JP2001348535A - Metal surface coating composition and metal surface coating agent - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a metal surface coating composition capable of giving a coating film excellent in fundamental characteristics, such as adhesiveness and corrosion resistance, applicable to various purposes, and further capable of sufficiently decreasing a thickness of the coating film. SOLUTION: This metal surface coating composition contains (I) a cationic resin and/or an ampholytic resin, (II) a phosphoric acid compound, and (III) a multifunctional crosslinking agent, wherein the phosphoric acid compound (II) and the multifunctional crosslinking agent (III) are contained in amounts of 0.5-50 pts.wt. and 0.5-30 pts.wt. per 100 pts.wt. of a nonvolatile content of the cationic resin and/or the ampholytic resin (I), respectively.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a metal surface coating composition and 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 for making a coating film formed by various paints adhere, and to protect the metal surface. And is indispensable for beauty.

[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]

DISCLOSURE OF THE INVENTION The present invention has been made in view of the above-mentioned circumstances, and the coating film has excellent basic performances such as adhesion and corrosion resistance, can be applied to various uses, and has a sufficient effect. It is an object of the present invention to provide a metal surface coating composition which can be formed into a thin film.

[0007]

The present invention relates to a cationic resin and / or amphoteric resin (I), a phosphate compound (I).
A metal surface coating composition comprising (I) and a polyfunctional crosslinking agent (III), wherein the content of the phosphoric acid compound (II) is at least one of a cationic resin and / or a zwitterionic resin (I). 0.5 to 50 parts by weight with respect to 100 parts by weight per minute,
The content ratio of the polyfunctional crosslinking agent (III) is 0.5 to 30 parts by weight with respect to 100 parts by weight of the non-volatile content of the cationic resin and / or the amphoteric resin (I). A composition. The present invention is also a metal surface coating agent containing the metal surface coating composition. Hereinafter, the present invention will be described in detail.

The metal surface coating composition of the present invention contains a cationic resin and / or amphoteric resin (I), a phosphate compound (II) and a polyfunctional crosslinking agent (III). The form of the cationic resin and / or amphoteric resin (I) may be any of water-soluble, water-dilutable, water-dispersible, non-aqueous-dispersible, and solvent-soluble. 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 forming a cation in a main chain or a side chain in a molecule and a resin having an atom forming an anion are also included.

When the metal surface coating composition of the present invention contains a cationic resin and / or a zwitterionic resin (I), the film formed by the metal surface coating composition can be used for various metal surfaces or coatings. Has sufficient adhesion to the film, and
This has the effect of sufficiently blocking corrosive substances and protecting the metal surface. Thereby, the corrosion resistance of the metal surface is improved.

The above-mentioned cationic resin has a cationic nitrogen atom such as a primary amino group, a secondary amino group, a tertiary amino group, or an amide group as a group forming a cation in a main chain or a side chain in a molecule. It is preferable that the resin has at least one of them. 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 (1)
7) 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 zwitterionic resin having a carboxyl group as a group forming an anion in the main chain or side chain in the 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 ordinary methods. 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, when measured 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.

It is preferable that the cationic resin and / or amphoteric resin (I) include a resin having at least one of a primary amino group and a secondary amino group in a side chain. Thus, the cationic resin has at least one of a primary amino group and a secondary amino group, and the amphoteric resin has a carboxyl group and at least one of a primary amino group and a secondary amino group. And have one
Since a tertiary amino group or a secondary amino group has a more excellent action than a tertiary amino group or an amide group, the adhesion to various metal surfaces or coating films becomes excellent.

The primary amino group and the secondary amino group include, for example, the following general formula (1):

[0018]

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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 (I), they may be the same or different. Good.

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 general formula (1), when the alkyl group, aralkyl group or aryl group has a substituent, the substituent is not particularly limited, and examples thereof include a cyano group, a halogen atom, an amino group, and a hydroxyl group. Groups, alkoxyl groups, carboalkoxyl groups and the like.

The alkoxyl group or the 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 above-mentioned polyvinylamines is not particularly restricted but includes, for example, hydrolysis of polyvinylformamide with an acid or a basic substance; reduction of polynitroethylene and its derivatives; 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, all the carboxyl groups are modified, and 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.

The polymerization method of 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.

In the above-mentioned resin having a carboxyl group, all the carboxyl groups are modified, and the method for modifying the carboxyl group to a primary and / or secondary amino group is not particularly limited. For example, a method using an alkylene imine 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 alkyleneimine is not particularly restricted but includes, for example, compounds represented by the following general formula (2). These may be used alone or in combination of two or more.

[0033]

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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.

[0036]

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In the above 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 the amount of 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 composition may not be sufficient. If it exceeds 30% by weight,
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. If the molar amount exceeds 10 times, the water resistance of the coating formed by the metal surface coating composition may be insufficient. 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, and examples thereof include (7)
(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, 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.

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 above resin having a carboxyl group partially modified with a carboxyl group is not particularly limited. For example, alkylene imine may be used. 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 the amount of 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 composition may not be sufficient. If it exceeds 30% by weight,
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 cationic nitrogen atoms introduced is small and the adhesion to the metal may not be sufficient. If the molar amount exceeds 10 times, the film formed by the metal surface coating composition may be used. May not have sufficient water resistance. More preferably, the molar amount is 0.5 to 5 times the molar amount.

The above cationic and amphoteric resin (I)
Further, since a film formed thereby has excellent performance, those having a carbon-carbon bond, an amide bond, a urethane bond, and an amine epoxy bond in the main chain structure are preferable. Thereby, the basic performance such as the water resistance of the coating is improved.

In the metal surface coating composition of the present invention,
The content ratio of the cationic resin and / or the amphoteric resin (I) is not particularly limited. For example, when used as a metal surface coating agent, 1000 g of a metal surface coating composition
It is preferable that the resin nonvolatile content is 5 to 600 g. 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 40
0 g. That is, the preferable content of the polymer component (nonvolatile content) of the cationic resin and / or amphoteric resin (I) of the present invention is 0.5 to 100% by weight based on the total composition.
60% by weight. More preferably, it is 1 to 40% by weight.

The phosphoric acid compound (II) in the metal surface coating composition of the present invention may be a cationic atom such as a cationic nitrogen atom or a cation in the cationic resin and / or the amphoteric resin (I). It forms a phosphate with a functional group, and this phosphate has an action of improving affinity with a metal surface.
Thereby, the corrosion resistance and the like of the film formed by the metal surface coating composition are improved.

The phosphoric acid compound (II) is not particularly restricted but includes, for example, orthophosphoric acid, pyrophosphoric acid, polyphosphoric acid, metaphosphoric acid, phytic acid; heteropolyacid formed by molybdic acid or tungstic acid and phosphorus atoms Is mentioned. Also, sodium phosphate, sodium monohydrogen phosphate, sodium dihydrogen phosphate, potassium phosphate,
Metal salts of phosphoric acid such as potassium monohydrogen phosphate, potassium dihydrogen phosphate, magnesium monohydrogen phosphate and zinc monohydrogen phosphate; phosphoric acid such as ammonium phosphate, ammonium monohydrogen phosphate and ammonium dihydrogen phosphate Ammonium salts; 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 phosphate compound (II) is not particularly limited. For example, when the phosphate compound (II) is used as a metal surface coating agent, the cation contained in the cationic resin and / or the amphoteric resin (I) Non-volatile of the cationic resin and / or zwitterionic resin (I), including phosphoric acid used for converting a part or all of the nitrogen atom into a salt or obtaining a hydrolyzate of an alkoxysilane compound. The amount is preferably 0.5 to 50 parts by weight based on 100 parts by weight. When the amount is less than 0.5 part by weight, the phosphoric acid compound (III)
There is a possibility that the function of the above cannot be sufficiently exhibited.
If the amount exceeds 50 parts by weight, 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 1 to 40 parts by weight. Furthermore, in the metal surface coating composition of the present invention,
The content ratio of the phosphoric acid compound (III) is not particularly limited. For example, when used as a metal surface coating agent,
0.1 to 30 per 1000 g of the metal surface coating composition
It is preferably 0 g. If the amount is less than 0.1 g, the action of the phosphoric acid compound (III) 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 polyfunctional crosslinking agent (III) in the metal surface coating composition of the present invention has a function of crosslinking the cationic resin and / or the amphoteric resin (I) at the time of film formation. Thereby, in the film formed by the metal surface coating composition, the cationic resin and / or the amphoteric resin (I) are sufficiently cross-linked to act to block corrosive substances, The strength and adhesion of the coating are improved, and the corrosion resistance is improved.

The above-mentioned polyfunctional crosslinking agent (III) is not particularly limited as long as it can be crosslinked with a cationic resin and / or amphoteric resin (I) by forming a covalent bond when forming a film. . The above polyfunctional crosslinking agent (III)
When a cationic surface resin and / or an amphoteric resin is crosslinked by covalent bonding to form a metal surface coating film, the water resistance and corrosion resistance of the coating film can be sufficiently imparted. The polyfunctional crosslinking agent (III) includes, for example, aldehyde group, ketone group, alkyl halide group, isocyanate group, thioisocyanate group, blocked isocyanate group, active double bond group, epoxy group, carboxyl group, acid anhydride group, active ester Compounds having two or more functional groups of one or more of a group, an oxazoline group, a hydroxyl group, an azirinyl group, and the like. The polyfunctional crosslinking agent (III) may be a low molecular weight compound or a high molecular weight compound.
Examples of such a compound include an isocyanate group-containing compound, a blocked isocyanate group-containing compound, an epoxy group-containing compound, an oxazoline group-containing compound, and an azilinyl group-containing compound. These may be used alone or in combination of two or more.

Commercial products can be used as the polyfunctional crosslinking agent. For example, as the isocyanate group-containing compound,
Aquanate 100, 110, 200, 210 (all trade names, manufactured by Nippon Polyurethane), Duranate WB
-40-100 (trade name, manufactured by Asahi Kasei Corporation), and as a blocked isocyanate group-containing compound, bihydrol TP
LS2016 (trade name, manufactured by Sumitomo Bayer), Elastron BN-04, 5, 08, 11, 27, 31, 44,
45, 50, 69 (all trade names, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.), and as the epoxy group-containing compound, Denacol EX
-313, 321 (both trade names, manufactured by Nagase Kasei Kogyo Co., Ltd.), EPICLON EM-85 (trade name, manufactured by Dainippon Ink Co., Ltd.), and as the oxazoline group-containing compound, Epocross WS-500 (trade name, Nippon Shokubai Co., Ltd.) ), Epocloth K-2010E, 2020E, 2030E (all trade names, manufactured by Nippon Shokubai Co., Ltd.), and as the azirinyl group-containing compound, Chemitite DZ-22E (trade name, manufactured by Nippon Shokubai Co., Ltd.), Chemitite PZ-33 (product) Name, manufactured by Nippon Shokubai Co., Ltd.).

The content of the above-mentioned polyfunctional crosslinking agent (III) is determined by taking into consideration the reactivity with the cationic resin and / or the amphoteric resin, the pot life, and the like, when forming the film on the metal surface. The ionic resin and / or amphoteric resin is preferably set so as to be crosslinked. For example, when the ionic resin and / or amphoteric resin (I) is used as a metal surface coating agent, For 100 parts by weight,
It is preferably 0.5 to 30 parts by weight. If the amount is less than 0.5 part by weight, the function of the polyfunctional crosslinking agent (IV) may not be sufficiently exhibited. If the amount exceeds 30 parts by weight, the adhesion of the coating formed with the metal surface coating composition 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, in the metal surface coating composition of the present invention, the content ratio of the polyfunctional crosslinking agent (IV) is not particularly limited. For example, when the metal surface coating composition is used as a metal surface coating composition,
It is preferably 0.1 to 300 g per g.
If the amount is less than 0.1 g, the function of the polyfunctional crosslinking agent (IV) may not be sufficiently exhibited. If it exceeds 300 g, the adhesion to the metal surface or the coating film in the coating film formed by the metal surface coating composition may be inferior,
Also, the basic performance of the coating may be reduced. More preferably, it is 1 to 200 g.

The metal surface coating composition of the present invention further comprises:
It is preferable to contain at least one of water-dispersible silica (IV) and a tri- and / or dialkoxysilane compound or a hydrolyzate (V) thereof. This allows
The coating formed by the metal surface coating composition includes a coating layer of water-dispersible silica (IV), a tri- and / or dialkoxysilane compound or a hydrolyzate (V) thereof, and a cationic resin and / or Since the amphoteric resin (I) is crosslinked, the corrosion resistance and the like are improved.

The above-mentioned water-dispersible silica (IV) means what is generally called colloidal silica which is a condensate of silicic acid. The water-dispersible silica (IV) 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 2
0, Snowtex C (all trade names, manufactured by Nissan Chemical Industries, Ltd.), Cataloid SN, Cataloid S
i-500 (all are trade names, manufactured by Catalyst Chemical Industry Co., Ltd.) and the like. As the surface-treated one, for example, Cataloid SA treated with aluminate
(Trade name, manufactured by Catalyst Chemicals, Inc.) can also be used. These may be used alone or in combination of two or more.

The mode for incorporating the water-dispersible silica (IV) into the metal surface coating composition is not particularly limited.
For example, it can be contained in the metal surface coating composition in its original form, but in order to improve dispersibility,
Cationic resins and / or amphoteric resins (I) and
It is preferable that the surface treatment is performed in advance with an amine such as a quaternary ammonium salt, or an aziridine derivative such as ethyleneimine is grafted on the surface to be contained in the metal surface coating composition.

The content of the water-dispersible silica (IV) is not particularly limited. For example, when used as a metal surface coating agent, the non-volatile content of the cationic resin and / or the amphoteric resin (I) The amount is preferably 5 to 30 parts by weight based on 100 parts by weight. If the amount is less than 5 parts by weight, the action of the water-dispersible silica (IV) may not be sufficiently exhibited. There is a possibility that welding, workability and the like may be inferior. More preferably, it is 5 to 25 parts by weight. Further, in the metal surface coating composition of the present invention, the content ratio of the water-dispersible silica (IV) is not particularly limited. For example, when used as a metal surface coating agent, the content per 1000 g of the metal surface coating composition , 0.5-180g
It is preferred that If the amount is less than 0.5 g, the effect of the water-dispersible silica (IV) may not be sufficiently exerted. There is a possibility that workability and the like may be poor. More preferably, it is 1.5 to 100 g.

The tri- and / or dialkoxysilane compound or its hydrolyzate (V) is not particularly limited. For example, those obtained by hydrolyzing a tri- and / or dialkoxysilane compound with an acid may be used. Can be used. These may be used alone or in combination of two or more.

The 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 preferable because of their excellent miscibility and dispersion stability with the cationic resin and / or the amphoteric resin (I).

The acid used for the hydrolysis of the tri- and / or dialkoxysilane compound is not particularly limited, and includes, for example, 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 (IV), a cationic resin and / or an amphoteric resin (I). Among these methods, when hydrolysis is performed in the presence of water-dispersible silica (IV), a reaction occurs between the tri- and / or dialkoxysilane compound and water-dispersible silica (IV), and the water-dispersible silica (IV) Is preferably surface-treated, so that both can be integrated and dispersed.
It is preferable to disperse at least 50% by weight of the tri- and / or dialkoxysilane compound as a hydrolyzate in the metal surface coating composition by the hydrolysis. More preferably, it is completely dispersed as a hydrolyzate.

By the above-mentioned hydrolysis, silicic acid or polysilicic acid derivative having an organic group is generated, and alcohol is by-produced. The hydrolyzate thus produced may be used as it is for the metal surface coating composition 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 tri- and / or dialkoxysilane compound or its hydrolyzate (V) is not particularly limited. For example, when it is used as a metal surface coating agent, the cationic resin and / or both The amount is preferably 5 to 30 parts by weight in terms of SiO _{2 based} on 100 parts by weight of the non-volatile content of the ionic resin (I). When the amount is less than 5 parts by weight, the action of the tri- and / or dialkoxysilane compound or the hydrolyzate (V) 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 composition may be deteriorated. . More preferably, it is 10 to 25 parts by weight. Further, in the metal surface coating composition of the present invention, the content ratio of the above tri- and / or dialkoxysilane compound or its hydrolyzate (V) is not particularly limited. The amount is preferably 0.5 to 180 g per 1000 g of the metal surface coating composition. 0.5
If it is less than g, the action of the tri- and / or dialkoxysilane compound or its hydrolyzate (V) may not be sufficiently exhibited. If it exceeds 180 g,
The coating may become too thick, resulting in poor electrical welding and workability of the rust-treated steel sheet, and the stability of the metal surface coating composition may be deteriorated. More preferably, it is 3 to 100 g.

The composition for coating a metal surface of the present invention is obtained by the synergistic action of a cationic resin and / or amphoteric resin (I), a phosphate compound (II) and a polyfunctional crosslinking agent (III).
Adhesion of the cationic resin and / or amphoteric resin (I) to various metal surfaces and coating films is improved, and the action of blocking corrosive substances, the strength of the coating film, and the like are improved. Thereby, the metal surface coating composition can impart excellent corrosion resistance to the metal surface. In addition, by further containing the above-described components, the corrosion resistance and the like of the film are further improved by the synergistic action of the components, so that the film has the film depending on the use of the metal surface coating composition, required performance, and the like. Corrosion resistance and the like can be appropriately set.

The metal surface coating composition of the present invention comprises a cationic resin and / or amphoteric resin (I), a phosphate compound (II) and a polyfunctional crosslinking agent (III). Further, if necessary, as an embodiment, the metal surface coating composition of the present invention can include a diluting solvent such as water, an organic solvent alcohol or toluene, a dispersion solvent, and the like. It may be dissolved in a solvent, or may be in a dispersed state or an emulsion state. In the embodiment, for example, a dispersion having a nonvolatile content of 5 to 80% is easily used as the water dispersion. In consideration of the solubility of the polymer, the solvent type can be used in the range of 1 to 80% in non-volatile content. These forms are not limited as long as they are selected as desired. In the embodiment, the polymer itself as the resin of the present invention may be dispersed or dissolved in water or a solvent. If a predetermined amount of a phosphoric acid compound and a polyfunctional crosslinking agent are added here, the composition for metal surface coating of the present invention is obtained. At this time, the phosphoric acid compound and the polyfunctional crosslinking agent may be added as they are, or may be dissolved or dispersed in a solvent or water as needed. These are forms that can be appropriately selected as needed and can be used in producing the metal surface coating composition of the present invention.

The metal surface coating agent containing the metal surface coating composition of the present invention can impart a function such as corrosion resistance to the metal surface and has a sufficient adhesion to various metal surfaces and coating films. Therefore, for example, a metal surface treating agent for the purpose of rust prevention treatment, a primer paint for the purpose of imparting corrosion resistance and adhesion, and a pre-coated metal (PCM ) Paints. Such a metal surface coating agent is also one of the present invention. When the metal surface coating composition of the present invention is used as a metal surface coating agent, it can be used as it is, or can be used after being appropriately diluted with water or a solvent. The amount of the nonvolatile component in the metal surface coating agent is 0.01 to 100% by weight per 100% by weight of the metal surface coating agent.
60% by weight, more preferably 0.1 to 40% by weight
It is.

The metal surface coating agent may contain a filler such as an inorganic pigment or an organic pigment; and an additive such as a rust preventive, if necessary. Moreover, you may contain resins other than a cationic resin and / or amphoteric resin (I). These fillers and additives may be used alone or in combination of two or more. As the inorganic pigment, any one of water-insoluble or water-dispersible may be used, and is not particularly limited, for example, 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 inorganic pigment is not particularly limited. For example, when the inorganic pigment is used as a metal surface treating agent, 10 parts by weight based on 100 parts by weight of the metal surface coating composition.
It is desirable that the content be 0 parts by weight or less. More preferably,
50 parts by weight or less. If it exceeds 100 parts by weight, the film thickness of the coating film becomes too thick, and the electric welding, workability and the like of the rust-proof treated steel sheet may be deteriorated.

The organic pigment is not particularly limited. For example, when it is used as a paint for PCM or the like, a commonly used organic pigment 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.

When the above-mentioned metal surface coating agent is used as a metal surface treatment agent, a conductive pigment, a compound having a heavy metal, an etching agent, an etching auxiliary, a polyvalent anion, aluminum It may contain ions, oxidizing agents, lubricants, coloring agents, and the like.
When used as a primer paint or a paint for PCM, it may further contain a thickener, an ultraviolet absorber, a light stabilizer and the like, if necessary.

When the above-mentioned metal surface coating agent is used as a metal surface treatment agent to perform anticorrosion treatment, it may be performed by coating a metal substrate that has been subjected to a chemical conversion treatment, or may be performed by coating a metal substrate that has not been subjected to a chemical conversion treatment. May be carried out by painting. When coating on a metal substrate that has not been subjected to chemical conversion, reduce the cost of the chemical conversion process,
Further, environmental pollution due to wastewater treatment of the chemical conversion treatment liquid can be suppressed. Preferably, it is used for anti-corrosion treatment of non-chromium. In this case, a surface-treated metal having excellent corrosion resistance can be obtained without using a chromium compound of which toxicity is concerned.

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 for coating 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, most preferably 120-200 ° C. When the final temperature of the metal substrate surface is 100 ° C. or higher, preferably 120 ° C. or higher, the cationic resin and / or amphoteric resin (I) and the polyfunctional crosslinking agent (III) are sufficiently crosslinked. be able to.

The thickness of the film formed by the above metal surface coating agent is not particularly limited. For example, when used as a metal surface treatment agent, the average thickness is 0.1 to 5
μm is preferred. More preferably, 0.2 to
It is 3 μm, more preferably 0.3 to 2 μm, and 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. In addition, since the coating has sufficient followability when processing the steel sheet, the workability of the rust-resistant 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 being used 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,
In addition, since corrosion resistance and paint base properties equal to or higher than those of the conventional rust prevention treatment can be imparted, production costs can be suppressed and environmental pollution can be suppressed. Furthermore, even if the film thickness is 1 μm or less, since the film has sufficient corrosion resistance and basic performance, it is possible to perform electric welding of the rust-proofed steel sheet or to improve the workability to prevent the corrosion. The versatility and practicality of the rust-treated steel sheet can be further improved. A metal steel sheet coated with the metal surface coating agent of the present invention and thus subjected to rust-proofing is a preferred embodiment of the present invention.

The metal surface coating agent of the present invention can also be used as a primer paint or a paint for PCM, etc.
Since the coating formed thereby has excellent corrosion resistance and adhesion, a coated steel sheet having excellent corrosion resistance and basic performance can be produced.

[0083]

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”.

Synthesis Example 1 48 parts of acrylic acid, 57 parts of methyl methacrylate, 157 parts of butyl acrylate and 138 parts of styrene were mixed with water,
Polymerization was carried out in the presence of an anionic emulsifier and a radical polymerization initiator to obtain an emulsion polymer. Ethylene imine 3
By adding and reacting 0 parts, a water-dispersible zwitterionic resin (1) having a nonvolatile content of 30% was obtained.

Synthesis Example 2 80 parts of methacrylic acid, 81 parts of methyl methacrylate, 137 parts of butyl acrylate and 70 parts of styrene were mixed with 280 parts of isopropyl alcohol and butoxyethanol 1 part.
In 26 parts, polymerization was carried out in the presence of a radical polymerization initiator,
Further, a solution of a polymer to which 41 parts of triethylamine was added was obtained. To this, 23 parts of ethyleneimine was added, and after the reaction, deionized water was added to obtain a water-dilutable zwitterionic resin (2) having a nonvolatile content of 30%.

Comparative Synthesis Example 1 48 parts of acrylic acid, 57 parts of methyl methacrylate, 157 parts of butyl acrylate and 138 parts of styrene were mixed with water,
Polymerization was carried out in the presence of an anionic emulsifier and a radical polymerization initiator to obtain a water-dispersible anionic resin (3) having a nonvolatile content of 30%.

Preparation Example 1 85 parts per 100 parts of the water-dispersible zwitterionic resin (1)
% Phosphoric acid, 3.5 parts, and 4 parts of Epocross WS-500 (trade name, manufactured by Nippon Shokubai Co., Ltd.) as a polyfunctional crosslinking agent are added, and the mixture having a pH of about 3 is obtained by sufficiently stirring. Obtained. This was designated as metal surface coating agent (A). Preparation Example 2 85 parts per 100 parts of water-dilutable zwitterionic resin (2)
% Phosphoric acid and 4 parts of Epocross WS-500 as a polyfunctional crosslinking agent were added, and the mixture was sufficiently stirred to obtain a composition having a pH of about 3. This was designated as metal surface coating agent (B).

Preparation Example 3 As a polyfunctional crosslinking agent, Aquanate 110 (trade name, manufactured by Nippon Polyurethane Co., Ltd.) was dispersed in water and had a nonvolatile content of 50%.
A composition was obtained in the same manner as in Preparation Example 1, except that 2.5 parts of the emulsion was used. This was designated as metal surface coating agent (C). Preparation Example 4 As a polyfunctional crosslinking agent, 3.7 parts of Elastron BN-08 (trade name, manufactured by Daiichi Kogyo Seiyaku) and 0.2 parts of Elastron Catalyst (trade name, manufactured by Daiichi Kogyo Seiyaku) are used. Except for the above, a composition was obtained in the same manner as in Preparation Example 1. This was designated as metal surface coating agent (D). Preparation Example 5 As a multifunctional crosslinking agent, 3.0 parts of Elastron BN-44 (trade name, manufactured by Daiichi Kogyo Seiyaku) and 0.2 parts of Elastron Catalyst (trade name, manufactured by Daiichi Kogyo Seiyaku) are used. Except for the above, a composition was obtained in the same manner as in Preparation Example 1. This was designated as metal surface coating agent (E). Preparation Example 6 Preparation Example 1 except that 1.3 parts of Denacol EX-313 (trade name, manufactured by Nagase Kasei Co., Ltd.) was used as a polyfunctional crosslinking agent.
In the same manner as in the above, a composition was obtained. This was designated as metal surface coating agent (F).

Preparation Example 7 Preparation Example 1 except that 1.3 parts of Denacol EX-321 (trade name, manufactured by Nagase Kasei Co., Ltd.) was used as a polyfunctional crosslinking agent.
In the same manner as in the above, a composition was obtained. This was designated as metal surface coating agent (G). Preparation Example 8 A composition was obtained in the same manner as in Preparation Example 1, except that 3.0 parts of Epocross K-2010E (trade name, manufactured by Nippon Shokubai Co., Ltd.) was used as a polyfunctional crosslinking agent. This is a metal surface coating agent (H)
And Preparation Example 9 A composition was obtained in the same manner as in Preparation Example 1, except that 5.0 parts of Chemitite DZ-22E (trade name, manufactured by Nippon Shokubai Co., Ltd.) was used as a polyfunctional crosslinking agent. This is a metal surface coating agent (I)
And

Preparation Example 10 A composition was obtained in the same manner as in Preparation Example 1, except that 1.5 parts of phytic acid was used as the phosphate compound. This was designated as metal surface coating agent (J). Preparation Example 11 Water-dispersible colloidal silica liquid Snowtex C (trade name, manufactured by Nissan Chemical Industries, Ltd.) was added to metal surface coating agent (A) at 7.5 parts per 100 parts of water-dispersible zwitterionic resin (1). And the mixture was sufficiently stirred to obtain a composition. This was designated as metal surface coating agent (K).

Preparation Example 12 To the metal surface coating agent (A), 3 parts of γ-aminopropyltriethoxysilane were added to 100 parts of the water-dispersible zwitterionic resin (1), and the composition was sufficiently stirred. I got something. This was designated as metal surface coating agent (L).

Examples 1 to 12 An electrogalvanized steel sheet having a thickness of 0.5 mm was degreased, washed with water and dried to obtain a test plate. As shown in Table 1, the metal surface coating agents (A) to (L) of the present invention were applied to this steel sheet so as to have a predetermined film thickness after drying with a bar coater, respectively.
Heat drying was performed in a hot air dryer at 150 ° C. for 1 minute to obtain a surface coated plate. The final temperature of the test plate at this time was 120
° C. To see the corrosion resistance of these surface coated plates,
A salt spray test according to JIS-Z2371 was performed, and the evaluation was made at a time when the area ratio of white rust was 5% or more. In addition, in order to check the adhesion, a cross-cut tape peeling test with a clearance of 1 mm according to JIS-K5400 was performed, and the evaluation was made out of 10 points.

[0093]

[Table 1]

Comparative Preparation Example 1 A composition comprising 100 parts of a water-dispersible zwitterionic resin (1) was used as a comparative metal surface coating agent (M). Comparative Preparation Example 2 A composition comprising the water-dispersible anionic resin (3) 100 was used as a comparative metal surface coating agent (N). Comparative Preparation Example 3 85 parts per 100 parts of the water-dispersible zwitterionic resin (1)
% Phosphoric acid is added and stirred sufficiently to obtain p
A composition having an H of about 3 was obtained. This was used as a comparative metal surface coating agent (O). Comparative Preparation Example 4 To 100 parts of the water-dispersible zwitterionic resin (1), 4 parts of Epocross WS-500 (trade name, manufactured by Nippon Shokubai) as a polyfunctional crosslinking agent was added, and the composition was sufficiently stirred. I got something. This was used as a comparative metal surface coating agent (P).

Comparative Examples 1 to 4 Comparative metal surface coating agents (M) to
After obtaining a surface-coated plate in the same manner as in the example except that (P) was used, the performance was evaluated by the same method as in the example.

Table 2 shows the evaluation results of the comparative examples. As is clear from the evaluation results, the metal plate coated with the metal surface coating agent containing the metal surface coating composition of the present invention has sufficient corrosion resistance and excellent adhesion.

[0097]

[Table 2]

[0098]

The composition for coating a metal surface according to the present invention has the above-mentioned constitution, so that the coating is excellent in basic properties such as adhesion and corrosion resistance, and can be sufficiently thinned. It can be applied to various uses such as agents, primer coatings, and PCM coatings. Since the metal surface coating agent of the present invention has the above-described configuration, it is possible to suppress the production cost by eliminating the need for chemical conversion treatment on the metal surface, to suppress environmental pollution, and to perform a rust prevention treatment. It is capable of enabling electric welding of a steel sheet and improving workability. Further, a coated steel sheet having excellent corrosion resistance and basic performance can be produced.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4J038 CG141 CK021 CQ011 CR071 DB002 DB382 DB391 DD001 DF021 DG001 DG012 DG061 DG302 DH021 DJ002 DJ011 DL022 GA06 GA09 HA406 HA416 HA426 HA446 JA07 JA34 JC24 NA03 NA12 NA27 PA19 A02A02A BA01 BA03 BB06 BB08 BB10 CA16 CA23 CA26 CA37 CA38 CA39 CA41 4K044 AA02 AB02 BA10 BA14 BA17 BA21 BB03 BC02 BC05 CA16 CA18 CA53

Claims (4)

[Claims] 1. A cationic resin and / or amphoteric resin (I), a phosphate compound (II) and a polyfunctional crosslinking agent (II)
A metal surface coating composition comprising I), wherein the content of the phosphoric acid compound (II) is based on 100 parts by weight of a non-volatile content of the cationic resin and / or the amphoteric resin (I).
0.5 to 50 parts by weight, and the content of the polyfunctional crosslinking agent (III) is 0.5 to 0.5 parts by weight with respect to 100 parts by weight of the nonvolatile content of the cationic resin and / or the amphoteric resin (I). ~ 30
A composition for coating a metal surface, which is in parts by weight. 2. The cationic resin and / or amphoteric resin (I) includes a resin having at least one of a primary amino group and a secondary amino group in a side chain. Item 4. The composition for coating a metal surface according to Item 1. 3. A water-dispersible silica (IV), and
It contains at least one of a tri- and / or dialkoxysilane compound or a hydrolyzate (V) thereof, and the content of the water-dispersible silica (IV) is at least one of a cationic resin and / or
Alternatively, the content of the tri- and / or dialkoxysilane compound or its hydrolyzate (V) is 5 to 30 parts by weight with respect to 100 parts by weight of the nonvolatile content of the amphoteric resin (I). claim, characterized in that with respect to nonvolatile content 100 parts by weight of the sex resin and / or zwitterionic resin (I), from 5 to 30 parts by weight in terms of SiO ₂ 1
Or the composition for coating a metal surface according to 2. 4. A metal surface coating agent comprising the metal surface coating composition according to claim 1, 2 or 3.