Micro-hole stainless steel fabric plating method

Abstract

The present invention provides a method for plating a stainless steel fabric with microholes, comprising the steps of: preparing a stainless steel fabric having microholes formed therein; pre-treating the stainless steel fabric; electrolessly plating the pre-treated stainless steel fabric to form an electroless nickel plating layer; forming a film layer containing chromium on the electroless nickel plating layer; and forming a water-repellent coating layer on the film layer containing chromium.

Description

Technology Field

[0001] The present invention relates to a stainless steel substrate containing microholes, and more specifically, to a plating method for improving the uniformity and corrosion resistance of a plating layer while maintaining the shape and opening characteristics of the microholes for a stainless steel substrate, which is prone to reduced plating adhesion due to a passivation film. Background Technology

[0002] Stainless steel is an alloy steel with chromium as its main component, exhibiting excellent corrosion resistance due to a chromium oxide-based passivation film that forms naturally in air. However, this passivation film hinders interfacial bonding between the metal surface and the plating layer, leading to insufficient adhesion during electroplating or electroless plating processes.

[0003] In particular, in the case of micro-hole stainless steel fabrics used for applications such as precision filters, sound meshes, sensor protective films, and fine spray nozzles, the following problems appear significantly because high-density micro-holes are formed throughout the entire fabric.

[0004] First, due to the non-uniform current distribution or degree of activation inside the micro-holes and near the edges surrounding the holes, significant variations in plating thickness occur.

[0005] Second, the effective opening ratio of the microhole is reduced and fluid flow characteristics are degraded by plating protrusions or bridges formed inside the hole.

[0006] Third, localized corrosion is accelerated due to plating peeling, pinholes, and pores at the edges around the holes, resulting in a shortened overall corrosion life.

[0007] Conventionally, methods have been proposed to roughen the stainless steel surface by sandpaper polishing, sandblasting, pickling, or activation, or to remove the passivation film using a strong acid-based activator and then perform a plating process.

[0008] However, this method entails problems such as hole shape collapse due to excessive etching at the micro-hole edges, poor cleaning and subsequent corrosion resulting from solution trapping inside the holes, and the burden of using strong acids in terms of environment and safety.

[0009] In addition, although a technology is known to enhance corrosion resistance by forming an additional organic coating or paint film after plating, there are problems such as partially closing the micro-holes or the coating film remaining inside the holes, which reduces the effective opening ratio.

[0010] Therefore, there is a need to develop a new plating method that can resolve the problem of reduced adhesion caused by the stainless steel passivation film, maintain the shape and aperture ratio of microholes, and simultaneously form a uniform plating thickness inside and around the holes. Prior art literature

[0011] Republic of Korea Registered Patent No. 10-2766585 The problem to be solved

[0012] The objective of the present invention is to provide a method for plating a stainless steel fabric with micro-holes.

[0013] The problems of the present invention are not limited to those mentioned above, and other problems not mentioned will be clearly understood by those skilled in the art from the description below. means of solving the problem

[0014] To achieve the above objective, the present invention

[0015] Step of preparing a stainless steel fabric with micro-holes formed therein;

[0016] A step of pre-treating the above stainless steel fabric;

[0017] A step of forming an electroless nickel plating layer by electroless nickel plating on a pretreated stainless steel substrate;

[0018] A step of forming a chromium-containing film layer on the above electroless nickel plating layer; and

[0019] A method for plating a micro-hole stainless steel fabric is provided, comprising the step of forming a water-repellent coating layer on a film layer containing chromium.

[0020] In addition, the above preprocessing step is,

[0021] A step of primary pre-treating the above stainless steel material with an alkaline solution;

[0022] Step of performing a first rinse on the first pre-treated stainless steel fabric;

[0023] A step of secondary pre-treating the primary washed stainless steel material with an acid solution; and

[0024] It is characterized by performing a step of washing the stainless steel fabric that has undergone secondary pretreatment with water.

[0025] In addition, the alkaline solution comprises 2-4 parts by weight of sodium hydroxide, 0.8-1.2 parts by weight of sodium phosphate, 0.8-1.2 parts by weight of a first surfactant, and 94-96 parts by weight of purified water, and

[0026] The above acid solution comprises 3-5 parts by weight of sulfuric acid, 1-3 parts by weight of hydrochloric acid, 0.8-1.2 parts by weight of a second surfactant, and 92-94 parts by weight of purified water, and

[0027] The first surfactant is a first acrylic copolymer comprising 23-27 parts by weight of N-butyl acrylate monomer units, 23-27 parts by weight of acrylic acid monomer units, 23-27 parts by weight of polyethylene glycol monomethyl ether methacrylate monomer units, and 23-27 parts by weight of 2-(methacryloyloxy)ethyl dihydrogen phosphate monomer units, and

[0028] The second surfactant is characterized by being a second acrylic copolymer comprising 23-27 parts by weight of N-butyl acrylate monomer units, 23-27 parts by weight of acrylic acid monomer units, 23-27 parts by weight of 1H,1H,7H-dodecafluoroheptyl methacrylate monomer units, and 23-27 parts by weight of 2-(methacryloyloxy)ethanesulfonic acid monomer units.

[0029] In addition, the water-repellent coating layer is characterized by being formed from a composition for forming a water-repellent coating layer comprising 68-72 parts by weight of a silicone polymer comprising 23-27 parts by weight of methyltrimethoxysilane monomer units, 23-27 parts by weight of vinyltrimethoxysilane monomer units, and 48-52 parts by weight of (tridecafluoro-1,1,2,2-tetrahydrooctyl)triethoxysilane monomer units, 18-22 parts by weight of silica nanoparticles, and 8-12 parts by weight of ethylnonafluoroisobutyl ether.

[0030] In addition, the water-repellent coating layer is characterized by being formed from a composition for forming a water-repellent coating layer comprising 68-72 parts by weight of a silicone polymer comprising 23-27 parts by weight of methyltrimethoxysilane monomer units, 23-27 parts by weight of vinyltrimethoxysilane monomer units, 23-27 parts by weight of (tridecafluoro-1,1,2,2-tetrahydrooctyl)triethoxysilane) monomer units, and 23-27 parts by weight of 3-methacrylamidopropyltris(trimethylsiloxy)silane monomer units, 18-22 parts by weight of silica nanoparticles, and 8-12 parts by weight of ethylnonafluoroisobutyl ether.

[0031] In addition, the present invention

[0032] Stainless steel fabric with micro-holes formed therein;

[0033] Electroless nickel plating layer formed on the upper surface of the above stainless steel fabric;

[0034] A film layer containing chromium formed on the upper portion of the above electroless nickel plating layer; and

[0035] A water-repellent coating layer formed on top of the film layer containing the above chromium; comprising

[0036] The above water-repellent coating layer is,

[0037] The present invention provides a stainless steel fabric with microhole plating treatment, characterized by being formed from a composition for forming a water-repellent coating layer comprising 68-72 parts by weight of a silicone polymer comprising 23-27 parts by weight of methyltrimethoxysilane monomer units, 23-27 parts by weight of vinyltrimethoxysilane monomer units, 23-27 parts by weight of (tridecafluoro-1,1,2,2-tetrahydrooctyl)triethoxysilane) monomer units, and 23-27 parts by weight of 3-methacrylamidopropyltris(trimethylsiloxy)silane monomer units, 18-22 parts by weight of silica nanoparticles, and 8-12 parts by weight of ethylnonafluoroisobutyl ether. Effects of the invention

[0038] The micro-hole stainless steel fabric plating method according to the present invention can ensure plating uniformity, enables plating while maintaining the micro-hole shape and opening ratio, and has high corrosion resistance through a double barrier consisting of a chromium-containing film layer and a water-repellent coating layer. Specific details for implementing the invention

[0039] Various embodiments are described in more detail below. The embodiments described herein may be modified in various ways. Specific embodiments may be described in detail in the detailed description. However, the specific embodiments disclosed are intended only to facilitate understanding of various embodiments. Accordingly, the technical concept is not limited by the specific embodiments disclosed, and it should be understood that it includes all equivalents or substitutions that fall within the spirit and scope of the invention.

[0040] Terms including ordinal numbers, such as first, second, first, second, etc., may be used to describe various components, but these components are not limited by the aforementioned terms. The aforementioned terms are used solely for the purpose of distinguishing one component from another.

[0041] In this specification, terms such as "comprising" or "having" are intended to indicate the existence of the features, numbers, steps, actions, components, parts, or combinations thereof described in the specification, and should be understood as not precluding the existence or addition of one or more other features, numbers, steps, actions, components, parts, or combinations thereof. When a component is described as being "connected" or "connected" to another component, it should be understood that it may be directly connected to or connected to that other component, or that there may be other components in between. On the other hand, when a component is described as being "directly connected" or "directly connected" to another component, it should be understood that there are no other components in between.

[0042] In this specification, the term "stainless steel fabric" refers to a material made primarily of stainless steel, and refers to a sheet-type or roll-type material having a substrate, plate, fiber, wire, filament, or a woven, knitted, braided, or mesh structure thereof. Specifically, it includes austenitic, ferritic, or martensitic stainless alloys such as SUS 304, SUS 316, and SUS 316L that are formed into a substrate, plate, fiber, or fine wire and then woven or compressed. The stainless steel fabric is characterized as a sheet-type fabric with a thickness in the range of 10 to 200 μm, primarily having a high-density microhole (microhole, average diameter 5 to 500 μm) pattern formed by etching, laser processing, or electrolytic processing, and is used for purposes such as filter mesh, sound mesh, mist spray nozzle sheet, sensor protective film, or precision separation membrane.

[0043] Furthermore, in describing the present invention, if it is determined that a detailed description of related known functions or configurations may unnecessarily obscure the essence of the invention, such detailed description is abbreviated or omitted.

[0044] The present invention

[0045] Step of preparing a stainless steel fabric with micro-holes formed therein;

[0046] A step of pre-treating the above stainless steel fabric;

[0047] A step of forming an electroless nickel plating layer by electroless nickel plating on a pretreated stainless steel substrate;

[0048] A step of forming a chromium-containing film layer on the above electroless nickel plating layer; and

[0049] A method for plating a micro-hole stainless steel fabric is provided, comprising the step of forming a water-repellent coating layer on a film layer containing chromium.

[0050] Hereinafter, the method for plating a stainless steel fabric with micro-holes according to the present invention will be described in detail step by step.

[0052] First, the micro-hole stainless steel fabric plating method according to the present invention includes the step of preparing a stainless steel fabric having micro-holes formed therein.

[0053] The stainless steel fabric having the above-mentioned microholes may be a substrate made of stainless steel; a plate; or a sheet-type or roll-type material having a fiber, wire, filament, or a woven, knitted, braided, or mesh structure thereof.

[0055] Next, the micro-hole stainless steel fabric plating method according to the present invention includes a step of pre-treating the stainless steel fabric.

[0056] The above pretreatment step may be performed by including an alkaline degreasing process and pickling or mixed acid treatment to remove the passivation film and organic and inorganic contaminants from the stainless steel surface and to form an active surface suitable for plating.

[0057] Specifically, the above preprocessing step is,

[0058] A step of primary pre-treating the above stainless steel material with an alkaline solution;

[0059] Step of performing a first rinse on the first pre-treated stainless steel fabric;

[0060] A step of secondary pre-treating the primary washed stainless steel material with an acid solution; and

[0061] It is desirable to perform a step of washing the stainless steel fabric that has undergone secondary pretreatment with water.

[0062] Preferably, the alkaline solution comprises 2-4 parts by weight of sodium hydroxide, 0.8-1.2 parts by weight of sodium phosphate, 0.8-1.2 parts by weight of a first surfactant, and 94-96 parts by weight of purified water, and the first surfactant comprises a first acrylic copolymer comprising 23-27 parts by weight of N-butyl acrylate monomer unit, 23-27 parts by weight of acrylic acid monomer unit, 23-27 parts by weight of polyethylene glycol monomethyl ether methacrylate monomer unit, and 23-27 parts by weight of 2-(methacryloyloxy)ethyl dihydrogen phosphate monomer unit.

[0063] By mixing the sodium hydroxide and sodium phosphate mentioned above, and using an alkaline solution mixed with a first acrylic copolymer comprising 23-27 parts by weight of N-butyl acrylate monomer unit, 23-27 parts by weight of acrylic acid monomer unit, 23-27 parts by weight of polyethylene glycol monomethyl ether methacrylate monomer unit, and 23-27 parts by weight of 2-(methacryloyloxy)ethyl dihydrogen phosphate monomer unit as a surfactant, metal oxide particles, corrosion products, etc. generated on the surface of the stainless steel fabric containing microholes can be effectively removed.

[0064] The first surfactant described above contains a 2-(methacryloyloxy)ethyl dihydrogen phosphate monomer unit, which is anionized under alkaline conditions and adsorbs to a metal surface, making it advantageous for emulsification, dispersion, and sludge stabilization. It also contains an ethylene oxide chain, which wets both the oil and water phases simultaneously, making it advantageous for oil penetration / striping and re-emulsification. Furthermore, through hydrophobic groups based on butyl groups, it secures affinity for oil stains (lubricating oil, cutting oil, etc.), lowers interfacial tension to increase solubility for contaminants, and plays a role in dispersing oxides / sludge detached during cleaning and preventing re-attachment.

[0065] In addition, the acid solution preferably comprises 3-5 parts by weight of sulfuric acid, 1-3 parts by weight of hydrochloric acid, 0.8-1.2 parts by weight of a second surfactant, and 92-94 parts by weight of purified water, and the second surfactant is a second acrylic copolymer comprising 23-27 parts by weight of N-butyl acrylate monomer unit, 23-27 parts by weight of acrylic acid monomer unit, 23-27 parts by weight of 1H,1H,7H-dodecafluoroheptyl methacrylate monomer unit, and 23-27 parts by weight of 2-(methacryloyloxy)ethanesulfonic acid monomer unit.

[0066] By mixing the above sulfuric acid and hydrochloric acid, and using an acid solution mixed with a second acrylic copolymer comprising 23-27 parts by weight of N-butyl acrylate monomer unit, 23-27 parts by weight of acrylic acid monomer unit, 23-27 parts by weight of 1H,1H,7H-dodecafluoroheptyl methacrylate monomer unit, and 23-27 parts by weight of 2-(methacryloyloxy)ethanesulfonic acid monomer unit as a surfactant, the stainless steel material having microholes can be secondarily pretreated to minimize surface damage and completely remove foreign substances that interfere with the formation of a passivation film such as an oxide layer and a nickel plating layer.

[0067] The above second surfactant applies a 2-(methacryloyloxy)ethanesulfonic acid monomer unit to chemically adsorb (chelate) Cr2O3, Fe2O3, etc. formed on the stainless steel surface, thereby suppressing excessive etching of the acid, forming a uniformly active surface, being stable in sulfuric acid / hydrochloric acid, and improving the adhesion of subsequent plating after picking.

[0069] Next, the micro-hole stainless steel fabric plating method according to the present invention includes the step of forming an electroless nickel plating layer by electroless nickel plating on a pretreated stainless steel fabric.

[0070] In the above step, a nickel plating layer is formed using an electroless method.

[0071] A general electroless nickel plating method can be applied to a metal substrate. For example, in the above step, a stainless steel substrate can be immersed in an electroless nickel plating bath containing a nickel ion source such as a nickel salt, a reducing agent such as sodium hypophosphite or ammonium hypophosphite, a buffer, a complexing agent, and a stabilizer, to form a nickel or nickel alloy layer through a self-catalytic reaction. As another example, a nickel plating layer can be formed by immersing the substrate in a nickel plating bath containing a nickel salt such as NiSO4·6H2O, a reducing agent, lactic acid, a buffer, and a stabilizer at a temperature of 50-100°C for 10-60 minutes.

[0073] Next, the micro-hole stainless steel fabric plating method according to the present invention includes the step of forming a film layer containing chromium on the electroless nickel plating layer.

[0074] In the above step, a film layer containing chromium is formed.

[0075] The above film layer may be chromium alone, a chromium alloy, or a chromium oxide.

[0076] In the above step, a dense film layer based on chromium oxide or chromium hydroxide is formed on the surface of the electroless nickel plating layer by using electrolytic oxidation or chemical oxidation conditions in an aqueous solution containing chromic acid or chromate (CrO3, Na2Cr2O7). For example, a film layer containing chromium can be formed by applying an electric current at a temperature of 20-70°C and a treatment time of 0.5-10 minutes in a solution containing 10-200 g / L of chromic acid. Alternatively, it is also possible to form an electroless chromium oxide film layer using chemical oxidation conditions combining chromate and an oxidizing agent. A process for manufacturing a chromium oxide coating layer or a chromium alloy coating layer, which are generally applied, can be performed.

[0078] Next, the micro-hole stainless steel fabric plating method according to the present invention includes the step of forming a water-repellent coating layer on the chromium-containing film layer.

[0079] In the above step, a water-repellent coating layer is formed on a film layer containing chromium.

[0080] By sequentially forming a chromium-containing film layer and a water-repellent coating layer on an electroless nickel plating layer, a double barrier consisting of a chemical film and a physical water-repellent layer can be realized, thereby providing a plating method that improves long-term corrosion resistance and stain resistance.

[0081] The above water-repellent coating layer is preferably formed from a composition for forming a water-repellent coating layer comprising 68-72 parts by weight of a silicone polymer comprising 23-27 parts by weight of methyltrimethoxysilane monomer units, 23-27 parts by weight of vinyltrimethoxysilane monomer units, and 48-52 parts by weight of (tridecafluoro-1,1,2,2-tetrahydrooctyl)triethoxysilane monomer units, 18-22 parts by weight of silica nanoparticles, and 8-12 parts by weight of ethylnonafluoroisobutyl ether.

[0082] The above silicone polymer can be manufactured specifically by performing the following process. Specifically, raw materials for constituting each monomer unit are added to a reactor, and an organic solvent is added in an amount of 0.3 to 1.5 times the total weight of the monomer. Then, an appropriate amount of acidic solution is dropped to adjust the pH to between 1.0 and 5.5, and the mixture is stirred sufficiently and uniformly. The organic solvent is ethanol, methanol, butanol, xylene, butyl acetate, or acetone. Additionally, the acidic solution is hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid, or acetic acid. Next, water is added in an amount of 0.1 to 1.0 times the total weight of the monomer described above, and the mixture is heated and circulated at a temperature of 50 to 80°C. Once the mixture changes to a single phase through the reaction and becomes completely transparent, it is kept warm for 1 to 6 hours. The pH is adjusted to between 5.5 and 6.5, the aforementioned solvent corresponding to 20% by weight of the solid content is added, and after cooling, the mixture is filtered to complete the silicone polymer.

[0083] Excellent water-repellent functionality can be secured by applying a silicone polymer as the main resin to the above water-repellent coating layer, comprising 23-27 parts by weight of methyltrimethoxysilane monomer units, 23-27 parts by weight of vinyltrimethoxysilane monomer units, and 48-52 parts by weight of (tridecafluoro-1,1,2,2-tetrahydrooctyl)triethoxysilane monomer units.

[0084] In addition, it is more preferable that the water-repellent coating layer is formed from a composition for forming a water-repellent coating layer comprising 68-72 parts by weight of a silicone polymer comprising 23-27 parts by weight of methyltrimethoxysilane monomer units, 23-27 parts by weight of vinyltrimethoxysilane monomer units, 23-27 parts by weight of (tridecafluoro-1,1,2,2-tetrahydrooctyl)triethoxysilane) monomer units, and 23-27 parts by weight of 3-methacrylamidopropyltris(trimethylsiloxy)silane monomer units, 18-22 parts by weight of silica nanoparticles, and 8-12 parts by weight of ethylnonafluoroisobutyl ether.

[0085] Excellent water-repellent functionality and scratch resistance can be secured by applying a silicone polymer as the main resin to the above water-repellent coating layer, comprising 23-27 parts by weight of methyltrimethoxysilane monomer unit, 23-27 parts by weight of vinyltrimethoxysilane monomer unit, 23-27 parts by weight of (tridecafluoro-1,1,2,2-tetrahydrooctyl)triethoxysilane) monomer unit, and 23-27 parts by weight of 3-methacrylamidopropyltris(trimethylsiloxy)silane monomer unit.

[0087] In addition, the present invention

[0088] Stainless steel fabric with micro-holes formed therein;

[0089] Electroless nickel plating layer formed on the upper surface of the above stainless steel fabric;

[0090] A film layer containing chromium formed on the upper portion of the above electroless nickel plating layer; and

[0091] A water-repellent coating layer formed on top of the film layer containing the above chromium; comprising

[0092] The above water-repellent coating layer is,

[0093] The present invention provides a stainless steel fabric with microhole plating treatment, characterized by being formed from a composition for forming a water-repellent coating layer comprising 68-72 parts by weight of a silicone polymer comprising 23-27 parts by weight of methyltrimethoxysilane monomer units, 23-27 parts by weight of vinyltrimethoxysilane monomer units, 23-27 parts by weight of (tridecafluoro-1,1,2,2-tetrahydrooctyl)triethoxysilane) monomer units, and 23-27 parts by weight of 3-methacrylamidopropyltris(trimethylsiloxy)silane monomer units, 18-22 parts by weight of silica nanoparticles, and 8-12 parts by weight of ethylnonafluoroisobutyl ether.

[0094] The micro-hole stainless steel fabric plating method according to the present invention can ensure plating uniformity, enables plating while maintaining the micro-hole shape and opening ratio, and has high corrosion resistance through a double barrier consisting of a chromium-containing film layer and a water-repellent coating layer.

[0096] The present invention will be explained in more detail below by the following examples.

[0097] However, the following examples are merely illustrative of the content of the invention, and the scope of the invention is not limited by the examples and experimental examples.

[0098] <Example 1> Preparation of a composition for forming a water-repellent coating layer-1

[0099] A composition for forming a water-repellent coating layer was prepared by mixing 70 parts by weight of a silicone polymer containing 25 parts by weight of methyltrimethoxysilane monomer units, 25 parts by weight of vinyltrimethoxysilane monomer units, and 50 parts by weight of (tridecafluoro-1,1,2,2-tetrahydrooctyl)triethoxysilane monomer units, 20 parts by weight of silica nanoparticles, and 10 parts by weight of ethylnonafluoroisobutyl ether.

[0100] <Example 2> Preparation of a composition for forming a water-repellent coating layer-2

[0101] A composition for forming a water-repellent coating layer was prepared by mixing 70 parts by weight of a silicone polymer comprising 25 parts by weight of methyltrimethoxysilane monomer unit, 25 parts by weight of vinyltrimethoxysilane monomer unit, 25 parts by weight of (tridecafluoro-1,1,2,2-tetrahydrooctyl)triethoxysilane) monomer unit, and 25 parts by weight of 3-methacrylamidopropyltris(trimethylsiloxy)silane monomer unit, 20 parts by weight of silica nanoparticles, and 10 parts by weight of ethylnonafluoroisobutyl ether.

[0102] <Comparative Example 1>

[0103] A composition for forming a water-repellent coating layer was prepared by mixing 70 parts by weight of polymethyldisiloxane, 20 parts by weight of silica nanoparticles, and 10 parts by weight of ethylnonafluoroisobutyl ether.

[0104] <Experimental Example 1>

[0105] In order to confirm the characteristics of the compositions for forming a water-repellent coating layer prepared in Examples 1-2 and Comparative Example 1 above, each composition was applied to a polycarbonate film to form a water-repellent coating layer with a thickness of 100 μm, and the characteristics were confirmed through the following experiment.

[0106] - Surface hardness measurement: This was performed in accordance with JIS 5600-5-4, with a load of 1 kgf, which is a harsh condition. Mitsubishi pencils were used, and the test was performed 5 times per pencil hardness. If two or more scratches occurred, it was judged to be defective.

[0107] - Eraser wear resistance test: Conducted in accordance with KS B ISO 9211-4. A dedicated eraser for wear resistance testing was used, and the test was performed 1,500 times back and forth with a load of 1 kgf. The contact angle values ​​of the substrate surface were measured before and after the test, and the change in contact angle was analyzed.

[0108] - Scratch resistance: In accordance with JIS K5600-5-9, #0000 steel wool was used with a load of 1 kgf. At this time, the number of reciprocating cycles was 10,000 under harsh conditions, and the presence or absence of scratches was checked using an optical microscope.

[0109] - Durability evaluation: In accordance with JIS K5600-5-9, the test was conducted using #0000 steel wool with a load of 1 kgf. At this time, the number of reciprocating cycles was 10,000 under harsh conditions, and the contact angle values ​​of the substrate surface were measured before and after the test.

[0110] The results are shown in Table 1 below.

[0111] Example 1 Example 2 Comparative Example 1 Surface hardness 6H 8H 2H Wear resistance (DI contact angle change, °) 115 -> 104 117 -> 116 95 -> Unmeasurable Scratch resistance (1 kgf / 10,000 times) ○ ○ × Durability (DI contact angle change, °) 115 -> 105 117 -> 116 95 -> Unmeasurable

[0112] As shown in Table 1 above, it was confirmed that the water-repellent coating layer according to the present invention has excellent surface hardness and excellent physical properties such as wear resistance, scratch resistance, and durability.

Claims

Claim 1 A step of preparing a stainless steel material having microholes formed therein; a step of first pre-treating the stainless steel material with an alkaline solution; a step of first washing the stainless steel material that has been first pre-treated; a step of second pre-treating the stainless steel material that has been first washed with an acidic solution; a step of second washing the stainless steel material that has been second pre-treated; a step of forming an electroless nickel plating layer by electroless nickel plating on the stainless steel material that has been secondarily washed; and a step of forming a film layer containing chromium on the electroless nickel plating layer. and a step of forming a water-repellent coating layer on a film layer containing chromium; wherein the alkaline solution comprises 2-4 parts by weight of sodium hydroxide, 0.8-1.2 parts by weight of sodium phosphate, 0.8-1.2 parts by weight of a first surfactant, and 94-96 parts by weight of purified water, and the acid solution comprises 3-5 parts by weight of sulfuric acid, 1-3 parts by weight of hydrochloric acid, 0.8-1.2 parts by weight of a second surfactant, and 92-94 parts by weight of purified water, and the first surfactant comprises 23-27 parts by weight of N-butyl acrylate monomer unit, 23-27 parts by weight of acrylic acid monomer unit, 23-27 parts by weight of polyethylene glycol monomethyl ether methacrylate monomer unit, and 23-27 parts by weight of 2-(methacryloyloxy)ethyl dihydrogen phosphate monomer unit. A method for plating a micro-hole stainless steel fabric, characterized in that the first acrylic copolymer comprises a first acrylic copolymer, and the second surfactant comprises a second acrylic copolymer comprising 23-27 parts by weight of an N-butyl acrylate monomer unit, 23-27 parts by weight of an acrylic acid monomer unit, 23-27 parts by weight of a 1H,1H,7H-dodecafluoroheptyl methacrylate monomer unit, and 23-27 parts by weight of a 2-(methacryloyloxy)ethanesulfonic acid monomer unit. Claim 2 delete Claim 3 delete Claim 4 delete Claim 5 delete Claim 6 delete