Ester derivative corrosion-inhibiting low-conductivity coolant and use thereof

Abstract

The present application relates to the technical field of cooling liquid, disclose a kind of ester derivative corrosion-inhibiting low conductivity cooling liquid and its application.The cooling liquid includes organic corrosion inhibitor, and the organic corrosion inhibitor is sodium diethyl dithiocarbamate (DDTC) derivative.The cooling liquid provided by the present application can not only improve the corrosion inhibition effect on aluminum alloy, but also maintain low conductivity for a long time, so it has good application and promotion prospect.

Description

Technical Field

[0001] This invention relates to the field of coolant technology, specifically to an ester derivative corrosion-inhibiting low-conductivity coolant and its application. Background Technology

[0002] With the increasing prevalence of electronic equipment in automobiles, aircraft, and military radar, cooling systems are becoming more widely used. Currently, liquid cooling is commonly used for equipment thermal regulation, and liquid cooling systems primarily rely on coolant. In recent years, to address the safety hazards caused by coolant leakage, numerous researchers both domestically and internationally have designed and developed ethylene glycol-based low-conductivity coolants, improving the heat dissipation of electronic equipment while enhancing system safety.

[0003] Although glycol-based low-conductivity coolants are less corrosive, they will inevitably corrode various metals in the liquid cooling system after prolonged operation. For decades, corrosion inhibitor modification has been one of the most important methods of corrosion prevention. A corrosion inhibitor is a substance that prevents metal corrosion, primarily by forming a surface film on the metal substrate, isolating the substrate from the corrosive medium to reduce the metal's corrosive activity. Compared to other technologies, corrosion inhibitor modification is convenient, effective, economical, and widely applicable, and is therefore commonly used in industrial and social production.

[0004] Corrosion inhibitors can be added directly to the metal working medium, or the metal sample can be pre-filmed in an ethanol solution (or other solvent soluble in the inhibitor) to form a dense film before being applied to the specific working environment. Therefore, the development and exploration of green and efficient low-conductivity corrosion inhibitors has become an important current research topic. Summary of the Invention

[0005] The purpose of this invention is to overcome the problems existing in the prior art and provide an ester derivative corrosion-inhibiting low conductivity coolant and its application, thereby improving the corrosion resistance of the coolant to metal equipment.

[0006] To achieve the above objectives, the first aspect of the present invention provides the application of sodium diethyldithiocarbamate derivatives as a corrosion inhibitor for coolants.

[0007] A second aspect of the present invention provides a coolant, wherein the coolant includes an organic corrosion inhibitor, wherein the organic corrosion inhibitor is a sodium diethyldithiocarbamate derivative.

[0008] A third aspect of the present invention provides the application of the coolant according to the second aspect in power batteries, engines, and electronic equipment.

[0009] The beneficial technical effects achieved by the present invention through the above technical solution are as follows: (1) The coolant provided by the present invention covers and forms a hydrophobic corrosion inhibitor film on the metal surface through physical and chemical adsorption, effectively reducing the ions generated by the corrosion of metal equipment in the coolant, thereby reducing the conductivity during long-term use. The novel ester corrosion inhibitor exhibits a low conductivity, less than 2 μS / cm, and the conductivity remains stable after 20 days of operation.

[0010] (2) Due to the presence of electron-donating groups such as methyl, ethyl and propyl in the corrosion inhibitor molecule, it helps to increase the electron cloud density of heteroatoms and improve their bonding ability with metals. The selected organic corrosion inhibitors show excellent ability to inhibit aluminum corrosion even with very small amounts of addition.

[0011] (3) The coolant provided by the present invention has the advantages of low conductivity, stability, improved metal corrosion resistance and simple preparation method, and overcomes the disadvantages of high conductivity, poor stability and short service life of adding inorganic corrosion inhibitors, which is convenient for promotion and application. Attached Figure Description

[0012] Figure 1 The corrosion inhibitor molecule Mt-DTC prepared in Example 1 of this invention... 1 H NMR spectrum.

[0013] Figure 2 The corrosion inhibitor molecule Et-DTC prepared in Example 2 of this invention 1 H NMR spectrum.

[0014] Figure 3 The corrosion inhibitor molecule Pro-DTC prepared in Example 3 of this invention 1 H NMR spectrum.

[0015] Figure 4 The graphs show the change in conductivity of the coolant systems in Examples 4, 8, and 12 of this invention over time.

[0016] Figure 5 The results are the test results of corrosion rate in the coolant systems of Examples 4, 8, 12 and Comparative Example 1 of this invention. Detailed Implementation

[0017] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0018] One objective of this invention is to address the shortcomings of current market coolants, which have high conductivity and which increases significantly over time during use; another objective is to solve the problem of corrosion of aluminum cold plates caused by long-term use of traditional coolants in cooling systems.

[0019] The first aspect of this invention provides the application of sodium diethyldithiocarbamate derivatives as a corrosion inhibitor for coolants.

[0020] In some embodiments of the present invention, the sodium diethyldithiocarbamate derivative is selected from at least one of methyl diethyldithiocarbamate (Mt-DTC), ethyl diethyldithiocarbamate (Et-DTC), and propyl diethyldithiocarbamate (Pro-DTC).

[0021] In some embodiments of the present invention, the sodium diethyldithiocarbamate derivative is methyl diethyldithiocarbamate (Mt-DTC), ethyl diethyldithiocarbamate (Et-DTC), or propyl diethyldithiocarbamate (Pro-DTC), preferably methyl diethyldithiocarbamate (Mt-DTC).

[0022] In this invention, methyl diethyl dithiocarbamate (Mt-DTC), ethyl diethyl dithiocarbamate (Et-DTC), and propyl diethyl dithiocarbamate (Pro-DTC) can be prepared using sodium diethyl dithiocarbamate (DDTC) as a precursor. The presence of electron-donating alkyl side chains such as methyl, ethyl, and propyl groups in the novel ester corrosion inhibitor increases the electron cloud density of electron-rich heteroatoms, enhancing their binding ability with empty d orbitals in the metal. This effectively reduces ions generated by corrosion of metal equipment in the coolant, thereby lowering the conductivity of the coolant during long-term use and improving its operational safety. Adding the aforementioned organic corrosion inhibitor to the coolant yields a coolant with low conductivity and high corrosion inhibition performance, solving the problems of high conductivity and low corrosion inhibition performance of traditional inorganic corrosion inhibitors.

[0023] In some embodiments of the present invention, the sodium diethyldithiocarbamate derivative is added as a corrosion inhibitor to an ethylene glycol-water solution to obtain a coolant.

[0024] In some embodiments of the present invention, the ethylene glycol-water solution contains 20-80 wt.%, preferably 62.5 wt.%.

[0025] In some embodiments of the present invention, the concentration of the sodium diethyldithiocarbamate derivative in the coolant is 0.2-2 g / L, for example 0.2 g / L, 0.5 g / L, 1 g / L, 2 g / L, etc., and any value within the range of any two of the above values, preferably 2 g / L.

[0026] A second aspect of the present invention provides a coolant, wherein the coolant includes an organic corrosion inhibitor, wherein the organic corrosion inhibitor is a sodium diethyldithiocarbamate derivative.

[0027] The coolant provided by this invention can solve the problem of high conductivity while ensuring efficient corrosion inhibition, and has excellent corrosion resistance.

[0028] The coolant preparation method provided by this invention is simple; for example, an organic corrosion inhibitor is added to ethylene glycol. In a water-based coolant, stir for 5 minutes in a reaction vessel. Mix thoroughly for 20 minutes to obtain the coolant.

[0029] In some embodiments of the present invention, the sodium diethyldithiocarbamate derivative is selected from one of methyl diethyldithiocarbamate, ethyl diethyldithiocarbamate, and propyl diethyldithiocarbamate, preferably methyl diethyldithiocarbamate.

[0030] In some embodiments of the present invention, the sodium diethyldithiocarbamate derivative is methyl diethyldithiocarbamate, ethyl diethyldithiocarbamate, or propyl diethyldithiocarbamate, preferably methyl diethyldithiocarbamate.

[0031] In some embodiments of the present invention, the concentration of the sodium diethyldithiocarbamate derivative in the coolant is 0.2-2 g / L, for example 0.2 g / L, 0.5 g / L, 1 g / L, 2 g / L, etc., and any value within the range of any two of the above values, preferably 2 g / L.

[0032] In some embodiments of the present invention, the base liquid of the coolant is an ethylene glycol-water solution.

[0033] In some embodiments of the present invention, the ethylene glycol-water solution contains 20-80 wt.%, preferably 62.5 wt.%.

[0034] A third aspect of the present invention provides the application of the coolant according to the second aspect in power batteries, engines, and electronic equipment.

[0035] The present invention will be described in detail below through embodiments.

[0036] Unless otherwise specified in the following examples and comparative examples, all conditions were performed under standard conditions or conditions recommended by the manufacturer. Reagents or instruments used, unless otherwise specified, are all commercially available products.

[0037] Preparation Example 1 The preparation process of methyl diethyl dithiocarbamate includes the following steps: A. Add 3.3 mmol of iodomethane to 12 mL of acetone solution (containing 2.2 mmol DDTC) and stir at 0 °C for 12 h; B. Evaporate the solvent, dissolve the residue in CH2Cl2, wash with water, and perform Al2O3 column chromatography (Bz / CHCl3 = 3:1, R...). f =0.2) Separate the product to obtain methyl diethyl dithiocarbamate (Mt-DTC).

[0038] Figure 1 Analysis indicates that the target Mt-DTC was successfully synthesized.

[0039] Preparation Example 2 The preparation process of ethyl diethyl dithiocarbamate includes the following steps: A. Add 3.3 mmol of iodoethane to 12 mL of acetone solution (containing 2.2 mmol DDTC) and stir at 0 °C for 12 h; B. Evaporate the solvent, dissolve the residue in CH2Cl2, wash with water, and perform Al2O3 column chromatography (Bz / CHCl3 = 3:1, R...). f =0.2) Separate the product to obtain ethyl diethyl dithiocarbamate (Et-DTC).

[0040] Figure 2 Analysis shows that the target Et-DTC was successfully synthesized.

[0041] Preparation Example 3 The preparation process of propyl diethyldithiocarbamate includes the following steps: A. Add 3.3 mmol of iodopropane to 12 mL of acetone solution (containing 2.2 mmol DDTC) and stir at 0 °C for 12 h; B. Evaporate the solvent, dissolve the residue in CH2Cl2, wash with water, and perform Al2O3 column chromatography (Bz / CHCl3 = 3:1, R...). f =0.2) Separate the product to obtain propyl diethyldithiocarbamate (Pro-DTC).

[0042] Figure 3 Analysis indicates that the target Pro-DTC was successfully synthesized.

[0043] Example 1 This example illustrates the preparation of a Mt-DTC-containing coolant.

[0044] A. Stir 80g of ethylene glycol and 48g of deionized water in a reaction vessel for 10 minutes to obtain a mixture; B. Add methyl diethyl dithiocarbamate (Mt-DTC) to the mixture of ethylene glycol and deionized water, stir for 10 min, and then sonicate to disperse it evenly, to obtain a cooling solution with an Mt-DTC addition amount of 0.2 g / L.

[0045] Example 2 The coolant was prepared according to the method of Example 1, except that the amount of Mt-DTC added to the resulting coolant was 0.5 g / L.

[0046] Example 3 The coolant was prepared according to the method of Example 1, except that the amount of Mt-DTC added to the resulting coolant was 1 g / L.

[0047] Example 4 The coolant was prepared according to the method of Example 1, except that the amount of Mt-DTC added to the resulting coolant was 2 g / L.

[0048] Example 5 This example illustrates the preparation of Et-DTC-containing coolant.

[0049] A. Stir 80g of ethylene glycol and 48g of deionized water in a reaction vessel for 10 minutes to obtain a mixture; B. Add ethyl diethyl dithiocarbamate (Et-DTC) to the mixture of ethylene glycol and deionized water, stir for 10 minutes, and then sonicate to disperse it evenly, to obtain a cooling solution with an Et-DTC addition amount of 0.2 g / L.

[0050] Example 6 The coolant was prepared according to the method in Example 5, except that the amount of Et-DTC added to the resulting coolant was 0.5 g / L.

[0051] Example 7 The coolant was prepared according to the method of Example 5, except that the amount of Et-DTC added to the resulting coolant was 1 g / L.

[0052] Example 8 The coolant was prepared according to the method in Example 5, except that the amount of Et-DTC added to the resulting coolant was 2 g / L.

[0053] Example 9 This example illustrates the preparation of a Pro-DTC-containing coolant.

[0054] A. Stir 80g of ethylene glycol and 48g of deionized water in a reaction vessel for 10 minutes to obtain a mixture; B. Add propyl diethyl dithiocarbamate (Pro-DTC) to the mixture of ethylene glycol and deionized water, stir for 10 minutes, and then sonicate to disperse it evenly, to obtain a cooling solution with an addition amount of 0.2 g / L of Pro-DTC.

[0055] Example 10 The coolant was prepared according to the method of Example 9, except that the amount of Pro-DTC added to the resulting coolant was 0.5 g / L.

[0056] Example 11 The coolant was prepared according to the method of Example 9, except that the amount of Pro-DTC added to the resulting coolant was 1 g / L.

[0057] Example 12 The coolant was prepared according to the method of Example 9, except that the amount of Pro-DTC added to the resulting coolant was 2 g / L.

[0058] Comparative Example 1 The coolant was prepared according to the method of Example 1, except that Et-DTC in step B was replaced with DDTC.

[0059] Test Example 1 At room temperature, aluminum alloy 6063 specimens were immersed in different coolants for 20 days for testing.

[0060] Corrosion rate ( v, g·m -2 ·d -1 It is derived from the following formula:

[0061] In the formula, m The change in mass of the aluminum sample (g); S The surface area of ​​the test piece (m²) 2 ); t For time (d).

[0062] Based on the corrosion rate, the corrosion inhibition efficiency is further calculated ( η, % ):

[0063] In the formula, v 0 (g·m -2 ·d -1 )and v (g·m) -2 ·d -1 ( ) represent the corrosion rates of the metal without and with corrosion inhibitors, respectively.

[0064] The test results are shown in Table 1.

[0065] Table 1

[0066] As can be seen from the results in Table 1, the conductivity of coolants containing Mt-DTC, Et-DTC and Pro-DTC is much lower than 5 μs / cm, and the coolant provided by the present invention has improved corrosion inhibition efficiency, so it can be used in low conductivity coolant systems.

[0067] The results in Table 1 show that the corrosion rate of aluminum alloy 6063 in the coolant of Comparative Example 1 is 0.1330 g. m -2 d -1 After replacing the corrosion inhibitors with Mt-DTC, Et-DTC, and Pro-DTC, the corresponding corrosion rate values ​​all decreased. Table 1 also shows that different types of corrosion inhibitors have different corrosion inhibition efficiencies on aluminum alloys (DDTC < Pro-DTC < Et-DTC < Mt-DTC).

[0068] The inventors speculate that the corrosion inhibitor's effectiveness may be related to the formation of coordinate bonds between the lone pairs of electrons on the heteroatoms in the structure and the empty d orbitals of the metal atoms. Furthermore, the presence of alkyl side chains in ester-based corrosion inhibitors increases the electron cloud density of heteroatoms, enhancing their bonding strength with the metal surface and thus improving the corrosion inhibition effect.

[0069] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. Application of sodium diethyldithiocarbamate derivatives as corrosion inhibitors for coolants.

2. The application according to claim 1, wherein, The sodium diethyldithiocarbamate derivative is selected from at least one of methyl diethyldithiocarbamate, ethyl diethyldithiocarbamate, and propyl diethyldithiocarbamate. Preferably, the sodium diethyldithiocarbamate derivative is methyl diethyldithiocarbamate, ethyl diethyldithiocarbamate, or propyl diethyldithiocarbamate, and more preferably methyl diethyldithiocarbamate.

3. The application according to claim 1 or 2, wherein, The sodium diethyldithiocarbamate derivative was added as a corrosion inhibitor to an ethylene glycol-water solution to obtain a coolant; Preferably, the ethylene glycol content in the ethylene glycol-water solution is 20-80 wt.%, more preferably 62.5 wt.%. Preferably, the concentration of the sodium diethyldithiocarbamate derivative in the coolant is 0.2-2 g / L, more preferably 2 g / L.

4. A coolant, characterized in that, The coolant includes an organic corrosion inhibitor, wherein the organic corrosion inhibitor is a sodium diethyldithiocarbamate derivative.

5. The coolant according to claim 4, wherein, The sodium diethyldithiocarbamate derivative is selected from one of methyl diethyldithiocarbamate, ethyl diethyldithiocarbamate, and propyl diethyldithiocarbamate, preferably methyl diethyldithiocarbamate.

6. The coolant according to claim 4 or 5, wherein, The sodium diethyldithiocarbamate derivative is methyl diethyldithiocarbamate, ethyl diethyldithiocarbamate, or propyl diethyldithiocarbamate, preferably methyl diethyldithiocarbamate.

7. The coolant according to any one of claims 4-6, wherein, The concentration of the sodium diethyldithiocarbamate derivative in the coolant is 0.2-2 g / L, preferably 2 g / L.

8. The coolant according to any one of claims 4-7, wherein, The base liquid of the coolant is an ethylene glycol-water solution.

9. The coolant according to any one of claims 4-8, wherein, The ethylene glycol-water solution contains 20-80 wt.% ethylene glycol, preferably 62.5 wt.%.

10. According to claim 4 The application of the coolant described in any one of the 9 in power batteries, engines and electronic equipment.

Images