KR20170035471A

KR20170035471A - Galvanized steel sheet and mehtod of mamufacturing the same

Info

Publication number: KR20170035471A
Application number: KR1020150134344A
Authority: KR
Inventors: 이래성
Original assignee: 현대제철 주식회사
Priority date: 2015-09-23
Filing date: 2015-09-23
Publication date: 2017-03-31

Abstract

A galvanized steel sheet and a manufacturing method thereof are disclosed. A galvanized steel sheet and a method of manufacturing the same according to the present invention include a steel sheet base material, a zinc plating layer formed on the steel sheet base material, and a resin coating layer formed on the zinc plating layer, wherein the resin coating layer is formed of a dried material of the resin composition, Includes pure water of a urethane resin, an acrylic resin, a silicate, a silica inorganic compound, a silane, a chelating agent, a curing agent, a wetting agent, a solvent and the remainder.

Description

[0001] DESCRIPTION [0002] GALVANIZED STEEL SHEET AND MEHTOD OF MAMUFACTURING THE SAME [0003]

The present invention relates to a galvanized steel sheet and a method of manufacturing the same, and more particularly, to a galvanized steel sheet which is excellent in corrosion resistance without containing chromium and exhibits physical properties such as adhesiveness and heat resistance by increasing the content of inorganic additives, &Lt; / RTI >

In general, a coating method of a coated steel sheet using a coating liquid is mainly used to increase the corrosion resistance of a steel sheet. The galvanized steel sheet is mainly used as household appliances because of the surface beauty. Recently, various attempts have been made to apply various coatings on the surface of the zinc plated layer in order to secure additional functions of the steel plate. The surface of the steel sheet may be subjected to a chromate treatment to form a ground layer, and then a resin layer may be formed thereon to coat the surface. However, chromium is a hazardous substance and its use is now regulated. Therefore, there is a need for a technique capable of ensuring high corrosion resistance without containing chromium components. Related Prior Art Korean Patent Laid-Open Publication No. 10-2006-0073483 (Jun. 28, 2006, a chromium-free metal surface treatment composition and surface treated steel sheet) is known.

According to one aspect of the present invention, there is provided a zinc-plated steel sheet excellent in corrosion resistance without containing chromium.

According to another aspect of the present invention, there is provided a zinc-plated steel sheet which is free from discoloration upon exposure to a coating part even at a high temperature and is excellent in heat resistance.

According to still another aspect of the present invention, there is provided a method of manufacturing a galvanized steel sheet, which is excellent in lubricity during steel sheet production and can prevent blackening or whitening of the friction surface.

According to another aspect of the present invention, there is provided a method of manufacturing a galvanized steel sheet capable of realizing physical properties such as excellent corrosion resistance, lubricity and heat resistance even when heated and dried under low temperature conditions within a few seconds.

According to another aspect of the present invention, there is provided a method of manufacturing a galvanized steel sheet, which realizes energy saving, facility simplification, and productivity increase effect.

The above and other objects to be solved by the present invention can be achieved by the present invention described below.

According to an aspect of the present invention, there is provided a galvanized steel sheet comprising: a steel sheet base material; A zinc plated layer formed on the steel plate base material; And a resin coating layer formed on the zinc plated layer, wherein the resin coating layer is formed of a dried product of a resin composition, the resin composition comprising a urethane resin; Acrylic resin; Silicates; Silica; Inorganic compounds; Silane; Chelating agents; Curing agent; Wetting agents; A solvent, and pure water of the remainder.

In one embodiment, the inorganic compound is selected from the group consisting of silicon oxide (SiO2), aluminum oxide (Al2O3), calcium oxide (CaO), potassium oxide (K2O), magnesium oxide (MgO), sodium oxide (Na2O) ) Or the like, or a mixture of two or more thereof.

In one embodiment, the chelating agent comprises an aromatic triazole; Titanium coupling agent, ammonium phosphate or the like, alone or in combination of two or more.

In one embodiment, the curing agent is one or more selected from the group consisting of aziridine and melamine.

In one embodiment, the resin composition comprises 10 to 20% by weight of a urethane-based resin; 5 to 10% by weight of an acrylic resin; 10 to 25% by weight silicate; 20 to 30% by weight of silica; 1 to 5% by weight of an inorganic compound; 1 to 5% by weight silane; 0.2 to 5 wt% chelating agent; 0.5 to 2% by weight of a hardener; 0.2 to 1% by weight wetting agent; 10 to 20% by weight of a solvent; And pure water of the remainder.

In one embodiment, the resin coating layer is characterized by a layer thickness of 0.5 to 2.5 占 퐉.

According to another aspect of the present invention, there is provided a method of manufacturing a galvanized steel sheet, comprising: forming a galvanized layer on a surface of a steel sheet base material; Forming a resin composition, coating the resin composition on the zinc plating layer, and then heating and drying to form a resin coating layer, wherein the resin composition comprises a urethane resin; Acrylic resin; Silicates; Silica; Inorganic compounds; Silane; Chelating agents; Curing agent; Wetting agents; A solvent, and pure water of the remainder.

In one embodiment, the heat drying is performed at a temperature of 180 to 230 ° C at a peak metal temperature (PMT).

The zinc-coated steel sheet and the manufacturing method thereof according to the present invention are excellent in corrosion resistance without containing chromium and have excellent heat resistance because no discoloration occurs at the time of exposure to a coating area at high temperatures and have excellent lubricity in the production of steel sheet, And whitening phenomenon can be prevented and it is possible to realize properties such as excellent corrosion resistance, lubricity and heat resistance even when heated and dried at a low temperature within a few seconds, and to realize energy saving, facility simplification and productivity increase effect.

1 is a schematic cross-sectional view of a galvanized steel sheet according to one embodiment of the present invention.
2 is a flow chart showing a process for producing a galvanized steel sheet according to one embodiment of the present invention.

Embodiments of the present application will now be described in more detail with reference to the accompanying drawings. However, the techniques disclosed in the present application are not limited to the embodiments described herein but may be embodied in other forms. The embodiments disclosed herein are provided so that the disclosure can be thorough and complete, and will fully convey the scope of the present application to those skilled in the art.

It is to be understood that the singular forms "a", "an", and "the" include plural referents unless the context clearly dictates otherwise, and the terms "comprise" Components, components, or combinations thereof, and does not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, or combinations thereof .

Further, in carrying out the method or the manufacturing method, the respective steps of the method may take place differently from the stated order unless clearly specified in the context. That is, each process may occur in the same order as described, may be performed substantially concurrently, or may be performed in the opposite order.

Hereinafter, the present invention will be described in more detail.

Resin composition

The resin composition according to one embodiment of the present invention comprises a urethane resin; Acrylic resin; Silicates; Silica; Inorganic compounds; Silane; Chelating agents; Curing agent; Wetting agents; Solvent and the remainder pure water.

Hereinafter, each component and content of the resin composition forming the resin coating layer will be described.

Urethane resin

The urethane resin is included for the purpose of improving the high-temperature reactivity and increasing the processability, solvent resistance, fuel resistance, etc. of the resin coating layer when forming the galvanized steel sheet according to one embodiment of the present invention.

The urethane resin is contained together with a high molecular weight acrylic resin to form a resin coating layer, and through this, the molecular weight and the baking temperature are different, so that the urethane resin can perform one layer but two layers.

In order to realize the object of the present invention, the urethane-based resin may be used singly or in combination of two or more in, for example, a soft type or hard type polycarbonate type, polyester type, Can be used.

The urethane-based resin may be contained in an amount of, for example, 10 to 20% by weight, for example, 12 to 18% by weight, for example, 14 to 16% by weight based on 100% When the content of the acrylic resin is less than 10% by weight, the binder can not sufficiently act as a binder, resulting in insufficient adhesion of the film and difficulty in workability and solvent resistance. On the other hand, when the content of the acrylic resin exceeds 20% , The physical properties such as the corrosion resistance of the film are deteriorated, and the object of the present invention becomes difficult to implement.

Acrylic resin

The acrylic resin is included for the purpose of improving the low-temperature reactivity and increasing the adhesion of the resin coating layer when forming the galvanized steel sheet according to one embodiment of the present invention.

The acrylic resin is included together with the above-mentioned high molecular weight urethane-based resin so that the resin coating layer can be held at a high temperature even when forming a resin coating layer, and the acrylic resin can serve as one layer but two layers by changing the molecular weight and the baking temperature.

The acrylic resin may be prepared, for example, by adding acrylic acid, ethylene or the like to an amine-based solution such as ethanolamine to form an acid neutralizing group, and then neutralizing the amine-based neutralizing agent such as triethylamine.

The acrylic resin may have a number average molecular weight of, for example, 10,000 to 14,000, for example, 11,000 to 13,000, for example, 11,500 to 12,500. When the number average molecular weight of the acrylic resin is less than 10,000, it is difficult to exhibit sufficient adhesion and it is difficult to burn at a high temperature. On the contrary, when the number average molecular weight of the acrylic resin exceeds 14,000, There is a problem that a roll mark or the like is generated.

The acrylic resin preferably has a pH of 7.8 to 10.2, for example, a pH of 8.8 to 9.8, for example, a pH of 8.4 to 9.4. There is an advantage that the degradation of water dispersibility can be prevented in the pH range of the acrylic resin.

The acrylic resin may be contained in an amount of, for example, 5 to 10% by weight, for example, 6 to 9% by weight, for example, 7 to 8% by weight based on 100% When the content of the acrylic resin is less than 5% by weight, the binder can not sufficiently act as a binder, resulting in insufficient adhesion of the film. On the contrary, when the content of the acrylic resin exceeds 10% by weight, there is a problem.

Silicate

The silicate is included for the purpose of enhancing the bonding strength of the resin coating layer when forming a galvanized steel sheet according to one embodiment of the present invention.

The silicate may have a molecular structure, for example NaSiO3 or NaSi5O11, for example NaSiO3 being particularly preferred. As a result, when the galvanized steel sheet is coated, it has a three-dimensional network structure, so that excellent bonding strength with the galvanized steel sheet can be realized.

The silicate may include a mixture of different average particle diameters to maximize the packing effect when the resin coating layer is formed. The packing effect of the silicates can prevent penetration of the corrosion factor into the resin coating layer. The silicate may have a mean particle size of, for example, 18 to 20 nm; 10 to 12 nm; And silicates in the range of 5 to 7 nm in weight ratio, for example, 25 to 30%: 25 to 30%: 35 to 40%. Through the use of the mixture, the packing effect is maximized when the resin coating layer is formed, and prevention of permeation of the corrosion factor is realized.

The silicate may include, for example, 10 to 25% by weight, for example, 13 to 22% by weight, for example, 16 to 18% by weight based on 100% by weight of the total resin composition. If the content of the silicate is less than 10% by weight, the content of the silicate may be too small to reduce the adhesion with the steel sheet and the corrosion resistance. Conversely, when the content of the silicate exceeds 25% by weight, And the corrosion resistance after processing is deteriorated.

Silica

The silica is included for the purpose of contributing to improvement of wear resistance, corrosion resistance, etc. of the resin coating layer according to one embodiment of the present invention.

In one embodiment of the present invention, the silica is preferably used in the form of a colloidal silica.

The silica may also include a mixture of different average particle diameters in order to maximize the packing effect when forming the resin coating layer. The packing effect of the silica can prevent penetration of the corrosion factor into the resin coating layer. The silica may have, for example, an average particle diameter of 18 to 20 nm; 10 to 12 nm; And silica having a particle diameter of 5 to 7 nm in a weight ratio of, for example, 25 to 30%: 25 to 30%: 35 to 40%. Through the use of the mixture, the packing effect is maximized when the resin coating layer is formed, and prevention of permeation of the corrosion factor is realized.

The silica may be contained in an amount of 20 to 30% by weight, for example, 22 to 28% by weight, for example, 24 to 26% by weight based on 100% by weight of the total resin composition. When the content of the silica is less than 20% by weight, the effect of adding the silica is insufficient and it is difficult to realize hardness and corrosion resistance improvement effect. On the other hand, when the content of the silica is more than 30% by weight, The effect of improving the physical properties is insignificant, so that the adhesion of the resin coating layer is lowered, and the workability is lowered, and problems such as lowering of adhesion force and surface defects may occur.

Inorganic compound

The inorganic compound is included for the purpose of improving physical properties such as weldability in forming a resin coating layer according to one embodiment of the present invention.

The inorganic compound may be used alone or in combination of two or more of silicon oxide (SiO 2), aluminum oxide (Al 2 O 3), calcium oxide (CaO), potassium oxide (K 2 O), magnesium oxide (MgO), sodium oxide (Na 2 O) and titanium oxide Two or more kinds of them may be mixed and included.

The inorganic compound may be a metal such as Si, Al, Ca, K, Mg, Na, and Ti in the metal oxide . In addition, it may further include metal oxides such as manganese (Mn), cerium (Ce), zinc (Zn), molybdenum (Mo), vanadium (V) and zirconium (Zr)

It is more preferable that the inorganic compound is present in the form of a salt or nano-sized colloid in water rather than precipitated in the resin composition. This can be accomplished by controlling the composition or particle size of the inorganic compound.

The inorganic compound may also include a mixture of different average particle diameters in order to maximize the packing effect when the resin coating layer is formed. The penetration of the corrosion factor into the resin coating layer can be blocked by the packing effect of the inorganic compounds. The inorganic compound may have a mean particle size of, for example, 18 to 20 nm; 10 to 12 nm; And 25 to 30%: 25 to 30%: 35 to 40% by weight of inorganic compounds having a particle diameter of 5 to 7 nm. Through the use of the mixture, the packing effect is maximized when the resin coating layer is formed, and prevention of permeation of the corrosion factor is realized.

The inorganic compound may be contained in an amount of 1 to 5% by weight, for example, 1.5 to 4.5% by weight, for example, 2 to 4% by weight based on 100% by weight of the entire resin composition. When the content of the inorganic compound is less than 1% by weight, the effect of the crosslinking catalyst becomes insufficient, the effect of addition is insignificant and it is difficult to realize the effect of improving the corrosion resistance and the like. On the other hand, There is a problem that it becomes brittle due to the deterioration and the corrosion resistance after processing is lowered and melting or swelling phenomenon may occur in a solvent such as water.

Silane

The silane is hydrolyzed in water to form a siloxane bond, and binds strongly to the steel sheet. At the same time, the silane acts as a binder for binding various inorganic materials. The silane improves the adhesion and corrosion resistance of the resin coating layer according to one embodiment of the present invention. In order to ensure that

The silane can be, for example, 3-glycidoxypropyltrimethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 2- (3,4-epoxycyclohexyl) Silane, and 3-glycidoxypropylmethyldiethoxysilane, or a mixture of two or more thereof.

The silane may also include a mixture of different average particle diameters in order to maximize the packing effect when the resin coating layer is formed. It is possible to prevent penetration of corrosion factors into the resin coating layer through the packing effect of the silanes. The silane may have, for example, an average particle diameter of 18 to 20 nm; 10 to 12 nm; And 25 to 30%: 25 to 30%: 35 to 40% of silane having a particle diameter of 5 to 7 nm, for example, in a weight ratio. Through the use of the mixture, the packing effect is maximized when the resin coating layer is formed, and prevention of permeation of the corrosion factor is realized.

The silane may be contained in an amount of 1 to 5% by weight, for example, 1.5 to 4.5% by weight, for example, 2 to 4% by weight based on 100% by weight of the total resin composition. If the content of the silane is less than 1% by weight, the adhesion effect of the resin coating layer is lowered due to insufficient addition effect. On the other hand, when the content of the silane exceeds 5% by weight, residues are generated after the reaction to adversely affect the physical properties of the resin coating layer And the solution stability can be lowered.

Chelating agent

The chelating agent serves to bridge the resin coating layer and the zinc plating layer and is included for the purpose of improving physical properties such as corrosion resistance.

The chelating agent may include, for example, an aromatic triazole, a titanium coupling agent, ammonium phosphate or the like, alone or in combination of two or more.

The aromatic triazole may be used singly or in combination of two or more, for example, benzotriazole, alkyl-substituted aromatic triazole, and the like. However, the types are not limited thereto as long as they are for realizing the object of the present invention.

The aromatic triazole may be contained in an amount of from 1 to 3% by weight, for example, from 1.2 to 2.8% by weight, for example, from 1.5 to 2.5% by weight based on 100% by weight of the entire resin composition. If the content of the aromatic triazole is less than 1% by weight, the effect of addition thereof may be insufficient and the corrosion resistance and fuel resistance may be insufficient. On the other hand, when the content of the aromatic triazole is more than 3% by weight, There is a problem of deterioration.

The titanium coupling agent may be, for example, titanium acetylacetonate, iso-butoxy titanium ethylacetoacetate, di-iso-propoxy titanium bis ethylacetoacetate, tetraisopropyl titanate, tetranormal butyl titanate, Nitrate, titanyl sulfate, and fluorotitanic acid, or a mixture of two or more thereof. However, the types are not limited thereto as long as they are for realizing the object of the present invention.

The titanium coupling agent may be included in an amount of 0.2 to 1% by weight, for example, 0.4 to 0.8% by weight, for example, 0.5 to 0.7% by weight based on 100% by weight of the total resin composition. If the content of the titanium coupling agent is less than 0.2% by weight, the effect of addition thereof may be insufficient and the corrosion resistance and fuel resistance may be insufficient. On the other hand, when the content of the titanium coupling agent is more than 1% by weight, There is a problem of deterioration.

The ammonium phosphate may be used singly or in combination of two or more of them, such as ammonium monophosphate ((NH4) H2PO4), ammonium dihydrogen phosphate ((NH4) 2HPO4) and triammonium phosphate ((NH4) 3PO4). However, the types are not limited thereto as long as they are for realizing the object of the present invention.

The ammonium phosphate may be contained in an amount of 0.2 to 1% by weight, for example, 0.4 to 0.8% by weight, for example, 0.5 to 0.7% by weight based on 100% by weight of the resin composition. If the content of ammonium phosphate is less than 0.2% by weight, the effect of addition thereof may be insufficient and the corrosion resistance and fuel resistance may be insufficient. On the other hand, when the ammonium phosphate content is more than 1% by weight, there is a problem.

In one embodiment of the present invention, the chelating agent may be contained in an amount of 0.2 to 5% by weight, for example, 0.4 to 4.5% by weight, for example, 0.6 to 3.5% by weight based on 100% by weight of the total resin composition. If the content of the chelating agent is less than 0.2% by weight, the effect of addition thereof may be insufficient and the corrosion resistance and fuel resistance may be insufficient. On the other hand, when the content of the chelating agent is more than 5% by weight, there is a problem.

Hardener

The curing agent is included for the purpose of promoting curing at the time of baking after applying the solution of the resin composition to the zinc plating layer at the time of forming the resin coating layer.

The curing agent may include, for example, aziridine and melamine, alone or in combination of two or more. However, the type is not limited thereto as long as the object of the present invention can be realized.

The aziridine may be contained in an amount of 0.5 to 1% by weight, for example, 0.6 to 0.9% by weight, for example, 0.7 to 0.8% by weight, based on 100% by weight of the entire resin composition. If the content of aziridine is less than 0.5% by weight, the addition effect is insufficient and the resin is melted or discolored to harden the resin, resulting in poor solventability. On the other hand, when the aziridine content exceeds 1% by weight There is a problem that contamination such as discoloration occurs due to excessive use and the acceleration of curing is lowered.

The melamine may be contained in an amount of 0.5 to 1% by weight, for example, 0.6 to 0.9% by weight, for example, 0.7 to 0.8% by weight based on 100% by weight of the total of the resin composition. If the content of the melamine is less than 0.5% by weight, the effect of the addition of the melamine is insufficient and the resin is melted or discolored, and the curing is not properly carried out to degrade the solventability. On the other hand, when the content of the melamine is more than 1% There is a problem that contamination such as discoloration occurs due to excessive use and curing acceleration is lowered.

In one embodiment of the present invention, the curing agent may be contained in an amount of 0.5 to 2% by weight, for example, 0.7 to 1.8% by weight, for example, 0.9 to 1.5% by weight based on 100% by weight of the total resin composition. If the content of the curing agent is less than 0.5% by weight, the effect of the addition is insignificant, and the resin is melted or discolored, and the curing is not properly performed to degrade solventability. On the other hand, when the content of the curing agent is more than 2% There is a problem that contamination such as discoloration occurs due to excessive use and curing acceleration is lowered.

Wetting agent

The wetting agent is included for the purpose of improving the leveling property when the resin coating layer is formed according to one embodiment of the present invention.

The above? Polyethylene wax, synthetic paraffin, micro wax, polytetrafluoroethylene resin, fatty acid amide compound, fluorine resin, etc., alone or in combination of two or more. Preferably, a polytetrafluoroethylene resin can be used.

The wetting agent may be contained in an amount of 0.2 to 1% by weight, for example, 0.4 to 0.8% by weight, for example, 0.5 to 0.7% by weight, based on 100% by weight of the entire resin composition. When the content of the wetting agent is less than 0.2% by weight, the effect of addition is insignificant and the coefficient of friction is low, so that it is difficult to realize the leveling of the resin coating layer. On the other hand, when the content of the wetting agent is more than 1% by weight, And wrinkles may occur during processing.

solvent

The above-mentioned solvent is included for the purpose of improving the wettability of the steel sheet of various processing agents, compatibility, hydrolysis, and speed of drying after coating the steel sheet when forming the resin coating layer, when forming the resin composition according to one embodiment of the present invention.

The solvent may be used alone or in admixture of two or more in methanol, ethanol, 2-propanol, 2-methoxypropanol and 2-butoxyethanol. However, the type is not limited thereto as long as the object of the present invention can be realized.

The solvent may include 10 to 20% by weight, for example, 12 to 18% by weight, for example, 14 to 16% by weight based on 100% by weight of the total of the resin composition. If the content of the solvent is less than 10% by weight, the compatibility with water may be lowered and the storage stability may be affected. On the other hand, when the content of the solvent is more than 20% by weight, There is a risk of fire and explosion.

pure

The pure water is appropriately contained as much as the rest of the total amount of the resin composition by adjusting the amount of addition to 100% by weight of the resin composition according to the content of the other components of the resin composition according to one embodiment of the present invention.

The resin composition of the present invention is excellent in corrosion resistance without containing chromium and exhibits excellent heat resistance due to no discoloration at the time of exposure to a coating part at a high temperature and has excellent lubricity in the production of steel sheet to prevent blackening and whitening of the friction surface And can realize physical properties such as excellent corrosion resistance, lubrication and heat resistance even when heated and dried under low temperature conditions within a few seconds, and can realize a galvanized steel sheet excellent in energy saving, facility simplification and productivity increase and its manufacturing method .

galvanized steel

One aspect of the present invention relates to a steel plate preform; A zinc plated layer formed on the steel plate base material; And a resin coating layer formed on the zinc plated layer, wherein the resin coating layer is formed of a dried product of a resin composition, the resin composition comprising a urethane resin; Acrylic resin; Silicates; Silica; Inorganic compounds; Silane; Chelating agents; Curing agent; Wetting agents; A solvent, and a pure water of the remainder.

Hereinafter, a galvanized steel sheet according to one embodiment of the present invention will be described in detail.

1 is a schematic cross-sectional view of a galvanized steel sheet according to one embodiment of the present invention.

Referring to FIG. 1, a galvanized steel sheet 100 according to an embodiment of the present invention includes a steel sheet base material 110, a zinc coating layer 130, and a resin coating layer 150.

Steel plate base material

The steel sheet base material 110 may be a hot-rolled steel sheet or a cold-rolled steel sheet. It is preferable to use the steel sheet base material 110 in a state where surface contamination is cleanly treated through a pretreatment process such as pickling and degreasing in order to improve the characteristics of zinc plating.

Zinc plated layer

The zinc plating layer 130 is formed on one side or both sides of the base material 110, preferably on both sides of the base material 110, for the purpose of securing the corrosion resistance of the zinc-plated steel sheet 100.

The zinc plating layer 130 may be formed by a method such as hot dip galvanizing or electroplating and may be formed of one or more of zinc, zinc alloy, nickel and nickel alloy such as Zn, Ni, Zn-Ni and Zn- As shown in FIG. However, the type and form thereof are not limited thereto, as long as the object of the present invention is realized.

In one embodiment of the present invention, a zinc plated layer may be formed using, for example, an electro-galvanizing method to form the zinc plated layer 130. [ The zinc-plated steel sheet 100 may have an adhesion amount of 100 to 1100 mg / m 2, for example, 300 to 900 mg / m 2, for example, 500 to 700 mg / m 2 for the purpose of securing corrosion resistance after drying of the zinc- have. If the coating amount after drying is less than 100 mg / m 2, there is a problem that the corrosion resistance of the coating is inadequate. Conversely, if the coating amount after drying exceeds 1100 mg / m 2, adhesion to the base steel sheet may become insufficient, Fume is generated and the work becomes difficult and the weldability may be lowered. In the zinc plating deposition amount range, it is possible to realize high corrosion resistance properties even under low-temperature curing conditions. The plating adhesion amount can be controlled by controlling the application amount of the resin composition or the like, and this can be caused by the formation of a highly corrosion resistant resin coating layer 150 described later.

Resin coating layer

The resin coating layer 150 is formed on the surface of the steel plate base material 110 and is formed for the purpose of imparting corrosion resistance, durability, lubricity, heat resistance and chemical resistance of the steel sheet according to the usage form.

The resin coating layer 150 may be formed on the surface of the zinc plated layer 130. 1, the resin coating layer 150 is formed on both surfaces of the steel plate base material 110. However, the resin coating layer 150 may be formed only on one side of the steel plate base material 110 .

The resin coating layer 150 preferably has a thickness of 0.5 to 2.5 占 퐉, for example, 1.0 to 2.0 占 퐉, for example, 1.3 to 1.7 占 퐉. When the thickness of the resin coating layer 150 is less than 0.5 탆, the workability is improved but the corrosion resistance and the adhesion force may be lowered. On the other hand, when the thickness of the resin coating layer 150 is more than 2.5 탆, It acts as a factor to increase only the thickness of the coating film without increasing the effect, and it causes a problem that the workability is lowered due to the increase of the thickness of the coating film, and cracks are caused.

The resin coating layer 150 is formed of the dried product of the resin composition, and the components and the content ratios of the resin composition are the same as described above, and the description thereof is omitted.

According to one embodiment of the present invention, the zinc-plated steel sheet is excellent in corrosion resistance without containing chromium, exhibits excellent heat resistance due to no discoloration upon exposure to a coating portion even at a high temperature and has excellent lubricity, There is an effect that the phenomenon can be prevented.

Manufacturing method of galvanized steel sheet

Another aspect of the present invention is a method for manufacturing a steel plate, comprising: forming a zinc plated layer on a surface of a steel plate base material; Forming a resin composition; And coating the resin composition on the zinc plated layer and then heating and drying to form a resin coating layer, wherein the resin composition comprises a urethane resin; Acrylic resin; Silicates; Silica; Inorganic compounds; Silane; Chelating agents; Curing agent; Wetting agents; A solvent, and a pure water of the remainder.

Hereinafter, a method of manufacturing a galvanized steel sheet according to one embodiment of the present invention will be described in detail.

2 is a flow chart showing a process for producing a galvanized steel sheet according to one embodiment of the present invention.

Referring to FIG. 2, a method of manufacturing a galvanized steel sheet according to an embodiment of the present invention includes a zinc plating layer forming step (S100), a resin composition forming step (S200), and a resin coating layer forming step (S300).

Zinc plated layer formation

The zinc plating layer forming step (S100) is performed for the purpose of forming a zinc plated layer (130) on one side or both sides of the steel plate base material (110). Since the zinc plated layer is as described above, its explanation is omitted.

Resin composition formation

The resin composition forming step (S200) is performed for preparing each component of the resin composition in order to form the resin coating layer (150) on the zinc plated steel sheet (100) and for mixing the components.

Formation of resin coating layer

The resin coating layer forming step S300 is carried out for the purpose of forming a resin coating layer 150 by applying a resin composition having the composition described above to one side or both sides of the zinc plating layer 130, followed by heating and drying.

In the step S300 of forming the resin coating layer, coating is performed by one or more methods such as a spray-squeezing method, a roll coating method, and a dipping method when the resin coating layer 150 is formed . However, the method is not limited thereto as long as it is to realize the object of the present invention.

In the resin coating layer forming step (S300), the resin coating layer (150) may be heated and dried in one or more ways in hot air drying, oven drying, high frequency induction heating drying, infrared heat drying and the like. However, the method is not limited thereto as long as it is to realize the object of the present invention.

In the resin coating layer forming step (S300), the heating and drying may be performed at a heating and drying temperature PMT (Peak Metal Temperature) of 180 to 230 ° C, for example, 190 to 220 ° C, for example, 195 to 215 ° C. If the heating and drying temperature is lower than 180 ° C, the curing reaction of the resin is not sufficiently carried out and it is difficult to expect corrosion resistance and other physical properties of the resin coating layer. On the other hand, It is difficult to cure at a low temperature for the curing of the resin coating layer.

In the resin coating layer formation step (S300), the drying time during the heat drying may be shortened for 5 to 10 seconds, for example, for 6 to 9 seconds, for example, for 7 to 8 seconds. It is possible to omit the pretreatment coating process for a short time in the drying time range and to realize properties such as excellent corrosion resistance, high heat resistance and lubricity.

The step of forming the resin coating layer (S300) may further include pre-drying the resin coating layer at a temperature of, for example, 140 to 170 ° C, for example, 145 to 165 ° C, for example, 150 to 160 ° C . It is advantageous that the resin coating layer is formed more easily through the preliminary drying in the temperature range and the production efficiency is increased.

In the resin coating layer forming step (S300), after the resin coating layer is heated and dried, it may be cooled by a known method such as air cooling or water cooling.

The method of manufacturing a galvanized steel sheet according to one embodiment of the present invention is excellent in corrosion resistance without containing chromium and exhibits excellent heat resistance due to no discoloration upon exposure to a coating portion even at a high temperature, This makes it possible to prevent the occurrence of blackening and whitening of the friction surface and realize physical properties such as excellent corrosion resistance, lubricity and heat resistance even when heated and dried under low temperature conditions within a few seconds, and to realize energy saving, simplification of facility and increase of productivity .

Hereinafter, the configuration and operation of the present invention will be described in more detail with reference to preferred embodiments of the present invention. It is to be understood, however, that the same is by way of illustration and example only and is not to be construed in a limiting sense.

The contents not described here are sufficiently technically inferior to those skilled in the art, and a description thereof will be omitted.

Example

The components used in the following Examples 1 to 5 and Comparative Examples 1 to 5 are as follows.

A: urethane resin,

B: acrylic resin,

C: silicate,

D: colloidal silica,

E: Inorganic compound,

F: Silane,

G: chelating agent (G-1: aromatic triazole, G-2: titanium coupling agent, G-3: ammonium phosphate)

H: Hardener (H-1: aziridine, H-2: melamine),

I: wetting agent,

J: Solvent

Example 1

15 wt% of a urethane resin, 8 wt% of an acrylic resin, 15 wt% of a silicate, 25 wt% of a colloidal silica, 3 wt% of an inorganic compound, 3 wt% of a silane, (0.5% by weight of aziridine and 0.5% by weight of melamine), 0.5% by weight of a wetting agent, 0.5% by weight of a solvent, and 2% by weight of a chelating agent (1% by weight of aromatic triazole, 0.5% by weight of titanium coupling agent and 0.5% 15% by weight, and the remainder pure water.

Then, the resin composition was applied to both sides of the steel sheet base material to form a zinc plating layer with a plating adhesion amount of 200 g / m < 2 >, and a resin composition having the composition shown in the following Table 1 was applied on both surfaces of the zinc plating layer to a thickness of 1.5 [ For 5 seconds to obtain a zinc-coated steel sheet specimen.

Examples 2 to 5

A zinc-coated steel sheet specimen was prepared in the same manner as in Example 1, except that the resin composition was completed in the content range shown in Table 1 below.

Comparative Examples 1 to 5

A zinc-coated steel sheet specimen was prepared in the same manner as in Example 1 except that the resin composition was completed in the content range shown in Table 2 below.

Example 1 Example 2 Example 3 Example 4 Example 5 A 15 10 12 18 20 B 8 5 6 7 10 C 15 10 20 17 18 D 25 20 25 26 21.5 E 3 One 2 4 3.5 F 3 One 4 2 3.5 G G-1 One 2 1.5 2.5 3 G-2 0.5 0.2 0.6 0.7 One G-3 0.5 One 0.7 0.2 0.6 H H-1 0.5 0.7 0.6 0.9 One H-2 0.5 One 0.8 0.7 0.9 I 0.5 0.2 0.8 0.6 One J 15 10 16 14 11 pure 12.5 37.9 10 6.4 5 Total content 100 100 100 100 100

(Component:% by weight)

Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 A 5 12 9 0 28 B 12 0 5 26 27 C 19 13 0 17 18 D 0 12 19 26 0 E 15 One 0 4 0 F 19 3.2 25 0.1 3.5 G G-1 One 6 19 2.8 3 G-2 0 0.2 5 1.2 One G-3 0.5 One 0 0.4 0.6 H H-1 0.1 0.7 0.5 0.1 One H-2 0.5 One 5 1.2 0.9 I 0.4 2 2.1 0.8 One J 15 10 0.4 14 11 pure 12.5 37.9 10 6.4 5 Total content 100 100 100 100 100

(Component:% by weight)

Property evaluation

Test Example

Table 3 shows properties of the steel plate specimens according to Examples 1 to 5 and Comparative Examples 1 to 5, such as corrosion resistance, lubricity, heat resistance, workability, adhesion and weldability, as described below.

(1) Corrosion resistance

The corrosion resistance was evaluated by a 5%, 35 NaCl salt spray test according to KS D 9502 (ASTM B-117), cut-edge cut method. At this time, the salt concentration was 5% NaCl (50 g / L) and the pH was 6.5 ~ 7.2 (sprayed solution). The salt water and the ambient temperature were 35 ± 2 ° C and deionized water was used. The specimens were covered with only the top surface and the edges were not covered, and the corrosion depth after 120 hours was measured.

The evaluation criteria are as follows.

Very good (◎): less than 5%

Excellent (○): area of occurrence of white rye more than 10% ~ less than 15%

Normal (△): White rust occurrence area 15% to less than 20%

Defective (X): Ryegrass area 20% or more

(2) Lubrication

The lubricity evaluation was carried out according to a conventional friction coefficient measurement method, and the blackening or whitening phenomenon of the friction surface (allowable value: 1.54 or less within 1.5) was observed.

Very good (◎): Excellent lubricity

Excellent (○): Good lubricity

Normal (△): Lubrication Normal

Defect (X): Decrease in lubricity due to friction

(3) Heat resistance

After holding for 24 hours in an oven at 250 ℃, the color change was observed and evaluated.

Very good (◎): Excellent heat resistance

Excellent (○): Excellent heat resistance

Normal (△): Heat resistance Usually

Poor (X): Poor heat resistance

(4) Processability

The T-bending test was performed to evaluate the workability, and whether or not the resin peeling occurred at a bending radius of 0 mm was evaluated as follows.

Very good (◎): No peeling

Excellent (O): Almost no peeling

Normal (△): Peeling Normal

Defective (X): Severe peeling

(5) Adhesion

When the peeled area is 50% or more, it is classified as grade 3 (normal). When the peeled area is less than 25%, the grade is 2 (excellent). When the peeled area is less than 5% (Very good).

Very good (◎): Very good adhesion

Excellent (O): Good adhesion

Normal (△): Adhesion Usually

Bad (X): poor adhesion

(6) Weldability

Weldability was evaluated as poor and good, depending on the degree of spark generation during welding and the physical properties of the welded part.

Very good (◎): Excellent weldability

Excellent (O): Good weldability

Normal (△): Weldability Usually

Poor (X): Poor weldability

Corrosion resistance Lubricity Heat resistance Processability Adhesiveness Weldability Example 1 ◎ ◎ ○ ◎ ◎ ◎ Example 2 ◎ ○ ◎ ○ ◎ ○ Example 3 ○ ◎ ○ ◎ ◎ ◎ Example 4 ○ ○ ◎ ◎ ○ ○ Example 5 ◎ ○ ◎ ◎ ◎ ◎ Comparative Example 1 ○ ○ X ○ △ △ Comparative Example 2 X ○ △ ○ ○ ○ Comparative Example 3 △ X ○ △ X △ Comparative Example 4 X △ △ X △ X Comparative Example 5 △ △ △ X △ △

Results of physical property evaluation

As in Comparative Examples 1 to 5, when the component elements of the resin composition of the present invention were not included or included in a trace amount or an excessive amount, the results for corrosion resistance, lubricity, heat resistance, workability, &Lt; / RTI > This is particularly because, when the urethane resin and the acrylic resin, which are the polymer resin groups of the resin composition, are included in a larger amount, the binding of the polymeric binder is broken and the coating site is discolored.

On the other hand, as in Examples 1 to 5, when each component of the resin composition of the present invention was maintained at a proper value to produce a zinc-plated steel sheet after the resin composition was formed, , Corrosion resistance, lubricity, heat resistance, workability, adhesion and the like are obtained. This is because the coating can be stably maintained at a high temperature by adding a large amount of the inorganic additive among the components of the resin composition, as in the present invention, resulting in improved adhesion and durability.

Therefore, through the above experimental results, it can be seen that the zinc-plated steel sheet comprising the resin composition according to the present invention has excellent corrosion resistance without containing chromium, improves the processing characteristics in the press working, and maintains wear resistance even after the lubricant is added It can be understood that there is an excellent effect.

The zinc-coated steel sheet and the manufacturing method thereof according to the present invention are excellent in corrosion resistance without containing chromium and exhibit excellent heat resistance due to no discoloration at the time of exposure to a coating at a high temperature and have excellent lubricity in the production of steel sheet, And it is possible to realize properties such as excellent corrosion resistance, lubricity and heat resistance even when heated and dried under low temperature conditions within a few seconds, and to realize energy saving, facility simplification and productivity increase effect.

While the invention has been shown and described with reference to certain preferred embodiments thereof, it will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims. This is possible.

Therefore, the scope of the present invention should not be limited by the described embodiments, but should be determined by the scope of the appended claims as well as the appended claims.

110 Steel plate base material 130 Zinc plated layer
150 resin coating layer

Claims

Steel plate base material;
A zinc plated layer formed on the steel plate base material; And
A resin coating layer formed on the zinc plating layer;
/ RTI >
The resin coating layer is formed of a dried product of the resin composition,
The resin composition may comprise a urethane-based resin; Acrylic resin; Silicates; Silica; Inorganic compounds; Silane; Chelating agents; Curing agent; Wetting agents; A solvent, and a pure water.

The method according to claim 1,
The inorganic compound may be selected from the group consisting of silicon oxide (SiO2), aluminum oxide (Al2O3), calcium oxide (CaO), potassium oxide (K2O), magnesium oxide (MgO), sodium oxide (Na2O) and titanium oxide And at least one selected from the group consisting of zinc oxide and zinc oxide are included singly or in combination.

The method according to claim 1,
The chelating agent may be selected from the group consisting of aromatic triazole; A titanium coupling agent, and an ammonium phosphate, either singly or in combination.

The method according to claim 1,
Wherein the curing agent comprises at least one of aziridine and melamine, either singly or in combination.

The method according to claim 1,
In the resin composition,
10 to 20% by weight of urethane-based resin;
5 to 10% by weight of an acrylic resin;
10 to 25% by weight silicate;
20 to 30% by weight of silica;
1 to 5% by weight of an inorganic compound;
1 to 5% by weight silane;
0.2 to 5 wt% chelating agent;
0.5 to 2% by weight of a hardener;
0.2 to 1% by weight wetting agent; And
10 to 20 wt% solvent; And
Pure water;
Wherein the zinc-coated steel sheet is a zinc-coated steel sheet.

The method according to claim 1,
Wherein the resin coating layer has a layer thickness of 0.5 to 2.5 占 퐉.

Forming a zinc plated layer on the surface of the steel sheet base material;
Forming a resin composition; And,
Coating the resin composition on the zinc plated layer and then heating and drying to form a resin coating layer;
Lt; / RTI >
Wherein the resin composition comprises a urethane-based resin; Acrylic resin; Silicates; Silica; Inorganic compounds; Silane; Chelating agents; Curing agent; Wetting agents; A solvent, and a remainder pure water.

8. The method of claim 7,
The method for producing a galvanized steel sheet according to claim 1, wherein the heat drying is performed at a temperature of 180 to 230 DEG C at a peak dry temperature (PMT).