Highly hydrolytically stable organoborates, methods for their preparation and use as lubricating oil additives

Abstract

The application discloses high-hydrolysis-stability organic borate and a preparation method and application thereof as a lubricating oil additive. 4-formylphenyl boronic acid and phenylhydrazine compounds are added into an ethanol solvent, and stirring is continuously carried out at 80 DEG C for 5-6 hours; after the reaction is completed, the solvent is evaporated to obtain a crude product. The crude product is recrystallized to obtain an intermediate. The intermediate is added into a toluene solvent together with a fatty alcohol, and refluxing reaction is carried out at 110 DEG C for 12-13 hours; after the reaction is completed, the solvent is evaporated to obtain the target product, organic borate. The application solves and improves the problems of low hydrolysis stability, oil solubility and low heat resistance of the organic borate lubricating oil additive.

Description

Technical Field

[0001] This invention belongs to the field of fine chemicals, specifically relating to an organic borate ester lubricating oil additive with high hydrolytic stability and its preparation method. Background Technology

[0002] Modern instruments are developing towards higher power and higher loads, which will make friction between mechanical contact surfaces increasingly severe. Prolonged, high-intensity friction will exacerbate wear and tear on industrial instruments. Effectively reducing and controlling friction on the contact surfaces of industrial instruments and equipment is essential, and finding high-performance lubricants has always been an important direction for solving this problem.

[0003] Traditional lubricating oils are generally made by simply mixing different types of additives and base oils, which did meet certain needs for lubricating oils for a considerable period of time. However, with the continuous development of modern industry, traditional lubricating oil additives, such as phosphate ester extreme pressure anti-wear agents, chlorinated paraffins, and zinc dialkyl dithioaminophosphate, are gradually being restricted in their use due to their negative impacts on metals and the environment. Meanwhile, environmentally friendly organoboroesters are limited in their application due to their poor hydrolytic stability. Summary of the Invention

[0004] To overcome the problem of poor hydrolytic stability of organoboroesters, this invention provides an organoboroester with high hydrolytic stability and applies it as a lubricant additive.

[0005] The technical solution adopted in this invention is: a highly hydrolyzable organic borate ester, the preparation method of which includes the following steps:

[0006] 1) Add 4-formylphenylboronic acid and phenylhydrazine compounds to ethanol solvent and stir continuously at 80°C for 5-6 hours. After the reaction is completed, evaporate the solvent to obtain the crude product.

[0007] 2) The crude product obtained in step 1) is recrystallized to obtain an intermediate.

[0008] 3) Add the intermediate obtained in step 2) and the fatty alcohol to an organic solvent and reflux at 60-160℃ for 12-13 h. After the reaction is complete, evaporate the solvent to obtain the target product, organoboroester.

[0009] Furthermore, in the above-mentioned highly hydrolytically stable organoboroester, in step 1), the phenylhydrazine compound is 2,4-dinitrophenylhydrazine.

[0010] Furthermore, the above-mentioned highly hydrolytically stable organoboroesters are prepared in a molar ratio of 4-formylphenylboronic acid:2,4-dinitrophenylhydrazine = 1:1.

[0011] Furthermore, in the above-mentioned highly hydrolytically stable organoboroester, in step 2), the recrystallization solvent is anhydrous ethanol.

[0012] Furthermore, in the above-mentioned highly hydrolyzed stable organic borate ester, in step 3), the fatty alcohol is selected from n-dodecyl alcohol, n-hexadecyl alcohol, and n-eicosyl alcohol.

[0013] Furthermore, the above-mentioned highly hydrolyzed stable organoboroesters, in a molar ratio of intermediate:fatty alcohol 1:2.

[0014] Furthermore, in the above-mentioned highly hydrolytically stable organoboroester, in step 3), the organic solvent is toluene, acetonitrile, DMF, or tetrahydrofuran.

[0015] The application of the high hydrolysis stability organic borate ester provided by this invention as a lubricating oil additive.

[0016] Further, the method is as follows: mix the highly hydrolyzed stable organic borate ester with the base oil and sonicate for 30-40 minutes.

[0017] Furthermore, the amount of highly hydrolyzed stable organoboroester added is 0.01-0.1% of the base oil mass.

[0018] Furthermore, the base oil is liquid paraffin.

[0019] The beneficial effects of this invention are as follows: This invention discloses the preparation of an organoborolate lubricating oil additive material with high hydrolytic stability. It utilizes 4-formylphenylboronic acid and 2,4-dinitrophenylhydrazine as synthetic intermediates, increasing the hydrolytic stability of the phenylborolate by introducing nitrogen atoms. Furthermore, it introduces long alkyl chains through esterification with fatty alcohols, increasing the solubility of the organoborolate in oil. This invention solves and improves the problems of low hydrolytic stability, oil solubility, and low heat resistance in organoborolate lubricating oil additives. Attached Figure Description

[0020] Figure 1 This is the FTIR spectrum of Borate-12 prepared in Example 1.

[0021] Figure 2 This is a mapping image of Borate-12 prepared in Example 1.

[0022] Figure 3 This is a SEM-EDS image of Borate-12 prepared in Example 1. Detailed Implementation

[0023] The following examples are a detailed description of the invention, but not a limitation thereof.

[0024] Example 1

[0025] (I) Didodecyl (4-(2-(2,4-dinitrophenyl)hydrazide)methyl)phenylboronic acid bis(dodecanyl)ester, prepared by the following method:

[0026] 1. Preparation of the intermediate (4-(2-(2,4-dinitrophenyl)hydrazide)methyl)phenylboronic acid:

[0027] 4-Formylphenylboronic acid (10 mmol) and 2,4-dinitrophenylhydrazine (10 mmol) were dissolved in 30 mL of ethanol solution and stirred continuously at 80 °C for 6 h. After the reaction was completed, the mixture was allowed to stand, filtered, and the solvent was evaporated to obtain crude product yellowish-brown crystals.

[0028] The crude product was dissolved in anhydrous ethanol, recrystallized three times, filtered, and dried to obtain the intermediate (4-(2-(2,4-dinitrophenyl)hydrazide)methyl)phenylboronic acid.

[0029] 2. Preparation of organoboroester – (4-(2-(2,4-dinitrophenyl)hydrazide)methyl)phenylboronic acid disodium dodecyl ester:

[0030] The intermediate (10 mmol) and n-dodecyl alcohol (20 mmol) were dissolved in 30 mL of toluene solution and refluxed at 110 °C for 12 h. After the reaction was completed, the solvent was removed by rotary evaporation to obtain the product (4-(2-(2,4-dinitrophenyl)hydrazide)methyl)phenylboronic acid disodium dodecyl ester, labeled as Borate-12.

[0031] (II) Characterization

[0032] 1. The prepared Borate-12 was characterized by FTIR, and the results are as follows: Figure 1 As shown. Figure 1 The main functional groups shown in the figure all correspond to the target product, which indicates that the target product was successfully synthesized.

[0033] 2. The prepared Borate-12 was characterized by EA, and the results are shown in Table 1.

[0034] Table 1

[0035]

[0036] As shown in Table 1, the C, N, and H contents of the tested target product are similar to those of the target product, indicating that the target product was successfully synthesized.

[0037] Example 2

[0038] (4-(2-(2,4-dinitrophenyl)hydrazide)methyl)phenylboronic acid disodium dodecyl ester, prepared by the following method:

[0039] 1. Preparation of intermediate (4-(2-(2,4-dinitrophenyl)hydrazide)methyl)phenylboronic acid: Same as in Example 1.

[0040] 2. Preparation of organoboroester – (4-(2-(2,4-dinitrophenyl)hydrazide)methyl)phenylboronic acid disodium dodecyl ester:

[0041] The intermediate (10 mmol) and n-dodecyl alcohol (20 mmol) were dissolved in 30 mL of DMF solution and refluxed at 153 °C for 12 h. After the reaction was completed, the solvent was removed by rotary evaporation to obtain the product (4-(2-(2,4-dinitrophenyl)hydrazide)methyl)phenylboronic acid disodate, labeled as Borate-12.

[0042] Example 3

[0043] (4-(2-(2,4-dinitrophenyl)hydrazide)methyl)phenylboronic acid disodium dodecyl ester, prepared by the following method:

[0044] 1. Preparation of intermediate (4-(2-(2,4-dinitrophenyl)hydrazide)methyl)phenylboronic acid: Same as in Example 1.

[0045] 2. Preparation of organoboroester – (4-(2-(2,4-dinitrophenyl)hydrazide)methyl)phenylboronic acid disodium dodecyl ester:

[0046] The intermediate (10 mmol) and n-dodecyl alcohol (20 mmol) were dissolved in 30 mL of tetrahydrofuran solution and refluxed at 64 °C for 12 h. After the reaction was completed, the solvent was removed by rotary evaporation to obtain the product (4-(2-(2,4-dinitrophenyl)hydrazide)methyl)phenylboronic acid disodium dodecyl ester, labeled as Borate-12.

[0047] Example 4

[0048] (4-(2-(2,4-dinitrophenyl)hydrazide)methyl)phenylboronic acid dihexadecanyl ester, prepared by the following method:

[0049] 1. Preparation of intermediate (4-(2-(2,4-dinitrophenyl)hydrazide)methyl)phenylboronic acid: Same as in Example 1.

[0050] 2. Preparation of organoboroester – (4-(2-(2,4-dinitrophenyl)hydrazide)methyl)phenylboronic acid dihexadecanyl ester:

[0051] The intermediate (10 mmol) and n-hexadecyl alcohol (20 mmol) were dissolved in 30 mL of toluene solution and refluxed at 110 °C for 12 h. After the reaction was completed, the solvent was removed by rotary evaporation to obtain the product (4-(2-(2,4-dinitrophenyl)hydrazide)methyl)phenylboronic acid dihexadecyl ester, labeled as Borate-16.

[0052] Example 5

[0053] (4-(2-(2,4-dinitrophenyl)hydrazide)methyl)phenylboronic acid dihexadecanyl ester, prepared by the following method:

[0054] 1. Preparation of intermediate (4-(2-(2,4-dinitrophenyl)hydrazide)methyl)phenylboronic acid: Same as in Example 1.

[0055] 2. Preparation of organoboroester – (4-(2-(2,4-dinitrophenyl)hydrazide)methyl)phenylboronic acid dihexadecanyl ester:

[0056] The intermediate (10 mmol) and n-hexadecyl alcohol (20 mmol) were dissolved in 30 mL of DMF solution and refluxed at 153 °C for 12 h. After the reaction was completed, the solvent was removed by rotary evaporation to obtain the product (4-(2-(2,4-dinitrophenyl)hydrazide)methyl)phenylboronic acid dihexadecyl ester, labeled as Borate-16.

[0057] Example 6

[0058] (4-(2-(2,4-dinitrophenyl)hydrazide)methyl)phenylboronic acid dihexadecanyl ester, prepared by the following method:

[0059] 1. Preparation of intermediate (4-(2-(2,4-dinitrophenyl)hydrazide)methyl)phenylboronic acid: Same as in Example 1.

[0060] 2. Preparation of organoboroester – (4-(2-(2,4-dinitrophenyl)hydrazide)methyl)phenylboronic acid dihexadecanyl ester:

[0061] The intermediate (10 mmol) and n-hexadecyl alcohol (20 mmol) were dissolved in 30 mL of tetrahydrofuran solution and refluxed at 64 °C for 12 h. After the reaction was completed, the solvent was removed by rotary evaporation to obtain the product (4-(2-(2,4-dinitrophenyl)hydrazide)methyl)phenylboronic acid dihexadecyl ester, labeled as Borate-16.

[0062] Example 7

[0063] (4-(2-(2,4-dinitrophenyl)hydrazide)methyl)phenylboronic acid bis(eicosyl)ester is prepared by the following method:

[0064] 1. Preparation of intermediate (4-(2-(2,4-dinitrophenyl)hydrazide)methyl)phenylboronic acid: Same as in Example 1.

[0065] 2. Preparation of organoboroester – (4-(2-(2,4-dinitrophenyl)hydrazide)methyl)phenylboronic acid bis(eicosyl)ester:

[0066] The intermediate (10 mmol) and n-eicosyl alcohol (20 mmol) were dissolved in 30 mL of toluene solution and refluxed at 110 °C for 12 h. After the reaction was completed, the solvent was removed by rotary evaporation to obtain the product (4-(2-(2,4-dinitrophenyl)hydrazide)methyl)phenylboronic acid bis(eicosyl)ester, labeled as Borate-20.

[0067] Example 8

[0068] (4-(2-(2,4-dinitrophenyl)hydrazide)methyl)phenylboronic acid bis(eicosyl)ester is prepared by the following method:

[0069] 1. Preparation of intermediate (4-(2-(2,4-dinitrophenyl)hydrazide)methyl)phenylboronic acid: Same as in Example 1.

[0070] 2. Preparation of organoboroester – (4-(2-(2,4-dinitrophenyl)hydrazide)methyl)phenylboronic acid bis(eicosyl)ester:

[0071] The intermediate (10 mmol) and n-eicosyl alcohol (20 mmol) were dissolved in 30 mL of DMF solution and refluxed at 153 °C for 12 h. After the reaction was completed, the solvent was removed by rotary evaporation to obtain the product (4-(2-(2,4-dinitrophenyl)hydrazide)methyl)phenylboronic acid bis(eicosyl)ester, labeled as Borate-20.

[0072] Example 9

[0073] (4-(2-(2,4-dinitrophenyl)hydrazide)methyl)phenylboronic acid bis(eicosyl)ester is prepared by the following method:

[0074] 1. Preparation of intermediate (4-(2-(2,4-dinitrophenyl)hydrazide)methyl)phenylboronic acid: Same as in Example 1.

[0075] 2. Preparation of organoboroester – (4-(2-(2,4-dinitrophenyl)hydrazide)methyl)phenylboronic acid bis(eicosyl)ester:

[0076] The intermediate (10 mmol) and n-eicosyl alcohol (20 mmol) were dissolved in 30 mL of tetrahydrofuran solution and refluxed at 64 °C for 12 h. After the reaction was completed, the solvent was removed by rotary evaporation to obtain the product (4-(2-(2,4-dinitrophenyl)hydrazide)methyl)phenylboronic acid bis(eicosyl)ester, labeled as Borate-20.

[0077] Example 10: Application of organoboroesters as lubricating oil additives in lubricating oils

[0078] This embodiment uses liquid paraffin as the base oil, but the base oil is not limited to liquid paraffin.

[0079] (I) The method is as follows:

[0080] The organoboroate ester Borate-12 prepared in Example 1 was mixed with liquid paraffin and dissolved by ultrasonication for 30 min. The amount of organoboroate ester added was 0.01-0.1% of the mass of liquid paraffin.

[0081] (II) Testing

[0082] 1. SEM analysis was performed on the surface of a steel ball subjected to friction testing using 0.1 wt% Borate-12 as a lubricant additive added to liquid paraffin. The mapping results are as follows: Figure 2 As shown. Figure 2 The results showed that N and B were evenly dispersed, indicating that the lubricating oil additives were evenly distributed on the metal surface.

[0083] 2. EDS tests were performed on the surface of steel balls subjected to friction experiments after adding 0.1 wt% Borate-12 as a lubricant additive to liquid paraffin. The EDS results are as follows: Figure 3 As shown. Figure 3 The results showed that the additives formed a chemical protective film containing nitrogen and boron on the metal surface.

[0084] 3. The friction reduction performance of adding Borate-12 as a lubricant additive was tested using a four-ball friction tester. The coefficient of friction was 0.0924 when the mass fraction was 0.01%, 0.0873 when it was 0.04%, 0.0879 when it was 0.07%, 0.0893 when it was 0.1%, and 0.0886 when it was 0.1%.

[0085] 4. The anti-wear performance of adding Borate-12 as a lubricant additive was tested using a four-ball friction tester. The wear scar diameter was 0.9927 when the mass fraction was 0.01%, 0.9575 when the mass fraction was 0.04%, 0.8742 when the mass fraction was 0.07%, 0.8201 when the mass fraction was 0.1%, and 0.8579 when the mass fraction was 0.1%.

[0086] Example 11: Application of different organoboroesters as lubricating oil additives in lubricating oils

[0087] This embodiment uses liquid paraffin as the base oil, but the base oil is not limited to liquid paraffin.

[0088] (I) The method is as follows:

[0089] The organoboroesters prepared in Examples 1, 4, and 7 were mixed with liquid paraffin and dissolved by ultrasonication for 30 min. The amount of organoboroester added was 0.01-0.1% of the mass of the liquid paraffin.

[0090] (II) Testing

[0091] Tribological properties were tested using an MMW-1A microcomputer-driven universal four-ball friction and wear testing machine. The testing environment was: 1200 r / min, load capacity: 392 N, testing time: 60 min, room temperature. Data on the coefficient of friction as a function of additive mass fraction (friction reduction performance) are shown in Table 1. Data on the scratch diameter as a function of additive mass fraction (wear resistance performance) are shown in Table 2.

[0092] Table 1. Data on friction coefficient as a function of additive mass fraction (friction reduction performance)

[0093] Sample / Amount Added 0wt% 0.01wt% 0.04wt% 0.07wt% 0.10wt% Borate-12 0.0924 0.0873 0.0879 0.0893 0.0886 Borate-16 0.0924 0.0815 0.0824 0.0827 0.0817 Borate-20 0.0924 0.0829 0.0847 0.0851 0.0845

[0094] Table 2. Data on scratch diameter as a function of additive mass fraction (wear resistance)

[0095] Sample / Amount Added 0wt% 0.01wt% 0.04wt% 0.07wt% 0.10wt% Borate-12 0.9927mm 0.9575mm 0.8742mm 0.8201mm 0.8579mm Borate-16 0.9927mm 0.9602mm 0.8603mm 0.8010mm 0.8453mm Borate-20 0.9927mm 0.9716mm 0.8620mm 0.7313mm 0.8170mm

[0096] As shown in Table 1, when the mass fractions of Borate-12, Borate-16, and Borate-20 are in the range of 0–0.10%, the friction coefficients of Borate-12, Borate-16, and Borate-20 all reach their minimum values ​​at an addition of 0.01 wt%, which are 0.0873, 0.0815, and 0.0829, respectively. Compared with the friction coefficient of liquid paraffin, these values ​​are reduced by 5.52%, 11.80%, and 10.28%, respectively. This is because when the addition amount is below 0.04 wt%, the content of Schiff basic phenylboronic acid in liquid paraffin is not high, thus leading to a decrease in the friction coefficient of the small steel in the four-ball friction pair. The additive molecules on the surface of the ball are not numerous, and they are mainly adsorbed onto the surface of the small steel ball through weak adsorption. When 0.01 wt% is added, the adsorption on the metal surface reaches saturation. When the added Schiff basic phenylboronic acid is greater than 0.01 wt%, since the metal surface is already saturated with adsorption, a large number of additional additive molecules will deposit on the surface of the steel ball. This will not only hinder the adsorption of other additive molecules, but also hinder the removal of small metal solids generated by friction, thus leading to an increase in the coefficient of friction. When the added amount is greater than 0.07 wt%, not only physical adsorption but also chemical adsorption occurs, thereby reducing the coefficient of friction.

[0097] As shown in Table 2, when the addition amount of Borate-12, Borate-16 and Borate-20 was 0.07wt%, the wear scar diameter reached the minimum value. The WSD values ​​of the three organoboroesters Borate-12, Borate-16 and Borate-20 were 0.8201mm, 0.8010mm and 0.7313mm, respectively, with WSD values ​​reduced by 17.38%, 19.31% and 26.33%, respectively.

[0098] When the amount of synthesized Schiff basic phenylboronic acid ester added is greater than 0.07 wt%, the WSD value increases accordingly. This is because nitrogen and boron elements undergo tribochemical reactions on the surface of small steel balls during metal friction to generate some N and B-containing compounds with low shear strength, thereby improving the anti-wear performance of the lubricating oil. However, as the mass fraction of the additive continues to increase, Schiff basic phenylboronic acid ester molecules will accumulate on the metal surface, preventing small metal particles generated by wear from being effectively removed, thus accumulating on the metal surface and causing the WSD value to increase.

[0099] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Other variations and modifications are possible without departing from the technical solutions described in the claims.

Claims

1. An organoborolate, characterized in that, The organic borate ester is prepared by the following steps: 1) Add 4-formylphenylboronic acid and 2,4-dinitrophenylhydrazine to an ethanol solvent and stir continuously at 80 °C for 5-6 h. After the reaction is complete, evaporate the solvent to obtain the crude product. 2) Recrystallize the crude product obtained in step 1) to obtain the intermediate; 3) Add the intermediate obtained in step 2) and the fatty alcohol to an organic solvent and reflux at 60-160 °C for 12-13 h. After the reaction is complete, evaporate the solvent to obtain the target product, an organoboroester ester. The fatty alcohol is selected from n-dodecyl alcohol, n-hexadecyl alcohol, and n-eicosyl alcohol.

2. The organoboroester according to claim 1, characterized in that, The molar ratio is 4-formylphenylboronic acid:2,4-dinitrophenylhydrazine = 1:

1.

3. The organoboroester according to claim 1, characterized in that, Molar ratio, intermediate: fatty alcohol 1:

2.

4. The organoboroester according to claim 1, characterized in that, In step 3), the organic solvent is toluene, DMF, or tetrahydrofuran.

5. The use of the organoboroester ester of claim 1 as a lubricating oil additive in lubricating oil.

6. The application according to claim 5, characterized in that, The method is as follows: Mix the organic borate ester with the base oil and sonicate for 30-40 minutes.

7. The application according to claim 6, characterized in that, The amount of organic borate ester added is 0.01-0.1% of the base oil mass.

8. The application according to claim 6 or 7, characterized in that, The base oil is liquid paraffin.

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