Microemulsified metal cutting fluid and preparation method thereof

Abstract

The invention discloses a micro-emulsified metal cutting fluid, and relates to the technical field of lubricating compositions, the micro-emulsified metal cutting fluid comprises the following components by weight: 10-30 parts of base oil, 10-20 parts of a nonionic surfactant, 5-15 parts of a substance A, and 30-60 parts of water, the substance A has a cross-linked network structure, and the substance B has a cross-linked network structure. The substance A is obtained by carrying out cross-linking polymerization on amino boric acid ester and hydroxyl-containing unsaturated polyester resin. The amino boric acid ester and the hydroxyl-containing unsaturated polyester resin are subjected to cross-linking polymerization to obtain a substance A with a cross-linked three-dimensional network structure, and the substance A is added into the basic liquid, so that the boundary lubricating capacity of the metal cutting fluid can be improved when the metal cutting fluid is applied to aerospace high-temperature alloy processing.

Description

Technical Field

[0001] The present application relates to the technical field of lubricating compositions, and in particular to a microemulsified metal cutting fluid and a preparation method thereof. Background Art

[0002] In the aerospace industry, superalloys, thanks to their exceptional high-temperature strength, oxidation resistance, hot corrosion resistance, and fatigue resistance, have become key materials for the manufacture of critical components in aircraft engines and spacecraft. However, the difficult-to-machine properties of superalloys, such as high hardness, high strength, and low thermal conductivity, place extremely stringent demands on cutting fluids used in the machining process. In metalworking, cutting fluids play an important role in cooling, lubricating, cleaning, and preventing rust.

[0003] Currently, microemulsified cutting fluids, a type of water-based cutting fluid, are being used in aerospace high-temperature alloy machining due to their excellent cooling performance, low oil mist generation, and relative environmental friendliness. However, when used in aerospace high-temperature alloy machining, water-based metal cutting fluids suffer from weak boundary lubrication. This leads to increased friction between the tool and the workpiece, accelerated tool wear, and a decrease in machined surface quality, such as increased surface roughness and scratches. This seriously affects the machining accuracy and service performance of aerospace components. Summary of the Invention

[0004] In view of this, the present application provides a microemulsified metal cutting fluid, which is used to provide a microemulsified metal cutting fluid with excellent performance in aspects such as boundary lubrication ability and can meet the various performance requirements of aerospace high-temperature alloy processing.

[0005] In a first aspect, the present application provides a microemulsified metalworking fluid comprising the following ingredients in parts by weight: 10-30 parts base oil, 10-20 parts nonionic surfactant, 5-15 parts substance A, and 30-60 parts water. Substance A has a crosslinked network structure, is a polymer having a crosslinked network structure, and is obtained by crosslinking and polymerizing an amino borate ester and a hydroxyl-containing unsaturated polyester resin. The fluid satisfies at least one of the following conditions: Condition I: The hydroxyl-containing unsaturated polyester resin is obtained by a condensation reaction of maleic anhydride, isophthalic acid, and propylene glycol; Condition II: The amino borate ester comprises α-amino borate.

[0006] This application involves adding a substance A containing a cross-linked network structure to a base fluid. The cross-linked network structure of substance A is obtained by cross-linking and polymerizing an amino borate ester and a hydroxyl-containing unsaturated polyester resin. Specifically, the amino borate ester and the hydroxyl-containing unsaturated polyester resin can form a cross-linked three-dimensional network structure through ester exchange or coordination, forming BOC covalent bonds or BO coordination bonds. This coordination bond is dynamically reversible, giving the material a certain self-repairing ability and continuously ensuring the lubrication effect.

[0007] The cross-linking polymerization of aminoborates and hydroxyl-containing unsaturated polyester resins enhances boundary lubrication. Even if the three-dimensional cross-linked network breaks under extreme pressure, its self-healing ability can repair the broken parts. If this repair is incomplete, the lubrication performance at the broken part will be weakened, shortening the overall service life. Therefore, self-healing can maintain protection for a longer period of time, thereby ensuring lubrication effectiveness. Furthermore, the cross-linked three-dimensional network structure, due to its unique spatial structure, provides support and cushioning even when the lubricating film is thin. This reduces direct contact between the tool and the workpiece, reduces friction and wear, and enhances boundary lubrication. A suitable cross-linked three-dimensional network structure possesses a large number of active groups that can tightly bind to the surface atoms of the superalloy through physical and chemical adsorption. This strong adsorption allows the lubricant to more easily form a continuous and stable lubricating film on the superalloy surface and resists desorption under the high temperatures, pressures, and shear forces encountered during machining, thereby improving the problem of a difficult to form lubricating film.

[0008] In some embodiments, the mass of the amino borate ester is denoted as a, and the mass of the hydroxyl-containing unsaturated polyester resin is denoted as b, with 0.3 ≤ a / b ≤ 0.8. Preferably, 0.6 ≤ a / b ≤ 0.8. And / or, the hydroxyl-containing unsaturated polyester resin has an average molecular weight of 2500-3000, a hydroxyl value of 25-30 mgKOH / g, and a primary hydroxyl content of greater than or equal to 70%. The α-amino borate ester includes at least phenylalanine α-amino borate, which is an α-amino borate compound formed from phenylalanine and borate. The resulting cross-linked network structure exhibits excellent mechanical and thermal stability, making it less susceptible to damage under the harsh conditions of high-temperature alloy processing.

[0009] In some embodiments, the microemulsified metal cutting fluid further comprises the following components by weight: 1-5 parts rust inhibitor, 1-5 parts cleaning agent, and 1-5 parts defoaming agent. Preferably, the microemulsified metal cutting fluid comprises the following components by weight: 25-30 parts base oil, 10-15 parts nonionic surfactant, 5-10 parts substance A, 50-60 parts water, 1-3 parts rust inhibitor, 1-3 parts cleaning agent, and 1-3 parts defoaming agent.

[0010] In some embodiments, the base oil includes at least one of soybean oil, cottonseed oil, palm oil, coconut oil, palm kernel oil, castor oil, olive oil, tea oil, linseed oil, or rapeseed oil.

[0011] In some embodiments, the nonionic surfactant includes at least one of polyoxyethylene sorbitan monolaurate, polyoxyethylene castor oil, polyoxyethylene stearate, polyoxyethylene stearyl glyceryl, polyoxyethylene laurate polyglyceryl, polyoxyethylene sucrose laurate, polyoxyethylene palmitic acid glyceryl or polyoxyethylene rosin acid ether.

[0012] In the second aspect, the present application provides a method for preparing a microemulsified metal cutting fluid, which comprises at least: mixing base oil, nonionic surfactant, rust inhibitor, cleaning agent, defoaming agent and water according to a ratio, heating and stirring to obtain a base liquid, cross-linking and polymerizing the dried amino borate and hydroxyl-containing unsaturated polyester resin to obtain substance A, adding substance A to the base liquid and placing it in a stirring environment of 80~120r / min for 20~30min to wrap the oil molecules in the cross-linked network.

[0013] In some embodiments, the heating and stirring temperature is 40 to 60° C., the time is 1 to 3 hours, and the cross-linking polymerization reaction temperature is 100 to 120° C.

[0014] The present application obtains substance A containing a cross-linked three-dimensional network structure by cross-linking polymerization of amino borate and hydroxyl-containing unsaturated polyester resin, and then fully mixes substance A containing the cross-linked three-dimensional network structure with a base liquid so that the oil molecules are wrapped and evenly dispersed in the cross-linked network. On the one hand, the cross-linked three-dimensional network structure has a large number of active groups, which can be tightly combined with the surface atoms of the high-temperature alloy through physical adsorption and chemical adsorption, thereby enhancing the boundary lubrication ability. On the other hand, it can also improve the uniformity of the oil phase dispersion, thereby improving the thermodynamic stability of the micro-emulsified metal cutting fluid. DETAILED DESCRIPTION

[0015] In order to make the purpose, technical solutions and advantages of this application more clear, the following further describes this application in detail with reference to the embodiments. It should be understood that the specific embodiments described herein are only used to explain this application and are not intended to limit this application.

[0016] Microemulsion metal cutting fluid

[0017] The invention comprises the following ingredients in parts by weight: 10-30 parts base oil, 10-20 parts nonionic surfactant, 5-15 parts substance A, and 30-60 parts water. Substance A has a cross-linked network structure and is obtained by cross-linking and polymerizing an amino borate ester and a hydroxyl-containing unsaturated polyester resin. The invention satisfies at least one of the following conditions: Condition I: The hydroxyl-containing unsaturated polyester resin is obtained by polycondensation of maleic anhydride, isophthalic acid, and propylene glycol; Condition II: The amino borate ester comprises an α-amino borate ester. The α-amino borate ester comprises at least phenylalanine α-amino borate, which is an α-amino borate compound formed from phenylalanine and a borate ester.

[0018] The microemulsified metal cutting fluid further comprises the following components in weight fractions: 1 to 5 parts of a rust inhibitor, 1 to 5 parts of a cleaning agent, and 1 to 5 parts of a defoaming agent.

[0019] The mass of the amino borate ester is denoted as a, and the mass of the hydroxyl-containing unsaturated polyester resin is denoted as b, wherein 0.3≤a / b≤0.8. a / b is 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, or within a range consisting of any two of the aforementioned values.

[0020] The hydroxyl-containing unsaturated polyester resin has an average molecular weight of 2500-3000 and a hydroxyl value of 25-30 mgKOH / g, wherein the primary hydroxyl content is greater than or equal to 70%. The average molecular weight is 2500, 2600, 2700, 2800, 2900, 3000, or within a range consisting of any two of the foregoing values. The hydroxyl value is 25 mgKOH / g, 26 mgKOH / g, 27 mgKOH / g, 28 mgKOH / g, 29 mgKOH / g, 30 mgKOH / g, or within a range consisting of any two of the foregoing values.

[0021] The microemulsified metal cutting fluid includes the following components in weight fractions: 25 to 30 parts of base oil, 10 to 15 parts of nonionic surfactant, 5 to 10 parts of substance A, 50 to 60 parts of water, 1 to 3 parts of rust inhibitor, 1 to 3 parts of cleaning agent, and 1 to 3 parts of defoaming agent.

[0022] The base oil comprises at least one of soybean oil, cottonseed oil, palm oil, coconut oil, palm kernel oil, castor oil, olive oil, tea oil, linseed oil or rapeseed oil; and / or,

[0023] The nonionic surfactant includes at least one of polyoxyethylene sorbitan monolaurate, polyoxyethylene castor oil, polyoxyethylene stearate, polyoxyethylene stearate glyceryl, polyoxyethylene laurate polyglyceryl, polyoxyethylene sucrose laurate, polyoxyethylene palmitic acid glyceryl or polyoxyethylene rosin acid ether.

[0024] Preparation method

[0025] Mix the base oil, nonionic surfactant, rust inhibitor, cleaning agent, defoaming agent and water according to the ratio, heat and stir at 40 to 60°C for 1 to 3 hours to obtain a base liquid;

[0026] placing an amino borate ester and a hydroxyl-containing unsaturated polyester resin at 100 to 120° C. for a cross-linking polymerization reaction for 1 to 2 hours to obtain substance A;

[0027] Add substance A to the base liquid and stir at 80-120 r / min for 20-30 minutes.

[0028] The preparation of microemulsified metal cutting fluid is described below with reference to specific examples. Those skilled in the art will understand that the preparation method described in this application is only an example, and any other suitable preparation method is within the scope of this application.

[0029] Example 1

[0030] A micro-emulsified metal cutting fluid comprises the following raw materials in parts by weight: 25g of base oil, 15g of a nonionic surfactant, 10g of a substance A, 50g of water, 1g of a rust inhibitor, 1g of a cleaning agent, and 1g of a defoaming agent.

[0031] The base oil is soybean oil;

[0032] The nonionic surfactant is polyoxyethylene stearyl glyceryl;

[0033] The rust inhibitor is monoethanolamine borate;

[0034] The cleaning agent is triethanolamine oleate;

[0035] The defoamer is a polyether type defoamer;

[0036] The aminoboronate is phenylalanine α-aminoboronate;

[0037] The hydroxyl-containing unsaturated polyester resin has an average molecular weight of 2500, a hydroxyl value of 28 mgKOH / g, a primary hydroxyl content of 70%, and a / b of 0.6.

[0038] The mass of substance A = (the mass of the aminoborate + the mass of the hydroxyl-containing unsaturated polyester resin). That is, if a + b = 10, then the mass of phenylalanine α-aminoborate is a = 0.6 × 6.25 = 3.75 g, and the mass of the hydroxyl-containing unsaturated polyester resin is b = 10 - 3.75 = 6.25 g. The calculations used in the following examples are similar and will not be repeated here.

[0039] Preparation method:

[0040] (1) According to the proportion, 25g soybean oil, 15g polyoxyethylene stearyl glyceride, 1g boric acid monoethanolamine, 1g oleic acid triethanolamine, 1g polyether defoamer and water were mixed, heated and stirred at 40°C for 1h to obtain a base liquid;

[0041] (2) According to the mass ratio, 3.75 g of dried phenylalanine α-amino borate and 6.25 g of hydroxyl-containing unsaturated polyester resin were placed in a reaction temperature environment of 105°C and stirred for 1.5 hours to obtain substance A;

[0042] (3) Substance A was added to the base fluid and stirred at 110 r / min for 30 min to obtain a microemulsified metal cutting fluid.

[0043] The preparation order of step (1) and step (2) is not specific.

[0044] Test Method

[0045] 1. Boundary lubrication ability test

[0046] Four-ball testing machine test (MQ-800 series four-ball friction testing machine)

[0047] Test conditions: speed 1200 r / min, load 392 N, test time 30 min, temperature 75°C. Pour the microemulsified cutting fluid into the sample cup and immerse the steel ball.

[0048] Test process: Start the equipment and record the change in friction torque. After the test, use a 50x microscope to measure the diameter of the wear spot on the steel ball. Measure three different positions on each steel ball and take the average value.

[0049] Test results: The average diameter of the four-ball wear spot is N≤0.1mm, and N is 0.06mm to 0.08mm.

[0050] 2. Stability performance test

[0051] Centrifugal stability test

[0052] Test method: Place the microemulsified cutting fluid into a centrifuge tube and centrifuge it at 3000r / min for 15 minutes. Observe whether precipitation or stratification occurs after centrifugation.

[0053] Measurement indicators: The mass of the sediment after centrifugation was measured by weighing method, and the sedimentation rate was calculated as sedimentation mass / initial sample mass × 100%.

[0054] Test results: precipitation rate ≤1%.

[0055] Example 2

[0056] A micro-emulsified metal cutting fluid comprises the following raw materials in parts by weight: 30g of base oil, 10g of a nonionic surfactant, 5g of a substance A, 60g of water, 3g of a rust inhibitor, 3g of a cleaning agent, and 3g of a defoaming agent.

[0057] The base oil is soybean oil;

[0058] The nonionic surfactant is polyoxyethylene stearyl glyceryl;

[0059] The rust inhibitor is monoethanolamine borate;

[0060] The cleaning agent is triethanolamine oleate;

[0061] The defoamer is a polyether type defoamer;

[0062] The aminoboronate is phenylalanine α-aminoboronate;

[0063] The hydroxyl-containing unsaturated polyester resin has an average molecular weight of 2500, a hydroxyl value of 28 mgKOH / g, a primary hydroxyl content of 70%, and a / b of 0.8.

[0064] The preparation method is the same as that of Example 1. Test results show that the average diameter of the four-ball wear spot N is ≤ 0.1 mm, N is 0.06 mm to 0.08 mm, and the precipitation rate is ≤ 2%.

[0065] Example 3

[0066] A micro-emulsified metal cutting fluid comprises the following raw materials in parts by weight: 10g of base oil, 20g of a nonionic surfactant, 15g of a substance A, 30g of water, 1g of a rust inhibitor, 1g of a cleaning agent, and 1g of a defoaming agent.

[0067] The base oil is soybean oil;

[0068] The nonionic surfactant is polyoxyethylene stearyl glyceryl;

[0069] The rust inhibitor is monoethanolamine borate;

[0070] The cleaning agent is triethanolamine oleate;

[0071] The defoamer is a polyether type defoamer;

[0072] The aminoboronate is phenylalanine α-aminoboronate;

[0073] The hydroxyl-containing unsaturated polyester resin has an average molecular weight of 2500, a hydroxyl value of 28 mgKOH / g, a primary hydroxyl content of 70%, and a / b of 0.6.

[0074] The preparation method is the same as that of Example 1. Test results show that the average diameter of the four-ball wear spots N is ≤ 0.3 mm, N is 0.26 mm to 0.28 mm, and the precipitation rate is ≤ 3%.

[0075] Example 4

[0076] A micro-emulsified metal cutting fluid comprises the following raw materials in parts by weight: 25g of base oil, 15g of a nonionic surfactant, 10g of a substance A, 50g of water, 1g of a rust inhibitor, 1g of a cleaning agent, and 1g of a defoaming agent.

[0077] The base oil is tea oil;

[0078] The nonionic surfactant is stearic acid polyoxyethylene ether;

[0079] The rust inhibitor is monoethanolamine borate;

[0080] The cleaning agent is triethanolamine oleate;

[0081] The defoamer is a polyether type defoamer;

[0082] The aminoboronate is phenylalanine α-aminoboronate;

[0083] The hydroxyl-containing unsaturated polyester resin has an average molecular weight of 3000, a hydroxyl value of 25 mgKOH / g, a primary hydroxyl content of 75%, and a / b of 0.6.

[0084] The preparation method is the same as that of Example 1. Test results show that the average diameter of the four-ball wear spot N is ≤ 0.1 mm, N is 0.08 mm to 0.1 mm, and the precipitation rate is ≤ 3%.

[0085] Example 5

[0086] A micro-emulsified metal cutting fluid comprises the following raw materials in parts by weight: 25g of base oil, 15g of a nonionic surfactant, 10g of a substance A, 50g of water, 1g of a rust inhibitor, 1g of a cleaning agent, and 1g of a defoaming agent.

[0087] The base oil is soybean oil;

[0088] The nonionic surfactant is polyoxyethylene stearyl glyceryl;

[0089] The rust inhibitor is monoethanolamine borate;

[0090] The cleaning agent is triethanolamine oleate;

[0091] The defoamer is a polyether type defoamer;

[0092] The aminoboronate is phenylalanine α-aminoboronate;

[0093] The hydroxyl-containing unsaturated polyester resin has an average molecular weight of 2500, a hydroxyl value of 35 mgKOH / g, a primary hydroxyl content of 70%, and a / b of 0.6.

[0094] The preparation method was the same as in Example 1. Test results showed that the average diameter of the four-ball wear spot, N, was ≤ 0.3 mm, with N ranging from 0.28 mm to 0.3 mm, and the precipitation rate was ≤ 8%. The inventors speculate that this may be due to the excessively high crosslinking density of the hydroxyl-containing unsaturated polyester resin, which has a hydroxyl value greater than 30 mgKOH / g. This reduces the degree of freedom of the molecular chains and forms a rigid network structure, which is easily broken, resulting in a significantly increased precipitation rate.

[0095] Example 6

[0096] A micro-emulsified metal cutting fluid comprises the following raw materials in parts by weight: 25g of base oil, 15g of a nonionic surfactant, 10g of a substance A, 50g of water, 1g of a rust inhibitor, 1g of a cleaning agent, and 1g of a defoaming agent.

[0097] The base oil is soybean oil;

[0098] The nonionic surfactant is polyoxyethylene stearyl glyceryl;

[0099] The rust inhibitor is monoethanolamine borate;

[0100] The cleaning agent is triethanolamine oleate;

[0101] The defoamer is a polyether type defoamer;

[0102] The aminoboronate is phenylalanine α-aminoboronate;

[0103] The hydroxyl-containing unsaturated polyester resin has an average molecular weight of 1500, a hydroxyl value of 25 mgKOH / g, a primary hydroxyl content of 75%, and a / b of 0.6.

[0104] The preparation method was the same as in Example 1. Test results showed that the average diameter of the four-ball wear spot, N, was ≤ 0.3 mm, with N ranging from 0.28 mm to 0.3 mm, and the precipitation rate was ≤ 8%. The inventors speculate that this may be due to the fact that when the average molecular weight of the hydroxyl-containing unsaturated polyester resin is less than 2500, the low-molecular-weight polyester has short molecular chains and small spacing between hydroxyl functional groups. When cross-linked with aminoboronic acid ester, it tends to form a short-chain or highly branched fragmented network, rather than a continuous macromolecular network structure, resulting in a significantly improved precipitation rate.

[0105] Example 7

[0106] A micro-emulsified metal cutting fluid comprises the following raw materials in parts by weight: 25g of base oil, 15g of a nonionic surfactant, 10g of a substance A, 50g of water, 1g of a rust inhibitor, 1g of a cleaning agent, and 1g of a defoaming agent.

[0107] The base oil is soybean oil;

[0108] The nonionic surfactant is polyoxyethylene stearyl glyceryl;

[0109] The rust inhibitor is monoethanolamine borate;

[0110] The cleaning agent is triethanolamine oleate;

[0111] The defoamer is a polyether type defoamer;

[0112] The aminoboronate is phenylalanine α-aminoboronate;

[0113] The hydroxyl-containing unsaturated polyester resin has an average molecular weight of 2500, a hydroxyl value of 25 mgKOH / g, a primary hydroxyl content of 65%, and a / b of 0.6.

[0114] The preparation method was the same as in Example 1. Test results showed that the average diameter of the four-ball wear spot, N, was ≤ 0.3 mm, with N ranging from 0.28 mm to 0.3 mm, and the precipitation rate was ≤ 8%. The inventors speculate that this may be due to the fact that when the primary hydroxyl content of the hydroxyl-containing unsaturated polyester resin is less than 70%, the crosslinking degree is insufficient, forming a loose, porous network structure that is easily broken by shear force or water penetration, resulting in a significantly increased precipitation rate.

[0115] Example 8

[0116] A micro-emulsified metal cutting fluid comprises the following raw materials in parts by weight: 30g of base oil, 10g of a nonionic surfactant, 5g of a substance A, 60g of water, 3g of a rust inhibitor, 3g of a cleaning agent, and 3g of a defoaming agent.

[0117] The base oil is soybean oil;

[0118] The nonionic surfactant is polyoxyethylene stearyl glyceryl;

[0119] The rust inhibitor is monoethanolamine borate;

[0120] The cleaning agent is triethanolamine oleate;

[0121] The defoamer is a polyether type defoamer;

[0122] The aminoboronate is phenylalanine α-aminoboronate;

[0123] The hydroxyl-containing unsaturated polyester resin has an average molecular weight of 2500, a hydroxyl value of 28 mgKOH / g, a primary hydroxyl content of 70%, and a / b of 0.4.

[0124] The preparation method is the same as that of Example 1. Test results show that the average diameter of the four-ball wear spot N is ≤ 0.2 mm, N is 0.18 mm to 0.2 mm, and the precipitation rate is ≤ 2%.

[0125] Example 9

[0126] A micro-emulsified metal cutting fluid comprises the following raw materials in parts by weight: 30g of base oil, 10g of a nonionic surfactant, 5g of a substance A, 60g of water, 3g of a rust inhibitor, 3g of a cleaning agent, and 3g of a defoaming agent.

[0127] The base oil is soybean oil;

[0128] The nonionic surfactant is polyoxyethylene stearyl glyceryl;

[0129] The rust inhibitor is monoethanolamine borate;

[0130] The cleaning agent is triethanolamine oleate;

[0131] The defoamer is a polyether type defoamer;

[0132] The aminoboronate is phenylalanine α-aminoboronate;

[0133] The hydroxyl-containing unsaturated polyester resin has an average molecular weight of 2500, a hydroxyl value of 28 mgKOH / g, a primary hydroxyl content of 70%, and a / b of 0.25.

[0134] The preparation method is the same as that of Example 1. Test results show that the average diameter of the four-ball wear spots N is ≤ 0.6 mm, N is 0.56 mm to 0.58 mm, and the precipitation rate is ≤ 5%.

[0135] Comparative Example 1

[0136] A microemulsified metal cutting fluid comprises the following raw materials in parts by weight: 25g of base oil, 15g of a nonionic surfactant, 10g of phenylalanine α-amino borate, 50g of water, 1g of a rust inhibitor, 1g of a cleaning agent, and 1g of a defoaming agent.

[0137] The base oil is soybean oil;

[0138] The nonionic surfactant is polyoxyethylene stearyl glyceryl;

[0139] The rust inhibitor is monoethanolamine borate;

[0140] The cleaning agent is triethanolamine oleate;

[0141] The defoaming agent is a polyether type defoaming agent.

[0142] Preparation method:

[0143] Soybean oil, polyoxyethylene stearin, monoethanolamine borate, triethanolamine oleate, and a polyether defoamer were mixed with water in a specific proportion and heated with stirring at 40°C for 1 hour to obtain a base solution. Phenylalanine α-amino borate was then added to the base solution and stirred at 110 rpm for 30 minutes. Test results showed that the average diameter of the four-ball wear spot was greater than 0.6 mm, and the precipitation rate was greater than 8%.

[0144] Comparative Example 2

[0145] A micro-emulsified metal cutting fluid comprises the following raw materials in parts by weight: 25g of base oil, 15g of nonionic surfactant, 10g of hydroxyl-containing unsaturated polyester resin, 50g of water, 1g of rust inhibitor, 1g of cleaning agent, and 1g of defoaming agent.

[0146] The base oil is soybean oil;

[0147] The nonionic surfactant is polyoxyethylene stearyl glyceryl;

[0148] The rust inhibitor is monoethanolamine borate;

[0149] The cleaning agent is triethanolamine oleate;

[0150] The defoamer is a polyether type defoamer;

[0151] The hydroxyl-containing unsaturated polyester resin has an average molecular weight of 2500, a hydroxyl value of 28 mgKOH / g, and a primary hydroxyl content of 70%.

[0152] Preparation method:

[0153] Soybean oil, polyoxyethylene stearyl glyceryl, monoethanolamine borate, triethanolamine oleate, and a polyether defoamer were mixed with water in a specific proportion and heated with stirring at 40°C for 1 hour to obtain a base solution. A hydroxyl-containing unsaturated polyester resin was then added to the base solution and stirred at 110 rpm for 30 minutes. Test results showed that the average diameter of the four-ball wear spot was >0.6 mm, and the precipitation rate was >8%.

[0154] Comparative Example 3

[0155] A micro-emulsified metal cutting fluid comprises the following raw materials in parts by weight: 25g of base oil, 15g of a nonionic surfactant, 10g of a substance A, 50g of water, 1g of a rust inhibitor, 1g of a cleaning agent, and 1g of a defoaming agent.

[0156] The base oil is soybean oil;

[0157] The nonionic surfactant is polyoxyethylene stearyl glyceryl;

[0158] The rust inhibitor is monoethanolamine borate;

[0159] The cleaning agent is triethanolamine oleate;

[0160] The defoamer is a polyether type defoamer;

[0161] The aminoboronate is phenylalanine α-aminoboronate;

[0162] The hydroxyl-containing unsaturated polyester resin has an average molecular weight of 2500, a hydroxyl value of 28 mgKOH / g, a primary hydroxyl content of 70%, and a / b of 0.6.

[0163] Preparation method:

[0164] (1) Soybean oil, polyoxyethylene stearyl glyceryl, monoethanolamine borate, triethanolamine oleate, polyether defoamer and water were mixed in proportion, heated and stirred at 40°C for 1 hour to obtain a base liquid;

[0165] (2) According to the mass ratio, the dried amino borate and hydroxyl-containing unsaturated polyester resin were stirred at 45°C for 1.5 hours;

[0166] (3) Add the product of step (2) to the base liquid and stir at 110 r / min for 30 min. Test results: The average diameter of the four-ball wear spot is greater than 0.6 mm, and the precipitation rate is greater than 8%.

[0167] The above are only preferred embodiments of the present application and are not intended to limit the present application. Any modifications, equivalent replacements, and improvements made within the spirit and principles of the present application should be included in the scope of protection of the present application.

Claims

1. A microemulsified metal cutting fluid, characterized in that: The composition comprises the following components in parts by weight: 10 to 30 parts of base oil, 10 to 20 parts of nonionic surfactant, 5 to 15 parts of substance A, and 30 to 60 parts of water; The substance A has a cross-linked network structure, and the substance A is obtained by cross-linking polymerization of amino borate and hydroxyl-containing unsaturated polyester resin; And at least one of the following conditions is met: Condition I: The hydroxyl-containing unsaturated polyester resin is obtained by polycondensation of maleic anhydride, isophthalic acid and propylene glycol; Condition II: The aminoboronic acid ester includes α-aminoboronic acid ester.

2. The microemulsified metal cutting fluid according to claim 1, characterized in that The mass of the amino borate ester is denoted as a, and the mass of the hydroxyl-containing unsaturated polyester resin is denoted as b, satisfying the following: 0.3≤a / b≤0.

8.

3. The microemulsified metal cutting fluid according to claim 2, characterized in that 0.6≤a / b≤0.

8.

4. The microemulsified metal cutting fluid according to claim 1 or 2, characterized in that: The hydroxyl-containing unsaturated polyester resin has an average molecular weight of 2500-3000 and a hydroxyl value of 25-30 mgKOH / g, wherein the primary hydroxyl content is greater than or equal to 70%.

5. The microemulsified metal cutting fluid according to claim 1 or 2, characterized in that: The α-amino borate ester includes at least phenylalanine α-amino borate; The phenylalanine α-amino borate is an α-amino borate compound formed by phenylalanine and borate.

6. The microemulsified metal cutting fluid according to claim 3, characterized in that The following weight fractions are also included: 1 to 5 parts of rust inhibitor, 1 to 5 parts of cleaning agent, and 1 to 5 parts of defoaming agent.

7. The microemulsified metal cutting fluid according to claim 6, characterized in that: The following ingredients are included in weight fractions: 25 to 30 parts of base oil, 10 to 15 parts of nonionic surfactant, 5 to 10 parts of substance A, 50 to 60 parts of water, 1 to 3 parts of rust inhibitor, 1 to 3 parts of cleaning agent, and 1 to 3 parts of defoaming agent.

8. The microemulsified metal cutting fluid according to claim 1, characterized in that The base oil comprises at least one of soybean oil, cottonseed oil, palm oil, coconut oil, palm kernel oil, castor oil, olive oil, tea oil, linseed oil or rapeseed oil; and / or, The nonionic surfactant includes at least one of polyoxyethylene sorbitan monolaurate, polyoxyethylene castor oil, polyoxyethylene stearate ether, polyoxyethylene stearate glyceryl, polyoxyethylene laurate polyglyceryl, polyoxyethylene sucrose laurate, polyoxyethylene palmitate glyceryl or polyoxyethylene rosin acid ether.

9. The method for preparing a microemulsified metal cutting fluid according to any one of claims 6 to 8, wherein: The preparation method at least comprises: According to the ratio, the base oil, the nonionic surfactant, the rust inhibitor, the cleaning agent, the defoaming agent and water are mixed, heated and stirred to obtain a base liquid; Cross-linking and polymerizing the amino borate and the hydroxyl-containing unsaturated polyester resin to obtain substance A; Add the substance A into the base liquid and stir at 80-120 r / min for 20-30 min to obtain the product.

10. The preparation method according to claim 9, characterized in that The heating and stirring temperature is 40 to 60° C., and the time is 1 to 3 hours. The cross-linking polymerization reaction temperature is 100 to 120° C., and the time is 1 to 2 hours.