JP3519483B2 - Aqueous paint composition - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a composition for water-based paints, and in particular, it is useful as a paint composition for metals, and forms a coating film excellent as a paint for organic composite coated steel sheets, PCM steel sheets, can inner surfaces and the like. The present invention relates to a self-emulsifying water-based coating composition that can be used.

[0002]

2. Description of the Related Art Solvent-based paints using an organic solvent as a solvent have recently been restricted in use because of problems of resource saving, energy saving and environmental protection caused by the use of the organic solvent. Therefore, it is desired to shift to a coating material using an aqueous solvent. In particular, in can paints and the like for coating metal surfaces, the shift from solvent-based paints to paints that use an aqueous solvent has been studied centering on epoxy resin-based paints, and various methods have been proposed for making epoxy resins water-soluble. There is. For example, in JP-A-53-1228, a radical polymerization initiator such as benzoyl peroxide is used to graft-copolymerize an acrylic monomer containing a carboxyl group-containing monomer in the presence of an epoxy resin to obtain an epoxy resin There is disclosed a method of graft-copolymerizing at an aliphatic site and dispersing the obtained polymer in water using a basic compound such as ammonia and amine.

However, in the above method, in order to obtain a polymer that forms a highly safe emulsion, it is necessary to use a polymer having a high graft ratio, and at the time of production, it is expensive and has a high risk of explosion such as benzoyl peroxide. There is a drawback in that a large amount of radical polymerization initiator must be used.

As a method for solving this drawback, Japanese Unexamined Patent Publication No. Sho.
In JP-A No. 5-3481 and JP-A No. 55-3482, an esterification reaction of a carboxyl group-containing vinyl polymer with an epoxy group of an epoxy resin is carried out in the presence of an amine-based catalyst, and an epoxy resin is substantially used. A method of obtaining a carboxyl group-containing vinyl polymer-modified epoxy resin having no group, neutralizing this with a base, and dispersing it in water is disclosed.

[0005]

However, in the modified epoxy resin prepared by the method disclosed in JP-A-55-3481, the epoxy group of the epoxy resin as the main skeleton is substantially completely consumed. Since it has been subjected to the esterification reaction up to this point, it is inevitable that the resin becomes a high molecular weight or highly crosslinked resin. In particular, a can coating material is required to have flexibility to withstand processing as well as hardness of a coating film, but a resin coating material having a high molecular weight or highly crosslinked has poor flexibility of the coating film and has a problem in processability. is there.

Further, when these compositions are used for a paint for the inner surface of a can, a low molecular weight compound derived from the main component epoxy resin or acrylic resin is eluted into the contents of the can, which causes a problem in food hygiene. Was. Furthermore, in order to prevent the elution of such low molecular weight compounds, it is necessary to completely cure the coating film, and therefore it is necessary to perform baking at a high temperature, which requires a large amount of energy for baking and the baking speed. However, there is a problem that it becomes slow and causes a decrease in productivity.

On the other hand, urethane resin, acrylic resin, polyester resin, etc. have been studied for the transition of organic composite-coated steel sheet paint, which is the same kind of metal surface anti-corrosion paint as can paint, and PCM steel sheet paint to a paint using an aqueous solvent, Studies on epoxy resins have not been well reported. For example, JP-A-5-301070 describes an example in which an epoxy resin is used in an emulsion. However, in the technique disclosed in Japanese Patent Application Laid-Open No. 5-301070, the epoxy resin is used as a curing agent, and cannot serve as a so-called main binder.

Also, in the technique described in JP-A-6-145559, an epoxy resin is used, but this is also a conventional epoxy emulsion in which a low molecular weight epoxy resin is forcibly emulsified with an emulsifier. In addition, the epoxy resin is not used as a main binder because it does not exceed the range of additives and modifiers, which is about 10% of the composition ratio of epoxy to all resins.

Therefore, an object of the present invention is to provide a metal coating composition which is excellent in stability over time, can cure a coating film at a low temperature, has excellent adhesion to a metal substrate, and is excellent in corrosion resistance. An object of the present invention is to provide an aqueous coating composition for use.

[0010]

DISCLOSURE OF THE INVENTION The inventors of the present invention recognized the above-mentioned drawbacks of the prior art, and further conducted extensive research to find a composition that serves as a main binder. Based on this finding, the present invention has been completed based on the finding that it can be used as an aqueous paint having excellent stability over time, a coating film that can be cured at low temperature, and various physical properties.

That is, the present invention relates to an aromatic epoxy resin (A-1), a copolymerizable unsaturated compound (B) containing a monovalent carboxyl group, and an acrylic resin (C containing a carboxyl group). ) Is chemically bonded to the copolymerizable unsaturated compound (E) containing a glycidyl group to obtain a reaction product (F), and this reaction product (F) Water formed by neutralizing a mixture (H) of a carboxylic acid with an aromatic epoxy resin (A-2) and / or an aromatic polyol resin (G) with a basic compound (I) and self-emulsifying in water. in dispersible composition, neutralized mixture (H) the reaction product in the (F), and aromatic epoxy resin (a-2), an aromatic polyol resin (G) and / or copolymer Water-based coating obtained by emulsion polymerization of a water-saturated compound (J) There is provided a use composition.

In a first aspect of the present invention, an aromatic epoxy resin (A-1), a copolymerizable unsaturated compound (B) containing a monovalent carboxyl group, and a carboxyl group are contained. The reaction product (D) with the acrylic resin (C) is chemically bonded to the copolymerizable unsaturated compound (E) containing a glycidyl group to obtain a reaction product (F),
Further, water formed by neutralizing the mixture (H-1) of the reaction product (F) and the aromatic epoxy resin (A-2) with the basic compound (I) and self-emulsifying in water. In the dispersible composition, the reaction product (F) and the aromatic epoxy resin (A-2) in the neutralized mixture (H-1)
The present invention provides a composition for water-based coatings, which is obtained by emulsion polymerization of and.

In a second aspect of the present invention, an aromatic epoxy resin (A-1), a copolymerizable unsaturated compound (B) containing a monovalent carboxyl group, and a carboxyl group are contained. The reaction product (D) with the acrylic resin (C) is chemically bonded to the copolymerizable unsaturated compound (E) containing a glycidyl group to obtain a reaction product (F),
Furthermore, the mixture (H-2) of the reaction product (F) with the aromatic epoxy resin (A-2) and the aromatic polyol resin (G) is neutralized with the basic compound (I). Reaction product (F) in the neutralized mixture (H-2) in a water-dispersible composition formed by self-emulsification in water
A water-based coating composition obtained by emulsion-polymerizing an aromatic epoxy resin (A-2) and an aromatic polyol resin (G).

In a third aspect of the present invention, an aromatic epoxy resin (A-1), a copolymerizable unsaturated compound (B) containing a monovalent carboxyl group, and a carboxyl group are contained. The reaction product (D) with the acrylic resin (C) is chemically bonded to the copolymerizable unsaturated compound (E) containing a glycidyl group to obtain a reaction product (F),
Further, water formed by neutralizing the mixture (H-1) of the reaction product (F) and the aromatic epoxy resin (A-2) with the basic compound (I) and self-emulsifying in water. In the dispersible composition, the reaction product (F) in the neutralized mixture (H-1) and the aromatic epoxy resin (A-
The present invention provides an aqueous coating composition obtained by emulsion polymerization of 2) and a copolymerizable unsaturated compound (J).

Furthermore, in a fourth aspect of the present invention, an aromatic epoxy resin (A-1), a copolymerizable unsaturated compound (B) containing a monovalent carboxyl group, and a carboxyl group are contained. The reaction product (D) with the acrylic resin (C) is chemically bonded to the copolymerizable unsaturated compound (E) containing a glycidyl group to obtain a reaction product (F),
Furthermore, the mixture (H-2) of the reaction product (F) with the aromatic epoxy resin (A-2) and the aromatic polyol resin (G) is neutralized with the basic compound (I). Reaction product (F) in the neutralized mixture (H-2) in a water-dispersible composition formed by self-emulsification in water
And an aromatic epoxy resin (A-2) and an aromatic polyol resin (G), and a copolymerizable unsaturated compound (J) are emulsion-polymerized to provide a composition for an aqueous coating composition. Is.

Hereinafter, the composition for aqueous paint of the present invention (hereinafter, referred to as
"The composition of the present invention" will be described in detail.

In the preparation of the composition of the present invention, the aromatic epoxy resin (A
-1) and the aromatic epoxy resin (A-2) mixed with the reaction product (F) of the latter stage are particularly limited as long as they have a structural unit derived from an aromatic hydrocarbon in the resin skeleton. Not done. The aromatic epoxy resin (A-1) and the aromatic epoxy resin (A-2) may be the same or different. Specific examples of the aromatic epoxy resins (A-1) and (A-2) include bisphenol A type epoxy resin, bisphenol AD type epoxy resin, bisphenol F type epoxy resin and novolac type epoxy resin.

The aromatic epoxy resins (A-1) and (A-2) usually have an average of 1.1 to 2.
It has 0 epoxy groups and a number average molecular weight of 700 or more,
It is preferably 1400 or more.

When the aromatic epoxy resin (A-1) or (A-2) used in the composition of the present invention has a large molecular weight, phenols, particularly bisphenol, are used. A is useful . Against the concentration of the hydroxyl group of bi Sufeno <br/> Lumpur A, the use of the excess amount of the raw material epoxy resin having an epoxy group at an end, and a molecular weight of greater aromatic epoxy resin (A-1) or (A-
2) can be obtained.

The copolymerizable unsaturated compound (B) containing a monovalent carboxyl group used in the composition of the present invention is a monovalent monomer having a carboxyl group and a copolymerizable unsaturated group as a structural unit in its molecular skeleton. There is no particular limitation as long as it is a carboxylic acid, and for example, α, β-unsaturated carboxylic acid such as acrylic acid, methacrylic acid, or ethylacrylic acid, or a conjugated double bond such as dehydrated castor oil fatty acid or linseed oil fatty acid is used. The fatty acid which it has, etc. are mentioned. These may be used alone or in combination of two or more. Among these, acrylic acid and Metakururi acid, has high copolymerizability, in that it is advantageous when you Keru emulsion and graft polymerizing the subsequent process, preferably.

The carboxyl group-containing acrylic resin (C) used in the composition of the present invention has a carboxylic acid structural unit in the resin skeleton and is obtained by polymerizing at least one copolymerizable monomer. For example, the group consisting of (i) carboxyl group-containing vinyl monomer, (ii) aromatic vinyl monomer, and (iii) alkyl ester, hydroxyalkyl ester and N-hydroxyalkylamide of α, β-ethylenically unsaturated carboxylic acid. At least one monomer selected from the group consisting of these monomers or a mixture thereof such that the resulting polymer has a carboxyl group, and radicals such as azobisisobutyronitrile and benzoyl peroxide in an organic solvent. Polymerize or copolymerize at a temperature of 60 ° C to 160 ° C using a polymerization initiator. It can be obtained by

Examples of the (i) carboxyl group-containing vinyl monomer include acrylic acid, methacrylic acid, crotonic acid, itaconic acid, maleic acid and fumaric acid.

(Ii) As the aromatic vinyl monomer,
Examples thereof include styrene-based monomers such as styrene, vinyltoluene, 2-methylstyrene, t-butylstyrene, and chlorostyrene.

(Iii) Examples of the alkyl ester of α, β-ethylenically unsaturated carboxylic acid include methyl acrylate, ethyl acrylate, isopropyl acrylate, n-butyl acrylate, isobutyl acrylate and n-acrylic acid. Amyl, isoamyl acrylate, n-acrylic acid
Acrylic esters such as hexyl, 2-ethylhexyl acrylate, n-octyl acrylate, decyl acrylate, dodecyl acrylate; methyl methacrylate, propyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, n-methacrylate. Examples thereof include amines, isoamyl methacrylate, n-hexyl methacrylate, 2-ethylhexyl methacrylate, n-octyl methacrylate, decyl methacrylate, dodecyl methacrylate, and other methacrylate esters.

Examples of the hydroxyalkyl ester of α, β-ethylenically unsaturated carboxylic acid include hydroxyalkyl acrylate monomers such as hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxyethyl methacrylate and hydroxypropyl methacrylate. Is mentioned.

Further, examples of the N-hydroxyalkylamide of α, β-ethylenically unsaturated carboxylic acid include N-substituted (meth) amides such as N-methylol (meth) acrylamide and N-butoxymethyl (meth) acrylamide. Examples include acrylic monomers.

The content of the (i) carboxyl group-containing vinyl monomer in the acrylic resin (C) containing a carboxyl group is within a suitable range because the viscosity of the acrylic resin (C) at the time of production is in the appropriate range. From the viewpoint of ease, it is preferably 25 to 75% by weight, more preferably 30 to 6%.
It is 0% by weight. Further, when the content of the (i) carboxyl group-containing vinyl monomer in the carboxyl group-containing acrylic resin (C) is within this range, the dispersion stability in an aqueous medium is excellent, and the solvent resistance after coating is excellent. A water-based paint that can obtain a coating film having excellent corrosion resistance, which has excellent flavor resistance when coated on the inner surface of a can and has excellent water resistance, especially when used on an organic composite coated steel sheet. It is preferred because it gives a composition.

The carboxyl group-containing acrylic resin (C) does not gel during the reaction between the aromatic epoxy resin (A-1) and the monovalent carboxyl group-containing copolymerizable unsaturated compound (B). The number average molecular weight is from 300 to 600 in that it does not occur and a coating film having an appropriate crosslink density and excellent processability can be obtained by coating the composition of the present invention.
00, preferably in the range of 400 to 20000. The acid value of the acrylic resin (C) is 25 to 450 (KOHmg / g) in terms of solid content, preferably 20.
0 to 350 (KOHmg / g).

In the present invention, a reaction product of an aromatic epoxy resin (A-1), a monovalent carboxyl group-containing copolymerizable unsaturated compound (B), and a carboxyl group-containing acrylic resin (C). (D) is, for example, in the presence or absence of a catalyst of ammonia or amines, an aromatic epoxy resin (A-1), a monovalent carboxyl group-containing copolymerizable unsaturated compound (B), The equivalent ratio of the carboxyl group-containing acrylic resin (C) is 0.2 <(B) /
(A-1) <0.8, solid content weight ratio 0.5 <(A-
1) / (C) <5, the reaction temperature is 70 ° C. to 160 ° C.
It can be obtained by reacting at 0 ° C, preferably 100 ° C to 140 ° C.

In the production of this reaction product (D), examples of the ammonia or amines used as a catalyst include alkylamines such as ethylamine, butylamine, diethylamine, trimethylamine, triethylamine and butylamine; 2-dimethylaminoethanol, Alcohol amines such as diethanolamine, triethanolamine, aminomethyl propanol and dimethylaminomethyl propanol; morpholine; and polyamines such as ethylenediamine and diethylenetriamine. When this ammonia or amines is used as a catalyst, the amount thereof is usually the aromatic epoxy resin (A-1), the monovalent carboxyl group-containing copolymerizable unsaturated compound (B), and the carboxyl group. In the reaction with the group-containing acrylic resin (C), it is 0.1 with respect to the amount of the residual carboxyl group when the carboxyl group and the epoxy group present in the reaction mixture theoretically react with each other.
~ 1.0 times the amount, preferably 0.5 ~
The amount is about 0.95 times.

In the preparation of the composition of the present invention, the aromatic epoxy resin (A-1), the monovalent carboxyl group-containing copolymerizable unsaturated compound (B), and the carboxyl group-containing acrylic resin are used. The reaction product (D) with (C)
Further, the reaction product (F) is prepared by chemically bonding to the copolymerizable unsaturated compound (E) containing a glycidyl group. This reaction product (F) is prepared, for example, by adding the reaction product (D) and the copolymerizable unsaturated compound (E) containing a glycidyl group in the presence or absence of ammonia or amines. Below, 1 mol% of the content of the carboxyl group in the reaction product (D) <molar amount of (E) <
It can be obtained by reacting at a reaction temperature of 70 ° C to 160 ° C, preferably 100 ° C to 140 ° C so that the content of the carboxyl group in (D) is in the range of 50 mol%.

The copolymerizable unsaturated compound (E) containing a glycidyl group is, for example, a methacrylic acid glycidyl ester, an acrylic acid glycidyl ester, or a dibasic base such as tetrahydrophthalic acid diglycidyl ester or maleic acid diglycidyl ester. Examples thereof include glycidyl ester of acid. Since Among these, the highly copolymerizable unsaturated group of the double bonds, and the like remaining after the reaction, it is advantageous in the emulsion and graft polymerization in the subsequent step,
Methacrylic acid glycidyl ester and acrylic acid glycidyl ester are preferred.

In the preparation of the reaction product (F), examples of the ammonia or amines used as a catalyst include the same ones used in the preparation of the reaction product (D). When the reaction product (D) is prepared in the presence of ammonia or amines as a catalyst, the ammonia or amines used in the preparation of the reaction product (D) can be directly used as a catalyst. . When the reaction product (D) is prepared in the absence of ammonia or amines as a catalyst and ammonia or amines is used as a catalyst when preparing the reaction product (F), the amount used Is the same amount as that used when the reaction product (D) was prepared.

Next, in the present invention, an aqueous coating composition can be obtained according to the following methods (1) to (3). Reaction product (F) and aromatic epoxy resin (A-
In a water-dispersible composition formed by neutralizing the mixture (H-1) with 2) with the basic compound (I) and self-emulsifying in water, in the neutralized mixture (H-1). The reaction product (F) and the aromatic epoxy resin (A-2) are emulsion polymerized. Reaction product (F) and aromatic epoxy resin (A-
2) and a mixture (H-2) with an aromatic polyol resin (G) are neutralized with a basic compound (I) and self-emulsified in water to form a water-dispersible composition, The reaction product (F), the aromatic epoxy resin (A-2) and the aromatic polyol resin (G) in the neutralized mixture (H-2) are emulsion polymerized. Reaction product (F) and aromatic epoxy resin (A-
In a water-dispersible composition formed by neutralizing the mixture (H-1) with 2) with the basic compound (I) and self-emulsifying in water, in the neutralized mixture (H-1). The reaction product (F), the aromatic epoxy resin (A-2), and the copolymerizable unsaturated compound (J) are emulsion-polymerized. Reaction product (F) and aromatic epoxy resin (A-
2) and a mixture (H-2) with an aromatic polyol resin (G) are neutralized with a basic compound (I) and self-emulsified in water to form a water-dispersible composition, The reaction product (F) in the neutralized mixture (H-2), the aromatic epoxy resin (A-2) and the aromatic polyolefin.
The resin (G) and the copolymerizable unsaturated compound (J) are emulsion-polymerized. In the emulsion polymerization carried out in the final stage of the production of the composition of the present invention, the unsaturated group in the reaction product (F) and / or the unsaturated group of the copolymerizable unsaturated compound (J) added Any one or more of the vinyl polymerization and the graft polymerization starting from the reaction initiation point generated by hydrogen abstraction from the aliphatic part of each resin in the reaction system.

The composition of the present invention may be prepared by any of the above-mentioned methods (1) to (5) without any particular limitation. In particular, among these methods, the methods (1) and (2) are preferable in that emulsification can be easily performed because the increase in viscosity until reaching the phase inversion point is small when self-emulsifying in water.

The aromatic polyol resin (G) used in the above-mentioned methods (1) and (2) contains a primary hydroxyl group in the resin skeleton and contains substantially no epoxy group. It is obtained by modifying an epoxy group with a sealant. The aromatic epoxy resin as a raw material is not particularly limited as long as it has a structural unit derived from aromatic hydrocarbon in the resin skeleton. Examples thereof include bisphenol A type epoxy resin, bisphenol AD type epoxy resin, bisphenol F type epoxy resin, and novolac type epoxy resin. This aromatic epoxy resin usually has an average of 1.1 to 2.0 epoxy groups in one molecule and a number average molecular weight of 700 or more, preferably 1400 or more.

The sealant used for modifying the epoxy group of the aromatic epoxy resin is, for example, phenols, carboxylic acids, primary amines, secondary amines,
Those having a reactive hydrogen atom such as mercaptans, alcohols and water, or those having no reactive hydrogen atom such as an alkyl halide, a Grignard reagent and a nucleophile such as an alkyllithium can be used.

Examples of the mercaptans include methyl mercaptan, ethyl mercaptan, propyl mercaptan, isopropyl mercaptan, n-butyl mercaptan, acrylic mercaptan, benzyl mercaptan and the like. Examples of alcohols include methyl alcohol, ethyl alcohol, n-propyl alcohol, n-butyl alcohol, n-pentyl alcohol,
Examples thereof include benzyl alcohol, methyl cellosolve, ethyl cellosolve, propyl cellosolve, and methyl carbitol. Examples of the alkyl halides include methyl chloride, ethyl chloride, propyl chloride, methyl bromide, ethyl bromide and the like. Examples of the Grignard reagent include methyl magnesium bromide, ethyl magnesium bromide, propyl magnesium bromide, and henzyl magnesium bromide. Examples of the alkyl lithium and the like include methyl lithium, ethyl lithium, propyl lithium, n-butyl lithium and the like.

Examples of phenols used as the sealing agent include bisphenol A, alkyl monophenol, resorcinol and the like.

The carboxylic acids include, for example, benzoic acid, palmitic acid, lauric acid, myristic acid, stearic acid, etc., castor oil fatty acid, soybean oil fatty acid, and carboxylic acid.
Monocarboxylic acid compounds such as animal oil and plant oil fatty acids such as oleic oil fatty acid, flaxseed oil fatty acid, cottonseed oil fatty acid, glutaric acid, maleic acid, adipic acid, succinic acid, trimellitic acid, pyromellitic acid, glyco-acrylic acid, tartaric acid, etc. Examples thereof include polycarboxylic acid compounds.

Examples of primary amines or secondary amines include hydroxylamines such as ethanolamine and diethanolamine, and alkylamines such as propylamine, ethylamine, dipropylamine and diethylamine. .

When it is necessary to increase the molecular weight of the aromatic epoxy resin, phenols,
Bisphenol A is particularly effective. By using an excess amount of bisphenol A with respect to the concentration of the epoxy group of the aromatic epoxy resin as the raw material, the molecular weight can be increased and the epoxy group of the aromatic epoxy resin can be sealed. Further, when it is not necessary to increase the molecular weight, it is effective to use a monocarboxylic acid compound and primary and secondary amines as the sealing agent because the reactivity with the epoxy group is high.

In the preparation of the aromatic polyol resin (G), the sealing agent for modifying the epoxy group of the aromatic epoxy resin may be only one kind or a combination of two or more kinds. May be.

The sealing agent has an aromatic polyol resin (G) having a number average molecular weight of 350 to 40,000, an epoxy group having an average of 0 to 0.4, and a primary hydroxyl group. It is used in an amount of 0.01 to 1.0 on average in one molecule. When the amount of epoxy groups in the aromatic polyol resin (G) is in this range, destabilization of the aqueous dispersion and deterioration of the coating film due to the ring-opening reaction of the epoxy groups can be prevented, which is more preferable. When the primary hydroxyl group in the aromatic polyol resin (G) is within this range, generation of a microgel body having a network structure due to an excessive esterification reaction can be suppressed, which is more preferable.

In the present invention, the weight of the reaction product (F), the aromatic epoxy resin (A-2), and the aromatic polyol resin (G) in the mixture (H-1) or (H-2). The ratio is adjusted to be in the range shown by the following formula. (F) + (G) + (A-2) = 100 0 <(G) + (A-2) ≦ 80 0 <(A-2) ≦ 80 Preferably, 1 ≦ (G) + (A-2 ) ≦ 80 1 ≦ (A-2) ≦ 80 More preferably, 30 ≦ (G) + (A-2) ≦ 70 20 ≦ (A-2) ≦ 70, and (G) is preferably , 0 ≦ (G) ≦ 5
0 is more preferable, and 0 ≦ (G) ≦ 40.

In preparing the mixture (H-1) or (H-2), the aromatic epoxy resin (A-2) and / or the aromatic polyol resin (G) is used as a reaction product (F).
The addition amount of the acrylic resin (C) containing a carboxyl group in the preparation of the reaction product (D) can be reduced, and the content of the acrylic resin (C) in the composition of the present invention can be reduced. The free carboxyl groups after the curing reaction of the coating film formed by applying the composition of the present invention are reduced, and the gel fraction is increased. Therefore, the coating film physical properties such as water resistance, chemical resistance, and adhesion are improved, which is preferable.

In the preparation of the composition of the present invention, the mixture (H-1) and (H-2) are the reaction product (F), the aromatic epoxy resin (A-2) and // Alternatively, it is prepared by mixing with an aromatic polyol resin (G), further neutralized with a basic compound (I) and self-emulsified in water to form an emulsion. The mixing of the reaction product (F) with the aromatic epoxy resin (A-2) and / or the aromatic polyol resin (G) is not particularly limited, and for example, in a batch reactor, a turbine blade is used. , A ribbon blade, a paddle blade, a propeller blade and the like can be used for stirring and mixing.

Neutralization with the basic compound (I)
The excess carboxyl groups present in mixture (H-1) or (H-2) are carried out as ammonium or amine salts using ammonia or amines as basic compound (I). This neutralization preferably involves adding ammonia or amines in an amount such that the aqueous coating composition of the present invention has a pH of 5-11.

Examples of the amines used as the basic compound (I) include ethylamine, butylamine,
Alkylamines such as diethylamine, trimethylamine, triethylamine, butylamine; alcohol amines such as 2-dimethylaminoethanol, diethanolamine, triethanolamine, aminomethylpropanol, dimethylaminomethylpropanol; morpholine; polyvalent ethylenediamine, diethylenetriamine, etc. Examples include amines.

Further, the mixture (H-1) or (H-
The emulsification of 2) can be carried out in a conventional apparatus according to a method such as stirring while dropping water or warm water at an optimum temperature of the phase inversion point, usually in the range of 50 to 90 ° C.
Alternatively, a commercially available emulsifier capable of high stirring may be used.

In the present invention, the emulsion comprising the mixture (H-1) or (H-2) is subjected to emulsion polymerization and graft polymerization in the presence or absence of the copolymerizable unsaturated compound (J). To be In this emulsion polymerization and graft polymerization, the reaction product (F) in the mixture (H-1) or (H-2) and the aromatic epoxy resin (A- 2 )
And the aromatic polyol resin (G) and / or the copolymerizable unsaturated compound (J) undergo a polymerization reaction to obtain an aqueous coating composition.

The copolymerizable unsaturated compound (J) used in the present invention is not particularly limited as long as it has a copolymerizable unsaturated group as a structural unit in its molecular skeleton, and examples thereof include a carboxyl group-containing vinyl monomer. , Aromatic vinyl monomer, alkyl ester of α, β-ethylenically unsaturated carboxylic acid, hydroxyalkyl ester of α, β-ethylenically unsaturated carboxylic acid, N-hydroxy of α, β-ethylenically unsaturated carboxylic acid Examples thereof include alkylamides.

Specific examples of the carboxyl group-containing vinyl monomer include acrylic acid, methacrylic acid, crotonic acid,
Examples thereof include itaconic acid, maleic acid and fumaric acid. Specific examples of the aromatic vinyl monomer include styrene, vinyltoluene, 2-methylstyrene, t-butylstyrene, chlorostyrene and the like.

Specific examples of the alkyl ester of α, β-ethylenically unsaturated carboxylic acid include methyl acrylate,
Ethyl acrylate, isopropyl acrylate, n-butyl acrylate, isobutyl acrylate, n-acrylate
Amyl, isoamyl acrylate, n-hexyl acrylate, 2-ethylhexyl acrylate, n-octyl acrylate, decyl acrylate, dodecyl acrylate, glycidyl acrylate, and other acrylate esters, methyl methacrylate, propyl methacrylate, Methacrylic acid n-
Methacrylic acid esters such as butyl, isobutyl methacrylate, n-amine methacrylate, isoamyl methacrylate, n-hexyl methacrylate, 2-ethylhexyl methacrylate, n-octyl methacrylate, decyl methacrylate, dodecyl methacrylate, glycidyl methacrylate. And the like.

Specific examples of the hydroxyalkyl ester of α, β-ethylenically unsaturated carboxylic acid include hydroxyethyl acrylate, hydroxypropyl acrylate,
Hydroxyl alkyl ester monomers such as hydroxyethyl methacrylate and hydroxypropyl methacrylate are mentioned. Specific examples of the N-hydroxyalkylamide of α, β-ethylenically unsaturated carboxylic acid include N-
Examples thereof include N-substituted (meth) acrylic monomers such as methylol (meth) acrylamide and N-butoxymethyl (meth) acrylamide.

In preparing the aqueous coating composition of the present invention,
When the copolymerizable unsaturated compound (J) is used, these copolymerizable unsaturated compounds (J) may be used alone or in combination of two or more. Among these, a water-based coating composition that reacts with a carboxyl group neutralized during curing to form a coating film having excellent coating properties such as water resistance, gel fraction, and adhesion by increasing the crosslink density is obtained. In terms of
Copolymerizable unsaturated compounds containing a glycidyl group such as glycidyl methacrylate and glycidyl acrylate are preferred. Also, hydroxyethyl methacrylate, by using the copolymerizable unsaturated compound containing a hydroxy group such as hydroxyethyl acrylate, the substrate and topcoat composition at the time of forming a coating film for the increase of the hydrogen bond component There is an advantage that the adhesion is improved.

When the copolymerization unsaturated compound (J) is used in the emulsion polymerization, the mixture (H-1) or (H-
0.1% by weight of the solid weight of 2) ≦ 30% by weight of (J) ≦ (H) solid content, more preferably 0.1% by weight of solid content of (H) ≦ (J) ≦ (H) It is advisable to add an amount of 15% by weight of the solid content. The emulsion polymerization can be carried out at a temperature of 120 ° C. or lower using a conventionally known initiator.

The composition of the present invention is used as an aqueous paint by adding and dispersing an aqueous medium. Here, the aqueous medium means water alone in which at least 10% by weight or more is water, or a mixture of water and a hydrophilic organic solvent. As the hydrophilic organic solvent, for example, methanol, ethanol,
Alkyl alcohols such as isopropanol, n-butanol, sec-butanol, tert-butanol, and isobutanol, ether alcohols such as methyl cellosolve, ethyl cellosolve, propyl cellosolve, butyl cellosolve, methyl carbitol and ethyl carbitol, methyl cellosolve acetate, Ether esters such as ethyl cellosolve acetate and others, dioxane, dimethylformamide, diacetone alcohol and the like are used.

In the composition of the present invention, the mixing ratio of the neutralized mixture [(H-1) or (H-2)] / water is
Usually, it is about 25/75, and depending on the purpose of use, conditions of use, etc., the mixture may be appropriately mixed by reducing the amount of the aqueous medium used by emulsification and then distilling under reduced pressure, or by increasing the amount by additional addition. The proportion can be adjusted.
For example, the neutralized mixture [(H-1) or (H-
2)] / The ratio of the aqueous medium is preferably 5/95 to 70 /, in order to obtain an aqueous coating composition having good stability.
30 and more preferably 20/80 to 50/50.

The aqueous coating composition of the present invention can be used as an aqueous coating by adding a pigment. The pigment used is not particularly limited, and various known pigments can be used. Further, the composition of the present invention, as long as not impairing the above properties as an aqueous coating, if necessary, for example, hexamethoxymethylmelamine, methylolated benzoguanamine resin, aqueous aminoplast resin such as methylolated urea resin. , And a curing agent such as a phenol resin, or a surfactant for improving the coating property, an antifoaming agent and the like can be added.

The object to be coated on which the composition of the present invention is applied to form a coating film is not particularly limited. In particular, the composition of the present invention is suitable as a paint for forming a cured coating film by coating a treated steel plate such as an untreated steel plate, a zinc-nickel plated steel plate, a zinc iron plate, and a tin plate. The coating method is not particularly limited, and for example, any method such as spray coating such as air spray, airless spray, electrostatic spray, dip coating, roll coater coating, and electrodeposition coating is possible. The baking condition for forming the cured coating film is preferably 10 ° C.
It can be selected from the range of 0 ° C to 240 ° C and the time of 10 seconds to 30 minutes.

[0062]

EXAMPLES The present invention will be described below with reference to Examples and Comparative Examples. In addition, "part" and "%" in a sentence show "weight part" and "weight%", respectively. Throughout the examples and comparative examples, the paints or paint plates were evaluated according to the following methods, unless otherwise specified. The results are shown in Table 1.

(Evaluation of Painted Plates) (1) Evaluation of Corrosion Resistance Painted Plates The aqueous paint compositions obtained in Examples or Comparative Examples were treated with a water paste of SiO ₂ having a solid content of 13%. A solid content weight ratio of 85:15 is added and mixed, and water is further added and mixed to prepare a varnish having a solid content of 10%. Using a No. 5 bar coater, this varnish was applied onto a 0.8 mm thick zinc-nickel plated steel plate or a nickel plated steel plate, and baked and hardened at 150 ° C. for 20 seconds to give a thickness of about 1 to 1. A coated plate with a cured coating of 2 μm is produced. Evaluation-1 A part of this coated plate was immersed in an aqueous sodium hydroxide solution having a pH of 12 at 45 ° C for 2.5 minutes, and then 5% saline solution was further sprayed at 35 ° C on Table 1 for a continuous period of time to prepare salt water. Perform a spray test and evaluate according to the following criteria. No abnormalities ……………… ◎ Slightly corroded… ○ Significantly corroded ・ ・ ・ △ Totally corroded …… × Evaluation-2 A part of this coated plate with pH 12 After immersing in a sodium hydroxide aqueous solution at 45 ° C. for 2.5 minutes, it is washed with ion-exchanged water, and further immersed in a pH 3 phosphoric acid aqueous solution at 40 ° C. for 2 minutes. Next, after washing with ion-exchanged water, 170 ℃ × 2
After drying for 0 minutes, 5% saline solution at 35 ° C. is continuously sprayed in Table 1 for an hour to perform a salt spray test, and the following criteria are evaluated. No abnormalities ……………… ◎◎ Slightly corroded… ○ Significantly corroded …… △ Whole corroded …… ×

(2) Evaluation of Adhesion Production of Painted Plate Water is added to the aqueous coating composition obtained in Examples or Comparative Examples to prepare a solid content of 10%. Using a No. 5 bar coater, apply a thickness of 0.8
It is applied on a galvanized steel sheet of mm and heated at 100 ° C. for 20 seconds to be baked and cured to produce a coated plate having a cured coating film having a thickness of about 1 to 2 μm. Further, a melamine alkyd resin was applied onto the cured coating film using a No. 60 bar coater and baked and cured at 130 ° C. for 20 minutes to give a coating film having a thickness of about 35 to 40 μm. And Evaluation-1 (Cross-cut test) Eleven cuts were made in the length and width of the coating plate of the painted plate with a knife to a width of about 1 mm to form 100 cross-cuts. Next, a 24 mm wide cellophane adhesive tape
After adhering to the surface of the coating film, the cellophane adhesive tape was strongly peeled off, with 100 being the denominator, and the number of unpeeled squares is the numerator, which is shown as an index of adhesion. Evaluation-2 After immersing a part of the coated plate in boiling water for 2 hours, the cross-cut test and blister conditions of Evaluation-1 were evaluated.

(Example 1) -Preparation of carboxyl group-containing acrylic resin (C) solution-A four-necked flask purged with nitrogen gas was charged with 500 parts of ethylene glycol monobutyl ether, and 150-1 was used.
Styrene 123 while heating to 60 ° C and maintaining that temperature
Parts, 70 parts of ethyl acrylate, 307 parts of methacrylic acid,
A homogeneous solution in which 5.5 parts of dicumylpa-oxide was mixed was gradually put into a four-necked flask for 2 hours. After completion of the appropriate temperature, the mixture was stirred for 6 hours while maintaining the temperature, and then 250 parts of ethylene glycol monobutyl ether was added and dissolved. Next, when the reaction mixture was cooled to room temperature, the acid value (100% of resin) 278 KOHmg / 1
A carboxyl group-containing acrylic resin solution having a solid content of 40% was obtained. The produced carboxyl group-containing acrylic resin had a weight average molecular weight of about 5,000 and a carboxylic acid unit of 43%.

-Preparation of Aromatic Polyol Resin (G) Solution- 1000 parts of bisphenol A type epoxy resin (number average molecular weight: about 3200, epoxy equivalent: about 2700 g / eq) was placed in a four-necked flask substituted with nitrogen gas. Xylene 2
Charge 00 parts, gradually heat to raise the internal temperature to 120 ° C, stir for 1 hour to completely dissolve it, and then 150 ° C.
Heated slowly until. After the internal temperature reached 150 ° C., 38.9 parts of diethanolamine was appropriately added over 1 hour, and the reaction was further performed for 6 hours. Next, 492.6 parts of ethylene glycol monobutyl ether was added to and dissolved in the reaction mixture, and then cooled to room temperature. As a result, an epoxy polyol having an epoxy equivalent of 30,000 g / eq or more and a solid content of 60% was used. A solution of The number average molecular weight of the produced aromatic polyol resin was 3,300, and the average number of epoxy groups in one molecule was 0.1 or less.

[0067] - made adjustment of the aqueous coating composition - necked flask was replaced with nitrogen gas, the number average molecular weight of about 3700 and an epoxy equivalent weight of about 2700 bisphenol - 300 parts Le A type epoxy resins, methacrylic acid 4. 8
Parts, 375 parts of the carboxyl group-containing acrylic resin solution (solid content 40%) obtained above, and 225 parts of ethylene glycol monobutyl ether are gradually heated to raise the internal temperature to 120 ° C. and stirred for 1 hour. After completely dissolving, the mixture was gradually heated to 130 ° C. After the internal temperature reached 130 ° C, dimethylaminoethanol 5
6.4 parts were added. Furthermore, after reacting at 130 ° C. for 3 hours, 17.6 parts of glycidyl methacrylate was added and reacted at 130 ° C. for 3 hours. The acid value (converted to 100% of resin) of the reaction mixture at this time was measured to be 65.
It was KOHmg / 1g. Next, the number average molecular weight is about 3
700 and bisphenol having an epoxy equivalent of about 2700
350 parts of A-type epoxy resin, 500 parts of the aromatic polyol resin solution (solid content 40%) obtained above, and 117 parts of ethylene glycol monobutyl ether are added, and the mixture is completely stirred by maintaining the temperature for 1 hour. After letting
233 parts of n-butyl alcohol was added and cooled to 100 ° C. After maintaining this state for 3 hours, 2933 parts of ion-exchanged water was gradually added and emulsified using a disperser. At this time, a milky white dispersion liquid having a solid content of 20% was obtained. Next, 5100 parts of this dispersion was heated to 95 ° C., 0.6 part of azobisisobutyronitrile was added,
The temperature was maintained and the reaction was carried out for 6 hours. Then, the solvent ethylene glycol monobutyl ether and n-butyl alcohol were distilled off from the reaction mixture under reduced pressure, and the total amount of the solvent was 5%.
Ion-exchanged water was added every time the solid content exceeded 40%, and the mixture was evaporated under reduced pressure to prepare an aqueous coating composition. The resulting aqueous coating composition had a solid content of 28% and a viscosity of 2
The content was 5 cps and the solvent content was 3% or less. Further, this aqueous coating composition was stored at room temperature for 3 months, but no abnormality was observed.

[0068] (Example 2) - made adjustment of the aqueous coating composition - necked flask was replaced with nitrogen gas, the number average molecular weight of about 3700 and an epoxy equivalent of about 2700 bisphenol - Le A type epoxy resin 300 parts , Methacrylic acid 4.8
Parts, 375 parts of the carboxyl group-containing acrylic resin solution (solid content 40%) obtained above, and 225 parts of ethylene glycol monobutyl ether are gradually heated to raise the internal temperature to 120 ° C. and stirred for 1 hour. Completely dissolved, and then gradually heated to 130 ° C. After the internal temperature reached 130 ° C., 56.4 parts of dimethylaminoethanol was added. Furthermore, after reacting at 130 ° C. for 3 hours, 35.2 parts of glycidyl methacrylate ester was added and reacted at 130 ° C. for 3 hours. At this time, the acid value (converted to 100% of the resin) of the reaction mixture was 49 KOHmg / 1g. Next, 550 parts of a bisphenol A type epoxy resin having a number average molecular weight of about 3700 and an epoxy equivalent of about 2700 and 417 parts of ethylene glycol monobutyl ether were added and completely stirred by maintaining the temperature for 1 hour. Then, 233 parts of n-butyl alcohol was added and cooled to 100 ° C. Furthermore, after maintaining this state for 3 hours, ion-exchanged water 293
Emulsification was performed using a disperser while gradually adding 3 parts.
At this time, a milky white dispersion liquid having a solid content of 20% was obtained.
Next, 5100 parts of this dispersion was heated to 95 ° C., 1.0 part of azobisisobutyronitrile was added, and the reaction was carried out for 6 hours while maintaining the temperature. Then, from the reaction mixture, under reduced pressure, the solvent ethylene glycol monobutyl ether and n-
Butyl alcohol was distilled off, and ion-exchanged water was added every time the solid content exceeded 40% to distill under reduced pressure until the total amount of the solvent became 5% or less, to prepare an aqueous coating composition. The resulting water-based coating composition had a solid content of 28% and a viscosity of 500 cp.
and the solvent content was 3% or less. Further, this aqueous coating composition was stored at room temperature for 1 month, but no abnormality was observed.

[0069] (Example 3) - made adjustment of the aqueous coating composition - necked flask was replaced with nitrogen gas, the number average molecular weight of about 3700 and an epoxy equivalent of about 2700 bisphenol - Le A type epoxy resin 500 parts , Methacrylic acid 8.0
Parts, 500 parts of the carboxyl group-containing acrylic resin solution (solid content 40%) obtained above, and 400 parts of ethylene glycol monobutyl ether were charged and gradually heated to raise the internal temperature to 120 ° C. and stirred for 1 hour. Completely dissolved, and then gradually heated to 130 ° C. After the internal temperature reached 130 ° C., 80 parts of dimethylaminoethanol was added. Furthermore, after reacting at 130 ° C. for 3 hours, 17.6 parts of glycidyl methacrylate was added and reacted at 130 ° C. for 3 hours. At this time, the acid value (converted to 100% of resin) of the reaction mixture was 38.
It was KOHmg / 1g. Next, the number average molecular weight is about 3
700 and bisphenol having an epoxy equivalent of about 2700
300 parts of A-type epoxy resin and 100 parts of ethylene glycol monobutyl ether were added, and the mixture was stirred for 1 hour while maintaining the temperature to completely dissolve it. Then, 328 parts of n-butyl alcohol was added and cooled to 100 ° C. . further,
After maintaining this state for 3 hours, 2933 parts of ion-exchanged water was gradually added and emulsified using a disperser. At this time, a milky white dispersion liquid having a solid content of 20% was obtained. Next, 5100 parts of this dispersion was heated to 95 ° C., 0.7 part of azobisisobutyronitrile was added, and the reaction was carried out for 6 hours while maintaining the temperature. Then, the solvent ethylene glycol monobutyl ether and n-butyl alcohol were distilled off under reduced pressure, and the solid content was adjusted to 40% until the total amount of the solvent became 5% or less.
Ion-exchanged water is added every time the concentration exceeds%, and vacuum distillation is performed.
An aqueous coating composition was prepared. The resulting aqueous coating composition had a solid content of 21%, a viscosity of 760 cps and a solvent content of 5% or less. Further, this aqueous coating composition was stored at room temperature for 3 months, but no abnormality was observed.

[0070] (Example 4) - made adjustment of the aqueous coating composition - necked flask was replaced with nitrogen gas, the number average molecular weight of about 3700, and an epoxy equivalent of about 2700 bisphenol - Le A type epoxy resin 500 Parts, methacrylic acid 8.
0 parts, 500 parts of the carboxyl group-containing acrylic resin solution (solid content 40%) obtained above, and 400 parts of ethylene glycol monobutyl ether were charged and gradually heated to raise the internal temperature to 120 ° C. and stirred for 1 hour. After completely dissolving, the mixture was gradually heated to 130 ° C. After the internal temperature reached 130 ° C., 80 parts of dimethylaminoethanol was added. Furthermore, after reacting at 130 ° C. for 3 hours, 17.6 parts of glycidyl methacrylate was added and reacted at 130 ° C. for 3 hours. At this time, the acid value (converted to 100% of resin) of the reaction mixture was 38.
It was KOHmg / 1g. Next, the number average molecular weight is about 3
700, and 300 parts of a bisphenol A type epoxy resin having an epoxy equivalent of about 2700, and 100 parts of ethylene glycol monobutyl ether were added, and the mixture was stirred for 1 hour while maintaining the temperature to completely dissolve it, and then n-butyl alcohol- 328 parts were added and the mixture was cooled to 100 ° C. Furthermore, after maintaining this state for 3 hours, ion-exchanged water 293
Emulsification was performed using a disperser while gradually adding 3 parts.
At this time, a milky white dispersion liquid having a solid content of 20% was obtained.
Next, 5100 parts of this dispersion was heated to 95 ° C., 0.7 parts of azobisisobutyronitrile and 7.0 parts of glycidyl methacrylate were added, and the mixture was reacted for 6 hours while maintaining the temperature. Then, the solvent ethylene glycol monobutyl ether and n-butyl alcohol were distilled off under reduced pressure, and ion-exchanged water was added every time the solid content exceeded 40% until the total amount of the solvent became 8% or less. Then, an aqueous coating composition was prepared. The obtained aqueous coating composition had a solid content of 21%, a viscosity of 3900 cps, and a solvent content of 7% or less. In addition, this water-based coating composition, at room temperature
It was stored for a month, but no abnormalities were observed.

[0071] (Comparative Example 1) - made adjustment of the aqueous coating composition - necked flask was replaced with nitrogen gas, the number average molecular weight of about 3700, and an epoxy equivalent of about 2700 bisphenol - Le A type epoxy resin 500 Parts, methacrylic acid 8.
0 parts, 500 parts of the carboxyl group-containing acrylic resin solution (solid content 40%) obtained above, and 400 parts of ethylene glycol monobutyl ether were charged and gradually heated to raise the internal temperature to 120 ° C. and stirred for 1 hour. After completely dissolving, the mixture was gradually heated to 130 ° C.
After the internal temperature reached 130 ° C, dimethylaminoethanol
80 parts was added. Furthermore, after reacting at 130 ° C. for 3 hours, a bisphenol A type epoxy resin 30 having a number average molecular weight of about 3700 and an epoxy equivalent of about 2700.
0 parts and 100 parts of ethylene glycol monobutyl ether were added, and the mixture was stirred for 1 hour while maintaining the temperature to completely dissolve it. Then, 328 parts of n-butyl alcohol was added and cooled to 100 ° C. After maintaining this state for 3 hours, 2933 parts of ion-exchanged water was gradually added and emulsified using a disperser. At this time, a milky white dispersion having a solid content of 20% was obtained. Then, the solvent ethylene glycol monobutyl ether and n-butyl alcohol were distilled off under reduced pressure, and ion-exchanged water was added every time the solid content exceeded 40% until the total amount of the solvent became 8% or less. Then, an aqueous coating composition was obtained. The obtained aqueous coating composition had a solid content of 29%, a viscosity of 1010 cps, and a solvent content of 7%.
It was: Further, this aqueous coating composition was stored at room temperature for 3 months, but no abnormality was observed.

[0072] (Comparative Example 2) - made adjustment of the aqueous coating composition - necked flask was replaced with nitrogen gas, the number average molecular weight of about 3700, and an epoxy equivalent of about 2700 bisphenol - Le A type epoxy resin 300 Parts, methacrylic acid 4.
Charge 8 parts, 375 parts of the carboxyl group-containing acrylic resin solution (solid content 40%) obtained above, and 225 parts of ethylene glycol monobutyl ether, gradually heat to raise the internal temperature to 120 ° C., and stir for 1 hour. After completely dissolving, the mixture was gradually heated to 130 ° C.
After the internal temperature reached 130 ° C, dimethylaminoethanol
56.4 parts. Furthermore, after reacting at 130 ° C. for 3 hours, 350 parts of a bisphenol A type epoxy resin having a number average molecular weight of about 3700 and an epoxy equivalent of about 2700, the aromatic polyol resin solution obtained above (solid content 40 %) And 117 parts of ethylene glycol monobutyl ether were added, and the mixture was stirred for 1 hour while maintaining the temperature to completely dissolve it, and then 233 parts of n-butyl alcohol was added and cooled to 100 ° C. further,
After maintaining this state for 3 hours, 2933 parts of ion-exchanged water was gradually added and emulsified using a disperser. At this time, a milky white dispersion liquid having a solid content of 20% was obtained. Then, the solvent ethylene glycol monobutyl ether and n-butyl alcohol were distilled off under reduced pressure, and the total amount of the solvent was 5%.
Each time the solid content exceeded 40%, ion-exchanged water was added and the mixture was distilled off under reduced pressure to prepare an aqueous coating composition. The obtained aqueous coating composition had a solid content of 30% and a viscosity of 5
The content was 0 cps and the solvent content was 4% or less. Further, this aqueous coating composition was stored at room temperature for 3 months, but no abnormality was observed.

[0073]

[Table 1]

[0074]

The water-based coating composition of the present invention has excellent stability over time, can be cured at a low temperature, and can be applied to a metal substrate to obtain a cured coating film having excellent adhesion and corrosion resistance. You can Therefore, the aqueous coating composition of the present invention is suitable as a main component of an aqueous coating for metals.

Continuation of the front page (56) Reference JP-A-6-240202 (JP, A) JP-A-2-229820 (JP, A) JP-A-59-51909 (JP, A) JP-A-60-110765 (JP , A) JP-A-4-285636 (JP, A) JP-A-3-500785 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) C09D 5/00-201/10

Claims (11)

(57) [Claims] 1. A reaction between an aromatic epoxy resin (A-1), a copolymerizable unsaturated compound (B) containing a monovalent carboxyl group, and an acrylic resin (C) containing a carboxyl group. The product (D) is chemically bonded to the copolymerizable unsaturated compound (E) containing a glycidyl group to obtain a reaction product (F), and the reaction product (F) and an aromatic system A water-dispersible composition formed by neutralizing a mixture (H) with an epoxy resin (A-2) and / or an aromatic polyol resin (G) with a basic compound (I) and self-emulsifying in water. And the reaction product (F) in the neutralized mixture (H) and the aromatic epoxy resin (A-
A water-based coating composition obtained by emulsion-polymerizing 2) with an aromatic polyol resin (G) and / or a copolymerizable unsaturated compound (J). 2. A reaction between an aromatic epoxy resin (A-1), a copolymerizable unsaturated compound (B) containing a monovalent carboxyl group, and an acrylic resin (C) containing a carboxyl group. The product (D) is chemically bonded to the copolymerizable unsaturated compound (E) containing a glycidyl group to obtain a reaction product (F), and the reaction product (F) and an aromatic system Mixture (H-1) with epoxy resin (A-2)
Is neutralized with a basic compound (I) and self-emulsified in water to form a water-dispersible composition, wherein the reaction product (F) and the aromatic compound in the neutralized mixture (H-1) A water-based coating composition obtained by emulsion polymerization of a base epoxy resin (A-2). 3. A reaction between an aromatic epoxy resin (A-1), a copolymerizable unsaturated compound (B) containing a monovalent carboxyl group, and an acrylic resin (C) containing a carboxyl group. The product (D) is chemically bonded to the copolymerizable unsaturated compound (E) containing a glycidyl group to obtain a reaction product (F), and the reaction product (F) and an aromatic system Water dispersibility formed by neutralizing a mixture (H-2) of an epoxy resin (A-2) and an aromatic polyol resin (G) with a basic compound (I) and self-emulsifying in water. In the composition, the reaction product (F) and the aromatic epoxy resin (A-2) in the neutralized mixture (H-2)
And an aqueous paint composition obtained by emulsion-polymerizing an aromatic polyol resin (G). 4. A reaction between an aromatic epoxy resin (A-1), a copolymerizable unsaturated compound (B) containing a monovalent carboxyl group, and an acrylic resin (C) containing a carboxyl group. The product (D) is chemically bonded to the copolymerizable unsaturated compound (E) containing a glycidyl group to obtain a reaction product (F), and the reaction product (F) and an aromatic system Mixture (H-1) with epoxy resin (A-2)
Is neutralized with a basic compound (I) and self-emulsified in water to form a water-dispersible composition, and the reaction product (F) in the neutralized mixture (H-1) and an aroma A water-based coating composition obtained by emulsion-polymerizing a group-based epoxy resin (A-2) and a copolymerizable unsaturated compound (J). 5. A reaction between an aromatic epoxy resin (A-1), a copolymerizable unsaturated compound (B) containing a monovalent carboxyl group, and an acrylic resin (C) containing a carboxyl group. The product (D) is chemically bonded to the copolymerizable unsaturated compound (E) containing a glycidyl group to obtain a reaction product (F), and the reaction product (F) and an aromatic system Water dispersibility formed by neutralizing a mixture (H-2) of an epoxy resin (A-2) and an aromatic polyol resin (G) with a basic compound (I) and self-emulsifying in water. In the composition, the reaction product (F) in the neutralized mixture (H-2) and the aromatic epoxy resin (A-
2) A water-based coating composition obtained by emulsion-polymerizing the aromatic polyol resin (G) and the copolymerizable unsaturated compound (J). 6. The aromatic epoxy resins (A-1) and (A-2) have an average of 1.1 to 2.0 epoxy groups in one molecule and a number average molecular weight of 700. It is above, The composition for water-based paints in any one of Claims 1-5. 7. A copolymerizable unsaturated compound (B) containing a monovalent carboxyl group is added to an aromatic epoxy resin (A).
The aqueous coating composition according to any one of claims 1 to 5, which is used in a proportion of 0.1 to 0.9 mol% of the epoxy group contained in -1). 8. The carboxyl group-containing acrylic resin (C) has a number average molecular weight of 300 to 60000, contains 25% by weight or more of a carboxylic acid unit, and has an acid value of 25.
~ 450 (KOHmg / g) is the one.
The composition for water-based paints according to any one of to 5. 9. The glycidyl group-containing copolymerizable unsaturated compound (E) is used in a proportion of 1 to 50 mol% of the carboxyl groups in the reaction product (D). The composition for aqueous paints according to Crab. 10. The aromatic polyol resin (G) comprises:
The number-average molecular weight of 350 to 40,000, having an average of 0.01 to 4.0 primary hydroxyl groups in one molecule and containing substantially no epoxy groups, the aqueous solution according to claim 3 or 5. Paint composition. 11. The aromatic epoxy resin (A-1).
And (A-2), a carboxyl group-containing acrylic resin (C), a reaction product (F), and an aromatic polyol resin (G) satisfy the following formulas (1) to (4). The water-based coating composition according to any one of claims 1 to 5, wherein the composition is included in a solid conversion weight ratio.