Steel wire and spring with excellent antibacterial and corrosion resistance, and manufacturing method thereof

Abstract

The present invention relates to a steel wire and spring having excellent antibacterial and corrosion-resistant properties, and a manufacturing method thereof. The antibacterial and corrosion-resistant steel wire of the present invention includes a steel wire and a plating layer formed on the steel wire, the plating layer including a Zn-Al plating layer plated on a surface of the steel wire, and a doping layer formed by doping a metal in a colloidal form on the surface of the Zn-Al plating layer. The manufacturing method of the present invention includes a plating step of forming a plating layer on a surface of the steel wire, the plating step including a surface plating step of plating a surface of the steel wire to form a Zn-Al plating layer, and a doping step of doping a metal in a colloidal form on the surface of the Zn-Al plating layer to form a doping layer.

Description

[Technical Field]

[0001] The present invention relates to a steel wire and spring having excellent antibacterial and corrosion resistance properties, and a manufacturing method thereof. More particularly, the present invention relates to a steel wire and spring having excellent antibacterial and corrosion resistance properties, which are obtained by doping a Zn-Al plating layer with copper in a colloidal form, thereby having excellent antibacterial properties and high corrosion resistance, and a manufacturing method thereof. [Background technology]

[0002] In the medical field, auto injectors are used as medical equipment designed to inject medication in emergency situations. The auto injector is a medical device that injects medication by pushing a piston inside the syringe via a spring.

[0003] Generally, the springs used in medical pen syringes are made of stainless steel wire. However, when the springs of medical pen syringes are made of stainless steel wire, the following problems arise.

[0004] Steel wires used in the medical field must not be harmful to the human body because they are used for treatment purposes, and it is preferable that steel wires used in the medical field are not contaminated by bacteria and have antibacterial properties.

[0005] However, the springs of medical pen syringes made of stainless steel wire not only lack antibacterial properties, but also contain substances harmful to the human body, such as hexavalent chromium. Steel wires are used in a variety of industrial fields other than medical pen syringes, and there is a demand in these fields for the development of steel wires that are not harmful to the human body and have excellent antibacterial properties. Summary of the Invention [Problem to be solved by the invention]

[0006] The present invention is intended to solve the above-mentioned problems, and more specifically, relates to a steel wire and spring having excellent antibacterial properties and corrosion resistance, which are obtained by doping a Zn-Al plating layer with copper in a colloidal form, and which have excellent antibacterial properties and high corrosion resistance, and a method for manufacturing the same. [Means for solving the problem]

[0007] The antibacterial and corrosion-resistant steel wire according to the above-described embodiment of the present invention includes a steel wire and a plating layer formed on the steel wire, the plating layer including a Zn-Al plating layer plated on a surface of the steel wire, and a doping layer formed by doping a metal in a colloidal form on a surface of the Zn-Al plating layer.

[0008] The doping layer of the antibacterial and corrosion-resistant steel wire according to the above-described embodiment of the present invention may be formed by doping copper (Cu) in a colloidal form onto the surface of the Zn-Al plating layer.

[0009] The plating layer of the antibacterial and corrosion-resistant steel wire according to the above-described embodiment of the present invention also contains 84.5 to 96.5 wt % of zinc (Zn), 3 to 15 wt % of aluminum (Al), and 0.01 to 0.5 wt % of copper (Cu).

[0010] The doping layer of the antibacterial and corrosion-resistant steel wire according to the above-described embodiment of the present invention may be formed by doping silver (Ag) or titanium oxide (TiO) in a colloidal form onto the surface of the Zn-Al plating layer.

[0011] The doping layer of the steel wire having excellent antibacterial properties and corrosion resistance according to the above-described embodiment of the present invention may be doped along the plating particle interface formed in the Zn—Al plating layer. The doping layer of the antibacterial and corrosion-resistant steel wire according to the above-described embodiment of the present invention may be doped onto the surface of the Zn-Al plating layer through an electroless plating method.

[0012] The antibacterial and corrosion-resistant steel wire according to the embodiment of the present invention, on which the plating layer is formed, can be drawn at a cross-sectional area reduction rate of 60 to 99%.

[0013] The steel wire of the above-described antibacterial and corrosion-resistant steel wire according to the embodiment of the present invention may be plated with the Zn-Al plating layer, doped with the doping layer, and then wiredrawn, or may be plated with the Zn-Al plating layer, drawn, and then doped with the doping layer.

[0014] The antibacterial and corrosion-resistant spring according to the above-described embodiment of the present invention includes a steel wire and a plating layer formed on the steel wire, the plating layer including a Zn-Al plating layer plated on a surface of the steel wire, and a doping layer formed by doping a metal in a colloidal form on the surface of the Zn-Al plating layer, and the steel wire is processed into a spring shape.

[0015] The method for manufacturing a steel wire having excellent antibacterial properties and corrosion resistance according to the above-described embodiment of the present invention includes a plating step of forming a plating layer on a surface of the steel wire, the plating step including a surface plating step of plating the surface of the steel wire to form a Zn-Al plating layer, and a doping step of doping a metal in a colloidal form onto the surface of the Zn-Al plating layer to form a doping layer.

[0016] In the doping step of the method for manufacturing a steel wire having excellent antibacterial properties and corrosion resistance according to the above-described embodiment of the present invention, copper (Cu) may be doped in a colloidal form onto the surface of the Zn-Al plating layer.

[0017] In the method for producing a steel wire having excellent antibacterial properties and corrosion resistance according to the above-described embodiment of the present invention, the plating layer contains 84.5 to 96.5 wt % of zinc (Zn), 3 to 15 wt % of aluminum (Al), and 0.01 to 0.5 wt % of copper (Cu).

[0018] In the doping step of the method for manufacturing a steel wire having excellent antibacterial properties and corrosion resistance according to the above-described embodiment of the present invention, silver (Ag) or titanium oxide (TiO) may be doped in a colloidal form onto the surface of the Zn-Al plating layer.

[0019] In the doping step of the method for manufacturing a steel wire having excellent antibacterial properties and corrosion resistance according to the above-described embodiment of the present invention, the doping layer may be doped along the plating grain interface formed in the Zn-Al plating layer through an electroless plating method.

[0020] The method for manufacturing a steel wire having excellent antibacterial properties and corrosion resistance according to the above-described embodiment of the present invention may further include a wiredrawing step of drawing the steel wire having the plating layer formed thereon after the doping step, wherein the steel wire having the plating layer formed thereon may be drawn at an area reduction rate of 60 to 99%.

[0021] In the wiredrawing step of the method for manufacturing a steel wire having excellent antibacterial properties and corrosion resistance according to the above-described embodiment of the present invention, the doping layer may be formed on the steel wire through the doping step, and then the steel wire may be wiredrawn, or the Zn-Al plating layer may be formed on the steel wire through the surface plating step, and then the steel wire may be wiredrawn, and then the doping layer may be formed through the doping step.

[0022] The method for manufacturing a spring having excellent antibacterial and corrosion resistance according to the above-described embodiment of the present invention includes a plating step of forming a plating layer on a surface of a steel wire, the plating step including a surface plating step of plating the surface of the steel wire to form a Zn-Al plating layer, and a doping step of doping a metal in a colloidal form on the surface of the Zn-Al plating layer to form a doping layer, and further includes a spring fabrication step of fabricating the steel wire having the plating layer formed thereon into a spring. [Effects of the Invention]

[0023] The present invention relates to a steel wire and spring having excellent antibacterial properties and corrosion resistance, and a manufacturing method thereof. The present invention has an advantage in that it can provide a steel wire having excellent antibacterial properties and high corrosion resistance by doping a Zn-Al plating layer with copper in a colloidal form.

[0024] Furthermore, the present invention has the advantage of being able to provide a special plated steel wire made of high carbon steel material, which has a lower manufacturing cost and is more price competitive than stainless steel.

[0025] In addition, the present invention has the advantage that a spring having high strength and excellent performance compared to stainless steel can be manufactured by manufacturing the spring using steel wire that has excellent antibacterial and corrosion resistance. [Brief explanation of the drawings]

[0026] [Figure 1] 1 is a diagram showing a steel wire plated with a plating layer including a Zn-Al plating layer and a doping layer according to an embodiment of the present invention. FIG. [Figure 2] 1A and 1B are diagrams illustrating a doping layer doped at the interface between plating particles of a Zn-Al plating layer according to an embodiment of the present invention. [Figure 3] 1A-1C show a spring manufactured via steel wire and a syringe to which the spring may be attached, according to an embodiment of the present invention; [Figure 4] 1(a) and 1(b) are process diagrams relating to a method for manufacturing a steel wire having excellent antibacterial properties and corrosion resistance according to an embodiment of the present invention. [Figure 5] FIG. 1 is a time of flight secondary ion mass spectrometry (TOF-SIMS) analysis photograph of a steel wire having a coating layer formed thereon according to an embodiment of the present invention, which shows that copper (Cu) is uniformly dispersed in the Zn-Al coating layer. DETAILED DESCRIPTION OF THE INVENTION

[0027] This specification explains the principles of the present invention and discloses embodiments so as to clarify the scope of the present invention and enable those skilled in the art to practice the invention. The disclosed embodiments may be embodied in various forms.

[0028] The terms "comprise" or "also comprise," as used in various embodiments of the present invention, indicate the presence of the disclosed feature, operation, component, etc., and do not limit the presence of one or more additional features, operations, components, etc. Furthermore, in various embodiments of the present invention, terms such as "comprise" or "have" should be understood to specify the presence of a specified feature, number, step, operation, component, part, or combination thereof, but do not preclude the presence or addition of one or more other features, numbers, steps, operations, components, parts, or combinations thereof.

[0029] When a component is referred to as being "connected" or "coupled" to another component, it should be understood that the component may be directly connected or coupled to the other component, but that there may be additional components between the component and the other component. On the other hand, when a component is referred to as being "directly connected" or "directly coupled" to another component, it should be understood that there are no additional components between the component and the other component.

[0030] As used herein, terms such as "first" and "second" may be used to describe various components, but the components are not limited by the terms. The terms are used only to distinguish one component from another.

[0031] The present invention relates to a steel wire and spring having excellent antibacterial and corrosion resistance properties, and a manufacturing method thereof. The present invention relates to a steel wire and spring having excellent antibacterial and corrosion resistance properties, which are obtained by doping a Zn-Al plating layer with copper in a colloidal form, thereby providing excellent antibacterial properties and high corrosion resistance, and a manufacturing method thereof.

[0032] The antibacterial and corrosion-resistant steel wire according to an embodiment of the present invention may be used as a spring for a medical pen-type syringe. However, the present invention is not limited thereto, and the antibacterial and corrosion-resistant steel wire according to an embodiment of the present invention is not harmful to the human body and can be used in various fields where antibacterial properties are required. Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

[0033] Referring to FIG. 1, a steel wire having excellent antibacterial properties and corrosion resistance according to an embodiment of the present invention includes a steel wire 10 and a plating layer 110.

[0034] The steel wire 10 may be in the form of a wire and may be a high-carbon steel wire containing iron, and may contain 0.35 to 1.00 weight percent carbon (C), 0.1 to 0.3 weight percent silicon (Si), 0.3 to 1.2 weight percent manganese (Mn), 0.001 to 0.035 weight percent phosphorus (P), 0.001 to 0.035 weight percent sulfur (S), 0.001 to 0.30 weight percent copper (Cu), the remainder being iron (Fe), and unavoidable impurities.

[0035] The plating layer 110 may be formed on the steel wire 10 by plating the surface of the steel wire 10 .

[0036] The plating layer 110 includes a Zn-Al plating layer 120 and a doping layer 130. The Zn-Al plating layer 120 is a zinc-aluminum alloy plating layer and can be plated on the surface of the steel wire 10.

[0037] The Zn-Al plating layer 120 can be formed by plating a zinc-aluminum alloy on the surface of the steel wire 10 using various plating methods such as hot dip plating and electroplating.

[0038] The Zn-Al plating layer 120 uses a highly reactive Zn-based plating to prevent corrosion of the iron-containing steel wire 10. Specifically, the Zn-based plating of the Zn-Al plating layer 120 is exposed to the outside and acts as a sacrificial cathode, corroding instead of the iron (Fe) base of the steel wire 10, thereby protecting the iron (Fe) base layer of the steel wire 10. The doped layer 130 is formed by doping a metal in a colloidal form onto the surface of the Zn-Al plating layer 120. According to an embodiment of the present invention, the doped layer 130 may be formed by doping copper (Cu) onto the surface of the Zn-Al plating layer 120 in a colloidal form.

[0039] Here, doping with copper (Cu) in a colloidal form means that copper (Cu) is doped onto the surface of the Zn-Al plating layer 120 in the form of particles, rather than covering the entire surface of the Zn-Al plating layer 120 as shown in FIGS. 1, 2(a) and 2(b).

[0040] As described above, the Zn-based plating of the Zn-Al plating layer 120 can function as a sacrificial positive electrode only when it is exposed to the outside. If copper (Cu) is doped to cover the entire surface of the Zn-Al plating layer 120, even if the plating thickness is thin, the exposed area of ​​the Zn-Al plating layer 120 becomes small, resulting in a small positive and large negative phenomenon in which the Zn-Al plating layer 120 cannot function as a sacrificial positive electrode. This may result in a risk of rapid corrosion of the steel wire 10.

[0041] To prevent this, the doping layer 130 may be formed by doping a metal in a colloidal form onto the surface of the Zn-Al plating layer 120. Specifically, by doping the surface of the Zn-Al plating layer 120 with copper (Cu) in the form of colloidal particles, the Zn-Al plating layer 120 may be exposed to the outside and function as a sacrificial positive electrode.

[0042] The doping layer 130 containing copper (Cu) can ensure antibacterial properties through copper (Cu) even if it is present in trace amounts. Therefore, if copper (Cu) is doped into the surface of the Zn-Al plating layer 120 in the form of colloidal particles, the Zn-Al plating layer 120 can function as a sacrificial positive electrode and improve antibacterial properties through the doping layer 130 containing copper (Cu).

[0043] 2(a) and 2(b), the doping layer 130 may be doped along the plating particle interface 121 formed on the Zn-Al plating layer 120. The Zn-Al plating layer 120 may be formed by plating the steel wire 10 with a zinc-aluminum alloy, and at this time, fine gaps having a honeycomb structure may be formed on the surface of the Zn-Al plating layer 120.

[0044] The minute gaps in the honeycomb structure are difficult to observe with the naked eye and can only be seen under a microscope. The plating grain interfaces 121 formed in the Zn-Al plating layer 120 are also the minute gaps in the honeycomb structure, and the doping layer 130 can be formed along the plating grain interfaces 121.

[0045] More specifically, the Zn-Al plating grain boundary (plating grain interface 121) is a boundary where Zn-Al plating crystals meet while forming, and has high energy, so copper (Cu) particles (the doping layer 130) precipitated on the Zn-Al plating grain boundary (the plating grain interface 121) gather.

[0046] The doping layer 130 containing copper (Cu) may be doped onto the surface of the Zn-Al plating layer 120 by pulse plating, electroless plating, sputtering, spraying, or the like.

[0047] In order to dope the doping layer 130 along the plating grain interface 121 formed on the Zn-Al plating layer 120, the doping layer 130 is preferably doped onto the surface of the Zn-Al plating layer 120 by an electroless plating method.

[0048] The electroless plating method is a method in which metal ions in a metal salt aqueous solution are autocatalytically reduced by the power of a reducing agent without the need for an external supply of electrical energy, thereby depositing metal on the surface of the object to be treated.

[0049] If the doping layer 130 is doped onto the surface of the Zn-Al plating layer 120 through an electrolytic plating method that utilizes the principle of electrolysis to cover the surface of a metal with a thin film of another metal, there is a risk that the doping layer 130 will dope the entire surface of the Zn-Al plating layer 120.

[0050] If the doping layer 130 is doped onto the entire surface of the Zn-Al plating layer 120, the exposed area of ​​the Zn-Al plating layer 120 becomes small, and the Zn-Al plating layer 120 cannot function as a sacrificial positive electrode.

[0051] Therefore, in order to dope the doping layer 130 along the plating grain interface 121 formed on the Zn-Al plating layer 120, it is preferable that the doping layer 130 is doped on the surface of the Zn-Al plating layer 120 through an electroless plating method.

[0052] Specifically, the doping layer 130 may be doped by the principle of a galvanic cell due to the potential difference between copper (Cu) and Zn-Al. Zn particles in the Zn-Al plating layer 120 lose electrons and are oxidized (dissolved) (Zn → Zn2+ +2 e- ) and Cu cations receive electrons and are deposited on the surface (Cu 2+ +2 e- Zn oxidation and Cu deposition occur primarily at the Zn-Al plated interface.

[0053] Once the plating layer 110, including the Zn-Al plating layer 120 and the doping layer 130, is formed on the steel wire 10, the steel wire 10 may be drawn. By drawing the steel wire 10 on which the plating layer 110, including the Zn-Al plating layer 120 and the doping layer 130, is formed, the doping layer 130 may be attached while being uniformly dispersed.

[0054] Specifically, the doping layer 130 has weak adhesion because copper (Cu) is deposited and doped into the Zn-Al plating layer 120. If the steel wire 10 on which the plating layer 110 is formed is subjected to a wiredrawing process, the adhesion of the doping layer 130 can be improved and the doping layer 130 can be attached to the Zn-Al plating layer 120.

[0055] At the same time, the doping layer 130 can be uniformly dispersed on the surface of the Zn-Al plating layer 120, thereby improving antibacterial properties. Figure 5 is a time of flight secondary ion mass spectrometry (TOF-SIMS) analysis photograph of the steel wire 10 having the plating layer 110 formed thereon, when the wire is drawn (Figure 5 shows copper (Cu) dispersed on the surface of the Zn-Al plating layer, and different colors are formed depending on the concentration of copper (Cu)).

[0056] 5, when the steel wire 10 having the plating layer 110 formed thereon is drawn, copper (Cu) is uniformly dispersed on the surface of the Zn-Al plating layer 120, thereby improving antibacterial properties. The steel wire 10 having the plating layer 110 formed thereon can be drawn at a cross-sectional area reduction rate of 60 to 99%.

[0057] According to an embodiment of the present invention, the steel wire 10 is plated with the Zn-Al plating layer 120, doped with the doping layer 130, and then wiredrawn. According to another embodiment of the present invention, the Zn-Al plating layer 120 is plated, the steel wire 10 is wiredrawn, and then the doping layer 130 is doped.

[0058] 3, the antibacterial and corrosion-resistant steel wire according to an embodiment of the present invention can be fabricated into a spring 140. The spring 140 can be used in a medical pen-type injector (auto injector) 141.

[0059] By manufacturing a spring 140 using the steel wire 10 on which the plating layer 110 including the Zn-Al plating layer 120 and the doping layer 130 is formed, a spring 140 with excellent antibacterial properties and corrosion resistance can be manufactured.

[0060] Specifically, the doping layer 130 containing copper (Cu) can improve antibacterial properties, and the Zn-Al plating layer 120 can prevent corrosion of the steel wire 10, thereby improving corrosion resistance.

[0061] The doping layer 130 is doped on the surface of the Zn-Al plating layer 120 in the form of colloidal particles, and therefore does not reduce the corrosion resistance of the Zn-Al plating layer 120, and at the same time, can improve antibacterial properties through copper (Cu).

[0062] According to an embodiment of the present invention, the plating layer 110 including the Zn-Al plating layer 120 and the doping layer 130 may contain 84.5 to 96.5 wt % of zinc (Zn), 3 to 15 wt % of aluminum (Al), and 0.01 to 0.5 wt % of copper (Cu).

[0063] The copper (Cu) contained in the doping layer 130 can improve antibacterial properties even in a small amount, so the copper (Cu) content is preferably 0.01 to 0.5 wt %.

[0064] In the above description, the doping layer 130 is formed through copper (Cu), but is not limited thereto. The doping layer 130 may be formed of various materials as long as the material capable of improving antibacterial properties can be doped into the Zn-Al plating layer 120 in a colloidal form.

[0065] According to another embodiment of the present invention, the doping layer 130 may be formed by doping silver (Ag) or titanium oxide (TiO) in a colloidal form onto the surface of the Zn-Al plating layer 120.

[0066] The antibacterial and corrosion-resistant spring according to an embodiment of the present invention is manufactured by processing the steel wire 10 having the plating layer 110 into a spring shape. The characteristics of the steel wire 10 and the plating layer 110 used in the spring 140 are the same as those described above, and therefore a detailed description thereof will be omitted.

[0067] By manufacturing a spring 140 using the steel wire 10 on which the plating layer 110 including the Zn-Al plating layer 120 and the doping layer 130 is formed, a spring 140 with excellent antibacterial properties and corrosion resistance can be manufactured.

[0068] Furthermore, by manufacturing the spring 140 using the steel wire 10 on which the plating layer 110 including the Zn-Al plating layer 120 and the doping layer 130 is formed, the spring 140 can be manufactured with superior performance and higher strength than stainless steel.

[0069] The antibacterial and corrosion-resistant steel wire according to the embodiment of the present invention may be manufactured by the following method. Referring to Fig. 4(a), the method for manufacturing the antibacterial and corrosion-resistant steel wire according to the embodiment of the present invention includes a plating step (S110) of forming a plating layer 110 on the surface of the steel wire 10.

[0070] The plating step (S110) includes a surface plating step (S120) of plating the surface of the steel wire 10 to form a Zn-Al plating layer 120, and a doping step (S130) of doping the surface of the Zn-Al plating layer 120 with a metal in a colloidal form to form a doped layer 130.

[0071] The steel wire 10 can be in the form of a wire and is a high-carbon steel wire containing iron. The steel wire 10 also contains 0.35 to 1.00 weight percent carbon (C), 0.1 to 0.3 weight percent silicon (Si), 0.3 to 1.2 weight percent manganese (Mn), 0.001 to 0.035 weight percent phosphorus (P), 0.001 to 0.035 weight percent sulfur (S), 0.001 to 0.30 weight percent copper (Cu), and the remainder iron (Fe), as well as unavoidable impurities.

[0072] The surface plating step (S120) forms a Zn-Al plating layer 120 on the surface of the steel wire 10. The Zn-Al plating layer 120 can be formed by plating a zinc-aluminum alloy on the surface of the steel wire 10 through various plating methods such as hot dip plating and electroplating.

[0073] The Zn-Al plating layer 120 uses a highly reactive Zn-based plating to prevent corrosion of the iron-containing steel wire 10. Specifically, the Zn-based plating of the Zn-Al plating layer 120 is exposed to the outside and acts as a sacrificial cathode, corroding instead of the iron (Fe) base of the steel wire 10, thereby protecting the iron (Fe) base layer of the steel wire 10.

[0074] The doping step (S130) is a step of doping a metal in a colloidal form onto the surface of the Zn-Al plating layer 120 to form a doped layer 130. The doped layer 130 may be formed by doping a metal in a colloidal form onto the surface of the Zn-Al plating layer 120.

[0075] In the doping step (S130) according to an embodiment of the present invention, copper (Cu) may be doped in a colloidal form onto the surface of the Zn-Al plating layer 120 to form the doped layer 130.

[0076] Here, doping with copper (Cu) in a colloidal form refers to doping of copper (Cu) in the form of particles onto the surface of the Zn-Al plating layer 120, rather than covering the entire surface of the Zn-Al plating layer 120 as shown in FIGS. 1, 2(a) and 2(b).

[0077] As described above, the Zn-based plating of the Zn-Al plating layer 120 can function as a sacrificial positive electrode only when it is exposed to the outside. If copper (Cu) is doped to cover the entire surface of the Zn-Al plating layer 120, even if the plating thickness is thin, the exposed area of ​​the Zn-Al plating layer 120 becomes small, resulting in a small positive electrode / large negative electrode phenomenon in which the Zn-Al plating layer 120 cannot function as a sacrificial positive electrode. This may result in a risk of rapid corrosion of the steel wire 10.

[0078] To prevent this, in the doping step (S130), the doped layer 130 may be formed by doping the surface of the Zn-Al plating layer 120 with a metal in a colloidal form.

[0079] 2(a) and 2(b), in the doping step (S130), the doping layer 130 may be doped along the plating particle interface 121 formed on the Zn-Al plating layer 120 using an electroless plating method. The Zn-Al plating layer 120 may be formed by plating the steel wire 10 with a zinc-aluminum alloy, and at this time, fine voids having a honeycomb structure may be formed on the surface of the Zn-Al plating layer 120.

[0080] The fine gaps in the honeycomb structure are difficult to see with the naked eye and can only be seen under a microscope. The plating grain interfaces 121 formed in the Zn-Al plating layer 120 are also the fine gaps in the honeycomb structure, and the doping layer 130 can be doped along the plating grain interfaces 121.

[0081] More specifically, the Zn-Al plating grain boundary (plating particle interface 121) is a boundary where Zn-Al plating crystals meet each other while they are being generated, and has high energy, so copper (Cu) particles (doping layer 130) precipitated on the Zn-Al plating grain boundary (plating particle interface 121) gather.

[0082] The doping layer 130 containing copper (Cu) may be doped onto the surface of the Zn-Al plating layer 120 by pulse plating, electroless plating, sputtering, spraying, or the like.

[0083] However, in the doping step (S130), it is preferable to use an electroless plating method to dope the doped layer 130 along the plating particle interface 121 formed in the Zn—Al plating layer 120.

[0084] The electroless plating method is a method in which metal ions in a metal salt aqueous solution are autocatalytically reduced by the power of a reducing agent without the need for an external supply of electrical energy, thereby depositing metal on the surface of the object to be treated.

[0085] If the doping layer 130 is plated on the surface of the Zn-Al plating layer 120 through an electrolytic plating method that uses the principle of electrolysis to cover the surface of a metal with a thin film of another metal, there is a risk that the doping layer 130 will dope the entire surface of the Zn-Al plating layer 120.

[0086] If the doping layer 130 is doped onto the entire surface of the Zn-Al plating layer 120, the exposed area of ​​the Zn-Al plating layer 120 becomes small, and the Zn-Al plating layer 120 cannot function as a sacrificial positive electrode.

[0087] Therefore, in order to dope the doping layer 130 along the plating grain interface 121 formed on the Zn-Al plating layer 120, it is preferable that the doping layer 130 is doped on the surface of the Zn-Al plating layer 120 through an electroless plating method.

[0088] Specifically, the doping layer 130 may be doped by the galvanic cell principle due to the potential difference between copper (Cu) and Zn-Al. Zn particles in the Zn-Al plating layer 120 lose electrons and are oxidized (dissolved) (Zn → Zn 2+ +2 e- ), Cu cations receive electrons and are deposited on the surface (Cu 2+ +2 e- Zn oxidation and Cu deposition occur primarily at the Zn-Al plated interface.

[0089] The method for manufacturing a steel wire having excellent antibacterial properties and corrosion resistance according to an embodiment of the present invention may further include a wire drawing step (S140) and a spring manufacturing step (S150).

[0090] The wire-drawing step (S140) is a step of drawing the steel wire 10 on which the plating layer is formed. Once the plating layer 110, including the Zn-Al plating layer 120 and the doping layer 130, is formed on the steel wire 10, the steel wire 10 can be drawn through the wire-drawing step (S140). By drawing the steel wire 10 on which the plating layer 110, including the Zn-Al plating layer 120 and the doping layer 130, is formed, the doping layer 130 can be attached while being uniformly dispersed.

[0091] Specifically, the doping layer 130 has weak adhesion because copper (Cu) is deposited and doped into the Zn-Al plating layer 120. If the steel wire 10 on which the plating layer 110 is formed is subjected to a wiredrawing process, the adhesion of the doping layer 130 can be improved and the doping layer 130 can be attached to the Zn-Al plating layer 120.

[0092] At the same time, the doping layer 130 can be uniformly dispersed on the surface of the Zn-Al plating layer 120, thereby improving antibacterial properties. Figure 5 is a TOF-SIMS analysis photograph of the steel wire 10 having the plating layer 110 formed thereon when the steel wire 10 is drawn (Figure 5 shows copper (Cu) dispersed on the surface of the Zn-Al plating layer, and different colors are formed depending on the concentration of copper (Cu)).

[0093] 5, when the steel wire 10 having the plating layer 110 formed thereon is drawn, copper (Cu) is uniformly dispersed on the surface of the Zn-Al plating layer 120, thereby improving antibacterial properties. In the drawing step (S140), the steel wire 10 having the plating layer 110 formed thereon may be drawn at a cross-sectional area reduction rate of 60 to 99%.

[0094] According to an embodiment of the present invention, the wire-drawing step (S140) may be performed by forming the doping layer 130 on the steel wire 10 through the doping step (S130) as shown in FIG. 4(a) and then drawing the steel wire. According to another embodiment of the present invention, as shown in FIG. 4(b), the Zn-Al plating layer 120 may be formed on the steel wire 10 through the surface plating step 120, then drawing the steel wire 10, and then forming the doping layer 130 through the doping step (S130).

[0095] The spring preparation step (S150) is a step of preparing the steel wire drawn in the wire drawing step (S140) into a spring shape. Referring to Fig. 3, the steel wire drawn in the wire drawing step (S140) can be prepared as a spring 140. The spring 140 can be used in a medical pen-type injector (auto injector) 141. By manufacturing a spring 140 using the steel wire 10 on which the plating layer 110 including the Zn-Al plating layer 120 and the doping layer 130 is formed, a spring 140 with excellent antibacterial properties and corrosion resistance can be manufactured.

[0096] Specifically, the doping layer 130 containing copper (Cu) can improve antibacterial properties, and the Zn-Al plating layer 120 can prevent corrosion of the steel wire 10, thereby improving corrosion resistance.

[0097] The doping layer 130 is doped on the surface of the Zn-Al plating layer 120 in the form of colloidal particles, and therefore does not reduce the corrosion resistance of the Zn-Al plating layer 120, and at the same time, can improve antibacterial properties through copper (Cu).

[0098] According to an embodiment of the present invention, the plating layer 110 including the Zn-Al plating layer 120 and the doping layer 130 may contain 84.5 to 96.5 wt % of zinc (Zn), 3 to 15 wt % of aluminum (Al), and 0.01 to 0.5 wt % of copper (Cu).

[0099] The copper (Cu) contained in the doping layer 130 can improve antibacterial properties even in a small amount, so the copper (Cu) content is preferably 0.01 to 0.5 wt %.

[0100] In the above description, the doping layer 130 is formed through copper (Cu), but is not limited thereto. The doping layer 130 may be formed of various materials as long as the material capable of improving antibacterial properties is doped into the Zn-Al plating layer 120 in a colloidal form.

[0101] According to another embodiment of the present invention, the doping step (S120) may also be performed by doping silver (Ag) or titanium oxide (TiO) in a colloidal form onto the surface of the Zn-Al plating layer 120 to form the doped layer 130.

[0102] The method for manufacturing a spring having excellent antibacterial and corrosion resistance according to an embodiment of the present invention includes a plating step (S110) of forming a plating layer 110 on the surface of the steel wire 10, and a spring manufacturing step (S140).

[0103] The plating step (S110) includes a surface plating step (S120) of plating the surface of the steel wire 10 to form the Zn-Al plating layer 120, and a doping step (S130) of doping the surface of the Zn-Al plating layer 120 with a metal in a colloidal form to form the doped layer 130.

[0104] In the method for manufacturing a spring having excellent antibacterial properties and corrosion resistance according to an embodiment of the present invention, the steel wire 10 having the plating layer 110 formed thereon is processed into a spring shape.

[0105] The features of the steel wire 10 and the plating layer 110 used in the spring 140 are the same as those described above, and therefore detailed descriptions thereof will be omitted. In addition, the features of the surface plating step (S120) of forming a plating layer on the steel wire 10, the doping step (S130), and the wire drawing step (S140) of drawing the steel wire 10 with the plating layer 110 formed thereon are the same as those of the method for manufacturing a steel wire having excellent antibacterial properties and corrosion resistance according to the above-described embodiment of the present invention, and therefore detailed descriptions thereof will be omitted.

[0106] The spring fabrication step (S150) is a step of fabricating the steel wire 10 having the plating layer 110 into a spring, and is the same step as the step of fabricating the antibacterial and corrosion-resistant steel wire into a spring according to an embodiment of the present invention. The details of the spring fabrication step (S150) have been described above, so a detailed description thereof will be omitted.

[0107] By manufacturing a spring 140 using the steel wire 10 on which the plating layer 110 including the Zn-Al plating layer 120 and the doping layer 130 is formed, a spring 140 with excellent antibacterial properties and corrosion resistance can be manufactured.

[0108] Furthermore, by manufacturing the spring 140 using the steel wire 10 on which the plating layer 110 including the Zn-Al plating layer 120 and the doping layer 130 is formed, the spring 140 can be manufactured with superior performance and higher strength than stainless steel.

[0109] The steel wire and spring having excellent antibacterial properties and corrosion resistance and the manufacturing method thereof according to the above-described embodiment of the present invention have the following advantages.

[0110] The antibacterial and corrosion-resistant steel wire and its manufacturing method according to an embodiment of the present invention have an advantage in that it can provide a steel wire that has excellent antibacterial properties and high corrosion resistance by doping copper in a colloidal form into a Zn-Al plating layer.

[0111] Specifically, the antibacterial and corrosion-resistant steel wire and its manufacturing method according to an embodiment of the present invention have the advantages of improving antibacterial properties through a doping layer containing copper (Cu) and improving corrosion resistance by preventing corrosion of the steel wire through a Zn-Al plating layer.

[0112] In particular, the antibacterial and corrosion-resistant steel wire and its manufacturing method according to the embodiment of the present invention has an advantage that the doping layer is doped in the form of colloidal particles on the surface of the Zn-Al plating layer, so that the corrosion resistance of the Zn-Al plating layer is not reduced and at the same time, the antibacterial property can be improved through copper (Cu).

[0113] In addition, the antibacterial and corrosion-resistant steel wire and its manufacturing method according to the embodiment of the present invention have the advantage that it can provide a special plated steel wire made of high-carbon steel material that has a lower manufacturing cost and is more price competitive than stainless steel.

[0114] In addition, the antibacterial and corrosion-resistant spring and its manufacturing method according to the embodiment of the present invention has an advantage that a spring with superior performance and higher strength than stainless steel can be manufactured by manufacturing the spring using steel wire with excellent antibacterial and corrosion resistance.

[0115] Although the present invention has been described with reference to the embodiments shown in the drawings, these are merely illustrative, and those skilled in the art will appreciate that various modifications and variations of the embodiments are possible therefrom. Therefore, the true technical scope of protection of the present invention is defined by the technical spirit of the appended claims.

Claims

1. A method for producing a steel wire having a plating layer formed thereon, comprising: a plating step of forming a plating layer on the surface of the steel wire, The plating step includes: a surface plating step of plating the surface of the steel wire to form a Zn-Al plating layer; and doping the surface of the Zn—Al plating layer with a metal in a colloidal form to form a doped layer; The doping step comprises: A method for manufacturing a steel wire having excellent antibacterial properties and corrosion resistance, characterized in that the doping layer is doped along the plating particle interface formed in the Zn-Al plating layer via an electroless plating method.

2. The doping step comprises:

2. The method for manufacturing a steel wire having excellent antibacterial and corrosion resistance according to claim 1, wherein copper (Cu) is doped in a colloidal form on the surface of the Zn-Al plating layer.

3. The plating layer is 3. The method for producing a steel wire having excellent antibacterial properties and corrosion resistance according to claim 2, characterized in that the steel wire contains 84.5 to 96.5 wt % of zinc (Zn), 3 to 15 wt % of aluminum (Al), and 0.01 to 0.5 wt % of copper (Cu).

4. The doping step comprises:

2. The method for manufacturing a steel wire having excellent antibacterial and corrosion resistance according to claim 1, wherein silver (Ag) or titanium oxide (TiO) is doped in a colloidal form on the surface of the Zn-Al plating layer.

5. The method further includes a wiredrawing step of drawing the steel wire on which the plating layer is formed, 2. The method for manufacturing a steel wire having excellent antibacterial and corrosion resistance according to claim 1, wherein, in the wiredrawing, the steel wire having the plating layer formed thereon is drawn at a cross-sectional area reduction rate of 60 to 99%.

6. The wire drawing step includes: After the doping step is performed to form the doped layer on the steel wire, the steel wire is drawn; or 6. The method for manufacturing a steel wire having excellent antibacterial properties and corrosion resistance as claimed in claim 5, wherein the Zn-Al plating layer is formed on the steel wire through the surface plating step, the steel wire is then wiredrawn, and the doping layer is formed through the doping step.

7. A method for manufacturing a spring using a steel wire having a plated layer formed thereon, a plating step of forming a plating layer on the surface of the steel wire, The plating step includes: a surface plating step of plating the surface of the steel wire to form a Zn-Al plating layer; and doping the surface of the Zn—Al plating layer with a metal in a colloidal form to form a doped layer; The method further includes manufacturing the steel wire having the plating layer formed thereon into a spring. The doping step comprises: A method for manufacturing a spring having excellent antibacterial and corrosion resistance, characterized in that the doping layer is doped along the plating particle interface formed in the Zn-Al plating layer through an electroless plating method.

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