JP5865250B2 - Aqueous epoxy resin coating composition kit, aqueous epoxy resin coating composition, method for forming coated article, and coated article - Google Patents

Description

  The present invention relates to a kit for aqueous epoxy resin coating composition, an aqueous epoxy resin coating composition formed from the kit, a method for forming a coated article using the aqueous epoxy resin coating composition, and a method for forming a coated article. Related to painted articles.

In recent years, considering environmental pollution due to organic solvents, effects on the human body, etc., solvent-based paints are being replaced by water-based paints.
For example, as a water-based paint in the field of anticorrosive paint, a room temperature drying type two-component water-based epoxy resin paint composition composed of a main agent containing an epoxy resin emulsion and an amine curing agent is often used (Patent Documents 1, 2, etc.) . In this field, in order to prevent pigment sedimentation in the storage stage of the main agent and to improve the finish of the formed coating film, for example, a viscosity modifier (thickener, anti-settling agent, etc.) Are generally added). Examples of the viscosity modifier include an associative viscosity modifier.

  The associative viscosity modifier generally has a hydrophilic part and a hydrophobic part in one molecule, and in the aqueous medium, the hydrophobic part is adsorbed on the surface of pigments, emulsion particles, etc. in the paint. A network structure can be formed due to the association of hydrophobic portions and the like, and a thickening action can be exhibited. The associative viscosity modifier usually forms a network structure by hydrophobic interaction and expresses viscosity, while the hydrophobic interaction has a relatively weak binding force, so when a large shear force is applied, It is believed that the network structure collapses and the viscosity decreases. For this reason, the water-based paint containing the associative viscosity modifier tends to have a viscosity characteristic in which the viscosity decreases as the shear rate increases.

  Conventionally, in the field of two-component aqueous epoxy resin coating compositions, the above associative viscosity modifiers are widely used.

JP-A-6-228272 JP 2000-226537 A

The two-component water-based epoxy resin coating composition is often applied by spray coating, which applies a large shearing force during coating. In the two-component water-based epoxy resin coating composition, the main component and an amine curing agent are mixed. After that, when water was added to adjust the viscosity to be suitable for spray coating, the viscosity of the coating material was extremely lowered, and there were cases where problems in coating workability such as sagging of the coating film occurred.
Accordingly, an object of the present invention is to provide a kit for an aqueous epoxy resin coating composition that can form an aqueous epoxy resin coating composition that is difficult to sag and is excellent in coating workability.

As a result of intensive studies to achieve the above object, the present inventors have found that the first composition (I) containing an epoxy resin emulsion and two or more functional groups capable of reacting with an epoxy group are contained in one molecule. A water-based epoxy resin coating composition kit comprising a second composition (II) containing a compound having the following composition, wherein the first composition (I) and / or the second composition (II) comprises the following skeleton: (A): a polymer chain and a polymerizable non-polymerizable polymer obtained by polymerizing a monomer component (b) containing at least 5% by mass of a polymerizable unsaturated monomer (b ₁ ) having a C 3-24 alkyl group. A macromonomer (m ₁ ) having a saturated group and a number average molecular weight in the range of 1,000 to 10,000, and a polymerizable unsaturated monomer (m ₂ ) having a nonionic hydrophilic group. Aqueous features The carboxy resin coating composition kit, found that it is possible to solve the above problems.

Specifically, the present invention relates to the following aspects.
[Aspect 1]
An aqueous epoxy resin coating composition having a first composition (I) containing an epoxy resin emulsion and a second composition (II) containing a compound having two or more functional groups capable of reacting with an epoxy group in one molecule A kit for
The copolymer (A) in which the first composition (I) and / or the second composition (II) includes the following skeleton:
A polymer chain and a polymerizable unsaturated group obtained by polymerizing a monomer component (b) containing at least 5% by mass of a polymerizable unsaturated monomer (b ₁ ) having a C 3-24 alkyl group. A macromonomer (m ₁ ) having a number average molecular weight in the range of 1,000 to 10,000, and a polymerizable unsaturated monomer (m ₂ ) having a nonionic hydrophilic group,
A kit for the above-mentioned aqueous epoxy resin coating composition, comprising:

[Aspect 2]
The copolymer (A) contains a skeleton of the macromonomer (m ₁ ) and a skeleton of the polymerizable unsaturated monomer (m ₂ ) having a nonionic hydrophilic group, respectively, in an amount of 1 to 29 parts by mass and 20 to 99 parts by mass. The kit according to aspect 1, comprising at a ratio of

[Aspect 3]
The copolymer (A) has a skeleton of the other polymerizable unsaturated monomer (m ₃ ) other than the skeleton of the macromonomer (m ₁ ) and the polymerizable unsaturated monomer (m ₂ ) having a nonionic hydrophilic group. Furthermore, the skeleton of the macromonomer (m ₁ ), the skeleton of the polymerizable unsaturated monomer (m ₂ ) having a nonionic hydrophilic group, and the skeleton of the other polymerizable unsaturated monomer (m ₃ ) are each 1 The kit according to embodiment 1 or 2, wherein the kit is present in a ratio of ˜29 mass%, 20 to 98 mass%, and 1 to 79 mass%.

[Aspect 4]
The kit according to any one of aspects 1 to 3, wherein the polymerizable unsaturated monomer (m ₂ ) having a nonionic hydrophilic group is N-substituted (meth) acrylamide.
[Aspect 5]
The kit according to any one of Embodiments 1 to 4, wherein the macromonomer (m ₁ ) is obtained by polymerizing the monomer component (b) containing a hydroxyl group-containing polymerizable unsaturated monomer.

[Aspect 6]
The kit according to any one of Embodiments 1 to 5, wherein the epoxy resin emulsion has nonionic properties.
[Aspect 7]
The kit according to any one of aspects 1 to 6, which is a two-component type or a two-component one-powder type.

[Aspect 8]
Based on the solid content of the aqueous epoxy resin composition formed from the kit, the kit is based on 100 parts by mass of the total resin contained in the first composition (I) and the second composition (II). The kit according to any one of Embodiments 1 to 7, comprising the copolymer (A) so as to contain the copolymer (A) in a range of 0.05 to 30 parts by mass.
[Aspect 9]
An aqueous epoxy resin coating composition formed from the kit according to any one of aspects 1 to 8.

[Aspect 10]
Applying an object to be coated with the aqueous epoxy resin coating composition according to aspect 9 to form a coating film;
A method for forming a coated article, comprising:
[Aspect 11]
A coated article formed by the method for forming a coated article according to aspect 10.

  The aqueous epoxy resin coating composition kit of the present invention can form an aqueous epoxy resin coating composition that is difficult to sag and is excellent in painting workability.

Hereinafter, the kit for the aqueous epoxy resin coating composition of the present invention will be described in detail.
The aqueous epoxy resin coating composition kit of the present invention includes a first composition (I) containing an epoxy resin emulsion and a second composition containing a compound having two or more functional groups capable of reacting with an epoxy group in one molecule. And one of the first composition (I) or the second composition (II), or both the first composition (I) and the second composition (II) is a copolymer (A )including.

<Copolymer (A)>
The copolymer (A) is a polymer obtained by polymerizing a monomer component (b) containing at least about 5% by mass of a polymerizable unsaturated monomer (b ₁ ) having an alkyl group having about 3 to about 24 carbon atoms. Polymerization having a skeleton derived from a macromonomer (m ₁ ) having a chain and a polymerizable unsaturated group and having a number average molecular weight in the range of about 1,000 to about 10,000, and a nonionic hydrophilic group And a skeleton derived from an unsaturated monomer (m ₂ ).

  When present in the coating composition, the copolymer (A) has a viscosity property that is highly viscous and decreases with increasing shear rate. In particular, when present in an aqueous epoxy resin coating composition, it has a viscosity characteristic in which the viscosity development is stable and the viscosity decreases with increasing shear rate. The copolymer (A) is suitable as a viscosity modifier because it has the above viscosity characteristics.

<Macromonomer (m ₁ )>
In the present specification, obtained by polymerizing a monomer component (b) containing about 5 to about 100 mass% of a polymerizable unsaturated monomer (b ₁ ) having an alkyl group having about 3 to about 24 carbon atoms, When the macromonomer (m ₁ ) having a polymer chain and a polymerizable unsaturated group and having a number average molecular weight in the range of about 1,000 to about 10,000 is simply referred to as “macromonomer (m ₁ )” There is.
In the present specification, the “macromonomer” means a high molecular weight compound having a polymerizable unsaturated group at at least one of its ends.

<Monomer component (b)>
The copolymer (A) is formed by polymerizing the monomer component (b), and the monomer component (b) contains at least about a polymerizable unsaturated monomer (b ₁ ) having an alkyl group having about 3 to about 24 carbon atoms. 5% by mass is contained.

<Polymerizable unsaturated monomer (b ₁ ) having an alkyl group having about 3 to about 24 carbon atoms>
Examples of the polymerizable unsaturated monomer (b ₁ ) having an alkyl group having about 3 to about 24 carbon atoms include, for example, a monohydric alcohol composed of (meth) acrylic acid and a monohydric alcohol having an alkyl group having about 3 to about 24 carbon atoms. Examples include esterified products. Specifically, for example, alkyl or cycloalkyl (meth) acrylate such as n-propyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, tert-butyl ( (Meth) acrylate, pentyl (meth) acrylate, hexyl (meth) acrylate, octyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, nonyl (meth) acrylate, dodecyl (meth) acrylate (lauryl (meth) acrylate), tridecyl (Meth) acrylate, stearyl (meth) acrylate, isostearyl (meth) acrylate, cyclohexyl (meth) acrylate, methylcyclohexyl (meth) acrylate, t-butylcyclohexyl (Meth) acrylate, cyclododecyl (meth) acrylate, isobornyl (meth) acrylate, adamantyl (meth) acrylate, and tricyclodecanyl (meth) acrylate, and combinations thereof.

  In the present specification, “(meth) acrylate” means acrylate and / or methacrylate, and “(meth) acrylic acid” means acrylic acid and / or methacrylic acid. Further, “(meth) acryloyl” means acryloyl and / or methacryloyl, and “(meth) acrylamide” means “acrylamide and / or methacrylamide”.

As the polymerizable unsaturated monomer (b ₁ ) having an alkyl group having about 3 to about 24 carbon atoms, a polymerizable unsaturated monomer having an alkyl group having about 4 to about 18 carbon atoms can be used from the viewpoint of the finish of the resulting coating film. Saturated monomers are preferred, and polymerizable unsaturated monomers having an alkyl group having from about 4 to about 8 carbon atoms are more preferred. Specifically, n-butyl methacrylate, isobutyl methacrylate, tert-butyl methacrylate, and 2-ethylhexyl methacrylate are preferable as the polymerizable unsaturated monomer (b ₁ ) having an alkyl group having about 4 to about 18 carbon atoms, And n-butyl methacrylate and 2-ethylhexyl methacrylate are suitable from the viewpoint of viscosity development after adjusting to coating viscosity.

The monomer component (b) contains at least about 5% by weight of a polymerizable unsaturated monomer (b ₁ ) having an alkyl group having about 3 to about 24 carbon atoms, and the monomer component (b) From the viewpoint of finish, it is preferable that the polymerizable unsaturated monomer (b ₁ ) having an alkyl group having about 3 to about 24 carbon atoms is contained at least about 20% by mass, more preferably at least about 45% by mass. It is more preferred that it contains at least about 50% by weight.
In addition, in the monomer component (b), the upper limit of the amount of the polymerizable unsaturated monomer (b ₁ ) having an alkyl group having about 3 to about 24 carbon atoms is about 100 mass from the viewpoint of the finish of the resulting coating film. %, Preferably about 95% by weight, more preferably about 90% by weight, even more preferably about 85% by weight, and most preferably about 80% by weight.

Monomer component (b) may contain a polymerizable unsaturated monomer having from about 3 to about 24 alkyl group carbon atoms (b ₁₎ other than the polymerizable unsaturated monomer (b _2).
In the present specification, the polymerizable unsaturated monomer (b ₂ ) other than the polymerizable unsaturated monomer (b ₁ ) having an alkyl group having 3 to 24 carbon atoms is simply referred to as “polymerizable unsaturated monomer (b _2). ) ".

Examples of the polymerizable unsaturated monomer (b ₂ ) include alkyl (meth) acrylates having an alkyl group having 1 or 2 carbon atoms such as methyl (meth) acrylate and ethyl (meth) acrylate; benzyl (meth) acrylate, Aromatic ring-containing polymerizable unsaturated monomers such as styrene, α-methylstyrene, vinyltoluene; vinyltrimethoxysilane, vinyltriethoxysilane, vinyltris (2-methoxyethoxy) silane, γ- (meth) acryloyloxypropyltrimethoxysilane , Polymerizable unsaturated monomers having an alkoxysilyl group such as γ- (meth) acryloyloxypropyltriethoxysilane; perfluoroalkyl (meth) such as perfluorobutylethyl (meth) acrylate and perfluorooctylethyl (meth) acrylate Acrylate; polymerizable unsaturated monomer having a fluorinated alkyl group such as fluoroolefin; polymerizable unsaturated monomer having a photopolymerizable functional group such as maleimide group; N-vinylpyrrolidone, ethylene, butadiene, chloroprene, vinyl propionate, Vinyl compounds such as vinyl acetate; (meth) acrylic acid such as 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, and 4-hydroxybutyl (meth) acrylate; Monoesterified product of 2 to 8 carbon dihydric alcohol, ε-caprolactone modified product of monoesterified product of (meth) acrylic acid and 2 to 8 carbon dihydric alcohol, N-hydroxymethyl (meth) Acrylamide, allyl alcohol, molecular end is water Hydroxyl group-containing polymerizable unsaturated monomers such as (meth) acrylate having a polyoxyethylene chain as a group; carboxyl group-containing polymerizable unsaturated monomers such as (meth) acrylic acid, maleic acid, crotonic acid, and β-carboxyethyl acrylate Allyl (meth) acrylate, ethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, 1,3-butylene glycol di (meth) acrylate, trimethylolpropane tri ( (Meth) acrylate, 1,4-butanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, pentaerythritol di (meth) acrylate, pentae Lithritol tetra (meth) acrylate, glycerol di (meth) acrylate, 1,1,1-trishydroxymethylethane di (meth) acrylate, 1,1,1-trishydroxymethylethanetri (meth) acrylate, 1,1 , 1-trishydroxymethylpropane tri (meth) acrylate, triallyl isocyanurate, diallyl terephthalate, divinylbenzene, and other polymerizable unsaturated monomers having at least two polymerizable unsaturated groups in one molecule; (meth) acrylonitrile; (Meth) acrylamide, N, N-dimethylaminoethyl (meth) acrylate, N, N-diethylaminoethyl (meth) acrylate, N, N-dimethylaminopropyl (meth) acrylamide, glycidyl (meth) acrylate and amines Addition Nitrogen-containing polymerizable unsaturated monomers such as glycidyl (meth) acrylate, β-methylglycidyl (meth) acrylate, 3,4-epoxycyclohexylmethyl (meth) acrylate, 3,4-epoxycyclohexylethyl (meth) acrylate, 3 Epoxy group-containing polymerizable unsaturated monomers such as 1,4-epoxycyclohexylpropyl (meth) acrylate and allyl glycidyl ether; Isocyanato such as 2-isocyanatoethyl (meth) acrylate and m-isopropenyl-α, α-dimethylbenzyl isocyanate Group-containing polymerizable unsaturated monomer; (meth) acrylate having a polyoxyethylene chain whose molecular end is an alkoxy group; acrolein, diacetone acrylamide, diacetone methacrylamide, acetoacetoxyethyl methacrylate Examples include carbonyl group-containing polymerizable unsaturated monomers such as chlorate, formylstyrene, vinyl alkyl ketones having 4 to 7 carbon atoms (eg, vinyl methyl ketone, vinyl ethyl ketone, vinyl butyl ketone), and combinations thereof. .

Monomer component (b), in addition to the polymerizable unsaturated monomer having an alkyl group of 3 to 24 carbon atoms (b _1), when containing a polymerizable unsaturated monomer (b ₂₎ is 3 carbon The ratio of the polymerizable unsaturated monomer (b ₁ ) having 24 alkyl groups and the polymerizable unsaturated monomer (b ₂ ) is about 5 to about 95% by mass and about 5% from the viewpoint of the finish of the resulting coating film. To about 95% by weight, more preferably about 20 to about 90% by weight and about 10 to about 80% by weight, more preferably about 45 to about 85% by weight and about 15 to about 55% by weight. And more preferably from about 50 to about 80 weight percent and from about 20 to about 50 weight percent.

The monomer component (b) may contain one or more hydroxyl group-containing polymerizable unsaturated monomers as the polymerizable unsaturated monomer (b ₂ ) from the viewpoint of viscosity development after adjusting to the coating viscosity. preferable.
Examples of the hydroxyl group-containing polymerizable unsaturated monomer include those exemplified in the term of polymerizable unsaturated monomer (b ₂ ), and from the viewpoint of coating workability, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate. 3-hydroxypropyl methacrylate and 4-hydroxybutyl methacrylate are preferred, and 2-hydroxyethyl methacrylate is more preferred.

When the monomer component (b) contains a hydroxyl group-containing polymerizable unsaturated monomer as the polymerizable unsaturated monomer (b ₂ ), the hydroxyl group-containing polymerizable unsaturated monomer is from the viewpoint of coating workability and water resistance, Preferably, from about 5 to about 60 weight percent, more preferably from about 10 to about 55 weight percent, more preferably from about 10 to about 50 weight percent, and most preferably from about 10 weight percent based on the total weight of monomer component (b). Within the range of about 45% by weight.

The macromonomer (m ₁ ) obtained by polymerizing the monomer component (b) described above has a number average molecular weight in the range of about 1,000 to about 10,000 from the viewpoint of coating workability, preferably It is in the range of about 1,000 to about 5,000, and more preferably in the range of about 1,000 to about 3,000. The number average molecular weight of the macromonomer (m ₁ ) can be adjusted by, for example, the amount of the chain transfer agent, the reaction temperature, the reaction time, and the like when the monomer component (b) is polymerized.

The macromonomer (m ₁ ) can be obtained by a method known per se. Specifically, for example, it can be obtained by the following method (1), method (2), method (3) and the like.
Method (1): When polymerizing the monomer component (b), polymerization is carried out in the presence of a chain transfer agent having a first chemically reactive group such as a carboxyl group, a hydroxyl group, an amino group, etc. A reactant having a first chemically reactive group is formed. Next, by reacting the reactant with a polymerizable unsaturated monomer having a second chemically reactive group capable of reacting with the first chemically reactive group in the reactant, the macromonomer (m ₁ ) Can be obtained.

  Examples of the chain transfer agent having a first chemically reactive group such as a carboxyl group, a hydroxyl group, and an amino group include mercaptoacetic acid, 2-mercaptopropionic acid, 3-mercaptopropionic acid, 2-mercaptoethanol, and 2-aminoethanethiol. Etc.

  As the polymerizable unsaturated monomer having a second chemically reactive group capable of reacting with the first chemically reactive group in the copolymer (A), for example, when the first chemically reactive group is a carboxy group, For example, an epoxy group-containing polymerizable unsaturated monomer can be used, and when the first chemically reactive group is a hydroxyl group, for example, an isocyanate group-containing polymerizable unsaturated monomer can be used, and the first chemical When the reactive group is an amino group, for example, an epoxy group-containing polymerizable unsaturated monomer can be mentioned.

  Examples of the epoxy group-containing polymerizable unsaturated monomer include glycidyl acrylate and glycidyl methacrylate. Examples of the isocyanate group-containing polymerizable unsaturated monomer include isocyanatoethyl methacrylate and m-isopropenyl-α. , Α-dimethylbenzyl isocyanate and the like.

Method (2): A macromonomer (m ₁ ) can be obtained by catalytic chain transfer polymerization (CCTP method) using a metal complex. The CCTP method includes, for example, JP-B-6-23209, JP-B-7-35411, JP-B-9-501457, JP-A-9-176256, Macromolecules 1996, 29, 8083-8089. Etc. are described. Specifically, the macromonomer (m ₁ ) can be produced by subjecting the monomer component (b) to catalytic chain transfer polymerization in the presence of a metal complex. The catalytic chain transfer polymerization can be performed by, for example, a solution polymerization method in an organic solvent, an emulsion polymerization method in water, or the like. Moreover, in the case of superposition | polymerization, you may use a radical polymerization initiator as needed in addition to the said metal complex.

Examples of the metal complex include a cobalt complex, an iron complex, a nickel complex, a ruthenium complex, a rhodium complex, a palladium complex, a rhenium complex, and an iridium complex. Of these, the cobalt complex is efficiently used as a catalytic chain transfer agent. Works. The amount of the metal complex used is not particularly limited, but is usually about 1 × 10 ⁻⁶ to about 1 part by mass, preferably about 1 × based on 100 parts by mass of the total mass of the monomer component (b). It exists in the range of 10 ^{<-4> -about} 0.5 mass part.

  Examples of the radical polymerization initiator include benzoyl peroxide, octanoyl peroxide, lauroyl peroxide, stearoyl peroxide, cumene hydroperoxide, tert-butyl peroxide, di-tert-amyl peroxide, and tert-butyl peroxide. Organic peroxides such as oxylaurate, tert-butylperoxyisopropyl carbonate, tert-butylperoxyacetate, diisopropylbenzene hydroperoxide, tert-butylperoxy-2-ethylhexanoate; azobisisobutyronitrile , Azobis (2,4-dimethylvaleronitrile), azobis (2-methylpropiononitrile), azobis (2-methylbutyronitrile), 4,4′-azobis (4- Anobutanoic acid), dimethylazobis (2-methylpropionate), azobis [2-methyl-N- (2-hydroxyethyl) -propionamide], azobis {2-methyl-N- [2- (1-hydroxy Butyl)]-propionamide}; persulfates such as potassium persulfate, ammonium persulfate, and sodium persulfate, and combinations thereof. The amount of the radical polymerization initiator is not particularly limited, but is usually about 0.1 to about 10 parts by mass, preferably about 0.1, based on 100 parts by mass of the total mass of the monomer component (b). To about 8 parts by weight, and more preferably in the range of about 0.1 to about 6 parts by weight.

Method (3): A macromonomer (m ₁ ) can be obtained by an addition-cleavage chain transfer polymerization method using an addition-cleavage chain transfer agent. The above addition-cleavage type chain transfer polymerization method is described in, for example, JP-A-7-2954. Specifically, the macromonomer (m ₁ ) can be produced by subjecting the monomer component (b) to addition-cleavage chain transfer polymerization in the presence of the addition-cleavage chain transfer agent. The addition-cleavage chain transfer polymerization can be performed by, for example, a solution polymerization method in an organic solvent, an emulsion polymerization method in water, or the like. Moreover, in the case of superposition | polymerization, in addition to the said addition cleavage type | mold chain transfer agent, a radical polymerization initiator can be used together as needed.

  As the addition-cleavage chain transfer agent, for example, 2,4-diphenyl-4-methyl-1-pentene (sometimes abbreviated as “α-methylstyrene dimer” or “MSD”) is preferable. The amount of the above addition-cleavage chain transfer agent is not particularly limited, but is usually about 1 to about 20 parts by weight, preferably about 2 to about based on 100 parts by weight of the total weight of the monomer component (b). It is in the range of 15 parts by weight, and more preferably from about 3 to about 10 parts by weight.

  As said radical polymerization initiator, the radical polymerization initiator enumerated in method (2) is mentioned, for example. The amount of the radical polymerization initiator is not particularly limited, but is usually about 1 to about 20 parts by mass, preferably about 2 to about 15 parts by mass, based on 100 parts by mass of the total mass of the monomer component (b). Parts, and more preferably in the range of about 3 to about 10 parts by weight.

Among the methods (1) to (3), the method (1) includes the step of polymerizing the monomer component (b) to obtain a polymer, and reacting the obtained polymer with a polymerizable unsaturated monomer to produce the polymer. Two reaction steps are required, including the step of introducing a polymerizable unsaturated group into the. In addition, since the method (2) uses a metal complex, there are cases where catalytic chain transfer polymerization occurs in the production of a copolymer (graft polymer) described later, and the resulting copolymer is colored.
For this reason, from the viewpoint of reducing the number of reaction steps and suppressing coloration in the resulting copolymer, the macromonomer (m ₁ ) is obtained by the addition-cleavage type chain transfer polymerization method using the addition-cleavage type chain transfer agent of the method (3). It is preferable to obtain.

<Polymerizable unsaturated monomer having nonionic hydrophilic group (m ₂ )>
In the present invention, examples of the polymerizable unsaturated monomer (m ₂ ) having a nonionic hydrophilic group include N-substituted (meth) acrylamide, a polymerizable unsaturated monomer having a polyoxyalkylene chain, and N-vinyl- There may be mentioned 2-pyrrolidone and combinations thereof. N-substituted (meth) acrylamide is preferred from the viewpoint of developing viscosity after adjusting to the coating viscosity.

  Examples of the N-substituted (meth) acrylamide include N-methyl acrylamide, N-methyl methacrylamide, N-methylol acrylamide butyl ether, N-methylol methacrylamide butyl ether, N-ethyl acrylamide, N-ethyl methacrylamide, N- n-propylacrylamide, Nn-propylmethacrylamide, N-isopropylacrylamide, N-isopropylmethacrylamide, N-cyclopropylacrylamide, N-cyclopropylmethacrylamide, diacetoneacrylamide, diacetonemethacrylamide, N-hydroxymethyl Acrylamide, N-hydroxymethyl methacrylamide, N-hydroxyethyl acrylamide, N-hydroxyethyl methacrylamide, N, N- Methyl acrylamide, N, N-dimethylmethacrylamide, N, N-diethylacrylamide, N, N-diethylmethacrylamide, N-methyl, N-ethylacrylamide, N-methyl, N-ethylmethacrylamide, N, N-dimethyl Aminopropyl acrylamide, N, N-dimethylaminopropyl methacrylamide, N-methylol acrylamide methyl ether, N-methylol methacrylamide methyl ether, N-methylol acrylamide ethyl ether, N-methylol methacrylamide ethyl ether, N-methylol acrylamide propyl ether , N-methylol methacrylamide propyl ether, acryloyl morpholine, and methacryloyl morpholine, and combinations thereof.

  From the viewpoint of coating workability, Nn-propylacrylamide, Nn-propylmethacrylamide, N-isopropylacrylamide, N-isopropylmethacrylamide, N-hydroxyethylacrylamide, N-hydroxyethylmethacrylamide, N, N- Dimethylacrylamide, N, N-dimethylmethacrylamide, N, N-diethylacrylamide, and N, N-diethylmethacrylamide are preferred, and N, N-dimethylacrylamide and N, N-dimethylmethacrylamide are more preferred.

The polymerizable unsaturated monomer having a polyoxyalkylene chain is a monomer containing a polyoxyalkylene chain and a polymerizable unsaturated group in one molecule.
Examples of the polyoxyalkylene chain include a polyoxyethylene chain, a polyoxypropylene chain, a chain composed of a polyoxyethylene block and a polyoxypropylene block, and a polyoxyethylene block and a polyoxypropylene that are randomly bonded. These polyoxyalkylene chains are preferably about 100 to about 5,000, more preferably about 200 to about 4,000, and still more preferably about 300 to about 3,000. Having a number average molecular weight in the range of

［式中、Ｒ^１は、水素原子又はメチル基を表し、Ｒ^２は、水素原子又は炭素数約１〜約４のアルキル基、好ましくは水素原子、メチル基又はエチル基、そしてより好ましくは水素原子又はメチル基を表し、Ｒ^３は、炭素数約２〜約４、好ましくは炭素数約２又は約３、そしてより好ましくは炭素数約２のアルキレン基を表し、ｍは、約３〜約１５０、好ましくは約５〜約８０、そしてより好ましくは約８〜約５０の整数を表し、ｍ個のオキシアルキレン単位（Ｏ−Ｒ^３）は、互いに同じであっても又は互いに異なっていてもよい］
で示される重合性不飽和モノマーを挙げることができる。Representative examples of the polymerizable unsaturated monomer having a polyoxyalkylene chain include, for example, the following general formula (1)

[Wherein R ¹ represents a hydrogen atom or a methyl group, R ² represents a hydrogen atom or an alkyl group having about 1 to about 4 carbon atoms, preferably a hydrogen atom, a methyl group or an ethyl group, and more preferably a hydrogen atom. Represents an atom or a methyl group, R ³ represents an alkylene group having from about 2 to about 4 carbon atoms, preferably about 2 or about 3 carbon atoms, and more preferably about 2 carbon atoms, and m is from about 3 to about Represents an integer of 150, preferably from about 5 to about 80, and more preferably from about 8 to about 50, and the m oxyalkylene units (O—R ³ ) may be the same or different from each other. Good]
The polymerizable unsaturated monomer shown by these can be mentioned.

  Specific examples of the polymerizable unsaturated monomer represented by the general formula (1) include, for example, tetraethylene glycol (meth) acrylate, methoxytetraethylene glycol (meth) acrylate, ethoxytetraethylene glycol (meth) acrylate, n- Butoxytriethylene glycol (meth) acrylate, n-butoxytetraethylene glycol (meth) acrylate, tetrapropylene glycol (meth) acrylate, methoxytetrapyroprene glycol (meth) acrylate, ethoxytetrapropylene glycol (meth) acrylate, n-butoxy Tetrapropylene glycol (meth) acrylate, polyethylene glycol (meth) acrylate, polypropylene glycol (meth) acrylate, polyethylene (polypropylene glycol) Pyrene) glycol (meth) acrylate, methoxy polyethylene glycol (meth) acrylate, ethoxy polyethylene glycol (meth) acrylate, methoxy polypropylene glycol (meth) acrylate, ethoxy polypropylene glycol (meth) acrylate, methoxy polyethylene (propylene) glycol (meth) acrylate And ethoxypolyethylene (propylene) glycol (meth) acrylate, and combinations thereof. In the present specification, “polyethylene (propylene) glycol” means a copolymer of ethylene glycol and propylene glycol, and includes both a block copolymer and a random copolymer.

<Other polymerizable unsaturated monomer (m ₃ )>
The other polymerizable unsaturated monomer (m ₃ ) is a monomer that can form a part of the skeleton of the copolymer (A), and the polymerizable unsaturated monomer having a macromonomer (m ₁ ) and a nonionic hydrophilic group A polymerizable unsaturated monomer other than (m ₂ ) is meant.
The copolymer (A) can contain a skeleton derived from another polymerizable unsaturated monomer (m ₃ ) as necessary, but the skeleton is not necessarily contained in the copolymer (A).

The other polymerizable unsaturated monomer (m ₃ ) can be appropriately selected depending on the properties desired for the copolymer (A).
Specific examples of other polymerizable unsaturated monomer (m ₃ ) are listed below. These can be used alone or in combination of two or more.

  (I) alkyl or cycloalkyl (meth) acrylate: for example, methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl ( (Meth) acrylate, tert-butyl (meth) acrylate, n-hexyl (meth) acrylate, n-octyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, nonyl (meth) acrylate, tridecyl (meth) acrylate, lauryl ( (Meth) acrylate, stearyl (meth) acrylate, isostearyl (meth) acrylate, cyclohexyl (meth) acrylate, methylcyclohexyl (meth) acrylate, t-butylcyclohexyl (meth) a Relate, cyclododecyl (meth) acrylate, tricyclodecanyl (meth) acrylate.

(Ii) Polymerizable unsaturated monomer having an isobornyl group: for example, isobornyl (meth) acrylate.
(Iii) Polymerizable unsaturated monomer having an adamantyl group: for example, adamantyl (meth) acrylate and the like.

(Iv) Polymerizable unsaturated monomer having a tricyclodecenyl group: for example, tricyclodecenyl (meth) acrylate.
(V) Aromatic ring-containing polymerizable unsaturated monomers: for example, benzyl (meth) acrylate, styrene, α-methylstyrene, vinyltoluene and the like.

  (Vi) polymerizable unsaturated monomers having hydrolyzable silyl groups: for example, vinyltrimethoxysilane, vinylmethyldimethoxysilane, vinyltriethoxysilane, vinylmethyldiethoxysilane, vinyltris (2-methoxyethoxy) silane, vinyltri Isopropoxysilane, γ- (meth) acryloyloxypropyltrimethoxysilane, γ- (meth) acryloyloxypropylmethyldimethoxysilane, γ- (meth) acryloyloxypropyltriethoxysilane, γ- (meth) acryloyloxypropylmethyldi Ethoxysilane, γ- (meth) acryloyloxypropyltri-n-propoxysilane, γ- (meth) acryloyloxypropyltriisopropoxysilane, vinyltriacetoxysilane, β- (meth) acrylo Oxyethyl trimethoxysilane.

(Vii) Polymerizable unsaturated monomer having a fluorinated alkyl group: for example, perfluoroalkyl (meth) acrylate such as perfluorobutylethyl (meth) acrylate and perfluorooctylethyl (meth) acrylate; fluoroolefin and the like.
(Viii) A polymerizable unsaturated monomer having a photopolymerizable functional group such as a maleimide group.
(Ix) Vinyl compound: For example, N-vinyl pyrrolidone, ethylene, butadiene, chloroprene, vinyl propionate, vinyl acetate and the like.

  (X) Phosphoric acid group-containing polymerizable unsaturated monomer: for example, 2-acryloyloxyethyl acid phosphate, 2-methacryloyloxyethyl acid phosphate, 2-acryloyloxypropyl acid phosphate, 2-methacryloyloxypropyl acid phosphate and the like.

  (Xi) Hydroxyl-containing polymerizable unsaturated monomer: for example, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, etc. Monoesterified product of (meth) acrylic acid and C2-C8 dihydric alcohol; ε-caprolactone modified product of monoesterified product of (meth) acrylic acid and C2-C8 dihydric alcohol; allyl Alcohol etc.

(Xii) Carboxyl group-containing polymerizable unsaturated monomer: For example, (meth) acrylic acid, maleic acid, crotonic acid, β-carboxyethyl acrylate and the like.
(Xiii) nitrogen-containing polymerizable unsaturated monomers: for example, (meth) acrylonitrile, (meth) acrylamide, methylenebis (meth) acrylamide, ethylenebis (meth) acrylamide, 2- (methacryloyloxy) ethyltrimethylammonium chloride, glycidyl (meth) ) Adducts of acrylates and amines.

(Xiv) A polymerizable unsaturated monomer having at least two polymerizable unsaturated groups in one molecule: for example, allyl (meth) acrylate, 1,6-hexanediol di (meth) acrylate and the like.
(Xv) Epoxy group-containing polymerizable unsaturated monomer: for example, glycidyl (meth) acrylate, β-methylglycidyl (meth) acrylate, 3,4-epoxycyclohexylmethyl (meth) acrylate, 3,4-epoxycyclohexylethyl (meth) ) Acrylate, 3,4-epoxycyclohexylpropyl (meth) acrylate, allyl glycidyl ether and the like.

(Xvi) (meth) acrylate having a polyoxyethylene chain whose molecular end is an alkoxy group.
(Xvii) polymerizable unsaturated monomer having a sulfonic acid group: for example, 2-acrylamido-2-methylpropanesulfonic acid, 2-sulfoethyl (meth) acrylate, allylsulfonic acid, 4-styrenesulfonic acid, etc .; Sodium salt and ammonium salt.

  (Xviii) polymerizable unsaturated monomer having a UV-absorbing functional group: for example, 2-hydroxy-4- (3-methacryloyloxy-2-hydroxypropoxy) benzophenone, 2-hydroxy-4- (3-acryloyloxy-2) -Hydroxypropoxy) benzophenone, 2,2'-dihydroxy-4- (3-methacryloyloxy-2-hydroxypropoxy) benzophenone, 2,2'-dihydroxy-4- (3-acryloyloxy-2-hydroxypropoxy) benzophenone, 2- (2′-hydroxy-5′-methacryloyloxyethylphenyl) -2H-benzotriazole and the like.

  (Xix) photostable polymerizable unsaturated monomer: for example, 4- (meth) acryloyloxy-1,2,2,6,6-pentamethylpiperidine, 4- (meth) acryloyloxy-2,2,6, 6-tetramethylpiperidine, 4-cyano-4- (meth) acryloylamino-2,2,6,6-tetramethylpiperidine, 1- (meth) acryloyl-4- (meth) acryloylamino-2,2,6 , 6-tetramethylpiperidine, 1- (meth) acryloyl-4-cyano-4- (meth) acryloylamino-2,2,6,6-tetramethylpiperidine, 4-crotonoyloxy-2,2,6 6-tetramethylpiperidine, 4-crotonoylamino-2,2,6,6-tetramethylpiperidine, 1-crotonoyl-4-crotonoyloxy-2,2, , 6-tetramethylpiperidine and the like.

(Xx) polymerizable unsaturated monomer having a carbonyl group: for example, acrolein, diacetone acrylamide, diacetone methacrylamide, acetoacetoxyethyl methacrylate, formylstyrol, vinyl alkyl ketone having 4 to 7 carbon atoms (for example, vinyl Methyl ketone, vinyl ethyl ketone, vinyl butyl ketone) and the like.
(Xxi) A polymerizable unsaturated monomer having an acid anhydride group: for example, maleic anhydride, itaconic anhydride, citraconic anhydride and the like.

In the case where the copolymer (A) contains a skeleton derived from other polymerizable unsaturated monomer (m ₃ ), the copolymer (A) is used from the viewpoint of viscosity development of the paint and finish of the formed coating film. A skeleton derived from the macromonomer (m ₁ ), a skeleton derived from the polymerizable unsaturated monomer (m ₂ ) having a nonionic hydrophilic group, and a skeleton derived from the other polymerizable unsaturated monomer (m ₃ ). Can be included in the following ranges based on their total mass.
Skeleton derived from macromonomer (m ₁ ):
Preferably about 1 to about 29% by weight, more preferably about 3 to about 20% by weight,
A skeleton derived from a polymerizable unsaturated monomer (m ₂ ) having a nonionic hydrophilic group:
Preferably about 20 to about 98% by weight, more preferably about 40 to about 92% by weight,
Skeletons derived from other polymerizable unsaturated monomers (m ₃ ):
Preferably about 1 to about 79% by weight, more preferably about 5 to about 57% by weight.

When the copolymer (A) contains a skeleton derived from another polymerizable unsaturated monomer (m ₃ ), the skeleton derived from the other polymerizable unsaturated monomer (m ₃ ) is adjusted to the coating viscosity. From the viewpoint of developing the viscosity of the polymer, it contains a skeleton derived from the hydroxyl group-containing polymerizable unsaturated monomer represented by (xi) (hereinafter sometimes referred to as “hydroxyl group-containing polymerizable unsaturated monomer (xi)”). Is preferred. Examples of the hydroxyl group-containing polymerizable unsaturated monomer (xi) include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, and 4-hydroxybutyl (meth) acrylate. 2-hydroxyethyl (meth) acrylate is more preferable. The hydroxyl group-containing polymerizable unsaturated monomer (xi) is preferably an acrylate such as 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 3-hydroxypropyl acrylate, and 4-hydroxybutyl acrylate, and 2-hydroxy More preferred is ethyl acrylate.

The copolymer (A) includes a skeleton derived from another polymerizable unsaturated monomer (m ₃ ), and the skeleton derived from the other polymerizable unsaturated monomer (m ₃ ) is a hydroxyl group-containing polymerizable unsaturated. When the skeleton derived from the monomer (xi) is contained, the amount of the skeleton derived from the hydroxyl group-containing polymerizable unsaturated monomer (xi) has a skeleton derived from the macromonomer (m ₁ ) and a nonionic hydrophilic group. Preferably about 5 to about 79% by weight, based on the total weight of the skeleton derived from the polymerizable unsaturated monomer (m ₂ ) and the skeleton derived from the other polymerizable unsaturated monomer (m ₃ ), and More preferably, it is in the range of about 10 to about 57% by mass.

The copolymer (A) is usually a graft polymer having a main chain and a side chain, in which the macromonomer (m ₁ ) forms a side chain portion, and a polymerizable unsaturated monomer (m ₂₎ having a nonionic hydrophilic group. ) And optionally other polymerizable unsaturated monomers (m ₃ ) form the main chain portion.

The copolymer (A) is known per se from a macromonomer (m ₁ ) and a polymerizable unsaturated monomer (m ₂ ) having a nonionic hydrophilic group, and optionally other polymerizable unsaturated monomers (m ₃ ). It can be produced by copolymerization by a method such as a solution polymerization method in an organic solvent or an emulsion polymerization method in water. In particular, a solution polymerization method capable of easily producing the copolymer (A) is preferable.
In the present specification, the macromonomer (m ₁ ), the polymerizable unsaturated monomer (m ₂ ) having a nonionic hydrophilic group, and other polymerizable unsaturated monomers as desired, which can form the copolymer (A). (M ₃ ) may be collectively referred to as a monomer component (m).

  Examples of the polymerization initiator used when copolymerizing the monomer component (m) include benzoyl peroxide, octanoyl peroxide, lauroyl peroxide, stearoyl peroxide, cumene hydroperoxide, tert-butyl peroxide, Di-tert-amyl peroxide, tert-butyl peroxylaurate, tert-butyl peroxyisopropyl carbonate, tert-butyl peroxyacetate, diisopropylbenzene hydroperoxide, tert-butyl peroxy-2-ethylhexanoate, etc. Organic peroxides of: azobisisobutyronitrile, azobis (2,4-dimethylvaleronitrile), azobis (2-methylpropiononitrile), azobis (2-methylbutyronitrite) 4,4′-azobis (4-cyanobutanoic acid), dimethylazobis (2-methylpropionate), azobis [2-methyl-N- (2-hydroxyethyl) -propionamide], azobis {2 -Azo compounds such as methyl-N- [2- (1-hydroxybutyl)]-propionamide}; persulfates such as potassium persulfate, ammonium persulfate, sodium persulfate, and the like. The said polymerization initiator may be used individually or in combination of 2 or more types. Further, if necessary, for example, a reducing agent such as sugar, sodium formaldehyde sulfoxylate, or iron complex can be used as the redox initiator.

  The amount of the polymerization initiator is usually about 0.01 to about 5 parts by mass, and preferably about 0.1 to about 3 parts by mass, based on 100 parts by mass of the total mass of the monomer components (m). The method for adding the polymerization initiator is not particularly limited, and can be appropriately selected according to the type and amount thereof. For example, the polymerization initiator can be added to the monomer component (m) or the reaction solvent in advance, or the polymerization initiator can be added all at once or added dropwise in small amounts during the polymerization of the monomer component (m). it can.

  Further, as the solvent in the solution polymerization method, an organic solvent which is less likely to cause chain transfer to the solvent and is water-soluble is preferable. Examples of such solvents include ester solvents such as ethylene glycol monomethyl ether acetate and diethylene glycol monobutyl ether acetate; ketone solvents such as methyl ethyl ketone, methyl isobutyl ketone, diisobutyl ketone, and cyclohexanone; methanol, ethanol, isopropanol, and n-butanol. , Sec-butanol, isobutanol, and other alcohol solvents; 1,4-dioxane, tetrahydrofuran, ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, propylene glycol dimethyl ether, dipropylene glycol dimethyl ether, and other ether solvents; ethylene glycol monomethyl ether, ethylene glycol mono Ethyl ether, ethylene glycol Glycol ether solvents ether and the like; and combinations thereof. As the solvent in the solution polymerization method, ether solvents and glycol ether solvents are preferable.

  The amount of the organic solvent during the polymerization reaction is usually about 500 parts by mass or less, preferably about 50 to about 400 parts by mass, and more preferably about 100, based on 100 parts by mass of the total mass of the monomer components (m). To about 200 parts by weight.

  The weight average molecular weight of the copolymer (A) is preferably from about 20,000 to about 1,000,000, more preferably from about 50,000 to about the viscosity development property of the paint and the finish of the coating film to be formed. It is in the range of about 600,000, and more preferably about 100,000 to about 400,000.

In the present specification, the number average molecular weight typified by the macromonomer (m ₁ ) and the weight average molecular weight typified by the copolymer (A) are retention times measured using a gel permeation chromatograph (GPC). (Retention capacity) is a value obtained by converting to the molecular weight of polystyrene by the retention time (retention capacity) of standard polystyrene having a known molecular weight measured under the same conditions.

  The above number average molecular weight uses “HLC-8120GPC” (trade name, manufactured by Tosoh Corporation) as a gel permeation chromatograph apparatus, one “TSKgel G4000HXL”, two “TSKgel G3000HXL”, And four “TSKgel G2000HXL” (trade name, all manufactured by Tosoh Corporation), using a differential refractometer as the detector, mobile phase: tetrahydrofuran, measurement temperature: 40 ° C., flow rate It can be measured under the condition of 1 mL / min.

  The weight average molecular weight is “HLC-8120GPC” (trade name, manufactured by Tosoh Corporation) as a gel permeation chromatograph, and “TSKgel GMHHR-L” (trade name, manufactured by Tosoh Corporation) is used as a column. , Using a differential refractometer as a detector, mobile phase: dimethylformamide (containing 10 mM each of lithium bromide and phosphoric acid), measurement temperature: 25 ° C., flow rate: 1 mL / min Can be measured.

The copolymer (A) is suitable as a viscosity adjusting agent for water-based paints because it has a high viscosity expression and has a viscosity characteristic that the viscosity decreases as the shear rate increases. For this reason, the aqueous epoxy resin coating composition kit of the present invention is difficult to dripping and can form an aqueous epoxy resin coating composition excellent in coating workability, and from the aqueous epoxy resin coating composition kit of the present invention. The formed aqueous epoxy resin coating composition can form a thick film having excellent finish.
The copolymer (A) can be contained in either one or both of the first composition (I) and the second composition (II) constituting the kit for the aqueous epoxy resin coating composition of the present invention.

<First composition (I)>
<Epoxy resin emulsion>
The first composition (I) contains an epoxy resin emulsion.
The epoxy resin emulsion can be formed, for example, by emulsifying and dispersing an epoxy resin in an aqueous medium. The epoxy resin emulsion can be anionic, nonionic or cationic, but from the viewpoint of viscosity development due to interaction with the copolymer (A), storage stability of the first composition, etc. The emulsion is preferably nonionic.

  The epoxy resin capable of forming an epoxy resin emulsion is preferably a resin having at least two epoxy groups in one molecule, and the epoxy resin is preferably about 100 to about 10,000, more preferably about Having an epoxy equivalent weight ranging from 150 to about 5,000, and more preferably from about 160 to about 1,000, and preferably from about 200 to about 20,000, more preferably from about 300 to about 10,000, and More preferably, it has a number average molecular weight in the range of about 320 to about 2,000.

  Examples of the epoxy resin include bisphenol type epoxy resins such as bisphenol A type epoxy resin, bisphenol F type epoxy resin, and bisphenol AD type epoxy resin; epoxy ester resins obtained by modifying the bisphenol type epoxy resin with a dibasic acid; Cyclic epoxy resins; polyglycol type epoxy resins; epoxy group-containing acrylic resins, and the like, and bisphenol type epoxy resins are preferred, and bisphenol A type epoxy resins are preferred from the viewpoint of corrosion resistance and adhesion of the formed coating film. More preferred.

The number average molecular weight of the epoxy resin can be measured in the same manner as the number average molecular weight of the macromonomer (m ₁ ).
Examples of the nonionic epoxy resin emulsion include an emulsion in which the above epoxy resin is dispersed in an aqueous medium in the presence of a dispersion stable resin derived from polyoxyalkylene.

  As the dispersion stabilizing resin derived from the polyoxyalkylene, a resin having a polyoxyalkylene unit and an epoxy group in one molecule is preferable, and polyethylene glycol, an epoxy resin having a hydroxyl group and an epoxy group, and 1 A modified epoxy resin obtained by a reaction between a compound having one active hydrogen in the molecule and a compound having two or more isocyanate groups in one molecule is more preferable.

The polyethylene glycol preferably has a number average molecular weight in the range of about 400 to about 20,000, particularly about 600 to about 10,000.
The number average molecular weight of the polyethylene glycol can be measured in the same manner as the number average molecular weight of the macromonomer (m ₁ ).

  Examples of the epoxy resin having a hydroxyl group and an epoxy group include bisphenol type epoxy resins such as bisphenol A type epoxy resins and bisphenol F type epoxy resins, and bisphenol A type epoxy resins are preferred.

  The compound having one active hydrogen in one molecule is a compound for blocking the isocyanate group in the modified epoxy resin. For example, methanol, ethanol, propylene glycol monoethyl ether, diethylene glycol monomethyl ether, diethylene glycol monobutyl ether Monohydric alcohols such as acetic acid and propionic acid; monovalent thiols such as ethyl mercaptan; secondary amines such as diethylamine; one secondary amino group such as diethylenetriamine and monoethanolamine; By reacting a primary amino group of an amine compound containing at least one primary amino group with a ketone, aldehyde or carboxylic acid, for example at a temperature of about 100 to about 230 ° C., Ketimine Compound was converted to oxazoline or imidazoline; oximes such as methyl ethyl ketoxime; phenol, phenols nonylphenol and the like. The compounds having one active hydrogen per molecule generally have a molecular weight in the range of about 30 to about 2,000, and preferably about 30 to about 200.

  Examples of the compound having two or more isocyanate groups in one molecule include known aliphatic, alicyclic or aromatic polyisocyanate compounds such as hexamethylene diisocyanate, isophorone diisocyanate, Examples thereof include hydrogenated xylylene diisocyanate, hydrogenated 4,4′-diphenylmethane diisocyanate, tolylene diisocyanate, xylylene diisocyanate and the like, biuretized and isocyanurated products of these polyisocyanate compounds, and combinations thereof.

The modified epoxy resin can be produced according to a method known per se, for example, by mixing raw materials and reacting until substantially no unreacted isocyanate group is present.
When the modified epoxy resin is used as a dispersion stabilizing resin, the ratio of epoxy resin / modified epoxy resin is preferably about 50/50 to about 80/20, and more preferably about 60, based on the solid mass ratio. / 40 to about 75/25. The nonionic epoxy resin emulsion can be obtained by adding water to the epoxy resin and the modified epoxy resin and mixing and stirring.

<Second composition (II)>
The second composition (II) includes a compound having two or more functional groups capable of reacting with an epoxy group contained in the epoxy resin emulsion of the first composition (I) in one molecule, and as the compound, For example, known polyamines having an active hydrogen equivalent weight within the range of about 40 to about 300 can be mentioned. Specific examples of the polyamine include polyamines such as metaxylenediamine, diaminodiphenylmethane, isophoronediamine, 1,3-bisaminocyclohexylamine, diethylenetriamine, triethylenetetramine, hexamethylenediamine, and polyoxypropylene polyamine; Examples thereof include epoxy resin adducts, ketiminates, polyamidoamines, polyamide resins, and the like of the above polyamines, and combinations thereof. Moreover, the modified polyamine which modified | denatured the said polyamine can be employ | adopted from a viewpoint of the storage stability in water as a compound which has 2 or more of functional groups which can react with the said epoxy group.
As 2nd composition (II), what disperse | distributed the said polyamine or modified polyamine in water using a dispersion stable resin is mentioned.

<Water-based epoxy resin coating composition kit>
In the aqueous epoxy resin coating composition kit of the present invention, the ratio between the first composition (I) and the second composition (II) is not particularly limited as long as it is a ratio that is usually used in the art. Although not preferred, the epoxy groups in the first composition (I) and the functional groups capable of reacting with the epoxy groups in the second composition (II) are preferably about 0.01 to about 2.0, more preferably in the range of about 0.1 to about 1.0, and even more preferably in the range of about 0.2 to about 0.8. This is from the viewpoints of curability and corrosion resistance of the coating film formed from the kit.

  The amount of epoxy groups in the first composition (I) is determined according to JIS K 7236: 2001 by reacting a sample with a tetraethylammonium bromide solution and titrating unreacted tetraethylammonium bromide with perchloric acid. Therefore, it can be measured. For example, in the case of active hydrogen in a polyamine, the amount of the functional group capable of reacting with the epoxy group in the second composition (II) is titrated with perchloric acid acetic acid according to JIS K 7237: 1995. Can be measured.

  In the present invention, the copolymer (A) can be contained in either one or both of the first composition (I) and the second composition (II). In particular, the nonionic copolymer (A) can be added to both the first composition (I) and the second composition (II), so that the degree of freedom in coating design can be expanded according to the purpose. Is possible.

In the aqueous epoxy resin coating composition kit of the present invention, the aqueous epoxy resin coating composition formed from the aqueous epoxy resin coating composition kit is based on 100 parts by mass of the resin (that is, the first composition). (I) and 100 parts by weight of the resin contained in the second composition (II)), the copolymer (A) is preferably from about 0.05 to about 30 parts by weight, more preferably from about 0.1 to about 0.1 parts by weight. Copolymer (A) is included to include about 20 parts by weight, and more preferably in the range of about 0.5 to about 10 parts by weight. This is from the standpoint of viscosity development and corrosion resistance.
In the present specification, “solid content” means a residual obtained by removing volatile components such as water and organic solvent from a sample, and can be calculated by multiplying the mass of the sample by the solid content concentration. The solid content concentration can be measured by dividing the mass of a residue obtained by drying about 2 g of a sample at 105 ° C. for 3 hours by the mass before drying.

  The water-based epoxy resin coating composition kit of the present invention, more specifically, the first composition (I) and / or the second composition (II) may optionally contain a pigment; a curing catalyst, a surfactant, Additives for paints such as foaming agents, pigment dispersants, anti-settling agents, thickeners, organic solvents, film-forming aids, coating surface modifiers; aqueous resins other than the above epoxy resin emulsions, and the like can be further included.

Examples of the pigment include rust preventive pigments, extender pigments and colored pigments.
Examples of the rust preventive pigment include zinc phosphate, phosphorous zinc silicate, aluminum zinc phosphate, calcium zinc phosphate, calcium phosphate, aluminum pyrophosphate, calcium pyrophosphate, aluminum trihydrogenphosphate, aluminum metaphosphate, calcium metaphosphate, phosphorus Examples include zinc molybdate, aluminum phosphomolybdate, and zinc dust. Examples of the color pigment include titanium oxide, red rose, cyanine color pigment, carbon black, and zircon powder. Examples of the extender pigment include silica, barita powder, precipitated barium sulfate, barium carbonate, calcium carbonate, gypsum, clay, white carbon, diatomaceous earth, talc, magnesium carbonate, alumina white, gloss white, and tankal.

  It is preferable that the kit for aqueous | water-based epoxy resin coating composition of this invention contains a rust preventive pigment as said pigment from a corrosion-resistant viewpoint of the coating film formed. The kit for an aqueous epoxy resin coating composition of the present invention comprises a two-component composition comprising a first composition (I) containing an epoxy resin emulsion, a copolymer (A) and a rust preventive pigment, and a second composition (II). It is preferable that it is a thing.

  In the aqueous epoxy resin coating composition formed from the kit for the aqueous epoxy resin coating composition of the present invention, the anticorrosive pigment is generally based on the solid content and the anticorrosive pigment per 100 parts by mass of the resin total. Specifically, it is preferably contained in the kit for aqueous epoxy resin coating composition of the present invention so as to be contained in the range of about 10 to about 80 parts by weight, and more generally about 15 to about 70 parts by weight.

  Further, when the anticorrosive pigment is zinc dust, in the coating film formed from the aqueous epoxy resin coating composition kit of the present invention, based on the solid content, Is contained in the range of about 800 to about 2000 parts by weight, particularly about 1200 to about 1800 parts by weight. When the kit for aqueous epoxy resin coating composition of the present invention contains zinc powder in the above range, a zinc rich paint can be formed.

The water-based epoxy resin coating composition kit of the present invention includes, for example, a two-component coating composition comprising a first composition (I) and a second composition (II), a first composition (I), and a second composition. It can be a two-component one-powder type comprising the composition (II) and a pigment. The aqueous epoxy resin coating composition kit of the present invention can generally be mixed immediately before painting to form an aqueous epoxy resin coating composition.
By coating various coated objects with the aqueous epoxy resin coating composition formed from the kit for the aqueous epoxy resin coating composition of the present invention, a coating film having excellent anticorrosion properties can be formed.

It does not restrict | limit especially as said to-be-coated object, For example, steel materials, such as a steel pipe which is a structural member of a steel structure, a steel pipe sheet pile, a steel sheet pile, a steel plate, are mentioned.
Examples of the steel materials include austenitic, ferritic and martensitic stainless steel plates; titanium or titanium alloy plates; aluminum plates; corrosion resistant steel materials such as hot dip zinc or zinc alloy plated plates; and weather resistance such as SPA materials and SMA materials. Steel.
The steel material may be preliminarily coated with rust prevention coating, primer coating, or the like.

  The aqueous epoxy resin coating composition formed from the kit for the aqueous epoxy resin coating composition of the present invention can be applied using various coating means. Examples of the coating means include rollers, air sprays, airless sprays, lysing guns, universal guns, brushes, roll coaters, and the like, and the coating means can be appropriately selected depending on the use of the object to be coated. . The formed coating film can be dried at room temperature, but can be heated and forced-dried as desired.

  The aqueous epoxy resin coating composition kit of the present invention contains the copolymer (A) as a viscosity modifier. Therefore, the aqueous epoxy resin coating composition formed from the kit for the aqueous epoxy resin coating composition of the present invention similarly includes the copolymer (A) as a viscosity modifier, and is more than a coating composition containing a conventional viscosity modifier. However, it is difficult to sag, has good coating workability, and can form a coating film with excellent finish even under conditions of room temperature drying. The aqueous epoxy resin coating composition has a thick film when the first composition, the second composition, and a desired pigment are mixed, and water is added to adjust the viscosity to be suitable for coating. It is possible to form a coating film excellent in finish.

EXAMPLES Hereinafter, although an Example and a comparative example are given and this invention is demonstrated further more concretely, this invention is not limited only to these Examples.
In the following examples, “parts” and “%” mean “parts by mass” and “% by mass”, respectively.

<Manufacture of macromonomer>
[Production Example 1 Production of Macromonomer (m ₁ -1)]
A reaction vessel equipped with a thermometer, thermostat, stirrer, reflux condenser, nitrogen gas inlet tube and dropping device was charged with 16.0 parts of ethylene glycol monobutyl ether and 3.5 parts of MSD, and nitrogen gas was passed through the gas phase. The temperature was raised to 160 ° C. while stirring the liquid phase. When the liquid phase reaches 160 ° C., a liquid mixture comprising 80 parts of 2-ethylhexyl methacrylate, 20 parts of 2-hydroxyethyl methacrylate and 3.5 parts of di-tert-amyl peroxide is added dropwise to the liquid phase over 3 hours. The liquid phase was stirred at the same temperature for 2 hours. Next, the liquid phase was cooled to 30 ° C. and diluted with ethylene glycol monobutyl ether to obtain a macromonomer (m ₁ -1) solution having a solid content of 65%. The number average molecular weight of the macromonomer (m ₁ -1) was 2,200. When analyzed by proton NMR, in the macromonomer (m ₁ -1), 97% or more of the ethylenically unsaturated groups derived from MSD were present at the end of the polymer chain, and 2% had disappeared.

The analysis in the proton NMR was carried out as follows.
(1) Using deuterated chloroform as a solvent, the peak (4.8 ppm, 5.1 ppm) based on the proton of the unsaturated group of MSD before and after the polymerization reaction, and the proton of the ethylenically unsaturated group at the end of the macromonomer chain The peak based on (5.0 ppm, 5.2 ppm) and the peak of aromatic proton derived from MSD (7.2 ppm) are measured.
(2) Next, assuming that the peak of aromatic protons (7.2 ppm) derived from the MSD does not change before and after the polymerization reaction, each unsaturated group is determined based on the peak of the aromatic protons derived from MSD. Whether it was unreacted, present at the end of the macromonomer chain, or disappeared.

[Production Examples 2, 3 and 5]
Except that the blending were changed as shown in Table 1, in the same manner as in Production Example 1, a solid content of 65% macromonomer _(m 1 _-2), the _(m 1 -3) and _(m 1 -5) A solution was obtained.

[Production Examples 4 and 6]
The solutions of the macromonomers (m ₁ -4) and (m ₁ -6) were changed in the same manner as in Production Example 1 except that the formulation was changed as shown in Table 1 and the polymerization temperature was changed to 120 ° C. Obtained.
Table 1 shows a polymerizable unsaturated monomer having an alkyl group having 3 to 24 carbon atoms in a raw material composition (parts) of a solution of macromonomers (m ₁ -1) to (m ₁ -6) and a monomer component (b). The ratio of (b ₁ ), the hydroxyl value (mgKOH / g) and the number average molecular weight are shown.

<Production of copolymer>
[Production Example 7 Production of Copolymer (A-1)]
In a reaction vessel equipped with a thermometer, a thermostat, a stirrer, a reflux condenser, a nitrogen gas inlet tube and two dripping devices, 15.4 parts (solid) of the macromonomer (m ₁ -1) solution obtained in Production Example 1 10 parts), 20 parts of ethylene glycol monobutyl ether and 30 parts of diethylene glycol monoethyl ether acetate were added, and the temperature was raised to 85 ° C. while blowing nitrogen gas into the liquid. Next, in a reaction vessel maintained at the same temperature, a mixed solution consisting of 81 parts of N, N-dimethylacrylamide, 9 parts of 2-hydroxyethyl acrylate, 10 parts of ethylene glycol monobutyl ether and 40 parts of diethylene glycol monoethyl ether acetate, Perbutyl O "(trade name, manufactured by NOF Corporation, polymerization initiator, tert-butyl peroxy-2-ethylhexanoate) 0.2 part and 20 parts of ethylene glycol monobutyl ether, Over time, it was dropped into the reaction vessel at the same time. After completion of the dropping, the mixture was aged by stirring for 2 hours at the same temperature.

  Then, in a reaction vessel maintained at the same temperature, a mixed solution consisting of 0.3 part of 2,2′-azobis (2,4-dimethylvaleronitrile) and 15 parts of ethylene glycol monobutyl ether was dropped over 1 hour, After completion of dropping, the mixture was aged by stirring at the same temperature for 1 hour. Then, while adding ethylene glycol monobutyl ether, it was cooled to 30 ° C., and 215 parts of deionized water was added to obtain a solution of copolymer (A-1) having a solid content of 20%. The weight average molecular weight of the obtained copolymer (A-1) was 150,000.

[Production Examples 8 to 13]
Except having changed mixing | blending as shown in Table 2, it carried out similarly to manufacture example 7, and obtained the copolymer solution (A-2)-(A-7) of 20% of solid content.

<Production of water-based epoxy resin coating composition kit and water-based epoxy resin coating composition>
[Examples 1-6 and Comparative Examples 1-5]
As shown in Table 3, an epoxy resin emulsion, a copolymer solution, a rust preventive pigment (zinc phosphate) and an extender pigment (talc) as a pigment were mixed to obtain a first composition. Next, the first composition and the amine curing agent as the second composition were mixed at the ratio shown in Table 3, and diluted with water to a viscosity of 10 poise with a B-type viscometer (60 rpm). An aqueous epoxy resin coating composition was obtained. Example 4 is a reference example.

[Example 7]
As shown in Table 3, an epoxy resin emulsion, a rust preventive pigment (zinc phosphate) and an extender pigment (talc) as a pigment were mixed to obtain a first composition. Next, as shown in Table 3, the amine curing agent and the copolymer solution were mixed to obtain a second composition. Next, the first composition and the second composition are mixed in the ratio shown in Table 3, and diluted with water so that the viscosity becomes 10 poise with a B-type viscometer (60 rpm), and an aqueous epoxy resin paint A composition was obtained.

[Example 8]
The first composition was obtained by mixing 10 parts of the epoxy resin emulsion and 2.5 parts of the copolymer solution (RC-1). Subsequently, 12.5 parts of 1st compositions, 4.2 parts of amine hardening | curing agents, and 75 parts of zinc dust were mixed, and the water-based epoxy resin coating composition as a water-based epoxy zinc rich paint was obtained.

<Creation of painted articles>
The aqueous epoxy resin coating compositions produced in Examples 1 to 8 and Comparative Examples 1 to 5 were applied onto a polished steel plate by air spray so as to have a dry film thickness of 60 to 80 μm, and 23 ° C. and 50% relative A test coating plate was obtained by drying at humidity for 7 days.

  With respect to the aqueous epoxy resin coating compositions produced in Examples 1 to 8 and Comparative Examples 1 to 5, the coating workability was evaluated according to the procedure described below, and the anticorrosion and curing were performed according to the procedure described below with respect to the test coating plate. Sex was evaluated. The results are also shown in Table 3.

(Note 1) Epoxy resin emulsion:
In a glass three-necked flask equipped with a thermometer, a stirrer and a condenser, 600 g of polyethylene glycol having a number average molecular weight of 6000, 13.5 g of propylene glycol monomethyl ether, “jER-834” (trade name, Mitsubishi Chemical Corporation) Manufactured, bisphenol A type epoxy resin, epoxy equivalent; 250, number average molecular weight 500) 500 g, mixed with stirring at 100 ° C., and after homogenizing, 52.2 g of tolylene diisocyanate was added to the flask, After reacting for 2 hours, the temperature of the flask was raised to 120 ° C., and further reacted for 4 hours. Then, it was confirmed that the isocyanate value of the system was 0.5 or less, and 117 g of propylene glycol monomethyl ether was added for dilution to produce a dispersion stable resin. To 40 g of this dispersion stable resin, 65 g of “jER-828” (trade name, manufactured by Mitsubishi Chemical Corporation, bisphenol A type epoxy resin, epoxy equivalent: 190, number average molecular weight 380) is added, and 95 g of water is added while stirring with a stirrer. In addition, an epoxy resin emulsion having a solid content of 51% was obtained.

(Note 2) Urethane associative thickener: “Coapur 6050”, trade name, manufactured by COATEX, 50% active ingredient, polyurethane associative (Note 3) amine curing agent: “TXH-694”, trade name, Fuji Kasei Industrial Co., Ltd., active ingredient 80%, modified polyaminoamide type aqueous curing agent, active hydrogen equivalent 200.

[Anti-corrosion]
The rust and swelling after the test coating plate was subjected to JIS K5600-7-1: 1999 medium-resistance salt spray test for 500 hours were evaluated according to the following criteria.
○: No rust and swelling are observed. Δ: Rust and swelling are observed only slightly. ×: Rust and swelling are slightly generated. Note that the JIS K5600-7-1 neutral salt resistance spray test is 35. In a spray cabinet set at ± 2 ° C., a test solution prepared by dissolving 50 ± 5 g of sodium chloride in 1 L of distilled water or the like is collected on a test coating plate installed at an angle of 20 ± 5 ° from the vertical. It is carried out by spraying continuously in an amount of 1-2 mL / h per 80 cm ^{2 of} collecting area.

[Curing property]
A certain amount of the coating film was peeled off from the test coating plate, and the peeled coating film was immersed in tetrahydrofuran and allowed to stand at 20 ° C. for 24 hours. Then, the coating film was taken out from tetrahydrofuran, dried at 110 ° C. for 1 hour, and gel The fraction is expressed by the following formula (2):
Gel fraction (%)
= (Mass of coating film after immersion and drying / mass of coating film before immersion) × 100
And evaluated according to the following criteria.
◎: Gel fraction is 70% or more ○: Gel fraction is 60% or more and less than 70% △: Gel fraction is 50% or more and less than 60% ×: Gel fraction is less than 50% is there

[Coating workability]
A water-based epoxy resin coating composition is applied to a vertically-finished polished steel plate using an air spray so that the film thickness gradually increases, and after drying for 7 days at 23 ° C. and 50% relative humidity, The maximum dry film thickness ([mu] m) of the portion without dripping was measured and evaluated as the coating workability ([mu] m). The coating workability (μm) means that the larger the value, the better the sagging resistance.

Claims (9)

An aqueous epoxy resin coating composition having a first composition (I) containing an epoxy resin emulsion and a second composition (II) containing a compound having two or more functional groups capable of reacting with an epoxy group in one molecule A kit for
The copolymer (A) in which the first composition (I) and / or the second composition (II) includes the following skeleton:
Polymer obtained by polymerizing a monomer component (b) containing at least 5% by mass of a polymerizable unsaturated monomer (b ₁ ) having a C 3-24 alkyl group and a hydroxyl group-containing polymerizable unsaturated monomer A macromonomer (m ₁ ) having a chain and a polymerizable unsaturated group and having a number average molecular weight in the range of 1,000 to 10,000, and a polymerizable unsaturated monomer (m ₂ ) having a nonionic hydrophilic group ),
A kit for the water-based epoxy resin coating composition, comprising: The copolymer (A) contains a skeleton of the macromonomer (m ₁ ) and a skeleton of the polymerizable unsaturated monomer (m ₂ ) having a nonionic hydrophilic group, respectively, in an amount of 1 to 29 parts by mass and 20 to 99 parts by mass, respectively. The kit according to claim 1, comprising: The copolymer (A) has a skeleton of the other polymerizable unsaturated monomer (m ₃ ) other than the skeleton of the macromonomer (m ₁ ) and the polymerizable unsaturated monomer (m ₂ ) having a nonionic hydrophilic group. Furthermore, the skeleton of the macromonomer (m ₁ ), the skeleton of the polymerizable unsaturated monomer (m ₂ ) having a nonionic hydrophilic group, and the skeleton of the other polymerizable unsaturated monomer (m ₃ ) are each 1 The kit according to claim 1 or 2, wherein the kit is present in a ratio of -29% by mass, 20-98% by mass, and 1-79% by mass. Polymerizable unsaturated monomers having a nonionic hydrophilic group (m ₂₎ is an N- substituted (meth) acrylamide, kit according to any one of claims 1-3.   The kit according to any one of claims 1 to 4, wherein the epoxy resin emulsion has nonionic properties.   The kit according to any one of claims 1 to 5, which is a two-component type or a two-component one-powder type.   Based on the solid content of the aqueous epoxy resin composition formed from the kit, the kit is 100 parts by mass of the resin total contained in the first composition (I) and the second composition (II). The kit as described in any one of Claims 1-6 containing a copolymer (A) so that a copolymer (A) may be included in 0.05-30 mass parts.   The aqueous epoxy resin coating composition formed from the kit as described in any one of Claims 1-7. Applying an object to be coated with the aqueous epoxy resin coating composition according to claim 8 to form a coating film;
A method for forming a coated article, comprising: