KR102210641B1 - A sealing composition for anodized aluminium member - Google Patents

Abstract

The present invention relates to a sealing composition for an anodizing aluminum member and a sealing method of an anodizing aluminum member using the same. According to an embodiment, the sealing composition for an anodizing aluminum member comprises: 1-4 wt% of sodium acetate; 2-5 wt% of zinc acetate; 2-5 wt% of a phosphate-based compound; 2-5 wt% of a naphthalene sulfonic acid-based dispersant; 0.01-1 wt% of organic acid; and the remainder of water.

Description

Sealing composition for anodized aluminum members {A SEALING COMPOSITION FOR ANODIZED ALUMINIUM MEMBER}

The present invention relates to a sealing composition for an anodized aluminum member.

When a metal member containing aluminum (Al) comes into contact with oxygen in the atmosphere, its surface is oxidized to form an oxide film (aluminum oxide) naturally. However, since the thickness of the surface oxide film is not constant, there is a problem that the appearance of the metal member is deteriorated. Therefore, a process of artificially forming a film having a constant thickness is required.

Anodizing refers to a process of immersing a metal member, which is a material to be plated, in an electrolytic solution, and then electrochemically forming an oxide film using the metal member as an anode. In anodizing, when electrolysis is performed using a metal member as an anode in an electrolytic solution, an oxide film having excellent adhesion to the metal member is formed on the surface of the anode by oxygen generated from the anode. Such anodizing is widely used for surface treatment of aluminum-based members because of its excellent corrosion resistance of oxide films and adhesion to metal members.

On the other hand, when the oxide film is formed on the surface of the metal member by anodizing, fine pores are generated.If the pores are left unattended, corrosion may proceed by reacting with oxygen, etc., and foreign substances may penetrate through the pores and become easily contaminated. In order to prevent such corrosion and contamination, sealing (sealing, or sealing) of the pores on the surface of the oxide film is required.

Conventional sealing methods have been applied to a metal member using boiling water, a hydration sealing method using pressurized steam, a metal salt sealing method using hot water containing a metal salt, an organic sealing oil, etc. A metal salt sealing method using fluorine or acetate of (Ni) or cobalt (Co) was mainly used.

However, the metal salt sealing method using a salt of nickel (Ni) or cobalt (Co) has a high risk of pollution of the water quality by heavy metals, and regulations related to this are increasing recently. Accordingly, there is a need for a sealing treatment technology for anodized metal members without applying environmentally hazardous substances such as heavy metals.

Background technology related to the present invention is disclosed in Korean Patent Application Publication No. 2015-0144457 (published on December 28, 2015, title of the invention: surface treatment method of an aluminum material for heat dissipation).

One object of the present invention is to provide a sealing composition for an anodized aluminum member having excellent antimicrobial properties of an anodized aluminum member and a pore sealing effect formed on an oxide layer.

Another object of the present invention is to provide a composition for anodizing aluminum having excellent chemical resistance such as corrosion resistance and alkali resistance, and excellent discoloration and discoloration prevention effect.

Another object of the present invention is to provide a composition for aluminum anodizing that has excellent penetration efficiency into the pores of the oxide layer and has excellent work time reduction effects.

Another object of the present invention is to provide a composition for anodizing aluminum having excellent surface smoothness, light resistance and weather resistance of an oxide layer.

Another object of the present invention is to provide a composition for anodizing aluminum having excellent formulation stability and excellent workability and eco-friendliness.

One aspect of the present invention relates to a sealing composition for an anodized aluminum member. In one embodiment, the sealing composition for the anodized aluminum member is 1 to 4% by weight of sodium acetate; 2-5% by weight of zinc acetate; 2 to 5% by weight of a phosphate-based compound; 2 to 5% by weight of a naphthalene sulfonic acid-based dispersant; 0.01 to 1% by weight of organic acid; And the remaining amount of water.

In one embodiment, the naphthalene sulfonic acid-based dispersant may include a condensate of naphthalenesulfonic acid and a sulfuric acid disodium salt.

In one embodiment, the organic acid may include at least one of acetic acid, malic acid, citric acid, formic acid, and lactic acid.

In one embodiment, the phosphate-based compound may include at least one of sodium polyphosphate, ammonium polyphosphate, and potassium polyphosphate.

In one embodiment, the sealing composition may have a pH of 4.4 to 5.0.

In one embodiment, the phosphate-based compound and the naphthalene sulfonic acid-based dispersant may be included in a weight ratio of 1:1 to 1:1.5.

The sealing composition according to the present invention has excellent antimicrobial and pore sealing effects of the oxide film layer of an anodized aluminum-based member, excellent chemical resistance such as corrosion resistance and alkali resistance, and excellent light resistance and weather resistance of the oxide film layer, and the oxide film layer The penetration efficiency inside the pores is excellent, the work time reduction effect is excellent, the discoloration and discoloration prevention effect of the member is excellent without going through a separate discoloration prevention process, so the process efficiency is excellent, and the workability and eco-friendliness are excellent. have.

1 is a test report showing the antimicrobial test results of Example 1.
Figure 2 is a photograph showing the results of the antibacterial test for E. coli of Example 1.
3 is a photograph showing the results of an antibacterial test against Pseudomonas aeruginosa of Example 1.
4 is a photograph showing the results of the antibacterial test against staphylococcus aureus of Example 1.
5 shows the results of an antibacterial test against Salmonella in Example 1.
6(a) shows the results of the hot water resistance test of Example 1, and FIG. 6(b) is a photograph showing the results of the UV resistance test of Example 1.
7(a) shows the heat resistance test results of Example 1, and FIG. 7(b) is a photograph showing the wear resistance test results of Example 1.
8(a) shows the results of the constant temperature and humidity test of Example 1, FIG. 8(b) shows the results of the thermal shock test of Example 1, and FIG. 8(c) shows the results of the salt spray test of Example 1. This is the picture shown.

In describing the present invention, if it is determined that a detailed description of a related known technology or configuration may unnecessarily obscure the subject matter of the present invention, a detailed description thereof will be omitted.

In addition, terms to be described later are terms defined in consideration of functions in the present invention and may vary according to the intentions or customs of users and operators, and thus their definitions should be made based on the contents throughout the present specification describing the present invention.

Sealing composition for anodized aluminum member

One aspect of the present invention relates to a sealing composition for an anodized aluminum member. In one embodiment, the sealing composition for the anodized aluminum member is 1 to 4% by weight of sodium acetate; 2-5% by weight of zinc acetate; 2 to 5% by weight of a phosphate-based compound; 2 to 5% by weight of a naphthalene sulfonic acid-based dispersant; 0.01 to 1% by weight of organic acid; And the remaining amount of water.

The anodizing (anodizing) film of an aluminum member has a problem in that porous pores are formed, and the surface is easily contaminated due to adsorption, or contamination or corrosion occurs inside the member due to the influence of residues such as sulfuric acid in the pores. Therefore, a sealing (sealing) treatment was performed to fill the pores to prevent such contamination and corrosion and to improve corrosion resistance.

In the case of a conventional sealing treatment agent that does not contain nickel, when applied to a dye-colored aluminum member, dye discoloration is severe, so that a treatment to prevent dye discoloration is first performed first, and then a process of secondary sealing treatment is required.

On the other hand, since the sealing composition according to the present invention does not contain nickel, it has excellent eco-friendliness, has antibacterial properties, and realizes both the decolorization prevention effect and corrosion resistance of the aluminum member without a separate decolorization prevention process, so that process efficiency and economy can be excellent. .

Hereinafter, the components of the sealing composition will be described in more detail.

Sodium acetate

The sodium acetate may control the PH of the sealing composition and seal micropores formed in the oxide film layer formed on the anodized aluminum member.

In one embodiment, the sodium acetate is included in 1 to 4% by weight based on the total weight of the sealing composition. When the sodium acetate is included in an amount of less than 1% by weight, durability and chemical resistance of the sealing portion are deteriorated, and discoloration or discoloration occurs, and when it is included in an amount exceeding 4% by weight, the surface quality of the aluminum-based member may be deteriorated after sealing treatment. For example, it may be included in 2 to 3% by weight. For example, it may be included in 2 to 3% by weight.

Zinc acetate

The zinc acetate may serve to secure antimicrobial properties of the oxide layer, penetrate into micropores and stably bond to seal.

In one embodiment, the zinc acetate is contained in 2-5% by weight based on the total weight of the sealing composition. When the zinc acetate is included in an amount of less than 2% by weight, the antimicrobial properties of the present invention are deteriorated, durability and chemical resistance of the sealed portion are decreased, and when it is included in an amount exceeding 5% by weight, the blendability and dispersibility of the composition decrease , The surface quality of the aluminum-based member may be deteriorated. For example, it may be included in 2.5 to 4% by weight.

In one embodiment, the sodium acetate and zinc acetate may be included in a weight ratio of 1:1.1 to 1:2. When included in the above weight range, the mixing and dispersing properties of the sealing composition of the present invention are excellent, antibacterial properties are excellent, and durability and chemical resistance of the sealed portion may be excellent at the same time.

Phosphate compound

The phosphate-based compound may be included for the purpose of improving the blendability and sealing workability of the sealing composition. In one embodiment, the phosphate-based compound may include at least one of sodium polyphosphate, ammonium polyphosphate, and potassium polyphosphate. When the phosphate-based compound of the above type is included, the mixing and dispersibility of the sealing composition is excellent, and the penetration efficiency of the fine pores of the oxide layer is excellent, so that the sealing process time can be shortened. For example, the phosphate-based compound may include sodium polyphosphate.

In one embodiment, the phosphate-based compound is contained in 2 to 5% by weight based on the total weight of the sealing composition. When the phosphate-based compound is included in an amount of less than 2% by weight, the sealing work time of the present invention decreases, the durability of the sealed area decreases, and when it is included in an amount exceeding 5% by weight, the chemical resistance of the sealed area decreases, and discoloration Or, discoloration may occur. For example, it may be included in 2.5 to 4% by weight.

Naphthalene sulfone dispersant

When the naphthalene sulfone-based dispersant is included, the dispersibility of the components of the sealing composition may be improved, and the sealing effect of the fine pores formed in the oxide layer formed on the anodized aluminum member may be excellent.

In one embodiment, the naphthalene sulfonic acid-based dispersant may include a condensation product of naphthalenesulfonic acid and sulfuric acid disodium salt. When the dispersant is applied, the sealing effect of the fine pores is excellent, and the durability of the sealed portion may be excellent.

In one embodiment, the naphthalene sulfone-based dispersant is included in 2 to 5% by weight based on the total weight of the sealing composition. When the dispersant is included in an amount of less than 2% by weight, the dispersibility and blendability of the sealing composition of the present invention are deteriorated, and when it is included in an amount of more than 5% by weight, the sealed portion may be powdered, and durability may be rather reduced. .

In one embodiment, the phosphate-based compound and the naphthalene sulfonic acid-based dispersant may be included in a weight ratio of 1:1 to 1:1.5. When included in the above weight range, the mixing and dispersibility of the components of the sealing composition may be excellent, and thus durability and chemical resistance of the sealed portion may be excellent. For example, it may be included in a weight ratio of 1:1.1 to 1:1.3. For another example, it may be included in a weight ratio of 1:1.1 to 1:1.2.

Organic acid

The organic acid may improve reaction efficiency during sealing treatment by adjusting the pH of the sealing composition. In one embodiment, the organic acid may include at least one of acetic acid, malic acid, citric acid, formic acid, and lactic acid.

In one embodiment, the organic acid is contained in an amount of 0.01 to 1% by weight based on the total weight of the sealing composition. When the organic acid is included in an amount of less than 0.01% by weight, the sealing efficiency of the present invention is lowered, resulting in a decrease in chemical resistance of the aluminum-based member, and discoloration or discoloration occurs, and when it contains more than 1% by weight, the pH of the sealing composition is excessively lowered. As a result, durability and chemical resistance of the sealing area may decrease, and discoloration or discoloration may occur. For example, it may be included in 0.05 to 0.1% by weight.

The water is included to adjust the pH of the sealing composition, and for easy mixing and dispersion.

In one embodiment, the sealing composition may have a pH of 4.4 to 5.0. In the pH condition, when the sealing composition and the oxide layer are in contact with each other, the reactivity is excellent, so that defects such as powdering do not occur during sealing, and the pores of the oxide layer may be efficiently sealed. For example, it may be pH 4.4-4.6.

Sealing method of anodized aluminum member using sealing composition for anodized aluminum member

Another aspect of the present invention relates to a method for sealing an anodized aluminum member using a sealing composition for an anodized aluminum member. In one embodiment, the sealing method includes a step of contacting the sealing composition and an anodized aluminum-based member.

In one embodiment, the anodizing treatment of the present invention may be carried out in a conventional manner. For example, the anodizing process comprises: preparing an aluminum base material; Pre-treating the aluminum base material by degreasing, etching and neutralizing it; And electrolyzing the pretreated aluminum base material to form an oxide film layer on the surface of the aluminum base material.

In one embodiment, in the electrolysis, the aluminum base material is immersed in an electrolytic solution, and the aluminum base material is used as an anode to conduct electricity to form an oxide layer on the surface of the aluminum base material by oxidation reaction.

In one embodiment, the electrolyte may include oxalic acid (H ₂ C ₂ O ₄ ) and sulfuric acid (H ₂ SO ₄ ), but is not limited thereto. For example, the electrolyte may contain 18 to 20% by volume of sulfuric acid and may have a temperature of 18 to 20°C. For example, the electrolysis time using the electrolyte may be performed under a condition of 12 to 15 V for 30 to 40 minutes, but is not limited thereto.

In one embodiment, the aluminum-based member may include aluminum (Al) or an aluminum (Al)-based alloy. The aluminum-based alloy is an alloy for wrought materials such as rods, plates, wires, tubes and forgings; And casting alloys such as die cast and mold casting. The wrought alloy and the casting alloy may include both non-heat treatment or heat treatment methods.

For example, the aluminum-based member is pure aluminum (Al), aluminum (Al)-manganese (Mn) alloy, aluminum (Al)-silicon (Si) alloy, aluminum (Al)-magnesium (Mg) alloy, aluminum ( Manufactured including Al)-copper (Cu) alloy, aluminum (Al)-silicon (Si)-copper (Cu)-magnesium (Mg) alloy and aluminum (Al)-zinc (Zn)-magnesium (Mg) alloy, etc. May be, but is not limited thereto.

In one embodiment, the sealing composition may be mixed with water (ion-exchanged water) to prepare a sealing solution, but is not limited thereto.

In one embodiment, the anodized aluminum-based member includes an aluminum base material; And an oxide film layer formed on the surface of the base material.

In one embodiment, after the electrolysis step, the step of coloring the surface of the aluminum base material on which the oxide layer is formed; may further include. The coloring may be performed using a conventional pigment or dye, and may be performed by a method known in the art.

Since the sealing composition may be the same as described above, a detailed description thereof will be omitted.

In one embodiment, the temperature of the sealing composition may be 70 ~ 95 ℃. Under the above conditions, the sealing process of the oxide layer may occur efficiently.

Hereinafter, the configuration and operation of the present invention will be described in more detail through preferred embodiments of the present invention. However, this is presented as a preferred example of the present invention and cannot be construed as limiting the present invention in any sense. Contents not described herein can be sufficiently technically inferred by those skilled in the art, and thus description thereof will be omitted.

Examples and Comparative Examples

The components used in the Examples and Comparative Examples are as follows.

(A) Sodium acetate was used.

(B1) Zinc acetate was used.

(B2) Nickel acetate was used.

(C) Sodium polyphosphate was used as the phosphate compound.

(D1) As a dispersant, a condensation product of naphthalenesulfonic acid and sulfuric acid disodium salt (available from BASF, Tamol® N) was used.

(D2) Dodecyl benzene sulfonic acid was used as a dispersing agent.

(E) Acetic acid was used as an organic acid.

(F) Water was used.

Examples 1 to 3 and Comparative Examples 1 to 11

A sealing composition was prepared by a known method by applying the components of the contents according to Table 1 and Table 2 below. The PH of the sealing compositions of the prepared Examples and Comparative Examples were measured and shown in Tables 1 and 2 below.

(1) Aluminum base material anodizing process: An aluminum base material (Al 6063 alloy) was prepared, and the aluminum base material was degreased, etched, and neutralized to perform pretreatment. Then, the pretreated aluminum base material was immersed in an electrolytic solution containing 18 to 20 vol% of sulfuric acid (H ₂ SO ₄ ), and the aluminum base material was used as a positive electrode and energized under conditions of 12 to 15 V to electrolyze for 30 to 40 minutes. , An aluminum-based member was manufactured by forming an oxide film layer having a thickness of 5 to 25 μm on the surface of the aluminum base material. Then, the oxide film layer was colored using a dye.

(2) Sealing process: The sealing compositions of Examples 1 to 3 and Comparative Examples 1 to 11 were mixed in water (ion-exchanged water, CaCO ₃ 20 ppm or less) at a concentration of 20 to 40 cc/l, A sealing solution was prepared. Then, the aluminum base material was each immersed and reacted to perform a sealing process.

Test Example (1)

(1) Antimicrobial: Among the above Examples and Comparative Examples, antimicrobial properties were typically performed for Example 1. The antimicrobial test was carried out using a film attachment method according to the KFIA-FI-1003 standard, and specifically Escherichia coli, E. coli , ATCC 25922), Pseudomonas aeruginosa , on the surface of the samples in Examples and Comparative Examples. ATCC 15442), Staphylococcus aureus (Staphylococcus, ATCC 6538) and Salmonella (Salmonella entrica, ATCC 8326), each 24 hours of incubation, the concentration (CFU / ml), and to evaluate the bacteriostatic reduction rate also Fig. 1 to the results are 5 Shown in.

(2) Mixability of sealing composition: When mixing the composition for Examples 1 to 3 and Comparative Examples 1 to 11, the mixability and dispersibility were evaluated. Specifically, separation and precipitation of constituents after preparation of the composition were visually evaluated and shown in Table 3 below.

* Mixability and dispersibility evaluation criteria

0: no change, 1: very little separation/sedimentation, 2: little separation/sedimentation, 3: severe separation/sedimentation.

(3) Discoloration or discoloration: For Examples 1 to 3 and Comparative Examples 1 to 11, whether surface discoloration or discoloration was observed with the naked eye, and the results are shown in Table 3 below.

* Evaluation standard

0: No discoloration/discoloration, 1: Very partial discoloration or discoloration, 2: Part of discoloration or discoloration, 3: Discoloration or discoloration occurs severely.

1 is a test report showing the results of the antibacterial test of Example 1, FIG. 2 is a photograph showing the results of the E. coli antibacterial test of Example 1, and FIG. 2 is a photograph showing the results of the antibacterial test against E. coli of Example 1. , FIG. 3 is a photograph showing the results of the antibacterial test against Pseudomonas aeruginosa of Example 1, FIG. 4 is a photograph showing the results of the antibacterial test against Staphylococcus aureus of Example 1, and FIG. 5 is an antibacterial against Salmonella of Example 1 It shows the test results.

Referring to the results of FIGS. 1 to 5, Example 1 according to the present invention had a bacteriostatic reduction rate of 99.9% against E. coli, Pseudomonas aeruginosa, Staphylococcus aureus, and Salmonella, from which it was found that antibacterial properties were excellent.

In addition, referring to the results of Table 3, in the case of Examples 1 to 3 of the present invention, the blendability and dispersibility were excellent during the preparation of the composition, but in the case of Comparative Examples 2 to 6 and 8-11 outside the content range of the present invention , Separation or precipitation of the composition occurred.

In addition, when sealing an aluminum-based member using Examples 1 to 3, durability and chemical resistance of the sealing portion were excellent, and no discoloration or discoloration occurred, but Comparative Examples 1 to 11 applied outside the conditions of the present invention. In the case of, it was found that durability or chemical resistance of the sealing portion was lowered, or discoloration or discoloration occurred compared to Examples 1 to 3.

Test Example (2)-Reliability Test

Reliability was evaluated by the following method for the aluminum member subjected to the sealing treatment using the Examples and Comparative Examples.

(1) Hot water: The specimens of Examples and Comparative Examples were each dipped in water at 80° C. for 30 minutes, taken out, and allowed to stand for 1 hour, and then subjected to a cross-cutting test along with observation of the appearance of the surface to evaluate. In the cross-cutting test, the coating film formed on the specimen was cut into 100 checkerboard-shaped sections with a size of 1 mm x 1 mm, and then the tape was attached to the section and the number of pieces that were peeled off was measured to evaluate adhesion, and the results were evaluated. It is shown in Table 4 below (X: appearance deformation, cracking, or peeling of 6 or more pieces of coating film, ○: peeling of 1 to 5 pieces of coating film, ◎: no abnormality).

(2) UV-resistant: After irradiating for 48 hours under conditions of output: 15W, separation distance: 2cm using an ultraviolet UV-B wavelength lamp on the specimens of the examples and comparative examples, respectively, the appearance was observed with the naked eye and the results are as follows. It is shown in Table 4 (X: deformation|transformation of the external appearance, occurrence of cracks, or severe peeling of the coating film, (circle): deformation of the external appearance, occurrence of cracks, or slight peeling of the coating film, ?: no abnormality).

(3) Heat resistance: The Example and Comparative Example specimens were each loaded into an oven tester and left at 80° C. for 48 hours, and the appearance was visually observed, and the results are shown in Table 4 below (X: deformation of the appearance , Cracking or peeling of the coating film is severe, (circle): deformation of the appearance, cracking or peeling of the coating film slightly occur, ◎: no abnormality).

(4) Abrasion resistance: After carrying out 5000 times at a rate of 50 times per minute with a stroke of 5cm and a load of 500g/cm using an abrasion tester, respectively, the specimens of Examples and Comparative Examples were visually observed, and the results are shown in Table 4 below. (X: deformation of the external appearance, occurrence of cracks or peeling of the coating film is severe, (circle): deformation of the external appearance, generation of cracks, or slight peeling of the coating film, ◎: no abnormality)

(5) Constant temperature and humidity: Each of the specimens of Example and Comparative Example was put into a constant temperature and humidity chamber, left for 48 hours at 55 to 65°C and 90 to 95% humidity, and then left at room temperature for 1 hour, and then visually observed And the results are shown in Table 4 below (X: severe rust, corrosion or discoloration on the surface, ○: slight rust, corrosion or discoloration on the surface, ◎: no abnormality).

(6) Thermal shock: The specimens of Example and Comparative Example were allowed to stand at -30°C for 30 minutes and at 60°C for 30 minutes as 1 cycle, followed by a total of 3 cycles, and then visually observed the appearance and the results are as follows. It is shown in Table 4 (X: rust, corrosion or discoloration is severe on the surface, ○: slight rust, corrosion or discoloration occurs on the surface, ◎: no abnormality).

(7) Salt spray: A salt spray test was performed for a total of 72 hours using salt water (Nacl 5%, 35±5° C.) on the specimen surfaces of the Examples and Comparative Examples, respectively. The brine was sprayed for 8 hours and allowed to stand for 16 hours as 1 cycle, followed by a total of 3 cycles, and then visually observed and the results are shown in Table 4 below (X: Severe rust, corrosion or discoloration on the surface. , ○: Slight rust, corrosion or discoloration occurs on the surface, ◎: No abnormality).

6(a) shows the heat resistance test result of Example 1, FIG. 6(b) is a photograph showing the UV resistance test result of Example 1, and FIG. 7(a) is the heat resistance test result of Example 1 7(b) is a photograph showing the wear resistance test result of Example 1, FIG. 8(a) shows the constant temperature and humidity test result of Example 1, and FIG. 8(b) is Example 1 Figure 8 (c) is a photograph showing the result of the salt spray test of Example 1. Meanwhile, the aluminum member samples of Example 1 in FIGS. 6 to 8 were manufactured by molding using surface sanding or a general extrusion method.

Referring to the results of Table 4 and FIGS. 6 to 8, it was found that the aluminum member having the sealing treatment according to the embodiment of the present invention has excellent heat resistance, light resistance, abrasion resistance, thermal shock resistance, and chemical resistance compared to the comparative example. .

Through this, when the sealing treatment according to the present invention does not contain heavy metals such as cadmium and nickel, it has excellent eco-friendliness, has antimicrobial properties, and implements both the decolorization prevention effect and corrosion resistance of the aluminum member at the same time without a separate decolorization prevention process. And economics can be excellent.

So far, the present invention has been looked at around the examples. Those of ordinary skill in the art to which the present invention pertains will be able to understand that the present invention may be implemented in a modified form without departing from the essential characteristics of the present invention. Therefore, the disclosed embodiments should be considered from an illustrative point of view rather than a limiting point of view. The scope of the present invention is shown in the claims rather than the above description, and all differences within the scope equivalent thereto should be construed as being included in the present invention.

Claims (6)

1-4% by weight of sodium acetate;
2-5% by weight of zinc acetate;
2 to 5% by weight of a phosphate-based compound;
2 to 5% by weight of a naphthalene sulfonic acid-based dispersant;
0.01 to 1% by weight of organic acid; And
A sealing composition for an anodized aluminum member comprising a residual amount of water.
The sealing composition according to claim 1, wherein the naphthalene sulfonic acid-based dispersant comprises a condensate of naphthalenesulfonic acid and sulfuric acid disodium salt.
The anodized aluminum member of claim 1, wherein the organic acid comprises at least one of acetic acid, malic acid, citric acid, formic acid, and lactic acid. For sealing composition.
The sealing composition for an anodized aluminum member according to claim 1, wherein the phosphate-based compound comprises at least one of sodium polyphosphate, ammonium polyphosphate, and potassium polyphosphate.
The sealing composition for an anodized aluminum member according to claim 1, wherein the sealing composition has a pH of 4.4 to 5.0.
The sealing composition for an anodized aluminum member according to claim 1, wherein the phosphate-based compound and the naphthalene sulfonic acid-based dispersant are included in a weight ratio of 1:1 to 1:1.5.

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