JP2002194292A - Water-based undercoating - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an undercoating having adhesion to a substrate and a topcoating, and lifting resistance as well and, at the same time, crack resistance and composed of one component. SOLUTION: The undercoating is constituted of an emulsion composition to be obtained by the emulsion polymerization of an ethylenically unsaturated monomer in an aqueous medium containing a reactive surface active agent having a surface tension of <=40 mN/m.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an aqueous base paint obtained using a predetermined reactive surfactant.

[0002]

BACKGROUND OF THE INVENTION Building materials (i.e., groundwork) and finish paints generally do not have adhesion. For this reason, in general,
A multi-layer structure such as a sealer / underlayer adjusting material / intermediate material / finish paint is employed. That is, in order to apply the finish paint, three types of coating materials, a sealer, a base adjustment material, and an intermediate coating material, and when no intermediate coating material is used, two types of coating materials, a sealer and a base adjustment material, are required.

[0003] The sealer has adhesion to a base, the base adjustment material has adhesion to a finish paint, and lifting resistance, and the intermediate coating material has crack resistance.

[0004]

However, there is no known base paint having one of the above characteristics.

Accordingly, an object of the present invention is to provide a single kind of base paint having adhesion to a base and a finish paint, having lifting resistance and crack resistance. .

[0006]

SUMMARY OF THE INVENTION The present invention relates to an emulsion obtained by emulsion polymerization of an ethylenically unsaturated monomer in an aqueous medium containing a reactive surfactant having a surface tension of 40 mN / m or less. The above problem was solved by using the composition.

Since a surfactant having a predetermined surface tension is used, it is possible to improve the adhesion between the undercoat and the finish paint. In addition, since a reactive surfactant is used as the surfactant, water-resistant adhesion can be improved.

[0008]

Embodiments of the present invention will be described below.

The aqueous base coating material according to the present invention is obtained from an emulsion composition obtained by emulsion-polymerizing an ethylenically unsaturated monomer in an aqueous medium containing a reactive surfactant having a predetermined surface tension. It becomes.

[0010] The aqueous medium contains a surfactant. The surfactant may be one kind or a mixture of two or more kinds, and contains at least the reactive surfactant having the above-mentioned predetermined surface tension.

The term "reactive surfactant" refers to a surfactant having a radical polymerizable double bond in the molecule and having the same emulsifying, dispersing and wetting functions as general surfactants. Say. Since this reactive surfactant constitutes a part of the resin by polymerization, the amount of free surfactant is reduced,
Unlike general surfactants, they have the characteristic of not reducing water resistance.

The reactive surfactant has a surface tension of 40.
It is necessary to use one having a mN / m or less, preferably 35 mN / m or less. Surface tension is 40mN /
By using a reactive surfactant having a low surface tension of not more than m, the wettability with the undercoat and the finish is improved, and thereby the adhesion with the undercoat and the finish can be improved. The surface tension may be 40 mN / m or less, and may be 0 mN / m. However, since a surfactant having such a surface tension does not actually exist, the surface tension of the reactive surfactant exceeds 40 to 40 mN / m.
The range is as follows.

The content of the reactive surfactant having a surface tension of 40 mN / m or less (hereinafter, referred to as "low surface tension reactive surfactant") is based on 100 parts by weight of the ethylenically unsaturated monomer. 0.8 to 3 parts by weight of active ingredient
2 parts by weight are preferred. When the amount is less than 0.8 part by weight, the stability of the emulsion becomes insufficient and sufficient adhesion cannot be obtained. On the other hand, when the amount is more than 3 parts by weight, the water resistance decreases, and In some cases, the water-resistant adhesion may be reduced.

The above-mentioned surfactants include, in addition to the above-mentioned low surface tension reactive surfactants, reactive surfactants having a surface tension of more than 40 mN / m and 50 mN / m or less (hereinafter referred to as “high surface tension reactive surfactants”). ), May be contained as necessary. By using this high surface tension reactive surfactant, polymerization stability and water resistance can be improved.

When the above-mentioned high surface tension reactive surfactant is contained, its content is determined by the amount of the ethylenically unsaturated monomer 10
The active ingredient is preferably 0.5 to 3 parts by weight based on 0 part by weight. If the amount is less than 0.5 part by weight, the effect of the high surface tension reactive surfactant is difficult to appear, while if it is more than 3 parts by weight, the water resistance is reduced and the emulsion may have a high viscosity.

As the low surface tension-reactive surfactant and the high surface tension-reactive surfactant, any of anionic and cationic surfactants can be used. The effect can be exhibited more.

Further, in addition to the low surface tension-reactive surfactant and the high surface tension-reactive surfactant, the above-mentioned surfactants include nonionic reactive surfactants and nonionic or anionic surfactants. A non-reactive surfactant may be contained within a range that does not adversely affect water resistance. The content is preferably 1 part by weight or less based on 100 parts by weight of the ethylenically unsaturated monomer.

Anionic low surface tension reactive surfactants (abbreviated as “A type” in Tables 1 and 3), anionic high surface tension reactive surfactants (Tables 1 and 3 B type), nonionic reactive surfactants (abbreviated as “C type” in Tables 1 and 3), and non-reactive surfactants (in Tables 1 and 3, “ D
Type ". ) Can be exemplified by those shown in Table 1. In addition, it is not limited to these surfactants.

[0019]

[Table 1]

The surface tension in Table 1 is 0.1% by weight of the surfactant active ingredient according to the Wellhermy method.
Are measured.

The content ratio of the low surface tension reactive surfactant to the total amount of the surfactant contained in the aqueous medium is preferably 50% by weight or more, and more preferably 65% by weight or more. If it is less than 50% by weight, the adhesion tends to be insufficient.

The content ratio of the high surface tension reactive surfactant to the total amount of the surfactant contained in the aqueous medium is preferably 50% by weight or less, and more preferably 30% by weight or less. If it is more than 50% by weight, the adhesion may be poor.

The total amount of the low surface tension reactive surfactant and the high surface tension reactive surfactant is 90% by weight based on the total amount of the surfactant contained in the aqueous medium.
The above is good, and 100% by weight is preferable. If the content is less than 90% by weight, the water resistance may be reduced, and the water-resistant adhesion to a base or a finish paint may be deteriorated.

The aqueous medium refers to water or a mixed solution of water containing water as a main component and a water-soluble organic solvent. Examples of the water-soluble organic solvent include alcohols such as methyl alcohol, ethyl alcohol, isopropyl alcohol, normal propyl alcohol, and butyl alcohol; ketones such as methyl ethyl ketone; ethylene glycol monomethyl ether; ethylene glycol monoethyl ether; Ethers such as butyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, and propylene glycol monobutyl ether; These solvents must be used in consideration of the affinity with the resin to be polymerized. This is because gelling and precipitation of the resin may occur depending on the solvent used.

The ethylenically unsaturated monomer is a carbon-
It refers to a monomer having a carbon double bond, and includes an acid group-containing unsaturated monomer, a hydroxyl group-containing unsaturated monomer, and other unsaturated monomers.

Examples of the acid group-containing unsaturated monomer include:
Unsaturated carboxylic acids such as (meth) acrylic acid, itaconic acid, crotonic acid, maleic acid, fumaric acid, etc., unsaturated sulfonic acids such as 2-acrylamido-2-methylpropanesulfonic acid, sulfoethyl methacrylate, styrenesulfonic acid and the like. And unsaturated phosphoric acids such as salts, acid phosphoxyethyl methacrylate, acid phosphoxyethyl propyl methacrylate, and 3-chloro-2-acid phosphoxypropyl methacrylate, and salts thereof.

Examples of the hydroxyl group-containing unsaturated monomer include 2-hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, 2-hydroxy-3-chloropropyl methacrylate, acryloyloxyethyl hydrogen phthalate, β -Hydroxyethyl-β-
Acryloyloxyethyl phthalate, 1,4-butylene glycol monoacrylate, N-methylol acrylamide, hydroxystyrene, vinyl alcohol (polymerized using vinyl acetate and then hydrolyzed), allyl alcohol, methallyl alcohol, isopropenyl alcohol , 1-butenyl alcohol, ethylene glycol monoacrylate, 1,4-butanediol monoacrylate and the like.

Examples of the other unsaturated monomers described above include:
(Meth) acrylate compounds such as methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, hexyl (meth) acrylate, and lauryl (meth) acrylate; Unsaturated acetates such as vinyl acetate and vinyl propionate, unsaturated hydrocarbons such as styrene, α-methylstyrene, vinylnaphthalene, butadiene and isoprene;
Unsaturated amides such as (meth) acrylamide, N, N-dimethylacrylamide, diacetone acrylamide,
Unsaturated polyoxyalkylene derivatives such as polyethylene glycol methyl ether (meth) acrylate, N, N
Of unsaturated amphoteric compounds such as -dimethyl-N-methacryloxyethyl-N- (3-sulfopropyl) -ammonium betaine and glycols such as ethylene glycol, 1,4-butanediol, 1,6-hexanediol and diethylene glycol; Examples thereof include poly (meth) acrylates of polyols such as di (meth) acrylate, glycerin, trimethylolpropane, and pentaerythritol, and (meth) acrylates such as allyl alcohol and methallyl alcohol.

The above (meth) acryl means acryl or methacryl.

In addition to the above ethylenically unsaturated monomers, unsaturated polyfunctional crosslinkable monomers for causing intramolecular crosslinking can be used. Examples of this include divinylbenzene, diallyl phthalate, ethylene glycol dimethacrylate, trimethylolpropane triacrylate, allyl acrylate, glycidyl methacrylate, glycidyl acrylate, N-methylol acrylamide, and the like.

The combination of the above ethylenically unsaturated monomers is not particularly limited, but may be an acid group-containing unsaturated monomer, a hydroxyl group-containing unsaturated monomer, another unsaturated monomer, or an unsaturated polyfunctional crosslink. It is preferable to use a water-soluble monomer in terms of stability, lifting resistance, adjustment of glass transition temperature (Tg), and the like. The preferred compounding ratio in this case is: acid group-containing unsaturated monomer / hydroxyl group-containing unsaturated monomer / other unsaturated monomer / unsaturated polyfunctional crosslinkable monomer = 0.1 to 5/1. ５5/8
9.5 to 98.9 / 0 to 0.5 (% by weight).

In the above-mentioned method of emulsion-polymerizing an ethylenically unsaturated monomer, an emulsifier is present in an aqueous medium, and the above-mentioned ethylenically unsaturated monomer and a polymerization initiator are supplied at once or continuously under stirring. And a polymerization reaction.

In the present invention, the low surface tension reactive surfactant described above can be used as the emulsifier. Specific examples include those described above.

As the polymerization initiator that can be used in the emulsion polymerization, any known polymerization initiator can be used, and both hydrophobic and hydrophilic polymerization initiators can be used. Representative examples include inorganic initiators such as potassium persulfate and ammonium persulfate, and organic initiators such as azobisisobutyronitrile and t-butylperoxypivalate.

If necessary, various chain transfer agents such as mercaptans, α-methylstyrene and alkyl halides may be used. The amount used is preferably from 0.01 to 10% by weight based on the total amount of the monomers used for the polymerization. If it is less than 0.01% by weight, the effect of lowering the molecular weight is small, and if it exceeds 10% by weight, polymerization may be inhibited and a problem may occur in the polymerizability.

The weight average molecular weight of the polymer obtained by the emulsion polymerization method is preferably from 500 to 500,000, and from 1,000 to 500,000.
300,000 is preferred.

Since the polymer obtained by the above polymerization is obtained in an emulsified state dispersed in water, it can be used as it is or by adding necessary additives according to the purpose.

[0038] The emulsion composition obtained by the above method can be used for building, civil engineering construction and building civil engineering materials (ie,
It has good adhesion to both the undercoat and the finish, and can be used as a water-based undercoat used between them.

[0039]

Next, the present invention will be described in more detail by way of examples, which should not be construed as limiting the present invention. First, measurement methods used in the following examples and comparative examples will be described.

(Surface Tension) The active ingredient of the sample emulsion was adjusted to 5%, and the surface tension was measured by the Well Helmy method. As a measuring instrument, "FACE CBVP type surface tensiometer (CBVP-A3 type, manufactured by Kyowa Interface Science)" was used.

(Blending of Base Adjusting Material (Fine Elastic Resin Filler)) The base adjusting material (fine elastic resin filler) was prepared according to the formulation shown in Table 2 below.

[0042]

[Table 2]

In this case, titanium oxide (manufactured by Teica Co., Ltd., trade name JR-600E) was used as a coloring pigment in order to improve the concealing property of the coating film. As a filler, calcium carbonate (manufactured by Nitto Powder Chemical Co., Ltd .; trade name)
NS-100). It can also be a viscosity and viscosity modifier and extender. Furthermore, powdered methylcellulose (manufactured by Shin-Etsu Chemical Co., Ltd .; trade name 90SH-15000) was used as a thickener. This also serves as a viscosity modifier that provides thixotropic viscosity. Furthermore,
Mineral terpenes and butyl cellosolve were used as solvents. The main role of mineral turpen is to impart permeability to the base, and the main role of butyl cellosolve is temporary plasticization (film forming aid) and wettability to the base. As a dispersant, a low molecular weight ammonium polyacrylate (manufactured by San Nopco; trade name: SN Dispersant 5027) was used. This is used for the purpose of helping the deflocculation and dispersion of the filler and lowering the viscosity of the undercoating material.

((Waterproof) Adhesion to Substrate)
Mortar, slate, and solvent-based acrylic coated slate were used. The substrate adjusting material obtained by the above method was applied to the substrate at a thickness of 1 mm (wet state), allowed to stand in a 65% atmosphere at 20 ° C. for 16 hours, and then left at 50 ° C. for 6 hours. The obtained coating film was subjected to a forced peeling test as it was to evaluate the normal adhesion. After immersion in water for one day, a forced peeling test, that is, a test in which the surface of the coating film was scratched with a nail and forcedly peeled off, was also performed to evaluate water resistance. The criteria for the evaluation are shown below. ：: The substrate was destroyed in both the normal adhesion test and the water resistance test. Δ: In the normal adhesion test, although the substrate was destroyed or the interface was destroyed, there was resistance to destruction. In addition, in the test for water adhesion resistance, the interface was broken, but there was resistance to breaking. ×: The interface was broken without resistance in both the normal adhesion test and the water resistance test.

(Adhesion (Water Resistance) to Finishing Paint) As a base, mortar, slate, and slate coated with a solvent-based acrylic resin were used. The underlayer adjusting material obtained by the above method is applied to the underlayer at a thickness of 1 mm (wet state), and is applied at 20 ° C and 65 ° C.
% Atmosphere for 16 hours and then at 50 ° C. for 6 hours. A 0.4 mm-thick (wet state) is applied on the obtained coating film at 20 ° C. in a 65% atmosphere.
Left for hours. The finishing paint used was a water-based multi-layer elastic middle coat material (manufactured by Tsuneka Chemical Industry Co., Ltd .; trade name: Diamond Super Daisei), and a water-based single-layer elastic middle coat material (Kikusui Chemical Industry Co., Ltd.)
(Trade name: Ultrasoft), solvent-based acrylic. The obtained coating film was subjected to a forced peeling test as it was to evaluate the normal state adhesion. After immersion in water for one day, the film was similarly subjected to a forced peeling test to evaluate water resistance. The criteria for the evaluation are shown below. ：: The finish paint film was destroyed in both the normal adhesion test and the water resistance test. Δ: In the normal adhesion test, although the finish paint film was destroyed or the interface was destroyed, there was resistance to destruction. In the water adhesion test, the interface was destroyed, but there was resistance to destruction. ×: The interface was broken without resistance in both the normal adhesion test and the water resistance test.

(Lifting resistance) As a base, a slate coated with a solvent-based acrylic was used. The underlayer adjusting material obtained by the above method was applied to the underlayer in a thickness of 0.1 mm (wet state), and allowed to stand at 20 ° C. and 65% atmosphere for 16 hours. About 1 thinner of solvent-based acrylic coating material was applied on the obtained coating film.
The evaluation was performed by spot dropping at a diameter of cm. The criteria for the evaluation are shown below. ：: No lifting (wrinkles or shrinkage) was observed. Δ: Lifting (wrinkles and shrinkage) was slightly observed. ×: Many liftings (wrinkles and shrinkage) were observed.

Example 1 In a reactor equipped with a stirrer, a reflux condenser, a thermometer and a dropping funnel, 54 parts by weight of water and Aqualon HS-10 as a surfactant (manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) Was added and the temperature was raised to 65 ° C.

Next, 2.0 parts by weight of a 10% aqueous solution of ammonium persulfate is added with stirring. As a monomer component, 2-ethylhexyl acrylate (hereinafter referred to as “2EH
A ". ) 47 parts by weight, 41.5 parts by weight of methyl methacrylate (hereinafter abbreviated as “MMA”), 10 parts by weight of styrene (hereinafter abbreviated as “SM”) and acrylic acid (hereinafter “AA”). 1.5 parts by weight, 2 parts by weight of Eliminol JS-2 (manufactured by Sanyo Chemical Industries, Ltd.) and 1 part by weight of Aqualon HS-10 (manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) as surfactant components And a monomer emulsion from 44 parts by weight of water.

The monomer emulsion is continuously dropped into the reaction vessel with a dropping funnel over 3 hours. During this period, the polymerization temperature was maintained at 65 ° C, and after the completion of the dropwise addition, an aging reaction was performed at 75 ° C for 3 hours. After the reaction, the reaction solution was allowed to cool to 30 ° C., and 25%
1.5 parts by weight of aqueous ammonia, Adekanol B-940
0.03 parts by weight (manufactured by Asahi Denka Co., Ltd., antifoaming agent), 0.3 part by weight of chloroacetamide (manufactured by Clariant Japan Co., Ltd., antiseptic / antifungal agent) and Texanol CS-12 (manufactured by Chisso Corporation) 4 parts by weight of a film-forming aid) and a surface tension of 3
8.6 mN / m, nonvolatile content 50.2%, viscosity 2200 m
A styrene acrylic emulsion having a Pa · s of PH 9.1 was obtained.

Using the obtained styrene acrylic emulsion, the (water resistant) adhesion to the base, the (water resistant) adhesion to the finish paint, and the lifting resistance were evaluated. Table 3 shows the results.

Example 2 The surfactant charged to the reactor was Aqualon HS-10 (Daiichi Kogyo Seiyaku Co., Ltd.) 0.2
Eliminol ES-70 (manufactured by Sanyo Chemical Industries)
Except having changed to 0.08 weight part, it carried out similarly to Example 1, and carried out surface tension 38.5mN / m, nonvolatile content 50.1%,
A styrene acrylic emulsion having a viscosity of 3900 mPa · s and a pH of 9.0 was obtained.

Using the obtained styrene acrylic emulsion, the (water resistant) adhesion to the base, the (water resistant) adhesion to the finish paint, and the lifting resistance were evaluated. Table 3 shows the results.

Example 3 As a copolymer component, 40 parts by weight of MMA was added, and 1.5 parts by weight of hydroxyethyl methacrylate (hereinafter abbreviated as "HEMA") as a hydroxyl group-containing unsaturated monomer was added. Other than the above, in the same manner as in Example 2, the surface tension was 38.5 mN / m, and the nonvolatile content was 50.0 mN / m.
%, A styrene acrylic emulsion having a viscosity of 4800 mPa · s and a pH of 8.9.

Using the obtained styrene acrylic emulsion, the (water-resistant) adhesion to a base, the (water-resistant) adhesion to a finish paint, and the lifting resistance were evaluated. Table 3 shows the results.

Example 4 2EHA and MM Copolymerization Components
A surface tension of 38.6 mN / m and a non-volatile content of 50.1 were obtained in the same manner as in Example 3 except that the ratio of A was changed to the value shown in Table 2.
%, A styrene acrylic emulsion having a viscosity of 4500 mPa · s and a PH of 9.1. The glass transition temperature Tg (calculation method of Japan Emulsion Association) is -0.5.
° C.

Using the obtained styrene acrylic emulsion, the (water-resistant) adhesion to the base, the (water-resistant) adhesion to the finish paint, and the lifting resistance were evaluated. Table 3 shows the results.

Example 5 A surface tension of 38.4 mN / m, a non-volatile content of 50.0% and a viscosity of 100 were obtained in the same manner as in Example 3 except that HS-10 and ES-70 were not used.
A styrene acrylic emulsion having a pressure of 0 mPa · s and a pH of 8.8 was obtained.

Using the obtained styrene acrylic emulsion, the (water-resistant) adhesion to a base, the (water-resistant) adhesion to a finish paint, and the lifting resistance were evaluated. Table 3 shows the results.

Example 6 A surface tension of 43.degree. Was obtained in the same manner as in Example 3 except that the amount of JS-2 was changed to 1.0 part by weight.
9 mN / m, nonvolatile content 50.3%, viscosity 1800 mPa
-A styrene acrylic emulsion having a pH of 9.0 was obtained.

Using the obtained styrene acrylic emulsion, the (water-resistant) adhesion to the base, the (water-resistant) adhesion to the finish paint, and the lifting resistance were evaluated. Table 3 shows the results.

Example 7 A surface tension of 41.9 mN / m and a non-volatile content were obtained in the same manner as in Example 6 except that 0.6 parts by weight of Aqualon RN-20 (manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) was used. Min 50.2%, viscosity 2000 mPa · s, PH 8.9
A styrene acrylic emulsion was obtained.

Using the obtained styrene acrylic emulsion, the (water-resistant) adhesion to the base, the (water-resistant) adhesion to the finish paint, and the lifting resistance were evaluated. Table 3 shows the results.

[Comparative Example 1] HS-
Surface tension 44.8 mN / m, nonvolatile content 50.4
%, A styrene acrylic emulsion having a viscosity of 4100 mPa · s and a PH of 9.1.

Using the obtained styrene acrylic emulsion, the (water resistant) adhesion to the base, the (water resistant) adhesion to the finish paint, and the lifting resistance were evaluated. Table 3 shows the results.

Comparative Example 2 A non-reactive surfactant Nonipol 200 (manufactured by Sanyo Chemical Industries) was added in an amount of 1.0 part by weight, except that HEMA was not used as a copolymerization component. In the same manner as in Comparative Example 1, a surface tension of 45.
9 mN / m, nonvolatile content 50.2%, viscosity 3300 mPa
-A styrene acrylic emulsion having a pH of 9.0 was obtained.

Using the obtained styrene acrylic emulsion, the (water resistant) adhesion to the base, the (water resistant) adhesion to the finish paint, and the lifting resistance were evaluated. Table 3 shows the results.

[0067]

[Table 3]

[0068]

According to the present invention, the base preparation material (fine elastic resin filler) using the water-based base coating material is a coating material having both performances of a sealer and a base preparation material, and also has the performance of an intermediate coating material. ing. For this reason, it has adhesiveness to both the base and the finish paint, has lifting resistance, and has crack resistance. For this reason, it is possible to use a single type of coating material instead of a conventional type requiring a plurality of types.

Further, this makes it possible to simplify the working process.

Further, since this aqueous base coating is a water-based coating, it is environmentally preferable.

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Akira Masumoto 1-13, Shodaida, Hirakata City, Osaka Central Rika Kogyo Co., Ltd. F-term (reference) 4J038 CC021 CG141 GA03 MA08 MA10 PB05

Claims (8)

[Claims] 1. An aqueous base paint comprising an emulsion composition obtained by emulsion polymerization of an ethylenically unsaturated monomer in an aqueous medium containing a reactive surfactant having a surface tension of 40 mN / m or less. 2. The aqueous base coating composition according to claim 1, wherein the ethylenically unsaturated monomer is a monomer containing a (meth) acrylate compound. 3. The aqueous base coating composition according to claim 2, wherein the ethylenically unsaturated monomer is a monomer containing styrene. 4. The aqueous base paint according to claim 2, wherein the ethylenically unsaturated monomer is a monomer containing 1 to 5% by weight of a (meth) acrylate compound having a hydroxyl group in a side chain. . 5. The aqueous base paint according to claim 1, wherein the reactive surfactant having a surface tension of 40 mN / m or less is an anionic surfactant. 6. The reactive surfactant having a surface tension of 40 mN / m or less is mixed with the ethylenically unsaturated monomer in a total amount of 1
The aqueous base coating material according to any one of claims 1 to 5, wherein the water content is 0.8 to 3 parts by weight based on 00 parts by weight. 7. The surface tension exceeds 40 mN / m and 50 mN.
/ M or less of an anionic reactive surfactant in an amount of 0.5 to 3 parts by weight based on 100 parts by weight of the ethylenically unsaturated monomer, and the surfactant contained in the aqueous medium. The aqueous base coating material according to any one of claims 1 to 6, wherein the water-based base coating material is contained so as to be 50% by weight or less of the total amount. 8. A reactive surfactant having a surface tension of not more than 40 mN / m and a surface tension of more than 40 mN / m.
The aqueous base coating composition according to any one of claims 1 to 7, wherein the total amount of the anionic reactive surfactant of mN / m or less is 90% by weight or more of the total amount of the surfactant contained in the aqueous medium.