Degradable environment-friendly vegetable oil-based semi-synthetic cutting fluid and preparation method thereof

Abstract

The invention relates to the technical field of metal working fluids, in particular to a degradable environment-friendly vegetable oil-based semi-synthetic cutting fluid and a preparation method thereof. The cutting fluid comprises 20-30 parts of vegetable lubricating oil, 10-20 parts of an alkali storage agent, 2-5 parts of a corrosion inhibitor, 3-5 parts of a coupling agent, 5-8 parts of a surfactant and 6-11 parts of a composite anti-rust agent, the composite anti-rust agent comprises an anti-rust agent A and an anti-rust agent B, the anti-rust agent A comprises N-[3-(dimethylamino) propyl]-N, N-dimethylformamide, and the anti-rust agent B comprises N-[3-(dimethylamino) propyl]-N, N-dimethylformamide. The antirust agent A comprises at least one of N, N ', N'-trimethyl-1, 3-propanediamine, benzotriazole, sebacic acid and 2, 4, 6-tri (aminocaproic acid)-1, 3, 5-triazine, and the antirust agent B comprises at least one of an imidazoline compound and fatty acid sarcosine ester. The cutting fluid provided by the invention has excellent corrosion resistance, rust resistance, defoaming property, biodegradability and storage stability, and has a good application prospect.

Description

Technical Field

[0001] This invention relates to the technical field of metalworking fluids, specifically to a biodegradable, environmentally friendly, vegetable oil-based semi-synthetic cutting fluid and its preparation method. Background Technology

[0002] Aluminum alloys, due to their excellent mechanical properties, corrosion resistance, and low density, are widely used in aerospace, automotive, and other industries. During aluminum alloy machining, cutting fluids play multiple roles, including lubrication, cooling, cleaning, and corrosion prevention. Traditional cutting fluids are typically based on mineral or synthetic oils, which may have adverse effects on the environment and worker health during use. Traditional petroleum-based cutting fluids generate pollutants such as fumes, wastewater, and waste liquid during production and use, and petroleum resources are finite and difficult to sustain. Therefore, developing environmentally friendly cutting fluids has become an urgent problem for the industry.

[0003] Vegetable oil-based cutting fluids offer superior lubrication, effectively reducing heat and friction during aluminum alloy cutting, thereby extending tool life and improving machining accuracy and efficiency. Furthermore, they are biodegradable after processing, minimizing environmental impact and aligning with green manufacturing requirements. Additionally, the vegetable oil components in vegetable oil-based cutting fluids are less toxic than mineral oils, making them more environmentally friendly. However, vegetable oil-based cutting fluids still face some challenges, such as poor emulsification stability, insufficient biodegradability, and inadequate corrosion resistance.

[0004] Therefore, developing a plant oil-based environmentally friendly semi-synthetic cutting fluid with good emulsification stability, biodegradability, and corrosion resistance is of great significance for improving the quality, efficiency, and environmental friendliness of aluminum alloy machining. Summary of the Invention

[0005] In a first aspect, the present invention provides a biodegradable, environmentally friendly, vegetable oil-based semi-synthetic cutting fluid, comprising the following components in parts by weight: 20-30 parts of vegetable lubricating oil, 10-20 parts of alkali reserve agent, 2-5 parts of corrosion inhibitor, 3-5 parts of coupling agent, 5-8 parts of surfactant, and 6-11 parts of composite rust inhibitor; wherein the composite rust inhibitor comprises rust inhibitor A and rust inhibitor B; wherein rust inhibitor A comprises N-[3-(dimethylamino)propyl]-N,N',N'-trimethyl-1,3-propanediamine, benzotriazole, sebacic acid, and 2,4,6-tris(aminohexanoic acid)-1,3,5-triazine; wherein rust inhibitor B comprises at least one of imidazoline compounds and fatty acid sarcosine esters.

[0006] The inventors discovered that rust inhibitor A, by compounding N-[3-(dimethylamino)propyl]-N,N',N'-trimethyl-1,3-propanediamine (CAS No.: 3855-32-1), benzotriazole, sebacic acid, and 2,4,6-tris(aminohexanoic acid)-1,3,5-triazine, enables N-[3-(dimethylamino)propyl]-N,N',N'-trimethyl-1,3-propanediamine, sebacic acid, and 2,4,6-tris(aminohexanoic acid)-1,3,5-triazine to form a pH-balanced buffer pair, maintaining the pH environment of the cutting fluid. Benzotriazole can effectively inhibit the oxidative degradation of N-[3-(dimethylamino)propyl]-N,N',N'-trimethyl-1,3-propanediamine, allowing the composite rust inhibitor to stably exert its rust-preventive properties. Rust inhibitor B is a compound of imidazoline compounds and fatty acid sarcosine esters. The imidazoline compounds form a chemical adsorption film to prevent rust and effectively neutralize acidic substances (such as metal corrosion products and bacterial metabolites) and small amounts of alkaline contaminants generated during processing, maintaining the stability of the cutting fluid system. Fatty acid sarcosine esters possess excellent surface activity, reducing surface tension. Their carboxyl and amino groups allow them to adsorb onto metal surfaces, assisting the imidazoline compounds in forming a dense, protective rust-preventing film. The composite rust inhibitor, by combining rust inhibitor A and rust inhibitor B, achieves comprehensive rust prevention through a synergistic effect of multiple film-forming mechanisms, including adsorption and metal ion complexation. Furthermore, while ensuring rust prevention and stability, the resulting cutting fluid also exhibits excellent lubricity, anti-foaming properties, and corrosion resistance.

[0007] In some preferred embodiments, the mass ratio of N-[3-(dimethylamino)propyl]-N,N',N'-trimethyl-1,3-propanediamine, benzotriazole, sebacic acid and 2,4,6-tris(aminohexanoic acid)-1,3,5-triazine in the rust inhibitor A is (10-12):1:(2-2.5):(2-2.5).

[0008] In some preferred embodiments, the imidazoline compounds include hydroxyethyl oleoyl imidazoline, and the fatty acid sarcosine esters include at least one of oleoyl sarcosine and oleoyl sarcosine octadecylamine salt.

[0009] In some embodiments, the mass ratio of rust inhibitor A to rust inhibitor B is (5-10):1.

[0010] In some embodiments, the plant-based lubricant includes at least one of trimethylolpropane tristearate, pentaerythritol tetraester, and triglycerides.

[0011] In some embodiments, the surfactant includes at least one of cyclocarboxylic oleic acid, long-chain fatty amide polyurethane vinyl ether, synthetic ester amide, and dehydrated sorbitan oleate.

[0012] In some embodiments, the alkali stocking agent includes at least one of N,N-dimethylpropanolamine, diethylene glycolamine, and 3-butoxypropylamine, and the coupling agent includes at least one of Guerbert alcohol, fatty alcohol ethoxylate, and castor oil ethoxylate.

[0013] In some embodiments, the corrosion inhibitor includes at least one of silane-type aluminum corrosion inhibitors and alkyl phosphates.

[0014] In some embodiments, the biodegradable, environmentally friendly, vegetable oil-based semi-synthetic cutting fluid further includes a dispersant, a bactericide, a defoamer, and deionized water. In some preferred embodiments, the dispersant includes at least one of propylene glycol phenyl ether and diethylene glycol butyl ether, the bactericide includes benzisothiazolinone, and the defoamer includes a siloxane compound. In some preferred embodiments, the dispersant has a weight fraction of 2-5 parts, the bactericide has a weight fraction of 2-4 parts, the defoamer has a weight fraction of 0.05-0.2 parts, and the deionized water has a weight fraction of 20-50 parts.

[0015] In a second aspect, the present invention provides a method for preparing the above-mentioned biodegradable environmentally friendly vegetable oil-based semi-synthetic cutting fluid, comprising the following steps: stirring an alkali stockpile, a corrosion inhibitor, a vegetable lubricant, a composite rust inhibitor, and a portion of deionized water evenly, then adding a dispersant, a surfactant, a coupling agent, and a bactericide and stirring evenly, then adding the remaining deionized water and a defoamer and stirring evenly to obtain the cutting fluid.

[0016] In a third aspect, the present invention provides the application of the above-mentioned biodegradable environmentally friendly vegetable oil-based semi-synthetic cutting fluid in metal cutting and grinding processes.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] This invention, through optimized design of components and their dosages, produces a biodegradable, environmentally friendly, vegetable oil-based semi-synthetic cutting fluid that is not only odorless but also possesses excellent corrosion resistance, rust prevention, defoaming properties, biodegradability, lubricity, and storage stability. This is significant for improving the quality, efficiency, and environmental friendliness of alloy processing and has promising application prospects. Furthermore, this invention, through optimized design of the types and proportions of rust inhibitors, reveals that composite rust inhibitors, under specific components and proportions, can significantly enhance the corrosion resistance, rust prevention, and lubricity of the cutting fluid. Detailed Implementation

[0019] The following detailed embodiments further illustrate the content of the present invention. These embodiments do not constitute a limitation on the scope of protection of the present invention. Non-essential modifications and adjustments made by others based on the concept of the present invention still fall within the scope of protection of the present invention. The raw materials, reagents, or devices used in the embodiments are all available from conventional commercial sources or can be obtained through existing technical methods. Unless otherwise specified, the experimental or testing methods are conventional methods in the art.

[0020] Information on the reagents used in the examples is shown in Table 1.

[0021] Table 1

[0022]

[0023]

[0024] The cutting fluid compositions of Examples 1-6 are shown in Table 2.

[0025] Table 2

[0026]

[0027] Note: In the rust inhibitor A of Examples 1-6 in Table 2, the mass ratio of N-[3-(dimethylamino)propyl]-N,N',N'-trimethyl-1,3-propanediamine, benzotriazole, sebacic acid, and 2,4,6-tris(aminohexanoic acid)-1,3,5-triazine is 10:1:2:2.

[0028] The cutting fluid compositions of Comparative Examples 1-7 are shown in Table 3.

[0029] Table 3

[0030]

[0031] Note: In the rust inhibitor A of Comparative Examples 1-5 and Comparative Example 7 in Table 3, the mass ratio of N-[3-(dimethylamino)propyl]-N,N',N'-trimethyl-1,3propanediamine, benzotriazole, sebacic acid, and 2,4,6-tris(aminohexanoic acid)-1,3,5-triazine is 10:1:2:2.

[0032] The cutting fluids of Comparative Examples 8-12 differ from those of Example 1 only in the composition of rust inhibitor A; the other components and their amounts are the same as those of Example 1.

[0033] The composition of the composite rust inhibitors in Comparative Examples 8-12 is shown in Table 4.

[0034] Table 4

[0035]

[0036] The preparation methods of the cutting fluids in Examples 1-6 and Comparative Examples 1-12 include the following steps:

[0037] S1. Stir the alkali storage agent, corrosion inhibitor, vegetable lubricating oil, compound rust inhibitor, and deionized water at room temperature for 30 minutes. The mass ratio of compound rust inhibitor to deionized water is 3:1.

[0038] S2. Then add dispersant, surfactant, coupling agent and bactericide, and stir evenly at room temperature for 30 minutes;

[0039] S3. Then add the remaining deionized water and defoamer, stir evenly at room temperature for 60 minutes to obtain the cutting fluid.

[0040] Cutting fluid performance test

[0041] The cutting fluids prepared in Examples 1-6 and Comparative Examples 1-12 were diluted with deionized water to a mass fraction of 5%, and their performance was tested using the following methods:

[0042] (1) Odor test: Professional evaluators will conduct a subjective evaluation of the odor of the raw cutting fluid.

[0043] (2) pH test: The pH value of the cutting fluid dilution was tested using a pH meter.

[0044] (3) Corrosion resistance, rust prevention, defoaming and storage stability test: The corrosion resistance, rust prevention, defoaming and storage stability test of the cutting fluid dilution was carried out using the test method of GB / T 6144 standard.

[0045] (4) Biodegradability test: The biodegradability of the cutting fluid dilution was tested using the OECD No. test method.

[0046] (5) Average Torque Force Test: The Microtap Test system was used to simulate the on-site machining process (using a 7075 aluminum alloy test plate, at room temperature, a rotation speed of 800 rpm, a maximum torque of 400 Ncm, and a tapping depth of 20 mm) to measure the average torque force required by the diluted cutting fluid during the cutting or deformation process in metal processing. The average torque force reflects the magnitude of the interaction force between the tool and the workpiece during the cutting process. A lower average torque force means a smoother cutting process and less resistance to the tool, which helps to reduce cutting heat and cutting force during the cutting process, thereby reducing the risk of tool wear and workpiece deformation.

[0047] The performance test data of Examples 1-6 and Comparative Examples 1-12 are shown in Table 5.

[0048] Table 5

[0049]

[0050]

[0051] As shown in Table 5, the cutting fluid prepared by the present invention through component optimization and ratio optimization has excellent corrosion resistance, rust prevention, defoaming, biodegradability and storage stability.

[0052] Compared with Example 1, when the weight percentage of the composite rust inhibitor in the cutting fluid of Comparative Example 1 was 4 parts, the resulting cutting fluid exhibited poor rust prevention and lubrication performance; when the cutting fluid of Comparative Example 2 did not contain a corrosion inhibitor, the resulting cutting fluid exhibited poor corrosion resistance, long defoaming time, and poor lubrication; when the weight percentage of the surfactant in the cutting fluid of Comparative Example 3 was 3 parts, the resulting cutting fluid exhibited long defoaming time, poor lubrication, and poor storage stability; when the weight percentage of the coupling agent in the cutting fluid of Comparative Example 4 was 2 parts, the resulting cutting fluid exhibited poor corrosion resistance, poor rust prevention, long defoaming time, poor lubrication, and poor storage stability; and the cutting fluid of Comparative Example 5… When the mass ratio of rust inhibitor A to rust inhibitor B is 12:1, the resulting cutting fluid exhibits poor corrosion resistance, poor rust prevention, long defoaming time, poor lubrication, and poor storage stability. In Comparative Example 6, the cutting fluid without rust inhibitor A also exhibits poor corrosion resistance, poor rust prevention, long defoaming time, poor lubrication, and poor storage stability. In Comparative Example 7, the cutting fluid without rust inhibitor B also exhibits poor rust prevention, long defoaming time, poor lubrication, and poor storage stability. In Comparative Example 8, the component ratio of rust inhibitor A in the cutting fluid is N-[3-(dimethylamino)propyl]-N,N',N'-trimethyl- When the ratio of 1,3-propanediamine:benzotriazole: sebacic acid: 2,4,6-tris(aminohexanoic acid)-1,3,5-triazine = 5:1:2:2, the resulting cutting fluid exhibits poor rust prevention and a long defoaming time. In Comparative Example 9, when the component ratio of rust inhibitor A in the cutting fluid is N-[3-(dimethylamino)propyl]-N,N',N'-trimethyl-1,3-propanediamine:benzotriazole: sebacic acid: 2,4,6-tris(aminohexanoic acid)-1,3,5-triazine = 15:1:1:1, the resulting cutting fluid exhibits poor rust prevention, a long defoaming time, poor lubrication, and poor storage stability. The cutting fluid in Comparative Example 10... When rust inhibitor A in Comparative Example 11 does not contain 2,4,6-tris(aminohexanoic acid)-1,3,5-triazine, the resulting cutting fluid exhibits poor rust prevention, long defoaming time, and poor lubrication. When rust inhibitor A in Comparative Example 12 does not contain sebacic acid, the resulting cutting fluid also exhibits poor rust prevention, long defoaming time, and poor lubrication. When 2-amino-2-methyl-1-propanol is used to replace N-[3-(dimethylamino)propyl]-N,N',N'-trimethyl-1,3-propanediamine in rust inhibitor A, the resulting cutting fluid exhibits poor corrosion resistance, poor rust prevention, long defoaming time, poor lubrication, and poor storage stability.

[0053] In summary, the cutting fluid prepared by this invention through component optimization and ratio optimization has excellent corrosion resistance, rust prevention, defoaming properties, biodegradability, and storage stability. It is of great significance for improving the quality, efficiency, and environmental friendliness of aluminum alloy processing and has a promising application prospect.

[0054] The above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. A biodegradable, environmentally friendly, vegetable oil-based semi-synthetic cutting fluid, characterized in that, It includes the following components in parts by weight: 20-30 parts vegetable lubricating oil, 10-20 parts alkali stocking agent, 2-5 parts corrosion inhibitor, 3-5 parts coupling agent, 5-8 parts surfactant and 6-11 parts composite rust inhibitor; The composite rust inhibitor includes rust inhibitor A and rust inhibitor B; The rust inhibitor A includes N-[3-(dimethylamino)propyl]-N,N',N'-trimethyl-1,3propanediamine, benzotriazole, sebacic acid and 2,4,6-tris(aminohexanoic acid)-1,3,5-triazine; The rust inhibitor B includes at least one of imidazoline compounds and fatty acid sarcosine esters; In the rust inhibitor A, the mass ratio of N-[3-(dimethylamino)propyl]-N,N',N'-trimethyl-1,3-propanediamine, benzotriazole, sebacic acid and 2,4,6-tris(aminohexanoic acid)-1,3,5-triazine is (10-12):1:(2-2.5):(2-2.5).

2. The biodegradable, environmentally friendly, vegetable oil-based semi-synthetic cutting fluid as described in claim 1, characterized in that, The mass ratio of rust inhibitor A to rust inhibitor B is (5-10):

1.

3. The biodegradable, environmentally friendly, vegetable oil-based semi-synthetic cutting fluid as described in claim 1, characterized in that, The imidazoline compounds include hydroxyethyl oleoyl imidazoline, and the fatty acid sarcosine esters include at least one of oleoyl sarcosine and oleoyl sarcosine octadecylamine salt.

4. The biodegradable, environmentally friendly, vegetable oil-based semi-synthetic cutting fluid as described in claim 1, characterized in that, The plant-based lubricant includes at least one of trimethylolpropane tristearate, pentaerythritol tetraester, and triglycerides, and the surfactant includes at least one of cyclic carboxylic oleic acid, long-chain fatty amide polyurethane vinyl ether, synthetic ester amide, and dehydrated sorbitan oleate.

5. The biodegradable, environmentally friendly, vegetable oil-based semi-synthetic cutting fluid as described in claim 1, characterized in that, The alkali stockpile includes at least one of N,N-dimethylpropanolamine, diethylene glycolamine, and 3-butoxypropylamine, and the coupling agent includes at least one of Guerbert alcohol, fatty alcohol ethoxylate, and castor oil ethoxylate.

6. The biodegradable, environmentally friendly, vegetable oil-based semi-synthetic cutting fluid as described in claim 1, characterized in that, The environmentally friendly vegetable oil-based semi-synthetic cutting fluid also includes dispersants, bactericides, defoamers, and deionized water.

7. The biodegradable, environmentally friendly, vegetable oil-based semi-synthetic cutting fluid as described in claim 6, characterized in that, The dispersant includes at least one of propylene glycol phenyl ether and diethylene glycol butyl ether.

8. The biodegradable, environmentally friendly, vegetable oil-based semi-synthetic cutting fluid as described in claim 6, characterized in that, The dispersant has a weight fraction of 2-5 parts, the bactericide has a weight fraction of 2-4 parts, the defoamer has a weight fraction of 0.05-0.2 parts, and the deionized water has a weight fraction of 20-50 parts.

9. A method for preparing a biodegradable, environmentally friendly, vegetable oil-based semi-synthetic cutting fluid as described in claim 6, characterized in that, Includes the following steps: The alkali stocking agent, corrosion inhibitor, vegetable lubricating oil, composite rust inhibitor, and part of deionized water are stirred evenly. Then, the dispersant, surfactant, coupling agent, and bactericide are added and stirred evenly. Finally, the remaining deionized water and defoamer are added and stirred evenly to obtain the cutting fluid.

10. The application of the biodegradable environmentally friendly vegetable oil-based semi-synthetic cutting fluid as described in any one of claims 1-8 in metal cutting and grinding processes.

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