JP2002249719A - Emulsion coating composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a composition for coating having excellent adhesion and water and weather resistances, capable of achieving high appearance properties as a coating and suitable as the coating, especially for a hardly bonding metal (alloy) such as a magnesium alloy or polyphenylene sulfide(PPS) or (engineering) plastics. SOLUTION: This emulsion coating composition comprises (B) an acrylic emulsion prepared by carrying out emulsion polymerization of (X) radically polymerizable unsaturated monomers containing at least two kinds selected from (x-1) a hydroxy group-containing unsaturated monomer, (x-2) a carboxy group-containing unsaturated monomer and (x-3) an epoxy group-containing unsaturated monomer with (Y) other unsaturated monomers in the presence of (A) an organic polymer having >=50% gel fraction.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an emulsion paint composition designed to satisfy various performances as a paint while taking into consideration the mitigation of environmental pollution caused by organic solvents and others discharged at the time of painting. It is.

[0002]

2. Description of the Related Art In recent years, environmental pollution on a global scale, such as global warming and destruction of the ozone layer, has often been taken up as a serious problem.

[0003] In the world of paints and coatings, intensive studies and developments are being made to solve these problems. That is,
Solvent-free paints (powder paints, reactive paints), high solids and water-based paints correspond to this.

[0004] On the other hand, the functions required of paints are design properties (improvement of aesthetics) and protection of objects to be coated, but the current development situation is not always satisfactory. That is,
Solventless paints require high-temperature baking and light irradiation during coating film formation, resulting in poor coating workability. Deterioration of the coating performance mainly on basic performance such as water resistance and water resistance. In addition, water-based paints are different from low-humidity areas such as Europe, and particularly in high-humidity areas such as Japan, there is a concern that the coating film is sticky and lacks durability.

[0005]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a coating material which is excellent in adhesion, water resistance and weather resistance and which can achieve high appearance as a coating material, especially magnesium alloys and polyphenylene sulfide (PPS). An object of the present invention is to provide a coating composition suitable as a coating for adhesive metals and plastics.

[0006]

To solve the above-mentioned problems, the present invention comprises the following constitution. That is, the present invention
In the presence of an organic polymer (A) having a gel fraction of 50% or more, a hydroxyl group-containing unsaturated monomer (x-1), a carboxyl group-containing unsaturated monomer (x-2) and an epoxy group-containing unsaturated monomer Acrylic emulsion (B) obtained by emulsion-polymerizing a radically polymerizable unsaturated monomer (X) containing at least two kinds selected from monomers (x-3) and another unsaturated monomer (Y). It is an emulsion coating composition containing.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The emulsion coating composition of the present invention comprises a hydroxyl-containing unsaturated monomer (x-1) and a carboxyl-containing unsaturated monomer in the presence of an organic polymer (A) having a gel fraction of 50% or more. A radical polymerizable unsaturated monomer (X) containing at least two selected from an unsaturated monomer (x-2) and an epoxy group-containing unsaturated monomer (x-3), and another unsaturated monomer It is an emulsion coating composition containing an acrylic emulsion (B) obtained by emulsion polymerization of the body (Y), and it is recommended that the organic polymer (A) is fine acrylic polymer particles having a specific composition.

The organic polymer (A) having a gel fraction of 50% or more has no limitation except that the gel fraction determined by the following formula 1 is 50% or more. It is recommended to use acrylic polymer fine particles (A-1 and / or A-2) having the following composition. When the gel fraction is less than 50%, the crosslinkability of the coating material is reduced, and the chemical resistance and solvent resistance of the coating film are deteriorated.

Here, the gel fraction can be determined as follows. That is, the organic polymer (A) is
In the case of a lump, pulverize it to a fine powder, and in the case of a solution or suspension, spread it thinly and apply it at 40 ° C, 100-70
Vacuum dry at a vacuum of 00 Pa for 48 hours.

Pg of vacuum-dried organic polymer (A)
With a mixed solvent of acetone and methyl alcohol (= 50 /
(50% by volume) as the extraction solvent and perform an extraction test in a Soxhlet extractor under reflux for 3 hours. The unextracted polymer is recovered and dried under the same conditions as above. The weight of this is measured (Qg). The gel fraction (%) is calculated according to the following equation (1). Gel fraction (%) = [weight of unextracted polymer (Qg) / polymer weight before Soxhlet extraction test (Pg)] × 100 (Formula 1) As the organic polymer (A) used in the present invention, acrylic polymer, Examples include polyester, polyurethane, epoxy resin, benzoguanamine resin, silicone polymer, and fluorine resin. The organic polymer (A) may be a single compound or a mixture of two or more compounds. Of these, acrylic polymers, acrylic polymers modified with silicone, and silicone polymers can be suitably used, and the appearance of coating films, adhesion, storage stability of coatings, and chemical resistance are improved.

The organic polymer (A) having a gel fraction of 50% or more is a carboxyl group-containing unsaturated monomer (x-2) or an epoxy group-containing unsaturated monomer represented by the following structural formula I or II. Polymer particles (A-1) having a particle diameter of 200 nm or less, obtained by emulsion polymerization of a monomer (x-3) and another unsaturated monomer (Y), or an epoxy group in one molecule. In the presence of a silane compound (C) having an alkoxysilane group, a carboxyl group-containing unsaturated monomer (x-2) represented by the structural formula I or II and another unsaturated monomer (Y) are emulsified. Acrylic polymer fine particles having a particle size of 200 nm or less (A
-2), and by using these,
The storage stability, coating film hardness, chemical resistance, solvent resistance and weather resistance of the paint are improved.

[0012]

Embedded image

[0013]

Embedded image The acrylic polymer fine particles (A-1) are represented by the structural formula I
Alternatively, the carboxyl group-containing unsaturated monomer (x-2) represented by the structural formula II and the epoxy group-containing unsaturated monomer (x
-3) and other unsaturated monomers (Y) by emulsion copolymerization.

Examples of the carboxyl group-containing unsaturated monomer (x-2) represented by the above structural formula I include β-carboxyethyl acrylate, β-carboxyethyl methacrylate and the like. The carboxyl group-containing unsaturated monomer (x-2) represented by the structural formula I may be used alone or as a mixture of two or more.
A carboxyl group-containing unsaturated monomer (x-2) represented by the structural formula I is converted to an organic polymer (A) having an acid value of 0.5 to 5;
It is desirable to copolymerize so as to be 0 mgKOH, preferably 1 to 40 mgKOH. Acid value 0.5mgK
When it is less than OH, a sufficient degree of crosslinking cannot be imparted to the organic polymer (A), and the chemical resistance, the solvent resistance and the like may be deteriorated. On the other hand, when the acid value exceeds 50 mgKOH, the storage stability and the film forming property of the paint tend to be slightly deteriorated.

Examples of the carboxyl group-containing unsaturated monomer (x-2) represented by the above structural formula II include 2-acryloylethylsuccinic acid and 2-methacryloylethylsuccinic acid. The carboxyl group-containing unsaturated monomer (x-2) represented by the structural formula II may be used alone or as a mixture of two or more. The carboxyl group-containing unsaturated monomer (x-2) represented by the structural formula II is copolymerized so that the acid value of the organic polymer (A) is 0.5 to 50 mgKOH, preferably 1 to 40 mgKOH. Is desirable. When the acid value is less than 0.5 mgKOH, a sufficient degree of crosslinking cannot be imparted to the organic polymer (A), and the chemical resistance and the solvent resistance may be deteriorated. On the other hand, when the acid value exceeds 50 mgKOH, the storage stability and the film forming property of the paint tend to be slightly deteriorated.

The unsaturated epoxy group-containing monomer (x-3) used in the present invention includes glycidyl acrylate,
Compounds having an epoxy group and an unsaturated double bond in a molecule such as glycidyl methacrylate, methyl glycidyl acrylate, methyl glycidyl methacrylate, 3,4-epoxycyclohexylmethyl acrylate, and 3,4-epoxycyclohexylmethyl methacrylate can be exemplified. . Epoxy group-containing unsaturated monomer (x-
3) may be a single compound or a mixture of two or more compounds.

Epoxy group-containing unsaturated monomer (x-3)
Is preferably copolymerized at 0.2 to 10.0 mole times the carboxyl group-containing unsaturated monomer (x-2) represented by the structural formula I or II. The number of moles of copolymerization of the epoxy group-containing unsaturated monomer (x-3) is represented by Structural Formula I or Structural Formula II.
If the ratio is less than 0.2 times that of -2), the crosslinking property of the paint is not sufficient, and the chemical resistance and the solvent resistance tend to deteriorate. Further, when the acrylic emulsion (B) is produced, it cannot react with the unsaturated monomer constituting the acrylic emulsion (B), and cannot homogenize the polymer. May worsen. Also, the copolymerization mole number of the epoxy group-containing unsaturated monomer (x-3) is 10.0 with respect to the carboxyl group-containing unsaturated monomer (x-2) represented by the structural formula I or II. If it exceeds twice, the weather resistance of the coating film tends to slightly decrease.

Other unsaturated monomers (Y) used in the present invention include methyl acrylate, ethyl acrylate, butyl acrylate, isobutyl acrylate, tertiary butyl acrylate, propyl acrylate, and cyclohexyl acrylate. , 2-ethylhexyl acrylate,
Lauryl acrylate, tricyclodecyl acrylate, isobornyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate, isobutyl methacrylate, tertiary butyl methacrylate, propyl methacrylate, cyclohexyl methacrylate, 2-ethylhexyl methacrylate, (Meth) acrylic acid alkyl esters such as lauryl methacrylate, tricyclodecyl methacrylate, isobornyl methacrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 4-hydroxybutyl acrylate, polyethylene glycol monoacrylate , Polypropylene glycol monoacrylate, polytetramethylene glycol monoacrylate, polyethylene glycol polytetramethylene glycol Monoacrylate, polypropylene glycol polytetramethylene glycol monoacrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, 4-hydroxybutyl methacrylate, polyethylene glycol monomethacrylate, polypropylene glycol monomethacrylate, polytetramethylene glycol monomethacrylate, Hydroxyl-containing unsaturated monomers (x-1) such as polyethylene glycol polytetramethylene glycol monomethacrylate and polypropylene glycol polytetramethylene glycol monomethacrylate, and carboxyl-containing unsaturated monomers such as acrylic acid, methacrylic acid, maleic acid and itaconic acid. Monomer (x-2), glycidyl acrylate, glycidyl methacrylate, methyl glycidide An epoxy group-containing unsaturated monomer having an epoxy group and an unsaturated double bond in a molecule such as acrylate, methyl glycidyl methacrylate, 3,4-epoxycyclohexylmethyl acrylate, 3,4-epoxycyclohexylmethyl methacrylate (x-3 ), N, N-dimethylaminoethyl methacrylate, N, N-diethylaminoethyl methacrylate, 4-methacryloylamino-2,2,6,
Tertiary amino group-containing unsaturated monomer (y-1) such as 6-tetramethylpiperidine, amide compound (y-2) such as acrylamide, diacetone acrylamide, N, N-dimethylacrylamide, 3-methacryloyloxypropyl Reactive silicon atom-containing unsaturated monomers such as trimethoxysilane and 3-methacryloyloxypropyltriethoxysilane, 2- (2′-hydroxy-5′-methacryloyloxyethylphenyl) -2H-benzotriazole, 4-meta Acryloylamino-2,2,6
Examples thereof include unsaturated monomers having an ultraviolet absorbing group and a hindered amine light-stable group in a molecule such as 6-tetramethylpiperidine, and vinyl compounds such as vinyl acetate, styrene and α-methylstyrene. . The other unsaturated monomers (Y) may be used alone or as a mixture of two or more.

Among the other unsaturated monomers (Y), 2- (2'-hydroxy-5) is used to improve the weather resistance of the coating film.
'-Methacryloyloxyethylphenyl) -2H-benzotriazole, 4-methacryloylamino-2,
Unsaturated monomers having a UV-absorbing group and a hindered amine-based photostable group in a molecule such as 2,6,6-tetramethylpiperidine are extremely suitably used. The unsaturated monomer having an ultraviolet absorbing group and a hindered amine light-stable group is contained in the acrylic emulsion (B) in an amount of 0.02 to 3%.
It is desirable that the copolymer is copolymerized so as to be 0% by weight, preferably 0.2 to 20% by weight. The copolymerization amount is 0.02%
If it is less than 3, the effect of improving the weather resistance may not be remarkably exhibited. When the copolymerization is more than 30% by weight, the storage stability of the paint tends to be deteriorated, and the viscosity of the paint may be observed over time after storage.

The acrylic polymer fine particles (A-1) can be produced, for example, as follows. Water (p
H5 to 7/25 ° C. is preferred) as a dispersion medium, at a polymerization temperature of 30 to 100 ° C., using dodecylbenzenesulfonic acid, polyoxyethylene nonylphenyl ether or the like as an emulsifier, and ammonium persulfate as a polymerization initiator. , Potassium persulfate or the like, using a carboxyl group-containing unsaturated monomer (x-2), an epoxy group-containing unsaturated monomer (x-3) represented by the above structural formula I or the above structural formula II, and It can be produced by emulsion copolymerization of another unsaturated monomer (Y). On this occasion,
It is recommended to use a reactive emulsifier represented by the following structural formula III as the emulsifier. By using the reactive emulsifier, acrylic polymer fine particles (A-1) excellent in various properties such as storage stability, water resistance, and chemical resistance can be produced.

[0021]

Embedded image As the reactive emulsifier represented by the structural formula III, α-
Sulfo-ω- (1-((nonylphenoxy) methyl-2
-(2-propenyloxy) ethoxy-poly (oxy-
1,2-ethanediyl) ammonium salt and the like. The reactive emulsifier may be used alone or as a mixture of two or more.

Further, in the present invention, it is recommended that the pH during the emulsion polymerization be 1 to 8, preferably 1.5 to 5.0, and more preferably 1.8 to 5.0. If the pH during the emulsion polymerization is less than 1, the emulsion polymerization cannot be carried out well, and aggregates tend to occur. When the pH during the emulsion polymerization exceeds 8, it is not possible to produce acrylic polymer fine particles (A-1) having a sufficient degree of crosslinking,
The water resistance, chemical resistance and solvent resistance of the paint may slightly deteriorate.

Of particular note in the present invention is the oxygen concentration during the emulsion polymerization. The oxygen concentration can be easily measured with an oximeter. In the present invention, it is recommended that the oxygen concentration during the emulsion polymerization be 0.01% to 15% by volume, preferably 3% to 12% by volume. If the oxygen concentration during the emulsion polymerization is less than 0.01% by volume, the particle size control of the acrylic polymer fine particles (A-1) becomes insufficient, and a good appearance of the coating film may not be obtained. If the oxygen concentration during the emulsion polymerization exceeds 15% by volume, it is difficult to sufficiently raise the degree of polymerization of the polymer, while avoiding the danger of explosion and fire, and the water resistance of the paint,
Chemical resistance tends to deteriorate.

The acrylic polymer fine particles (A-1) preferably have a particle diameter of 200 nm or less, preferably 120 nm or less, more preferably 80 nm or less. When the particle size is larger than 200 nm, the coating film appearance (gloss,
Sharpness) tends to slightly deteriorate.

Here, the particle size is determined as an average particle size using, for example, “Laser Particle Size Analysis System LPA-3000 / 3100” (a measuring device of Otsuka Electronics Co., Ltd.). The lower limit of the particle diameter is not particularly limited as long as it can be produced by emulsion polymerization. Particle size is 20
0 nm or less, but the particle diameter is 20 to 200 nm.
In this case, the production of the acrylic emulsion (B) is preferred because it is easy to carry out.

Further, acrylic polymer fine particles (A-2)
Can be manufactured, for example, as follows.
Water (preferably ion-exchanged water having a pH of 5 to 7/25 ° C.) is used as a dispersion medium, and at a polymerization temperature of 30 to 100 ° C., dodecylbenzenesulfonic acid, polyoxyethylene nonylphenyl ether, or the like is used as an emulsifier, and a polymerization initiator is used. Using ammonium persulfate, potassium persulfate, etc., in the presence of a silane compound (C) having an epoxy group and an alkoxysilane group in one molecule, a carboxyl group-containing unsaturated compound represented by the above structural formula I or the above structural formula II Monomer (x
-2) and another unsaturated monomer (Y) by emulsion copolymerization. At this time, it is recommended to use a reactive emulsifier represented by the above structural formula III as the emulsifier. By using the reactive emulsifier, acrylic polymer fine particles (A-2) excellent in various properties such as storage stability, water resistance and chemical resistance can be produced. Examples of the silane compound (C) having an epoxy group and an alkoxysilane group in one molecule used in the present invention include 3-glycidoxypropyltrimethoxysilane,
-Glycidoxypropyltriethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3,4-epoxycyclohexylmethyltrimethoxysilane, and hydrolysates and condensates of these silane compounds. The silane compound (C) having an epoxy group and an alkoxysilane group in one molecule may be used alone or
It may be a mixture of more than one kind.

The silane compound (C) is added to the unsaturated monomer constituting the acrylic polymer fine particles (A-2) in an amount of 0.1 to 0.1%.
It is desirable that the content is 2 to 300% by weight, preferably 0.5 to 200% by weight. If the amount is less than 0.2% by weight, the crosslinking property of the paint and the adhesion to the substrate may be slightly deteriorated. If the amount exceeds 300% by weight, the storage stability of the paint tends to be slightly deteriorated.

The reactive emulsifier represented by the structural formula III includes α-sulfo-ω- (1-((nonylphenoxy) methyl-2- (2-propenyloxy) ethoxy-).
Examples thereof include ammonium salts of poly (oxy-1,2-ethanediyl). The reactive emulsifier may be used alone or as a mixture of two or more.

Further, in the present invention, it is recommended that the pH during the emulsion polymerization be 1 to 8, preferably 1.5 to 5.0, and more preferably 1.8 to 5.0. If the pH during the emulsion polymerization is less than 1, the emulsion polymerization cannot be carried out well, and aggregates tend to occur. Further, when the pH during the emulsion polymerization exceeds 8, the acrylic polymer fine particles (A-1) having a sufficient degree of crosslinking cannot be produced, and the water resistance, chemical resistance, and solvent resistance of the paint are slightly increased. May worsen.

Of note in the present invention is the oxygen concentration during the emulsion polymerization. The oxygen concentration can be easily measured with an oximeter. In the present invention, it is recommended that the oxygen concentration during the emulsion polymerization be 0.2% to 15% by volume, preferably 3% to 12% by volume. When the oxygen concentration during the emulsion polymerization is less than 0.2% by volume, the particle size control of the acrylic polymer fine particles (A-1) becomes insufficient, and a good appearance of the coating film may not be obtained. Also,
If the oxygen concentration during the emulsion polymerization exceeds 15% by volume,
In addition to the risk of explosion and fire, it is difficult to sufficiently increase the degree of polymerization of the polymer, and the water resistance and chemical resistance of the paint tend to deteriorate.

The acrylic polymer fine particles (A-2) preferably have a particle diameter of 200 nm or less, preferably 120 nm or less, more preferably 80 nm or less. When the particle size is larger than 200 nm, the coating film appearance (gloss,
Sharpness) tends to slightly deteriorate.

Here, the particle diameter is determined as an average particle diameter using, for example, “Laser Particle Size Analysis System LPA-3000 / 3100” (a measuring device of Otsuka Electronics Co., Ltd.). The lower limit of the particle diameter is not particularly limited as long as it can be produced by emulsion polymerization. Particle size is 20
0 nm or less, but the particle diameter is 20 to 200 nm.
In this case, the production of the acrylic emulsion (B) is preferred because it is easy to carry out.

The organic polymer (A) is contained in the acrylic emulsion (B) in an amount of 0.2 to 98% by weight, preferably 2 to 98% by weight.
It is desirable to contain 98% by weight, more preferably 5 to 60% by weight. When the content of the organic polymer (A) is less than 0.2% by weight, the hardness of the coating film is slightly lowered, and the coating film tends to be easily damaged. When the content of the organic polymer (A) exceeds 98% by weight, the film formability of the acrylic emulsion (B) may be slightly deteriorated, and the appearance of the coating film such as gloss and smoothness may be slightly deteriorated. is there.

The acrylic emulsion (B) used in the present invention is prepared by adding a hydroxyl group-containing unsaturated monomer (x-) in the presence of an organic polymer (A) having a gel fraction of 50% or more.
1) a radical polymerizable unsaturated monomer (X) containing at least two selected from a carboxyl group-containing unsaturated monomer (x-2) and an epoxy group-containing unsaturated monomer (x-3); And other unsaturated monomers (Y) by emulsion polymerization.

Examples of the hydroxyl group-containing unsaturated monomer (x-1) include 2-hydroxyethyl acrylate and 2-hydroxyethyl acrylate.
Hydroxypropyl, 4-hydroxybutyl acrylate, polyethylene glycol monoacrylate, polypropylene glycol monoacrylate, polytetramethylene glycol monoacrylate, polyethylene glycol polytetramethylene glycol monoacrylate,
Polypropylene glycol polytetramethylene glycol monoacrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, 4-hydroxybutyl methacrylate, polyethylene glycol monomethacrylate, polypropylene glycol monomethacrylate, polytetramethylene glycol monomethacrylate, polyethylene glycol poly Compounds having a hydroxyl group and an unsaturated group in one molecule such as tetramethylene glycol monomethacrylate and polypropylene glycol polytetramethylene glycol monomethacrylate can be exemplified. The hydroxyl group-containing unsaturated monomer (x-
1) may be a single compound or a mixture of two or more compounds.

When the hydroxyl group-containing unsaturated monomer (x-1) is copolymerized, when the acrylic emulsion (B) is produced, 1 to 40 of the unsaturated monomers used for emulsion polymerization are used.
It is desirable that the copolymer be copolymerized so as to be 2% by weight, preferably 2 to 25% by weight. When the copolymerization amount is less than 1% by weight, the adhesion to the article to be coated and the cross-linking property of the paint may be slightly deteriorated. When the copolymerization amount exceeds 40% by weight, the chemical resistance of the paint may be slightly deteriorated. The hydroxyl group-containing unsaturated monomer (x-1) has an effect of imparting adhesion to a coating material and crosslinkability with a curing agent to a coating material.

The unsaturated monomer having a carboxyl group (x-
Examples of 2) include those having a carboxyl group and an unsaturated group in one molecule, such as acrylic acid, methacrylic acid, maleic acid and itaconic acid. The carboxyl group-containing unsaturated monomer (x-2) may be used alone or as a mixture of two or more.

The carboxyl group-containing unsaturated monomer (x-
In the case of copolymerizing 2), when producing the acrylic emulsion (B), 0.2 to 50% by weight, preferably 0.5 to 30% by weight, based on the unsaturated monomer used for emulsion polymerization. % Is desirably copolymerized. The copolymerization amount is 0.
If the amount is less than 2% by weight, the crosslinkability becomes insufficient, and the chemical resistance and solvent resistance of the coating film tend to deteriorate. If the copolymerization amount exceeds 50% by weight, the storage stability of the paint tends to deteriorate. The carboxyl group-containing unsaturated monomer (x-2) is suitably used for improving the pigment dispersibility of a coating material, the adhesion to an object to be coated, and the like.

More preferably, the carboxyl group-containing unsaturated monomer (x-2) is a monomer represented by the structural formula I or II. At this time, there is a tendency that the water resistance, alkali resistance, adhesiveness, and curability of the paint when a curing agent is blended are remarkably improved. In particular, copolymerization of the carboxyl group-containing unsaturated monomer (x-2) of the structural formula I is preferable, and the above-mentioned various properties and the durability of the coating film tend to be further improved.

In the case of copolymerizing the epoxy group-containing unsaturated monomer (x-3), when producing the acrylic emulsion (B), 1 to 3 of the unsaturated monomers used for emulsion polymerization are used.
It is desirable to copolymerize so as to be 50% by weight, preferably 2 to 30% by weight, more preferably 5 to 25% by weight. If the copolymerization amount is less than 1% by weight, the storage stability of the paint tends to be poor. When the copolymerization amount is 50
If the amount is more than 10% by weight, the curability of the paint may be deteriorated, and the chemical resistance and the solvent resistance may be deteriorated.

Among the other unsaturated monomers (Y), 2- (2'-hydroxy-) is used in order to improve the weather resistance of the coating film.
5'-methacryloyloxyethylphenyl) -2H-
Benzotriazole, 4-methacryloylamino-
Unsaturated monomers having a UV-absorbing group and a hindered amine light-stable group in a molecule such as 2,2,6,6-tetramethylpiperidine are extremely preferably used. The other unsaturated monomer is desirably copolymerized in the acrylic emulsion (B) so as to be 0.02 to 30% by weight, preferably 0.2 to 20% by weight. If the copolymerization amount is less than 0.02%, the effect of improving weather resistance may not be remarkably exhibited. When the copolymerization is more than 30% by weight, the storage stability of the paint tends to be deteriorated, and the viscosity of the paint may be observed over time after storage.

Further, an acrylic emulsion (B)
It is recommended that a silane compound (C) having an epoxy group and an alkoxysilane group in one molecule be present during emulsion polymerization. The presence of the silane compound (C) at the time of the emulsion polymerization improves the cross-linking property of the paint, and improves the chemical resistance of the coating film,
The solvent resistance, weather resistance, and adhesion to various objects to be coated tend to be dramatically improved. It should be particularly noted that they exhibit extremely good adhesion to aluminum alloys, magnesium alloys, and the like, which are difficult to adhere to.

When producing the acrylic emulsion (B), the silane compound (C) is used in an amount of 0.2 to 300% by weight, preferably 0.1 to 300% by weight, based on the unsaturated monomer used for emulsion polymerization.
It is desirable to mix 5 to 200% by weight. If the amount is less than 0.2% by weight, the crosslinking property of the paint and the adhesion to the substrate may be slightly deteriorated. If the amount exceeds 300% by weight, the storage stability of the paint tends to be slightly deteriorated.

The acrylic emulsion (B) can be produced, for example, as follows. Water (pH5
7/25 ° C. is preferably used as a dispersion medium, at a polymerization temperature of 30 to 100 ° C., using dodecylbenzenesulfonic acid, polyoxyethylene nonylphenyl ether or the like as an emulsifier, ammonium persulfate as a polymerization initiator, Use potassium sulfate etc. and gel fraction is 5
In the presence of 0% or more of the organic polymer (A), a hydroxyl group-containing unsaturated monomer (x-1), a carboxyl group-containing unsaturated monomer (x-2) and an epoxy group-containing unsaturated monomer ( x
-3) a radically polymerizable unsaturated monomer (X) containing at least two kinds selected from the group consisting of: and another unsaturated monomer (Y)
Can be produced by emulsion copolymerization of
At this time, it is recommended to use a reactive emulsifier represented by the above structural formula III as the emulsifier. By using the reactive emulsifier, an acrylic meter emulsion (B) excellent in various properties such as storage stability, water resistance and chemical resistance can be produced. As the reactive emulsifier represented by the above structural formula III, α-sulfo-ω- (1-((nonylphenoxy) methyl-2- (2-propenyloxy) ethoxy-poly (oxy-1,2-ethanediyl)) The reactive emulsifier may be used alone or as a mixture of two or more.

Further, the pH during the emulsion polymerization is 1 to 8, preferably 1.5 to 5.0, more preferably 1.8 to 5.
It is recommended that it be zero. If the pH during the emulsion polymerization is less than 1, emulsion polymerization cannot be carried out well, and aggregates tend to be formed. On the other hand, when the pH during the emulsion polymerization exceeds 8, it is not possible to produce an acrylic emulsion (B) having a sufficient cross-linking property, and the water resistance of the paint,
Chemical resistance and solvent resistance may slightly deteriorate. More preferably, a carboxyl group-containing unsaturated monomer (x-2)
In the case of containing, the pH during the emulsion polymerization is 1.8 to 5.0,
More preferably, the pH during emulsion polymerization is from 4.0 to 6.0, more preferably from 4.0 to 6.0, when the carboxyl group-containing unsaturated monomer (x-2) is not contained. 5-5.
8 is recommended. When the emulsion polymerization is carried out under these conditions, an emulsion having a small amount of aggregates and a uniform particle size is produced, and an acrylic emulsion (B) having excellent curability and crosslinkability of the paint tends to be produced. .

What should be noted in the present invention is the oxygen concentration during the emulsion polymerization. The oxygen concentration can be easily measured with an oximeter. In the present invention, it is recommended that the oxygen concentration during the emulsion polymerization be 0.2% to 15% by volume, preferably 3% to 12% by volume. When the oxygen concentration during the emulsion polymerization is less than 0.2% by volume, the particle size control of the acrylic polymer fine particles (A-1) becomes insufficient, and a good appearance of the coating film may not be obtained. Also,
If the oxygen concentration during the emulsion polymerization exceeds 15% by volume,
In addition to the risk of explosion and fire, it is difficult to sufficiently increase the degree of polymerization of the polymer, and the water resistance and chemical resistance of the paint tend to deteriorate.

In the present invention, the aqueous acrylic resin (D) having a tertiary amino group and a carboxyl group in the side chain, the compound (E) having a tertiary amino group (E), and the quaternary ammonium salt (F) are cured. Agent and curing catalyst. These polymers and compounds may be used alone or as a mixture of two or more.

The aqueous acrylic resin (D) having a tertiary amino group and a carboxyl group in the side chain includes an unsaturated monomer having a tertiary amino group (y-1) and an unsaturated monomer having a carboxyl group (x- It can be produced by radical copolymerization of 2) and other unsaturated monomers (Y). At this time, the tertiary amino group-containing unsaturated monomer (y-1) was 0.2%.
Preferably, the unsaturated monomer (x-2) having a carboxyl group is copolymerized at 0.5 to 50% by weight. When the copolymerization amount of the tertiary amino group-containing unsaturated monomer (y-1) is less than 0.2% by weight, the low-temperature curability of the coating material may be slightly deteriorated. When the amount of the tertiary amino group-containing unsaturated monomer (y-1) exceeds 30% by weight, water resistance, chemical resistance, and weather resistance tend to deteriorate.

The unsaturated monomer having a carboxyl group (x-
When the copolymerization amount of 2) is less than 0.5% by weight, the curability of the coating and the adhesion to the object to be coated tend to be slightly deteriorated.
If the amount of the carboxyl group-containing unsaturated monomer (x-2) exceeds 50% by weight, the coating water resistance and wet heat resistance tend to be slightly deteriorated.

The aqueous acrylic resin (D) having a tertiary amino group and a carboxyl group in the side chain is produced, for example, as follows. In the case of solution polymerization using an (aqueous) organic solvent as a medium, water-soluble solvents such as methyl alcohol, ethyl alcohol, isopropyl alcohol, ethylene glycol monobutyl ether, and propylene glycol monomethyl ether (10 g / g)
Water, having a water solubility of 20 ° C. or more) at a polymerization temperature of 30 to 150 ° C. and α, α-azobisisobutyronitrile, benzoyl peroxide, t-butylperoxy-2.
Tertiary amino group-containing unsaturated monomer (y-1), carboxyl group-containing unsaturated monomer (x-2), and other unsaturated monomers using a polymerization initiator such as -ethylhexanoate It can be produced by radical copolymerization of (Y).

A light-colorless and transparent water-based acrylic resin (D)
It is preferable that the polymerization is carried out in an atmosphere of an inert gas such as a nitrogen gas, a helium gas, an argon gas or the like, since it is easy to obtain a light-colored enamel paint and a clear paint.

Further, to control the molecular weight, mercaptans such as n-dodecyl mercaptan may be used as a polymerization degree regulator. In the present invention, 2,4-diphenyl-4-methyl-1-pentene (α- Methylstyrene dimer) can be suitably used, and it is possible to produce an aqueous acrylic resin (D) which is colorless and transparent, and is excellent in weather resistance and storage stability.

The aqueous acrylic resin (D) having a tertiary amino group and a carboxyl group in the side chain is 0.5 to 500 parts by weight based on 100 parts by weight of the acrylic emulsion (B).
Preferably, 2 to 50 parts by weight are blended.
If the amount of the aqueous acrylic resin (D) having a tertiary amino group and a carboxyl group in the side chain is less than 0.5 part by weight, the curability of the paint is slightly insufficient, and the water resistance and chemical resistance of the paint are poor. Tends to worsen. If the amount of the aqueous acrylic resin (D) having a tertiary amino group and a carboxyl group in the side chain exceeds 500 parts by weight, the storage stability of the coating and the appearance of the coating tend to deteriorate.

Examples of the compound (E) having a tertiary amino group include triethylamine, diethylbenzylamine and tri (2,4,6-dimethylaminomethyl) phenol. The compound (E) having a tertiary amino group may be a single compound or a mixture of two or more compounds. Preferably, a compound having a tertiary amino group such as tri (2,4,6-dimethylaminomethyl) phenol and a phenolic hydroxyl group is used. By using these compounds, the curability, crosslinking property, chemical resistance, Water resistance is improved.

The compound (E) having a tertiary amino group was added in an amount of 0.1 to 100 parts by weight of the acrylic emulsion (B).
It is desirable that the compounding amount be from 02 to 30 parts by weight, preferably 0.5 to 20 parts by weight. When the compounding amount of the compound (E) having a tertiary amino group is less than 0.02 parts by weight, the curability of the paint tends to deteriorate. If the compounding amount of the compound (E) having a tertiary amino group exceeds 30 parts by weight, coloring may be observed in the paint, and it may be impossible to produce a light-colored enamel or clear paint.

Examples of the quaternary ammonium salt (F) include triethylbenzylammonium chloride and tetrabutylammonium bromide.
The quaternary ammonium salt (F) may be used alone or as a mixture of two or more. The quaternary ammonium salt (F) is used in an amount of 0.02 to 30 parts by weight, preferably 0.5 to 2 parts by weight, based on 100 parts by weight of the acrylic emulsion (B).
It is desirable to mix 0 parts by weight. If the amount of the quaternary ammonium salt (F) is less than 0.02 parts by weight, the curability of the coating tends to deteriorate. When the amount of the quaternary ammonium salt (F) exceeds 30 parts by weight,
Coloring may be observed in the paint, making it impossible to produce a light-colored enamel or clear paint.

In the present invention, if necessary, pigments such as titanium oxide, carbon black, zinc white and aluminum pigment, toluene, xylene, ethyl acetate,
Various paint additives such as organic solvents such as butyl acetate (non-aromatic solvents are recommended for the purpose of the present invention), pigment dispersants, leveling agents, defoamers, sedimentation inhibitors, γ-glycides Silane coupling agents (silane compounds having a reactive silicon atom) such as xypropyltrimethoxysilane, 3-aminoethylaminopropyltrimethoxysilane, amino group-containing silane compounds in which amino groups are blocked with methyl isobutyl ketone, etc., triethylamine And other curing agents such as dibutyltin dilaurate, ultraviolet absorbers such as benzotriazole and benzophenone, and weathering agents such as hindered amine light stabilizers (preferably having a base constant (pKb) of 8 or more). Can be blended. More preferably, it is recommended to mix inorganic fine particles such as silica sol and alumina sol having a particle diameter of less than 100 nm, and the effect of increasing the hardness of the coating film and improving the scratch resistance is high.

The emulsion coating composition of the present invention can be applied by various coating methods such as spray coating, brush coating, curtain flow coating and roller coater.

The emulsion paint composition of the present invention can be applied to all fields of paints applied to architecture, building materials, home appliances, information home appliances such as mobile phones and personal computers, automobiles, ships, motorcycles and the like. It is possible. In this case, as a substrate (object to be coated), acrylonitrile-styrene-butadiene resin (ABS), polycarbonate (PC), nylon (NY), polyester (PE
S), plastics such as polypropylene (PP) and their alloys, fiber-reinforced products such as carbon fiber and glass fiber, or thermosetting plastics such as epoxy resin and unsaturated polyester, magnesium, aluminum, iron, tin, tinplate And the like, and alloys thereof, and those subjected to chemical conversion treatment, those subjected to electrodeposition coating, and the like. In particular, it exhibits good adhesion and scratch resistance and is suitable for use as a plastic for hard-to-adhesive metals (alloys) such as magnesium alloys and polyphenylene sulfide (PPS).

[0060]

The present invention will be described in more detail with reference to the following examples.

The test methods and evaluations of the emulsion coating compositions obtained in the examples and comparative examples are performed as follows.

1. Adhesiveness A coating material is applied to an ABS plate degreased with isopropyl alcohol so as to have a film thickness of 30 to 40 μm, and dried at room temperature for 10 minutes. Next, baking is performed at 80 ° C. for 30 minutes.

A coating material is applied to a magnesium alloy (AZ91D) so as to have a thickness of 30 to 40 μm.
And bake for 20 minutes. JIS K
54008.5.2 The test is performed by the crosscut tape method. A pass is 100/100.

2. Prepare a coated board for testing in the same manner as for water resistance and adhesion. After immersing the coated plate in warm water at 50 ° C. for 10 days, the appearance of the coating film (discoloration, blistering, peeling, etc.) and adhesion are evaluated. There was no change in the appearance of the coating film, and the adhesion was 100/100, which was regarded as acceptable.

3. Gel fraction (%) of organic polymer (A) Each organic polymer (A) is thinly spread on a polypropylene plate (PP) and vacuum dried at 40 ° C. and a degree of vacuum of 100 to 7000 Pa for 48 hours. An extraction test is performed on Pg of the vacuum-dried organic polymer (A) for 3 hours under reflux with a Soxhlet extractor using a mixed solvent of acetone and methyl alcohol (= 50/50% by volume) as an extraction solvent. . The unextracted polymer is recovered and dried under the same conditions as above. The weight of this is measured (Qg). The gel fraction (%) is calculated according to the following equation. Gel fraction (%) = [weight of unextracted polymer (Qg) / polymer weight before Soxhlet extraction test (Pg)] × 10
0 4. Curability of paint (solvent resistance) Prepare a coated plate for testing in the same manner as for adhesion. The felt for rubbing test is made to contain toluene, and the coating film surface is rubbed (rubbed) 50 times with this, and the coating film is observed for damage, peeling and dissolution. The evaluation is as follows. ○ Good with no change in coating film. Pass. B: The coating film is glossy, but the base does not appear, and the coating film is retained. Pass. × The coating film dissolves and the undercoat appears. failure.

Examples and comparative examples will be described below. In addition,
Unless otherwise specified, the compounding amount indicates% by weight.

Example 1 A 2 L four-necked flask was charged with 285.4 g of ion-exchanged water (PW). 200m in which a mixed gas of air and oxygen was blown to adjust the oxygen concentration to 8%
1 In a conical beaker, add 32 g of PW, “Adekariasorb SE-10N” (SE-10N) (α-sulfo-ω-
(Ammonium salt of 1-((nonylphenoxy) methyl-2- (2-propenyloxy) ethoxy-poly (oxy-1,2-ethanediyl) (reactive emulsifier of structural formula III), available from Asahi Denka Kogyo KK) Product) 2.4g, Methyl methacrylate (MMA) / "SIPOMER β-CEA"
(Β-CEA) (β-carboxyethyl acrylate (unsaturated carboxylic acid of structural formula I), a product of Rhone Poulin Co.) / Glycidyl methacrylate (GMA)
(= 85/5/10) 80 g, ammonium persulfate (A
(PS) of 0.16 g, stirred with a stirrer, and emulsified (the conductivity of this emulsion was 1250 μs / cm (2
5 ° C.). ). This is charged in a flask,
The temperature rose. Polymerization was performed at 80 ° C. for 2 hours to produce an organic polymer (A-1). The organic polymer (A-1) had a particle size of 55 nm and a gel fraction of 85%.

Further, 141.8 g of PW was charged into the flask and maintained at 80 ° C. P gas was introduced into a 1L conical beaker in which a mixed gas of air and oxygen was blown to adjust the oxygen concentration to 8%.
W128 g, SE-10N 9.6 g, MMA / n-butyl methacrylate (BMA) / n-butyl acrylate (B
A) / GMA / 2-hydroxyethyl methacrylate (H
EMA) (= 40/20/20/10/10) 320
g, 0.64 g of ammonium persulfate (APS), and stirred with a stirrer to emulsify (the conductivity of this emulsion was 1150 μs / cm (25 ° C.)). This was added dropwise to the flask in 3 hours, and after the completion of the addition, polymerization was continued for another 1 hour to produce an acrylic emulsion (B-1). The acrylic emulsion (B-1) had a solid content of 40%, a pH of 2.8, and a particle size of 110 nm. "CS-1" was added to the acrylic emulsion (B-1).
2 "(2,2,4-trimethyl-1.3-pentanediol monoisobutyrate (film-forming aid), a product of Chisso Petrochemical Co., Ltd.) in an amount of 10 PHR, and the emulsion coating composition of Example 1 was added. Was manufactured.

Example 2 285.4 g of ion-exchanged water (PW) was charged into a 2 L four-necked flask, and a mixed gas of air and oxygen was blown into the flask to adjust the oxygen concentration to 8%. A mixture gas of air and oxygen was blown to adjust the oxygen concentration to 8%.
PW32g, SE-10N in 0ml conical beaker
2.4 g, MMA / β-CEA / GMA (= 85/5 /
10) 80 g and 0.16 g of APS were charged, stirred with a stirrer, and emulsified (the conductivity of this emulsion was 1250).
μs / cm (25 ° C.). ). This was charged into a flask and heated to 80 ° C. Polymerization was performed at 80 ° C. for 2 hours to produce an organic polymer (A-1). Organic polymer (A-1) has a particle diameter of 55 nm and a gel fraction of 85%.
Met.

Further, 141.8 g of PW and 0.2 g of sodium hydrogen carbonate were charged into the flask, and the temperature was maintained at 80.degree. A mixed gas of air and oxygen was blown into the 1 L conical beaker adjusted to an oxygen concentration of 8%.
9.6 g of 10N, MMA / BMA / BA / GMA / HE
320 g of MA (= 40/20/20/10/10), A
0.64 g of PS was charged and stirred with a stirrer to emulsify (the conductivity of this emulsion was 1150 μs / cm (25
° C). ). This is dropped into the flask in 3 hours,
After the completion of the dropwise addition, the polymerization was further continued for 1 hour to produce an acrylic emulsion (B-2). Acrylic emulsion (B-2) has a solid content of 40%, pH 6.2, and a particle size of 11
It was 5 nm. 10 CSHR of “CS-12” was blended with the acrylic emulsion (B-2) to produce an emulsion coating composition of Example 2.

Example 3 293.4 g of ion-exchanged water (PW) was charged into a 2 L four-necked flask, and air and water were added thereto.
The oxygen concentration was adjusted to 8% by blowing in a mixed gas of oxygen. PW32g, S into a 200ml conical beaker in which a mixed gas of air and oxygen was blown to adjust the oxygen concentration to 8%.
2.4 g of E-10N, MMA / BMA / β-CEA / G
80 g of MA (= 55/30/5/10), "SH-60
40 "(3-glycidoxypropyltrimethoxysilane, a product of Dow Corning Toray Silicone Co., Ltd.)
8 g and APS 0.16 g were charged, stirred with a stirrer, and emulsified (the conductivity of this emulsion was 1250 μs /
cm (25 ° C.). ). This was charged into a flask and heated to 80 ° C. Polymerization was performed at 80 ° C. for 2 hours to produce an organic polymer (A-2). Organic polymer (A-
2) had a particle diameter of 52 nm and a gel fraction of 92%.

Further, 141.8 g of PW was charged into the flask, and 80 ° C. was maintained. A mixed gas of air and oxygen was blown into the 1L conical beaker adjusted to an oxygen concentration of 8%,
28 g, SE-10N 9.6 g, MMA / BMA / BA
/ GMA / HEMA (= 40/20/20/10/1)
0) 320 g of APS and 0.64 g of APS were charged, stirred with a stirrer, and emulsified (the conductivity of this emulsion was 1150).
μs / cm (25 ° C.). ). This was added dropwise to the flask in 3 hours, and after the addition was completed, polymerization was continued for another 1 hour.
An acrylic emulsion (B-3) was produced. Acrylic emulsion (B-3) has a solid content of 40%, pH
Was 2.8, and the particle size was 108 nm. 10 PHR of "CS-12" in acrylic emulsion (B-3)
The emulsion coating composition of Example 3 was produced.

Example 4 A 2 L four-necked flask was charged with 293.4 g of ion-exchanged water (PW).
The oxygen concentration was adjusted to 8% by blowing in a mixed gas of oxygen. PW32g, S into a 200ml conical beaker in which a mixed gas of air and oxygen was blown to adjust the oxygen concentration to 8%.
2.4 g of E-10N, MMA / BMA / β-CEA / G
80 g of MA (= 55/30/5/10), "SH-60
40 ", 8 g and APS 0.16 g were stirred and stirred with a stirrer to emulsify (the conductivity of this emulsion was 1250 μm).
s / cm (25 ° C.). ). This was charged into a flask and heated to 80 ° C. Polymerization was performed at 80 ° C. for 2 hours to produce an organic polymer (A-2). Organic polymer (A
The particle diameter of -2) was 52 nm, and the gel fraction was 92%.

Further, the flask was charged with 206 g of PW,
80 ° C. was maintained. PW1 was introduced into a 1 L conical beaker in which a mixed gas of air and oxygen was blown and the oxygen concentration was adjusted to 8%.
28 g, SE-10N 9.6 g, MMA / BMA / BA
/ GMA / HEMA (= 40/20/20/10/1)
0) 320 g, "SH-6040" 64 g, APS0.
64 g was charged, stirred with a stirrer, and emulsified (the conductivity of this emulsion was 1150 μs / cm (25 ° C.)). This was added dropwise to the flask in 3 hours, and after the completion of the addition, polymerization was continued for another 1 hour to produce an acrylic emulsion (B-5). Acrylic emulsion (B-
5) The solid content is 40%, the pH is 2.3, and the particle size is 98 n.
m. Acrylic emulsion (B-5) with "C
S-12 "was blended at 10 PHR to produce an emulsion coating composition of Example 4.

Example 5 MMA / BMA / BA / HEMA / methacrylic acid / N, N-dimethylaminoethyl methacrylate (tertiary amino group-containing non-tertiary amino group) was prepared using ethylene glycol monobutyl ether / isopropyl alcohol (80/20) as a solvent. Saturated monomer) (= 40/20/2)
Aqueous acrylic resin (D) having a tertiary amino group and a carboxyl group in the side chain consisting of (0/5/10/5) was produced. (However, as a chain transfer agent, 2,4-diphenyl-
4-methyl-1-pentene (α-methylstyrene dimer) was used, and nitrogen gas was blown during the polymerization reaction. )
The aqueous acrylic resin (D) had a solid content of 50% and a number average molecular weight of 3,000.

The aqueous acrylic resin (D) was neutralized with triethylamine to a neutralization ratio of 60%, and PW was added to adjust the solid content to 40%.

The aqueous acrylic resin (D) diluted with water and the acrylic emulsion (B-2) were mixed at a solid content ratio of 10 /
Mix to 90, and further add “CS-12” to 10
The PHR was blended and stirred until uniform, whereby an emulsion coating composition of Example 5 was produced.

(Example 6) 293.4 g of ion-exchanged water (PW) was charged into a 2 L four-necked flask, and air and water were added thereto.
The oxygen concentration was adjusted to 8% by blowing in a mixed gas of oxygen. PW32g, SE into a 200 ml conical beaker in which a mixed gas of air and oxygen was blown to adjust the oxygen concentration to 8%.
2.4 g of -10N, MMA / BMA / β-CEA / GM
A (= 55/30/5/10) 80 g, "SH-604
0 ", 8 g of APS and 0.16 g of APS were stirred, stirred with a stirrer, and emulsified (the conductivity of this emulsion was 1250 μs).
/ Cm (25 ° C.). ). This was charged into a flask and heated to 80 ° C. Polymerization was performed at 80 ° C. for 2 hours to produce an organic polymer (A-2). Organic polymer (A-
In 2), the particle diameter was 52 nm and the gel fraction was 92%.

Further, 206 g of PW was charged into the flask,
80 ° C. was maintained. PW1 was introduced into a 1 L conical beaker in which a mixed gas of air and oxygen was blown and the oxygen concentration was adjusted to 8%.
28 g, SE-10N 9.6 g, MMA / BMA / BA
/ (Β-CEA) / HEMA (= 45/20/20/5
/ 10) 320 g, “SH-6040” 64 g, APS
0.64 g was charged, stirred with a stirrer, and emulsified (the conductivity of this emulsion was 1150 μs / cm (25 ° C.)
Met. ). This was added dropwise to the flask in 3 hours, and after the completion of the addition, polymerization was continued for 1 hour to produce an acrylic emulsion (B-6). Acrylic emulsion (B
-6) The solid content is 40%, the pH is 2.5, and the particle size is 12
It was 0 nm. 10 CSHR of “CS-12” was blended with the acrylic emulsion (B-6) to produce an emulsion coating composition of Example 6.

(Example 7) Acrylic emulsion (B
-5), an aqueous ammonia solution (25% aqueous solution) was added to adjust the pH to 8.0 (25 ° C.).
2 "was blended at 10 PHR to produce an emulsion coating composition of Example 7.

Comparative Example 1 A 2 L four-necked flask was charged with 293.4 g of ion-exchanged water (PW), and a mixed gas of air and oxygen was blown into the flask to adjust the oxygen concentration to 8%. PW32g, S into a 200ml conical beaker in which a mixed gas of air and oxygen was blown to adjust the oxygen concentration to 8%.
2.4 g of E-10N, MMA / BMA / β-CEA / G
80 g of MA (= 55/30/5/10), "SH-60
40 "and 0.16 g of APS, and stirred with a stirrer to emulsify (the conductivity of this emulsion was 1250 μs /
cm (25 ° C.). ). This was charged into a flask and heated to 80 ° C. Polymerization was performed at 80 ° C. for 2 hours to produce an organic polymer (A-2). Organic polymer (A-
The particle diameter of 2) was 52 nm, and the gel fraction was 92%.

Further, 141.8 g of PW was charged into the flask, and 80 ° C. was maintained. P gas was introduced into a 1L conical beaker in which a mixed gas of air and oxygen was blown to adjust the oxygen concentration to 8%.
W128g, SE-10N 9.6g, MMA / BMA /
BA / HEMA (= 50/20/20/10) 320
g, APS 0.64 g, and stirred with a stirrer,
Emulsified (the conductivity of this emulsion is 1150 μs / cm
(25 ° C.). ). This was added dropwise to the flask in 3 hours, and after the completion of the addition, polymerization was continued for 1 hour to produce an acrylic emulsion (B-6). The solid content of the acrylic emulsion (B-6) was 40%, the pH was 2.8, and the particle size was 108 nm. 25% ammonia water was added to this acrylic emulsion (B-6) to adjust the pH to 8.0 (25 ° C.).
2 "was blended at 10 PHR to produce an emulsion coating composition of Comparative Example 1.

(Comparative Example 2) PW was placed in a 2 L four-necked flask.
428.5 g was charged, and a mixed gas of air and oxygen was blown into this to adjust the oxygen concentration to 8%. A mixed gas of air and oxygen was blown into the 200 ml conical beaker adjusted to an oxygen concentration of 8%, and PW 160 g, SE-10N10.
8g, MMA / BMA / β-CEA / GMA (= 55 /
30/5/10) 360 g, "SH-6040" 40
g, APS 0.72 g, and stirred with a stirrer,
Emulsified (the conductivity of this emulsion is 1250 μs / cm
(25 ° C.). ).

56 g of the emulsion was charged into a flask, and
C., and the polymerization was carried out at 80.degree. C. for 30 minutes.

The remaining emulsion was dropped into the flask in 3 hours, and after completion of the dropping, polymerization was carried out at 80 ° C. for 1 hour.
The emulsion has a solid content of 40% and a pH of 2.2 (2
5 ° C.), and the gel fraction was 80%.

After cooling to room temperature, 25% aqueous ammonia was added to adjust the pH to 8.0 (25 ° C.).
-12 "was blended at 10 PHR to produce an emulsion coating composition of Comparative Example 2.

The test results of the paints carried out using the respective emulsion paint compositions of the above Examples and Comparative Examples were as follows:
The results are shown in Table 1.

[0088]

[Table 1]

[0089]

According to the present invention, an emulsion coating composition having a number of excellent and well-balanced performances can be obtained. In particular, it exhibits remarkable performance in water resistance and solvent resistance of the paint, which was difficult to achieve with the conventional emulsion paint composition. Furthermore, an emulsion coating composition having good adhesion to non-ferrous metals such as magnesium alloys and aluminum alloys, which are considered to have poor adhesion, can be obtained.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C08F 265/04 C08F 265/04 C09D 5/02 C09D 5/02 133/00 133/00 201/02 201 / 02 F term (reference) 4J011 PA47 PA69 PB40 4J026 AA43 AA45 AA48 AC09 BA24 BA27 BA30 BB03 BB04 BB09 DA04 DA07 DA14 DB04 DB08 DB14 GA08 GA09 4J038 CD092 CG002 CG141 CG192 CH262 DA172 DB002 DD002 GA03 GA03 GA03 GA07 GA07 GA03 MA08 MA10 MA14 NA01 NA03 NA04 NA12 NA27 PA19 PC02 PC08 4J100 AJ02R AJ08R AJ09R AL03R AL04R AL05R AL08P AL08Q AL08R AL09R AL10Q AL10R AM15R AM21R BA03R BA08R BA09R BA15P BA16P BA21P BA31R BA77R BC04 BC0775

Claims (5)

[Claims] 1. The method according to claim 1, wherein a hydroxyl group-containing unsaturated monomer (x-
1) a radical polymerizable unsaturated monomer (X) containing at least two selected from a carboxyl group-containing unsaturated monomer (x-2) and an epoxy group-containing unsaturated monomer (x-3); An emulsion coating composition containing an acrylic emulsion (B) obtained by emulsion polymerization of another unsaturated monomer (Y). 2. An organic polymer (A) comprising a carboxyl group-containing unsaturated monomer (x-2) and an epoxy group-containing unsaturated monomer (x-2) represented by the following structural formulas I and / or II. 3. The emulsion paint according to claim 1, which is an acrylic polymer fine particle (A-1) having a particle diameter of 200 nm or less, obtained by emulsion-polymerizing -3) and another unsaturated monomer (Y). Composition. Embedded image Embedded image 3. An organic polymer (A) containing a carboxyl group represented by the following structural formulas I and / or II in the presence of a silane compound (C) having an epoxy group and an alkoxysilane group in one molecule. Unsaturated monomer (x-
2. The emulsion paint according to claim 1, which is an acrylic polymer fine particle (A-2) having a particle diameter of 200 nm or less, obtained by emulsion polymerization of 2) and another unsaturated monomer (Y). Composition. Embedded image Embedded image 4. A molded magnesium alloy comprising a coating film formed from the emulsion coating composition according to any one of claims 1 to 3. 5. A plastic molded article comprising a coating film formed from the emulsion coating composition according to claim 1.