Economical and environment-friendly fast drying rust removal and rust conversion agent, preparation method and use thereof

Abstract

The application discloses an economic and environment-friendly type fast drying rust removal and rust conversion agent, a preparation method and application thereof, and belongs to the field of metal surface corrosion prevention. The rust removal and rust conversion agent comprises the following components: modified acrylic emulsion, sodium gluconate, fatty alcohol polyoxyethylene ether sodium sulfate, sodium nitrite, tannic acid, phosphoric acid, ethanol, ethylene glycol, essence and deionized water. The modified acrylic emulsion with the rust conversion function is used as the main component, the fatty alcohol polyoxyethylene ether sodium sulfate and the sodium nitrite with the cleaning function are matched, the dirt on the surface of the metal substrate can be cleaned quickly, the tannic acid and the phosphoric acid with the rust conversion function are matched, the rust removal and rust conversion are complete, the sodium gluconate is efficiently chelated with the metal substrate, a dense coating is formed, the adhesion of the coating is good, the contact of air and water vapor with the metal substrate is prevented, secondary rusting is avoided, the coating can be applied in an environment with humidity greater than or equal to 85%RH, and the water on the surface of the substrate is quickly removed by volatilization of the ethanol and the ethylene glycol.

Description

Technical Field

[0001] This invention belongs to the field of metal surface corrosion protection technology, specifically relating to an economical and environmentally friendly fast-drying rust remover and rust converter, its preparation method, and its uses. Background Technology

[0002] Different types of metal substrates exhibit different surface rust patterns, thus requiring different rust removal methods. Currently, surface treatment of steel substrates mainly includes chemical and mechanical methods. The choice of rust removal method varies depending on the steel component's configuration and its environment. Chemical rust removal has limitations when working outdoors without dismantling the steel components. Sandblasting can cause environmental pollution and is difficult to perform outdoors, especially in high-humidity environments, resulting in strong odors and potential for secondary rusting due to moisture buildup on the metal surface after rust removal.

[0003] Chinese Patent 201510887837.7 discloses a highly efficient and rapid rust-removing and rust-preventing liquid and its preparation method. The main raw materials consist of 5-10% phosphoric acid, 2-4% organic acid, 0.5-1.0% ammonium molybdate, 3-6% EDTA cyclohexane ammonium salt solution, 1-3% penetrant, 0.5-1% thiourea, 1-1.5% sodium hexametaphosphate, 4-8% nano-stabilizing dispersant, 0.5-1% nickel nitrate, 6-8% 10wt% hydroquinone ethanol aqueous solution, and 65-75% deionized water. This rust-removing and rust-preventing liquid has a good rust-removing effect; however, because rust removal relies entirely on acid rinsing, the operation is relatively dangerous, and secondary corrosion is easily generated on the metal surface, making secondary rusting more likely. It also suffers from the problem of rust removal without rust formation, and has disadvantages such as long production time and complex process. Summary of the Invention

[0004] This invention addresses the technical problems of existing rust removers, such as failure to transfer rust after removal, strong odor during outdoor application, and long production time. It provides an economical and environmentally friendly fast-drying rust remover and rust-transfer agent, its preparation method, and its applications. The product of this invention has a short production time, can be applied in humid outdoor environments, and exhibits excellent rust-transfer performance.

[0005] To achieve the above objectives, the present invention adopts the following technical solution.

[0006] An economical and environmentally friendly fast-drying rust remover and rust converter, comprising the following components by weight:

[0007] The mixture consists of 20-30 parts modified acrylic emulsion, 2-4 parts sodium gluconate, 2-4 parts sodium fatty alcohol polyoxyethylene ether sulfate, 2-4 parts sodium nitrite, 4-5 parts tannic acid, 1-2 parts phosphoric acid, 13-17 parts ethanol, 6-8 parts ethylene glycol, 4-6 parts fragrance, and 40-60 parts water.

[0008] Preferably, the economical and environmentally friendly fast-drying rust remover / rust converter is composed of the following components by mass parts: 26 parts modified acrylic emulsion, 3 parts sodium gluconate, 3 parts sodium fatty alcohol polyoxyethylene ether sulfate, 3 parts sodium nitrite, 4 parts tannic acid, 2 parts phosphoric acid, 15 parts ethanol, 7 parts ethylene glycol, 5 parts fragrance, and 6 parts water.

[0009] Furthermore, the modified acrylic emulsion is prepared by adding gallic tannic acid to deionized water, heating and stirring to completely dissolve it, lowering the temperature, and then adding epoxy ester, methacrylic acid, unsaturated fatty acid, and potassium persulfate. The temperature is then raised to 50-70℃ and stirred for 1 hour to obtain the modified acrylic emulsion.

[0010] Furthermore, the weight ratio of gallic tannic acid, deionized water, epoxy ester, methacrylic acid, unsaturated fatty acid, and potassium persulfate is 3:40:25:7:4:0.2.

[0011] This invention also provides a method for preparing the above-mentioned economical and environmentally friendly fast-drying rust remover and rust converter, the specific steps of which are as follows:

[0012] (1) Preparation of modified acrylic emulsion

[0013] Gallic tannic acid was added to deionized water, heated and stirred until completely dissolved, the temperature was lowered, and then epoxy ester, methacrylic acid, unsaturated fatty acid and potassium persulfate were added. The temperature was raised to 50-70℃ and stirred for 1 hour to obtain modified acrylic emulsion.

[0014] (2) Preparation of water-based rust remover and rust-transfer agent

[0015] ① Add a certain amount of deionized water to the reaction vessel and heat it to 45℃;

[0016] ② Add sodium gluconate to the reaction vessel, and stir at a speed of 400-600 r / min for 5-15 min. At the same speed, add sodium fatty alcohol polyoxyethylene ether sulfate and sodium nitrite again, and stir thoroughly for 5-15 min to obtain a particle-free slurry.

[0017] ③ Add tannic acid and phosphoric acid to the slurry in step ②, and control the stirring speed to 400-600 r / min, stirring for 5-15 min;

[0018] ④ Cool the slurry obtained in step ③ to 20-30℃, control the stirring speed to 200-400 r / min, add ethanol, ethylene glycol and fragrance, stir for 5-10 min, then control the temperature between 30-50℃, add modified acrylic emulsion, continue stirring for 0.5 h, filter and package.

[0019] Furthermore, the dropping rates of both the tannic acid and phosphoric acid are 20–40 mL / min.

[0020] Furthermore, the dropping rate of the modified acrylic emulsion is 50–80 mL / min.

[0021] Furthermore, in step ③, the pH value is adjusted to 5.5 using tannic acid and phosphoric acid.

[0022] This invention also provides the application of the above-mentioned economical and environmentally friendly fast-drying rust remover / rust converter in rust removal or rust prevention on metal substrates. The product of this invention is particularly suitable for the renovation of outdoor highway guardrails and can be recycled and reused using specialized equipment, reducing product waste and saving construction costs.

[0023] Due to the adoption of the above technical solution, the beneficial technical effects of the present invention are as follows:

[0024] 1. This invention uses a modified acrylic emulsion with rust-removing function as the main component, combined with sodium sulfate and sodium nitrite with cleaning properties of fatty alcohol polyoxyethylene ether. It can quickly clean all the dirt on the surface of the metal substrate. Combined with tannic acid and phosphoric acid with rust-removing function, the rust removal and rust removal are thorough. Sodium gluconate is efficiently chelated with the metal substrate to form a dense coating with good adhesion. The coating can prevent air and moisture from contacting the metal substrate and causing secondary rusting. It can be applied in an environment with humidity ≥85%RH. The evaporation of ethanol and ethylene glycol can quickly remove moisture from the surface of the substrate.

[0025] The economical and environmentally friendly fast-drying rust remover and rust converter of this invention has weak acidity, no odor, and is safer and more environmentally friendly for outdoor use, thus solving the shortcomings of outdoor coating.

[0026] The economical and environmentally friendly fast-drying rust remover and rust converter of this invention has a short production time, is easy to operate in preparation process, and has low raw material costs.

[0027] The product of this invention is recyclable, especially in the renovation of outdoor highway guardrails, where it can be recycled using specialized equipment, reducing product waste and saving construction costs. Detailed Implementation

[0028] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0029] It should be noted that all raw materials in the following embodiments of the present invention are commercially available. Among them, sodium gluconate, sodium fatty alcohol polyoxyethylene ether sulfate, sodium nitrite, tannic acid, phosphoric acid, ethanol, ethylene glycol, and fragrance are all industrial grade, and the modified acrylic emulsion is a self-made product.

[0030] Example 1

[0031] (1) Preparation of modified acrylic emulsion with rust-transfer function:

[0032] By weight, 3 parts gallic tannic acid were added to 40 parts deionized water, heated and stirred until completely dissolved, the temperature was lowered, and then 25 parts epoxy ester, 7 parts methacrylic acid, 4 parts unsaturated fatty acid, and 0.2 parts potassium persulfate were added. The temperature was raised to 50-70℃ and stirred for 1 hour to obtain a modified acrylic emulsion.

[0033] (2) Preparation of rust remover and rust converter

[0034] Add 6000g of deionized water to a reactor and heat to 45℃. Add 200g of sodium gluconate to the reactor and stir at 400-600 rpm for 5-15 minutes. At the same stirring speed, add 200g of sodium fatty alcohol polyoxyethylene ether sulfate and 200g of sodium nitrite, and stir thoroughly for 5-15 minutes to obtain a particle-free slurry. Add 400g of tannic acid and 100g of phosphoric acid to the slurry and stir at 400-600 rpm for 5-15 minutes. Cool the resulting slurry to 20-30℃ and stir at 200-400 rpm. Add 1300g of ethanol, 600g of ethylene glycol, and 400g of fragrance, and stir for 5-10 minutes. Then, maintain the temperature between 30-50℃ and add 2000g of modified acrylic emulsion. Continue stirring for 0.5 hours, filter, and package.

[0035] Example 2

[0036] (1) Preparation of modified acrylic emulsion with rust-transfer function:

[0037] By weight, 3 parts gallic tannic acid were added to 40 parts deionized water, heated and stirred until completely dissolved, the temperature was lowered, and then 25 parts epoxy ester, 7 parts methacrylic acid, 4 parts unsaturated fatty acid, and 0.2 parts potassium persulfate were added. The temperature was raised to 50-70℃ and stirred for 1 hour to obtain a modified acrylic emulsion.

[0038] (2) Preparation of rust remover and rust converter

[0039] Add 5000g of deionized water to a reactor and heat to 45℃. Add 300g of sodium gluconate to the reactor and stir at 400-600 rpm for 5-15 minutes. At the same speed, add 300g of sodium fatty alcohol polyoxyethylene ether sulfate and 300g of sodium nitrite, and stir thoroughly for 5-15 minutes to obtain a particle-free slurry. Add 450g of tannic acid and 150g of phosphoric acid to the slurry and stir at 400-600 rpm for 5-15 minutes. Cool the resulting slurry to 20-30℃ and stir at 200-400 rpm. Add 1400g of ethanol, 650g of ethylene glycol, and 500g of fragrance, and stir for 5-10 minutes. Maintain the temperature between 30-50℃ and add 2500g of modified acrylic emulsion. Continue stirring for 0.5 hours, filter, and package.

[0040] Example 3

[0041] (1) Preparation of modified acrylic emulsion with rust-transfer function

[0042] By weight, 3 parts gallic tannic acid were added to 40 parts deionized water, heated and stirred until completely dissolved, the temperature was lowered, and then 25 parts epoxy ester, 7 parts methacrylic acid, 4 parts unsaturated fatty acid, and 0.2 parts potassium persulfate were added. The temperature was raised to 50-70℃ and stirred for 1 hour to obtain a modified acrylic emulsion.

[0043] (2) Preparation of rust remover and rust converter

[0044] Add 5500g of deionized water to the reactor and heat to 45℃. Add 350g of sodium gluconate to the reactor and stir at 400-600 rpm for 5-15 minutes. At the same speed, add 350g of sodium fatty alcohol polyoxyethylene ether sulfate and 350g of sodium nitrite and stir thoroughly for 5-15 minutes to obtain a particle-free slurry. Add 400g of tannic acid and 200g of phosphoric acid to the slurry and stir at 400-600 rpm for 5-15 minutes. Cool the resulting slurry to 20-30℃ and stir at 200-400 rpm. Add 1500g of ethanol, 650g of ethylene glycol, and 500g of fragrance and stir for 5-10 minutes. Maintain the temperature between 30-50℃ and add 2700g of modified acrylic emulsion. Continue stirring for 0.5 hours, filter, and package.

[0045] Example 4

[0046] (1) Preparation of modified acrylic emulsion with rust-transfer function

[0047] By weight, 3 parts gallic tannic acid were added to 40 parts deionized water, heated and stirred until completely dissolved, the temperature was lowered, and then 25 parts epoxy ester, 7 parts methacrylic acid, 4 parts unsaturated fatty acid, and 0.2 parts potassium persulfate were added. The temperature was raised to 50-70℃ and stirred for 1 hour to obtain a modified acrylic emulsion.

[0048] (2) Preparation of rust remover and rust converter

[0049] Add 6000g of deionized water to a reactor and heat to 45℃. Add 400g of sodium gluconate to the reactor and stir at 400-600 rpm for 5-15 minutes. At the same stirring speed, add 400g of sodium fatty alcohol polyoxyethylene ether sulfate and 400g of sodium nitrite, and stir thoroughly for 5-15 minutes to obtain a particle-free slurry. Add 500g of tannic acid and 200g of phosphoric acid to the slurry and stir at 400-600 rpm for 5-15 minutes. Cool the resulting slurry to 20-30℃ and stir at 200-400 rpm. Add 1500g of ethanol, 650g of ethylene glycol, and 500g of fragrance, and stir for 5-10 minutes. Maintain the temperature between 30-50℃ and add 3000g of modified acrylic emulsion. Continue stirring for 0.5 hours, filter, and package.

[0050] Comparative Example

[0051] Add 7g of phosphoric acid, 1g of sodium hexametaphosphate, 4g of acetic acid, 0.5g of thiourea, 0.5g of nickel nitrate, 4g of ethylene glycol, 0.5g of ammonium molybdate, and 6g of 10% hydroquinone ethanol aqueous solution to 70g of deionized water and mix thoroughly. While stirring continuously, add 5g of EDTA cyclohexane ammonium salt solution and 5g of nano-montmorillonite dispersant. Finally, control the temperature between 35 and 55℃ and continue stirring for 0.5-1h to obtain the high-efficiency and rapid rust removal and rust prevention liquid.

[0052] Test case

[0053] The target products of the present invention prepared in Examples 1-4 were sprayed onto steel surfaces with rust, old paint film, and oil stains in an environment with humidity ≥85%RH. The spraying was carried out using specialized equipment at a pressure of 10-15MPa. The outdoor rust removal and rust conversion were mainly investigated, and the drying time, rust removal speed, rust conversion film adhesion, odor intensity, and compatibility with various types of primers and topcoats were tested. The results are shown in Table 1.

[0054]

[0055] The results show that the product obtained in the example has excellent rust removal and rust conversion function, fast drying speed, excellent adhesion of rust conversion film, good compatibility with various types of primers and topcoats, is not prone to rusting in humid environments, has less odor during outdoor construction, and has good storage stability.

[0056] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An economical and environmentally friendly fast-drying rust remover and rust converter, characterized in that, It includes the following components by mass parts: 20-30 parts modified acrylic emulsion, 2-4 parts sodium gluconate, 2-4 parts sodium fatty alcohol polyoxyethylene ether sulfate, 2-4 parts sodium nitrite, 4-5 parts tannic acid, 1-2 parts phosphoric acid, 13-17 parts ethanol, 6-8 parts ethylene glycol, 4-6 parts fragrance, and 40-60 parts deionized water; The modified acrylic emulsion is prepared by adding gallic tannic acid to deionized water, heating and stirring until completely dissolved, lowering the temperature, and then adding epoxy ester, methacrylic acid, unsaturated fatty acid, and potassium persulfate. The temperature is then raised to 50-70℃ and stirred for 1 hour to obtain the modified acrylic emulsion. The weight ratio of gallic tannic acid, deionized water, epoxy ester, methacrylic acid, unsaturated fatty acid, and potassium persulfate used in the preparation of the modified acrylic emulsion is 3:40:25:7:4:0.

2.

2. The preparation method of the economical and environmentally friendly fast-drying rust remover and rust converter as described in claim 1, characterized in that, The specific steps are as follows: (1) Preparation of modified acrylic emulsion Gallic tannic acid was added to deionized water, heated and stirred until completely dissolved, the temperature was lowered, and then epoxy ester, methacrylic acid, unsaturated fatty acid and potassium persulfate were added. The temperature was raised to 50-70℃ and stirred for 1 hour to obtain modified acrylic emulsion. (2) Preparation of rust remover and rust converter ① Add a certain amount of deionized water to the reaction vessel and heat it to 45℃; ② Add sodium gluconate to the reaction vessel, and stir at a speed of 400-600 r / min for 5-15 min. At the same speed, add sodium fatty alcohol polyoxyethylene ether sulfate and sodium nitrite again, and stir thoroughly for 5-15 min to obtain a particle-free slurry. ③ Add tannic acid and phosphoric acid to the slurry in step ②, and control the stirring speed to 400-600 r / min, stirring for 5-15 min; ④ Cool the slurry obtained in step ③ to 20-30℃, control the stirring speed to 200-400 r / min, add ethanol, ethylene glycol and fragrance, stir for 5-10 min, then control the temperature between 30-50℃, add modified acrylic emulsion, continue stirring for 0.5 h, filter and package.

3. The preparation method of the economical and environmentally friendly fast-drying rust remover and rust converter according to claim 2, characterized in that: The dropping rates for both tannic acid and phosphoric acid are 20–40 mL / min.

4. The preparation method of the economical and environmentally friendly fast-drying rust remover and rust converter according to claim 2, characterized in that: The dropping rate of the modified acrylic emulsion is 50–80 mL / min.

5. The preparation method of the economical and environmentally friendly fast-drying rust remover and rust converter according to claim 2, characterized in that: In step ③, the pH value is adjusted to 5.5 using tannic acid and phosphoric acid.

6. The application of the economical and environmentally friendly fast-drying rust remover and rust converter as described in claim 1 in rust removal or rust prevention on metal substrate surfaces.

Images