阅读说明：本技术 一种不锈钢的抗菌电化学氧化液和电化学氧化工艺 (Antibacterial electrochemical oxidation liquid and electrochemical oxidation process for stainless steel ) 是由 王琪 于 2020-07-06 设计创作，主要内容包括：本发明公开了一种不锈钢的抗菌电化学氧化液和电化学氧化工艺,所述电化学氧化液包括酸性氧化基液、金属盐添加剂和阴离子表面活性剂；所述酸性氧化基液包括硫酸、磷酸、草酸、柠檬酸、氨基磺酸中的一种或多种的组合液；所述金属盐添加剂包括三价铬盐、银盐、铜盐。将待处理不锈钢置于所述电化学氧化液内,通电进行电化学氧化处理,得到抗菌防霉、耐腐蚀的不锈钢。本发明成本低且环保性强。(The invention discloses an antibacterial electrochemical oxidation liquid and an electrochemical oxidation process for stainless steel, wherein the electrochemical oxidation liquid comprises an acidic oxidation base liquid, a metal salt additive and an anionic surfactant; the acidic oxidation base solution comprises one or more of sulfuric acid, phosphoric acid, oxalic acid, citric acid and sulfamic acid; the metal salt additive comprises trivalent chromium salt, silver salt and copper salt. And (3) placing the stainless steel to be treated in the electrochemical oxidation solution, and electrifying to perform electrochemical oxidation treatment to obtain the stainless steel with the characteristics of antibiosis, mildew prevention and corrosion resistance. The invention has low cost and strong environmental protection.)

1. An antibacterial electrochemical oxidation solution for stainless steel is characterized by comprising an acidic oxidation base solution, a metal salt additive and an anionic surfactant; the acidic oxidation base solution comprises one or more of sulfuric acid, phosphoric acid, oxalic acid, citric acid and sulfamic acid; the metal salt additive comprises trivalent chromium salt, silver salt, manganese salt, cerium salt, zinc salt, nickel salt and cobalt salt.

2. The antimicrobial electrochemical oxidation solution for stainless steel according to claim 1, wherein the acidic oxidation base solution comprises pure sulfuric acid, or pure phosphoric acid, or pure oxalic acid, or pure citric acid, or pure sulfamic acid, or a mixture of phosphoric acid and sulfuric acid, or a mixture of sulfuric acid and oxalic acid, or a mixture of sulfuric acid, citric acid and sulfamic acid;

the concentration of the pure sulfuric acid is 300-500 g/L.

3. The antimicrobial electrochemical oxidation solution of stainless steel of claim 1, wherein the anionic surfactant comprises sodium dodecyl sulfate, sodium dodecyl benzene sulfonate.

4. An antibacterial electrochemical oxidation process of stainless steel, which adopts the antibacterial electrochemical oxidation solution of the stainless steel of the claims 1 to 4, and is characterized in that the stainless steel to be treated is placed in the electrochemical oxidation solution, and is electrified for electrochemical oxidation treatment, and the temperature of the electrochemical oxidation solution is controlled between 30 and 70 ℃;

the power supply is a positive and negative alternating power supply;

the current density is in the range of 0.001-2A/dm²。

5. The antibacterial electrochemical oxidation process of stainless steel according to claim 4, wherein a degreasing agent is further used for degreasing the stainless steel to be treated before the electrochemical oxidation treatment, wherein the degreasing agent comprises sodium hydroxide, sodium phosphate, sodium carbonate, and a surfactant OP-10;

the temperature in the oil removing treatment process is controlled to be 50-60 ℃, and the oil removing time is 10-30 min.

6. The process of antimicrobial electrochemical oxidation of a stainless steel according to claim 4 or 5, wherein an activator comprising phosphoric acid, molybdate, trivalent chromium salt is further used to activate the stainless steel to be treated prior to the electrochemical oxidation treatment;

the activation treatment process is kept at normal temperature, the working voltage is 3-6V, and the time is 2-5 min.

7. The antibacterial electrochemical oxidation process of stainless steel according to claim 4, wherein a sealing agent is further required to be used for sealing the stainless steel to be treated after the electrochemical oxidation treatment, wherein the sealing agent comprises benzotriazole, silicate, and molybdate;

the temperature in the sealing treatment process is controlled to be 60-100 ℃, and the sealing treatment time is 30 min.

8. The antimicrobial electrochemical oxidation process of stainless steel according to claim 7, wherein during the sealing treatment, the stainless steel to be treated is placed in a lubricating fluid; the lubricating liquid is a nano-scale PTFE emulsion.

Technical Field

The invention relates to the technical field of stainless steel, in particular to an antibacterial electrochemical oxidation liquid and an electrochemical oxidation process for stainless steel.

Background

Stainless steel is widely used in industrial fields of semiconductors, electronics, vacuum, aviation, medical treatment, pharmaceuticals, fine chemical engineering, instruments and meters, etc., because of its excellent corrosion resistance, wear resistance, toughness and good workability. Although stainless steel is often used in fields with higher requirements on sanitation, cleanliness and the like, the stainless steel is basically in a neutral state in most environments by utilizing the characteristic of good corrosion resistance, cannot cause negative effects on use occasions, and certainly has no self-cleaning and antibacterial functions. The prior art has the following processes for carrying out antibacterial and mildewproof treatment on stainless steel: metallurgical, coating (plating), and electrochemical methods.

The metallurgical method is that in the smelting process of stainless steel, antibacterial metal elements (silver, copper, etc.) are added, and then through a special treatment process, the antibacterial metal elements are separated out on the surface of the stainless steel to play an antibacterial role. For example, patent application No. 201010238697.8, "an antibacterial stainless steel and its heat treatment method and application" proposes: under the special heat treatment condition, 2.0-4.0 wt% of copper in the stainless steel is uniformly dispersed in the steel to precipitate a copper-rich phase with the size of nano level, so that the stainless steel is endowed with an antibacterial function. However, copper is used as an antibacterial factor in the process, and is easily oxidized in the air, so that verdigris is formed on the surface, the appearance is influenced, and the antibacterial function is eliminated. For example, in the 'duplex antibacterial stainless steel and manufacturing method thereof' of the patent application No. 200710039746.3, an Ag-Cu binary intermediate alloy is added in the smelting process of common duplex stainless steel, and then the duplex antibacterial stainless steel is manufactured through the working procedures of hot rolling, solid solution, acid washing, cold rolling, annealing and the like. Nisshin Steel works, Kawasaki Steel works, and domestic stainless Steel manufacturing enterprises: tai Gao, Bao Gao and so on all have the production of the relevant antibacterial stainless steel plate, but because its cost of manufacture is high, the antibacterial effect is not obvious, the market acceptance is not high.

The coating (plating) method is to attach a coating (plating) layer having an antibacterial function to the surface of stainless steel by physical, chemical, vapor deposition or the like. For example, the new japanese iron and steel company develops an antibacterial lubricating stainless steel, namely, an antibacterial and mildewproof agent is added into a surface lubricating coating to play a relevant role. For example, a "KENIFINE" plating layer, which is an alloy plating technique developed by japan stevens company and is composed of nickel plating, addition of other highly reducing elements and non-metallic ions having antibacterial properties and a low harmful effect, achieves an antibacterial effect equivalent to 100 times or more of pure nickel due to a geometric effect exerted by the antibacterial properties of metallic nickel ions in the nickel plating layer and the antibacterial properties of the non-metallic ions present at the same time, and is applicable to stainless steel, aluminum, and iron metal products. It can also be attached to the surface of resin or plastic by electroless plating techniques, which can also have related effects. The coating (plating) method has problems in that: the antibacterial efficiency is general, the aging failure is easy, and the possibility of falling off due to insufficient binding force exists.

The electrochemical method is characterized in that a stainless steel material is placed in an antibacterial factor oxidation solution containing silver and the like through an electrochemical method, a film layer with the thickness of about 50-100 nanometers is formed on the surface of the stainless steel through special current, and antibacterial factor particles are uniformly deposited in micropores of the film layer, so that the antibacterial and sterilization effects can be achieved under the condition that the original surface of the stainless steel is attractive. For example, in the 'stainless steel surface antibacterial layer based on an anodized porous oxide film' of patent application No. 201020240917.6, a porous oxide film is formed on the surface of stainless steel by an anodizing solution such as sulfuric acid, and then an antibacterial metal element is deposited on the anodized porous oxide film by an ac voltage-stabilizing power supply, thereby oxidizing the anodized porous oxide film to play an antibacterial role. The process only deposits silver, copper and other elements in micropores of the stainless steel oxide film, the silver and copper elements are simple substances, and the silver and copper elements are easily oxidized and lose the antibacterial effect in the using process.

Disclosure of Invention

Aiming at the defects and shortcomings of the prior art, the antibacterial electrochemical oxidation liquid for stainless steel is provided, and comprises an acidic oxidation base liquid, a metal salt additive and an anionic surfactant; the acidic oxidation base solution comprises one or more of sulfuric acid, phosphoric acid, oxalic acid, citric acid and sulfamic acid; the metal salt additive comprises trivalent chromium salt, silver salt, manganese salt, cerium salt, zinc salt, nickel salt and cobalt salt. Specifically, the trivalent chromium salt can be chromium nitrate, chromium sulfate, chromium trichloride, chromium phosphate, chromium acetate, chromium sesquioxide, etc.; the silver salt can be silver nitrate, silver iodide, silver chloride, silver sulfate, silver bromide, etc.; the molybdenum salt can be sodium molybdate, ammonium molybdate, potassium molybdate, magnesium molybdate, silver molybdate, etc.; manganese salt can be manganese sulfate, manganese nitrate, manganese chloride, etc.; cerium salt can be cerium sulfate, cerium nitrate, etc.; the zinc salt can be zinc nitrate, zinc chloride, zinc sulfate, zinc acetate, etc.; the nickel salt can be nickel sulfate, nickel nitrate, nickel chloride, nickel sulfamate, ammonium nickel sulfate, nickel acetate, nickel bromide, nickel carbonyl, etc.; the copper salt can be copper sulfate, copper nitrate, copper chloride, etc.; the cobalt salt can be cobalt sulfate, cobalt nitrate, cobalt carbonate, cobalt chloride, etc.

Preferably, the acidic oxidation base solution comprises pure sulfuric acid, or pure phosphoric acid, or pure oxalic acid, or pure citric acid, or pure sulfamic acid, or a mixture of phosphoric acid and sulfuric acid, or a mixture of sulfuric acid and oxalic acid, or a mixture of sulfuric acid, citric acid and sulfamic acid; the concentration of the pure sulfuric acid is 300-500 g/L.

Preferably, the anionic surfactant comprises sodium dodecyl sulfate, sodium dodecyl sulfonate, sodium dodecyl benzene sulfonate.

The antibacterial electrochemical oxidation solution for stainless steel is adopted, the stainless steel to be treated is placed in the electrochemical oxidation solution, the electrochemical oxidation treatment is carried out by electrifying, and the temperature of the electrochemical oxidation solution is controlled to be 30-70 ℃; the power supply is a positive and negative alternating power supply, and an alternating current power supply, an alternating current and direct current power supply, a direct current superposed pulse power supply, a double pulse power supply, a silicon controlled rectifier power supply and a voltage transformation direct current power supply can also be used; the current density is in the range of 0.001-2A/dm²The oxidation time is 5-30 minutes.

Preferably, before the electrochemical oxidation treatment, a degreasing agent is further adopted for degreasing treatment and activation treatment of the stainless steel to be treated, wherein the degreasing agent comprises sodium hydroxide, sodium phosphate, sodium carbonate and a surfactant OP-10; the temperature in the oil removing treatment process is controlled to be 50-60 ℃, and the oil removing time is 10-30 min. The activating agent comprises phosphoric acid, molybdate and trivalent chromium salt; the activation treatment process is kept at normal temperature, the working voltage is 3-6V, and the time is 2-5 min. Through the oil removal treatment and the activation treatment, the influence of dirt and oxidation on the surface of the stainless steel to be treated on the antibacterial treatment effect can be eliminated.

Preferably, a sealing agent is adopted to seal the stainless steel to be treated after the electrochemical oxidation treatment, wherein the sealing agent comprises benzotriazole, silicate and molybdate; the temperature in the sealing treatment process is controlled to be 60-100 ℃, and the sealing treatment time is 30 min.

Preferably, in the sealing treatment process, the stainless steel to be treated is placed in lubricating liquid, so that the effects of friction reduction and self lubrication can be achieved; the lubricating liquid is a nano-scale PTFE emulsion.

Preferably, by adjusting the components, the proportion and the processing parameters of the antibacterial oxidation liquid medicine, oxidation film layers with different thicknesses can be formed on the surface of the stainless steel. According to the interference principle of light, the colored stainless steel with the antibacterial functions of tawny, golden yellow, blue, purple, green, gray, black and the like can be made.

According to the invention, through electrochemical reaction of stainless steel in acidic anodic oxidation liquid, a layer of oxide film with the thickness of tens of nanometers is formed on the surface of the stainless steel, and meanwhile, a spinel film with trivalent chromium as a core is formed on the oxide film on the surface of the stainless steel, and the spinel film enables the stainless steel to have long-term effective antibacterial and mildewproof effects. And because metal elements containing silver, copper, nickel, zinc, cobalt, manganese, cerium and the like are added, and then the power is switched on, the antibacterial metal elements can enter the micropores of the oxidation film layer, and the antibacterial factors and the like are combined with the spinel film taking trivalent chromium as the core through electrochemical reaction, so that the antibacterial and mildewproof effects of the film layer are longer and more stable. Compared with the prior art, the process has the characteristics that the process does not use hexavalent chromium of heavy metal elements to form a spinel film layer, and replaces the hexavalent chromium with trivalent chromium to become the core of the spinel film, so that the whole process is more environment-friendly. In conclusion, the film has the characteristics of antibiosis and mildew resistance, corrosion resistance, low processing cost, no toxic or side effect on human bodies, long-acting property, no heavy metal precipitation and the like.

Detailed Description

The present invention will be described in more detail hereinafter with reference to the illustrated embodiments of the invention. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.