JPS58914B2 - Tomaku no Keiseihouhou - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for forming a coating film using an aqueous solution of a water-soluble or water-dispersible vinyl monomer, and particularly to a method for forming a coating film using the above-mentioned aqueous solution and having excellent properties in the presence of oxygen. The present invention relates to a method for forming a .

Conventionally known methods for polymerizing radically polymerizable compounds in the presence of oxygen include redox polymerization using a combination of peroxide and a reducing agent, or redox polymerization using a combination of cerium ions and a reducing agent. has been used as a modification method by graft polymerization of vinyl monomers such as natural fibers and starch, but these graft polymerizations of vinyl monomers by redox polymerization tend to have extremely limited grafting base materials, It is difficult to create three-dimensional crosslinked monomers, and the polymerization inhibition effect of oxygen on these vinyl monomers cannot be sufficiently suppressed, making it extremely difficult to use them in coating film formation methods that require strict properties. It has been thought that there is.

However, these radically polymerizable compounds, especially water-soluble or water-dispersible vinyl compounds, have extremely small molecular weights compared to conventional coating materials, and have microscopic structures that were thought to be impossible to penetrate using conventional coating methods. For example, if we take advantage of the fact that the vinyl compound can easily penetrate into the rusted structure and three-dimensionally crosslink the vinyl compound that has penetrated into this fine structure, this would be unthinkable using conventional methods. From this perspective, the present inventors considered that it would be a method for forming a coating film, and found that ceric ions, hydroxyl groups or groups that can form hydroxyl groups in the molecule, amine groups, or amino A group capable of forming a group or a salt thereof or a quaternary ammonium salt, a compound having a mercapto group or an aldehyde group, and a compound having the formula 5xoyn- (in the formula
is an integer of 1 to 6, y is an integer of 1 to 7, and n is an integer of 0 or 2). The inventors have discovered that the polymerization and crosslinking reaction of water-dispersible or water-dispersible vinyl monomers can proceed satisfactorily even in an oxygen-containing atmosphere, and have accomplished the present invention.

The gist of the present invention is to combine at least one water-soluble or water-dispersible vinyl compound, a sulfur compound capable of producing a formula 5xOyn- ion (wherein x, y, and n are the same as above) and an aqueous medium. An aqueous composition A containing a ceric compound capable of producing ceric ions is prepared, and at least one of compositions A or B has at least one hydroxyl group or hydroxyl group in the molecule. A compound having a mercapto group or an aldehyde group, a salt thereof, a quaternary amine salt, a mercapto group, or an aldehyde group is added, and a water-based composition A is first applied onto the coating material. After that, a composition mainly composed of aqueous composition B is applied, or a composition mainly composed of aqueous composition B is first applied on the coating material, and then a composition mainly composed of aqueous composition A is applied. The first invention comprises a method for forming a coating film, characterized in that the coating film is formed by applying a coating film, and the first invention comprises a method for forming a coating film, which comprises at least one hydroxyl group or a group capable of forming a hydroxyl group in the molecule, an amine group, or As a compound having a group capable of forming an amine group, a salt thereof, a quaternary amine salt, a mercapto group, or an aldehyde group, it is recommended to use a compound having at least one of these functional groups and at least one polymerizable unsaturated group. This invention consists of a second invention comprising a characteristic method for forming a coating film.

The water-soluble or water-dispersible polymerizable vinyl compound used in carrying out the present invention has 1 to 4 carbon atoms.
Alkyl acrylates or methacrylates with alkyl groups such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, acrylamide, methacrylamide, acrylic acid, methacrylic acid, itaconic acid , crotonic acid, α
- Methylene glutaric acid, P-vinylbenzenesulfonic acid, soda salts, potassium salts, ammonium salts of these acids, etc., as well as the above carboxylic acids and polyols, such as ethylene glycol, propylene glycol, diethylene glycol, tetraethylene glycol, glycerin, Monoesters obtained by condensation with trimethylolpropane, neopentyl glycol, etc., aminoalkyl esters of monoethylenically unsaturated carboxylic acids such as dimethylaminoethyl acrylate or methacrylate, diethylaminoethyl acrylate or methacrylate, 2-sulfonate Ethyl acrylate or methacrylate, 2-acrylamide-2-
Methylpropanesulfonic acid, 2-nuccrylamide-2
- Monovinyl compounds selected from methylpropanesulfonic acid and salts thereof, polyvinyl compounds with a molecular weight of 1000 or less, such as methylenebisacrylamide or methacrylamide, unsaturated monocarboxylic or dicarboxylic acids or their anhydrides, and hydroxyethyl acrylate or condensation products or addition reaction products with hydroxy group-containing vinyl compounds such as methacrylates, allyl alcohols, methallyl alcohols, N-methylolated or N-alkylolated benzoguanamines, N-methylolated polyesters or N-alkylols. condensation products of melamines and the above-mentioned hydroxy group-containing vinyl compounds, ethylene glycol diacrylate or methacrylate, diethylene glycol dimethacrylate or acrylate, triethylene glycol diacrylate or methacrylate, tetraethylene glycol diacrylate or methacrylate, glycerin triacrylate Or methacrylate, trimethylolpropane triacrylate or methacrylate, trimethylolpropane diacrylate or dimethacrylate, pentaerythritol diacrylate, pentaerythritol diacrylate, tetraethylene glycol tetraacrylate or methacrylate, and compounds represented by the formula.

In addition, at this time, other polymerizable compounds are added in proportions that do not impair the solubility or dispersibility of these vinyl compounds in the aqueous medium, such as acrylates or methacrylates having 5 or more carbon atoms, styrene, divinyl Benzene, α-
Methylstyrene or the like can also be used in combination.

Specific examples of compounds having a hydroxyl group in the molecule used in carrying out the present invention include methanol, ethanol,
isopropanol, butanol, isobutanol, tertiary
water-soluble alcohols such as butanol, cyclohexanol, cyclopentanol, ethylene glycol,
Polyols such as propylene glycol, diethylene glycol, glycerin, trimethylolpropane, neopentyl glycol, 1,3-butylene glycol, 1,4-butylene glycol, or monoesters and polyesters of these polyols and unsaturated monocarboxylic acids. and has at least one hydroxyl group in the molecule, diethylene glycol monovinyl ether, allyl alcohol glycerin monovinyl ether, crotonyl alcohol, vinylethynyl carbinol, N-methylolacrylamide or methacrylamide, N-
(1-deoxy-D-flurosyl)acrylamide or methacrylamide, hydroxyacetic vinyl ester,
Hydroxyacetic acid allyl ester, etc. Compounds that generate hydroxyl groups in aqueous media and have vine groups include water-soluble polyepoxy compounds such as ethylene oxide and propylene oxide, allyl glycidyl ether, methacryl glycidyl ether, Examples include glycidyl acrylate or methacrylate.

In addition to these compounds, methylolated melamine, methylolated benzoguanamine, polyvinyl alcohol,
Hydrophilic compounds such as starch, sucrose, fibers such as wood and cotton, and fine particles can also be used in the same manner as the above compounds.

Specific examples of compounds having an amine group or a quaternary ammonium group include ammonia, hydroxylamine,
Methylamine, ethylamine, isopropylamine, iso-butylamine, tertiary butylamine, cyclopentylamine, cyclohexylamine, cyclopentylamine, n-laurylamine, aminoacetone, stearylamine, benzylamine, acetamide, benzylhydroxylamine, glycine, alanine, glutamic acid,
Lysine, tyrosine, ethylenediamine, propylenediamine, hexamethylenediamine, phenylenediamine,
Compounds with non-polymerizable primary, secondary or tertiary amine groups such as urea, ammonium carbamate, hydrazine, diethylamine, dimethylamine, triethylamine, ethylene urea, dimethylaminoethyl acrylate or methacrylate, diethylamine Tunatyl acrylate or methacrylate, tertiary butylaminoethyl acrylate or methacrylate, β-aminoethyl vinyl ester, glycine allyl ester, condensates of the above amino acids and hydroxyl group-containing compounds, diallylmelamine, allyl urea, pyridine, allyl thiourea , 2-(N,N'-dimethylamine)-4-vinylpyrindi, 2,4-diamino-6-pinyl-striamine, P-dimethylaminostyrene, 3-(styrene)-β
-alanine, 2-(styrene)-glycine, allyl-butyl-β-hydroxyethylamine, vinylamide, vinyl-diethylamine, vinyl-dimethylamine, dibutyl-β-hydroxyethylamine, N-diethylaminomethylmaleimide, diallyl-dimethylammonium bromide , N,N,N-triethyl-N-(2-methacryloxyethyl)ammonium iosite, salts thereof, and quaternary ammonium salts.

Further, specific examples of compounds having a group capable of generating an amine group in the presence of water include N-vinyl isocyanate, 2-
Examples include (1-allysilinyl)ethyl acrylate and methacrylate.

Specific examples of mercapto group-containing compounds include methyl mercaptan, ethyl mercaptan, n-lauryl mercaptan, n-butyl mercaptan, secondary-butyl mercaptan, tertiary-butyl mercaptan, cyclohexyl mercaptan, stearyl mercaptan, allyl mercaptan, In addition to non-polymerizable compounds such as thiophenol, thioglycolic acid, mercaptopyrimidine, benzyl mercaptan, dithiol compounds such as allyl mercaptan, N-mercaptoethyl acrylamide or methacrylamide, 2-mercaptoethyl thioacrylate or methacrylate, and acrylic acid; Specific examples include polymerizable compounds such as condensates with methacrylic acid or derivatives thereof.

Specific examples of aldehyde group-containing compounds include n-butyraldehyde, iso-butyraldehyde, n-valeraldehyde, isovaleraldehyde, crotonaldehyde, benzaldehyde, furfural, acrolein, methacrolein, glyoxal, n-caproaldehyde, etc. be able to.

Compounds having these specific functional groups play an extremely important role in carrying out the present invention.

First, it first forms a relatively stable complex with the ceric compound used as a polymerization catalyst, and then 5X
The above-identified cerium has a mechanism of forming a redox polymerization catalyst system by contacting with a sulfur compound that can generate Oyn- ions and acting as a polymerization initiator for the above-mentioned water-soluble or water-dispersible vinyl compounds. Not only does the action of the complex formed with the compound having a functional group suppress the polymerization inhibiting effect of oxygen on the vinyl monomer, but conversely, the formation of this complex
The second reason is that the polymerization of the vinyl monomer can be promoted, and the second reason is that since these specific functional groups serve as addition reaction sites with the vinyl monomer, a partially crosslinked structure can be formed.

Therefore, when a compound having at least one of these specific functional groups and at least one polymerizable unsaturated group in the molecule is used as these compounds, it is possible to form the compound by the method of the present invention. Since a crosslinked coating film with extremely high density can be formed, the coating film can have excellent coating performance.

Among the above-mentioned compounds, α:
β-Ethylenically unsaturated carboxylic acids, particularly those made using acrylic acid, exhibit the effect of suppressing the polymerization inhibiting effect of oxygen during the coating film formation process in the practice of the present invention.

Specific examples of compounds capable of generating ceric ions used in carrying out the present invention include cerium nitrate,
Examples include salts such as oxalates and sulfates, as well as halides such as cerium iosate, bromide, and chloride.

Specific examples of sulfur compounds that can release ions represented by the formula 5xOyn- include 5O2SO2°S2O,
Sulfoxylic acid, sulfite, dithionite, pyrosulfite,
SO22-, SO32-, S such as pyrosulfuric acid, nithionic acid, trithionic acid, tetrathionic acid, pentathionic acid, hexathionic acid, etc.
O32-, 52O42-.

52O52-, 52O62-2S2O72-, 53O6
2-.

Acids having groups capable of generating divalent ions such as 54O62-, 55O62-, 56O62- and their sodium salts, potassium salts, ammonium salts, acetates, sulfuryl chloride, dichloromonosulfane, dichlorodisulfane, dichloro Specific examples thereof include dichloropolysulfanes represented by tri- or tetra-, pen-co-, hexa-, octasulfane, etc., and mesides such as benzenesulfinic acid and dodecanesulfinic acid.

Although the theoretical basis of the polymerization and curing mechanism of the vinyl compound in the aqueous composition of the present invention is not clear, firstly, an intermolecular compound is temporarily formed between the cerium ion and the above-mentioned specific polar group-containing compound used in the present invention. Subsequently, under the influence of the compound represented by 5xOyn-, a radical polymerization catalyst is formed from the intermolecular compound, and rapid polymerization and curing of the vinyl compound present in the aqueous medium is initiated.

Such a polymerization curing reaction of a vinyl compound in an aqueous medium is faster than the conventional polymerization initiation reaction using a redox polymerization catalyst between cerium ions of a vinyl compound and a reducing agent such as potassium persulfate. The major feature of the present invention is that the reaction is extremely easy and that what was previously thought to be practically impossible can be used as a crosslinked coating film.

A polymerization reaction of a vinyl monomer is caused by a complex formed between a ceric ion and a compound having a functional group specified in the present invention, and a vinyl compound is polymerized and crosslinked by a polymerization reaction caused by attack of the formula 5xOyn- ion on this complex. However, due to the effect of the complex formed between the ceric ion and the specific compound, the effect of inhibiting the polymerization of vinyl monomer in the presence of oxygen is suppressed, and the interaction between oxygen and the complex is suppressed. Due to the effect of accelerating the polymerization of the vinyl monomer, a crosslinked coating film with extremely excellent properties can be formed.

Furthermore, in the method of the present invention, ceric ions and 5x
The crosslinking density of the coating film formed on the coated material is further improved by the redox polymerization catalyst system formed between the Oyn- ion and the coating film having excellent performance.

Furthermore, according to the method of the present invention, in the conventional polymerization method of vinyl monomer using a redox polymerization catalyst that combines cerium ions and a reducing agent, the vinyl compound is precipitated due to the salting-out effect of the salt generated in the polymerization catalyst system. However, it has been extremely difficult to produce crosslinked polymers with excellent properties, but by using the specific catalyst combination described above, the effect of salting out the polymer due to salt can be virtually eliminated. A coating film having a sufficiently crosslinked structure can be formed.

Furthermore, the compounds having specific functional groups used in the present invention are thought to themselves act as crosslinking initiation points during the coating film formation process, and once polymerization begins, the coating film gels rapidly. It is possible to form a coating film with an extremely dense structure.

Furthermore, compounds having a polymerizable unsaturated group in these compounds such as hydroxyethyl acrylate, glycidyl acrylate, dimethylaminoethyl acrylate, or acrylate of dimethylaminoethyl acrylate,
When compounds such as the addition reaction product of succinic acid and glycidyl acrylate are used, the crosslinking density of the resulting coating film can be further increased, resulting in excellent chemical resistance and other mechanical properties.

The water-soluble or water-dispersible vinyl compound used in the present invention usually has a molecular weight of 1000 or less, which is extremely small compared to conventionally used coating materials, and has the property of easily penetrating into fine structures. A major feature of the method of the invention is that it can easily form a crosslinked coating film in the presence of oxygen, especially in air, and even when applied to rusted materials, which was previously thought to be impossible. It can form a coating film that penetrates deep into the rust, and its uses are extremely wide.

The present invention will be explained in more detail with reference to Examples below.

Example 1 To 98 ml of an aqueous solution of a monomer mixture with an acrylamide concentration of 0.99 mol/l and an N,N-methylenebisacrylamide concentration of 90.01 mol/l, 200 mg of each of the 114 combinations shown in Table 1 were added. Subsequently, a 2% aqueous sodium sulfite solution was added to adjust the total volume to 100 ml, producing 114 types of aqueous coating materials.

Further, ceric nitrate ions were dissolved in a 0.1 N nitric acid aqueous solution to a concentration of 0.1 mol/l.

A coated material was prepared by degreasing a commercially available polished mild steel plate, washing it with water, drying it, and leaving the degreased and washed polished mild steel plate in the air for 15 days to obtain a coated material with red rust all over its entire surface.

A ceric nitrate ion solution was applied to 114 cleaned polished mild steel plates and 114 rusted mild steel plates, dried, and then a water-based coating material prepared by the method described above was applied. It was confirmed that polymerization started immediately and a completely cured coating was formed after a few minutes.

When these coated plates were left for a day and night and subjected to a bending test, it was confirmed that the coating film adhered to the material and that the adhesion of the coating film was good.

In addition, when we scraped off the paint film of a rusted material with a knife and examined the inside of it, we confirmed that the hardened paint film had sufficiently penetrated into the rusted internal structure.

Example 2 200 mg of methanol was added to 98 ml of an aqueous solution of a monomer mixture with an acrylamide concentration of 0.99 mol/l and an N,N-methylenebisacrylamide concentration of 0.01 mol/l, and 2 of the sulfur compounds shown in Table 2 were added. An aqueous solution was added to bring the total volume to 100 ml to create 13 types of aqueous coating materials.

The deoiled and washed polished mild steel plates prepared in Example 1 and the rusted mild steel plates were coated with ceric ammonium nitrate solution and dried, and then coated with 13 types of water-based coating materials prepared by the above method. , the coating begins to gel immediately,
After several minutes, it was confirmed that the coating film was completely cured.

In addition, the adhesion of the coating film to the material and the penetration of rust into the internal structure were tested in the same manner as in Example 1, and both were found to be good.

Example 3 Acrylamide concentration 0.89 mol/l, N,N'-methylenebisacrylamide concentration 0.01 mol/l and third
200 mg of methanol for 98 ml of an aqueous solution of a monomer mixture with a comonomer concentration of 0.1 mol/l shown in the table.
Add a 2% aqueous solution of sodium sulfite and bring the total to 10
Twelve types of aqueous coating materials were prepared so that the total volume was 0 ml.

After applying a ceric ammonium layer on a steel plate treated for rusting by the same method as in Example 1, the above water-based composition was applied, and the curability of the coating film and the adhesion of the coating film to the substrate were tested. The results are shown in Table 3.

HEA: Hydroxyethyl acrylate HEMA: Hydroxyethyl methacrylate AA Niacrylic acid AEMA Ni-dimethylmethineethyl methacrylate IMA
:2(1-aziridinyl)ethyl methacrylate IAg
: Itaconic acid IA-Na2: Itaconic acid-sodium salt In terms of curability and adhesion to substrates, those that were extremely good were marked ◎, and those that were good were marked ○.

In the above method, tetraethylene glycol dimethacrylate or di(diethylene glycol methacrylate) phthalate was used instead of the comonomers shown in Table 3.
A seed coating material was prepared and a coating film was formed using the same method as described above, and it was confirmed that a completely cured coating film had been formed.

Example 4 A sample was prepared in Example 1 on a mild steel plate that had been subjected to rust treatment in the same manner as in Example 1.

After 114 types of water-based coating materials were applied by flow coating, a 2% ceric ammonium nitrate aqueous solution was sprayed, and the coating immediately began to gel, and after a few minutes, the coating completely cured. It was confirmed that a gelatinous coating was formed on the internal structure of the rust.

In addition, in the above method, 2 of ceric ammonium nitrate
Exactly the same results were obtained when a 30% aqueous solution of isopropyl alcohol was used as the solvent for the % solution.

Example 5 37 parts of dodecyl methacrylate, 26 parts of styrene, 2
- 15 parts of β-dimethylaminoethanol is added to 100 parts of a copolymer solution obtained by polymerizing 12 parts of hydroxyethyl nuccrylate, 15 parts of N-butoxymethylacrylamide, and 4 parts of itaconic acid in 79 parts of Impropatool. was added to neutralize it.

To 3,000 parts of the neutralized resin solution obtained as described above, 750 parts of red iron oxide was added, mixed in a ball mill for 24 hours, and diluted to 5 times the volume with water.

Acrylamide and N,N'-methylenebisacrylamide were added to the red iron-containing aqueous resin obtained by the above method so that the acrylamide concentration was 0.99 mol/l and the N,N'-methylenebisacrylamide concentration was 0.01 mol/l. Acrylamide was added, and 2 ml of a 2% aqueous sodium sulfite solution was added to 98 ml of this mixture to prepare a dressing composition.

When the above-mentioned coating material composition was flow-coated on a rusted mild steel plate whose surface had been treated with an aqueous ceric salt solution in the same manner as in Example 1, gelation began immediately and the coating film hardened within a few minutes. .

The curing properties of the coating films were good in all cases, and when the coating films were scraped off with a knife after drying, it was confirmed that the coating films had penetrated into the chains.

It was also confirmed that the properties of the resulting coating film, such as impact resistance, were the same as above.

Example 6 Acrylamide concentration 0.99 mol/l and N.

N'-methylenebisacrylamide concentration 0.01 mol/
1.0 g of one of the repolymerizable monomers shown in the table below was added to 96 ml of an aqueous solution of a monomer mixture with stirring.

On the other hand, separately using 1N nitric acid solution, 0.1mole
The ceric ammonium nitrate solution was adjusted to have a concentration of /l.

1 ml of this ceric ion solution was added to the above monomer aqueous solution, the whole was made up to 98 ml with deionized water, and 18
A seed dressing composition was prepared.

At this time, most of the solutions form complexes of ceric ions, which causes the solution to turn brown or become cloudy.

On the other hand, a commercially available polished mild steel plate was washed to remove oil adhering to it, washed with water, and left in the air for two weeks to prepare a steel plate with uniform reddish-brown rust.

The above-mentioned 18 types of coating material compositions are applied by flow coating onto a rusted steel plate prepared by the above method, and then sulfur dioxide gas is uniformly sprayed over the entire surface for several seconds, and gelation immediately begins. The coating was cured within a few minutes.

The curing properties of the coating films were good in all cases, and when the coating films were scraped off with a knife after drying, it was confirmed that the coating films had penetrated into the chains.

Example 7 A coating material made by using and selecting hydroxyethyl acrylate from the repolymerized monomers shown in Table 4 in Example 6 was used, and the sulfur compound shown in Table 5 below was used instead of sulfur dioxide. A coating film was formed in exactly the same manner as in Example 6, except that 2 ml of an approximately 2% aqueous solution of the compound was sprayed in the form of a mist. The coating immediately began to gel, and the coating formed within a few minutes. has hardened.

The curing properties of the coating films were good in all cases, and when the coating films were scraped off with a knife after drying, it was confirmed that the coating films had penetrated into the chains.

Example 8 98 ml of an aqueous solution with an acrylamide concentration of 0.89 mol/l, an N,N'-methylenebisacrylamide concentration of 0.01 mol/l, and a comonomer concentration of 0.1 mol/l shown in the table below was prepared, and this was poured into Five coatings were prepared by adding a small amount (approximately 500 mg) of dimethylaminoethyl methacrylate followed by 2 ml of the ceric salt solution used in Example 6.

The above coating material was flow-coated onto a rusted steel plate prepared in the same manner as in Example 7, and then a small amount of 2% sodium sulfite solution was sprayed onto the surface. The results of examining the adhesion to the substrate after drying are also shown in Kento below.

The abbreviations of comonomers used in the above table are: It is as follows HEMA: Hydroxyethylmethac relate EA: Ethyl acrylate AA Niacrylic Acid ■A: Itaconic acid IA-Na2: itaconic acid sodium salt In addition, those with good curability Marked with ◎, and the adhesion is extremely ◎, good quality Indicated by ○.

Further, when the same molar amounts of tetraethylene glycol dimethacrylate and fucuric acid di(diethylene glycol methacrylate) ester were used in place of the comonomers in the above table, the coating film was completely cured.

Example 9 A 2% aqueous solution of sodium sulfite was applied by flow coating onto the rust-prone steel sheet prepared in Example 1, and then dried to form a thin layer of sodium sulfite on the steel sheet.

When the 18 types of coating material compositions prepared in Example 6 were applied to this, gelation immediately started and the coating film was cured within a few minutes, as in Example 6.

It was confirmed that the condition of the cured coating film was essentially the same as in Example 6.

Example 10 37 parts of dodecyl methacrylate, 26 parts of styrene, 2-
Add 3 parts of β-dimethylaminoethanol to 100 parts of a copolymer solution obtained by polymerizing 12 parts of hydroxyethyl methacrylate, 15 parts of N-butoxymethylacrylamide, and 4 parts of itaconic acid in 79 parts of Impropatool. It was neutralized.

To 3,000 parts of the neutralized resin solution obtained as described above, 750 parts of red iron oxide was added, mixed in a ball mill for 24 hours, and diluted to 5 times the volume with water.

The above monomers were dissolved in the red iron-containing aqueous resin obtained by the above method so that the acrylamide concentration was 0.99 mol/l and the N,N'-methylenebisacrylamide concentration was 0.01 mol/l. A coating material composition was prepared by adding 1 ml of hydroxyethyl acrylate to 2 ml of the ceric salt solution prepared in Example 6.

When this product was flow-coated onto the rusted steel plate prepared in Example 1 and then sulfur dioxide gas was sprayed, gelation immediately began and the coating hardened within a few minutes.

When this was further left in the air at room temperature, a painted board having a red crosslinked coating film was obtained.

Claims (1)

[Claims] 1. At least one water-soluble or water-dispersible vinyl compound and the formula 5xOyn- (wherein X is an integer of 1 to 6, y is an integer of 1 to 7, and n is 0 or 2). An aqueous composition A consisting of a sulfur compound capable of generating ions and an aqueous medium and an aqueous composition B containing ceric ions capable of generating ceric ions are prepared, and at least one of compositions A or B contains molecules. A compound having at least one hydroxyl group or a group capable of producing a hydroxyl group, an amino group or a group capable of producing an amine group, a salt thereof, a quaternary amine salt, a mercapto group or an aldehyde group is added to the coating material, and then an aqueous solution is first applied to the coating material. After applying a composition mainly consisting of composition A, subsequently applying a composition mainly consisting of an aqueous composition B, or after first applying a composition mainly consisting of an aqueous composition B on the coating material, A method for forming a coating film, which comprises forming a coating film by applying an aqueous composition A. 2. Compounds having at least one hydroxyl group or a group capable of producing a hydroxyl group, an amino group or a group capable of producing an amine group, a salt thereof, a quaternary amine salt, a mercapto group, or an aldehyde group in the molecule in Claim 1. A method for forming a coating film, comprising using a compound having at least one of these functional groups and at least one polymerizable unsaturated group.