Acid system oil removal, rust removal and passivation three-in-one metal cleaning agent

Abstract

The invention discloses a three-in-one metal cleaning agent for oil removal, rust removal and passivation of an acidic system. The three-in-one metal cleaning agent comprises the following components in percentage by mass: 0.5% of sodium dodecyl benzene sulfonate, 0.7% of NP-7, 1.2% of sulfamic acid, 2.2% of organic composite acid, 0.13% of urotropine, 0.05% of thiourea, 0.5% of a film-forming agent and 94.72% of water. The organic composite acid is formed by mixing malonic acid, glycolic acid and lactic acid, and the mass percent of the malonic acid is 34%, the mass percent of the glycolic acid is 36%, and the mass percent of the lactic acid is 30%. The derusting and passivating agent is suitable for cleaning carbon steel equipment, all the components have a synergistic effect, the derusting, derusting and passivating functions are integrated, the derusting rate reaches 94.2%, the deoiling rate reaches 97.5%, the surface of a passivated test piece is smooth, the red dot time is 22 s, and the good passivating effect is achieved. The cleaning operation process is simple, the efficiency is high, and the equipment and material investment is saved.

Description

Technical Field

[0001] The invention belongs to the technical field of cleaning agent preparation, and in particular relates to an acidic system three-in-one metal cleaning agent for degreasing, derusting and passivation. Background Art

[0002] The surfaces of metal components need to be cleaned during the processing process due to oil stains, floating rust, heavy rust, scale and high-temperature oxides of welding. Existing cleaning agents mainly have the functions of degreasing and derusting. Metal degreasing is a treatment process for removing oil, grease or other organic matter from the metal surface; metal derusting aims to remove rust, oxide layer and other pollutants on the metal surface. Existing document 1 (Corrosion and Protection, 2006, 27 (7): 358-360) discloses "Ultrasonic composite cleaning agent suitable for galvanized steel wire production [J]". The low-concentration acidic degreasing and derusting cleaning medium determined by the research can quickly and effectively remove oil stains, rust and phosphating film on the surface of steel wire under ultrasonic sonication and low temperature conditions. The specific formula is: hydrochloric acid concentration 10-20%, additive concentration 7-10%. Reference 2 (Electroplating and Environmental Protection, 1994, (04): 32-33, Application of a New Two-in-One Process of Citric Acid Degreasing and Rust Removal [J]) discloses the use of a citric acid cleaning agent for degreasing and rust removal. The main components of the cleaning agent are: citric acid, surfactant, corrosion inhibitor, etc. The finished product is a white crystalline powder.

[0003] In addition to metal degreasing and rust removal, metal passivation is also very important. Metal passivation is a process of forming a dense, uniform oxide film or other compound film on the metal surface through a series of chemical treatments. The formation of this film can improve the corrosion resistance and wear resistance of the metal, thereby extending the service life of metal components. Existing passivators include sulfuric acid passivator formulas suitable for galvanized steel surface treatment, the main components of which are sulfuric acid, nitric acid, phosphoric acid, ammonium chloride, etc.; alkaline passivator formulas suitable for stainless steel surface treatment, the main components of which are sodium hydroxide, potassium oxide, phosphoric acid, sodium carbonate, etc.

[0004] So far, there has been no relevant report on the acid system degreasing, rust removal and passivation three-in-one metal cleaning agent, so degreasing, rust removal and passivation need to be carried out in at least two steps. Not only is the cleaning operation process complicated and inefficient, but the investment in equipment and materials is also large. Summary of the invention

[0005] The present invention aims to solve the above technical problems existing in the prior art and provides an acid system three-in-one metal cleaning agent for degreasing, derusting and passivation.

[0006] The technical solution of the present invention is: an acidic system degreasing, rust removal and passivation three-in-one metal cleaning agent, which is mixed with sodium dodecylbenzene sulfonate, NP-7, aminosulfonic acid, organic composite acid, urotropine, thiourea, a film-forming agent and water as components, and the mass percentages of the components are as follows: 0.5-0.9% of sodium dodecylbenzene sulfonate, 0.3-0.8% of NP-7, 1-2% of aminosulfonic acid, 2-3% of organic composite acid, 0.1-0.2% of urotropine, 0.05-0.1% of thiourea, 0.2-0.8% of film-forming agent, and the balance is water; The organic composite acid is prepared by mixing malonic acid, glycolic acid and lactic acid, and the mass percentages of the organic composite acid are as follows: 30-40% malonic acid, 30-40% glycolic acid and 20-40% lactic acid.

[0007] The preferred technical solution is that the mass percentages of the components are as follows: 0.5% sodium dodecylbenzene sulfonate, 0.7% NP-7, 1.2% aminosulfonic acid, 2.2% organic composite acid, 0.13% urotropine, 0.05% thiourea, 0.5% film-forming agent, and 94.72% water; the mass percentages of the organic composite acid are as follows: 33% malonic acid, 35% glycolic acid, and 32% lactic acid.

[0008] The preferred technical solution is that the mass percentages of the components are as follows: 0.6% sodium dodecylbenzenesulfonate, 0.5% NP-7, 1.5% aminosulfonic acid, 2.5% organic composite acid, 0.16% urotropine, 0.07% thiourea, 0.6% film-forming agent, and 94.07% water; the mass percentages of the organic composite acid are as follows: 34% malonic acid, 36% glycolic acid, and 30% lactic acid.

[0009] The preferred technical solution is that the mass percentages of the components are as follows: 0.7% sodium dodecylbenzenesulfonate, 0.4% NP-7, 1.8% sulfamic acid, 2.8% organic composite acid, 0.18% urotropine, 0.07% thiourea, 0.3% film-forming agent, and 93.75% water; the mass percentages of the organic composite acid are as follows: 36% malonic acid, 39% glycolic acid, and 25% lactic acid.

[0010] The acid system cleaning agent of the present invention is suitable for cleaning carbon steel equipment. The components work synergistically, integrating degreasing, rust removal and passivation functions. The rust removal rate reaches 94.2%, the degreasing rate reaches 97.5%, the surface of the passivated test piece is relatively smooth, the red dot time is 22s, and a good passivation effect is achieved. The cleaning operation process is simple and efficient, saving equipment and material investment. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 This is a photo of a carbon steel test piece before rust removal taken with a metallographic microscope.

[0012] Figure 2 This is a graph showing the results of the carbon steel surface rust removal experiment in comparative example 1.

[0013] Figure 3 This is a graph showing the results of the carbon steel surface rust removal experiment in comparative example 2.

[0014] Figure 4 This is a graph showing the results of the carbon steel surface rust removal experiment in comparative example 3.

[0015] Figure 5 This is a graph showing the results of a carbon steel surface rust removal experiment in Example 2 of the present invention. DETAILED DESCRIPTION Example 1

[0016] The invention discloses an acidic system degreasing, rust removing and passivation three-in-one metal cleaning agent, which is prepared by mixing sodium dodecylbenzene sulfonate, NP-7, aminosulfonic acid, organic composite acid, urotropine, thiourea, a film-forming agent and water as components, wherein the mass percentages of the components are as follows: 0.5% of sodium dodecylbenzene sulfonate, 0.7% of NP-7, 1.2% of aminosulfonic acid, 2.2% of organic composite acid, 0.13% of urotropine, 0.05% of thiourea, 0.5% of film-forming agent and 94.72% of water; and the organic composite acid is prepared by mixing malonic acid, glycolic acid and lactic acid, wherein the mass percentages of the organic composite acid are 33% of malonic acid, 35% of glycolic acid and 32% of lactic acid. Example 2

[0017] The invention discloses an acidic system degreasing, rust removing and passivation three-in-one metal cleaning agent, which is prepared by mixing sodium dodecylbenzene sulfonate, NP-7, aminosulfonic acid, organic composite acid, urotropine, thiourea, a film-forming agent and water as components, wherein the mass percentages of the components are as follows: 0.6% sodium dodecylbenzene sulfonate, 0.5% NP-7, 1.5% aminosulfonic acid, 2.5% organic composite acid, 0.16% urotropine, 0.07% thiourea, 0.6% film-forming agent and 94.07% water; the organic composite acid is prepared by mixing malonic acid, glycolic acid and lactic acid, wherein the mass percentages are 34% malonic acid, 36% glycolic acid and 30% lactic acid. Example 3

[0018] The invention discloses an acidic system degreasing, rust removing and passivation three-in-one metal cleaning agent, which is prepared by mixing sodium dodecylbenzene sulfonate, NP-7, aminosulfonic acid, organic composite acid, urotropine, thiourea, a film-forming agent and water as components, wherein the mass percentages of the components are as follows: 0.7% sodium dodecylbenzene sulfonate, 0.4% NP-7, 1.8% aminosulfonic acid, 2.8% organic composite acid, 0.18% urotropine, 0.07% thiourea, 0.3% film-forming agent and 93.75% water; the organic composite acid is prepared by mixing malonic acid, glycolic acid and lactic acid, wherein the mass percentages are 36% malonic acid, 39% glycolic acid and 25% lactic acid.

[0019] In Examples 1-3, the components are added into a stirrer at room temperature according to their mass percentages and stirred evenly.

[0020] experiment: In order to verify the synergistic effect between the components of the present invention, the cleaning agents of comparative examples 1-3 and embodiment 2 of the present invention were subjected to rust removal experiments. The experimental method was to add 5g of cleaning agent and 95mL of water into a 100mL beaker, put a carbon steel test piece in it, and observe the rust removal on the surface of the test piece. The carbon steel test piece before rust removal was photographed with a metallographic microscope. Figure 1 shown.

[0021] The distribution ratios of the cleaning agents in Comparative Examples 1-3 are shown in Table 1.

[0022]

[0023] The composition of the organic composite acid in Comparative Example 2-3 is the same as that in Example 2 of the present invention.

[0024] The results of the rust removal experiment of the cleaning agent of comparative examples 1-3 and embodiment 2 of the present invention are as follows: Figure 2-5 As shown in Table 2.

[0025]

[0026] It can be seen from the experimental results in Table 2 that Example 2 of the present invention has a good rust removal ability on carbon steel compared with Comparative Examples 1-3, and at the same time proves that there is a good synergistic effect between the components.

[0027] The following application examples are all carried out at room temperature, and the cleaning agent prepared in Example 2 of the present invention is selected for use in the application examples.

[0028] Application Example 1: First, immerse the standard 20# carbon steel test piece in 5% hydrochloric acid solution, take it out and let it rust naturally for 48 hours, and put it in a dryer for use. The weight of the rusted test piece is calculated as W0; then put the rusted test piece into a cleaning agent with a mass concentration of 5%, and weigh it after rust removal as W1; clean the rusted test piece with 5% hydrofluoric acid, take it out and rinse it with water, dry it and weigh it as W2; calculate the rust removal rate and oil removal rate according to the following formula.

[0029] Rust removal rate calculation formula: Rust removal amount: ΔW1 = W0-W1 Standard rust removal amount: ΔW2 = W0-W2 Average rust removal speed:

[0030] Rust removal rate: η=(ΔW1 / ΔW2)×100% =[(W0 - W1) / (W0 -W2)]×100% Where W0 is the weight of the untreated test piece, W1 is the weight of the test piece after rust removal, W2 is the weight of the test piece after standard rust removal, and the rust removal time is t.

[0031] Oil removal rate calculation formula: Blank test metal surface oil content: F0 = [(W0-W) × V / V0 × 10 7 ] / S Oil content on metal surface: F=[(W1-W)×V / V1×10 7 ] / S - F0 Where F0 is the residual oil content of the blank test result, unit (mg / m 2 ), W0-weight of the evaporating dish after evaporating the oil-free carbon tetrachloride, unit (g), W-original weight of the evaporating dish, unit (g), V-total volume of the oil-containing carbon tetrachloride solution to be tested, unit (mL), V0-volume of evaporated oil-free carbon tetrachloride, unit (mL), S-surface area of ​​the metal to be sampled, unit (cm 2 ), F-the oil content of the metal surface to be tested, unit (mg / m 2 ), W1-the weight of the evaporating dish after evaporating the oil-free carbon tetrachloride, unit (g), V1-the volume of evaporated oil-free carbon tetrachloride, unit (mL).

[0032] The calculation results show that the rust removal rate in this application example is 91.3% and the oil removal rate is 95.3%.

[0033] Secondly, prepare the red dot solution. Take 4.1 g of copper sulfate pentahydrate, 3.5 g of sodium chloride, and 4.745 mg of hydrogen chloride. Add 98 mL of water and mix well for use. Drop the red dot solution onto the test piece. Use a stopwatch to record the time from when the red dot solution is dropped onto the test piece surface to when the red dot solution changes from blue to red. This is the red dot time. In Application Example 1, the red dot time is 18 s.

[0034] Application Example 2: Immerse the standard 20# carbon steel test piece in 5% hydrochloric acid solution, take it out and rust it naturally for 48 hours, and put it in a dryer for use. Put the rusted test piece into a cleaning agent with a mass concentration of 7%. According to the calculation formula of Application Example 1 and the red dot timing method, the rust removal rate of the carbon steel test piece in Application Example 2 is 93.1%, the oil removal rate is 96.4%, and the red dot time is 20s.

[0035] Application Example 3: Immerse the standard 20# carbon steel test piece in 5% hydrochloric acid solution, take it out and rust it naturally for 48 hours, and put it in a dryer for use. Put the rusted test piece into the corrosion inhibitor with a mass concentration of 10%. According to the calculation of the formula in Application Example 1 and the red dot timing method, the rust removal rate of the carbon steel test piece in Application Example 3 is 94.2%, the oil removal rate is 97.5%, and the red dot time is 22s.

[0036] The results of application examples 1-3 show that Example 2 of the present invention has a higher rust removal rate, oil removal rate and passivation time, which shows that the components of the present invention work synergistically and integrate the oil removal, rust removal and passivation functions.

Claims

1. A three-in-one metal cleaning agent for acidic system degreasing, rust removal and passivation, characterized in that The invention is prepared by mixing sodium dodecylbenzene sulfonate, NP-7, aminosulfonic acid, organic composite acid, urotropine, thiourea, a film-forming agent and water as components, wherein the mass percentages of the components are as follows: 0.5-0.9% sodium dodecylbenzene sulfonate, 0.3-0.8% NP-7, 1-2% aminosulfonic acid, 2-3% organic composite acid, 0.1-0.2% urotropine, 0.05-0.1% thiourea, 0.2-0.8% film-forming agent and the balance is water; The organic composite acid is prepared by mixing malonic acid, glycolic acid and lactic acid, and the mass percentages of the organic composite acid are as follows: 30-40% malonic acid, 30-40% glycolic acid and 20-40% lactic acid.

2. The acidic system degreasing, rust removal and passivation three-in-one metal cleaning agent according to claim 1 is characterized in that The mass percentages of the components are as follows: 0.5% sodium dodecylbenzene sulfonate, 0.7% NP-7, 1.2% aminosulfonic acid, 2.2% organic composite acid, 0.13% urotropine, 0.05% thiourea, 0.5% film-forming agent, and 94.72% water; the mass percentages of the organic composite acid are as follows: 33% malonic acid, 35% hydroxyacetic acid, and 32% lactic acid.

3. The acidic system degreasing, rust removal and passivation three-in-one metal cleaning agent according to claim 1 is characterized in that The mass percentages of the components are as follows: 0.6% sodium dodecylbenzene sulfonate, 0.5% NP-7, 1.5% aminosulfonic acid, 2.5% organic composite acid, 0.16% urotropine, 0.07% thiourea, 0.6% film-forming agent, and 94.07% water; the mass percentages of the organic composite acid are as follows: 34% malonic acid, 36% glycolic acid, and 30% lactic acid.

4. The acidic system degreasing, rust removal and passivation three-in-one metal cleaning agent according to claim 1, characterized in that The mass percentages of the components are as follows: 0.7% sodium dodecylbenzenesulfonate, 0.4% NP-7, 1.8% aminosulfonic acid, 2.8% organic composite acid, 0.18% urotropine, 0.07% thiourea, 0.3% film-forming agent, and 93.75% water; the mass percentages of the organic composite acid are as follows: 36% malonic acid, 39% glycolic acid, and 25% lactic acid.

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