Cutting oil special for copper alloy and preparation method thereof

Abstract

The invention relates to the field of metal processing oil, in particular to special cutting oil for copper alloy and a preparation method thereof. The special cutting oil for the copper alloy comprises the following components in percentage by mass: 80%-91.5% of base oil, 5%-15% of synthetic ester, 2%-5% of an anti-wear reagent at extreme pressure, 0.1%-0.5% of an antioxidant, 0.3%-0.6% of a corrosion inhibitor and 1%-3% of an anti-oil mist agent, the extreme pressure anti-wear agent comprises oily phosphate ester; the corrosion inhibitor comprises a benzotriazole derivative. The special cutting oil for the copper alloy has good lubricating and cooling properties, does not corrode the copper alloy, can inhibit atomization dissipation under high-speed cutting, and reduces the risks of oil consumption, component pollution and the like.

Description

Technical Field

[0001] This invention relates to the field of metalworking fluids, and in particular to a special cutting fluid for copper alloys and its preparation method. Background Technology

[0002] Copper alloys (such as brass, bronze, and beryllium copper) are widely used in electronic components, bathroom hardware, aerospace, and other fields due to their excellent electrical conductivity, corrosion resistance, and ease of machining. However, their processing faces several challenges, including: 1. Surface oxidation and discoloration: Sulfur and chlorine react with copper to form black spots, affecting the product's appearance and performance; 2. Tool sticking and built-up edge: High ductility causes chips to adhere to the tool, reducing surface finish and shortening tool life; 3. Thermal damage and loss of precision control: Localized temperature rises cause deformation, resulting in large dimensional deviations in thin-walled parts; 4. Excessive oil mist and high oil consumption: During high-speed cutting, the atomization and dispersion of oil components leads to low effective utilization; 5. Environmental hazards: Traditional chlorinated / nitrite-containing oils generate hazardous waste with high treatment costs.

[0003] Scientific oil selection can simultaneously achieve efficient processing, quality upgrades, and environmental compliance, serving as a core guarantee for the high value-added production of copper alloys. Currently, publicly available information on cutting oils specifically for copper alloys is limited. The lubricating media found that can be applied to copper alloy machining all have several problems, such as: some lubricants have poor film thickness and strength, insufficient lubrication, and difficulty in controlling the surface precision of copper alloy machining; some lubricants contain active ingredients that corrode copper, potentially causing localized corrosion of copper alloy parts under high temperature and pressure; some oils have poor thermal oxidation stability, easily atomizing and dissipating, resulting in high oil consumption; some lubricating media use traditional machine oil as a base oil, which has high volatility, heat-sensitive additives, and low viscosity characteristics, leading to significant smoke problems when used as a cutting oil base oil, and posing risks such as insufficient lubrication and component contamination.

[0004] It is evident that existing technologies still need improvement and enhancement. Summary of the Invention

[0005] In view of the shortcomings of the prior art, the purpose of this invention is to provide a special cutting oil for copper alloys and its preparation method, which aims to improve the overall performance of the cutting oil in machining copper alloys.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] The first aspect of this invention provides a cutting oil specifically for copper alloys, comprising, by mass percentage: 80%–91.5% base oil, 5%–15% synthetic ester, 2%–5% extreme pressure anti-wear agent, 0.1%–0.5% antioxidant, 0.3%–0.6% corrosion inhibitor, and 1%–3% anti-oil mist agent; wherein the extreme pressure anti-wear agent comprises an oily phosphate ester; and the corrosion inhibitor comprises a benzotriazole derivative.

[0008] The copper alloy-specific cutting oil, wherein the base oil includes multiple types of 150N, 150SN, 100N, 100SN, 70N, 70SN, 60N, 60SN, Lu'an 3#, and PAO.

[0009] The copper alloy-specific cutting oil, wherein the synthetic ester includes multiple varieties selected from isooctyl oleate, methyl oleate, fatty acid methyl ester, trimethylolpropane oleate, isooctyl stearate, isooctyl cocoate, pentaerythritol ester, and dioctyl terephthalate.

[0010] The copper alloy-specific cutting oil, wherein the oily phosphate ester includes one or more of isooctyl phosphate, isooctyl phosphite, oleyl phosphite, tricresyl phosphate, oleyl alcohol polyether phosphate, oleyl alcohol polyether phosphate, pentyl phosphate, and C18 alkyl phosphate.

[0011] The copper alloy-specific cutting oil, wherein the antioxidant is one or more of 2,6-di-tert-butylamino-p-cresol, N-phenyl-α-naphthylamine, 2,6-di-tert-butyl-p-cresol, alkylphenthiazide, and 4,4-dioctyldiphenylamine.

[0012] The copper alloy-specific cutting oil, wherein the corrosion inhibitor is a 1:1 mixture of benzotriazole derivative and salicylate derivative.

[0013] The copper alloy-specific cutting oil, wherein the anti-oil mist agent includes one or both of polyisobutylene PIB 2400 and polyisobutylene PIB 1300.

[0014] The copper alloy cutting oil, by mass percentage, comprises the following components: 64.5% 150N, 22% 60N, 10% methyl oleate, 2% oleyl alcohol polyether phosphate, 0.2% T501, 0.3% benzotriazole derivative, and 1% PIB2400.

[0015] The copper alloy cutting oil, by mass percentage, comprises the following components: 76.5% 150SN, 15% 60N, 5% trimethylolpropane oleate, 2% tricresyl phosphate, 0.2% T501, 0.3% benzotriazole derivative, and 1% PIB2400.

[0016] A second aspect of this invention provides a method for preparing a cutting oil, used to prepare the copper alloy-specific cutting oil described above, comprising the following steps:

[0017] The base oil and synthetic ester are mixed and stirred at room temperature until homogeneous and transparent to obtain a mixed solution;

[0018] Slowly add antioxidants, corrosion inhibitors, and anti-oil mist agents to the mixed solution, and stir at 55-60°C until the solution is clear and transparent;

[0019] Further, an extreme pressure anti-wear agent was added to the mixed solution and stirred evenly to obtain a special cutting oil for copper alloys.

[0020] Beneficial effects: This invention provides a special cutting oil for copper alloys. The special cutting oil for copper alloys uses base oil and synthetic ester as basic components, and is compounded with extreme pressure anti-wear agents, antioxidants, corrosion inhibitors, and anti-oil mist agents. By selecting oily phosphate esters as extrusion anti-wear agents and benzotriazole derivatives as corrosion inhibitors, the special cutting oil for copper alloys can achieve the characteristics of being sulfur-free, chlorine-free, having good lubricity, low oil consumption, low viscosity, and non-corrosive to copper parts, thus meeting the processing requirements of various copper alloys. Attached Figure Description

[0021] Figure 1 This is a photograph of the copper alloy-specific cutting oil from Example 1. Detailed Implementation

[0022] This invention provides a special cutting oil for copper alloys and its preparation method. To make the objectives, technical solutions, and effects of this invention clearer and more explicit, the invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only for explaining the invention and are not intended to limit the invention.

[0023] The first aspect of this invention provides a cutting oil specifically for copper alloys, comprising, by mass percentage: 80%–91.5% base oil, 5%–15% synthetic ester, 2%–5% extreme pressure anti-wear agent, 0.1%–0.5% antioxidant, 0.3%–0.6% corrosion inhibitor, and 1%–3% anti-oil mist agent; wherein the extreme pressure anti-wear agent comprises an oily phosphate ester; and the corrosion inhibitor comprises a benzotriazole derivative.

[0024] This invention uses a high proportion of base oil, combined with suitable extreme pressure anti-wear agents and synthetic greases as the lubricant matrix. It can form a high-strength lubricating film even at low viscosity, resulting in cutting oil with excellent lubrication and cooling properties. This invention also avoids the use of additives that pose a corrosive risk to copper. Furthermore, it selects an appropriate proportion of corrosion inhibitors to protect copper alloys. In addition, this invention can suppress atomization and dispersion under high-speed cutting by using low-volatility base oils and other additives, or by selecting low-heat-sensitive substances and adding an appropriate proportion of anti-fogging agents, thereby reducing oil consumption and the risk of component contamination.

[0025] Of the above components, the oily phosphate ester can form a stable phosphate film under high temperature and high pressure conditions, effectively reducing the contact pressure on metal surfaces, preventing direct contact between metals, thereby improving lubrication and extending the service life of mechanical parts. The oily phosphate ester also maintains good stability under high temperature conditions, is not easily decomposed or fails, and is suitable for high-temperature working environments. Preferably, the oily phosphate ester includes one or more of isooctyl phosphate, isooctyl phosphite, oleyl phosphite, tricresyl phosphate, oleyl alcohol polyether phosphate, oleyl alcohol polyether phosphate, pentyl phosphate, and C18 alkyl phosphate.

[0026] The base oil not only provides lubrication but also forms an effective coating on the metal friction surface, providing protection and significantly reducing the risk of oxidation and corrosion of copper alloys. The base oil is preferably a high-flash-point refined mineral oil. Specifically, the base oil includes multiple types selected from 150N, 150SN, 100N, 100SN, 70N, 70SN, 60N, 60SN, Lu'an 3#, and PAO.

[0027] Synthetic esters can form a strong boundary oil film on friction surfaces, thereby reducing wear and scratches. When used in conjunction with extreme pressure anti-wear agents, they can also exert a synergistic effect. Preferably, the synthetic esters include a variety of isooctyl oleate, methyl ester, fatty acid methyl ester, trimethylolpropane oleate, isooctyl stearate, isooctyl cocoate, pentaerythritol ester, and dioctyl terephthalate.

[0028] Antioxidants form a protective film on the metal surface, isolating it from air and moisture, and slowing down the oxidation reaction of the metal, thereby preventing oxidation and corrosion during production and use. The choice of antioxidant can affect the quality and durability of the film formation; common types include phenols, amines, and organic acid salts. Preferably, the antioxidant is one or more of 2,6-di-tert-butylamino-p-cresol (T501), N-phenyl-α-naphthylamine, 2,6-di-tert-butyl-p-cresol, alkylphenhiazine, and 4,4-dioctyldiphenylamine.

[0029] Preferably, the corrosion inhibitor is a 1:1 mixture of a benzotriazole derivative and a sulfadiazole derivative. Benzotriazole has a good corrosion inhibition effect in alkaline environments, while sulfadiazole has a good corrosion inhibition effect in acidic environments.

[0030] Anti-oil misting agents are used to suppress the atomization and dispersion of lubricating oil in high-speed operating equipment. They reduce oil mist generation by altering the surface tension and viscoelasticity of the oil, thereby lowering the concentration of pollutants in the working environment, saving oil costs, and improving equipment safety. Anti-oil misting agents are high-molecular polymers (such as polyisobutylene, polymethyl methacrylate) or special surfactants that increase the cohesive force of the oil, making it difficult for oil droplets to break into micron-sized aerosol particles. Preferably, the anti-oil misting agent includes one or both of polyisobutylene PIB 2400 and polyisobutylene PIB 1300.

[0031] A second aspect of this invention provides a method for preparing a cutting oil, used to prepare the copper alloy-specific cutting oil described above, comprising the following steps:

[0032] S1. Mix the base oil and synthetic ester, and stir at room temperature until homogeneous and transparent to obtain a mixed solution;

[0033] S2. Slowly add antioxidants, corrosion inhibitors, and anti-oil misting agents to the mixed solution, and stir at 55-60°C until the solution is clear and transparent;

[0034] S3. Further add extreme pressure anti-wear agent to the mixed solution and stir evenly to obtain copper alloy special cutting oil.

[0035] The present invention will be further illustrated by specific embodiments and comparative examples below.

[0036] Example 1

[0037] A cutting oil specifically for copper alloys, comprising the following components by weight percentage:

[0038] 64.5% 150N, 22% 60N, 10% methyl oleate, 2% oleyl alcohol polyether phosphate, 0.2% T501, 0.3% benzotriazole derivative, 1% PIB2400;

[0039] The preparation method of copper alloy-specific cutting oil is as follows:

[0040] S1. Mix the base oil and synthetic ester, and stir at room temperature until homogeneous and transparent to obtain a mixed solution;

[0041] S2. Slowly add antioxidant, corrosion inhibitor, and anti-oil mist agent to the mixed solution, and stir at 58-60℃ until the solution is clear and transparent;

[0042] S3. Further add extreme pressure anti-wear agent to the mixed solution and stir evenly to obtain a special cutting oil for copper alloys.

[0043] Example 2

[0044] A cutting oil specifically for copper alloys, comprising the following components by weight percentage:

[0045] 69.5% 150N, 22% 60N, 5% methyl oleate, 2% oleyl alcohol polyether phosphate, 0.2% T501, 0.3% benzotriazole derivative, 1% PIB2400;

[0046] The preparation method is the same as in Example 1.

[0047] Comparative Example 1

[0048] A cutting oil specifically for copper alloys, comprising the following components by weight percentage:

[0049] 71.5% 150N, 22% 60N, 5% methyl oleate, 0.2% T501, 0.3% benzotriazole derivative, 1% PIB2400;

[0050] The preparation method is the same as in Example 1.

[0051] Comparative Example 2

[0052] A cutting oil specifically for copper alloys, comprising the following components by weight percentage:

[0053] 76.5% 150N, 22% 60N, 0.2% T501, 0.3% benzotriazole derivatives, 1% PIB2400;

[0054] The preparation method is the same as in Example 1.

[0055] Example 3

[0056] A cutting oil specifically for copper alloys, comprising the following components by weight percentage:

[0057] It consists of the following components by mass percentage: 76.5% 150SN, 15% 60N, 5% trimethylolpropane oleate, 2% tricresyl phosphate, 0.2% T501, 0.3% benzotriazole derivative, and 1% PIB2400.

[0058] The preparation method is the same as in Example 1.

[0059] Example 4

[0060] A cutting oil specifically for copper alloys, comprising the following components by weight percentage:

[0061] By mass percentage, it consists of the following components: 76.2% 150SN, 15% 60N, 5% trimethylolpropane oleate, 2% sulfurized olefin, 0.2% T501, 0.3% benzotriazole derivative, 0.3% pyridazole derivative, and 1% PIB2400.

[0062] The preparation method is the same as in Example 1.

[0063] Comparative Example 3

[0064] A cutting oil specifically for copper alloys, comprising the following components by weight percentage:

[0065] It consists of the following components by mass percentage: 76.5% 150SN, 15% 60N, 5% trimethylolpropane oleate, 2% sulfurized olefin, 0.2% T501, 0.3% benzotriazole derivative, and 1% PIB2400.

[0066] The preparation method is the same as in Example 1.

[0067] Comparative Example 4

[0068] A cutting oil specifically for copper alloys, comprising the following components by weight percentage:

[0069] It consists of the following components by mass percentage: 76.2% 150SN, 15% 60N, 5% trimethylolpropane oleate, 2% sulfurized olefin, 0.2% T501, 0.6% benzotriazole derivative, and 1% PIB2400.

[0070] The preparation method is the same as in Example 1.

[0071] The performance of the above embodiments and comparative examples was tested, including kinematic viscosity (40°C, mm). 2 The test methods for extreme pressure lubrication performance are as follows: Flash point (open cup, °C) (GB / T 3536, ASTM D92), Pour point ( °C) (GB / T 3535, ASTM D97), Copper strip corrosion (grade) (GB / T 5096, ASTM D130), Saponification value (mgKOH / g) (GB / T 5530), Aluminum strip corrosion (ADC12) (GB / T 6144), Cast iron strip corrosion (HT300) (GB / T 6144). The extreme pressure lubrication performance test method shall be performed according to GB / T12583-1998. Test instrument model: Xiamen Tianji MS-10A.

[0072] Table 1.1

[0073]

[0074]

[0075] Table 1.2

[0076]

[0077]

[0078] Comparing Examples 1, 2, Comparative Example 1, and Comparative Example 2 with Tables 1.1 and 1.2, it is evident that Example 1 exhibits the best lubrication performance, with the highest maximum non-seize load (PB) value. Example 2 shows the second best lubrication performance, indicating that a certain concentration of synthetic grease can effectively increase the oil film thickness and improve lubrication performance. Comparative Example 1 shows a significant decrease in lubrication performance compared to Example 2, demonstrating that phosphate esters can significantly enhance oil film strength and increase seize load. Comparative Example 2 exhibits the worst overall performance. Among the four oil samples, Example 1 has the lowest kinematic viscosity, at 20.32 mm⁻¹. 2 / s, as the content of 150N in the formula increases, the viscosity of the oil sample also increases accordingly, with the viscosity of Example 2 being 22.68 mm. 2 / s, Comparative Example 1 is 25.46mm 2 / s, Comparative Example 2 is 28.91mm 2 / s. Generally speaking, the higher the viscosity of an oil, the easier it is for an oil film to form during lubrication, resulting in better lubrication performance. However, high viscosity can also lead to poorer cooling performance. Compared with other comparative examples, Example 1 not only has the best lubrication performance but also the lowest viscosity, indicating that it has both good lubricity and cooling performance.

[0079] Table 1.3

[0080]

[0081]

[0082] Table 1.4

[0083]

[0084]

[0085] Comparing Examples 3, 4, Comparative Example 3, and Comparative Example 4 with Tables 1.3 and 1.4, Example 3 showed the best performance in metal corrosion tests, achieving the highest levels for copper sheet corrosion, aluminum sheet corrosion, and cast iron corrosion. This is because Example 3 does not contain substances that significantly corrode metals, and the polar groups of the base oil, synthetic ester, and phosphate ester adsorb onto the metal surface, providing a certain degree of protection against metal corrosion by isolating it from water and other substances in the air. Comparative Example 3 showed a copper corrosion result of 3c, indicating severe corrosion of copper. Generally, copper exhibits a more pronounced discoloration tendency compared to iron and aluminum, especially at high temperatures or in contact with specific additives (such as sulfur- or chlorine-containing extreme pressure anti-wear agents). The active compounds in these additives react with copper to form color-changing products, such as dark brown or green copper soap precipitates. Therefore, corrosion inhibitors are often added to oils to prevent copper discoloration and protect the copper surface. However, the test results of Comparative Example 3 show that even with the addition of a certain amount of metallic corrosion inhibitor, corrosion cannot be effectively prevented. In the design of copper alloy cutting oil formulations, active compounds that corrode copper should be avoided as much as possible. Based on Comparative Example 3, the content of the benzotriazole derivative was doubled to 0.6% to obtain Comparative Example 4. The copper corrosion result was 3a, showing some improvement, but the effect was limited. The copper corrosion result of Example 4 was 1b, indicating that using a mixture of benzotriazole and pyridazole derivatives in equal proportions at the same content resulted in a better corrosion inhibition effect than using either alone, effectively preventing copper discoloration.

[0086] Further comparing Examples 1-4, the copper alloy-specific cutting oils of Examples 1-3 also have the advantage of low odor.

[0087] It is understood that those skilled in the art can make equivalent substitutions or modifications to the technical solution and inventive concept of the present invention, and all such substitutions or modifications should fall within the protection scope of the appended claims.

Claims

1. A cutting oil specifically for copper alloys, characterized in that, By mass percentage, it comprises the following components: 80%–91.5% base oil, 5%–15% synthetic ester, 2%–5% extreme pressure anti-wear agent, 0.1%–0.5% antioxidant, 0.3%–0.6% corrosion inhibitor, and 1%–3% anti-oil mist agent; wherein the extreme pressure anti-wear agent includes oily phosphate ester; and the corrosion inhibitor includes benzotriazole derivatives.

2. The copper alloy-specific cutting oil according to claim 1, characterized in that, The base oils include a variety of 150N, 150SN, 100N, 100SN, 70N, 70SN, 60N, 60SN, Lu'an 3#, and PAO.

3. The copper alloy-specific cutting oil according to claim 1, characterized in that, The synthetic esters include a variety of isooctyl oleate, methyl oleate, fatty acid methyl ester, trimethylolpropane oleate, isooctyl stearate, isooctyl cocoate, pentaerythritol ester, and dioctyl terephthalate.

4. The copper alloy-specific cutting oil according to claim 1, characterized in that, The oleic phosphate esters include one or more of isooctyl phosphate ester, isooctyl phosphite ester, oleo-based phosphite ester, tricresyl phosphate ester, oleyl alcohol polyether phosphate ester, oleyl alcohol polyether phosphate ester, pentyl phosphate ester, and C18 alkyl phosphate ester.

5. The copper alloy-specific cutting oil according to claim 1, characterized in that, The antioxidant is one or more of 2,6-di-tert-butylamino-p-cresol, N-phenyl-α-naphthylamine, 2,6-di-tert-butyl-p-cresol, alkylphenthiazide, and 4,4-dioctyldiphenylamine.

6. The copper alloy-specific cutting oil according to claim 1, characterized in that, The corrosion inhibitor is a 1:1 mixture of benzotriazole derivatives and thiamethoxam derivatives.

7. The copper alloy-specific cutting oil according to claim 1, characterized in that, The anti-oil mist agent includes one or both of polyisobutylene PIB 2400 and polyisobutylene PIB 1300.

8. The copper alloy-specific cutting oil according to claim 1, characterized in that, By mass percentage, it consists of the following components: 64.5% 150N, 22% 60N, 10% methyl oleate, 2% oleyl alcohol polyether phosphate, 0.2% T501, 0.3% benzotriazole derivative, and 1% PIB2400.

9. The copper alloy-specific cutting oil according to claim 1, characterized in that, By mass percentage, it consists of the following components: 76.5% 150SN, 15% 60N, 5% trimethylolpropane oleate, 2% tricresyl phosphate, 0.2% T501, 0.3% benzotriazole derivative, and 1% PIB2400.

10. A method for preparing a cutting oil, characterized in that, The method for preparing the copper alloy-specific cutting oil as described in any one of claims 1-9 comprises the following steps: The base oil and synthetic ester are mixed and stirred at room temperature until homogeneous and transparent to obtain a mixed solution; Slowly add antioxidants, corrosion inhibitors, and anti-oil mist agents to the mixed solution, and stir at 55-60°C until the solution is clear and transparent; Further, an extreme pressure anti-wear agent was added to the mixed solution and stirred evenly to obtain a special cutting oil for copper alloys.

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