KR20090107835A - Chromium free resin composition for improved thermal and scratch resistance properties, method thereof, and surface-treated steel sheet using the same - Google Patents

Abstract

PURPOSE: A chromium-free resin composition with improved thermal and scratch resistance properties is provided to ensure excellent conductivity, corrosion resistance, and processability, and to be easily used as processing meterials. CONSTITUTION: A chromium-free resin composition with improved thermal and scratch resistance properties includes a water-soluble organic resin, silica particles surface-treated with silane coupling agent, a hardener for improving corrosion resistance of Ti or Zr organic oxide, and a solvent. A method for manufacturing a surface-treated steel plate comprises a step of drying the resin composition and coating it on the upper surface of the steel plate to become bond quantity 300 ~ 1,800mg/m^2.

Description

Chromium free resin composition for improved thermal and scratch resistance properties, method approximately, and surface-treated steel sheet using the same

The present invention provides a resin solution composition for surface treatment of a steel sheet, which is particularly excellent in heat resistance and scratch resistance, and excellent in conductivity, corrosion resistance and workability, containing no chromium component, a method for producing the same, and a method for manufacturing a steel sheet using the same It relates to a manufactured surface treated steel sheet.

Chromate to give corrosion resistance and paint adhesion to galvanized steel sheet and zinc alloy plated steel sheet, aluminum plated steel sheet, aluminum alloy plated steel sheet, cold rolled steel sheet, hot rolled steel sheet, etc. Although the surface treatment method of coating the coating has been generally performed, various measures including corrosion resistance, alkali resistance, conductivity, etc., without containing hexavalent chromium are required as various measures are required in the working environment and drainage treatment due to the toxicity of hexavalent chromium. Surface-treated steel sheets that do not contain chromium that can satisfy required characteristics have been developed. However, the surface-treated steel sheet to which the conventional organic or organic-inorganic composite coating is applied may be discolored and deteriorated due to deterioration of the resin component due to deterioration of the thermal stability of the organic material, which is a coating component, when used for a long time at a high temperature of 200 to 250 degrees, such as a PDP panel. There is a problem.

In order to solve the problem of the surface-treated steel sheet, conventionally, a coated steel sheet using a silicone resin or a fluorine resin having excellent heat resistance has been used. However, the coated steel sheet is typically coated with a thickness of 20 to 30 μm on a bottom of about 5 μm in order to secure durability, and thus, electrical conductivity cannot be secured. Its use is restricted for reuse. As a surface-treated steel sheet for inner plates for home appliances, commonly used anti-fingerprint steel sheets having a film thickness of about 1 μm on galvanized steel sheets are widely used.

Conventionally, Japanese Patent Application Laid-Open No. 8-92479 discloses a method of coating polyaniline on a metal plate as a coating method that satisfies the characteristics of the surface-treated steel sheet without containing hexavalent chromium and considering heat resistance and scratch resistance. It is disclosed in Japanese Patent Laid-Open No. 8-500770. However, since polyaniline having high rigidity and low adhesion exists between the metal and the resin film, the film can be easily peeled off from the polyaniline and the metal interface and the polyaniline and the resin interface. In particular, some products that are applied for the severe processing use is insufficient workability due to the damage of the resin layer and the plating layer of the processing friction portion, the resin layer is lost, or the surface becomes black.

In addition, there is a problem in that the solution stability is low, there is a lot of sediment generated, workability, such as overall inhibition of the working environment. In addition, Japanese Patent Application Laid-Open No. JP1999-335642 discloses an antirust pigment composed of a polyaniline derivative and protonic acid impurities, but also has the same problem as described above.

In addition, WO01 / 023639 discloses a method of improving heat resistance by dispersing a zinc or aluminum metal compound having a thickness of 1 to 10 μm in a solution composition by using a thickener and a silane binder. In order to disperse, a large amount of thickeners must be used, and thus there is a problem that the solution viscosity is not suitable for thin film coating.

In addition, US Patent Publication No. 2004-54044 discloses a composition in which an organic film former, a hexafluoro complex such as titanium and zirconium, at least one inorganic compound, and the like are mixed with water, but it contains a fluoride complex. This may affect the environment, and the solution is acidic, so care must be taken when handling. In addition, Japanese Laid-Open Patent Publication No. 2002-030460 discloses a composition in which a vanadium compound, Zi, Ti, and the like are mixed with a mixed resin. There is a problem that must be accompanied.

In addition, Korean Patent Laid-Open Publication No. 2004-0016456 has a layered silica and ethylene-acrylic resin composition having a particle size of 5 nm or less and a Si content of 13-20% on a phosphate-treated galvanized steel sheet. However, this is limited to the layered silica and no method for controlling the particle size is described.

In addition, Japanese Patent Laid-Open No. 2005-281863 has registered a resin composition which has improved scratch resistance by using a composition containing an inorganic rust inhibitor in a crosslinked resin matrix, but this is a carboxylic acid that uses a crosslinked resin matrix and is not neutralized with an alkali metal. It should be used, and simply containing silica particles, it is difficult to expect the improvement effect, such as heat resistance.

In addition, Korean Patent No. 0458984 has prepared a polyurethane prepolymer and added colloidal silica by an in situ method, and these composites were dispersed in water to improve flame retardancy and scratch resistance, but the polyurethane-colloidal silica composite was prepared from the prepolymer production step. There is a disadvantage that the step of forming and dispersing the prepolymer in water and then polymerizing must be done in the same process.

In addition, Korean Patent Nos. 0385158 and 0676953 disclose an organic resin and inorganic binder composite using a silane coupling agent, and a surface treatment composition including a rust preventive agent and a metal chelating agent is disclosed, but an organic resin and an inorganic binder composite are prepared in advance. There is a downside to it. In addition, some products that require alkali resistance lacks alkali resistance, and when contacted with an alkaline solution, the resin layer is partially damaged, resulting in a loss or severe discoloration of the surface.

One object of the present invention is to provide a coating layer which does not contain chromium, which improves heat resistance, scratch resistance, and is excellent in conductivity, corrosion resistance, processability, and the like, through a method of coating a resin solution composition on a steel sheet. It is for providing a surface treatment composition.

Another object of the present invention is to provide a coated steel sheet coated with the surface treatment composition.

Still another object of the present invention is to provide a method for producing a surface-treated steel sheet by forming a resin solution coating layer with the resin solution composition according to the present invention.

The object of the present invention is not limited to those mentioned above, and other objects that are not mentioned will be clearly understood by those skilled in the art from the following description.

In order to achieve the above object, the present invention is to provide a resin solution composition applied to a steel sheet and / or galvanized layer, a method for producing a surface-treated steel sheet using the same and a surface-treated steel sheet prepared by the method, the present invention silver

As a first aspect, a resin solution composition for surface treatment of a steel sheet comprising a water-soluble organic resin, silica particles surface-modified with a silane coupling agent, a corrosion resistance improving curing agent and a solvent of Ti or Zr organic oxide,

As a second aspect, a water-soluble organic resin, including a silica particle surface-modified with a silane coupling agent, a corrosion-resistant curing agent and a solvent of Ti or Zr organic oxide; and based on the solids of the total resin solution composition, 10 to 90 weight percent; 1 to 50% by weight of silica particles surface-modified with a silane coupling agent; And 1 to 20% by weight of Ti or Zr-based organic oxide resin solution composition for surface treatment of steel sheet,

As a third aspect, the resin solution composition for surface treatment of a steel sheet, characterized in that the water-soluble organic resin is selected from the group consisting of urethane resin, acrylic resin, epoxy resin, ester resin, olefin resin or mixtures thereof;

As a fourth aspect, the resin solution composition for surface treatment of a steel sheet, characterized in that the water-soluble organic resin is a urethane resin,

As a fifth aspect, the urethane resin may be selected from isophorene diisocyanate of polyurethane dispersion resin or polyethylene modified polyurethane resin; Polyurethane resins prepared from adipic acid and polyhydric alcohols; Polyurethane resins prepared from acrylic polyols and polyisocyanates of acrylic-urethane resins or polyethylene-acrylic modified polyurethane resins; And polyurethane resins prepared from polycaprolactone polyols or polycarbonate polyols and isocyanates; Polyurethane resins prepared from 4,4'-bis (ω-hydroxyalkyleneoxy) biphenyl and methyl-2,6-diisocyanatehexanoate; Polyurethane resin having an acetal bond; Resin solution composition for surface treatment of a steel sheet, characterized in that at least one selected from the group consisting of,

As a sixth aspect, the molecular weight of the water-soluble organic resin is a urethane resin 5,000 to 2,000,000, acrylic resin 50,000 to 2,000,000, epoxy resin 500 to 25,000, ester resin 5,000 to 15,000, and olefin resin 500,000 to 2,000,000 Resin solution composition for surface treatment of

In a seventh aspect, the surface modification of the silica particles is performed by reacting colloidal silica particles with a silane coupling agent so that the hydroxyl groups on the surface of the colloidal silica particles can be amine groups, epoxy groups, hydroxyl groups, vinyl groups, methoxy groups, alkoxy groups and chlorides. A resin solution composition for surface treatment of a steel sheet, which is performed by replacing at least one of the groups,

As a eighth aspect, the silane coupling agent is a surface treatment of a steel sheet, characterized in that one or more mixtures selected from the group consisting of methoxysilane, aminosilane, epoxysilane, hydroxy silane, vinylsilane, alkoxysilane and chloride silane. Resin solution composition,

As a ninth aspect, the silane coupling agent is a resin solution composition for surface treatment of a steel sheet, characterized in that 5 to 95% of the hydroxy group content of the silica surface,

As a tenth aspect, the reaction of the silica particles and the silane coupling agent is a surface-modified resin solution composition of the steel sheet, characterized in that the surface modified by the silane coupling agent at pH 4.0 ~ 10.0,

As an eleventh aspect, the reaction of the silica particles and the silane coupling agent is carried out at 10 to 40 ° C, wherein the resin solution composition for surface treatment of a steel sheet,

As a twelfth aspect, the resin solution composition for surface treatment of a steel sheet, wherein the reaction between the silica particles and the silane coupling agent is performed using a cyclic homogenizer,

As a thirteenth aspect, the resin solution composition for surface treatment of a steel sheet, characterized in that the average particle size of the silica particles is 10 ~ 30nm,

In a fourteenth aspect, the Ti or Zr organic oxide is titanium diisopropoxide bis (acetylacetonate), titanium orthoester, titanium (IV) butoxide, titanium (IV) (triethanol aminato) isopropoxide Tetrakis (triethanolaminato) zirconium (IV), titanium (IV) 2-ethylhexoxide, titanium (IV) isopropoxide, zirconium (IV) bis (diethyl citrato) -dipropoxide or these Resin solution composition for surface treatment of a steel sheet, characterized in that selected from a mixture of

As a fifteenth aspect, the solvent is a resin solution composition for surface treatment of a steel sheet, characterized in that water,

In a sixteenth aspect, the solvent comprises one or more alcohol solvents selected from ethanol, methanol, propanol, isopropanol and glycerol; One or two or more alkaline aqueous solutions selected from amine compounds, N-methylpyrrolidone, sodium hydroxide, potassium hydroxide, sodium carbonate and ammonium hydroxide; Or a resin solution composition for surface treatment of a steel sheet, further comprising a mixture thereof;

As a seventeenth aspect, silica, Ti, or Zr-based organic oxides surface-treated with a water-soluble resin or a silane coupling agent; Method for producing a surface-treated steel sheet comprising the step of coating a resin solution composition comprising a solvent on the top of the steel sheet to dry after the coating weight 300 to 1,800 mg / ㎡,

As an eighteenth aspect, silica, Ti, or Zr-based organic oxides surface-treated with a water-soluble resin or a silane coupling agent; And coating a resin solution composition comprising a solvent; and then coating the resin solution composition with an adhesion amount of 300 to 1,800 mg / m 2 on the upper portion of the steel sheet, based on the solids of the total resin solution composition; 1 to 50% by weight of silica surface-treated with a silane coupling agent; Method for producing a surface-treated steel sheet containing 1 to 20% by weight of Ti or Zr-based organic oxide,

In a nineteenth aspect, the water-soluble organic resin is isophorene diisocyanate of the polyurethane dispersion resin or polyethylene modified polyurethane resin; Polyurethane resins prepared from adipic acid and polyhydric alcohols; Polyurethane resins prepared from acrylic polyols and polyisocyanates of acrylic-urethane resins or polyethylene-acrylic modified polyurethane resins; And polyurethane resins prepared from polycaprolactone polyols or polycarbonate polyols and isocyanates; Polyurethane resins prepared from 4,4'-bis (ω-hydroxyalkyleneoxy) biphenyl and methyl-2,6-diisocyanatehexanoate; Polyurethane resin having an acetal bond; Method of producing a surface-treated steel sheet, characterized in that at least one urethane resin selected from the group consisting of,

As a twentieth aspect, the molecular weight of the water-soluble organic resin is a surface treatment, characterized in that the urethane resin 5,000 to 2,000,000, acrylic resin 50,000 to 2,000,000, epoxy resin 500 to 25,000, ester resin 5,000 to 15,000, and olefin resin 500,000 to 2,000,000 Manufacturing method of steel sheet,

In a twenty-first aspect, the silane coupling agent is at least one member selected from the group consisting of methoxysilane, aminosilane, epoxysilane, hydroxy silane, vinyl silane, alkoxysilane, and chloride silane. ,

As a twenty-second aspect, the method of manufacturing a surface-treated steel sheet, further comprising the step of drying the steel sheet coated with a resin solution composition at a temperature PMT 120 ~ 250 ℃,

In a twenty third aspect, a steel sheet; And a resin coating layer; wherein the resin coating layer is a water-soluble organic resin; Silica surface-modified with a silane coupling agent; Ti or Zr-based organic oxides; Surface-treated steel sheet, characterized in that the resin solution composition comprising a solvent; and coated on the upper surface of the steel sheet with an adhesion amount of 300 to 1,800 mg / ㎡

In a twenty fourth aspect, a steel sheet; And a resin solution coating layer; wherein the resin solution coating layer is a water-soluble organic resin; Silica surface-modified with a silane coupling agent; Ti or Zr-based organic oxides; And a solvent; wherein the amount of the main resin is 10 to 90% by weight based on the total solids of the solution composition, and the amount of silica surface-treated with the silane coupling agent is 1 to 50% by weight based on the total solids of the solution composition, Ti Or Zr-based organic oxide is a surface-treated steel sheet, characterized in that the resin solution composition of 1 to 20% by weight is coated on the upper surface of the steel sheet after coating with an adhesion amount of 300 to 1,800 mg / ㎡,

In a twenty-fifth aspect, the water-soluble organic resin is isophorene diisocyanate of polyurethane dispersion resin or polyethylene modified polyurethane resin; Polyurethane resins prepared from adipic acid and polyhydric alcohols; Polyurethane resins prepared from acrylic polyols and polyisocyanates of acrylic-urethane resins or polyethylene-acrylic modified polyurethane resins; And polyurethane resins prepared from polycaprolactone polyols or polycarbonate polyols and isocyanates; Polyurethane resins prepared from 4,4'-bis (ω-hydroxyalkyleneoxy) biphenyl and methyl-2,6-diisocyanatehexanoate; Polyurethane resin having an acetal bond; Resin solution composition for surface treatment of the steel sheet, characterized in that at least one urethane resin selected from the group consisting of,

In a twenty-sixth aspect, the molecular weight of the water-soluble organic resin is 5,000 to 2,000,000 urethane resin, 50,000 to 2,000,000 acrylic resin, 500 to 25,000 epoxy resin, 5,000 to 15,000 ester resin, and 500,000 to 2,000,000 olefin resin, respectively. Resin solution composition for surface treatment,

In a twenty-seventh aspect, the silane coupling agent provides a surface-treated steel sheet, characterized in that at least one member selected from the group consisting of methoxysilane, aminosilane, epoxysilane, hydroxy silane, vinylsilane, alkoxysilane, and chloride silane. .

As described above, the metal surface treatment composition and the surface treated steel sheet having the coating layer which is excellent in heat resistance and scratch resistance and do not contain chromium components are excellent in conductivity, corrosion resistance, processability, etc. It can be used easily.

Hereinafter, the present invention will be described in detail.

The present invention is coated on a plated or unplated steel sheet by coating a resin solution composition comprising a water-soluble organic resin, which is a main resin, a silica particle surface-modified with a silane-based compound, a corrosion-resistant hardening agent of Ti or Zr organic oxide, and a solvent, The present invention relates to a resin solution composition for surface treatment that can improve scratch resistance and heat resistance, and can produce a metal steel sheet having excellent conductivity, corrosion resistance, and workability.

As the main resin in the resin solution composition of the present invention, the above water-soluble organic resin can be used, and specific examples thereof include a urethane resin, an acrylic resin, an epoxy resin, an ester resin, and an olefin resin.

The water-soluble organic resin is a solid content concentration, it is preferable to have a content of 10 to 90% by weight relative to the solid content of the entire resin solution composition. When the solids content of the entire water-soluble organic resin is less than 10% by weight, the salt resistance of the water-soluble organic resin and the chemical resistance against the penetration of the chemicals against the penetration of the corrosion ions are not exhibited, thereby reducing the corrosion resistance, the chemical resistance and the alkali resistance. For this reason, when degreasing at 60 ° C. for 5 minutes with an alkaline solution having a pH of 10 or more, there is a problem of discoloration or peeling of the resin film, and if it exceeds 90% by weight, solution stability due to entanglement is lowered and the price increases. have.

Among the above-mentioned main resins, urethane resins are used to prevent scratches on the surface of steel sheets by coating them on steel sheets or aluminum plates because urethane resins have strong water resistance, chemical resistance, acid resistance, and alkali resistance and are soft and strong. In order to provide chemical property, it is widely used and it is especially preferable.

The urethane-based resin is a polyurethane resin prepared from isophorene diisocyanate, adipic acid and polyhydric alcohol such as polyurethane dispersion resin, polyethylene modified polyurethane resin and the like, and acrylic such as acrylic-urethane resin, polyethylene-acrylic modified polyurethane resin and the like. Polyurethane resins made from polyols and polyisocyanates and polycaprolactone polyols or polycarbonate polyols and isocyanates, in particular polyurethane resins made from paraphenylenediisocyanates, 4,4'-bis (ω-hydroxyalkyl Polyurethane resins prepared from lenoxy) biphenyl and methyl-2,6-diisocyanatehexanoate, polyurethane resins having acetal bonds, and the like can be used. Here, as said polyhydric alcohol, an acryl polyol, polyester polyol, polyether polyol, polyolefin polyol, etc. can be used.

In addition, the molecular weight of the urethane-based resin is preferably 5,000 to 2,000,000. If the molecular weight of the rigid urethane-based resin is less than 5,000, the cured coating film is dense, the effect of improving the corrosion resistance, but the workability is lowered is not preferable, and if it exceeds 2,000,000, the stability of the solution decreases, the viscosity of the resin solution rises to workability There is a problem of deterioration.

The acrylic resin is widely used for metal surface treatment because it is excellent in high temperature, high humidity, cold resistance, processability, and low self-dialysis. As the acrylic resin that can be used in the present invention, an acrylic resin synthesized in a conventional monomer composition including a carboxyl group of an acceptable level can be used. The acrylic resin monomer is methyl (meth) acrylate, ethyl (meth) acrylate, isopropyl (meth) acrylate, normal butyl (meth) acrylate, isobutyl (meth) acrylate, 2-ethylhexyl (meth ) Acrylate, hydroxypropyl (meth) acrylate, stearyl (meth) acrylate, and hydroxybutyl (meth) acrylate.

The molecular weight of the acrylic resin is preferably 50,000 to 2,000,000. When the molecular weight of the acrylic resin is 50,000 or less, there is no effect of improving workability, and when the molecular weight exceeds 2,000,000, the stability of the solution decreases and the viscosity of the resin solution rises, thereby degrading workability.

The said epoxy resin is excellent in adhesiveness, corrosion resistance, a top coat, etc., and is widely used for the coating | covering material of a metal material. As the epoxy resin that can be used in the present invention, a bisphenol A resin, a bisphenol F resin, a novolak resin, and the like can be used. It is preferable that the molecular weight of the epoxy resin is 500 to 25,000. If the molecular weight of the epoxy resin is less than 500, the crosslinking density becomes high, making it difficult to secure workability, and if it exceeds 25,000, the water solubility is difficult. This is because it is degraded.

Among the above-mentioned main resins, ester resins have excellent curability, excellent chemical resistance, heat resistance, plasticity, and excellent adhesion to organic substances, and are widely used as metal surface treatment materials. Ester resins that can be used in the present invention are polyester resins prepared from maleic anhydride, isophthalic acid, terephthalic acid, tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, adipic acid, pimic acid and ethylene glycol modified ester resins, propyleneene glycol modified Ester resin and neopentyl glycol modified ester resin are mentioned.

It is preferable that the molecular weight of the ester resin is 5,000 to 15,000, but if the molecular weight of the ester resin is less than 5,000, the workability becomes weak due to the increase in the crosslinking density, the price rises if it is 15,000 or more, and the salt water resistance becomes weak due to the increase in the crosslinking density, It is because corrosion resistance falls.

Among the main resins, the olefin resin is effective in preventing scratches on the painted surface after the metal surface treatment because the olefin resin is strong in water resistance, acid resistance, and salt water resistance. As the olefin resin that can be used in the present invention, a water-soluble polyolefin resin can be used, and polyethylene, vinyl-modified polyethylene resin, polyvinyl butylene resin, vinyl chloride copolymer resin, vinyl acetate copolymer resin, polyvinyl alcohol resin can be used. It is preferable that the molecular weight of the olefin resin is 500,000 to 2,000,000, but if the molecular weight of the olefin resin is less than 500,000, the crosslinking density becomes high, and processability is difficult to be secured. This is because the density decreases and the stone resistance decreases.

The resin solution composition for coating a steel sheet of the present invention includes silica particles in order to improve adhesion between the resin and the steel sheet to secure corrosion resistance and to improve mechanical properties of the coated steel sheet. As the silica particles, colloidal nano silica particles having a size of 10-30 nm may be used. The silica particles use silica particles whose surface is modified with a silane coupling agent for increasing compatibility with the main resin, improving dispersion stability of the silica particles, and suppressing aggregation.

Surface modification of the silica particles may produce silica nanoparticles whose surface is modified by reacting the silica particles with a silane coupling agent. A silane coupling agent is used to substitute a hydroxy group on the surface of the colloidal silica with an amine group, an epoxy group, a hydroxyl group, a vinyl group, a methoxy group, an alkoxy group or a chloride group to induce a chemical bond. This maintains higher reactivity compared to the hydroxyl groups of the silica itself, and by introducing excellent chemical bonds can improve the mechanical and chemical properties compared to the case of simple blending.

Examples of the silane coupling agent include methoxysilane, aminosilane, epoxysilane, hydroxysilane, vinylsilane, alkoxysilane or chloride silane. In the case of using these silane compounds alone, for example, when treated with aminosilane alone, the saline resistance is improved, but the dispersion stability of particles in the resin composition is deteriorated, and when treated only with epoxy silane, The dispersion stability is excellent, but the salt water resistance property is deteriorated. In the case of vinylsilane, when the surface treatment is performed at a high concentration, silica particles are gelled during the surface treatment. Therefore, a mixture of these silane coupling agents is used. It is more preferable.

Silane coupling agents react with water to form silanol, which participates in two competing reactions. The first is the reaction with hydroxyl groups on the surface of the silica particles, and the second is the self-polycondensation between silanols. When the self-condensation reaction is dominant, the silane coupling agent may not be introduced to the surface of the silica particles, and the silane coupling agents may react with each other to aggregate. Most silanols are made into polymer form or nanoparticles through the self-condensation reaction between silanols, or change the surface of silica from hydrophilicity to hydrophobicity through reaction with hydroxy group of silica nanoparticles in water phase. In this process, the zeta-potential value of the negatively charged silica surface is decreased from negative to zero, and thus the stability of the particles is reduced, and due to the inter-particle reaction of silica, the aggregation phenomenon between particles ( agglomeration occurs, which results in the formation of significantly larger particles compared to the particles before the reaction, and these particles are easily precipitated, and reversible re-dispersion is impossible.

In order to solve this problem, an ultrasonic process or a circulating homogenizer may be used to uniformly disperse the silica particles. After the silica emulsion is added to the reactor, pure water is added, anhydrous methanol may be mixed with the silane coupling agent, and then stirred using a circulating homogenizer. The reaction temperature of the silica and the silane coupling agent does not contribute significantly to the formation of the surface-modified silica nanoparticles, but in order to improve the amount of silica introduced, it is preferable to carry out at room temperature, specifically, in the range of 10 to 40 ° C.

The content of the silane coupling agent may be added in an amount of 5 to 95% relative to the hydroxy group content on the surface of the silica particles. If the silane coupling agent is less than 5% of the hydroxy group on the surface of the silica particles, it is difficult to form surface-modified silica particles, which is not effective in improving heat resistance and scratch resistance, and if it exceeds 95%, a gel is formed, which is reversible but further addition It is not preferable because it does not have a great effect on the surface modification of the silica at the time of addition.

When the surface modification of the silica is not particularly limited, but the pH is less than 4.0, the silica surface modification content is lowered, and if the pH exceeds 10, a portion of the surface-modified silica is agglomerated to increase the average particle size, Preference is given to performing silica surface modification at pH 4.0-10.0.

The content of silica surface-modified with the silane is preferably 1 to 50% by weight based on the solids of the total solution composition. If the content of the surface-modified silica is less than 1% by weight, it is not effective in improving heat resistance and scratch resistance, and if the content of the surface-modified silica is 50% by weight or more, the electrical conductivity is lowered and the workability of the surface-treated steel sheet is not preferable. not.

Ti or Zr organic oxide is added to the solution composition as a corrosion resistant hardener. As said corrosion-resistant hardening | curing agent, it is 1 to 20 weight% based on solid content of the whole resin solution composition. At this time, if the content of the anti-corrosion hardener is less than 1% by weight, the corrosion resistance is lowered and there is almost no effect of addition. When the content of the anti-corrosion agent is more than 20% by weight, the concentration is saturated and a large amount of precipitate is generated. The problem of decreasing hydrothermal deterioration appears.

Preferred examples of the Ti or Zr organic oxide include titanium diisopropoxide bis (acetylacetonate), titanium ortho ester, titanium (IV) butoxide, titanium (IV) (triethanol aminato) isopropoxide, Tetrakis (triethanolaminato) zirconium (IV), titanium (IV) 2-ethylhexoxide, titanium (IV) isopropoxide, zirconium (IV) bis (diethyl citrato) -dipropoxide and the like. It may comprise at least one compound selected from them. Since the resin solution composition is dispersed in the particles of the corrosion-resistant curing agent uniformly reacted and dispersed in the organic functional group of the resin, the resin solution is excellent in stability and the corrosion resistance, alkali resistance, high temperature and high humidity resistance of the anticorrosive coating layer is further improved. do.

Components except the solids in the resin solution composition is a solvent, water may be used as the solvent. Furthermore, in order to enhance the properties such as wettability and dispersibility of the coating composition, a separate alcohol solvent and an alkaline aqueous solution may be further added. Ethanol, methanol, propanol, isopropanol, glycerol, and the like may be used as the alcohol solvent, and as the alkaline aqueous solution, an amine compound, N-methylpyrrolidone, sodium hydroxide, potassium hydroxide, sodium carbonate, ammonium hydroxide, or the like may be used. Can be.

In addition, the surface treatment composition of the present invention may further include one or more additives such as a wetting agent, a crosslinking agent, a lubricant, and an antifoaming agent. The wetting agent is effective in streaking and adhesion, the crosslinking agent in corrosion resistance and alkali resistance, the lubricant in friction coefficient and processability, and the antifoaming agent in further improving workability. These additives are preferably used in an amount of 5 to 25% by weight in total based on the solids content of the resin solution composition. If the content of the additive is less than 5% by weight, the use of additives such as corrosion resistance, alkali resistance does not appear, and if the content exceeds 25% by weight, the effect is saturated, and further addition is not meaningful, and there is a problem of reducing solution stability.

The wetting agent includes a deagglomerated wet dispersant, a polymer wet dispersant, and the like. Examples of the wetting agent include a wet dispersant commercially available from EFKA and Tego, and the like. EFKA 3580 (Ciba) and BW-W500 (Bumwoo Chemical) Or WET 500 (Ciba).

As the crosslinking agent, silazane, silylating agent, melamine, melamine resin, alkyl melamine, alkyl melamine resin, fluorinated melamine and fluorinated melamine resin, polyamine-based, alkylated aromatic polyamine-based, polyamide-based or acid anhydride-based curing agent, etc. may be used. .

The lubricant includes silicone wax, polyethylene wax, polypropylene wax, amide wax, polytetrafluoroethylene (PTFE) wax, paraffin wax, and the like.

As the antifoaming agent, oil type, modified type, solution type, powder type, emulsion type silicone and acrylic antifoaming agent may be used.

The deposition amount of the coating layer coated with the composition of the resin solution of the present invention is preferably 300 to 1,800 mg / m 2 as the deposition amount after drying, and the drying temperature (PMT) is 120 ° C. to 250 ° C. which is similar to the drying temperature of a conventional resin-based surface treatment solution. to be. At this time, if the adhesion amount after drying is 300 mg / m 2 or less, there is no effect of improving the corrosion resistance and workability. In addition, the higher the drying temperature shows a tendency to improve the corrosion resistance of the resin film, but if the 120-250 ℃ is not unreasonable to meet the customer's quality requirements.

Further, the applicable metal sheet of the present invention may be a galvanized steel sheet, a zinc nickel plated steel sheet, a galvanized steel sheet, a zinc titanium plated steel sheet, a zinc magnesium plated steel sheet, a zinc manganese plated steel sheet, or a zinc-based electroplated steel sheet, such as a zinc aluminum plated steel sheet. Plated steel sheet, aluminum plated steel sheet, and plated steel sheet containing, for example, cobalt, molybdenum, tungsten, nickel, titanium, aluminum, manganese, iron, magnesium, tin, copper, etc., as dissimilar metals or impurities in these plating layers. Galvanized steel sheet in which inorganic materials such as silica and alumina are dispersed in these plating layers, or an aluminum alloy sheet containing silicon, copper, magnesium, iron, manganese, titanium, zinc, or the like, or a galvanized steel sheet coated with phosphate, cold rolled steel sheet, hot rolled steel Steel plate or the like. Moreover, it is applicable also to the multilayer plating board which processed two or more types sequentially during said plating.

Hereinafter, the present invention will be described in more detail with reference to Examples. However, the present invention is not limited by the following examples.

Example

[Example 1-22 and Comparative Examples 1-19]

1-1. With silane coupling agent  Surface treatment of silica

Various silane coupling agents (Shinetsu, Japan) were applied to water-disperse colloidal silica (Snowtex-N, Nissan Chemical Co., Ltd.) with an average particle diameter of 15 nm using a circulating homogenizer at 20 ° C. while varying the content compared to the silica surface hydroxy group content. Modification was performed.

The surface of the thus-prepared silica particles (Comparative Example 6) and the surface of the silica particles (Example 3) surface-treated with a silane coupling agent were observed with a scanning electron microscope. The results are shown in FIGS. 2 and 3, respectively.

As shown in Example 3, the silica particles surface-treated with the silane coupling agent showed excellent dispersibility, whereas the unsurfaced silica particles shown in Comparative Example 6 exhibited a phenomenon in which the silica particles were not dispersed and aggregated by themselves. have.

1-2. Preparation of Resin Solution Composition

Prepared and prepared urethane resins (PUD 7008, Bumwoo Chemical) having a number average molecular weight (Mn) of 2,500,000, 100,000 and 3,000 consisting of isophorene diisocyanate, adipic acid and polyhydric alcohol monomers as monomers of urethane resins as main resins. , Acrylic resin (Mn = 100,000), epoxy resin (Mn = 15,000), ester resin (Mn = 12,000) and olefin resin (Mn = 1,000,000) were prepared, respectively. The prepared main resin, the surface modified silica particles, and Ti organic oxide (trade name Tyzor TE® titanium (IV) (triethanol aminato) isopropoxide) from DuPont were mixed as described in Table 1.

As an additive, 0.5 wt% of a siloxane wetting agent (Ciba EFKA 3580), 1.5 wt% of an amine curing agent (Cytec Cymel 303), 1.5 wt% polyethylene lubricant (Noveon Lanco PE 1500), an emulsion type siloxane defoaming agent 0.1 Weight percent (BYK, BYK-024) were each added in bulk. Solid content concentration of the surface treatment composition was about 15% by weight. For reference, water was used as the main ingredient except solids, and about 3% by weight of ethanol and about 0.5% by weight of amine compound were added as an alkaline solvent.

The type and content of the main resin, the content of the surface-modified silica, the type and content of the silane coupling agent used in the surface modification of the silica, the content of the Ti corrosion-resistant curing agent, and other additives were adjusted as shown in Table 1 to evaluate the solution stability. The results are shown in Table 1, and the evaluation method is as described later.

1-3. Manufacture of Coated Steel Sheet

1) Specimen: An electro galvanized steel sheet (EG) having an adhesion amount of 20 g / m 2 on one side was used as a material steel sheet for applying the surface treatment composition.

2) Coating method: The resin solution was coated on the top of the sample using a continuous roll coating simulator, and dried under conditions of 200 ° C PMT. The resin adhesion amount of the dry film was 1,000 mg / m <2>. The quality characteristics of the coated steel sheet were measured and evaluated as follows, and the results are shown in Table 1.

1-3. Performance evaluation

(1) Heat resistance: After loading the specimen in an oven set at 250 ℃ for 1 hour, and left to room temperature, the color difference of the resin coating layer was measured and evaluated by the following criteria.

○: color difference less than 5.0

(Triangle | delta): Color difference change 5.0 or more and less than 10.0

×: color difference change 10.0 or more

(2) Scratch resistance: Using the draw bead friction tester (load 1,000 kg _f , speed 1,000mm / min, distance 100mm), measure the color difference after the resin film of the specimen was scratched and damaged by the bead surface of the friction tester. The evaluation was carried out according to the following criteria.

○: color difference change less than 0.5

△: color difference change 0.5 or more and less than 1.0

×: color difference change 1.0 or more

(3) Workability: After measuring the friction coefficient using a draw bead friction tester (load 1,000 kg _f , speed 1,000 mm / min, distance 100 mm), the resin film of the specimen was scratched on the bead surface of the friction tester and damaged. The evaluation was made according to the following criteria.

○: less than 5% damage area

△: damage area of 5% or more but less than 10%

×: damage area 10% or more

(4) Corrosion resistance: The specimens were subjected to a salt spray test according to JIS-Z2371 for 96 hours, and the degree of corrosion was evaluated according to the following criteria.

○: less than 5% of white blue

(Triangle | delta): More than 5% of white rust less than 20%

×: 20% of white blue

(5) Conductivity: The surface of the resin coated coating specimen was measured by a surface resistance meter (Loresta-GP), and evaluated by the following criteria.

○: surface resistance less than 1mΩ

△: surface resistance 1 mΩ or more 1Ω or less

×: extremely poor conductivity or weldability with a surface resistance of 1 Ω or more

(6) Alkali resistance: After washing with water for 5 minutes by dipping in alkaline solution (Gardoclean 4292L, pH12), the color difference and peeling degree of resin coating layer were visually observed and evaluated by the following criteria.

○: no peeling, color difference change less than 2.0

△: no peeling, color difference change 2.0 or more occurs

X: peeling occurrence

(7) Solution stability: After 100 days of leaving 100g of the surface treatment composition in an oven at 50 ℃, the degree of precipitation, gelation and separation of the solution was evaluated according to the following criteria.

○: no precipitation, gelation or separation

△: One of fine precipitation, gelation and separation

×: at least one of precipitation, gelation, and separation occurs to some extent

division Solution Composition Components and Contents Quality evaluation No. Resin Silane Silica Hardener additive Heat resistance Scratch resistance Machinability Corrosion resistance conductivity Alkali resistance Solution stability Example One 10 5 45 20 25 ○ ○ ○ ○ ○ ○ ○ 2 30 10 40 10 20 ○ ○ ○ ○ ○ ○ ○ 3 30 50 50 10 10 ○ ○ ○ ○ ○ ○ ○ 4 50 90 40 5 5 ○ ○ ○ ○ ○ ○ ○ 5 80 95 14 One 5 ○ ○ ○ ○ ○ ○ ○ 6 90 5 4 One 5 ○ ○ ○ ○ ○ ○ ○ 7 75 50 10 5 10 ○ ○ ○ ○ ○ ○ ○ 8 79 90 10 One 10 ○ ○ ○ ○ ○ ○ ○ 9 55 30 10 20 15 ○ ○ ○ ○ ○ ○ ○ 10 55 60 20 10 15 ○ ○ ○ ○ ○ ○ ○ 11 60 10 20 5 15 ○ ○ ○ ○ ○ ○ ○ 12 59 60 20 One 20 ○ ○ ○ ○ ○ ○ ○ 13 20 30 40 20 20 ○ ○ ○ ○ ○ ○ ○ 14 30 95 40 10 20 ○ ○ ○ ○ ○ ○ ○ 15 35 10 40 5 20 ○ ○ ○ ○ ○ ○ ○ 16 24 95 50 One 25 ○ ○ ○ ○ ○ ○ ○ 17 20 5 50 5 25 ○ ○ ○ ○ ○ ○ ○ 18 15 95 50 10 25 ○ ○ ○ ○ ○ ○ ○ 19 75 50 10 5 10 ○ ○ ○ ○ ○ ○ ○ 20 60 50 20 10 10 ○ ○ ○ ○ ○ ○ ○ 21 65 50 10 15 10 ○ ○ ○ ○ ○ ○ ○ 22 45 50 20 20 15 ○ ○ ○ ○ ○ ○ ○ 23 20/25 50 20 20 15 ○ ○ ○ ○ ○ ○ ○ Comparative example One 0 50 40 20 40 ○ ○ X X ○ X ○ 2 5 50 50 20 25 ○ ○ △ X ○ ○ ○ 3 97 50 One One One ○ △ ○ ○ X ○ ○ 4 75 50 10 5 10 ○ ○ X ○ ○ ○ ○ 5 70 50 15 5 10 ○ ○ ○ X ○ ○ ○ 6 50 - 40 5 5 X X ○ ○ ○ ○ ○ 7 50 3 20 15 15 X X ○ ○ ○ ○ ○ 8 80 100 5 5 10 △ △ ○ ○ ○ ○ ○ 9 80 - 0 10 10 X X ○ ○ ○ ○ ○ 10 15 40 55 15 15 ○ ○ X ○ X ○ ○ 11 10 30 80 5 5 ○ ○ X ○ X ○ ○ 12 4 50 90 One 5 ○ ○ X X X ○ ○ 13 70 50 10 0 20 X X X X ○ X ○ 14 25 50 20 30 25 ○ ○ ○ ○ ○ ○ X 15 25 40 20 50 15 ○ X X ○ ○ ○ X 16 40 30 40 20 0 ○ ○ ○ X ○ X ○ 17 27 50 50 20 3 ○ ○ ○ X ○ X ○ 18 15 50 40 15 30 ○ ○ △ ○ ○ ○ X 19 10 40 30 10 50 ○ ○ △ ○ ○ ○ X

The content of each component represents parts by weight unless otherwise specified. However, silane represents% with respect to the hydroxyl group content of a silica surface.

Examples of the main resin include Examples 1 to 18, Comparative Examples 2, 3, 6 to 10, 12 to 17, and 19 for urethane resins having a number average molecular weight of 100,000, Comparative Example 4 for urethane resins having a number average molecular weight of 3,000, and In Comparative Example 5, a urethane resin having a number average molecular weight of 2,500,000 was used, Example 19 and Comparative Example 11 were acrylic resins having a molecular weight of 100,000, Example 20 and Comparative Example 18 were epoxy resins having a molecular weight of 15,000, and Example 21 was molecular weight. In Example 22, an olefin resin was used, and Example 23 used an olefin resin, and Example 23 used a urethane resin having a molecular weight of 100,000 and an acrylic resin having a molecular weight of 100,000 (urethane / acrylic).

As the silane, Examples 1 to 5, 19 to 23, Comparative Examples 1 to 3, 8, 14, and 18 represent epoxy silanes, and Examples 6 to 8, Comparative Examples 4, 7, 10, 15, and 19 represent aminesilanes. , Examples 9 and 10 are hydroxy silane, Examples 11, 12, Comparative Examples 11 and 16 are vinylsilane, Examples 13, 14, Comparative Examples 12 and 17 are methoxysilane, Examples 15, 16 and Comparative Example 5 modified the silica surface using alkoxysilanes, and Examples 17 and 18 using silane chloride. Comparative Examples 6 and 9 used silica which did not modify the surface with a silane coupling agent.

Example 24-29 and Comparative Example 20-22

2-1. Manufacture of Coated Steel Sheet

1) Specimen: An electro galvanized steel sheet (EG) having an adhesion amount of 20 g / m 2 on one side was used as a material steel sheet for applying the surface treatment composition.

2) Coating method: The resin solution composition having the composition of Example 7 was applied to the upper portion of the steel sheet using a continuous roll coating simulator, and dried under the adhesion amount and PMT conditions as shown in Table 2.

2-2. Performance evaluation

The heat resistance, scratch resistance, conductivity and corrosion resistance of the specimen prepared under the above conditions were evaluated by applying the evaluation method shown in [Table 1], and the results are shown in Table 2.

Coating condition Quality characteristic Amount of Attachment (mg / ㎡) PMT (℃) Heat resistance Scratch resistance conductivity Corrosion resistance Example 24 1,000 200 ○ ○ ○ ○ 25 500 180 ○ ○ ○ ○ 26 800 165 ○ ○ ○ ○ 27 1,500 230 ○ ○ ○ ○ 28 1,000 120 ○ ○ ○ ○ 29 1,200 150 ○ ○ ○ ○ Comparative Example 20 200 180 × × ○ × 21 2,000 200 ○ ○ × ○ 22 1,000 110 × × ○ ×

As described in Table 2, the surface-treated steel sheets of Examples 24 to 29 according to the present invention showed excellent quality characteristics, but Comparative Examples 20 to 22 showed deteriorated characteristics.

1 is a schematic structural diagram of a steel sheet manufactured by applying a resin solution coating layer as an example of the present invention.

2 is an electron scanning micrograph of the silica particles (a) prepared by Comparative Example 6.

3 is an electron scanning microscope photograph of silica particles (c) surface-modified with a silane coupling agent prepared in Example 3 of the present invention.

Claims (27)

A resin solution composition for surface treatment of a steel sheet, comprising a water-soluble organic resin, silica particles surface-modified with a silane coupling agent, a corrosion resistance improving curing agent and a solvent of Ti or Zr organic oxides. It includes a water-soluble organic resin, a silica particle surface-modified with a silane coupling agent, a corrosion resistance improving curing agent and a solvent of Ti or Zr organic oxide; 10 to 90% by weight of water-soluble organic resin, based on the solids content of the total resin solution composition; 1 to 50% by weight of silica particles surface-modified with a silane coupling agent; And 1 to 20% by weight of Ti or Zr-based organic oxides. The resin solution composition for surface treatment of a steel sheet according to claim 1 or 2, wherein the water-soluble organic resin is selected from the group consisting of urethane resins, acrylic resins, epoxy resins, ester resins, olefin resins or mixtures thereof. . The resin solution composition for surface treatment of a steel sheet according to claim 1 or 2, wherein the water-soluble organic resin is a urethane resin. The method of claim 4, wherein the urethane resin is isophorene diisocyanate of the polyurethane dispersion resin or polyethylene modified polyurethane resin; Polyurethane resins prepared from adipic acid and polyhydric alcohols; Polyurethane resins prepared from acrylic polyols and polyisocyanates of acrylic-urethane resins or polyethylene-acrylic modified polyurethane resins; And polyurethane resins prepared from polycaprolactone polyols or polycarbonate polyols and isocyanates; Polyurethane resins prepared from 4,4'-bis (ω-hydroxyalkyleneoxy) biphenyl and methyl-2,6-diisocyanatehexanoate; Polyurethane resin having an acetal bond; Resin solution composition for surface treatment of a steel sheet, characterized in that at least one selected from the group consisting of. The steel sheet according to claim 4, wherein the water-soluble organic resin has a molecular weight of urethane resin 5,000 to 2,000,000, acrylic resin 50,000 to 2,000,000, epoxy resin 500 to 25,000, ester resin 5,000 to 15,000, and olefin resin 500,000 to 2,000,000, respectively. Resin solution composition for surface treatment. According to claim 1 or 2, wherein the surface modification of the silica particles by reacting the colloidal silica particles with a silane coupling agent, the hydroxy group on the surface of the colloidal silica gel particles amine group, epoxy group, hydroxyl group, vinyl group, methoxy group A resin solution composition for surface treatment of a steel sheet, which is carried out by substituting at least one of an alkoxy group and a chloride group. The surface of the steel sheet according to claim 7, wherein the silane coupling agent is one or a mixture of two or more selected from the group consisting of methoxysilane, aminosilane, epoxysilane, hydroxy silane, vinylsilane, alkoxysilane and chloride silane. Resin solution composition for processing. 8. The resin solution composition for surface treatment of a steel sheet according to claim 7, wherein the silane coupling agent is 5 to 95% with respect to the hydroxy group content of the silica surface. 8. The resin solution composition of claim 7, wherein the reaction between the silica particles and the silane coupling agent is surface-modified by the silane coupling agent at pH 4.0 to 10.0. The resin solution composition for surface treatment of a steel sheet according to claim 7, wherein the reaction between the silica particles and the silane coupling agent is performed at 10 to 40 ° C. 8. The resin solution composition for surface treatment of a steel sheet according to claim 7, wherein the reaction between the silica particles and the silane coupling agent is performed using a cyclic homogenizer. 8. The resin solution composition for surface treatment of a steel sheet according to claim 7, wherein the average particle size of the silica particles is 10 to 30 nm. The method of claim 1 or 2, wherein the Ti or Zr organic oxide is titanium diisopropoxide bis (acetylacetonate), titanium ortho ester, titanium (IV) butoxide, titanium (IV) (triethanol aminato ) Isopropoxide, tetrakis (triethanolaminato) zirconium (IV), titanium (IV) 2-ethylhexoxide, titanium (IV) isopropoxide, zirconium (IV) bis (diethyl citrato) -dip A resin solution composition for surface treatment of a steel sheet, characterized in that it is selected from rhoposide or a mixture thereof. The resin solution composition for surface treatment of a steel sheet according to claim 1 or 2, wherein the solvent is water. The method of claim 15, wherein the solvent comprises one or more alcohol solvents selected from ethanol, methanol, propanol, isopropanol and glycerol; One or two or more alkaline aqueous solutions selected from amine compounds, N-methylpyrrolidone, sodium hydroxide, potassium hydroxide, sodium carbonate and ammonium hydroxide; Or a resin solution composition for surface treatment of a steel sheet, characterized in that it further comprises a mixture thereof. Silica, Ti, or Zr-based organic oxides surface-treated with a water-soluble resin, a silane coupling agent; And coating a resin solution composition comprising a solvent on the upper surface of the steel sheet so as to have an adhesion amount of 300 to 1,800 mg / m 2 after drying. Silica, Ti, or Zr-based organic oxides surface-treated with a water-soluble resin, a silane coupling agent; And comprising a step of coating a resin solution composition comprising a solvent; and then coated with an adhesion amount of 300 to 1,800 mg / ㎡ on the steel sheet, 10 to 90% by weight of the main resin, based on the solids of the total resin solution composition; 1 to 50% by weight of silica surface-treated with a silane coupling agent; Method for producing a surface-treated steel sheet containing 1 to 20% by weight of Ti or Zr-based organic oxide. 19. The method of claim 17 or 18, wherein the water-soluble organic resin is isophorene diisocyanate of the polyurethane dispersion resin or polyethylene modified polyurethane resin; Polyurethane resins prepared from adipic acid and polyhydric alcohols; Polyurethane resins prepared from acrylic polyols and polyisocyanates of acrylic-urethane resins or polyethylene-acrylic modified polyurethane resins; And polyurethane resins prepared from polycaprolactone polyols or polycarbonate polyols and isocyanates; Polyurethane resins prepared from 4,4'-bis (ω-hydroxyalkyleneoxy) biphenyl and methyl-2,6-diisocyanatehexanoate; Polyurethane resin having an acetal bond; at least one urethane resin selected from the group consisting of a method for producing a surface-treated steel sheet. 20. The surface of claim 19, wherein the water-soluble organic resin has a molecular weight of urethane resin 5,000 to 2,000,000, acrylic resin 50,000 to 2,000,000, epoxy resin 500 to 25,000, ester resin 5,000 to 15,000, and olefin resin 500,000 to 2,000,000. Method for producing treated steel sheet. The surface of claim 17 or 18, wherein the silane coupling agent is at least one member selected from the group consisting of methoxysilane, aminosilane, epoxysilane, hydroxy silane, vinyl silane, alkoxysilane and chloride silane. Method for producing treated steel sheet. 19. The method of claim 17 or 18, further comprising the step of drying the steel sheet coated with the resin solution composition at a temperature of PMT 120 ~ 250 ℃. Steel plate; And a resin coating layer, wherein the resin coating layer is Water-soluble organic resins; Silica surface-modified with a silane coupling agent; Ti or Zr-based organic oxides; And menstruum; Surface-treated steel sheet characterized in that the resin solution composition comprising a coated with a coating amount of 300 to 1,800 mg / ㎡ after drying on the upper steel sheet. Steel plate; And a resin solution coating layer; consisting of, the resin solution coating layer Water-soluble organic resins; Silica surface-modified with a silane coupling agent; Ti or Zr-based organic oxides; And menstruum; The amount of the main resin is 10 to 90% by weight based on the total solids of the solution composition, the amount of silica surface-treated with the silane coupling agent is 1 to 50% by weight based on the total solids of the solution composition, and based on Ti or Zr The organic oxide is a surface-treated steel sheet, characterized in that the resin solution composition of 1 to 20% by weight is coated on the upper surface of the steel sheet with an adhesion amount of 300 to 1,800 mg / ㎡. 25. The method of claim 23 or 24, wherein the water-soluble organic resin is isophorene diisocyanate of the polyurethane dispersion resin or polyethylene modified polyurethane resin; Polyurethane resins prepared from adipic acid and polyhydric alcohols; Polyurethane resins prepared from acrylic polyols and polyisocyanates of acrylic-urethane resins or polyethylene-acrylic modified polyurethane resins; And polyurethane resins prepared from polycaprolactone polyols or polycarbonate polyols and isocyanates; Polyurethane resins prepared from 4,4'-bis (ω-hydroxyalkyleneoxy) biphenyl and methyl-2,6-diisocyanatehexanoate; Polyurethane resin having an acetal bond; Resin solution composition for surface treatment of a steel sheet, characterized in that at least one urethane resin selected from the group consisting of. The steel sheet according to claim 27, wherein the water-soluble organic resin has a molecular weight of urethane resin 5,000 to 2,000,000, acrylic resin 50,000 to 2,000,000, epoxy resin 500 to 25,000, ester resin 5,000 to 15,000, and olefin resin 500,000 to 2,000,000, respectively. Resin solution composition for surface treatment. The surface according to claim 23 or 24, wherein the silane coupling agent is at least one member selected from the group consisting of methoxysilane, aminosilane, epoxysilane, hydroxy silane, vinyl silane, alkoxysilane and chloride silane. Processed steel plate.

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