JPH0892500A - Aqueous coating composition - Google Patents

Abstract

PURPOSE: To improve the dispersion stability of the principal component to thereby obtain a water-base coating composition which is excellent in foam controlling ability and antifoaming properties, can form a defect-free film and has a high safety by incorporating a specified dithiocarboxylic acid ester into the principal component of the composition. CONSTITUTION: This composition is obtained by using a principal component having a compound of the formula incorporated therein. In the formula, R<1> and R<2> are each a 1-4C alkyl; and R<3> and R<4> are each a 10-20C alkyl. The compound of the formula is incorporated in an amount of preferably 0.01-10wt.%, still preferably 0.1-0.5wt.% from the viewpoint of the antifoaming effect, based on the solids of the principal component. When it is added in an amount less than 0.01wt.%, the antifoaming effect will be insufficient and, when in an amount more than 10wt.%, a film reduced in strength will be formed, thus are both undesirable. A representative example of the principal component of the water-base coating material is the one composed mainly of an epoxy resin from the viewpoints of film strength, durability and stability.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water-based coating composition, and more particularly to a water-based coating composition suitable for coating the inner surface of a metal can and having excellent foam suppression and defoaming properties.

[0002]

2. Description of the Related Art Conventionally, in the field of paints, in order to avoid problems caused by the use of a solvent, a shift to water-based paints has been studied in various applications.
In particular, paints used for the inner surface coating of metal cans for foods and beverages are desired to shift to water-based paints from the viewpoint of resource saving, energy saving, low pollution, and safety.
As the main component of the water-based paint, an epoxy resin is mainly studied from the viewpoint of the properties of the coating, as in the case of the solvent-based paint, and various techniques for suitably dispersing the epoxy resin in water have been proposed. Among these techniques, the method of dispersing an epoxy resin using a surfactant is not suitable for practical use because the surfactant used tends to deteriorate the epoxy resin or deteriorate the dispersion stability over time. .

In order to solve this drawback, it has been attempted to obtain an epoxy resin having a self-emulsifying property by modifying the epoxy resin. Typical examples of these are JP-A-55-75460 and 57-10.
No. 5418, No. 53-1228, etc. are mentioned, For example, the carboxyl group in the carboxyl group-containing acrylic resin copolymerized with the monomer containing acrylic acid, methacrylic acid, and the aromatic epoxy resin Examples thereof include a method of partially esterifying an epoxy group to introduce a carboxyl group into the epoxy resin, and neutralizing the carboxyl group with a base to make the epoxy resin aqueous. In all of the above techniques, a segment having an emulsifying power is introduced into an epoxy resin by the action of acrylic acid or methacrylic acid. It has also been proposed to produce an aqueous resin dispersion in which an epoxy resin is dispersed by forcibly dispersing an unmodified epoxy resin by utilizing the surface active action of an acrylic resin, and to use it in a paint.

However, these water-based paints have a high thixotropic property, so that there is a possibility that the coating film may be defective depending on the coating method.

If a coating method by spray coating, which is a closed system, is used as a coating method for these water-based paints, a coating film having a certain degree of uniformity can be formed, but it can be easily coated on a large number of metal plates at low cost. When the roll coating of the system is used, the water-based paint is agitated by the roll, and since the water-based paint is purely involved, air is entrained, a large amount of bubbles are generated, and film defects caused by the bubbles are generated. There was a problem. This becomes a big problem especially in the inner coating of the can that encloses foods and the like. That is, when a film defect occurs, the food comes into direct contact with the metal surface of the can, which may cause deterioration or deterioration of the food, which may cause safety and hygiene problems. In order to prevent this, it is also considered to add an antifoaming agent, but among the known antifoaming agents, the effective one is a silicone type, but there is a problem of safety and a coating film defect is caused by cissing. Therefore, it cannot be used for the inner coating of food cans that come into direct contact with food.

[0006]

The present invention has been made in view of the above-mentioned drawbacks, and an object of the present invention is to improve the dispersion stability of a water-based paint main agent such as an epoxy resin and to suppress foaming, An object of the present invention is to provide a water-based coating composition which is excellent in defoaming property, can form a film without defects, and is suitable for an inner surface coating of a can which is highly safe and can be used for foods and the like.

[0007]

The water-based coating composition according to claim 1 of the present invention comprises the following main formula (I)
It is characterized in that a compound represented by

[0008]

[Chemical 2]

(In the formula, R ¹ and R ² are each a carbon number of 1 to 4
Represents an alkyl group and may be the same as or different from each other. R ³ and R ⁴ represent an alkyl group having 10 to 20 carbon atoms and may be the same or different. ) The aqueous coating composition according to claim 2 of the present invention is the aqueous coating composition according to claim 1, wherein the compound represented by the general formula (I) is added to the solid content of the main component of the aqueous coating composition. 0.
It is characterized by being blended in an amount of 01 to 10% by weight.

An aqueous coating composition according to claim 3 of the present invention is the aqueous coating composition according to claim 1 or 2, wherein the main component of the aqueous coating material contains an epoxy resin.

Next, the present invention will be described in more detail. The compound represented by the following general formula (I) of the present invention comprises a thiodicarboxylic acid represented by the following general formula (II) and a carbon number of 10 to 2
Esters with aliphatic alcohols having 0.

[0012]

[Chemical 3]

(In the formula, R ¹ and R ² have 1 to 4 carbon atoms.
Represents an alkyl group and may be the same as or different from each other. R ³ and R ⁴ represent an alkyl group having 10 to 20 carbon atoms and may be the same or different. )

[0014]

[Chemical 4]

(In the formula, R ¹ and R ² have the same meanings as in formula (I).) Here, R ¹ and R ² represent an alkyl group having 1 to 4 carbon atoms, and a methyl group. , Ethyl group and propyl group are preferred. R ³ and R ⁴ represent an alkyl group having 10 to 20 carbon atoms, and have 12 to 1 carbon atoms.
The alkyl group of 8 is preferable, and from the viewpoint of defoaming property,
It is preferably a lauryl group, a stearyl group, a myristyl group, or a cetyl group. In addition, R ¹ and R ² , R ³ and R
Compounds having the same ⁴ are preferable from the viewpoint of easy production.

Specific examples include the compounds represented by the following formulas, but the compound of the present invention is not limited thereto.

[0017]

[Chemical 5]

Of these, a particularly preferable one is
Examples include (1) dilauryl thiodipropionate and (2) distearyl thiodipropionate. These are, for example, DLTP "Yoshitomi", DSTP "Yoshitomi" (trade name: manufactured by Yoshitomi Pharmaceutical Co., Ltd.), Smit LG, Rasmit SG (trade name: manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.), Antiox L, Antiox S (product). (Name: manufactured by Nippon Oil & Fats Co., Ltd.), it is a highly safe compound that has passed US FDA and can be used for packaging foods and the like.

These compounds are preferably added in an amount of 0.01 to 10% by weight based on the solid content of the main component of the water-based paint, and more preferably 0.1 to 0.5% by weight from the viewpoint of defoaming effect. preferable. If the added amount is less than 0.01% by weight, the defoaming property is insufficient, and if the added amount exceeds 10% by weight, the strength of the coating film formed is reduced, and thus both are not preferable.

There is no particular limitation on the main component of the aqueous coating composition used in the aqueous coating composition of the present invention, and the main component of the aqueous coating composition itself can withstand heat sterilization and can form a good film on the metal surface. In this case, by adding the compound of the general formula (I), the compound having the antifoaming property can be used, so that the compound can be optionally used. In the present invention, the main component of the water-based paint refers to a material in the water-based paint composition that contributes to the formation of a coating film. Representative water-based paint main agents include water-based paint main agents mainly composed of epoxy resin from the viewpoint of strength, durability, and stability of the coating, and various self-emulsifying epoxy resins and acrylic resins were forcibly emulsified. An epoxy resin dispersion or the like can be used. As specific examples, a) a carboxyl group in a carboxyl group-containing acrylic resin obtained by copolymerizing a monomer containing acrylic acid or methacrylic acid and an epoxy group in an aromatic epoxy resin are combined with an ester such as dimethylaminoethanol or diethanolamine. Partial esterification in the presence of a cationization catalyst, introducing a carboxyl group into the epoxy resin, and neutralizing the carboxyl group with a base to make the epoxy resin aqueous-based water-based paint base agent, b) acrylic acid, methacryl The carboxyl group of the acid and the epoxy group in the epoxy resin are partially esterified in the presence of an esterification catalyst such as sodium hydroxide to obtain an acryl-modified epoxy resin having an acryloyl group introduced into the epoxy resin. Monomer containing modified epoxy resin and acrylic acid, methacrylic acid A carboxyl group is introduced into the epoxy resin by copolymerization, and the carboxyl group is neutralized with a base to make the epoxy resin aqueous. A water-based coating main agent, c) an epoxy resin and acrylic acid, methacrylic acid are contained. A mixture of a carboxyl group-containing acrylic resin and a polymer in which acrylic acid or methacrylic acid is graft-polymerized on the fatty chain skeleton of an epoxy resin by polymerizing a monomer and a radical generator such as a peroxide. A graft-modified product is obtained, and the epoxy resin is made water-based by neutralizing the carboxyl groups in the graft-modified product with a base; d) Epoxy resin and phenol resin By applying high shear force to force dispersion and adding water to invert the phase, and then, if desired, a solvent Water-based paint base resin of the aqueous coating base component or the like using the obtained aqueous resin dispersion are removed can be used.

The epoxy resin which can be used here is obtained by condensing bisphenols such as bisphenol A, bisphenol B and bisphenol F with epichlorohydrin in the presence of an alkali catalyst, and is 1.1 per molecule. Those having a number of epoxy groups of up to 2.0 and a number average molecular weight of 1400 or more are mentioned. As a commercial product,
Epicoat 1004 and Epicoat 10 manufactured by Shell Chemical Co.
07, Epicoat 1009, Epicoat 1010 (above, trade name) and the like. Further, a modified epoxy resin or a phenoxy resin obtained by reacting a dehydrating castor oil fatty acid, a soybean oil fatty acid, a coconut oil fatty acid or the like vegetable oil fatty acid or a bisphenol A or the like modifying agent with the epoxy group or hydroxyl group of the bisphenol type epoxy resin is also used. be able to.

Further, the amount of the main component of the water-based coating composition can be arbitrarily selected depending on the kind of the substrate to which the water-based coating composition is applied, the desired film strength and the like.

In addition to the above, the water-based coating composition of the present invention contains an organic solvent and a surfactant in order to improve the coating property and impart a function depending on the application, as long as the effects of the present invention are not impaired. Additives such as a lubricant, a rust preventive, a pigment, and a filler can be added.

The base material such as a metal plate to which the water-based coating composition of the present invention is applied includes untreated steel plate, treated steel plate, zinc plate,
Tin plates, tin-fu steels such as chrome-plated steel plates and chromic acid-treated steel plates, nickel-plated steel plates, aluminum-plated steel plates, and aluminum are listed.

The method of coating the metal plate is not particularly limited, and examples thereof include spray coating such as air spray, airless spray, electrostatic spray, roll coater coating, dip coating, and electrodeposition coating. Of these, the effect of the present invention is remarkable when applied to roll coater coating, in which film defects due to generation of bubbles pose a problem.

The baking conditions for the aqueous coating composition of the present invention are not particularly limited, but generally the temperature is 150 to 23.
The baking time at 0 ° C. is selected from the range of 2 to 30 minutes.

[0027]

The present invention will be described in more detail with reference to specific examples, but the present invention is not limited thereto.
Hereinafter, unless otherwise specified, “part” and “%” represent “part by weight” and “% by weight”, respectively. (Production Example 1) 1-1. Preparation of acrylic resin solution (B-1) (1) Propylene glycol monopropyl ether 200 parts (2) 2-butanol 300 parts (3) Methacrylic acid 133 parts (4) Styrene 100 parts (5) Ethyl acrylate 100 parts ( 6) Benzoyl peroxide 12 parts In a four-necked flask filled with nitrogen gas, (1) and (2)
Was charged and 1/4 amount of the mixed liquid of (3) to (6) was added. After heating to 100 ° C., stirring (3)-
The remaining amount of the mixed solution of (6) was added dropwise over 2 hours. After the completion of dropping, the mixture was further stirred for 2 hours while maintaining the temperature at 100 ° C. Thus, an acrylic resin solution (B-1) having a solid content of 40% was obtained.

1-2. Preparation of Water-based Paint Main Agent (C-1) (1) Propylene glycol monopropyl ether 66 parts (2) Epicoat 1009 (produced by Yuka Shell Epoxy Co., Ltd.) 200 parts (3) Acrylic resin solution (B-1) 150 parts (4) Dimethylaminoethanol 13 parts (5) Ion-exchanged water 871 parts In a four-necked flask filled with nitrogen gas, (1) and (2).
Was charged and heated and stirred at 120 ° C. for 2 hours to dissolve the epoxy resin. After cooling, after adding (3), 1
While stirring at 00 ° C, (4) was added, reacted for 1 hour, and then cooled. After lowering the temperature to 60 ° C, set (5) to 1
It is dripped over 20 minutes, and the desired water-based coating main agent (C-
1) was obtained. The solid content of the paint is 20%, the amount of solvent is 12
%, Viscosity was 18 sec / 25 ° C. in # 4 Ford cup.

(Production Example 2) 2-1. Preparation of phenol resin solution (A-1) (1) Ion-exchanged water 80 parts (2) 21.5% sodium hydroxide aqueous solution 72 parts (3) Bisphenol A 140 parts (4) 37% formalin 400 parts (5) 20 % Hydrochloric acid 70 parts (6) 1-Butanol 180 parts (1) to (4) were charged in a four-necked flask filled with nitrogen gas, reacted at 50 ° C for 2 hours, and then heated to 70 ° C. After reacting for 1 hour, a reddish brown transparent resin solution was obtained. When the resin solution was cooled to 40 ° C. and (5) was added, the upper layer was separated into a colorless transparent aqueous layer and the lower layer was a brown organic layer within a few minutes. After separating the upper layer by decantation, (6) was added to obtain a phenol resin solution (A-1) having a solid content of 54%.

2-2. Preparation of Aqueous Paint Base Agent (C-2) To 100 parts of the aqueous paint base agent (C-1) in Production Example 1, 2.0 parts of the phenol resin solution (A-1) was added at room temperature with stirring. Water-based paint base agent (C-2)
Got The paint had a solids content of 20% and a viscosity of 16 seconds / 25 ° C. in a # 4 Ford cup.

(Production Example 3) 3-1. Preparation of Epoxy-Modified Product (1) 350 parts of ethylene glycol monoethyl ether (2) Epicoat 1100L (produced by Yuka Shell Epoxy Co., Ltd.) 645 parts (3) 10% aqueous sodium hydroxide solution 1 part (4) Hydroquinone 02 parts (5) Methacrylic acid 4 parts In a four-neck flask filled with nitrogen gas (1) and (2)
Was charged and heated and stirred at 120 ° C. for 2 hours to dissolve the epoxy resin. Thereafter, the temperature was raised, (3) to (5) were added with stirring at 130 ° C., the temperature was kept at 130 ° C., the reaction was carried out for 3 hours, and then the mixture was cooled and taken out. The resulting resin solution had a solid content of 64.5% and a resin acid value of 0.2 (per solid content).

3-2. Production of Aqueous Dispersion (D-1) (1) Methyl isobutyl ketone 23 parts (2) Epoxy modified modified product 171 parts (3) Styrene 16.7 parts (4) Ethyl acrylate 19.5 parts (5) Methacrylic acid 19.5 parts (6) Butyl cellosolve 33.4 parts (7) Azobisisobutyronitrile 2.4 parts (8) Azobisisobutyronitrile 0.6 parts (9) Methyl ethyl ketone 10 parts (10) Dimethylaminoethanol 8 parts (11) Ion-exchanged water 537 parts Charge (1) into a 4-necked flask filled with nitrogen gas,
While refluxing at 80 ° C., the mixed solution of (2) to (7) was added dropwise over 3 hours. After the dropping was completed, the temperature was raised to 90 ° C., and 60 minutes after the dropping was completed, (8) was added. After reacting at 90 ° C. for 60 minutes, it was cooled. After cooling to 70 ° C., (9) and (10) were added. Then (11) 1
The solution was added dropwise over 20 minutes to obtain an aqueous dispersion (D-1). The solid content of the dispersion is 19.7%, the amount of solvent is 15%, the viscosity is #
It was 15 seconds / 25 ° C. in a 4 Ford cup.

3-3. Preparation of Aqueous Paint Main Agent (C-3) With stirring 100 parts of the aqueous dispersion (D-1), 3.0 parts of the phenol resin solution (A-1) of Production Example 1 at room temperature. Then, the main component of the water-based paint (C-3) was obtained. The paint had a solids content of 21% and a viscosity of 17 seconds / 25 ° C. in a # 4 Ford cup.

(Production Example 4) 4-1. Production of Aqueous Dispersion (D-2) (1) Ethylene glycol monobutyl ether 100 parts (2) 1-Butanol 60 parts (3) Epicoat 1010 (produced by Yuka Shell Epoxy Co., Ltd.) 150 parts (4) Methacrylic acid 20 Parts (5) styrene 10 parts (6) ethyl acrylate 7.5 parts (7) benzoyl peroxide 2 parts (8) dimethylaminoethanol 15 parts (9) ion-exchanged water 285 parts (10) ion-exchanged water 350 parts nitrogen gas (1) to (3) were charged into a four-necked flask in which was sealed and heated and dissolved. After heating to 110 ° C., a solution in which (4) to (7) are uniformly mixed and dissolved while stirring,
It dripped over 2 hours. After the dropping was completed, the temperature was maintained at 110 ° C., the mixture was stirred for 4 hours, and then cooled. After the temperature was lowered to 80 ° C., the mixed solution of (8) and (9) was added dropwise over 60 minutes. After the dropwise addition, (10) was added dropwise over 120 minutes to obtain an aqueous dispersion (D-2). The neutralization rate of the carboxyl groups contained in the acrylic resin in the dispersion was 72.5 mol%, the solid content of this dispersion was 18.8%, the amount of solvent was 16%, and the viscosity was 18 in a # 4 Ford cup. Seconds / 25 ° C.

4-2. Preparation of Aqueous Paint Main Agent (C-4) With stirring 100 parts of the aqueous dispersion (D-2), 2.0 parts of the phenol resin solution (A-1) of Production Example 1 at room temperature. Then, the main component of the water-based paint (C-4) was obtained. The coating had a solids content of 20% and a viscosity of 19 seconds / 25 ° C. in a # 4 Ford cup.

(Production Example 5) 5-1. Preparation of Epoxy Resin Solution (1) Epicoat 1009 (manufactured by Yuka Shell Epoxy Co., Ltd.) 40 parts (2) Butyl acetate 45 parts (3) n-Butanol 15 parts In a four-necked flask filled with nitrogen gas (1) -(3) were charged and gradually heated to 110 ° C. and dissolved for 3 hours to obtain an epoxy resin solution having a solid content of 40.0%.

5-2. Preparation of Phenolic Resin Solution (A-2) (1) Bisphenol A 264 Parts (2) p-Cresol 66 Parts (3) 37% Folimarin 176 Parts (4) 25% Ammonia Water 20 Parts Nitrogen Gas Sealed 4 Ports The flask was charged with (1) to (3), heated and dissolved at 80 ° C. for 30 minutes, then cooled to 70 ° C., and (4) was added dropwise while paying attention to heat generation. The reaction temperature was kept at 80 ° C. and the reaction was carried out for 3 hours. After completion of the reaction, a mixed solvent of butyl acetate 50% and n-butanol 50% 47
It is extracted with 4 parts and dehydrated by heating under reflux at a temperature of 90 to 110 ° C. for about 3 hours to obtain a solid content of 40.5.
%, A phenol resin solution having a weight average molecular weight of 1560 (A
-2) was obtained.

5-3. Preparation of Epoxy Resin and Phenol Resin Mixture (1) Epoxy Resin Solution 80 Parts (2) Phenol Resin Solution (A-2) 20 Parts Solid Content of Mixing Epoxy Resin Solution and Phenolic Resin Solution of (1) and (2) A 40.1% mixed solution was obtained.

5-4. Preparation of acrylic resin solution (B-2) (1) n-butanol 598 parts (2) styrene 60 parts (3) ethyl acrylate 120 parts (4) methyl methacrylate 60 parts (5) methacrylic acid 160 parts (6) Benzoyl peroxide 2 parts Half of each of (1) to (6) was charged into a four-necked flask filled with nitrogen gas, heated and kept at 90 ° C. 90 ° C
After heating up to, the remaining amount of the mixed liquid of (1) to (6) was added dropwise over 2 hours while stirring. After the dropping, the temperature is set to 9
The mixture was further stirred for 5 hours while maintaining it at 0 ° C. Thus, an acrylic resin solution (B-2) having a solid content of 39.1% and a weight average molecular weight of 112000 was obtained.

5-5. Preparation of water-based paint (C-5) (1) Epoxy resin and phenol resin mixed solution 340 parts (2) Acrylic resin solution (B-2) 60 parts (3) 25% ammonia water 15 parts (4) Ion-exchanged water 225 Parts (5) Ion-exchanged water 360 parts (1) and (2) were sufficiently stirred in the reaction vessel until they became uniform, and then the mixed solution of (3) and (4) was gradually added dropwise with vigorous stirring. . After sufficiently stirring until the system became uniform, (5) was gradually added dropwise with vigorous stirring to obtain a dispersion having a solid content of 16.0%. afterwards,
Solid content 38.0% by azeotropic distillation at 60 to 90 torr
Most of the solvent was removed with water until it became 5% by weight of isobutanol and butyl carbitol respectively in the paint. It was added so as to be 10% and diluted with ion-exchanged water to obtain an aqueous coating material (C-5). The paint had a solids content of 28.3% and a viscosity of 45 seconds / 25 ° C in a # 4 Ford cup.

(Examples 1 to 7 and Comparative Examples 1 to 7) (Preparation and Evaluation of Aqueous Coating Compositions) The aqueous coating base materials (C-1) to (C-5) obtained in Production Examples 1 to 5 were used. Using Table 1
An aqueous coating composition was prepared with the compounding amount as shown in. Examples 1 to 7 were prepared by mixing dilauryl thiodipropionate and distearyl thiodipropionate (manufactured by Yoshitomi Pharmaceutical Co., Ltd.), which are compounds of the general formula (I) of the present invention, respectively. In addition, a composition containing no antifoaming agent (Comparative Examples 1, 3,
5) and the above compounds, in place of the antifoaming agent outside the scope of the present invention, 2,4,7,9-tetramethyl-5-decyne-
A product to which an ethylene oxide adduct of 4,7-diol (Safinol 420, manufactured by Air Product Co.) and an ethylene oxide-propylene oxide block copolymer (Adeka Pluronic L-61, manufactured by Asahi Denka Kogyo Co., Ltd.) were added (Comparative Example 2). 4, 7, 8) are Comparative Examples 1-7, respectively.
And

[0042]

[Table 1]

100 ml of each aqueous coating composition was added to a volume of 500
Weighed into a ml graduated cylinder. 1m diameter at the tip
A glass tube molded into m was inserted into the paint in a graduated cylinder, and nitrogen gas was caused to flow at a flow rate of 200 ml / min for 3 minutes. Immediately thereafter, the volume of the paint containing bubbles was weighed, and the results of evaluating the defoaming property according to the following criteria are shown in Table 1. (Evaluation Criteria) The volume of paint containing foam is less than 110 ml: ◎ (very excellent in defoaming property) The volume of paint containing foam is 110 ml or more and less than 150 ml: ○ (excellent in defoaming property) Contains foam The volume of the paint is 150 ml or more and less than 300 ml: △ (slightly inferior in defoaming property) The volume of paint containing foam is 300 ml or more: × (inferior in defoaming property) As is clear from the results in Table 1, It was found that Examples 1 to 7, which are water-based coating compositions of the invention, were excellent in defoaming property, but Comparative Products 1 to 7 to which other defoaming agents were added had poor defoaming property. When these paints were applied to a metal plate by roll coating, the metal plates to which the paints of Examples 1 to 7 were visually observed showed no film defects due to bubbles, but comparative products 1 to 7 In all the metal plates coated with the above coating, film defects due to bubbles were observed.

[0044]

EFFECTS OF THE INVENTION The water-based coating composition of the present invention, having the above-mentioned constitution, improves the dispersion stability of the water-based coating main agent such as epoxy resin, is excellent in the foam suppressing property and the defoaming property, and has a defect-free coating film. It has an excellent effect that it can be formed, and is highly safe and can be used for foods and the like.

Claims (3)

[Claims] 1. A water-based coating composition comprising a main component of a water-based coating and a compound represented by the following general formula (I). [Chemical 1] (In the formula, R ¹ and R ² represent an alkyl group having 1 to 4 carbon atoms and may be the same or different from each other. R ³ and R ⁴ represent an alkyl group having 10 to 20 carbon atoms, and It may be the same or different.) 2. A compound represented by the general formula (I),
The water-based coating composition according to claim 1, which is blended in an amount of 0.01 to 10% by weight based on the solid content of the main component of the water-based coating. 3. The aqueous coating composition according to claim 1, wherein the main component of the aqueous coating material contains an epoxy resin.