Synthesis method of low-foam hard-water-resistant fatty acid amide and metal cutting lubricant composition

Abstract

The invention discloses a preparation method of low-foam hard-water-resistant fatty acid amide and a metal cutting lubricant composition, amide is prepared from mixed fatty acid and mixed amine, foam of diglycolamine can be reduced through the characteristic of slight soap precipitation of dimer acid, and application difficulty of customers caused by high-foam products is avoided. Meanwhile, a part of a diisopropanolamine product is degraded in a primary amine form through diglycolamine (especially a byproduct ester of a reaction of diisopropanolamine and fatty acid, and the ester can be hydrolyzed to separate out a large amount of fatty acid, resulting in reduction of hard water resistance of a system), and the overall HLB of the product is increased by using high-HLB diglycolamine amide, so that the hard water resistance of the product is improved. According to the method, the condition that the HLB (Hydrophile-Lipophile Balance) of a product is reduced when diethanol amine is replaced by diisopropanolamine, so that the formula incompatibility of customers is caused, and the adjustability of the formula is reduced is avoided, the product with excellent performance can be prepared, and the product has good quality and stability.

Description

Technical Field

[0001] The invention belongs to the technical field of organic synthesis, and in particular relates to a synthesis method of amide compounds used in semi-synthetic metalworking fluids and a cutting lubricant. Background Art

[0002] Metalworking cutting fluids are used for various stamping, drawing, cutting, grinding and other operations on various materials. Products need to meet the requirements of cooling, lubricity, cleanliness and environmental safety. There are many types of metalworking fluids. In terms of composition, metalworking fluids can be roughly divided into pure oils, chemical fluids (fully synthetic fluids) and semi-chemical fluids (semi-synthetic fluids). Currently, semi-synthetic metalworking fluids on the market have good lubricity and cooling properties. Amides are usually used in their formulas as multi-functional lubricants and emulsifiers. Common amides mainly wrap various types of coconut oil amides such as 6501 and 6502, and also contain diethanolamine amides of tall oil and oleic acid. The free diethanolamine in the product is easy to form nitrosamines with sodium nitrite in the formula of metalworking fluids, which is highly carcinogenic. It is necessary to improve existing products, take into account price, performance and formula compatibility, and form practical products. In the prior art, when diisopropanolamine is used instead of diethanolamine, the hard water resistance and emulsification properties deteriorate. That is, due to the mismatch of HLB values, the emulsifier will be reduced. An additional emulsifier with a high HLB value is required to increase the HLB value (such as AEO9), but this will result in higher foam and cannot meet actual needs. Summary of the Invention

[0003] Purpose of the invention: In response to the defects and technical problems existing in the background technology, the present invention provides a method for preparing low-foaming and hard water-resistant fatty acid amide and a metal cutting lubricant composition, aiming to solve the harm to the human body caused by the large-scale use of cheap substitute diethanolamine in existing neutralizers, while meeting the requirements of formula harmony, lubricity and rust resistance in application.

[0004] Technical solution: To achieve the above-mentioned purpose of the invention, the present invention adopts the following technical solution: a method for synthesizing low-foaming and hard water-resistant fatty acid amide, comprising the following steps:

[0005] S1, in a reactor, after uniformly mixing dimer acid and oleic acid, add diisopropanolamine and stir to mix uniformly;

[0006] S2, under the protection of nitrogen flow, raise the temperature to 160±10℃ within 4 hours and keep it warm. Under the condition of maintaining nitrogen flow, fully react for 2-5 hours until the acid value of the reaction product stabilizes, and the reaction is completed;

[0007] S3, after the reaction product obtained in step S2 is cooled to 95-110° C., potassium hydroxide solution and diglycolamine are added to carry out aminolysis reaction, and stirred until the acid value meets the requirements;

[0008] In step S4, the reaction mixture is filtered to separate and remove unreacted potassium hydroxide to obtain the finished fatty acid amide. Furthermore, the molar ratio of dimer acid, oleic acid, and diisopropyl alcohol added in step S1 is (0.05-0.1):1:(1.2-1.5). Furthermore, in step S1, the temperature is maintained at 20-90°C when adding diisopropylamine.

[0009] Furthermore, in steps S2 and S3, the nitrogen flow rate in the 1 L reaction space is controlled at 200-550 mL / min.

[0010] Furthermore, in step S3, the mass percentage concentration of the potassium hydroxide solution is 40%, and the input amount of potassium hydroxide is 0.15-0.3% of the total input amount of dimer acid, oleic acid and diisopropyl alcohol.

[0011] Furthermore, the acid value in step S2 is controlled to be below 15 mgKOH / g; and the acid value in step S3 is controlled to be below 5 mgKOH / g.

[0012] Furthermore, in step S3, the added amount of diglycolamine is 30-50% of the molar amount of oleic acid, and the added amount of diisopropanolamine is 120-150% of the molar amount of oleic acid.

[0013] The present invention also provides a metal cutting lubricant composition, comprising the following components in parts by weight: 30-45 parts of 22# cycloalkyl base oil, 2-5 parts of tricarboxylic acid, 8-20 parts of triethanolamine, 3-10 parts of the above-mentioned fatty acid amide, and 3-10 parts of Genifol 1894 polymer ester.

[0014] Genifol 6062 alkoxy alcohol ether 3-10 parts, industrial pure water 20-50 parts, coupling agent (leveling) 2-5 parts.

[0015] Preferably, the 22# cycloalkyl base oil is selected from Northern Asphalt A1004, the tricarboxylic acid is BASF IRGACOR L190 PLUS, and the coupling agent is diethylene glycol butyl ether.

[0016] Beneficial effects: Compared with the prior art, the present invention prepares amides by mixing fatty acids and mixed amines, and can reduce the foam of diglycolamine by virtue of the slight soap precipitation property of dimer acid, thereby avoiding the application difficulties of customers caused by high-foam products. At the same time, a portion of diisopropanolamine products (especially esters, a by-product of the reaction of diisopropanolamine with fatty acids, which will hydrolyze to release a large amount of fatty acids, resulting in reduced hard water resistance of the system) are degraded by diglycolamine in the form of primary amines, and the high-HLB diglycolamine amide is used to raise the overall HLB of the product, thereby avoiding the reduction of the HLB of the product when diethanolamine is replaced by diisopropanolamine, causing incompatibility of the customer's formula and reduced compatibility of the formula, thereby preparing a product with excellent performance and good product quality and stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a picture of the wear spots after the long mold test of Example 1 of the present invention.

[0018] Figure 2 This is a picture of the wear spots after the long mold test of Example 2 of the present invention.

[0019] Figure 3 This is a picture of the wear spots after the long mold test of Example 3 of the present invention.

[0020] Figure 4 This is a picture of the wear spots after the long mold test of Example 4 of the present invention.

[0021] Figure 5 This is a picture of the wear spots after the long mold test of Example 5 of the present invention.

[0022] Figure 6 This is a picture of the wear spots of Example 9 of the present invention after long mold testing. DETAILED DESCRIPTION

[0023] The present invention is further illustrated below with reference to the accompanying drawings and specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and are not used to limit the scope of the present invention. After reading the present invention, modifications of various equivalent forms of the present invention made by those skilled in the art all fall within the scope defined by the claims attached to this application.

[0024] Example 1

[0025] Step 1. Prepare raw materials: dimer acid, oleic acid, diisopropanolamine, diglycolamine, potassium hydroxide, and deionized water, wherein: dimer acid is commercial product CAS-61788;89; oleic acid is an unsaturated fatty acid derived from ordinary vegetable oil, with a melting point of 8 to 18°C; diisopropanolamine, diglycolamine, and potassium hydroxide are all AR reagents.

[0026] Step 2, mixing process: first weigh 0.05 mol of dimer acid and 1 mol of oleic acid respectively and mix them. At a stirring speed of not less than 200 rpm, the weighed dimer acid and oleic acid are mixed. Then, at room temperature not less than 20°C, 1.2 mol of diisopropanolamine is slowly added. The feeding speed of diisopropanolamine needs to be controlled (the feeding is completed in about 4 hours) to avoid the reaction heating too fast. Heating above 90°C will cause the material to turn red by side reaction.

[0027] Step 3, heating process: The above mixture is transferred into a 1L reactor and heated to a reaction temperature of 160±10° at a uniform rate over 4 hours under the protection of a nitrogen flow, maintaining a nitrogen flow rate of 200-550mL / min. Through experiments and experience, the inventors found that: because the nitrogen flow is too large, diisopropanolamine will be blown out, and the yield will be reduced by about 15-30%. However, the actual blowing situation is very complicated and will also affect the HLB value. Therefore, it is necessary to control the nitrogen flow rate not too low, otherwise it will lead to a slow reaction and the inability to desorb water. If it is too high, the diisopropanolamine will volatilize and the product yield will be reduced.

[0028] Step 4, insulation process: When the reaction temperature reaches the specified value (insulation at about 160°C, nitrogen flow dehydration, at which time the acid value of the reaction product remains essentially unchanged, and the acid value is less than 15 mgKOH / g), insulation and nitrogen flow are maintained for 3 hours to allow the reaction to proceed fully; during the reaction, the reaction progress can be controlled by monitoring the rate of decrease of the acid value of the reaction mixture;

[0029] Step 5, cooling process: the mixture after the reaction is naturally cooled to 95-110°C, and then 40% potassium hydroxide solution and 0.3 mol diglycolamine are added (the product of the previous step contains both amides and esters. The addition of saponification products converts the unreacted esters and acids into amides under the action of diglycolamine, thereby making the reaction more complete. This process is called aminolysis. The product after aminolysis contains lower free acid and ester, and its hydrolysis resistance and hard water resistance are better), stirred, and the acid value is 3.3 mgKOH / g, which is qualified.

[0030] Step 6, discharging process: the mixture after the reaction is filtered and separated (the purpose is to filter out the unreacted KOH) to obtain the finished product amide.

[0031] Examples 2-8

[0032] The difference between this embodiment and embodiment 1 is that the addition amount of each reaction raw material is different, as shown in Table 1 below.

[0033] Table 1

[0034]

[0035] Application performance test: Based on the fatty acid amide obtained in the above embodiment, a metal cutting lubricant was prepared according to the following component proportions, as shown in Table 2.

[0036] Table 2

[0037] Components Proportion,% Tricarboxylic acid (purchased from BASF IRGACORL190PLUS) 3 Triethanolamine (purchased from Dow TEA) 12 22# cycloalkyl base oil (purchased from Northern Asphalt A1004) 36 Low foaming hard water resistant fatty acid amide 5 Genifol 1894 polymer 5 Genifol6062 alkoxy alcohol ether 5 Coupling agent diethylene glycol butyl ether 3 Industrial pure water 30

[0038] The fatty acid amide obtained in Examples 1-9 was used to prepare a metal cutting fluid according to the above formula, and the foam height, rust resistance and hard water resistance were tested. The test results are shown in Table 3. The test method is as follows:

[0039] (1) Foam test method

[0040] Test instrument: Guangdong Platinum Metalworking Fluid Stability Tester, model: BSV-11

[0041] Test conditions are: temperature: 25°C; pressure: 2.5 kg; dilution concentration: 5% tap water dilution (150 ppm); cycle time: 10 min;

[0042] Test method: 1. Clean the metalworking fluid stability tester and set it aside; 2. Take 50g of each prepared finished sample, pour it into the instrument's measuring cylinder, then add 900ml of tap water to each sample, turn on the circulation pump and circulate for 1 minute, then turn it off; 3. After the foam on the liquid surface disappears, record the initial liquid level; 4. Turn on the circulation pump and circulate for 10 minutes, recording the foam height every 1 minute; 5. Stop the circulation at the same time after 10 minutes of circulation, and record the foam height and the time when the foam is completely eliminated every 1 minute.

[0043] (2) Hard water resistance test method

[0044] Test instrument: 100ml stoppered graduated cylinder;

[0045] Test conditions: 800ppm hard water, temperature 25℃;

[0046] Test method: 1. Clean two 100ml stoppered graduated cylinders and dry them for later use. 2. Add 45ml of 800ppm hard water to each cylinder, followed by 5ml of sample. 3. Shake the cylinders upside down 20 times to fully dissolve the sample in the hard water. 4. Leave the prepared liquid on the bench and observe the liquid state after 24 hours to check for precipitation, oil precipitation, soap precipitation, etc.

[0047] (3) Tapping torque test method

[0048] Testing instrument: German tapping torque machine TTT microtap G8;

[0049] Test conditions: Test plate: 7075 aluminum alloy, tap: M4F, speed: 1500 rpm, hole depth: 12 mm. Test method: 1. Preheat the tapping torque machine and set the test parameters. 2. Drop the prepared sample into the plate hole (be careful not to leave any air in the hole) and apply it to the tap surface to completely wet it. 3. After the tap is aligned with the hole, fix the position, turn on the motor, and gently press the handle to accurately tap the tap into the plate hole. 4. Collect tapping data and repeat the tapping operation in steps 2 / 3 four times. 5. Use the instrument processing software to compare the average of the four experimental data and draw conclusions.

[0050] (4) Semi-synthetic solution PB value test method

[0051] Testing instrument: Xiamen Tianji four-ball friction tester MS-10A

[0052] Test conditions: motor speed: 1450rpm, temperature: 25℃, dilution ratio: 5% tap water dilution test method: 1. Turn on the four-ball friction tester to preheat and set the parameters; 2. Set the Pb parameters, refer to the standard GB / T3142; 3. Add corresponding weights according to the test level; 4. Place three steel balls in the oil cup and one steel ball in the spindle, and tighten them; 5. Pour the oil sample to be tested into the oil cup, and the liquid level should be consistent with the scale line on the inner wall of the oil cup, about 15mL; 6. Place the oil cup with the oil sample under the spindle, lower the lever arm, add weights, and lower the spindle oil cup retaining ring; 7. Turn on the motor switch and start the test. After the test is completed, first turn off the motor switch, then record the friction curve and wear spot diameter, and draw conclusions after summarizing the data.

[0053] (5) Long wear test method

[0054] Testing instrument: Xiamen Tianji four-ball friction tester MS-10A

[0055] Test conditions: motor speed: 1200rpm, initial temperature: 40℃, pressure level: 40Kg; long grinding time: 30min; dilution ratio: 5% tap water dilution test method: 1. Turn on the four-ball friction tester to preheat and set the parameters; 2. Set the long grinding parameters, refer to the standard GB / T3142; 3. Add corresponding weights according to the test level; 4. Put three steel balls in the oil cup and one steel ball in the spindle, and tighten them; 5. Pour the oil sample to be tested into the oil cup, and the liquid level height is consistent with the scale line on the inner wall of the oil cup, about 15mL; 6. Place the oil cup with the oil sample under the spindle, lower the lever arm, add weights, and lower the spindle oil cup retaining ring; 7. Turn on the motor switch and start the test. After the test is completed, first turn off the motor switch, then record the friction curve and wear spot diameter, and draw conclusions after summarizing the data.

[0056] Table 3

[0057]

[0058] From the results in Table 3, it can be seen that: As can be seen from the above table, Formulas 6 and 7 are formulas without diglycolamine compared with the same period last year. Because the HLB value exceeds the range of the formula emulsifier, the formula is turbid and the formula tolerance is poor. Example 9 is a conventional oleic acid and tall oil acid ethylene glycol amine formula, with deviated lubricity, average foam height, and good hard water resistance. However, after replacing diethanolamine with diisopropanolamine in equal moles, that is, Example 8, the formula is still turbid and has poor controllability.

[0059] By comparing Examples 1, 2, 3, 4, and 5, it can be observed that with a large amount of diglycolamine added, the overall hard water resistance will be improved, but the foam and HLB value will also be relatively large. The addition of dimer acid can suppress the foam to a certain extent and improve lubrication. However, with an increase in the amount of dimer acid added, the hard water resistance of the system will decrease. It reaches an extreme value in specific Example 5, with a hard water resistance of 500 ppm, a dimer acid addition amount of 0.1 mol, and a diglycolamine amount of 0.3 mol. However, at this time, the lubricity is the best and the foam is the lowest. Comparing the data, it can be observed that dimer acid and diglycolamine have an antagonistic relationship in foam and hard water resistance, and it is necessary to provide differentiated and diversified products based on the formula and performance.

[0060] The following illustrates the use of abrasion scars. For long-term abrasion, the sample was diluted with 5% tap water, 40 kg, and tested at 1200 rpm for 30 minutes at room temperature. After the long-term abrasion test, the test sample was removed from the oil cup and the surfaces of the three steel balls in the oil cup were cleaned with anhydrous ethanol. After cleaning, the oil cup was placed under a microscope for observation. The position of the wear spots on the steel balls was adjusted and fixed using the knobs on the microscope base. Wear spot selection and measurement were performed using the wear spot observation software of the four-ball tribometer. The measurement results and images of the wear spots were saved to the computer hard drive using the software.

[0061] Table 4

[0062] Average friction coefficient Average scar, mm Example 1 0.098 0.427 Example 2 0.094 0.419 Example 3 0.089 0.393 Example 4 0.103 0.439 Example 5 0.087 0.392 Example 6 -(Formula is turbid) -(Formula is turbid) Example 7 -(Formula is turbid) -(Formula is turbid) Example 8 -(Formula is turbid) -(Formula is turbid) Example 9 0.11 0.423

[0063] from Figure 1-6 As shown in Table 4, the addition of dimer acid not only suppresses foaming, but also significantly improves the lubrication performance of the product. In particular, when compared with the similar product Example 9, it can be observed that even in Example 4, which has the smallest amount of dimer acid added and the largest amount of diglycolamine added, its lubrication performance is still better than that of the conventional product. In combination with Table 4, it can be seen that while maintaining high lubricity, the product still has relatively low foaming and hard water resistance.

[0064] The above embodiments are merely illustrative of the principles and effects of this application and are not intended to limit this application. Anyone skilled in the art may modify or alter the above embodiments without departing from the spirit and scope of this application. Therefore, all equivalent modifications or alterations made by one of ordinary skill in the art without departing from the spirit and technical concepts disclosed in this application shall be covered by the claims of this application.

Claims

1. A method for synthesizing low-foaming hard water resistant fatty acid amide, characterized in that The following steps are involved: S1, in a reactor, after uniformly mixing dimer acid and oleic acid, add diisopropanolamine and stir to mix uniformly; S2, under the protection of nitrogen flow, raise the temperature to 160±10℃ within 4 hours and keep it warm. Under the condition of maintaining nitrogen flow, fully react for 2-5 hours until the acid value of the reaction product stabilizes, and the reaction is completed; S3, after the reaction product obtained in step S2 is cooled to 95-110° C., potassium hydroxide solution and diglycolamine are added to carry out aminolysis reaction, and stirred until the acid value meets the requirements; S4, the mixture after the reaction is filtered and separated to remove unreacted potassium hydroxide to obtain the finished fatty acid amide.

2. The synthetic method of low-foaming hard water resistant fatty acid amide according to claim 1, wherein: The molar ratio of dimer acid, oleic acid and diisopropyl alcohol added in step S1 is (0.05-0.1):1:(1.2-1.5).

3. The synthetic method of low-foaming hard water resistant fatty acid amide according to claim 1, wherein: In step S1, the temperature is maintained at 20-90° C. when diisopropanolamine is added.

4. The synthetic method of low-foaming hard water resistant fatty acid amide according to claim 1, wherein: In steps S2 and S3, the nitrogen flow rate in the 1 L reaction space is controlled at 200-550 mL / min.

5. The method for synthesizing the low-foaming, hard water-resistant fatty acid amide according to claim 1, wherein: In step S3, the mass percentage concentration of the potassium hydroxide solution is 40%, and the input amount of potassium hydroxide is 0.15-0.3% of the total input amount of dimer acid, oleic acid and diisopropyl alcohol.

6. The method for synthesizing the low-foaming, hard water-resistant fatty acid amide according to claim 1, wherein: In step S2, the acid value is controlled to be below 15 mgKOH / g; in step S3, the acid value is controlled to be below 5 mgKOH / g.

7. The method for synthesizing the low-foaming, hard water-resistant fatty acid amide according to claim 1, wherein: In step S3, the added amount of diglycolamine is 30-50% of the molar amount of oleic acid, and the added amount of diisopropanolamine is 120-150% of the molar amount of oleic acid.

8. A metal cutting lubricant composition, characterized in that Includes the following mass parts: 30-45 parts of 22# naphthenic base oil, 2-5 parts of tricarboxylic acid, 8-20 parts of triethanolamine, 3-10 parts of the fatty embolic acid amide according to any one of claims 1-7, Genifol 1894 polymer 3-10 parts, Genifol 6062 alkoxy alcohol ether 3-10 parts, 20-50 parts of industrial pure water, 2-5 parts of coupling agent.

9. The metal cutting lubricant composition according to claim 8, characterized in that: The 22# cycloalkyl base oil is selected from Northern Asphalt A1004, the tricarboxylic acid is BASF IRGACOR L190 PLUS, and the coupling agent is diethylene glycol butyl ether.

Images