WO2010035641A1

WO2010035641A1 - Aqueous coating composition

Info

Publication number: WO2010035641A1
Application number: PCT/JP2009/065807
Authority: WO
Inventors: 克彦庄; 宗夫今村; 崇宏雲林院
Original assignee: 日本ペイント株式会社
Priority date: 2008-09-29
Filing date: 2009-09-10
Publication date: 2010-04-01
Also published as: JP5421921B2; MY153920A; KR20110071094A; KR101474056B1; JPWO2010035641A1; CN102165027A; CN102165027B

Abstract

An aqueous coating composition having excellent low-temperature curability. The aqueous coating composition contains a water-soluble or water-dispersed polyamine resin (A) having one or more first amine groups and/or second amine groups in each molecule, and a compound (B) having one or more (meth)acryloyl groups in each molecule. The polyamide resin (A) has an amine equivalent weight of 100-3000, and the compound (B) has a viscosity at 25˚C of not more than 3000 mPa·s.

Description

Water-based paint composition

The present invention relates to a water-based coating composition.

Recently, from the viewpoint of environmental protection, there is a social demand to switch from solvent-based paints to water-based paints. As such a water-based paint, for example, a two-component water-based paint composition containing an epoxy resin and a polyamine compound can be cited (Patent Document 1). Such an aqueous coating composition exhibits sufficient curability at a temperature of room temperature or higher and can form a normal coating film. However, since it is inferior in curability at low temperatures (for example, around 5 ° C.), there is a problem that when it is used in low-temperature areas (for example, outdoors in winter), it is difficult to exhibit the original sufficient coating film performance.

JP-A-11-166153

The present invention has been made to solve the above-described conventional problems, and an object of the present invention is to provide an aqueous coating composition having excellent low-temperature curability.

The aqueous coating composition of the present invention comprises a water-soluble or water-dispersible polyamine resin (A) having one or more primary amine groups and / or secondary amine groups in the molecule, and one or more in the molecule. And a compound (B) having a (meth) acryloyl group, the amine equivalent of the polyamine resin (A) is 100 to 3000, and the viscosity of the compound (B) at 25 ° C. is 3000 mPa · s or less.

In a preferred embodiment, the aqueous coating composition is a two-component aqueous coating composition, the main coating liquid contains the polyamine resin (A), and the curing agent contains the compound (B).

In a preferred embodiment, the polyamine resin (A) is an acrylic polyamine resin or an epoxy polyamine resin.

In a preferred embodiment, the molecular weight of the compound (B) is 150 or more and 2000 or less.

In a preferred embodiment, the compound (B) is a water-soluble compound, and the polyamine resin (A) is a water-dispersed resin.

In a preferred embodiment, the compound (B) is a self-emulsifying compound.

In a preferred embodiment, the compound (B) is emulsified or dispersed by the polyamine resin (A).

In a preferred embodiment, the compound (B) is a mixture of a water-soluble compound and a water-insoluble compound.

In a preferred embodiment, the compound (B) is an emulsion.

In a preferred embodiment, the curing agent further contains an emulsifier.

The aqueous coating composition of the present invention comprises a water-soluble or water-dispersible polyamine resin (A) having one or more primary amine groups and / or secondary amine groups in the molecule, and one or more in the molecule. By including the compound (B) having a (meth) acryloyl group, excellent low temperature curability is exhibited. That is, when the polyamine resin (A) and the compound (B) are used, they exhibit high reactivity with each other and the reaction proceeds even at low temperatures, so that an aqueous coating composition having excellent curability at low temperatures can be obtained. Can do. Furthermore, since the product obtained by the reaction of the polyamine resin (A) and the compound (B) can have a structure in which the polyamine resin (A) is crosslinked by the compound (B), the coating performance is improved. An excellent aqueous coating composition can be obtained.

A. Overview of aqueous coating composition The aqueous coating composition of the present invention comprises a water-soluble or water-dispersed polyamine resin (A) having one or more primary amine groups and / or secondary amine groups in the molecule, and a molecule. It contains a compound (B) having one or more (meth) acryloyl groups therein, and is cured by a reaction between the polyamine resin (A) and the compound (B) to obtain a coating film.

The aqueous coating composition of the present invention is preferably a two-component aqueous coating composition comprising a main component coating liquid and a curing agent, and the main component coating liquid contains the polyamine resin (A), and the curing agent is the above compound. (B) is included. By using the polyamine resin (A) and the compound (B) as a two-component aqueous coating composition, a combination of the polyamine resin (A) and the compound (B) that exhibits high reactivity with each other is selected. Therefore, an aqueous coating composition having excellent low temperature curability can be obtained.

The content of the polyamine resin (A) as a solid content is preferably 5 to 95% by weight, more preferably 10 to 90% by weight, based on the total solid content of the aqueous coating composition.

The content of the compound (B) is preferably 2 to 40% by weight, more preferably 5 to 30% by weight, based on the total solid content of the aqueous coating composition.

The ratio of the number of amine groups of the polyamine resin (A) to the number of (meth) acryloyl groups of the compound (B) (amine group: acryloyl group) is preferably 1: 0.5 to 1: 1. 5, more preferably 1: 0.75 to 1: 1.25, and particularly preferably 1: 0.9 to 1: 1.1. In this specification, “the number of amine groups” means that when the polyamine resin (A) has a primary amine group in its molecule (including cases where it has a primary amine group and a secondary amine group). It means the number of one amine group (that is, does not include the number of secondary amine groups), and when it has only the secondary amine group in the molecule, it means the number of secondary amine groups.

The water-based coating composition of the present invention may contain a pigment, a solvent, an additive and the like as necessary. Examples of the pigment include titanium oxide, yellow iron oxide, red iron oxide, carbon black, phthalocyanine blue, phthalocyanine green, azo red, quinacridone red, benzimidazolone yellow, and the like; calcium carbonate, barium sulfate, kaolin, clay, Examples include extender pigments such as talc. Examples of the solvent include glycol solvents such as ethylene glycol, propylene glycol, ethylene glycol monobutyl ether, propylene glycol monobutyl ether, diethylene glycol, dipropylene glycol, diethylene glycol monobutyl ether, dipropylene glycol monobutyl ether, diethylene glycol dibutyl ether; xylene, Solvesso 100, Aromatic solvents such as Solvesso 150 and Solvesso 200; Hydrocarbon solvents such as mineral spirits; 2,2,4-trimethyl-1,3-pentanediol monoisobutyrate (CS-12), 2,2,4 -Ester solvents such as trimethyl-1,3-pentanediol diisobutyrate (CS-16), diethyl adipate, diisobutyl adipate It is. Examples of the additive include a dispersant, a viscosity adjusting agent, a curing catalyst, a surface adjusting agent, an antifoaming agent, a plasticizer, a film forming aid, an ultraviolet absorber, and an antioxidant.

B. Polyamine resin (A)
The polyamine resin (A) used in the aqueous coating composition of the present invention may be any resin as long as it has one or more primary amine groups and / or secondary amine groups and is a water-soluble or water-dispersible resin. A suitable resin can be employed. Examples of such resins include aliphatic polyamine resins, aromatic polyamine resins, and alicyclic polyamine resins.

The amount of amine groups contained in the polyamine resin (A) is 100 to 3000 as an amine equivalent, more preferably 500 to 2000, and particularly preferably 800 to 1500. When the amine equivalent of the polyamine resin (A) is in such a range, the polyamine resin (A) has water solubility or water dispersibility, and a coating film having excellent low-temperature curability can be obtained. When the polyamine resin (A) has a primary amine, the amine equivalent is indicated by the molecular weight of the resin solids per primary amine group, and when the polyamine resin (A) does not have a primary amine group, It is indicated by the molecular weight of the resin solid content per secondary amine group. The amine equivalent of polyamine resin (A) can be calculated | required from raw material compounding quantity.

Any appropriate molecular weight can be adopted as the molecular weight (number average) of the polyamine resin (A) depending on the desired film properties. Preferably, it is 500 to 20000 in terms of standard polystyrene using gel permeation chromatography (GPC), and more preferably 1000 to 3000. When the molecular weight of the polyamine resin (A) is in such a range, the polyamine resin (A) and the compound (B) can be easily mixed, and thus can be reacted efficiently. Moreover, if the molecular weight of a polyamine resin (A) is such a range, the coating film which is excellent in corrosion resistance, water resistance, and adhesiveness can be obtained.

Any suitable glass transition temperature can be adopted as the glass transition temperature of the polyamine resin (A) depending on the desired physical properties of the coating film. Preferably it is −50 to 100 ° C., more preferably 0 to 50 ° C.

As the polyamine resin (A), an aqueous solution obtained by neutralizing an amine group with an acid can be used. The type of acid and the neutralization rate (neutralization rate with respect to the amine group of the polyamine resin before being made water-based) can be arbitrarily selected depending on the desired state of the polyamine resin (A) (water-soluble to aqueous dispersion) The type of acid and the neutralization rate can be employed. Examples of the acid include acetic acid, formic acid, lactic acid, and phosphoric acid. The neutralization rate (neutralization rate with respect to the amine group of the polyamine resin before being made water-based) is preferably 10 to 70%, and more preferably 15 to 50%.

The polyamine resin (A) is preferably an epoxy polyamine resin obtained by amine-modifying an epoxy resin or an acrylic polyamine resin obtained by amine-modifying an acrylic resin, and more preferably an epoxy polyamine resin. This is because an epoxy-based polyamine resin can provide an aqueous coating composition with better anticorrosion performance. That is, by using the epoxy-based polyamine resin as the polyamine resin (A) and the compound (B), a coating exhibiting excellent anticorrosion performance equal to or better than that of a conventional epoxy resin coating composition comprising an epoxy resin-polyamine compound. An aqueous coating composition capable of forming a film even at a low temperature can be obtained.

The epoxy polyamine resin and acrylic polyamine resin can be obtained by any suitable modification method. Examples of the modification method include a method of adding a primary amine group-containing polyamine to an epoxy resin or an acrylic resin, and a method of adding a ketiminated amine group-containing compound to an epoxy resin or an acrylic resin. The polyamine resin (A) thus obtained has one or more primary amine groups and / or secondary amine groups and secondary hydroxyl groups in the molecule. The polyamine resin is a compound having a functional group such as an epoxy group, an acid anhydride group, an acid halogen group or an isocyanate group in a part of the primary amine group, secondary amine group and / or hydroxyl group of the polyamine resin (A). It may be a resin obtained by reacting. By including a polyamine resin reacted with such a functional group as a part of the polyamine resin to be used, the physical properties of the obtained coating film can be adjusted.

The method of adding the first amine group-containing polyamine to the epoxy resin or acrylic resin means that the first amine group of the first amine group-containing polyamine and the reactive group (for example, epoxy group) of the epoxy resin or acrylic resin. In this method, a second amine group is formed by reaction, and as a result, the epoxy polyamine resin or the acrylic polyamine resin having the second amine group is produced.

The method of adding the ketiminated amine group-containing compound to an epoxy resin or an acrylic resin means that the ketimine group is hydrolyzed after reacting the ketiminated amine group-containing compound with an epoxy resin or an acrylic resin. In this method, the first amine group is formed, and as a result, the epoxy polyamine resin or the acrylic polyamine resin having the first amine group is produced. When reacting the ketiminated amine group-containing compound with an epoxy resin or an acrylic resin, a secondary amine such as diethanolamine, methylethanolamine, or diethylamine may coexist.

Any appropriate epoxy resin can be used. Bisphenol A type epoxy resins or bisphenol F type epoxy resins are preferred, and bisphenol A type epoxy resins are particularly preferred.

The epoxy equivalent of the epoxy resin can be determined according to the desired film properties. It is preferably 180 to 2000, more preferably 400 to 1500. If the epoxy equivalent of an epoxy resin is such a range, the coating film which is excellent in water resistance, corrosion resistance, and adhesiveness can be obtained.

The above-mentioned epoxy resin can be chain-extended using the reaction between an active hydrogen-containing compound capable of reacting with an epoxy group and the epoxy group to increase the molecular weight or be modified. Examples of the active hydrogen-containing compound include bifunctional compounds such as dimer acid, diamine, and polyether polyol.

Depending on the application, the epoxy resin may be used by adding a fatty acid to reduce the number of epoxy groups before reducing the amine, thereby reducing the number of amine-modified sites and reducing the reactivity.

Any appropriate resin can be used as the acrylic resin. An acrylic resin obtained by copolymerizing a monomer composition containing a radical polymerizable monomer having an epoxy group and / or a glycidyl group is preferable. Examples of the radical polymerizable monomer having an epoxy group and / or glycidyl group include glycidyl acrylate, glycidyl methacrylate, methyl glycidyl acrylate, methyl glycidyl methacrylate, 3,4-epoxycyclohexyl methyl acrylate, and 3,4-epoxycyclohexyl. Examples include methyl methacrylate.

Examples of the first amine group-containing polyamine include diethylenetriamine, dipropylenetriamine, dibutylenetriamine, and triethylenetetramine. These may be used alone or in combination.

The above-mentioned ketiminated amine group-containing compound can be obtained by reacting a first amine group-containing compound with a ketone. Examples of the primary amine group-containing compound include primary amine group-containing polyamines such as diethylenetriamine, dipropylenetriamine, dibutylenetriamine, and triethylenetetramine; aminoethylethanolamine, methylaminopropylamine, ethylaminoethylamine, and the like. It is done. These may be used alone or in combination. Examples of the ketone include methyl ethyl ketone, acetone, and methyl isobutyl ketone.

C. Compound (B)
The compound (B) used in the aqueous coating composition of the present invention has one or more (meth) acryloyl groups in the molecule.

The molecular weight of the compound (B) is preferably 150 or more and 2000 or less, more preferably 200 or more and 1700 or less, and particularly preferably 250 or more and 1300 or less. When the molecular weight of the compound (B) is within such a range, the polyamine resin (A) and the compound (B) can be easily mixed without using a special mixing apparatus, and the coating composition has excellent dispersibility. You can get things. As a result, the polyamine resin (A) and the compound (B) can be efficiently reacted with each other, and an aqueous coating composition having excellent curability can be obtained. The molecular weight of the compound (B) can be calculated from the chemical formula.

The number of (meth) acryloyl groups possessed by the compound (B) is 1 or more, preferably 2 to 4. The number of (meth) acryloyl groups possessed by the compound (B) can be determined according to the desired physical properties of the coating film.

The viscosity of the compound (B) at 25 ° C. is 3000 mPa · s or less, preferably 50 mPa · s or more and 3000 mPa · s or less, more preferably 50 mPa · s or more and 2200 mPa · s or less, and particularly preferably 50 mPa · s. · S to 1100 mPa · s. If the viscosity of the compound (B) is in such a range, the polyamine resin (A) and the compound (B) can be easily mixed without using a special mixing device, and the coating composition has excellent dispersibility. Can be obtained. As a result, the polyamine resin (A) and the compound (B) can be efficiently reacted with each other, and an aqueous coating composition having excellent curability can be obtained.

Examples of the compound (B) include polymerizable unsaturated monocarboxylic acid ester compounds of polyhydric alcohols (for example, ethylene glycol diacrylate, ethylene glycol dimethacrylate, triethylene glycol diacrylate, triethylene glycol dimethacrylate, Tetraethylene glycol diacrylate, tetraethylene glycol dimethacrylate, 1,3-butylene glycol diacrylate, 1,3-butylene glycol dimethacrylate, trimethylolpropane triacrylate, trimethylolpropane trimethacrylate, 1,4-butane Diol diacrylate, 1,4-butanediol dimethacrylate, neopentyl glycol diacrylate, neopentyl glycol dimethacrylate 1,6-hexanediol diacrylate, 1,6-hexanediol dimethacrylate, pentaerythritol diacrylate, pentaerythritol dimethacrylate, pentaerythritol triacrylate, pentaerythritol trimethacrylate, pentaerythritol tetraacrylate, pentaerythritol tetra Methacrylate, glycerol diacrylate, glycerol dimethacrylate, glycerol acoxydimethacrylate, 1,1,1-trishydroxymethylethane diacrylate, 1,1,1-trishydroxymethylethane dimethacrylate, 1,1, 1-trishydroxymethylethane triacrylate, 1,1,1-trishydroxymethylethane trimethacrylate, , 1,1-trishydroxymethylpropane diacrylate, 1,1,1-trishydroxymethylpropane dimethacrylate, etc.), epoxy group-containing ethylenically unsaturated monomer and carboxyl group-containing ethylenically unsaturated group monomer (For example, a reaction product of glycidyl acrylate or glycidyl methacrylate with acrylic acid, methacrylic acid, crotonic acid, maleic acid, etc.), a polymerizable unsaturated monocarboxylic amide compound of a polyvalent amine (for example, ethylenediamine Acrylate etc.). These may be used alone or in combination.

As described above, the compound (B) needs to be easily mixed with the polyamine resin (A) (both can react). Preferably, the polyamine resin (A) and the compound (B) are used in a non-uniform state as long as they can be easily mixed (both can react). More preferably, the compound (B) and the polyamine resin (A) are used in different phase states. In such a state, the rapid progress of the reaction between the polyamine resin (A) and the compound (B) can be suppressed, and the reactivity can be appropriately adjusted. When the coating composition is used as a two-pack type coating, an aqueous coating composition having excellent handleability can be obtained. As preferable examples of such a state, when the compound (B) is a water-soluble compound and the polyamine resin (A) is a water-dispersible resin, the compound (B) is self-emulsifying, and the compound ( A case where B) can be emulsified or dispersed by the polyamine resin (A) is mentioned. It should be noted that whether the compound (B) is “water-insoluble”, “water-soluble” or “self-emulsifying” is determined by adding 5 g of compound (B) to 100 g of water at room temperature. The state after stirring (for example, 3 minutes) and leaving still (for example, after 5 minutes) can be visually observed. After settling, it can be judged as “water-insoluble” if precipitation occurs, “water-soluble” if there is no precipitate and clear, and “self-emulsifying” if there is no precipitation and turbidity.

For example, when the compound (B) is modified with polyethylene oxide, it can be made water-soluble or self-emulsifiable compound by increasing the number of moles of ethylene oxide added to increase hydrophilicity.

Examples of the water-soluble compound (B) include ethoxylated bisphenol A diacrylate (EO 30 mol), ethoxylated trimethylolpropane triacrylate (EO 20 mol), ethoxylated trimethylolpropane triacrylate (EO 30 mol), and ethoxylated pentaerythritol tetra. Examples include acrylate (EO 35 mol), ethoxylated glycerin triacrylate (EO 20 mol), and ethoxylated bisphenol A dimethacrylate (EO 30 mol). These may be used alone or in combination. In the present specification, for example, “EO 30 mol” represents that 30 ethylene oxides are contained in the molecule.

Examples of the self-emulsifying compound (B) include polyethylene glycol # 400 diacrylate (EO 9 mol), polyethylene glycol # 600 diacrylate (EO 14 mol), polyethylene glycol # 1000 diacrylate (EO 23 mol), and ethoxylated bisphenol A diacrylate. (EO 10 mol), ethoxylated bisphenol A diacrylate (EO 20 mol), ethoxylated glycerin triacrylate (EO 9 mol), polyethylene glycol # 1000 dimethacrylate (EO 23 mol), and the like. These may be used alone or in combination.

Examples of the compound (B) that can be emulsified or dispersed by the polyamine resin (A) include polyethylene glycol # 200 glycol diacrylate (EO 4 mol), ethoxylated bisphenol A diacrylate (EO 3 mol), and ethoxylated bisphenol A diacrylate (EO 4 mol). ), Propoxylated bisphenol A diacrylate (PO 3 mol), 1,10-decanediol diacrylate, tricyclodecane dimethanol diacrylate, ethoxylated 2-methyl-1,3-propanediol diacrylate (EO 2 mol), neopentyl glycol Diacrylate, 1,6-hexanediol diacrylate, 1,9-nonanediol diacrylate, dipropylene glycol diacrylate (PO2 mol), tri Lopylene glycol diacrylate (PO3 mol), polypropylene glycol # 400 diacrylate (PO7 mol), polypropylene glycol # 700 diacrylate (PO12 mol), ethoxylated trimethylolpropane triacrylate (EO3 mol), ethoxylated trimethylolpropane triacrylate (EO9 mol), Trimethylolpropane triacrylate, propoxylated trimethylolpropane triacrylate (PO3 mol), pentaerythritol triacrylate, ethoxylated pentaerythritol tetraacrylate (EO4 mol), ditrimethylolpropane tetraacrylate, propoxylated pentaerythritol tetraacrylate (PO4 mol), propoxylated Bisphenol A di Acrylate (PO 4 mol), ethylene glycol dimethacrylate (EO 1 mol), diethylene glycol dimethacrylate (EO 2 mol), triethylene glycol dimethacrylate (EO 3 mol), tetraethylene glycol dimethacrylate (EO 4 mol), polyethylene glycol # 400 dimethacrylate (EO 9 mol), polyethylene glycol # 600 Dimethacrylate (EO 14 mol), 1,3-butanediol dimethacrylate, 1,4-butanediol dimethacrylate, 1,6-hexanediol dimethacrylate, 1,9-nonanediol dimethacrylate, ethoxylated bisphenol A dimethacrylate (EO 2.6 mol), ethoxylated bisphenol A dimethacrylate (EO 4 mol), Toxylated bisphenol A dimethacrylate (EO 6 mol), ethoxylated bisphenol A dimethacrylate (EO 10 mol), ethoxylated bisphenol A dimethacrylate (EO 17 mol), neopentyl glycol dimethacrylate, ethoxylated polypropylene glycol # 700 dimethacrylate (PO 12 mol, EO 6 mol), Examples include glycerin dimethacrylate, tripropylene glycol dimethacrylate (PO3 mol), polypropylene glycol # 400 dimethacrylate (PO7 mol), trimethylolpropane trimethacrylate, ethoxylated trimethylolpropane trimethacrylate (EO 9 mol), and the like. These may be used alone or in combination.

The compound (B) is preferably used as a mixture of a water-soluble compound and a water-insoluble compound. Thus, if a mixture of a water-soluble compound and a water-insoluble compound is used, the water-insoluble compound can be easily introduced into the reaction system by the water-soluble compound. Moreover, the coating material obtained is excellent in low-temperature curability. Examples of the water-soluble compound having one or more (meth) acryloyl groups in the molecule include the above-mentioned water-soluble compound (B). Examples of the water-insoluble compound having one or more (meth) acryloyl groups in the molecule include compounds that are not completely water-soluble, such as propoxylated bisphenol A diacrylate (PO4 mol). The mixing ratio (water-soluble / water-insoluble) of the water-soluble compound (B) and the water-insoluble compound (B) is preferably 1/9 to 9/1, more preferably 2/8 to 8 / 2.

In one embodiment, the compound (B) may be diluted with an organic solvent before the polyamine resin (A) and the compound (B) are mixed. Examples of the organic solvent include ethylene glycol monobutyether (BC) and diethylene glycol monobutyl ether (BDG). Thus, if the compound (B) is diluted with an organic solvent in advance, the polyamine resin (A) and the compound (B) can be mixed without using a special mixing device, and a coating composition having excellent dispersibility can be obtained. Obtainable. As a result, the polyamine resin (A) and the compound (B) can be efficiently reacted with each other.

In another embodiment, the compound (B) is an emulsion. That is, before mixing the polyamine resin (A) and the compound (B), an emulsifier may be mixed with the compound (B), and the compound (B) is emulsified or dispersed by a dispersant, an emulsifier or an aqueous resin. May be. Moreover, when the aqueous coating composition of the present invention is a two-component aqueous coating composition, the curing agent may further contain an emulsifier. By performing these treatments, the polyamine resin (A) and the compound (B) can be mixed without using a special mixing apparatus, and a coating composition having excellent dispersibility can be obtained. As a result, the polyamine resin (A) and the compound (B) can be efficiently reacted with each other. Moreover, if these processes are performed, a compound (B) can be handled as a non-dangerous substance. As said emulsifier, a nonionic emulsifier, an anionic emulsifier, etc. are used, for example. Examples of the nonionic emulsifier include polyoxyethylene alkylphenol ether, polyoxyethylene styrenated phenyl ether, polyoxyethylene alkyl ether, polyoxyethylene polyoxypropylene block polymer, sorbitan fatty acid ester and the like. Examples of the anionic emulsifier include dodecylbenzene sulfonate, dialkyl succinate sulfonate, polyoxyethylene alkyl ether sulfate, polyoxyethylene styrenated phenyl ether sulfate, alkyl diphenyl ether disulfonate, and the like. . Examples of the dispersant include polyacrylic acid sodium salt, ammonium salt of half ester of styrene maleic acid copolymer, and the like. As said aqueous resin, the soda salt of polyacrylic acid ester etc. are mentioned, for example.

In still another embodiment, the compound (B) may be dispersed in a dispersion of a resin different from the polyamine resin (A) before mixing the polyamine resin (A) and the compound (B). Good. Examples of the resin dispersion include an acrylic resin emulsion and dispersion, a urethane resin emulsion and dispersion, and the like. Thus, if compound (B) is previously dispersed in a resin dispersion, polyamine resin (A) and compound (B) can be mixed without using a special mixing apparatus, and the dispersibility is excellent. A coating composition can be obtained. As a result, the polyamine resin (A) and the compound (B) can be efficiently reacted with each other.

D. Application Method The water-based coating composition of the present invention can be applied to any appropriate article to be coated. Typically, it is the surface of iron.

Examples of the coating method of the aqueous coating composition of the present invention include brush coating, air spray, airless spray, roller coating, and the like.

The coating amount of the aqueous coating composition of the present invention can be set to any appropriate coating amount depending on the application. Generally, it is preferably 10 to 300 g / m ² .

Any appropriate drying method may be employed as a method for drying the aqueous coating composition of the present invention. Natural drying or heat drying is preferred. That is, the aqueous coating composition of the present invention may be used as a room temperature curable coating composition or a heat curable coating composition. In the case of natural drying, the drying time is preferably 24 hours or longer, more preferably 1 week or longer.

Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples. Unless otherwise specified, parts and% in the examples are based on weight. Moreover, the evaluation items in the examples are as follows.

(Coating state)
The glass plates obtained by coating and drying (24 hours) the coating materials obtained in Examples and Comparative Examples at 25 ° C. were visually evaluated for coating film gloss, transparency, coating film abnormalities such as unevenness and repellency.
Shiny ○: Highly glossy △: Semi-glossy ×: Non-glossy
Transparency ○: No or almost no turbidity
Δ: Somewhat turbid ×: Large turbidity
Abnormal coating film ○: No or almost no creaking / repelling △: Slightly stuffing / repelling ×: Thickness / repelling all over (curability)
The paints obtained in Examples and Comparative Examples were coated and dried (24 hours) on glass plates at 25 ° C. and 5 ° C. to obtain a coating film, and then the coating film was the same as that at the time of coating and drying, respectively. Then, the sample was rubbed with gauze containing methyl ethyl ketone (MEK), and the number of reciprocations until the glass substrate was exposed was measured. In addition, the notation of “> 200” in the table means that the glass substrate was not exposed even after 200 reciprocations. Moreover, the coating film whose reciprocation frequency until exposure is 100 times or more is acceptable.
(Anti-corrosion)
A test piece was obtained by applying the paint obtained in the example to a sandblast plate with a brush so as to be 200 g / m ² and drying at 20 ° C. for 7 days. The test piece was subjected to a cyclic corrosion test defined in JIS K 5600 7-7, and the coating state after 120 cycles was confirmed based on the following criteria.
Ratio of rust area generated in coating film on surface of test piece A: Less than 0.05% B: 0.05% or more and less than 0.1% B: 0.1% or more and less than 0.3% %more than

[Production Example 1] Production of polyamine resin (epoxy-based polyamine resin) 702 parts of epoxy resin having an epoxy equivalent of 188 synthesized from bisphenol A and epichlorohydrin in a reaction vessel equipped with a stirrer, a cooler, a nitrogen introduction tube and a thermometer 269 parts of bisphenol A, 108 parts of dimer acid and 190 parts of methyl isobutyl ketone (hereinafter referred to as “MIBK”) were added and reacted at 117 ° C. in the presence of 1 part of benzyldimethylamine until reaching an epoxy equivalent of 1270. Thereafter, 255 parts of a ketimine compound of aminoethylethanolamine (73 mass% MIBK solution) was added and reacted at 117 ° C. for 1 hour. Then, it diluted with MIBK until it became non-volatile content 75%, and the epoxy-type polyamine resin of number average molecular weight 2400 and amine equivalent 1184 was obtained.

[Production Example 2] Emulsification of epoxy-based polyamine resin Acetic acid is added to the epoxy-based polyamine resin obtained in Production Example 1 to obtain a neutralization rate of 20.0% (neutralization rate with respect to amine groups of the resin). Diluted by adding exchange water. Thereafter, the mixture of MIBK and water was removed under reduced pressure until the solid content became 40% by mass, whereby an emulsion I was prepared.

[Production Example 3] Production of polyamine resin (acrylic polyamine resin) Into a reaction vessel equipped with a stirrer, a cooler, a nitrogen introduction tube, a thermometer, and a dropping funnel, 670 parts of MIBK was charged and heated to 110 ° C. A solution consisting of 540 parts of styrene, 400 parts of n-butyl acrylate, 140 parts of glycidyl methacrylate, 100 parts of MIBK and 20 parts of t-butyl peroctoate was dropped into the reaction vessel over 3 hours using a dropping funnel. . After maintaining at 110 ° C. for 30 minutes after the completion of dropping, a solution consisting of 2 parts of t-butyl peroctoate and 50 parts of MIBK was added dropwise over 30 minutes. After the completion of this dropping, the reaction was continued for an additional hour at 110 ° C. to obtain an acrylic resin varnish containing an epoxy group and having a nonvolatile content of 60%. To 1,920 parts of the resulting varnish, 255 parts of an aminoethylethanolamine ketimine compound (73 mass% MIBK solution) was added and reacted at 117 ° C. for 1 hour to obtain an acrylic polyamine resin having a number average molecular weight of 10,000 and an amine equivalent of 1184. It was.

[Production Example 4] Emulsification of acrylic polyamine resin Acetic acid was added to the acrylic polyamine resin obtained in Production Example 3 to achieve a neutralization rate of 20.0% (neutralization rate relative to the amine group of the resin). Diluted by adding exchange water. Thereafter, the mixture of MIBK and water was removed under reduced pressure until the solid content became 40% by mass, thereby preparing Emulsion II.

[Production Example 5] Production of polyamine resin (epoxy-based polyamine resin) 742 parts of epoxy resin having an epoxy equivalent of 188 synthesized from bisphenol A and epichlorohydrin in a reaction vessel equipped with a stirrer, a cooler, a nitrogen introduction tube and a thermometer , 336 parts of bisphenol A and 190 parts of MIBK were charged and reacted at 117 ° C. in the presence of 1 part of benzyldimethylamine until an epoxy equivalent of 1270 was reached. Thereafter, 350 parts of a diethylenetriamine ketimine compound (73% by mass MIBK solution) was added and reacted at 117 ° C. for 1 hour. Thereafter, 27 parts of ion-exchanged water and 188 parts of neodecanoic acid glycidyl ester (Cardura E10-P) were charged and reacted at 100 ° C. for 2 hours. Then, it diluted with MIBK until it became non-volatile content 75%, and the epoxy type polyamine resin of number average molecular weight 2600 and amine equivalent 947 was obtained.

[Production Example 6] Emulsification of epoxy-based polyamine resin Acetic acid is added to the epoxy-based polyamine resin obtained in Production Example 5 so that the neutralization rate is 20.0% (neutralization rate with respect to the cationic group of the resin). Ion exchange water was added for dilution. Thereafter, the mixture of MIBK and water was removed under reduced pressure until the solid content became 40% by mass, thereby preparing Emulsion III.

[Example 1]
118 parts of dipropylene glycol n-butyl ether (DPnB) was added to 2960 parts of the emulsion I obtained in Production Example 2 as a polyamine resin (A) while stirring with a disper, and then the compound (B ), 392 parts of ethoxylated trimethylolpropane triacrylate (EO 20 mol) (trade name “AT-20E” manufactured by Shin-Nakamura Chemical Co., Ltd.) was added and stirred for 10 minutes to obtain a clear paint. The obtained paint was applied to a glass plate with a 6 mil applicator in an environment of 25 ° C. and 5 ° C., and dried for 24 hours in the same environment as that used for coating to obtain a coating film. Then, the coating film state and curability of the obtained coating film were evaluated. The results are shown in Table 2.

[Examples 2 to 10]
Except having replaced the compound (B) with 392 parts of ethoxylated trimethylolpropane triacrylate (EO 20 mol) in the same manner as in Example 1 except that the compound (B) shown in Table 1 was used in the content shown in Table 2, A coating film was obtained. Then, the coating film state and curability of the obtained coating film were evaluated. The results are shown in Table 2.

[Example 11]
A coating film was obtained in the same manner as in Example 10 except that the emulsion I obtained in Production Example 4 was used instead of the emulsion I in the polyamine resin (A). Then, the coating film state and curability of the obtained coating film were evaluated. The results are shown in Table 2.

[Example 12]
159 parts of ion-exchanged water and 16 parts of New Coal 740 (manufactured by Nippon Emulsifier Co., Ltd., nonionic emulsifier) were stirred with a disper and dissolved uniformly to prepare an aqueous emulsifier solution. Thereafter, 143 parts of ethoxylated trimethylolpropane triacrylate (EO 3 mol) as compound (B) was added, and the mixture was stirred and dispersed roughly for 10 minutes with a disper. Further, the mixture was dispersed with an ultrasonic homogenizer until the average particle size became 350 nm to obtain an emulsion of the compound (B).
After 118 parts of dipropylene glycol n-butyl ether (DPnB) was added to 2367 parts of the emulsion III obtained in Production Example 6 as a polyamine resin (A) while stirring with a disper, the mixture was further obtained while stirring with a disper. 318 parts of the resulting compound (B) emulsion (content of compound (B) 143 parts) was added and stirred for 10 minutes to obtain a clear coating. About the obtained coating material, it carried out similarly to Example 1, and obtained the coating film. Then, the coating film state and curability of the obtained coating film were evaluated. The results are shown in Table 2.

[Example 13]
100 parts of tap water, 34 parts of DISPERBYK-190 (pig dispersant manufactured by Big Chemie), 2 parts of BYK-019 (antifoaming agent produced by Big Chemie), 170 parts of calcium carbonate, 185 parts of titanium oxide, 2 parts of calcium-based anticorrosive pigment The pigment dispersion composition consisting of was dispersed with a disper for 30 minutes. Subsequently, 450 parts of the emulsion I obtained in Production Example 2 as polyamine resin (A), 18 parts of DPnB, and 10 parts of Adecanol UH-420 (Adeka Co., Ltd. associative thickener) were added and mixed to obtain a base coating liquid. Further, while stirring with a disper, 41 parts of propoxylated bisphenol A diacrylate (PO4 mol) as compound (B) dissolved in 41 parts of DPnB was added and stirred for 10 minutes to obtain an enamel paint. The obtained paint was applied to a glass plate with a 6 mil applicator in an environment of 25 ° C. and 5 ° C., and dried for 24 hours in the same environment as that used for coating to obtain a coating film. Then, the coating film state of the obtained coating film, sclerosis | hardenability, and corrosion resistance were evaluated. The results are shown in Table 3.

[Example 14]
Instead of 41 parts of propoxylated bisphenol A diacrylate (PO 4 mol), 33 parts of ethoxylated glycerin triacrylate (EO 9 mol) (trade name “A-GLY-9E”, compound (B) No. 6) manufactured by Shin-Nakamura Chemical Co., Ltd.) A coating film was obtained in the same manner as in Example 13 except that it was used. Then, the coating film state of the obtained coating film, sclerosis | hardenability, and corrosion resistance were evaluated. The results are shown in Table 3.

[Example 15]
A coating film was obtained in the same manner as in Example 13 except that 450 parts of emulsion II obtained in Production Example 4 was used in place of 450 parts of emulsion I obtained in Production Example 2 as the polyamine resin (A). Then, the coating film state of the obtained coating film, sclerosis | hardenability, and corrosion resistance were evaluated. The results are shown in Table 3.

Instead of 450 parts of the emulsion I obtained in Production Example 2 as the polyamine resin (A), 450 parts of the emulsion III obtained in Production Example 6 was used, and as the compound (B), propoxylated bisphenol A diacrylate (PO4 mol) ) In the same manner as in Example 13, except that 41 parts of DPnB was dissolved in 41 parts of DPnB, and 61 parts of an emulsion of ethoxylated trimethylolpropane triacrylate (EO 3 mol) produced in Example 12 was used. A coating film was obtained. Then, the coating film state of the obtained coating film, sclerosis | hardenability, and corrosion resistance were evaluated. The results are shown in Table 3.

[Comparative Example 1]
A coating film was obtained in the same manner as in Example 1 except that the compound (B) was not used. Then, the coating film state and curability of the obtained coating film were evaluated. The results are shown in Table 4.

[Comparative Example 2]
In the same manner as in Example 1, except that 2100 parts of urethane acrylate having a molecular weight of 4200, a viscosity of 30,000 mPa · s, and a functional group number of 2 (UA-W2 manufactured by Shin-Nakamura Chemical Co., Ltd.) was used in place of the compound (B). A coating film was obtained. Then, the coating film state and curability of the obtained coating film were evaluated. The results are shown in Table 4.

[Comparative Example 3]
A coating film was obtained in the same manner as in Example 1 except that 94 parts of dipentaerythritol hexaacrylate having a molecular weight of 562, a viscosity of 6600 mPa · s, and a functional group number of 6 was used instead of the compound (B). Then, the coating film state and curability of the obtained coating film were evaluated. The results are shown in Table 4.

[Comparative Example 4]
The same as Example 1 except that 255 parts of a bisphenol type epoxy resin (Lipoxy VR-77 manufactured by Showa Polymer Co., Ltd.) having a molecular weight of 510, a viscosity of 100,000 mPa · s, and an acryloyl group number of 2 was used in place of the compound (B). Thus, a coating film was obtained. Then, the coating film state and curability of the obtained coating film were evaluated. The results are shown in Table 4.

[Comparative Example 5]
1000 parts of Adeka Resin EM-101-50 (Adeka water-based epoxy resin emulsion; epoxy equivalent 1000, solid content 50%) and 50 parts of DPnB were mixed to obtain a main coating liquid.
Next, 200 parts of sunmide WH-900 (Modified aliphatic polyamine manufactured by Air Products, non-volatile content 60%, amine value 220) as a curing agent was added to the main coating liquid and mixed by stirring with a disper. The obtained paint was applied to a glass plate with a 6 mil applicator in an environment of 25 ° C. and 5 ° C., and dried for 24 hours in the same environment as that used for coating to obtain a coating film. When the curability of the obtained coating film was evaluated, the curability at 25 ° C. was good (MEK resistance> 200 times), and it was not cured at 5 ° C. (dissolved easily in MEK).

As is clear from Tables 2 and 3, according to the aqueous coating composition of the present invention, sufficient curability at a low temperature, which was not obtained with the conventional aqueous coating (Comparative Example 5), can be obtained.

Further, as is clear from the results of Examples 13, 14, and 16 (Table 3), when an epoxy polyamine resin is used as the polyamine resin, a coating film exhibiting excellent anticorrosive properties in addition to low-temperature curability can be obtained. An aqueous coating composition can be obtained.

The water-based paint composition of the present invention can be suitably used as a rust preventive, sealer, primer, etc. for bridges, exteriors of buildings, floors, building materials, etc. as construction paints and heavy duty anti-corrosion paints.

Claims

A water-soluble or water-dispersible polyamine resin (A) having one or more primary amine groups and / or secondary amine groups in the molecule;
A compound (B) having one or more (meth) acryloyl groups in the molecule,
The amine equivalent of the polyamine resin (A) is 100 to 3000,
The viscosity of the compound (B) at 25 ° C. is 3000 mPa · s or less.
Water-based paint composition.
The aqueous coating composition is a two-component aqueous coating composition;
The water-based coating composition of Claim 1 in which a main ingredient coating liquid contains the said polyamine resin (A), and a hardening | curing agent contains the said compound (B).
The water-based coating composition according to claim 1 or 2, wherein the polyamine resin (A) is an acrylic polyamine resin or an epoxy polyamine resin.
The water-based coating composition according to any one of claims 1 to 3, wherein the molecular weight of the compound (B) is 150 or more and 2000 or less.
The water-based coating composition according to any one of claims 1 to 4, wherein the compound (B) is a water-soluble compound and the polyamine resin (A) is a water-dispersed resin.
The aqueous coating composition according to any one of claims 1 to 4, wherein the compound (B) is a self-emulsifying compound.
The aqueous coating composition according to any one of claims 1 to 4, wherein the compound (B) is emulsified or dispersed by the polyamine resin (A).
The aqueous coating composition according to any one of claims 1 to 4, wherein the compound (B) is a mixture of a water-soluble compound and a water-insoluble compound.
The aqueous coating composition according to any one of claims 1 to 4, wherein the compound (B) is an emulsion.
The water-based coating composition in any one of Claim 2 to 4 in which the said hardening | curing agent further contains an emulsifier.