KR102237992B1 - Cr-FREE SURFACE TREATMENT COMPOSITION HAVING HIGH CORROSION RESISTANCE FOR SURFACE COLORING AND SURFACE REPAIRING, AND METHOD FOR APPLYING THE SAME - Google Patents

Abstract

The present invention relates to a highly corrosion-resistant chromium-free surface treatment composition having a surface coloring and surface repair effect of a galvanized metal, and a method of treating the surface of a galvanized metal using the same.
Specifically, in the present invention, a binder composition comprising ethyl silicate, hydrochloric acid, ethanol, isopropyl alcohol, a methoxysilane-based compound, and deionized water; Coloring dyes; And as the chromium-free surface treatment composition comprising a colored pigment; the color of the surface of the galvanized metal while being able to replace the chromate treatment by remarkably improving the corrosion resistance, blackening resistance, white rust resistance and rust resistance of the galvanized metal It provides a chrome-free surface treatment composition that can be imparted and repaired, and a surface treatment method of galvanized metal using the same.
More specifically, in the present invention, by further comprising zinc flakes, a chrome-free surface treatment composition that implements more excellent surface repair properties, corrosion resistance, blackening resistance, white rust resistance and rust resistance, and a surface treatment method of galvanized metal using the same do.

Description

High corrosion resistance chrome-free surface treatment composition having surface coloring and surface repair effect of galvanized metal and its application method {Cr-FREE SURFACE TREATMENT COMPOSITION HAVING HIGH CORROSION RESISTANCE FOR SURFACE COLORING AND SURFACE REPAIRING, AND METHOD FOR APPLYING THE SAME}

The present invention relates to a highly corrosion-resistant chromium-free surface treatment composition having a surface coloring and surface repair effect of a galvanized metal, and a method of applying the same to the surface of a galvanized metal.

Specifically, the present invention relates to a chromium-free surface treatment composition capable of improving corrosion resistance and repairing the surface while coloring the surface of a galvanized metal, and a method of applying the same to the surface of a galvanized metal.

In general, to prevent corrosion on the surface of galvanized metal, chromate treatment is performed. In the chromate treatment, a liquid containing chromic acid is treated on the galvanized metal, and a chromate film is formed on the galvanized surface. , It refers to a treatment method that improves the gloss of the surface while improving the corrosion resistance. Such chromate treatment is low in cost and excellent in the degree of improvement in corrosion resistance and gloss of galvanized metal, and thus is mainly used for surface treatment of galvanized metal.

For example, in Korean Patent Registration No. 10-0405908, in order to improve the corrosion resistance and fuel resistance of a galvanized steel sheet, a galvanized steel sheet is added to an aqueous solution of chromium with a composition ratio of 3 carchrome of 0.4 to 0.8 in phosphoric acid, hydrofluoric acid, and colo. This month, a method of treating with a solution containing a main solution prepared by adding silica, sulfuric acid, and sodium phosphate, and a curing agent solution is disclosed.

The above-described chromate treatment has the advantage of improving the corrosion resistance and gloss of the galvanized metal, but there is a problem in that a large amount ^{of hexavalent chromium (Cr 6+ ), which is an environmentally harmful substance, is discharged during the chromate treatment.} In addition, the conventional chromate treatment is only possible to improve the glossiness of the galvanized metal, but does not realize the effect of imparting various colors of the galvanized surface.

Accordingly, recently, in order to replace the use of chromium, the development of a method for preventing surface corrosion of galvanized metal by forming a film on the surface of galvanized using polymers, molybdenum anions, silica, and bicarbonate is in progress. Has become. For example, in Korean Patent Application Laid-Open No. 10-2011-0049462, a coating layer is formed with a transparent resin of poly-ethylene-based, poly-urethane-based, poly-acrylic-based or poly-alkyd-based on the surface of galvanized metal, and galvanized. It is improving the corrosion resistance of the metal.

However, the coating or film formed of the conventional chromium-free surface treatment composition has low adhesion to zinc plating, and has a lower effect of improving the corrosion resistance, blackening resistance, white rust resistance, and rust resistance of the galvanized metal compared to the conventional chromate treatment. There was a problem. In addition, the effect of imparting various colors to the surface of the galvanized metal has not been realized.

Therefore, as a chromium-free surface treatment composition that has replaced the existing chromate treatment, it is possible to secure the corrosion resistance of the galvanized metal at a level similar or improved to that of the existing chromate treatment, while providing various colors to the surface of the galvanized metal. There is a need to develop a composition having an effect and a method of treating a galvanized metal using the same.

On the other hand, the conventional chromium-free surface treatment composition developed to date has not considered the effect of repairing the surface of the galvanized metal that has already been exposed to the outside and corrosion has occurred.

Accordingly, the Applicant is a chromium-free surface treatment composition that has replaced the existing chromate treatment, and can achieve high corrosion resistance similar to or improved from the existing chromate treatment, while simultaneously performing surface coloring and surface repair of galvanized metal. By developing a composition that is present, the present invention has been completed.

Korean Patent Registration No. 10-0405908 Republic of Korea Patent Publication No. 10-2011-0049462

The first object of the present invention is to significantly improve the corrosion resistance, blackening resistance, white rust resistance, and rust resistance of the galvanized metal, so that it is possible to replace the existing chromate treatment, while giving various colors to the surface of the galvanized metal. It is to provide a chromium-free surface treatment composition capable of repairing the surface of a galvanized metal that has already been exposed to the outside and has been subjected to corrosion.

The second object of the present invention is to replace the existing chromate treatment, to significantly improve the corrosion resistance, blackening resistance, white rust resistance, rust resistance, etc. of the galvanized metal, while providing various colors to the surface of the galvanized metal. In addition, it is to provide a method for surface treatment of galvanized metal that can repair the surface of galvanized metal that has already been exposed to the outside and has been subjected to corrosion.

The object of the present invention is not limited to the above-described technical problem, and another technical problem may be derived from the following description.

In order to achieve the first object, the present invention is a chromium-free surface treatment composition for improving the surface coloring and corrosion resistance of galvanized metal, including ethyl silicate, hydrochloric acid, ethanol, isopropyl alcohol, methoxy silane compound, and deionized water. Binder composition comprising a; Coloring dyes; And it provides a chromium-free surface treatment composition for improving the surface coloring and corrosion resistance of the galvanized metal containing;

The binder composition includes 45 to 60% by weight of ethyl silicate, 0.1 to 4% by weight of hydrochloric acid, 10 to 25% by weight of ethanol, 2 to 7% by weight of isopropyl alcohol, and 5 to 15 of methoxy silane compounds based on the total weight of the binder composition. It may contain 10 to 20% by weight and 10 to 20% by weight of deionized water.

It may include 0.1 to 20 parts by weight of the colored dye and 0.1 to 20 parts by weight of the colored pigment based on 100 parts by weight of the binder composition.

The methoxy silane-based compound may include glycidoxypropyltrimethoxysilane and methyltrimethoxysilane.

The methoxy silane-based compound may include glycidoxypropyltrimethoxysilane and methyltrimethoxysilane in a weight ratio of 1: 0.5 to 2.

The colored dye is one selected from the group consisting of azo dyes, anthraquinone dyes, xanthene dyes, triarylmethane dyes, phthalocyanine dyes, quinone imine dyes, quinoline dyes, nitro dyes and methine dyes. It may include more than one.

The colored pigment may include one or more selected from the group consisting of inorganic pigments and organic pigments.

The chrome-free surface treatment composition may further include zinc flakes.

The zinc flake may be further included in an amount of 10 to 40 parts by weight based on 100 parts by weight of the binder composition.

The zinc flake may have a length: 18 to 25 micrometers and an average particle diameter (D50): 15 to 20 micrometers.

In order to achieve the second object, as a method of treating the surface of a galvanized metal with a chromium-free surface treatment composition for improving the surface coloration and corrosion resistance of the galvanized metal, (a) chromium on the surface of the galvanized metal. A first step of applying the pre-surface treatment composition; And (b) a second step of drying the chromium-free surface treatment composition applied to the surface of the galvanized metal, wherein the chromium-free surface treatment composition is ethyl silicate, hydrochloric acid, ethanol, isopropyl alcohol, methoxy silane compound And a binder composition comprising deionized water; Coloring dyes; It provides a method of treating the surface of a galvanized metal with a chrome-free surface treatment composition comprising; and a colored pigment.

In the first step, applying the chromium-free surface treatment composition to the surface of the galvanized metal may be carried out by any one method selected from the group consisting of coating, immersion, dip spin, and spray spray.

The chromium-free surface treatment composition according to the present invention can significantly improve the corrosion resistance, blackening resistance, white rust resistance, rust resistance, etc. of the galvanized metal, thereby replacing the existing chromate treatment.

The coating film formed of the chromium-free surface treatment composition according to the present invention may have excellent adhesion to the galvanized surface. In addition, the coating film formed of the chromium-free surface treatment composition according to the present invention may have excellent adhesion to another coating film, which is formed on an upper portion of the coating film formed of the chromium-free surface treatment composition. In this case, the other coating film may mean that it is formed of a composition for another use or purpose in addition to the coating film formed of the chromium-free surface treatment composition.

The chromium-free surface treatment composition according to the present invention can impart various colors to the surface of the galvanized metal, thereby improving the aesthetics of the object to which galvanizing or galvanizing is applied.

The chromium-free surface treatment composition according to the present invention can repair the surface of galvanized metal that has already been exposed to the outside and has been subjected to corrosion. At this time, repairing the surface of the galvanized metal may mean improving the corrosion resistance of the surface of the galvanized metal in which the corrosion has occurred, and at the same time making the appearance of the surface uniform through coloring.

The chrome-free surface treatment composition according to the present invention may further improve properties such as surface repair properties, durability, and corrosion resistance by further comprising zinc flakes. In addition, flaky zinc flakes supplement zinc lost due to corrosion and prevent the penetration of corrosion factors from the outside while improving the compactness of the structure, thereby improving properties such as surface repair, durability, and corrosion resistance. It can be further improved.

The chromium-free surface treatment composition according to the present invention can be cured at room temperature and thus has excellent usability.

In addition, according to the method for surface treatment of galvanized metal using the chromium-free surface treatment composition according to the present invention, the corrosion resistance, blackening resistance, white rust resistance, and rust resistance of the galvanized metal can be remarkably improved. While being replaceable, it is possible to realize the effect of surface coloring and surface repair of galvanized metal.

1 is a view showing a (A) hot-dip galvanized steel sheet surface-treated with the composition of Example 2.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those of ordinary skill in the art can easily implement the present invention. However, the present invention may be implemented in various different forms and is not limited to the embodiments described herein. In the drawings, parts not related to the description are omitted in order to clearly describe the present invention.

The terms or words used in the specification and claims of the present invention are not limited to a conventional or dictionary meaning, and the inventor can appropriately define the concept of terms in order to describe his own invention in the best way. Based on the principle, it should be interpreted as a meaning and concept consistent with the technical idea of the present invention.

Throughout the specification of the present invention, when a certain part "includes" a certain component, it means that other components may be further included rather than excluding other components unless specifically stated to the contrary. .

In the entire specification of the present invention, "A and/or B" means A or B, or A and B.

Hereinafter, the present invention has been described in detail, but the present invention is not limited thereto.

The present invention provides a highly corrosion-resistant chromium-free surface treatment composition having surface coloring and surface repair effects of galvanized metal.

In an embodiment of the present invention, a binder composition comprising ethyl silicate, hydrochloric acid, ethanol, isopropyl alcohol, a methoxy silane compound, and deionized water; Coloring dyes; It provides a chrome-free surface treatment composition comprising; and a colored pigment. The chromium-free surface treatment composition of the present embodiment may be applied or applied to the surface of a galvanized metal to form a coating film.

The coating film may mean a coating layer, a film, a thin film, etc. formed by applying or applying the chromium-free surface treatment composition of the present embodiment to a galvanized metal surface.

The chromium-free surface treatment composition according to the present embodiment can significantly improve corrosion resistance, blackening resistance, white rust resistance, rust resistance, and the like of galvanized metal, thereby replacing the existing chromate treatment. Accordingly, human body hazards and environmental pollution problems caused by chromate treatment can be prevented.

In addition, the chromium-free surface treatment composition according to the present embodiment can impart various colors to the surface of the galvanized metal, thereby improving the aesthetics of the object to which galvanizing or galvanizing is applied.

In addition, the chromium-free surface treatment composition according to the present embodiment can repair the surface of the galvanized metal that has already been exposed to the outside and has been subjected to corrosion. That is, the chromium-free surface treatment composition according to the present embodiment can be applied to both the surface of the galvanized metal in which corrosion has not occurred and the surface of the galvanized metal that has already been exposed to the outside to cause corrosion. At this time, repairing the surface of the galvanized metal may mean improving the corrosion resistance of the surface of the galvanized metal in which the corrosion has occurred, and at the same time making the appearance of the surface uniform through coloring.

The chromium-free surface treatment composition of this embodiment includes a binder composition containing ethyl silicate, hydrochloric acid, ethanol, isopropyl alcohol, a methoxy silane compound, and deionized water.

Ethyl silicate imparts strong caking properties to sand or refractories, and has the property of depositing silica from a solution while drying, and is also called ethyl silicate. The molecular formula of the ethyl silicate is Si(OC ₂ H ₅ ) ₄ . In this embodiment, ethyl silicate can improve the adhesion between the surface of the galvanized metal and the coating film formed using the chromium-free surface treatment composition of this embodiment, as well as improve corrosion resistance, blackening resistance, white rust resistance, and rust resistance. .

In more detail, ethyl silicate is hydrolyzed to form polysilicate in the chromium-free surface treatment composition of the present embodiment, thereby increasing the compactness of the structure. In addition, by forming a zinc-silicon bond at the interface between the galvanized metal and the coating film formed using the chromium-free surface treatment composition of this embodiment, between the galvanized metal and the coating film formed using the chromium-free surface treatment composition of this embodiment. It can improve adhesion.

The binder composition of this embodiment may contain 45 to 60% by weight of ethyl silicate, preferably 47 to 55% by weight, and more preferably 50 to 52% by weight, based on the total weight.

If the amount of ethyl silicate is less than 45% by weight based on the total weight of the binder composition of this embodiment, the adhesion between the surface of the galvanized metal and the coating film formed using the binder composition of this embodiment is lowered, corrosion resistance, There may be a problem that blackening resistance, white rust resistance, and rust resistance are deteriorated. On the other hand, when containing more than 60% by weight of ethyl silicate based on the total weight of the binder composition of the present embodiment, there may be a problem that cracks and breakages of the coating film formed of the binder composition of the present embodiment are easily generated.

Hydrochloric acid can act as a catalyst to accelerate the hydrolysis of ethyl silicate. The binder composition of this embodiment may contain hydrochloric acid in an amount of 0.1 to 4% by weight, preferably 0.5 to 2% by weight, more preferably 0.7 to 1.5% by weight, based on the total weight.

If, based on the total weight of the binder composition of the present embodiment, hydrochloric acid is included in an amount of less than 0.1% by weight, the hydrolysis time of ethyl silicate increases, and the degree of hydrolysis is insufficient, so adhesion, corrosion resistance, blackening resistance, There may be a problem in that properties such as white rust resistance and rust resistance are deteriorated. On the other hand, in the case of containing more than 4% by weight of hydrochloric acid based on the total weight of the binder composition of the present embodiment, the pH of the binder composition of the present embodiment is rapidly lowered, thereby deteriorating formulation stability, storage stability, and usability, as well as galvanizing. There may be a problem that promotes corrosion of the metal.

Ethanol may play a role in controlling the flowability and viscosity of the binder composition of the present embodiment. In addition, a coating film having a uniform thickness and an even surface can be formed on the surface of the galvanized metal.

The binder composition of this embodiment may contain 10 to 25% by weight of ethanol, preferably 15 to 22% by weight, and more preferably 17 to 20% by weight, based on the total weight.

If the amount of ethanol is less than 10% by weight based on the total weight of the binder composition of this example, the viscosity of the binder composition of this example increases, the flowability decreases, the thickness of the coating film becomes thicker, and the cracking of the coating film. And there may be a problem that breakage easily occurs. On the other hand, when containing more than 25% by weight of ethanol based on the total weight of the binder composition of this example, the content of ethyl silicate in the binder composition of this example is relatively reduced, so that adhesion, corrosion resistance, blackening resistance, white rust resistance, rust resistance, etc. There may be a problem with this deterioration.

Isopropyl alcohol may serve to improve the stability of the binder composition of the present embodiment and to control flowability and viscosity. The binder composition of this embodiment may contain 2 to 7% by weight, preferably 3 to 6% by weight, and more preferably 4 to 5% by weight of isopropyl alcohol based on the total weight.

If the binder composition of the present embodiment contains less than 2% by weight of isopropyl alcohol based on the total weight, the stability and flowability of the binder composition of the present embodiment may decrease, and viscosity may increase. On the other hand, when the binder composition of this example contains more than 7% by weight of isopropyl alcohol based on the total weight, as the content of ethyl silicate in the binder composition of this example is relatively reduced, adhesion, corrosion resistance, and blackening resistance , There may be a problem that the white rust resistance, rust resistance, etc. are deteriorated.

The methoxy silane-based compound may include glycidoxypropyltrimethoxysilane and methyltrimethoxysilane.

The glycidoxypropyltrimethoxysilane improves adhesion and adhesion of the coating film formed using the binder composition of the present embodiment, and prevents excessive increase in viscosity, thereby improving flowability. . The methyltrimethoxysilane may improve the water resistance of the coating film formed by using the binder composition of the present embodiment. In addition, by making the coating film hydrophobic, it is possible to have a self-cleaning effect from an external contaminant.

Preferably, in this embodiment, when the glycidoxypropyltrimethoxysilane and methyltrimethoxysilane are included in a weight ratio of 1: 0.5 to 2 as a methoxy silane compound, more excellent adhesion, corrosion resistance, and blackening resistance , White rust resistance, may have properties such as rust resistance.

More preferably, the methoxy silane-based compound of the present embodiment may include the glycidoxypropyltrimethoxysilane and methyltrimethoxysilane in a weight ratio of 1: 1.25. In particular, when the methoxy silane compound of this embodiment contains the glycidoxypropyltrimethoxysilane and methyltrimethoxysilane in a weight ratio of 1: 1.25, remarkably excellent adhesion, corrosion resistance, blackening resistance, white rust resistance, It may have properties such as rust prevention.

The binder composition of the present embodiment may include 5 to 15% by weight, preferably 7 to 13% by weight, and more preferably 9 to 10% by weight of the methoxy silane compound based on the total weight.

If, based on the total weight of the binder composition of the present embodiment, the methoxy silane compound is included in an amount of less than 5% by weight, adhesion, adhesion, and flow properties are deteriorated, and water resistance and hydrophobicity are not sufficiently improved, so self-cleaning ability. There may be a problem with this deterioration. On the other hand, when containing more than 15% by weight of the methoxysilane-based compound based on the total weight of the binder composition of the present embodiment, the effect of improving adhesion and adhesion is insignificant, and there is a problem that cracks and breakage of the coating film are easily generated. In addition, there may be a problem in that the stability is deteriorated due to the precipitation of white powder on the surface of the coating film.

Deionized water serves to aid in the hydrolysis of ethyl silicate. As ethyl silicate is hydrolyzed by deionized water to form polysilicate, it may have the same effect as described above.

The binder composition of this embodiment may contain 10 to 20% by weight, preferably 12 to 17% by weight, and more preferably 14 to 15% by weight of deionized water based on the total weight.

If the amount of deionized water is less than 10% by weight based on the total weight of the binder composition of the present embodiment, as the ethyl silicate is not sufficiently hydrolyzed, adhesion, corrosion resistance, blackening resistance, white rust resistance, rust resistance, There may be a problem of deteriorating stability, etc. On the other hand, when the amount of deionized water exceeds 20% by weight based on the total weight of the binder composition of the present embodiment, the stability of the chromium-free surface treatment composition according to the present embodiment may be deteriorated, and there may be a problem that deterioration occurs. .

The chromium-free surface treatment composition of this embodiment contains a colored dye.

The colored dye serves to impart various colors to the chromium-free surface treatment composition of the present embodiment and a coating film formed using the same. Particularly, the chromium-free surface treatment composition of the present embodiment includes the above-described binder composition and a colored dye together, so that stable color can be realized by the colored dye.

The colored dye is one selected from the group consisting of azo dyes, anthraquinone dyes, xanthene dyes, triarylmethane dyes, phthalocyanine dyes, quinone imine dyes, quinoline dyes, nitro dyes and methine dyes. It may include the above, but is not limited thereto.

The azo dyes, anthraquinone dyes, xanthene dyes, triarylmethane dyes, phthalocyanine dyes, quinone imine dyes, quinoline dyes, nitro dyes and methine dyes are all known types of Dyes can be used.

For example, the azo dye, anthraquinone dye, xanthene dye, triarylmethane dye, phthalocyanine dye, quinone imine dye, quinoline dye, nitro dye and methine dye include the following The same color index (CI) name may be used, but is not limited thereto.

The azo dyes are CI Acid Yellow 11, CI Acid Orange 7, CI Acid Red 37, CI Acid Red 180, CI Acid Blue 29, CI Solvent Red 89, CI Direct Red 28, CI Direct Red 83, CI Direct Yellow 12, CI Direct Orange 26, CI Direct Green 28, CI Direct Green 59, CI Reactive Yellow 2, CI Reactive Red 17, CI Reactive Red 120, CI Disperse Orange 5, CI Disperse Red 58, CI Disperse Blue 165 , CI Basic Blue 41, CI Basic Red 18, CI Mordant Red 7, CI Mordant Yellow 5, C.1. Acid Yellow 21, CI It may include at least one selected from the group consisting of acid blue 70 and C.I. acid black 27, but is not limited thereto.

The anthraquinone dyes are CI Bat Blue 4, CI Acid Blue 40, CI Acid Green 25, CI Reactive Blue 19, CI Reactive Blue 49, CI Disperse Red 60, CI Disperse Blue 56, CI Disperse Blue 60 And one or more selected from the group consisting of CI solvent red 127, but is not limited thereto.

The xanthene-based dye may include at least one selected from the group consisting of C.I. basic red 1, C.I. basic red 1:1, C.I. basic violet 10, and C.I. solvent red 49, but is not limited thereto.

The triarylmethane-based dye may include one or more selected from the group consisting of C.I. basic blue 7 and C.I. basic blue 11, but is not limited thereto.

The phthalocyanine-based dye may include C.I. pad blue 5, but is not limited thereto.

The quinone imine-based dye may include at least one selected from the group consisting of C.I. basic blue 3 and C.I. basic blue 9, but is not limited thereto.

The quinoline-based dye may include at least one selected from the group consisting of C.I. solvent yellow 33, C.I. acid yellow 3, C.I. disperse yellow 64 and C.I. pigment red 122, but is not limited thereto.

The nitro-based dye may include at least one selected from the group consisting of C.I. acid yellow 1, C.I. acid orange 3, C.I. disperse yellow 42, and C.I. solvent orange 62, but is not limited thereto.

The methine-based dye may include C.I. solvent yellow 179, but is not limited thereto.

The colored dye according to the present embodiment may include the above-described dye as it is, or may be included in the form of a mixture obtained by dispersing, mixing, or dissolving the above-described dye in an organic solvent such as alcohol. For example, the organic solvent may be ethanol, isopropyl alcohol, or the like.

The chrome-free surface treatment composition of this embodiment may include 0.1 to 20 parts by weight of the coloring dye, specifically 1 to 17 parts by weight, and more specifically 3 to 10 parts by weight, based on 100 parts by weight of the binder composition, but is limited thereto. It doesn't work.

If the chromium-free surface treatment composition of the present embodiment contains less than 0.1 parts by weight of the coloring dye based on 100 parts by weight of the binder composition, the color realization effect may be reduced. On the other hand, when the chromium-free surface treatment composition of this embodiment contains more than 20 parts by weight of the coloring dye based on 100 parts by weight of the binder composition, there is a problem that the formulation stability and adhesion of the chromium-free surface treatment composition are deteriorated. There may be.

The chrome-free surface treatment composition of this embodiment contains a colored pigment.

The colored pigment imparts various colors to the chromium-free surface treatment composition of the present embodiment and a coating film formed using the same, and serves to impart a hiding power. In particular, the chromium-free surface treatment composition of the present embodiment includes the above-described binder composition and a colored pigment together, thereby improving the dispersibility and stability of the colored pigment and implementing an anti-aggregation effect.

The colored pigment may include one or more selected from the group consisting of inorganic pigments and organic pigments.

The inorganic pigment may include at least one selected from the group consisting of carbon black, graphite, titanium oxide, zinc oxide, iron oxide sulfur, iron oxide red, brown iron oxide, and black iron oxide, but is not limited thereto.

As the organic pigment, all kinds of known organic pigments may be applied, and there is no particular limitation.

The chrome-free surface treatment composition of this embodiment may include 0.1 to 20 parts by weight of the colored pigment, specifically 3 to 15 parts by weight, and more specifically 5 to 12 parts by weight, based on 100 parts by weight of the binder composition, but is limited thereto. It doesn't work.

If the chromium-free surface treatment composition of the present embodiment contains less than 0.1 parts by weight of the colored pigment with respect to 100 parts by weight of the binder composition, the hiding power is lowered, so that color realization may not be sufficient. On the other hand, when the chromium-free surface treatment composition of this embodiment contains more than 20 parts by weight of the colored pigment with respect to 100 parts by weight of the binder composition, there is a problem that the formulation stability and adhesion of the chromium-free surface treatment composition are deteriorated There may be.

The chrome-free surface treatment composition of the present embodiment may further include zinc flakes.

Zinc flakes may improve properties such as surface repair properties, durability, and corrosion resistance of the chromium-free surface treatment composition of the present embodiment, and may serve to supplement zinc lost due to corrosion. In addition, since the zinc flake is formed in a flake shape, it is possible to remarkably improve the compactness of the structure while preventing the penetration of corrosion factors from the outside.

The zinc flake of this embodiment may have a length: 18 to 25 micrometers and an average particle diameter (D50): 15 to 20 micrometers. Specifically, the zinc flakes of this embodiment may have a length: 18 to 25 micrometers, an average particle diameter (D50): 15 to 20 micrometers, and a thickness: 0.5 to 1 micrometer, but are not limited thereto. In this case, the zinc flake may have a color of silver or silver gray.

The chrome-free surface treatment composition of the present embodiment may further include 10 to 40 parts by weight of the zinc flake, specifically 10 to 20 parts by weight, based on 100 parts by weight of the binder composition, but is not limited thereto.

If the chromium-free surface treatment composition of the present embodiment contains less than 10 parts by weight of the zinc flake relative to 100 parts by weight of the binder composition, the effect of improving the surface repair effect, surface coloring effect, and corrosion resistance may be insignificant. . On the other hand, when the chromium-free surface treatment composition of the present embodiment contains more than 40 parts by weight of the zinc flake with respect to 100 parts by weight of the binder composition, there is a problem that the formulation stability and adhesion of the chromium-free surface treatment composition are deteriorated. There may be.

In addition to ethyl silicate, hydrochloric acid, ethanol, isopropyl alcohol, methoxy silane-based compounds, deionized water, colored dyes and colored pigments, the chromium-free surface treatment composition of this example is a curing agent, stabilizer, softener, curing agent, curing accelerator, pH It may further include additives such as a modifier, a brightener, a dispersant, an antifoaming agent, an antioxidant, and an anti-aging agent. As the additive, all kinds of known additives may be applied.

The chrome-free surface treatment composition of this embodiment is a liquid, and may be formed at a pH of 5 to 6, and a viscosity of 10 to 20 cps. (20° C., B type viscometer). Accordingly, properties such as adhesion, corrosion resistance, blackening resistance, white rust resistance, and rust resistance of the surface treatment composition according to the present embodiment may be improved.

The chromium-free surface treatment composition of this embodiment may be applied and applied to the surface of a galvanized metal to form a coating film. The thickness of the coating film may be 3 to 15 micrometers. For example, when the galvanized metal is a steel sheet, the thickness of the coating film may be about 3 micrometers, but is not limited thereto.

In addition, when the chromium-free surface treatment composition of this example is applied to a galvanized metal, the chromium-free surface treatment composition of this example penetrates or reacts at the interface to the surface of the galvanized metal, resulting in polysilicate and zinc-silicon bonding. The formed first layer may be formed. In addition, on the first layer, a second layer including a silicon-oxygen bond by a reaction between the chromium-free surface treatment composition of the present embodiment and air may be formed.

The adhesion, adhesion, and bonding strength between the metal galvanized by the first layer and the coating film formed using the chromium-free surface treatment composition of the present embodiment may be excellent, thereby preventing the penetration of foreign substances, thereby preventing corrosion resistance and blackness. Denaturation, white rust resistance, rust resistance, etc. can be improved. In addition, as the penetration of external substances is prevented by the second layer, corrosion resistance, blackening resistance, white rust resistance, rust resistance, and the like may be further improved. The first layer and the second layer are randomly separated by each material or bonding state, and are one continuous layer.

In addition, the present invention provides a method of treating the surface of a galvanized metal with a highly corrosion-resistant chromium-free surface treatment composition having a surface coloring and surface repair effect of the galvanized metal.

In another embodiment of the present invention, as a method of treating the surface of a galvanized metal with the above-described chromium-free surface treatment composition, (a) ethyl silicate, hydrochloric acid, ethanol, isopropyl alcohol, methoxyl on the surface of the galvanized metal. A binder composition containing a silane-based compound and deionized water; Coloring dyes; And a first step of applying a chromium-free surface treatment composition comprising a colored pigment; And (b) a second step of drying the chromium-free surface treatment composition applied to the surface of the galvanized metal, and provides a method of treating the surface of the galvanized metal with the chromium-free surface treatment composition.

According to the surface treatment method of galvanized metal using the chromium-free surface treatment composition of this embodiment, corrosion resistance, blackening resistance, white rust resistance, and rust resistance of the galvanized metal can be remarkably improved, thereby replacing the existing chromate treatment. At the same time, it is possible to repair the surface of the galvanized metal, which has already been exposed to the outside and corroded, while giving various colors to the surface of the galvanized metal.

(a) the first step of applying a chromium-free surface treatment composition to the surface of the galvanized metal

In the first step of applying the chromium-free surface treatment composition to the surface of the galvanized metal of the present embodiment, the chromium-free surface treatment composition may be applied to the surface of the galvanized metal by any known method. Specifically, applying the chromium-free surface treatment composition to the surface of the galvanized metal in the first step of the present embodiment may be carried out by any one method selected from the group consisting of coating, immersion, dip spin, and spray spray. However, it is not limited thereto.

For example, the application may be performed by applying the chrome-free surface treatment composition of the present embodiment to the surface of the galvanized metal by means such as a brush or a roller.

In addition, the immersion may be carried out by immersing the galvanized metal in the chromium-free surface treatment composition of the present embodiment and then leaving it for a certain period of time. Specifically, it may be carried out by immersing the galvanized metal in the chromium-free surface treatment composition of the present embodiment for about 10 to 60 seconds, but is not limited thereto.

In addition, the dip spin is, after immersing the galvanized metal in the chromium-free surface treatment composition of this embodiment for about 10 to 60 seconds, and then put into a rotating basket at a rotation speed of 200 to 400 rpm, about 5 to 15 By removing for seconds, this can be done, but is not limited thereto.

In addition, the spray spraying may be carried out by spraying and applying the chromium-free surface treatment composition according to the present embodiment to the surface of the galvanized metal by a known method, but is not limited thereto.

(b) the second step of drying the chromium-free surface treatment composition applied to the surface of the galvanized metal

In the second step of drying the chromium-free surface treatment composition applied to the surface of the (b) galvanized metal of this embodiment, the galvanized metal to which the chromium-free surface treatment composition is applied in the step (a) is dried and cured at a specific temperature. By doing so, a coating film using the chromium-free surface treatment composition of the present embodiment can be formed on the surface of the galvanized metal.

Specifically, drying in step (b) of the present embodiment may be performed at a temperature of room temperature to 100° C., but is not limited thereto.

More specifically, drying in step (b) of the present embodiment may be performed at room temperature, but is not limited thereto. In particular, the chromium-free surface treatment composition of this embodiment can be naturally dried and cured at room temperature, so it can be convenient to use.

The method of treating the surface of a galvanized metal with the chromium-free surface treatment composition for improving the surface coloring and corrosion resistance of the galvanized metal of the present invention is chromium-free for improving the surface coloring and corrosion resistance of the galvanized metal of the present invention. It includes all the contents of the surface treatment composition.

Hereinafter, a chromium-free surface treatment composition for improving the surface coloring and corrosion resistance of the galvanized metal of the present invention and a method of applying the same will be described in detail through Examples, Comparative Examples, and Experimental Examples. Since these examples are for illustrative purposes only, the scope of the present invention is not to be construed as being limited by these examples.

[Example]

Examples 1 to 3

(1) Preparation of binder composition

According to the composition of the following Table 1 [unit: weight%] and Table 2 [unit: weight ratio], a binder composition was prepared. In Table 1, the methoxy silane-based compounds in Table 2 were used, respectively.

(2) Preparation of chrome-free surface treatment composition

A chrome-free surface treatment composition comprising 5 parts by weight of a colored dye (C.I red 122) and 5 parts by weight of a colored pigment (red iron oxide) was prepared based on 100 parts by weight of the binder composition prepared according to (1).

Example 4

It was prepared in the same manner as in Example 3, except that a chromium-free surface treatment composition including a binder composition using only glycidoxypropyltrimethylmethoxysilane was used as a methoxy silane compound.

Example 5

It was prepared in the same manner as in Example 3, except that a chromium-free surface treatment composition including a binder composition using only methyltrimethoxysilane was used as a methoxy silane compound.

Examples 6 to 8

It was prepared in the same manner as in Example 2, except that the following zinc flakes were further included in Table 3 [unit: parts by weight] in 100 parts by weight of the binder composition.

At this time, zinc flakes were used having a length of 18 to 25 micrometers, and an average particle diameter (D50) of 15 to 20 micrometers.

[Comparative Example]

Comparative Example 1

The existing chromate treatment process was performed according to the following.

The galvanized metal was washed with water, immersed in 0.5 to 1% acetic acid solution, and then washed with water and chromated. At this time, the chromate treatment was performed by immersing the galvanized metal washed according to the above in a solution of KCr(SO ₄ ) ₂ 20 g/L (Cr ³⁺ standard = 2.344 g/L) and then drying.

Subsequently, the chromate-treated galvanized metal was washed with water and hot water, and then dried at about 60°C to prepare a chromated galvanized metal.

Comparative Examples 2 to 13

It was prepared in the same manner as in Example 3, except that a chromium-free surface treatment composition containing a binder composition according to the composition ratio of Table 4 [unit: wt%] was used.

[Experimental Example]

Experimental Example 1: Corrosion resistance test of hot-dip galvanized metal

(1) Corrosion resistance evaluation 1 (Molten galvanized steel sheet → composition application)

After a salt spray test (ASTM B 117 test method: NaCl 5% solution, 35° C.) using each of the galvanized metal (melted zinc-plated steel sheet) on which a coating film was formed by the chromium-free surface treatment composition according to Example 1, The occurrence of rust (white or red rust) was observed with the naked eye. Table 5 shows the results observed with the naked eye according to the above. At this time, when rust (white or red rust) occurred, it was marked as ○, and if rust (white or red rust) did not occur, it was marked as X.

Meanwhile, a method of treating the surface of a galvanized metal with a chrome-free surface treatment composition is as follows.

After immersing the galvanized metal in the chromium-free surface treatment composition according to Example 1 and drying it at room temperature, a coating film was formed with the chromium-free surface treatment composition on the surface of the galvanized metal. At this time, the surface treatment was performed using a hot-dip galvanized steel sheet as the galvanized metal, and FIG. 1 shows that the hot-dip galvanized steel sheet was surface-treated. The hot-dip galvanized steel sheet was hot-dip galvanized to a thickness of about 75 micrometers according to HDZ55 conditions of KS D 8308 standard. Specifically, in the case of the hot-dip galvanized steel sheet, after the hot-dip galvanized steel sheet was immersed in a chrome-free surface treatment composition, it was dried by dropping a paint (Drain method) for about 1 to 3 minutes.

In the same manner as above, the chromium-free surface treatment compositions of Examples 2 to 8 and Comparative Examples 1 to 13 were applied to a hot-dip galvanized steel sheet, and then corrosion resistance was evaluated, and the results are shown in Table 5.

(2) Corrosion resistance evaluation 2 (after forced corrosion of hot-dip galvanized steel sheet → application of composition)

First, according to the HDZ55 conditions of the KS D 8308 standard, a hot-dip galvanized steel sheet with a thickness of about 75 micrometers is prepared, and it is ASTM B 117 standard (pH: 6.5 ~ 7.2, chamber temperature: 35 ℃, 5% NaCl solution. Spraying amount: 1 ~ 2 mL/h), the hot-dip galvanized steel sheet was forcibly damaged by exposing it to a neutral salt water spray tester for about 300 hours. That is, in order to give the same effect that the hot-dip galvanized metal was damaged by exposure to the external environment, after accelerating aging through salt spray, the following experiment was conducted.

Thereafter, the chromium-free surface treatment composition according to Example 1 was applied to the damaged hot-dip galvanized steel sheet, and allowed to stand at room temperature for about 5 minutes to cure, thereby forming a coating film with the composition according to Example 1. The process of applying the chromium-free surface treatment composition according to Example 1 to the damaged hot-dip galvanized steel sheet was the same as in (1) of Experimental Example 1.

Subsequently, after exposing the hot-dip galvanized steel sheet on which the coating film was formed with the composition according to Example 1 to brine according to the ASTM B 117 standard, while observing it with the naked eye, the occurrence of rust (white or red rust) over time was evaluated. Then, the results are shown in Table 6. In this case, if rust (white or red rust) occurred regardless of the amount of occurrence, it was marked as'○', and if rust (white or red rust) did not occur, it was marked as'Х'.

In addition, using the compositions of Examples 2 to 8 and Comparative Examples 1 to 13 in the same manner as above, the corrosion resistance of the hot-dip galvanized metal was evaluated in the same manner as above, and the results are shown in Table 6.

Looking at Tables 5 and 6, it can be seen that rust is rapidly generated in the case of the comparative example not according to the present embodiment compared to the example according to the present embodiment.

In more detail, referring to Examples 1 to 3 and Comparative Example 1, it can be seen that the rust prevention effect is remarkably superior when the chromium-free surface treatment composition of this example is treated as compared to the conventional chromate treatment. In addition, referring to Examples 1 to 3 and Comparative Examples 2 to 13, the chromium-free surface treatment composition of this example contains ethyl silicate, hydrochloric acid, ethanol, isopropyl alcohol, methoxy silane compound, colorant, and deionized water in a specific amount. When the containing binder composition is included, it can be seen that the rust prevention effect is improved.

In addition, looking at Examples 1 to 3 and Examples 4 to 5, it can be seen that when glycidoxypropyltrimethoxysilane and methyltrimethoxysilane are included together as a methoxysilane-based compound, the rust prevention effect is improved. have. Particularly, referring to Examples 1 to 3, when glycidoxypropyltrimethoxysilane and methyltrimethoxysilane are included as methoxy silane compounds, when they are included in a specific ratio (1: 1.25 weight ratio), rust prevention It can be seen that the effect is improved.

In addition, looking at Examples 2 and 6 to 8, the chrome-free surface treatment composition of the present embodiment further comprises zinc flakes, but further comprises 10 to 40 parts by weight of the zinc flakes based on 100 parts by weight of the binder composition. In this case, it can be seen that the effect of improving the corrosion resistance is remarkably excellent. In particular, looking at the results of Table 6 using the already corroded hot-dip galvanized metal, it can be seen that when the zinc flake is further included in an amount of 10 to 40 parts by weight with respect to 100 parts by weight of the binder composition, the effect of improving corrosion resistance is excellent. . That is, when the chromium-free surface treatment composition of the present embodiment further contains 10 to 40 parts by weight of the zinc flake relative to 100 parts by weight of the binder composition, corrosion resistance is generated by repairing the surface of the hot-dip galvanized metal damaged. It means making it possible to re-implement it.

Experimental Example 2: Corrosion resistance test of electro-galvanized metal

The corrosion resistance of Example 1 was evaluated in the same manner as in Experimental Example 1, but an electro-galvanized steel sheet was used in place of the hot-dip galvanized steel sheet, and the results are shown in Tables 7 and 8.

Corrosion resistance evaluation of the compositions according to Examples 2 to 8 and Comparative Examples 1 to 13 was performed in the same manner as in Example 1.

(1) Corrosion resistance evaluation 1 (electric galvanized steel sheet → composition application)

(2) Corrosion resistance evaluation 2 (after forcibly damaging the electro-galvanized steel sheet → application of the composition)

Referring to Tables 7 and 8, it can be seen that rust is rapidly generated in the case of the comparative example not according to the present embodiment compared to the example according to the present embodiment.

In addition, looking at Examples 1 to 3 and Comparative Example 1, it can be seen that the rust prevention effect is remarkably superior when the chromium-free surface treatment composition of this example is treated as compared to the conventional chromate treatment. In addition, referring to Examples 1 to 3 and Comparative Examples 2 to 13, the chromium-free surface treatment composition of this example contains ethyl silicate, hydrochloric acid, ethanol, isopropyl alcohol, methoxy silane compound, colorant, and deionized water in a specific amount. When the containing binder composition is included, it can be seen that the rust prevention effect is improved.

In addition, looking at Examples 1 to 3 and Examples 4 to 5, it can be seen that when glycidoxypropyltrimethoxysilane and methyltrimethoxysilane are included together as a methoxysilane-based compound, the rust prevention effect is improved. have. Particularly, referring to Examples 1 to 3, when glycidoxypropyltrimethoxysilane and methyltrimethoxysilane are included as methoxy silane compounds, when they are included in a specific ratio (1: 1.25 weight ratio), rust prevention It can be seen that the effect is improved.

In addition, looking at Examples 2 and 6 to 8, the chrome-free surface treatment composition of the present embodiment further comprises zinc flakes, but further comprises 10 to 40 parts by weight of the zinc flakes based on 100 parts by weight of the binder composition. In this case, it can be seen that the effect of improving the corrosion resistance is remarkably excellent. In particular, looking at the results of Table 8 using the electro-galvanized metal that has already been corroded, it can be seen that when the zinc flake is further included in an amount of 10 to 40 parts by weight with respect to 100 parts by weight of the binder composition, the effect of improving corrosion resistance is excellent. . That is, when the chromium-free surface treatment composition of the present embodiment further contains 10 to 40 parts by weight of the zinc flake relative to 100 parts by weight of the binder composition, corrosion resistance is generated by repairing the surface of the electro-galvanized metal damaged. It means making it possible to re-implement it.

Experimental Example 3: Adhesion test

In the same manner as in Experimental Example 1, after applying the chromium-free surface treatment composition according to Example 1 to the surface of the hot-dip galvanized steel sheet to form a coating film, according to the cross-cut test method (ASTM D 3359 test standard), molten zinc The adhesion between the plated metal and the chromium-free surface treatment composition was evaluated as 0B to 5B, and is shown in Table 9.

In Table 9, the average value of repeating the experiment 5 times is described, and in the case of 5B, it means the most excellent adhesion.

0B: more than 65% of the separated area

1B: 35-65% of separated area

2B: Separated area is 15 ~ 35%

3B: 5 ~ 15% of the separated area

4B: Separated area is less than 5%

5B: 0% of separated area

Referring to Table 9, it can be seen that in Examples 1 to 8 according to the present embodiment, adhesion is superior compared to Comparative Examples 1 to 13 not according to the present embodiment.

As described above, the description of the present invention is for illustrative purposes only, and those of ordinary skill in the art to which the present invention pertains can easily transform into other specific forms without changing the technical spirit or essential features of the present invention. You can understand. Therefore, the embodiments described above are illustrative in all respects, and should be understood as non-limiting. For example, each component described as a single type may be implemented in a distributed manner, and similarly, components described as being distributed may also be implemented in a combined form.

The scope of the present invention is indicated by the claims to be described later rather than the detailed description, and all changes or modified forms derived from the meaning and scope of the claims and their equivalent concepts should be construed as being included in the scope of the present invention. do.

Claims (12)

As a chrome-free surface treatment composition for treating the surface of galvanized metal,
A binder composition containing ethyl silicate, hydrochloric acid, ethanol, isopropyl alcohol, a methoxy silane compound, and deionized water;
Coloring dyes; And
Including; a colored pigment;
Based on the total weight of the binder composition, ethyl silicate 47 to 55% by weight, hydrochloric acid 0.1 to 4% by weight, ethanol 10 to 25% by weight, isopropyl alcohol 2 to 7% by weight, methoxy silane compound 5 to 15% by weight and dehydration Contains 10 to 20% by weight of ionized water,
Further comprising 10 to 40 parts by weight of zinc flakes based on 100 parts by weight of the binder composition, wherein the zinc flakes have a length: 18 to 25 micrometers and an average particle diameter (D50): 15 to 20 micrometers, zinc High corrosion resistance chrome-free surface treatment composition having surface coloring and surface repair effect of plated metal.
delete The method of claim 1,
Based on 100 parts by weight of the binder composition
0.1 to 20 parts by weight of the colored dye and 0.1 to 20 parts by weight of the colored pigment.
The method of claim 1,
The methoxy silane compound is
A highly corrosion-resistant chromium-free surface treatment composition comprising glycidoxypropyltrimethoxysilane and methyltrimethoxysilane, characterized in that it has a surface coloring and surface repair effect of a galvanized metal.
The method of claim 4,
The methoxy silane compound is
High corrosion resistance chromium-free surface treatment having surface coloring and surface repair effect of galvanized metal, characterized in that it contains glycidoxypropyltrimethoxysilane and methyltrimethoxysilane in a weight ratio of 1: 0.5 to 2 Composition.
The method of claim 1,
The coloring dye is
Azo dyes, anthraquinone dyes, xanthene dyes, triarylmethane dyes, phthalocyanine dyes, quinone imine dyes, quinoline dyes, nitro dyes and methine dyes. A highly corrosion-resistant chromium-free surface treatment composition having a surface coloring and surface repair effect of galvanized metal.
The method of claim 1,
The colored pigment is
A highly corrosion-resistant chromium-free surface treatment composition comprising at least one selected from the group consisting of inorganic pigments and organic pigments, and having surface coloring and surface repair effects of galvanized metal.
delete delete delete As a method of treating the surface of a galvanized metal with the chromium-free surface treatment composition of claim 1,
(a) a first step of applying a chromium-free surface treatment composition to the surface of the galvanized metal; And
(b) a second step of drying the chromium-free surface treatment composition applied to the surface of the galvanized metal,
The chrome-free surface treatment composition
A binder composition containing ethyl silicate, hydrochloric acid, ethanol, isopropyl alcohol, a methoxy silane compound, and deionized water; Coloring dyes; And a colored pigment; including,
Based on the total weight of the binder composition, ethyl silicate 47 to 55% by weight, hydrochloric acid 0.1 to 4% by weight, ethanol 10 to 25% by weight, isopropyl alcohol 2 to 7% by weight, methoxy silane compound 5 to 15% by weight and dehydration Contains 10 to 20% by weight of ionized water,
Further comprising 10 to 40 parts by weight of zinc flakes based on 100 parts by weight of the binder composition, wherein the zinc flakes have a length: 18 to 25 micrometers and an average particle diameter (D50): 15 to 20 micrometers, chromium A method of treating the surface of galvanized metal with a free surface treatment composition.
The method of claim 11,
In the first step
Applying the chromium-free surface treatment composition to the surface of the galvanized metal is carried out by any one method selected from the group consisting of coating, immersion, dip spin, and spray spraying. To treat the surface of galvanized metal with a method.

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