阅读说明：本技术 一种生物稳定型的金属加工用切削液 (Biostable cutting fluid for metal processing ) 是由 张立 边峰 张兴芝 赵登峰 李传峰 赵新刚 周晓蔚 朱建华 于 2021-01-12 设计创作，主要内容包括：本发明属于金属切削加工技术领域,具体涉及一种生物稳定型的金属加工用切削液,该金属加工用切削液的原料按照重量百分比包括以下组成：基础油15～40％,合成酯12～30％,乳化剂4～14％,防锈剂3～13％,极压剂2～16％,杀菌剂0.2～2.5％,其余为去离子水,所述的杀菌剂为负载金属铜的纳米FAU-EMT混晶分子筛,该杀菌剂能够取代常见的有毒的甲醛缩合物、酚类化合物、硼酸胺等化学杀菌剂。本发明的金属加工用切削液,能够满足现场加工时所要求的润滑、冷却、乳液稳定性、抗腐蚀性等要求,同时具有安全环保的特点,复合绿色化学的理念,应用前景十分广阔。(The invention belongs to the technical field of metal cutting machining, and particularly relates to a biostable cutting fluid for metal machining, which comprises the following raw materials in percentage by weight: 15-40% of base oil, 12-30% of synthetic ester, 4-14% of emulsifier, 3-13% of antirust agent, 2-16% of extreme pressure agent, 0.2-2.5% of bactericide and the balance of deionized water, wherein the bactericide is a nano FAU-EMT mixed crystal molecular sieve loaded with metal copper, and can replace common chemical bactericides such as toxic formaldehyde condensation compounds, phenolic compounds, amine borate and the like. The cutting fluid for metal processing can meet the requirements of lubrication, cooling, emulsion stability, corrosion resistance and the like required by field processing, has the characteristics of safety and environmental protection, is compounded with the concept of green chemistry, and has a very wide application prospect.)

1. The cutting fluid for metal processing is characterized by comprising the following raw materials in percentage by weight: 15-40% of base oil, 12-30% of synthetic ester, 4-14% of emulsifier, 3-13% of antirust agent, 2-16% of extreme pressure agent, 0.2-2.5% of bactericide and the balance of deionized water, wherein the bactericide is a nano FAU-EMT mixed crystal molecular sieve loaded with metal copper; the nano FAU-EMT mixed crystal molecular sieve comprises 5-95% of FAU by mass and the balance of EMT; the crystal size of the nano FAU-EMT mixed crystal molecular sieve is 5-95 nanometers, and the preparation method of the cutting fluid for metal processing comprises the following steps:

1) preparing a nano FAU-EMT mixed crystal molecular sieve: dissolving sodium metaaluminate and sodium hydroxide in a polytetrafluoroethylene beaker filled with deionized water at the temperature of 20-90 ℃, stirring for 0.5-12 hours to form a suspension A, dissolving sodium silicate and sodium hydroxide in the polytetrafluoroethylene beaker filled with deionized water, stirring for 0.5-12 hours to form a suspension B, placing the suspension A and the suspension B in an ice water mixed solution, cooling for 30 minutes, slowly dripping the suspension A into the suspension B which is continuously stirred, and fully stirring for 30 minutes to obtain a sol-gel solution; according to the mass of EMT and FAU in the required nano FAU-EMT mixed crystal molecular sieve, the molar chemical composition of the gel liquid is adjusted to Al by adding deionized water₂O₃：SiO₂：Na₂O：H₂O15: 1: 14: (60-300), stirring for 1 hour, crystallizing for 24-96 hours at the temperature of 20-90 ℃, performing vacuum filtration and washing with distilled water until the pH is 7.5, and freeze-drying for 1-48 hours at the temperature of 5-95 ℃ to obtain the nano FAU-EMT mixed crystal molecular sieve;

2) preparing a nano FAU-EMT mixed crystal molecular sieve loaded with metal copper: adding the nano FAU-EMT mixed crystal molecular sieve into deionized water, stirring to form a colloidal solution, dissolving a metallic copper precursor in the deionized water to obtain a mixed solution, gradually dropwise adding the mixed solution into the colloidal solution, and controlling the mass ratio of the metallic elements to the nano FAU-EMT mixed crystal molecular sieve to be 0.001-0.05: 1, stirring and reacting for 0.5-48 hours at the temperature of 5-95 ℃ to ensure that a metallic copper precursor in the solution and cations in the nano FAU-EMT mixed crystal molecular sieve are thoroughly exchanged, dispersing the nano FAU-EMT mixed crystal molecular sieve loaded with the metallic copper precursor into an aqueous solution again after filtering and washing, adding a reducing agent with a certain mass, controlling the molar ratio of the reducing agent to the metallic copper to be 0.5-2: 1, irradiating for 2-48 hours at the temperature of 5-40 ℃ by ultraviolet light, and reducing the metallic copper precursor into metal by ultraviolet light irradiation to obtain the metal-loaded nano FAU-EMT mixed crystal molecular sieve;

3) preparing oil-based mixed liquid: heating the base oil to 30-80 ℃, adding the synthetic ester and the emulsifier, and uniformly stirring for later use;

4) preparing a water-based mixed solution: dissolving the antirust agent and the extreme pressure agent by using deionized water to form a mixed solution, adding the nano FAU-EMT mixed crystal molecular sieve bactericide loaded with the metal copper obtained in the step 1) into the mixed solution, and uniformly stirring the mixed solution for later use;

5) synthesis of cutting fluid for Metal working: and (3) mixing the oil-based mixed solution and the water-based mixed solution obtained in the steps 3) and 4), and stirring at a high speed to form a uniform transparent solution, thus obtaining the biological stable cutting fluid for metal processing.

2. The cutting fluid according to claim 1, wherein the copper metal precursor is one or a combination of two of copper sulfate, copper chloride, copper nitrate, copper acetate and copper oxalate; the reducing agent is one or the combination of two of sodium sulfite, potassium iodide, ferrous nitrate and sodium hydrosulfite.

3. The biostable cutting fluid for metal working according to claim 1, wherein the wavelength of the ultraviolet light is 100 to 200 nm.

4. The biostable cutting fluid for metal working according to claim 1, wherein the base oil is one or a combination of two of naphthenic mineral oil, paraffin-based mineral oil and hydrorefined oil; the synthetic ester is one or the combination of two of trimethylolpropane oleate, isooctanol oleate, polyricinoleate and polyol ester; the emulsifier is one or the combination of two of fatty alcohol polyoxyethylene ether, fatty alcohol polyoxyethylene polyoxypropylene ether, alkylphenol polyoxyethylene ether and alkanolamide; the antirust agent is one or the combination of two of sodium dodecyl benzene sulfonate, sodium benzoate, triethanolamine, diisopropanolamine, triisopropanolamine, dimethyl pelargylamine, dimethyl ethanolamine and benzoic acid monoethanolamine; the extreme pressure agent is one or the combination of two of oleic acid boric acid ester, water-soluble boric acid ester and fatty alcohol polyoxyethylene phosphate.

5. The biostable cutting fluid for metal working according to claim 1, wherein the cutting fluid for metal working is suitable for cutting and grinding of various machine parts.

Technical Field

The invention belongs to the technical field of metal cutting machining, and particularly relates to a biostable cutting fluid for metal machining.

Background

Along with the continuous and rapid development of Chinese economy, the urban process and the industrialization process are continuously increased, and the national attention on environmental protection is higher and higher. The cutting fluid for metal processing is easily polluted by microorganisms due to the properties of the cutting fluid, namely emulsion, semisynthetic or fully synthetic cutting fluid, and the cutting fluid for metal processing is easy to decay due to the mass propagation of the microorganisms particularly in spring and summer. When bacteria are propagated in a large amount in the cutting fluid for metal processing, the pH value of the processing fluid is reduced, and unpleasant gas is generated; when fungi multiply in the cutting fluid for metal processing, lumps appear in the cutting fluid and easily block a machine tool circulating system. These harmful microorganisms cause the deterioration of machining fluids, cause the reduction of the lubricity, rust prevention, stability and other properties of cutting fluids for metal machining, cause abrasion and corrosion of machines, machined workpieces and machining tools, and generate offensive odors which affect the environment of factories and irritate the skin and respiratory tract of operators, thus seriously affecting the health of users.

Currently, the most common method for inhibiting microbial growth in cutting fluids for metal working is to add chemical fungicides, the main types of which are formaldehyde condensates, phenolic compounds, amine borates, and the like. The chemical bactericide plays a role: firstly, the metabolic activity of microorganisms is inhibited, and the growth of the microorganisms is inhibited; secondly, the microbial metabolism mechanism or the thallus structure is destroyed, and the sterilization effect is achieved. Although effective, the addition of common chemical disinfectants inevitably volatilizes and contacts the skin of the user, which can seriously harm the environment and the physical health of the user. Chinese patent 201710313546.6 clearly states that formaldehyde condensates, phenolic compounds, amine borates, etc. have been banned from use in developed countries in europe and america. Therefore, there is a need in the art to find a new type of environmentally friendly bactericide for use in cutting fluids for metal processing.

The grain size of the molecular sieve synthesized by the conventional method in industry is generally larger than 1 μm, while the nano molecular sieve refers to the molecular sieve with the grain size smaller than 100nm, and because of the smaller grain size and the larger specific surface area, the nano molecular sieve shows the size effect, the surface effect, the volume effect and the quantum tunneling effect which are not possessed by the conventional-scale molecular sieve. Because the grain size of the nano molecular sieve is less than 100nm, the nano molecular sieve can form a very stable colloidal solution after being dispersed in an aqueous solution, which improves the possibility that the nano molecular sieve loaded metal is used as an environment-friendly bactericide of a cutting fluid for metal processing, and the common micron molecular sieve is easy to form precipitates after being dissolved in water and cannot be used as a bactericide of the cutting fluid for metal processing. At present, no literature reports that the metal-loaded nano molecular sieve is used in the cutting fluid for metal processing, mainly because the formula system of the cutting fluid for metal processing is very complex, the metal-loaded nano molecular sieve not only needs to meet the characteristics of lubrication, cooling, emulsion stability, corrosion resistance and the like required in field processing, but also needs to meet good biological stability. In addition, it should be noted that the metal precursor-loaded nano molecular sieve needs to be calcined at a high temperature to convert the metal precursor into a metal oxide, and then reduced at a high temperature (such as hydrogen) to obtain the bactericidal performance. However, the high-temperature roasting and high-temperature reduction process can cause the clustering of the nano molecular sieve to form the micron-scale molecular sieve, and the formed micron-scale molecular sieve is easy to form precipitates in the cutting fluid for metal processing and cannot be used as a bactericide of the cutting fluid for metal processing. Therefore, there is a need in the art to find a new preparation method of a metal-loaded nano molecular sieve fungicide, which can be successfully applied to a cutting fluid product for metal processing.

The molecular sieve is a porous crystalline silicon-aluminum substance, can effectively load antibacterial metals such as copper, silver and the like, and is a better inorganic antibacterial agent carrier. Because the single molecular sieve has uniform structure and property, the antibacterial effect on certain bacteria after loading antibacterial metal is not ideal. The mixed crystal molecular sieve containing two or more components has diversified duct effects and acid properties, and can be used for coping with more complicated bacterial environments (such as cutting fluid for metal processing), so that the synergistic bactericidal effect of different molecular sieves can be fully exerted on a nanoscale scale. However, few studies on the synthesis of mixed crystal molecular sieves exist at present, and no reports on the application of metal-loaded nano mixed crystal molecular sieves in bactericides exist at present.

Disclosure of Invention

In view of the above problems in the prior art, an object of the present invention is to provide a cutting fluid for metal working which is biostable.

In order to achieve the purpose, the invention adopts the following technical scheme:

the invention relates to a biostable cutting fluid for metal processing, which is characterized by comprising the following raw materials in percentage by weight: 15-40% of base oil, 12-30% of synthetic ester, 4-14% of emulsifier, 3-13% of antirust agent, 2-16% of extreme pressure agent, 0.2-2.5% of bactericide and the balance of deionized water, wherein the bactericide is a nano FAU-EMT mixed crystal molecular sieve loaded with metal copper; the nano FAU-EMT mixed crystal molecular sieve comprises 5-95% of FAU by mass and the balance of EMT; the crystal size of the nano FAU-EMT mixed crystal molecular sieve is 5-95 nanometers, and the preparation method of the cutting fluid for metal processing comprises the following steps:

1) preparing a nano FAU-EMT mixed crystal molecular sieve: dissolving sodium metaaluminate and sodium hydroxide in a polytetrafluoroethylene beaker filled with deionized water at the temperature of 20-90 ℃, stirring for 0.5-12 hours to form a suspension A, dissolving sodium silicate and sodium hydroxide in the polytetrafluoroethylene beaker filled with deionized water, stirring for 0.5-12 hours to form a suspension B, placing the suspension A and the suspension B in an ice water mixed solution, cooling for 30 minutes, slowly dripping the suspension A into the suspension B which is continuously stirred, and fully stirring for 30 minutes to obtain a sol-gel solution; according to the mass of EMT and FAU in the required nano FAU-EMT mixed crystal molecular sieve, the molar chemical composition of the gel liquid is adjusted to Al by adding deionized water₂O₃：SiO₂：Na₂O：H₂O15: 1: 14: (60-300), stirring for 1 hour, crystallizing for 24-96 hours at the temperature of 20-90 ℃, performing vacuum filtration and washing with distilled water until the pH is 7.5, and freeze-drying for 1-48 hours at the temperature of 5-95 ℃ to obtain the nano FAU-EMT mixed crystal molecular sieve;

2) preparing a nano FAU-EMT mixed crystal molecular sieve loaded with metal copper: adding the nano FAU-EMT mixed crystal molecular sieve into deionized water, stirring to form a colloidal solution, dissolving a metallic copper precursor in the deionized water to obtain a mixed solution, gradually dropwise adding the mixed solution into the colloidal solution, and controlling the mass ratio of the metallic elements to the nano FAU-EMT mixed crystal molecular sieve to be 0.001-0.05: 1, stirring and reacting for 0.5-48 hours at the temperature of 5-95 ℃ to ensure that a metallic copper precursor in the solution and cations in the nano FAU-EMT mixed crystal molecular sieve are thoroughly exchanged, dispersing the nano FAU-EMT mixed crystal molecular sieve loaded with the metallic copper precursor into an aqueous solution again after filtering and washing, adding a reducing agent with a certain mass, controlling the molar ratio of the reducing agent to the metallic copper to be 0.5-2: 1, irradiating for 2-48 hours at the temperature of 5-40 ℃ by ultraviolet light, and reducing the metallic copper precursor into metal by ultraviolet light irradiation to obtain the metal-loaded nano FAU-EMT mixed crystal molecular sieve;

3) preparing oil-based mixed liquid: heating the base oil to 30-80 ℃, adding the synthetic ester and the emulsifier, and uniformly stirring for later use;

4) preparing a water-based mixed solution: dissolving the antirust agent and the extreme pressure agent by using deionized water to form a mixed solution, adding the nano FAU-EMT mixed crystal molecular sieve bactericide loaded with the metal copper obtained in the step 1) into the mixed solution, and uniformly stirring the mixed solution for later use;

5) synthesis of cutting fluid for Metal working: and (3) mixing the oil-based mixed solution and the water-based mixed solution obtained in the steps 3) and 4), and stirring at a high speed to form a uniform transparent solution, thus obtaining the biological stable cutting fluid for metal processing.

Preferably, the metallic copper precursor is one or a combination of two of copper sulfate, copper chloride, copper nitrate, copper acetate and copper oxalate.

Preferably, the reducing agent is one or a combination of two of sodium sulfite, potassium iodide, ferrous nitrate and sodium hydrosulfite.

Preferably, the wavelength of the ultraviolet light is 100-200 nm.

Preferably, the base oil is one or a combination of two of naphthenic base mineral oil, paraffin base mineral oil and hydrofined oil.

Preferably, the synthetic ester is one or a combination of two of trimethylolpropane oleate, isooctanol oleate, polyricinoleate and polyol ester.

Preferably, the emulsifier is one or a combination of two of fatty alcohol-polyoxyethylene ether, fatty alcohol-polyoxyethylene polyoxypropylene ether, alkylphenol polyoxyethylene ether and alkanolamide.

Preferably, the rust inhibitor is one or a combination of two of sodium dodecyl benzene sulfonate, sodium benzoate, triethanolamine, diisopropanolamine, triisopropanolamine, dimethyl pelargylamine, dimethyl ethanolamine and monoethanolamine benzoate.

Preferably, the extreme pressure agent is one or a combination of two of oleic acid boric acid ester, water-soluble boric acid ester and fatty alcohol polyoxyethylene phosphate.

The invention relates to a biostable cutting fluid for metal processing, which is based on the chemical principle that ultraviolet rays are electromagnetic waves with the wavelength of 100-400 nanometers, the shorter the wavelength of the ultraviolet rays is, the stronger the energy of the ultraviolet rays is, the stronger the excitation capability of the ultraviolet rays on molecules is, and the ultraviolet rays with the wavelength of 100-200 nanometers are selected. The ultraviolet light with strong excitation capability can excite a reducing agent (such as sodium sulfite, potassium iodide, ferrous nitrate and sodium hydrosulfite) to generate a reducing free radical with higher reduction potential, so that the metallic copper precursor is reduced into metal. It is pointed out that the ultraviolet irradiation can provide a uniform, extremely pure, efficient and stable environment for the reduction of the metallic copper precursor on the nano molecular sieve and the nucleation growth process of the metal clusters, and can be carried out at normal temperature and normal pressure, thus effectively avoiding the defects of the conventional high-temperature roasting and high-temperature reduction process.

The invention relates to a biostable cutting fluid for metal processing, the molar chemical composition of a gel liquid is an important parameter for synthesizing a mixed crystal molecular sieve, and Al is adjusted₂O₃：SiO₂：Na₂O：H₂The content of water in O can effectively control the nucleation growth process of the molecular sieve and effectively promote or inhibit the EMT and FAU molecular sieves, thereby changing the mass content of the EMT and FAU in the mixed crystal molecular sieve.

Compared with the prior art, the invention has the beneficial effects that:

(1) the invention provides a biostable cutting fluid for metal processing, and provides an environment-friendly bactericide of a metal-loaded nano FAU-EMT mixed crystal molecular sieve, which has the characteristics of low cost, safety, no toxicity, environmental protection and the like, can replace common chemical bactericides such as toxic formaldehyde condensation compounds, phenolic compounds, amine borate and the like, and avoids the pollution of the common chemical bactericides to the environment and the harm of users.

(2) The invention provides a biostable cutting fluid for metal processing, and provides a novel preparation method of a nano FAU-EMT mixed crystal molecular sieve bactericide for loading metal copper.

(3) The invention discloses a biostable cutting fluid for metal processing, and provides a novel preparation method of a nano FAU-EMT mixed crystal molecular sieve, which is prepared by adjusting Al₂O₃：SiO₂：Na₂O：H₂The content of water in O can effectively control the nucleation growth process of the molecular sieve, and effectively promote or inhibit the EMT and FAU molecular sieves, so that the mass contents of the EMT and FAU in the mixed crystal molecular sieve are changed, and the nano FAU-EMT mixed crystal molecular sieve with different mass contents of the EMT and FAU is prepared.

(4) The invention discloses a biostable cutting fluid for metal processing, which is found to have good bactericidal effect and biological stability, can meet the requirements of lubrication, cooling, emulsion stability, corrosion resistance and the like required by field processing, has the characteristics of safety and environmental protection, is compounded with a green chemical concept, and has wide market prospect.

Drawings

FIG. 1 is an SEM image of the metallic copper loaded nano FAU-EMT molecular sieve prepared in example 1;

FIG. 2 is an XRD pattern of the copper metal loaded nano FAU-EMT molecular sieve prepared in example 1;

FIG. 3 is an SEM image of the metallic copper loaded nano FAU-EMT molecular sieve prepared in example 2;

FIG. 4 is an XRD pattern of the copper metal loaded nano FAU-EMT molecular sieve prepared in example 2;

fig. 5 is an XRD pattern of the metallic copper supported nano FAU-EMT molecular sieve prepared in example 3.

Detailed Description

For the purpose of facilitating an understanding of the contents of the present invention, the present invention will now be described in detail with reference to the following examples. The examples are only for the purpose of facilitating understanding of the present invention and should not be construed as specifically limiting the present invention. Since the present invention may be described and illustrated in other embodiments without departing from the technical features of the present invention, all changes that come within the scope of the invention or the range of equivalents thereof are intended to be embraced therein.

The invention is further illustrated by the following examples and application examples.

Example 1

1) Preparing a nano FAU-EMT mixed crystal molecular sieve: dissolving sodium metaaluminate and sodium hydroxide in a polytetrafluoroethylene beaker filled with deionized water at the temperature of 25 ℃, stirring for 6 hours to form a suspension A, dissolving sodium silicate and sodium hydroxide in the polytetrafluoroethylene beaker filled with deionized water, stirring for 8 hours to form a suspension B, placing the suspension A and the suspension B in an ice-water mixed solution, cooling for 30 minutes, slowly dripping the suspension A into the suspension B which is continuously stirred, and fully stirring for 30 minutes to obtain a sol-gel solution; according to the mass of EMT and FAU in the required nano FAU-EMT mixed crystal molecular sieve, the molar chemical composition of the gel liquid is adjusted to Al by adding deionized water₂O₃：SiO₂：Na₂O：H₂O15: 1: 14: 70, stirring for 1 hour, crystallizing for 30 hours at the temperature of 45 ℃, performing vacuum filtration and washing by distilled water until the pH value is 7.5, and performing freeze drying for 30 hours at the temperature of 55 ℃ to obtain the nano FAU-EMT mixed crystal molecular sieve;

2) preparing a nano FAU-EMT mixed crystal molecular sieve loaded with metal copper: adding the nano FAU-EMT mixed crystal molecular sieve into deionized water, stirring to form a colloidal solution, dissolving copper sulfate in the deionized water to obtain a mixed solution, gradually dropwise adding the mixed solution into the colloidal solution, and controlling the mass ratio of the metal elements to the nano FAU-EMT mixed crystal molecular sieve to be 0.002: 1, stirring and reacting for 24 hours at the temperature of 50 ℃ to ensure that copper sulfate in the solution and cations in the nano FAU-EMT mixed crystal molecular sieve are completely exchanged, dispersing the nano FAU-EMT mixed crystal molecular sieve loaded with the copper sulfate into an aqueous solution again after filtering and washing, adding a certain mass of reducing agent sodium sulfite, controlling the molar ratio of the reducing agent to metal copper to be 0.8:1, then irradiating for 4 hours by 120 nano ultraviolet light at the temperature of 25 ℃, and reducing the copper sulfate into metal by ultraviolet light irradiation in one step to obtain the nano FAU-EMT mixed crystal molecular sieve loaded with the metal;

3) preparing oil-based mixed liquid: heating paraffin-based mineral oil to 35 ℃, adding isooctanol oleate and polyricinoleate, and uniformly stirring for later use;

4) preparing a water-based mixed solution: dissolving diisopropanolamine, sodium benzoate and water-soluble boric acid ester with deionized water to form a mixed solution, adding the nano FAU-EMT mixed crystal molecular sieve bactericide loaded with metal copper obtained in the step 1) into the mixed solution, and uniformly stirring the mixed solution for later use;

5) synthesis of cutting fluid for Metal working: mixing the oil-based mixed liquid and the water-based mixed liquid obtained in the steps 3) and 4), and stirring at a high speed to form a uniform transparent solution, thereby obtaining the biological stable cutting fluid for metal processing, wherein the cutting fluid for metal processing comprises the following raw materials in percentage by weight: 15.5% of base oil, 28% of synthetic ester, 4.5% of emulsifier, 8% of antirust agent, 9% of extreme pressure agent, 1.2% of nano FAU-EMT mixed crystal molecular sieve bactericide loaded with metal copper and the balance of deionized water.

Fig. 1 is an SEM image of the metallic copper loaded nano FAU-EMT mixed crystal molecular sieve prepared in this example, and it is shown that the average particle size of the nano FAU-EMT mixed crystal molecular sieve is counted to be 40 nm, which indicates that the ultraviolet irradiation method can effectively prevent the nano molecular sieve from agglomerating to generate a micron-sized molecular sieve, and further indicates that the metallic copper loaded nano FAU-EMT mixed crystal molecular sieve can be stably dispersed in a cutting fluid for metal processing for a long period of time without forming precipitates. Fig. 2 is an XRD chart of the nano FAU-EMT mixed crystal molecular sieve loaded with metallic copper prepared in this example, without diffraction peaks of metallic copper and copper oxide, which shows that the copper element has a higher dispersity, and the XRD chart can quantitatively analyze that the mass content of the EMT molecular sieve in the nano FAU-EMT mixed crystal molecular sieve is 60%, and the proportion of the FAU molecular sieve in the nano FAU-EMT mixed crystal molecular sieve is 40%.

Example 2

1) Preparing a nano FAU-EMT mixed crystal molecular sieve: dissolving sodium metaaluminate and sodium hydroxide in a polytetrafluoroethylene beaker filled with deionized water at the temperature of 85 ℃, stirring for 0.8 hour to form suspension A, dissolving sodium silicate and sodium hydroxide in the polytetrafluoroethylene beaker filled with deionized water, and stirring for 7 hours to form suspensionB, placing the suspension A and the suspension B in an ice-water mixed solution for cooling for 30 minutes, then slowly dripping the suspension A into the suspension B which is continuously stirred, and fully stirring for 30 minutes to obtain a sol-gel solution; according to the mass of EMT and FAU in the required nano FAU-EMT mixed crystal molecular sieve, the molar chemical composition of the gel liquid is adjusted to Al by adding deionized water₂O₃：SiO₂：Na₂O：H₂O15: 1: 14: 290, stirring for 1 hour, crystallizing for 90 hours at the temperature of 55 ℃, performing vacuum filtration and washing by distilled water until the pH is 7.5, and freeze-drying for 2 hours at the temperature of 6 ℃ to obtain the nano FAU-EMT mixed crystal molecular sieve;

2) preparing a nano FAU-EMT mixed crystal molecular sieve loaded with metal copper: adding the nano FAU-EMT mixed crystal molecular sieve into deionized water, stirring to form a colloidal solution, dissolving copper nitrate in the deionized water to obtain a mixed solution, gradually dropwise adding the mixed solution into the colloidal solution, and controlling the mass ratio of metal elements to the nano FAU-EMT mixed crystal molecular sieve to be 0.045: 1, stirring and reacting for 0.6 hour at the temperature of 6 ℃ to ensure that copper nitrate in the solution and cations in the nano FAU-EMT mixed crystal molecular sieve are completely exchanged, dispersing the nano FAU-EMT mixed crystal molecular sieve loaded with the copper nitrate into an aqueous solution again after filtering and washing, adding a certain mass of reducing agent potassium iodide, controlling the molar ratio of the reducing agent to metal copper to be 0.6:1, then irradiating for 45 hours by 150 nano ultraviolet light at the temperature of 20 ℃, and reducing the copper nitrate into metal by ultraviolet light irradiation in one step to obtain the metal-loaded nano FAU-EMT mixed crystal molecular sieve;

3) preparing oil-based mixed liquid: heating naphthenic base mineral oil to 40 ℃, adding trimethylolpropane oleate and polyol ester, and uniformly stirring for later use;

4) preparing a water-based mixed solution: dissolving diisopropanolamine, monoethanolamine benzoate and fatty alcohol polyoxyethylene phosphate by using deionized water to form a mixed solution, adding the nano FAU-EMT mixed crystal molecular sieve bactericide loaded with metal copper obtained in the step 1) into the mixed solution, and uniformly stirring the mixed solution for later use;

5) synthesis of cutting fluid for Metal working: mixing the oil-based mixed liquid and the water-based mixed liquid obtained in the steps 3) and 4), and stirring at a high speed to form a uniform transparent solution, thereby obtaining the biological stable cutting fluid for metal processing, wherein the cutting fluid for metal processing comprises the following raw materials in percentage by weight: 39% of base oil, 12.5% of synthetic ester, 13% of emulsifier, 3.5% of antirust agent, 2.5% of extreme pressure agent, 0.25% of nano FAU-EMT mixed crystal molecular sieve bactericide loaded with metal copper and the balance of deionized water.

Fig. 3 is an SEM image of the metallic copper loaded nano FAU-EMT mixed crystal molecular sieve prepared in this example, and it is shown that the average particle size of the nano FAU-EMT mixed crystal molecular sieve is 75 nm by statistics, which indicates that the ultraviolet irradiation method can effectively prevent the nano molecular sieve from agglomerating to generate a micron-sized molecular sieve, and further indicates that the metallic copper loaded nano FAU-EMT mixed crystal molecular sieve can be dispersed in the cutting fluid for metal processing for a long time without forming precipitates. Fig. 4 is an XRD chart of the nano FAU-EMT mixed crystal molecular sieve loaded with metallic copper prepared in this example, without diffraction peaks of metallic copper and copper oxide, which shows that the copper element has a higher dispersity, and it can be quantitatively analyzed from the XRD chart that the mass content of the EMT molecular sieve in the nano FAU-EMT mixed crystal molecular sieve is 25%, and the proportion of the FAU molecular sieve in the nano FAU-EMT mixed crystal molecular sieve is 75%.

Example 3

1) Preparing a nano FAU-EMT mixed crystal molecular sieve: dissolving sodium metaaluminate and sodium hydroxide in a polytetrafluoroethylene beaker filled with deionized water at the temperature of 40 ℃, stirring for 11 hours to form a suspension A, dissolving sodium silicate and sodium hydroxide in the polytetrafluoroethylene beaker filled with deionized water, stirring for 0.6 hour to form a suspension B, placing the suspension A and the suspension B in an ice-water mixed solution, cooling for 30 minutes, slowly dripping the suspension A into the suspension B which is continuously stirred, and fully stirring for 30 minutes to obtain a sol-gel solution; according to the mass of EMT and FAU in the required nano FAU-EMT mixed crystal molecular sieve, the molar chemical composition of the gel liquid is adjusted to Al by adding deionized water₂O₃：SiO₂：Na₂O：H₂O15: 1: 14: 180, stirring for 1 hour, crystallizing at 25 deg.C for 50 hours, vacuum filtering, washing with distilled water until pH is 7.5Freeze-drying at 90 deg.C for 45 hr to obtain nanometer FAU-EMT mixed crystal molecular sieve;

2) preparing a nano FAU-EMT mixed crystal molecular sieve loaded with metal copper: adding the nano FAU-EMT mixed crystal molecular sieve into deionized water, stirring to form a colloidal solution, dissolving copper acetate in the deionized water to obtain a mixed solution, gradually dropwise adding the mixed solution into the colloidal solution, and controlling the mass ratio of metal elements to the nano FAU-EMT mixed crystal molecular sieve to be 0.02: 1, stirring and reacting for 46 hours at the temperature of 94 ℃ to ensure that copper acetate in the solution and cations in the nano FAU-EMT mixed crystal molecular sieve are completely exchanged, dispersing the nano FAU-EMT mixed crystal molecular sieve loaded with the copper acetate into an aqueous solution again after filtering and washing, adding a certain mass of reducing agent ferrous nitrate, controlling the molar ratio of the reducing agent to metal copper to be 1:1, then irradiating for 30 hours by using 180 nano ultraviolet light at the temperature of 8 ℃, and reducing the copper acetate into metal by further irradiating the copper acetate by using the ultraviolet light to obtain the metal-loaded nano FAU-EMT mixed crystal molecular sieve;

3) preparing oil-based mixed liquid: heating paraffin-based mineral oil to 60 ℃, adding isooctanol oleate, polyricinoleate and fatty alcohol-polyoxyethylene ether, and uniformly stirring for later use;

4) preparing a water-based mixed solution: dissolving sodium benzoate, triethanolamine and water-soluble boric acid ester with deionized water to form a mixed solution, adding the nano FAU-EMT mixed crystal molecular sieve bactericide loaded with metal copper obtained in the step 1), and uniformly stirring for later use;

5) synthesis of cutting fluid for Metal working: mixing the oil-based mixed liquid and the water-based mixed liquid obtained in the steps 3) and 4), and stirring at a high speed to form a uniform transparent solution, thereby obtaining the biological stable cutting fluid for metal processing, wherein the cutting fluid for metal processing comprises the following raw materials in percentage by weight: 28% of base oil, 20% of synthetic ester, 9% of emulsifier, 12.8% of antirust agent, 15.5% of extreme pressure agent, 2.3% of nano FAU-EMT mixed crystal molecular sieve bactericide loaded with metal copper and the balance of deionized water.

Fig. 5 is an XRD chart of the nano FAU-EMT mixed crystal molecular sieve loaded with metallic copper prepared in this example, without diffraction peaks of metallic copper and copper oxide, which shows that the copper element has a higher dispersity, and it can be quantitatively analyzed from the XRD chart that the mass content of the EMT molecular sieve in the nano FAU-EMT mixed crystal molecular sieve is 85%, and the proportion of the FAU molecular sieve in the nano FAU-EMT mixed crystal molecular sieve is 15%.

Example 4

1) Preparing a nano FAU-EMT mixed crystal molecular sieve: dissolving sodium metaaluminate and sodium hydroxide in a polytetrafluoroethylene beaker filled with deionized water at the temperature of 60 ℃, stirring for 9 hours to form a suspension A, dissolving sodium silicate and sodium hydroxide in the polytetrafluoroethylene beaker filled with deionized water, stirring for 11.5 hours to form a suspension B, placing the suspension A and the suspension B in an ice-water mixed solution, cooling for 30 minutes, slowly dripping the suspension A into the suspension B which is continuously stirred, and fully stirring for 30 minutes to obtain a sol-gel solution; according to the mass of EMT and FAU in the required nano FAU-EMT mixed crystal molecular sieve, the molar chemical composition of the gel liquid is adjusted to Al by adding deionized water₂O₃：SiO₂：Na₂O：H₂O15: 1: 14: 220, stirring for 1 hour, crystallizing at 85 ℃ for 65 hours, carrying out vacuum filtration and washing with distilled water until the pH is 7.5, and freeze-drying at 70 ℃ for 35 hours to obtain the nano FAU-EMT mixed crystal molecular sieve;

2) preparing a nano FAU-EMT mixed crystal molecular sieve loaded with metal copper: adding the nano FAU-EMT mixed crystal molecular sieve into deionized water, stirring to form a colloidal solution, dissolving copper oxalate in the deionized water to obtain a mixed solution, gradually dropwise adding the mixed solution into the colloidal solution, and controlling the mass ratio of metal elements to the nano FAU-EMT mixed crystal molecular sieve to be 0.03: 1, stirring and reacting for 30 hours at the temperature of 70 ℃ to ensure that copper oxalate in the solution and cations in the nano FAU-EMT mixed crystal molecular sieve are completely exchanged, dispersing the nano FAU-EMT mixed crystal molecular sieve loaded with the copper oxalate into an aqueous solution again after filtering and washing, adding a certain mass of reducing agent sodium hydrosulfite, controlling the molar ratio of the reducing agent to the metal copper to be 1.9:1, then irradiating for 24 hours by 190 nano ultraviolet light at the temperature of 35 ℃, and reducing the copper oxalate into metal by ultraviolet light irradiation in one step to obtain the metal-loaded nano FAU-EMT mixed crystal molecular sieve;

3) preparing oil-based mixed liquid: heating naphthenic base mineral oil to 90 ℃, adding isooctanol oleate, polyol ester and fatty alcohol polyoxyethylene polyoxypropylene ether, and uniformly stirring for later use;

4) preparing a water-based mixed solution: dissolving sodium benzoate, triethanolamine, water-soluble boric acid ester and fatty alcohol polyoxyethylene phosphate with deionized water, adding the nano FAU-EMT mixed crystal molecular sieve bactericide loaded with metal copper obtained in the step 1) into the deionized water, and uniformly stirring the mixture for later use;

5) synthesis of cutting fluid for Metal working: mixing the oil-based mixed liquid and the water-based mixed liquid obtained in the steps 3) and 4), and stirring at a high speed to form a uniform transparent solution, thereby obtaining the biological stable cutting fluid for metal processing, wherein the cutting fluid for metal processing comprises the following raw materials in percentage by weight: 20% of base oil, 24% of synthetic ester, 11% of emulsifier, 10% of antirust agent, 13% of extreme pressure agent, 2% of nano FAU-EMT mixed crystal molecular sieve bactericide loaded with metal copper and the balance of deionized water.

Comparative example 1

1) Same as step 2) of example 1;

2) same as step 3 of example 1);

3) the same mass of phenolic compound as that of the embodiment 1 is used for replacing the nano FAU-EMT mixed crystal molecular sieve bactericide of the loaded copper, and the other steps are the same as the step 4) of the embodiment 1;

4) same as step 5 of example 1).

Comparative example 2

1) Same as step 2) of example 1;

2) same as step 3 of example 1);

3) the same mass of formaldehyde condensate as that of the embodiment 1 is used for replacing the nano FAU-EMT mixed crystal molecular sieve bactericide for loading the metallic copper, and the other steps are the same as the step 4) of the embodiment 1);

4) same as step 5 of example 1).

Comparative example 3

1) Same as step 2) of example 1;

2) same as step 3 of example 1);

3) the same mass of amine borate as that of the embodiment 1 is used for replacing the nano FAU-EMT mixed crystal molecular sieve bactericide for loading the metal copper, and the other steps are the same as the step 4) of the embodiment 1);

4) same as step 5 of example 1).

The nano FAU-EMT mixed crystal molecular sieve bactericide loaded with metallic copper prepared in examples 1 to 4 is dispersed in deionized water, and formation of a colloidal solution can be observed, because the average grain size of the nano FAU-EMT mixed crystal molecular sieve is 5 to 95 nanometers, which meets the conditions for forming a colloid. Through 2 months of observation, the colloidal solution is still stable, which shows that the ultraviolet irradiation method can effectively avoid the agglomeration of the nano molecular sieve to generate the micron-scale molecular sieve, and further shows that the nano FAU-EMT mixed crystal molecular sieve loaded with the metallic copper can be stably dispersed in the cutting fluid for metal processing for a long time without forming precipitates.

The cutting fluids for metal working prepared in examples 1 to 4 and comparative examples 1 to 3 were placed in a laboratory for biological stability testing, the pH change of the cutting fluid for metal working was a standard parameter for the cutting fluid for metal working to deteriorate, and the more significant the pH change, the more serious the cutting fluid for metal working deteriorated, and the deteriorated cutting fluid for metal working resulted in the reduction of the lubricity, rust prevention, stability and other properties of the cutting fluid for metal working, and caused wear and corrosion to machines, work pieces, and working tools. In addition, the odor change of the cutting fluid for metal working is another standard parameter for the cutting fluid for metal working to generate putrefaction, for example, the cutting fluid for metal working can release a trace amount of hydrogen sulfide gas with strong toxicity and odor due to the reducing sulfate bacteria, and the larger the odor is, the more serious the cutting fluid for metal working generates putrefaction, the generated odor can affect the environment of a factory, irritate the skin and respiratory tract of an operator, and the like, and seriously affect the body health of a user.

As can be seen from table 1, the pH changes of examples 1 to 4 using the metal copper-loaded nano molecular sieve bactericide were small (0.8 to 1.3%), while the pH changes of comparative examples 1 to 3 using the common formaldehyde condensate, phenolic compound, and amine borate were significant (5.3 to 7.2%), and the examples 1 to 4 using the metal-loaded nano molecular sieve bactericide did not have any odor after 6 weeks of testing, while the comparative examples 1, 2, and 3 using the common formaldehyde condensate, phenolic compound, and amine borate had significant malodorous odors at 4 weeks, 5 weeks, and 4 weeks, respectively. Through the standards of pH value and bad smell, the biological stability and the anti-putrefaction performance of the examples 1-4 are obviously superior to those of the comparative examples 1-3, which shows that the nano FAU-EMT molecular sieve loaded with the metal copper adopted in the examples 1-4 has excellent bactericidal performance, and the mixed crystal molecular sieve of the nano EMT and the nano FAU can fully play a synergistic effect in a nano scale, so that the bactericidal effect is greatly promoted.

TABLE 1 pH and biostability of cutting fluids for metalworking prepared in examples 1-4 and comparative examples 1-3

It is emphasized that the skin, eyes and the like of the user inevitably come into contact with the cutting fluid for metal working when the cutting fluid for metal working is used, and the chemical bactericides such as the formaldehyde condensate, the phenol compound, the amine borate and the like in comparative examples 1 to 3 seriously affect the physical health of the user. Chinese patent 201710313546.6 clearly states that formaldehyde condensates, phenolic compounds, amine borates, etc. have been banned from use in developed countries in europe and america. The metal-loaded nano-molecular sieves used in examples 1-4 have been proven to be non-toxic and harmless to human body (Laurent, S, etc., Corona protein composition and cytoxicity evaluation of ultra-small zeolite synthesized from platelet precursors. toxicol. Res.2013,2, 270-shaped 279). The safety to human bodies is an important feature that examples 1-4 are superior to comparative examples 1-3.

The results of the lubricity tests of the cutting fluids for metal working prepared in examples 1 to 4 and comparative examples 1 to 3 are shown in table 2, the smaller the tapping torque value is, the better the lubricating performance is, and it can be seen from table 2 that the lubricating performance of examples 1 to 4 of the present invention is significantly better than that of comparative examples 1 to 3 on representative iron and aluminum workpieces.

TABLE 2 lubricating properties of cutting fluids for metal working prepared in examples 1 to 4 and comparative examples 1 to 3

Tapping torque value (Ncm)	Example 1	Example 2	Example 3	Example 4
					Aluminum workpiece (Al 6021)	88	90	87	87
Iron work (304)	104	102	105	102
					Tapping torque value (Ncm)	Comparative example 1	Comparative example 2	Comparative example 3
Aluminum workpiece (Al 6021)	98	100	92
					Iron work (304)	123	125	120

The defoaming performance test results of the cutting fluids for metal processing prepared in examples 1 to 4 and comparative examples 1 to 3 are shown in table 3, the lower the defoaming height and the shorter the defoaming time, the better the defoaming performance, and it can be seen from table 3 that the defoaming performance of examples 1 to 4 of the present invention is significantly better than that of comparative examples 1 to 3.

TABLE 3 defoaming Properties of cutting fluids for metalworking prepared in examples 1 to 4 and comparative examples 1 to 3

Sample (I)	Example 1	Example 2	Example 3	Example 4
					Defoaming height (ml)	52	51	54	48
Defoaming time (minutes)	16	15	19	20
					Sample (I)	Comparative example 1	Comparative example 2	Comparative example 3
Defoaming height (ml)	82	76	78
					Defoaming time (minutes)	39	35	40

From tables 1, 2 and 3, the following conclusions can be drawn: the environment-friendly bactericide of the metal-loaded nano FAU-EMT mixed crystal molecular sieve can replace common chemical bactericides such as toxic formaldehyde condensation compounds, phenolic compounds, amine borate and the like, and avoids the pollution of the common chemical bactericides to the environment and the harm of users. The environment-friendly bactericide of the metal-loaded nano FAU-EMT mixed crystal molecular sieve can fully play the synergistic bactericidal action of different molecular sieves in a nano scale. The cutting fluid containing the nano FAU-EMT mixed crystal molecular sieve bactericide loaded with the metallic copper for metal processing has good bactericidal effect and biological stability, can meet the requirements of lubrication, cooling, emulsion stability, corrosion resistance and the like required in field processing, and has the characteristics of safety and environmental protection.