KR20160071219A - Chromium-free composition for treating a metal surface, the metal sheet using the same, and the method of preparing the same - Google Patents

Abstract

The present invention relates to a composition for surface-treating chrome-free steel sheet. According to the present invention, the composition includes: 0.1-40.0 wt% of silicon compound; 0.1-10.0 wt% of silane-based compound; 0.1-10.0 wt% of a chelating agent based on titanium, zirconium, or combination of both; 2.0-50.0 wt% of an acryl-urethane copolymeric binder resin; 1.0-20.0 wt% of a hardening agent containing amine-based, melamine-based, or combination of both; and a remainder of a solvent, with respect to 100 wt% of the total composition.

Description

TECHNICAL FIELD The present invention relates to a chrome-free surface-treated steel sheet using a composition for surface treatment of a chrome-free steel sheet, and a method of manufacturing the same. BACKGROUND ART [0002]

Free surface treated steel sheet using the composition for surface treatment of Cr-free steel sheet, and a method for producing the same.

Since the fuel tank steel plate for automobiles is an important part that is very important to the safety of the vehicle and the image of the external product quality, it can be said that the product quality is required such as fuel leaks, durability and corrosion resistance of constant strength, joint part. The material used for fuel tank steel for automobiles is mostly made of plastic in Europe, but in Korea and Japan, it is mainly composed of zinc-nickel alloy plating or tin-zinc alloy plating, Has been used. The quality of the steel sheet on which the organic-inorganic hybrid coating is formed depends on the components constituting the coating and the kind and content of the additives. Conventionally, a coating layer containing a hexavalent chromium component has been formed in order to improve corrosion resistance and fuel resistance. However, since a chromium component, which is harmful to the environment in a scrapping vehicle, is eluted from a surface treated steel sheet using a coating layer containing a hexavalent chromium component, Regulated use. On the other hand, the development of alternative fuels is proceeding due to the strengthening of high rust prevention regulations for automotive steel plates and the sharp increase in fossil fuel prices. Ethanol fuel produced using sugar cane as a raw material can be mixed with gasoline, and biodiesel that can be mixed with diesel is also being developed. Examples of biodiesel include soybean oil, which is being developed mainly in Japan and Japan, biodiesel using waste cooking oil, and biodiesel using seed oil, which is mainly used in Europe. In the case of biodiesel, the mixing amount is limited in each country. In conventional biodiesel production, when soybean oil or fluid oil is subjected to hydrogen substitution reaction with methanol, it is decomposed into methyl ester and glycerin, and among them, methyl-ester is used as biodiesel. Therefore, there is a need for a steel sheet for a fuel tank which improves the corrosion resistance of a new type of automotive fuel such as ethanol fuel or biodiesel.

Korean Patent Application No. 2007-0137882 discloses an automobile fuel tank steel plate treated with a zinc-alloy-plated steel sheet with a chromium-free organic-inorganic hybrid-liquid treatment solution without a separate resin treatment. In the present invention, the characteristics of a fuel tank steel sheet molded into various shapes in an organic / inorganic composite fuel tank steel sheet not containing chromium exhibit excellent corrosion resistance and fuel resistance after severe processing such as deep drawing, And more particularly, to a fuel tank steel plate that effectively copes with the above problems.

Free surface treated steel sheet using the composition for surface treatment of Cr-free steel sheet and a method for producing the same.

The composition for surface treatment of a chrome-free steel sheet according to an embodiment of the present invention may contain 0.1 to 40.0 weight% of a silicon compound, 0.1 to 10.0 weight% of a silane compound, 0.1 to 10.0 weight% of a titanium compound, Or a combination thereof, 0.1 to 10.0% by weight of a chelating agent, 2.0 to 50.0% by weight of an acryl-urethane copolymer binder resin, 1.0 to 20.0% by weight of a curing agent comprising an amine type, a melamine type, It is possible to provide a composition for surface treatment of a chromium-free steel sheet containing a solvent.

Wherein the composition further comprises 0.1-15.0 parts by weight of a co-curing agent comprising ethylene acrylic acid, aziridine or a combination thereof, based on 100 parts by weight of the composition.

Wherein the composition further comprises 0.1-20.0 parts by weight of a adhesion promoter comprising phosphoric acid ester, ammonium phosphate, or a combination thereof, based on 100 parts by weight of the composition.

Wherein the composition further comprises 0.1 to 5.0 parts by weight of a wax comprising polyethylene, polytetrafluoroethylene, or a combination thereof, based on 100 parts by weight of the composition. have.

Wherein the silicon compound comprises colloidal silica, silica sol, silicate or a combination thereof.

The silane compound may be at least one selected from the group consisting of g-glycidoxypropyl triethoxy silane, g-aminopropyltriethoxy silane, tetraethoxy silane, Methyl trimethoxy silane, 3-glycidoxypropyl trimethoxysilane, or a combination thereof. The chromium-free steel sheet may be a composition for surface treatment of chrome-free steel sheet.

The chelating agent may be a form obtained by neutralizing hexafluoro titanic acid with an amine.

The chelating agent may be a composition for surface treatment of Cr-free steel sheet, wherein the hexafluorotitanic acid is neutralized with 3.0-10.0 wt% (relative to 100 wt% of chelating agent) to amine.

The amine may be triethylamine.

The acrylic-urethane copolymer binder resin may be a block copolymer of an acrylic resin and a urethane resin.

The acryl-urethane copolymer binder resin may be a composition for surface treatment of a chromium-free steel sheet, wherein the copolymerization ratio of the acrylic resin in the binder resin is 40-60%.

The Cr-free surface-treated steel sheet according to an embodiment of the present invention includes: a zinc-base alloy coated steel sheet; And a coating disposed on a surface of the zinc alloy-plated steel sheet; Wherein the coating comprises the following composition: < tb > < TABLE >

Wherein the composition comprises 0.1 to 40.0 wt% of a silicone compound, 0.1 to 10.0 wt% of a silane compound, 0.1 to 10.0 wt% of a chelating agent, which is a combination of a titanium compound and a zirconium compound, or a combination thereof, based on 100 wt% , An acryl-urethane copolymer binder resin: 2.0-50.0 wt%, an amine-based, melamine-based, or a combination thereof: 1.0-20.0 wt% and a residual solvent have.

In addition, adhesion promoters comprising 0.1-15.0 parts by weight of a co-curing agent comprising ethylene acrylic acid, aziridine, or a combination thereof, 100 parts by weight of the composition, phosphoric acid ester, ammonium phosphate, 0.1 to 20.0 parts by weight of a wax selected from the group consisting of polyethylene, polytetrafluoroethylene, and combinations thereof. The chromium-free organic composite coating composition may further comprise 0.1 to 5.0 parts by weight of a wax.

The zinc alloy-plated steel sheet; May be a chrome-free surface-treated steel sheet that includes a galvanized layer, a zinc-nickel plated layer, or a combination thereof on the surface of the cold-rolled steel plate.

And the adhesion amount of the zinc plating layer is 30-100 g / m < ² >.

And the adhesion amount of the zinc-nickel plating layer is 20-50 g / m < ² >.

And the coating amount of the coating located on the surface of the zinc-based alloy plated steel sheet is 300-2,500 mg / m < ² >.

A method of manufacturing a chrome-free surface-treated steel sheet according to an embodiment of the present invention includes: preparing a zinc-coated alloy steel sheet; And forming a coating on the surface of the zinc alloy-plated steel sheet; Wherein the coating comprises the following composition: < tb > < TABLE >

Wherein the composition comprises 0.1 to 40.0 wt% of a silicone compound, 0.1 to 10.0 wt% of a silane compound, 0.1 to 10.0 wt% of a chelating agent, which is a combination of a titanium compound and a zirconium compound, or a combination thereof, based on 100 wt% , 1.0 to 2.0 wt% of a curing agent comprising an acrylic-urethane copolymer binder resin: 2.0 to 50.0 wt%, an amine-based, melamine-based, or a combination thereof and a residual solvent can do.

In addition, adhesion promoters comprising 0.1 to 15.0 parts by weight of a co-curing agent comprising ethylene acrylic acid, aziridine, or a combination thereof, phosphoric acid ester, ammonium phosphate, or combinations thereof, per 100 parts by weight of the composition, 0.1 to 20.0 parts by weight of a wax selected from the group consisting of polyethylene, polytetrafluoroethylene, and combinations thereof. The chromium-free organic composite coating composition may further comprise 0.1 to 5.0 parts by weight of a wax.

Preparing a zinc alloy-plated steel sheet; Preparing a cold-rolled steel sheet; And forming a galvanized layer, a zinc-nickel plated layer, or a combination thereof on the surface of the cold-rolled steel sheet; Free surface treated steel sheet according to the present invention.

Preparing a zinc alloy-plated steel sheet; Preparing a cold-rolled steel sheet; Wherein the cold-rolled steel sheet is rolled at a thickness of 0.5 to 1.5 mm at room temperature.

Preparing a zinc alloy-plated steel sheet; Forming a zinc-plated layer, a zinc-nickel plated layer, or a combination thereof on the surface of the cold-rolled steel sheet; And a plating layer is formed on one side or both sides of the cold-rolled steel sheet by the above-mentioned method.

Preparing a zinc alloy-plated steel sheet; Forming a zinc-plated layer, a zinc-nickel plated layer, or a combination thereof on the surface of the cold-rolled steel sheet; Wherein the zinc plating layer, the zinc-nickel plating layer or a combination thereof is formed by an electroplating method or a hot-dip plating method.

Forming a coating on the surface of the zinc alloy-plated steel sheet; Applying a chromium-free steel sheet surface treatment composition onto the zinc-based alloy plating layer; And baking a steel sheet coated with the composition for surface treatment of Cr-free steel sheet; . ≪ / RTI >

Forming a coating on the surface of the zinc alloy-plated steel sheet; Applying a chromium-free steel sheet surface treatment composition onto the zinc-based alloy plating layer; Free steel sheet surface treatment composition is applied to the zinc-based alloy plating layer by a roll coating method, a spray method, or a dipping method.

Forming a coating on the surface of the zinc alloy-plated steel sheet; Baking a steel sheet coated with the composition for surface treatment of Cr-free steel sheet; , A step of baking the zinc alloy plated steel sheet coated with the composition for surface treatment of Cr-free steel sheet at a temperature of 120 to 250 캜 to form a chromium free coating layer.

The Cr-free surface-treated steel sheet and the method of manufacturing the same using the composition for surface treatment of Cr-free steel sheet according to an embodiment of the present invention perform the surface treatment of the zinc-base alloy coated steel sheet using a composition not containing a chromium component, It is possible to manufacture a fuel tank steel sheet for an automobile which is environmentally friendly and has a simple manufacturing process.

In addition, by limiting the composition of the organic-inorganic hybrid coating film containing no chromium to the standard composition of this application, by limiting the adhesion amount of the zinc-based alloy plating layer, the adhesion amount of the chromium-free organic composite coating layer and the baking temperature of the steel sheet, It has an advantage of excellent fuel property. Further, it is possible to provide a fuel tank steel sheet excellent in adhesion and weldability.

1 shows a coating layer structure according to an embodiment of the present invention.
2 is a schematic view of an apparatus for evaluating fuel resistance according to an embodiment of the present invention.

The composition for surface treatment of a chrome-free steel sheet according to an embodiment of the present invention may contain 0.1 to 40.0 weight% of a silicon compound, 0.1 to 10.0 weight% of a silane compound, 0.1 to 10.0 weight% of a titanium compound, Or a combination thereof, 0.1 to 10.0% by weight of a chelating agent, 2.0 to 50.0% by weight of an acryl-urethane copolymer binder resin, 1.0 to 20.0% by weight of a curing agent comprising an amine type, a melamine type, And a solvent for the surface treatment of a chromium-free steel sheet.

0.1-15.0 parts by weight of a co-curing agent comprising ethylene acrylic acid, aziridine or a combination thereof, based on 100 parts by weight of the composition; adhesion promoter comprising 0.1 to 1.0 part by weight of phosphoric acid ester, ammonium phosphate, 20.0 parts by weight of a wax, and 0.1-5.0 parts by weight of a wax containing polyethylene, polytetrafluoroethylene, or a combination thereof.

In addition, the silicone compound may include colloidal silica, silica sol, silicate, or a combination thereof.

The silane compound may be at least one selected from the group consisting of g-glycidoxypropyl triethoxy silane, g-aminopropyltriethoxy silane, tetraethoxy silane, Methyl trimethoxy silane, 3-glycidoxypropyl trimethoxysilane, or a combination thereof. The term " glycidoxypropyl trimethoxysilane "

In the present specification, the silane-based compound includes silicon hydride and silicon hydride in which hydrogen is substituted with a different functional group. The functional group is not limited to the present invention as far as it is commonly used for organic compounds. Specific examples of the functional groups include, but are not limited to, alkyl groups, alkoxy groups, amino groups, and the like.

The chelating agent may include Hexafluro Titanic Acid in an amount of 3.0-10.0 wt% (relative to 100 wt% of the chelating agent) to the amine,

The amine may be triethylamine.

Hereinafter, reasons for limiting the components of the present invention will be described.

The silicone compound is a main constituent material of the post-treatment coating according to an embodiment of the present invention, and acts as a barrier to corrosive factors and enhances the bonding force between the plating layer and the resin component.

If the content of the silicone compound is less than 0.1% by weight, the adhesion between the steel sheet and corrosion resistance may deteriorate. If the content of the silicone compound exceeds 40.0% by weight, the bonding strength with the resin may be weakened.

The silane-based compound is hydrolyzed in water to form a siloxane bond, which serves as a binding agent for bonding various inorganic materials to the steel sheet.

Therefore, when the content of the silane compound is less than 0.1% by weight, the adhesion with the steel sheet and the corrosion resistance thereof are deteriorated and the binding can not be performed properly. If the content is more than 10.0% by weight, the economical efficiency may not be good.

The chelating agent, which is a titanium-based, zirconium-based, or a combination thereof, stably disperses the inorganic components in the solution to enhance solution stability and solidify the film formation.

If the amount of the chelating agent is less than 0.1% by weight, the corrosion resistance effect may deteriorate, and if it is more than 10.0% by weight, the economical aspect and solution stability may become unstable. .

The acrylic-urethane copolymer binder resin serves to improve the corrosion resistance and hydrophobicity of the coating.

The acrylic-urethane copolymer binder resin is a block copolymer of an acrylic resin having a number average molecular weight of 500,000-1,500,000 and a urethane resin having a number average molecular weight of 5,000-15,000, wherein the copolymerization ratio of the acrylic resin in the binder resin is 40-60% Lt; RTI ID = 0.0 > acryl-urethane < / RTI >

When the content of the binder resin is less than 2.0% by weight, surface irregularity may occur on the surface of the steel sheet during flushing, and if it exceeds 50.0% by weight, corrosion resistance and hydrophobicity may be deteriorated.

The curing agent comprising an amine type, a melamine type, or a combination thereof serves to crosslink the binder resin.

When the content of the curing agent is less than 1.0% by weight, crosslinking may not be sufficiently formed. When the content of the curing agent is more than 20.0% by weight, the curing agent resin containing amine, melamine or a combination thereof is not reacted, Can be degraded.

The auxiliary curing agent comprising ethylene acrylic acid type, aziridine type, or a combination thereof is an auxiliary curing agent for the above-mentioned copolymer binder resin, and serves to strengthen the binding of the inorganic components.

When the auxiliary curing agent is used in an amount of 0.1 to 15.0 parts by weight based on 100 parts by weight of the composition, the desired sufficient crosslinking can be achieved. In addition, a film having improved stability can be obtained.

The adhesion promoter containing phosphoric acid ester, ammonium phosphate, or a combination thereof improves the adhesion between the steel sheet and the resin, so that it does not cause peeling of the coat layer under deep processing conditions and has a role of improving the processing adhesion.

When the adhesion promoter for 100 parts by weight of the composition is 0.1-20.0 parts by weight, the effect of improving the adhesion and corrosion resistance can be satisfied and the solution stability stability can be improved.

The wax containing polyethylene, polytetrafluoroethylene, or a combination thereof serves to improve corrosion resistance and fuel resistance.

When the wax is 0.1 to 5.0 parts by weight based on 100 parts by weight of the composition, desired corrosion resistance and fuel resistance can be achieved after processing.

Hereinafter, a chromium-free surface treated steel sheet according to an embodiment of the present invention will be described.

1 shows a coating layer structure according to an embodiment of the present invention. However, FIG. 1 is only an embodiment of the present invention, and the present invention is not limited to FIG.

As can be seen from Fig. 1, the zinc alloy-plated steel sheet; And a coating disposed on a surface of the zinc alloy-plated steel sheet; Wherein the coating comprises the following composition: < tb >< TABLE >

The composition of the coating on the surface of the zinc-base alloy coated steel sheet is 0.1 to 40.0 wt% of a silicon compound, 0.1 to 10.0 wt% of a silane compound, 0.1 to 10.0 wt% of a titanium compound, or a zirconium compound based on 100 wt% , 1.0 to 2.0 wt% of a chelating agent which is a combination of an amine-based compound, a melamine-based compound, or a combination of these: 1.0 to 2.0 wt% And a composition for surface treatment of Cr-free steel sheet.

The above description of the composition is the same as that of the chrome-free surface treatment composition according to one embodiment of the present invention, and the description thereof is omitted.

The zinc-based alloy plated steel sheet may include a galvanized layer, a zinc-nickel plated layer, or a combination of these layers.

The adhesion amount of the zinc plating layer may be 30-100 g / m ² .

If the zinc plating coating weight can be sufficient corrosion resistance and fuel resistance when 30-100g / m ² day, exceeding 100g / m ² may not be economical because of the ring occurs during powder processing and increase the material cost.

The adhesion amount of the zinc-nickel plating layer may be 20-50 g / m ² .

When the zinc-nickel plated layer has an adhesion amount of 20-50 g / m ² , corrosion resistance and fuel resistance can be sufficient. If it exceeds 50 g / m ² , cracks may occur during processing, which may not be economical.

The deposition amount of the coating on the surface of the zinc-base alloy coated steel sheet may be 300-2,500 mg / m ² .

When the deposition amount is more than 2,500 mg / m ² , the adhesion and weldability of the film can be deteriorated, and the corrosion resistance and the fuel resistance can be secured easily at 300 mg / m ² or more.

Hereinafter, a method of manufacturing a chrome-free surface-treated steel sheet according to an embodiment of the present invention will be described.

Preparing a zinc-based alloy-plated steel sheet; And

Forming a coating on the surface of the zinc alloy-plated steel sheet;

/ RTI >

Wherein the coating comprises the following composition: < tb > < TABLE >

The composition of the coating film is preferably a chelating agent which is 0.1 to 40.0 wt% of a silicon compound, 0.1 to 10.0 wt% of a silane compound, a titanium-based, zirconium-based compound, or a combination thereof, based on 100 wt% A composition for surface treatment of chrome-free steel sheet comprising 1.0-20.0% by weight of a curing agent comprising an acrylic-urethane copolymer binder resin, 2.0-50.0% by weight, an amine type, a melamine type or a combination thereof, . ≪ / RTI >

The above description of the composition is the same as that of the chrome-free surface treatment composition according to one embodiment of the present invention, and the description thereof is omitted.

Preparing a zinc alloy-plated steel sheet; Preparing a cold-rolled steel sheet; And forming a galvanized layer, a zinc-nickel plated layer, or a combination thereof on the surface of the cold-rolled steel sheet; . ≪ / RTI >

Preparing a zinc alloy-plated steel sheet; Preparing a cold-rolled steel sheet; , The steel sheet for a fuel tank can be rolled to a thickness of 0.5 to 1.5 mm at a room temperature temperature range.

Preparing a zinc alloy-plated steel sheet; Forming a zinc-plated layer, a zinc-nickel plated layer, or a combination thereof on the surface of the cold-rolled steel sheet; The plated layer may be formed on one side or both sides of the cold-rolled steel sheet by an electroplating method or a hot-dip plating method.

In addition, the adhesion amount of the zinc plated layer may be formed as 30-100g / m ^2, the zinc-coating weight of the nickel plated layer can be 20-50g / m ^2.

Forming a coating on the surface of the zinc alloy-plated steel sheet; Applying a chromium-free steel sheet surface treatment composition onto the zinc-based alloy plating layer; And baking a steel sheet coated with the composition for surface treatment of Cr-free steel sheet; . ≪ / RTI >

Forming a coating on the surface of the zinc alloy-plated steel sheet; Applying a chromium-free steel sheet surface treatment composition onto the zinc-based alloy plating layer; , The composition for surface treatment of chromium-free steel sheet can be applied to the zinc-base alloy-coated steel sheet by a method such as roll coating, spraying, or dipping.

Forming a coating on the surface of the zinc alloy-plated steel sheet; Baking a steel sheet coated with the composition for surface treatment of Cr-free steel sheet; , The composition for surface treatment of Cr-free steel sheet may be coated on a zinc alloy plated steel sheet and then baked at a temperature of 120 to 250 ° C to form a Cr free coating layer.

In this specification, the firing temperature refers to the final temperature of the steel sheet, which is the peak metal temperature (PMT), and the time to reach the firing temperature may vary depending on various external variables.

When the baking temperature is less than 120 캜 after the chromium-free composition coating is applied, the reaction between the resin and the inorganic material is not well formed, so that it may become difficult to ensure corrosion resistance. On the other hand, if the temperature exceeds 250 ° C, the curing reaction no longer occurs, and the heat loss can be increased, thereby reducing the economical efficiency.

BRIEF DESCRIPTION OF THE DRAWINGS The advantages and features of the present invention and the manner of achieving them will become apparent with reference to the embodiments described in detail below with reference to the accompanying drawings. However, it is to be understood that the present invention is not limited to the disclosed embodiments, but may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. It is intended that the disclosure of the present invention be limited only by the terms of the appended claims. Like reference numerals refer to like elements throughout the specification.

Thus, in some embodiments, well-known techniques are not specifically described to avoid an undesirable interpretation of the present invention. Unless defined otherwise, all terms (including technical and scientific terms) used herein may be used in a sense commonly understood by one of ordinary skill in the art to which this invention belongs. Whenever a component is referred to as "including" an element throughout the specification, it is to be understood that the element may include other elements, not the exclusion of any other element, unless the context clearly dictates otherwise. Also, singular forms include plural forms unless the context clearly dictates otherwise.

Hereinafter, the embodiment will be described in detail. The following examples are illustrative of the present invention only and are not intended to limit the scope of the present invention.

Inorganic composite film By composition  Quality evaluation

The steel sheet for the fuel tank was rolled at a room temperature with a thickness of 0.8 mm and a width of 1260 m to prepare a cold-rolled steel sheet.

On the cold-rolled steel sheet, a plating layer was formed on one side by electroplating.

The plating layer was a zinc-nickel alloy plating layer, and a zinc alloy-plated steel sheet was prepared so that the adhesion amount was 30 g / m ² .

The zinc-based alloy-plated steel sheet was coated with a chrome-free organic-inorganic hybrid coating film by a roll coating method by 1000 mg / m ² .

The steel sheet coated with the chromium-free organic composite coating was baked to a final temperature of 210 ° C to prepare a fuel tank steel sheet.

At this time, the organic / inorganic hybrid coating film applied to the zinc-base alloy coated steel sheet may contain 0.1 to 40.0 wt% of a silicon compound, 0.1 to 10.0 wt% of a silane compound, 0.1 to 10.0 wt% of a titanium compound, and zirconium compound based on 100 wt% 1.0-20.0 wt.% Of a curing agent comprising an amine-based, melamine-based, or a combination thereof, and 0.1-10.0 wt.% Of a chelating agent, The remainder was made up of a composition comprising a solvent.

In addition, adhesion promoters comprising 0.1 to 15.0 parts by weight of a co-curing agent comprising ethylene acrylic acid, aziridine, or a combination thereof, phosphoric acid ester, ammonium phosphate, or combinations thereof, per 100 parts by weight of the composition, 0.1-20.0 parts by weight of a wax selected from the group consisting of polyethylene, polytetrafluoroethylene, and combinations thereof, to prepare a chromium-free organic composite coating composition.

As described above, the coating composition for surface treatment of the fuel tank steel sheet was produced by changing the composition of the composite coating film within the above range.

The corrosion resistance and adhesion of the fuel tank steel sheet produced under the above conditions were evaluated by the following methods. The results are shown in Table 1 below.

<Evaluation method of corrosion resistance>

It was evaluated as% of the generated rust after 500 hours of spraying pressure at 5% salt concentration and 1 kg / cm ² at 35 ° C in a flat plate state, and the evaluation criteria are as follows.

◎: Corrosion area is 0% ○: Corrosion area less than 5%

□: Corrosion area is 5-30% ?: Corrosion area is 30-50%

X: Greater than or equal to 50% of corrosion area

<Adhesiveness Evaluation Method>

The adhesion between the chromium-free organic-inorganic hybrid film and the zinc-based alloy plating layer was evaluated for adhesion after processing. First, the steel sheet was punched with 95 pie, then cupped to a height of 25 mm so that the radius of curvature of the processing die was 4, and then the processed wall surface was adhered to the steel sheet with a tape and peeled off. The evaluation criteria are as follows.

⊚: The peeled area is 0-5% ○: The peeled area was 5-20%

□: The peeled area is 20-50% ?: The peeled area was 50-75%

X: The peeled area was 75-100%

division Solution composition (% by weight) Solution composition (parts by weight) Quality evaluation result silicon
compound Silane compound Titanium chelate Acrylic-urethane Melamine-based curing agent menstruum Ethylene acrylic acid Phosphoric acid
ester Wax Corrosion resistance Adhesiveness boiling Processing Comparison 1 0 7.7 7.7 48.8 12.8 23 12.8 7.7 2.5 □ △ □ Inventory 1 0.1 8.7 8 47.4 12.8 23 12.8 7.7 2.5 ○ ○ ○ Inventory 2 20 7.9 7.7 39.8 8.5 16.1 8.5 5.1 2.5 ◎ ◎ ◎ Inventory 3 40 7.9 7.7 25.5 6.3 12.6 6.3 3.8 2.5 ◎ ◎ ◎ Comparative material 2 50 3.4 3.4 26.1 5.6 11.5 5.6 3.4 2.5 ◎ ○ □ Comparative material 3 35.7 0 5.4 33.2 8.9 16.8 8.9 5.4 2.5 △ □ ○ Invention 4 35.7 0.1 5.4 33.2 8.9 16.7 8.9 5.3 2.5 ○ ○ ○ Invention Article 5 33.9 5.1 5.1 31.3 8.5 16.1 8.5 5.1 2.5 ◎ ◎ ◎ Inventions 6 30.3 10 7.7 29.8 7.6 14.6 7.6 4.5 2.5 ◎ ◎ ◎ Comparison 4 28.2 21.1 4.2 25.8 7 13.7 7 4.2 2.5 □ ○ ◎ Comparative material 5 35.7 5.4 0 33.2 8.9 16.8 8.9 5.4 2.5 □ ◎ ◎ Invention 7 35.7 5.3 0.1 33.3 8.9 16.7 8.9 5.3 2.5 ○ ◎ ◎ Invention 8 33.9 5.1 5.1 31.3 8.5 16.1 8.5 5.1 2.5 ◎ ◎ ◎ Invention 9 32.8 4.9 8.2 30.3 8.2 15.6 8.2 4.9 2.5 ◎ ◎ ◎ Inventions 10 30.3 7.7 10 29.8 7.6 14.6 7.6 4.5 2.5 ◎ ◎ ◎ Comparative material 6 29.4 4.4 17.6 26.9 7.4 14.3 7.4 4.4 2.5 ◎ □ ◎ Comparison 7 38 8.5 8.5 One 15.5 28.5 13.5 12.5 2.5 △ □ □ Invention invention 11 35.9 8.7 8.7 2 15 29.7 12.2 15 2.5 ○ ○ ◎ Invention 12 31.3 5.1 5.1 33.9 8.5 16.1 8.5 5.1 2.5 ◎ ◎ ◎ Invention invention 13 20 7.7 5.2 50 5.6 11.5 5.6 3.4 2.5 ○ ◎ ◎ COMPARISON 8 18.3 3 3 60 5.1 10.6 5.1 3 2.5 □ ◎ ◎ Comparative material 9 34.2 5.9 5.5 36.7 0.5 17.2 9.2 5.5 2.5 △ □ □ Invention Article 14 33.7 6.3 5.5 36.4 One 17.1 9.1 5.5 2.5 ◎ ◎ ◎ Invention material 15 28.7 7.7 7.3 31.3 10 15 7.8 4.7 2.5 ◎ ◎ ◎ Invention material 16 27 7.7 7.7 24.2 20 13.4 6.8 4.1 2.5 ◎ ◎ ◎ Comparative material 10 25.3 3.8 3.8 24.5 30 12.6 6.3 3.8 2.5 □ ◎ ◎ Comparative material 11 36.7 5.9 5.5 34.2 9.2 8.5 0 5.0 2.5 △ □ □ Inventions 17 33.7 6.3 5.5 36.4 9.1 9 0.1 6.4 2.5 ◎ ◎ ◎ Inventions 18 28.7 7.7 7.3 31.3 7.8 17.2 10 4.7 2.5 ◎ ◎ ◎ Inventions 19 29 7.7 7.7 26.6 7.2 21.8 15 4.3 2.5 ◎ ◎ ◎ Comparative material 12 27 4.1 4.1 24.4 6.8 33.6 27 4.1 2.5 □ ◎ ◎ Comparative material 13 33.2 5.4 5.4 35.7 8.9 11.4 8.9 0 2.5 ○ □ □ Inventions 20 33.2 5.4 5.3 35.7 8.9 11.5 8.9 0.1 2.5 ◎ ◎ ◎ Invention Article 21 27.8 7.7 6.5 30.3 7.6 20.1 7.6 10 2.5 ◎ ◎ ◎ Invention Article 22 26.3 7.7 6.5 23.8 6.6 29.1 6.6 20 2.5 ◎ ◎ ◎ Comparative material 14 23.3 3.5 3.5 25.6 5.8 38.3 5.8 30 2.5 ◎ ◎ □ Comparative material 15 27.8 7.7 6.5 32.8 7.6 17.6 7.6 10 0 □ ◎ ◎ Invention Article 23 27.8 7.7 6.5 32.7 7.6 17.7 7.6 10 0.1 ◎ ◎ ◎ Invention 24 27.8 7.7 6.5 30.8 7.6 19.6 7.6 10 2 ◎ ◎ ◎ Inventions 25 27.8 7.7 6.5 27.8 7.6 22.6 7.6 10 5 ◎ ◎ ◎ Comparative material 16 23.3 7.7 6.5 30.3 7.6 24.6 7.6 10 7 △ □ ○

In Table 1, ethylene acrylic acid, phosphoric acid ester, and wax described in terms of parts by weight include the silicone compound, silane compound, titanium chelate, acryl-urethane copolymer resin, melamine curing agent, To the main ingredient. This is expressed in parts by weight of each composition relative to 100 parts by weight of the composition as the main component.

As shown in Table 1, the compositions of the chrome-free organic-inorganic hybrid coatings were changed and the physical properties were compared. As a result, it was found that the corrosion resistance and adhesion were excellent within the standard composition range set in Example 1 of the present invention.

Electrolytic zinc-nickel alloy plating By deposition amount  Quality evaluation

The steel sheet for the fuel tank was rolled at a room temperature with a thickness of 0.8 mm and a width of 1260 m to prepare a cold-rolled steel sheet.

On the cold-rolled steel sheet, a plating layer was formed on one side by electroplating.

The zinc plated layer or the zinc-nickel plated layer was deposited on the cold-rolled steel sheet to prepare a zinc-based alloy plated steel sheet.

The zinc-based alloy-plated steel sheet was coated with a chrome-free organic-inorganic hybrid coating film by a roll coating method by 1000 mg / m ² .

The steel sheet coated with the chromium-free organic composite coating was baked to a final temperature of 210 ° C to prepare a fuel tank steel sheet.

In this case, the organic / inorganic hybrid coating film applied to the zinc-alloy-plated steel sheet had 27.8% by weight of a silicone compound, 7.7% by weight of a silane compound, 6.5% by weight of a titanium chelating agent, - urethane copolymerizable binder resin: 30.8% by weight, melamine-based curing agent: 7.6% by weight, and a residual solvent.

In addition, the chromium-free organic composite coating composition was further comprised of 100 parts by weight of the composition, 7.6 parts by weight of an ethylene acrylic acid-based co-curing agent, 10.0 parts by weight of a phosphate ester adhesion promoter, and 2.0 parts by weight of a polytetrafluoroethylene- .

As described above, the fuel tank steel sheet was produced by varying the plating adhesion amount.

The corrosion resistance, fuel resistance, and workability of the fuel tank steel sheet produced under the above conditions were evaluated. The fuel resistance and workability were evaluated by the following methods. The corrosion resistance evaluation method is the same as the evaluation method in Example 1, and the results are the same as those in Table 2 below.

&Lt; Evaluation method of fuel property &

The evaluation of fuel resistance was performed to evaluate the fuel resistance of hot gasoline and biodiesel at high temperature. As shown in Fig. 1, the evaluation of resistance to fuel using deteriorated gasoline using preheated gasoline was conducted as follows: 78.58% by volume gasoline + 20% by volume ethanol + 1.42% by volume pure water + 100 ppm formic acid + 100 ppm acetic acid at 60 DEG C for 3 months, The corrosion state of biodiesel was checked at 81 ° C for 3 days at 85 ° C and 81% by volume of diesel + 9% by volume of BIO diesel + 5% by volume of pure water + 5% by volume of methanol + 20 ppm of formic acid + The corrosion condition of the steel sheet after the standing was checked and evaluated. The evaluation criteria are as follows.

◎: Corrosion area is 0% ○: Corrosion area less than 5%

□: Corrosion area is 5-30% ?: Corrosion area is 30-50%

X: Greater than or equal to 50% of corrosion area

&Lt; Processability evaluation method &

The machinability was evaluated based on the presence or absence of powdering or cracking in the cup working for evaluation of fuel resistance in FIG. 2, and evaluation criteria were provided in two modes of good (O) and poor (X).

division Plating adhesion amount (g / m ² ) Quality evaluation result Electric zinc
Plated Electrolytic zinc-nickel alloy plating Corrosion resistance Fuel resistance Processability Comparison 1 10 - × × ○ Comparative material 2 20 - × △ ○ Comparative material 3 120 - ◎ ◎ × Comparison 4 - 5 × × ○ Comparative material 5 - 10 × △ ○ Comparative material 6 - 60 ◎ ◎ × Inventory 1 30 - ◎ ◎ ○ Inventory 2 50 - ◎ ◎ ○ Inventory 3 100 - ◎ ◎ ○ Invention 4 - 20 ◎ ◎ ○ Invention Article 5 - 30 ◎ ◎ ○ Inventions 6 - 50 ◎ ◎ ○

As shown in Table 2 above, according to Example 2 of the present invention, the adhesion amount of the zinc-based alloy plating layer of the inventive material and the comparative material was different, and as a result, the zinc-plated layer included 30-100 g / m ² of adhesion amount, When the plated layer contains an adhesion amount of 20-50 g / m ² , it is found that the corrosion resistance, the fuel resistance, and the workability are excellent.

The amount of inorganic and organic composite coating and Sob  Quality evaluation by temperature

The steel sheet for the fuel tank was rolled at a room temperature with a thickness of 0.8 mm and a width of 1260 m to prepare a cold-rolled steel sheet.

On the cold-rolled steel sheet, a plating layer was formed on one side by electroplating.

A zinc-based alloy-coated steel sheet was prepared so that the adhesion amount of the zinc-nickel plating layer on the cold-rolled steel sheet was 30 g / m ² .

The zinc-based alloy-plated steel sheet was coated with a chromium-free organic-inorganic hybrid coating film by a roll coating method with a different deposition amount.

Further, the steel plate coated with the chromium-free organic composite coating was subjected to bake drying while changing the final temperature of the steel sheet to prepare a fuel tank steel sheet.

In this case, the organic / inorganic hybrid coating film applied to the zinc-alloy-plated steel sheet had 27.8% by weight of a silicone compound, 7.7% by weight of a silane compound, 6.5% by weight of a titanium chelating agent, - urethane copolymerizable binder resin: 30.8% by weight, melamine-based curing agent: 7.6% by weight, and a residual solvent.

In addition, the chromium-free organic composite coating composition was further comprised of 100 parts by weight of the composition, 7.6 parts by weight of an ethylene acrylic acid-based co-curing agent, 10.0 parts by weight of a phosphate ester adhesion promoter, and 2.0 parts by weight of a polytetrafluoroethylene- .

As described above, the fuel tank steel sheet was manufactured by varying the deposition amount of the organic-inorganic hybrid coating film and the firing temperature.

The adhesion, corrosion resistance, fuel resistance and weldability of the fuel tank steel sheet produced under the above conditions were evaluated, and the weldability was evaluated in the following manner. In addition, the evaluation methods of adhesion, corrosion resistance, and fuel resistance are the same as in the evaluation methods of Examples 1 and 2, and the results are the same as those shown in Table 3 below.

<Weldability Evaluation Method>

Weldability was evaluated by using a pneumatic AC spot welder to maintain a constant strength without spatter at a pressing force of 250 kg, a welding time of 15 cycles, and an energizing current of 7.5 kA. The criteria were welding (◎), impossible (◎) ×) and poor welding quality (△).

division Manufacturing conditions Quality evaluation result Coating weight
(mg / m ² ) Steel plate temperature
(° C) Adhesiveness Corrosion resistance Fuel resistance Weldability Comparison 1 1000 100 □ △ △ ◎ Comparative material 2 200 210 ◎ × △ ◎ Comparative material 3 3000 210 □ ◎ ◎ × Inventory 1 1000 210 ◎ ◎ ◎ ◎ Inventory 2 1200 230 ◎ ◎ ◎ ◎ Inventory 3 800 180 ◎ ◎ ◎ ◎

Table 3 shows the results of evaluating the adhesion, corrosion resistance, fuel resistance and weldability of the fuel tank steel sheet prepared by varying the deposition amount and the firing temperature of the chrome-free organic-inorganic hybrid coating film according to the conditions of Example 3 of the present invention.

As shown in Table 3, when the adhesion amount of the chrome-free organic-inorganic hybrid coating film is 300-2,500 mg / m ² and the firing temperature of the steel sheet is in the range of 120-250 ° C., adhesion, corrosion resistance, fuel resistance, It can be seen that it is excellent.

On the other hand, in the case of the comparative material 1, the deposition amount of the chrome-free organic-inorganic hybrid coating film is 1,000 g / m ² , which is the same as the deposition amount of the inventive material 1 but the baking temperature is 100 ° C., Adhesion, corrosion resistance, and fuel resistance are not satisfactory.

In the case of comparative materials 2 to 3, although the firing temperature of the steel sheet is in the range of 120 to 250 캜, the range of the amount of the chrome-free organic-inorganic hybrid coating film exceeds 2,500 mg / m ² , .

While the present invention has been described in connection with what is presently considered to be practical exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, You will understand.

It is therefore to be understood that the above-described embodiments are illustrative in all aspects and not restrictive. The scope of the present invention is defined by the appended claims rather than the detailed description, and all changes or modifications derived from the meaning and scope of the claims and their equivalents should be interpreted as being included in the scope of the present invention .

Claims (24)

0.1 to 10.0% by weight of a chelating agent, 0.1 to 10.0% by weight of a silicon compound, 0.1 to 10.0% by weight of a silane compound, 0.1 to 10.0% by weight of a titanium compound, A composition for surface treatment of a chromium-free steel sheet, comprising 2.0 to 50.0% by weight of a copolymer binder resin, 1.0-20.0% by weight of a curing agent comprising an amine type, a melamine type or a combination thereof and a residual solvent.

The method according to claim 1,
With respect to 100 parts by weight of the composition,
Wherein the composition further comprises 0.1-15.0 parts by weight of a co-curing agent comprising ethylene acrylic acid, aziridine, or a combination thereof.
3. The method of claim 2,
With respect to 100 parts by weight of the composition,
Wherein the composition further comprises 0.1 to 20.0 parts by weight of an adhesion promoting agent comprising phosphoric acid ester, phosphoric acid ester, ammonium phosphate, or a combination thereof.
The method of claim 3,
With respect to 100 parts by weight of the composition,
Wherein the composition further comprises 0.1-5.0 parts by weight of a wax comprising polyethylene, polytetrafluoroethylene or a combination thereof.
The method according to claim 1,
Wherein the silicone compound comprises colloidal silica, silica sol, silicate, or a combination thereof.
The method according to claim 1,
The silane compound may be at least one selected from the group consisting of g-glycidoxypropyl triethoxy silane, g-aminopropyltriethoxy silane, tetraethoxy silane, Methyl trimethoxy silane, 3-glycidoxypropyl trimethoxysilane, or a combination thereof. The composition for surface treatment of chromium-free steel sheet according to claim 1,
The method according to claim 1,
Wherein the chelating agent is a form obtained by neutralizing hexafluoro titanic acid with an amine.
8. The method of claim 7,
Wherein the chelating agent is a form obtained by neutralizing a hexafluorotitanic acid with an amine in an amount of 3.0-10.0 wt% (relative to 100 wt% of a chelating agent).
9. The method of claim 8,
Wherein the amine is triethylamine. &Lt; RTI ID = 0.0 &gt; 11. &lt; / RTI &gt;
10. The method of claim 9,
Wherein the acrylic-urethane copolymer binder resin is a block copolymer of an acrylic resin and a urethane resin.
11. The method of claim 10,
Wherein the acrylic-urethane copolymer binder resin has a copolymerization ratio of acrylic resin in the binder resin of 40-60%.
Galvanized alloy steel plate; And
A coating disposed on the surface of the zinc-coated alloy steel plate;
/ RTI &gt;
Wherein the coating comprises the following composition.
(0.1-10.0 wt.% Of a silicone compound, 0.1-10.0 wt.% Of a silane compound, 0.1-10.0 wt.% Of a chelating agent, which is a titanium compound, a zirconium compound, or a combination thereof, based on 100 wt. A composition for surface treatment of a chrome-free steel sheet comprising 1.0 to 2.0% by weight of a curing agent comprising an amine-based, melamine-based, or a combination thereof, and a residual solvent;
13. The method of claim 12,
The zinc alloy-plated steel sheet; Wherein the surface of the cold-rolled steel sheet comprises a zinc-plated layer, a zinc-nickel plated layer, or a combination thereof.
14. The method of claim 13,
Wherein the amount of the zinc plating layer adhered is 30-100 g / m ² .
15. The method of claim 14,
Wherein the zinc-nickel plating layer has an adhesion amount of 20 to 50 g / m &lt; ² &gt;.
16. The method of claim 15,
Wherein the coating amount of the coating on the surface of the zinc-based alloy plated steel sheet is 300-2,500 mg / m ² .
Preparing a zinc-based alloy-plated steel sheet; And
Forming a coating on the surface of the zinc alloy-plated steel sheet;
/ RTI &gt;
Wherein the coating comprises the following composition: &lt; tb &gt;&lt; TABLE &gt;
(0.1-10.0 wt.% Of a silicone compound, 0.1-10.0 wt.% Of a silane compound, 0.1-10.0 wt.% Of a chelating agent, which is a titanium compound, a zirconium compound, or a combination thereof, based on 100 wt. A composition for surface treatment of a chrome-free steel sheet comprising 1.0 to 2.0% by weight of a curing agent comprising an amine-based, melamine-based, or a combination thereof, and a residual solvent;
18. The method of claim 17,
Preparing a zinc alloy-plated steel sheet; Quot;
Preparing a cold-rolled steel sheet; And
Forming a galvanized layer, a zinc-nickel plated layer, or a combination thereof on the surface of the cold-rolled steel sheet; Free surface treated steel sheet.
19. The method of claim 18,
Preparing a zinc alloy-plated steel sheet; in
Preparing a cold-rolled steel sheet; By this,
Wherein the cold-rolled steel sheet is rolled to a thickness of 0.5 to 1.5 mm at room temperature.
20. The method of claim 19,
Preparing a zinc alloy-plated steel sheet; in
Forming a galvanized layer, a zinc-nickel plated layer, or a combination thereof on the surface of the cold-rolled steel sheet; By this,
Wherein a coating layer is formed on one or both surfaces of the cold-rolled steel sheet.
21. The method of claim 20,
Preparing a zinc alloy-plated steel sheet; in
Forming a galvanized layer, a zinc-nickel plated layer, or a combination thereof on the surface of the cold-rolled steel sheet; By this,
Wherein the zinc plating layer, the zinc-nickel plating layer or a combination thereof is formed by an electroplating method or a hot-dip plating method.
22. The method of claim 21,
Forming a coating on the surface of the zinc alloy-plated steel sheet; Quot;
Applying a composition for surface treatment of a chromium-free steel sheet on the zinc alloy-plated layer; And
Baking a steel sheet coated with the composition for surface treatment of Cr-free steel sheet; Free surface treated steel sheet.
23. The method of claim 22,
Forming a coating on the surface of the zinc alloy-plated steel sheet; in,
Applying a composition for surface treatment of a chromium-free steel sheet on the zinc alloy-plated layer; By this,
Wherein the composition for surface treatment of chrome-free steel sheet is applied to the zinc-based alloy plating layer by roll coating, spraying, or dipping.
24. The method of claim 23,
Forming a coating on the surface of the zinc alloy-plated steel sheet; in,
Baking a steel sheet coated with the composition for surface treatment of Cr-free steel sheet; By this,
And baking the zinc alloy plated steel sheet coated with the chromium-free steel plate surface treating composition at a temperature of 120 to 250 캜 to form a chromium free coating layer.

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