ include ethanediol-1,2-diglycidyl ether, propanediol-1,2-diglycidyl, and the like. Ether, propanediol-1,3-diglycidyl ether, butanediol-1,4-diglycidyl ether, pentanediol-1,5-diglycidyl ether, 3-methyl-pentanediol-1,5-diglycidyl ether, Neopentyl glycol-diglycidyl ether, hexanediol-1,6-diglycidyl ether, polybutadiene glycol-diglycidyl ether, cyclohexanediol-1,4-diglycidyl ether, 2,2-bis (4-hydroxycyclohexyl) -propane (Hydrogenated bisphenol And diglycidyl ether of hydrogenated dihydroxydiphenylmethane (hydrogenated bisphenol F).

In addition, as raw materials for obtaining those in which R ₁ is a residue of a dihydric phenol, for example, resorcinol-diglycidyl ether, hydroquinone-diglycidyl ether, 2,2-bis (4-hydroxyphenyl) -propane ( Diglycidyl ether of bisphenol A), isomer mixture of dihydroxydiphenylmethane (bisphenol F), diglycidyl ether of 4,4′-dihydroxy-3-3′-dimethyldiphenylpropane, 4,4′-dihydroxydiphenyl Diglycidyl ether of cyclohexane, diglycidyl ether of 4,4′-dihydroxydiphenyl, diglycidyl ether of 4,4′-dihydroxydibenzophenone, diglycidyl ether of bis (4-hydroxyphenyl) -1,1-ethane, Of diglycidyl ether of bis (4-hydroxyphenyl) -1,1-isobutane, diglycidyl ether of bis (4-hydroxy-3-tertbutylphenyl) -2,2-propane, bis (2-hydroxynaphthyl) methane Diglycidyl ether, diglycidyl ether of bis (4-hydroxyphenyl) sulfone (bisphenol S), and the like can be used.

Examples of the raw material for obtaining R ₁ having a polyoxyalkylene chain include diethylene glycol-diglycidyl ether, dipropylene glycol-diglycidyl ether, and polyoxyalkylene having 3 to 60 repeating oxyalkylene units. Glycol-diglycidyl ether, for example, polyoxyethylene glycol-diglycidyl ether and polyoxypropylene glycol-diglycidyl ether, diglycidyl ether of ethylene oxide-propylene oxide copolymer, polyoxytetraethylene glycol-diglycidyl ether, etc. Can be used.

Among these, since the water dispersibility of the cationic polyurethane resin can be further improved, the diglycidyl ether of polyoxyalkylene glycol in which R ₁ of the general formula [IV] is a polyoxyalkylene chain, It is preferable to use oxyethylene glycol-diglycidyl ether and / or polyoxypropylene glycol-diglycidyl ether and / or diglycidyl ether of ethylene oxide-propylene oxide copolymer.

As the epoxy equivalent of the polyoxyalkylene glycol diglycidyl ether in which R ₁ of the general formula [IV] is a polyoxyalkylene chain, the cationic polyurethane resin (A) aqueous dispersion used in the present invention is used. In view of minimizing the influence on physical properties such as various mechanical properties and thermal properties of the above, and designing the cation concentration in the aqueous dispersion of the cationic polyurethane resin over a wide range, preferably 1000 g / equivalent or less. The amount is preferably 500 g / equivalent or less, particularly preferably 300 g / equivalent or less.

  In the above-described method, a secondary amine (a-2) is used to produce a tertiary amino group-containing polyol (a) by a ring-opening addition reaction with a compound (a-1) having two epoxy groups in one molecule. )is required.

  Although various compounds can be used as the secondary amine (a-2), a branched or linear aliphatic secondary amine is preferable from the viewpoint of easy reaction control.

  Examples of the secondary amine (a-2) that can be used include dimethylamine, diethylamine, di-n-propylamine, diisopropylamine, di-n-butylamine, di-tert-butylamine, di- sec-butylamine, di-n-pentylamine, di-n-peptylamine, di-n-octylamine, diisooctylamine, dinonylamine, diisononylamine, di-n-decylamine, di-n-undecylamine, di- Examples include n-dodecylamine, di-n-pentadecylamine, di-n-octadecylamine, di-n-nonadecylamine, di-n-eicosylamine.

  Among these, it is difficult to volatilize when producing the tertiary amino group-containing polyol (a), or a part or all of the contained tertiary amino groups are neutralized with an acid, or 4 with a quaternizing agent. For reasons such as the ability to reduce steric hindrance when classifying, an aliphatic secondary amine having 2 to 18 carbon atoms is preferred, and an aliphatic secondary amine having 3 to 8 carbon atoms is more preferred.

  A tertiary amino group-containing polyol (a) is obtained by neutralizing part or all of the tertiary amino group of the tertiary amino group-containing polyol (a) with an acid or quaternizing with a quaternizing agent. Water dispersibility can be imparted to the cationic polyurethane resin (A) obtained by reacting with the polyisocyanate (g).

  Examples of the acid that can be used for neutralizing part or all of the tertiary amino group include formic acid, acetic acid, propionic acid, succinic acid, glutaric acid, butyric acid, lactic acid, malic acid, and citric acid. , Organic acids such as tartaric acid, malonic acid, adipic acid, organic sulfonic acids such as sulfonic acid, paratoluenesulfonic acid, methanesulfonic acid, and hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid, boric acid, phosphorous acid, hydrofluoric acid Inorganic acids such as can be used. These acids may be used alone or in combination of two or more.

  Examples of the quaternizing agent that can be used for quaternizing a part or all of the tertiary amino group include dialkyl sulfates such as dimethyl sulfate and diethyl sulfate, methyl chloride, and ethyl chloride. Alkyl halides such as benzyl chloride, methyl bromide, ethyl bromide, benzyl bromide, methyl iodide, ethyl iodide, benzyl iodide, and alkyl or aryl sulfonates such as methyl methanesulfonate and methyl paratoluenesulfonate Epoxy such as ethylene oxide, propylene oxide, butylene oxide, styrene oxide, epichlorohydrin, allyl glycidyl ether, butyl glycidyl ether, 2-ethylhexyl glycidyl ether, and phenyl glycidyl ether It is possible to use kind and the like. These may be used alone or in combination of two or more.

  In the present invention, the amount of the acid or quaternizing agent used for neutralization or quaternization of the tertiary amino group is not particularly limited, but excellent dispersion stability of the cationic polyurethane resin (A) used in the present invention. In order to express the properties, it is preferably in the range of 0.1 to 3 equivalents and more preferably in the range of 0.3 to 2.0 equivalents with respect to 1 equivalent of the tertiary amino group.

  When the cationic polyurethane resin (A) used in the present invention is compared with the cationic polyurethane resin obtained by the conventional method with the same cation concentration present in the resin, it has better self-water dispersibility. The resulting cationic polyurethane resin has good dispersion stability in an aqueous medium.

  As a mechanism capable of exhibiting such an effect, it is well known that urethane bonds in a polyurethane resin have a pseudo-crystal structure due to hydrogen bonds or the like, and a tertiary that exists in the side chain of the cationic polyurethane resin (A). The neutralized salt of the amino group or the quaternary amino group is, for example, compared with the case where the neutralized salt of the tertiary amino group or the quaternary amino group is present in the main chain of the polyurethane resin skeleton as in the conventional technique. It is presumed that it is difficult to be affected by steric hindrance and has a high degree of freedom, so that it can easily form an association structure with water molecules important for water dispersion.

A reaction method of the compound (a-1) having two epoxy groups in one molecule and the secondary amine (a-2) for obtaining the tertiary amino group-containing polyol (a) will be described below.
The reaction ratio [NH group / epoxy group] of the epoxy group of the compound (a-1) having two epoxy groups in one molecule and the NH group of the secondary amine (a-2) is preferably equivalent. The ratio is in the range of 0.5 / 1 to 1.1 / 1, more preferably the equivalent ratio is in the range of 0.9 / 1 to 1/1.

  These reactions can be carried out under solvent-free conditions, but can also be carried out using an organic solvent for the purpose of facilitating the reaction control, or for the purpose of reducing the stirring load due to a decrease in viscosity or causing a uniform reaction. .

  The organic solvent may be any organic solvent that does not inhibit the reaction. For example, ketones, ethers, acetate esters, hydrocarbons, chlorinated hydrocarbons, amides, and nitriles can be used. .

  As said ketones, acetone, diethyl ketone, methyl ethyl ketone, methyl isobutyl ketone etc. can be used, for example. Examples of ethers that can be used include diethyl ether, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol dibutyl ether, tetrahydrofuran, and dioxane.

  Examples of the acetates include ethyl acetate, butyl acetate, propyl acetate and the like. As hydrocarbons, n-pentane, n-hexane, cyclohexane, n-heptane, benzene, toluene, xylene and the like can be used. As chlorinated hydrocarbons, for example, carbon tetrachloride, dichloromethane, chloroform, trichloroethane and the like can be used. Examples of amides that can be used include dimethylformamide, and examples of nitriles include N-methylpyrrolidone and acetonitrile.

  Among the organic solvents described above, when an organic solvent having a low boiling point is used, it is preferable to perform a pressure reaction in a closed system in order to prevent scattering due to volatilization.

  The compound (a-1) having two epoxy groups in one molecule and the secondary amine (a-2) may be supplied together in a reaction vessel and reacted, and an epoxy group is contained in one molecule. Either one of the two compounds (a-1) and the secondary amine (a-2) may be charged into a reaction vessel and the other may be dropped.

  Since the reaction between the compound (a-1) having two epoxy groups in one molecule and the secondary amine (a-2) is highly reactive, it usually does not require a catalyst. However, when the substituent of the nitrogen atom of the secondary amine (a-2) is large and the reaction with the compound (a-1) is slowed by steric hindrance, phenol, acetic acid, water A proton donating substance typified by alcohols may be used as a catalyst.

The reaction temperature is preferably in the range of room temperature to 160 ° C, more preferably in the range of 60 to 120 ° C. The reaction time is not particularly limited, but is usually in the range of 30 minutes to 14 hours. The end point of the reaction can be confirmed by disappearance of the absorption peak near 842 cm ⁻¹ due to the epoxy group by infrared spectroscopy (IR method). Moreover, an amine equivalent (g / equivalent) and a hydroxyl equivalent (g / equivalent) can be calculated | required by a conventional method.

  When producing the cationic polyurethane resin (A), in addition to the tertiary amino group-containing polyol (a), various polyols (f) generally used for the synthesis of polyurethane depending on the purpose and application. Can be used.

  Among them, the polyester polyol, polyether polyol, polycarbonate polyol, polyester amide polyol, polyacetal polyol, polythioether polyol having a number average molecular weight of preferably in the range of 200 to 10,000, more preferably in the range of the number average molecular weight of 300 to 5,000. And various polyols such as polybutadiene polyol. These may be used alone or in combination of two or more.

  Among the above polyols, representative compounds are exemplified below for polyester polyols, polyether polyols, and polycarbonate polyols that are industrially easily available.

  As said polyester polyol, what is obtained by esterifying a low molecular weight polyol and polycarboxylic acid can be used.

  Examples of the low molecular weight polyol include ethylene glycol, propylene glycol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, and 3-methyl-1,5. -Pentanediol, 1,6-hexanediol, neopentyl glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, dipropylene glycol, tripropylene glycol, 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, polyethylene glycol (Number average molecular weight 300-6000 range), polypropylene glycol (number average molecular weight 300-6000 range), ethylene oxide-propylene oxide copolymer (number average molecular weight 300-6000) Circumference); bisphenol A, hydrogenated bisphenol A and alkylene oxide adducts thereof; trimethylolpropane, trimethylolethane, pentaerythritol, it can be used sorbitol.

  Examples of the polycarboxylic acid that can be used in producing the polyester polyol include succinic acid, adipic acid, azelaic acid, sebacic acid, todecanedicarboxylic acid, maleic anhydride, fumaric acid, 1,3-cyclopentanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, terephthalic acid, isophthalic acid, phthalic acid, 1,4-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, naphthalic acid, biphenyldicarboxylic acid, 1,2-bis (phenoxy) ethane p, p′-dicarboxylic acid, trimellitic acid, pyromellitic acid, and anhydrides or ester-forming derivatives of these polycarboxylic acids can be used.

  Moreover, as said polyester polyol, polyester obtained by ring-opening polymerization reaction of cyclic ester compounds, such as (epsilon) -caprolactone, these copolyesters, etc. can also be used.

  Further, as the polyether polyol, for example, a compound having at least two active hydrogen atoms described later is used as an initiator, and a compound such as ethylene oxide, propylene oxide, butylene oxide, styrene oxide, epichlorohydrin, tetrahydrofuran, cyclohexylene, etc. What is obtained by addition-polymerizing 1 or more types can be used.

  Examples of the compound having at least two active hydrogen atoms include ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, and hexamethylene glycol. , Sucrose, methylene glycol, glycerin, sorbitol; actinic acid, trimellitic acid, hemimellitic acid, phosphoric acid, ethylenediamine, propylenediamine, diethylenetriamine, triisopropanolamine, pyrogallol, dihydrobenzoic acid, hydroxyphthalic acid, 1,2,3 -Propane trithiol or the like can be used.

  Examples of the polycarbonate polyol include 1,3-propanediol, 1,4-butanediol, 1,6-hexanediol, cyclohexanedimethanol, diethylene glycol, polyethylene glycol, polypropylene glycol, and polytetramethylene glycol (PTMG). And a reaction product of a dialkyl carbonate represented by dimethyl carbonate or the like and a cyclic carbonate represented by ethylene carbonate or the like.

  Among them, in order to prevent deterioration of the obtained coating film and maintain a stable coating film for a long period of time, it is preferable to use a highly durable polyol as a polyol. It is preferable to introduce a structural unit derived from a polycarbonate polyol into the cationic polyurethane resin (A).

  Examples of the polyisocyanate (g) that can be used in the production of the cationic polyurethane resin (A) used in the present invention include aqueous polyurethanes such as aromatic polyisocyanates, alicyclic polyisocyanates, and aliphatic polyisocyanates. Examples include various organic polyisocyanates used in the production of resins.

  Examples of the aromatic polyisocyanate include 1,3- and 1,4-phenylene diisocyanate, 1-methyl-2,4-phenylene diisocyanate, 1-methyl-2,6-phenylene diisocyanate, 1-ethyl-2, 4-phenylene diisocyanate, 1-isopropyl-2,4-phenylene diisocyanate, 1,3-dimethyl-2,4-phenylene diisocyanate, 1,3-dimethyl-4,6-phenylene diisocyanate, 1,4-dimethyl-2, 5-phenylene diisocyanate, 1,3-bis (isocyanatomethyl) -benzene, 1,4-bis (isocyanatomethyl) -benzene, meta-tetramethylxylylene diisocyanate, para-tetramethylxylylene diisocyanate, diethylbenzene diisocyanate Ne Diisopropylbenzene diisocyanate, 1-methyl-3,5-diethylbenzene diisocyanate, 3-methyl-1,5-diethylbenzene-2,4-diisocyanate, 1,3,5-triethylbenzene-2,4-diisocyanate, naphthalene- 1,4-diisocyanate, naphthalene-1,5-diisocyanate, 1-methyl-naphthalene-1,5-diisocyanate, naphthalene-2,6-diisocyanate, naphthalene-2,7-diisocyanate, 1,1′-dinaphthyl-2 , 2′-diisocyanate, biphenyl-2,4′-diisocyanate, biphenyl-4,4′-diisocyanate, 3,3′-dimethylbiphenyl-4,4′-diisocyanate, diphenylmethane-4,4′-diisocyanate, dipheny Methane-2,2'-diisocyanate, diphenylmethane-2,4'-diisocyanate and the like can be used.

  Examples of the alicyclic polyisocyanate and aliphatic polyisocyanate include tetramethylene diisocyanate, 1,6-hexamethylene diisocyanate, dodecamethylene diisocyanate, trimethylhexamethylene diisocyanate, 1,3-cyclopentylene diisocyanate, 1,3. -Cyclohexylene diisocyanate, 1,4-cyclohexylene diisocyanate, 1,3-bis (isocyanatomethyl) cyclohexane, 1,4-bis (isocyanatomethyl) cyclohexane, lysine diisocyanate, isophorone diisocyanate, 4,4'-dicyclohexylmethane Diisocyanate, 2,4'-dicyclohexylmethane diisocyanate, 2,2'-dicyclohexylmethane diisocyanate, 3,3'-di It can be used chill-4,4'-dicyclohexylmethane diisocyanate and trimers thereof and the like.

  1-methyl-2,4-phenylene diisocyanate, 1-methyl-2,6-phenylene diisocyanate, 1,3-bis (isocyanatomethyl) -benzene, 1 , 4-bis (isocyanatomethyl) -benzene, diphenylmethane-4,4′-diisocyanate, diphenylmethane-2,2′-diisocyanate, diphenylmethane-2,4′-diisocyanate, 1,6-hexamethylene diisocyanate, isophorone diisocyanate, 4,4′-dicyclohexylmethane diisocyanate, 2,4′-dicyclohexylmethane diisocyanate, and 2,2′-dicyclohexylmethane diisocyanate are preferred.

  In addition, as described above, in order to prevent deterioration of the coating film due to heat discoloration and light discoloration of the obtained coating film, an alicyclic polyisocyanate and / or an aliphatic polyisocyanate generally referred to as non-yellowing type is used as the polyisocyanate. It is preferable to introduce a structural unit derived from the alicyclic polyisocyanate and / or aliphatic polyisocyanate according to the cationic polyurethane resin (A).

  In addition, as the polyisocyanate (g), considering the availability of raw materials, 1,6-hexamethylene diisocyanate, isophorone diisocyanate, 4,4′-dicyclohexylmethane diisocyanate, 2,4′-dicyclohexylmethane diisocyanate, Particular preference is given to using 2,2′-dicyclohexylmethane diisocyanate.

  Furthermore, in order to further improve the water resistance of the resulting coating film, it is preferable to introduce a structural unit containing a silanol group into the cationic polyurethane resin (A). When a structural unit containing a silanol group is introduced, a crosslinked structure is formed between particles made of a cationic polyurethane resin (A), which is an organic component, and an inorganic metal oxide matrix formed by a metal alkoxide (B). Therefore, a stronger organic-inorganic hybrid coating film can be obtained.

  As a structural unit containing a silanol group, the structural unit represented by the following general formula [II] can be illustrated.

（式［ＩＩ］中、Ｒ_５は水素原子、アルキル基、アリール基、又はアラルキル基であり、、Ｒ_６はハロゲン原子、アルコキシル基、アシロキシ基、フェノキシ基、イミノオキシ基又はアルケニルオキシ基であり、ｎは０、１又は２である。）

(In the formula [II], R ₅ is a hydrogen atom, an alkyl group, an aryl group, or an aralkyl group, R ₆ is a halogen atom, an alkoxyl group, an acyloxy group, a phenoxy group, an iminooxy group, or an alkenyloxy group, n is 0, 1 or 2.)

  The compound used for introducing the structural unit represented by the general formula [II] into the cationic polyurethane resin (A) is preferably a compound (h) represented by the following general formula [III].

（式［ＩＩＩ］中、Ｒ_５は水素原子、アルキル基、アリール基、又はアラルキル基であり、Ｒ_６はハロゲン原子、アルコキシル基、アシロキシ基、フェノキシ基、イミノオキシ基又はアルケニルオキシ基であり、ｎは０、１又は２であり、Ｙは活性水素基を少なくとも１個以上含有する有機残基である。）

(In the formula [III], R ₅ is a hydrogen atom, an alkyl group, an aryl group, or an aralkyl group, R ₆ is a halogen atom, an alkoxyl group, an acyloxy group, a phenoxy group, an iminooxy group, or an alkenyloxy group, and n Is 0, 1 or 2, and Y is an organic residue containing at least one active hydrogen group.)

  Examples of the compound (h) represented by the general formula [III] include γ- (2-aminoethyl) aminopropyltrimethoxysilane, γ- (2-hydroxylethyl) aminopropyltrimethoxysilane, γ- (2 -Aminoethyl) aminopropyltriethoxysilane, γ- (2-hydroxylethyl) aminopropyltriethoxysilane, γ- (2-aminoethyl) aminopropylmethyldimethoxysilane, γ- (2-aminoethyl) aminopropylmethyldi Ethoxysilane, γ- (2-hydroxylethyl) aminopropylmethyldimethoxysilane, γ- (2-hydroxylethyl) aminopropylmethyldiethoxysilane or γ- (N, N-di-2-hydroxylethyl) aminopropyltriethoxy Silane, γ-aminopropyltrimethoxy Silane, γ-aminopropyltriethoxysilane, γ-aminopropylmethyldimethoxysilane, γ-aminopropylmethyldiethoxysilane or γ- (N-phenyl) aminopropyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane, γ- Examples include mercaptophenyltrimethoxysilane.

  When the cationic polyurethane resin (A) is produced, polyamine may be used as a chain extender for the purpose of designing a polyurethane resin having physical properties such as various mechanical properties and thermal properties.

  Examples of the polyamine that can be used as the chain extender include ethylenediamine, 1,2-propanediamine, 1,6-hexamethylenediamine, piperazine, 2,5-dimethylpiperazine, isophoronediamine, and 4,4′-dicyclohexylmethane. Diamines such as diamine, 3,3′-dimethyl-4,4′-dicyclohexylmethanediamine, 1,4-cyclohexanediamine; N-hydroxymethylaminoethylamine, N-hydroxyethylaminoethylamine, N-hydroxypropylaminopropylamine Diamines containing one primary amino group and one secondary amino group such as N-ethylaminoethylamine and N-methylaminopropylamine; polyethylene such as diethylenetriamine, dipropylenetriamine and triethylenetetramine Hydrazines such as hydrazine, monomethylhydrazine, N, N′-dimethylhydrazine; dihydrazides such as succinic acid dihydrazide, adipic acid dihydrazide, glutaric acid dihydrazide, sebacic acid dihydrazide, isophthalic acid dihydrazide; , Semicarbazides such as 3-semicarbazide-propyl-carbazate, semicarbazide-3-semicarbazide methyl-3,5,5-trimethylcyclohexane, and the like can be used. In addition, water can also be used as a chain extender.

  When the cationic polyurethane resin (A) is produced, in addition to the polyamine, other chain extenders containing active hydrogen atoms are used for the purpose of adjusting physical properties such as various mechanical properties and thermal properties of the polyurethane resin. Can also be used.

  Examples of the other active hydrogen-containing chain extenders include ethylene glycol, diethylene recall, triethylene glycol, propylene glycol, 1,3-propanediol, 1,3-butanediol, 1, Glycols such as 4-butanediol, hexamethylene glycol, saccharose, methylene glycol, glycerin, sorbitol; bisphenol A, 4,4′-dihydroxydiphenyl, 4,4′-dihydroxydiphenyl ether, 4,4′-dihydroxydiphenylsulfone, Examples thereof include hydrogenated bisphenol A, phenols such as hydroquinone, and water, and these may be used alone or in combination within a range not deteriorating the storage stability of the cationic polyurethane resin aqueous dispersion of the present invention. There.

  Examples of the method for producing the cationic polyurethane resin (A) used in the present invention include the following methods. According to these methods, an aqueous dispersion in which particles made of the cationic polyurethane resin (A) are uniformly dispersed in an aqueous medium can be obtained.

[Method 1] A polyol (f), a polyisocyanate (g), a tertiary amino group-containing polyol (a), and a compound (h) are charged all at once or separately and reacted in a solvent or under no solvent. A polyurethane resin is produced, and some or all of the tertiary amino groups in the obtained polyurethane resin are neutralized with an acid and / or quaternized with a quaternizing agent, and then water is added to disperse in water. Method.

[Method 2] A polyol (f), a polyisocyanate (g), a tertiary amino group-containing polyol (a) and a compound (h) are charged all at once or in a divided manner, and reacted in a solvent or in the absence of a solvent. After producing a urethane prepolymer having an isocyanate group at the terminal, a polyurethane resin is produced by chain extension using a polyamine, and a part or all of the tertiary amino groups in the polyurethane resin are neutralized with an acid, and A method of adding water and dispersing it after quaternization with a / and quaternizing agent.

[Method 3] A polyol (f), a polyisocyanate (g), a tertiary amino group-containing polyol (a), and a compound (h) are charged all at once or divided and reacted in a solvent or in the absence of a solvent. After producing a urethane prepolymer having an isocyanate group at the terminal, neutralizing part or all of the tertiary amino group in the obtained urethane prepolymer with an acid and / or quaternizing with a quaternizing agent, A method in which water is added and dispersed in water, and then chain extension is performed using polyamine.

[Method 4] A polyol (f), a polyisocyanate (g), a tertiary amino group-containing polyol (a) and a compound (h) are batched or divided, charged, and reacted in a solvent or in the absence of a solvent. This produced a urethane prepolymer having an isocyanate group at the terminal, and part or all of the tertiary amino groups in the resulting urethane prepolymer were neutralized with an acid and / or quaternized with a quaternizing agent. Thereafter, a method of forcibly emulsifying in an aqueous medium using a machine such as a homogenizer to make it water-soluble or water-dispersed, and then chain-extending using polyamine.

[Method 5] By charging the polyol (f), the polyisocyanate (g), the tertiary amino group-containing polyol (a), the compound (h) and the polyamine all together and reacting them in a solvent or in the absence of a solvent. A polyurethane resin is produced, and some or all of the tertiary amino groups in the obtained polyurethane resin are neutralized with an acid and / or quaternized with a quaternizing agent, and then water is added to make the solution water-soluble or Method to disperse in water.

[Method 6] A polyurethane resin is produced by charging a polyol (f), a polyisocyanate (g), and a tertiary amino group-containing polyol (a) in a batch or divided and reacting them in a solvent or in the absence of a solvent. A method in which part or all of the tertiary amino groups in the obtained polyurethane resin are neutralized with an acid and / or quaternized with a quaternizing agent, and then water is added to disperse in water.

[Method 7] A polyol (f), a polyisocyanate (g), and a tertiary amino group-containing polyol (a) are charged all at once or separately, and reacted in a solvent or in the absence of a solvent to form an isocyanate group at the terminal. After producing a urethane prepolymer having a polyurethane resin, a polyurethane resin is produced by chain extension using a polyamine, and some or all of the tertiary amino groups in the obtained polyurethane resin are neutralized with an acid, and / or 4 A method in which water is added and dispersed after quaternization with a classifier.

[Method 8] A polyol (f), a polyisocyanate (g), and a tertiary amino group-containing polyol (a) are charged all at once or separately, and reacted in a solvent or in the absence of a solvent to form an isocyanate group at the terminal. The urethane prepolymer is produced, and part or all of the tertiary amino groups in the obtained urethane prepolymer are neutralized with an acid and / or quaternized with a quaternizing agent, and then water is added thereto. A method in which water is dispersed and then chain elongation is performed using polyamine.

[Method 9] A polyol (f), a polyisocyanate (g), and a tertiary amino group-containing polyol (a) are charged together or divided and charged, and reacted in a solvent or in the absence of a solvent to react with an isocyanate at the end. After producing a urethane prepolymer having a group and neutralizing a part or all of the tertiary amino group with an acid and / or quaternizing with a quaternizing agent, using a machine such as a homogenizer in an aqueous medium A method of forcibly emulsifying and dispersing in water, followed by chain elongation using polyamine.

[Method 10] A polyurethane resin is produced by charging a polyol (f), a polyisocyanate (g), a tertiary amino group-containing polyol (a) and a polyamine in a lump and reacting them in a solvent or in the absence of a solvent. A method in which part or all of the tertiary amino groups in the obtained polyurethane resin are neutralized with an acid and / or quaternized with a quaternizing agent, and then water is added to disperse in water.

  In addition, in the manufacturing method of said [Method 1]-[Method 10], you may use an emulsifier as needed.

  The emulsifier that can be used in the present invention is not particularly limited, but is basically nonionic or cationic from the viewpoint of maintaining excellent storage stability of the aqueous dispersion of the cationic polyurethane resin (A). Is preferred. For example, nonionic emulsifiers such as polyoxyethylene nonylphenyl ether, polyoxyethylene lauryl ether, polyoxyethylene styryl phenyl ether, polyoxyethylene sorbitol tetraoleate, polyoxyethylene / polyoxypropylene copolymer; alkylamine salts, It is preferable to use cationic emulsifiers such as alkyltrimethylammonium salts and alkyldimethylbenzylammonium salts. An anionic or amphoteric emulsifier may be used in combination as long as the mixing stability of the emulsifier to the cationic polyurethane resin aqueous dispersion is maintained.

  When the cationic polyurethane resin (A) is produced by the above-described method, a compound having a group capable of becoming a hydrophilic group (hereinafter referred to as a hydrophilic group-containing compound) is used as an aid for assisting water dispersibility of the resin. May be.

  As such a hydrophilic group-containing compound, an anionic group-containing compound, a cationic group-containing compound, an amphoteric group-containing compound, or a nonionic group-containing compound can be used, but the excellent storage stability of the cationic polyurethane resin aqueous dispersion is excellent. From the viewpoint of maintaining the properties, a nonionic group-containing compound is preferable.

  The nonionic group-containing compound includes a group having at least one active hydrogen atom in the molecule and consisting of a repeating unit of ethylene oxide, and a group consisting of a repeating unit of ethylene oxide and another repeating unit of alkylene oxide. A compound having at least one functional group selected from the group can be used.

  For example, polyoxyethylene glycol or polyoxyethylene-polyoxypropylene having a number average molecular weight of 300 to 20,000 containing at least 30% by mass of repeating units of ethylene oxide and containing at least one active hydrogen atom in the polymer Nonionic group-containing compounds such as copolymer glycols, polyoxyethylene-polyoxybutylene copolymer glycols, polyoxyethylene-polyoxyalkylene copolymer glycols or their monoalkyl ethers, or polyesters obtained by copolymerizing these Compounds such as polyether polyols can be used.

  Next, the raw material charging ratio (equivalent ratio) when producing the cationic polyurethane resin (A) will be described in detail.

  When the polyol (f), the tertiary amino group-containing polyol (a), and the polyisocyanate (g) are reacted, the equivalent ratio of the isocyanate group to the active hydrogen atom-containing group [equivalent of isocyanate group possessed by (g)] / [Equivalent hydroxyl group of (f) + Equivalent hydroxyl group of (a)] is preferably adjusted to a range of 0.9 / 1 to 1.1 / 1.

  When the cationic polyurethane resin (A) is produced, for example, when a polyamine is used as the chain extender, the equivalent ratio of isocyanate group to active hydrogen atom-containing group [equivalent of isocyanate in (g)] / [(f ) + Equivalent of hydroxyl group possessed by (a) + equivalent of hydroxyl group possessed by (a) + equivalent of amino group possessed by polyamine] is preferably adjusted in the range of 0.9 / 1 to 1.1 / 1.

  Moreover, you may manufacture the said cationic polyurethane resin (A) by making chain | strand extension reaction using a polyamine, after manufacturing a urethane prepolymer. In this case, the equivalent ratio of the isocyanate group to the active hydrogen atom-containing group [equivalent of isocyanate group possessed by (g)] / [equivalent hydroxyl group possessed by (f) + equivalent hydroxyl group possessed by (a)] It is preferable to adjust to the range of 1/1 to 3/1, and it is more preferable to adjust to the range of 1.2 / 1 to 2/1. In this case, the equivalent ratio of the amino group and excess isocyanate group of the polyamine when chain-extending with the polyamine is preferably in the range of 1.1 / 1 to 0.9 / 1.

  Further, when the polyol (f), the tertiary amino group-containing polyol (a), the compound (h), and the polyisocyanate (g) are reacted, the equivalent ratio of the isocyanate group and the active hydrogen atom-containing group [(g) Equivalents of isocyanate groups possessed by] / [equivalents of hydroxyl groups possessed by (f) + equivalents of hydroxyl groups possessed by (a) + equivalents of active hydrogen groups possessed by (h)] are 0.9 / 1 to 1.1 / It is preferable to adjust to the range of 1.

  When the cationic polyurethane resin (A) is produced, for example, when a polyamine is used as a chain extender, the equivalent ratio of the isocyanate group and the active hydrogen atom-containing group [equivalent of isocyanate group possessed by (g)] / [ (F) equivalent of hydroxyl group + equivalent of hydroxyl group of (a) + equivalent of active hydrogen group of (h) + equivalent of active hydrogen group of polyamine] is 0.9 / 1 to 1.1 / It is preferable to adjust to the range of 1.

  Moreover, you may manufacture the said cationic polyurethane resin (A) by making chain | strand extension reaction using a polyamine, after manufacturing a urethane prepolymer. In this case, the equivalent ratio of the isocyanate group to the active hydrogen atom-containing group [equivalent of isocyanate group possessed by (g)] / [equivalent hydroxyl group possessed by (f) + equivalent hydroxyl group possessed by (a) + (h) The equivalent of active hydrogen group] is preferably in the range of 1.1 / 1 to 3/1, and more preferably in the range of 1.2 / 1 to 2/1. In this case, the equivalent ratio of the amino group and excess isocyanate group of the polyamine when chain-extending with the polyamine is preferably in the range of 1.1 / 1 to 0.9 / 1.

  In such a reaction, the reaction temperature is preferably in the range of 20 to 120 ° C, more preferably in the range of 30 to 100 ° C.

  Further, the tertiary amino group-containing polyol (a) is preferably 0.005 to 1.5 with respect to the finally obtained cationic polyurethane resin (A) for the purpose of expressing excellent storage stability. The range is 5 eq / kg, more preferably 0.03 to 1.0 eq / kg, and still more preferably 0.15 to 0.5 eq / kg.

  The compound (h) is preferably 0 with respect to the finally obtained cationic polyurethane resin (A) for the purpose of forming a stronger organic / inorganic hybrid coating film with the metal alkoxide (B). The range is from 1 to 20% by mass, and more preferably from 0.5 to 10% by mass.

The cationic polyurethane resin (A) can be produced under solvent-free conditions, but for the purpose of facilitating the reaction control, or for the purpose of reducing the stirring load due to a decrease in viscosity or causing a uniform reaction, under an organic solvent. It is also possible to manufacture with.
Examples of the organic solvent include ketones such as acetone, diethyl ketone, methyl ethyl ketone, and methyl isobutyl ketone; ethers such as diethyl ether, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol dibutyl ether, tetrahydrofuran, and dioxane; ethyl acetate Acetates such as butyl acetate and propyl acetate; nitriles such as acetonitrile; hydrocarbons such as n-pentane, n-hexane, cyclohexane, n-heptane, benzene, toluene, xylene; carbon tetrachloride, dichloromethane, chloroform Chlorinated hydrocarbons such as trichloroethane; amides such as dimethylformamide and N-methylpyrrolidone can be used.

  The cationic polyurethane resin (A) can be produced without a catalyst, but various catalysts such as stannous octylate, dibutyltin dilaurate, dibutyltin dimaleate, dibutyltin diphthalate, dibutyltin dimethoxide Tin compounds such as dibutyltin diacetyl acetate and dibutyltin diversate, titanate compounds such as tetrabutyl titanate, tetraisopropyl titanate, and triethanolamine titanate, other tertiary amines, quaternary ammonium salts, and the like may be used.

  The organic solvent contained in the aqueous dispersion of the cationic polyurethane resin (a) obtained as described above is preferably removed by, for example, a method such as vacuum distillation during the reaction or after the completion of the reaction.

[Metal alkoxide (B)]
Preferred examples of the metal in the metal alkoxide or its condensate (B) used in the present invention include silicon, titanium, and aluminum.

  The silicon alkoxide or its condensate is not particularly limited as long as it is an alkoxysilane generally used in a sol-gel reaction. For example, tetraalkoxysilanes such as tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane, tetraisopropoxysilane, tetrabutoxysilane, methyltrimethoxysilane, methyltriethoxysilane, methyltripropoxysilane, methyltributoxy Silane, ethyltrimethoxysilane, ethyltriethoxysilane, n-propyltrimethoxysilane, n-propyltriethoxysilane, isopropyltrimethoxysilane, isopropyltriethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, 3-glycid Xylpropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane , Phenyltrimethoxysilane, phenyltriethoxysilane, 3,4-epoxycyclohexylethyltrimethoxysilane, trialkoxysilanes such as 3,4-epoxycyclohexylethyltrimethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, diethyl Examples include dimethoxysilane, diethyldiethoxysilane, and partial condensates thereof.

  Examples of the titanium alkoxide include titanium isopropoxide, titanium lactate, and titanium triethanolamate. Examples of the aluminum alkoxide include aluminum isopropoxide.

  Among these, it is preferable to use silicon alkoxide or a condensate thereof from the viewpoint of industrial availability. Of these, tetramethoxysilane and its condensate are most preferred. In addition, by using together an alkoxysilane having a functional group that reacts with the cationic functional group in the cationic polyurethane resin (A), the cross-linking of the coating film can be made more precise, and the coating film properties such as water resistance Can be further improved. Most preferred in this case is 3-glycidoxypropyltrimethoxysilane.

  The ratio of the mass of the cationic polyurethane resin (A) to the mass (B1) after hydrolysis condensation of the metal alkoxide or its condensate (B) is represented by (A) / (B1). Is preferably in the range of 10/90 to 70/30, more preferably 20/80 to 70/30, and even more preferably 30/70 to 70/30. The hydrolysis reaction formula of metal alkoxide is as follows.

〔式中、Ｒ^１は有機基であり、Ｒ^２はアルキル基であり、Ｘは（ｍ＋ｎ）価の金属原子である。〕

[Wherein, R ¹ is an organic group, R ² is an alkyl group, and X is a (m + n) -valent metal atom. ]

  Therefore, the mass (B1) of the metal alkoxide after complete hydrolysis condensation is calculated by (charge amount) / (formula amount of metal alkoxide before hydrolysis reaction) × (formula amount of metal alkoxide after hydrolysis reaction). be able to.

[Acid catalyst (C)]
As the acid catalyst (C) used in the present invention, various acid catalysts can be used. For example, inorganic acids such as hydrochloric acid, boric acid, sulfuric acid, hydrofluoric acid, and phosphoric acid, and organic acids such as acetic acid, phthalic acid, maleic acid, fumaric acid, and paratoluenesulfonic acid can be used. These acids may be used alone or in combination of two or more. Among these, maleic acid can be easily adjusted to the target pH range, the storage stability of the obtained water-based coating composition is good, and the resulting organic-inorganic composite coating film has excellent water resistance. Is preferably used.

  Further, the pH of the liquid after adding the acid catalyst (C) to the aqueous dispersion of the cationic polyurethane resin (A) is less likely to cause problems such as mechanical corrosion due to acid, and the resulting aqueous coating composition From the point that the storage stability is good, it is usually in the range of 1.0 to 4.0, preferably in the range of 1.0 to 3.0, more preferably in the range of 2.0 to 3.0. . It is important to adjust the pH within this range in order to obtain an organic-inorganic composite coating film excellent in wear resistance and water resistance, and the pH can be adjusted while gradually dropping the acid catalyst (C). preferable.

[Water-based paint composition]
As a method for preparing the aqueous coating composition of the present invention, the aqueous dispersion of the cationic polyurethane resin (A) and the acid catalyst (C) are mixed and homogenized, and then the metal alkoxide or its condensate (B) is added. Mixing is most preferred. In addition, the alcohol produced by hydrolysis of the metal alkoxide or its condensate (B) may be left as the aqueous coating composition of the present invention, and may be left or heated under various methods, for example, under reduced pressure. Then, after removing the alcohol, an aqueous coating composition may be obtained.

  Various additives such as thickeners, wetting agents, thixotropic agents, fillers, and the like may be added to the aqueous coating composition of the present invention as long as the effects of the present invention are not hindered. Furthermore, a crosslinking agent that reacts with a functional group in the cationic polyurethane resin (A), for example, a crosslinking agent such as a polyepoxy compound, a dialdehyde compound, or a dicarboxylic acid compound may be used in combination.

  The aqueous coating composition of the present invention can be used as a clear coating composition, but can also be used as a colored coating composition by mixing various pigment dispersions and dyes.

  The nonvolatile content of the aqueous coating composition of the present invention is not particularly limited, but it is preferably 10% by mass or more and 50% by mass or less from the viewpoint of good storage stability.

  The method for coating the water-based coating composition of the present invention on the equipment is not particularly limited, but examples include various coating methods such as an air spray method, a flow coater method, and a roll coater method. Can be painted with.

  The coating object of the water-based coating composition of the present invention is not particularly limited. For example, iron, stainless steel, aluminum and other metals, ABS, polycarbonate, PMMA, PET, polystyrene and other plastics, glass, wood, cement In addition, it can be used for the purpose of forming a film on the surface of another substrate, or a granular or fibrous body.

  Furthermore, for the purpose of improving adhesion to the substrate, coloring the substrate, protecting the substrate, and the like, after coating the various substrates with various primers, sealants, undercoats, etc., the aqueous coating composition of the present invention Can also be painted.

  Moreover, it is although it does not specifically limit as drying conditions after coating, It is preferable to dry between 20 to 250 degreeC, and it is more preferable to dry between 60 to 200 degreeC.

  The organic / inorganic composite coating film of the present invention is characterized in that particles of the cationic polyurethane resin (A) are dispersed in a matrix made of a metal oxide (B ′).

  The metal oxide (B ′) is obtained by hydrolysis / condensation reaction of the metal alkoxide or the condensate (B) described above, and forms a matrix in the composite coating film. This is because the metal gel is concentrated so that the cationic polyurethane resin (A) surrounds the surface of the fine particles formed in the aqueous dispersion as described above. It is formed by crosslinking the metal gel on the surface. Accordingly, the fine particles of the cationic polyurethane resin (A) are not condensed and are dispersed in the organic-inorganic composite coating film. This is apparent from the attached drawing (electron micrograph).

  The method for producing an organic-inorganic composite coating film of the present invention is an aqueous solution obtained by adding an acid catalyst (C) to an aqueous dispersion of a cationic polyurethane resin (A) and then adding a metal alkoxide or a condensate (B) thereof. Applying a coating composition on a substrate and drying to produce a composite coating film in which particles made of a cationic polyurethane resin (A) are dispersed in a matrix made of a metal oxide (B ′) It is characterized by. The manufacturing method is industrially simple and useful because it does not require any special equipment and does not use moisture in the air, so it has no environmental dependency and is therefore not limited to the application range. It is a thing.

  Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to the examples. Unless otherwise specified, “parts” and “%” represent “parts by mass” and “mass%”.

(Synthesis example 1) Preparation of aqueous dispersion of cationic urethane resin (A-1) Polypropylene glycol-diglycidyl ether (epoxy equivalent) was added to a four-necked flask equipped with a thermometer, a stirring device, a reflux condenser, and a dropping device. (201 g / equivalent) 590 parts were charged, and the atmosphere in the flask was replaced with nitrogen. Subsequently, after heating using the oil bath until the temperature in the said flask becomes 70 degreeC, 378 parts of di-n-butylamine is dripped in 30 minutes using a dripping apparatus, and 10 degreeC is 90 degreeC after completion | finish of dripping. Reacted for hours. After completion of the reaction, using an infrared spectrophotometer (FT / IR-460Plus, manufactured by JASCO Corporation), it is confirmed that the absorption peak near 842 cm ⁻¹ due to the epoxy group of the reaction product has disappeared. A tertiary amino group-containing polyol (amine equivalent 339 g / equivalent, hydroxyl equivalent 339 g / equivalent) was obtained.

  In a four-necked flask equipped with a thermometer, a stirrer, a reflux condenser, and a dropping device, 500 parts of Nipponran 980R [Nippon Polyurethane Industry Co., Ltd., Polycarbonate polyol, molecular weight 2000], neopentyl glycol / 1,4-butane 500 parts of a polyester polyol (molecular weight 2000) composed of diol / terephthalic acid / adipic acid was dissolved in 558 parts of ethyl acetate. Next, after adding 236 parts of 4,4′-dicyclohexylmethane diisocyanate and 0.2 part of stannous octylate and reacting at 75 ° C. for 2 hours, 66.2 parts of the tertiary amino group-containing polyol was added, By making it react for 4 hours, the urethane prepolymer which has an isocyanate group at the terminal was obtained. Next, 478 parts of ethyl acetate and 918 parts of isopropyl alcohol were added to the urethane prepolymer solution and mixed uniformly, and then 17 parts of 80% hydrated hydrazine was added to carry out a chain extension reaction for 1 hour. Next, 11.7 parts of glacial acetic acid was added for neutralization, and 3610 parts of ion-exchanged water was added dropwise to carry out water dispersion, followed by desolvation under reduced pressure to obtain a non-volatile content of 35% and a pH of 4 .2, an aqueous dispersion of a cationic polyurethane resin (A-1) having a particle size of 0.2 μm (measured by a particle size analyzer FPAR-1000 manufactured by Otsuka Electronics Co., Ltd.) and a cation equivalent of 0.15 equivalent / kg was obtained. .

(Synthesis example 2) Preparation of aqueous dispersion of cationic polyurethane resin (A-2) In a four-necked flask equipped with a thermometer, a stirring device, a reflux condenser, and a dropping device, 1000 parts of Nippolan 980R were mixed with ethyl acetate. Dissolved in 600 parts. Next, 262 parts of 4,4′-dicyclohexylmethane diisocyanate and 0.2 part of stannous octylate were added and reacted at 75 ° C. for 2 hours, and then 95 parts of the tertiary amino group-containing polyol was added and reacted for 4 hours. After cooling to 60 ° C., 44 parts of Z-6011 [γ-aminopropyltriethoxysilane manufactured by Toray Dow Corning Co., Ltd.] was added, and the mixture was further reacted for 1 hour to make a urethane prepolymer having an isocyanate group at the terminal. A polymer was obtained. Next, 515 parts of ethyl acetate and 986 parts of isopropyl alcohol were added to the urethane prepolymer solution and mixed uniformly, and then 15 parts of 80% hydrated hydrazine was added to carry out a chain extension reaction for 1 hour. Next, after 16.8 parts of glacial acetic acid was added for neutralization, 3800 parts of ion-exchanged water was added dropwise to carry out water dispersion, followed by desolvation under reduced pressure to obtain a non-volatile content of 35% and a pH of 4 An aqueous dispersion of a cationic urethane resin (A-2) having a particle diameter of 0.15 μm and a cation equivalent of 0.2 equivalent / kg was obtained.

Synthesis Example 3 Preparation of Aqueous Dispersion of Cationic Polyurethane Resin (A-3) In a four-necked flask equipped with a thermometer, a stirrer, a reflux condenser, and a dripping device, 640 parts of Nippolan 980R were added to methyl ethyl ketone 390. Dissolved in the part. Next, 133 parts of isophorone diisocyanate and 0.2 part of stannous octylate were added and reacted at 75 ° C. for 2 hours, and then 122 parts of the tertiary amino group-containing polyol was added and reacted for 4 hours. After cooling to ° C., 22 parts of Z-6011 were added and reacted for 1 hour to obtain a urethane prepolymer having an isocyanate group at the terminal. Next, 45 parts of dimethylsulfuric acid was added to the urethane prepolymer solution, and the mixture was further reacted at 60 ° C. for 2 hours for quaternization. Then, 2080 parts of ion-exchanged water was added dropwise to carry out water dispersion, followed by reduced pressure. By removing the solvent under water, an aqueous dispersion of cationic polyurethane resin particles (A-3) having a nonvolatile content of 35%, pH 6.5, particle diameter of 0.05 μm, and cation equivalent of 0.39 equivalent / kg was obtained.

(Comparative Synthesis Example 1)
A reaction vessel equipped with a stirrer, thermometer, reflux condenser and inert gas inlet and outlet was charged with 116 parts of hexamethylenediamine and maintained at 50 ° C. with stirring under a nitrogen atmosphere. Propylene carbonate was slowly added dropwise over about 1 hour. When the reaction vessel was kept at 90 to 100 ° C. for 20 hours, hexamethylenediamine bishydroxycarbamate (hereinafter referred to as A′-1), which was a white waxy soft solid, was obtained. As a result of acid titration, the amine content was 0.1% or less.

[Coating composition]
Example 1
After stirring and mixing 20 parts of an aqueous dispersion of the cationic urethane resin (A-1) obtained in Synthesis Example 1, 5 parts of ion-exchanged water, and 8 parts of 2-propanol (hereinafter referred to as IPA), 10% malee 7 parts of an acid aqueous solution was gradually added dropwise. The pH of the mixed solution at this time was 1.6. Subsequently, 14.4 parts of tetramethoxysilane condensate (methyl silicate 51: product of Tama Chemical Industry Co., Ltd., hereinafter referred to as MS-51) and 3-glycidoxypropyltrimethoxysilane (hereinafter referred to as GPTMS) are stirred. The mixed liquid consisting of 4.3 parts was gradually added and stirred for 1 hour to obtain an aqueous coating composition (1).

(Examples 2 to 15)
In the same manner as in Example 1, water-based coating compositions were prepared with the formulations shown in Tables 1 and 2 to obtain water-based coating compositions (2) to (15).

(Comparative Example 1)
20 parts of tetraethoxysilane (hereinafter referred to as TEOS) and curing were added to a solution obtained by mixing 15 parts of the hydroxyl group-containing polymer A′-1 synthesized in Comparative Synthesis Example 1, 15 parts of ion-exchanged water, and 5 parts of methanol. As an agent, 0.5 part of melamine resin Cymel 303 (manufactured by Cytec Corporation) was added to prepare a uniform solution. To this solution, 0.3 part of concentrated hydrochloric acid as a catalyst was added and heated at about 30 ° C. for 1 hour to obtain a comparative aqueous coating composition (1 ′).

(Stability evaluation method of water-based paint composition)
The coating liquid state when the water-based coating compositions obtained in Examples 1 to 15 and Comparative Example 1 were stored at 23 ° C. was visually observed, and the number of days until gelation occurred was described.

Footnotes in Tables 1 and 2 (A) / (B1): Ratio of the mass of the cationic polyurethane resin (A) to the mass (B1) after hydrolysis condensation of the metal alkoxide or its condensate (B) MTMS: Methyltri Methoxysilane

Footnotes in Table 3 (A ′) / (B1): Ratio of the mass of (A′-1) to the mass after hydrolysis condensation of the metal alkoxide (B) (B1) TEOS: Tetraethoxysilane

[Coating]
(Examples 16 to 30)
The aqueous paint compositions (1) to (15) obtained in Examples 1 to 15 were applied on a polycarbonate film (product name: Iupilon, manufactured by Mitsubishi Gas Chemical Co., Ltd., film thickness: 100 μm) and then dried at 130 ° C. for 30 minutes. An organic-inorganic composite coating film (coating film 1 to coating film 15) having a film thickness of about 5 μm was obtained.

(Comparative Example 2)
The aqueous coating composition obtained in Comparative Example 1 was applied onto a polycarbonate film (Mitsubishi Gas Chemical Co., Ltd., product name Iupilon, film thickness: 100 μm) and then dried at 130 ° C. for 30 minutes, and a comparative organic film having a film thickness of about 5 μm. An inorganic composite coating film (comparative coating film 1 ') was obtained.

(Examples 31-33)
After applying the aqueous coating compositions (2), (10), and (13) obtained in Examples 2, 10, and 13 on a polycarbonate film (Mitsubishi Gas Chemical Co., Ltd., product name Iupilon, film thickness 100 μm) And dried at 80 ° C. for 30 minutes to obtain an organic-inorganic composite coating film (coating film 16 to coating film 18) having a film thickness of about 5 μm.

(Examples 34 to 36)
After applying the aqueous coating compositions (2), (10), and (13) obtained in Examples 2, 10, and 13 on a polycarbonate film (Mitsubishi Gas Chemical Co., Ltd., product name Iupilon, film thickness 100 μm) And dried at 23 ° C. for 24 hours to obtain an organic-inorganic composite coating film (coating film 19 to coating film 21) having a film thickness of about 5 μm.

  The physical property measurement results of the obtained coating films 1 to 21 and comparative coating film 1 'are shown in Tables 4 to 8. The coating film was evaluated by the following method.

(Abrasion resistance)
Evaluation was performed using a Gakushin type abrasion tester (Daiei Scientific Instruments Seisakusho, RT-200). Wear body: Steel wool (made by Nippon Steel Wool Co., Ltd., trade name Bonster, product number No. 0000), load: 500 g, number of reciprocations: 250 times. The numbers in the table are obtained by quantifying the difference in turbidity of the coating film before and after the test, and the smaller the number, the better the wear resistance.

(water resistant)
The coating film was immersed in warm water at 40 ° C., and the presence or absence of a change in the surface state of the coating film was visually determined.
A: No change after 2 weeks immersion.
○: No change after one week immersion.
X: The film was whitened or cracked after being immersed for one week.

(Coating state)
The state of the coating film was visually evaluated.
○: The coating film is transparent.
X: The coating film was cracked.

  The cross section of the organic-inorganic composite coating film 13 obtained in Example 28 was observed with a transmission electron microscope (JEM-2200FS, manufactured by JEOL Ltd.), and the obtained image is shown in FIG. From this, it can be confirmed that the fine particles of the cationic resin are uniformly dispersed in the coating film. Similarly, it was confirmed that fine particles of the cationic resin were dispersed in the coating films obtained in other examples.

4 is a transmission electron micrograph of the cross-sectional structure of an organic-inorganic composite coating film 13 obtained in Example 28. FIG.

Claims (10)

The following general formula [I]

[In Formula (I), R ₁ is an alkylene chain which may contain an aliphatic cyclic structure, a residue of a dihydric phenol, or a polyoxyalkylene chain, and R ₂ and R ₃ are independent of each other. An alkyl group which may contain an aliphatic cyclic structure, R ₄ is a hydrogen atom or a residue of a quaternizing agent introduced by a quaternization reaction, X ⁻ is an anionic counter ion is there. ]
An aqueous coating composition comprising an aqueous dispersion of a cationic polyurethane resin (A) containing a structural unit represented by formula (I), a metal alkoxide or a condensate thereof (B), and an acid catalyst (C). . The aqueous paint composition according to claim 1, wherein the cationic polyurethane resin (A) is a resin having a structural unit derived from an alicyclic polyisocyanate and / or an aliphatic polyisocyanate. The cationic polyurethane resin (A) is further represented by the following general formula (II)

[In the formula (II), R ₅ is a hydrogen atom, an alkyl group, an aryl group or an aralkyl group, R ₆ is a halogen atom, an alkoxy group, an acyloxy group, a phenoxy group, an iminooxy group or an alkenyloxy group, and n is 0, 1 or 2. ]
The water-based coating composition of Claim 1 containing the structural unit represented by these. The cationic polyurethane resin (A) is represented by the following general formula [III]

Wherein R ₅ is a monovalent organic residue selected from the group consisting of a hydrogen atom, an alkyl group, an aryl group and an aralkyl group, and R ₆ is a halogen atom, an alkoxyl group, an acyloxy group, a phenoxy group, an iminooxy group or An alkenyloxy group, n is 0, 1 or 2, and Y is an organic group containing at least one active hydrogen group.
The aqueous coating composition according to claim 3, which is a resin having a structural unit obtained by reacting a compound represented by formula (I) with an isocyanate compound. The water-based coating composition according to claim 1, wherein an average particle diameter of particles made of the cationic polyurethane resin (A) in the aqueous dispersion of the cationic polyurethane resin (A) is in a range of 0.01 to 0.4 µm. The aqueous coating composition according to claim 1, wherein the metal alkoxide or the condensate thereof (B) is a silicon alkoxide or a condensate thereof. The ratio of the mass of the cationic polyurethane resin (A) to the mass (B1) after hydrolytic condensation of the metal alkoxide or its condensate (B) is 10 by mass ratio represented by (A) / (B1). It is the range of / 90-70 / 30, The water-based coating composition as described in any one of Claims 1-6. An organic-inorganic composite coating film obtained by using the water-based coating composition according to claim 1, wherein the matrix of the metal oxide (B ') has the following general formula [I]:

[In Formula (I), R ₁ is an alkylene chain which may contain an aliphatic cyclic structure, a residue of a dihydric phenol, or a polyoxyalkylene chain, and R ₂ and R ₃ are independent of each other. An alkyl group which may contain an aliphatic cyclic structure, R ₄ is a hydrogen atom or a residue of a quaternizing agent introduced by a quaternization reaction, X ⁻ is an anionic counter ion is there. ]
An organic-inorganic composite coating film in which particles comprising a cationic polyurethane resin (A) containing a structural unit represented by formula (A) are dispersed. The following general formula [I]

[In Formula (I), R ₁ is an alkylene chain which may contain an aliphatic cyclic structure, a residue of a dihydric phenol, or a polyoxyalkylene chain, and R ₂ and R ₃ are independent of each other. An alkyl group which may contain an aliphatic cyclic structure, R ₄ is a hydrogen atom or a residue of a quaternizing agent introduced by a quaternization reaction, X ⁻ is an anionic counter ion is there. ]
An aqueous coating composition obtained by adding an acid catalyst (C) to an aqueous dispersion of a cationic polyurethane resin (A) containing the structural unit represented by formula (A) and then adding a metal alkoxide or a condensate (B) thereof is used as a substrate. The composite coating film in which the particles made of the cationic polyurethane resin (A) are dispersed in the matrix made of the metal oxide (B ′) is prepared by applying the coating onto the substrate and drying. A method for producing an organic-inorganic composite coating film. The following general formula [I]

[In formula (I), R ₁ Is an alkylene chain which may contain an aliphatic cyclic structure, a residue of a dihydric phenol, or a polyoxyalkylene chain, and R ₂ And R ₃ Are alkyl groups which may contain an aliphatic cyclic structure independently of each other, and R ₄ Is a hydrogen atom or the residue of a quaternizing agent introduced by a quaternization reaction, X ⁻ Is an anionic counterion. ]
The aqueous dispersion of the cationic polyurethane resin (A) containing the structural unit represented by the above and the acid catalyst (C) are mixed and homogenized to adjust the pH to 1.0 to 3.0, and then the metal alkoxide or its A method for producing an aqueous coating composition, comprising mixing the condensate (B).

Images