Low-conductivity cooling liquid and preparation method thereof

Abstract

The invention discloses a low-conductivity cooling liquid and a preparation method thereof. The low-conductivity cooling liquid comprises an alcohol coolant, deionized water, a low-ionization-degree organic carboxylic acid corrosion inhibitor, an azole corrosion inhibitor, alkoxy alkyl silane, an inositol phosphate compound, a pH regulator and a defoaming agent. During preparation, all the components are sequentially stirred and added to obtain the low-conductivity cooling liquid. According to the low-conductivity cooling liquid disclosed by the invention, the low-ionization-degree organic carboxylic acid corrosion inhibitor, the azole corrosion inhibitor, the alkoxy alkyl silane and the inositol phosphate compound are compounded to form a specific system formula, and then the specific system formula is combined with the alcohol cooling agent and the water, so that the low-conductivity cooling liquid not only has strong corrosion resistance, but also has excellent system stability; the stability of the anti-freezing liquid during working or storage can be guaranteed, and the components are prevented from being decomposed and reacting to generate complexes or precipitates, so that the conductivity of the cooling liquid is stabilized.

Description

Technical Field

[0001] This invention belongs to the technical field of coolants and their preparation methods, and particularly relates to a low conductivity coolant and its preparation method. Background Technology

[0002] With the rapid development of industrialization and the automotive industry, coolant, as an important heat transfer fluid, is widely used in automotive engines, industrial equipment, electronic components, and other applications. However, most existing coolants use inorganic salt formulations or organic acid / inorganic salt mixtures, resulting in high electrical conductivity, typically above 3000 μS / cm. This high conductivity leads to a series of problems, including decreased cooling efficiency, severe metal corrosion, and shortened equipment lifespan. These issues have become significant challenges that need to be addressed in industrial production and daily use.

[0003] Coolant typically consists primarily of water and alcohols, supplemented with various functional additives such as antifreeze, corrosion inhibitors, and dispersants. However, during use, additives in the coolant, such as organic acid corrosion inhibitors, continuously dissociate, significantly increasing the coolant's conductivity. Furthermore, under high temperature and high pressure environments, the chemical additives in the coolant are prone to decomposition or reaction, further reducing the coolant's stability and causing the product to fail to meet production and usage requirements. With the rapid popularization of electronic devices, especially the rise of electric vehicles, the requirements for low conductivity in coolant fluids are becoming increasingly stringent.

[0004] In addition, the static corrosion performance of coolant is also a critical factor. Currently, the improper ratio of coolant leads to corrosion of metal parts, especially in cooling systems for metals such as aluminum, copper, or iron, where corrosion problems are extremely serious.

[0005] Based on this, a coolant with strong system stability and strong corrosion resistance is being developed. This coolant can avoid the decomposition or reaction of chemical components and maintain stable conductivity under high temperature and high pressure environments. Summary of the Invention

[0006] Purpose of the invention: The purpose of this invention is to provide a low-conductivity coolant with strong system stability and corrosion resistance, and its preparation method. This coolant can avoid the decomposition or reaction of chemical components and maintain stable conductivity under high temperature and high pressure environments.

[0007] Technical solution: The low conductivity coolant of the present invention comprises the following raw materials by weight: 40-60 parts of alcohol coolant, 40-60 parts of deionized water, 0.05-0.5 parts of low ionization organic carboxylic acid corrosion inhibitor, 0.1-2 parts of azole corrosion inhibitor, 0.1-1.5 parts of alkoxyalkylsilane, 0.05-0.5 parts of inositol phosphate compound, 0.02-0.15 parts of pH adjuster, and 0.01-0.05 parts of defoamer.

[0008] Furthermore, the alcohol-based coolant used in this coolant can be selected from one of ethylene glycol, monoethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, monopropylene glycol, dipropylene glycol, 1,3-propanediol, polyalkylene glycol, alkylene glycol ether, or glycerol.

[0009] Furthermore, the low-ionization organic carboxylic acid corrosion inhibitor used in the coolant is selected from 2-ethylhexanoic acid, octanoic acid, nonanoic acid, 2-propenheptaic acid, sebacic acid, undecanoic acid, dodecanoic acid, tridecanoic acid, or tetradecanoic acid. Preferably, it can be selected from octanoic acid, nonanoic acid, or sebacic acid.

[0010] Furthermore, the azole corrosion inhibitor used in this coolant is selected from benzimidazole, benzotriazole, methylbenzotriazole or hydrogenated toluenetriazole.

[0011] Furthermore, the alkoxyalkylsilane used in the coolant is selected from methoxysilane, ethoxysilane, propoxysilane, butoxysilane, tetra(trimethoxysilane)silane, or ethoxydimethyl[3-(epoxyethoxy)propyl]silane. Preferably, it is selected from methoxysilane, ethoxysilane, or butoxysilane.

[0012] Furthermore, the inositol phosphate compounds used in this coolant are selected from inositol tetraphosphate or inositol hexaphosphate.

[0013] Furthermore, the pH adjuster used in this coolant is an organic amine, selected from monoethanolamine, diethanolamine, or triethanolamine.

[0014] Furthermore, the defoamer is an organosilicon defoamer, preferably polydimethylsiloxane.

[0015] The method for preparing the above-mentioned low conductivity coolant according to the present invention includes the following steps:

[0016] (1) Mix and disperse the alcohol coolant and deionized water evenly to obtain the base fluid;

[0017] (2) Gradually add low-ionization organic carboxylic acid corrosion inhibitors, azole corrosion inhibitors, alkoxyalkylsilanes, and inositol phosphate compounds to the base fluid. Stir well after each addition to obtain a homogeneous mixed solution.

[0018] (3) Add pH adjuster and defoamer to the mixed solution in step (2), stir and mix evenly to obtain a low conductivity coolant.

[0019] Beneficial effects: Compared with the prior art, the significant advantages of the present invention are: the low conductivity coolant is formulated by compounding low ionization organic carboxylic acid corrosion inhibitors with azole corrosion inhibitors, alkoxyalkylsilanes, and inositol phosphate compounds to form a specific system, which is then combined with alcohol coolant and water. This not only has excellent system stability, ensuring the stability of the antifreeze during operation or storage, but also prevents the components from decomposing, reacting to form complexes or precipitates during storage or operation, and at the same time has strong corrosion resistance. Attached Figure Description

[0020] Figure 1 Photographs of the coolant obtained in Example 1 after storage stability tests;

[0021] Figure 2 The image shows a photograph of the coolant obtained in Comparative Example 1 after a storage stability test. Detailed Implementation

[0022] The technical solution of the present invention will be further described in detail below with reference to the embodiments and accompanying drawings.

[0023] It should be noted that all raw materials used in this invention are commercially available. The CAS numbers of the raw materials used in the following embodiments are shown in Table 1 below.

[0024] Table 1 Source of Raw Materials

[0025] Serial Number raw material CAS number or source 1 Ethylene glycol 107-21-1 2 sebacic acid 111-20-6 3 Methylbenzotriazole 29385-43-1 4 ethoxysilane 78-10-4 5 Inositol hexaphosphate 83-86-3 6 Triethanolamine 102-71-6 7 polydimethylsiloxane 9016-00-6

[0026] Example 1

[0027] The composition of the low conductivity coolant in Example 1 is shown in Table 2 below.

[0028] Table 2. Low conductivity coolant composition formulation of Example 1

[0029]

[0030] The low-conductivity coolant of Example 1 is prepared by the following steps:

[0031] (1) Ethylene glycol and deionized water were mixed in a mixing tank in a certain proportion to obtain a basic fluid. The rotation speed was 1000 rpm / min and the time was 10 min to obtain a homogeneous mixed solution.

[0032] (2) In accordance with the above proportions, add sebacic acid, methylbenzotriazole, ethoxysilane and inositol hexaphosphate to the homogeneous mixed solution obtained in step (1), and stir for 60 min for each additive added;

[0033] (3) On this basis, add triethanolamine and polydimethylsiloxane, stir and mix for 60 min to obtain a pure and uniform low conductivity coolant.

[0034] Comparative Example 1

[0035] Comparative Example 1 is basically the same as Example 1, except that inositol hexaphosphate is not added to the coolant. The specific component contents are shown in Table 3 below.

[0036] Table 3 Coolant composition formula for Comparative Example 1

[0037] Serial Number raw material Content / serving 1 Ethylene glycol 50 2 water 48.78 3 sebacic acid 0.1 4 Methylbenzotriazole 0.5 5 ethoxysilane 0.5 6 Inositol hexaphosphate 0 7 Triethanolamine 0.1 8 polydimethylsiloxane 0.02

[0038] The low-conductivity coolant of Comparative Example 1 was prepared by the following steps:

[0039] (1) Ethylene glycol and water were mixed in a mixing tank in a certain proportion to obtain a basic fluid. The rotation speed was 1000 rpm / min and the time was 10 min to obtain a homogeneous mixed solution.

[0040] (2) Add sebacic acid, methylbenzotriazole and ethoxysilane to the homogeneous mixed solution obtained in step (1) according to the above proportions, and stir for 60 min for each additive added;

[0041] (3) On this basis, add triethanolamine and polydimethylsiloxane, stir and mix for 60 min to obtain a pure and uniform low conductivity coolant.

[0042] Comparative Example 2

[0043] Comparative Example 2 is basically the same as Example 1, except that ethoxysilane is not added to the coolant. The specific component contents are shown in Table 4 below.

[0044] Table 4 Coolant composition formulation of Comparative Example 2

[0045] Serial Number raw material Content / serving 1 Ethylene glycol 50 2 water 49.18 3 sebacic acid 0.1 4 Methylbenzotriazole 0.5 5 ethoxysilane 0 6 Inositol hexaphosphate 0.1 7 Triethanolamine 0.1 8 polydimethylsiloxane 0.02

[0046] The low-conductivity coolant of Comparative Example 2 was prepared by the following steps:

[0047] (1) Ethylene glycol and water were mixed in a mixing tank in a certain proportion to obtain a basic fluid. The rotation speed was 1000 rpm / min and the time was 10 min to obtain a homogeneous mixed solution.

[0048] (2) Add sebacic acid, methylbenzotriazole and inositol hexaphosphate to the homogeneous mixed solution obtained in step (1) according to the above proportions, and stir for 60 min for each additive added;

[0049] (3) On this basis, add triethanolamine and polydimethylsiloxane, stir and mix for 60 min to obtain a pure and uniform low conductivity coolant.

[0050] Example 2

[0051] The composition of the low conductivity coolant in Example 2 is shown in Table 5 below. The preparation method is the same as in Example 1.

[0052] Table 5. Low conductivity coolant composition formulation for Example 2

[0053]

[0054]

[0055] Example 3

[0056] The composition of the low conductivity coolant in Example 3 is shown in Table 6 below. The preparation method is the same as in Example 1.

[0057] Table 6. Low Conductivity Coolant Component Formulation of Example 3

[0058] Serial Number raw material Content / serving 1 Ethylene glycol 50 2 water 47.58 3 sebacic acid 0.2 4 Methylbenzotriazole 1 5 ethoxysilane 1 6 Inositol hexaphosphate 0.1 7 Triethanolamine 0.1 8 polydimethylsiloxane 0.02

[0059] Performance testing

[0060] I. Storage Stability Verification

[0061] The low-conductivity coolants prepared in Example 1 and Comparative Example 1 were subjected to stability tests according to the national standard GB29743.2-2025 "Motor Vehicle Coolants Part 2: Electric Vehicle Coolants". The results are as follows. Figure 1 and 2 As shown. Among them, Figure 1 It should be clear and transparent, without any sediment or suspended matter; Figure 2 White flocculent material appeared.

[0062] In Example 1, the inositol phosphate compound, combined with an alkoxyalkylsilane and a corrosion inhibitor, produced a clear and transparent solution with no precipitate or suspended matter after stability testing, demonstrating strong stability. In contrast, in Comparative Example 1, without the addition of inositol phosphate compounds, the solution showed obvious white flocculent matter after stability testing, indicating poor stability.

[0063] II. Conductivity and Static Corrosion Resistance Tests

[0064] The low conductivity coolants prepared in Examples 1-3 and Comparative Examples 1-2 were subjected to conductivity and static corrosion resistance tests in accordance with the national standard GB29743.2-2025. The results are shown in Table 7.

[0065] Table 7 Performance Test Data

[0066]

[0067] According to Table 7 and Figure 1 , Figure 2 It can be seen that the coolant in Examples 1-3 of the present invention not only has strong stability, but also greatly improved static corrosion resistance.

[0068] Comparative Example 1 is a coolant formulated with low-ionization organic carboxylic acid corrosion inhibitors, azole corrosion inhibitors, alkoxyalkylsilanes, and alcohol-based coolants (water and alcohol-based coolants). It exhibits excellent corrosion resistance, but its stability test results are not satisfactory. Figure 2 The results showed that the system produced precipitates and had poor stability. Comparative Example 2 was a coolant formulated with low-ionization organic carboxylic acid corrosion inhibitors, azole corrosion inhibitors, inositol phosphate compounds, and alcohol-based coolants (water and alcohol-based coolants). Static corrosion test data showed that this coolant had poor corrosion resistance.

[0069] This invention is based on the coolant compounded with low-ionization organic carboxylic acid corrosion inhibitors, azole corrosion inhibitors, alkoxyalkylsilanes, and alcohol-based coolants (water and alcohol-based coolants) in Comparative Example 1. By introducing inositol phosphate compounds, specific coolant systems from Examples 1 to 3 were constructed. Stability and corrosion tests were conducted on these coolants, demonstrating that the composite system not only exhibits excellent system stability (remaining clear and transparent after stability tests, without sediment or suspended matter), but also shows minimal fluctuation in conductivity and strong stability. This demonstrates that the entire formulation system can maintain system stability and conductivity stability under prolonged high temperature and high pressure conditions. Furthermore, as shown in Table 1, the corrosion resistance of the prepared coolant system is also effectively improved.

[0070] In addition to the above embodiments, it should be noted that the technical effects claimed by the present invention can be achieved by using the preparation process and the limited parameter range of the present invention, and therefore no further examples will be provided to support these claims.

[0071] For example, in this invention, the alcohol coolant can be selected from ethylene glycol, monoethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, monopropylene glycol, dipropylene glycol, 1,3-propanediol, polyalkylene glycol, alkylene glycol ether, or glycerol. The low-ionization organic carboxylic acid corrosion inhibitor can be selected from 2-ethylhexanoic acid, octanoic acid, nonanoic acid, 2-propenheptanic acid, sebacic acid, undecanoic acid, dodecanoic acid, tridecanoic acid, or tetradecanoic acid. Preferably, the low-ionization organic carboxylic acid corrosion inhibitor is selected from octanoic acid, nonanoic acid, or sebacic acid. The azole corrosion inhibitor can be selected from benzimidazole, benzotriazole, methylbenzotriazole, or hydrogenated toluenetriazole. The alkoxyalkylsilane can be selected from methoxysilane, ethoxysilane, propoxysilane, butoxysilane, tetra(trimethylsiloxy)silane, or ethoxydimethyl[3-(epoxyethoxy)propyl]silane. Preferably, the compound can be selected from methoxysilane, ethoxysilane, or butoxysilane. Inositol phosphate compounds can be selected from inositol tetraphosphate or inositol hexaphosphate. The pH adjuster can be an organic amine, selected from monoethanolamine, diethanolamine, or triethanolamine.

Claims

1. A low conductivity coolant, characterized by, The raw materials include, by weight, 40-60 parts of an alcohol coolant, 40-60 parts of deionized water, 0.05-0.5 parts of a low-ionization organic carboxylic acid inhibitor, 0.1-2 parts of an azole inhibitor, 0.1-1.5 parts of an alkoxyalkyl silane, 0.05-0.5 parts of an inositol phosphate compound, 0.02-0.15 parts of a pH regulator, and 0.01-0.05 parts of an antifoaming agent.

2. The low conductivity coolant of claim 1, wherein, The inositol phosphate compound is selected from inositol tetraphosphate or inositol hexaphosphate.

3. The low conductivity coolant of claim 1, wherein, The alcohol coolant is selected from ethylene glycol, monoethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, monopropylene glycol, dipropylene glycol, 1,3-propanediol, polyalkylene glycol, alkylene glycol ether, or glycerol.

4. The low conductivity coolant of claim 1, wherein, The low-ionization organic carboxylic acid inhibitor is selected from 2-ethylhexanoic acid, octanoic acid, nonanoic acid, 2-propylheptanoic acid, sebacic acid, undecanoic acid, dodecanoic acid, tridecanoic acid, or tetradecanoic acid.

5. The low conductivity coolant of claim 4, wherein, The low-ionization organic carboxylic acid inhibitor is selected from octanoic acid, nonanoic acid, or sebacic acid.

6. The low conductivity coolant of claim 1, wherein, The azole inhibitor is selected from benzimidazole, benzotriazole, methylbenzotriazole, or hydrogenated toluene triazole.

7. The low conductivity coolant of claim 1, wherein, The alkoxyalkyl silane is selected from methoxysilane, ethoxysilane, propoxysilane, butoxysilane, tetrakis(trimethylsiloxy)silane, or ethoxydimethyl[3-(oxiranyloxy)propyl]silane.

8. The low conductivity coolant of claim 7, wherein, The alkoxyalkyl silane is selected from methoxysilane, ethoxysilane, or butoxysilane.

9. The low conductivity coolant of claim 1, wherein, The pH regulator is an organic amine selected from monoethanolamine, diethanolamine, or triethanolamine; and the antifoaming agent is a silicone antifoaming agent.

10. A method of preparing the low conductivity coolant of any one of claims 1 to 9, characterized by, The method comprises the following steps: (1) mixing and stirring the alcohol coolant and the deionized water to disperse uniformly to obtain a base fluid; (2) gradually adding the low-ionization organic carboxylic acid inhibitor, the azole inhibitor, the alkoxyalkyl silane, and the inositol phosphate compound to the base fluid, and stirring uniformly after each addition to obtain a uniformly mixed solution; (3) adding the pH regulator and the antifoaming agent to the mixed solution in step (2) and stirring to obtain a low-conductivity coolant.

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