Formula and preparation method of cleaning agent

Abstract

The invention discloses a formula of a cleaning agent and a preparation method of the cleaning agent, and the cleaning agent is prepared from the following components in percentage by mass: 8-10% of sodium chloride, 25-30% of citric acid monohydrate, 15-20% of sodium dithionite, 15-20% of tetrasodium glutamate diacetate, 5-10% of tetrasodium iminodisuccinate, 1-3% of maleic acid-acrylic acid copolymer, 10-15% of 30% hydrogen peroxide, 1-3% of polyether, 3-6% of sodium carbonate and 1-3% of oxalic acid. And the balance of deionized water or soft water. The method has the advantages that the stainless steel substrate cannot be corroded by an acidic agent, the treated surface is smooth and not rough, the dimensional precision of the stainless steel cannot be influenced, and the situation that the stainless steel is damaged by removal is avoided; rust removal and then independent passivation are not needed, rust can be cleaned up through one-time treatment, a compact protective film is rapidly formed, and time and working procedures are saved; the biodegradable chelating agent is adopted, so that the environment is not polluted, waste liquid treatment is simple, and the environmental protection cost is reduced; the device is suitable for a common environment and severe environments such as ocean and high humidity, and is wide in applicability.

Description

Technical Field

[0001] This application relates to the field of stainless steel rust and passivation treatment technology, and in particular to a cleaning agent formulation and its preparation method. Background Technology

[0002] Stainless steel, with its excellent corrosion resistance, mechanical properties, and processing performance, has been widely used in various fields such as machinery manufacturing, chemical equipment, building decoration, and marine engineering. However, during production (such as rolling and welding), storage (such as in humid environments), or use, the surface of stainless steel is prone to oxidation and contact with impurities, resulting in the formation of rust and oxide scale. If not treated promptly, the rust will continue to penetrate and corrode the substrate, leading to a significant decrease in the corrosion resistance of the stainless steel, and even causing pitting corrosion, intergranular corrosion, and other failure problems, seriously affecting the service life and safety of the workpiece. Therefore, rust removal and passivation treatment of stainless steel surfaces is a key process to ensure its performance and reliability.

[0003] Currently, commonly used stainless steel treatment agents in industry are mainly divided into three categories: acidic, alkaline, and neutral. Although acidic rust removers and passivators have the advantages of fast rust removal and good activation effect, they have obvious drawbacks: the strong acidic environment can easily cause excessive corrosion to the stainless steel substrate, leading to increased surface roughness and decreased dimensional accuracy, especially for austenitic stainless steel, which may cause intergranular corrosion risk; at the same time, the use of acidic agents will generate a large amount of acid mist and waste liquid containing heavy metal ions, which not only pollutes the environment but also requires additional investment in environmental protection treatment costs, which does not meet the current development needs of green production.

[0004] Alkaline rust removers and passivators primarily function as passivators, but their rust removal ability is relatively weak. They usually require pretreatment with high temperature or mechanical grinding to remove stubborn rust, resulting in low processing efficiency and high energy consumption. Furthermore, in alkaline systems, metal ions easily form hydroxide precipitates that adhere to the workpiece surface, affecting the uniformity and adhesion of the passivation film and making it difficult to meet the processing requirements of high-precision stainless steel workpieces.

[0005] To address the aforementioned issues with acidic and alkaline agents, neutral stainless steel rust removers and passivators have gradually become a research hotspot. Existing neutral agents mostly consist of a combination of a single chelating agent and a corrosion inhibitor. While this can balance rust removal and passivation effects to some extent, it still has many shortcomings: insufficient rust removal specificity, limited ability to dissolve complex rust layers, often requiring extended treatment time, and sometimes even failing to completely remove rust; poor passivation film density, limited corrosion resistance, prone to red rust after neutral salt spray testing, and unsuitable for harsh environments such as marine environments and high humidity; poor biodegradability of some chelating agents, leading to environmental burden from long-term accumulation; insufficient storage stability, with some components prone to reaction leading to ineffectiveness, stratification, and precipitation, affecting the consistency of performance; and a lack of refined control over formulation and application processes, making it easy for parameter fluctuations to cause unstable agent performance, failing to meet the needs of large-scale industrial production.

[0006] Therefore, a cleaning agent formulation and its preparation method are proposed. Summary of the Invention

[0007] This application aims to at least partially solve one of the technical problems in the aforementioned technologies.

[0008] To achieve the above objectives, the first aspect of this application provides a formula for a cleaning agent, comprising the following components in weight percentages: Sodium chloride 8-10%, citric acid monohydrate 25-30%, sodium dithionite 15-20%, tetrasodium glutamate diacetate 15-20%, tetrasodium iminodisuccinate 5-10%, maleic acid-acrylic acid copolymer 1-3%, 30% hydrogen peroxide 10-15%, polyether 1-3%, sodium carbonate 3-6%, oxalic acid 1-3%, with the balance being deionized water or soft water.

[0009] In addition, the cleaning agent formulation proposed in this application may also have the following additional technical features: As a further description of the above technical solution: It is composed of the following components in the following mass percentages: sodium chloride 9%, citric acid monohydrate 27%, sodium dithionite 18%, tetrasodium glutamate diacetate 18%, tetrasodium iminodisuccinate 7%, maleic acid-acrylic acid copolymer 2%, 30% hydrogen peroxide 13%, polyether 2%, sodium carbonate 4%, oxalic acid 2%, and the balance being deionized water or soft water.

[0010] The second aspect of this application discloses a method for preparing a cleaning agent, based on 1000 kg, comprising the following preparation steps: 1) Add 600 kg of deionized water to the anti-corrosion container, turn on the stirring device, control the stirring speed at 60-80 r / min, and maintain the water temperature at 25-30℃; 2) Add 150-200 kg of tetrasodium diacetate and 50-100 kg of tetrasodium iminodisuccinate, and stir for 15-20 minutes until completely dissolved; 3) Take 100-150 kg of deionized water and heat it to 30-40℃. Add 10-30 kg of oxalic acid and 80-100 kg of sodium chloride. Stir for 10 min until completely dissolved. Then, pump the solution into the system of step 2) at a rate of 5-8 L / min and continue stirring for 10 min. 4) Add 100-150 kg of citric acid monohydrate in batches, stirring for 5 minutes after each batch, and adjust the pH to 6-7; 5) Add 30-60 kg of sodium carbonate and 150-200 kg of sodium dithionite, and stir for 15 minutes; 6) Add the remaining 150-200 kg of citric acid monohydrate, 100-150 kg of 30% hydrogen peroxide and 10-30 kg of polyether, stir for 20 minutes, add deionized water to bring the total weight to 1000 kg, and check that the pH is stable at 5-7. 7) After filtering with a 100-mesh nylon filter, store in a sealed, corrosion-resistant container.

[0011] In addition, the method for preparing the cleaning agent proposed in this application may also have the following additional technical features: As a further description of the above technical solution: In step 1), the anti-corrosion container is made of PP or 304 stainless steel.

[0012] As a further description of the above technical solution: In step 3), oxalic acid and sodium chloride are ground into 80-100 mesh fine powder, and sodium dithionite is sealed and used, and the solution turns pale yellow after being added.

[0013] As a further description of the above technical solution: In step 4), a precision pH meter with an accuracy of ±0.1 is used to monitor the pH. If the pH is <5, 5-10 kg of sodium carbonate is added, and if the pH is >7, citric acid is added.

[0014] As a further description of the above technical solution: In step 7), if bubbling is vigorous, add 5-10 kg of hydrogen peroxide to neutralize.

[0015] Advantages of this invention: According to the formulation and preparation method of the cleaning agent in this application, it will not corrode the stainless steel substrate like acidic agents. The surface after treatment is smooth and not rough, and it will not affect the dimensional accuracy of stainless steel, thus avoiding the situation where the more it is cleaned, the worse it becomes. No need to remove rust first and then passivate separately; one treatment can clean up the rust and quickly form a dense protective film, saving time and steps. Using biodegradable chelating agents, it will not pollute the environment, and the waste liquid treatment is simple, reducing environmental protection costs; It is suitable for both general environments and harsh environments such as the ocean and high humidity, making it widely applicable.

[0016] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0017] The above and / or additional aspects and advantages of this application will become apparent and readily understood from the following description of the embodiments taken in conjunction with the accompanying drawings, wherein: Figure 1This is a schematic flowchart of the preparation method of the cleaning agent of this application. Detailed Implementation

[0018] The embodiments of this application are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this application, and should not be construed as limiting this application.

[0019] The formulation and preparation method of the cleaning agent according to embodiments of this application will be described below with reference to the accompanying drawings.

[0020] The cleaning agent formulation of Example 1 of this application consists of the following components in mass percentage: Sodium chloride 8-10%, citric acid monohydrate 25-30%, sodium dithionite 15-20%, tetrasodium glutamate diacetate 15-20%, tetrasodium iminodisuccinate 5-10%, maleic acid-acrylic acid copolymer 1-3%, 30% hydrogen peroxide 10-15%, polyether 1-3%, sodium carbonate 3-6%, oxalic acid 1-3%, with the balance being deionized water or soft water; Among them, the grade of sodium chloride is 7647-14-5, the grade of citric acid monohydrate is 5949-29-1, the grade of tetrasodium glutamate diacetate is 51981-21-6, the grade of tetrasodium iminodisuccinate is 144538-83-0, the grade of hydrogen peroxide is 7722-84-1, the grade of polyether is L35, and the grade of oxalic acid is 144-62-7.

[0021] Based on the above component ratios, select the optimal values: Sodium chloride 9%, citric acid monohydrate 27%, sodium dithionite 18%, tetrasodium glutamate diacetate 18%, tetrasodium iminodisuccinate 7%, maleic acid-acrylic acid copolymer 2%, 30% hydrogen peroxide 13%, polyether 2%, sodium carbonate 4%, oxalic acid 2%, with the balance being deionized water or soft water.

[0022] like Figure 1 As shown, the preparation method of the cleaning agent in Example 1 of this application includes the following preparation steps: 1) Add 600 kg of deionized water to the corrosion-resistant container (made of PP or 304 stainless steel), turn on the stirring device, control the stirring speed at 60-80 r / min, and maintain the water temperature at 25-30℃. 2) Add 150-200 kg of tetrasodium diacetate and 50-100 kg of tetrasodium iminodisuccinate, and stir for 15-20 minutes until completely dissolved; 3) Take 100-150 kg of deionized water and heat it to 30-40℃. Add 10-30 kg of oxalic acid (ground to 80-100 mesh fine powder) and 80-100 kg of sodium chloride (ground to 80-100 mesh fine powder). Stir for 10 min until completely dissolved. Then, pump it into the system of step 2) at a rate of 5-8 L / min and continue stirring for 10 min. Sodium dithionite should be sealed and used in a sealed container. The solution will turn pale yellow after it is added. 4) Add 100-150 kg of citric acid monohydrate in batches, stirring for 5 minutes after each batch. Adjust the pH to 6-7 and monitor it with a precision pH meter with an accuracy of ±0.1. When the pH is <5, add 5-10 kg of sodium carbonate; when the pH is >7, add citric acid. 5) Add 30-60 kg of sodium carbonate and 150-200 kg of sodium dithionite, and stir for 15 minutes; 6) Add the remaining 150-200 kg of citric acid monohydrate, 100-150 kg of 30% hydrogen peroxide and 10-30 kg of polyether, stir for 20 minutes, add deionized water to bring the total weight to 1000 kg, and check that the pH is stable at 5-7. 7) After filtering with a 100-mesh nylon filter, store in a sealed, corrosion-resistant container. If bubbling becomes vigorous, add 5-10 kg of hydrogen peroxide to neutralize.

[0023] The following is a detailed explanation of the optimal value in Example 1, using 1000 kg of the reagent as a baseline, and Example 2 is provided: Add 300 kg of deionized water (60% of the total water volume) to a 500 L PP mixing tank, turn on the stirring device, set the stirring speed to 70 r / min, and control the water temperature to 28 °C. Slowly add 180 kg of tetrasodium glutamate diacetate and 70 kg of tetrasodium iminodisuccinate, and stir continuously for 18 minutes, observing the state of the solution during this period, until a uniform and transparent chelating agent mother liquor is formed with no visible particles. Add 75 kg of deionized water (15% of the total water volume) to a 100 L dissolving tank, heat to 35 °C, then add 20 kg of fine oxalic acid powder and 90 kg of fine sodium chloride powder in sequence, stir for 10 min until the solid is completely dissolved to form a clear and transparent mixed salt solution. The mixed salt solution was pumped into the chelating agent stock solution in the stirred tank at a rate of 6 L / min using a metering pump, and stirred continuously for 10 min to ensure full mixing and no localized excessive concentration. 270 kg of citric acid monohydrate was divided into two batches (130 kg in the first batch and 140 kg in the second batch). The first batch of 130 kg of citric acid monohydrate was added to the mixed system first. After adding 30 kg, the mixture was stirred for 5 minutes. The pH was monitored in real time with a precision pH meter and finally adjusted to 6.5. Add 40 kg of sodium carbonate and 180 kg of sodium dithionite in sequence, stir for 15 min. At this time, the solution is light yellow and transparent, and no precipitate is formed, confirming that the sodium dithionite has not been oxidized and deactivated. Add the remaining 140 kg of citric acid monohydrate, 130 kg of 30% hydrogen peroxide, and 20 kg of polyether, and stir for 20 minutes. During this time, the solution will bubble slightly. After the bubbling stops, add the remaining 25 kg of deionized water and test the pH value again. The pH value is 6.2 and it is stable in the range of 5-7. The reagent is filtered through a 100-mesh nylon filter into a sealed HDPE storage tank. After filtration, the reagent is a pale yellow transparent liquid with no layering or sedimentation, thus completing the preparation.

[0024] The reagent and the treated workpiece in this embodiment were tested, and the results are as follows: Three representative pipe fittings were selected and tested by weight method. The average rust removal rate was 96.8% (≥95% qualified standard), and the rust was completely removed. After 48 hours of neutral salt spray testing, the pipe fittings showed no red rust or pitting on the surface, with a corrosion area of ​​less than 1%. After 24 hours of acetic acid salt spray testing, no corrosion spread was observed, meeting the requirements for use in harsh environments. In the cross-cut test, after the tape was torn off 180°, the passivation film did not fall off, and the adhesion level was 0. After being stored at 50℃ for 14 days, the agent remained a pale yellow transparent liquid with a pH value of 5.9 (fluctuation ≤ ±0.5), and the rust removal rate decreased to 94.2% (decrease ≤ 5%), indicating good stability. The total content of tetrasodium glutamate diacetate and tetrasodium iminodisuccinate was determined by complexometric titration to be 31.2% (≥30% of the acceptable standard), which is 1.2% (≤±2%) different from the value stated in the formula.

[0025] This embodiment uses a cleaning agent formulated with an optimal formula and standardized process to treat moderately rusted 304 stainless steel pipe fittings. This achieves thorough rust removal and a dense, corrosion-resistant passivation film. The agent is neutral and mild, and does not corrode the pipe substrate. The dimensional accuracy of the pipe fittings remains unchanged after treatment. Furthermore, the agent is environmentally friendly, biodegradable, and stable in storage. It is easy to use and suitable for industrial-scale batch processing, fully meeting the rust removal and passivation requirements of stainless steel workpieces.

[0026] In the description of this specification, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0027] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0028] Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of this application.

Claims

1. A formula for a cleaning agent, characterized in that, Composed of the following components by mass percentage: Sodium chloride 8-10%, citric acid monohydrate 25-30%, sodium dithionite 15-20%, tetrasodium glutamate diacetate 15-20%, tetrasodium iminodisuccinate 5-10%, maleic acid-acrylic acid copolymer 1-3%, 30% hydrogen peroxide 10-15%, polyether 1-3%, sodium carbonate 3-6%, oxalic acid 1-3%, with the balance being deionized water or soft water.

2. The formula of the cleaning agent according to claim 1, characterized in that, Composed of the following components by mass percentage: Sodium chloride 9%, citric acid monohydrate 27%, sodium dithionite 18%, tetrasodium glutamate diacetate 18%, tetrasodium iminodisuccinate 7%, maleic acid-acrylic acid copolymer 2%, 30% hydrogen peroxide 13%, polyether 2%, sodium carbonate 4%, oxalic acid 2%, with the balance being deionized water or soft water.

3. The method for preparing the cleaning agent according to claim 1, based on 1000 kg, is characterized in that, The preparation steps include the following: 1) Add 600 kg of deionized water to the anti-corrosion container, turn on the stirring device, control the stirring speed at 60-80 r / min, and maintain the water temperature at 25-30℃; 2) Add 150-200 kg of tetrasodium diacetate and 50-100 kg of tetrasodium iminodisuccinate, and stir for 15-20 minutes until completely dissolved; 3) Take 100-150 kg of deionized water and heat it to 30-40℃. Add 10-30 kg of oxalic acid and 80-100 kg of sodium chloride. Stir for 10 min until completely dissolved. Then, pump the solution into the system of step 2) at a rate of 5-8 L / min and continue stirring for 10 min. 4) Add 100-150 kg of citric acid monohydrate in batches, stirring for 5 minutes after each batch, and adjust the pH to 6-7; 5) Add 30-60 kg of sodium carbonate and 150-200 kg of sodium dithionite, and stir for 15 minutes; 6) Add the remaining 150-200 kg of citric acid monohydrate, 100-150 kg of 30% hydrogen peroxide and 10-30 kg of polyether, stir for 20 minutes, add deionized water to bring the total weight to 1000 kg, and check that the pH is stable at 5-7. 7) After filtering with a 100-mesh nylon filter, store in a sealed, corrosion-resistant container.

4. The method for preparing the cleaning agent according to claim 3, characterized in that: In step 1), the anti-corrosion container is made of PP or 304 stainless steel.

5. The method for preparing the cleaning agent according to claim 3, characterized in that: In step 3), oxalic acid and sodium chloride are ground into 80-100 mesh fine powder, and sodium dithionite is sealed and used, and the solution turns pale yellow after being added.

6. The method for preparing the cleaning agent according to claim 3, characterized in that: In step 4), a precision pH meter with an accuracy of ±0.1 is used to monitor the pH. If the pH is <5, 5-10 kg of sodium carbonate is added, and if the pH is >7, citric acid is added.

7. The method for preparing the cleaning agent according to claim 3, characterized in that: In step 7), if bubbling is vigorous, add 5-10 kg of hydrogen peroxide to neutralize.

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