Corrosion inhibitor, high-efficiency lubricating water-based cutting fluid and application thereof

Abstract

The application relates to the field of cutting fluids, and discloses an inhibitor, a high-efficiency lubricating water-based cutting fluid and application thereof. A long-chain alkyl phosphate betaine is selected as a key inhibitor. Phosphate anions and quaternary ammonium salt cations in the molecule can be firmly adsorbed on metal surfaces with different electricities, and long-chain alkyls can form a dense hydrophobic layer on the metal surface, laying a foundation for multi-metal compatibility. The inhibitor has a synergistic effect with a semi-synthetic composite lubricating system. In addition, the system uses a thiophosphate and an organic phosphonic acid to be compounded as extreme pressure anti-wear agents. In the absence of chlorine and boron, the extreme pressure anti-wear agents can form a high-strength chemical reaction film with the above-mentioned adsorption film under extreme pressure conditions, so that the carrying capacity is further improved.

Description

Technical Field

[0001] This invention relates to the field of cutting fluids, and particularly to a corrosion inhibitor, a high-efficiency lubricating water-based cutting fluid, and their applications. Background Technology

[0002] With the transformation and upgrading of the manufacturing industry, product components in fields such as aerospace and precision instruments are becoming increasingly complex, mainly composed of difficult-to-machine materials such as titanium alloys, high-temperature alloys, and high-hardness steel combined with lightweight, high-thermal-conductivity metals such as aluminum alloys and copper alloys. These complex product components place higher comprehensive demands on cutting fluids used in machining processes: they must not only meet the ultra-high lubricity and extreme pressure anti-wear properties required by difficult-to-machine materials to overcome problems such as tool sticking and work hardening and protect expensive tools; they must also possess excellent multi-metal compatibility, effectively preventing corrosion and discoloration of active metals such as aluminum and copper, while meeting inter-process rust prevention requirements; furthermore, they must comply with increasingly stringent global environmental regulations and occupational health standards to meet international compliance requirements for product exports.

[0003] Currently, technological research and development in this field mainly revolves around the core contradiction of balancing performance and environmental protection. Most existing solutions achieve performance targets through the combination of multiple functional additives, but significant limitations remain. To pursue extreme pressure performance, some solutions still rely on specific types of sulfur-phosphorus compound systems. While this avoids explicit chlorine-based additives, the active sulfur in these systems can corrode copper alloys, and insufficient lubrication is still felt in the machining of high-hardness alloys. To achieve multi-metal rust prevention, formulations often require the introduction of multiple targeted corrosion inhibitors, such as copper, aluminum, and steel corrosion inhibitors. This "cocktail-like" formulation easily leads to complex formulations, antagonistic effects between components, poor long-term stability, and the potential introduction of substances restricted by environmental regulations. More importantly, existing technologies often focus on solving a single performance aspect (such as specializing in lubrication for titanium alloy machining or focusing on aluminum-copper rust prevention), lacking a fundamental solution that can uniformly address the three major issues of lubrication, protection, and environmental protection at the molecular design level. This makes it difficult to truly meet the general needs of modern multi-material, green machining centers.

[0004] In summary, existing water-based cutting fluid technologies have the following significant shortcomings: First, it is difficult to achieve both high performance and broad compatibility. Fluids specifically designed for difficult-to-machine materials often pose a high risk of corrosion to aluminum and copper, while those compatible with aluminum and copper often perform poorly under extreme lubrication conditions. Second, environmental compliance has become a bottleneck. Although the industry has recognized and avoided the use of clearly restricted substances such as chlorinated paraffins, certain alternative additives used to achieve performance (such as certain boron and amine compounds) may still face potential restrictions from environmental regulations and export markets. Third, the formulation system has poor synergy. Simply mixing multiple additives physically cannot achieve a synergistic effect of "1+1>2" and may instead lead to stability problems.

[0005] To address the above-mentioned industry pain points, this invention aims to break through traditional thinking by introducing an innovative core component and designing a brand-new compounding system, fundamentally developing a general-purpose water-based cutting fluid that combines ultra-high lubricity, multi-metal compatibility, and inherent environmental friendliness. Summary of the Invention

[0006] In view of the shortcomings of the prior art, the purpose of this invention is to provide a high-performance, environmentally friendly water-based cutting fluid based on a multifunctional zwitterionic corrosion inhibitor. Long-chain alkyl phosphate betaine is selected as the key corrosion inhibitor. The phosphate anions and quaternary ammonium cations in its molecule can be firmly adsorbed onto metal surfaces with different electrical charges, while the long-chain alkyl group can form a dense hydrophobic layer on the metal surface, laying the foundation for multi-metal compatibility. This specific structure has a synergistic effect with the semi-synthetic composite lubrication system (a compound of oxidized vegetable oil / hydroxy fatty acid ester and synthetic ester) used in this invention. This lubrication system not only has good lubricity itself, but its polar groups can also work together with the betaine corrosion inhibitor to make the adsorption film more robust and complete, thereby significantly improving rust prevention performance and lubrication durability. Furthermore, this system uses a high molecular weight thiophosphate compound with environmentally friendly organophosphonic acid as an extreme pressure anti-wear agent. Without chlorine or boron, it can form a high-strength chemical reaction film with the above-mentioned adsorption film under extreme pressure conditions, further enhancing the load-bearing capacity. The entire system is supplemented with specific emulsifiers, rust inhibitors, hard water inhibitors, bactericides, and defoamers. All materials are screened in strict accordance with the limits of hazardous substances in environmental regulations to ensure the inherent environmental friendliness and export compliance of the formula.

[0007] To achieve the above objectives, the present invention adopts the following technical solution:

[0008] A corrosion inhibitor, wherein the corrosion inhibitor is a long-chain alkyl phosphate betaine, and its general molecular formula is: C x H 2x+1 -O-PO3 2- -(CH2) n -N + (R1R2R3); where the alkyl chain C x H 2x+1 The number of carbon atoms x is 14–22; an alkylene chain (CH2) connecting the phosphate group and the quaternary ammonium group. n n can be 2, 3, or 4.

[0009] The corrosion inhibitor, wherein the alkyl chain C x H 2x+1 The number of carbon atoms x is 16–18; alkylene chain (CH2) n n is 2 or 3.

[0010] A high-efficiency water-based cutting fluid, calculated per 100 parts, comprises the following components: base oil: 20-25 parts; a composite lubricant composed of oxidized vegetable oil, hydroxy fatty acid esters, and synthetic esters: 20-30 parts; an extreme pressure anti-wear agent composed of thiophosphate esters and organophosphonic acids: 3-5 parts; a corrosion inhibitor: 2-4 parts; an emulsifier: 2-4 parts; a pH adjuster: 8-10 parts; a rust inhibitor: 3-5 parts; a biological stabilizer: 5-7 parts; an anti-hard water agent: 2-3 parts; a defoamer: 0.001-0.002 parts; and the balance being deionized water.

[0011] The high-efficiency lubricating water-based cutting fluid, wherein the base oil is a naphthenic base oil.

[0012] The high-efficiency lubricating water-based cutting fluid, wherein the oxidized vegetable oil is one of oxidized rapeseed oil, oxidized palm oil, and oxidized soybean oil; the hydroxy fatty acid ester is tetrameric castor oil ester; and the synthetic ester is a compound product of trimethylolpropane oleate and pentaerythritol oleate.

[0013] The high-efficiency lubricating water-based cutting fluid, wherein the emulsifier is a mixture of oleic acid and polyethylene glycol.

[0014] The high-efficiency lubricating water-based cutting fluid, wherein the pH adjuster is one or two of methyldiethanolamine and triethanolamine; and the rust inhibitor is a mixed dicarboxylic acid.

[0015] The high-efficiency lubricating water-based cutting fluid, wherein the biological stabilizer is a bactericide composed of 1,2-benzisothiazolin-3-one, 2-methyl-4-isothiazolin-3-one and 3-iodo-2-propynyl-N-n-butylcarbamate.

[0016] The high-efficiency lubricating water-based cutting fluid, wherein the anti-hard water agent is an ether carboxylic acid polymer; and the defoamer is one of a polyether defoamer or an organosilicon defoamer.

[0017] An application of a high-efficiency lubricating water-based cutting fluid: applying the above-mentioned high-efficiency lubricating water-based cutting fluid to the machining of titanium alloys, high-temperature alloys, aluminum alloys, and copper alloys.

[0018] Beneficial effects:

[0019] This invention provides a high-performance, environmentally friendly water-based cutting fluid constructed based on a multifunctional zwitterionic corrosion inhibitor. Long-chain alkyl phosphate betaine is selected as the key corrosion inhibitor. The phosphate anions and quaternary ammonium cations in its molecule can be firmly adsorbed onto metal surfaces with different electrical charges, while the long-chain alkyl group can form a dense hydrophobic layer on the metal surface, laying the foundation for multi-metal compatibility. This specific structure has a synergistic effect with the semi-synthetic composite lubrication system (a compound of oxidized vegetable oil / hydroxy fatty acid ester and synthetic ester) used in this invention. This lubrication system not only has good lubricity itself, but its polar groups also work together with the betaine corrosion inhibitor to make the adsorption film more robust and complete, thereby significantly improving rust prevention performance and lubrication durability. Furthermore, this system uses a high-molecular-weight thiophosphate compound with environmentally friendly organophosphonic acid as an extreme pressure anti-wear agent. Without chlorine or boron, it can form a high-strength chemical reaction film with the above-mentioned adsorption film under extreme pressure conditions, further enhancing the load-bearing capacity. The entire system is supplemented with specific emulsifiers, rust inhibitors, hard water inhibitors, bactericides, and defoamers. All materials are screened in strict accordance with the limits of hazardous substances in environmental regulations to ensure the inherent environmental friendliness and export compliance of the formula.

[0020] The high-efficiency lubricating water-based cutting fluid provided by this invention brings the following technical effects: First, it achieves exceptional lubrication extreme pressure performance, with low friction coefficient and low extreme pressure carrying capacity (P). B / P D Key performance indicators such as tapping torque are comparable to traditional high-performance chlorine-containing additives, effectively extending tool life and improving workpiece surface quality, especially suitable for difficult-to-machine materials such as titanium alloys and high-temperature alloys; secondly, it has excellent multi-metal compatibility, providing uniform and reliable corrosion protection for aluminum alloys, copper alloys and steel products simultaneously, meeting the needs of mixed machining of multi-material workpieces; finally, it ensures inherent environmental protection and safety characteristics, the product is non-toxic and easily degradable, and fully avoids environmental regulations and market access risks. Detailed Implementation

[0021] This invention provides a corrosion inhibitor, a high-efficiency lubricating water-based cutting fluid, and their applications. To make the objectives, technical solutions, and effects of this invention clearer and more explicit, the following embodiments are provided to further illustrate the invention in detail. It should be understood that the specific embodiments described herein are only for explaining the invention and are not intended to limit the scope of protection of the invention.

[0022] This invention provides a corrosion inhibitor, wherein the corrosion inhibitor is a long-chain alkyl phosphate betaine, and its general molecular structure can be illustrated as: C x H 2x+1 -O-PO3 2- -(CH2) n -N + (R1R2R3); Alkyl chain C x H2x+1 The number of carbon atoms x is 14–22; an alkylene chain (CH2) connecting the phosphate group and the quaternary ammonium group. n n can be 2, 3, or 4.

[0023] The mechanism of action and direct effects of the corrosion inhibitor provided by this invention are as follows:

[0024] For aluminum alloys: negatively charged phosphate ions (-PO3) in the molecule 2- Through electrostatic interaction, it preferentially adsorbs onto the positively charged aluminum oxide film surface in an alkaline environment, and its long-chain alkyl groups form a dense hydrophobic layer outward, thus giving the corrosion inhibitor excellent anti-pitting and anti-white rust effects on aluminum alloys.

[0025] For copper alloys: The entire molecule is electrically neutral in solution, avoiding electrochemical displacement reactions with copper. The corrosion inhibitor is uniformly coated on the copper surface through physical adsorption, forming an effective isolation barrier and improving the copper alloy's resistance to discoloration and loss of luster.

[0026] For steel: its quaternary ammonium cation (-N) + (R1R2R3) can be physically adsorbed onto the surface of steel to help prevent rust.

[0027] Synergistic lubrication: The highly polar functional groups provided by corrosion inhibitors can align together with lubricant molecules in water-based cutting fluids on the metal surface, enhancing and stabilizing the boundary lubrication film.

[0028] Specifically, alkyl chain C x H 2x+1 The number of carbon atoms (x) in the medium-chain alkyl group is 16-18, and the alkyl chain can be saturated (e.g., hexadecyl, octadecyl) or unsaturated (e.g., oleylene). Longer alkyl chains can provide sufficiently strong hydrophobicity and steric hindrance on the metal surface, thereby forming a denser and more stable protective film. However, when using short-chain alkyl (C8-C12) phosphate betaines, the hydrophobicity decreases and the water solubility increases, resulting in poorer overall corrosion inhibition performance and multi-metal compatibility compared to long-chain alkyl phosphate betaines. More specifically, the long-chain alkyl phosphate betaine described in this invention can be selected from, but is not limited to, one of: tetradecyl dimethyl hydroxypropyl phosphate betaine, hexadecyl dimethyl hydroxypropyl phosphate betaine, and octadecyl dimethyl hydroxypropyl phosphate betaine. In addition, the phosphate anions and quaternary ammonium salt cations in the long-chain alkyl phosphate betaine molecules can be firmly adsorbed onto metal surfaces with different electrical charges, while the long-chain alkyl groups form a dense physical protective film on the metal surface through hydrophobic interactions, effectively preventing the intrusion of moisture and corrosive media, thereby improving the anti-corrosion effect.

[0029] Specifically, alkylene chains (CH2) nIn this context, n is either 2 or 3. These two preferred chain lengths offer an optimal balance between molecular flexibility and steric hindrance, ensuring effective adsorption of zwitterionic end groups on the metal surface.

[0030] This invention also provides a high-efficiency water-based cutting fluid, comprising the following components by weight: base oil: 20-25 parts; a composite lubricant composed of oxidized vegetable oil, hydroxy fatty acid esters, and synthetic esters: 20-30 parts; an extreme pressure anti-wear agent composed of high molecular weight thiophosphate esters and environmentally friendly organophosphonic acids: 3-5 parts; a corrosion inhibitor: 2-4 parts; an emulsifier: 2-4 parts; a pH adjuster: 8-10 parts; a rust inhibitor: 3-5 parts; a biological stabilizer: 5-7 parts; an anti-hard water agent: 2-3 parts; a defoamer: 0.001-0.002 parts; and the balance being deionized water.

[0031] The basic lubrication component of this system mainly consists of base oil, compound lubricant, and extreme pressure anti-wear agent, aiming to provide effective lubrication protection throughout the entire process from low temperature to high temperature (mainly provided by base oil and compound lubricant) and from normal to extreme pressure (mainly affected by the synergistic effect of base oil, compound lubricant, and extreme pressure anti-wear agent).

[0032] The base oil, acting as an oil phase carrier, provides a uniformly dispersed carrier for other oil-soluble components in the system, ensuring consistent distribution of each component within the system. It can also work in conjunction with emulsifiers in the system to quickly encapsulate and form a stable oil-in-water (O / W) emulsion. At the same time, the base oil itself has a certain degree of oiliness, which, in synergy with the composite lubricant, can improve lubrication performance.

[0033] The composite lubricant used is a composite lubricant system composed of natural ester oiliness agent and synthetic ester lubricant. Natural ester provides oiliness and friction reduction effect under normal to medium temperature and low load conditions, while synthetic ester provides thermal stability and anti-wear protection under medium to high temperature and extremely high load conditions, so as to achieve continuous and effective lubrication over a wide temperature range and multiple working conditions, which is the key to realizing the universal machining of multiple metals.

[0034] An environmentally friendly extreme pressure anti-wear compound system is formed by compounding high molecular weight thiophosphates (such as triphenyl thiophosphates and primary alcohol thiophosphates) with environmentally friendly organophosphonic acids (such as ASI80, or other environmentally friendly organophosphonic acid derivatives with corrosion-inhibiting functions). In this system, the sulfur and phosphorus atoms in the high molecular weight thiophosphates are firmly bound to the molecular framework, making them difficult to decompose under normal conditions and non-corrosive to non-ferrous metals such as copper. However, at friction contact points under extreme pressure and temperature, it can provide necessary extreme pressure protection, decomposing and releasing active sulfur and phosphorus elements, which react with the metal surface to form a soft, layered sulfide / phosphide chemical film. Specifically, the high molecular weight (400–600 g / mol) of the thiophosphates results in low chemical activity, slowing down the corrosion rate of copper alloys. The organophosphonic acids, while providing phosphorus-based extreme pressure properties, have -PO3H2 groups in their molecules that can be firmly anchored to the metal surface through chemisorption, providing extreme pressure anti-wear performance and a certain degree of corrosion inhibition.

[0035] Synergistic extreme pressure lubrication mechanism: The two extreme pressure agents mentioned above, together with long-chain alkyl phosphate betaine and composite base lubricants, work together to construct a high-strength, multi-layered composite protective film on the metal surface through adsorption synergy and tribochemical synergy. Betaine and synthetic esters provide a strong physical adsorption base layer, while the extreme pressure agents react under high pressure to generate a chemical film to supplement it, enabling the system to achieve exceptional extreme pressure anti-wear performance.

[0036] Environmental protection statement: The selected triphenyl thiophosphate is a high molecular weight product, and its potential ecotoxicity is lower than that of small molecule analogs, and it does not contain heavy metals.

[0037] Base oil: Naphthenic base oil is used. Due to its easy emulsification properties, naphthenic base oil is highly compatible with components such as emulsifiers and complex lubricants in the system, forming a stable oil-in-water emulsion and providing a uniformly dispersed carrier for lubricating and extreme pressure components.

[0038] In this embodiment, the oxidized vegetable oil is one of oxidized rapeseed oil, oxidized palm oil, and oxidized soybean oil; the hydroxy fatty acid ester is tetrameric castor oil ester; and the synthetic ester is a compound product of trimethylolpropane oleate (TMPTO) and pentaerythritol oleate (PETO). Both the oxidized vegetable oil and tetrameric castor oil ester possess excellent lubricity; increasing the amount of either substance alone cannot further improve the lubrication effect. However, the combination of these two substances, containing a large number of polar functional groups and long-chain fatty acid structures, can mutually promote the formation of a stronger, more uniform, and dense adsorption film on the metal surface, effectively reducing the coefficient of friction. Furthermore, when either substance is used alone, the adsorption film may be relatively uneven or weak, preventing a further reduction in the coefficient of friction.

[0039] Both TMPTO and PETO are structurally regular synthetic esters. TMPTO exhibits superior thermal and hydrolytic stability, along with high molecular film strength, enabling it to maintain the integrity of the lubricating film at higher temperatures. PETO, on the other hand, has greater steric hindrance, allowing it to maintain lubrication performance under high pressure.

[0040] Throughout the processing, at low temperatures and light loads, the natural ester combination primarily functions, resulting in an extremely low coefficient of friction. As the temperature rises and the load increases, the adsorption film of the natural ester begins to weaken, but at this point, the synthetic ester combination begins to demonstrate its advantages in thermal stability and high film strength, dominating lubrication. Under extreme pressure conditions, extreme pressure agents such as high molecular weight thiophosphates play a role, synergistically working with the robust lubricating film formed by the synthetic esters to generate a high-strength chemical reaction film.

[0041] Accessibility features:

[0042] Emulsification and auxiliary lubrication system: A mixture of oleic acid and polyethylene glycol (such as PEG-400) is used. Both can undergo partial esterification to form a lubricating ester, or they can synergistically adsorb at the oil-water interface, achieving a triple effect of emulsification, lubrication, and friction reduction. The emulsifier can also be replaced by a combination of other nonionic surfactants (such as sorbitan esters and alkyl glucosides) and auxiliary lubricants.

[0043] pH Adjustment and Rust Prevention: Methyldiethanolamine (MDEA) is used, its alkalinity adjusting the system pH to 9.0–9.5. Compared to triethanolamine (TEA), MDEA has a higher "alkali reserve" (providing more alkaline molecules per unit mass), maintaining system pH stability more economically and effectively. It also possesses rust-preventive properties and avoids environmental risks such as the formation of boric acid and secondary amines. Alternatively, a combination of TEA and MDEA can be used to balance alkali reserve and cost, or a composite system of organic amines (such as AMP-95) and inorganic alkalis (such as potassium carbonate) can be employed.

[0044] Rust prevention enhancement: The addition of mixed dicarboxylic acid GM1 enhances the inter-process rust prevention ability of cast iron and steel, and has good biodegradability. The mixed dicarboxylic acid can also be replaced by single dimer acid, azelaic acid, sebacic acid, etc., or a carboxylic acid rust inhibitor (such as lauroyl sarcosine) can be compounded with the dicarboxylic acid.

[0045] Biostabilization System: The biostabilizer is a fungicide composed of 1,2-benzisothiazolin-3-one (BIT), 2-methyl-4-isothiazolin-3-one (MIT), and 3-iodo-2-propynyl-N-n-butylcarbamate (IPBC). The three components have complementary mechanisms of action and synergistic effects, giving the product long-lasting resistance to microbial spoilage while avoiding the toxicity and irritation issues of formaldehyde-releasing fungicides. The proportions of the three components in the above BIT / MIT / IPBC compound system can be adjusted according to local regulations and resistance conditions, or other highly effective and low-toxicity fungicides (such as sodium pyrithione) can be used for partial substitution.

[0046] Anti-hard water agent: Ether carboxylic acid polymers (such as 4570LF) are selected as anti-hard water agents. These polymers contain both ether bonds and carboxyl groups in their molecular chains, which can efficiently complex calcium, magnesium, and other metal ions through lattice distortion and dispersion effects, preventing them from reacting with soap emulsifiers (such as oleic acid) in the system to form insoluble metal soaps. This effectively avoids solution turbidity, stratification, and decreased lubrication performance caused by hard water. Compared to traditional small-molecule chelating agents such as EDTA, this type of high-molecular-weight anti-hard water agent is less likely to increase system foaming and has better environmental characteristics.

[0047] Defoaming system: Polyether defoamers or silicone defoamers are selected as defoamers. Modified silicone defoamers can be used on the premise of ensuring that the surface coating is not affected, but modified polyether defoamers are the best choice. Polyether defoamers have good compatibility with the system, long-lasting foam suppression, and can avoid the "silicone spots" on the workpiece surface and environmental pollution problems that silicone defoamers may cause.

[0048] This invention also provides an application of a high-efficiency lubricating water-based cutting fluid, which is used to process titanium alloys, high-temperature alloys, aluminum alloys, and copper alloys.

[0049] To further illustrate the corrosion inhibitor, high-efficiency lubricating water-based cutting fluid and their applications provided by the present invention, the following examples and comparative examples, as well as performance tests, are provided.

[0050] Example 1

[0051] A high-efficiency lubricating water-based cutting fluid, calculated per 100 parts, comprises the following components: base oil (26# naphthenic base oil): 25 parts; oxidized vegetable oil (oxidized rapeseed oil): 10 parts; tetrameric castor oil oleate ML-4: 4 parts; trimethylolpropane oleate TMPTO: 7 parts; pentaerythritol oleate PETO: 5 parts; triphenyl thiophosphate: 1.5 parts; 1-octylphosphonic acid ASI80: 2 parts; corrosion inhibitor (hexadecyl dimethyl hydroxypropyl phosphate betaine MZI): 3 parts; emulsifier (oleic acid + PEG400): 3 parts; pH adjuster (methyl diethanolamine MDEA): 10 parts; rust inhibitor (mixed dicarboxylic acid rust inhibitor): 4 parts; biological stabilizer (BIT + MIT + IPBC30): 5.5 parts; anti-hard water agent (ether carboxylic acid polymer 4570LF): 2 parts; defoamer (1875): 0.001 parts; and the balance being deionized water.

[0052] Example 2

[0053] A high-efficiency lubricating water-based cutting fluid, calculated per 100 parts, comprises the following components: base oil (26# naphthenic base oil): 20 parts; oxidized vegetable oil (oxidized soybean oil): 8 parts; tetrameric castor oil oleate ML-4: 3 parts; trimethylolpropane oleate TMPTO: 6 parts; pentaerythritol oleate PETO: 4 parts; triphenyl thiophosphate: 2 parts; 1-octylphosphonic acid ASI80: 1.5 parts; corrosion inhibitor (octadecyl dimethyl hydroxypropyl phosphate betaine): 3 parts; emulsifier (oleic acid + PEG400): 3 parts; pH adjuster (methyl diethanolamine MDEA): 8 parts; rust inhibitor (mixed dicarboxylic acid rust inhibitor): 3 parts; biological stabilizer (BIT + MIT + IPBC30): 6 parts; anti-hard water agent (ether carboxylic acid polymer 4570LF): 2.5 parts; defoamer (1875): 0.002 parts; and the balance being deionized water.

[0054] Example 3

[0055] A high-efficiency lubricating water-based cutting fluid, calculated per 100 parts, comprises the following components: base oil (26# naphthenic base oil): 25 parts; oxidized vegetable oil (oxidized rapeseed oil): 10 parts; tetrameric castor oil oleate ML-4: 5 parts; trimethylolpropane oleate TMPTO: 9 parts; pentaerythritol oleate PETO: 6 parts; triphenyl thiophosphate: 1.5 parts; 1-octylphosphonic acid ASI80: 2 parts; corrosion inhibitor (tetradecyl dimethyl hydroxypropyl phosphate betaine): 3 parts; emulsifier (oleic acid + PEG400): 4 parts; pH adjuster (methyl diethanolamine MDEA): 9 parts; rust inhibitor (mixed dicarboxylic acid rust inhibitor): 5 parts; bio-stabilizer (BIT + MIT + IPBC30): 5.5 parts; anti-hard water agent (ether carboxylic acid polymer 4570LF): 2.5 parts; defoamer (1875): 0.001 parts; and the balance being deionized water.

[0056] Comparative Example 1

[0057] The corrosion inhibitor used was dodecyl dimethyl hydroxypropyl phosphate betaine, and the other conditions were the same as in Example 1.

[0058] Comparative Example 2

[0059] The corrosion inhibitor used was tetratetramethyldimethylhydroxypropyl phosphate betaine, and the other conditions were the same as in Example 1.

[0060] Comparative Example 3

[0061] The corrosion inhibitor used was an amphoteric low molecular weight water-soluble polymer: sodium polyaspartate, and other aspects were the same as in Example 1.

[0062] Comparative Example 4

[0063] The corrosion inhibitor used was a non-phosphate ester type zwitterionic surfactant: sulfobetaine, and the other properties were the same as in Example 1.

[0064] Comparative Example 5

[0065] The corrosion inhibitor from Example 1 was not added; otherwise, it was the same as in Example 1.

[0066] Comparative Example 6

[0067] The lubricant in Comparative Example 6 was 14 parts oxidized rapeseed oil and 12 parts trimethylolpropane oleate (TMPTO), and the rest was the same as in Example 1.

[0068] Comparative Example 7

[0069] The lubricant in Comparative Example 7 consisted of 12 parts oxidized rapeseed oil, 6 parts tetrameric castor oil ester ML-4, and 8 parts trimethylolpropane oleate TMPTO, with the other components the same as in Example 1.

[0070] Comparative Example 8

[0071] The water-based cutting fluid of Comparative Example 8 includes the following components: the extreme pressure anti-wear agent used is 4 parts of chlorinated paraffin, and the others are the same as in Example 1.

[0072] Comparative Example 9

[0073] The extreme pressure anti-wear agent used in Comparative Example 9 was 3.5 parts of triphenyl thiophosphate, and the other aspects were the same as in Example 1.

[0074] Comparative Example 10

[0075] Comparative Example 10 used 3.5 parts of 1-octylphosphonic acid ASI80 as the extreme pressure anti-wear agent, and the rest was the same as in Example 1.

[0076] Performance testing

[0077] The cutting fluids prepared in each embodiment and each comparative example were diluted with deionized water at a concentration of 5%.

[0078] 1. Lubrication extreme pressure performance test

[0079] Four-ball test (GB / T 3142): Verification of the stability of lubricating film over a wide temperature range

[0080] Experimental Design: To verify that the "compound of oxidized vegetable oil / tetrameric ricinoleate and TMPTO / PETO" can maintain stable lubrication over a wide temperature range, and the "compound of high molecular weight thiophosphate and environmentally friendly organophosphonic acid" improves extreme pressure performance, four-ball experiments (GB / T 3142) were conducted at room temperature (25℃) and high temperature (75℃). The high-temperature experiment simulated the high-temperature environment of the cutting zone.

[0081]

[0082] Data Analysis and Conclusions:

[0083] The embodiments provided by this invention can maintain extremely high P values ​​even at a high temperature of 75°C. B / P D The small wear scar diameter and low wear value indicate that the composite lubrication system has excellent wide-temperature stability and high-temperature lubrication retention capability.

[0084] The lubrication performance of Comparative Examples 1 and 2 was significantly lower than that of the Example 3, and the lubrication performance of Examples 1-2 was slightly better than that of Example 3, indicating that an unsuitable alkyl chain length will cause P B Value and P D Value downgraded.

[0085] The data from Comparative Example 3 show that the existing water-soluble polymer corrosion inhibitors exhibit the worst synergy with the oil-phase lubrication system, resulting in poor extreme pressure performance (P...). D ) and abrasion resistance (P B All of them have been downgraded to a lower level, which cannot meet the needs of high-performance processing.

[0086] Comparative Example 4 added amphoteric surfactant, P D The value remained at the highest level of 400 kgf, consistent with the example, but due to the lack of phosphate, its P... B The value dropped by one level, and the wear marks became larger, indicating that the strength of its adsorption membrane was insufficient.

[0087] Comparative Example 5 showed more significant performance degradation at high temperatures, indicating that the absence of MZI weakened the overall thermal stability and adsorption strength of the lubrication system. This demonstrates that long-chain alkyl phosphate betaine is an essential technical feature of this invention, and its absence leads to the failure of the lubrication synergy system.

[0088] The performance of Comparative Example 7 was superior to that of Comparative Example 6, indicating a significant synergistic effect between the natural and synthetic esters. Furthermore, the significant performance degradation in both Comparative Examples 6 and 7 demonstrates that the combination of natural and polyol esters provided by this invention is essential for maintaining high performance.

[0089] Comparative Example 9 showed acceptable extreme pressure properties but insufficient wear resistance; Comparative Example 8 showed decreased extreme pressure properties and lubrication continuity; Comparative Example 10 showed severely insufficient extreme pressure properties, which is sufficient to demonstrate the importance of compounding high molecular weight thiophosphates with environmentally friendly organophosphonic acids.

[0090] 2. Drilling experiment: Tool life verification

[0091] Experimental Design: Drilling experiments were conducted on titanium alloy (TC4) and high-temperature alloy (GH4169) test blocks using a φ6mm carbide drill bit, based on actual machining conditions. Parameters: Rotation speed 2500 rpm, feed rate 100 mm / min, through hole, hole depth 20 mm, using a pecking drill method (single drill depth 6 mm). The total number of holes that could be machined when the tool wear VB reached 0.3 mm was used as the criterion for tool life, and the VB value was measured after the experiment.

[0092]

[0093] Data Analysis and Conclusions:

[0094] When machining two difficult-to-machine materials, the embodiments provided by this invention can significantly extend tool life (by more than 30%). The drilling life data ranking is consistent with the aforementioned four-ball experiment.

[0095] The key role of the core corrosion inhibitor MZI: The tool life of Comparative Example 5 was the lowest in both materials, which once again proves that long-chain alkyl phosphate betaine MZI is crucial for maintaining the protection of tools under long-term, high-temperature friction.

[0096] Examples > Comparative Example 4 > Comparative Examples 1 & 2 > Comparative Example 3 > Comparative Example 5 demonstrate that the specific adsorption of phosphate groups is superior to other adsorption mechanisms for protecting cutting tools during dynamic cutting.

[0097] The tool life of Comparative Example 7 was slightly higher than that of Comparative Example 6, but both were much lower than those of the Example, indicating that the combination of natural esters and polyol esters is the key to obtaining excellent tool life.

[0098] Comparative Example 9 showed a longer lifespan than the chlorine-containing baseline (Comparative Example 8), but shorter than the Example 10, indicating that a single extreme pressure agent cannot achieve the comprehensive protective effect of the compound system. Comparative Example 10's lifespan was even shorter than the chlorine-containing baseline, proving that its extreme pressure properties were insufficient to handle difficult-to-process materials alone.

[0099] 3. Corrosion resistance test

[0100] (1) Multimetal semi-immersion corrosion test

[0101] Experimental Design: A multi-metal semi-immersion corrosion test was conducted according to GB / T 6144. Easily corroded aluminum alloy (ADC12, 5052, 6061, 7050) and copper alloy (T2) specimens were vertically inserted into the diluent, with half of the specimen submerged and the other half exposed to air. After being placed at 55℃ for 24 hours, the specimens were removed, and the corrosion above and below the liquid surface was observed and evaluated according to national standards. This method is more stringent than full immersion.

[0102]

[0103] Conclusion: The embodiments provided by this invention exhibit perfect protection against both aluminum and copper in the stringent semi-immersion test, demonstrating their excellent multi-metal compatibility and reliability under real-world conditions.

[0104] Data Analysis and Conclusions:

[0105] All examples (1-3) achieved Grade A for all metals and in all test locations (full immersion / underwater / on-water), demonstrating that the complete system containing MZI has excellent corrosion inhibition properties for copper and aluminum alloys.

[0106] In Comparative Example 5, the phosphonic acid group adsorption provided by ASI80 ensured that it achieved Class B corrosion inhibition for aluminum alloys in the liquid phase (full immersion / underwater). However, its protection level decreased significantly under gas phase (on-liquid) conditions, and its protection against copper alloys completely failed. This comparative result demonstrates that the zwitterionic structure of long-chain alkyl phosphate betaine (MZI) and its long-chain alkyl group play an irreplaceable role in forming a stable and oriented adsorption film at the gas-liquid interface and effectively inhibiting the electrochemical corrosion of copper. The decreased protective performance of Comparative Example 1 and Comparative Example 2 indicates that the alkyl chain length range (C14-C22, preferably C16-C18) defined in this patent is a necessary condition for achieving the best protective effect.

[0107] The sodium polyaspartate used in Comparative Example 3 exhibited poor corrosion inhibition performance. Comparative Examples 6, 7, 8, and 9, due to their well-developed corrosion inhibition systems (with appropriate amounts of MZI and ASI80), showed no corrosion to either aluminum or copper alloys.

[0108] (2) Rust prevention test of cast iron chips

[0109] Experimental design: Conducted according to IP 287 standard. 2g of evenly spread cast iron filings were added to a watch glass containing filter paper. 2mL of different concentrations of diluted cutting fluid were then evenly added to the casting iron filings and left at room temperature for 2 hours. The filings were then removed, and the corrosion on the test specimen surface at different concentrations was observed. The cutting fluid concentration at grade 0 was recorded.

[0110]

[0111] Conclusion: All formulations containing long-chain alkyl phosphate betaine (MZI) and a complete rust-preventive system (Examples 1-3, Comparative Examples 4, 7, 6, 9, 10) achieved complete rust prevention (Grade 0) at a low concentration of 1.0%-1.5%, indicating that the combination of MZI with the selected rust inhibitor (such as mixed dicarboxylic acid) can achieve highly efficient rust prevention.

[0112] Comparative Example 5 (without MZI) requires a concentration increase to 3.0% to achieve a rust prevention level of 0, which is the worst rust prevention performance.

[0113] Comparative Example 8 (containing chlorinated paraffin) required a concentration of 2.0%, which was better than the formulation without MZI, but significantly worse than all the examples containing MZI.

[0114] Comparative Examples 1 and 2 showed slightly better rust prevention than Comparative Example 3, indicating that the alkyl chain length (C16-C18) of MZI is one of the parameters for optimizing its rust prevention performance.

[0115] Effects of the technical solution of the present invention

[0116] Overall technical effect:

[0117] Exceptional lubrication and extreme pressure performance: Through the synergy of composite lubrication and extreme pressure system, it exhibits high P in four-ball experiments. B / P D It has a high value, resulting in a higher number of boreholes and significantly improved tool life in drilling experiments, and exhibits excellent lubricity.

[0118] Excellent multi-metal compatibility: Thanks to the adsorption of the core component zwitterionic corrosion inhibitor, it can simultaneously pass the aluminum alloy test piece immersion corrosion test, the copper sheet immersion corrosion test (reaching Grade A) and the cast iron chip rust prevention test, meeting the general needs of multi-material machining centers and eliminating workpiece corrosion loss.

[0119] The product boasts inherent environmental and safety characteristics: The formula fully complies with standards such as GB / T 32812-2016, and is free of chlorine, boron, nitrites, and formaldehyde emissions. Selected components prioritize biodegradability and low ecotoxicity, ensuring product safety, environmental friendliness, and no export barriers.

[0120] Technical effects resulting from specific technical features:

[0121] "Long-chain alkyl phosphate betaine" enables the formulation to solve the corrosion problems of aluminum, copper and steel with a single additive, simplifying the formulation and avoiding the antagonistic effects that may occur when multiple corrosion inhibitors (such as aluminum corrosion inhibitors, copper corrosion inhibitors and steel rust inhibitors) are combined.

[0122] The combination of oxidized vegetable oil / tetrameric castor oil ester and TMPTO / PETO ensures that the resulting lubricating film maintains stability and a low coefficient of friction over a wide range of temperatures, from room temperature to high cutting temperatures, enabling universal machining.

[0123] "The combination of high molecular weight thiophosphate and organophosphonic acid, along with betaine and synthetic esters, enables the system to form a robust composite lubricating film under extreme pressure, achieving extreme pressure anti-wear properties that surpass those of traditional chlorine-containing products, while ensuring low corrosion to copper alloys, thus achieving high performance and multi-metal compatibility."

[0124] The combination of MDEA and mixed dicarboxylic acids enables the system to maintain a stable alkaline environment and good rust prevention of steel even under boron-free conditions.

[0125] The "BIT / MIT / IPBC compound" gives the product broad-spectrum and long-lasting antibacterial capabilities, extending the service life of the working solution.

[0126] It is understood that those skilled in the art can make equivalent substitutions or changes to the technical solution and inventive concept of the present invention, and all such changes or substitutions should fall within the protection scope of the present invention.

Claims

1. A high-efficiency water-based cutting fluid, characterized in that, Based on 100 parts, the product comprises the following components: base oil: 20-25 parts; a composite lubricant formulated from oxidized vegetable oil, hydroxy fatty acid esters, and synthetic esters: 20-30 parts; extreme pressure anti-wear agent: 3-5 parts; corrosion inhibitor: 2-4 parts; emulsifier: 2-4 parts; pH adjuster: 8-10 parts; rust inhibitor: 3-5 parts; biological stabilizer: 5-7 parts; anti-hard water agent: 2-3 parts; defoamer: 0.001-0.002 parts; and the balance being deionized water; wherein the base oil is naphthenic. The base oil; the oxidized vegetable oil is one of oxidized rapeseed oil, oxidized palm oil, and oxidized soybean oil; the hydroxy fatty acid ester is tetrameric castor oil ester; the synthetic ester is a compound product of trimethylolpropane oleate and pentaerythritol oleate; the extreme pressure anti-wear agent is a compound of triphenyl thiophosphate and 1-octylphosphonic acid; the corrosion inhibitor is one of tetradecyl dimethyl hydroxypropyl phosphate betaine, hexadecyl dimethyl hydroxypropyl phosphate betaine, and octadecyl dimethyl hydroxypropyl phosphate betaine.

2. The high-efficiency lubricating water-based cutting fluid according to claim 1, characterized in that, The emulsifier is a mixture of oleic acid and polyethylene glycol.

3. The high-efficiency lubricating water-based cutting fluid according to claim 1, characterized in that, The pH adjuster is one or both of methyldiethanolamine and triethanolamine; the rust inhibitor is a mixed dicarboxylic acid.

4. The high-efficiency lubricating water-based cutting fluid according to claim 1, characterized in that, The biological stabilizer is a bactericide composed of 1,2-benzisothiazolin-3-one, 2-methyl-4-isothiazolin-3-one and 3-iodo-2-propynyl-N-n-butylcarbamate.

5. The high-efficiency lubricating water-based cutting fluid according to claim 1, characterized in that, The anti-hard water agent is an ether carboxylic acid polymer; the defoamer is one of a polyether defoamer or an organosilicon defoamer.

6. The application of a high-efficiency lubricating water-based cutting fluid, characterized in that, The high-efficiency lubricating water-based cutting fluid as described in any one of claims 1-5 is applied to the machining of titanium alloys, high-temperature alloys, aluminum alloys, and copper alloys.

Images