Hard-water-resistant long-life water-soluble metal cutting fluid and preparation method thereof

Abstract

The invention relates to the technical field of cutting fluid, in particular to hard-water-resistant long-life water-soluble metal cutting fluid and a preparation method thereof, and the hard-water-resistant long-life water-soluble metal cutting fluid comprises the following components in percentage by weight: 15%-20% of alcohol amine, 8%-10% of an antirust agent, 0.5%-2% of a nonferrous metal corrosion inhibitor, 15%-25% of a lubricant, 4%-6% of a hard-water-resistant agent, 0.3% of a bactericide, 0.1%-0.2% of a defoaming agent and the balance of water. The extreme pressure lubrication performance of the whole product is improved through the synergistic effect of several lubricants with excellent performance, tool abrasion in the machining process is reduced, and the machining precision is improved. Alcohol amine and tetrameric ricinoleate are preferentially heated and stirred, an amide compound can be generated through reaction and can also be used as an excellent lubricating agent, and the lubricating performance of the whole system is further improved. According to the cutting fluid, by optimizing a formula and a preparation process, the problems that a traditional water-based cutting fluid is poor in hard water resistance, insufficient in lubricity, short in service life, prone to foam generation and the like are solved, and meanwhile the cutting fluid has the excellent anti-rust property, cooling property and cleaning effect.

Description

Technical Field

[0001] The present invention relates to the technical field of cutting fluids, and in particular to a water-soluble metal cutting fluid with hard water resistance and long life and a preparation method thereof. Background Art

[0002] With the rapid development of the machinery industry, the performance requirements for cutting fluids are increasing day by day, especially in terms of environmental protection, cost control and service life.

[0003] Traditional emulsified cutting fluids and micro-emulsified cutting fluids contain mineral oil, and are prone to problems such as poor hard water resistance, poor stability, easy bacteria growth, and high maintenance costs.

[0004] After retrieval, a fully synthetic cutting fluid is disclosed in the patent with the patent application number CN201910159896.0. It can be found from the patent records that although the traditional fully synthetic cutting fluid has advantages such as long life, low odor, good rust prevention performance, and good cooling performance, its lubricating performance is insufficient, which limits its wide application in machining.

[0005] In the prior art, it is difficult to balance the lubricity and service life of water-based cutting fluids. Especially under the condition of high-hardness water quality, problems such as soap precipitation, delamination, and failure are likely to occur, affecting the machining effect.

[0006] Therefore, it is of great practical significance to develop a water-soluble metal cutting fluid with long life, high lubricity and hard water resistance. Summary of the Invention

[0007] One of the technical solutions adopted by the present invention to solve the above technical problems is: a water-soluble metal cutting fluid with hard water resistance and long life and a preparation method thereof, including the following components in percentage by weight: alkanolamine 15%-20%, rust inhibitor 8%-10%, non-ferrous metal corrosion inhibitor 0.5%-2%, lubricant 15%-25%, hard water resistance agent 4%-6%, bactericide 0.3%, defoamer 0.1%-0.2%, and the balance is water.

[0008] Based on any of the above technical solutions, further optimization is: the lubricant is a mixture of several of borate ester, tetra-polyricinoleic acid ester, polyether, and polyethylene glycol.

[0009] Based on any of the above technical solutions, further optimization is: the rust inhibitor is a mixture of several of ethanolamine, triethanolamine, dodecanedioic acid, sebacic acid, and ternary acid.

[0010] Based on any of the above technical solutions, further optimization is: the non-ferrous metal corrosion inhibitor is one or a mixture of benzotriazole and siloxanone.

[0011] The present invention also provides a method for preparing a water-soluble metal cutting fluid with hard water resistance and long service life, comprising the following steps: S1, preferentially mix alkanolamine and tetraricinoleic acid ester according to the ratio, heat and stir for about 1 hour, and control the reaction temperature at 60°C - 70°C; S2, add water, rust inhibitor, corrosion inhibitor, and hard water resistant agent into a container according to the ratio, stir for about 1 hour, and control the reaction temperature at 50°C - 60°C; S3, add lubricant, coupling agent, and bactericide into the container according to the ratio, control the reaction temperature at 50°C - 60°C, stop heating after stirring for 1 hour; S4, add defoaming agent into the container according to the ratio, stir at room temperature for 30 minutes until it becomes transparent.

[0012] Based on any of the above technical solutions, a further optimization is that: the hard water resistant agent is a mixture of tetrasodium ethylenediaminetetraacetate and low-foaming alcohol ether carboxylic acid.

[0013] Based on any of the above technical solutions, a further optimization is that: the bactericide is a mixture of isothiazolinone bactericide and carbamate bactericide.

[0014] Based on any of the above technical solutions, a further optimization is that: in the reaction of mixing the alkanolamine and the tetraricinoleic acid ester in step S1, the alkanolamine and the tetraricinoleic acid ester undergo amidation reaction through heating to generate an amide compound as an auxiliary lubricant.

[0015] Based on any of the above technical solutions, a further optimization is that: the defoaming agent is an organosilicon defoaming agent.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. The cutting fluid in the present invention solves the problems of poor hard water resistance, insufficient lubricity, short service life, and easy foam generation of traditional water-based cutting fluids by optimizing the formula and preparation process, and at the same time has excellent rust prevention, cooling, and cleaning effects.

[0017] 2. The extreme pressure lubrication performance of the whole product is improved through the synergistic effect of several lubricants with relatively excellent performance to reduce tool wear during the processing and improve the processing accuracy. Through preferential heating and stirring of alkanolamine and tetraricinoleic acid ester, an amide compound will be generated in the reaction, which can also be used as an excellent lubricant to further improve the lubrication performance of the whole system.

[0018] 3. The cutting fluid system of the present invention does not contain conventional fatty acid additives, and at the same time uses tetrasodium ethylenediaminetetraacetate combined with low-foaming alcohol ether carboxylic acid as the hard water resistant agent, and can maintain the stability of the working fluid under water quality conditions with a hardness range of up to 1500 ppm.

[0019] 4. This formulation is particularly suitable for high-hardness water environments and can meet the processing requirements with high demands for anti-rust performance, lubricating performance, and service life.

[0020] 5. This cutting fluid adopts a mode of combining excellent-performance ferrous metal anti-rust agent and non-ferrous metal corrosion inhibitor, enabling it to ensure a long anti-rust period for ferrous metals and the corrosion inhibition ability for non-ferrous metals such as copper alloys and aluminum alloys in water environments within a certain hardness range.

[0021] 6. Since this cutting fluid does not contain base oil, it can avoid the generation of oil mist, is not prone to bacteria growth, is easy to maintain, and has a long service life.

[0022] 7. The above raw materials in the present invention are formulated into this cutting fluid through scientific proportioning, which has the advantages of long service life, good lubricating performance, strong anti-hard water ability, long anti-rust period, good cooling performance, good cleaning effect, and low foam tendency. Specific Embodiments

[0023] The following embodiments are only used to illustrate the technical solutions of the present invention more clearly, so they are only examples and cannot be used to limit the protection scope of the present invention.

[0024] The following is an introduction in combination with specific embodiments: The component ranges of the cutting fluid in the following embodiments: alkanolamine 15% - 20%, anti-rust agent 8% - 10%, non-ferrous metal corrosion inhibitor 0.5% - 2%, lubricant 15% - 25%, anti-hard water agent 4% - 6%, fungicide 0.3%, defoamer 0.1% - 0.2%, and the balance is water.

[0025] Tetraricinoleate has excellent lubricating performance, can effectively reduce the friction between the tool and the workpiece, reduce wear, and extend the tool life. Under high pressure and high temperature conditions, tetraricinoleate can form a protective film on the metal surface to prevent direct contact between metals, reducing abrasion and sintering.

[0026] As a derivative of polybasic fatty acid esters, the long carbon chain and polar ester group in the molecular structure of tetraricinoleate endow it with dual functions: the long carbon chain forms a physical adsorption film through van der Waals forces, and the polar ester group reacts with the metal surface under high temperature and high pressure to generate a fatty acid metal salt film. The two together form a composite lubricating film, enhancing the lubricating effect under extreme pressure conditions. The high-temperature film-forming property of this substance enables it to withstand high loads during cutting, avoiding adhesive wear caused by direct contact between the tool and the workpiece, and is particularly suitable for high-hardness metal processing scenarios. The balance of lipophilicity and hydrophilicity in its molecular structure also helps to improve the emulsification stability of the cutting fluid and indirectly enhance the cooling and cleaning performance.

[0027] Polyether 1740 provides multiple functions such as lubrication, cooling, emulsification, rust prevention, cleaning, and anti-foaming in cutting fluids, which can significantly improve the performance and usage effect of cutting fluids.

[0028] As an extreme pressure anti-wear agent, borate ester can form a protective film on the metal surface under high pressure and high temperature conditions to reduce friction and wear; as a lubricant, it can provide certain lubrication performance and reduce the friction between the tool and the workpiece. Borate ester also has good rust prevention performance and the ability to buffer the pH value of the system to maintain its stability and prevent corrosion and deterioration caused by pH value fluctuations.

[0029] Polyethylene glycol can enhance the lubricity, cooling property, emulsification property, etc. of cutting fluids.

[0030] As a water-soluble polymer, the hydroxyl groups in the molecular chain of polyethylene glycol combine with water molecules through hydrogen bonds to form a high-viscosity hydration layer, enhancing the fluid lubrication effect; its high boiling point property makes it not easy to volatilize at high temperatures, maintaining continuous cooling ability; as a non-ionic dispersant, its molecular chain wraps the oily components (such as tetraricinoleate), preventing oil droplets from aggregating through steric hindrance effect and improving the emulsification stability; in addition, the hygroscopic property of polyethylene glycol can reduce the evaporation of water in cutting fluids, extend the service life of the working fluid, and its low toxicity and biodegradability also meet the environmental protection requirements.

[0031] The bactericide is a mixture of isothiazolinone-based and carbamate-based bactericides. The combined use of the two types of bactericides forms a synergistic antibacterial effect, effectively controlling problems such as odor, stratification, and performance decline caused by microbial reproduction in cutting fluids. By maintaining the microbial ecological balance, reducing the frequency of fluid replacement, and lowering the maintenance cost, while avoiding the toxicity and environmental risks of traditional chlorine-containing bactericides, it meets the requirements of industrial clean production.

[0032] Neo-decanoic acid can provide both extreme pressure lubrication and rust prevention functions in cutting fluids, and also has a unique coupling effect. This substance has extremely low surface tension and high permeability, which can reduce the viscosity of cutting fluids, improve their fluidity and lubrication performance, and significantly optimize the stability and performance of the cutting fluid system.

[0033] Component Proportion Alkanolamine 20% Rust inhibitor 10% Corrosion inhibitor 0.5% Lubricant 15% Anti-scaling agent 6% Bactericide 0.3% Defoamer 0.1% Water 48.1% Among them, the alkanolamine is a mixture of ethanolamine and triethanolamine, the rust inhibitor is a mixture of dodecanedioic acid and tricarboxylic acid, the metal corrosion inhibitor is benzotriazole, the lubricant is a mixture of polyether 1740, triethanolamine borate, tetraricinoleate, and polyethylene glycol 400, the water hardness inhibitor is a mixture of tetrasodium ethylenediaminetetraacetate and alcohol ether carboxylic acid, the bactericide is a mixture of isothiazolinone-based and carbamate-based bactericides, and the defoamer is an organosilicon defoamer.

[0034] The system does not contain conventional fatty acid additives. At the same time, through the compounding system of sodium ethylenediaminetetraacetate and alcohol ether carboxylic acid with a specific ratio, the chelating capacity for calcium and magnesium ions is improved, the working fluid is maintained clear and transparent, and the system achieves high resistance to hard water performance.

[0035] The preparation method is mainly divided into 4 steps: S1, preferentially mix the alkanolamine and tetraricinoleate according to the ratio, heat and stir for about 1 hour, and control the reaction temperature at 60°C - 70°C.

[0036] S2, add water, rust inhibitor, corrosion inhibitor, and hard water resistance agent into the container according to the ratio, stir for about 1 hour, and control the reaction temperature at 50°C - 60°C.

[0037] S3, add the lubricant and bactericide into the container according to the ratio, control the reaction temperature at 50°C - 60°C, and stop heating after stirring for 1 hour.

[0038] S4, add the defoamer into the container according to the ratio, stir at room temperature for 30 minutes until it becomes transparent.

[0039] All the detection items of this cutting fluid meet the relevant indicators of GB6144 - 2010, and it can meet the requirement that the working fluid with a configured water hardness within 1500 ppm does not separate soap.

[0040] The pH value of the 5% working fluid of this cutting fluid is in the range of 9.2 - 9.7, and it is mainly used for the processing of ferrous metals such as cast iron, carbon steel, and stainless steel.

[0041] This cutting fluid has been used in the machining center of a machinery factory in Jining, Shandong for one year. The fluid change cycle is twice as long as that of a previous brand of semi-synthetic cutting fluid, greatly reducing the fluid change cost.

[0042] Component Proportion Alkanolamine 15% Rust inhibitor 8% Corrosion inhibitor 2% Lubricant 25% Anti-scaling agent 4% Coupling agent 1% Bactericide 0.3% Defoamer 0.2% Water 44.5% Among them, the alkanolamine is a mixture of ethanolamine and triethanolamine, the rust inhibitor is a mixture of sebacic acid and tetracarboxylic acid, the corrosion inhibitor is a mixture of benzotriazole and silicone ketones, the lubricant is a mixture of polyether 1740, triethanolamine borate, tetraricinoleate, and polyethylene glycol 400, the hard water resistance agent is a mixture of sodium ethylenediaminetetraacetate and alcohol ether carboxylic acid, the coupling agent is neodecanoic acid, the bactericide is a mixture of isothiazolinone - type and carbamate - type bactericides, and the defoamer is an organosilicon defoamer.

[0043] The preparation method is mainly divided into 4 steps: S1, preferentially mix the alkanolamine and tetraricinoleate according to the ratio, heat and stir for about 1 hour, and control the reaction temperature at 60°C - 70°C.

[0044] S2, Add water, rust inhibitor, corrosion inhibitor, and anti-scaling agent into a container according to the ratio, stir for about 1 hour, and control the reaction temperature at 50°C to 60°C.

[0045] S3, Add lubricant, coupling agent, and bactericide into a container according to the ratio, control the reaction temperature at 50°C to 60°C, and stop heating after stirring for 1 hour.

[0046] S4, Add defoamer into a container according to the ratio, stir at room temperature for 30 minutes until it becomes transparent.

[0047] All the test items of this cutting fluid meet the relevant indicators of GB6144-2010, and it can meet the requirement of preparing a working fluid with a water hardness within 1200 ppm without soap precipitation. The pH value of the 5% working fluid of this cutting fluid is in the range of 9.0 to 9.5. It can be used not only for the processing of ferrous metals such as cast iron, carbon steel, and stainless steel, but also for the processing of most aluminum alloys and copper alloys.

[0048] The compound system of benzotriazole and silicone-based corrosion inhibitor forms a hydrophobic protective film on the surface of copper alloy to prevent the adsorption of corrosive ions such as chloride ions; the weakly alkaline pH value avoids alkali corrosion of aluminum alloy and maintains the rust prevention performance of ferrous metals at the same time. The extreme pressure performance is improved by increasing the proportion of lubricant, which is suitable for the processing scenarios of non-ferrous metals with higher lubrication requirements. The multi-functional compatibility of this formula reflects the design flexibility, and it can be adjusted adaptively according to different water quality conditions and processing objects, expanding the application scope of the technical solution.

[0049] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention; for those skilled in the technical field of the present invention, any alternative improvement or transformation made to the embodiments of the present invention falls within the protection scope of the present invention.

[0050] The details not described in the present invention are all well-known technologies to those skilled in the technical field.

Claims

1. A water-soluble metal cutting fluid with resistance to hard water and long service life and its preparation method, characterized in that: It comprises components in the following weight percentages: 15%-20% of alkanolamine, 8%-10% of rust inhibitor, 0.5%-2% of non-ferrous metal corrosion inhibitor, 15%-25% of lubricant, 4%-6% of water hardness reducer, 0.3% of bactericide, 0.1%-0.2% of defoamer, and the balance is water.

2. The water-soluble metal cutting fluid with resistance to hard water and long service life according to claim 1 and its preparation method are characterized in that: The lubricant is a mixture of several of borate ester, tetra-polyricinoleic acid ester, polyether, and polyethylene glycol.

3. The anti-hard water long-life water-soluble metal cutting fluid according to claim 2 and its preparation method are characterized in that: The rust inhibitor is a mixture of several of ethanolamine, triethanolamine, dodecanedioic acid, sebacic acid, and ternary acid.

4. The water-soluble metal cutting fluid with resistance to hard water and long service life according to claim 3 and its preparation method, characterized in that: The non-ferrous metal corrosion inhibitor is one or a mixture of benzotriazole and siloxanone.

5. The preparation method of the water-soluble metal cutting fluid with hard water resistance and long service life according to claim 4, wherein: It includes the following steps: S1, Mix the alkanolamine and tetra-polyricinoleic acid ester preferentially according to the ratio, heat and stir for about 1 hour, and control the reaction temperature at 60°C - 70°C; S2, Add water, rust inhibitor, corrosion inhibitor, and water hardness reducer into the container according to the ratio, stir for about 1 hour, and control the reaction temperature at 50°C - 60°C; S3, Add the lubricant, coupling agent, and bactericide into the container according to the ratio, control the reaction temperature at 50°C - 60°C, stop heating after stirring for 1 hour; S4, Add the defoamer into the container according to the ratio, stir at room temperature for 30 minutes until it becomes transparent.

6. The preparation method of the water-soluble metal cutting fluid with hard water resistance and long service life according to claim 5, characterized in that: The water hardness reducer is a mixture of sodium ethylenediaminetetraacetate and low-foaming alcohol ether carboxylic acid.

7. The preparation method of the water-soluble metal cutting fluid with resistance to hard water and long service life according to claim 6, characterized in that: The bactericide is a mixture of isothiazolinone bactericide and carbamate bactericide.

8. The preparation method of the water-soluble metal cutting fluid with hard water resistance and long service life according to claim 7, characterized in that: In the reaction of mixing the alkanolamine and the tetra-polyricinoleic acid ester in step S1, the alkanolamine and the tetra-polyricinoleic acid ester undergo amidation reaction by heating to generate amide compounds as auxiliary lubricants.

9. The preparation method of the water-soluble metal cutting fluid with hard water resistance and long service life according to claim 8, characterized in that: The defoamer is an organosilicon defoamer.