KR101792240B1 - Composition for surface-treating a single-side-plated steel sheet, surface-treated steel sheet using the same composition, and the method for surface-treatent sheet using the sam composition - Google Patents

Abstract

The present invention relates to a composition for surface treatment of a single-side coated steel sheet, a steel sheet surface-treated using the same, and a surface treatment method using the same. Specifically, the composition for surface treatment comprises an acrylic-urethane copolymer resin (A); Si-Zr-Ti organic / inorganic hybrid additive (B); And a solvent, and satisfy the following formulas (1) and (2).
[Formula 1] 0.3 <[A] / ([A] + [B]) <0.7
[Formula 2] 20 wt% <[A] + [B] <70 wt%
(A) and (B) in the above formulas (1) and (2) satisfy the content (% by weight) of A and the content (% by weight) of B relative to the total amount (100% Meaning)

Description

TECHNICAL FIELD [0001] The present invention relates to a composition for surface treatment of a single-side coated steel sheet, a steel sheet surface-treated using the same, and a surface treatment method using the same. BACKGROUND OF THE INVENTION METHOD FOR SURFACE-TREATENT SHEET USING THE SAM COMPOSITION}

The present invention relates to a composition for surface treatment of a single-side coated steel sheet, a steel sheet surface-treated using the same, and a surface treatment method using the same.

BACKGROUND ART A steel sheet used for a fuel tank of a vehicle such as an automobile or a motorcycle is a main component directly connected to the safety of a vehicle and has basically a certain strength and durability, It is necessary that the quality such as the weldability to prevent leakage of the fuel from the joint portion is secured to a certain level or more.

As a method for improving the quality of steel sheets, plating methods of heavy metal materials such as lead (Pb), tin (Sn), and chromium (Cr) have been actively studied. However, in the recent situation that these heavy metal substances are regulated as environmental pollutants, they are inadequate to be studied further.

On the other hand, as another method for improving the quality of a steel sheet, a coating method using an organic resin is known. However, in order to secure the corrosion resistance, there is a problem that it is coated with an excessively thick thickness or it is inevitably post-treated with a material having a non-conductive property, thereby deteriorating the weldability.

In order to solve the above-mentioned problems, the present invention provides a composition for surface treatment of a single-side coated steel sheet, a surface-treated steel sheet using the same, and a surface treatment method using the same.

Single-sided plating  Composition for surface treatment of steel sheet

In one embodiment of the invention,

Acrylic-urethane copolymer resin (A); Si-Zr-Ti organic / inorganic hybrid additive (B); And a solvent,

1 &lt; / RTI &gt; and 2,

A composition for surface treatment of a single-side coated steel sheet is provided, and a description of the composition for surface treatment is as follows.

[Formula 1] 0.3 <[A] / ([A] + [B]) <0.7

[Formula 2] 20 wt% <[A] + [B] <70 wt%

(A) and (B) in the above formulas (1) and (2) satisfy the content (% by weight) of A and the content (% by weight) of B relative to the total amount (100% Meaning)

First, the Si-Zr-Ti organic / inorganic hybrid additive (B) is formed by a reaction of a silicon (Si) based material, a zirconium (Zr) based chelating agent, a titanium Chelate compound.

In this case, the silicon-based material may be one selected from the group consisting of colloidal silica, silica sol, and silicate-based materials, or a mixture of two or three thereof.

The zirconium (Zr) based chelating agent may be one selected from a zirconium (Zr) based chelating agent including zirconium alkoxide, zirconium acylate, and tetraalkyl zirconate, Or a mixture of two or three species.

The titanium chelating agent may be selected from the group consisting of hexafluoro titanic acid, fluorotitanic acid, titanium dioxide, titanyl nitrate, titanyl sulfate, A titanium chelating agent including titanium tetrachloride, tetrabutoxytitanium, Hexafluoro Ammonium Titanate, and titanium alkoxide, or one or two selected from among titanium chelate chelating agents including titanium tetrachloride, tetrabutyl titanate, tetrabutoxytitanium, Or a mixture of three species.

The neutralizing agent may be one kind or a mixture of two or three kinds selected from amine compounds including isopropyl amine and triethyl amine.

On the other hand, the acryl-urethane copolymer resin (A) may be a block copolymer of an acrylic resin and a urethane resin.

The acrylic-urethane copolymer binder resin is a block copolymer of an acrylic resin having a number average molecular weight of 500,000 to 1,500,000 and a urethane resin having a number average molecular weight of 5,000 to 15,000, wherein the copolymerization ratio of the acrylic resin in the acrylic- 40 to 60% by weight.

On the other hand, the composition for surface treatment may further comprise a coupling agent, a adhesion promoter, or a mixture thereof.

The coupling agent may be selected from the group consisting of g-glycidoxypropyl triethoxy silane, g-aminopropyltriethoxy silane, tetraethoxy silane, A silane-based coupling agent comprising methyl trimethoxy silane, and 3-glycidoxypropyl trimethoxysilane, or one or two selected from among silane coupling agents comprising 3-glycidoxypropyl trimethoxysilane, Or a mixture of three or more.

Specifically, the surface treatment composition may further include the coupling agent, and the content of the coupling agent to the total amount (100 wt%) of the surface treatment composition is 0.5 to 10 wt% %. &Lt; / RTI &gt;

The adhesion promoter may be a phosphate ester, ammonium phosphate, or a mixture thereof.

Specifically, the composition for surface treatment may further include the adhesion promoter, and the content of the adhesion promoter may be 2 to 20% by weight based on the total amount (100% by weight) of the composition for surface treatment.

Surface-treated Single-sided plating  Steel plate

In another embodiment of the present invention,

Single - side coated steel; And a surface treatment layer,

Wherein the single-side coated steel sheet comprises a cold-rolled steel sheet and a first plating layer positioned on one side of the cold-rolled steel sheet,

Wherein the surface treatment layer comprises an acryl-urethane copolymer resin (A) and an Si-Zr-Ti organic / inorganic hybrid additive (B), which is located on the first plating layer of the single- Lt; / RTI &gt;

A surface treated single-sided coated steel sheet is provided.

[Formula 1] 0.3 <[A] / ([A] + [B]) <0.7

(A) and (B) in the above formula (1) mean the content (% by weight) of A and the content (% by weight) of B relative to the total amount (100%

Specifically, the surface treatment layer may be formed using the above-mentioned surface treatment composition. Hereinafter, a description is given of the surface-treated single-side coated steel sheet except for the description overlapping with that described above.

First, the mass of the surface treatment layer per one side of the single-side coated steel sheet may be 300 to 2500 mg / m ² .

The mass of the first plating layer per one surface of the cold-rolled steel sheet may be 5 to 300 g / m ² .

The first plating layer may include zinc, a zinc-based alloy, or a combination thereof.

On the other hand, the one-side plated steel sheet, the cold rolling includes the further two plating layer unavoidably existing on the other one side, and the mass of the second plating layer per one surface of said cold-rolled steel sheet of the steel sheet is 10 mg / m ² or less (where, 0 mg / m &lt; ² &gt;).

Single-sided plating  Surface treatment of steel sheet

In another embodiment of the present invention,

Preparing a single-sided coated steel sheet comprising a cold-rolled steel sheet and a first plating layer positioned on one side of the cold-rolled steel sheet;

Applying a surface treatment composition onto the first plating layer of the single-side coated steel sheet; And

And curing the applied surface treatment composition to form a surface treatment layer,

Wherein the surface treatment composition comprises an acrylic-urethane copolymer resin (A), an Si-Zr-Ti organic or inorganic hybrid additive (B), and a solvent, and satisfies the following formulas 1 and 2:

A method of surface treatment of a single-side coated steel sheet is provided.

[Formula 1] 0.3 <[A] / ([A] + [B]) <0.7

[Formula 2] 20 wt% <[A] + [B] <70 wt%

(A) and (B) in the above formulas (1) and (2) mean the content (% by weight) of A and the content (% by weight) of B with respect to the total amount (100% box)

Specifically, the surface treatment composition used in the surface treatment method of the single-side coated steel sheet may be the same as that described above. Hereinafter, a description will be given of a surface treatment method of the single-side coated steel sheet, except for the description overlapping with the above-described one.

The step of applying the surface treatment composition on the first plating layer of the single-side coated steel sheet may be carried out by a roll coating method, a spray method, or a deposition method.

The step of curing the applied surface treatment composition to form a surface treatment layer may be performed at a temperature ranging from 130 to 250 ° C.

Meanwhile, the step of preparing the single-side coated steel sheet may be carried out using a plating bath having an edge mask on one side.

According to the embodiments of the present invention, the surface-treated steel sheet using the composition for surface treatment of the single-side coated steel sheet is advantageous in that it is eco-friendly and excellent in corrosion resistance and weldability.

1 schematically shows a surface-treated single-side coated steel sheet according to an embodiment of the present invention.
2 schematically shows a fuel resistance evaluation apparatus used in an evaluation example of the present invention.
Fig. 3 schematically shows the entire process of single-sided plating and surface treatment used in the embodiment of the present invention.

Advantages and features of the present invention and methods of achieving them will become apparent with reference to the embodiments described below in detail. It should be understood, however, that the 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, To fully disclose the scope of the invention to those skilled in the art, and the invention is only defined by the scope of the claims.

Throughout the specification, when an element is referred to as "comprising ", it means that it can include other elements as well, without excluding other elements unless specifically stated otherwise.

Single-sided plating  Composition for surface treatment of steel sheet

In one embodiment of the invention,

Acrylic-urethane copolymer resin (A); Si-Zr-Ti organic / inorganic hybrid additive (B); And a solvent,

1 &lt; / RTI &gt; and 2,

A composition for surface treatment of a single-side coated steel sheet is provided.

[Formula 1] 0.3 <[A] / ([A] + [B]) <0.7

[Formula 2] 20 wt% <[A] + [B] <70 wt%

(A) and (B) in the above formulas (1) and (2) satisfy the content (% by weight) of A and the content (% by weight) of B relative to the total amount (100% Meaning)

The composition for surface treatment does not contain a heavy metal such as lead (Pb), tin (Sn), and chromium (Cr), and is thus eco-friendly and can secure excellent corrosion resistance by the acryl-urethane copolymer resin (A) The above-mentioned problems can be solved by exhibiting conductivity by the Si-Zr-Ti based organic / inorganic hybrid additive (B).

Specifically, in the composition for surface treatment, the acrylic-urethane copolymer resin (A) and the Si-Zr-Ti organic or inorganic hybrid additive (B) are included as main components, 1 and 2 at the same time.

With respect to Formula 1, when the total content of A and B is 70% by weight or more based on the total amount (100% by weight) of the surface treatment composition, the solid content is excessive, The surface properties of the surface-treated steel sheet may be deteriorated. On the other hand, if it is 10% by weight or less, there is a limit in which sufficient corrosion resistance can not be secured.

With respect to Formula 2, when the ratio of the content of A to the total content of A and B in the surface treatment composition is 0.3 or less, it is difficult to ensure sufficient corrosion resistance, Coated steel sheet) may be deteriorated. On the other hand, if it is 0.7 or more, the conductivity may deteriorate and the weldability may deteriorate.

This fact is supported by the following examples (when the above equations 1 and 2 are satisfied at the same time), the comparative example (when the above equations 1 and / or 2 are not satisfied), and their evaluation examples.

On the other hand, the composition for surface treatment can be used for surface treatment of single-sided plating. More specifically, when the surface treatment composition is coated on the plating layer of the single-side coated steel sheet and then baked and cured, a steel sheet on which a plating layer and a surface treatment layer are formed on only one side can be obtained.

In the case of a single-sided surface-coated single-sided coated steel sheet having a plating layer and a surface treatment layer formed thereon, it is excellent in corrosion resistance and weldability, and is suitable for application as a fuel contact surface. In the case of the other side, the plating layer and the surface treatment layer which are unavoidably formed at the time of forming the plating layer and the surface treatment of the fuel contact surface are not subjected to a separate plating treatment or surface treatment, It is possible to prevent problems such as a decrease in welding strength and generation of fumes.

Hereinafter, the surface treatment composition will be described in detail. A surface treatment method using the surface treatment composition and a surface-treated single-side coated steel sheet using the same will be described in detail later.

The acrylic-urethane copolymer resin (A) is a material having excellent corrosion resistance and hydrophobicity, and may be a block copolymer of an acrylic resin and a urethane resin.

At this time, the copolymerization ratio of the block copolymer may be 40:60 to 60:40 in terms of the weight ratio of the acrylic resin to the urethane resin. If the ratio is less than 40:60 and the copolymerization ratio of the acrylic resin in the block copolymer is small, the conductivity may be lowered. On the other hand, when the copolymerization ratio of the acrylic resin in the block copolymer is over 60:40 or more, the flexibility of the surface treatment layer is reduced and the workability is deteriorated.

Specifically, the block copolymer may be a block copolymer formed through a block copolymerization reaction of an acrylic resin having a number average molecular weight of 500,000 to 1,500,000 and a urethane resin having a number average molecular weight of 5,000 to 15,000.

At this time, melamine may be used as a curing agent, and ethylene acrylic acid or an aziridine type curing agent may be used as a curing agent.

More specifically, the block copolymer may be prepared by preparing a mixture of the urethane resin and the acrylic resin, and the mixing ratio of the mixture may be the same as the copolymerization ratio. The melamine curing agent may be added in an amount of 1 to 10 parts by weight based on 100 parts by weight of the mixture, and 2 to 15 parts by weight of the auxiliary curing agent may be added.

The addition amount of the melamine curing agent and the auxiliary curing agent is such that the block copolymerization reaction occurs insufficiently when the amount is lower than the lower limit and the stability of the surface treatment composition is lowered due to unreacted materials when the upper limit is exceeded.

Thereafter, irradiation with ultraviolet rays or heat induces a block copolymerization reaction, and consequently, the acrylic-urethane copolymer resin (A) can be obtained.

On the other hand, the Si-Zr-Ti organic / inorganic hybrid additive (B) is formed by the reaction of a silicon (Si) based material, a zirconium (Zr) based chelating agent, a titanium Chelate compound.

Specifically, the silicon (Si) -based material is chemically reacted (specifically, chelated) with the zirconium (Zr) based chelating agent and the titanium (Ti) based chelating agent to form a compound, And to form the appropriate conditions for the reaction.

The silicon (Si) based material may be one kind or a mixture of two or more species selected from among silicon (Si) based materials including colloidal silica, silica sol, and silicate.

The zirconium (Zr) based chelating agent may be one selected from a zirconium (Zr) based chelating agent including zirconium alkoxide, zirconium acylate, and tetraalkyl zirconate, Or a mixture of two or three species.

The titanium (Ti) chelating agent may be at least one selected from the group consisting of hexafluoro titanic acid, fluorotitanic acid, titanium dioxide, titanyl nitrate, titanyl sulfurate A titanium chelating agent including titanium tetrachloride, tetrabutoxytitanium, Hexafluoro Ammonium Titanate and titanium alkoxide, and a titanium chelating agent selected from the group consisting of titanium tetrachloride, tetrabutyl titanate, tetrabutyl titanate, Or a mixture of two or three species.

The neutralizing agent may be one kind or a mixture of two or three kinds selected from amine compounds including isopropyl amine and triethyl amine.

For example, colloidal silica having a particle size ranging from 5 to 50 nm is used as the silicon (Si) -based material, hexafluoro titanic acid (hexafluoro titanic acid) is added as the titanium (Ti) , And a mixture of tetraalkyl zirconate as a zirconium (Zr) based chelating agent may be added.

Based material is 40 to 90 wt% based on the total amount (100 wt%) of the silicon (Si) based material, the titanium (Ti) based chelating agent and the zirconium (Zr) based chelating agent, 5 to 30% by weight of the titanium (Ti) chelating agent, and 5 to 30% by weight of the zirconium (Zr) based chelating agent.

A chelating reaction can be induced by adding 3 to 10 parts by weight of an amine based on 100 parts by weight of such a mixture. However, when the amount of amine added is 3 parts by weight or less, basic conditions are hardly formed, and precipitation may occur. On the other hand, if the added amount of the amine is 10 parts by weight or more, the added amount of the amine is excessively large, and the stability of the reaction solution may be deteriorated.

On the other hand, the composition for surface treatment may further comprise a coupling agent, a adhesion promoter, or a mixture thereof.

In the case of the coupling agent, it serves to improve the corrosion resistance by inducing dense bonding of the acryl-urethane copolymer resin (A) and the Si-Zr-Ti organic / inorganic hybrid additive (B) .

For example, the coupling agent may be selected from the group consisting of g-glycidoxypropyl triethoxy silane, g-aminopropyltriethoxy silane, tetraethoxysilane A silane-based coupling agent comprising Tetraethoxy silane, methyl trimethoxy silane, and 3-glycidoxypropyl trimethoxysilane. Species, or a mixture of two or more species.

In the case of the adhesion promoter, the adhesion promoter can improve adhesion with the plating layer, and may be, for example, phosphoric acid ester, ammonium phosphate, or a mixture thereof.

Specifically, the content of the coupling agent is 0.5 to 10% by weight, the content of the adhesion promoter is 2 to 20% by weight, and the content of the coupling agent is 2 to 20% by weight with respect to the total amount (100% . If the lower limit of the above range is not exceeded, the stability of the surface treatment composition may deteriorate.

More specifically, the coupling agent may be selected from the group consisting of g-glycidoxypropyl triethoxy silane, g-aminopropyltriethoxy silane, tetraethoxysilane A silane-based coupling agent comprising Tetraethoxy silane, methyl trimethoxy silane, and 3-glycidoxypropyl trimethoxysilane. Species, or a mixture of two or more species.

The adhesion promoter may be a phosphate ester, ammonium phosphate, or a mixture thereof.

Surface-treated Single-sided plating  Steel plate

In another embodiment of the present invention,

Single - side coated steel; And a surface treatment layer (130)

The single-sided plated steel sheet includes a cold-rolled steel sheet (110) and a first plated layer (120) positioned on one side of the cold-rolled steel sheet,

The surface treatment layer 130 is disposed on the first plating layer 120 of the single-sided coated steel sheet and comprises an acrylic-urethane copolymer resin (A) and a Si-Zr-Ti organic or inorganic hybrid additive (B) And satisfies the following formula (1)

A surface-treated single-side coated steel sheet 100 is shown, which is schematically shown in Fig.

[Formula 1] 0.3 <[A] / ([A] + [B]) <0.7

(A) and (B) in the above formula (1) mean the content (% by weight) of A and the content (% by weight) of B relative to the total amount (100%

Specifically, the surface treatment layer 130 may be formed using the above-mentioned surface treatment composition. Hereinafter, a description is given of the surface-treated single-side coated steel sheet except for the description overlapping with that described above.

First, the mass of the surface treatment layer 130 per one surface of the single-side coated steel sheet may be 300 to 2500 mg / m ² . However, if the surface treatment layer 130 is less than 300 mg / m ² , the thickness of the surface treatment layer 130 becomes too thin, and it may be difficult to secure corrosion resistance. On the other hand, if the surface treatment layer 130 is more than 2500 mg / m ² , the thickness of the surface treatment layer 130 becomes excessively thick, and the weldability may deteriorate and the adhesion to the plating layer may deteriorate.

On the other hand, the mass of the first plating layer 120 per one surface of the cold-rolled steel sheet may be 5 to 300 g / m ² . However, if it is less than 5 g / m ² , the thickness of the first plating layer 120 becomes too thin, and it may be difficult to secure corrosion resistance. On the other hand, when the adhesion amount exceeds 300 g / m &lt; ² &gt;, there is a disadvantage that workability and economical efficiency are deteriorated.

At this time, the first plating layer 120 may include zinc, a zinc-based alloy, or a combination thereof. Specifically, the zinc-based alloy may be Zn-Ni, Zn-Mg, Zn-Al, or Zn-Al-Mg.

On the other hand, the single-sided plated steel sheet further includes a second plating layer (not shown) inevitably present on the other side of the cold-rolled steel sheet, and the mass of the second plating layer (not shown) 10 mg / m ² or less (but excluding 0 mg / m ² ).

As described above, when forming the first plating layer 120 on one side of the cold-rolled steel sheet, the second plating layer (not shown) may inevitably be formed on the other side, but is not intentionally formed.

Single-sided plating  Surface treatment of steel sheet

In another embodiment of the present invention,

Preparing a single-sided coated steel sheet including a cold-rolled steel sheet (110) and a first coating layer (120) positioned on one side of the cold-rolled steel sheet (110);

Applying a surface treatment composition onto the first plating layer of the single-side coated steel sheet; And

And curing the applied surface treatment composition to form a surface treatment layer 130,

Wherein the surface treatment composition comprises an acrylic-urethane copolymer resin (A), an Si-Zr-Ti organic or inorganic hybrid additive (B), and a solvent, and satisfies the following formulas 1 and 2:

A method of surface treatment of a single-side coated steel sheet is provided.

[Formula 1] 0.3 <[A] / ([A] + [B]) <0.7

[Formula 2] 20 wt% <[A] + [B] <70 wt%

(A) and (B) in the above formulas (1) and (2) mean the content (% by weight) of A and the content (% by weight) of B with respect to the total amount (100% box)

Specifically, the surface treatment composition used in the surface treatment method of the single-side coated steel sheet may be the same as that described above. Hereinafter, a description will be given of a surface treatment method of the single-side coated steel sheet, except for the description overlapping with the above-described one.

First, the step of preparing the single-side coated steel sheet may be carried out by using a plating bath having a current shielding edge mask on one side thereof.

Specifically, in the plating bath, current does not flow on one side where the current mask (edge mask) is located, and current can flow only on the other side. When the cold-rolled signboard is inserted into the plating vessel and operated, electroplating can be induced only on one side where current flows.

At this time, if the current shielding device is too close to the material steel sheet to be plated (i.e., the cold-rolled steel sheet 110), the material steel sheet and the current shielding device may be damaged. On the other hand, when the plating film is too far away, an electric current flows to the edge of the side not intended to be plated, plating can be performed, and the welding quality is deteriorated. Therefore, it is necessary to appropriately adjust the position of the material steel plate 110 to be plated in the current shielding device.

On the other hand, the step of applying the surface treatment composition on the first plating layer 120 of the single-side coated steel sheet may be carried out by a roll coating method, a spray method, or a deposition method. Specifically, the surface treatment composition may be coated on the first plating layer 120 of the single-side coated steel sheet with a coating amount of 300 to 2500 mg / m ^{2 by} a roll coating method. Such a coating amount is based on the above-mentioned contents.

On the other hand, the step of curing the applied surface treatment composition to form the surface treatment layer 130 may be performed in a temperature range of 130 to 250 ° C. Specifically, the temperature range is based on the steel sheet temperature (MT - Metal Temperature).

If the temperature is less than 130 ° C, the reaction of the acrylic-urethane copolymer resin (A) and the Si-Zr-Ti organic / inorganic hybrid additive (B) becomes insufficient, A part of the treatment layer may be dropped. On the other hand, when the temperature exceeds 250 DEG C, the curing reaction does not occur any more, and only the heat loss can be increased.

Best Mode for Carrying Out the Invention Hereinafter, embodiments of the present invention, comparative examples thereof, and evaluation examples thereof 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.

Specifically, the following examples and comparative examples are commonly used to prepare (1) a composition for surface treatment, (2) to produce a single-sided coated steel sheet, (3) ) The final surface-treated single-side coated steel sheet was evaluated.

In this connection, Fig. 3 is a general view of the single-side plating of (2) and the surface treatment of (3) using the composition prepared in the above (1).

3, the cold-rolled steel sheet 110 is passed through a welder and a leveler, followed by cleaning and pickling, and then moved to a horizontal cell type plating vessel Thereby performing the one-side plating of the above (2).

At this time, an edge mask is located on one side of the plating vessel, and current may not flow (Off-current) and plating may be non-plating. On the other hand, on-current plating may be performed to form a first plating layer 120 on the other side. At the same time, a part of the plating is inevitably made on the side where the current mask is located, so that a second plating layer (not shown) can be formed.

The single-side coated steel sheet is subjected to a post treatment process, then stripwise reversed, and then moved to a roll coater to carry out the surface treatment process of the above (3). At this time, only the surface of the first plating layer 120 can be treated using the composition prepared in the above (1).

Specifically, the roll of the surface on which the first plating layer 120 is located may be closed, and the composition prepared in the above (1) may be applied. At the same time, the roll on the side where the second plating layer (not shown) is located can be opened to prevent the composition prepared in the above (1) from being applied.

Thereafter, in the oven, the composition applied on the first plated layer 120 may be cured to form the surface treatment layer 130. Finally, the surface quality is inspected, .

Hereinafter, (1) to (4) will be described with reference to FIG.

(1) Preparation of composition for surface treatment

(A), an Si-Zr-Ti organic / inorganic hybrid additive (B), a silane-based coupling agent, a adhesion promoter, and water were mixed according to Tables 1 to 3 , A composition for surface treatment satisfying each composition was prepared.

Each of the raw materials used at this time was purchased and used for each product already commercialized.

(2) One side  Manufacture of coated steel sheet

According to Tables 1 to 3, a single-side-coated steel sheet was produced from zinc or a zinc-based alloy.

For zinc or zinc-based alloy plating, a plating solution of a pure zinc or zinc-based alloy plating composition was used. More specifically, a zinc or zinc-based alloy ingot ingot is melted at a concentration of 40 to 120 g / L in a sulfuric acid bath whose temperature is controlled at 40 to 90 占 폚 and which is controlled at a pH of 0.5 to 2.

When a cold-rolled steel plate (a steel plate rolled at a temperature of 0.4 to 2.3 mm in thickness) is charged into the plating bath and operated in a plating bath using the plating solution under a current density of 10 to 100 A / dm ² , Electroplating is induced only on the side surface, and the intended plating is performed only on one side of the cold-rolled signboard. The surface on which the desired plating is performed is described as "fuel contact surface" in Table 2 below.

However, a very small amount of plating was inevitably made on the other side of the cold-rolled signboard. Such a surface inevitably plated was described as "coating surface" in Table 2 below.

(3) Single-sided plating  Surface treatment of steel sheet

The surface treatment composition of the above (1) was coated on the fuel contact surface of the single-sided coated steel sheet of (2) using a roll coating method according to Tables 1 to 3, followed by baking and curing at 210 ° C, Treated single-side coated steel sheet was finally obtained.

(4) Surface-treated Single-sided plating  Evaluation of steel plate

According to Tables 1 to 3, the properties required for the steel plate of the fuel tank, such as solution stability, corrosion resistance, fuel resistance and weldability, were evaluated for the surface treatment composition of the above (1) or the surface treated single-side coated steel sheet of the above (3) Respectively. Specifically, the evaluation conditions of each physical property are as follows.

Solution stability : The composition for surface treatment of the above (1) was stored at room temperature for 60 days and at a temperature of 50 占 폚 for 45 days, and then the inside of the composition was observed for occurrence of precipitation or gelling, Respectively.

Corrosion Resistance : The surface treated single-side coated steel sheet of the above (3) was subjected to 500 hours of spraying at a spraying pressure of 1 kg / cm &lt; ² &gt; (% Of the area of the whole surface,% of the generated rust) was evaluated

◎: When the corrosion area is close to zero

○: When the corrosion area is 5 or less

□: When the corrosion area is more than 5 but less than 30

?: When the corrosion area is more than 30 but not more than 50

X: When the corrosion area exceeds 50

Fuel resistance : The fuel resistance of each of the deteriorated gasoline and the biodiesel was evaluated at high temperature using the fuel resistance evaluation apparatus of FIG.

Specifically, the fuel resistance evaluation for deteriorated gasoline was conducted by preparing a deteriorated gasoline solution (total 100 vol%) containing 78.58% by volume of gasoline, 20% by volume of ethanol and 1.42% by volume of pure water, 100 ppm (= 100 mg / kg) of formic acid and 100 ppm (= 100 mg / kg) of acetic acid were added to the solution on a weight basis (1 kg) and left at 60 ° C for 3 months. .

On the other hand, the evaluation of the fuel resistance for biodiesel was carried out using a biodiesel solution containing 81 vol% diesel, 9 vol% bio-diesel, 5 vol% pure water, and 5 vol% methanol %) And 20 parts per million (= 20 mg / kg) of formic acid and 0.3 part by weight peroxide based on the weight of the biodiesel solution (1 kg or 100 parts by weight) And then the corrosion of the steel sheet was checked.

The corrosion state of each steel sheet was evaluated as follows based on the corrosion area (percent area of rust generated relative to the total area of the surface)

◎: When the corrosion area is close to zero

○: When the corrosion area is 5 or less

□: When the corrosion area is more than 5 but less than 30

?: When the corrosion area is more than 30 but not more than 50

X: When the corrosion area exceeds 50

Weldability : Arc welding was carried out using an arc welder under conditions of a current of 95 A, a voltage of 15.9 Volt and a welding speed of 13.5 mpm under a KC-27 welding wire (diameter 1.2 mm), atmosphere gas Ar-20% CO ₂ , (X), and weld quality defects (r), were evaluated by observing the state of the steel sheet, the state of the steel sheet, the spatter, fume generation and strength.

Evaluation example  1: Evaluation according to each component content of the composition for surface treatment

According to the above steps (1) to (3), a coating layer was formed on one side of the cold-rolled signboard such that the adhesion amount of the zinc-nickel alloy plating was 30 g / m ² , m ² , and the steel sheet was baked under the condition that the steel sheet temperature was 210 ° C. Thereafter, quality evaluation was carried out in accordance with the above (4), and the results were recorded in Table 1.

division The content of each component in the composition for surface treatment Quality evaluation result [A] + [B] [A]
/ ([A] + [B]) Silane coupling agent Adhesion promoter Solution stability Corrosion resistance Fuel resistance Weldability Comparative Example 5 0.4




5









5 ○ × △ ○ Example 10 ○ ○ ○ ○ Example 30 ○ ◎ ◎ ○ Example 50 ○ ◎ ◎ ○ Example 70 ○ ◎ ○ ○ Comparative Example 80 ○ ○ □ × Comparative Example 50
















0.2 ○ △ □ ○ Example 0.3 ○ ○ ○ ○ Example 0.5 ○ ◎ ◎ ○ Example 0.7 ○ ○ ○ ○ Comparative Example 0.8 ○ □ △ △ Comparative Example 0.4











0.3 ○ □ △ ○ Example 0.5 ○ ○ ○ ○ Example 2 ○ ◎ ◎ ○ Example 5 ○ ◎ ◎ ○ Example 7 ○ ◎ ◎ ○ Example 10 ○ ○ ○ ○ Comparative Example 15 × × × △ Comparative Example 5




One ○ × △ △ Example 2 ○ ○ ○ ○ Example 7 ○ ◎ ◎ ○ Example 14 ○ ◎ ◎ ○ Example 20 ○ ○ ○ ○ Comparative Example 25 × × × △

Note: In Table 1, the respective contents of [A] + [B], the silane-based coupling agent, and the adhesion promoter are described based on 100 wt% of the total composition. However, the weight% unit is omitted.

The content of the acrylic-urethane copolymer resin (A) and the Si-Zr-Ti organic / inorganic hybrid additive (B) in the total amount (100 wt%) of each composition for surface treatment, It is found that all of the physical properties evaluation results are excellent only when the following formulas 1 and 2 are satisfied, the content of the coupling agent is 0.5 to 10 wt%, and the content of the adhesion promoter is 2 to 20 wt% have.

[Formula 1] 0.3 <[A] / ([A] + [B]) <0.7

[Formula 2] 20 wt% <[A] + [B] <70 wt%

Evaluation example  2: Evaluation according to plating amount

According to the above steps (1) to (3), a zinc-nickel alloy plating layer was formed on one side of the cold-rolled signboard at an adhesion amount shown in Table 2, and the surface treatment composition was coated with 1000 mg / m ² thereon. Lt; 0 &gt; C. Thereafter, the quality evaluation was carried out according to the above (4), and the results were recorded in Table 2.

division
Plating amount Quality evaluation result Fuel contact surface
(g / m ² ) Paint surface
(g / m ² ) Corrosion resistance Fuel resistance Weldability Comparative Example 3 5







× × ○ Example 5 ○ ○ ○ Example 10 ○ ○ ○ Example 30 ◎ ◎ ○ Example 50 ◎ ◎ ○ Example 100 ◎ ◎ ○ Example 200 ◎ ◎ ○ Example 300 ◎ ◎ ○ Comparative Example 350 ◎ ◎ △ Example 30 10 ◎ ◎ ○ Comparative Example 20 ◎ ◎ ×

It can be seen from Table 2 that all of the physical property evaluation results are excellent when the plating adhesion amount of the fuel contact surface is 5 to 300 g / m ² and the plating adhesion amount of the coating surface is 10 mg / m ² or less.

Evaluation example  3: Evaluation according to each component content of the composition for surface treatment

According to the above steps (1) to (3), a plating layer was formed on one side of the cold-rolled signboard so that the adhesion amount of the zinc-nickel alloy plating was 30 g / m ² , Thereby forming a surface treatment layer. Thereafter, the quality evaluation was carried out according to the above (4), and the results were recorded in Table 3.

division
Manufacturing conditions Quality evaluation result Surface treatment layer adhesion amount
(g / m ² ) Steel plate temperature
(° C) Corrosion resistance Fuel resistance Weldability Comparative Example 200 210






△ □ ○ Example 300 ○ ○ ○ Example 500 ○ ○ ○ Example 1000 ◎ ◎ ○ Example 1500 ◎ ◎ ○ Example 2000 ◎ ◎ ○ Example 2500 ◎ ◎ ○ Comparative Example 3000 ◎ ◎ × Comparative Example 1000




120 △ □ △ Example 130 ○ ○ ○ Example 150 ○ ○ ○ Example 200 ◎ ◎ ○ Example 250 ◎ ◎ ○ Comparative Example 300 □ □ ○

Table 3 shows that when the surface treatment layer adhesion amount (that is, the application amount of the surface treatment composition) of the fuel contact surface is 300 to 2500 mg / m ² and the steel sheet temperature is hardened in the temperature range of 130 to 250 ° C , All of the physical property evaluation results are excellent.

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 .

100: Surface treated single-side coated steel sheet
110: Cold rolled steel plate
120: First plating layer
130: Surface treatment layer

Claims (22)

Acrylic-urethane copolymer resin (A);
Si-Zr-Ti organic / inorganic hybrid additive (B); And
A solvent;
1 < / RTI &gt; and 2,
Composition for surface treatment of single side coated steel sheet.
[Formula 1] 0.3 <[A] / ([A] + [B]) <0.7
[Formula 2] 20 wt% <[A] + [B] <70 wt%
(A) and (B) in the above formulas (1) and (2) satisfy the content (% by weight) of A and the content (% by weight) of B relative to the total amount (100% Meaning)
The method according to claim 1,
The Si-Zr-Ti based organic / inorganic hybrid additive (B)
Which is a chelate compound formed by the reaction of a silicon (Si) based material, a zirconium (Zr) based chelating agent, a titanium (Ti)
Composition for surface treatment of single side coated steel sheet.
3. The method of claim 2,
The silicon (Si)
(Si) -based materials including silicon dioxide, silicon carbide, silica, colloidal silica, silica sol, and silicate.
Composition for surface treatment of single side coated steel sheet.
3. The method of claim 2,
The zirconium (Zr)
A zirconium (Zr) based chelating agent including zirconium alkoxide, zirconium acylate, and tetraalkyl zirconate, or a mixture of two or three thereof ,
Composition for surface treatment of single side coated steel sheet.
3. The method of claim 2,
The above-mentioned titanium (Ti)
Titanium tetrachloride, hexafluoro titanic acid, fluorotitanic acid, titanium dioxide, titanyl nitrate, titanyl sulfurate, titanium tetrachloride, (Ti) -based chelating agents including tetrabutyl titanic acid, Hexafluoro Ammonium Titanate, and titanium alkoxide, or a mixture of two or more selected from the group consisting of In fact,
Composition for surface treatment of single side coated steel sheet.
3. The method of claim 2,
The neutralizing agent,
Isopropylamine, triethylamine, and triethylamine. 3. The composition according to claim 1, wherein the amine compound is selected from the group consisting of isopropylamine, triethylamine, and triethylamine.
Composition for surface treatment of single side coated steel sheet.
The method according to claim 1,
The acrylic-urethane copolymer resin (A)
An acrylic resin having a number average molecular weight of 500,000 to 1,500,000, and a urethane resin having a number average molecular weight of 5,000 to 15,000.
Composition for surface treatment of single side coated steel sheet.
8. The method of claim 7,
The copolymerization ratio of the block copolymer,
Wherein the weight ratio of the acrylic resin to the urethane resin is 40:60 to 60:40.
Composition for surface treatment of single side coated steel sheet.
The method according to claim 1,
The above-mentioned composition for surface treatment,
A coupling agent, an adhesion promoter, or a mixture thereof.
Composition for surface treatment of single side coated steel sheet.
10. The method of claim 9,
Wherein the coupling agent is a coupling agent,
G-glycidoxypropyl triethoxy silane, g-aminopropyltriethoxy silane, tetraethoxy silane, methyl trimethoxy silane, methyl trimethoxy silane, silane-based coupling agents comprising a silane-based silane coupling agent and a silane-based coupling agent containing 3-glycidoxypropyl trimethoxysilane.
Composition for surface treatment of single side coated steel sheet.
10. The method of claim 9,
Wherein the composition for surface treatment further comprises a coupling agent,
Wherein the content of the coupling agent with respect to the total amount (100 wt%) of the surface treatment composition is 0.5 to 10 wt%
Composition for surface treatment of single side coated steel sheet.
10. The method of claim 9,
The adhesion-
Phosphoric acid ester, ammonium phosphate, or a mixture thereof.
Composition for surface treatment of single side coated steel sheet.
10. The method of claim 9,
Wherein the composition for surface treatment further comprises the adhesion promoter,
Wherein the content of the adhesion promoter to the total amount (100 wt%) of the surface treatment composition is 2 to 20 wt%
Composition for surface treatment of single side coated steel sheet.
Single - side coated steel; And
And a surface treatment layer,
Wherein the single-side coated steel sheet comprises a cold-rolled steel sheet and a first plating layer positioned on one side of the cold-rolled steel sheet,
Wherein the surface treatment layer comprises an acryl-urethane copolymer resin (A) and an Si-Zr-Ti organic / inorganic hybrid additive (B), which is located on the first plating layer of the single- Lt; / RTI &gt;
Surface - treated single - sided coated steel.
[Formula 1] 0.3 <[A] / ([A] + [B]) <0.7
(A) and (B) in the above formula (1) mean the content (% by weight) of A and the content (% by weight) of B relative to the total amount (100%
15. The method of claim 14,
The mass of the surface treatment layer per one side of the single-
300 to 2500 mg / m &lt; ² &gt;.
Surface - treated single - sided coated steel.
15. The method of claim 14,
The mass of the first plating layer per one side of the cold-
5 to 300 g / m &lt; ² &gt;.
Surface - treated single - sided coated steel.
15. The method of claim 14,
The first plating layer may be formed of a metal,
Zinc, a zinc-based alloy, or a combination thereof.
Surface - treated single - sided coated steel.
15. The method of claim 14,
Wherein the single-sided plated steel sheet further comprises a second plated layer present on the other side of the cold-rolled steel sheet,
The mass of the second plating layer per one side of the cold-
10 mg / m ² or less (but excluding 0 mg / m ² ).
Surface - treated single - sided coated steel.
Preparing a single-sided coated steel sheet comprising a cold-rolled steel sheet and a first plating layer positioned on one side of the cold-rolled steel sheet;
Applying a surface treatment composition onto the first plating layer of the single-side coated steel sheet; And
And curing the applied surface treatment composition to form a surface treatment layer,
Wherein the surface treatment composition comprises an acrylic-urethane copolymer resin (A), an Si-Zr-Ti organic or inorganic hybrid additive (B), and a solvent, and satisfies the following formulas 1 and 2:
Method of surface treatment of single side coated steel sheet.
[Formula 1] 0.3 <[A] / ([A] + [B]) <0.7
[Formula 2] 20 wt% <[A] + [B] <70 wt%
(A) and (B) in the above formulas (1) and (2) mean the content (% by weight) of A and the content (% by weight) of B with respect to the total amount (100% box)
20. The method of claim 19,
Applying the surface treatment composition onto the first plating layer of the single-side coated steel sheet;
A roll coating method, a spray coating method, or a deposition method.
Method of surface treatment of single side coated steel sheet.
20. The method of claim 19,
Curing the applied surface treatment composition to form a surface treatment layer,
Lt; RTI ID = 0.0 &gt; 130 C &lt; / RTI &gt; to 250 C,
Method of surface treatment of single side coated steel sheet.
20. The method of claim 19,
Preparing the single-side coated steel sheet,
Wherein a plating bath in which an edge mask is located on one side is used.
Method of surface treatment of single side coated steel sheet.

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