Environment-friendly neutral rust removal and prevention agent as well as preparation method and application thereof

Abstract

The invention provides an environment-friendly neutral rust removal and prevention agent which comprises the following components in percentage by mass: 10%-20% of organic acid, 5%-15% of a scale and corrosion inhibitor, 5%-15% of an antioxidant corrosion inhibitor, 1%-2% of a surfactant and the balance of tap water and a neutralizer. Specific components are compounded to achieve a mutual synergistic effect, the rust remover can be matched with tap water for use at the room temperature and the high temperature, efficient rust removal is achieved, the rust prevention period is long, especially for iron parts in a tap water medium at the high temperature, efficient rust removal can be achieved, scaling, secondary oxidation and rusting of rust-removed metal substrates in tap water can be prevented, and the rust removal effect is good. The preparation method has the characteristics of simplicity, no harm to human bodies, no environmental pollution and the like.

Description

Technical Field

[0001] The invention belongs to the technical field of metal rust removal and corrosion prevention, and specifically relates to an environmentally friendly neutral rust removal and rust prevention agent that can be used in conjunction with tap water at different temperatures, and a preparation method and application thereof. Background Art

[0002] Carbon steel or cast iron parts produced by various industries are inevitably corroded during storage or transportation, which not only affects the appearance of castings but also seriously affects the use of mechanical parts. In particular, the rust problem in metal steel, machinery manufacturing, machining and other industries is becoming increasingly prominent. The smelting of metal materials comes from mineral resources, which are non-renewable resources. Therefore, the corrosion of metal materials indirectly affects the sustainable development strategy. In addition, the corrosion of metal material surface may cause factory shutdown, product quality decline, toxic substance leakage and other hazards, directly or indirectly threatening people's life and property safety. Therefore, the demand for efficient rust removal and rust prevention methods for metal surfaces has become increasingly urgent.

[0003] Rust removal is the first process step before taking anti-corrosion measures on metal products. The methods are mainly divided into two categories: mechanical method and chemical method. The mechanical method is to manually knock and polish. Although this process will not cause excessive corrosion, it is labor-intensive, inefficient, and seriously polluted by dust. Rust is difficult to remove, which is obviously not a good way to remove rust. The chemical method generally uses hydrogen bubbles generated by pickling to peel off the rust layer on the metal surface. It has the advantages of high efficiency, low cost and simple process operation. For example, the more commonly used hydrochloric acid and nitric acid washing methods can quickly dissolve the oxide scale and rust on the surface of the substrate, but they are highly corrosive and can easily cause excessive corrosion or rust on the metal surface, thereby affecting the subsequent anti-corrosion coating; at the same time, the discharge of cleaning fluid after rust removal will also cause serious environmental pollution, which is difficult to meet the current national environmental protection requirements for the pickling industry.

[0004] At present, many rust removers prepared from organic acids and other raw materials are disclosed in the prior art, but most of them not only lack rust resistance, but also have low pH and are not environmentally friendly, and thus cannot meet direct emission standards. At the same time, some neutral rust removers and rust preventers are also disclosed in the prior art, but they are basically only suitable for use in room temperature and deionized water environments. If used in high-temperature tap water media, it is very easy to cause scaling, over-corrosion and rust on the metal surface, so the scope of use is limited. For example, metal castings produce defects such as micropores and cracks during the casting process, which can be remedied by a treatment process of sealing with an organic impregnant and then immersing in 90°C tap water for 10 to 30 minutes to solidify the organic impregnant; obviously, the high-temperature tap water immersion process will inevitably cause oxidation and rust of the metal castings. Therefore, in order to remove rust on the surface of the metal castings and prevent secondary rust from occurring during the curing process of the impregnant, a rust remover and rust preventer need to be added to the tap water for treatment and protection. However, the rust removal and rust prevention agents in the existing patented technologies cannot solve the hidden danger of secondary corrosion of metal castings after the above-mentioned heat treatment process, but are prone to new quality problems: on the one hand, it is difficult to achieve simultaneous rust removal and rust prevention of metal castings in a high temperature environment; on the other hand, the use of tap water media will inevitably cause scaling and corrosion of metal castings to intensify.

[0005] Chinese patent publication number CN105063643A discloses a neutral environmentally friendly rust remover and a preparation method thereof, wherein the rust remover is composed of 5-15% diethylenetriamine, 6-15% organic acid, 0.5-3% surfactant, 4-10% chlorinated inorganic salt, 5-20% alcohol solvent and 40-70% pure water by weight, and the neutral environmentally friendly rust remover not only has good rust removal ability, but also has certain rust prevention ability. However, the rust remover uses highly volatile organic reagents such as alcohols, in which highly toxic methanol is used as a solvent, so it is not suitable for the above processing or production process in high temperature and tap water environment.

[0006] Chinese patent publication number CN108315744A discloses a degreasing and rust removing agent and its preparation method and application. The degreasing and rust removing agent is prepared by mixing 10-30 parts of hydroxyethylidene diphosphonic acid, 0.5-3 parts of tartaric acid, 0-1 part of sodium pyrophosphate, 0-10 parts of zinc lactate, 0-10 parts of sodium citrate, and 0-10 parts of oxalic acid. Usually, 3-10 parts of degreasing and rust removing agent are added to 80-120 parts of water, and the heavy corrosion and heavy oil workpieces can be degreasing and rusting in a short time, generally about 5 minutes at room temperature and about 3 minutes under ultrasound; and the rust residue after falling off is often deposited at the bottom of the container, and the rust remover can be reused after simple filtration. However, the pH value of the rust remover is low, which is very easy to damage the metal substrate, and it does not have a rust-proof function, and is completely unsuitable for the above metal casting processing procedures.

[0007] Chinese patent publication number CN112176355 A discloses an environmentally friendly neutral rust remover and its preparation method, which is composed of 12-25% organic acid, 3-15% acidic neutralizer, 1-6% sodium benzoate, 2-6% sodium D-gluconate, 1-6% potassium oxalate, 3-8% sodium polyaspartate, 1-4% sodium DL-tartrate, 0.1-2% benzotriazole, 0.3-1% surfactant and pure water by weight. The rust remover can quickly remove rust at room temperature, and the rust removal time for heavy rust is only 5-8 minutes, and it will not damage the metal substrate, but the rust remover has no anti-rust function and cannot meet the use conditions of processing and production under high temperature and tap water environment.

[0008] Chinese patent publication number CN109136946 A discloses a food-grade environmentally friendly organic acid metal rust remover and its preparation method, use method and process. The rust remover is composed of 15.54-23.47 parts of citric acid, 0.94-1.10 parts of sodium gluconate, 0.45-0.55 parts of sodium glutamate, 0-0.93 parts of anhydrous ethanol and 75.12-82.90 parts of deionized water. The rust remover can effectively remove the oxide scale on iron parts at 40-60°C without producing acid mist. However, even under heating conditions, the rust removal time of the rust inhibitor can be up to 1.8 hours. Obviously, the rust removal time is long, and it does not have rust prevention performance, so it cannot be used in the above processing and production process. Summary of the invention

[0009] The purpose of the present invention is to provide an environmentally friendly neutral rust remover and rust preventer, and a preparation method and application thereof. The environmentally friendly neutral rust remover and rust preventer is mainly made of food-grade raw materials, does not contain strong volatile substances and is harmless to the human body. It not only removes rust gently and does not cause the problem of excessive metal corrosion during the rust removal process, but also has excellent rust prevention performance; at the same time, it can achieve simultaneous rust removal and rust prevention of metal castings when used in conjunction with tap water at room temperature or high temperature, with a short rust removal time, a long rust prevention period, easy operation and no harm to the environment caused by the discharged liquid.

[0010] In order to achieve the above object, the present invention provides the following technical solutions:

[0011] An environmentally friendly neutral rust remover and rust preventer comprises, by mass fraction, 10% to 20% of organic acid, 5% to 15% of scale inhibitor, 5% to 15% of antioxidant, 1% to 2% of surfactant, and the balance is supplemented to 100% by tap water and a neutralizer.

[0012] Preferably, the organic acid is 2 to 4 of citric acid, DL-tartaric acid, D-gluconic acid, D-glucaric acid, DL-malic acid, caffeic acid, salicylic acid and nicotinic acid.

[0013] In some preferred embodiments, the organic acids are citric acid, caffeic acid and nicotinic acid; the mass ratio is (1-2): (0.5-1.5): 1; more preferably, it is 8:5:5.

[0014] In some preferred embodiments, the organic acid is DL-tartaric acid, D-glucose acid and salicylic acid; the mass ratio is (1-2): (1-2): 1; further preferably, it is 7:7:5.

[0015] In some preferred embodiments, the organic acid is citric acid, DL-tartaric acid and salicylic acid; the mass ratio is (0.5-1.5):(0.5-1.5):1; further preferably, it is 1:1:1.

[0016] In some preferred embodiments, the organic acids are D-glucaric acid, DL-malic acid and nicotinic acid; the mass ratio is (1-2): (0.5-1.5): 1; more preferably, it is 8:5:5.

[0017] In some preferred embodiments, the organic acid is citric acid, D-gluconic acid and salicylic acid; the mass ratio is (1-1.5):(0.5-1.5):1; more preferably, it is 6:5:5.

[0018] In some preferred embodiments, the organic acid is citric acid, D-glucaric acid, DL-tartaric acid and salicylic acid; the mass ratio is (1-3): (1-3): (0.5-1.5): 1; further preferably, it is 2:2:1:1.

[0019] In some preferred embodiments, the organic acids are citric acid, D-gluconic acid, nicotinic acid and caffeic acid; the mass ratio is (1-3): (1-3): (0.5-1.5): 1; further preferably, it is 2:2:1:1.

[0020] The inventors have found that the rust removal effect and rate of rust removers and rust inhibitors can be improved by selecting the organic acids described in the present invention and compounding 2 to 4 of them. This may be because, on the one hand, they have good chelating effects on metal ions. After compounding, they can not only efficiently remove oxide scales and prevent the residues formed during the rust removal process from being deposited on the metal surface to cause secondary rust; but also have good cleaning and decontamination functions on the metal surface after compounding with different scale and corrosion inhibitors. By selecting 2 to 4 organic acids and adjusting their types and proportions, the formula can be optimized so that it can still maintain the rust removal effect and low corrosion on the metal substrate at high temperatures. This is because different organic acids not only have different acidities, but also can adjust the acidity of the mixed solution by matching, making it more suitable for rust removal and rust prevention treatment of specific metal substrates. In addition, organic acids can also ionize hydrogen ions and corresponding acid radical ions in the solution. These ions can enhance the surface activity of the solution and promote the adsorption and penetration of organic acid molecules on the metal surface. The combination of different organic acids can further enhance this surface activity, make up for the shortcomings of a single organic acid, improve the efficiency of rust removal and rust prevention, and achieve a more comprehensive rust removal effect. In addition, the mixed use of multiple organic acids can improve the stability of rust removal and rust prevention agents, reduce the performance changes caused by environmental changes (such as temperature, pH value, etc.) during use, and avoid affecting the rust removal and rust prevention effect. In actual application, organic acids with complementary properties can be selected for matching, such as strong acids (citric acid, DL-tartaric acid) and weak acids.

[0021] For example, the compounding of various organic acids further preferred herein. The compounding of citric acid, caffeic acid and nicotinic acid can not only quickly combine with metal ions to form soluble salts, thereby effectively removing the rust layer, but also protect the metal surface, reduce the occurrence of oxidation reactions and the growth of microorganisms, and improve the rust removal efficiency while reducing the secondary oxidation of the metal surface. The compounding of DL-tartaric acid, D-gluconic acid and salicylic acid can not only quickly remove the rust layer, but also provide corrosion inhibition while rust removal, forming a protective film covering the metal surface, slowing down the corrosion rate, effectively inhibiting the growth of microorganisms, and both ensuring the rust removal effect and extending the service life of the metal. The compounding of citric acid, DL-tartaric acid and salicylic acid, two strong acids jointly provide strong rust removal ability, and salicylic acid is responsible for enhancing the anti-corrosion effect, and the three work synergistically to achieve the comprehensive effect of rapid rust removal, effective corrosion inhibition and long-term anti-corrosion. The compounding of D-gluconic acid, DL-malic acid and nicotinic acid, on the one hand, D-gluconic acid and DL-malic acid work together, and can more comprehensively remove the rust layer on the metal surface and improve the rust removal effect. On the other hand, the compounding of D-gluconic acid and nicotinic acid can provide corrosion inhibition while removing rust, not only reducing the oxidation reaction on the metal surface, but also forming a protective film to protect the metal surface, thereby enhancing the protective effect of the metal surface. The compounding mechanism of citric acid, D-gluconic acid and salicylic acid is similar to the compounding of DL-tartaric acid, D-gluconic acid and salicylic acid. The compounding mechanism of citric acid, D-gluconic acid, DL-tartaric acid and salicylic acid is similar to the compounding of citric acid, DL-tartaric acid and salicylic acid. The addition of D-gluconic acid can not only synergize with citric acid and DL-tartaric acid to further improve the rust removal and corrosion inhibition effect, but also can improve the stability of the metal surface protective film together with salicylic acid. The compounding of citric acid, D-gluconic acid, nicotinic acid and caffeic acid, on the one hand, when citric acid, D-gluconic acid and nicotinic acid act together, can not only achieve the dual effects of rapid rust removal and effective corrosion inhibition, but also reduce the oxidation reaction and secondary corrosion on the metal surface. On the other hand, the synergistic effect of caffeic acid and niacin can not only reduce the oxidation reaction and the generation of free radicals on the metal surface, but also inhibit the growth and reproduction of microorganisms, further enhancing the antioxidant and anti-corrosion capabilities of the metal surface.

[0022] Preferably, the scale and corrosion inhibitor is 2 to 3 of hydroxyethylidene diphosphonic acid (HEDP), ethylenediaminetetramethylenephosphonic acid (EDTMP), aminotrimethylenephosphonic acid (ATMP), 2-phospho-1,2,4-tricarboxylic acid butane (PBTCA), lignin sulfonic acid, polyacrylic acid (PAA), polyaspartic acid and hydrolyzed polymaleic anhydride (PASP).

[0023] Preferably, the relative molecular mass of the lignin sulfonic acid is 5000-10000.

[0024] Preferably, the average molecular weight of the polyacrylic acid is 1000-3000; more preferably, it is 2000.

[0025] In some preferred embodiments, the lignin sulfonic acid and polyacrylic acid are both purchased from Shanghai MacLean Biochemical Technology Co., Ltd.

[0026] Preferably, the relative molecular weight of the polyaspartic acid is 1000-5000, the solid content is ≥40%, and the density is ≥1.2g / cm 3 .

[0027] In some preferred embodiments, the polyaspartic acid is purchased from Zhoukou Cairun Environmental Protection Materials Co., Ltd.

[0028] Preferably, the relative molecular weight of the hydrolyzed polymaleic anhydride is 400-800, the solid content is ≥48%, and the density is ≥1.18 g / cm 3 .

[0029] In some preferred embodiments, the hydrolyzed polymaleic anhydride is purchased from Shandong Aike Water Treatment Technology.

[0030] In some preferred schemes, the scale and corrosion inhibitor is hydroxyethylidene diphosphonic acid and polyaspartic acid; the mass ratio is (0.5-1.5):1; more preferably, it is 1:1.

[0031] In some preferred schemes, the scale and corrosion inhibitors are aminotri(methylenephosphonic acid) and polyacrylic acid; the mass ratio is (0.5-1.5):1; more preferably, it is 1:1.

[0032] In some preferred schemes, the scale and corrosion inhibitor is ethylenediaminetetramethylenephosphonic acid and hydrolyzed polymaleic anhydride; the mass ratio is (0.5-1.5):1; more preferably, it is 1:1.

[0033] In some preferred schemes, the scale and corrosion inhibitor is 2-phospho-1,2,4-tricarboxylic acid butane and polyaspartic acid; the mass ratio is (0.5-1.5):1; more preferably, it is 1:1.

[0034] In some preferred schemes, the scale and corrosion inhibitors are hydroxyethylidene diphosphonic acid, polyacrylic acid and lignin sulfonic acid; the mass ratio is (1-2): (0.5-1.5): 1; more preferably, it is 5:3:3.

[0035] In some preferred schemes, the scale and corrosion inhibitors are aminotri(methylenephosphonic acid), lignin sulfonic acid and polyaspartic acid; the mass ratio is (1-2): (0.5-1.5): 1; further preferably, it is 5:3:3.

[0036] The inventors have found that the scale inhibitors and corrosion inhibitors described in the present invention are selected, and 2 to 3 of them are used in combination, which can improve the scale and corrosion inhibition functions of rust removers and preventers, and can prevent scale-forming salts in water from forming scale, especially the formation of calcium carbonate and calcium sulfate scales, and have a good corrosion inhibition effect at higher concentrations. This is because on the one hand, these scale inhibitors and corrosion inhibitors form chelates with calcium and magnesium ions in the tap water medium as scale inhibitors, and thus have a strong scale inhibition effect; on the other hand, they are cathodic corrosion inhibitors. When the metal surface is attacked by oxidants, acids or other corrosive substances, they can combine with metal ions to form a stable protective film covering the metal surface to prevent further corrosion, and at the same time, they can also avoid secondary corrosion of the metal surface after rust removal.

[0037] For example, the compounding of various scale inhibitors and corrosion inhibitors is further preferred in this article. The compounding of hydroxyethylidene diphosphonic acid and polyaspartic acid, on the one hand, forms a stable complex with metal ions (such as calcium and magnesium) through chelation, thereby preventing them from scaling in water, while polyaspartic acid is adsorbed on the crystal surface through the carboxyl and amide groups on its molecular chain, preventing the crystals from further growing and aggregating, playing a role in dispersion and scale inhibition. The compounding mechanism of aminotrimethylphosphonic acid and polyacrylic acid is similar to that of hydroxyethylidene diphosphonic acid and polyaspartic acid. The compounding of ethylenediaminetetramethylphosphonic acid and hydrolyzed polymaleic anhydride, on the one hand, can inhibit the growth of microorganisms while chelating metal ions, reducing the causes of scaling and corrosion, and on the other hand, the carboxyl groups on the depolymerized maleic anhydride molecular chain are adsorbed on the metal surface to form a protective film, further preventing the occurrence of scaling and corrosion. 2-Phosphate-1,2,4-tricarboxylic acid butane is compounded with polyaspartic acid. The two work synergistically, not only forming a stable complex with metal ions, but also adsorbing on the crystal surface or metal surface, jointly preventing scaling and improving the overall scaling performance. Hydroxyethyl diphosphonic acid, polyacrylic acid and lignin sulfonic acid are compounded. On the one hand, hydroxyethyl diphosphonic acid and polyacrylic acid act on different stages of scaling respectively, and prevent scaling through chelation and dispersion. On the other hand, lignin sulfonic acid forms a protective film with the metal surface through the sulfonic acid group and hydroxyl group in its molecular structure, and disperses the already formed tiny particles, which can further enhance the scaling and corrosion inhibition effects. After the three are compounded, a multi-level protection system is formed. Aminotrimethylphosphonic acid, lignin sulfonic acid and polyaspartic acid are compounded. The combination of aminotrimethylphosphonic acid and lignin sulfonic acid reduces the causes of scaling and corrosion, and polyaspartic acid further enhances this protective effect. The three compounding forms a more comprehensive scaling and corrosion inhibition system, which jointly improves the scaling and corrosion inhibition effects.

[0038] Preferably, the antioxidant corrosion inhibitor is three of tryptophan, methionine, vitamin B1, sodium isovitamin C, naringenin, catechin, lipoic acid and 2-quinoxalinecarboxylic acid.

[0039] In some preferred embodiments, the antioxidant corrosion inhibitor is tryptophan, vitamin B1 and naringenin; the mass ratio is (2-3): (1-2): 1; more preferably, it is 5:3:2.

[0040] In some preferred embodiments, the antioxidant corrosion inhibitor is sodium isovitamin C, methionine and naringenin; the mass ratio is (2-3): (1-2): 1; further preferably, it is 5:3:2.

[0041] In some preferred embodiments, the antioxidant corrosion inhibitor is vitamin B1, catechin and lipoic acid; the mass ratio is (2-3): (1-2): 1; further preferably, it is 5:3:2.

[0042] In some preferred embodiments, the antioxidant corrosion inhibitor is sodium isovitamin C, lipoic acid and 2-quinoxaline carboxylic acid; the mass ratio is (2-3): (1-2): 1; further preferably, it is 5:3:2.

[0043] In some preferred embodiments, the antioxidant corrosion inhibitors are tryptophan, methionine and catechin; the mass ratio is (2-3): (1-2): 1; more preferably, it is 5:3:2.

[0044] The inventors found that the antioxidant corrosion inhibitors described in the present invention are selected and three of them are used in combination, which not only prevents tap water from aggravating the corrosion of the metal matrix, but also has efficient corrosion inhibition performance. This may be because these antioxidant corrosion inhibitors produce synergistic effects, on the one hand, they can remove free radicals and resist oxidation, and on the other hand, they can form a protective film on the metal surface. In addition, the chelating ability and sites of different components and metal ions are different, which will also produce a stronger chelating effect, thereby improving the corrosion inhibition performance.

[0045] For example, the compounding of various antioxidant corrosion inhibitors is further preferred in this article. Tryptophan, vitamin B1 and naringenin are compounded. The chelation of tryptophan not only reduces the active sites on the metal surface, but vitamin B1 promotes the formation of a passivation film, and naringenin enhances this protective effect through its antioxidant and film-forming ability. The three work synergistically to form a multi-level anti-corrosion system. Sodium isovitamin C, methionine and naringenin are compounded. Sodium isovitamin C and naringenin jointly scavenge free radicals to prevent the occurrence of oxidation reactions; methionine reduces corrosion on the metal surface through chelation. The three work synergistically to enhance the overall antioxidant and corrosion inhibition effects. Vitamin B1, catechins and lipoic acid are compounded. Vitamin B1 promotes the formation of a passivation film, catechins slow down corrosion through antioxidant and chelation effects, and lipoic acid penetrates into the metal surface or nearby areas to scavenge free radicals. The three work synergistically to form a comprehensive anti-corrosion system. Sodium isovitamin C, lipoic acid and 2-quinoxaline carboxylic acid are compounded. Sodium isovitamin C and lipoic acid play an antioxidant role in the water layer and the metal surface layer respectively, while 2-quinoxaline carboxylic acid enhances the overall anti-corrosion effect through its protective film effect. The three work synergistically to form an efficient anti-corrosion system. Tryptophan, methionine and catechins are compounded. Tryptophan and methionine reduce the corrosion of the metal surface through chelation and antioxidant properties respectively, while catechins further enhance this protective effect through its antioxidant and chelating abilities. The three work synergistically to form a powerful anti-corrosion system.

[0046] Preferably, the mass ratio of the organic acid, the scale inhibitor and the antioxidant inhibitor is (1.5-2): (0.8-1.2):1.

[0047] The inventors have found that the antioxidant corrosion inhibitor and scale inhibitor described in the present invention are selected, and the two are compounded to produce a synergistic corrosion inhibition effect, forming a good protective film on the surface of metals such as steel or iron, thereby effectively delaying metal corrosion. This may be because on the one hand, the organic phosphonic acid compounds and polymer compounds in the scale inhibitor can form a dense protective film on the metal surface, while the amino acids, vitamins, polyphenol compounds, etc. in the antioxidant corrosion inhibitor can further enhance the density and stability of this protective film. On the other hand, the scale inhibitor prevents the formation and deposition of scale by chelating metal ions and dispersing crystal particles; the antioxidant corrosion inhibitor inhibits the occurrence of oxidative corrosion by scavenging free radicals and forming complexes with metal ions. The two work together to significantly slow down the rate of metal corrosion.

[0048] The inventors have found that the use of the organic acid chelating agent, scale inhibitor and antioxidant corrosion inhibitor described in the present invention can achieve simultaneous rust removal and rust prevention. The organic acid chelating agent and scale inhibitor are compounded to remove the rust layer on the metal surface through chelation and pickling effects, and prevent the rust residue generated during the rust removal process from being re-deposited on the metal surface through their dispersion effect. While removing rust, the antioxidant corrosion inhibitor and scale inhibitor begin to form a protective film on the metal surface. On the one hand, they remove free radicals and active oxygen species on the metal surface to prevent the metal from being re-oxidized; on the other hand, they form a dense protective film through their chelation and adsorption effects to further isolate the corrosive medium. The compounding of the three components not only plays its unique role, but also enhances the overall rust removal and rust prevention effects through the synergistic effect between each other. The antioxidant corrosion inhibitor can enhance the adsorption capacity of the organic acid chelating agent on the metal surface, thereby making the protective film formed by it more stable.

[0049] Preferably, the surfactant is any one of sodium dodecyl sulfonate, sodium dodecylbenzene sulfonate, fatty alcohol polyoxyethylene ether and fatty alcohol polyoxyethylene ether phosphate; further preferably, it is sodium dodecylbenzene sulfonate.

[0050] The "surfactant" mentioned in this article refers to sodium dodecyl sulfonate, sodium dodecylbenzene sulfonate, fatty alcohol polyoxyethylene ether and fatty alcohol polyoxyethylene ether phosphate provided by the present invention. They are environmentally friendly surfactants with good penetration and antistatic properties. They can not only reduce the surface tension of the solution, but also facilitate the infiltration of the solution into the metal surface.

[0051] Preferably, the neutralizing agent is sodium hydroxide.

[0052] The preparation method of the environmentally friendly neutral rust remover and rust preventer comprises the following steps:

[0053] S1. Weigh each raw material according to mass fraction;

[0054] S2. 30% tap water and organic acid were added to the reactor and stirred for 15 min;

[0055] S3. Add anti-scaling and corrosion inhibitor and antioxidant corrosion inhibitor in sequence and stir thoroughly for 15 minutes;

[0056] S4. Add surfactant, then add remaining tap water, and stir thoroughly for 20 minutes;

[0057] S5. adding a neutralizing agent to adjust the pH value of the solution to neutral;

[0058] S6. Let stand for 2 hours.

[0059] The application of the environmentally friendly neutral rust remover and rust preventer is applied in the technical field of metal rust removal and corrosion prevention.

[0060] The specific application method comprises the following steps: preparing a rust removing and rust preventing working liquid by mixing 4% to 6% of the environmentally friendly neutral rust removing and rust preventing agent with 94% to 96% of tap water; immersing the workpiece in the rust removing and rust preventing working liquid at room temperature; and taking the workpiece out after 1.5 to 1.6 hours.

[0061] Preferably, the specific application method of the environmentally friendly neutral rust remover and rust preventer comprises the following steps: preparing a rust remover and rust preventer working liquid by mixing 4% to 6% of the environmentally friendly neutral rust remover and rust preventer with 94% to 96% of tap water, heating the liquid to 60°C, and then immersing the workpiece in the rust remover and rust preventer working liquid, and removing the workpiece after 0.6 to 0.7 hours.

[0062] Preferably, the specific application method of the environmentally friendly neutral rust remover and rust preventer comprises the following steps: taking 4% to 6% of the environmentally friendly neutral rust remover and rust preventer and mixing it with 94% to 96% of tap water to prepare a rust remover and rust preventer working solution, heating it to 90°C, and then immersing the workpiece in the rust remover and rust preventer working solution, and removing the workpiece after 15 to 25 minutes.

[0063] The workpiece is an iron piece with oxide scale and / or rust.

[0064] Compared with the prior art, the advantages and beneficial effects of the present invention are:

[0065] 1. The present invention provides an environmentally friendly neutral rust remover and rust preventer, the raw materials of which are mainly food-grade raw materials, do not contain strong acids and highly volatile substances, have a neutral pH, are non-toxic and harmless, are green and environmentally friendly products, and the discharged liquid is harmless to the environment, so it meets the direct discharge standard.

[0066] 2. The environmentally friendly neutral rust remover and rust preventer prepared by the present invention has multiple functions such as rust removal, scale inhibition, passivation and rust prevention in one. It is compounded with organic acid chelating agent, scale inhibitor and corrosion inhibitor and antioxidant corrosion inhibitor to achieve simultaneous rust removal and rust prevention.

[0067] 3. The environmentally friendly neutral rust remover and rust preventer prepared by the present invention is suitable for use in tap water medium.

[0068] The compound use of anti-scaling and corrosion inhibitors avoids the scaling of calcium and magnesium ions in the tap water medium, while enhancing the corrosion inhibition performance; the compound use of antioxidant corrosion inhibitors not only prevents tap water from aggravating the corrosion of the metal matrix, but also has efficient corrosion inhibition performance.

[0069] 4. The environmentally friendly neutral rust remover and rust preventer prepared by the present invention can not only remove rust and prevent rust at room temperature, but also can remove rust efficiently in high temperature environment and is non-corrosive to metal substrates; it forms a firm protective film on the metal surface to achieve good anti-rust effect and a long anti-rust period.

[0070] 5. The environmentally friendly neutral rust remover and rust preventer prepared by the present invention has a simple production process, is easy to operate, has high practicality, effectively saves production costs, and can provide good economic benefits. DETAILED DESCRIPTION

[0071] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0072] The raw materials used in the present invention are all commercially available, specifically:

[0073] Lignosulfonic acid, relative molecular weight of 5000-10000; polyacrylic acid, average molecular weight of 2000; both purchased from Shanghai MacLean Biochemical Technology Co., Ltd.

[0074] Polyaspartic acid, relative molecular weight 1000~5000, solid content ≥40%, density ≥1.2g / cm 3 ; Purchased from Zhoukou Cairun Environmental Protection Materials Co., Ltd.

[0075] Hydrolyzed polymaleic anhydride, relative molecular weight 400-800, solid content ≥48%, density ≥1.18g / cm 3 ; Purchased from Shandong Aike Water Treatment Technology.

[0076] Example 1

[0077] The present embodiment provides an environmentally friendly neutral rust remover and rust preventer. The raw materials for its preparation are, by mass fraction, 8% of citric acid, 5% of caffeic acid, 5% of nicotinic acid, 5% of hydroxyethylidene diphosphonic acid, 5% of polyaspartic acid, 5% of tryptophan, 3% of vitamin B1, 2% of naringenin, 2% of sodium dodecylbenzene sulfonate, and the balance is supplemented to 100% by tap water and a neutralizer.

[0078] The preparation method of the environmentally friendly neutral rust remover and rust preventer comprises the following steps:

[0079] S1. Weigh each raw material according to mass fraction;

[0080] S2. 30% tap water and organic acid were added to the reactor and stirred for 15 min;

[0081] S3. Add anti-scaling and corrosion inhibitor and antioxidant corrosion inhibitor in sequence and stir thoroughly for 15 minutes;

[0082] S4. Add surfactant, then add remaining tap water, and stir thoroughly for 20 minutes;

[0083] S5. adding a neutralizing agent to adjust the pH value of the solution to neutral;

[0084] S6. Let it stand for 2 hours to obtain an environmentally friendly neutral rust remover and rust inhibitor.

[0085] Take 5% of the finished product and 95% of tap water to prepare a working solution. Immerse the rusted iron parts in the working solution at room temperature. After 1.5 hours, the rust and oxide scale are completely removed, the surface of the iron parts is shiny, and the base is not damaged. There is no obvious rust mark after being placed at room temperature for 90 days.

[0086] Example 2

[0087] The difference between this embodiment and embodiment 1 is that the raw materials for preparing the environmentally friendly neutral rust remover and rust inhibitor are, by mass fraction, 7% DL-tartaric acid, 7% D-glucose acid, 5% salicylic acid, 5% aminotri(methylenephosphonic acid), 5% polyacrylic acid, 5% sodium isovitamin C, 3% methionine, 2% naringenin, 1% sodium dodecylbenzene sulfonate, and the balance is supplemented to 100% by tap water and a neutralizer.

[0088] Take 5% of the finished product and 95% of tap water to prepare a working solution. Immerse the rusted iron parts in the working solution at room temperature. After 1.6 hours, the rust and oxide scale are completely removed, the surface of the iron parts is shiny, and the base is not damaged. There is no obvious rust mark after being placed at room temperature for 80 days.

[0089] Example 3

[0090] The difference between this embodiment and embodiment 1 is that the environmentally friendly neutral rust remover and rust preventer is prepared from the following raw materials, by mass fraction: 6% citric acid, 6% DL-tartaric acid, 6% salicylic acid, 5% ethylenediaminetetramethylenephosphonic acid, 5% hydrolyzed polymaleic anhydride, 5% vitamin B1, 3% catechin, 2% lipoic acid and 2% sodium dodecylbenzene sulfonate, and tap water and a neutralizer are used to supplement the balance to 100%.

[0091] Take 5% of the finished product and 95% of tap water to prepare a working solution. Immerse the rusted iron parts in the working solution at room temperature. After 1.6 hours, the rust and oxide scale are completely removed, the surface of the iron parts is shiny, and the base is not damaged. There is no obvious rust mark after being placed at room temperature for 85 days.

[0092] Example 4

[0093] The difference between this embodiment and embodiment 1 is that the raw materials for preparing the environmentally friendly neutral rust remover and rust preventer are, by mass fraction, 6% citric acid, 6% DL-tartaric acid, 6% salicylic acid, 5% ethylenediaminetetramethylenephosphonic acid, 5% hydrolyzed polymaleic anhydride, 5% vitamin B1, 3% catechin, 2% lipoic acid and 2% sodium dodecylbenzene sulfonate.

[0094] Take 5% of the finished product and 95% of tap water to prepare a working solution, immerse the rusted iron parts in the working solution at 60°C. After 0.7h, the rust and scale are completely removed, the surface of the iron parts is glossy, and the base is not damaged. There is no obvious rust mark after being placed at room temperature for 85 days.

[0095] Example 5

[0096] The difference between this embodiment and embodiment 1 is that the raw materials for preparing the environmentally friendly neutral rust remover and rust inhibitor are, by mass fraction, 8% of D-glucaric acid, 5% of DL-malic acid, 5% of nicotinic acid, 5% of 2-phospho-1,2,4-tricarboxylic acid butane, 5% of polyaspartic acid, 5% of sodium isovitamin C, 3% of thioctic acid, 2% of 2-quinoxalinecarboxylic acid and 1% of sodium dodecylbenzenesulfonate, and the balance is supplemented to 100% by tap water and a neutralizer.

[0097] Take 5% of the finished product and 95% of tap water to prepare a working solution, immerse the rusted iron parts in the working solution at 60°C. After 0.6h, the rust and oxide scale are completely removed, the surface of the iron parts is glossy, and the base is not damaged. There is no obvious rust mark after being placed at room temperature for 90 days.

[0098] Example 6

[0099] The difference between this embodiment and embodiment 1 is that the raw materials for preparing the environmentally friendly neutral rust remover and rust inhibitor are, by mass fraction, 6% of citric acid, 5% of D-gluconic acid, 5% of salicylic acid, 5% of hydroxyethylidene diphosphonic acid, 3% of polyacrylic acid, 3% of lignin sulfonic acid, 5% of sodium isovitamin C, 3% of methionine, 2% of naringenin and 2% of sodium dodecylbenzene sulfonate, and the balance is supplemented to 100% by tap water and a neutralizer.

[0100] Take 5% of the finished product and 95% of tap water to prepare a working solution, immerse the rusted iron parts in the working solution at 60°C, and after 0.6h, the rust and scale are completely removed, the surface of the iron parts is glossy, and the base is not damaged. There is no obvious rust mark after being placed at room temperature for 80 days.

[0101] Example 7

[0102] The difference between this embodiment and embodiment 1 is that the raw materials for preparing the environmentally friendly neutral rust remover and rust inhibitor are, by mass fraction, 6% of citric acid, 5% of D-gluconic acid, 5% of salicylic acid, 5% of hydroxyethylidene diphosphonic acid, 3% of polyacrylic acid, 3% of lignin sulfonic acid, 5% of sodium isovitamin C, 3% of methionine, 2% of naringenin and 2% of sodium dodecylbenzene sulfonate, and the balance is supplemented to 100% by tap water and a neutralizer.

[0103] Take 5% of the finished product and 95% of tap water to prepare a working solution. Immerse the rusted iron parts in the working solution at 90°C. After 20 minutes, the rust and oxide scale are completely removed, the surface of the iron parts is glossy, and the base is not damaged. There is no obvious rust mark after being placed at room temperature for 80 days.

[0104] Example 8

[0105] The difference between this embodiment and embodiment 1 is that the raw materials for preparing the environmentally friendly neutral rust remover and rust preventer are, by mass fraction, 6% of citric acid, 6% of D-glucose diacid, 3% of DL-tartaric acid, 3% of salicylic acid, 5% of aminotri(methylenephosphonic acid), 3% of lignin sulfonic acid, 3% of polyaspartic acid, 5% of vitamin B1, 3% of catechin, 2% of lipoic acid and 2% of sodium dodecylbenzene sulfonate, and tap water and a neutralizer are used to supplement the balance to 100%.

[0106] Take 5% of the finished product and 95% of tap water to prepare a working solution. Immerse the rusted iron parts in the working solution at 90°C. After 25 minutes, the rust and oxide scale are completely removed, the surface of the iron parts is glossy, and the base is not damaged. There is no obvious rust mark after being placed at room temperature for 85 days.

[0107] Example 9

[0108] The difference between this embodiment and embodiment 1 is that the raw materials for preparing the environmentally friendly neutral rust remover and rust preventer are, by mass fraction, 6% of citric acid, 6% of D-gluconic acid, 3% of nicotinic acid, 3% of caffeic acid, 5% of aminotri(methylenephosphonic acid), 5% of polyacrylic acid, 5% of tryptophan, 3% of methionine, 2% of catechin and 1% of sodium dodecylbenzene sulfonate, and the balance is supplemented to 100% by tap water and a neutralizer.

[0109] Take 5% of the finished product and 95% of tap water to prepare a working solution. Immerse the rusted iron parts in the working solution at 90°C. After 20 minutes, the rust and oxide scale are completely removed, the surface of the iron parts is glossy, and the base is not damaged. There is no obvious rust mark after being placed at room temperature for 90 days.

[0110] Example 10

[0111] The difference between this embodiment and embodiment 1 is that the raw materials for preparing the environmentally friendly neutral rust remover and rust inhibitor are, by mass fraction, 8% of citric acid, 5% of caffeic acid, 5% of nicotinic acid, 5% of hydroxyethylidene diphosphonic acid, 5% of polyaspartic acid, 5% of tryptophan, 3% of vitamin B1, 2% of naringenin and 2% of sodium dodecylbenzene sulfonate, and tap water and a neutralizer are used to supplement the balance to 100%.

[0112] Take 5% of the finished product and 95% of tap water to prepare a working solution, immerse the rusted iron parts in the working solution at 90°C. After 15 minutes, the rust and oxide scale are completely removed, the surface of the iron parts is glossy, and the base is not damaged. There is no obvious rust mark after being placed at room temperature for 90 days.

[0113] Comparative Example 1

[0114] The difference between this ratio and Example 1 is that the raw materials for preparing the environmentally friendly neutral rust remover and rust inhibitor are, by mass fraction, 20% citric acid, 5% hydroxyethylidene diphosphonic acid, 5% polyaspartic acid, 5% tryptophan, 3% vitamin B1, 2% naringenin, 2% sodium dodecylbenzene sulfonate, and the balance is supplemented to 100% by tap water and a neutralizer.

[0115] Take 5% of the finished product and 95% of tap water to prepare a working solution. Immerse the rusted iron parts in the working solution at room temperature. After 1.5 hours, the rust and oxide scale are completely removed, the surface of the iron parts is matte, and the base is corrosively damaged.

[0116] Comparative Example 2

[0117] The difference between this ratio and Example 1 is that the raw materials for preparing the environmentally friendly neutral rust remover and rust inhibitor are, by mass fraction, 12% of citric acid, 8% of caffeic acid, 8% of nicotinic acid, 5% of tryptophan, 3% of vitamin B1, 2% of naringenin, and 2% of sodium dodecylbenzene sulfonate, and tap water and a neutralizer are used to supplement the balance to 100%.

[0118] Take 5% of the finished product and 95% of tap water to prepare a working solution. Immerse the rusted iron parts in the working solution at room temperature. After 1.6 hours, the rust and oxide scale are basically removed, there are more scale spots, the surface of the iron parts is dull, and the base is not damaged.

[0119] Comparative Example 3

[0120] The difference between this ratio and Example 3 is that the environmentally friendly neutral rust remover and rust preventer is prepared from the following raw materials, by mass fraction: 6% citric acid, 6% DL-tartaric acid, 6% salicylic acid, 5% ethylenediaminetetramethylenephosphonic acid, 5% hydrolyzed polymaleic anhydride, 10% thioctic acid and 2% sodium dodecylbenzenesulfonate, and the balance is supplemented to 100% by tap water and a neutralizer.

[0121] Take 5% of the finished product and 95% of tap water to prepare a working solution. Immerse the rusted iron parts in the working solution at room temperature. After 1.5 hours, the rust and oxide scale are completely removed, the surface of the iron parts is matte, and the base is pitted.

[0122] Comparative Example 4

[0123] The difference between this ratio and Example 1 is that the raw materials for preparing the environmentally friendly neutral rust remover and rust inhibitor are, by mass fraction, 12% of caffeic acid, 8% of nicotinic acid, 10% of polyaspartic acid, 5% of vitamin B1, 5% of naringenin, 2% of sodium dodecylbenzene sulfonate, and the balance is supplemented by tap water and a neutralizer to 100%.

[0124] Take 5% of the finished product and 95% of tap water to prepare a working solution, immerse the rusted iron parts in the working solution at 60°C. After 0.7h, the rust and oxide scale are not completely removed, and scale spots are present on the surface of the iron parts.

[0125] Comparative Example 5

[0126] The difference between this ratio and Example 6 is that the raw materials for preparing the environmentally friendly neutral rust remover and rust inhibitor are, by mass fraction, 6% of citric acid, 5% of D-gluconic acid, 5% of salicylic acid, 5% of hydroxyethylidene diphosphonic acid, 3% of polyacrylic acid, 3% of lignin sulfonic acid, 10% of naringenin and 2% of sodium dodecylbenzene sulfonate, and the balance is supplemented to 100% by tap water and a neutralizer.

[0127] Take 5% of the finished product and 95% of tap water to prepare a working solution, immerse the rusted iron parts in the working solution at 60°C. After 0.6h, the rust and scale are not completely removed, the surface of the iron parts is dull, and the base is pitted.

[0128] Comparative Example 6

[0129] The difference between this ratio and Example 6 is that the raw materials for preparing the environmentally friendly neutral rust remover and rust inhibitor are, by mass fraction, 10% citric acid, 8% salicylic acid, 8% polyacrylic acid, 3% lignin sulfonic acid, 5% sodium isovitamin C, 3% methionine, 2% naringenin and 2% sodium dodecylbenzene sulfonate, and the balance is supplemented to 100% by tap water and a neutralizer.

[0130] Take 5% of the finished product and 95% of tap water to prepare a working solution. Immerse the rusted iron parts in the working solution at 60°C. After 0.6 hours, the rust and scale are completely removed, the surface of the iron parts is matte, and the base is corrosively damaged.

[0131] Comparative Example 7

[0132] The difference between this ratio and Example 9 is that the raw materials for preparing the environmentally friendly neutral rust remover and rust inhibitor are, by mass fraction, 9% citric acid, 9% D-gluconic acid, 5% nicotinic acid, 5% caffeic acid, 5% tryptophan, 3% methionine, 2% catechin and 1% sodium dodecylbenzene sulfonate, and tap water and a neutralizer are used to supplement the balance to 100%.

[0133] Take 5% of the finished product and 95% of tap water to prepare a working solution. Immerse the rusted iron parts in the working solution at 90°C. After 15 minutes, the rust and oxide scale are completely removed, and the base is corrosively damaged.

[0134] Comparative Example 8

[0135] The difference between this ratio and Example 9 is that the raw materials for preparing the environmentally friendly neutral rust remover and rust inhibitor are, by mass fraction, 8% citric acid, 8% D-gluconic acid, 5% nicotinic acid, 5% caffeic acid, 7% aminotri(methylenephosphonic acid), 7% polyacrylic acid and 1% sodium dodecylbenzenesulfonate, and tap water and neutralizer are used to supplement the balance to 100%.

[0136] Take 5% of the finished product and 95% of tap water to prepare a working solution, immerse the rusted iron parts in the working solution at 90°C, and after 15 minutes, the rust and oxide scale are completely removed, the surface of the iron parts is matte, and the base is pitted.

[0137] Comparative Example 9

[0138] The difference between this ratio and Example 10 is that the raw materials for preparing the environmentally friendly neutral rust remover and rust inhibitor are, by mass fraction, 12% of hydroxyethylidene diphosphonic acid, 12% of polyaspartic acid, 6% of tryptophan, 4% of vitamin B1, 4% of naringenin and 2% of sodium dodecylbenzene sulfonate, and tap water and a neutralizer are used to supplement the balance to 100%.

[0139] Take 5% of the finished product and 95% of tap water to prepare a working solution, immerse the rusted iron parts in the working solution at 90°C. After 15 minutes, the rust and oxide scale are not completely removed, and the surface of the iron parts is dull.

[0140] According to statistics, the environmentally friendly neutral rust remover and rust inhibitor prepared by Examples 1 to 10 of the present invention has good surface rust removal effect, no damage to the workpiece surface, and excellent rust prevention ability. Comparative Example 1 increases the amount of organic acid citric acid added and deletes caffeic acid and nicotinic acid, Comparative Example 2 increases the total amount of organic acid added and deletes the scale inhibitor and corrosion inhibitor hydroxyethylidene diphosphonic acid and polyaspartic acid, Comparative Example 3 increases the amount of antioxidant corrosion inhibitor lipoic acid added and deletes vitamin B1 and catechins, Comparative Example 4 deletes the organic acid citric acid, scale inhibitor and corrosion inhibitor hydroxyethylidene diphosphonic acid and antioxidant corrosion inhibitor tryptophan and increases the amount of other compounding substances, Comparative Example 5 increases the amount of antioxidant naringenin added and deletes sodium isovitamin C and methionine, Comparative Example 6 deletes the organic acid D-gluconic acid and scale inhibitor and corrosion inhibitor hydroxyethylidene diphosphonic acid and increases the amount of other compounding substances, Comparative Example 7 increases the total amount of organic acid added and deletes the inhibitor Scale and corrosion inhibitors aminotri(methylene phosphonic acid) and polyacrylic acid, comparative example 8 increased the amount of organic acid and scale and corrosion inhibitor added and deleted the antioxidant corrosion inhibitors tryptophan, methionine and catechin, comparative example 9 deleted the organic acids citric acid, caffeic acid and nicotinic acid and increased the total amount of scale and corrosion inhibitors and antioxidant corrosion inhibitors added, and an environmentally friendly neutral rust remover and rust preventer was prepared, but the rust removal and rust prevention functions were poor. Therefore, the environmentally friendly neutral rust remover and rust preventer prepared by the raw materials and methods described in the present application not only has efficient rust removal, but also has a long rust prevention period, especially for iron parts in tap water media at high temperature, it can efficiently remove rust and prevent scaling, secondary oxidation and rust of metal base parts in tap water after rust removal, and has the characteristics of simple preparation method, harmlessness to human body, and no environmental pollution.

[0141] The above is a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. An environmentally friendly neutral rust remover and rust preventer, characterized in that: The invention comprises, by mass fraction, 10% to 20% of organic acid, 5% to 15% of scale inhibitor, 5% to 15% of antioxidant, 1% to 2% of surfactant, and the balance is supplemented by tap water and neutralizer to 100%; the organic acid is 2 to 4 of citric acid, DL-tartaric acid, D-gluconic acid, D-gluconic acid, DL-malic acid, caffeic acid, salicylic acid and nicotinic acid; the scale inhibitor is hydroxyethylidene diphosphonic acid, ethylenediaminetetramethyleneimine Phosphonic acid, aminotrimethylenephosphonic acid, 2-phospho-1,2,4-tricarboxylic acid butane, lignin sulfonic acid, polyacrylic acid, polyaspartic acid and hydrolyzed polymaleic anhydride. The relative molecular weight of the lignin sulfonic acid is 5000-10000; the average molecular weight of the polyacrylic acid is 1000-3000; the relative molecular weight of the polyaspartic acid is 1000-5000, the solid content is ≥40%, and the density is ≥1.2g / cm 3 The relative molecular weight of the hydrolyzed polymaleic anhydride is 400-800, the solid content is ≥48%, and the density is ≥1.18g / cm 3 The antioxidant corrosion inhibitors are three of tryptophan, methionine, vitamin B1, sodium isovitamin C, naringenin, catechin, lipoic acid and 2-quinoxaline carboxylic acid.

2. The environmentally friendly neutral rust remover and rust preventer according to claim 1, characterized in that: The organic acids are citric acid, caffeic acid and nicotinic acid; the mass ratio is (1-2):(0.5-1.5):

1.

3. The environmentally friendly neutral rust remover and rust preventer according to claim 1, characterized in that: The scale and corrosion inhibitor is hydroxyethylidene diphosphonic acid and polyaspartic acid; the mass ratio is (0.5-1.5):

1.

4. The environmentally friendly neutral rust remover and rust preventer according to claim 1, characterized in that: The antioxidant corrosion inhibitor is tryptophan, vitamin B1 and naringenin; the mass ratio is (2-3): (1-2):

1.

5. The environmentally friendly neutral rust remover and rust preventer according to claim 1, characterized in that: The surfactant is any one of sodium dodecyl sulfonate, sodium dodecylbenzene sulfonate, fatty alcohol polyoxyethylene ether and fatty alcohol polyoxyethylene ether phosphate.

6. A method for preparing the environmentally friendly neutral rust remover and rust preventer according to any one of claims 1 to 5, characterized in that: The following steps are involved: S1. Weigh each raw material according to mass fraction; S2. 30% tap water and organic acid were added to the reactor and stirred for 15 min; S3. Add anti-scaling and corrosion inhibitor and antioxidant corrosion inhibitor in turn and stir for 15 minutes; S4. Add surfactant, then add remaining tap water and stir for 20 min; S5. adding a neutralizing agent to adjust the pH value of the solution to neutral; S6. Let stand for 2 hours.

7. Use of the environmentally friendly neutral rust remover and rust inhibitor according to any one of claims 1 to 5 in the technical field of metal rust removal and corrosion prevention.

8. The use of the environmentally friendly neutral rust remover and rust inhibitor according to claim 7 in the field of metal rust removal and corrosion prevention technology, characterized in that: The application steps are: take 4% to 6% of the environmentally friendly neutral rust remover and rust preventer and 94% to 96% of tap water to prepare a rust remover and rust preventer working solution, soak the workpiece in the rust remover and rust preventer working solution at room temperature, and remove the workpiece after 1.5 to 1.6 hours.

9. The use of the environmentally friendly neutral rust remover and rust inhibitor according to claim 7 in the field of metal rust removal and corrosion prevention technology, characterized in that: The application steps are: take 4% to 6% of the environmentally friendly neutral rust remover and rust preventer and 94% to 96% of tap water to prepare a rust remover and rust preventer working solution, heat it to 60°C, then immerse the workpiece in the rust remover and rust preventer working solution, and remove the workpiece after 0.6 to 0.7 hours.

10. The use of the environmentally friendly neutral rust remover and rust inhibitor according to claim 7 in the field of metal rust removal and corrosion prevention technology, characterized in that: The application steps are: take 4% to 6% of the environmentally friendly neutral rust remover and rust preventer and 94% to 96% of tap water to prepare a rust remover and rust preventer working solution, heat it to 90°C, then immerse the workpiece in the rust remover and rust preventer working solution, and take out the workpiece after 15 to 25 minutes.