KR101276406B1 - Resin coating compositions for excellent self-cleaning ability and its coated steel sheet - Google Patents

Abstract

PURPOSE: A resin composition for surface treatment is provided to obtain a precoated metal coating with an improved self-cleaning performance and a staining performance while maintaining basic physical properties of a precoated material resin composition. CONSTITUTION: A resin composition for surface treatment comprises 20-75 parts by weight of a base resin, 5-60 parts by weight of a solvent, and 3-15 parts by weight of a dispersion material, based on 100.0 parts by weight of a total surface-treating resin composition. The base resin is one or more selected from a polyester-based resin, a modified polyester-based resin, a fluorine-based resin, a vinyl chloride resin, a melamine-based resin, an epoxy-based resin, a urethane-based resin, a silicon resin, a modified silicon resin, and an acryl-based resin. The surfactant is a cationic surfactant, an anionic surfactant, a nonionic surfactant, or an amphiprotic surfactant. [Reference numerals] (AA) Top coat: Self washing material + Color paint(the present invention); (BB) Base coat; (CC) Chromate pre-treatment; (DD) Material; (EE) Epoxy(rear side); (FF) Chromate pre-treatment(rear side)

Description

Resin coating compositions for excellent self-cleaning ability and its coated steel sheet}

The present invention relates to a resin composition for surface treatment excellent in self-cleaning properties and a steel sheet using the same.

In line with the ever-increasing interest in eco-business, the need for self-cleaning capability, one of the representative environmentally friendly functions, is increasing. In addition, in the case of buildings or home appliances where the surface appearance is easily contaminated due to exposure to the external environment, it is necessary to develop a material capable of maintaining cleanliness. Accordingly, research has been continuously conducted to give self-cleaning ability to the surface of products in order to reduce the management cost as much as possible.

Self-cleaning ability is to give a function to clean the contaminant on the surface of the coating film by rain water or the like by forming a special functional structure in the coating film, the method of implementing the self-cleaning can be largely divided into hydrophilic and hydrophobic.

The hydrophilic system has a low water contact angle on the surface of the product (contact angle of 40 ° or less, surface tension: 30mN / m or more). Mainly polyester resins are used [KCC, Union Steel, Dongbu Steel], and organic resins using TiO ₂ components with photoactivation effect are also used [POSCO, Yodogawa].

On the other hand, the hydrophobic system has a high water contact angle on the surface of the product (contact angle of 90 ° or more, surface tension: 15mN / m or less) as the water rolls down the surface to remove contaminants. A method of concentrating a hydrophobic material having a high hydrophobicity on a surface [Patent Document 1], a coating method of a nanostructure applied with a lotus leaf structure, and the like are used.

However, as described above, the commercially available self-cleaning method has a surface contact angle, which is a key factor of the cleanliness, at a level of 60 to 90 °, indicating a medium value that is difficult to express hydrophilicity / hydrophobicity.

In addition to cleaning properties, the following disadvantages exist depending on the implementation method. A self-cleaning steel sheet coated with a hydrophilic organic resin may have a thickness of 20 μm or more to secure physical properties other than self-cleaning.

TiO ₂ The photocatalytic self-cleaning steel sheet using the light decomposes contaminants by surface oxidation of the photocatalyst by ultraviolet rays, and it is useful for removing NOx and SOx even when the thickness is less than 1 μm. There is a disadvantage in that it exhibits self-cleaning through light reaction.

In addition, when imparting hydrophobicity to the surface by using a fluorine-based compound, there is a relatively small advantage of depositing contaminants, but it is difficult to concentrate the fluorine-based compound on the surface, there is a disadvantage that the self-cleaning is poor in oily contamination.

In the case of using the nano-projection structure, it is difficult to maintain the nano-projection structure after processing, and there is a disadvantage in that durability is insufficient.

In addition to each of the above disadvantages, there is a limit to the application in applications that require workability, adhesion, corrosion resistance and the like.

Domestic Patent Application No. 2007-0130961 Domestic Patent Application No.2009-0133815

Accordingly, it is an object of the present invention to provide a resin composition for surface treatment having excellent self-cleaning properties and a steel sheet using the same.

The present invention as a means for solving the above problems, a main resin; solvent; It provides a resin composition for surface treatment comprising a; and a dispersion containing a surfactant and a solvent for an organic paint.

The present invention also provides a steel sheet including a coating layer containing a cured product of the resin composition for surface treatment as another means for solving the above problems.

When the resin composition for surface treatment according to the present invention is applied to a steel sheet, a functional PCM coating film having improved self-cleaning property and non-pollution property can be obtained while maintaining the basic physical properties of the existing PCM resin composition such as workability, corrosion resistance, and adhesion. there was.

1 is a schematic cross-sectional view showing the structure of a self-cleaning polyester resin color steel sheet (hereinafter, self-cleaning steel sheet) coated with a resin composition for surface treatment according to an embodiment of the present invention.
2 is a photograph showing a process of evaluating self-cleaning.
3 is a photograph showing the results of self-cleaning evaluation of the self-cleaning steel sheet and the general color steel sheet for building materials (Comparative Example 1) according to Example 1 of the present invention.
4 is a photograph showing the results of measuring the water contact angle of the self-cleaning steel sheet according to Example 1 of the present invention and Comparative Example 1.
5 is a photograph showing the results of the adhesion evaluation of the self-cleaning steel sheet according to Example 1 of the present invention and Comparative Example 1.
6 is a photograph showing the results of evaluation of corrosion resistance of the self-cleaning steel sheet according to Example 1 of the present invention and Comparative Example 1.
7 is a photograph showing the results of the outdoor exposure evaluation of the self-cleaning steel sheet according to Example 1 of the present invention and Comparative Example 1.
8 is color difference and glossiness change data collected when the self-cleaning steel sheet according to Example 1 of the present invention and the outdoor exposure of Comparative Example 1 were evaluated.

The present invention is a subject resin; solvent; And a dispersion containing a surfactant and a solvent for an organic coating.

In the present invention, the main resin which uniformly disperses and supports various additives and is responsible for the main components of the final resin coating layer may use all kinds of resins commonly used in general PCM (precoated metal) industry. At least one main resin selected from the group consisting of polyester resins, modified polyester resins, fluorine resins, vinyl chloride resins (PVC), melamine resins, epoxy resins, urethane resins, silicone resins, modified silicone resins and acrylic resins Use The main resin is preferably used 20 to 75 parts by weight based on 100 parts by weight of the total resin composition for surface treatment, there is a problem in that the self-cleaning effect is insufficient.

An auxiliary resin may be used in addition to the main resin, and the auxiliary resin may be a thermoplastic acrylic resin, a thermosetting acrylic resin, or the like. The supplementary auxiliary resin may add 10 to 50 parts by weight based on 100 parts by weight of the main resin.

In the present invention, a surfactant is used as an additive that expresses self-cleaning and fouling resistance. As a result, the surface of the dried coating film is replaced with a hydrophilic group, and the water contact angle is lowered. When it meets, water penetrates between the contaminant and the surface of the coating film, and finally, the contaminant is washed off with the water (self-cleaning). In addition, the surfactant is also excellent in fouling resistance to hinder the adsorption of contaminants by activating exclusiveness with contaminants on the surface of the coating film. Surfactants added for self-cleaning and fouling-resistant expression include cationic, anionic, nonionic, amphoteric ionic and the like.

In the present invention, the cationic surfactant has a self-cleaning mechanism for optimizing the charge with the internal cation of the organic resin, and can be any conventionally known cationic surfactant, but preferably oleimidazolinium methyl sulfate (Oleyl imidazolinium) Methyl sulfate-based compound (DONAQUAT-OIMS 75, 90 series from Dongnam Synthetic, DONAQUAT-590ET, SOFNOL-CKY, R850), ammonium methyl sulfate-based compound (PD50, AT30A, ADEKA, Japan) and triethanol ammonium methyl At least one selected from the group consisting of triethanol ammonium methyl sulfate-based compounds (MICONIUM CTAC-29, 50 series, MICONIUM CTMS, MICONIUM STMS, etc.) is available. In particular, the cationic surfactant is preferably used as the main resin at least one selected from the group consisting of polyester resins and epoxy resins.

In the present invention, the anionic surfactant has a self-cleaning mechanism for maximizing the electronegativity and minimizing the surface tension, and may be any conventionally known anionic surfactant, but is preferably dialkylsulfosuccinate. At least one selected from the group consisting of a system compound (REVOGEN TS3 from Dongnam Synthetic) and an alkyl naphthalene compound (CARRIER series from Dongnam Synthetic) is preferred. In particular, it is preferable that the anionic surfactant use at least one selected from the group consisting of polyester resins, acrylic resins and urethane resins as the main resin.

In the present invention, the nonionic surfactant has a self-cleaning mechanism for hydrogen bonding of ethylene oxide, and any conventionally known nonionic surfactant can be used. Preferably, the polyoxyethylene cetyl ether compound (Southeast At least one selected from the group consisting of EMULON SPO1, 3 series, MONOPOL-SPO1, MONOPOL-LE1011 to LE1060 series of synthetic yarns and ethoxylate compounds (DF12, TNM6 from DOW, USA) is preferred. In particular, it is preferable to use at least one selected from the group consisting of a fluorine resin, a PVC-SOL resin, and a polyethylene terephthalate (PET) resin as the main resin.

In the present invention, the amphoteric surfactant has a self-cleaning mechanism for maximizing free radical properties, and any commonly known amphoteric surfactant can be used. Preferably, a betaine-based compound (E-7 of Dongnam Synthetic) And alkyl ethyl ammonium (Alkyl Ethyl Ammonium) -based compounds (AEA series of Dong-A Synthetic Co., Ltd.). In particular, it is preferable that the amphoteric surfactant uses at least one selected from the group consisting of a silicone resin and a modified silicone resin as the main resin.

The surfactant is included as an essential component of the resin composition of the present invention in the form of a dispersion dispersed in a solvent for an organic paint, and preferably contains 70 to 95% by weight based on 100% by weight of the total dispersion composition. Do. When mixing the surfactant and the solvent, be careful to mix the bubbles.

In addition, the dispersion is 5 to 30% by weight of the organic coating solvent based on 100% by weight of the total dispersion composition. The organic paint solvent in the group consisting of distilled water, methanol, ethanol, acetone, isophorone, methyl ethyl ketone (MEK), propylene glycol monomethyl ether (PGME), isophorone, cyclo hexanon and dibasic ester (DBE) It may be one or more selected, but is not limited thereto.

The dispersion is preferably used in an amount of 3 to 15 parts by weight based on 100 parts by weight of the total resin composition for surface treatment. When the content of the dispersion is less than 3 parts by weight, the self-cleaning and stain resistance are insignificant, and the weight is 15 parts by weight. Exceeding the portion reduces corrosion resistance and chemical resistance.

In the resin composition for surface treatment according to the present invention, the solvent may be a hydrocarbon-based, ester-based, acetate-based, isophorone-based, xylene-based, cyclohexanone-based compound or the like which is possible for smoothing the surface of the dried coating film and preventing defects. However, it is not limited thereto.

It is preferable to use 5-60 weight part of said solvents with respect to 100 weight part of resin compositions for whole surface treatment. When using less than 5 parts by weight of the solvent, there is a problem that the coating operation of the composition is difficult, if it exceeds 60 parts by weight there is a problem that it is difficult to control the thickness of the dry coating film.

The resin composition for surface treatment according to the present invention may further include one or more additives such as a crosslinking agent, a curing agent, a curing accelerator, a curing catalyst, a pigment, an antisettling agent, in addition to the main resin, a solvent, and a dispersion.

As the crosslinking agent, a melamine type and / or a polyisocyanate type may be used, and the melamine crosslinking resin is a high alkylated group, a high imino group, and a partially alkylated group. (Partially Alkylated) type and the like, and polyisocyanate crosslinking agents that can be used include hexamethylene diisocyanate (HMDI), isophorone diisocyanate (IPDI), xylene diisocyanate, 2, 4, 6-triisocyanate toluene and similar ones can be applied. For the purpose of PCM, products that mask the isocyanate group and dissociate by heat are mainly used. In the present invention, it is preferable to use 1 to 30 parts by weight (more preferably 1 to 15 parts by weight) of the melamine or polyisocyanate crosslinking agent with respect to 100 parts by weight of the total resin composition for surface treatment. If it is less than parts, the solvent resistance and hardness of the coating film are drastically lowered, and if the content is more than 30 parts by weight, the flexibility and impact resistance of the coating film is lowered. In the present invention, it is preferable to use a hexamethoxymethylmelamine type and a partially alkylated type crosslinking agent among the highly alkylated type, and when the urethane crosslinking agent is used, the physical properties are good. Because of this high price, it is not competitive.

As said hardening | curing agent, an amide type, a melamine type, an amine type, etc. are used, and 0.5-5 weight part is used with respect to 100 weight part of said resin compositions for total surface treatments. If the content of the curing accelerator is less than 0.1 parts by weight, there is a problem in that the coating film is not sufficiently cured, resulting in deterioration of the adhesion of the coating film. If the content is more than 5 parts by weight, curing may be performed in advance during paint storage to cause defects in the appearance of the coating film. There is.

The curing accelerator promotes the curing of the main resin and the curing agent to improve the density of the coating film, wherein the curing accelerator may be used a secondary amine shielding or epoxy resin shielding sulfonic acid. As the sulfonic acid, for example, p-toluenesulfonic acid, dodecylbenzenedisulfonic acid, dinonylnaphthalenedisulfonic acid, dinonylnaphthalenesulfonic acid, and the like may be used, and among these, it is preferable to use p-toluenesulfonic acid or dinonylnaphlenylene sulfonic acid. Do. The sulfonic acid is preferably shielded with a material that can be dissociated by heat, and as the shielding material, a secondary amine or an epoxy resin is used. In addition to secondary amines, primary amines or tertiary amines may be used as the shielding material of sulfonic acid, but primary amines cause a change in color such as yellowing in the coating film, and tertiary amines generally cause shrinkage of the coating film surface when used in excess. It is preferable to use a secondary amine as the masking material of sulfonic acid because of the disadvantages. Examples of the secondary amine include diethylamine, diisopropylamine, diisopropanolamine, di-n-propylamine, di-n-butylamine, isobutylamine, di-secondary-butylamine, diallyl Amine, diamylamine, N-ethyl-1,2-dimethylpropylamine, N-methylhexylamine, di-n-octylamine, piperidine, 2-pipecoline, 3-piecholine, 4-pi Echoline, morpholine, and the like, and by adding an effective amount of these to the composition, it was possible to greatly increase the stain resistance of the coating film.

In the present invention, the curing accelerator is used 0.1 to 5 parts by weight based on 100 parts by weight of the total resin composition for surface treatment. When the content of the curing accelerator is less than 0.1 parts by weight, curing of the coating film is insufficient depending on the working conditions, so that it is impossible to maintain proper stain resistance. When it exceeds 5 parts by weight, curing of the coating film takes place so rapidly that the coating film is paping during the painting work. Popping occurs or shrinkage of the coating film occurs.

As the curing catalyst, an imidazole series, an amine series, or the like is used, and it is preferable to use 0.1 to 3 parts by weight based on 100 parts by weight of the total resin composition for surface treatment.

As the pigment, it is preferable to use a pigment capable of imparting heat resistance and chemical resistance suitable for PCM paint. In addition, organic pigments include carbon black, Azo Lake, Phthalocyanine, Trene, Indigo, Perinone, Perylene, Phthalone, Dioxasine, quinacridone, isoindolinone, and the like may be used. As the inorganic pigment, cray, talc, minusil, silica, aluminum hydroxide compound, or the like may be used. It is preferable that the said pigment uses 0.1-50 weight part (more preferably 1-30 weight part) with respect to 100 weight part of whole resin compositions for surface treatment. If the content of the pigment is less than 0.1 parts by weight, there is a problem that can not implement the color of the color steel sheet, if more than 50 parts by weight there is a problem that the adhesion after curing the coating film is lowered.

As the anti-settling agent, silica, sulfonic acid, carbonic acid, sodium salt, chelate, butyl styrene and the like may be used, and it is preferable to use 0.01 to 3.0 parts by weight based on 100 parts by weight of the total resin composition for surface treatment.

The present invention also relates to a steel sheet comprising a coating layer containing the cured product of the resin composition for surface treatment.

The steel sheet means a metal used for the purpose of automobile materials, home appliances, building materials, and the like, specifically, a metal such as an iron plate, and may be any steel sheet commonly used in the art for this purpose. Cold rolled steel sheet; Galvanized electroplated steel sheets such as galvanized steel sheets, zinc-nickel-plated steel sheets, zinc-iron-plated steel sheets, zinc-titanium-coated steel sheets, zinc-magnesium coated steel sheets, zinc manganese-coated steel sheets and zinc- Hot - dip galvanized steel; Aluminum-plated steel sheet; A plating steel sheet containing a different metal or an impurity such as cobalt, molybdenum, tungsten, nickel, titanium, aluminum, manganese, iron, magnesium, tin or copper in these plating layers; A coated steel sheet in which inorganic substances such as silica and alumina are dispersed in these plating layers; Or an aluminum alloy plate to which silicon, copper, magnesium, iron, manganese, titanium, zinc or the like is added; Or zinc phosphate coated with phosphate; Or a hot-rolled steel sheet may be used, and if necessary, a multi-layered plated sheet obtained by sequentially treating two or more kinds of the above-mentioned platings may be used. The pretreatment layer may be formed by coating chromate or bichromate on the plated steel sheet. After forming a polyester-based undercoat on the pretreatment layer, a top coat layer is formed using the resin composition for surface treatment of the present invention.

The method for treating the steel sheet using the resin composition for surface treatment of the present invention may be performed after washing the surface of the steel sheet by a method generally known in the art in order to remove oil and stains adhered to the steel sheet as necessary. have. Although washing | cleaning is not limited to this, It can carry out using an alkali degreasing agent, an acidic degreasing agent, high temperature water, a solvent, etc. After washing, the surface can be adjusted with acid or alkali.

It is preferable to wash with water after washing so that the cleaning agent does not remain on the surface of the steel sheet as much as possible when cleaning the surface of the steel sheet. Although not limited to this, As an example, it is preferable to surface-treat with the resin composition for surface treatments of this invention, after wash | cleaning, water washing, and surface adjustment of the raw material metal (steel plate) surface as mentioned above.

In treating the metal surface by the method according to the present invention, the resin composition for surface treatment may be applied as a coating layer on the surface of the steel sheet by any coating method generally known in the art. The coating method used in the application is not particularly limited, and known coating methods such as bar coating, dip coating, roll coating, curtain coating, spray coating, slot coating, gravure coating, and the like can be used. At this time, the coating temperature is not particularly limited.

In addition, the final coating film thickness of the resin composition is preferably 5 ~ 30㎛ based on the dry coating film. If the thickness of the dry coating film is less than 5 μm, the hiding power and self-cleaning property of the coating film are inferior.

After applying the surface treatment resin composition of the present invention to the surface pretreated as described above, the solvent is volatilized by applying heat to the steel sheet through various methods such as hot air, induction heating and NIR at 200 to 250 ° C. and curing reaction in the resin coating layer. This progresses to form a dry coating film exhibiting final physical properties.

Hereinafter, the present invention will be described in more detail by way of examples. It should be noted, however, that the following examples are illustrative of the invention and are not intended to limit the scope of the invention.

Manufacturing example  1 to 4: Dispersion  Produce

The dispersion of Table 1 was prepared by mixing a selected surfactant and a solvent for each ionic system.

Example  1 to 7 and Comparative example  1-7: Resin composition for surface treatment and the production of color steel coated with the same

Only the dispersion composition was added to the compositions of Comparative Examples 1 to 7 and the coating solution composition and manufacturing process excluding the dispersion composition follow the basic recipe of the paint company. At this time, after the dispersion is mixed in the preparation of the resin composition should be made a coloration step. Since the dispersion has a unique color, mixing the dispersion after the coloration of the resin composition is completed may be different from the existing color.

0.5 x thickness 1070 ㎜ on the hot-dip aluminum zinc alloy plated steel plate by using a roll coating method at a production rate of 60 to 200 mpm, a thin film is coated on the surface, and dried at 60 to 140 ℃ to obtain a 10 ~ 120mg / ㎡ The pretreatment layer was formed, and the top coat film comprised from the polyester-type undercoat layer and the self-cleaning resin composition of Table 2-Table 8 was formed thereon. The polyester base coat layer was formed to have a dry coating thickness of 5 μm, and the self-cleaning resin composition top coat layer was roll coated to have a dry coating thickness of 20 to 21 μm, and then heated to 190 to 260 ° C. to produce a colored steel sheet. .

Test Example  1: Quality comparison with existing steel sheet

1. Self-cleaning

After applying an excessive amount of 1% carbon powder aqueous solution to the surface of the coating film, the color difference (ΔE) of the specimen and the initial specimen washed with a brush in flowing water (left and right reciprocating 30 times) was measured. The measurement process is shown in FIG.

The results are shown in FIG.

2. Water contact angle

It was measured using a water contact angle measuring instrument (SEO Phoenix450). The result is shown in FIG.

3. Processability

 The crack state was measured at 2T using T-bending evaluation.

4. Adhesiveness

After making 100 squares with 1mm cross cut, Ericsson 6mm was processed and tape peel-off test was performed. The result is shown in FIG.

5. Corrosion resistance

After X-cut, in the salt spray (NaCl 5%) tester, Beige color was measured for 500hr and metallic color for 150hr. The result is shown in FIG.

6. Outdoor revelation

After fixing to the exterior wall of the building perpendicular to the ground, it was left for about 6 months and the surface appearance was observed. The results are shown in FIG. 7 and FIG. 8.

As shown in Tables 9 to 15, when using a dispersion containing a surfactant to the existing steel sheet, it can be seen that the self-cleaning and non-pollution properties are significantly improved.

Test Example  2: magnetic Cleanliness  evaluation

Self-cleaning for general building steel plate, existing our product (Patent Application No. 2008-0138310), Union Steel's product (Domestic Patent Application No. 1999-0008073), Dongbu Steel's product (Sun Clean) and steel sheet of Example 1 Qualitative evaluation was made.

After applying an excessive amount of 1% carbon powder aqueous solution to the surface of the coating film, the color difference (ΔE) of the specimen and the initial specimen washed with a brush in flowing water (left and right reciprocating 30 times) was measured. The measurement process is shown in FIG.

In addition, after 1000 hours of weathering (Q-UV) test, the color difference was measured and compared with the initial specimen.

As shown in Figure 9, the steel sheet according to the present invention confirmed the superior self-cleaning power compared to the existing product, and even after 1000 hours test (weather resistance (Q-UV)) there was no difference in the initial cleanability and excellent durability.

Claims (17)

Subject resin;
solvent; And
Dispersion containing a surfactant and a solvent for an organic paint;
Resin composition for surface treatment comprising a.
The method of claim 1,
Based on 100 parts by weight of the resin composition for total surface treatment,
20 to 75 parts by weight of the main resin;
Solvent 5 to 60 parts by weight
3 to 15 parts by weight of the dispersion
Resin composition for surface treatment comprising a.
The method of claim 1,
The main resin is selected from the group consisting of polyester resin, modified polyester resin, fluorine resin, vinyl chloride resin (PVC), melamine resin, epoxy resin, urethane resin, silicone resin, modified silicone resin and acrylic resin Resin composition for surface treatment, characterized in that one or more.
The method of claim 1,
The surfactant is a surface treatment resin composition, characterized in that the cationic surfactant, anionic surfactant, nonionic surfactant or amphoteric surfactant.
The method of claim 4, wherein
The cationic surfactant is selected from the group consisting of oleyl imidazolinium methyl sulfate-based compounds, ammonium methyl sulfate-based compounds, and triethanol ammonium methyl sulfate-based compounds. Resin composition for surface treatment, characterized in that at least one selected.
The method of claim 4, wherein
The anionic surfactant is a resin composition for surface treatment, characterized in that at least one selected from the group consisting of a dialkylsulfosuccinate-based compound and an alkyl naphthalene-based compound.
The method of claim 4, wherein
The nonionic surfactant is a resin composition for surface treatment, characterized in that at least one selected from the group consisting of polyoxyethylene Cetyl Ether-based compound and ethoxylate-based compound.
The method of claim 4, wherein
The amphoteric surfactant is a resin composition for surface treatment, characterized in that at least one selected from the group consisting of a betaine-based compound and an alkyl ethyl ammonium (Alkyl Ethyl Ammonium) -based compound.
The method of claim 1,
The dispersion is a resin composition for surface treatment, characterized in that containing 70 to 95% by weight surfactant and 5 to 30% by weight of the solvent for the organic paint.
The method of claim 1,
The organic paint solvent in the group consisting of distilled water, methanol, ethanol, acetone, isophorone, methyl ethyl ketone (MEK), propylene glycol monomethyl ether (PGME), isophorone, cyclo hexanon and dibasic ester (DBE) Resin composition for surface treatment, characterized in that at least one selected.
The method of claim 1,
At least one main resin selected from the group consisting of polyester and epoxy resins;
solvent; And
Dispersions containing a cationic surfactant and a solvent for an organic paint;
Resin composition for surface treatment comprising a.
The method of claim 1,
At least one main resin selected from the group consisting of acrylic resins and urethane resins;
solvent; And
Dispersions containing anionic surfactants and solvents for organic coatings;
Resin composition for surface treatment comprising a.
The method of claim 1,
At least one main resin selected from the group consisting of fluorine resins and vinyl chloride resins;
solvent; And
Dispersions containing a nonionic surfactant and a solvent for an organic paint;
Resin composition for surface treatment comprising a.
The method of claim 1,
A main resin consisting of a silicone resin;
solvent; And
Dispersions containing an amphoteric surfactant and a solvent for an organic paint;
Resin composition for surface treatment comprising a.
The method of claim 1,
A resin composition for surface treatment, further comprising at least one additive selected from the group consisting of a crosslinking agent, a curing agent, a curing accelerator, a curing catalyst, a pigment and an antisettling agent.
The method of claim 15,
Based on 100 parts by weight of the resin composition for total surface treatment,
At least one selected from the group consisting of 1 to 30 parts by weight of crosslinking agent, 0.1 to 5 parts by weight of curing agent, 0.1 to 5 parts by weight of curing accelerator, 0.1 to 3 parts by weight of curing catalyst, 0.1 to 50 parts by weight of pigment, and 0.01 to 3.0 parts by weight of steel shield A resin composition for surface treatment, further comprising an additive.
A steel sheet comprising a coating layer containing a cured product of the resin composition for surface treatment according to any one of claims 1 to 16.

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