Method for manufacturing antibacterial stainless steel coated with ceramic powder and antibacterial stainless steel manufactured thereby

Abstract

The present invention provides a method for manufacturing an antibacterial stainless steel coated with ceramic powder, and an antibacterial stainless steel manufactured thereby.

Description

Method for manufacturing ceramic powder-coated antibacterial stainless steel and antibacterial stainless steel manufactured therefrom

[0001] The present invention relates to a method for manufacturing antibacterial stainless steel using a ceramic powder composition and antibacterial stainless steel obtained therefrom.

[0002] Stainless steel is increasingly being used in places where germs are likely to grow or where germ growth is undesirable. Furthermore, as the demand for antibacterial properties grows for medical devices, kitchen appliances, and building materials requiring sterility, efforts are being made to infuse stainless steel with its own antibacterial properties. Harmful bacteria such as Escherichia coli and Staphylococcus aureus exist on stainless steel as well. To address this issue, an alternating current electrolytic treatment is used to apply a noble potential to copper-containing ferritic stainless steel or austenitic stainless steel. This process causes the copper to dissolve in the electrolyte, and then a non-potential is applied to deposit the copper on the surface, imparting antibacterial properties.

[0003] Meanwhile, the technology to develop the antibacterial properties of stainless steel itself is prone to reducing the antibacterial properties or has problems in terms of yield.

[0004] [Prior Art Literature]

[0005] [Patent Document]

[0006] Domestic Patent Publication No. 10-2023-0076838

[0007] The problem to be solved by the present invention is to provide a method for manufacturing stainless steel having enhanced antibacterial properties by forming a film with a ceramic powder composition on stainless steel using an electroplating method, and an antibacterial stainless steel manufactured thereby.

[0008] In order to solve the above problem, the present invention provides a method for manufacturing ceramic powder-coated antibacterial stainless steel, comprising the steps of: preparing a plated material made of stainless steel; placing the plated material into an electrolytic bath to electrolytically degrease; etching the plated material that has undergone the electrolytic degreasing step using an acidic solution; first plating the plated material that has undergone the etching step with a nickel strike plating solution; second plating the plated material that has undergone the first plating step by immersing it in a mixed plating solution containing a ceramic powder composition and at least one selected from the group consisting of boric acid (H3BO3), nickel sulfate (NiSO4), and nickel chloride (NiCl2); and second plating the plated material that has undergone the second plating step by adding a brightener to the plated material that has undergone the second plating step to grow the ceramic powder-coated stainless steel. In addition, the present invention provides antibacterial stainless steel obtained by the above manufacturing method.

[0009] By using the method for manufacturing antibacterial stainless steel according to the present invention, it is possible to provide antibacterial stainless steel in which antibacterial and antiviral properties are maintained for a long period of time without early loss.

[0010] FIG. 1 is an image of antibacterial stainless steel coated with ceramic powder according to an embodiment of the present invention. FIG. 1(a) is an image taken at a 50-fold magnification, and FIG. 1(b) is an image taken at a 100-fold magnification.

[0011] Figure 2 shows the zeta potential of antibacterial stainless steel coated with ceramic powder according to one embodiment of the present invention.

[0012] Figure 3 shows the results of measuring the antibacterial effect of antibacterial stainless steel coated with ceramic powder according to one embodiment of the present invention. Non-plated stainless steel was used as a control group.

[0013] Figure 4 is an image of a product to which antibacterial stainless steel coated with ceramic powder according to one embodiment of the present invention is applied.

[0014] Hereinafter, various embodiments of the present invention will be described with reference to the accompanying drawings. It should be understood that the present invention is not limited to specific embodiments, but rather encompasses various modifications, equivalents, and / or alternatives of the embodiments of the present invention. In the description of the drawings, similar reference numerals may be used for similar components.

[0015] In this document, the expressions “has”, “may have”, “includes”, or “may include” indicate the presence of a feature (e.g., a number, function, operation, or component such as a part), but do not exclude the presence of additional features.

[0016] In this document, the expressions "A or B," "at least one of A and / or B," or "one or more of A and / or B" can include all possible combinations of the listed items. For example, "A or B," "at least one of A and B," or "at least one of A or B" can all refer to cases where (1) at least one A is included, (2) at least one B is included, or (3) at least one A and at least one B are included.

[0017] The expression "configured to" as used herein can be used interchangeably with, for example, "suitable for", "having the capacity to", "designed to", "adapted to", "made to", or "capable of". The term "configured to" does not necessarily mean "specifically designed to".

[0018] The terms used in this document are used only to describe specific embodiments and may not be intended to limit the scope of other embodiments. The singular expression may include the plural expression unless the context clearly indicates otherwise. Terms used herein, including technical or scientific terms, may have the same meaning as commonly understood by those of ordinary skill in the art described in this document. Terms defined in general dictionaries among the terms used in this document may be interpreted as having the same or similar meaning in the context of the relevant technology, and shall not be interpreted in an idealized or overly formal sense unless explicitly defined in this document. In some cases, even if a term is defined in this document, it cannot be interpreted to exclude the embodiments of this document.

[0019] The embodiments disclosed in this document are presented for the purpose of explaining and understanding the disclosed technical content and are not intended to limit the scope of the present invention. Therefore, the scope of this document should be interpreted to include all modifications or various other embodiments based on the technical concept of the present invention.

[0020] Hereinafter, preferred embodiments of the present invention will be described in detail. Prior to this, it should be noted that the terms and words used in this specification and claims should not be construed as limited to their conventional or dictionary meanings. Based on the principle that the inventor can appropriately define the concept of a term to best explain his or her invention, they should be interpreted in a way that aligns with the technical spirit of the present invention.

[0021] Accordingly, the configurations of the embodiments described in this specification are only some of the most preferred embodiments of the present invention and do not represent all of the technical ideas of the present invention, so it should be understood that there may be various equivalents and modified examples that can replace them at the time of filing this application.

[0022] Throughout the specification, whenever a part is said to "include" a component, this does not mean that it excludes other components, but rather that it may include other components, unless otherwise stated.

[0023] Hereinafter, the present invention will be described in detail.

[0024]

[0025] A method for manufacturing ceramic powder-coated antibacterial stainless steel according to one embodiment of the present invention comprises the steps of: preparing a plated material made of stainless steel; electrolytically degreasing the plated material by placing it in an electrolytic bath; etching the plated material that has undergone the electrolytic degreasing step using an acidic solution; first plating the plated material that has undergone the etching step with a nickel strike plating solution; second plating the plated material that has undergone the first plating step by immersing it in a mixed plating solution containing a ceramic powder composition and at least one selected from the group consisting of boric acid (H3BO3), nickel sulfate (NiSO4), and nickel chloride (NiCl2); and adding a brightener to the plated material that has undergone the second plating step to grow ceramic powder-coated stainless steel. Each step will be described in detail below.

[0026] The step of preparing the plated material made of the above stainless steel is performed to remove foreign substances from the plated material, and is performed by placing it in a washing tank using pure water (H20) and washing it thoroughly, followed by drying. The plated material is made of stainless steel, and may undergo a pretreatment step using water to remove contaminants attached to the surface of the plated material or solids generated by physical or chemical changes.

[0027] The step of electrolytically degreasing the above-mentioned plated material by placing it in an electrolytic bath is performed to completely remove contaminants on the surface of the plated material and activate the metal surface. The electrolytic degreasing step may utilize an anode electrolytic cleaning method that performs thorough pretreatment by oxidizing contaminants with oxygen generated at the anode. Electrolytic degreasing using the anode electrolytic cleaning method can remove compounds or contaminants on the surface of the plated material. After electrolytic degreasing, a step of neutralizing alkaline residues by immersing it in an acidic cleaning solution may be further included.

[0028] The step of electrolytic degreasing by placing the above-mentioned plated material into an electrolytic bath can be performed at a temperature of 35 to 55°C and a current of 1 to 5A for 4 to 10 minutes by placing an electrolytic degreasing agent into the electrolytic bath. The electrolytic degreasing agent can be EC #100F, a product of Circhem Co., Ltd., and can be introduced at 50 to 150 ml / L. Preferably, it can be introduced at 80 to 100 ml / L. In the electrolytic degreasing step, if the temperature of the electrolytic degreasing is below the above temperature range, oxygen generation may not be sufficient, and if it is performed at a temperature exceeding the above temperature range, oxides such as silicon or carbon remaining after the degreasing may reduce the adhesion. If the current of the electrolytic degreasing is below the above numerical range, the electrolytic degreasing speed is too slow, which lowers the work efficiency, and if the current exceeds the above numerical range, the plating surface may become rough, which may cause a problem of reduced adhesion. If the treatment time of the electrolytic degreasing agent is shorter than the above numerical range, poor adhesion may occur when plating on the surface of the plated material, and if the treatment time exceeds the above numerical range, stains may appear on the surface of the plated material. The electrolytic degreasing agent may include at least one selected from the group consisting of sodium orthosilicate, sodium metasilicate, sodium guarconate, caustic soda, sodium carbonate, and a surfactant.

[0029] The step of etching the plated material using an acid solution after the above electrolytic degreasing step refers to a shallow etching process that chemically dissolves and removes a portion of the surface of the plated material to improve adhesion with the nickel plating formed thereafter. The surface area of ​​the plated material is maximized by the above etching step, thereby increasing adhesion with the ceramic powder composition during plating.

[0030] In the above etching step, a hydrochloric acid solution (HCl) may be added at 300 to 400 ml / L and etching may be performed at a temperature of 10 to 30°C for 30 seconds to 1 minute. The hydrochloric acid solution may be used to condition the surface of the plated material and remove the electrolytic degreasing agent.

[0031] The step of first plating the plated material that has gone through the above etching step with a nickel strike plating solution is performed to increase adhesion with the subsequent mixed plating solution. The nickel strike plating step is performed by immersing the material in a nickel strike plating solution containing nickel chloride (NiCl2) and hydrochloric acid (HCl) to prevent the plating from lifting. The first plating step may be performed at room temperature at a current of 1 to 10 A for 5 to 10 minutes while immersed in the nickel strike plating solution. In the first plating step, if the current is less than the above numerical range, the plating speed may be slowed down, and if it exceeds the above numerical range, the plating thickness may become unnecessarily thick. In addition, if the immersion time in the first plating step is short, less than the above numerical range, poor adhesion may occur when plating the surface of the plated material, and if it is immersed for a long time exceeding the above numerical range, the surface of the plated material may become stained.

[0032] The nickel strike plating solution of the first plating step includes nickel chloride (NiCl2) and hydrochloric acid (HCl), and the weight ratio of the nickel chloride and hydrochloric acid may be 1:0.1 to 1. Preferably, the weight ratio of the nickel chloride and hydrochloric acid may be 1:0.4 to 0.6. If the weight ratio of the hydrochloric acid is less than the above numerical range, the plated layer may not be properly attached to the plated material and may peel off, and if it exceeds the above numerical range, the surface of the plated material may be damaged, which may cause plating defects.

[0033] The step of performing secondary plating by immersing the plated material that has undergone the first plating in a mixed plating solution containing the ceramic powder composition and at least one selected from the group consisting of boric acid (H3BO3), nickel sulfate (NiSO4), and nickel chloride (NiCl2) is performed to improve the antibacterial and antiviral properties of the plated material.

[0034] The above ceramic powder composition may include at least one selected from the group consisting of magnesium oxide (MgO), aluminum oxide (Al2O3), silicon dioxide (SiO2), potassium oxide (K2O), sodium oxide (Na2O), calcium oxide (CaO), and iron oxide (Fe2O3). In the above ceramic powder composition, the weight ratio of magnesium oxide (MgO), aluminum oxide (Al2O3), silicon dioxide (SiO2), potassium oxide (K2O), sodium oxide (Na2O), calcium oxide (CaO), and iron oxide (Fe2O3) may be 1:5 to 15:50 to 70:1 to 5:1 to 5:1 to 5:1 to 5:1 to 5. If the weight ratio of the above silicon dioxide is below the above numerical range, the antibacterial and antiviral properties of the antibacterial stainless steel may be reduced, and if it exceeds the above numerical range, the bonding strength between the ceramic powder composition and the plating solution in the second plating step may be reduced, and the adhesion of the ceramic powder may be reduced.

[0035] The weight ratio of boric acid (H3BO3), nickel sulfate (NiSO4), and nickel chloride (NiCl2) in the plating solution of the secondary plating step may be 1:5 to 10:1 to 5. If the weight ratio of nickel sulfate or nickel chloride is less than the above numerical range, the fixing force of the ceramic powder composition may decrease, thereby reducing the durability of the antibacterial or antiviral properties of the stainless steel. If the weight ratio exceeds the above numerical range, the plating adhesion may decrease and the antibacterial properties may decrease.

[0036] In the above secondary plating step, the weight ratio of the plating solution and the ceramic powder composition may be 1:0.01 to 2. Preferably, it may be 1:0.1 to 1. If the weight ratio of the ceramic powder composition is less than the above numerical range, nickel ions may not be able to fix the ceramic powder, which may result in a decrease in antibacterial and antiviral properties. If the weight ratio exceeds the above numerical range, it may be difficult for the ceramic powder composition to adhere evenly to the stainless steel.

[0037] The step of adding a polishing agent to the plated material that has undergone the above-mentioned secondary plating step to form a ceramic powder-coated stainless steel is intended to maintain a uniform and stable plating formation and color state, and to enhance the glossiness to provide decorative properties to the product surface. The polishing agent can increase the plating speed and have the effect of agglomerating metal particles.

[0038] According to another embodiment of the present invention, a ceramic powder coated antibacterial stainless steel manufactured by any one of the above manufacturing methods is provided.

[0039] The zeta potential of the ceramic powder-coated antibacterial stainless steel manufactured by the above manufacturing method may be -40.0 mV to -30.0 mV. Preferably, the zeta potential of the ceramic powder-coated antibacterial stainless steel manufactured by the above manufacturing method may be -37.7 mV. Since the ceramic powder-coated antibacterial stainless steel has a zeta potential of -37.7 mV, the antibacterial activity of the ceramic powder composition may be enhanced.

[0040]

[0041] Hereinafter, the present invention will be described in more detail through examples. These examples are intended solely to illustrate the present invention more specifically, and it will be apparent to those skilled in the art that the scope of the present invention is not limited by these examples, in accordance with the gist of the present invention.

[0042]

[0043] Examples and Comparative Examples

[0044] Example 1

[0045] The plated material made of stainless steel was placed in a washing tank and washed cleanly (S1).

[0046] The plating material was placed in an electrolytic cell, 90 ml / L of EC #100F from Sechem Co., Ltd. was added to the electrolytic cell, and electrolytic degreasing was performed by flowing a current of 1 to 4 A at a temperature of 45°C (S2).

[0047] The plated material that had gone through the above electrolytic degreasing step was treated with 350 ml / L of a 350 ml / L solution of Yongsan and etched at a temperature of 20°C for 40 seconds (S3).

[0048] The plated material that went through the above etching step was treated with 200 ml / L of nickel chloride and 100 ml / L of hydrochloric acid, and a current of 1 to 8 A was applied for 8 minutes at room temperature to perform primary plating through nickel strike plating (S4).

[0049] A mixed plating solution was prepared by stirring a plating solution composed of 120 mL / L of a ceramic powder composition, 40 ml / L of boric acid (H3BO3), 280 ml / L of nickel sulfate, and 80 ml / L of nickel chloride, and the plated material that had undergone the first plating was supported thereon to perform a second plating (S5).

[0050] A polishing agent was added to the plated material that had gone through the above-mentioned second plating step to form a ceramic powder-coated stainless steel (S6).

[0051] Example 2

[0052] The final ceramic powder-coated stainless steel was obtained in the same manner as in Example 1, except that 4 ml / L of the ceramic powder composition was applied in step S5 of Example 1.

[0053] Example 3

[0054] The final ceramic powder-coated stainless steel was obtained in the same manner as in Example 1, except that 40 ml / L of the ceramic powder composition was applied in step S5 of Example 1.

[0055] Example 4

[0056] The final ceramic powder-coated stainless steel was obtained in the same manner as in Example 1, except that 400 ml / L of the ceramic powder composition was applied in step S5 of Example 1.

[0057] Example 5

[0058] The final ceramic powder-coated stainless steel was obtained in the same manner as in Example 1, except that 800 ml / L of the ceramic powder composition was applied in step S5 of Example 1.

[0059] Comparative Example 1

[0060] Stainless steel was obtained in the same manner as in Example 1, except that the ceramic powder composition was not mixed in step S5 of Example 1.

[0061]

[0062] Experimental Example 1

[0063] Antibacterial efficacy against Escherichia coli was measured (CFU / ml, bacterial reduction rate %) according to the ASTM E2149 test method. Non-plated stainless steel was used as a control.

[0064] Measurement of antibacterial effect against Escherichia coli Initial bacterial count (CFU / mL) Bacterial count after 24 hours (CFU / mL) Bacterial reduction rate % Example 12.6×105 < 3099.9 Example 22.6×10 5 2.4×10 5 7.69 Example 32.6×10 5 1.8×10 5 30.7 Example 42.6×10 5 1.5×10 5 42.3 Example 52.6×10 5 2.3×10 5 11.5 Comparative example 12.6×10 5 3.4×10 5 -Control group 2.6×10 5 2.2×10 5 15.3

[0065] Test conditions: TEST SEPCIMEN WEIGHT: 1.0g

[0066] Buffer solution: PHOSPHATE BUFFER 50 mL (pH 7.2)

[0067] Strain used: Escherichia coli ATCC 25922

[0068]

[0069] Experimental Example 2

[0070] The antibacterial effect against Staphylococcus aureus was measured according to the ASTM E2149 test method (CFU / ml, bacterial reduction rate %). Non-plated stainless steel was used as a control.

[0071] Measurement of antibacterial effect against Staphylococcus aureus. Initial bacterial count (CFU / ml) Number of bacteria after 24 hours (CFU / ml) Bacterial reduction rate % Example 11.9×10 5 < 3099.9 Example 21.9×10 5 1.7×10 5 10.5 Example 31.9×10 5 1.2×10 5 36.3 Example 41.9×10 5 1.1×10 5 42.1 Example 51.9×10 5 1.7×10 510.5 Comparative example 11.9×10 5 3.0×10 5 -Control group 1.9×10 5 1.5×10 5 21.0

[0072] Test conditions: TEST SEPCIMEN WEIGHT: 1.0g

[0073] Buffer solution: PHOSPHATE BUFFER 50 mL (pH 7.2)

[0074] Strain used: Staphylococcus aureus ATCC 6538

[0075]

[0076] Experimental Example 3

[0077] The antibacterial effect against Klebsiella pneumoniae was measured (CFU / ml, bacterial reduction rate %) according to the ASTM E2149 test method. Non-plated stainless steel was used as a control.

[0078] Measurement of antibacterial effect against Klebsiella pneumoniae Initial bacterial count (CFU / ml) Bacterial count after 24 hours (CFU / ml) Bacterial reduction rate % Example 11.6×10 5 < 3099.9 Example 21.6×10 5 1.4×10 5 12.5 Example 31.6×10 5 0.9×10 5 43.7 Example 41.6×10 5 1.0×10 5 37.5 Example 51.6×10 5 1.3×10 5 18.7 Comparative example 11.6×10 5 3.2×10 5 -Control group 1.6×10 5 1.3×10 5 18.7

[0079] Test conditions: TEST SEPCIMEN WEIGHT: 1.0g

[0080] Buffer solution: PHOSPHATE BUFFER 50 mL (pH 7.2)

[0081] Strain used: Klebsiella pneumoniae ATCC 4352

[0082]

[0083] Experimental Example 4

[0084] The antibacterial effect against Pseudomonas aeruginosa was measured (CFU / ml, bacterial reduction rate %) according to the ASTM E2149 test method. Non-plated stainless steel was used as a control.

[0085] Measurement of antibacterial effect against Pseudomonas aeruginosa Initial bacterial count (CFU / ml) Bacterial count after 24 hours (CFU / ml) Bacterial reduction rate % Example 12.0×10 5 < 3099.9 Example 22.0×10 5 1.7×10 5 15.0 Example 32.0×10 5 1.5×10 5 25.0 Example 42.0×10 5 1.4×10 5 30.0 Example 52.0×10 5 1.5×10 5 25.0 Comparative example 12.0×10 5 3.2×10 5 -Control group 2.0×10 5 1.8×10 5 10.0

[0086] Test conditions: TEST SEPCIMEN WEIGHT: 1.0g

[0087] Buffer solution: PHOSPHATE BUFFER 50 mL (pH 7.2)

[0088] Strain used: Pseudomonas aeruginosa ATCC 27853

Claims

1. A step of preparing a plated material made of stainless steel; A step of electrolytic degreasing by putting the above-mentioned plating material into an electrolytic cell; A step of etching the plated material that has gone through the above electrolytic degreasing step using an acid solution; A step of first plating the plated material that has gone through the above etching step with a nickel strike plating solution; A step of performing a second plating by placing the plated material that has undergone the first plating in a mixed plating solution containing a ceramic powder composition and at least one selected from the group consisting of boric acid (H3BO3), nickel sulfate (NiSO4), and nickel chloride (NiCl2); A step of growing ceramic powder-coated stainless steel by adding a polishing agent to the plated material that has gone through the above-mentioned second plating step. A method for manufacturing an antibacterial stainless steel coated with ceramic powder comprising:

2. In claim 1, A method for manufacturing a ceramic powder-coated antibacterial stainless steel, wherein the nickel strike plating solution of the first plating step contains nickel chloride (NiCl2) and hydrochloric acid (HCl), and the weight ratio of the nickel chloride and hydrochloric acid is 1:0.1 to 1.

3. In claim 1, A method for manufacturing a ceramic powder-coated antibacterial stainless steel, wherein the ceramic powder composition comprises at least one selected from the group consisting of magnesium oxide (MgO), aluminum oxide (Al2O3), silicon dioxide (SiO2), potassium oxide (K2O), sodium oxide (Na2O), calcium oxide (CaO), and iron oxide (Fe2O3).

4. In claim 1, A method for manufacturing ceramic powder-coated antibacterial stainless steel, wherein the weight ratio of boric acid (H3BO3), nickel sulfate (NiSO4), and nickel chloride (NiCl2) in the plating solution of the above-mentioned secondary plating step is 1:5 to 10:1 to 5.

5. Ceramic powder coated antibacterial stainless steel manufactured by any one of the manufacturing methods of claims 1 to 4.

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