KR20190132719A - Double surface treatment composition and dual surface treatment method using the same - Google Patents

Abstract

The present invention relates to a dual surface treatment agent composition which comprises: a base surface treatment agent including a paste composition in which zinc and aluminum are dispersed at a ratio of 11:1 to 15:1; and a top surface treatment agent including iron oxide, and to a dual surface treatment method. The dual surface treatment agent composition and the dual surface treatment method using the same reduce hazards to the human body and environmental pollution.

Description

Double surface treatment composition and dual surface treatment method using the same

The present invention relates to a double surface treatment agent composition and a double surface treatment method using the same for the purpose of improving the corrosion resistance and coloration of the low-floor floor parts used in the welfare vehicle for the disabled.

The low floor of the welfare vehicle is designed for each type of vehicle so that wheelchair users can easily ride and get off the vehicle. The low floor includes a base frame and a lower auxiliary device and ramp device of the base frame. The base frame of the low floor consists of a bottom plate, which is in the form of a lower floor than a normal vehicle, and the ramp device is configured as a lift or ramp for getting on and off the vehicle of a wheelchair user.

In general, the low floor of a welfare vehicle uses a steel plate made of iron material as a lower plate of the base frame, and in order to protect the low phase floor from the external environment, an antirust surface treatment may be performed on one surface of the lower plate. Examples of the antirust surface treatment for iron-based workpieces include chromate and dark chromate, and medium epoxy black paint.

The chromate and dark chromium treatment method is applied to the coating material (iron steel) using an aqueous solution composed of zinc, aluminum, chromic acid, deionized water, and other additives, and then forms anhydrous zinc chromium / aluminum composite film by hot air drying or heat drying. This is to improve the corrosion resistance of the coating. However, chromate and darker treatment methods require the development of alternative technologies as they contain harmful substances and environmental pollution.

In addition, the medium-type epoxy coating may have corrosion resistance when a coating layer of at least 50 μm or more is formed on a single coating basis, and may also be harmful to the human body due to the use of volatile organic compounds, and may cause environmental pollution. Can be.

Japanese Patent Laid-Open No. 2003-160878 (published: 2003. 06. 06.) Japanese Patent Laid-Open No. 2001-342575 (published date: December 14, 2001)

The technical problem to be achieved by the present invention is to reduce the harmfulness of the human body and environmental pollution, improve the corrosion resistance of the base metal by the surface treatment using the sacrificial anode action of zinc and aluminum, and to secure the colorability by the top surface treatment using iron oxide. It is an object of the present invention to provide a double surface treatment composition and a double surface treatment method using the same.

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

In order to solve the above technical problem, the present invention is characterized by consisting of a surface coating agent comprising a paste composition in which zinc and aluminum are dispersed at a ratio within 11: 1 to 15: 1, and a top coating agent including iron oxide. A double surface treatment agent composition can be provided.

The undercoat surface treating agent may include 20 to 40 parts by weight of a binder based on 100 parts by weight of the zinc and aluminum dispersion paste, and the binder may include at least one or more of silane, titanate, and aluminate.

The undercoat surface treatment agent may include 2 to 4 parts by weight of a dispersant based on 100 parts by weight of the zinc and aluminum dispersion paste, and the dispersant may include an acrylic copolymer having a molecular weight of 4500 to 5500.

The undercoat surface treatment agent may include 10 to 30 parts by weight of a thickener based on 100 parts by weight of the zinc and aluminum dispersion paste, and the thickener may include a polyamide salt.

The top coat surface treatment agent may include 100 to 130 parts by weight of a binder based on 100 parts by weight of iron oxide, and the binder may include a methoxy silicon intermediate resin.

The top coat surface treatment agent may include 5 to 15 parts by weight of a dispersant based on 100 parts by weight of iron oxide, and the dispersant may include an acrylic copolymer having a molecular weight of 5500 to 7000.

The top coat surface treatment agent may include 10 to 20 parts by weight of a thickener and 100 parts by weight of distilled water based on 100 parts by weight of iron oxide, and the thickener includes talc and fumed silica dispersed in a ratio of 10: 0.1 to 10: 1. can do.

In addition, in order to solve the above technical problem, the present invention comprises the steps of applying a surface treatment agent containing a paste composition in which zinc and aluminum are dispersed in a ratio within 11: 1 to 15: 1 on one side of the substrate and dried; And it can provide a double surface treatment method comprising the step of applying and drying the top surface treatment agent containing iron oxide on the upper surface of the bottom surface treatment agent is formed.

Preparing the undercoat surface treatment agent, comprising: mixing the zinc and aluminum dispersion paste with the dispersant, stirring at a rate of 1250 to 1500rpm while maintaining a temperature of 50 to 60 ℃ for 60 minutes to 90 minutes; And adding a binder and a thickener to the mixture may be prepared to include a step of stirring at a rate of 500 to 1000rpm at room temperature for 120 minutes to 150 minutes.

To prepare the top coat surface treatment agent, 8 to 15% of the total amount of the binder to be mixed with the dispersant and distilled water and agitated at a speed of 400 to 600rpm for 25 to 35 minutes at room temperature; Mixing the iron oxide with the mixture and stirring at a rate of 800 to 1200 rpm for 60 to 90 minutes at room temperature; And adding the remainder of the binder and the thickener may be prepared to include a step of stirring at a rate of 400 to 600rpm for 25 minutes to 35 minutes at room temperature.

The dual surface treatment composition and the double surface treatment method using the same according to the present invention have the advantage of reducing the harmfulness and environmental pollution of the human body, improving the corrosion resistance of the base metal and securing colorability.

1 is a flow chart showing a method of manufacturing a double surface treatment agent and a surface treatment method using the same according to an embodiment of the present invention,
2A and 2B are image views showing the results of Comparative Example 1 and Example 5 according to Test Example 1 of the present invention,
3A and 3B are image views showing the results of Comparative Example 4 and Example 10, respectively, according to Test Example 1 of the present invention;
4A and 4B are image views showing the results of Comparative Example 4 and Example 10, respectively, according to Test Example 2 of the present invention;
5A and 5B are image views showing the results of Comparative Example 1 and Example 5, respectively, according to Test Example 3 of the present invention;
6A and 6B are image diagrams showing the results of Comparative Example 4 and Example 10 according to Test Example 4 of the present invention, respectively.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. The following embodiments are to be provided as examples to ensure that the spirit of the present invention to those skilled in the art will fully convey. Accordingly, the present invention is not limited to the embodiments described below and may be embodied in other forms. In the drawings, lengths, thicknesses, and the like of layers and regions may be exaggerated for convenience. Like numbers refer to like elements throughout.

The double surface treatment composition according to the present invention is composed of a top surface treatment agent applied on a base metal and a top surface treatment agent formed thereon. The undercoat surface treatment agent includes a paste composition in which zinc and aluminum are dispersed at a ratio within 11: 1 to 15: 1, and the topcoat surface treatment agent includes iron oxide.

For example, the zinc and aluminum may be dispersed in an aqueous solution in the form of flakes. The iron oxide (Fe ₃ O ₄ · MnO) may have a black spherical powder form, may include MnO powder, and may have a particle size of 3 to 5㎛.

The double surface treatment agent composition may be composed of a top surface treatment agent for forming a sacrificial anode type undercoat and a top surface treatment agent for forming a ceramic topcoat, and are used for surface treatment to improve corrosion resistance and coloration of low-floor floors for disabled welfare vehicles. Can be.

The undercoat surface treating agent may include 20 to 40 parts by weight of a binder based on 100 parts by weight of the zinc and aluminum dispersion paste, and the binder may include at least one or more of silane, titanate, and aluminate. If the binder exceeds 40 parts by weight, there is no change in the adhesion and corrosion resistance with the base metal, but the increase in the viscosity according to the storage period of the surface treatment agent increases, making the process difficult due to the increased viscosity when applied to the base metal after a certain period of storage. Can lose.

The undercoat surface treatment agent may include 2 to 4 parts by weight of a dispersant based on 100 parts by weight of the zinc and aluminum dispersion paste, and the dispersant may include an acrylic copolymer having a molecular weight of 4500 to 5500. When the dispersing agent is added in less than 2 parts by weight, the aggregation of zinc and aluminum in the composition may occur, which may make it difficult to form a uniform surface during application, and when it exceeds 4 parts by weight, the corrosion resistance may be reduced again.

In addition, the undercoat agent may include 10 to 30 parts by weight of a thickener based on 100 parts by weight of the zinc and aluminum dispersion paste, and the thickener may include a polyamide salt. When the thickener exceeds 30 parts by weight, since coating defects such as swelling, cracking and cracking of the coating film may occur after drying, it is preferably included in the range of the weight part.

The top coat surface treatment agent may include 100 to 130 parts by weight of a binder based on 100 parts by weight of iron oxide, and the binder may include a methoxy silicon intermediate resin. The methoxy silicone intermediate resin may have a polysiloxane structure of at least 3: 1 methyl and phenyl groups. As with the surface treatment agent, when the binder of the surface treatment agent exceeds 130 parts by weight, the rate of increase of the viscosity according to the storage period of the coating surface treatment agent increases, so that it may be difficult to control the thickness during application. It can be difficult.

The top coat agent may include 5 to 15 parts by weight of a dispersant based on 100 parts by weight of iron oxide, and the dispersant may include an acrylic copolymer having a molecular weight of 5500 to 7000. When the dispersant is added in less than 5 parts by weight of the iron oxide in the composition may occur due to the coagulation of the coating layer may be difficult to form a uniform surface, and if it exceeds 15 parts by weight may be reduced the corrosion resistance again because the weight Addition is preferred.

The top coat surface treatment agent may include 10 to 20 parts by weight of a thickener and 100 parts by weight of distilled water based on 100 parts by weight of iron oxide. The thickener may include talc and fumed silica dispersed in a ratio of 10: 0.1 to 10: 1, and the talc and fumed silica may have a size of 1 μm or less.

1 is a flow chart showing a method for producing a double surface treatment agent and a surface treatment method using the same according to an embodiment of the present invention.

Referring to FIG. 1, first, a surface coating agent preparation (S102a) and a top coating agent preparation (S102b) are performed.

Producing the undercoat surface treatment agent (S102a) may include a paste composition in which zinc and aluminum are dispersed in a ratio of 11: 1 to 15: 1 within the base metal to form an effective sacrificial anode undercoat. For example, the zinc and aluminum may be dispersed in an aqueous solution in the form of flakes.

To prepare the undercoat surface treatment agent (S102a), first, by mixing the zinc and aluminum dispersion paste with the dispersant, and stirring at a rate of 1250 to 1500rpm while maintaining a temperature of 50 to 60 ℃ for 60 to 90 minutes, Ensure even distribution of zinc and aluminum.

The dispersant may be included in an amount of 2 to 4 parts by weight based on 100 parts by weight of the zinc and aluminum dispersion paste, and may include an acrylic copolymer having a molecular weight of 4500 to 5500. When the dispersing agent is added in less than 2 parts by weight, cohesion may occur in the composition, which may make it difficult to form a uniform surface during application, and when the dispersant exceeds 4 parts by weight, corrosion resistance may be reduced.

Next, a binder and thickener may be added to the mixture to prepare a surface coating agent by stirring at a rate of 500 to 1000 rpm at room temperature for 120 to 150 minutes. Stirring can be performed using a stirrer, such as a general impeller of rotary or propeller type.

The binder may be included in an amount of 20 to 40 parts by weight based on 100 parts by weight of the zinc and aluminum dispersion paste, and may include at least one or more of silane, titanate, and aluminate. When the binder exceeds 40 parts by weight, there is no change in adhesion and corrosion resistance to the base metal, but the increase in viscosity according to the storage period of the undercoat surface treatment agent may increase the process when applying to the base metal.

The thickener may be included in 10 to 30 parts by weight based on 100 parts by weight of the zinc and aluminum dispersion paste, and may include a polyamide salt. When the thickener exceeds 30 parts by weight, coating defects such as swelling, cracking, and cracking may occur. Therefore, the thickener is preferably prepared in the range of the weight part.

To prepare the top surface treatment agent (S102b), first, 8 to 15% of the total amount of the binder to be mixed with the dispersant and distilled water are stirred at a speed of 400 to 600 rpm for 25 to 35 minutes at room temperature. This is to ensure that the binder and the dispersant are uniformly mixed first, so that the distribution of iron oxide (Fe ₃ O ₄ · MnO) to be mixed afterwards is uniform.

The total amount of the binder may be 100 to 130 parts by weight based on 100 parts by weight of iron oxide, and the distilled water may be 100 parts by weight. The binder may include a methoxy silicon intermediate resin, and the methoxy silicon intermediate resin may have a methyl and phenyl group of 3: 1 or more in a polysiloxane structure. If the binder exceeds 130 parts by weight, the increase in viscosity according to the storage period of the top coat surface treatment agent is increased, so that it is difficult to control the thickness of the coating during application, and the process may be difficult due to an increase in drying time.

The dispersant may be included in an amount of 5 to 15 parts by weight based on 100 parts by weight of iron oxide, and may include an acrylic copolymer having a molecular weight of 5500 to 7000. If the dispersing agent is added in less than 5 parts by weight, the aggregation of iron oxide inside the composition may occur, it may be difficult to form a uniform surface during application, and if it exceeds 15 parts by weight, the corrosion resistance may be reduced again, so the above weight parts are preferable. .

Next, the iron oxide is mixed with the mixture and stirred at a speed of 800 to 1200 rpm for 60 to 90 minutes at room temperature, so that the iron oxide is uniformly distributed. For example, the iron oxide (Fe ₃ O ₄ · MnO) may have a black spherical powder form, may include MnO powder, and may have a particle size of 3 to 5㎛.

Finally, by adding the remainder of the binder and a thickener, it is possible to prepare a top coat surface treatment agent by stirring at a rate of 400 to 600rpm for 25 to 35 minutes at room temperature.

The thickener may be included in 10 to 20 parts by weight based on 100 parts by weight of iron oxide. The thickener may include talc and fumed silica dispersed in a ratio of 10: 0.1 to 10: 1, and the talc and fumed silica may have a size of 1 μm or less.

Next, the undercoat surface preparation prepared in step S102a is applied and dried on the base metal (S104). For example, the metal may be a lower plate of the low floor of the welfare vehicle for the disabled. The coating of the undercoat surface treatment agent may be performed by spraying with a pneumatic spray gun under a spray pressure of 2.5 to 3.0 bar and a spraying distance of 300 to 500 mm, and applying a thickness of 30 to 60 μm based on a wet film in consideration of the thickness after drying. can do. The coated undercoating agent may be dried by heat drying or natural drying. The undercoat layer formed after drying may be formed to a thickness of 12 to 15 μm.

After applying the top surface treatment agent to the top of the undercoat layer and dried (S106). The application and drying conditions of the top coat agent may be similar to those of the top coat agent. Like the undercoat layer, the top coat layer formed after drying may be formed to a thickness of 12 to 15 μm.

By performing the surface treatment for forming the sacrificial anode undercoat layer on the base metal as described above, and performing the top surface treatment including iron oxide to form the top layer, the corrosion resistance of the base metal is improved and coloration is secured. can do. This may be more helpful in improving the corrosion resistance of the low floor of the welfare vehicle lower than the lower part of the general vehicle and thereby increasing the life of the low floor.

Hereinafter, the preparation of the dual surface treatment agent composition and the surface treatment method according to the present invention will be described through the following examples, the following examples are merely illustrative for explaining the present invention and the present invention is not limited thereto.

Examples 1-5

Zinc flakes: The aluminum flakes were water-dispersible at a ratio of 12: 1 for at least 1 hour. Thereafter, a binder composed of silane, titanate, and aluminate, an acrylic copolymer having a molecular weight of 5100 as a dispersant, and a polyamide salt as a thickener were mixed, followed by stirring at 500 to 1000 rpm at room temperature for 2 hours. The undersurface treatment composition of Examples 1 to 5 was prepared in the same composition as in Table 1 below. Thereafter, the base metal was applied to a thickness of 30 to 40 μm under the conditions of a spray pressure of 2.5 to 3.0 bar, a spray distance of 300 to 500 mm, and a spray nozzle of 0.2 mm. After coating, the coating was dried to form an undercoat layer. The thickness of the undercoat layer was 12-13 μm as measured by KS M ISO 2802 microscopy.

division Example 1 Example 2 Example 3 Example 4 Example 5 Addition ratio Paste (Zn: Al) 100
(12: 1) 100
(12: 1) 100
(12: 1) 100
(12: 1) 100
(12: 1) Binder 20 30 30 30 30 Dispersant 2 2 3 3 3 Thickener 10 10 10 20 30

Examples 6-10

With a polysiloxane structure, methyl and phenyl groups of at least 3: 1 methoxy silicone intermediate resin were used as binders, and an acrylic copolymer having a molecular weight of 6300 as a dispersant and 8-15% of the total amount of the binder, and distilled water were mixed at 500 rpm for 30 minutes at room temperature. Stir at speed. Thereafter, black iron oxide powder (Fe ₃ O ₄ .MnO) was mixed with the mixture and stirred at a speed of 800 to 1200 rpm for 60 minutes at room temperature. And the remainder of the binder and 1 μm or less talc and fumed silica was added to the water-dispersed thickener in a 10: 0.5 ratio and stirred at a speed of 500rpm for 30 minutes at room temperature to prepare a top surface treatment agent, A topcoat surface treatment composition of Examples 6 to 10 was prepared in the same composition as in Example 2).

On the undercoat layer formed by the composition ratio of Example 5, the injection pressure of 2.5 to 3.0 bar, the injection distance of 300 to 500 mm, the injection nozzle of 0.2 mm using the top coating agent composition of each of Examples 6 to 10 50 to 60 The thickness was applied at a thickness. After drying to form a top coat layer, the sum of the thickness of the top coat and the bottom coat layer was found to be 24 to 26㎛.

division Example 6 Example 7 Example 8 Example 9 Example 10 Addition ratio Iron oxide powder 100 100 100 100 100 Binder 100 120 100 100 100 Dispersant 5 5 10 5 5 Thickener 10 10 10 15 20 Distilled water 100 100 100 100 100

Comparative Examples 1 to 3

The primer coating agent composition was prepared using the method of Examples 1 to 5, but the ratio of zinc flakes to aluminum flakes was varied. The composition ratio is shown in Table 3 below.

division Comparative Example 1 Comparative Example 2 Comparative Example 3 Addition ratio Paste (Zn: Al) 100
(8: 1) 100
(10: 1) 100
(12: 1) Binder 30 30 10 Dispersant 2 2 2 Thickener 10 10 10

Comparative Examples 4 to 6

Using the manufacturing method of Examples 6 to 10, but the top surface treatment agent was prepared, but was prepared by varying the ratio of the binder, dispersant, thickener, respectively, the composition ratio is as shown in Table 4 below. The top coat layer was formed on the undercoat layer formed by the composition ratio of Example 5 in the same manner as in Examples 6 to 10 using the top coat surface treatment agents of Comparative Examples 4 to 6, and as a result, the top coat layer and the undercoat layer The sum of the thicknesses was found to be 24 to 26 mu m.

division Comparative Example 4 Comparative Example 5 Comparative Example 6 Addition ratio Iron oxide powder 100 100 100 Binder 80 100 100 Dispersant 5 3 5 Thickener 10 10 5 Distilled water 100 100 100

Test Example 1-Corrosion Resistance Test 1

The base metal on which the undercoat layers obtained in Examples 1 to 5 and Comparative Examples 1 to 3 were formed, and the double layers of the undercoat and the topcoat layers obtained in Examples 6 to 10 and Comparative Examples 4 to 6 were formed. Base metal was used as a sample to test the corrosion resistance. The corrosion resistance test was based on KS D 9502 neutral salt spray test. After 1000 hours of salt spraying, the surface of the sample was observed and compared.

Test Example 2-Corrosion Resistance Test 2

After the salt spray was performed on the samples obtained in Examples 6 to 10 and Comparative Examples 4 to 6 by the method of Test Example 1, the surface of the samples was observed and compared after 1500 hours.

Test Example 3-electrolytic resistance test 1

Electrolytic resistance was tested on the samples obtained in Examples 1 to 5 and Comparative Examples 1 to 3. The grooves of the X-shape in a 0.5mm width on the surface of the sample were compared and observed for corrosion resistance according to the KS D 9502 neutral salt spray test. After 360 hours after saline spraying, the surface of the sample was observed and compared.

Test Example 4-Electrolytic Resistance Test 2

The samples obtained in Examples 6 to 10 and Comparative Examples 4 to 6 were compared and observed for corrosion resistance based on the salt spray test by the method of Test Example 3. Unlike Test Example 3, the surface of the sample was observed and compared after 720 hours after saline spraying.

Test Example 5-Adhesiveness

Adhesiveness on the samples obtained in Examples 1 to 5, Comparative Examples 1 to 3 and the samples obtained in Examples 6 to 10 and Comparative Examples 4 to 6 based on the KS M ISO 2409 lattice peeling test. Tested.

result

The results of Test Examples 1 to 5 are shown in Tables 5 and 6 below. ● is low, ○ is usually, ◎ is excellent, and ◆ is very good.

division Comparative Example 1 Comparative Example 2 Comparative Example 3 Example 1 Example 2 Example 3 Example 4 Example 5 Corrosion resistance ● ● ○ ○ ○ ○ ◎ ◎ Electric resistance ● ● ○ ○ ○ ◎ ◎ ◎ Adhesiveness ◎ ◎ ● ○ ◎ ◎ ◎ ◎

division Comparative Example 4 Comparative Example 5 Comparative Example 6 Example 6 Example 7 Example 8 Example 9 Example 10 Corrosion resistance ● ● ● ○ ○ ○ ◆ ◆ Electric resistance ● ● ● ○ ○ ○ ◆ ◆ Adhesiveness ● ◎ ◎ ◎ ◎ ◎ ◎ ◎

2A and 2B are image views showing the results of Comparative Example 1 and Example 5 according to Test Example 1 of the present invention, and FIGS. 3A and 3B are Comparative Examples 4 and 10 according to Test Example 1 of the present invention. 4A and 4B are image diagrams showing results of Comparative Example 4 and Example 10 according to Test Example 2 of the present invention, respectively, and FIGS. 5A and 5B are examples of Test Example 3 of the present invention. 6A and 6B are image diagrams showing the results of Comparative Example 4 and Example 10 according to Test Example 4 of the present invention, respectively.

Comparing Table 5 with FIG. 2A and FIG. 2B, unlike FIG. 2A, the corroded region A is shown, FIG. 2B shows that there is no corroded region, which is a surface treatment agent according to an embodiment of the present invention. It can be seen that the corrosion resistance of the formed base metal was improved. Similarly, as shown in Table 5 and FIGS. 5A and 5B, it can be seen that the electrolytic resistance of the base metal on which the surface treatment agent was formed according to the embodiment of the present invention was also improved.

Comparing Table 6 with FIGS. 3A to 4B, FIGS. 6A and 6B, in the comparative example, as shown in FIG. 4A, the surface was corroded after the salt spray, but the embodiment of FIG. Able to know. In addition, even in the electrolytic resistance test, since the corroded region B form of FIG. 6A as a comparative example was not shown in FIG. 6B as an example, it can be seen that the corrosion resistance was improved.

Furthermore, even after the corrosion and electrolytic resistance tests in Figures 3b, 4b and 6b there was no black color deformation, it can be seen that the colorability of the sample is secured through this. In addition, the adhesiveness was excellent in all the examples except that the adhesiveness of Example 1 having the lowest addition amount of the binder, the dispersant, and the thickener was normal.

It can be seen that the corrosion resistance of the base metal is improved by performing a bottom surface treatment for forming a sacrificial anode-type undercoat on the base metal and performing a top surface treatment composed of iron oxide for forming a ceramic top layer. In addition, it can be seen that the black color of the top coat layer is kept constant to ensure colorability. When applied to the lower floor of the disabled welfare vehicle lower than the lower portion of the general vehicle it can be more helpful to improve the corrosion resistance, it can be helpful to improve the life of the low floor of the disabled welfare vehicle.

As described above, the dual surface treatment agent composition and the double surface treatment method according to the present invention have advantages in reducing human hazards, minimizing environmental pollution, improving corrosion resistance of base metals, and securing colorability.

Although described above with reference to a preferred embodiment of the present invention, those skilled in the art will be variously modified and changed within the scope of the invention without departing from the spirit and scope of the invention described in the claims below I can understand that you can.

A, B; Corroded area

Claims (16)

A double surface treatment agent composition comprising a top coat agent comprising a paste composition in which zinc and aluminum are dispersed in a ratio of 11: 1 to 15: 1, and a top coat agent comprising iron oxide. The method of claim 1,
The undercoat surface treatment agent, the double surface treatment agent composition, characterized in that it comprises 20 to 40 parts by weight of the binder based on 100 parts by weight of the zinc and aluminum dispersion paste. The method of claim 2,
Wherein said binder comprises at least one of silane, titanate, and aluminate. The method of claim 1,
The undercoat surface treatment agent, characterized in that it comprises 2 to 4 parts by weight of a dispersant based on 100 parts by weight of the zinc and aluminum dispersion paste. The method of claim 4, wherein
The dispersant is a dual surface treatment agent composition, characterized in that it comprises an acrylic copolymer having a molecular weight of 4500 to 5500. The method of claim 1,
The undercoat surface treating agent comprises a 10 to 30 parts by weight of a thickener based on 100 parts by weight of the zinc and aluminum dispersion paste. The method of claim 6,
Double thickener composition, characterized in that the thickener comprises a polyamide salt. The method of claim 1,
The top coat surface treatment agent, characterized in that it comprises 100 to 130 parts by weight of the binder based on 100 parts by weight of iron oxide. The method of claim 8,
The binder is a dual surface treatment composition, characterized in that it comprises a methoxy silicone intermediate resin. The method of claim 1,
The top coat agent, the dual surface treatment agent composition, characterized in that it comprises 5 to 15 parts by weight of a dispersant based on 100 parts by weight of iron oxide. The method of claim 10,
The dispersant is a dual surface treatment agent composition, characterized in that it comprises an acrylic copolymer having a molecular weight of 5500 to 7000. The method of claim 1,
The top coat surface treatment agent, characterized in that it comprises 10 to 20 parts by weight of thickener and 100 parts by weight of distilled water based on 100 parts by weight of iron oxide. The method of claim 12,
The thickener is a dual surface treatment composition, characterized in that it comprises talc and fumed silica dispersed in a ratio of 10: 0.1 to 10: 1. Applying and drying a surface treatment agent on one surface of the substrate including a paste composition in which zinc and aluminum are dispersed at a ratio of 11: 1 to 15: 1; And
And coating and drying the top coat surface treatment agent containing iron oxide on the upper surface of the bottom surface treatment agent. The method of claim 14,
Producing the undercoat surface treatment agent,
Mixing the zinc and aluminum dispersion paste with a dispersant and stirring at a rate of 1250 to 1500 rpm while maintaining a temperature of 50 to 60 ° C. for 60 to 90 minutes; And
Adding a binder and a thickener to the mixture, characterized in that the manufacturing method comprising the step of stirring at a rate of 500 to 1000rpm at room temperature for 120 to 150 minutes. The method of claim 14,
Producing the top coat surface treatment agent,
8 to 15% of the total amount of the binder to be mixed with the dispersant and distilled water, followed by stirring at a speed of 400 to 600 rpm for 25 to 35 minutes at room temperature;
Mixing the iron oxide with the mixture and stirring at a rate of 800 to 1200 rpm for 60 to 90 minutes at room temperature; And
Adding the remainder of the binder and a thickener, a double surface treatment method comprising the step of stirring at a rate of 400 to 600rpm for 25 to 35 minutes at room temperature.

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