Title of Invention: Surface Treatment Solution Composition Containing Trivalent Chromium and Inorganic Compounds, and Method for Manufacturing a Surface-treated Hot-dip Galvanized Steel Sheet
technical field
[One]
The present invention relates to a surface treatment solution composition containing high corrosion resistance trivalent chromium and an inorganic compound, and to a method for manufacturing a hot-dip galvanized steel sheet surface-treated using the composition.
background
[2]
The hot-dip plated material with a zinc (Zn) plating layer is widely used as a material for construction materials because of its excellent corrosion resistance due to the protective effect of the base iron by the sacrificial method. However, since the exposed surface of the hot-dip plated material is made of Zn, white rust, which is zinc oxide, is easily generated on the surface when exposed to a general corrosive environment, particularly, a wet atmosphere, thereby deteriorating the quality characteristics of the material. In addition, when the zinc plating material is exposed to a high temperature and high humidity environment, there is a problem that the blackening phenomenon in which the surface color changes to black easily occurs.
[3]
In order to solve this problem, conventionally, corrosion resistance and blackening resistance have been secured by performing hexavalent chromium or chromate treatment on a plated steel sheet. However, as such hexavalent chromium is designated as a hazardous environmental material, regulations on the use of hexavalent chromium are currently being strengthened. Moreover, when hexavalent chromium is used as a surface treatment agent for hot-dip galvanized steel sheet, there have been problems such as the surface of the steel sheet turning black or the occurrence of black spots.
[4]
Therefore, recently, in order to solve the environmental hazard problem of hexavalent chromium, a method for securing corrosion resistance and blackening resistance of a galvanized steel sheet by coating a surface treatment solution composition containing trivalent chromium on a steel sheet has been applied. For example, in Korean Patent Laid-Open Publication Nos. 2006-0123628, 2005-0052215, and 2009-0024450, corrosion resistance and blackening are secured by immersing a steel sheet in a composition containing trivalent chromium and chemical conversion treatment, and However, the immersion time is long to be applied to the continuous process of steel mills, and the chemical conversion treatment method has problems such as lowering of anti-fingerprint properties.
[5]
In addition, in Korean Patent Laid-Open No. 2004-0046347 and Japanese Patent Laid-Open No. 2002-069660, a composition containing trivalent chromium is coated on a plated steel sheet by spray or roll coater method, so that it can be applied to the continuous process of steel mills and has anti-fingerprint properties. it is possible to obtain However, since the composition contains a porous silica component, it is not suitable for Mg and Al alloys, which cause severe discoloration in a wet atmosphere. Since the porous silica has a strong moisture absorption property, there is a problem of causing rapid discoloration in Mg, Al, and Zn alloy steel sheets.
DETAILED DESCRIPTION OF THE INVENTION
technical challenge
[6]
One aspect of the present invention is to provide a surface treatment solution composition that does not contain hexavalent chromium, which is a harmful environmental substance, and contains trivalent chromium and inorganic compounds harmless to the human body as main components.
[7]
Another aspect of the present invention is a hot-dip galvanized steel sheet surface-treated with trivalent chromium and inorganic compounds having excellent corrosion resistance, blackening resistance, crude oil reactivity and alkali resistance by applying the surface treatment solution composition of the present invention to the surface of the hot-dip galvanized steel sheet. is to provide
[8]
Another aspect of the present invention is to provide a method for manufacturing a surface-treated hot-dip galvanized steel sheet using the surface treatment solution composition of the present invention.
means of solving the problem
[9]
An aspect of the present invention is 30 to 51 wt% of a trivalent chromium compound comprising chromium phosphate (A) and chromium nitrate (B), and the content ratio A/(A+B) satisfies 0.3 to 0.6; 5-15 wt% of a silane coupling agent; 0.2 to 3 wt% of a vanadium-based anti-corrosion agent; 3-12 wt% colloidal silica; 0.5-5% by weight of polysiloxane copolymer; And it provides a surface treatment solution composition comprising 14 to 61.3% by weight of water.
[10]
Another aspect of the present invention is a steel plate; a hot-dip galvanized layer formed on at least one surface of the steel sheet; and a trivalent chromate coating layer formed on the hot-dip galvanizing layer, wherein the trivalent chromate coating layer includes chromium phosphate (A) and chromium nitrate (B), and a content ratio A/(A+B) thereof is 0.89 37.7-58.1 wt% of a trivalent chromium compound satisfying ~0.95; 34.6-40.7 wt% of a silane coupling agent; 1.4 to 8.2 wt% of a vanadium-based anti-corrosion agent; 4.2-6.6% by weight of colloidal silica; And it provides a surface-treated hot-dip galvanized steel sheet comprising 1.7 to 6.8% by weight of the polysiloxane copolymer.
[11]
Another aspect of the present invention comprises the steps of coating the surface treatment solution composition on a hot-dip galvanized steel sheet formed with a hot-dip galvanized layer; and drying the coated surface treatment solution composition to form a trivalent chromate coating layer.
Effects of the Invention
[12]
The hot-dip galvanized steel sheet treated with the surface treatment solution composition containing trivalent chromium and inorganic compounds according to the present invention has excellent corrosion resistance, blackening resistance, weldability, and alkali resistance.
Modes for carrying out the invention
[13]
Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. However, the embodiments of the present invention may be modified in various other forms, and the scope of the present invention is not limited to the embodiments described below.
[14]
The present invention relates to a surface treatment solution composition containing trivalent chromium, a hot-dip galvanized steel sheet surface-treated using the composition, and a method for manufacturing the hot-dip galvanized steel sheet.
[15]
The surface treatment solution composition according to an embodiment of the present invention contains 30 to 51% by weight of a trivalent chromium compound, 5 to 15% by weight of a silane coupling agent, 0.2 to 3% by weight of a vanadium-based anticorrosive agent, based on the total weight of the solution composition. , colloidal silica 3 to 12% by weight, polysiloxane copolymer 0.5 to 5% by weight, and water 14 to 61.3% by weight, wherein the trivalent chromium compound is chromium phosphate (A) and chromium nitrate (B), and the content ratio A/(A+B) satisfies 0.3~0.6.
[16]
The hot-dip galvanized steel sheet surface-treated with the surface treatment solution composition containing trivalent chromium according to the present invention has excellent corrosion resistance, blackening resistance, weldability, and alkali resistance. In addition, it does not contain hexavalent chromium, which is a harmful environmental substance, and contains trivalent chromium harmless to the human body as a main component, thereby preventing damage to the human body and problems of environmental pollution.
[17]
The trivalent chromium compound is a component included as a main component in the surface treatment solution composition of the present invention, has a self-healing effect and self-lubrication similar to hexavalent chromium, and has corrosion resistance and blackening resistance. it works The trivalent chromium compound included in the composition of the present invention includes chromium phosphate (A) and chromium nitrate (B).
[18]
As the ratio of chromium phosphate increases, corrosion resistance may be improved while blackening resistance may be inferior. On the other hand, while blackening resistance is improved as the proportion of chromium nitrate is increased, corrosion resistance may be inferior. Specifically, since the phosphoric acid component is not volatilized when the film is formed with the chromium phosphate, a chromium phosphate film is formed on the surface of the film to improve corrosion resistance, but blackening resistance may be reduced due to the moisture absorbing property of the chromium phosphate. On the other hand, when the chromium nitrate film is formed, most of the nitrate component is volatilized and does not affect the blackening resistance, but as the content of chromium nitrate increases, it is difficult to form a chromium phosphate film on the surface of the film relatively, so corrosion resistance may be deteriorated.
[19]
Therefore, according to an embodiment of the present invention, the content of each component is controlled so that the content ratio A/(A+B) of the chromium phosphate (A) and chromium nitrate (B) satisfies 0.3 to 0.6. If the content ratio is less than 0.3, corrosion resistance after processing may be reduced, and if it exceeds 0.6, blackening resistance may be reduced.
[20]
The total content of the trivalent chromium compound including chromium phosphate (A) and chromium nitrate (B) is 30 to 51 wt%, preferably 35 to 45 wt%. If the content of the trivalent chromium compound is less than 30% by weight, the solid insoluble film layer becomes thin, and thus it cannot effectively block water penetration on the surface of the plated steel sheet requiring corrosion resistance, causing blackening, and corrosion resistance is also reduced. On the other hand, when the content of the trivalent chromium compound exceeds 51% by weight, the content of the vanadium-based anticorrosive agent, colloidal silica, and the silane coupling agent serving as a binder added to improve corrosion resistance is relatively reduced, resulting in sufficient corrosion resistance and blackening resistance. There is a problem that it is difficult to secure.
[21]
The silane coupling agent serves to crosslink the inorganic component and the organic component, thereby promoting drying and securing high corrosion resistance. The type of the silane coupling agent is not particularly limited, but for example, 2-(3,4epoxycyclohexyl)-ethyltrimethoxysilane, 3-glycyloxypropyl trimethoxysilane, 3-glycyloxypropyl Methyldiethoxysilane, 3-glycyloxypropyl triethoxysilane, N-2-(aminoethyl)-3-aminopropyl methyldimethoxysilane, N-2-(aminoethyl)-3-aminopropyl trimethoxy Silane, N-2-(aminoethyl)-3-aminopropyl triethoxysilane, 3-aminopropyl trimethoxy silane, 3-aminopropyl triethoxy silane, 3-ureido propyltrimethoxy silane, and tetra At least one selected from the group consisting of ethyl orthosilicate is preferable.
[22]
The content of the silane coupling agent is 5 to 15% by weight, preferably 7 to 12% by weight. When the content of the silane coupling agent is less than 5% by weight, alkali resistance and fuel resistance are inferior, and when it exceeds 15% by weight, the dryness of the film is increased to form an excessively hard film, and the corrosion resistance of the processing part is inferior.
[23]
The vanadium-based anticorrosive agent is included to improve the corrosion resistance of the plated steel sheet by forming a passivation film on the surface of the hot-dip galvanized steel sheet surface-treated with the surface treatment solution composition of the present invention. For this reason, when the film of the hot-dip galvanized steel sheet is damaged, tetravalent vanadium in the adjacent film is eluted and reduced to trivalent, and a passivation film is formed on the exposed plating surface to suppress corrosion. In addition, vanadium is preferentially eluted under a corrosive environment, thereby suppressing an increase in pH due to dissolution of the plating component, thereby improving the corrosion resistance of the hot-dip galvanized steel sheet. In addition, the vanadium-based anticorrosive agent may have an effect of improving the blackening resistance of the plating layer by preventing the blackening of the surface of the plating layer due to the formation of odd electron ions of zinc.
[24]
Vanadium pentoxide (V 2 O 5 ), metavanadic acid (HVO 3 ), ammonium metavanadate, sodium metavanadate, vanadium oxytrichloride (VOCl 3 ) vanadium trioxide (V 2 O 3 ), vanadium dioxide (VO 2 ), vanadium oxysulfate (VOSO 4 ), vanadium oxyoxalate [VO(COO) 2 ], vanadium oxyacetylacetonate [VO(OC(CH 3 )=CHCOCH 3 )) 2 ], vanadium acetylacetonate [V (OC (CH 3 ) = CHCOCH 3 )) 3 ], vanadium trichloride (VCl 3 ), vanadium sulfate (VSO 4 and 8H 2 O), vanadium dichloride (VCl 2 ), and vanadium oxide (VO) may be at least one selected from the group consisting of.
[25]
The content of the vanadium-based anticorrosive agent is 0.2 to 3% by weight, preferably 0.5 to 2% by weight. If the content of the anticorrosive agent is less than 0.2% by weight, there is a problem in that it is difficult to secure corrosion resistance, and when it exceeds 3% by weight, there is a problem in that it is difficult to secure blackening resistance and alkali resistance.
[26]
The colloidal silica forms a bond with the trivalent chromium compound and inorganic silica to strengthen the compactness of the film to prevent the penetration of corrosion factors, thereby improving the corrosion resistance of the hot-dip galvanized steel sheet surface-treated with the surface treatment solution composition of the present invention there is The colloidal silica may have a particle size of 5 to 15 nm and may be dispersed in an acidic aqueous solution having a pH of 3 to 5. At this time, when the particle size of the colloidal silica exceeds 15 nm, a problem of lowering solution stability may occur during the water dispersion process. As a result, it may cause a problem of deterioration of machinability. In addition, when the particle size of the colloidal silica is less than 5 nm, there may be a problem in securing corrosion resistance by blocking corrosion factors. Furthermore, when the pH of the acidic solution in which the colloidal silica is dispersed in water is out of the range of 3 to 5, there is a problem in that solution stability is also deteriorated due to precipitation of the dispersed silica particles.
[27]
The colloidal silica is stably dispersed in a liquid such as water or an organic solvent in a state in which solid silica particles are not precipitated and agglomerated, and the type is not limited, but Ludox HAS (snowtex-O) is preferably used. can
[28]
The content of the colloidal silica is 3 to 12% by weight, preferably 5 to 10% by weight. If the content of the colloidal silica is less than 3% by weight, the corrosion resistance of the processed part is inferior, and if it exceeds 12% by weight, there is a problem in that the blackening resistance is lowered due to the increase in hygroscopicity of the film.
[29]
The polysiloxane copolymer forms a dense film on the surface of hot-dip galvanized steel sheet surface-treated with the surface treatment solution composition of the present invention through organic-mechanical bonding, and improves the corrosion resistance of flat plates and processed parts by imparting flexibility to the film. . In addition, it prevents the penetration of corrosion factors to improve the blackening resistance of the hot-dip galvanized steel sheet, and is effective in improving workability by giving a flexible film property.
[30]
The polysiloxane copolymer may include at least one siloxane compound selected from the group consisting of polydimethylsiloxane, polyvinylsiloxane, polyphenylmethylsiloxane, hexamethylsilonic acid, and the like; and methyltrimethoxysilane, ethyltrimethoxysilane, hexamethyldisilane, triethylethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, gammaglycidoxytriethylsilane, gammaglycidoxytrimethylsilane It may include at least one component of one or more silane compounds selected from the group consisting of.
[31]
In addition, the polysiloxane copolymer is preferably synthesized in the presence of at least one acid catalyst selected from the group consisting of phosphoric acid and organophosphoric acid, oxalic acid, citric acid, and formic acid by using the siloxane compound and/or silane compound, and A copolymer having a weight average molecular weight of 300 to 1500, more preferably a copolymer having a weight average molecular weight of 650 to 750. If the weight average molecular weight of the polysiloxane copolymer is less than 300, a film may not be stably formed during the film drying process, and thus corrosion resistance may be deteriorated.
[32]
The content of the polysiloxane copolymer is 0.5 to 5% by weight, preferably 1.0 to 4.5% by weight. If the content of the polysiloxane copolymer is less than 0.5 wt%, corrosion resistance, blackening resistance, and workability of the processing part are inferior, and if it exceeds 5 wt%, alkali resistance is deteriorated.
[33]
The water is a solvent of the surface treatment solution composition of the present invention, and is used to dilute the components of the surface treatment solution composition. The water may be, for example, deionized water or distilled water. The solvent is included as the remainder in addition to each component of the present invention, and the content thereof is, for example, preferably 14 to 61.3% by weight.
[34]
According to another embodiment of the present invention, there is provided a hot-dip galvanized steel sheet surface-treated with the above-described trivalent chromium-containing surface treatment solution composition and a method for manufacturing the same.
[35]
Specifically, the surface-treated hot-dip galvanized steel sheet includes a steel sheet, a zinc plating layer formed on at least one surface of the steel sheet, and a trivalent chromate coating layer formed on the zinc plating layer. In this case, the surface treatment solution composition of the present invention described above may be used as the trivalent chromate film layer, and more specifically, 37.7 to 58.1 wt% of a trivalent chromium compound, 34.6 to 40.7 wt% of a silane coupling agent, and a vanadium-based anticorrosive agent 1.4 to 8.2% by weight, 4.2 to 6.6% by weight of colloidal silica, and 1.7 to 6.8% by weight of a polysiloxane copolymer. Furthermore, the trivalent chromium compound includes chromium phosphate (A) and chromium nitrate (B), and the content ratio A/(A+B) satisfies 0.89 to 0.95.
[36]
The trivalent chromate coating layer is a coating layer obtained by drying the surface treatment solution composition described above, and corresponds to a component remaining after all the volatile substances included in the trivalent chromate coating layer are volatilized. For this reason, the said trivalent chromate film layer does not contain the water which is a solvent, and also contains the water contained in the trivalent chromate compound and a silane coupling agent. Accordingly, the component included in the trivalent chromate coating layer corresponds to a content based on 100% by weight of the total solid content of the trivalent chromate coating layer.
[37]
The trivalent chromium compound includes chromium phosphate (A) and chromium nitrate (B), and the content ratio A/(A+B) satisfies 0.89 to 0.95, and the content is the dried film layer on the plated steel sheet. Based on 37.7-58.1 wt%, preferably 44-51 wt%. When the content of the trivalent chromium compound is less than 37.7% by weight, the solid insoluble film layer becomes thin and does not effectively block moisture penetration on the surface of the plated steel sheet requiring corrosion resistance, thereby causing blackening, and corrosion resistance is also reduced. . On the other hand, when the content of the trivalent chromium compound exceeds 58.1% by weight, the content of the vanadium-based anticorrosive agent, colloidal silica, polysiloxane, and the silane coupling agent serving as a binder added to improve corrosion resistance is relatively reduced, resulting in sufficient corrosion resistance And there is a problem that it is difficult to secure blackening resistance.
[38]
In addition, the content ratio A/(A+B) of the chromium phosphate (A) and chromium nitrate (B) satisfies 0.89 to 0.95, and if the content ratio is less than 0.89, the corrosion resistance after processing may decrease, and exceeds 0.95 Doing so may reduce blackening resistance.
[39]
In the surface treatment solution composition, the content ratio A/(A+B) of chromium phosphate (A) to chromium nitrate (B) is 0.3 to 0.6. However, since the chromium phosphate and chromium nitrate contain a large amount of water, the water is removed in the process of forming the coating layer by coating-drying the surface treatment solution composition on the alloy galvanized steel sheet, thereby being included in the coating layer. The content ratio A/(A+B) of chromium phosphate (A) and chromium nitrate (B) is 0.89 to 0.95.
[40]
The content of the silane coupling agent is 34.6 to 40.7 wt%, preferably 38.7 to 40.7 wt%, based on the dried film layer on the plated steel sheet. If the content of the silane coupling agent is less than 34.6% by weight, alkali resistance and crude oil invasiveness are inferior, and when it exceeds 40.7% by weight, the dryness of the film increases and an excessively hard film is formed, so the corrosion resistance of the processing part becomes weak and fuel resistance become inferior
[41]
The content of the vanadium-based anticorrosive agent is 1.4 to 8.2% by weight, preferably 1.4 to 4.7% by weight, based on the dried film layer on the plated steel sheet. If the content of the anticorrosive agent is less than 1.4% by weight, it is difficult to secure corrosion resistance, and when it exceeds 8.2% by weight, it is difficult to secure blackening resistance and alkali resistance.
[42]
The content of the colloidal silica is 4.2 to 6.6 wt%, preferably 5.8 to 6.6 wt%, based on the dried film layer on the plated steel sheet. If the content of the colloidal silica is less than 4.2 wt%, there is a problem in that the corrosion resistance of the processed part is inferior, and if it exceeds 6.6 wt%, there is a problem in that the blackening resistance is lowered due to the increase in hygroscopicity of the film.
[43]
On the other hand, the content of the polysiloxane copolymer is 1.7 to 6.8 wt%, preferably 3.3 to 6.8 wt%, based on the dried film layer on the plated steel sheet. If the content of the polysiloxane copolymer is less than 1.7% by weight, there is a problem in that corrosion resistance, blackening resistance, and processability of the processing part are inferior, and when it exceeds 6.8% by weight, there is a problem in that alkali resistance is inferior.
[44]
According to an embodiment of the present invention, preparing a hot-dip galvanized steel sheet formed with a hot-dip galvanized layer; coating the surface treatment solution composition of the present invention on the hot-dip galvanizing layer; and drying the coated surface treatment solution composition to form a trivalent chromate coating layer.
[45]
The surface treatment solution composition includes 30 to 51 wt% of a trivalent chromium compound containing chromium phosphate (A) and chromium nitrate (B), and the content ratio A/(A+B) satisfies 0.3 to 0.6, silane 5 to 15% by weight of a coupling agent, 0.2 to 3% by weight of a vanadium-based anticorrosive agent, 3 to 12% by weight of colloidal silica, 0.5 to 5% by weight of a polysiloxane copolymer, and 14 to 61.3% by weight of water. The technical meanings of the content ranges of each component included in the surface treatment solution composition are as described above.
[46]
According to an embodiment of the present invention, the surface treatment solution composition may be applied to the plated steel sheet to a thickness of 2.14 to 3.57 μm. The surface treatment solution composition applied to this thickness may have a film layer thickness of 0.3 to 0.5 µm, preferably 0.3 to 0.4 µm, after drying through a drying process. If the coating thickness of the surface treatment solution composition is less than 2.14 μm, the surface treatment solution composition is thinly applied to the acid part of the roughness of the steel sheet, thereby reducing corrosion resistance. There may be problems with the lower back.
[47]
The method of coating the surface treatment solution composition is not particularly limited as long as it is a commonly performed coating method, but for example, roll coating, spraying, immersion, spray squeezing, and immersion squeezing It is performed by any one coating method selected from it is preferable
[48]
The process of drying the surface treatment solution composition coated on the hot-dip galvanized steel sheet is preferably performed at a temperature of 40 to 60° C. based on the final reached temperature (PMT) of the material steel sheet. If the drying temperature is less than 40 ℃ based on the final reaching temperature (PMT) of the material steel sheet, drying may not be done completely, so alkali resistance and crude oil penetration may be inferior. If it exceeds 60 ℃, the cooling process in air (air cooling) During the process, dew condensation may occur due to the steel sheet not being sufficiently cooled and being packed, resulting in poor blackening resistance of the steel sheet.
[49]
On the other hand, the drying is preferably carried out in a hot air drying furnace or an induction heating furnace. When drying the surface treatment coating composition using the hot air drying furnace, it is preferable that the internal temperature of the hot air drying furnace is 100 to 200 °C. On the other hand, when drying the surface treatment coating composition using the induction heating furnace, the current applied to the induction heating furnace is preferably 1000~3500A, more preferably 1500~3000A. If the internal temperature of the hot air drying furnace is less than 100 ° C. or the current applied to the induction heating furnace is less than 1000 A, the surface treatment coating composition is not completely dried, so that alkali resistance and crude oil penetrability may be inferior. In addition, when the internal temperature of the hot air drying furnace exceeds 200° C. or the current applied to the induction heating furnace exceeds 3500 A, during the cooling process in the air (air cooling), the steel sheet is not sufficiently cooled and is packaged, thereby dew condensation occurs. blackening resistance may be inferior.
[50]
In addition, after drying the surface treatment solution composition to form a trivalent chromate coating layer, the trivalent chromate coating layer is air-cooled to provide a finally surface-treated hot-dip galvanized steel sheet.
[51]
The method for manufacturing the hot-dip galvanized steel sheet according to an embodiment of the present invention may be a continuous process, and the speed of the continuous process is preferably 80 to 100 mpm. If the continuous process speed is less than 80 mpm, a problem of lowering productivity may occur, and if it exceeds 100 mpm, the solution may scatter in the process of drying the surface treatment solution composition, thereby causing surface defects.
[52]
Hereinafter, the present invention will be described in more detail through specific examples. The following examples are only examples to help the understanding of the present invention, and the scope of the present invention is not limited thereto.
[53]
Example
[54]
1. Changes in physical properties according to the content of trivalent chromium compounds
[55]
Chromium nitrate and chromium phosphate as trivalent chromium compounds in order to test the change of physical properties according to the content of each component of the surface treatment solution composition of the present invention; Vanadium acetylacetonate as a vanadium-based anti-corrosion agent; Ludox HAS (snowtex-O) as colloidal silica; a 1:1 mixture by weight of tetraethylorthosilicate and 3-glycyloxypropyl trimethoxysilane as a silane coupling agent; a polysiloxane copolymer having a weight average molecular weight of 650 synthesized using polyvinylsiloxane, vinyltrimethoxy silane as the polysiloxane copolymer, and phosphoric acid as an acid catalyst; And a surface treatment solution composition comprising water was prepared.
[56]
Meanwhile, in the following Examples, a case in which the surface treatment solution composition of the present invention satisfies the content range in Table 1 is described as an Example, and a case in which one or more components do not satisfy the content range in Table 1 below is used as a comparative example. described.
[57]
[Table 1]
division Solution component (wt%) Raw material solid content (% by weight) Ingredients after drying (wt%) Neutral content of dry film of the present invention (wt%)
Minimum maximum range of composition Ieast maximum Ieast maximum Ieast maximum
trivalent chromium compound 30 51 27.53 57.9213 38.163 58.1 37.7
Silane Coupling Agent 5 15 99 34.7149 40.3639 34.6 40.7
Vanadium-based anti-corrosion agent 0.2 3 100 1.4026 8.1543 1.4 8.2
colloidal silica 3 12 20 4.2079 6.5235 4.2 6.6
polysiloxane copolymer 0.5 5 50 1.7533 6.7953 1.7 6.8
water 61.3 14 0 0.0 0.0 0.0 0.0
Sum 100 100 - 100 100 100.0 100.0
[58]
The following experiment was conducted with the surface treatment solution composition having each component content according to Tables 2 to 8, and the content of each component described in Tables 2 to 8 below was described as "based on solid content". More specifically, the "solid content basis" means that water, which is a solvent included in the solution composition of the present invention, is removed in a dry film state, and water contained in a trivalent chromium compound and a silane coupling agent is removed in a dry film state. It is based on 100% of the solid content that appears due to this. Tables 2 to 8 below show the content (% by weight) measured when the solid content is converted to 100% by weight based on the case where the solid content is 14% by weight in the compositions prepared in Examples and Comparative Examples.
[59]
[Table 2]
division Composition composition (wt%) Plate corrosion resistance Machining part corrosion resistance blackening resistance
trivalent chromium compound Silane Coupling Agent Vanadium-based anti-corrosion agent colloidal silica polysiloxane copolymer
Comparative Example 1 37.0 40.7 8.2 6.6 7.5 X X X
Example 1 37.7 40.7 8.2 6.6 6.8 ○ ◎ ○
Example 2 44.0 39.0 6.5 5.5 5.0 ◎ ◎ ◎
Example 3 51.0 37.0 4.0 5.0 3.0 ◎ ◎ ◎
Example 4 58.1 34.6 1.4 4.2 1.7 ○ ◎ ○
Comparative Example 2 59.0 34.6 1.4 4.2 0.8 X X ○
[60]
In order to measure the change in physical properties according to the content of each component, the hot-dip galvanized steel sheet was cut to 7 cm X 15 cm (width X length) to remove oil, and then the trivalent chromium prepared in Table 2 was made to have a dry film layer thickness of 0.4 μm. The surface treatment solution composition was coated with a bar (BAR) and dried under the conditions of PMT 60° C. to prepare a specimen. Plate corrosion resistance, corrosion resistance of the processed part, and blackening resistance of the prepared specimen were evaluated, and the evaluation results are shown in Table 2 above. described. The evaluation method of the flat plate corrosion resistance, processing part corrosion resistance, and blackening resistance is as follows.
[61]

[62]
Based on the method specified in ASTM B117, the white rust generation rate of the steel sheet over time after the specimen was treated was measured. In this case, the evaluation criteria are as follows.
[63]
◎: White rust generation time is 144 hours or more
[64]
○: White rust occurrence time is more than 96 hours and less than 144 hours
[65]
△: White rust generation time less than 55 hours and less than 96 hours
[66]
X: White rust occurrence time is less than 55 hours
[67]

[68]
After the specimen was pushed up to a height of 6 mm using an Erichsen tester, the degree of white rust generation was measured when 24 hours had elapsed. In this case, the evaluation criteria are as follows.
[69]
◎: Less than 5% of white rust after 48 hours
[70]
△: White rust occurrence 5% or more and less than 7% after 48 hours
[71]
X: More than 7% of white rust after 48 hours
[72]

[73]
The color change (color difference: ΔE) of the specimen before and after the test was observed by leaving the specimen at 50° C. and in a constant temperature and humidity chamber maintained at 95% relative humidity for 120 hours. In this case, the evaluation criteria are as follows.
[74]
◎: ΔE ≤ 2
[75]
○: 2 < ΔE ≤ 3
[76]
Δ: 3 < ΔE ≤ 4
[77]
X: ΔE > 4
[78]
As shown in Table 2, when the content of the trivalent chromium compound satisfies the content suggested by the present invention (Examples 1 to 4), all physical properties showed good or better results.
[79]
On the other hand, when too little trivalent chromium compound was added (Comparative Example 1), poor results were shown in plate corrosion resistance, processing part corrosion resistance, and blackening resistance. It showed poor results in physical properties.
[80]
2. Changes in physical properties according to the ratio of chromium (III) phosphate and chromium (III) nitrate contained in the trivalent chromium compound
[81]
The trivalent chromium surface treatment solution composition according to Example 3 was used, but the ratios of chromium (III) phosphate and chromium (III) nitrate were controlled to be the ratios of chromium phosphate and chromium nitrate shown in Table 3 below. Specifically, a chromium phosphate compound and chromium nitrate were added to distilled water, reacted at 80° C. for 1 hour, and then cooled to room temperature to prepare trivalent chromium compounds (chromium (III) phosphate and chromium (III) nitrate). At this time, the content of each component was controlled so that the ratio of chromium phosphate and chromium nitrate satisfies the ratios in Table 3 below.
[82]
[Table 3]
division Trivalent chromium compound (wt%) Content ratio of chromium phosphate and chromium nitrate (weight ratio) flat plate corrosion resistance blackening resistance
chromium phosphate chromium nitrate
Comparative Example 3 51.0 7 0 ○ X
Comparative Example 4 51.0 0 0.35 X ○
Comparative Example 5 51.0 One 0.3 X ○
Example 5 51.0 2 0.25 ○ ◎
Example 6 51.0 3 0.2 ◎ ◎
Example 7 51.0 4 0.2 ◎ ○
Comparative Example 6 51.0 5 0.1 ○ X
[83]
After cutting the hot-dip galvanized steel sheet to 7 cm X 15 cm (width X length) to remove oil, the trivalent chromium surface treatment solution composition prepared in Table 3 was bar-coated with a dry film layer thickness of 0.4 μm (BAR) to PMT 60 Specimens were manufactured by drying them under the conditions of ℃. The plate corrosion resistance and blackening resistance of the prepared specimens were evaluated, and the evaluation results are shown in Table 3 above. As shown in Table 3, corrosion resistance is improved as the chromium phosphate ratio increases, while blackening resistance tends to improve as the chromium nitrate ratio increases. However, when the ratio of chromium phosphate to chromium nitrate shown in the present invention is less than or greater than the ratio, corrosion resistance or blackening resistance tends to be poor.
[84]
3. Changes in physical properties according to the content and type of the silane coupling agent
[85]
The surface treatment solution composition containing trivalent chromium of the present invention, chromium nitrate and chromium phosphate as trivalent chromium compounds; Vanadium acetylacetonate as a vanadium-based anti-corrosion agent; Ludox HAS (snowtex-O) as colloidal silica; a 1:1 mixture by weight of tetraethylorthosilicate and 3-glycyloxypropyl trimethoxysilane as a silane coupling agent; It contains a polysiloxane copolymer having a weight average molecular weight of 650 synthesized using polyvinylsiloxane, vinyltrimethoxysilane, and phosphoric acid as an acid catalyst as the polysiloxane copolymer, and based on the solid content of the composition, the content shown in Table 4 below mixed.
[86]
[Table 4]
division Composition composition (wt%) alkali resistance weldability flat plate corrosion resistance Machining part corrosion resistance blackening resistance
Silane Coupling Agent trivalent chromium compound Vanadium-based anti-corrosion agent colloidal silica polysiloxane copolymer
Comparative Example 7 34 45.4 8.0 6.6 6.0 X ○ ○ ◎ ○
Example 8 34.6 45.4 8.0 6.0 6.0 ○ ○ ◎ ◎ ○
Example 9 36.6 45.4 7.0 6.0 5.0 ○ ○ ◎ ◎ ◎
Example 10 38.7 45.4 7.0 5.0 3.9 ◎ ◎ ◎ ◎ ◎
Example 11 40.7 45.4 6.0 5.0 2.9 ◎ ◎ ◎ ◎ ○
Comparative Example 8 41 45.4 6.0 4.7 2.9 ○ △ ◎ X X
[87]
After cutting the hot-dip galvanized steel sheet to 7 cm X 15 cm (width X length) to remove oil, the trivalent chromium surface treatment solution composition prepared in Table 4 was bar-coated with a dry film layer thickness of 0.4 μm (BAR) to PMT 60 Specimens were prepared by drying them at a temperature of ℃. Plate corrosion resistance, corrosion resistance of processed parts, blackening resistance, alkali resistance, and weldability of the manufactured specimens were evaluated, and the evaluation results are shown in Table 4 above. The evaluation method of flat plate corrosion resistance, corrosion resistance of processing part, and blackening resistance is as described above, and the evaluation method of alkali resistance and weldability are as follows.
[88]

[89]
The specimen was immersed in an alkaline degreasing solution at 60° C. for 2 minutes, washed with water, and after air blowing, the color difference (ΔE) was measured. As the alkaline degreasing solution, Finecleaner L 4460 A: 20g/2.4L + L 4460 B 12g/2.4L (pH=12) manufactured by Daehan Parkerizing Co., Ltd. was used. In this case, the evaluation criteria are as follows.
[90]
◎: ΔE ≤ 2
[91]
○: 2 < ΔE ≤ 3
[92]
Δ: 3 < ΔE ≤ 4
[93]
X: ΔE > 4
[94]

[95]
Weldability was evaluated by using a pneumatic AC spot welding machine to maintain constant strength without spatter at 250 kg of pressing force and 15 cycles of welding time of 7.5 kA. At this time, evaluation criteria were presented in three modes: welding possible (○), impossible (X), and poor welding quality (Δ).
[96]
As shown in Table 4, when the content of the silane coupling agent satisfies the content suggested by the present invention (Examples 8 to 11), good (○) or higher results were obtained in all physical properties.
[97]
On the other hand, when too little of the silane coupling agent is added (Comparative Example 7), poor alkali resistance is obtained. It was weak and had poor blackening resistance and poor welding quality.
[98]
A trivalent chromium surface treatment solution composition according to Example 11 was prepared, and the silane coupling agent described in Table 5 below was used as the type of the silane coupling agent. As described above with the trivalent chromium surface treatment solution composition using the silane coupling agent shown in Table 5 below, the specimen was prepared by coating with a bar (BAR) and dried under the conditions of PMT 60° C., and plate corrosion resistance was evaluated, as a result is shown in Table 5.
[99]
[Table 5]
division A B C D E F G H I J K Plate corrosion resistance
content content content content content content content content content content content
Example 12 36.6 0 0 0 0 0 0 0 0 0 0 ○
Example 13 0 36.6 0 0 0 0 0 0 0 0 0 ◎
Example 14 0 0 36.6 0 0 0 0 0 0 0 0 ○
Example 15 0 0 0 36.6 0 0 0 0 0 0 0 ◎
Example 16 0 0 0 0 36.6 0 0 0 0 0 0 ○
Example 17 0 0 0 0 0 36.6 0 0 0 0 0 ◎
Example 18 0 0 0 0 0 0 36.6 0 0 0 0 ○
Example 19 0 0 0 0 0 0 0 36.6 0 0 0 ○
Example 20 0 0 0 0 0 0 0 0 36.6 0 0 ○
Example 21 0 0 0 0 0 0 0 0 0 36.6 0 ◎
Example 22 0 0 0 0 0 0 0 0 0 0 36.6 ○
Example 23 18.3 18.3 0 0 0 0 0 0 0 0 0 ○
Example 24 18.3 0 0 18.3 0 0 0 0 0 0 0 ○
Example 25 0 18.3 0 0 0 18.3 0 0 0 0 0 ◎
Example 26 0 0 0 18.3 0 18.3 0 0 0 0 0 ○
Example 27 0 0 0 0 18.3 0 18.3 0 0 0 0 ○
Example 28 0 0 0 0 0 18.3 0 0 0 18.3 0 ◎
Example 29 0 0 18.3 0 0 18.3 0 0 0 0 0 ○
Example 30 0 0 0 0 0 0 18.3 0 0 18.3 0 ○
Example 31 18.3 0 0 0 0 0 0 0 0 18.3 0 ○
Example 32 0 0 0 0 0 0 0 0 0 18.3 18.3 ○
Example 33 0 0 0 18.3 0 0 0 0 18.3 0 0 ○
Example 34 0 0 0 0 18.3 0 0 18.3 0 0 0 ○
Example 35 0 0 0 0 0 0 0 18.3 0 0 18.3 ○
Example 36 0 18.3 18.3 0 0 0 0 0 0 0 0 ◎
Example 37 0 0 18.3 0 0 0 0 0 0 0 18.3 ○
Example 38 0 0 0 0 0 0 18.3 0 18.3 0 0 ○
Example 39 0 0 0 0 18.3 0 0 0 18.3 0 0 ○
Example 40 0 18.3 0 18.3 0 0 0 0 0 0 0 ○
Example 41 0 18.3 0 0 0 0 0 0 0 0 18.3 ◎
Example 42 18.3 0 18.3 0 0 0 0 0 0 0 0 ○
Example 43 0 0 0 0 0 0 0 0 18.3 18.3 0 ○
Example 44 0 18.3 0 0 18.3 0 0 0 0 0 0 ○
Example 45 0 0 0 0 0 0 18.3 18.3 0 0 0 ○
A: 2-(3,4epoxycyclohexyl)-ethyltrimethoxysilane G: N-2-(aminoethyl)-3-aminopropyl triethoxysilane
B: 3-glycyloxypropyl trimethoxysilane H: 3-aminopropyl trimethoxy silane
C: 3-glycyloxypropyl methyldiethoxysilane I: 3-Aminopropyl triethoxy silane
D: 3-glycyloxypropyl triethoxysilane J: 3-Ureido propyltrimethoxy silane
E: N-2-(aminoethyl)-3-aminopropyl methyldimethoxysilane K: tetraethyl orthosilicate
F: N-2-(aminoethyl)-3-aminopropyl trimethoxysilane
[100]
As shown in Table 5, Examples 12 to 45 showed good or excellent plate corrosion resistance. In particular, in the case of the test specimen treated with the trivalent chromium surface treatment solution composition prepared according to the composition of Example 41, the white rust area generated after 144 hours or more was 0%, showing the best results.
[101]
4. Changes in physical properties according to the content of vanadium-based anticorrosive agents
[102]
The surface treatment solution composition containing trivalent chromium of the present invention, chromium nitrate and chromium phosphate as trivalent chromium compounds; Vanadium acetylacetonate as a vanadium-based anti-corrosion agent; Ludox HAS (snowtex-O) as colloidal silica; a 1:1 mixture by weight of tetraethylorthosilicate and 3-glycyloxypropyl trimethoxysilane as a silane coupling agent; A polysiloxane copolymer having a weight average molecular weight of 650 synthesized using polyvinylsiloxane, vinyltrimethoxy silane, and phosphoric acid as an acid catalyst was included as the polysiloxane copolymer, and the contents described in Table 6 below (based on the solid content of the composition) were mixed.
[103]
[Table 6]
division Composition composition (wt%) flat plate corrosion resistance Machining part corrosion resistance blackening resistance alkali resistance
Vanadium-based anti-corrosion agent trivalent chromium compound Silane Coupling Agent colloidal silica polysiloxane copolymer
Comparative Example 9 One 50 37 6 6 X X ◎ ◎
Example 46 1.4 50 36.6 6 6 ○ ◎ ◎ ◎
Example 47 4.7 49 36.6 5 4.7 ○ ◎ ◎ ◎
Example 48 8.2 49 35 5 2.8 ◎ ◎ ○ ○
Comparative Example 10 8.5 49 35 5 2.5 ◎ ◎ ○ X
Comparative Example 11 9 48 35 5 3 ◎ ◎ X X
[104]
After cutting the hot-dip galvanized steel sheet to 7 cm X 15 cm (width X length) to remove oil, the trivalent chromium surface treatment solution composition prepared in Table 6 was bar-coated with a dry film layer thickness of 0.4 μm (BAR) to PMT 60 Specimens were prepared by drying them under the conditions of ℃. Plate corrosion resistance, corrosion resistance of the processed part, blackening resistance, and alkali resistance of the prepared specimens were evaluated, and the evaluation results are shown in Table 6 above. The evaluation method of the flat plate corrosion resistance, the processing part corrosion resistance, blackening resistance, and alkali resistance is as described above. As shown in Table 6, when the content of the anticorrosive agent satisfies the content suggested by the present invention (Examples 46 to 48), the results of better than good in all physical properties were obtained by BAR-coating to obtain a PMT of 60°C. Specimens were prepared by drying under the conditions. Plate corrosion resistance, corrosion resistance of processed parts, blackening resistance, and alkali resistance of the prepared specimens were evaluated, and the evaluation results are shown in Table 6 above. The evaluation method of the flat plate corrosion resistance, the processing part corrosion resistance, blackening resistance, and alkali resistance is as described above. As shown in Table 6 above, when the content of the anticorrosive agent satisfies the content suggested by the present invention (Examples 46 to 48), the results were better than good in all physical properties.
[105]
On the other hand, when too little of the anticorrosive agent was added (Comparative Example 9), poor results were obtained in all physical properties except for blackening resistance and alkali resistance, and when too much was added (Comparative Examples 10 and 11), all properties except corrosion resistance were observed. It showed poor results in physical properties.
[106]
5. Changes in physical properties according to the content of colloidal silica
[107]
The surface treatment solution composition containing trivalent chromium of the present invention, chromium nitrate and chromium phosphate as trivalent chromium compounds; Vanadium acetylacetonate as a vanadium-based anti-corrosion agent; Ludox HAS (snowtex-O) as colloidal silica; a 1:1 mixture by weight of tetraethylorthosilicate and 3-glycyloxypropyl trimethoxysilane as a silane coupling agent; A polysiloxane copolymer having a weight average molecular weight of 650 synthesized using polyvinylsiloxane, vinyltrimethoxy silane, and phosphoric acid as an acid catalyst was included as the polysiloxane copolymer, and the content described in Table 7 below (based on the solid content of the composition) was mixed.
[108]
[Table 7]
division Composition composition (wt%) flat plate corrosion resistance Machining part corrosion resistance blackening resistance
colloidal silica trivalent chromium compound Silane Coupling Agent Vanadium-based anti-corrosion agent polysiloxane copolymer
Comparative Example 12 4 48 36 7 5 X X ◎
Example 49 4.2 48 36 7 4.8 ○ ○ ◎
Example 50 5 48 36 6 5 ○ ○ ○
Example 51 5.8 48 36 6 4.2 ○ ◎ ○
Example 52 6.6 48 36 6 3.4 ○ ◎ ○
Comparative Example 13 7 48 35.5 6 3.5 ○ ◎ X
[109]
After the hot-dip galvanized steel sheet was cut to 7 cm X 15 cm (width X length) to remove oil, the trivalent chromium surface treatment solution composition prepared in Table 7 was bar-coated with a dry film layer thickness of 0.4 μm (BAR) to PMT 60 Specimens were manufactured by drying them under the conditions of ℃. The plate corrosion resistance, corrosion resistance of the processed part, and blackening resistance of the prepared specimens were evaluated, and the evaluation results are shown in Table 7 above. As shown in Table 7, when the content of the anticorrosive agent satisfies the content suggested by the present invention (Examples 49 to 52), the results were better than good in all physical properties.
[110]
On the other hand, when too little of the anticorrosive agent was added (Comparative Example 12), the result showed poor blackening resistance, and when too much was added (Comparative Example 13), the corrosion resistance was poor.
[111]
6. Changes in physical properties according to the content of polysiloxane copolymer
[112]
The surface treatment solution composition containing trivalent chromium of the present invention, chromium nitrate and chromium phosphate as trivalent chromium compounds; Vanadium acetylacetonate as a vanadium-based anti-corrosion agent; Ludox HAS (snowtex-O) as colloidal silica; a 1:1 mixture by weight of tetraethylorthosilicate and 3-glycyloxypropyl trimethoxysilane as a silane coupling agent; A polysiloxane copolymer having a weight average molecular weight of 650 synthesized using polyvinylsiloxane, vinyltrimethoxy silane, and phosphoric acid as an acid catalyst was included as the polysiloxane copolymer, and the content described in Table 8 below (based on the solid content of the composition) was mixed.
[113]
[Table 8]
division Composition composition (wt%) Plate corrosion resistance Machining part corrosion resistance blackening resistance alkali resistance
polysiloxane copolymer trivalent chromium compound Silane Coupling Agent Vanadium-based anti-corrosion agent colloidal silica
Comparative Example 14 1.0 50.0 36.0 7.0 6.0 X X X ○
Example 53 1.7 50.0 36.0 7.0 5.3 ○ ○ ○ ○
Example 54 3.3 50.0 36.0 6.0 4.7 ○ ○ ◎ ○
Example 55 4.9 50.0 35.0 6.0 4.1 ○ ◎ ◎ ○
Example 56 6.8 49.0 35.0 6.0 3.2 ○ ◎ ○ ○
Comparative Example 15 7.5 48.0 35.0 6.0 3.5 ○ ◎ ○ X
[114]
After cutting the hot-dip galvanized steel sheet to 7cm X 15cm (width X length) to remove oil, the trivalent chromium surface treatment solution composition prepared in Table 8 was bar-coated with a dry film layer thickness of 0.4㎛ to PMT 60 Specimens were prepared by drying under the conditions of ℃. As shown in Table 8 above, when the content of the polysiloxane copolymer satisfies the content suggested by the present invention (Examples 53 to 56), results of better than good in all physical properties were obtained. seemed On the other hand, when too little of the anticorrosive agent is added (Comparative Example 14), the plate corrosion resistance, the corrosion resistance of the processing part, and the blackening resistance were poor results, and when too much was added (Comparative Example 15), the alkali resistance was poor. seemed
[115]
7. Changes in physical properties according to film thickness and drying temperature
[116]
After cutting the hot-dip galvanized steel sheet to 7cm X 15cm (width X length) to remove oil, the composition of Example 2 (the component of the silane coupling agent is based on Example 41) was BAR-coated and dried in a hot air furnace. The specimens were prepared by drying. The thickness of the coated film layer and the PMT temperature were controlled to the thicknesses shown in Table 9 below.
[117]
Alkali resistance, weldability, plate corrosion resistance, processing part corrosion resistance, and blackening resistance of the prepared specimens were evaluated, and the evaluation results are summarized in Table 9 below.
[118]
[Table 9]
division Film layer thickness (㎛) Drying temperature (℃) alkali resistance weldability flat plate corrosion resistance Machining part corrosion resistance blackening resistance
Comparative Example 16 0.1 50 △ ◎ △ X △
Example 57 0.3 50 ◎ ◎ ◎ ◎ ◎
Example 58 0.4 50 ◎ ◎ ◎ ◎ ◎
Example 59 0.5 40 ◎ ◎ ◎ ◎ ○
Comparative Example 17 0.8 50 ◎ △ ◎ ◎ ○
Example 60 0.4 30 △ ◎ ○ ○ ○
Example 61 0.4 60 ◎ ◎ ◎ ◎ ◎
Example 62 0.4 70 ◎ ◎ ◎ ◎ △
[119]
As shown in Table 8, when the film layer was formed with a thickness of 0.3 to 0.5 µm (Examples 57 to 59), the results were better than good in all physical properties. On the other hand, when the formed film was too thin (Comparative Example 16), the results were average (Δ) in all physical properties except for weldability, and the corrosion resistance of the processed part showed poor results. On the other hand, when it is formed too thickly (Comparative Example 17), all physical property results except for weldability show good or better results. I have this bad problem. In addition, as shown in Table 9, when the film layer was formed at a drying temperature of 40 to 60° C. (Examples 57 to 59 and 61), all physical properties showed better than good results.
[120]
On the other hand, when the drying temperature was too low (Example 60), sufficient drying was not performed, and the alkali resistance showed normal (Δ) results. On the other hand, when the drying temperature was too high (Example 62), the blackening resistance due to dew condensation was normal (Δ) because the steel sheet was not cooled sufficiently during the cooling process in air (air cooling).
[121]
Although the embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and variations are possible within the scope without departing from the technical spirit of the present invention described in the claims. It will be apparent to those of ordinary skill in the art.
Claims
[Claim 1]
30 to 51% by weight of a trivalent chromium compound containing chromium phosphate (A) and chromium nitrate (B), wherein the content ratio A/(A+B) satisfies 0.3 to 0.6; 5-15 wt% of a silane coupling agent; 0.2 to 3 wt% of a vanadium-based anti-corrosion agent; 3-12 wt% colloidal silica; 0.5-5% by weight of polysiloxane copolymer; and 14 to 61.3% by weight of water.
[Claim 2]
The method of claim 1, wherein the silane coupling agent is 2-(3,4epoxycyclohexyl)-ethyltrimethoxysilane, 3-glycyloxypropyl trimethoxysilane, 3-glycyloxypropyl methyldiethoxysilane, 3-Glycyloxypropyl triethoxysilane, N-2-(aminoethyl)-3-aminopropyl methyldimethoxysilane, N-2-(aminoethyl)-3-aminopropyl trimethoxysilane, N-2 with -(aminoethyl)-3-aminopropyl triethoxysilane, 3-aminopropyl trimethoxy silane, 3-aminopropyl triethoxy silane, 3-ureido propyltrimethoxy silane, and tetraethylorthosilicate At least one surface treatment solution composition selected from the group consisting of.
[Claim 3]
The method of claim 1, wherein the vanadium-based anticorrosive agent is vanadium pentoxide (V 2 O 5 ), metavanadic acid (HVO 3 ), ammonium metavanadate, sodium metavanadate, vanadium oxytrichloride (VOCl 3 ) vanadium trioxide ( V 2 O 3 ), vanadium dioxide (VO 2 ), vanadium oxysulfate (VOSO 4 ), vanadium oxyoxalate [VO(COO) 2 ], vanadium oxyacetylacetonate [VO(OC(CH 3 )=CHCOCH 3 )) 2 ], vanadium acetylacetonate [V (OC (CH 3 ) = CHCOCH 3 )) 3 ], vanadium trichloride (VCl 3 ), vanadium sulfate (VSO 4 and 8H 2 O), vanadium dichloride (VCl 2 ) and vanadium oxide (VO) at least one surface treatment solution composition selected from the group consisting of.
[Claim 4]
The surface treatment solution composition of claim 1, wherein the colloidal silica has a particle size of 5 to 15 nm, and is dispersed in an acidic aqueous solution having a pH of 3 to 5.
[Claim 5]
According to claim 1, wherein the colloidal silica is Ludox HAS (snowtex-O), the surface treatment solution composition.
[Claim 6]
The surface treatment solution composition of claim 1, wherein the polysiloxane copolymer comprises at least one of a siloxane compound and a silane compound.
[Claim 7]
The surface treatment solution composition of claim 6, wherein the siloxane compound is at least one selected from the group consisting of polydimethylsiloxane, polyvinylsiloxane, polyphenylmethylsiloxane and hexamethylsilonic acid.
[Claim 8]
The method of claim 6, wherein the silane compound is methyltrimethoxysilane, ethyltrimethoxysilane, hexamethyldisilane, triethylethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, gamma glycidoxy tri At least one selected from the group consisting of ethylsilane and gamma glycidoxytrimethylsilane, a surface treatment solution composition.
[Claim 9]
The surface treatment solution composition according to claim 6, wherein the polysiloxane copolymer has a weight average molecular weight of 300 to 1500.
[Claim 10]
grater; a hot-dip galvanized layer formed on at least one surface of the steel sheet; and a trivalent chromate coating layer formed on the hot-dip galvanizing layer, wherein the trivalent chromate coating layer includes chromium phosphate (A) and chromium nitrate (B), and a content ratio A/(A+B) thereof is 0.89 37.7-58.1 wt% of a trivalent chromium compound satisfying ~0.95; 34.6-40.7 wt% of a silane coupling agent; 1.4 to 8.2 wt% of a vanadium-based anti-corrosion agent; 4.2-6.6% by weight of colloidal silica; and a surface-treated hot-dip galvanized steel sheet comprising 1.7 to 6.8 wt% of a polysiloxane copolymer.
[Claim 11]
11. The method of claim 10, wherein the silane coupling agent is 2-(3,4epoxycyclohexyl)-ethyltrimethoxysilane, 3-glycyloxypropyl trimethoxysilane, 3-glycyloxypropyl methyldiethoxysilane, 3-Glycyloxypropyl triethoxysilane, N-2-(aminoethyl)-3-aminopropyl methyldimethoxysilane, N-2-(aminoethyl)-3-aminopropyl trimethoxysilane, N-2 with -(aminoethyl)-3-aminopropyl triethoxysilane, 3-aminopropyl trimethoxy silane, 3-aminopropyl triethoxy silane, 3-ureido propyltrimethoxy silane, and tetraethylorthosilicate One or more surface-treated hot-dip galvanized steel sheets selected from the group consisting of.
[Claim 12]
11. The method of claim 10, wherein the vanadium-based anti-corrosive agent is vanadium pentoxide (V 2 O 5 ), metavanadic acid (HVO 3 ), ammonium metavanadate, sodium metavanadate, vanadium oxytrichloride (VOCl 3 ) vanadium trioxide ( V 2 O 3 ), vanadium dioxide (VO 2 ), vanadium oxysulfate (VOSO 4 ), vanadium oxyoxalate [VO(COO) 2 ], vanadium oxyacetylacetonate [VO(OC(CH 3 )=CHCOCH 3 )) 2 ], vanadium acetylacetonate [V (OC (CH 3 ) = CHCOCH 3 )) 3 ], vanadium trichloride (VCl 3 ), vanadium sulfate (VSO 4 and 8H 2 O), vanadium dichloride (VCl 2 ) and vanadium oxide (VO) surface-treated at least one selected from the group consisting of hot-dip galvanized steel sheet.
[Claim 13]
The surface-treated hot-dip galvanized steel sheet according to claim 10, wherein the colloidal silica has a particle size of 5 to 15 nm.
[Claim 14]
The surface-treated hot-dip galvanized steel sheet according to claim 10, wherein the colloidal silica is Ludox HAS (snowtex-O).
[Claim 15]
The surface-treated hot-dip galvanized steel sheet according to claim 10, wherein the polysiloxane copolymer comprises at least one of a siloxane compound and a silane compound.
[Claim 16]
The surface-treated hot-dip galvanized steel sheet according to claim 15, wherein the siloxane compound is at least one selected from the group consisting of polydimethylsiloxane, polyvinylsiloxane, polyphenylmethylsiloxane and hexamethylsilonic acid.
[Claim 17]
16. The method of claim 15, wherein the silane compound is methyltrimethoxysilane, ethyltrimethoxysilane, hexamethyldisilane, triethylethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, gamma glycidoxy tri At least one surface-treated hot-dip galvanized steel sheet selected from the group consisting of ethylsilane and gamma glycidoxytrimethylsilane.
[Claim 18]
The surface-treated hot-dip galvanized steel sheet according to claim 15, wherein the polysiloxane copolymer has a weight average molecular weight of 300 to 1500.
[Claim 19]
The hot-dip galvanized steel sheet according to claim 10, wherein the trivalent chromate coating layer has a thickness of 0.3 to 0.5 μm.
[Claim 20]
10. A method comprising: coating the surface treatment solution composition of any one of claims 1 to 9 on a hot-dip galvanized steel sheet having a hot-dip galvanized layer formed thereon; and drying the coated surface treatment solution composition to form a trivalent chromate coating layer.
[Claim 21]
The method according to claim 20, wherein the coating of the surface treatment solution composition comprises coating to a thickness of 2.14 to 3.57 μm.
[Claim 22]
The method of claim 20, wherein the drying is performed at a temperature of 40 to 60° C. based on the final reaching temperature (PMT) of the raw material steel sheet.
[Claim 23]
The method of claim 20, wherein the drying is performed in a hot air drying furnace or an induction heating furnace.
[Claim 24]
The method of claim 23, wherein the hot-air drying furnace has an internal temperature of 100 to 200°C.
[Claim 25]
The method according to claim 23, wherein a current of 1000 to 3500 A is applied to the induction heating furnace.
[Claim 26]
The method of claim 20, further comprising air-cooling the trivalent chromate coating layer.
[Claim 27]
The method according to claim 20, wherein the method for manufacturing the hot-dip galvanized steel sheet is a continuous process, and the speed of the continuous process is 80 to 100mpm.