JPH10110093A - Water-base urethane resin composition and water-base metal-surface-treating composition containing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a metal-surface-treating compsn. which is satisfactory in both corrosion resistance and adhesion to a coating film by using a water-base dispersion of a urethane resin which has a specific backbone and is produced from a urethane prepolymer derived from a specific polyol. SOLUTION: This compsn. is a water-base dispersion compsn. of a prim.- amine-terminated urethane resin. The urethane resin is formed by reacting an active hydrogen component (a) comprising a polyol compd. (a1 ) having an average mol.wt. of 300 or higher, a dimethylolalkanoic acid (a2 ), and a compd. (a3 ) having at least three active hydrogen atoms with an org. polyisocyanate compd. (b) and reacting the resultant isocyanate-terminated urethane prepolymer with a polyamine compd. having at least tow prim-amino groups in a molar amt. of the prim-amino group of the polyamine higher than that of the isocylanate group of the prepolymer. Reactant a1 essentially contains a hydroxyl- terminated polyester polyol obtd. from an aliph. polyhydric alcohol and a polycarboxlic acid and a bisphenol-backbone-contg. diol compd. represented by the formula (wherein R<1> and R<2> are each H or lower alkyl; A is 2-4C alkylene; and m and n are each 1-20).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an aqueous urethane resin composition and a metal surface treatment composition containing the same and having excellent corrosion resistance and coating adhesion.

[0002]

2. Description of the Related Art Conventionally, zinc or zinc-based alloy-plated steel sheets have been widely used for home appliances and building materials. Since these steel sheets have insufficient corrosion resistance and paintability as they are, they are conventionally subjected to chromate chemical conversion treatment and phosphate chemical conversion treatment, followed by forming and painting such as pressing and bending. It is often applied, but depending on the application and purpose of use, there are many cases where it is used without painting. In a chromate-treated steel sheet, the corrosion resistance, color tone, fingerprint adhesion, and the like of a chromate film covering the steel sheet are regarded as important. In addition, depending on the application to be coated, in addition to the above-mentioned required performance, high coating adhesion to a top coat is required. Among these required performances, for example, an improvement in corrosion resistance can be dealt with by increasing the thickness of the chromate film, but the thickened chromate film thus obtained exhibits a unique yellow color of the chromate film. Therefore, there is a problem in color tone.

In order to solve these problems, in recent years, Japanese Patent Application Laid-Open Nos. 63-143265 and 3-1
No. 7189, JP-A-4-71840, JP-A-5-16
1874, JP-A-6-145559 and JP-A-6-166735 disclose various means.

Japanese Patent Laid-Open No. 63-143265 discloses that methanol, methanol,
A CrO ₃ reducing agent such as ethylene glycol, and phosphoric acid,
An acid group such as boric acid, a resin such as an acrylic resin, at least one of silica such as colloidal silica, is subjected to chromate treatment using a chromate treatment solution, and then, on this chromate film, acrylic, polyethylene, or A resin such as epoxy is baked at a baking temperature of 150 ° C. or less.
A method of baking with a thickness of 5 to 3 μm is disclosed.
However, the effect of improving the corrosion resistance of the surface coating layer obtained by this method was unsatisfactory.

JP-A-3-17189 discloses a resin film in which fluorine resin particles and silica particles are mixed with a urethane-modified polyolefin resin. However, since no crosslinking agent was used in this resin film, its corrosion resistance was insufficient.

[0006] The resin film layer disclosed in Japanese Patent Application Laid-Open No. 4-71840 has a chromate film layer having a specific adhesion amount and an organic resin film layer containing Ni powder on a galvanized or zinc-based alloy-plated steel sheet. They are coated in order. This resin film layer has a resin film thickness of 0.5 to 1.
Since it contains Ni powder having a particle size five times as much as 10 to 80 vol%, its weldability is excellent.
Moisture easily penetrated from the interface with the powder, and the resulting product was unsatisfactory in corrosion resistance and paint adhesion.

JP-A-5-161874 discloses a steel sheet in which a solvent-based thermosetting resin is formed on a chromate film of a galvanized steel sheet at a thickness of 0.3 to 3.0 μm per one side of the steel sheet. ing. As the solvent-based thermosetting resin, a hydroxyl group-containing urethane prepolymer obtained by using at least one polyol selected from a polyether polyol, a polyester polyol, and a polyether polyester polyol is used. In this case, since the resin used is a solvent-based resin, the composition is clearly different from the aqueous metal surface treatment composition of the present invention, and various problems (for example, environmental problems, drainage problems, cost problems, and the like) associated with the solvent are caused. ).

Japanese Patent Application Laid-Open No. 145559/1994 discloses an aqueous coating composition containing an aqueous urethane resin as a main component. The aqueous urethane resin used in the aqueous coating composition is a water-dispersible ether / ester type urethane resin having a bisphenol type skeleton, an ester skeleton and a carboxyl group and having an average molecular weight of 3000 or more, and a resin film formed therefrom. Were not always satisfactory.

JP-A-6-166735 discloses a water-based coating composition obtained by crosslinking a polyurethane emulsion having a primary amino group at a terminal with a water-soluble epoxy crosslinking agent. Since silica was not blended as a rust preventive pigment, the corrosion resistance of the resulting resin film was unsatisfactory.

In general, the corrosion resistance of the above-mentioned conventional surface-treated steel sheet largely depends on the water resistance and adhesion of the organic resin film. Therefore, in order to improve the water resistance of the resin film, it is necessary to include a hydrophobic portion in the resin. It is necessary to increase the ratio or use a crosslinking agent to minimize the influence of the hydrophilic portion. However, when the hydrophobic portion is increased, the resin tends to gel at the stage of conversion to an aqueous system, which tends to make the resin unusable. On the other hand, when a cross-linking agent is used, a long time and a high reaction temperature are required to perform sufficient cross-linking, but in many cases, the baking time of the surface-treated steel sheet paint is 30 seconds or less, With such a crosslinking treatment in a short time, it is difficult to sufficiently bring out the inherent performance of the resin.

[0011]

As shown in the above-mentioned summary of the prior art, a metal surface treatment composition which simultaneously satisfies both excellent corrosion resistance and solvent resistance within a short baking time of 30 seconds or less is required. Not yet obtained. In addition, there is a strong demand for the use of a solvent-based treatment agent in an aqueous system in order to improve the paint coating work environment. The present invention solves these problems,
An object of the present invention is to provide an aqueous urethane resin composition having excellent corrosion resistance and coating adhesion, and a metal surface treatment composition containing the same.

[0012]

Means for Solving the Problems The present inventors have conducted extensive studies on an aqueous polyurethane composition which simultaneously satisfies both the corrosion resistance and the paint adhesion performance, and a metal surface treatment composition containing the same. The present inventors have found that the above problems can be solved mainly by specifying the skeleton of the urethane resin, and have completed the present invention. That is, the aqueous urethane resin composition of the present invention has (I) an average molecular weight of 3
A urethane prepolymer obtained by reacting a polyol compound of at least 00, dimethylolalkanoic acid, a compound having three or more active hydrogens, and an organic polyisocyanate compound, and having a terminal isocyanate group,
(II) a polyamine compound having two or more primary amino groups, wherein the molar amount of the primary amino groups of the polyamine compound (II) is excessive relative to the molar amount of the isocyanate groups of the urethane prepolymer (I). A urethane resin obtained by reacting at a ratio and having a primary amino group at a terminal, and an aqueous medium for dispersing the same,
The polyol compound used for preparing the urethane prepolymer (I) is obtained from an aliphatic polyhydric alcohol and a polycarboxylic acid, and is represented by the following general formula (I) and a polyester polyol having a hydroxyl group at a terminal. Diol compounds containing a bisphenol skeleton:

Embedded image [However, in the above formula (I), R ¹ and R ² each independently represent a hydrogen atom or a lower alkyl group;
A represents an alkylene group having 2 to 4 carbon atoms, and m and n each independently represent an integer of 1 to 20. ] As an essential component. Further, the water-based metal surface treatment composition of the present invention having excellent corrosion resistance and coating adhesion, comprises (a) the water-based urethane resin composition of the present invention, (b) a curing agent,
(C) silica, wherein the total solid content of the components (a) and (b) is 50 to 97% based on the total solid weight of the components (a), (b) and (c). And
The solid content of the component (c) is 3 to 50% based on the total weight of the solid components (a), (b) and (c). Further, the aqueous metal surface treatment composition of the present invention further comprises:
(A) A polyolefin wax having a saponification value of 0 or 30 or less can be contained in a proportion of 1 to 30% by weight based on the total solid weight of the components (a) to (d).

Hereinafter, the configuration of the present invention will be described in detail. The aqueous metal surface treatment composition of the present invention has a skeleton structure in which the base resin contained therein, that is, the urethane resin in the aqueous urethane resin composition of the present invention has a side chain, and such a skeleton structure is a specific type. It is characterized by being obtained by mixing and reacting reaction components at a constant weight ratio. As the resin component used in the aqueous metal surface treatment composition of the present invention, it is necessary to select an aqueous urethane resin composition component (a) having a good balance of corrosion resistance, coating adhesion, solvent resistance, and chemical resistance. . Further, in order to satisfy these performances, the aqueous urethane resin composition (a) of the present invention is required.
In addition, it is necessary to use a combination of other specific components (b) and (c) and (d) if necessary.

In order to obtain a film having high corrosion resistance and high coating adhesion, it is necessary that the coating is uniform and has excellent adhesion to the metal surface, and that the obtained film has a sufficient network. It is important that the structure is formed. For this purpose, it is necessary to use a resin having a specific structure and a curing agent together. The base aqueous urethane resin composition comprises, as essential components, a polyester polyol having a hydroxyl group at a terminal obtained from an aliphatic polyhydric alcohol and a polycarboxylic acid, and a bisphenol skeleton-containing diol compound represented by the general formula (I). And a compound having an average molecular weight of 300 or more, dimethylolalkanoic acid, a compound having three or more active hydrogens, and an organic polyisocyanate compound. In this hydrogen urethane resin composition, a urethane prepolymer (I) having an isocyanate group at a terminal and a polyamine compound (II) having at least two primary amino groups are combined with the terminal isocyanate of the urethane prepolymer (I). A urethane resin obtained by reacting the polyamine compound (II) in a ratio such that the molar amount of the primary amino group is excessive with respect to the molar amount of the group, and having a primary amino group at the terminal is converted into an aqueous medium. It is emulsified and dispersed.

The polyester polyol compound used for producing the aqueous urethane resin composition used in the present invention is, for example, ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol. , Neopentyl glycol, 1,2-butylene glycol,
Low molecular weight polyols such as 1,3-butylene glycol, 1,4-butylene glycol, 3-methylpentanediol, hexamethylene glycol, hydrogenated bisphenol A, trimethylolpropane, and glycerin; and, for example, succinic acid, glutaric acid, adipine Acid, sebacic acid,
It is obtained by reaction with polybasic acids such as phthalic acid, isophthalic acid, terephthalic acid, trimellitic acid, tetrahydrophthalic acid, endmethylenetetrahydrophthalic acid, and hexahydrophthalic acid, and has a hydroxyl group at its terminal. It is selected from those having.

These polyester polyol compounds are contained in the polyol compound component in an amount of 2 to the total amount.
It is preferably contained at a ratio of 5 to 95% by weight, particularly 50 to 90% by weight, and when the content ratio is out of the above range, the corrosion resistance and adhesion of the obtained resin film become insufficient. Sometimes.

The bisphenol skeleton-containing glycol of the general formula (I) used for producing the aqueous urethane resin composition of the present invention includes methylene bisphenol,
Bisphenols in which R ¹ and R ² in formula (I) are lower alkyl groups, such as ethylidene bisphenol, butylidene bisphenol, isopropylidene bisphenol, etc., are added to alkylene oxides having 2 to 4 carbon atoms (eg, ethylene oxide, propylene). Oxide and butylene oxide), and the addition mole number of the alkylene oxide represented by m and n is 1 to 20, preferably 1 to 10. m and n are 20
When the content exceeds 2, the content ratio of the alkylene oxide component becomes excessively large, and the effect of improving the anticorrosion property of the obtained resin film becomes insufficient.

The bisphenol skeleton-containing glycol of the formula (I) is used in an amount of 5 to 5% based on the total amount of the polyol compound components.
It is preferable to use 75% by weight, preferably 10 to 50% by weight. When the above ratio is out of the above range, the corrosion resistance and adhesion of the obtained resin film may be insufficient.

It is also possible to use other polyol compounds in combination with the polyester polyol and the bisphenol skeleton-containing polyol in the polyol compound component, and in some cases, it is obtained by using such other polyols in combination. The adhesiveness and corrosion resistance of the resin film may be further improved.

Examples of these other polyol compounds include ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, neopentyl glycol, 1,2-butylene glycol, 1,3 -Low molecular weight polyols such as butylene glycol, 1,4-butylene glycol, 3-methylpentanediol, hexamethylene glycol, hydrogenated bisphenol A, trimethylolpropane, and glycerin, compounds and ethylene oxide and / or propylene of these polyethylene compounds Highly adduct of oxide, polyether polyol such as polyethylene glycol, polypropylene glycol, polyethylene / propylene glycol, polycaprolactone polyol , Polyolefin polyols, and polybutadiene polyol, and the like.

These other polyol compounds can be used in a proportion of less than 40% by weight, especially less than 30% by weight, based on the total amount of the polyol compound components.

Examples of the dimethylolalkanoic acid for preparing the urethane prepolymer (I) include 2,2-dimethylolpropionic acid, 2,2-dimethylolbutyric acid, and 2,2-dimethylolvaleric acid. The dimethylol alkanoic acid is neutralized with a neutralizing agent to prepare a self-emulsifying aqueous resin emulsified dispersion. These dimethylol alkanoic acids are 1 to 30% by weight based on the solid content of the urethane prepolymer (I).
Used in the amount used. If it is less than 1% by weight, the self-emulsifiability of the urethane resin may be insufficient, and if it exceeds 30% by weight, physical properties such as elongation of the obtained resin film become insufficient. Sometimes.

Examples of the neutralizing agent for dimethylolalkanoic acid include organic amines such as trimethylamine, triethylamine, tripropylamine, tributylamine, N-methyldiethanolamine and triethanolamine, and sodium hydroxide, water and the like. Examples include inorganic bases such as potassium oxide and ammonia, which are used in an amount sufficient to neutralize carboxyl groups.

In the present invention, the compound having at least three active hydrogens used for preparing the urethane prepolymer (I) has a urethane resin side chain to improve the strength, adhesion and corrosion resistance of the coating film. Is used to cause, for example, melamine, diethylenetriamine, trimethylolpropane, pentaerythritol,
Glycerin, or their low ethylene oxide and / or propylene oxide addition products having a molecular weight of less than 300, etc. In particular, when melamine is used, the effect of improving the performance of the obtained resin film is remarkable. .

These compounds having at least three active hydrogens are used in an amount of 0.1 to 10% by weight based on the solid weight of the urethane prepolymer (I). When the amount is less than 0.1% by weight, the effect of improving the performance of the obtained resin film is hardly recognized, and when it exceeds 10% by weight, the physical properties such as elongation of the obtained resin film are reduced. There is a risk of lowering.

When the urethane prepolymer (I) is produced, it is of course possible to add a commonly used low molecular weight compound having two active hydrogens (chain extender), if necessary. Examples of such a chain extender include polyols such as ethylene glycol, propylene glycol, neopentyl glycol, hexamethylene glycol and their ethylene oxide and / or low propylene oxide adducts: ethylene diamine, propylene diamine, hexamethylene diamine,
Those having a molecular weight of less than 300 such as amines such as tolylenediamine, xylylenediamine, diaminodiphenylmethane, diaminocyclohexylmethane, piperazine, 2-methylpiperazine, isophoronediamine, succinic dihydrazide, adipic dihydrazide, and phthalic dihydrazide. . The amount of these chain extenders varies depending on the molecular weight of the target polyurethane resin,
Usually, 10% by weight based on the weight of the prepolymer (I)
It is used in the following ratio.

In the present invention, examples of the organic polyisocyanate compound used for producing the urethane prepolymer (I) include aliphatic, alicyclic and aromatic polyisocyanates, preferably tetramethylene diisocyanate. Hexamethylene diisocyanate, lysine diisocyanate ester, hydrogenated xylylene diisocyanate, 1,4-cyclohexylene diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, 2,4'-dicyclohexylmethane diisocyanate, isophorone diisocyanate, 3,3 '
-Dimethoxy-4,4'-biphenylene diisocyanate, 1,5-nephthalenediisocyanate, 1,5-tetrahydronaphthalenediisocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 4,4'-diphenylmethane diisocyanate ,
2,4'-diphenylmethane diisocyanate, phenylene diisocyanate, xylylene diisocyanate,
And tetramethylxylerin diisocyanate. Among these, tetramethylene diisocyanate, hexamethylene diisocyanate, lysine diisocyanate ester, hydrogenated xylylene diisocyanate, 1,4-cyclohexylene diisocyanate,
4,4'-dicyclohexylmethane diisocyanate,
2,4'-dicyclohexylmethane diisocyanate,
When an aliphatic or alicyclic polyisocyanate compound such as isophorone diisocyanate or the like is used, a resin film excellent in weather resistance as well as chemical resistance and corrosion resistance can be obtained.

These organic polyisocyanate compounds include a polyol compound used for the production of the urethane prepolymer (I), dimethylolalkanoic acid, a compound having at least three active hydrogens, and a chain extender used if necessary. To the total amount of active hydrogen contained in
It is used so that it becomes equivalent or more, preferably 1.1 to 2 times equivalent. When the amount of the organic isocyanate compound used is less than 1 equivalent, since there is almost no isocyanate group remaining at the terminal of the molecule of the obtained urethane prepolymer (I), it is impossible to introduce an amino group at the molecular terminal. When it is more than twice equivalent, unreacted polyisocyanate groups remain in the molecule of the obtained urethane prepolymer (I).
When water is added, the urea bond is excessively formed or a low molecular weight product is generated in a large amount, which may deteriorate the properties of the obtained urethane prepolymer (I).

The urethane prepolymer (I) used for producing the aqueous urethane resin composition used in the present invention can be produced by reacting the above-mentioned raw material components in a solvent by a known method. . It is also possible to appropriately change the order of charging these raw material components, or to divide and charge them.

The solvent used for producing the urethane prepolymer (I) is preferably an organic solvent which is inert to the reaction and has a high affinity for water, for example, acetone, methyl ethyl ketone, dioxane, tetrahydrofuran, N- Methyl-2-pyrrolidone, dimethylformamide, dimethylacetamide, dimethylsulfoxide,
And ethyl acetate. These solvents are usually used in an amount of 10 to 100% by weight based on the weight of the raw material components used for producing the urethane prepolymer (I).
Used in the ratio of

Further, in the present invention, the urethane prepolymer (I) produced by the above-mentioned method is reacted with the polyamine compound (II) to introduce a primary amino group into the terminal of the resulting urethane resin molecule. Polyamine compound (I
As I), for example, ethylenediamine, propylenediamine, hexamethylenediamine, diethylenetriamine, triethylenetetramine, xylylenediamine,
Diaminodiphenylmethane, diaminocyclohexylmethane, piperazine, 2-methylpiperazine, isophoronediamine, melamine, succinic dihydrazide, adipic dihydrazide, and phthalic dihydrazide.In particular, when a dihydrazide compound of a dibasic acid is used, A resin film having excellent properties such as adhesion, corrosion resistance and strength can be obtained.

The above-mentioned polyamine compound (II) is used for the chain extension of urethane prepolymer (I) and the introduction of amino groups.
Such a polyamine compound (II) is used in an amount of at least an equivalent, preferably 1.05 to 2 times equivalent to the isocyanate group remaining in the urethane prepolymer (I). Used. If the amount used is less than 1 equivalent, free amino groups are hardly introduced into the obtained polyurethane, and if it is used in excess of 2 equivalents, an unreacted polyamine compound will remain. The performance of the obtained polyurethane may be adversely affected.

As a method of reacting the urethane prepolymer (I) with the polyamine compound (II), a well-known method for producing an aqueous urethane resin can be used. For example, the urethane prepolymer (I) ) Is dispersed in water and then a polyamine compound is added thereto to cause a reaction, and a urethane prepolymer (I) is added to an aqueous solution of the polyamine compound (II) and the two are reacted while dispersing them. And the polyamine compound (II) may be added all at once or may be added in portions.

The aqueous urethane resin emulsified dispersion of the present invention thus obtained usually has a resin solid content of 5%.
It is adjusted so as to be ~ 80% by weight, preferably 10-70% by weight. When the content of the resin solid content is less than 5% by weight, the resin composition contains a large amount of water, so that it takes a long time to dry the obtained coating film,
If it exceeds 80% by weight, the resulting composition tends to have a high viscosity and its handling tends to be difficult.

The aqueous urethane resin composition used in the present invention may contain a thioether-based antioxidant and / or a benzotriazole-based or benzophenone-based ultraviolet absorber, if necessary.

The water-based urethane resin composition (a) used in the present invention undergoes some self-crosslinking upon heating, but the crosslinking is insufficient, so that the resulting resin film has insufficient corrosion resistance and solvent resistance. Therefore, in the aqueous metal surface treatment composition of the present invention, the curing agent (b) is added thereto.
The curing agent (b) is selected from epoxy compounds, amines, polyhydric alcohols, polybasic acids, isocyanate compounds and the like. However, in order to obtain a resin film having better corrosion resistance and solvent resistance, as a curing agent, at least one or more functional groups selected from an epoxy group, an oxazoline group, an alkoxysilyl group, an isocyanate group and an aziridinyl group. It is more preferable to use a crosslinkable compound having: Other curing agent compounds such as amines, polyhydric alcohols, and polybasic acids have strong hydrophilic functional groups (amino group, hydroxyl group, carboxyl group, etc.), and thus the water resistance of the obtained resin film. Becomes insufficient. When an epoxy resin is used as the curing agent, the chemical resistance and coating adhesion of the obtained film are improved due to the chemical resistance and adhesiveness of the epoxy resin itself. Also, when a curing agent containing an oxazoline-based, alkoxysilyl-based, isocyanate-based, or aziridinyl-based compound is used, the same effect as that of the epoxy resin can be expected.

The amount of the curing agent (b) is determined according to the functional group (amino group, amino group, etc.) of the urethane resin in the urethane resin emulsified dispersion (a).
The equivalent ratio of the carboxyl group, hydroxyl group, etc.) to the functional group of the curing agent (equivalent of the functional group of the curing agent / equivalent of the functional group of the urethane resin) is 1/10 to 1/1, and the weight of the total solid content Curing agent (b) for ((a) + (b) + (c))
Is preferably 2 to 30% by weight. If the equivalent ratio is less than 1/10, or if the content of the curing agent (b) is less than 2% of the total solid weight ((a) + (b) + (c)), the effect of the curing agent (b) will not be obtained. Poor, and when the equivalent ratio exceeds 1/1, or when the content of the curing agent (b) exceeds 30% of the total solid content ((a) + (b) + (c)),
The characteristics of the aqueous urethane resin composition (a) of the present invention cannot be sufficiently exhibited, and an excess curing agent that has not reacted with the urethane resin remains and acts as a plasticizer for the urethane resin. Therefore, the corrosion resistance and coating adhesion of the obtained resin film become insufficient.

The total solid content of the components (a) + (b) with respect to the total solid weight (a) + (b) + (c) of the aqueous metal surface treatment composition is preferably 50 to 97%. . If the total content is less than 50%, the resulting resin film has insufficient corrosion resistance and coating adhesion. Also, when it exceeds 97%, a resin film having high corrosion resistance cannot be obtained.

In the aqueous metal surface treatment composition of the present invention,
To improve the corrosion resistance of the obtained resin film, silica (S
iO ₂ ) (c) by the total solid content weight ((a) + (b) +
It is contained at a ratio of 3 to 50% with respect to (c)). If the weight percentage of the solid content of silica (c) relative to the total weight of the solid content ((a) + (b) + (c)) is less than 3%, the effect of improving the corrosion resistance of the resulting resin film becomes insufficient, and it is 5%.
If it exceeds 0%, the binder effect of the resin component (a) and the curing agent component (b) becomes insufficient, and the corrosion resistance of the obtained resin film becomes insufficient. The particle size and type of the silica particles are not particularly limited in the present invention,
The particle size is preferably from 2 to 50 nm, and the type is preferably selected from gas-phase silica, silica sol and the like.

The aqueous metal surface treatment composition of the present invention comprises a surfactant called a wettability improver for obtaining a uniform film on the surface to be coated, a thickener, a conductive substance for improving weldability, Further, a coloring pigment or the like for improving the design can be contained.

Further, by adding a lubricating additive to the aqueous metal surface treatment composition of the present invention, the resulting surface-treated metal material can be formed without using press oil or the like. Further, such a treatment composition can be suitably applied to a surface-treated steel sheet that does not require a degreasing step and a coating base treatment. As a lubricating additive having such an effect,
Examples include inorganic solid lubricants such as graphite and molybdenum disulfide, and organic lubricants such as natural wax and synthetic wax. In the aqueous metal surface treatment composition of the present invention, the component (a), (b) and (c) has, as an additional component (d), a saponification value of 0 or 30 or less, preferably having a branched structure. The polyolefin wax can be contained at a ratio of 1 to 30% by weight based on the total solid weight of the components (a) to (d). When the saponification value exceeds 30, the resulting polyolefin wax has a high polarity and is easily compatible with the urethane resin component (a), so that it is difficult to distribute on the resin surface during film formation. In some cases, the desired performance may not be achieved if necessary. In addition, since the water resistance and coating adhesion of the obtained resin film become insufficient, it cannot be said that the resin film is suitable for the above use. More preferred as a lubricating additive does not have an ester bond having low compatibility with the resin component,
It is a polyolefin wax having a saponification value of 0. When the amount of the polyolefin wax (d) is less than 1% by weight, the effect of improving the moldability of the resin film by adding it is small, and when it exceeds 30% by weight, Since the wax is scattered to the press device and its periphery during the molding process, it is not preferable in the working environment, and the obtained resin film has insufficient corrosion resistance. The average particle size of the polyolefin wax (d) is 0.1 to 7.0 μm.
m is preferable. When the average particle size is less than 0.1 μm, the workability of the obtained resin film is insufficient, and when it exceeds 7.0 μm, the solidified polyolefin wax in the obtained resin film (d) Is not preferable because the distribution becomes uneven. As the shape of the wax particles, a true spherical shape is preferable in order to obtain high workability.

Examples of the metal material to which the aqueous metal surface treatment composition of the present invention is applied include a cold-rolled steel sheet, a galvanized steel sheet or an aluminum sheet. In order to improve the corrosion resistance, it is effective to perform a base treatment on the surface of the metal material. As such a base treatment, a known chromate treatment or phosphate treatment is appropriate. A coating containing the aqueous metal surface treatment composition of the present invention is applied on these base coats to form a coat of 0.3 to 6 g / m ² , and to impart properties such as corrosion resistance and solvent resistance. Is preferred. Examples of the method of applying the paint include a roll coater method, a dipping method, and an electrostatic coating method, but the present invention is not particularly limited to these.

[0043]

The present invention will be further described with reference to the following examples and comparative examples. The aqueous urethane resin compositions used in the following Examples and Comparative Examples were produced as follows.

1. Examples of Production of Aqueous Urethane Resin Composition for Examples Production Example 1 A mixture of isophthalic acid / adipic acid (molar ratio 1/1) as a dibasic acid component and 1,6- as a glycol component
100 parts of a polyester polyol obtained using hexanediol and having a terminal hydroxyl group and having an average molecular weight of 2,000, 50 parts of a bisphenol A propylene oxide adduct having an average molecular weight of 660, 15 parts of 2,2-bis (hydroxymethyl) propionic acid, and Five parts of melamine were mixed and the mixture was heated to 90 ° C to prepare a solution therefrom. Next, 110 parts of dicyclohexylmethane diisocyanate and N-methyl-2-
Mix 110 parts of pyrrolidone and mix the mixture up to 120 parts.
The mixture was stirred for 5 hours while being heated to ℃ to produce a prepolymer having an isocyanate group content of 2.6%, and neutralized by adding 14 parts of triethylamine. Separately, 5 parts of ethylenediamine and 20 parts of adipic dihydrazide were dissolved in 580 parts of deionized water, and the solution was heated to 40 ° C. The neutralized prepolymer is dropped into the solution while maintaining the temperature, whereby the solid content concentration is 31%.
A water-based urethane resin emulsion was obtained.

Production Example 2 A mixture of isophthalic acid / adipic acid (molar ratio 1/1) was used as the dibasic acid component, and 1,6 was used as the glycol component.
30 parts of a polyester polyol having an average molecular weight of 2000, obtained using -hexanediol and having a terminal hydroxyl group, 100 parts of a propylene oxide adduct of bisphenol A having an average molecular weight of 800, 2,2-bis (hydroxymethyl) propionic acid 12 Part, melamine 5
The parts were mixed and heated to 90 ° C. to form a solution therefrom. Next, 110 parts of dicyclohexylmethane diisocyanate and 100 parts of N-methyl-2-pyrrolidone are added to the solution, and heated to a maximum of 120 ° C. for 5 minutes.
After stirring for an hour, a prepolymer having an isocyanate content of 3.0% was produced, and neutralized by adding 10 parts of triethylamine. Separately, 5 parts of ethylenediamine, 2 parts of diethylenetriamine, and 17 parts of adipic dihydrazide were dissolved in 620 parts of deionized water. Heat this solution to 40 ° C.
While maintaining this temperature, the neutralized prepolymer / triethylamine mixture is added dropwise to the solution,
An aqueous urethane resin emulsion having a solid content of 29% was obtained.

Production Example 3 A mixture of isophthalic acid / adipic acid (molar ratio: 1/1) was used as the dibasic acid component, and 1,6 was used as the glycol component.
100 parts of a polyester polyol having an average molecular weight of 2,000 and having a terminal hydroxyl group, obtained using hexanediol, 70 parts of a propylene oxide adduct of bisphenol A having an average molecular weight of 1,000, 2,2-bis (hydroxymethyl) propionic acid 11 And 4 parts of melamine, and the mixture was heated to 90 ° C. and dissolved. Next, isophorone diisocyanate 85 was added to this solution.
And 100 parts of N-methyl-2-pyrrolidone, and stirred for 5 hours while heating up to 120 ° C. to produce a prepolymer having an isocyanate content of 2.9%, and 10 parts of triethylamine was added thereto. Neutralized. Separately, 6 parts of ethylenediamine and 25 parts of adipic dihydrazide were dissolved in 640 parts of deionized water. The solution was heated to 40 ° C., and the neutralized prepolymer / triethylamine mixture was dropped into the solution while maintaining the temperature, whereby an aqueous urethane resin emulsion having a solid concentration of 30% was obtained.

Production Example 4 A mixture of isophthalic acid / adipic acid (molar ratio 1/1) was used as the dibasic acid component, and 1,6 was used as the glycol component.
100 parts of a polyester polyol having an average molecular weight of 1500 and having a terminal hydroxyl group, obtained using hexanediol, and bisphenol A having an average molecular weight of 580
50 parts of propylene oxide adduct, 16 parts of 2,2-bis (hydroxymethyl) propionic acid, melamine 4
The parts were mixed and heated to 90 ° C. to dissolve. Next, 100 parts of isophorone diisocyanate and N
-Methyl-2-pyrrolidone 110 parts, add up to 12
The mixture was stirred for 5 hours while heating to 0 ° C. to produce a prepolymer having an isocyanate content of 3.4%, and neutralized by adding 13 parts of triethylamine. Separately, 3 parts of ethylenediamine and 20 parts of adipic dihydrazide were added to deionized water 5
Dissolved in 50 parts. The solution was heated to 40 ° C., and the neutralized prepolymer / triethylamine mixture was dropped into the solution while maintaining the temperature, thereby obtaining an aqueous urethane resin emulsion having a solid concentration of 31%.

Production Example 5 A mixture of isophthalic acid / adipic acid (molar ratio 1/1) was used as the dibasic acid component, and 1,6-
100 parts of a polyester polyol obtained using hexanediol and having a terminal hydroxyl group and having an average molecular weight of 2000, 60 parts of a propylene oxide adduct of bisphenol A having an average molecular weight of 580, and 16 parts of 2,2-bis (hydroxymethyl) propionic acid , And 4 parts of melamine were mixed and dissolved by heating to 90 ° C. Next, 100 parts of isophorone diisocyanate and 100 parts of N-methyl-2-pyrrolidone were added to the solution, and a maximum of 1 part was added.
The mixture was heated to 20 ° C. and stirred for 5 hours to produce a prepolymer having an isocyanate content of 2.4%, and neutralized by adding 13 parts of triethylamine. Separately, 3 parts of ethylenediamine, 1 part of diethylenetriamine, and 18 parts of adipic dihydrazide were dissolved in 500 parts of deionized water. This solution was heated to 40 ° C., and while maintaining this temperature, the above-mentioned neutralized prepolymer / triethylamine mixed solution was dropped into the solution, whereby an aqueous urethane resin emulsion having a solid content concentration of 34% was obtained. Was.

Production Example 6 A mixture of isophthalic acid / adipic acid (molar ratio 1/1) was used as the dibasic acid component, and 1,6-
50 parts of a polyester polyol obtained using hexanediol and having a terminal hydroxyl group and having an average molecular weight of 1000, 50 parts of a propylene oxide adduct of bisphenol A having an average molecular weight of 660, and 15 parts of 2,2-bis (hydroxymethyl) propionic acid And 5 parts of melamine, and the mixture was heated to 90 ° C. to prepare these solutions. Next, 110 parts of dicyclohexylmethane diisocyanate and 110 parts of N-methyl-2-pyrrolidone are added to this solution, and the mixture is stirred for 5 hours while heating to a maximum of 120 ° C. to give a preform having an isocyanate content of 2.8%. A polymer was prepared and neutralized by adding 14 parts of triethylamine. Separately ethylenediamine 5
Parts, adipic dihydrazide 20 parts by deionized water 480
Dissolves in the part. The solution is heated to 40 ° C., and the above-mentioned neutralized prepolymer / triethylamine mixture is dropped into the solution while maintaining the temperature, thereby obtaining an aqueous urethane resin emulsion having a solid content of 31% by weight. Was.

Production Example 7 A mixture of isophthalic acid / adipic acid (molar ratio 8/2) was used as the dibasic acid component, and 1,6-
100 parts of a polyester polyol obtained using hexanediol and having a terminal hydroxyl group and having an average molecular weight of 2,000, 50 parts of a propylene oxide adduct of bisphenol A having an average molecular weight of 660, and 15 parts of 2,2-bis (hydroxymethyl) propionic acid And melamine 5
Parts were mixed and the mixture was heated to 90 ° C. to prepare these solutions. Next, 110 parts of dicyclohexylmethane diisocyanate and N-methyl-2-
110 parts of pyrrolidone are added and the mixture is
The mixture was stirred for 5 hours while being heated to ℃ to produce a prepolymer having an isocyanate content of 2.6%, and neutralized by adding 14 parts of triethylamine. Separately, 5 parts of ethylenediamine and 20 parts of adipic dihydrazide were added to deionized water 5
Dissolved in 80 parts. The solution was heated to 40 ° C., and the solution was added to the solution while maintaining the temperature.
The triethylamine mixture was dropped, whereby an aqueous urethane resin emulsion having a solid content of 31% by weight was obtained.

Production Example 8 A mixture of isophthalic acid / adipic acid (molar ratio 1/1) was used as the dibasic acid component, and 1,6-
150 parts of a polyester polyol obtained using hexanediol and having a terminal hydroxyl group and having an average molecular weight of 2000, 150 parts of a propylene oxide adduct of bisphenol A having an average molecular weight of 660, and 15 parts of 2,2-bis (hydroxymethyl) propionic acid And melamine 5
And the mixture was heated to 90 ° C. to prepare these solutions. Next, 110 parts of dicyclohexylmethane diisocyanate and 110 parts of N-methyl-2-pyrrolidone are added to the solution, mixed, and the mixture is mixed up to 1 part.
The mixture was stirred for 5 hours while heating to 20 ° C. to produce a prepolymer having an isocyanate content of 2.4%, and neutralized by adding 14 parts of triethylamine. Separately, 5 parts of ethylenediamine and 20 parts of adipic dihydrazide were dissolved in 580 parts of deionized water. The solution was heated to 40 ° C., and the above-mentioned neutralized prepolymer / triethylamine mixture was added dropwise to the solution while maintaining the temperature, whereby an aqueous urethane resin emulsion having a solid concentration of 32% by weight was added. Obtained.

Production Example 9 A mixture of isophthalic acid / adipic acid (molar ratio 1/1) was used as the dibasic acid component, and 1,1 was used as the glycol component.
100 parts of a polyester polyol having an average molecular weight of 2,000 and having a terminal hydroxyl group and obtained from 6-hexanediol, bisphenol A having an average molecular weight of 660
Was mixed with 15 parts of 2,2-bis (hydroxymethyl) propionic acid and 5 parts of trimethylolpropane, and the mixture was heated to 90 ° C. to prepare these solutions. Next, 110 parts of dicyclohexylmethane diisocyanate and 110 parts of N-methyl-2-pyrrolidone were mixed with the solution, and the mixture was stirred for 5 hours while heating to a maximum of 120 ° C.
A prepolymer having an isocyanate content of 2.6% was prepared and neutralized by adding 14 parts of triethylamine.
Separately, 5 parts of ethylenediamine, adipic dihydrazide 2
0 parts were dissolved in 580 parts of deionized water. Add this solution to 40
C., and the above-mentioned neutralized prepolymer / triethylamine mixture was added dropwise to this solution while maintaining the above temperature, whereby an aqueous urethane resin emulsion having a solid concentration of 31% was obtained.

2. Production of Water-based Urethane Resin Composition for Comparative Example Production Example 10 (Comparative ) A mixture of isophthalic acid / adipic acid (molar ratio 1/1) was used as a dibasic acid component, and 1,6 was used as a glycol component.
A mixture of 229 parts of a polyester polyol having a terminal hydroxyl group and having an average molecular weight of 1500, obtained using hexanediol, 16 parts of 2,2-bis (hydroxymethyl) propionic acid, and 4 parts of melamine, and heated to 90 ° C. And dissolved. Next, 120 parts of isophorone diisocyanate and 110 parts of N-methyl-2-pyrrolidone were added to this solution, heated to a maximum of 120 ° C., and stirred for 5 hours to produce a prepolymer having an isocyanate content of 3.8%. This was neutralized by adding 13 parts of triethylamine. Separately, 9 parts of ethylenediamine and 2 parts of diethylenetriamine were dissolved in 660 parts of deionized water. The solution was heated to 40 ° C., and the neutralized prepolymer / triethylamine mixture was added dropwise to the solution while maintaining the temperature.
Thus, an aqueous urethane resin emulsion having a solid content of 33% was obtained.

Production Example 11 (comparative) 150 parts of a propylene oxide adduct of bisphenol A having an average molecular weight of 1000, 16 parts of 2,2-bis (hydroxymethyl) propionic acid, and trimethylolpropane 5
The parts were mixed and heated to 90 ° C. to dissolve. Next, 120 parts of isophorone diisocyanate and N-
Add 100 parts of methyl-2-pyrrolidone and add up to 120
The mixture was stirred for 5 hours while being heated to ℃ to prepare a prepolymer having an isocyanate content of 4.5%, and neutralized by adding 13 parts of triethylamine. Separately, 9 parts of ethylenediamine and 2 parts of diethylenetriamine were dissolved in 500 parts of deionized water. The solution was heated to 40 ° C., and the neutralized prepolymer / triethylamine mixture was added dropwise to the solution while maintaining the temperature.
% Of an aqueous urethane resin emulsion.

Production Example 12 (Comparative) 220 parts of a propylene oxide adduct of bisphenol A having an average molecular weight of 2,000, 20 parts of 2,2-bis (hydroxymethyl) propionic acid, and 2 parts of melamine were mixed and heated to 90 ° C. And dissolved. Next, 120 parts of isophorone diisocyanate and 130 parts of N-methyl-2-pyrrolidone are added to the solution, and the mixture is stirred for 5 hours while heating to a maximum of 120 ° C., and the isocyanate content is 4.
A 2% prepolymer was prepared and neutralized by adding 18 parts of triethylamine. Separately, 9 parts of ethylenediamine were dissolved in 640 parts of deionized water. The solution was heated to 40 ° C., and the neutralized prepolymer / triethylamine mixture was added dropwise to the solution while maintaining the temperature, whereby an aqueous urethane resin emulsion having a solid concentration of 32% was obtained.

Production Example 13 (Comparative ) A mixture of isophthalic acid / adipic acid (molar ratio 1/1) was used as a dibasic acid component, and 1,6-
100 parts of a polyester polyol obtained using hexanediol and having a terminal hydroxyl group and having an average molecular weight of 2,000, propylene oxide adduct of propylene glycol having an average molecular weight of 1000, 70 parts, 2,2-bis (hydroxymethyl) propionic acid 11 parts, Melamine 4
The parts were mixed and heated to 90 ° C. to dissolve it. Next, 85 parts of isophorone diisocyanate and 100 parts of N-methyl-2-pyrrolidone are added to the solution, and the mixture is stirred for 5 hours while heating to a maximum of 120 ° C. to produce a prepolymer having an isocyanate content of 2.9%. The mixture was neutralized by adding 10 parts of triethylamine. 6 parts of ethylenediamine were dissolved in 483 parts of deionized water. The solution was heated to 40 ° C., and the neutralized prepolymer / triethylamine mixture was dropped into the solution while maintaining the temperature, thereby obtaining an aqueous urethane resin emulsion having a solid concentration of 32%. .

Production Example 14 (Comparative ) A mixture of isophthalic acid / adipic acid (molar ratio 1/1) was used as the dibasic acid component, and 1,6-
160 parts of a polyester polyol having an average molecular weight of 2,000 and having a terminal hydroxyl group, obtained using hexanediol, and 67 parts of a propylene oxide adduct of bisphenol A having an average molecular weight of 660, and 15 parts of 2,2-bis (hydroxymethyl) propionic acid are used. They were mixed, heated to 90 ° C. and dissolved. Next, 93 parts of isophorone diisocyanate and 130 parts of N-methyl-2-pyrrolidone were added to the solution, and the solution was heated for 5 hours at a maximum of 120 ° C.
After stirring for an hour, a prepolymer having an isocyanate content of 2.2% was produced, and neutralized by adding 13 parts of triethylamine. Separately, 5 parts of ethylenediamine and 1 part of diethylenetriamine were dissolved in 587 parts of deionized water. The solution was heated to 40 ° C., and the prepolymer / triethylamine mixture was dropped into the solution while maintaining the temperature, whereby an aqueous urethane resin emulsion having a solid content of 32% was obtained.

Production Example 15 (Comparative ) A mixture of isophthalic acid / adipic acid (molar ratio 1/1) was used as the dibasic acid component, and 1,6-
212 parts of a polyester polyol having an average molecular weight of 2,000 obtained with hexanediol and having a terminal hydroxyl group, 87 parts of a propylene oxide adduct of bisphenol A having an average molecular weight of 660, and 5 parts of melamine were mixed, and the mixture was heated to 90 ° C. Dissolved. Next, 4,4-dicyclohexylmethane diisocyanate 11 was added to this solution.
0 parts and 160 parts of N-methyl-2-pyrrolidone were added, and the mixture was stirred for 5 hours while heating up to 120 ° C.,
A prepolymer having an isocyanate content of 1.7% was prepared and neutralized by adding 14 parts of triethylamine.
Separately, 6 parts of ethylenediamine were dissolved in 720 parts of deionized water. The solution was heated to 40 ° C., and the neutralized prepolymer / triethylamine mixture was dropped into the solution while maintaining the temperature. However, the neutralized prepolymer / triethylamine mixture was not dispersed in water, and the resin was not dispersed. Could not be obtained.

Production Example 16 (Comparative ) A mixture of isophthalic acid / adipic acid (molar ratio 1/1) was used as the dibasic acid component, and 1,6-
100 parts of a polyester polyol having a terminal hydroxyl group and having an average molecular weight of 2000, obtained using hexanediol, and 50 parts of a propylene oxide adduct of bisphenol A having an average molecular weight of 660 and 15 parts of 2,2-bis (hydroxymethyl) propionic acid And melamine 5
The parts were mixed and heated to 90 ° C. to dissolve. Next, 37 parts of isophorone diisocyanate and N-
Add 75 parts of methyl-2-pyrrolidone, max.
The mixture was stirred for 5 hours while heating to obtain a prepolymer having an isocyanate content of 0%, and 14 parts of triethylamine was added to neutralize the prepolymer. Separately, 350 parts of deionized water was heated to 40 ° C., and the above-mentioned neutralized prepolymer / triethylamine mixture was added dropwise while maintaining this temperature to obtain an aqueous urethane resin emulsion having a solid concentration of 32%. .

Production Example 17 (Comparative ) A mixture of isophthalic acid / adipic acid (molar ratio 1/1) was used as the dibasic acid component, and 1,6-
229 parts of a polyester polyol having a terminal hydroxyl group and having an average molecular weight of 1500, obtained using hexanediol, and 16 parts of 2,2-bis (hydroxymethyl) propionic acid, and 4 parts of melamine were mixed and heated to 90 ° C. To dissolve. Next, 120 parts of isophorone diisocyanate and 110 parts of N-methyl-2-pyrrolidone are added to this solution, and while heating to a maximum of 120 ° C., 5 parts are added.
After stirring for an hour, a prepolymer having an isocyanate content of 3.8% was produced, and neutralized by adding 13 parts of triethylamine. Separately, 9 parts of ethylenediamine and 12 parts of diethylenetriamine were dissolved in 693 parts of deionized water. The solution was heated to 40 ° C., and the neutralized prepolymer / triethylamine mixture was dropped into the solution while maintaining the temperature, whereby an aqueous urethane resin emulsion having a solid content of 32% was obtained.

Examples 1 to 19 and Comparative Examples 1 to 15 Pretreatment (1-1) Test material The following commercially available metal materials were used as test materials. (A) Double-sided electrogalvanized steel sheet (EG): sheet thickness = 0.8 mm (basis weight = 20/20 (g / m ² )) (b) aluminum sheet (A1): JIS5052 material, sheet thickness = 1.0 mm (c) Cold rolled steel plate (SPCC): SPCC material, plate thickness = 0.8 mm (1-2) Degreasing treatment For the degreasing treatment of the test material, a fine cleaner 4336 is used.
(Registered trademark: manufactured by Nippon Parkerizing Co., Ltd.). (Concentration = 20 g / l, temperature = 60 ° C., spray for 2 minutes). Immediately after the degreasing treatment, the test material was washed with water and subjected to the following undercoat chromate treatment or undercoat zinc phosphate treatment. (1-3-1) Base chromate treatment Zinc chrome 357 (registered trademark: manufactured by Nippon Parkerizing Co., Ltd.) is used to form a chromate film on the EG material.
For the formation of a film on the A1 plate, a spray treatment (bath temperature = 50 ° C., time = 5 seconds) with Alchrome 712 (registered trademark: manufactured by Nippon Parkerizing Co., Ltd.) is performed, and the formed base film is washed with water. Thereafter, drying was performed for 10 seconds at an ambient temperature of 220 ° C. (the temperature of the steel sheet reached 100 ° C.). The amount of chromium attached was 10 mg / m ² . (1-3-2) Zinc phosphate undercoat treatment To form a zinc phosphate film, Palbond L302 was used as a test material.
0 (registered trademark: manufactured by Japan Parkerizing Co., Ltd.) (immersion at 45 ° C. for 2 minutes), washed with water and air-dried. The coating weight is 2.0 g / m ² .

[0062] 2. Additives(2-1) Curing agent Used in Examples 1 to 13 and Comparative Examples 1 to 15
The curing agents are shown in Table 1. (2-2) Silica Table 2 shows the silica used in the examples and comparative examples.
Show.(2-3) Polyolefin wax Polyolefin used in Examples and Comparative Examples
The waxes are shown in Table 3.

[0063]

[Table 1]

[0064]

[Table 2]

[0065]

[Table 3]

3. Application of Resin Composition (3-1) Composition of Resin Composition Fifteen kinds of compositions for composition examples (No. 1 to 15) and 13 kinds of resin compositions for comparative examples (No. 16 to 28) were prepared.
The composition is shown in Tables 4 and 5.

[0067]

[Table 4]

[0068]

[Table 5]

Notes in Tables 4 and 5 * 1: Numerical values in parentheses indicate the ratio (%) of the solid weight of each component to the total solid weight of the composition. * 2: The composition could not be prepared because the urethane resin component did not disperse in water.

(3-2) Application of Resin Composition The metal surface treatment compositions shown in Tables 4 and 5 were applied to the surface of the test material with a bar coater, and the atmosphere temperature was 260 ° C. (160 ° C.) for 30 seconds. (Adhesion amount = 1.0 g / m ² )

4. Painted plate performance test (4-1) Corrosion resistance A salt spray test according to JIS-Z-2731 was performed for 200 hours, and the occurrence of white rust was observed. <Evaluation Criteria> ＝= Rust generation area is less than 3% of total area ○ = Rust generation area is 3% or more and less than 10% of total area △ = Rust generation area is 10% or more and less than 30% of total area × = Rust occurrence (4-2) Alkali-resistant silicate-based alkaline degreasing agent (Palclean N364)
S, manufactured by Nippon Parkerizing Co., Ltd., concentration = 20 g /
1, temperature = 60 ° C.) for 5 minutes, and then the corrosion resistance evaluation test was performed. <Evaluation Criteria> ＝= Rust-generated area is less than 3% of the entire area ○ = Rust-generated area is 3% or more and less than 10% of the total area △ = Rust-generated area is 10% or more of the entire area and there is no deterioration × = Rust Deterioration of performance when the generation area is 10% or more of the total area

(4-3) Coating Adhesion Melamine-based paint (Amirac # 1000, manufactured by Kansai Paint Co., Ltd.) is applied so that the film thickness after drying is 25 μm, and is baked at 125 ° C. for 20 minutes. After 24 hours, it was immersed in boiling water for 2 hours, and further evaluated after 24 hours. The paint adhesion evaluation method was performed according to JIS-5400, drawing, Goban-Erichsen, and impact tests.
Evaluation was made based on these comprehensive evaluations. (4-4) Workability Using a blank plate with a diameter of 115 mmφ, punch diameter = 5
A high-speed cylindrical deep drawing test was performed under the conditions of 0 mmφ, wrinkle holding pressure of 1 Ton, and deep drawing speed of 30 m / min. In the test, press oil (Nippon Kogyo Oil Co., Ltd., # 640) 2 g /
and m ² oiled. The aperture ratio at this time is 2.30. <Evaluation Criteria> ＝= No oil coating, squeezed out to squeezing ratio = 2.40. ＝= no oiling, squeezed out to 2.30. Δ = oil applied, squeezed out to squeezing ratio = 2.30. × = No oil applied, no drawing-out at drawing ratio = 2.30.

5. Test results Tables 6 and 7 show the test results.

[0074]

[Table 6]

[0075]

[Table 7]

Table 6 clearly shows that Examples 1 to 1
9, when a chromate or phosphate film is formed on a galvanized steel sheet, an aluminum sheet, and a cold-rolled steel sheet, and then the water-based surface treatment composition of the present invention is applied and dried to form a film. , Alkali resistance and coating adhesion were all good. It was also confirmed that good workability was obtained by adding a lubricant. On the other hand, in the case of Comparative Examples 1 to 15 different from the present invention, as is clear from Table 7, the corrosion resistance, alkali resistance and coating adhesion of the obtained films were all insufficient.

[0077]

As described above, by applying the aqueous surface treatment composition containing the aqueous urethane resin composition of the present invention to the surface of a metal material such as a galvanized steel sheet,
A film having excellent corrosion resistance, alkali resistance, and solvent resistance can be formed.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Tadahiro Nakata 7-35 Higashiogu, Arakawa-ku, Tokyo Asahi Denka Kako Kogyo Co., Ltd. (72) Inventor Tamotsu Nagamatsu 7-35 Higashiogu, Arakawa-ku, Tokyo Asahi Denka Kogyo Co., Ltd.

Claims (9)

[Claims] (I) A compound obtained by reacting a polyol compound having an average molecular weight of 300 or more, dimethylolalkanoic acid, a compound having three or more active hydrogens, and an organic polyisocyanate compound, and having a terminal isocyanate group And (II) a polyamine compound having two or more primary amino groups, and a primary amino group of the polyamine compound (II) with respect to a molar amount of isocyanate groups of the urethane prepolymer (I). Is obtained by reacting at a ratio where the molar amount of
A urethane resin having a primary amino group at a terminal, and an aqueous medium for dispersing the same, wherein the polyol compound used for preparing the urethane prepolymer (I) is obtained from an aliphatic polyhydric alcohol and a polycarboxylic acid. A polyester polyol having a hydroxyl group at a terminal and a bisphenol skeleton-containing diol compound represented by the following general formula (I): [However, in the above formula (I), R ¹ and R ² each independently represent a hydrogen atom or a lower alkyl group;
A represents an alkylene group having 2 to 4 carbon atoms, and m and n each independently represent an integer of 1 to 20. ] As an essential component. 2. The aqueous urethane resin composition according to claim 1, wherein the compound having three or more activated hydrogens used for preparing the urethane prepolymer (I) is melamine. 3. The aqueous system according to claim 1, wherein the content of the polyester polyol contained in the polyol compound for preparing the urethane prepolymer (I) is 25 to 95% by weight based on the total amount of the polyol compound. Urethane resin composition. 4. The method according to claim 1, wherein the content of the bisphenol skeleton-containing diol contained in the polyol compound for preparing the urethane prepolymer (I) is 5 to 75% by weight based on the total amount of the polyol compound. A water-based urethane resin composition. 5. The aqueous urethane resin composition according to claim 1, wherein the organic polyisocyanate for preparing the urethane prepolymer (I) is selected from aliphatic and alicyclic isocyanates. 6. The aqueous urethane resin composition according to claim 1, wherein the polyamine compound (II) is selected from dibasic acid dihydrazide. 7. (a) The aqueous urethane resin composition according to any one of claims 1 to 6, (b) a curing agent, and (c)
And silica, wherein the total solid content of the components (a) and (b) is 50 to 97% based on the total solid weight of the components (a), (b) and (c). And the solid content of the component (c) is 3 to 50% based on the total solid weight of the components (a), (b) and (c), and the corrosion resistance and coating adhesion are characterized by the following: Excellent aqueous metal surface treatment composition. 8. The curing agent (b) includes an epoxy group, an oxazoline group, an alkoxysilyl group, an isocyanate group,
The aqueous metal surface treatment composition according to claim 7, comprising an organic compound having at least one or more functional groups selected from and an aziridinyl group. 9. As an additional component, (d) a polyolefin wax having a saponification value of 0 or 30 or less in an amount of 1 to 30% by weight based on the total solid weight of the components (a) to (d). The aqueous metal surface treatment composition according to claim 7, wherein the composition is contained.