KR20010041809A - Surface treatment composition and surface treatment method for metallic materials - Google Patents

Abstract

Surface treatment compositions and surface treatment methods for providing a surface having a high degree of corrosion resistance and colorability. The surface treatment composition contains, as an aqueous solution, (A) a silane coupling agent, (B) a water-soluble polymer represented by the formula (I) below, and (C) inorganic compounds such as silica, silicate, and metal salt compounds in a colloidal state. The surface treatment method is to form a coating having a dry weight of 0.01 to 2.0 g / m 2 on the surface of the metal material using the surface treatment composition according to the present invention, wherein the pH value is adjusted to 2.0 to 6.5.

Description

Surface treatment agent composition and surface treatment method for metal materials {SURFACE TREATMENT COMPOSITION AND SURFACE TREATMENT METHOD FOR METALLIC MATERIALS}

In general, metal materials such as galvanized steel sheets and aluminum sheets are widely used for automobiles, building materials, and household appliances. However, both zinc and aluminum easily corrode in air, producing corrosives (so-called white rust), which deteriorate the appearance of metal materials and adversely affect the adhesion of the paint applied thereon.

In view of these problems, in order to improve the corrosion resistance and paint adhesion of the surface of the metal material, a chromate treatment process for treating the surface of the metal material with a treatment solution containing chromic acid, dichromic acid or a salt thereof as a main component is generally performed. Used.

However, in the context of more stringent environmental protection in recent years, chromate treatment has become rapidly unpopular, mainly due to the hexavalent chromium contained in the chromate solution harms the human body. In addition, in order to comply with the provisions of laws for the protection of water resources, wastewater containing hexavalent chromium is required to be treated in a special process, which increases the overall manufacturing cost. Furthermore, chromate treated metal materials cannot be recycled after use as classified as chromium pollution industrial waste. Because of these and other problems of chromate treatment, the use of such treatment processes is now a significant social problem.

Meanwhile, among known surface treatment methods, methods that do not involve the use of chromates include a method of using a surface treatment agent containing tannic acid and at least one polyphenol carboxylic acid. Corrosion resistance of the metal material treated with the aqueous solution of tannic acid is improved because the reactant of the tannic acid and the metal material acts as a protective film to prevent the penetration of corrosive substances.

As a result of the recent increase in the demand for high-quality metal materials, a protective film having excellent corrosion resistance is required today. However, a protective film on a metal material formed using only tannic acid or using a combination of tannic acid and one or more inorganic materials cannot satisfy the requirement of high corrosion resistance. Therefore, it is not industrially feasible today to use tannic acid for the surface treatment of metallic materials.

Japanese JPA 53-121034 provides a surface treatment method for applying an aqueous solution of water-dispersible silica, alkyd resin and trialkoxy silane compound to the surface of the metal material to improve the corrosion resistance of the metal material. It is starting.

In order to impart corrosion resistance to metal materials, a method of using a water-soluble resin of a hydroxy pyrone compound derivative and a method of using a water-soluble or water dispersible polymer of a hydroxy styrene compound are Japanese JPA 57-44751 and JPA. It is disclosed in several patent documents including 1-177380.

However, none of the methods listed above can satisfactorily form a protective film having excellent corrosion resistance on the surface of the metal material to replace the chromate coating film. Thus, the problems noted above still remain unresolved. In short, non-chromium surface treatment agents or surface treatment methods that provide excellent corrosion resistance to metal materials have not been realized until now.

The present invention relates to a surface treatment composition and a surface treatment method suitable for making the surface of a metal material very excellent in corrosion resistance and capable of good painting.

In view of the above situation, it is an object of the present invention to provide a non-chromic surface treatment agent which allows a metal material to have a high corrosion resistance and colorability.

As a result of intensive research and efforts to solve the problems of the prior art, the present inventors have prepared a silane coupling agent, a water-soluble polymer having a specific chemical structure, and a colloidally dispersed inorganic compound. It has been found that coatings having a high degree of corrosion resistance, colorability and coin-scratch-resistant properties can be formed on the surface of metal materials by using a surface treating agent comprising a metal oxide. The present invention is based on this finding.

Thus, according to the present invention, there is provided a surface treating composition for use in a metal material, the aqueous composition comprising the following.

(A) at least one reactive functional group selected from an active-hydrogen-containing amino group, an epoxy group, a vinyl group, a mercapto group and a methacryloxy group; Silane coupling agents containing at least one silane coupling compound having;

(B) at least one water-soluble polymer, each represented by formula (I) below and exhibiting an average degree of polymerization of 2 to 50;

Wherein X bonded to the benzene ring is a hydrogen atom, a hydroxyl group, an alkyl group having any of C1 to C5, a hydroxyalkyl group having any of C1 to C5, an aryl group having any of C6 to C12, benzyl group , A benzal group, an unsaturated hydrocarbon group condensed with the benzene ring to form a naphthalene ring, or a group represented by the following formula (II).

Wherein R1 and R2 each represent a hydrogen atom, a hydroxyl group, an alkyl group having any of C1 to C5 or a hydroxyalkyl group having any of C1 to C10, and each benzene in the formulas (I) and (II) Each of Y 1 and Y 2 bonded to the ring represents a Z group independently represented by the following formulas (III) and (IV).

Wherein R 3, R 4, R 5, R 6 and R 7 each independently of one another represent a hydrogen atom, an alkyl group having any of C 1 to C 10 or a hydroxyalkyl group having any of C 1 to C 10 and each of the polymer molecules The average number of substitutions of the Z groups in the benzene rings is 0.2 to 1.0.

(C) at least one inorganic compound selected from the group of the compounds of silica, silicates, metal salts and mixtures of any of them, dispersed in the colloidal state in said aqueous medium.

In the surface treating agent composition according to the present invention, preferably, the weight ratio of the component (A), that is, the silane coupling agent to the component (B), that is, the water-soluble polymer, that is, (A) :( B) is 1:10. To 10: 1, wherein the weight ratio of component (C), i.e., inorganic compound to [(A) + (B)], in other words (c): [(A) + (B)], is preferably 1 From 5: 5 to 5: 1.

In the surface treatment agent composition according to the present invention, the silane coupling agent (A) preferably comprises (a) a silane coupling agent containing at least one silane coupling compound having at least one active hydrogen-containing amino group, and (b) It contains a silane coupling agent containing at least one silane coupling compound having at least one epoxysilane group.

In the surface treating agent composition according to the present invention, preferably, the equivalent ratio of the active hydrogen-containing amino group contained in the silane coupling agent (a) to the epoxy silane group contained in the silane coupling agent (b) is 3: 1 to 1: 3.

In the surface treating agent composition according to the present invention, preferably, the weight ratio of the sum of the silane coupling agent (a) and the silane coupling agent (b) and the water-soluble polymer component (B), that is, [(a) + (b) ] :( B) The weight ratio is 1: 5 to 5: 1.

In another aspect of the present invention, there is provided a surface treatment method used for a metal material, the surface treatment method consisting of:

That is, using the surface-treated aqueous composition according to the present invention, the pH value is adjusted to 2.0 to 6.5, and coated on the surface of the metal material, and then dried to form a coating film having a dry weight of 0.01 to 2.0 g / ㎡.

In the surface treatment method according to the invention, preferably, the surface of the metal material to be treated is pretreated by a phosphating process or a plating process before adhering the aqueous surface treatment solution to the surface of the metal material.

As described above, the surface treatment composition to be used for the metal material according to the present invention contains the following components as an aqueous solution. That is, component (A) which is a silane coupling binder containing at least one silane coupling compound having a specific reactive functional group, at least one water-soluble phenolic resin polymer component (B) having a specific amino group, and silica, silicate, metal salt compound Or component (C), each selected from any mixtures thereof, which is one or more inorganic compounds dispersed in the colloidal state in the aqueous medium.

The silane coupling compound contained in the component (A) may be of any structural type as long as each of them has at least one reactive functional group selected from an active hydrogen-containing amino group, an epoxy group, a vinyl group, a mercapto group, and a methacryloxy group. No limitations apply. Specific examples of silane coupling compounds that can be used for the purposes of the present invention include those listed in (1) to (5) below.

(1) a compound having an amino group

N- (2-aminoethyl) 3-aminopropylmethyldimethoxysilane

N- (aminoethyl) 3-aminopropyltrimethoxysilane

3-aminopropyltriethoxysilane

(2) a compound having an epoxy group

3-glyoxideoxypropyltrimethoxysilane

3-glycidoxyoxymethyldimethoxysilane

2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane

(3) a compound having a vinyl group

Vinyltriethoxysilane

(4) a compound having a mercapto group

3-mercaptopropyltrimethoxysilane

(5) Compound having methacryloxy group]

3-methacryloxypropyltrimethoxysilane

3-methacryloxypropylmethyldimethoxysilane

Preferably, component (A), which is a silane coupling agent to be used for the purposes of the present invention, comprises (a) at least one silane coupling compound having at least one active hydrogen-containing amino group and (b) at least one epoxy A silane coupling agent containing at least one silane coupling compound having a silane group.

In the case where component (A) in the surface treatment composition according to the present invention contains (a) a silane coupling agent containing an active hydrogen-containing amino group and (b) an silane coupling agent containing an epoxysilane group, preferably, the silane The equivalent ratio of the active hydrogen-containing amino group and the epoxysilane group contained in the coupling agent is from 3: 1 to 1: 3. If the equivalent ratio of active hydrogen-containing amino group to epoxycysilane group exceeds 3: 1, the coating obtained by such a surface treatment composition is poor in corrosion resistance and colorability. On the other hand, if the equivalent ratio of active hydrogen-containing amino group to epoxysilane group is lower than 1: 3, the corrosion resistance and colorability of the resulting coating may be saturated.

Secondly, each of the water-soluble polymers of component (B) to be used for the purposes of the present invention is an oligomer or a polymer and the average degree of polymerization of formula (I) is 2 to 50.

In formula (I), X bonded to the benzene ring is any of C1 to C5, such as an alkyl group, hydroxymethyl group hydroxyethyl group, or hydroxypropyl group having any of C1 to C5, such as hydroxyl group, methyl group ethyl group or propyl group. An aryl group, benzyl group, benzal group, -CH = CH-CH = CH- group or = CH-CH = CH-CH = having any of C6 to C12, such as a hydroxyalkyl group, a phenyl group or a naphthyl group having As the group, an unsaturated hydrocarbon group or a group represented by formula (II), which is condensed with the benzene ring to form a naphthalene ring.

R 1 and R 2 are each independently of each other in C 1 to C 10, such as an alkyl group having any of C 1 to C 5 or a hydroxy methyl group, hydroxyethyl group or hydroxypropyl group, such as a hydrogen atom, a hydroxyl group, a methyl group ethyl group or a propyl group The hydroxyalkyl group which has any is shown.

Each of Y 1 and Y 2 bonded to the respective benzene rings of formulas (I) and (II) represents a Z group represented by formula (III) or (IV) above independently of one another. R3, R4, R5, R6 and R7 in the above formulas (III) and (IV) are each independently an alkyl group or a hydroxymethyl group hydroxide having any of C1 to C10, such as a methyl group ethyl group or a propyl group The hydroxyalkyl group which has any of C1-C5 like a hydroxyethyl group or hydroxypropyl group is shown.

Each of X and Y in formula (I) and Y2 in formula (II), bonded to the benzene ring in the polymer molecule, may be the same or different from X, Y1 or Y2 bonded to any other benzene ring of the molecule.

The average number of substitutions of the Z group in each of the benzene rings of the polymer molecule is 0.2 to 1.0. n represents the average degree of polymerization and it is 2-50. If the value of n is less than 2, the molecular weight of the polymer obtained is so small that the resulting coating does not have sufficient corrosion resistance. On the other hand, if the value of n exceeds 50, both the obtained surface treatment composition and the aqueous treatment solution containing such a composition become unstable and are disadvantageous for practical applications.

As used herein, the mean substitution of Z groups refers to the average value of the number of Z groups introduced into the entire benzene rings of the polymer molecule. If, for example, n is 10 in formula (I) and X represents a benzene ring-containing group as represented by formula (II), the number of benzene rings per polymer molecule is 20. If one Z group is introduced into each of the 10 benzene rings of the above 20 benzene rings, then the average substitution of the Z groups in the polymer molecule is [(1 × 10) + (0 × 10)] / 20 = 0.5 Will be.

If the average substitution number of the Z groups is less than 0.2, the polymer obtained does not exhibit a sufficient degree of solubility in water, making the surface treatment composition unstable. On the other hand, when the average substitution number of the Z groups exceeds 1.0, the polymer obtained has excessive water solubility that the resulting coating does not have sufficient corrosion resistance and colorability.

Each of R3 to R7 of the Z group as represented by the formula (III) or (IV) represents an alkyl group having any of C1 to C10 or a hydroxyalkyl group having any of C1 to C10. If the carbon number is 11 or more, the resulting coatings have poor performance in terms of corrosion resistance and colorability.

Third, for the purposes of the present invention at least one inorganic compound (C) selected from silica, silicates, metal salt compounds and any mixtures thereof must be able to be dispersed in the colloidal state in the aqueous medium. Therefore, the compound is preferably supplied in the form of fine powder. Specific materials that can be used for the purposes of the present invention include fumed silica or colloidal silica, precipitated silica, natural powerdry quartz, diatomaceous earth, ocher ( loess, silicates such as montmorillonite, synthetic magnesium silicates such as Labonite®, titania sol, zirconia sol, alumina sol, barium sulfate, zinc phosphate and iron oxide red. .

In the surface treatment composition according to the present invention, the weight ratio of the component (A) which is a silane coupling agent to the component (B) which is a water-soluble polymer, namely (A) :( B), is preferably 1:10 to 10: 1 , More preferably 1: 5 to 5: 1. If the weight ratio is less than 1:10, the degree of adhesion of the composition to the underlying metal material is reduced, so that the formed coating is not satisfactory in terms of corrosion resistance and paintability. If the weight ratio exceeds 10: 1 and the content ratio of component (A) becomes very high, the formed coating will exhibit only poor performance in terms of corrosion resistance and colorability.

In the surface treatment composition according to the present invention, the weight ratio of the sum of the component (C) to the component (A) and the component (B), that is, C: [(A) + (B)] is 1: 5 to 5: 1 desirable. If the weight ratio is less than 1: 5, and the content of the inorganic compound (C) is very low, the obtained film shows insufficient physical strength and is not satisfactory in terms of paintability and coin scratch resistance. On the other hand, when the weight ratio exceeds 5: 1 and the content of the inorganic compound (C) is very high, the obtained surface treatment composition film shows only poor performance in terms of corrosion resistance, colorability and adhesion.

Now, the surface treatment method according to the present invention will be described in detail. The method according to the present invention contains the above surface treatment composition and is coated on the surface of the metal material using an aqueous surface treatment solution having a pH value of 2.0 to 6.5, and then adhered to the surface of the metal material, followed by drying. To form a coating that is from 2.0 g / m 2, preferably from 0.05 to 1.0 g / m 2. The aqueous surface treatment solution is preferably brought into contact with the surface of the metal material for 0.1 to 30 seconds at a temperature of 10 to 60 ° C. before being heat dried.

In the surface treatment method according to the invention, the aqueous surface treatment solution is controlled by diluting the surface treatment composition with water when necessary. At this time, the pH value is adjusted to 2.0 to 6.5 using phosphoric acid, sulfuric acid, hydrochloric acid, nitric acid, hydrofluoric acid, complex fluoride and / or organic acid.

For the purposes of the present invention, preferably, the pH value of the aqueous surfacing solution is adjusted using fluoride, which may be fluoride of phosphoric acid, acidic phosphate and / or complex. More preferably, the pH value is adjusted to 3.0 to 5.0. If the pH value is less than 2.0, the composition and the surface of the metal material in the treatment solution react excessively with each other, resulting in a defective coating having insufficient corrosion resistance and colorability. On the other hand, when the pH value exceeds 6.5, component (B), which is a water-soluble polymer, tends to precipitate and precipitate from the aqueous surface treatment solution, thereby shortening the useful life of the aqueous treatment solution.

The technique for contacting the surface of the metal material with the surface treatment composition according to the present invention is not particularly limited. Techniques that can be used for the purposes of the present invention include immersion, spraying and roll coating. The treatment temperature and the treatment time are not particularly limited, but the treatment temperature is 10 to 60 ° C, and the treatment time is preferably 0.1 to 20 seconds. The treated metal material is preferably heated and dried. It is preferable that a heating temperature is 50-280 degreeC.

It should be noted that when the surface treatment composition according to the present invention comes into contact with a metal material, some of the metal ions generated from the metal material may be mixed with the surface treatment composition and react with component (B) to form a complex precipitate. do. In such a case, a metal sealing agent may be added to the surface treatment composition. Effective metal sealing agents that can be used for the purposes of the present invention include EDTA, Cy-DTA, triethanolamine, gluconic acid, heptgluconic acid, oxalic acid, tartaric acid, malic acid, organophosphoric acid.

Surfactant may be added to the aqueous surface treatment solution according to the present invention to improve contact with the metal material. Surfactants that can be used for the purposes of the present invention include commercially available carbonic acidate type, sulfate type, sulfonate type and phosphate type anionic surfactants, polyethylene glycol type Nonionic surfactants and cationic surfactants of polyalcohol and amine type.

For the purposes of the present invention, the metal material may be selected from iron sheet, galvanized iron sheet, aluminum sheet, aluminum alloy sheet and stainless steel sheet. In addition, it may be selected from steel sheets pretreated by a phosphate film forming process or a chemical plating process. Pretreated steel sheets provide an improvement in corrosion resistance and paintability. Chemical plating includes substitutional plating of cobalt, nickel, copper, iron, silver or gold.

It is not yet clear why the surface treatment composition according to the present invention improves the corrosion resistance and colorability of the metal material. However, the following theory is considered to be correct. First, the surface of the metal material is etched by the phosphoric acid, acidic phosphate, fluoride and fluoride complex contained in the surface treatment composition. As a result, the pH of the interface rises and metal ions appear to react with the water soluble polymer component to form a hardly soluble coating over the surface of the metal material. The poorly soluble coating then acts as a barrier to significantly improve the corrosion resistance of the metal material. However, since the coating is not strongly adhered to the metal material, the silane coupling agent component is used so that the functional group (-OR group) in the hydrolysed silane coupling agent is bound to the surface of the metal material. bonds) and other functional groups in the silane coupling agent to react with the water soluble polymer component to enhance adhesion of the water soluble polymer to the surface of the metal material.

In addition, the inorganic compound component dispersed in the colloidal state in the solution generates fine undulations on the surface of the metal material, and the fine undulations effectively fix the coating film formed on the surface, thereby providing satisfactory colorability of the surface of the metal material. And strong coin scratch resistance is guaranteed.

The present invention will now be described in more detail by examples, but it should be noted that the examples do not limit the scope of the invention.

1. Metallic Materials Used in the Examples

(1) cold rolled steel sheet (SPC)

Commercially available JIS G3141 grade 0.6 mm thick,

(2) galvanized steel

Commercially available hot dip galvanized steel sheet, 0.6 mm thick (GI)

Commercially available galvanized steel sheet, thickness 0.6 mm (EG),

(3) aluminum plate

Commercially available JIS A 5062 grade and 0.6 mm thick.

2. Pre-cleaning method of metal materials

The surface of all metal materials listed above is treated by spraying a medium alkaline degreasing agent (Fine Cleaner 4366 from Nihon Parkarizing Co., Ltd.) on the surface of the metal material at a temperature of 60 ° C. for 20 seconds. The surface was pre-cleaned to remove dirt and oil from the surface. Subsequently, the surface is washed with tap water in order to remove residual alkali solution to completely clean the surface of the metallic material.

3. Composition of Surface Treatment Solution

<Treatment solution A>

3-mercaptopropyltrimethoxysilane was used as the silane coupling agent component (A), n = 5, X = hydrogen, Y 1 = Z = -CH ₂ N (CH ₃ ) ₂ and the average substitution number of the Z group = 1 Phosphorus-soluble polymer was used as component (B), colloidal silica was used as inorganic compound component (C), and the three components were (A) :( B) = 1: 8, (C): [(A ) + (B)] = 1: 5. The pH value was then adjusted to 5.0 using H ₂ SiF ₆ and the composition was then diluted with distilled water to contain 10% of the composition calculated in solid weight.

<Processing Solution B>

N- (2-aminoethyl) -3-aminopropyltrimethoxysilane was used as the silane coupling agent component (A), where n = 5, X = -CH ₂ -C ₆ H ₄ -OH, Y1 = Z = A water-soluble polymer having an average substitution number of 0.7 groups —CH ₂ N (CH ₃ ) ₂ and Z = 0.75 was used as component (B), and an alumina sol was used as the inorganic compound component (C), wherein the three components were (A): (B) = 5: 1, (C): [(A) + (B)] = 1: 1. The pH value was then adjusted to 4.0 using HF and the composition was then diluted with distilled water to contain 10% of the composition calculated by solid weight.

<Processing Solution C>

3-aminopropyltriethoxysilane + 3-glycidoxyoxymethyldimethoxysilane (equivalent ratio of active hydrogen in amino and epoxy groups = 1: 2) was used as silane coupling agent component (A), n = 5, A water-soluble polymer having X = -CH ₂ -C ₆ H ₄ -OH, Y1 = Z = -CH ₂ N (CH ₃ ) ₂ and the average substitution number of the Z group = 0.75 was used as component (B), and barium sulfate was used as the inorganic Used as compound component (C), the three components were adjusted to be (A) :( B) = 1: 1, (C): [(A) + (B)] = 1: 2. The pH value was then adjusted to 4.0 using H ₂ TiF ₆ and the composition was then diluted with distilled water to contain 10% of the composition calculated in solid weight.

<Processing Solution D>

3-aminopropyltriethoxysilane + 3-glycidoxyoxymethylmethylmethoxymethoxy (equivalent ratio of active hydrogen in amino and epoxy groups = 1: 3) was used as silane coupling agent component (A), n = 5, A water-soluble polymer having X = -CH ₂ -C ₆ H ₄ -OH, Y1 = Z = -CH ₂ N (CH ₃ ) ₂ and the average substitution number of the Z group = 0.75 was used as component (B), and the colloidal silica was used. Was used as the inorganic compound component (C), and the three components were adjusted to be (A) :( B) = 1: 1, (C): [(A) + (B)] = 4: 1. The pH value was then adjusted to 3.0 using phosphoric acid and the composition was then diluted with distilled water to contain 10% of the composition calculated in solid weight.

<Processing Solution E>

N- (2-aminoethyl) -3-aminopropyltrimethoxysilane + 3-glycidoxyoxymethylmethyldimethoxysilane (equivalent ratio of active hydrogen in amino and epoxy groups = 1: 1) is a silane coupling agent component (A ), A water-soluble polymer with n = 5, X = hydrogen, Y1 = Z = -CH ₂ N (CH ₃ ) ₂ and the average substitution number of Z groups = 1 was used as component (B), and the colloidal silica Was used as the inorganic compound component (C), and the three components were adjusted to be (A) :( B) = 1: 1, (C): [(A) + (B)] = 1: 1. The pH value was then adjusted to 4.0 using H ₂ TiF ₆ and phosphoric acid and the composition was then diluted with distilled water to contain 10% of the composition calculated in solid weight.

<Processing Solution F-Comparative Example>

A water-soluble polymer having n = 5, X = hydrogen, Y1 = Z = -CH ₂ N (CH ₃ ) ₂ and an average substitution number of Z groups = 1 was used as component (B), while colloidal silica was used as an inorganic compound. Used as component (C), which was adjusted to be (C) :( B) = 1: 1. The pH value was then adjusted to 4.0 using H ₂ TiF ₆ and phosphoric acid and the composition was then diluted with distilled water to contain 10% of the composition calculated in solid weight.

<Processing Solution G-Comparative Example>

N- (2-aminoethyl) -3-aminopropyltrimethoxysilane + 3-glycidoxyoxymethylmethyldimethoxysilane (equivalent ratio of active hydrogen in amino and epoxy groups = 1: 1) is a silane coupling agent component (A ), While a water-soluble polymer having n = 5, X = hydrogen, Y1 = Z = -CH ₂ N (CH ₃ ) ₂ and an average substitution number of Z groups = 1 was used as component (B), Was adjusted to be (A) :( B) = 1: 1. The pH value was then adjusted to 3.0 using phosphoric acid and the composition was then diluted with distilled water to contain 10% of the composition calculated in solid weight.

<Processing Solution H-Comparative Example>

3-mercaptopropyltrimethoxysilane was used as the silane coupling agent component (A), n = 5, X = hydrogen, Y 1 = Z = -CH ₂ N (CH ₃ ) ₂ and the average substitution number of the Z group = 1 Phosphorus water-soluble polymer was used as component (B), while barium sulfate was used as inorganic compound component (C), and the three components were (A) :( B) = 1: 8, (C): [(A ) + (B)] = 1:20. The pH value was then adjusted to 4.5 using HF and the composition was then diluted with distilled water to contain 10% of the composition calculated by solid weight.

<Processing Solution I-Comparative Example>

3-aminopropyltriethoxysilane + 3-glycidoxyoxymethylmethylmethoxymethoxy (equivalent ratio of active hydrogen in amino and epoxy groups = 1: 3) was used as silane coupling agent component (A), n = 5, A water-soluble polymer having X = -CH ₂ -C ₆ H ₄ -OH, Y1 = Z = -CH ₂ N (CH ₃ ) ₂ and the average substitution number of the Z group = 0.75 was used as component (B), while colloidal state Was used as the inorganic compound component (C), and the three components were adjusted to be (A) :( B) = 1: 1, (C): [(A) + (B)] = 1: 2. . The pH value was then adjusted to 1.0 using phosphoric acid and the composition was then diluted with distilled water to contain 10% of the composition calculated in solid weight.

<Processing Solution J-Comparative Example>

Conventional Application Type Chromate Solution (Zinc Chromium-1300AN: Product of Nippon Parkarizing Co., Ltd.)

4. Application of treatment solution to metal materials

<Example 1>

Treatment solution A is applied to the hot dip galvanized steel sheet (GI) by roll coating at 25 ° C. at a rate of dry mass of 0.3 g / m 2. The solution is then heated to 80 ° C. and dried.

<Example 2>

Treatment solution B is applied to the aluminum plate AL by roll coating at 15 ° C. at a rate of dry mass of 0.1 g / m 2. The solution is then heated to 150 ° C. and dried.

<Example 3>

Treatment solution C is applied to the hot dip galvanized steel sheet (GI) by roll coating at 30 ° C. at a rate of 1.0 g / m 2 of dry mass. The solution is then heated to 100 ° C. and dried.

<Example 4>

Treatment solution D is applied to the electrical galvanized steel sheet (GI) by roll coating at 20 ° C. at a rate of dry mass of 0.05 g / m 2. The solution is then heated to 180 ° C. and dried.

<Example 5>

The hot dip galvanized steel sheet (GI) is treated with a nickel plating solution (preparene 4015: product of Nippon Parkering Co., Ltd.) to form a nickel plating layer of 20 mg / m2 on the surface in advance, and then the treatment solution E Is further applied by roll coating at 20 ° C. at a rate of 1,5 g / m 2 dry mass. The solution is then heated to 150 ° C. and dried.

<Example 6>

The hot dip galvanized steel sheet (GI) is treated with a nickel plating solution (preparene 4015) to form a nickel plating layer of 20 mg / m 2 on the surface in advance, and then the treatment solution C is roll-coated at 20 ° C. to a dry mass of 0.1. Apply additionally at a rate of g / m 2. The solution is then heated to 100 ° C. and dried.

<Example 7>

The hot dip galvanized steel sheet (GI) is treated with a phosphate treatment solution (Palbond-L 3300: product of Nippon Parkering Co., Ltd.) according to the conventional method to form a zinc phosphate layer of 2 g / m 2 on the surface in advance. Then, the treatment solution E is further applied by roll coating at 20 ° C. at a rate of 0.3 g / m 2 of dry mass. The solution is then heated to 100 ° C. and dried.

<Example 8>

Cold rolled steel sheet (SPC) was treated with a phosphate treatment solution (Palbond-L 3020: product of Nippon Parkering Co., Ltd.) according to a conventional method to form a zinc phosphate layer of 2 g / m 2 on the surface in advance, and The next treatment solution E is further applied by roll coating at 20 ° C. at a rate of 0.1 g / m 2 of dry mass. The solution is then heated to 100 ° C. and dried.

<Comparative Example 1>

Treatment solution F is applied to the hot dip galvanized steel sheet (GI) by roll coating at 30 ° C. at a rate of 1.0 g / m 2 of dry mass. The solution is then heated to 100 ° C. and dried.

<Comparative Example 2>

Treatment solution G is applied to the aluminum plate AL at a rate of 0.3 g / m 2 dry mass by roll coating at 30 ° C. The solution is then heated to 200 ° C. and dried.

<Comparative Example 3>

The hot dip galvanized steel sheet (GI) is treated with a nickel plating solution (preparene 4015) to form a nickel plating layer of 20 mg / m 2 on the surface in advance, and then the treatment solution H is roll-coated at 20 ° C. in dry mass 0.3 Apply additionally at a rate of g / m 2. The solution is then heated to 80 ° C. and dried.

<Comparative Example 4>

The hot dip galvanized steel sheet (GI) is treated with a nickel plating solution (preparene 4015) to form a nickel plating layer of 20 mg / m 2 on the surface in advance, and then the treatment solution I is dried by roll coating at 20 ° C. Apply additionally at a rate of g / m 2. The solution is then heated to 150 ° C. and dried.

<Comparative Example 5>

The hot dip galvanized steel sheet (GI) was treated with a nickel plating solution (preparene 4015) to form a nickel plating layer of 20 mg / m 2 on the surface in advance, and then the treatment solution J was roll coated to obtain 40 mg / m 2 of chromium. Apply additionally at speed. The solution is then heated to 80 ° C. and dried.

5. Specimen Preparation Method

Example 1 to Comparative Example 5 A commercially available undercoat (V-Kint # 200: product of Dainippon Paint Co., Ltd.) was applied to a thickness of 5.5 μm, and 200 ° C. After baking at commercially available, a commercially available finishing paint (V-Kint # 500: product of Dinihon Paint Co., Ltd.) is further applied to a thickness of 17 μm and then baked at 220 ° C. again.

6. Examination and Evaluation

6-1. Corrosion resistance

A cutting scratch having a depth up to the metal material with a cutter knife was formed on each specimen surface, and a salt water spray test conforming to JIS-Z 2371 was performed for 480 hours. The specimens were evaluated in the following grading system by observing the width (mm) of rust generated in the scratch area.

◎: less than 3 mm

: 3 mm or more and less than 5 mm

: 5 mm or more and less than 10 mm

×: 10 mm or more

6-2. Bending tack test

1st bending tack test

The specimen was bent at 20 ° C. to determine the peeling area of the coating in accordance with JIS-G3312.

Second bending tack test

The specimens were soaked in boiling water for 2 hours and exposed to air for one day. The bending tack test was then conducted in the same manner as in the first bending tack test.

Evaluation of Bending Adhesion Test

5: not peeled off

4: peeling area is less than 10%

3: peeling area 10 ~ 50%

2: the peeling area is 51 ~ 80%

1: peeling area exceeded 80%

6-3. Coin-Scratch-Test

The surface of the coating was scratched at a constant rate by applying a 3 kg load while keeping a 10 yen coin at 45 ° to the specimen. After such testing, the resulting wounds on the coating surface were investigated. The specimens were evaluated by the following grades.

5: No exposed metal surface (only bare painting is exposed)

4: less than 10% exposed metal surface

3: 10% or more and less than 50% exposed metal surface

2: 50% or more exposed metal surface is less than 80%

1: 80% or more of the exposed metal surface

The test results are summarized in Table 1. Comparative Example 5 in Table 1 shows excellent corrosion resistance and paintability. However, it is made using liquids containing chromates and is not suitable because it generates polluted industrial waste. In Examples 1 to 8 in Table 1, the surface treatment composition of the present invention was used and no harmful industrial waste was generated. Excellent corrosion resistance and colorability were obtained as in Comparative Example 5. Comparative Example 1 does not contain a silane coupling agent. In addition, Comparative Examples 2, 3 and 4 show that a solution different from the surface treatment composition of the present invention was used, which shows unsatisfactory results in corrosion resistance and / or colorability.

The surface treatment agents according to the invention provide a satisfactory level of corrosion resistance and colorability without the use of any chromates, allowing the industry to adapt in the future where the use of chromates is more strictly prohibited. In addition, the surface treatment composition according to the present invention does not selectively act according to the type of metal material to be used, thereby improving the corrosion resistance and paintability of many kinds of metal materials so that the advantages of each metal material can be exhibited to the maximum. Can be.

Therefore, the surface treatment composition according to the present invention is very suitable for practical application, especially in view of environmental protection and resource recycling.

Claims (7)

A surface treating agent aqueous composition for metal materials, comprising (A), (B) and (C) dissolved and / or dispersed. (A) a silane coupling agent containing at least one silane coupling compound having at least one reactive functional group selected from an active hydrogen-containing amino group, an epoxy group, a vinyl group, a mercapto group and a methacryloxy group; (B) at least one water-soluble polymer represented by the formula (I) below and exhibiting an average degree of polymerization of 2 to 50; Wherein X bonded to the benzene ring is a hydrogen atom, a hydroxyl group, an alkyl group having any of C1 to C5, a hydroxyalkyl group having any of C1 to C5, an aryl group having any of C6 to C12, benzyl group , A benzal group, an unsaturated hydrocarbon group condensed with the benzene ring to form a naphthalene ring, or a group represented by the following formula (II) Wherein R1 and R2 each represent a hydrogen atom, a hydroxyl group, an alkyl group having any of C1 to C5 or a hydroxyalkyl group having any of C1 to C10, and each benzene in the formulas (I) and (II) Each of Y 1 and Y 2 bonded to the ring represents a Z group independently represented by formulas (III) and (IV) below. Wherein R 3, R 4, R 5, R 6 and R 7 each independently of one another represent a hydrogen atom, an alkyl group having any of C 1 to C 10 or a hydroxyalkyl group having any of C 1 to C 10 of the polymer molecule The average number of substitutions of the Z groups in each of the benzene rings is 0.2 to 1.0. (C) at least one inorganic compound selected from the group of the compounds of silica, silicates, metal salts and mixtures of any of them, dispersed in the colloidal state in said aqueous medium. The weight ratio of said silane coupling agent component (A) to said water soluble polymer component (B), that is, the weight ratio of (A) :( B) is 1:10 to 10: 1, and said inorganic compound component ( C) the weight ratio of [(A) + (B)], in other words (c): [(A) + (B)], is from 1: 5 to 5: 1, Surface treatment agent aqueous composition for metal materials. The silane coupling agent component (A) according to claim 1, wherein the silane coupling agent component (A) has a silane coupling agent containing (a) at least one silane coupling compound having at least one active hydrogen-containing amino group, and (b) at least one epoxysilane group. Containing a silane coupling agent containing at least one silane coupling compound, Surface treatment agent aqueous composition for metal materials. The equivalent ratio of the active hydrogen-containing amino group contained in the silane coupling agent (a) to the epoxysilane group contained in the silane coupling agent (b) is 3: 1 to 1: 3. Surface treatment agent aqueous composition for metal materials. The weight ratio of the sum of the silane coupling agent (a) and the silane coupling agent (b) to the water-soluble polymer component (B), i.e., [(a) + (b)]: B) the weight ratio is 1: 5 to 5: 1, Aqueous composition for surface treatment agent for metal materials The surface treating agent aqueous composition according to any one of claims 1 to 5, wherein the pH value is adjusted to 2.0 to 6.5, is adhered to the surface of the metal material and dried to obtain a dry weight of 0.01 to 2.0 g / m 2. Forming a coating, Surface treatment method for metal materials. The method of claim 6, wherein the surface of the metal material to be treated is pretreated by a phosphate layer forming process or a plating layer forming process prior to using the aqueous surfacing solution. Surface treatment method for metal materials.