JP7200173B2 - Aqueous dispersions, metal coating agents and coatings - Google Patents

Description

The present invention relates to aqueous dispersions, metal coating agents and coatings.

Sulfuric acid esters (salts) and phosphate esters (salts) obtained by reacting polyoxyalkylene styrenated propenylphenyl ether with a sulfating agent or a phosphorylating agent are known. For example, Patent Documents 1 and 2 describe the use of the phosphate (salt) as a reactive emulsifier for emulsion polymerization. For example, when emulsion polymerization is performed using a phosphate metal salt as a reactive emulsifier, the phosphate metal salt is included as a structural unit in the resulting polymer.

By using the phosphate ester metal salt as a reactive emulsifier, the stability during emulsion polymerization is improved, and an aqueous polymer dispersion (polymer dispersion) obtained by such emulsion polymerization does not foam. The polymer film obtained from this aqueous dispersion has improved properties such as water resistance.

WO2013/108588 JP 2015-013921 A

However, since a coating film formed by coating a metal surface with an aqueous dispersion of a polymer containing the phosphate metal salt as a constituent monomer has excellent water resistance, it is suitable, for example, for coating metals. . However, in recent years, in applications such as coating on metals, there has been a demand for improving the adhesion of a coating film formed from an aqueous dispersion to metals and the abrasion resistance of the coating film. That is, in the application of coating on metals, etc., it is required that the formed coating film strongly adheres to the metal and that the coating film has excellent wear resistance. There was an urgent need for physical development.

The present invention has been made in view of the above, and an aqueous dispersion capable of forming a coating film having excellent adhesion and abrasion resistance to metal, a metal coating agent containing the aqueous dispersion, and the aqueous dispersion Alternatively, the object is to provide a coating film formed from the coating agent for metal.

As a result of intensive studies aimed at achieving the above object, the present inventors have found that the above object can be achieved by using a polymer having a specific structure into which a structural unit based on a reactive emulsifier is introduced. was completed.

That is, the present invention includes, for example, the subject matter described in the following sections.
Item 1
Containing a polymer containing polyoxyalkylene styrenated propenylphenyl ether phosphate and/or a salt thereof (A) as constituent monomers,
An aqueous dispersion obtained by synthesizing the polymer using a reactive emulsifier (C) (excluding polyoxyalkylene styrenated propenylphenyl ether phosphate and/or salt thereof (A)).
Item 2
Item 2. The aqueous dispersion according to Item 1, wherein the reactive emulsifier (C) comprises an anionic reactive emulsifier.
Item 3
Item 2. The aqueous dispersion according to Item 1, wherein the reactive emulsifier (C) comprises a nonionic reactive emulsifier.
Item 4
The anionic reactive emulsifier is a compound having a polymerizable unsaturated group, a polyoxyalkylene group and an anionic group (however, polyoxyalkylene styrenated propenyl phenyl ether sulfate salt and polyoxyalkylene alkyl propenyl phenyl ether sulfate 3. The aqueous dispersion according to Item 2, which contains the ester salt.).
Item 5
Any one of items 1 to 4, wherein the polymer further contains at least one monomer (B) selected from the group consisting of (meth)acrylic acid esters, aromatic vinyl compounds and vinyl carboxylates as constituent monomers. 1. Aqueous dispersion according to item 1.
Item 6
The polyoxyalkylene styrenated propenylphenyl ether phosphate salt (A) is at least one selected from the group consisting of alkali metal salts, alkaline earth metal salts, ammonium salts, alkylammonium salts and alkanolamine salts. The aqueous dispersion according to items 1 to 5.
Item 7
A metal coating agent comprising the aqueous dispersion according to any one of Items 1 to 6.
Item 8
A coating film obtained by using the aqueous dispersion according to any one of claims 1 to 6 or the metal coating agent according to claim 7.

According to the aqueous dispersion of the present invention, it is possible to form a coating film having excellent adhesion to metals and abrasion resistance.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail. In this specification, the expressions "contain" and "include" include the concepts of "contain", "include", "substantially consist of" and "consist only of".

1. Aqueous Dispersion The aqueous dispersion of the present invention contains a polymer containing a polyoxyalkylene styrenated propenylphenyl ether phosphate and/or a salt thereof (A) as a constituent monomer. In particular, the aqueous dispersion of the present invention uses a reactive emulsifier (C) (excluding polyoxyalkylene styrenated propenylphenyl ether phosphate and/or its salt (A)) to synthesize the polymer. It is obtained by That is, the aqueous dispersion of the present invention is produced by a method comprising the step of polymerizing polyoxyalkylene styrenated propenylphenyl ether phosphate and/or salt thereof (A) in the presence of the reactive emulsifier (C). be able to.

According to the aqueous dispersion of the present invention, it is possible to form a coating film excellent in adhesion to metals, weather resistance and abrasion resistance. In addition, the aqueous dispersion of the present invention, for example, has excellent wettability with respect to metals, and thus has excellent coatability.

In the present specification, the polyoxyalkylene styrenated propenylphenyl ether phosphate and/or its salt (A) is abbreviated as "monomer (A)".

In the aqueous dispersion of the present invention, the polymer contains the monomer (A) as a constituent monomer. As a reminder, as used herein, constituent monomers of a polymer refer to repeating building blocks to form a polymer. More strictly speaking, the polymer contains structural units derived from the monomer (A). As used herein, the term "structural unit derived from a monomer" refers to a structural unit formed by polymerizing a monomer or a derivative thereof. The derivative here means a structural unit formed by further neutralizing or hydrolyzing a structural unit formed by polymerizing a monomer. For example, when the monomer is the above monomer (A) and the structural unit formed after polymerization is in the salt form, the structural unit obtained by converting the salt form into the acid form corresponds to the derivative. Alternatively, when the monomer is the monomer (A) and the structural unit formed after polymerization is in the acid form, the structural unit obtained by neutralizing the acid form and converting it into the salt form also corresponds to the derivative. .

The monomer (A) may be a polyoxyalkylene styrenated propenylphenyl ether phosphate (hereinafter sometimes referred to as an acid-type phosphate) or its salt form. Alternatively, monomer (A) may be a mixture thereof. That is, the polymer contains both a polyoxyalkylene-styrenated propenylphenyl ether phosphate (acid-type phosphate) and a salt of the polyoxyalkylene-styrenated propenylphenyl ether phosphate as constituent monomers. You can also have it as

When the monomer (A) is in the form of a salt, the type of salt is not particularly limited, and is selected, for example, from the group consisting of alkali metal salts, alkaline earth metal salts, ammonium salts, alkylammonium salts and alkanolamine salts. It can be at least one. Alkali metals are exemplified by Na, K and the like, and alkaline earth metals are exemplified by Mg, Ca and the like. Examples of alkylammonium include monomethylammonium, dipropylammonium and the like, and examples of alkanolamine include monoethanolamine, diethanolamine, triethanolamine and the like.

More preferably, the monomer (A) is at least one selected from the group consisting of acid type phosphates, alkali metal salts, ammonium salts and alkanolamine salts. It is possible to form a coating film with excellent adhesion, excellent abrasion resistance, and excellent water whitening resistance.

For example, when monomer (A) is an ammonium salt, most of the ammonia is released upon heating and drying the aqueous dispersion. As a result, the monomer (A) can be the above-described acid-type phosphate ester, so that the polymer can contain the acid-type phosphate ester as a constituent monomer in the state of the coating film described later.

Monomer (A) may be a phosphate monoester or a phosphate diester. Monomer (A) can also be a mixture of both.

Further specific examples of the monomer (A) include the following general formula (1)
(X) _k P (=O) (OL) _3-k (1)
The compound represented by is mentioned.

In formula (1), k is 1 or 2, and L is a hydrogen atom or at least selected from the group consisting of alkali metals, alkaline earth metals, ammonium residues, alkylammonium residues and alkanolamine residues. 1 type is shown. In formula (1), X is a monovalent group represented by (2) below.

In formula (2), R ¹ represents a 1-propenyl group or an allyl group (that is, a 2-propenyl group), A represents an alkylene group having 2 to 4 carbon atoms, and n is the average addition mole of the oxyalkylene group. number, and m represents the number of substituents in the range of 1-3.

In Formula (1), when one molecule has multiple Ls, the multiple Ls may be the same, or may be partially or wholly different.

In formula (1), when L is an alkali metal, examples of the alkali metal include Na, K, etc., and when L is an alkaline earth metal, examples of the alkaline earth metal include Mg, Ca, and the like. be done. In formula (1), when L is an alkylammonium residue, the alkylammonium residue is exemplified by a monomethylammonium residue, a dipropylammonium residue, etc. In formula (1), L is an alkanolamine residue. , the alkanolamine residue is exemplified by a monoethanolamine residue, a diethanolamine residue, a triethanolamine residue, and the like.

In formula (1), L is more preferably a hydrogen atom or at least one selected from the group consisting of alkali metals, ammonium residues and alkanolamine residues. It is possible to form a coating film that has excellent adhesion to the surface, excellent abrasion resistance, and also excellent water whitening resistance.

In the compound represented by formula (1), R ¹ is preferably 1-propenyl group. The substitution position of R ¹ is preferably ortho-position and/or para-position, more preferably ortho-position.

In formula (2), the oxyalkylene group represented by AO may be linear or branched, and examples thereof include oxyethylene, oxypropylene and oxybutylene groups.

In formula (2), when AO is an alkylene oxide having 2 to 4 carbon atoms, the (AO) _n -chain moiety is ethylene oxide, propylene oxide, butylene oxide, tetrahydrofuran (1,4-butylene oxide), etc. It can be an addition polymer using one species or two or more species. The addition form of the oxyalkylene group is not particularly limited, and may be a single adduct using one type of alkylene oxide, a random adduct using two or more types of alkylene oxide, a block adduct, or random addition and block addition thereof. may be a combination of

The oxyalkylene group is preferably an oxyethylene group, and when two or more oxyalkylene groups are included, one of them is preferably an oxyethylene group. The (AO) _n -chain moieties preferably contain 50 to 100 mol %, more preferably 70 to 100 mol % of oxyethylene groups relative to the total number of moles of (AO).

In formula (2), n represents the average number of added moles of oxyalkylene groups, preferably in the range of 1-9, more preferably 2-8. In one embodiment, n may be 2-6, or 2-4.

In formula (2), m represents the number of substituents on the α-methylbenzyl group, and is in the range of 1 to 3 on average, preferably 1 to 2. The substitution position of the α-methylbenzyl group is preferably ortho position and/or para position.

Among the monovalent groups represented by formula (2) (that is, X in formula (1)), groups represented by formula (2-1) below are preferred.

In formula (2-1), n and m are synonymous with n and m in formula (2).

The monomer (A) can also be a mixture of an acid-type compound represented by the formula (1) in which L is a hydrogen atom and a compound in which L is in the form of various salts.

Further, the monomer (A) may be a mixture of a compound represented by formula (1) in which k is 1 (monoester phosphate) and a compound in which k is 2 (diester phosphate). can. When the monomer (A) is a phosphoric acid monoester, a phosphoric acid diester, or a mixture thereof, the phosphoric acid monoester can be exemplified by compounds represented by the following formula (1-1). Examples of diesters include compounds represented by the following formula (1-2).

In formulas (1-1) and (1-2), R ¹ , A, L, n, and m are synonymous with R ¹ , A, L, n, and m in formulas (1) and (2) above. is. When the monomer (A) is a mixture of both, both R ¹ , A, L, n and m may be the same or different. Further, when the monomer (A) contains a compound represented by formula (1-2), R ¹ in one molecule may be the same or different.

In the compounds represented by formulas (1-1) and (1-2), R ¹ is preferably a 1-propenyl group. The substitution position of R ¹ is preferably ortho-position and/or para-position, more preferably ortho-position.

The method for producing the monomer (A) is not particularly limited, and for example, the monomer (A) can be synthesized by adopting a known method. For example, the monomer (A) can be produced using styrenated phenol and allyl halide as raw materials. Specifically, a styrenated phenol and an allyl halide are reacted with a basic substance such as sodium hydroxide or potassium hydroxide to obtain a styrenated allyl phenyl ether, which is then heated to remove allyl groups. rearrangement to obtain the styrenated allylphenol; Next, adding an alkylene oxide to the styrenated allylphenol in the presence of an alkali catalyst at high temperature and high pressure to obtain a polyoxyalkylene styrenated propenylphenyl ether, which is reacted with a known phosphorylating agent. Phosphate can be obtained by After that, the neutralized salt can be obtained by neutralizing with an alkali neutralizing agent, if necessary. The neutralizing agent is not particularly limited.

In the aqueous dispersion of the present invention, the polymer contains the monomer (A) as a constituent monomer, and at least one polymer selected from the group consisting of (meth)acrylic acid esters, aromatic vinyl compounds and vinyl carboxylates. Seed monomers (B) can also be included as constituent monomers. That is, the polymer can contain structural units derived from the monomer (B).

When the polymer contains the monomer (B) as a constituent monomer, the coating film obtained from the aqueous dispersion tends to have improved adhesion to metal. Therefore, the monomer (B) is preferably the main component of the constituent monomers that form the polymer.

In monomer (B), (meth)acrylic acid ester means one or both of acrylic acid ester and methacrylic acid ester. Examples of (meth)acrylic acid esters include methyl (meth)acrylate, ethyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, sec-butyl (meth)acrylate, tert-butyl (meth) acrylate, n-octyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, decyl (meth) acrylate, dodecyl (meth) acrylate, tetradecyl (meth) acrylate, (meth) ) hexadecyl acrylate, octadecyl (meth) acrylate, octadecenyl (meth) acrylate, icosyl (meth) acrylate, docosyl (meth) acrylate, cyclopentyl (meth) acrylate, cyclohexyl (meth) acrylate, (meth) and benzyl acrylate. These can be used singly or in combination of two or more.

Examples of the aromatic vinyl compound in the monomer (B) include styrene, α-methylstyrene, o-, m-, p-methylstyrene, o-, m-, p-ethylstyrene, o-, m-, p-isopropylstyrene, o-, m-, p-tert-butylstyrene and the like. Any one of these may be used, or two or more thereof may be used in combination.

Examples of the vinyl carboxylate in the monomer (B) include vinyl acetate, vinyl propionate, and vinyl butyrate, and any one of these may be used alone, or two or more thereof may be used in combination.
A preferred vinyl carboxylate is vinyl acetate.

The method for producing the monomer (B) is not particularly limited, and for example, a wide range of known production methods can be adopted. Monomer (B) can also be obtained from commercial products and the like.

As described above, the polymer is obtained by a polymerization reaction in the presence of the reactive emulsifier (C), so the polymer may contain the reactive emulsifier (C) as a so-called constituent monomer. That is, the reactive emulsifier (C) can be copolymerized with a monomer component for forming a polymer such as the monomer (A), and the polymer is a mixture of the monomer (A) and the reactive emulsifier (C). It can also be called a copolymer. However, not all of the reactive emulsifier (C) used in the polymerization reaction is necessarily incorporated into the polymer (that is, not all of it is necessarily contained as a constituent monomer of the polymer). Reactive emulsifier (C) not incorporated into the polymer can be included in the aqueous dispersion as an emulsifier or dispersant. The reactive emulsifier (C) is a compound other than the monomer (A), specifically a compound other than the polyoxyalkylene styrenated propenylphenyl ether phosphate and its salt (A).

The type of reactive emulsifier (C) is not particularly limited, and a wide range of known reactive emulsifiers can be applied. Reactive emulsifiers (C) include anionic reactive emulsifiers and nonionic reactive emulsifiers.

Examples of anionic reactive emulsifiers include compounds each having a polymerizable unsaturated group, a polyoxyalkylene group (eg, alkylene having 2 to 4 carbon atoms and 1 to 20 oxyalkylene units) and an anionic group. can be mentioned. Hereinafter, such a compound is abbreviated as "compound C1". However, the compound C1 excludes the polyoxyalkylene styrenated propenylphenyl ether sulfate salt and the polyoxyalkylenealkylpropenylphenyl ether sulfate salt, and the compound C1 can be a compound other than these. As a result, the finally obtained aqueous dispersion tends to have improved wettability with respect to metals, easily forms a coating film, and the formed coating film has particularly excellent weather resistance.

It should be noted that the anionic emulsifier is compound C1 and polyoxyalkylene styrenated propenyl phenyl ether sulfate salt and/or polyoxyalkylene alkyl propenyl phenyl ether sulfate salt in combination with It is not even excluded. That is, when the reactive emulsifier (C) contains an anionic reactive emulsifier, the anionic reactive emulsifier contains at least compound C1, so that the finally obtained aqueous dispersion has improved wettability to metals. This makes it easy to form a coating film, and the resulting coating film has particularly excellent weather resistance.

Examples of the polymerizable unsaturated group include 1-propenyl group, 2-methyl-1-propenyl group, (meth)allyl group, (meth)acrylic group, etc., and have one or more of these can also Examples of the polyoxyalkylene group include an oxyethylene group, an oxypropylene group, an oxybutylene group, and the like, and one or more of these may be included. The polyoxyalkylene group preferably contains 50 to 100 mol % of oxyethylene groups, more preferably 70 to 100 mol %, and is preferably a polyoxyethylene group.

Further specific examples of anionic reactive emulsifiers include, for example, the aforementioned compound C1, polyoxyalkylene-1-(allyloxymethyl)alkyl ether sulfate and salts thereof, polyoxyalkylene-1-(allyloxy methyl) alkyl ether phosphate and its salts, polyoxyalkylene-1-alkoxymethyl-2-(2-propenyloxy) ethyl ether sulfate and its salts, and polyoxyalkylene-1-alkoxymethyl-2-( 2-propenyloxy)ethyl ether phosphate and at least one selected from the group consisting of salts thereof and the like. Examples of anionic emulsifiers other than compound C1 include one or more selected from the group consisting of alkylalkenyl sulfosuccinates.

On the other hand, the nonionic reactive emulsifier is not particularly limited as long as it has a polymerizable unsaturated group and is nonionic. For example, a wide range of known nonionic reactive emulsifiers can be used. can be done. Examples thereof include compounds having a polymerizable unsaturated group and a polyoxyalkylene moiety (eg, alkylene having 2 to 4 carbon atoms and 10 to 200 oxyalkylene units). Nonionic reactive emulsifiers may have styrenated phenyl moieties.

Specific examples of nonionic reactive emulsifiers include polyoxyalkylene styrenated propenyl phenyl ethers, polyoxyalkylene alkyl propenyl phenyl ethers, polyoxyalkylene-1-(allyloxymethyl) alkyl ethers, and polyoxyalkylene-1 -alkoxymethyl-2-(2-propenyloxy)ethyl ether.

When the reactive emulsifier (C) contains an anionic reactive emulsifier or a nonionic reactive emulsifier, the coating film formed from the aqueous dispersion exhibits adhesion to metal, weather resistance and abrasion resistance. tend to increase in sex. The reactive emulsifier (C) may be an anionic reactive emulsifier alone or a nonionic reactive emulsifier alone. Further, the reactive emulsifier (C) may be a mixture of an anionic reactive emulsifier and a nonionic reactive emulsifier. can.

In the aqueous dispersion of the present invention, the polymer may optionally contain other monomers as constituent monomers in addition to the monomers (A) and (B) and the reactive emulsifier (C). Examples of other monomers include conjugated diolefin monomers such as (meth)acrylic acid, acrylonitrile, vinyl chloride, vinylidene chloride, butadiene, isoprene and chloroprene, ethylene, maleic anhydride, methyl maleate and the like.

As described above, in the aqueous dispersion of the present invention, the polymer contains the monomer (A) as an essential constituent monomer as described above, and the reactive emulsifier (C) is also present in the polymer. Reactive emulsifier (C) can be copolymerized with the monomer components to form a polymer. Polymer (A) may contain monomer (B) in addition to monomer (A) and reactive emulsifier (C), and may further contain other monomers as constituent monomers.

The content of the monomer (A) in all constituent monomers of the polymer is not particularly limited. For example, the content of the monomer (A) can be 0.1 to 20% by mass, preferably 0.2 to 15% by mass, and 0.5 to 10% by mass, relative to the total mass of the polymer. % is more preferable.

The content of the monomer (B) in all constituent monomers of the polymer is not particularly limited. For example, with respect to the total mass of the polymer, the content of the monomer (B) can be 70 to 99.8% by mass, preferably 80 to 99.4% by mass, and 85 to 99% by mass. It is more preferable to have

The content of the component derived from the reactive emulsifier (C) contained in the polymer can be, for example, 0.1 to 20% by mass, and 0.2 to 15% by mass, based on the total mass of the polymer. and more preferably 0.5 to 10% by mass.

When the polymer contains other monomers as constituent monomers, the content may be, for example, 20% by mass or less, preferably 10% by mass, relative to the total mass of the polymer. More preferably, it is 5% by mass or less.

The weight average molecular weight (Mw) of the polymer is not particularly limited, and can be, for example, 100,000 to 10,000,000, preferably 1,000,000 to 5,000,000. Here, the weight average molecular weight of the polymer can be measured by a known method of polyethylene glycol conversion by gel permeation chromatography (GPC).

The shape and size of the polymer are also not particularly limited, for example, it can be the shape and size that are applied in metal coating agents, and in particular, the shape and size formed by known emulsion polymerization are widely adopted. be able to.

The aqueous dispersion of the present invention can contain an emulsifier in addition to the polymer. The emulsifier may contain a reactive emulsifier (C) used when producing the polymer. In other words, the reactive emulsifier (C) that has not been incorporated into the polymer may be dissolved in the water in the aqueous dispersion. Further, the aqueous dispersion may contain a reactive emulsifier other than the reactive emulsifier (C). Additionally, the emulsifier can also include non-reactive emulsifiers. A non-reactive emulsifier is an emulsifier that does not have a radically polymerizable functional group and does not exhibit polymerization reactivity in emulsion polymerization.

The type of non-reactive emulsifier is not particularly limited. For example, non-reactive emulsifiers include at least one emulsifier selected from the group consisting of anionic emulsifiers and nonionic emulsifiers.

Among non-reactive emulsifiers, anionic emulsifiers include, for example, a wide range of known anionic emulsifiers. For example, as an anionic emulsifier, a compound having a polyoxyalkylene alkyl ether moiety, a compound having a polyoxyalkylene alkenyl ether moiety, a compound having a polyoxyalkylene alkenylphenyl ether moiety, a compound having a polyoxyalkylene alkylphenyl ether moiety, a poly Compounds having an oxyalkylene styrenated phenyl ether moiety can be mentioned.

Specific non-reactive anionic emulsifiers include polyoxyalkylene alkyl ether sulfates and salts thereof, polyoxyalkylene alkenyl ether sulfates and salts thereof, polyoxyalkylene alkenyl phenyl ether sulfates and salts thereof, polyoxyalkylene alkyl Ether Phosphates and Their Salts, Polyoxyalkylene Alkenyl Ether Phosphates and Their Salts, Polyoxyalkylene Alkyl Phenyl Ether Phosphates and Their Salts, Polyoxyalkylene Alkenyl Phenyl Ether Phosphates and Their Salts, Polyoxyalkylene Styrenes phenyl ether phosphate and its salts, polyoxyalkylenealkylsulfosuccinic acid and its salts, polyoxyalkylenealkenylsulfosuccinic acid and its salts, alkylsulfosuccinic acid and its salts, dialkylsulfosuccinic acid and its salts, alkenylsulfosuccinic acid and its salts , polyoxyalkylene alkyl ether acetate esters and salts thereof, polyoxyalkylene alkenyl ether acetate esters and salts thereof, polyoxyalkylene alkylphenyl ether acetate esters and salts thereof, polyoxyalkylene alkenylphenyl ether acetate esters and salts thereof, polyoxyalkylene Examples include styrenated phenyl ether acetate and its salts, alkylbenzenesulfonic acid and its salts, alkylsulfuric acid and its salts, and alkylphosphoric acid and its salts. These can be used singly or in combination of two or more. The anionic emulsifier may also be a mixture of salt and non-salt forms.

Among the non-reactive emulsifiers, the anionic emulsifier preferably contains one selected from the group consisting of polyoxyalkylene alkyl ether sulfates and salts thereof, and polyoxyalkylene alkenyl ether sulfates and salts thereof.

In another aspect of the present invention, the anionic emulsifier as a non-reactive emulsifier may also contain a polyoxyalkylene styrenated phenyl ether sulfate salt and a polyoxyalkylene alkylphenyl ether sulfate salt. In this case, the polyoxyalkylene styrenated phenyl ether sulfate salt is preferably a polyoxyethylene styrenated phenyl ether sulfate salt in that the polymerization stability is likely to be improved. The ester salt is preferably a polyoxyethylene alkylphenyl ether sulfate salt.

Among non-reactive emulsifiers, nonionic emulsifiers include, for example, a wide range of known nonionic emulsifiers. For example, nonionic emulsifiers include compounds having polyoxyalkylene moieties.

Specific non-reactive nonionic emulsifiers include polyoxyalkylene alkyl ethers, polyoxyalkylene alkenyl ethers, polyoxyalkylene alkylphenyl ethers, polyoxyalkylene alkenyl phenyl ethers, polyoxyalkylene styrenated phenyl ethers, polyoxyalkylene Examples include naphthyl ether and polyoxyalkylene triblock polymers (eg, polyoxyethylene polyoxypropylene glycol, etc.). These can be used singly or in combination of two or more.

The non-reactive emulsifier preferably contains at least an anionic emulsifier from the viewpoint that the adhesion of the coating film to metal is likely to be improved and the abrasion resistance is also likely to be improved. In this case, the non-reactive emulsifier may be a combination of an anionic emulsifier and a nonionic emulsifier, or may be an anionic emulsifier alone. When an anionic emulsifier and a nonionic emulsifier are used in combination, for example, the content of the anionic emulsifier with respect to the total weight of the anionic emulsifier and nonionic emulsifier is 50% by mass, preferably 60% by mass or more, more preferably is 70% by mass or more, more preferably 80% by mass or more.

The emulsifier contained in the aqueous dispersion may be a single reactive emulsifier and a single non-reactive emulsifier. In this case, only one type of emulsifier may be used, or two or more types may be used. The emulsifier contained in the aqueous dispersion may also be a mixture of reactive and non-reactive emulsifiers. In the case of a mixture, the mixing ratio of the reactive emulsifier and the non-reactive emulsifier contained in the aqueous dispersion is not particularly limited. For example, with respect to 100 parts by mass of the reactive emulsifier, the content of the non-reactive emulsifier is preferably 1 to 1000 parts by mass, more preferably 5 to 500 parts by mass, and 10 to 100 parts by mass. is more preferred. Note that "100 parts by mass of the reactive emulsifier" includes both the reactive emulsifier that reacted with the monomer component and was incorporated into the polymer and the reactive emulsifier that was not incorporated but was present in water.

Examples of the medium for the aqueous dispersion include aqueous solvents. Water-based solvents include water, lower alcohols (eg, alcohols having 1 to 3 carbon atoms), and mixed solvents thereof. The water-based medium is preferably water in that the dispersibility of the polymer tends to be stable.

The concentration of the polymer in the aqueous dispersion is not particularly limited. The concentration of the polymer in the aqueous dispersion can be 20 to 70% by mass, preferably 35 to 55% by mass, in that a coating film can be easily formed from the aqueous dispersion.

In addition to the polymer and emulsifier, the aqueous dispersion may contain various additives as long as the effects of the present invention are not impaired. Examples of additives include colorants, pH adjusters, thickeners, pigments, preservatives and the like. One or more of these additives may be contained in the aqueous dispersion. The additive is, for example, 10 parts by mass or less, preferably 5 parts by mass or less, more preferably 1 part by mass or less per 100 parts by mass of the polymer.

The polymer contained in the aqueous dispersion of the present invention contains the monomer (A) as a constituent monomer and is obtained using the reactive emulsifier (C), so the coating film obtained from the aqueous dispersion is , it is possible to form a coating film excellent in adhesion to metal, weather resistance and abrasion resistance. It is also suitable for use as a metal coating agent, etc., since it has excellent wettability to metals.

2. Method for Producing Aqueous Dispersion The method for producing the aqueous dispersion according to the present embodiment is not particularly limited, and for example, a known emulsion polymerization method can be widely applied. As an example of an emulsion polymerization method, water is used as a solvent for polymerization, a monomer for polymerization is emulsified in water using an emulsifier, and a polymerization initiator is added to the emulsion to react to synthesize a polymer. A water dispersion is obtained by neutralizing with an alkali. As the alkali, a wide range of known compounds can be used, among which ammonia; hydroxides of alkali metals such as sodium hydroxide and potassium hydroxide; hydroxides of alkaline earth metals such as calcium hydroxide and magnesium hydroxide. alkylamines such as monomethylamine and dipropylamine; alkanolamines such as monoethanolamine and diethanolamine;

The polymerizable monomer contains at least the monomer (A). As the monomer (A), in one embodiment, it is preferable to use the aforementioned acid type phosphate ester. The monomer for polymerization can contain a monomer (B) in addition to the monomer (A). The content of the monomer (A) can be 0.1 to 20% by mass, preferably 0.2 to 15% by mass, and more preferably 0.5 to 10% by mass, based on the total amount of the monomers for polymerization. is more preferable. Further, the content of the monomer (B) can be 70 to 99.8% by mass, preferably 80 to 99.4% by mass, more preferably 85 to 99% by mass, relative to the total amount of the monomers for polymerization. is more preferable.

In the method for producing an aqueous dispersion, an emulsifier is used, and in particular, an emulsifier containing at least the reactive emulsifier (C) is used. The emulsifier may be the reactive emulsifier (C) alone, or may be used in combination with, for example, the non-reactive emulsifier as long as the desired aqueous dispersion can be produced. All or part of the reactive emulsifier (C) may be incorporated into the polymer by being copolymerized with the monomer (A) or the like, or may be partially incorporated into the polymer and partially not incorporated. It may remain as such and be included in the aqueous dispersion as an emulsifier or dispersant.

The amount of the reactive emulsifier (C) used can be, for example, 0.01 parts by mass or more, preferably 0.05 parts by mass or more, and 0.1 It is more preferably at least 0.2 parts by mass, particularly preferably at least 0.3 parts by mass. Further, the amount of the reactive emulsifier (C) used can be 20 parts by mass or less, preferably 15 parts by mass or less, more preferably 10 parts by mass or less, relative to 100 parts by mass of the monomer for polymerization. , more preferably 5 parts by mass or less, and particularly preferably 3 parts by mass or less.

When a non-reactive emulsifier is used in combination, the amount used is not particularly limited. For example, with respect to 100 parts by mass of the reactive emulsifier used, the content of the non-reactive emulsifier is preferably 1 to 1000 parts by mass, more preferably 5 to 500 parts by mass, and 10 to 100 parts by mass. It is even more preferable to have

In the emulsion polymerization, as the polymerization initiator used in the polymerization reaction, for example, a wide range of polymerization initiators used in known emulsion polymerization can be used. Examples include hydrogen peroxide, persulfate compounds, and azo compounds. Examples of persulfate compounds include ammonium persulfate, sodium persulfate, potassium persulfate and the like. Examples of azo compounds include 2,2'-azobis-2-methylpropionamidine hydrochloride, 2,2'- azobis-2-(2-imidazolin-2-yl)propane hydrochloride, 2-carbamoyl azoisobutyronitrile and the like. Moreover, you may use a well-known reaction accelerator together.

In the emulsion polymerization, polymerization conditions such as polymerization temperature and polymerization time are not particularly limited, and can be appropriately set according to the type of monomer to be used.

2. Metal Coating Agents and Coating Films The aqueous dispersion of the present invention can be applied to various uses. can be formed, it is suitable for use as a metal coating agent.

(metal coating agent)
The metal coating agent of the present invention is not particularly limited as long as it contains the water dispersion. The metal coating agent may consist of the aqueous dispersion alone, or may contain other additives. Other additives for metal coating agents are not particularly limited, and a wide range of additives contained in known metal coating agents can be used.

According to the metal coating agent of the present invention, a coating film having excellent adhesion to metal, weather resistance and abrasion resistance can be formed. Moreover, since it is excellent in wettability with respect to metal, coating is easy and a uniform coating film is likely to be formed.

The type of metal to be coated with the metal coating agent is not particularly limited, and various metal substrates such as substrates made of single metals, metal alloys containing two or more kinds of metals, and metal alloys can be used. Among them, a metal coating agent can form a coating film having excellent adhesion to stainless steel.

(Coating film)
Coatings can be obtained using aqueous dispersions or coating agents for metals. The method for forming the coating film is not particularly limited, and for example, a wide range of known coating film forming methods can be employed. As an example of a method of forming a coating film, a coating film can be formed on the surface of a substrate by applying an aqueous dispersion or a coating agent for metals to the substrate, followed by heating and drying. Accordingly, the coating includes an aqueous dispersion or a dry product of the metal coating agent. The metal substrate can be used as the base material.

Since the coating film is formed from an aqueous dispersion or a coating agent for metals, it is excellent in adhesion to metals, weather resistance and wear resistance, as well as water whitening resistance and rust prevention.

EXAMPLES The present invention will be described in more detail below with reference to examples, but the present invention is not limited to the embodiments of these examples.

(Monomer A)
[Synthesis Example 1: Synthesis of Monomer (A-1)]
230 g (1.0 mol), 40 g (1.0 mol) of NaOH and 210 g of acetone were charged, and the internal temperature was raised to 40° C. while stirring. Next, 91 g (1.2 mol) of allyl chloride was added dropwise over 1 hour. After the dropwise addition was completed, the temperature was kept at 40° C. for 2 hours to carry out the reaction. After the reaction product was filtered to remove the by-produced NaCl, acetone was removed under reduced pressure to obtain 314 g of styrenated allylphenyl ether.

This styrenated allyl phenyl ether was charged into an autoclave and stirred at 200° C. for 5 hours. A rearrangement reaction occurred at this stage to give styrenated 1-propenylphenol. 290 g of this styrenated 1-propenylphenol was transferred to an autoclave, and 132 g (3 mol) of ethylene oxide (EO) was added at a pressure of 147 kPa and a temperature of 130° C. using potassium hydroxide as a catalyst.

Next, 71 g (0.5 mol) of phosphoric anhydride was added dropwise to 422 g (1 mol) of this styrenated 1-propenylphenol EO adduct with 3 mols of styrenated EO while cooling the temperature not exceeding 20°C. and reacted for 5 hours. Through such a reaction, a polyoxyethylene (3 mol) styrenated 1-propenylphenyl ether phosphate monoester (hereinafter abbreviated as (A-1)) represented by the following formula (1-1-1) is obtained. rice field. In the formula, EO represents an oxyethylene group (same below).

[Synthesis Example 2: Synthesis of Monomer (A-2)]
By performing the same operation as in Synthesis Example 1 except that the amount of phosphoric anhydride used was 47 g (0.33 mol), the phosphoric acid monoester represented by the above formula (1-1-1) and the following Polyoxyethylene (3 mol) styrenated 1-propenylphenyl ether sesquiester phosphate (hereinafter referred to as (A -2)) was obtained.

[Synthesis Example 3: Synthesis of Monomer (A-3)]
Polyoxyethylene (3 mol) represented by the above formula (1-2-1) was obtained by performing the same operation as in Synthesis Example 1 except that the amount of phosphoric anhydride used was 36 g (0.25 mol). A styrenated 1-propenylphenyl ether phosphate diester (hereinafter abbreviated as (A-3)) was obtained.

[Synthesis Example 4: Synthesis of Monomer (A-4)]
By performing the same operation as in Synthesis Example 1 except that the amount of ethylene oxide used was 220 g (5 mol), polyoxyethylene (5 mol) styrenated 1 represented by the following formula (1-1-2) -propenylphenyl ether phosphate monoester (hereinafter abbreviated as (A-4)) was obtained.

[Synthesis Example 5: Synthesis of Monomer (A-5)]
The monoester represented by the above formula (1-1-2) and the following formula (1-2- Polyoxyethylene (5 mol) styrenated 1-propenylphenyl ether phosphate sesquiester (hereinafter abbreviated as (A-5)), which is a mixture with the diester represented by 2), was obtained.

[Synthesis Example 6: Synthesis of Monomer (A-6)]
By performing the same operation as in Synthesis Example 3 except that the amount of ethylene oxide used was 220 g (5 mol), the polyoxyethylene (5 mol) styrenated 1 represented by the above formula (1-2-2) was obtained. -propenylphenyl ether phosphate diester (hereinafter abbreviated as (A-6)) was obtained.

[Synthesis Example 7: Synthesis of Monomer (A-7)]
Polyoxyethylene (3 mol) styrenated 1-propenylphenyl ether phosphoric acid monoester was obtained by reacting 49.3 g of the monomer (A-1) obtained by the same operation as in Synthesis Example 1 with 4.0 g of sodium hydroxide. to obtain a sodium salt of (hereinafter abbreviated as (A-7)).

[Synthesis Example 8: Synthesis of Monomer (A-8)]
49.3 g of the monomer (A-1) obtained by the same operation as in Synthesis Example 1 was reacted with 6.8 g of 25% aqueous ammonia, and the water was distilled off to give polyoxyethylene (3 mol) styrenated 1- An ammonium salt of propenylphenyl ether phosphate monoester (hereinafter abbreviated as (A-8)) was obtained.

[Synthesis Example 9: Synthesis of Monomer (A-9)]
49.3 g of the monomer (A-1) obtained by the same operation as in Synthesis Example 1 was reacted with 6.1 g of monoethanolamine to give a polyoxyethylene (3 mol) styrenated 1-propenylphenyl ether phosphate monoester. An ethanolamine salt (hereinafter abbreviated as (A-9)) was obtained.

(Monomer B)
As the monomer B, the following (B-1) to (B-4) were prepared.
・(B-1): butyl acrylate ・(B-2): methyl methacrylate ・(B-3): styrene ・(B-4): vinyl acetate

(Reactive emulsifier C)
As the reactive emulsifier (C), the following (C-1) to (C-9) were prepared.
・ (C-1): “Aqualon KH-10” manufactured by Daiichi Kogyo Seiyaku Co., Ltd.
・ (C-2): ADEKA “Adekari Soap SR-10”
・ (C-3): “SINONATE LRS10” manufactured by Sino-Japan Chemical Co., Ltd.
・ (C-4): “Eleminol JS-20” manufactured by Sanyo Chemical Industries, Ltd.
・ (C-5): “Latemul PD-104” manufactured by Kao Corporation
・ (C-6): “Maxemul 6106” manufactured by Croda
・ (C-7): Daiichi Kogyo Seiyaku Co., Ltd. “Aqualon KH-20”
・ (C-8): “Aqualon AN-20” manufactured by Daiichi Kogyo Seiyaku Co., Ltd.
・ (C-9): “ADEKARI SOAP ER-20” manufactured by ADEKA

(Other emulsifiers)
As a reactive emulsifier other than reactive emulsifier (C), (c-1) shown below was prepared.
・ (c-1): Daiichi Kogyo Seiyaku Co., Ltd. “Aqualon BC-10”

(Other monomers)
As other monomers (a), the following (a-1) to (a-3) were prepared.
・ (a-1): acrylic acid ・ (a-2): hydroxyethyl methacrylate phosphate monoester (product name: Light Ester P-1M, manufactured by Kyoeisha Chemical Co., Ltd.)

(Example 1)
As shown in Table 1 below, 2.5 parts by mass of (A-1) obtained in Synthesis Example 1 as the monomer (A) and 123.75 parts by mass of (B-1) as the monomer (B) A mixture of 123.75 parts by mass of part and (B-2), 5 parts by mass of (C-1) as a reactive emulsifier (C), and 107.15 parts by mass of water are mixed and emulsified. A pre-emulsion was obtained. Separately, 117.11 parts by mass of water and 0.25 parts by mass of sodium hydrogen carbonate were charged into a flask equipped with a dropping funnel, a stirrer, a nitrogen gas inlet tube, a thermometer and a reflux condenser, and 36.0 parts by mass of the pre-emulsion was added. 46 parts by mass were added, heated to 80° C., and mixed for 15 minutes. Then, an aqueous solution prepared by dissolving 0.38 parts by mass of ammonium persulfate in 10 parts by mass of water was added as a polymerization initiator and allowed to react for 15 minutes. . Subsequently, an aqueous solution obtained by dissolving 0.12 parts by mass of ammonium persulfate in 10 parts by mass of water was added, reacted for 1 hour, cooled to 40° C., and adjusted to pH 8 with aqueous ammonia as a neutralizer. A water dispersion was obtained. By neutralizing with aqueous ammonia, the phosphoric acid ester of the monomer (A) among the constituent monomers of the polymer became an ammonium salt at the stage of the aqueous dispersion.

(Examples 2-8)
Same as Example 1, except that the type and amount (parts by mass) of the monomer (A), monomer (B), reactive emulsifier (C) and other monomer (a) were changed to those shown in Table 1 below. A water dispersion was obtained in a similar manner. In Example 7, an aqueous solution of sodium hydroxide was used as the neutralizing agent instead of aqueous ammonia, so the phosphate ester of the monomer (A) among the constituent monomers of the polymer became a sodium salt.

(Examples 9-16)
Same as Example 1, except that the types and amounts (parts by mass) of monomer (A), monomer (B), reactive emulsifier (C) and other monomers (a) used were changed to those shown in Table 2 below. A water dispersion was obtained in a similar manner. In Example 9, monoethanolamine was used as the neutralizing agent instead of ammonia water, so the phosphate ester of the monomer (A) among the constituent monomers of the polymer became a monoethanolamine salt.

(Examples 17-23)
Same as Example 1 except that the types and amounts (parts by mass) of monomer (A), monomer (B), reactive emulsifier (C) and other monomer (a) used were changed to those shown in Table 3 below. A water dispersion was obtained in a similar manner.

(Comparative Examples 1 to 5, Reference Example 1)
Same as Example 1 except that the types and amounts (parts by mass) of monomer (A), monomer (B), reactive emulsifier (C) and other monomer (a) used were changed to those shown in Table 4 below. A water dispersion was obtained in a similar manner.

(Evaluation method)
The aqueous dispersions obtained in Examples, Comparative Examples, and Reference Examples were evaluated for the following adhesion 1, adhesion 2, water whitening resistance, rust resistance, abrasion resistance, wettability to substrates, and weather resistance. bottom.

<Adhesion 1>
The aqueous dispersion was applied to a stainless steel (SUS) plate so as to have a film thickness of 22 μm (wet) and dried at 105° C. for 10 minutes to obtain a test piece. Using this test piece, a cross-cut test was performed according to JIS K 5400-8.5, and the percentage of peeling was evaluated according to the following criteria.
≪Judgment Criteria≫
A: The rate of peeling is 0%
B: The percentage of peeling is more than 0% and less than 25% C: The percentage of peeling is 25% or more and less than 50% D: The percentage of peeling is 50% or more and less than 75% E: The percentage of peeling is 75% or more

<Adhesion 2>
Evaluation was performed in the same manner as in Adhesion 1, except that the drying temperature after coating was changed to 60°C.

<Water whitening resistance>
The aqueous dispersion was applied to a glass plate to a thickness of 22 μm (wet), dried at 105° C. for 10 minutes, and the resulting film was immersed in water at 25° C. to evaluate the degree of whitening. A glass plate on which a film was formed was placed on a 10-point character, and the distinguishability of the characters viewed through the film was determined according to the following criteria.
≪Judgment Criteria≫
A: Letters are visible even after immersion for 3 days.
B: Letters are visible after immersion for 1 day, but letters are not visible after immersion for 3 days.
C: Letters are not visible after immersion for 1 day.

<Rust prevention>
The aqueous dispersion is applied to a stainless steel (SUS) plate so that the film thickness is 22 μm (wet), and the film obtained by drying at 60 ° C. for 10 minutes is subjected to the cross-cut method of JIS K 5600-5-6. and made a notch. The film was immersed in 3% by mass salt water at 20° C. for 10 days, and the state thereof was evaluated. The evaluation was made on the degree of rust generation, and was judged according to the following criteria.
≪Judgment Criteria≫
A: No rust B: Rust is seen only in the cross-cut part C: Rust is seen in the whole

<Abrasion resistance>
The aqueous dispersion was applied to a stainless steel (SUS) plate so that the film thickness was 22 μm (wet), and the film obtained by drying at 60 ° C. for 10 minutes was subjected to abrasion loss in accordance with JIS K 5600-5-10. was measured. Based on the abrasion loss (g) of the film formed from the aqueous dispersion obtained in Comparative Example 1 (as 100%), the ratio of abrasion loss of each film was calculated and judged according to the following criteria.
≪Judgment Criteria≫
A: 50% or less B: 50-80%
C: 80% or more

<Wettability to substrate>
A measurement sample was prepared by diluting the aqueous dispersion twice with water, and using this sample, the surface tension (mN / m) at 25 ° C. was measured with a Wilhelmy surface tension meter. The wettability to the substrate was evaluated. Lower surface tension indicates higher wettability to the substrate.
≪Judgment Criteria≫
○: surface tension is less than 40 mN / m ×: surface tension is 40 mN / m or more

<Weather resistance>
The aqueous dispersion was applied to a glass plate so that the film thickness was 254 μm (wet), and the film obtained by drying at 60 ° C. for 60 minutes was measured using an eye super UV tester SUV-W151 manufactured by Iwasaki Electric Co., Ltd. , to evaluate the weather resistance. The test conditions were light source: metal halide lamp, UV intensity: 1000 w/m ² , temperature: 20° C., humidity: 40% RH, irradiation time: 200 hours. The color difference ΔE*ab of the film before and after the test was measured using a color difference meter (SD6000 manufactured by Nippon Denshoku Industries Co., Ltd.) and evaluated based on the following criteria. The smaller the color difference before and after the test, the higher the weather resistance of the film.
≪Judgment Criteria≫
Good: ΔE*ab is less than 5.
x: ΔE*ab is 5 or more.

Tables 1 to 4 show the formulation conditions of the water dispersions prepared in Examples, Comparative Examples and Reference Examples, and the evaluation results of the coating films obtained from the water dispersions. In addition, in the compounding conditions of each table, a blank part means that the raw material is not used.

As can be seen from the comparison between the evaluation results shown in Tables 1 to 3 and the evaluation results shown in Table 4, a polymer containing any of the specific phosphate esters (A-1) to (A-9) as a constituent monomer The aqueous dispersion containing the coalescence and the reactive emulsifier (C) has high wettability to metals and excellent coating properties, and the coating film obtained from these aqueous dispersions has adhesion to metals (stainless steel) and weather resistance. In addition to being excellent in various performances such as durability and wear resistance, it was also excellent in water whitening resistance and rust prevention.

Claims (5)

At least one selected from the group consisting of polyoxyalkylene styrenated propenylphenyl ether phosphate and/or a salt thereof (A) as constituent monomers, (meth)acrylic acid esters, aromatic vinyl compounds and vinyl carboxylates a polymer containing the monomer (B),
Among the total constituent monomers of the polymer, the content of the polyoxyalkylene styrenated propenylphenyl ether phosphate and/or salt thereof (A) is 0.1 to 20% by mass, and the content of the monomer (B) is 70 to 99.8% by mass,
Obtained by synthesizing the polymer using a reactive emulsifier (C) (excluding the polyoxyalkylene styrenated propenylphenyl ether phosphate and/or salt thereof (A)),
The reactive emulsifier (C) comprises an anionic reactive emulsifier,
The content of the reactive emulsifier (C) is 0.1 to 20% by mass in the total constituent monomers of the polymer,
The anionic reactive emulsifier is a compound having a polymerizable unsaturated group, a polyoxyalkylene group and an anionic group (however, polyoxyalkylene styrenated propenyl phenyl ether sulfate salt and polyoxyalkylene alkyl propenyl phenyl ether sulfate Ester salts are excluded.), Aqueous dispersion. At least one selected from the group consisting of polyoxyalkylene styrenated propenylphenyl ether phosphate and/or a salt thereof (A) as constituent monomers, (meth)acrylic acid esters, aromatic vinyl compounds and vinyl carboxylates a polymer containing the monomer (B),
Among the total constituent monomers of the polymer, the content of the polyoxyalkylene styrenated propenylphenyl ether phosphate and/or salt thereof (A) is 0.1 to 20% by mass, and the content of the monomer (B) is 70 to 99.8% by mass,
Obtained by synthesizing the polymer using a reactive emulsifier (C) (excluding the polyoxyalkylene styrenated propenylphenyl ether phosphate and/or salt thereof (A)),
The reactive emulsifier (C) comprises a nonionic reactive emulsifier,
An aqueous dispersion in which the content of the reactive emulsifier (C) is 0.1 to 20% by mass in the total monomers constituting the polymer . The polyoxyalkylene styrenated propenylphenyl ether phosphate salt (A) is at least one selected from the group consisting of alkali metal salts, alkaline earth metal salts, ammonium salts, alkylammonium salts and alkanolamine salts. 3. The aqueous dispersion according to claim 1 or 2, wherein A metal coating agent comprising the aqueous dispersion according to any one of claims 1 to 3. A coating film formed on a metal substrate,
A coating film obtained by using the aqueous dispersion according to any one of claims 1 to 3 or the metal coating agent according to claim 4 .