Corrosion inhibitor and preparation method and application thereof

Abstract

The invention relates to a corrosion inhibitor and a preparation method and application thereof. The corrosion inhibitor comprises the following components in parts by weight: 5-25 parts of sodium phytate, 1-10 parts of urotropine, 5-12 parts of trisodium phosphate and 80-88 parts of citric acid. According to the corrosion inhibitor provided by the invention, on one hand, the corrosion inhibitor can coexist with hydrogen peroxide for a long time without seriously reducing the stability of a hydrogen peroxide solution, so that the cleaning effect of the hydrogen peroxide composite solution is ensured, and on the other hand, the hydrogen peroxide composite solution is effectively prevented from corroding a metal material; therefore, the influence on the precision of the metal product is reduced.

Description

Technical Field

[0001] This invention relates to the technical field of corrosion inhibitors, and more specifically, to a corrosion inhibitor, its preparation method, and its application. Background Technology

[0002] Hydrogen peroxide is a strong oxidizing agent, and its aqueous solution is commonly known as hydrogen peroxide solution. Because it has four atoms covalently bonded to form a nonpolar HOOH structure, hydrogen peroxide solution is chemically very active and decomposes easily into oxygen and water. It has no residual toxicity and does not cause secondary pollution to the environment, so it is known as the cleanest disinfectant.

[0003] To achieve disinfection, the cleaning time with hydrogen peroxide is often extended or the concentration of hydrogen peroxide is increased. However, hydrogen peroxide is corrosive to metal parts (such as stainless steel) and surgical instruments. Extending the cleaning time or increasing the concentration of hydrogen peroxide will increase the degree of corrosion to the metal parts, thereby affecting the precision of these metal products.

[0004] In Chinese patented hydrogen peroxide compound disinfectants, their application methods, and the main disinfectant and its adjuvants (containing corrosion inhibitors) must be packaged separately before use to prevent degradation by reactive oxygen species in the hydrogen peroxide. This method requires users to strictly mix the hydrogen peroxide solution and adjuvants according to the specified ratio, increasing the complexity of the operation. Furthermore, human error or uneven mixing may affect the stability and disinfection efficacy of the hydrogen peroxide solution.

[0005] Therefore, there is an urgent need to develop a corrosion inhibitor that can coexist with hydrogen peroxide for a long time and reduce the corrosion of metals by hydrogen peroxide. Summary of the Invention

[0006] The primary objective of this invention is to overcome the problem that existing corrosion inhibitors, while reducing the corrosion of metals by hydrogen peroxide, cannot coexist with hydrogen peroxide for extended periods. This invention provides a corrosion inhibitor that, on the one hand, can coexist with hydrogen peroxide for a long time without significantly reducing the stability of the hydrogen peroxide solution, thus ensuring the cleaning effect of the hydrogen peroxide composite solution; on the other hand, it effectively prevents the hydrogen peroxide composite solution from corroding metal materials, thereby reducing the impact on the precision of metal products.

[0007] A further object of the present invention is to provide a method for preparing the above-mentioned corrosion inhibitor.

[0008] Another object of the present invention is to provide the application of the above-mentioned corrosion inhibitor in the preparation of hydrogen peroxide composite solution.

[0009] Another object of the present invention is to provide a hydrogen peroxide composite solution.

[0010] Another object of the present invention is to provide the application of the above-mentioned hydrogen peroxide composite solution in cleaning metal parts.

[0011] The above-mentioned objective of the present invention is achieved through the following technical solution: A corrosion inhibitor comprising the following components in parts by weight: 5-25 parts sodium phytate, 1-10 parts hexamethylenetetramine, 5-12 parts trisodium phosphate, and 80-88 parts citric acid.

[0012] The inventors of this invention discovered through research that the simultaneous addition of sodium phytate, hexamethylenetetramine, and citric acid to a hydrogen peroxide solution can have a synergistic corrosion-inhibiting effect, preventing the oxidation of metals by hydrogen peroxide.

[0013] However, the simultaneous addition of hexamethylenetetramine and citric acid affects the stability of hydrogen peroxide, causing it to decompose or be consumed, making it impossible for the corrosion inhibitor to coexist with hydrogen peroxide for an extended period. The inventors of this invention further discovered that the addition of trisodium phosphate can inhibit the effects of hexamethylenetetramine and citric acid on hydrogen peroxide, thereby improving its stability. This is likely because trisodium phosphate regulates the pH of the system and inhibits the interaction between hexamethylenetetramine and citric acid.

[0014] Preferably, the corrosion inhibitor comprises the following components in parts by weight: 5-15 parts sodium phytate, 6-10 parts hexamethylenetetramine, 8-11 parts trisodium phosphate, and 84-88 parts citric acid.

[0015] The specific dosage of sodium phytate can be 5 parts, 8 parts, 12 parts, 15 parts, 18 parts, 22 parts, or 25 parts; the specific dosage of hexamethylenetetramine can be 1 part, 2 parts, 3 parts, 4 parts, 5 parts, 6 parts, 7 parts, 8 parts, 9 parts, or 10 parts; the specific dosage of trisodium phosphate can be 6 parts, 7 parts, 8 parts, 9 parts, 10 parts, or 11 parts; and the specific dosage of citric acid can be 80 parts, 81 parts, 82 parts, 83 parts, 84 parts, 85 parts, 86 parts, 87 parts, or 88 parts.

[0016] The present invention also protects the preparation method of the above-mentioned corrosion inhibitor, which includes the following steps: weighing each component according to the formula, mixing them, and thus obtaining the corrosion inhibitor.

[0017] This invention also protects the use of the above-mentioned corrosion inhibitor in the preparation of hydrogen peroxide composite solutions.

[0018] Preferably, the corrosion inhibitor is used to prevent hydrogen peroxide from corroding the metal.

[0019] More preferably, the metal material is one or more of stainless steel, carbon steel, copper, or aluminum.

[0020] More preferably, the metal material is stainless steel.

[0021] This invention also protects a hydrogen peroxide composite solution comprising the aforementioned corrosion inhibitor.

[0022] Preferably, the mass ratio of hydrogen peroxide to corrosion inhibitor in the hydrogen peroxide composite solution is (14~600):1.5.

[0023] More preferably, the mass ratio of hydrogen peroxide to corrosion inhibitor in the hydrogen peroxide composite solution is (300~600):1.5.

[0024] For example, the mass ratio of hydrogen peroxide to corrosion inhibitor in a hydrogen peroxide composite solution can be 300:1.5, 350:1.5, 400:1.5, 450:1.5, 500:1.5, 550:1.5, or 600:1.5.

[0025] Preferably, the concentration of hydrogen peroxide in the hydrogen peroxide composite solution is 1.5~50 wt.%.

[0026] More preferably, the concentration of hydrogen peroxide in the hydrogen peroxide composite solution is 27.5~50 wt.%.

[0027] For example, the concentration of hydrogen peroxide in the hydrogen peroxide complex solution can be 27.5 wt.%, 30 wt.%, 35 wt.%, 40 wt.%, 45 wt.%, or 50 wt.%.

[0028] This invention also protects the application of the above-mentioned hydrogen peroxide composite solution in cleaning metal parts.

[0029] Compared with the prior art, the beneficial effects of the present invention are: This invention provides a corrosion inhibitor that, on the one hand, can coexist with hydrogen peroxide for a long time without significantly reducing the stability of the hydrogen peroxide solution, thus ensuring the cleaning effect of the hydrogen peroxide composite solution; on the other hand, it effectively prevents the hydrogen peroxide composite solution from corroding metal materials, thereby reducing the impact on the precision of metal products. Detailed Implementation

[0030] To more clearly and completely describe the technical solution of the present invention, the present invention is further described in detail below through specific embodiments. It should be understood that the specific embodiments described herein are only for explaining the present invention and are not intended to limit the present invention. Various changes can be made within the scope of the claims of the present invention. In the present invention, the technical features described in an open-ended manner include both closed technical solutions composed of the listed features and open technical solutions that include the listed features. In the present invention, when numerical intervals (i.e., numerical ranges) are involved, unless otherwise specified, the distribution of selectable numerical values ​​within the numerical interval is considered continuous, and includes the two numerical endpoints (i.e., the minimum value and the maximum value) of the numerical interval, as well as every numerical value between the two numerical endpoints. Unless otherwise specified, when the numerical interval only points to the integers within the numerical interval, it includes the two integer endpoints of the numerical range, as well as every integer between the two endpoints, which is equivalent to directly listing every integer. When multiple numerical ranges are provided to describe features or characteristics, these numerical ranges can be merged. In other words, unless otherwise specified, the numerical ranges disclosed herein should be understood to include any and all sub-ranges included therein. The "numerical value" in the numerical interval can be any quantitative value, such as a number, percentage, ratio, etc. The term "numerical range" can be broadly defined to include numerical range types such as percentage ranges, proportion ranges, and ratio ranges.

[0031] Unless otherwise specified, the temperature parameters in this invention can be either constant temperature treatment or variations within a certain temperature range. It should be understood that the constant temperature treatment allows temperature fluctuations within the precision range controlled by the instrument. Fluctuations are permitted within ranges such as ±5℃, ±4℃, ±3℃, ±2℃, and ±1℃. In this invention, if the unit for a data range is only followed by the right endpoint, it indicates that the units for the left and right endpoints are the same. For example, 3~5 h means that the units for the left endpoint "3" and the right endpoint "5" are both h (hours). The mass or weight of the relevant components mentioned in the embodiments of this invention can refer not only to the specific content of each component but also to the proportional relationship of mass or weight between the components. Therefore, any scaling up or down of the content of the relevant components according to the embodiments of this invention is within the scope disclosed in the embodiments of this invention. Specifically, the mass or weight mentioned in the embodiments of this invention can be units known in the chemical industry, such as μg, mg, g, and kg.

[0032] In this invention, where the method involves multiple steps, unless otherwise explicitly stated herein, the execution of these steps is not strictly limited in order and can be performed in any order other than that described. Moreover, any step may include multiple sub-steps or multiple stages, which are not necessarily completed at the same time, but can be executed at different times, and their execution order is not necessarily sequential, but can be performed alternately or simultaneously with other steps or parts of the sub-steps or stages of other steps.

[0033] Examples 1-5 Examples 1-5 provide a series of corrosion inhibitors, the formulations of which are shown in Table 1.

[0034] Table 1. Formulations of corrosion inhibitors in Examples 1-5 (unit: parts by weight)

[0035] Examples 6-11 Examples 6-11 provide a series of hydrogen peroxide composite solutions, the formulations of which are shown in Table 2.

[0036] Table 2 Hydrogen peroxide composite solutions from Examples 6 to 11

[0037] In Table 2, the unit for corrosion inhibitor dosage is grams, and the unit for hydrogen peroxide solution dosage is liters. Hydrogen peroxide solution #1 has a hydrogen peroxide concentration of 27.5 wt.% (density 1.101 g / cm³). 3 The hydrogen peroxide concentration of hydrogen peroxide solution #2 is 50 wt.% (density is 1.198 g / cm³). 3 ).

[0038] The preparation methods of the hydrogen peroxide composite solutions in Examples 6-11 are as follows: Weigh each component of the corrosion inhibitor according to the formula in Table 1, mix them, and then add them to the hydrogen peroxide solution and stir until completely dissolved.

[0039] Comparative Examples 1-8 Comparative Examples 1-8 provide a series of corrosion inhibitors, the formulations of which are shown in Table 3.

[0040] Table 3 Formulations of corrosion inhibitors for comparative examples 1-8 (unit: parts by weight)

[0041] Comparative Examples 9-16 Comparative Examples 9-16 provide a series of hydrogen peroxide composite solutions, the formulations of which are shown in Table 4.

[0042] Table 4. Hydrogen peroxide composite solutions of Comparative Examples 9-16

[0043] In Table 4, the unit for the amount of corrosion inhibitor is grams, and the unit for the amount of hydrogen peroxide solution is liters. The hydrogen peroxide concentration of hydrogen peroxide solution #1 is 27.5 wt.%. The preparation methods of the hydrogen peroxide composite solutions of Comparative Examples 9-16 are as follows: Weigh each component of the corrosion inhibitor according to the formula in Table 3, mix them, and then add them to the hydrogen peroxide solution and stir until completely dissolved.

[0044] Performance Characterization 1. Determination of corrosion rate The hydrogen peroxide composite solutions from Examples 6-11 and Comparative Examples 9-16 were used to conduct corrosion tests on stainless steel according to the national standard "Evaluation Method for Metal Corrosion of Disinfectants - GB / T38498-2020". The immersion method of the full immersion corrosion test was selected. The corrosion rate (R) was calculated, as shown in Table 5. Based on the metal corrosion rate, the metal corrosivity of the disinfectant was divided into four corrosion levels: R < 0.0100, level is basically no corrosion; 0.0100 ≤ R < 0.1000, level is slight corrosion; 0.1000 ≤ R < 1.000, level is moderate corrosion; and R ≥ 1.000, level is severe corrosion.

[0045] 2. Stability Testing Take the hydrogen peroxide composite solutions from Examples 6-11 and Comparative Examples 9-16, and test them according to standard GB / T 1616-2014. First, determine the concentration of hydrogen peroxide in the hydrogen peroxide composite solution before storage (unit: wt.%). Then, store the prepared hydrogen peroxide composite solution in a glass bottle and place it at a constant temperature of 25°C for 14 days. Then, test the concentration of hydrogen peroxide after storage according to standard GB / T1616-2014 (unit: wt.%). Calculate the change in concentration. The change in concentration = concentration of hydrogen peroxide before storage - concentration of hydrogen peroxide after storage. See Table 5 for details.

[0046] Table 5 Corrosion Grade Determination and Stability Testing

[0047] As shown in Table 5, the hydrogen peroxide composite solutions in Examples 6-11 have virtually no corrosive effect on stainless steel, and the concentration of hydrogen peroxide changes very little after 14 days. This indicates that the corrosion inhibitor of the present invention not only effectively prevents corrosion of metal materials, but can also coexist with hydrogen peroxide for a long time.

[0048] Comparative Examples 9 and 13, with or without sodium phytate and with sodium phytate replaced by disodium ethylenediaminetetraacetate, respectively, produced moderate and mild corrosion of stainless steel, respectively, significantly affecting the stability of hydrogen peroxide.

[0049] Comparative Examples 10 and 14, with or without hexamethylenetetramine and with hexamethylenetetramine replaced by thiourea, respectively, both caused mild corrosion to stainless steel.

[0050] The hydrogen peroxide composite solutions in Comparative Examples 11 and 15, with the absence of trisodium phosphate and the replacement of trisodium phosphate with disodium hydrogen phosphate, respectively, had a significant impact on the stability of hydrogen peroxide.

[0051] Comparative Examples 12 and 16, with and without citric acid and with tartaric acid replaced by citric acid respectively, both produced moderate corrosion of stainless steel and significantly affected the stability of hydrogen peroxide.

[0052] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A corrosion inhibitor, characterized in that, It includes the following components in parts by weight: 5-25 parts sodium phytate, 1-10 parts hexamethylenetetramine, 5-12 parts trisodium phosphate, and 80-88 parts citric acid.

2. The corrosion inhibitor as described in claim 1, characterized in that, It includes the following components in parts by weight: 5-15 parts sodium phytate, 6-10 parts hexamethylenetetramine, 8-11 parts trisodium phosphate, and 84-88 parts citric acid.

3. The method for preparing the corrosion inhibitor according to claim 1 or 2, characterized in that, Includes the following steps: Weigh each component according to the formula, mix them, and the corrosion inhibitor is obtained.

4. The application of the corrosion inhibitor according to claim 1 or 2 in the preparation of hydrogen peroxide composite solution.

5. The application as described in claim 4, characterized in that, The corrosion inhibitor is used to prevent hydrogen peroxide from corroding metallic materials.

6. The application as described in claim 5, characterized in that, The metal material is one or more of stainless steel, carbon steel, copper, or aluminum.

7. A hydrogen peroxide composite solution, characterized in that, The hydrogen peroxide composite solution includes the corrosion inhibitor described in claim 1 or 2.

8. The hydrogen peroxide composite solution as described in claim 7, characterized in that, The mass ratio of hydrogen peroxide to corrosion inhibitor in the hydrogen peroxide composite solution is (14~600):1.

5.

9. The hydrogen peroxide composite solution as described in claim 7, characterized in that, The concentration of hydrogen peroxide in the hydrogen peroxide composite solution is 1.5~50 wt.%.

10. The application of the hydrogen peroxide composite solution according to claim 7 in cleaning metal parts.

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