JP2001348674A - Metallic surface coating agent - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a composition for metallic surface coating by which a coating film is made excellent in fundamental performances such as adhesion and corrosion resistance and is sufficiently made thin in thickness. SOLUTION: This metallic surface coating agent contains a hydrophilic colloidal solution of a water soluble resin. The hydrophilic colloidal solution contains a dispersion, the dispersion contains a cationic resin and/or an amphoteric resin. The cationic resin and/or the amphoteric resin contain the composition heaving at least one of a primary amino group and secondary amino group on its side chains. The ratio of the nonvolatile content in the dispersion is >=50 wt.% of the total weight of the water soluble resin and the nonvolatile content in the dispersion.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a metal surface coating agent.

[0002]

2. Description of the Related Art Metal surfaces are coated by various treatments or coatings for the purpose of imparting various functions to the metal. For example, after forming a coating by rust prevention treatment, coating with various paints is performed. And so on. Among these, the rust prevention treatment is performed to impart corrosion resistance to the metal surface, and also to provide a coating base property or the like for adhering a coating film formed of various paints, etc. Indispensable for protection and dress.

[0003] Such a rust preventive treatment is usually a chemical conversion treatment for forming an oxide film or a thin film of an inorganic salt on a metal surface, and further a surface coating treatment for sufficient corrosion resistance and paint base. It is performed by applying. In the chemical treatment in the rust prevention treatment, a chromate-based treatment agent is usually used, so that it is necessary to prevent chromium ions from being discharged during the chemical conversion treatment, thereby increasing production costs and removing chromium ions, which may be toxic from metal products. The elution may pollute the environment. In addition, even when a phosphate-based treatment agent is used, equipment costs are required in the chemical conversion treatment step, and two steps of chemical conversion treatment and surface coating treatment are required as a rust prevention treatment step, so that the metal surface There is room for contrivance to easily impart corrosion resistance, paint baseability, and the like.

JP-A-58-177473 discloses water-dispersible silica, a hydrolyzate of a tri- and / or dialkoxysilane compound, a cationic resin and / or a zwitterionic resin, and a phosphoric acid compound. A metal surface treatment composition is disclosed. This metal surface treatment composition can eliminate the need for chemical conversion treatment in the rust prevention treatment, and is effective for suppressing the production cost of the rust prevention treated steel sheet and preventing pollution. However, there is room for contriving to improve the corrosion resistance and reduce the thickness of the rust-prevention-treated film, thereby enabling electric welding of the rust-prevention-treated steel sheet and improving the workability.

[0005] JP-A-10-1782 discloses an aqueous metal surface treating agent containing an organic polymer compound having at least one nitrogen atom in a molecule and a phosphoric acid compound. Japanese Patent Application Laid-Open No. 10-1788 discloses an aqueous metal surface treating agent containing an organic polymer compound having at least one nitrogen atom in a molecule and an oxidizing agent.
These metal surface treatment agents exhibit corrosion resistance by protecting the metal surface with a phosphate or oxide film. However, these methods also have room for contriving to further increase the corrosion resistance and reduce the thickness of the rust preventive film.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in view of the above situation, and provides a metal surface coating agent which is excellent in basic properties such as adhesion and corrosion resistance and can be sufficiently thinned. It is intended to do so.

[0007]

The present invention relates to a metal surface coating agent comprising a hydrophilic colloid solution of a water-soluble resin, wherein the hydrophilic colloid solution comprises a dispersion, and the dispersion comprises: Including a cationic resin and / or amphoteric resin, the cationic resin and / or amphoteric resin,
The dispersion includes at least one of a primary amino group and a secondary amino group in a side chain, and the content of the nonvolatile content of the dispersion is 50% based on the total weight of the water-soluble resin and the nonvolatile content of the dispersion. It is a metal surface coating agent which is not less than% by weight. Hereinafter, the present invention will be described in detail.

[0008] The metal surface coating composition of the present invention comprises a hydrophilic colloid solution of a water-soluble resin. The water-soluble resin,
The resin is not particularly limited as long as it can form a hydrophilic colloid solution. For example, polyethyleneimine, a cationic resin and / or a zwitterionic resin can be suitably used. Other hydrophilic colloid solutions (water-soluble resin solutions) include, for example, polyvinyl alcohol,
Polyvinylpyrrolidone, polyethylene glycol, polyacrylic acid, polyacrylamide, gelatin, casein, albumin, starch, dextrin, alginate, acacia, pectin, tragacanth, gluten, carboxymethylcellulose, methylcellulose,
Starch phosphate and the like. The water-soluble resins may be used alone or in combination of two or more.

The hydrophilic colloid solution of the water-soluble resin means a molecular colloid in which the water-soluble resin is dissolved in an aqueous medium. The aqueous medium is a uniform medium containing water as a main component. Such a medium is not particularly limited, and includes, for example, water and water containing a hydrophilic solvent such as alcohol.

The weight-average molecular weight (Mw) of the water-soluble resin forming the molecular colloid is appropriately set depending on the kind of hydrophilic or hydrophobic functional groups of the water-soluble resin, their existing density, main chain structure and the like. It does not matter in particular,
For example, it is preferably from 500 to 1,000,000. If it is less than 500, the water resistance of the formed film may be inferior. If it exceeds 1,000,000, there is a possibility that it will aggregate in an aqueous medium. More preferably, 5000
~ 500,000, more preferably 10,000 ~
100,000.

The hydrophilic colloid solution contains a dispersion, and the dispersion contains a cationic resin and / or a zwitterionic resin. As a result, the coating formed by the metal surface coating agent has sufficient adhesion to various metal surfaces and coatings, and also has an improved effect of sufficiently blocking corrosive substances and protecting the metal surface. Therefore, excellent corrosion resistance can be imparted to the metal surface. In the present specification, a cationic resin means a resin having a group that forms a cation in a main chain or a side chain in a molecule. In this specification, a resin having an atom which forms a cation in a main chain or a side chain in a molecule is also included. The amphoteric resin means a resin having a group forming a cation and a group forming an anion in the main chain or side chain in the molecule.
In this specification, a resin having an atom which forms a cation in a main chain or a side chain in a molecule and a resin having an atom which forms an anion are also included.

The above-mentioned cationic resin includes a primary amino group, a secondary amino group, a tertiary amino group, and a cationic nitrogen atom such as an amide group as a group forming a cation in a main chain or a side chain in a molecule. Resins having at least one of them are exemplified.
Further, the amphoteric resin has at least one of a carboxyl group, a sulfonic acid group, a sulfate group, and a phosphate group as a group forming a cationic nitrogen atom and an anion in the main chain or side chain in the molecule. And a resin having a carboxyl group. These resins are not particularly limited, and for example, the following (1) to (17)
And the like. These may be used alone or in combination of two or more.

Examples of the cationic resin having a cationic nitrogen atom as a group forming a cation mainly in the main chain in the molecule include the following. (1) A cationic resin comprising a polyamine derivative such as polyethyleneimine, polypropyleneimine, and polyalkyleneimine. (2) A cationic resin comprising a polyamide polyamine formed by condensation of a polycarboxylic acid and a polyamine and a derivative thereof. (3) A cationic resin comprising an amine epoxy adduct and a derivative thereof obtained by reacting a polyglycidyl compound such as an epoxy resin with an amine and / or a polyamine. (4) A cationic urea resin obtained by reacting a polyisocyanate compound such as a urethane prepolymer with an amine and / or a polyamine. (5) A cationic resin having an aminomethyl group obtained by reacting a polymer having a chloromethyl group and / or a hydroxymethyl group with an amine and / or a polyamine. (6) A cationic resin comprising a polycondensate of at least one of polyhaloalkane, epihalohydrin and polyepihalohydrin with an amine and / or a polyamine.

Examples of the cationic resin having a cationic nitrogen atom as a group forming a cation mainly in a side chain in the molecule include the following. (7) a polymer obtained from at least one compound selected from compounds having a cationic nitrogen atom, such as vinyl compounds having an amino ester group such as dialkylaminoalkyl (meth) acrylate, vinylpyridine, vinylimidazole and salts thereof. And a cationic resin comprising a copolymer obtained from the compound and another monomer copolymerizable with the compound. (8) A cationic resin comprising a polyvinylamine obtained by a method such as hydrolysis of a vinylformamide polymer with an acid or a basic substance. (9) Allylamine or diallylamine and salts thereof at least one of compounds having a cationic nitrogen atom
A cationic resin comprising a polymer obtained from a kind of compound and a copolymer obtained from the compound and another monomer copolymerizable therewith. (10) (meth) acrylic resin, polyester resin,
All carboxyl groups of a resin having a carboxyl group such as polyurethane resin, alkyd resin or maleated polybutadiene are converted to aziridine compounds such as ethyleneimine, propyleneimine, hydroxyethylethyleneimine and hexamethylenediethyleneurea, and bases such as glycidylamine and salts thereof. A cationic resin obtained by reacting with at least one compound among alkylating agents having a neutral nitrogen atom. (11) A cationic resin obtained by reacting a glycidyl group of a resin having a glycidyl group such as a (meth) acrylic resin with ammonia or an amine compound. (12) A polymer obtained from a compound having a cationic nitrogen atom obtained by reacting a glycidyl group of a compound having a glycidyl group such as glycidyl (meth) acrylate with ammonia or an amine compound; A cationic resin comprising a copolymer obtained from another polymerizable monomer.

Examples of the amphoteric resin having a carboxyl group as a group forming an anion in the main chain or side chain in the above molecule include the following. (13) An amphoteric resin in which a carboxyl group is introduced as an anionic group by using chloroacetic acid or the like in the cationic resin. (14) (meth) acrylic resin, polyester resin,
Polyurethane resin, alkyd resin or a part of the carboxyl group of a resin having a carboxyl group such as maleated polybutadiene, ethyleneimine, propyleneimine,
A zwitterionic resin obtained by reacting with at least one compound of an aziridine compound such as hydroxyethylethyleneimine and hexamethylenediethyleneurea and an alkylating agent having a basic nitrogen atom such as glycidylamine and salts thereof. (15) A zwitterionic resin obtained by reacting a glycidyl group of a resin having a carboxyl group and a glycidyl group such as a (meth) acrylic resin with ammonia or an amine compound. (16) a compound having a glycidyl group such as glycidyl (meth) acrylate reacted with ammonia or an amine compound, and (meth) acrylic acid;
A zwitterionic resin comprising a polymer obtained from a compound having a carboxyl group such as crotonic acid and maleic acid, and a copolymer obtained from these compounds and other copolymerizable monomers. (17) At least one compound among the compounds having a cationic nitrogen atom of the above (7), (9) or (12) and a carboxyl group such as (meth) acrylic acid, crotonic acid and maleic acid A zwitterionic resin comprising a copolymer of at least one compound among compounds and a copolymer obtained from these compounds and another copolymerizable monomer. Note that the above classification is an example, and a resin having a cationic nitrogen atom in both the main chain and the side chain may be used.

Both the cationic resin and the amphoteric resin can be synthesized by a usual method. Further, a part or all of the cationic nitrogen atom may be neutralized with an organic acid and / or an inorganic acid such as hydrochloric acid, nitric acid, formic acid, and acetic acid. Alternatively, the whole may be neutralized with an organic and / or inorganic basic compound such as ammonia, an amine compound, and caustic soda.

The amount of cationic nitrogen atoms present in the cationic resin is not particularly limited. For example, as determined by a measuring method such as a colloid titration method or a conductivity titration method, the content per 1 g of the cationic resin is determined. Preferably it is 0.1 to 24 mmol. In addition, the abundance of the cationic nitrogen atom and the anionic carboxyl group in the amphoteric resin is not particularly limited, and, for example, when measured by the same measurement method as described above, each amount per 1 g of the amphoteric resin It is preferably 0.01 to 20 mmol. When the amount of the cationic nitrogen atom or the anionic carboxyl group is out of the above range, there is a possibility that various metal surfaces and the coating film cannot be sufficiently adhered.

The cationic resin and / or amphoteric resin include those having at least one of a primary amino group and a secondary amino group in a side chain. As a result, the cationic resin has at least one of a primary amino group and a secondary amino group, and the amphoteric resin has at least one of a carboxyl group and the like and a primary amino group and a secondary amino group. Since the primary amino group and the secondary amino group have more excellent adhesion than the tertiary amino group and the amide group, the adhesion to various metal surfaces and coating films is improved. It will be excellent.

The primary amino group and the secondary amino group are, for example, those represented by the following general formula (1):

[0020]

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Wherein R ¹ , R ² , R ³ , R ⁴ and R ⁵
Are the same or different and are a hydrogen atom, a halogen atom,
Represents an alkyl group, an aralkyl group or an aryl group which may have a substituent. a represents an integer of 0 or 1. b is
Represents an integer of 1 or more. And the like.
When two or more of the primary amino group and the secondary amino group are present in the cationic resin and / or the amphoteric resin, they may be the same or different.

In the above general formula (1), R ¹ , R ² , R ³ ,
When R ⁴ and R ⁵ represent an alkyl group, an aralkyl group or an aryl group, these preferably have 20 or less carbon atoms. More preferably, the carbon number is 10 or less. The alkyl group and the aralkyl group may be linear or branched.

In the above formula (1), when the alkyl group, aralkyl group or aryl group has a substituent, the substituent is not particularly restricted but includes, for example, a cyano group, a halogen atom, an amino group, a hydroxyl group. Groups, alkoxyl groups, carboalkoxyl groups and the like.

The above alkoxyl group or carboalkoxyl group preferably has 20 or less carbon atoms.
More preferably, the carbon number is 10 or less. Further, these may be linear or branched.

The cationic resin having at least one of the primary amino group and the secondary amino group in the side chain is not particularly limited.
(7), (8), (9), (10), (11) or (1)
Cationic resins having at least one of a primary amino group and a secondary amino group in the side chain, such as the resin shown in 2), may be mentioned. The polyvinylamines, polyallylamines and salts thereof may be a mono- or di-substituted alkyl group having 1 to 4 carbon atoms, or a quaternary product of the substituted product.

The above-mentioned polyvinylamines and salts thereof are not particularly restricted but include, for example, polyvinylamine, polymethvinylamine, polyvinylamine hydrochloride, polyvinylethylamine hydrochloride, polymethvinylmethylamine hydrochloride, polyvinyl-N-trimethyl. Ammonium bromide and the like.

The above-mentioned polyallylamines and salts thereof are not particularly restricted but include, for example, polyallylamine, polyallylamine hydrochloride, polyallylethylamine hydrochloride, polyallyldimethylethylammonium hydrochloride, diallylamine hydrochloride polymer, diallylmethylamine Hydrochloride polymer, diallyldimethylammonium hydrochloride polymer; these sulfur dioxide copolymer, acrylamide copolymer,
And a diallylamine hydrochloride derivative copolymer.

The method for preparing the polyvinylamines is not particularly limited, and includes, for example, hydrolysis of polyvinylformamide with an acid or a basic substance; reduction of polynitroethylene or a derivative thereof; Hoffmann decomposition of polyacrylamide; N-vinylphthalimide Examples thereof include a method of reducing the polymer by alkali. The method for preparing the polyallylamines is not particularly limited, and examples thereof include a method by alkali reduction of polyallylamine hydrochloride.

In the above-mentioned resin having a carboxyl group, in which all carboxyl groups are modified, the resin having a carboxyl group is a polymer obtained by polymerizing a monomer component containing at least one unsaturated carboxylic acid. Is preferred. The unsaturated carboxylic acid is not particularly limited and includes, for example, unsaturated monocarboxylic acids such as (meth) acrylic acid, cinnamic acid and crotonic acid; unsaturated dicarboxylic acids such as maleic acid, itaconic acid and fumaric acid; Monoesters and the like. These may be used alone,
More than one species may be used in combination.

The above monomer component can be copolymerized with an unsaturated carboxylic acid, if necessary, in addition to the unsaturated carboxylic acid.
In addition, an unsaturated monomer that does not react with a carboxyl group can be used.

The unsaturated monomer is not particularly restricted but includes, for example, (meth) acrylates such as methyl (meth) acrylate, butyl (meth) acrylate and 2-ethylhexyl (meth) acrylate; Unsaturated nitriles such as (meth) acrylonitrile; unsaturated amides such as (meth) acrylamide and N-methylol (meth) acrylamide; vinyl esters such as vinyl acetate and vinyl propionate; vinyl ethers such as methyl vinyl ether and ethyl vinyl ether Α-olefins such as ethylene and propylene; halogenated α, β-unsaturated monomers such as vinyl chloride, vinylidene chloride and vinyl fluoride; α, β-unsaturated aromatics such as styrene and α-methylstyrene And monomers. These may be used alone or in combination of two or more.

As the polymerization method of the above-mentioned polymer having a carboxyl group, a known polymerization method can be used and is not particularly limited. Examples thereof include a bulk polymerization method, a solution polymerization method, an emulsion polymerization method, and a suspension polymerization method. Can be performed. In this case, if necessary, the degree of polymerization can be controlled by using a chain transfer agent such as a mercaptan compound. The form of the polymer having a carboxyl group is not particularly limited, and examples thereof include water solubility, water dilutability, water dispersibility, non-aqueous dispersibility, and solvent solubility. The polymer having a carboxyl group may be used alone or in combination of two or more.

The method for modifying the carboxyl group into a primary and / or secondary amino group in the resin obtained by modifying all the carboxyl groups of the resin having a carboxyl group is not particularly limited. For example, a method using an alkyleneimine A method using a polyamine such as a polyoxyalkylene polyamine. Among these, the method of ring-opening addition using an alkylene imine is particularly preferable.

The alkylene imine is not particularly limited, and examples thereof include compounds represented by the following general formula (2). These may be used alone or in combination of two or more.

[0035]

Embedded image

In the general formula (2), R ¹ , R ² , R ³ ,
R ⁴ and R ⁵ are the same as above. Such alkylene imines are not particularly limited, and include, for example, ethylene imine, 1,2-propylene imine, 1,2-dodecylene imine, 1,1-dimethyl ethylene imine, phenyl ethylene imine, benzyl ethylene imine, and hydroxyethyl ethylene imine. , Aminoethylethyleneimine,
2-methylpropyleneimine, 3-chloropropylethyleneimine, methoxyethylethyleneimine, dodecylaziridinylformate, N-ethylethyleneimine, N- (2-aminoethyl) ethyleneimine, N-
(Phenethyl) ethyleneimine, N- (2-hydroxyethyl) ethyleneimine, N- (cyanoethyl) ethyleneimine, N-phenylethyleneimine, N- (p-chlorophenyl) ethyleneimine and the like. Among these, ethyleneimine and 1,2-propyleneimine are easily available industrially and are suitable.

In the above-mentioned method using an alkylene imine, when all the carboxyl groups in the polymer having a carboxyl group are modified with the alkylene imine, -CO
A polymer having a group represented by the following general formula (3) in which a primary and / or secondary amino group is bonded to an O- group is obtained.

[0038]

Embedded image

In the general formula (3), R ¹ , R ² , R ³ ,
R ⁴ , R ⁵ , a and b are the same as described above. The amount of the unsaturated carboxylic acid in the polymer and the amount of the alkylene imine used for the modification of the carboxylic acid in the polymer are determined based on the amount of the cationic nitrogen atom present in the modified cationic resin in the cationic resin. There is no particular limitation as long as the amount of the cationic nitrogen atom is within the preferable range.

In the above method using an alkylene imine, the carboxyl group modified by the alkylene imine is 1 to 30 as an amount of the unsaturated carboxylic acid in the polymer.
% By weight. If it is less than 1% by weight,
There is a possibility that the adhesion of the coating formed by the metal surface coating agent may not be sufficient. If it exceeds 30% by weight, the basic performance such as water resistance of the coating may be reduced. More preferably, it is 1 to 15% by weight. In the method using the alkylene imine, the amount of the alkylene imine used for the modification is not particularly limited as long as it is equal to or more than the amount of the unsaturated carboxylic acid in the polymer, and the amount of the unsaturated carboxylic acid in the polymer is An equimolar amount to 10-fold molar amount is preferred. 1
If the molar amount exceeds 0 times, the water resistance of the film formed by the metal surface coating agent may not be sufficient. More preferably, it is an equimolar amount to 5 times the molar amount. In the method using the alkylene imine, when all the carboxyl groups of the resin having a carboxyl group are modified, the carboxyl group may be modified by employing appropriate conditions such as using a low-polarity reaction solvent such as toluene or xylene. A resin in which all carboxyl groups of the group-containing resin are modified with alkylene imine is obtained.

The zwitterionic resin having at least one of the primary amino group and the secondary amino group in the side chain is not particularly limited.
(8), (9), (10), (11) or (12), a resin in which a carboxyl group is introduced by the method shown in (13), or (14), (15), ( 16) or a zwitterionic resin having at least one of the primary amino group and the secondary amino group of (17) in the side chain. The method of introducing a carboxyl group as an anionic group using chloroacetic acid or the like in the cationic resin is complicated, and the reaction between the compound having a cationic nitrogen atom and the compound having a carboxyl group is carried out. The method for obtaining the copolymer requires special consideration, for example, because allylamine and unsaturated carboxylic acid are low polymerizable and aminoethyl (meth) acrylate is an unstable monomer. The method of modifying a part of the carboxyl group of the resin having a carboxyl group is preferable because the method of modifying a part of the carboxyl group of the resin having a carboxyl group is the easiest. In the resin obtained by modifying a part of the carboxyl group of the resin having a carboxyl group, the resin having a carboxyl group may be a polymer obtained by polymerizing a monomer component containing at least one unsaturated carboxylic acid. preferable. The unsaturated carboxylic acid is not particularly limited and includes, for example, unsaturated monocarboxylic acids such as (meth) acrylic acid, cinnamic acid and crotonic acid;
Unsaturated dicarboxylic acids such as maleic acid, itaconic acid and fumaric acid, and their monoesters are exemplified. These may be used alone or in combination of two or more.

The above monomer component can be copolymerized with an unsaturated carboxylic acid in addition to the unsaturated carboxylic acid, if necessary.
In addition, an unsaturated monomer that does not react with a carboxyl group can be used.

The unsaturated monomer is not particularly restricted but includes, for example, (meth) acrylates such as methyl (meth) acrylate, butyl (meth) acrylate and 2-ethylhexyl (meth) acrylate; Unsaturated nitriles such as (meth) acrylonitrile; unsaturated amides such as (meth) acrylamide and N-methylol (meth) acrylamide; vinyl esters such as vinyl acetate and vinyl propionate; vinyl ethers such as methyl vinyl ether and ethyl vinyl ether Α-olefins such as ethylene and propylene; halogenated α, β-unsaturated monomers such as vinyl chloride, vinylidene chloride and vinyl fluoride; α, β-unsaturated aromatics such as styrene and α-methylstyrene And monomers. These may be used alone or in combination of two or more.

The polymerization method for the polymer having a carboxyl group can be a known polymerization method, and is not particularly limited. Examples thereof include a bulk polymerization method, a solution polymerization method, an emulsion polymerization method, and a suspension polymerization method. Can be performed. In this case, if necessary, the degree of polymerization can be controlled by using a chain transfer agent such as a mercaptan compound. The form of the polymer having a carboxyl group is not particularly limited, and examples thereof include water solubility, water dilutability, water dispersibility, non-aqueous dispersibility, and solvent solubility. The polymer having a carboxyl group may be used alone or in combination of two or more.

The method of modifying the carboxyl group into a primary and / or secondary amino group in the resin obtained by modifying a part of the carboxyl group of the resin having a carboxyl group is not particularly limited. Method: a method using a polyamine such as a polyoxyalkylene polyamine, and the like. Among these, the method of ring-opening addition using an alkylene imine is particularly preferable.

The alkyleneimine is not particularly restricted but includes, for example, the compounds represented by the general formula (2). These may be used alone or in combination of two or more.

In the above-mentioned method using an alkylene imine, when all the carboxyl groups in the polymer having a carboxyl group are modified with the alkylene imine, -CO
A polymer having a group represented by the general formula (3) wherein a primary and / or secondary amino group is bonded to the O- group is obtained.

The amount of the unsaturated carboxylic acid in the polymer and the amount of the alkylene imine used for modifying the carboxylic acid in the polymer are determined by the amount of the cationic nitrogen atom present in the modified amphoteric resin. There is no particular limitation as long as it is within the preferred range of the amount of cationic nitrogen atoms in the hydrophilic resin.

In the above method using an alkylene imine, the carboxyl group modified by the alkylene imine is 1 to 30 as an amount of the unsaturated carboxylic acid in the polymer.
% By weight. If it is less than 1% by weight,
There is a possibility that the adhesion of the coating formed by the metal surface coating agent may not be sufficient. If it exceeds 30% by weight, the basic performance such as water resistance of the coating may be reduced. More preferably, it is 1 to 15% by weight. In the method using the alkylene imine, the amount of the alkylene imine used for the modification is not particularly limited as long as the amount of the unsaturated carboxylic acid in the polymer is less than 0.1 times the molar amount to less than the molar amount. By adopting appropriate conditions such as using a highly polar reaction solvent such as, the amount of unsaturated carboxylic acid in the polymer and even more than the equimolar amount of some carboxyl groups of the resin having a carboxyl group A resin modified with an alkylene imine is obtained. For this reason, in the method using alkyleneimine, the amount of alkyleneimine used for the modification is preferably 0.1 to 10 times the molar amount of the unsaturated carboxylic acid in the polymer. If the molar amount is less than 0.1 times, the amount of the introduced cationic nitrogen atoms may be small and the adhesion to the metal may not be sufficient. If the molar amount exceeds 10 times, the water resistance of the film formed by the metal surface coating agent may be reduced. May not be sufficient.
More preferably, the molar amount is 0.5 to 5 times the molar amount.

The cationic and amphoteric resins also have excellent performance of the coating film formed thereby, so that the main chain structure has carbon-carbon bonds, amide bonds,
Those having a urethane bond or an amine epoxy bond are preferred. Thereby, the basic performance such as the water resistance of the coating is improved.

The above cationic and amphoteric resins further have a weight average molecular weight (Mw) of 10,000 to 10,000.
000 is preferred. If it is less than 10,000, the basic coating film performance such as flexibility and corrosion resistance of the coating film may be inferior. If it exceeds 10,000, the dispersion may be difficult to prepare. More preferably, 5
0000 to 1,000,000, more preferably 1
0000 to 500,000.

In the metal surface coating agent of the present invention, the content ratio of the cationic resin and / or the amphoteric resin is not particularly limited, and for example, 5 to 600 g as a resin non-volatile content per 1000 g of the metal surface coating agent. Preferably, there is. If the amount is less than 5 g, the adhesion to the metal surface may not be sufficient. If the amount exceeds 600 g, the film thickness of the coating may be too large, and the electric welding, workability, etc. of the rust-resistant steel sheet may be inferior. . More preferably, 10 to 400
g. That is, the preferable content of the polymer component (non-volatile content) of the cationic resin and / or the amphoteric resin in the present invention is 0.1% with respect to 100% by weight of the metal surface coating agent.
5 to 60% by weight. More preferably, it is 1 to 40% by weight. Further, the content ratio of the cationic resin and / or the amphoteric resin is preferably 50% by weight or more based on the total weight of the nonvolatile components of the water-soluble resin and the dispersion. Accordingly, when a resin containing a cationic resin and / or a zwitterionic resin is used as the water-soluble resin, the water-soluble resin and the solvent resistance of the water-soluble resin are sufficiently improved, so that the adhesion to the metal is improved. The water-soluble resin including the cationic resin and / or the amphoteric resin, which has excellent properties and excellent corrosion resistance, can be sufficiently exhibited. More preferably, it is 70% by weight or more.

In the above hydrophilic colloid solution, at least one of a primary amino group and a secondary amino group in a cationic resin and / or a zwitterionic resin obtained by combining a dispersion and a water-soluble resin is used. The content ratio of those in the chain is not particularly limited. For example, at least one of a primary amino group and a secondary amino group may be located on the side of the total amount of the non-volatile components of the cationic resin and / or the amphoteric resin. The non-volatile content of the cationic resin and / or amphoteric resin in the chain is preferably 30 to 100% by weight. If the amount is less than 30% by weight, the action of the cationic resin and / or zwitterionic resin having at least one of the primary amino group and the secondary amino group in the side chain may not be sufficiently exerted. More preferably, it is 50 to 100% by weight, still more preferably 60 to 100% by weight, and most preferably 70 to 100% by weight.

In the hydrophilic colloid solution of the present invention, the dispersion containing the cationic resin and / or zwitterionic resin may contain components other than the cationic resin and / or zwitterionic resin. The form of the dispersion in the hydrophilic colloid solution is not particularly limited, for example,
Any of an emulsion, a suspension and the like may be used. The average particle size of the dispersion is not particularly limited, and is preferably, for example, 10 nm to 1 μm.
If it is less than 10 nm, it may be difficult to obtain a stable dispersion because it may aggregate in a hydrophilic colloid solution, and if it exceeds 1 μm,
There is a possibility that the thickness of the film becomes too large. More preferably, it is 10 to 500 nm, still more preferably, 30 to 500 nm.
３００300 nm.

The average particle diameter of the dispersion is measured, for example, using a dynamic light scattering photometer “DLS” manufactured by Otsuka Electronics Co., Ltd.
-700 "(trade name) or the like by dynamic light scattering measurement. An example of the above measurement conditions is described below. Clock cycle: 20 μsec CORRE. CHANNEL: 256 Angle: 90 ° Number of accumulations: 100 Measurement temperature: 25 ° C TEMP MODE: WATER Modified the analysis of the data obtained by this method.
The average particle diameter of the dispersion can be determined by the method.

In the metal surface coating agent of the present invention, the content of the nonvolatile components in the dispersion is at least 50% by weight based on the total weight of the nonvolatile components of the water-soluble resin and the dispersion. Thereby, it is possible to perform a non-chromium rust prevention treatment on the metal base material without performing the chemical conversion treatment, and it is possible to impart corrosion resistance and paint baseness equal to or more than those of the conventional rust prevention treatment. In addition, even if the film thickness is 1 μm or less, the film has sufficient basic properties such as corrosion resistance. More preferably, it is 70% by weight or more.

Although the reason why the present invention exhibits the above effects is not completely clear, for example, (1) in a film formed by a metal surface coating agent, a water-soluble resin forming a molecular colloid is replaced with a cationic resin and By filling the gap between the dispersions of the amphoteric resin and / or the fusion of the dispersions and the fusion of the water-soluble resin and the dispersion,
The cationic resin and / or zwitterionic resin is sufficiently and uniformly filled in the coating without gaps, and the denseness of the coating is particularly improved, so that the cationic resin and / or zwitterionic resin is The effect of protecting the metal surface by sufficiently blocking corrosive substances is improved, and the adhesion to various metal surfaces and coatings is improved. (2) The average thickness of the coating is 1 μm or less. However, since the metal surface is coated with a cationic resin and / or a zwitterionic resin and a water-soluble resin with sufficient density, the above (1)
(3) including those in which the cationic resin and / or the amphoteric resin have at least one of a primary amino group and a secondary amino group in a side chain. As a result, the action of the cationic resin and / or the amphoteric resin becomes sufficient, so that the adhesion of the coating to various metal surfaces and coatings and the protection of metal surfaces by blocking corrosive substances This is considered to be due to the fact that even if a rust-proof treatment of non-chromium of 1 μm or less is performed, the effect of rust prevention is sufficient.

If the non-volatile content of the above-mentioned dispersion is less than 50% by weight based on the total weight of the non-volatile content of the water-soluble resin and the dispersion, the non-chromium content of the metal substrate can be reduced without chemical conversion treatment. In the case of performing the rust-prevention treatment, in the film formed by the metal surface coating agent, a portion where the water-soluble resin is not sufficiently filled in the gaps between the dispersions occurs, and the denseness becomes insufficient, so that the film defect is caused. This may cause sufficient corrosion resistance and paint base properties.

The method for preparing a hydrophilic colloid solution containing a dispersion of the above-mentioned cationic resin and / or amphoteric resin is not particularly limited. For example, emulsion polymerization or suspension polymerization is performed in an aqueous medium. The cationic resin and / or
Alternatively, an aqueous dispersion is prepared by polymerizing an amphoteric resin, and then the aqueous dispersion and a hydrophilic colloid solution are mixed, or the aqueous dispersion is prepared by dissolving a water-soluble resin in the aqueous dispersion. Method (Preparation method 1); A method of preparing a cationic resin and / or a zwitterionic resin by performing emulsion polymerization or suspension polymerization in a hydrophilic colloid solution (Preparation method 2); An aqueous dispersion is prepared by mechanically dispersing a hydrophilic resin and / or a zwitterionic resin in an aqueous medium, and then mixing the aqueous dispersion with a hydrophilic colloid solution, or A method in which a water-soluble resin is dissolved and prepared (Preparation method 3); A method in which a cationic resin and / or a zwitterionic resin is mechanically dispersed in a hydrophilic colloid solution (Preparation method 4) And the like. Among them, preparation methods 1 and 2 are preferable because dispersion particles have a uniform particle diameter.

The particle size of the dispersion is adjusted by the following Preparation Method 1.
And 2, a monomer, a polymerization initiator, a surfactant,
The polymerization can be carried out by appropriately setting the types and amounts of emulsifiers, dispersants, and the like; polymerization conditions such as polymerization temperature, polymerization time, and dropping conditions. In preparation methods 3 and 4, the stirring can be performed by appropriately setting the stirring speed, stirring time, and the like using a disperser such as a homomixer. Furthermore,
These adjustment methods may be performed in combination. The monomer, polymerization initiator, surfactant, emulsifier, dispersant and the like are not particularly limited as long as they can be used for preparing an emulsion or a suspension, for example.

The metal surface coating agent of the present invention can also be used in a hydrophilic colloid solution or dispersion in a phosphoric acid compound; an organic sulfur compound; a polyfunctional crosslinking agent; a water-dispersible silica, and a tri- and / or dialkoxy. It may contain at least one of a silane compound or a hydrolyzate thereof. By including these compounds, the coating formed by the metal surface coating agent can impart more excellent performance such as corrosion resistance to the metal surface.

The phosphoric acid compound is not particularly restricted but includes, for example, orthophosphoric acid, pyrophosphoric acid, polyphosphoric acid,
Metaphosphoric acid, phytic acid; and heteropolyacids formed by molybdic acid or tungstic acid and phosphorus atoms. Also, phosphoric acid such as sodium phosphate, sodium monohydrogen phosphate, sodium dihydrogen phosphate, potassium phosphate, potassium monohydrogen phosphate, potassium dihydrogen phosphate, magnesium monohydrogen phosphate, zinc monohydrogen phosphate, etc. Metal salts; ammonium phosphate, ammonium monohydrogen phosphate,
Examples thereof include ammonium salts of phosphoric acid such as ammonium dihydrogen phosphate; amine salts of phosphoric acid such as hydrazinium phosphate; and phosphate esters such as ethyl phosphate. These may be used alone or in combination of two or more.

The content ratio of the above-mentioned phosphoric acid compound is not particularly limited. For example, a part or all of the cationic nitrogen atoms contained in the cationic resin and / or the amphoteric resin may be converted into a salt, or as described later. Including all the phosphoric acid compounds contained in the metal surface coating agent such as phosphoric acid used to obtain the hydrolyzate of the alkoxysilane compound to be added, based on 100 parts by weight of the total of the nonvolatile components of the water-soluble resin and the dispersion. ,
It is preferably 0.5 to 50 parts by weight. If the amount is less than 0.5 part by weight, the action of the phosphoric acid compound may not be sufficiently exhibited. If it exceeds 50 parts by weight,
The water resistance and alkali resistance of the coating may be insufficient, and the adhesion to the coating may be poor. More preferably, it is 1 to 40 parts by weight. Furthermore, the content ratio of the phosphoric acid compound in the metal surface coating agent of the present invention is not particularly limited.
It is preferably 0.1 to 300 g per g.
If the amount is less than 0.1 g, the action of the phosphoric acid compound may not be sufficiently exhibited. If it exceeds 300 g, the water resistance and alkali resistance of the coating may not be sufficient, and the adhesion to the coating may be poor.
More preferably, it is 0.6 to 160 g.

The organic sulfur compound has a function of generating active sulfur and a function of forming a covalent bond between a sulfur atom in the organic sulfur compound and a metal atom. The active sulfur means a sulfur atom capable of forming a covalent bond with a metal atom and a metal sulfide having such a sulfur atom.

By containing the above organic sulfur compound,
By generating active sulfur, a coating layer in which metal atoms and sulfur atoms are repeatedly and covalently bonded can be formed on the metal surface. Further, it is possible to form a coating layer in which a sulfur atom in the organic sulfur compound and a metal atom on the metal surface are covalently bonded.

The coating layer in which the metal atom and the sulfur atom are repeatedly and covalently bonded is, for example,-(M _p-
And a coating layer formed of a repeating unit represented by _Sq )-. In the above repeating unit, M is
Represents a metal atom. P and q each represent an integer and may be the same or different in each repeating unit.

In order to generate the active sulfur from an organic sulfur compound or to form a covalent bond between a sulfur atom in the organic sulfur compound and a metal atom on the metal surface, for example, heat energy, ultraviolet light, electron beam, etc. Irradiation with an active energy ray such as a line can be performed.

The organic sulfur compound is not particularly limited as long as it has the above-mentioned action. Examples thereof include thiurams, metal salts of dithiocarbamic acid, xanthogenic acids, metal salts of xanthogenic acid, dithiomorpholines,
It is preferably at least one compound selected from the group consisting of thiazoles and thiourea analogs. These may be used alone or in combination of two or more. Among these, thiurams, metal salts of dithiocarbamic acid, xanthogenic acids, metal salts of xanthogenic acid, dithiomorpholines and thiazoles are mainly compounds having an action of generating active sulfur, for example, each of the following formulas Compounds having the chemical structures represented by (4-a) to (9-a) are mentioned. Also,
The thiourea analog is a compound mainly having an action of forming a covalent bond between a sulfur atom in an organic sulfur compound and a metal atom.

In the above organic sulfur compounds, thiurams, metal salts of dithiocarbamic acid, xanthogenic acids,
Examples of the metal xanthate, dithiomorpholine, thiazole and thiourea analogs include compounds represented by the following general formulas (4-b) to (10).

[0070]

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[0071]

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In the above formula, M represents a metal atom. In the above general formula, R is the same or different and has a hydrogen atom, a linear or branched alkyl group which may have a substituent having 1 to 20 carbon atoms, and a substituent having 6 to 20 carbon atoms. Represents an aryl group which may be substituted or an aralkyl group which may have a substituent having 7 to 20 carbon atoms. When both Rs bonded to the same nitrogen atom are not hydrogen atoms, two Rs may be bonded to each other. n represents an integer of 2 to 20.
Me represents a monovalent to tetravalent metal atom. m represents an integer of 1 to 4. Further, not only the form of the metal salt but also a piperidine salt or a pipericone salt may be used. The substituent is not particularly limited, and examples thereof include an amino group having an alkyl group having 1 to 10 carbon atoms.

The above-mentioned monovalent to tetravalent metal atoms are not particularly restricted but include, for example, metal atoms such as lithium, sodium, potassium, magnesium, calcium, iron, nickel, copper, zinc, aluminum and tellurium. Among these, a zinc atom is preferable.

Among the above-mentioned organic sulfur compounds, the active sulfur can be generated more and the sulfur atom in the organic sulfur compound can form more covalent bonds with the metal atom. Are preferred. It is preferably an oily or liquid substance because it can be easily added to and dispersed in the metal surface coating agent. As such organic sulfur compounds, for example, in the compounds represented by the above general formula, those having a high sulfur atom content include those having the above R having 8 or less carbon atoms, such as oil or liquid. As a product, R
Having 3 or more carbon atoms.

The content ratio of the organic sulfur compound is not particularly limited. For example, the content is preferably 1 to 50 parts by weight based on 100 parts by weight of the total nonvolatile components of the water-soluble resin and the dispersion. If the amount is less than 1 part by weight, the action of the organic sulfur compound may not be exhibited. If the amount is more than 50 parts by weight, the water resistance and the like of the film obtained by the metal surface coating agent may be insufficient. More preferably, it is 1 to 40 parts by weight. Furthermore, the content ratio of the organic sulfur compound in the metal surface coating agent of the present invention is not particularly limited, and for example, is preferably 2.5 to 300 g per 1000 g of the metal surface coating agent. 2.5
If it is less than g, the function of the organic sulfur compound may not be exhibited, and if it exceeds 300 g, the basic properties such as water resistance of the coating may not be sufficient.
More preferably, it is 5-200 g. That is, with respect to 100% by weight of the metal surface coating agent, the preferred total content of the water-soluble resin and the polymer component (nonvolatile content) of the dispersion is as follows:
0.5 to 60% by weight. More preferably, 1 to 40
% By weight. Further, the preferable content of the organic sulfur compound is 0.25 to 30% by weight. More preferably,
It is 0.5 to 20% by weight.

The polyfunctional crosslinking agent is not particularly limited as long as it can crosslink a water-soluble resin and a cationic resin and / or amphoteric resin. Examples thereof include an aldehyde group, a ketone group and an alkyl halide. Group, isocyanate group, thioisocyanate group, blocked isocyanate group, active double bond group, epoxy group, carboxyl group, acid anhydride group, active ester group, oxazoline group, hydroxyl group, azirinyl group, etc. Examples include compounds or polymers having two or more groups. Such compounds or polymers include, for example, polyfunctional isocyanates, melamine resins, epoxy resins, oxazoline resins, and the like. These may be used alone,
More than one species may be used in combination.

The content ratio of the above-mentioned polyfunctional crosslinking agent is not particularly limited. For example, it is preferably 0.5 to 30 parts by weight based on 100 parts by weight of the total nonvolatile components of the water-soluble resin and the dispersion. If the amount is less than 0.5 part by weight, the function of the polyfunctional crosslinking agent may not be sufficiently exhibited. If the amount exceeds 30 parts by weight, the adhesion of the coating formed by the metal surface coating agent to the metal surface or the coating may be poor, and the basic performance of the coating may be reduced. More preferably, it is 1 to 20 parts by weight. Furthermore,
The content ratio of the polyfunctional crosslinking agent in the metal surface coating agent of the present invention is not particularly limited, and for example, is preferably 0.1 to 300 g per 1000 g of the metal surface coating agent. If the amount is less than 0.1 g, the function of the polyfunctional crosslinking agent may not be sufficiently exhibited. If it exceeds 300 g, the adhesion of the coating formed by the metal surface coating agent to the metal surface or the coating may be poor, and the basic performance of the coating may be reduced. More preferably, it is 1 to 200 g.

The above-mentioned water-dispersible silica means those generally referred to as colloidal silica which is a condensate of silicic acid. The water-dispersible silica is not particularly limited, and for example, those having a particle diameter of 5 to 100 μm are preferable. As such a product, a commercially available product can be used. For example, Snowtex O, Snowtex N,
Snowtex NCS, Snowtex 20, Snowtex C (all trade names, manufactured by Nissan Chemical), Cata
loid SN, Cataloid Si-500 (both are trade names, manufactured by Catalyst Chemical Industry Co., Ltd.) and the like. Further, as the surface-treated material, for example, Cataloid SA (trade name, manufactured by Catalyst Chemical Industry Co., Ltd.) treated with aluminate can be used. These may be used alone or in combination of two or more.

The mode in which the water-dispersible silica is contained in the metal surface coating agent is not particularly limited. For example, the water-dispersible silica can be contained in the metal surface coating agent as it is. Surface treatment with amines such as cationic resins and / or amphoteric resins and quaternary ammonium salts or grafting of aziridine derivatives such as ethyleneimine on the surface It is preferable to contain them.

The content ratio of the water-dispersible silica is not particularly limited, and is preferably, for example, 5 to 30 parts by weight based on 100 parts by weight of the total nonvolatile components of the water-soluble resin and the dispersion. If the amount is less than 5 parts by weight, the effect of the water-dispersible silica may not be sufficiently exhibited,
If the amount exceeds 30 parts by weight, the film thickness of the coating film becomes too large, and the electric welding, workability, and the like of the rust-proof treated steel sheet may be deteriorated.
More preferably, it is 5 to 25 parts by weight. Further, the content ratio of the water-dispersible silica in the metal surface coating agent of the present invention is not particularly limited.
It is preferably 0.5 to 180 g per 00 g. If the amount is less than 0.5 g, the effect of the water-dispersible silica may not be sufficiently exerted. If the amount exceeds 180 g, the film thickness of the coating becomes too thick, and the electric welding and workability of the rust-proof treated steel sheet are increased. May be inferior. More preferably, it is 1.5 to 100 g.

The tri- and / or dialkoxysilane compound or its hydrolyzate is not particularly limited.
For example, a tri- and / or dialkoxysilane compound
Those obtained by hydrolysis with an acid can be used. These may be used alone or in combination of two or more.

The above tri- and / or dialkoxysilane compound means a silane compound in which one or two organic groups and three or two alkoxyl groups are bonded to a silicon atom. Such a silane compound is not particularly limited, and examples thereof include the following.

One organic group per silicon atom,
Examples of the silane compound bonded to three or two alkoxyl groups include silane compounds having an alkyl group such as methyltriethoxysilane; vinyltriethoxysilane, vinyl-tris- (β-methoxyethoxy) silane, and the like. Silane compound having a vinyl group; silane compound having a methacryloyl group such as γ-methacryloxypropyltrimethoxysilane; β- (3,4-epoxycyclohexyl) -ethyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane A silane compound having a halogen atom such as γ-chloropropyltrimethoxysilane; a silane compound having a mercapto group such as γ-mercaptopropyltriethoxysilane; γ-aminopropyltriethoxysilane; -(Β-ami Examples thereof include silane compounds having an amino group such as (noethyl) -γ-aminopropyltrimethoxysilane, γ-aminopropylmethyldiethoxysilane, and γ- (3-aminoethyl) -aminopropylmethyldimethoxysilane.

Two organic groups with respect to the silicon atom,
Examples of the silane compound bonded to three or two alkoxyl groups include γ-glycidoxypropylmethyldiethoxysilane, γ-mercaptopropylmethyldimethoxysilane, γ-chloropropylmethyldimethoxysilane, γ-ureidopropyl Trimethoxysilane and the like. Among the above tri- and / or dialkoxysilane compounds, those having an amino group are preferred because of their excellent miscibility and dispersion stability with cationic resins and / or amphoteric resins.

The acid used for the hydrolysis of the above tri- and / or dialkoxysilane compound is not particularly limited, and examples thereof include mineral acids such as hydrochloric acid, phosphoric acid and sulfuric acid; and organic acids such as formic acid, acetic acid and lactic acid. Can be These may be used alone or in combination of two or more.

As the above-mentioned hydrolysis method, a usual hydrolysis method can be used and is not particularly limited. For example, a tri- and / or dialkoxysilane compound may be hydrolyzed alone, Hydrolysis may be carried out in the presence of silica, a cationic resin and / or a zwitterionic resin. Among these methods, when hydrolysis is performed in the coexistence of water-dispersible silica, a reaction occurs between the tri- and / or dialkoxysilane compound and the water-dispersible silica, the surface of the water-dispersible silica is treated, and the two are integrated. It is preferable because it can be dispersed. By the above hydrolysis, birds and / or
Alternatively, it is preferable to disperse 50% by weight or more of the dialkoxysilane compound as a hydrolyzate in the metal surface coating agent. More preferably, it is completely dispersed as a hydrolyzate.

By the above-mentioned hydrolysis, silicic acid or a polysilicic acid derivative having an organic group is formed, and alcohol is by-produced. The hydrolyzate thus produced may be used as it is for the metal surface coating agent of the present invention, or may be used after removing part or all of the alcohol by a method such as distillation under reduced pressure.

The content of the above-mentioned tri- and / or dialkoxysilane compound or its hydrolyzate is not particularly limited. For example, 100 parts by weight of the nonvolatile content of the water-soluble resin and the dispersion is converted to SiO ₂ . 5-30
It is preferably in parts by weight. If it is less than 5 parts by weight,
There is a possibility that the action of the tri- and / or dialkoxysilane compound or the hydrolyzate thereof may not be sufficiently exhibited. If the amount exceeds 30 parts by weight, the thickness of the coating film may be too large, and the electric welding and workability of the rust-prevention-treated steel sheet may be deteriorated, and the stability of the metal surface coating agent may be deteriorated. More preferably, it is 10 to 25 parts by weight. Furthermore, the content ratio of the tri and / or dialkoxysilane compound or the hydrolyzate thereof in the metal surface coating agent of the present invention is not particularly limited, and is, for example, 0.5 to 180 g per 1000 g of the metal surface coating agent. Is preferred. If the amount is less than 0.5 g, the action of the tri- and / or dialkoxysilane compound or a hydrolyzate thereof may not be sufficiently exhibited. 18
If it exceeds 0 g, the film thickness of the coating becomes too thick, and the electric welding and workability of the rust-proofed steel sheet may be deteriorated.
There is a possibility that the stability of the metal surface coating agent may deteriorate. More preferably, it is 3 to 100 g.

The metal surface coating agent of the present invention may further contain, if necessary, a filler such as an inorganic pigment or an organic pigment; and an additive such as a rust preventive. These fillers and additives may be used alone or in combination of two or more. As the inorganic pigment, any of water-insoluble or water-dispersible may be used, and is not particularly limited.
Fine powdered silica, talc, diatomaceous earth, calcium carbonate, clay, titanium dioxide, aluminum silicate,
Alumina sol, magnesia sol, titania sol, zirconia sol and the like can be mentioned.

The content ratio of the above-mentioned inorganic pigment is not particularly limited. For example, the content is preferably 100 parts by weight or less based on 100 parts by weight of the total of the nonvolatile components of the water-soluble resin and the dispersion. More preferably, it is 50 parts by weight or less. 1
If it exceeds 00 parts by weight, the thickness of the coating film becomes too large, and the electric welding, workability and the like of the rust-prevention-treated steel sheet may be deteriorated.

The organic pigment is not particularly limited, and for example, an organic pigment usually used for a metal surface coating agent can be used. The rust preventive is not particularly limited, and examples thereof include tannic acid and gallic acid.

The pH of the solution in the metal surface coating agent is not particularly limited as long as it is 0.5 to 13, and is preferably, for example, 0.5 to 7. If it is less than 0.5, the metal surface may be eroded. If it exceeds 7, the effect on the metal surface may not be sufficient, and the stability of the solution may be poor. More preferably, it is 1-6. To adjust the pH to such a value, it is preferable to use a pH adjuster or the like. The pH adjuster is not particularly limited, and includes, for example, the above-mentioned acids such as phosphoric acid. It is preferable to use phosphoric acid because corrosion resistance is improved.

The above-mentioned metal surface coating agent may also be used, if necessary, with a commonly used conductive pigment, a compound having a heavy metal, an etching agent, an etching aid, a polyvalent anion, an aluminum ion, an oxidizing agent, a lubricant, It may contain a coloring agent and the like. Also, if necessary, a curing agent,
It may contain a thickener, an ultraviolet absorber, a light stabilizer and the like.

The metal surface coating agent of the present invention can be used as a metal surface treatment agent for rust prevention treatment.
The method of the rust prevention treatment is not particularly limited, for example,
The coating may be performed by coating a metal substrate that has not been subjected to a chemical conversion treatment, or may be performed by coating a metal substrate that has been subjected to a chemical conversion treatment. In this case, the metal surface coating agent of the present invention can perform a non-chromium rust prevention treatment on the metal substrate without performing a chemical conversion treatment with a chromium compound or the like, and is equal to or more than the conventional rust prevention treatment. Since it can impart the corrosion resistance and the coating base property of the metal substrate, the production cost is suppressed, and also, in order to suppress the environmental pollution, the metal base material which has not been subjected to a chemical conversion treatment with a chromium compound or the like. It is desirable to perform a chrome-free rust-proof treatment by eliminating the chemical treatment step by painting.

The metal substrate is not particularly limited, and may be, for example, metals such as iron, steel, alloy steel, zinc, zinc alloy, aluminum, and aluminum alloy; and plating or spraying a metal containing zinc or the like on the surface of these metals. And the like, and the like. Among these, since the coating with the metal surface coating agent of the present invention can sufficiently exert its effect, metals such as zinc, zinc alloys, aluminum and aluminum alloys, and metals containing zinc and the like are plated or sprayed. It is preferable to use a metal coated with a. More preferably, the metal surface contains zinc.

The method of applying the metal surface coating agent is not particularly limited, and examples thereof include ordinary methods such as brush coating, spray coating, roll coating, and dip coating. The method of drying and curing after applying the metal surface coating agent is not particularly limited. In the case of drying with heat or hot air,
For example, it is preferable to dry at an ambient temperature of normal temperature to 250 ° C. for several seconds to several minutes. More preferably, 80 to 20
The temperature is 0 ° C, more preferably 100 to 180 ° C. In this case, the final temperature on the surface of the metal substrate is from room temperature to 250 ° C.
It is preferred that More preferably 80 to 200
° C, more preferably 100-200 ° C. The final temperature of the metal substrate surface is 80 ° C. or more, preferably 100 ° C.
When the temperature is at least ° C, active sulfur can be sufficiently generated when an organic sulfur compound is contained.

The thickness of the film formed by the metal surface coating agent is not particularly limited, and for example, is preferably 0.1 to 5 μm as an average film thickness. More preferably, it is 0.2 to 3 μm, even more preferably, 0.3 to 3 μm.
It is 2 μm, most preferably 0.4 to 1.0 μm. When the film thickness of the rust preventive treatment is 1 μm or less, the rust preventive steel sheet is hardly insulated by the film, and thus electric welding is possible. Also, since the coating will have sufficient followability when processing the steel sheet,
The workability of the rust-proofed steel sheet can be improved.

The metal surface coating agent of the present invention imparts excellent corrosion resistance to the metal surface and has sufficient adhesion and basic performance. In addition, even if the adhered oil is removed (degreased) performed in the pre-coating process on the formed film, or the coating with various paints is performed, the film is peeled or the basic performance is impaired. It is something that you do not have. For this reason, by using it as a metal surface treatment agent, it is possible to perform a non-chromium rust prevention treatment on a metal substrate without performing a chemical conversion treatment. Further, when the film thickness is 1 μm or less, the versatility and practicality of the rust-proofed steel sheet can be further improved.

The metal surface coating agent of the present invention can be used as a metal surface treatment agent as described above, and can also be used to provide a primer paint for the purpose of imparting corrosion resistance, adhesion, and the like, and to impart cosmetics and the like. Can be used as a paint for pre-coated metal (PCM) and the like. As a result, a coated steel sheet having excellent corrosion resistance and basic performance can be produced.

[0100]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples. Note that “parts” indicates “parts by weight”.

Preparation Example 1 In a 1 L flask equipped with a stirrer, a reflux condenser, a thermometer, a nitrogen inlet tube and a dropping funnel, 707 parts of deionized water, 2
After charging 40 parts of an aqueous solution of 5% anionic activator (“HITENOL 18E”, trade name, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.),
The temperature was raised to 65 ° C. while introducing nitrogen. Acrylic acid 48
, A monomer mixture 8 consisting of 57 parts of methyl methacrylate, 157 parts of butyl acrylate and 138 parts of styrene.
After adding 0 parts to the flask and stirring for 15 minutes, 1.
14 parts of an 8% aqueous hydrogen peroxide solution and 13 parts of a 3% aqueous L-ascorbic acid solution were added to initiate initial polymerization. After 15 minutes, the remaining monomer was added dropwise over 1.5 hours. During this time, 0.8
32 parts of a 30% aqueous hydrogen peroxide solution and 29 parts of a 3% aqueous L-ascorbic acid solution were added dropwise over 1.5 hours. After dropping, 7
After aging for 2 hours at 0 ° C., the mixture was cooled and 25% aqueous ammonia 14
Was added and stirred uniformly to obtain a polymer. To this polymer, 220 parts of a 13% aqueous solution of ethyleneimine was added dropwise at 40 ° C. or lower for 1 hour, and then reacted at 50 ° C. for 4 hours to obtain a water-dispersible zwitterionic resin (A) having a nonvolatile content of 30%.
I got This water-dispersible zwitterionic resin (A) has a weight average molecular weight (Mw) of 400,000 and an average particle diameter of 140.
nm. In the examples, the measurement of the average particle diameter was based on the dynamic light scattering method described above.

Preparation Example 2 The same procedure as in Preparation Example 1 was carried out except that the initial polymerization was carried out at 67 ° C. The obtained water-dispersible zwitterionic resin (B) has a weight average molecular weight (Mw) of 400,000 and an average particle diameter of 1
00 nm.

Preparation Example 3 99 parts of methyl methacrylate, methyl methacrylate 12
1 part, 137 parts of butyl acrylate and 190 of styrene
Was polymerized in 550 parts of 2-ethoxyethanol in the presence of a radical polymerization initiator to obtain a polymer solution.
To this, 124 parts of ethyleneimine was added, and after the reaction, the mixture was acidified with a 38% aqueous hydrochloric acid solution to adjust the pH to 5.0, and deionized water was added. Obtained.

Comparative Preparation Example 1 The same procedure as in Preparation Example 2 was repeated except that the initial polymerization was carried out at 67 ° C. The obtained water-dispersible anionic resin (D)
Had a weight average molecular weight (Mw) of 400,000 and an average particle diameter of 100 nm.

Example 1 100 parts of the water-dispersible zwitterionic resin (A) obtained in Preparation Example 1 was added to the water-dilutable zwitterionic resin (C) 10 obtained in Preparation Example 3.
And 4.0 parts of 85% phosphoric acid, and stirred sufficiently to obtain a metal surface coating agent. Next, a 0.5 mm-thick electrogalvanized steel sheet was degreased, washed with water and dried to obtain a test plate. The obtained metal surface coating agent was applied to this steel sheet so as to have a predetermined thickness after drying with a bar coater.
Heat drying was performed for 1 minute in a hot-air dryer at ℃ to obtain a surface-coated plate. The final temperature of the test plate at this time was 80 ° C. In order to check the corrosion resistance of this surface coated plate, JIS-Z2
A salt spray test according to 371 showed that the area ratio of white rust was 5
%.

Example 2 100 parts of the water-dispersible zwitterionic resin (B) obtained in Preparation Example 2 was added to 100 parts of the water-dilutable zwitterionic resin (C) obtained in Preparation Example 3.
And 4.0 parts of 85% phosphoric acid, and stirred sufficiently to obtain a metal surface coating agent. Using the obtained metal surface coating agent, a surface coated plate was obtained and evaluated in the same manner as in Example 1. Example 3 Epomin P-1000 (trade name, as a water-soluble resin) was added to 100 parts of the water-dispersible zwitterionic resin (B) obtained in Preparation Example 2.
Nippon Shokubai Co., Ltd. polyethylene imine) 10 parts, further 85%
4.0 parts of phosphoric acid was added and sufficiently stirred to obtain a metal surface coating agent. Using the obtained metal surface coating agent, a surface coated plate was obtained and evaluated in the same manner as in Example 1. Example 4 To 100 parts of the water-dispersible zwitterionic resin (B) obtained in Preparation Example 2, 30 parts of a 10% aqueous solution of PVA-205 (trade name, polyvinyl alcohol manufactured by Kuraray) as a water-soluble resin,
Further, 4.0 parts of 85% phosphoric acid was added and sufficiently stirred to obtain a metal surface coating agent. Using the obtained metal surface coating agent, a surface coated plate was obtained and evaluated in the same manner as in Example 1.

Example 5 To 100 parts of the water-dispersible zwitterionic resin (B) obtained in Preparation Example 2, 3.0 was added polyethylene glycol as a water-soluble resin.
And 4.0 parts of 85% phosphoric acid, and stirred sufficiently to obtain a metal surface coating agent. Using the obtained metal surface coating agent, a surface coated plate was obtained and evaluated in the same manner as in Example 1. Example 6 The water-dispersible zwitterionic resin (C) 10 obtained in Preparation Example 3 was added to 100 parts of the water-dispersible zwitterionic resin (B) obtained in Preparation Example 2.
Then, 4.0 parts of 85% phosphoric acid and 1.7 parts of diethylthiourea were added and sufficiently stirred to obtain a metal surface coating agent. Using the obtained metal surface coating agent, a surface coated plate was obtained and evaluated in the same manner as in Example 1. Example 7 The water-dilutable zwitterionic resin (C) 10 obtained in Preparation Example 3 was added to 100 parts of the water-dispersible zwitterionic resin (B) obtained in Preparation Example 2.
Parts, further 4.0 parts of 85% phosphoric acid and EPOCROS WS-5
4.1 (trade name, manufactured by Nippon Shokubai Co., Ltd.) and sufficiently stirred to obtain a metal surface coating agent. Using the obtained metal surface coating agent, a surface coated plate was obtained and evaluated in the same manner as in Example 1.

Example 8 100 parts of the water-dispersible zwitterionic resin (B) obtained in Preparation Example 2 was added to the water-dilutable zwitterionic resin (C) 10 obtained in Preparation Example 3.
Part, further 4.0 parts of 85% phosphoric acid and water-dispersible colloidal silica liquid Snowtex C (trade name, manufactured by Nissan Chemical Industries, Ltd.)
8.0 parts were added and sufficiently stirred to obtain a metal surface coating agent. Using the obtained metal surface coating agent, a surface coated plate was obtained and evaluated in the same manner as in Example 1. Example 9 The water-dilutable zwitterionic resin (C) 10 obtained in Preparation Example 3 was added to 100 parts of the water-dispersible zwitterionic resin (B) obtained in Preparation Example 2.
Then, 4.0 parts of 85% phosphoric acid and 10 parts of γ-aminopropyltriethoxysilane were added thereto and sufficiently stirred to obtain a metal surface coating agent. Using the obtained metal surface coating agent, a surface coated plate was obtained and evaluated in the same manner as in Example 1.

[0109]

[Table 1]

Comparative Example 1 3.5 parts of 85% phosphoric acid was added to 100 parts of the water-dispersible zwitterionic resin (A) obtained in Preparation Example 1 and sufficiently stirred to obtain a comparative metal surface coating agent. . Using the obtained comparative metal surface coating agent, a surface coated plate was obtained and evaluated in the same manner as in Example 1. Comparative Example 2 3.5 parts of 85% phosphoric acid was added to 100 parts of the water-dispersible zwitterionic resin (B) obtained in Preparation Example 2 and sufficiently stirred to obtain a comparative metal surface coating agent. Using the obtained comparative metal surface coating agent, a surface coated plate was obtained and evaluated in the same manner as in Example 1. Comparative Example 3 To 100 parts of the water-dispersible zwitterionic resin (A) obtained in Preparation Example 1, 200 parts of a 10% aqueous solution of PVA-205 as a water-soluble resin, and further 10.5 parts of 85% phosphoric acid were added. To obtain a comparative metal surface coating agent. Using the obtained comparative metal surface coating agent, a surface coated plate was obtained and evaluated in the same manner as in Example 1. Comparative Example 4 Water-dispersible anionic resin (D) 10 obtained in Comparative Preparation Example 1
In 0 parts, the water-dilutable zwitterionic resin (C) obtained in Preparation Example 3
By adding 10 parts and sufficiently stirring, a comparative metal surface coating agent was obtained. Using the obtained comparative metal surface coating agent, a surface coated plate was obtained and evaluated in the same manner as in Example 1.

[0111]

[Table 2]

Tables 1 and 2 show the evaluation results of Examples and Comparative Examples. As is clear from the evaluation results, the metal plate coated with the metal surface coating agent of the present invention was found to be excellent in corrosion resistance and adhesion.

[0113]

Since the metal surface coating composition of the present invention has the above-mentioned constitution, it is possible to perform a chromium-free rust-preventive treatment without the need for chemical conversion treatment on the metal surface.
The production cost can be suppressed, environmental pollution can be suppressed, and the film thickness of 1 μm or less can further increase the versatility and practicality of the rust-proofed steel sheet.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4J038 BA092 BA102 BA112 BA132 BA162 BA172 BA192 BA222 CE022 CG012 CG141 CG172 CK021 CK032 CQ011 CR071 DB391 DD001 DF021 DF022 DG001 DG061 DH021 DJ011 GA06 GA09 MA10 MA14 A02A02 PC AA12 AA22 BA01 BA03 BB06 BB08 BB10 CA16 CA26 CA37 CA38 CA39 CA41 DA15 4K044 AA02 AB02 BA10 BA17 BA21 BB03 BC02 BC04 CA16 CA53

Claims (1)

[Claims] 1. A metal surface coating agent comprising a hydrophilic colloid solution of a water-soluble resin, wherein the hydrophilic colloid solution comprises a dispersion, wherein the dispersion comprises a cationic resin and / or
Or a cationic resin and / or a zwitterionic resin including a resin having at least one of a primary amino group and a secondary amino group in a side chain thereof, The metal surface coating agent, wherein the content of the metal component is at least 50% by weight based on the total weight of the non-volatile components of the water-soluble resin and the dispersion.