Galvanizing corrosion inhibitor for high-concentration hydrochloric acid medium

Abstract

The invention discloses a zinc plating corrosion inhibitor for a high-concentration hydrochloric acid medium, which is prepared by mixing the following components in percentage by mass: 0.01 to 0.19 percent of salicylaldehyde, 0.02 to 0.85 percent of n-butylamine, 0.07 to 0.65 percent of n-ethylamine, 0.01 to 0.35 percent of urotropine and quinoline, and 96.37 to 99.88 percent of ethanol. When the concentration of HCl is 10%, the corrosion rate of zinc is 0.6 g.h <-1 >. M <-2 >, the corrosion inhibition efficiency is still greater than 99.7%, and the corrosion inhibitor does not lose efficacy. Therefore, the corrosion inhibitor can quickly form an adsorption film on the surface of the galvanized mold, and has good acid resistance in a high-concentration hydrochloric acid medium.

Description

Technical Field

[0001] The invention belongs to the technical field of corrosion inhibitor preparation and relates to a zinc plating corrosion inhibitor for a high-concentration (mass concentration 10%) hydrochloric acid medium. Background Art

[0002] Metallic zinc can form a stable oxide film in dry air. Currently, galvanizing technology is widely used to form a galvanized film on the surface of metal workpieces. However, when the coated workpiece is placed in an acidic or alkaline environment for cleaning, the galvanized film on the surface is easily damaged, causing corrosion of the metal workpiece.

[0003] Corrosion inhibitor is a chemical substance that exists in a medium at a low concentration. It effectively slows down the interaction between metal and medium and prevents the medium from corroding the metal. Compared with other anti-corrosion technologies, metal corrosion inhibition technology has the advantages of low cost, quick effect, simple operation and no effect on equipment performance. At present, most corrosion inhibitors contain aromatic rings or heteroatoms such as N, O, and S. The lone electron pairs of heteroatoms are more likely to interact with metal atoms, thereby achieving the effect of corrosion inhibition. However, existing corrosion inhibitors are mainly concentrated on metal materials such as carbon steel, stainless steel, aluminum and copper, and research on corrosion inhibitors for metal zinc is relatively limited.

[0004] The existing literature (Applied Chemical Industry, 2020, 49 (11): 1671-3026) discloses “The corrosion inhibition performance of imidazoline corrosion inhibitor on metallic zinc[J]”. The results show that the corrosion rate of zinc is 7.0893 g·h after adding the corrosion inhibitor by compounding the amphoteric imidazoline corrosion inhibitor in 0.365% hydrochloric acid. -1 ·m -2 Document 2 (Cleaning World, 2019, 35(11):1671-8909) discloses “Corrosion inhibition performance of chlorhexidine and benzalkonium bromide on metallic zinc in hydrochloric acid medium [J]”. 21 H 38 ClN, the main component is dodecyl dimethyl benzyl ammonium chloride) in 0.365% hydrochloric acid medium. It was found that after adding the corrosion inhibitor, the corrosion rate of zinc was 5.6875g·h -1 ·m -2 The corrosion inhibitors for zinc metal disclosed in the above two documents do not meet the corrosion rate standard of metal materials in GB / T25146-2010 (1g·h -1 ·m -2 ), and the hydrochloric acid concentration is much less than 10%. Summary of the invention

[0005] The present invention aims to solve the above technical problems existing in the prior art and provides a zinc plating corrosion inhibitor for a high-concentration hydrochloric acid medium.

[0006] The technical solution of the present invention is: a zinc plating corrosion inhibitor for high-concentration hydrochloric acid medium, which is mixed with salicylaldehyde, n-butylamine, n-ethylamine, urotropine + quinoline, sodium iodide and ethanol as components, and the mass percentage of each component is as follows: salicylaldehyde 0.01-0.19%, n-butylamine 0.02-0.85%, n-ethylamine 0.07-0.65%, urotropine + quinoline 0.01-0.35%, ethanol 96.37-99.88%.

[0007] The preferred technical solution is that the mass ratio of the components is as follows: salicylaldehyde 0.05%, n-butylamine 0.06%, n-ethylamine 0.1%, hexamethylenetetramine + quinoline 0.1%, and ethanol 99.69%.

[0008] The preferred technical solution is that the mass ratio of the components is as follows: salicylaldehyde 0.19%, n-butylamine 0.09%, n-ethylamine 0.1%, hexamethylenetetramine + quinoline 0.05%, and ethanol 99.57%.

[0009] The preferred technical solution is that the mass ratio of the components is as follows: salicylaldehyde 0.06%, n-butylamine 0.26%, n-ethylamine 0.14%, urotropine + quinoline 0.13%, and ethanol 99.41%.

[0010] The preferred technical solution is that the mass ratio of the components is as follows: salicylaldehyde 0.15%, n-butylamine 0.19%, n-ethylamine 0.22%, urotropine + quinoline 0.16%, and ethanol 99.28%.

[0011] The present invention is a mixture of salicylaldehyde, n-butylamine, n-ethylamine, urotropine + quinoline and ethanol in mass percentage, which effectively improves the corrosion inhibition rate. When the HCl concentration is 10%, the corrosion rate of zinc is reduced to 0.6g·h -1 ·m -2 The corrosion inhibitor did not fail, indicating that the corrosion inhibitor of the present invention has good acid resistance in high concentration hydrochloric acid medium. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 This is a picture of the zinc sheet before the reaction, taken with a high-magnification camera.

[0013] Figure 2 This is a diagram showing the bubbles emerging from the zinc sheet surface in the corrosion inhibitor experiment of comparative example 1.

[0014] Figure 3 This is a diagram showing the bubbles emerging from the zinc sheet surface in the corrosion inhibitor experiment of comparative example 2.

[0015] Figure 4 This is a diagram showing the bubbles emerging from the zinc sheet surface in the corrosion inhibitor experiment of comparative example 3.

[0016] Figure 5This is a diagram showing the bubbles emerging from the zinc sheet surface in the corrosion inhibitor experiment of comparative example 4.

[0017] Figure 6 This is a diagram showing the bubbles emerging from the zinc sheet surface in the corrosion inhibitor experiment of comparative example 5.

[0018] Figure 7 This is a diagram showing bubbles emerging from the surface of a zinc sheet in a corrosion inhibitor experiment in Example 1 of the present invention.

[0019] Figure 8 The zinc flakes are obtained after reacting in a hydrochloric acid solution containing the corrosion inhibitor of Example 1 of the present invention.

[0020] Fig. 9 The zinc flakes are obtained after reacting in a hydrochloric acid solution without the corrosion inhibitor of Example 1 of the present invention. DETAILED DESCRIPTION Example 1

[0021] The invention discloses a zinc plating corrosion inhibitor for a high-concentration hydrochloric acid medium, which is prepared by mixing salicylaldehyde, n-butylamine, n-ethylamine, urotropine+quinoline, sodium iodide and ethanol as components, wherein the mass ratio of the components is as follows: 0.05% of salicylaldehyde, 0.06% of n-butylamine, 0.1% of n-ethylamine, 0.1% of urotropine+quinoline and 99.69% of ethanol.

[0022] Embodiment 2: The invention discloses a zinc plating corrosion inhibitor for a high-concentration hydrochloric acid medium, which is prepared by mixing salicylaldehyde, n-butylamine, n-ethylamine, urotropine+quinoline, sodium iodide and ethanol as components, wherein the mass ratio of the components is as follows: 0.19% of salicylaldehyde, 0.09% of n-butylamine, 0.1% of n-ethylamine, 0.05% of urotropine+quinoline and 99.57% of ethanol.

[0023] Embodiment 3: The invention discloses a zinc plating corrosion inhibitor for a high-concentration hydrochloric acid medium, which is prepared by mixing salicylaldehyde, n-butylamine, n-ethylamine, urotropine+quinoline, sodium iodide and ethanol as components, wherein the mass ratio of the components is as follows: 0.06% of salicylaldehyde, 0.26% of n-butylamine, 0.14% of n-ethylamine, 0.13% of urotropine+quinoline and 99.41% of ethanol.

[0024] Embodiment 4: The invention discloses a zinc plating corrosion inhibitor for a high-concentration hydrochloric acid medium, which is prepared by mixing salicylaldehyde, n-butylamine, n-ethylamine, urotropine+quinoline, sodium iodide and ethanol as components, wherein the mass ratio of the components is as follows: 0.15% of salicylaldehyde, 0.19% of n-butylamine, 0.22% of n-ethylamine, 0.16% of urotropine+quinoline and 99.28% of ethanol.

[0025] experiment: Take beakers respectively and add 100 mL of hydrochloric acid with a mass concentration of 10%, then add 3 mL of the corrosion inhibitor of Example 1 of the present invention and Comparative Examples 1-5 respectively, put the galvanized sheet in, and observe the bubbles on the surface of the galvanized sheet.

[0026] The galvanized sheet before reaction was photographed by a high-power camera. Figure 1 As shown, it can be seen that its surface is flat and smooth.

[0027] The corrosion inhibitors used in Comparative Examples 1-5 are shown in Table 1, and the experimental results are shown in Figure 2-7 As shown in Table 2.

[0028] Table 1

[0029] Table 2

[0030] Depend on Figure 2-7 It can be seen from the experimental results in Table 2 that Example 1 of the present invention has a good corrosion inhibition effect on metallic zinc, and at the same time proves that there is a good synergistic effect between the components.

[0031] After reacting in a hydrochloric acid solution containing the corrosion inhibitor of Example 1 of the present invention, the zinc sheet is as follows Figure 8 shown.

[0032] from Figure 8 It can be seen that with the addition of various components of the corrosion inhibitor, the number of bubbles on the surface of the zinc sheet decreases, and almost no bubbles emerge.

[0033] After the zinc sheet reacts in a hydrochloric acid solution without the corrosion inhibitor of Example 1 of the present invention, Fig. 9 shown.

[0034] from Fig. 9 It can be seen that when there is no corrosion inhibitor, there are many bubbles on the surface of zinc and the reaction is violent.

[0035] The application examples selected the corrosion inhibitor prepared in Example 1, and all were carried out at room temperature.

[0036] Application Example 1: Use ethanol and acetone to wash off the oil on the surface of the zinc test piece, blow dry, and weigh it with an electronic balance, recorded as M0. Add the corrosion inhibitor of Example 1 of the present invention to 10% hydrochloric acid, and the final mass concentration of the corrosion inhibitor is 0.5%. Put the cleaned zinc test piece upright therein, and take out the zinc test piece after reaction for 4 hours. Treat the zinc test piece after the reaction with acetone and anhydrous ethanol, blow dry and weigh it, recorded as M. The corrosion rate of zinc is calculated according to the formula: K=(M0-M) / S·T, where M0 is the initial weight of the zinc test piece, M is the weight of the zinc sheet after corrosion, S is the area of ​​the zinc sheet, and T is the reaction time. The corrosion rate of the zinc sheet in this application example is 0.62578g·h-1 ·m -2 .

[0037] Application Example 2: Use ethanol and acetone to wash off the oil on the surface of the zinc test piece, blow dry, and weigh it with an electronic balance, recorded as M0. Add the corrosion inhibitor of Example 1 of the present invention to 10% hydrochloric acid, and the final mass concentration of the corrosion inhibitor is 0.6%. Put the cleaned zinc test piece upright therein, and take out the zinc test piece after reaction for 4 hours. Treat the reacted zinc test piece with acetone and anhydrous ethanol, blow dry and weigh it, recorded as M. The corrosion rate of zinc is calculated according to the formula: K=(M0-M) / S·T, where M0 is the initial weight of the zinc test piece, M is the weight of the zinc sheet after corrosion, S is the area of ​​the zinc sheet, and T is the reaction time. The corrosion rate of the zinc sheet in this application example is 0.60465g·h -1 ·m -2 .

[0038] Application Example 3: Use ethanol and acetone to wash off the oil on the surface of the zinc test piece, blow dry, and weigh it with an electronic balance, recorded as M0. Add the corrosion inhibitor of Example 1 of the present invention to 10% hydrochloric acid, and the final mass concentration of the corrosion inhibitor is 0.7%. Put the cleaned zinc test piece upright therein, and take out the zinc test piece after reaction for 4 hours. Treat the zinc test piece after the reaction with acetone and anhydrous ethanol, blow dry and weigh it, recorded as M. The corrosion rate of zinc is calculated according to the formula: K=(M0-M) / S·T, where M0 is the initial weight of the zinc test piece, M is the weight of the zinc sheet after corrosion, S is the area of ​​the zinc sheet, and T is the reaction time. The corrosion rate of the zinc sheet in this application example is 0.61745g·h -1 ·m -2 .

[0039] The results of application examples 1-3 show that when the hydrochloric acid concentration is 10%, the corrosion rate of zinc is 0.6 g·h -1 ·m -2 The corrosion inhibitor did not fail, indicating that the corrosion inhibitor of the present invention has good acid resistance in high concentration hydrochloric acid medium.

Claims

1. A zinc plating corrosion inhibitor for high concentration hydrochloric acid medium, characterized in that The invention is a mixture of salicylaldehyde, n-butylamine, n-ethylamine, urotropine + quinoline, sodium iodide and ethanol, and the mass percentages of the components are as follows: salicylaldehyde 0.01-0.19%, n-butylamine 0.02-0.85%, n-ethylamine 0.07-0.65%, urotropine + quinoline 0.01-0.35%, and ethanol 96.37-99.88%.

2. The zinc plating corrosion inhibitor for high concentration hydrochloric acid medium according to claim 1, characterized in that The mass ratio of the components is as follows: salicylaldehyde 0.05%, n-butylamine 0.06%, n-ethylamine 0.1%, hexamethylenetetramine + quinoline 0.1%, and ethanol 99.69%.

3. The zinc plating corrosion inhibitor for high concentration hydrochloric acid medium according to claim 1, characterized in that The mass ratio of the components is as follows: salicylaldehyde 0.19%, n-butylamine 0.09%, n-ethylamine 0.1%, hexamethylenetetramine + quinoline 0.05%, and ethanol 99.57%.

4. The zinc plating corrosion inhibitor for high concentration hydrochloric acid medium according to claim 1, characterized in that The mass ratio of the components is as follows: salicylaldehyde 0.06%, n-butylamine 0.26%, n-ethylamine 0.14%, hexamethylenetetramine + quinoline 0.13%, and ethanol 99.41%.

5. The zinc plating corrosion inhibitor for high concentration hydrochloric acid medium according to claim 1, characterized in that The mass ratio of the components is as follows: salicylaldehyde 0.15%, n-butylamine 0.19%, n-ethylamine 0.22%, hexamethylenetetramine + quinoline 0.16%, and ethanol 99.28%.

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