Trimethylolpropane ester composition as well as preparation method and application thereof

Abstract

The invention provides a trimethylolpropane ester composition as well as a preparation method and application thereof. The trimethylolpropane ester composition provided by the invention comprises the following components: # imgabs0, wherein R1, R2 and R3 groups are respectively and differently selected from C4-C9 straight chain or branched chain alkyl groups, and the carbon numbers in the R1, R2 and R3 groups are different from one another; the molar ratio of the component (a) to the component (b) to the component (c) is 1: (1.7-2.3): (0.7-1.3). The trimethylolpropane ester composition has excellent high and low temperature performance, low pour point and low evaporation loss, and is suitable for being used as lubricant base oil.

Description

Technical Field

[0001] The present invention relates to a trimethylolpropane ester composition and a preparation method and application thereof, and in particular to a trimethylolpropane ester composition suitable for being used as a lubricant base oil. Background Art

[0002] Lubricating oil is a necessary working medium for the normal operation of mechanical equipment and the manufacturing and processing of materials. With the development of industry and the advancement of mechanical equipment, more stringent requirements have been gradually put forward for the performance of lubricating oil. In this context, a series of different types of synthetic lubricating oils have emerged, such as synthetic lubricating oil products with excellent viscosity-temperature performance, low temperature performance, thermal oxidation stability, low volatility, chemical stability and radiation resistance.

[0003] Polyol esters have good high and low temperature performance and additive sensitivity and are widely used in aviation lubricants. By adjusting the substituents, polyol ester products with different performances can be obtained. IN338518B and US3309318A reported the performance comparison of polyol esters prepared using different raw acid. However, synthetic esters that have both excellent high temperature performance and low temperature performance are still rare in the prior art. Summary of the invention

[0004] The invention provides a trimethylolpropane ester composition and a preparation method and application thereof.

[0005] The trimethylolpropane ester composition of the present invention comprises the following components:

[0006]

[0007] Where R 1 , R 2 , R 3 The groups are each selected from C4 to C9 straight or branched alkyl groups, and R 1 , R 2 , R 3 The carbon numbers in the groups are different from each other; the molar ratio between the components (a), (b) and (c) is 1:(1.7-2.3):(0.7-1.3).

[0008] According to the present invention, R 1 , R 2 , R 3 The carbon numbers of the groups are different from each other in the C4 straight chain or branched chain alkyl, C5 straight chain or branched chain alkyl, C6 straight chain or branched chain alkyl, C7 straight chain or branched chain alkyl, C8 straight chain or branched chain alkyl, and C9 straight chain or branched chain alkyl. For example, R 1 , R 2 , R 3The groups are each selected from n-heptyl, n-pentyl, and n-hexyl groups; or, R 1 , R 2 , R 3 The groups are each selected from n-heptyl, n-octyl, and n-nonyl groups; or, R 1 , R 2 , R 3 The groups are each selected from n-hexyl, n-butyl and n-pentyl groups.

[0009] According to the present invention, optionally, R 1 The group is selected from n-heptyl, R 2 , R 3 The groups are each selected from n-pentyl and n-hexyl groups; or, R 1 The group is selected from n-hexyl, R 2 , R 3 The groups are each selected from n-pentyl and n-heptyl; or, R 1 The group is selected from n-heptyl, R 2 , R 3 The groups are each selected from n-octyl and n-nonyl groups; or, R 1 The group is selected from n-hexyl, R 2 , R 3 The groups are each selected from n-butyl and n-pentyl groups.

[0010] According to the present invention, the preparation method of the trimethylolpropane ester composition comprises the following steps:

[0011] (1) allowing trimethylolpropane to undergo an alcohol hydroxyl group protecting reaction with an alcohol hydroxyl group protecting agent to obtain a monohydroxyl product;

[0012] (2) the monohydroxy product obtained in step (1) is reacted with R 1 COX undergoes an acylation reaction to obtain an acylated product;

[0013] (3) subjecting the acylated product obtained in step (2) to a deprotection reaction of the alcoholic hydroxyl group to obtain a dihydroxy product;

[0014] (4) making the dihydroxy product obtained in step (3) and R 2 COX', R 3 COX' undergoes acylation reaction and collects the product;

[0015] Among them, R 1 , R 2 , R 3 The groups are each selected from C4 to C9 straight or branched alkyl groups, and R 1 , R 2 , R 3The carbon numbers in the groups are different from each other; the X group is selected from F, Cl, Br, I, OH; the X' groups are each independently selected from F, Cl, Br, I, OH; the R 1 COX, R 2 COX', R 3 The molar ratio between COX' is 1:(0.9~1.2):(0.9~1.2).

[0016] According to the present invention, in step (1), the molar ratio of trimethylolpropane to the alcoholic hydroxyl protecting agent can be 1:2 to 200, preferably 1:10 to 50; the temperature of the alcoholic hydroxyl protecting reaction can be -20 to 80°C, preferably 15 to 70°C; the time of the alcoholic hydroxyl protecting reaction can be 1 to 120 hours, preferably 30 to 100 hours.

[0017] According to the present invention, in step (1), the alcoholic hydroxyl protecting agent can be selected from one or more of acetone, 2,2-dimethoxypropane and 2-methoxypropylene, preferably acetone. When acetone is selected as the alcoholic hydroxyl protecting agent, the unreacted acetone can play the role of a solvent to promote the smooth progress of the reaction, so the amount of acetone added can be excessive, generally in excess to the amount of solvent added in the alcoholic hydroxyl protection reaction. The unreacted acetone can be removed by distillation, rectification or other methods known in the art after the reaction is completed.

[0018] According to the present invention, a first solvent may be added to the reaction in step (1), and the first solvent may be one or more of ethyl acetate, dichloromethane, chloroform, toluene and acetonitrile. The first solvent may be removed by distillation, rectification or other methods known in the art after the reaction is completed. In step (1), the volume ratio between the alcoholic hydroxyl protecting agent and the first solvent may be 10:1 to 1:20. When acetone is selected as the alcoholic hydroxyl protecting agent, the first solvent may be added to carry out the alcoholic hydroxyl protection reaction, or the first solvent may not be added. When acetone is selected as the alcoholic hydroxyl protecting agent and the first solvent is not added, because the unreacted acetone can play the role of a solvent to promote the smooth progress of the reaction, the amount of acetone added may be excessive, generally to the sum of the amount added as the alcoholic hydroxyl protecting agent and the amount added of the first solvent.

[0019] According to the present invention, an acidic catalyst may be added in step (1), and the acidic catalyst may be selected from one or more of p-toluenesulfonic acid, hydrochloric acid, sulfuric acid, benzenesulfonic acid and dodecylbenzenesulfonic acid; the molar ratio between the acidic catalyst and trimethylolpropane may be 1:10 to 1000, preferably 1:20 to 800. After the reaction is completed, the acidic catalyst may be removed by one or more of alkali neutralization, solvent extraction and water washing methods, and the alkali in the alkali neutralization method may be selected from one or more of sodium carbonate, potassium carbonate, sodium hydroxide and potassium hydroxide or aqueous solutions of these substances, and the solvent in the solvent extraction method may be the first solvent described above.

[0020] According to the present invention, in step (1), the monohydroxy product obtained after the reaction may be purified, or the monohydroxy product obtained after the reaction may be directly subjected to step (2) without being purified. The purification method may include one or more of solvent extraction, water washing, drying, filtering, and solvent removal methods, and is not particularly limited. The solvent in the solvent extraction may use the first solvent described above.

[0021] According to the present invention, in step (2), the monohydroxy product obtained in step (1) is reacted with R 1 The molar ratio of COX can be 1:0.5-2, preferably 1:0.8-1.5; the reaction temperature can be 0-80°C, preferably 15-70°C, and the reaction time can be 1-48 hours, preferably 5-40 hours.

[0022] According to the present invention, a second solvent and / or an alkaline catalyst may be added to the reaction of step (2). The second solvent may be one or more of tetrahydrofuran, dichloromethane, chloroform, acetone, ethyl acetate and acetonitrile, preferably dichloromethane. The second solvent may be removed by distillation, rectification or other methods known in the art after the reaction. The alkaline catalyst may be one or more of triethylamine, tert-butylamine, pyridine, diisopropylethylamine and hexamethyldisilazane, preferably triethylamine. Based on the monohydroxy product obtained in step (1), the mass ratio of the second solvent to the monohydroxy product obtained in step (1) is 1:0.02-0.5, preferably 1:0.05-0.25; the molar ratio of the alkaline catalyst to the monohydroxy product obtained in step (1) is 1:0.5-2, preferably 1:0.8-1.5.

[0023] According to the present invention, in step (2), the acylated product obtained after the reaction may be purified, or the acylated product obtained after the reaction may be directly subjected to step (3) without being purified. The purification method may include one or more of filtration, acid washing, alkali washing, water washing, drying, solvent extraction, and solvent removal, and is not particularly limited. The purpose of the acid washing method is to remove the alkaline catalyst in step (2), and the purpose of the alkali washing method is to remove R 1 The solvent may be the second solvent described above.

[0024] According to the present invention, in step (3), the acylation product obtained in step (2) can be subjected to a deprotection reaction of the alcoholic hydroxyl group with a C1-C5 alcohol or an acid solution.

[0025] According to the present invention, in step (3), the C1-C5 alcohol may be one or more of methanol, ethanol, propanol, isopropanol, butanol and pentanol, preferably methanol; the acid solution may be an aqueous solution of an inorganic acid, for example, one or more of a hydrochloric acid aqueous solution, a sulfuric acid aqueous solution, a nitric acid aqueous solution and a phosphoric acid aqueous solution, preferably a hydrochloric acid aqueous solution, more preferably a hydrochloric acid aqueous solution with a molar concentration of 0.5 to 2M.

[0026] According to the present invention, in step (3), the molar concentration of the acylated product obtained in step (2) in the solution formed by the C1-C5 alcohol, the acid solution and the acylated product obtained in step (2) is 0.5-5 mol / L, preferably 1-2.5 mol / L; the acid solution is prepared by mixing H + The molar ratio of the acylated product obtained in step (2) to the acid solution can be 1:0.01-1, preferably 1:0.05-0.25; the reaction temperature can be 20-80°C, preferably 30-70°C; the reaction time can be 1-48 hours, preferably 5-40 hours.

[0027] According to the present invention, in step (3), the dihydroxy product obtained after the reaction may be purified, or the dihydroxy product obtained after the reaction may be directly subjected to step (4) without being purified. The purification method may include one or more of solvent extraction, water washing, drying, filtering, and solvent removal. The solvent may be a third solvent. The third solvent may be one or more of ethyl acetate, tetrahydrofuran, dichloromethane, chloroform, acetone, and acetonitrile, preferably ethyl acetate. The third solvent may be removed after the purification by distillation, rectification, or other methods known in the art. In step (3), the mass ratio between the acylated product obtained in step (2) and the third solvent is 1:1 to 20, preferably 1:2 to 10.

[0028] According to the present invention, in step (4), the dihydroxy product obtained in step (3) is reacted with R 2 COX', R 3 The molar ratio of COX' can be 1:0.8-1.5:0.8-1.5, preferably 1:1.0-1.3:1.0-1.3; the reaction temperature can be 0-80°C, preferably 15-70°C, and the reaction time can be 1-48 hours, preferably 5-40 hours.

[0029] According to the present invention, a carbodiimide condensation reagent and / or an activator may be added in step (4). The carbodiimide condensation reagent may be one or more of 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride (EDCI), dicyclohexylcarbodiimide (DCC) and N,N'-diisopropylcarbodiimide (DIC), preferably 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride (EDCI). The activator may be one or more of 4-dimethylaminopyridine (DMAP), 1-hydroxybenzotriazole (HOBt) and 1-hydroxy-7-azabenzotriazole (HOAt), preferably 4-dimethylaminopyridine (DMAP). The molar ratio between the dihydroxy product obtained in step (3) and the carbodiimide condensation reagent is 1:0.5-2, preferably 1:0.8-1.5; the molar ratio between the dihydroxy product obtained in step (3) and the activator is 1:0.01-0.5, preferably 1:0.05-0.1.

[0030] According to the present invention, a fourth solvent may be added in the reaction of step (4), and the fourth solvent may be one or more of dichloromethane, ethyl acetate, tetrahydrofuran, chloroform, acetone and acetonitrile, preferably dichloromethane. In step (4), the mass ratio between the dihydroxy product obtained in step (3) and the fourth solvent is 1:0.5-10, preferably 1:1-5. The fourth solvent may be removed by distillation, rectification or other methods known in the art after the reaction is completed.

[0031] According to the present invention, in step (4), the crude product obtained after the reaction can be purified to obtain the final reaction product. The purification method can include one or more of solvent extraction, acid washing, alkali washing, water washing, drying, filtering, and solvent removal. The solvent in the solvent extraction method can be the fourth solvent described above.

[0032] The trimethylolpropane ester composition of the present invention can be used as a lubricating oil base oil.

[0033] The trimethylolpropane ester composition of the present invention has excellent high and low temperature performance, low pour point, low evaporation loss, and is suitable for use as a lubricating oil base oil. The preparation method of the trimethylolpropane ester composition of the present invention has mild reaction conditions and high product purity. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 This is the gas chromatogram of the crude product of step (4) in Example 1. DETAILED DESCRIPTION

[0035] The present invention is described below by means of specific embodiments, but the present invention is not limited thereto.

[0036] The experimental methods described in the following examples are conventional methods unless otherwise specified; the reagents and materials described are commercially available unless otherwise specified. Unless otherwise specified, the percentages in the present invention are all mass percentages.

[0037] Main raw material sources:

[0038] Trimethylolpropane, Aladdin Biochemical Technology Co., Ltd., analytical grade;

[0039] Acetone, Sinopharm Chemical Reagent Co., Ltd., analytical grade;

[0040] 2-Methoxypropylene, Aladdin Biochemical Technology Co., Ltd., analytical grade;

[0041] 2,2-Dimethoxypropane, Aladdin Biochemical Technology Co., Ltd., analytical grade;

[0042] p-Toluenesulfonic acid monohydrate, Sinopharm Chemical Reagent Co., Ltd., analytical grade

[0043] Potassium carbonate, Sinopharm Chemical Reagent Co., Ltd., analytical grade

[0044] Ethyl acetate was purchased from Sinopharm Chemical Reagent Co., Ltd., analytical grade;

[0045] Dichloromethane, Sinopharm Chemical Reagent Co., Ltd., analytical grade;

[0046] Triethylamine, analytical grade, Sinopharm Chemical Reagent Co., Ltd.

[0047] Octanoyl chloride, Aladdin Biochemical Technology Co., Ltd., analytical grade;

[0048] Heptanoyl chloride, Aladdin Biochemical Technology Co., Ltd., analytical grade;

[0049] DMAP, Beijing Inokai Technology Co., Ltd., analytical grade;

[0050] Hexanoic acid, Beijing Inokai Technology Co., Ltd., analytical grade;

[0051] n-Heptanoic acid, Beijing Inokai Technology Co., Ltd., analytical grade;

[0052] Octanoic acid, Beijing Inokai Technology Co., Ltd., analytical grade;

[0053] N-nonanoic acid, Beijing Inokai Technology Co., Ltd., analytical grade;

[0054] Decanoic acid, Beijing Inokai Technology Co., Ltd., analytical grade;

[0055] EDCI was from Beijing Inokai Technology Co., Ltd., analytical grade.

[0056] Comparison of polyol esters, trimethylolpropane n-heptanoate, Nico, France, industrial product.

[0057] Example 1: Synthesis of trimethylolpropane ester compositions (structural formulas I-a1, I-a2 and I-a3)

[0058] (1) Weigh trimethylolpropane (100 g, 745.32 mmol) in a 1 L reaction bottle, add acetone 700 mL, add p-toluenesulfonic acid monohydrate (1.42 g, 7.45 mmol), stir at room temperature for 3 days, add potassium carbonate (1.03 g, 7.45 mmol), stir at room temperature for 1 hour to generate a suspension. Remove acetone from the suspension by rotary evaporation, add 700 mL of ethyl acetate to dissolve, wash twice with water (2*200 mL), then dry with anhydrous sodium sulfate, filter and spin dry the solvent to obtain the product of step (1). The H NMR spectrum of the product of step (1) is: 1 H-NMR (700MHz, CDCl3) δ (ppm) = 3.72 (s, 2H), 3.70-3.60 (m, 4H), 2.80 (br, 1H), 1.43 (s, 3H), 1.39 (s, 3H), 1.30 (q, J = 7.0 Hz, 2H), 0.84 (t, J = 7.0 Hz, 3H). The NMR carbon spectrum of the product of step (1) is: 13 C-NMR (175MHz, CDCl3) δ (ppm) = 99.27, 65.25, 62.54, 37.05, 27.35, 23.86, 20.38, 7.12.

[0059] (2) Add the product of step (1) (58.72 g, 0.3336 mol), 500 mL of dichloromethane, and triethylamine (37.14 g, 0.367 mol) to a reaction flask, stir at room temperature, and dropwise add octanoyl chloride (59.72 g, 0.367 mol) to the reaction system, and react for 12 hours under stirring at room temperature. Filter to remove solids, wash the filtrate twice with saturated sodium bicarbonate solution, wash three times with water, and dry over anhydrous sodium sulfate. Filter and spin dry the solvent to obtain the product of step (2). The H NMR spectrum of the product of step (2) is: 1 H-NMR (700MHz, CDCl3) δ (ppm) = 4.19 (s, 2H), 3.70-3.61 (m, 4H), 2.33 (t, J = 7.6Hz, 2H), 1.70-1.60 (m, 4H), 1.42 (s, 3H), 1.39 (s, 3H), 1.37-1.22 (m, 10H), 0.88 (t, J = 7.0Hz, 3H), 0.83 (t, J = 7.8Hz, 3H). The NMR carbon spectrum of the product of step (2) is: 13 C-NMR (175MHz, CDCl3) δ (ppm) = 173.9, 97.4, 65.2, 63.9, 37.2, 34.4, 31.8, 29.2, 29.1, 26.8, 25.1, 24.1, 22.7, 20.8, 14.2, 7.1.

[0060] (3) The product of step (2) was dissolved in methanol (200 mL), 40 mL of 1 M hydrochloric acid was prepared and added to the reaction bottle, and the reaction was carried out at 40° C. for 24 hours. The crude product was spin-dried, and then 350 mL of ethyl acetate was added to dissolve it, and it was washed with water for several times. When the pH test paper showed that the washed water phase was neutral, it was dried with anhydrous sodium sulfate, filtered and spin-dried to obtain the product of step (3). The nuclear magnetic hydrogen spectrum of the product of step (3) is: 1 H-NMR (700MHz, CDCl3) δ (ppm) = 4.16 (s, 2H), 3.56 (dd, J = 21.0, 7.0Hz, 4H), 3.41 (br, 2H), 2.35 (t, J = 7.6Hz, 2H), 1.70-1.60 (m, 2H), 1.42-1.21 (m, 10H), 0.92-0.85 (m, 6H). The nuclear magnetic carbon spectrum of the product of step (3) is: 13 C-NMR (175MHz, CDCl3) δ (ppm) = 175.1, 65.5, 64.1, 42.9, 34.5, 31.8, 29.2, 29.1, 25.2, 22.7, 22.5, 14.2, 7.5.

[0061] (4) The product of step (3) (i.e., diol compound) (169.26 g, 0.65 mol) was dissolved in 400 mL of dichloromethane, and DMAP (15.86 g, 0.13 mol), n-hexanoic acid (90.48 g, 0.78 mol) and n-heptanoic acid (101.4 g, 0.78 mol) were added. Then, EDCI (299.52 g, 1.56 mol) was added to the system and stirred at room temperature for 12 hours to obtain a crude product. A small amount of crude product sample was extracted and subjected to gas chromatography analysis. The results are shown in FIG. Figure 1 The crude product was washed with 1M hydrochloric acid solution, washed twice with water, the dichloromethane solvent was removed by rotary evaporation, and the excess acid was removed by reduced pressure distillation. After reduced pressure distillation, the product was washed with 1% potassium hydroxide solution at 80°C, then washed twice with water, and dried to obtain 300g of the final product, which is the trimethylolpropane ester composition of the present invention. The mass spectrum data of the final product include: HRMS (FT-ICRMS) calculation for C 26 H 48 NaO6(M+Na):479.3343,found:479.3340;calcd for C 27 H 50 NaO6(M+Na):493.3500,found:493.3494;calcd for C 28 H 52 NaO6(M+Na):507.3656,found:507.3653. Figure 1 The gas chromatography results of the crude product in step (4) show that a mixture of three compounds is obtained after the reaction, and the molar ratio between the three compounds is close to 1:2:1.

[0062] After structural identification, the final product synthesized is indeed a composition of the target compound trimethylolpropane ester (structural formulas are I-a1, I-a2 and I-a3).

[0063] The synthetic reaction formula of Example 1 is shown below.

[0064]

[0065] Example 2: Synthesis of trimethylolpropane ester compositions (structural formulas I-b1, I-b2 and I-b3)

[0066] (1) Weigh trimethylolpropane (100.05 g, 745.32 mmol) in a 1 L reaction bottle, add 700 mL of dichloromethane and 2,2-dimethoxypropane (2329 g, 22.36 mol), add p-toluenesulfonic acid monohydrate (1.418 g, 7.45 mmol), stir at room temperature for 3 days, add potassium carbonate (1.037 g, 7.45 mmol), stir at room temperature for 1 hour to generate a suspension. Remove the solvent from the suspension by rotary evaporation, add 700 mL of ethyl acetate to dissolve, wash twice with water (2*200 mL), then dry with anhydrous sodium sulfate, filter and dry the solvent to obtain the product of step (1). The H NMR spectrum of the product of step (1) is: 1 H-NMR (700MHz, CDCl3) δ (ppm) = 3.72 (s, 2H), 3.70-3.60 (m, 4H), 2.80 (br, 1H), 1.43 (s, 3H), 1.39 (s, 3H), 1.30 (q, J = 7.0 Hz, 2H), 0.84 (t, J = 7.0 Hz, 3H). The NMR carbon spectrum of the product of step (1) is: 13 C-NMR (175MHz, CDCl3) δ (ppm) = 99.27, 65.25, 62.54, 37.05, 27.35, 23.86, 20.38, 7.12.

[0067] (2) Add the product of step (1) (58.74 g, 0.3336 mol), 500 mL of dichloromethane, and triethylamine (37.18 g, 0.367 mol) to a reaction flask, stir at room temperature, and dropwise add heptanoyl chloride (54.55 g, 0.367 mol) to the reaction system, and react for 12 hours under stirring at room temperature. Filter to remove solids, wash the filtrate twice with saturated sodium bicarbonate solution, wash three times with water, and dry over anhydrous sodium sulfate. Filter and spin dry the solvent to obtain the product of step (2). The H NMR spectrum of the product of step (2) is: 1 H-NMR (700MHz, CDCl3) δ (ppm) = 4.18 (s, 2H), 3.71-3.61 (m, 4H), 2.34 (t, J = 7.6Hz, 2H), 1.70-1.60 (m, 4H), 1.43 (s, 3H), 1.40 (s, 3H), 1.38-1.22 (m, 8H), 0.88 (t, J = 7.0Hz, 3H), 0.82 (t, J = 7.8Hz, 3H). The nuclear magnetic carbon spectrum of the product of step (2) is: 13 C-NMR (175MHz, CDCl3) δ (ppm) = 174.0, 97.5, 65.1, 63.8, 37.3, 34.5, 31.7, 29.3, 26.9, 25.2, 22.7, 22.4, 20.9, 14.2, 7.1.

[0068] (3) The product of step (2) was dissolved in methanol (200 mL), 40 mL of 1M hydrochloric acid was prepared and added to the reaction bottle, and the reaction was carried out at 40°C for 24 hours. The crude product was spin-dried, and then 350 mL of ethyl acetate was added to dissolve it, and it was washed with water for several times. When the pH test paper showed that the washed water phase was neutral, it was dried with anhydrous sodium sulfate, filtered and spin-dried to obtain the product of step (3). The nuclear magnetic hydrogen spectrum of the product of step (3) is: 1 H-NMR (700MHz, CDCl3) δ (ppm) = 4.18 (s, 2H), 3.57 (dd, J = 21.0, 7.0 Hz, 4H), 3.40 (br, 2H), 2.33 (t, J = 7.6 Hz, 2H), 1.75-1.60 (m, 2H), 1.44-1.21 (m, 8H), 0.94-0.85 (m, 6H). The nuclear magnetic carbon spectrum of the product of step (3) is: 13 C-NMR (175MHz, CDCl3) δ (ppm) = 175.4, 65.3, 64.2, 43.1, 34.4, 31.6, 29.2, 25.2, 22.7, 22.5, 14.2, 7.5.

[0069] (4) The product of step (3) (160.17 g, 0.65 mol) was dissolved in 400 mL of dichloromethane, DMAP (15.88 g, 0.13 mol), hexanoic acid (90.55 g, 0.78 mol) and octanoic acid (112.48 g, 0.78 mol) were added, and then EDCI (300.10 g, 1.56 mol) was added to the system and stirred at room temperature for 12 hours. The crude product was washed with 1 M hydrochloric acid solution, washed twice with water, and the dichloromethane solvent was removed by rotary evaporation, and the excess acid was removed by reduced pressure distillation. After reduced pressure distillation, the product was washed with 1% potassium hydroxide solution at 80° C., then washed twice with water, and dried to obtain 307 g of the final product, which was the trimethylolpropane ester composition of the present invention. The mass spectrum data of the final product include: HRMS (FT-ICRMS) calculation for C 25 H 46 NaO6(M+Na):465.3187,found:465.3192; calcd for C 27 H 50 NaO6(M+Na):493.3500,found:493.3504;calcd for C 29 H 54 NaO6(M+Na):521.3813,found:521.3819.

[0070] After structural identification, the final product synthesized is indeed a composition of the target compound trimethylolpropane ester (structural formula I-b1, I-b2 and I-b3). The synthetic reaction formula of Example 2 is shown below.

[0071]

[0072] Example 3: Synthesis of trimethylolpropane ester compositions (structural formulas I-d1, I-d2 and I-d3)

[0073] (1) Weigh trimethylolpropane (100.10 g, 745.32 mmol) in a 1 L reaction bottle, add acetone 700 mL, add p-toluenesulfonic acid monohydrate (1.416 g, 7.45 mmol), stir at room temperature for 3 days, add potassium carbonate (1.030 g, 7.45 mmol), stir at room temperature for 1 hour to generate a suspension. Remove acetone from the suspension by rotary evaporation, add 700 mL of ethyl acetate to dissolve, wash twice with water (2*200 mL), and then dry over anhydrous sodium sulfate. Filter and spin dry the solvent to obtain the product of step (1). The H NMR spectrum of the product of step (1) is: 1 H-NMR (700MHz, CDCl3) δ (ppm) = 3.72 (s, 2H), 3.70-3.60 (m, 4H), 2.80 (br, 1H), 1.43 (s, 3H), 1.39 (s, 3H), 1.30 (q, J = 7.0 Hz, 2H), 0.84 (t, J = 7.0 Hz, 3H). The NMR carbon spectrum of the product of step (1) is: 13 C-NMR (175MHz, CDCl3) δ (ppm) = 99.27, 65.25, 62.54, 37.05, 27.35, 23.86, 20.38, 7.12.

[0074] (2) Add the product of step (1) (58.73 g, 0.3336 mol), 500 mL of dichloromethane, and triethylamine (37.17 g, 0.367 mol) to a reaction flask, stir at room temperature, and dropwise add heptanoyl chloride (54.55 g, 0.367 mol) to the reaction system, and stir at room temperature for 12 hours. Filter to remove solids, wash the filtrate twice with saturated sodium bicarbonate solution, wash three times with water, and dry over anhydrous sodium sulfate. Filter and spin dry the solvent to obtain the product of step (2). The H NMR spectrum of the product of step (2) is: 1H-NMR (700MHz, CDCl3) δ (ppm) = 4.18 (s, 2H), 3.71-3.61 (m, 4H), 2.34 (t, J = 7.6 Hz, 2H), 1.70-1.60 (m, 4H), 1.43 (s, 3H), 1.40 (s, 3H), 1.38-1.22 (m, 8H), 0.88 (t, J = 7.0 Hz, 3H), 0.82 (t, J = 7.8 Hz, 3H). The NMR carbon spectrum of the product of step (1) is: 13 C-NMR (175MHz, CDCl3) δ (ppm) = 174.0, 97.5, 65.1, 63.8, 37.3, 34.5, 31.7, 29.3, 26.9, 25.2, 22.7, 22.4, 20.9, 14.2, 7.1.

[0075] (3) The product of step (2) was dissolved in methanol (200 mL), 40 mL of 1M hydrochloric acid was prepared and added to the reaction bottle, and the reaction was carried out at 40°C for 24 hours. The crude product was spin-dried, and then 350 mL of ethyl acetate was added to dissolve it, and it was washed with water for several times. When the pH test paper showed that the washed water phase was neutral, it was dried with anhydrous sodium sulfate, filtered and spin-dried to obtain the product of step (3). The nuclear magnetic hydrogen spectrum of the product of step (3) is: 1 H-NMR (700MHz, CDCl3) δ (ppm) = 4.18 (s, 2H), 3.57 (dd, J = 21.0, 7.0 Hz, 4H), 3.40 (br, 2H), 2.33 (t, J = 7.6 Hz, 2H), 1.75-1.60 (m, 2H), 1.44-1.21 (m, 8H), 0.94-0.85 (m, 6H). The nuclear magnetic carbon spectrum of the product of step (3) is: 13 C-NMR (175MHz, CDCl3) δ (ppm) = 175.4, 65.3, 64.2, 43.1, 34.4, 31.6, 29.2, 25.2, 22.7, 22.5, 14.2, 7.5.

[0076] (4) The product of step (3) (160.17 g, 0.65 mol) was dissolved in 400 mL of dichloromethane, DMAP (15.88 g, 0.13 mol), hexanoic acid (90.52 g, 0.78 mol) and pentanoic acid (79.67 g, 0.78 mol) were added, and then EDCI (300.17 g, 1.56 mol) was added to the system and stirred at room temperature for 12 hours. The crude product was washed with 1 M hydrochloric acid solution, washed twice with water, and the dichloromethane solvent was removed by rotary evaporation. The excess acid was removed by vacuum distillation. After vacuum distillation, the product was washed with 1% potassium hydroxide solution at 80° C., then washed twice with water, and dried to obtain 301 g of the final product, which was the trimethylolpropane ester composition of the present invention. The mass spectrum data of the final product include: HRMS (FT-ICRMS) calculation for C 23 H 42 NaO6(M+Na):437.2874,found:437.2877;calcd for C 24 H 44 NaO6(M+Na):451.3030,found:451.3037; calcd for C 25 H 46 NaO6(M+Na):465.3187,found:465.3192.

[0077] After structural identification, the final product synthesized is indeed a composition of the target compound trimethylolpropane ester (structural formulas are I-d1, I-d2 and I-d3).

[0078] The synthetic reaction formula of Example 3 is shown below.

[0079]

[0080] The physical properties of the final products in Examples 1 to 3 and commercially available trimethylolpropane n-heptanoate (as Comparative Example 1) were evaluated by the methods of kinematic viscosity determination and dynamic viscosity calculation of petroleum products (GB / T 265), pour point determination of petroleum products (GB / T 3535) and lubricating oil evaporation loss determination-Noack method (NB / SH / T 0059-2010), and the evaluation results are shown in Table 1. The corresponding physical properties of trimethylolpropane n-nonanoate in the document "Synthetic Lubricants" (China Petrochemical Press, published in June 1996) are listed in Table 1 as Comparative Example 2 for comparison.

[0081] Table 1

[0082]

Claims

1. A trimethylolpropane ester composition comprising the following components: (a) (b) (c) Where R 1 , R 2 , R 3 The groups are each selected from C4 to C9 straight or branched alkyl groups, and R 1 , R 2 , R 3 The carbon numbers in the groups are different from each other; the molar ratio between the components (a), (b) and (c) is 1:(1.7-2.3):(0.7-1.3).

2. The trimethylolpropane ester composition according to claim 1, characterized in that R 1 , R 2 , R 3 The groups are C4 straight chain or branched chain alkyl, C5 straight chain or branched chain alkyl, C6 straight chain or branched chain alkyl, C7 straight chain or branched chain alkyl, C8 straight chain or branched chain alkyl, and C9 straight chain or branched chain alkyl groups with different carbon numbers.

3. The trimethylolpropane ester composition according to claim 1, characterized in that R 1 The group is selected from n-heptyl, R 2 , R 3 The groups are each selected from n-pentyl and n-hexyl groups; or, R 1 The group is selected from n-hexyl, R 2 , R 3 The groups are each selected from n-pentyl and n-heptyl; or, R 1 The group is selected from n-heptyl, R 2 , R 3 The groups are each selected from n-octyl and n-nonyl groups; or R 1 The group is selected from n-hexyl, R 2 , R 3 The groups are each selected from n-butyl and n-pentyl groups.

4. The method for preparing the trimethylolpropane ester composition according to claim 1, comprising the following steps: (1) allowing trimethylolpropane to undergo an alcohol hydroxyl group protecting reaction with an alcohol hydroxyl group protecting agent to obtain a monohydroxyl product; (2) the monohydroxy product obtained in step (1) is reacted with R 1 COX undergoes an acylation reaction to obtain an acylated product; (3) subjecting the acylated product obtained in step (2) to a deprotection reaction of the alcoholic hydroxyl group to obtain a dihydroxy product; (4) making the dihydroxy product obtained in step (3) and R 2 COX', R 3 COX' undergoes acylation reaction and collects the product; Among them, R 1 , R 2 , R 3 The groups are each selected from C4 to C9 straight or branched alkyl groups, and R 1 , R 2 , R 3 The carbon numbers in the groups are different from each other; the X group is selected from F, Cl, Br, I, OH; the X' groups are each independently selected from F, Cl, Br, I, OH; the R 1 COX, R 2 COX', R 3 The molar ratio between COX' is 1:(0.9~1.2):(0.9~1.2).

5. The preparation method according to claim 4, characterized in that: In step (1), the molar ratio of trimethylolpropane to the alcoholic hydroxyl protecting agent is 1:2-200; the temperature of the alcoholic hydroxyl protecting reaction is -20-80°C; and the time of the alcoholic hydroxyl protecting reaction is 1-120 hours.

6. The preparation method according to claim 5, characterized in that: The alcohol hydroxyl protecting agent is selected from one or more of acetone, 2,2-dimethoxypropane and 2-methoxypropylene.

7. The preparation method according to claim 5, characterized in that: In step (1), an acidic catalyst is added, wherein the acidic catalyst is selected from one or more of p-toluenesulfonic acid, hydrochloric acid, sulfuric acid, benzenesulfonic acid and dodecylbenzenesulfonic acid; and the molar ratio between the acidic catalyst and trimethylolpropane is 1:10-1000.

8. The preparation method according to claim 4, characterized in that: In step (2), the monohydroxy product obtained in step (1) is reacted with R 1 The molar ratio of COX is 1:0.5-2; the reaction temperature is 0-80°C, and the reaction time is 1-48 hours.

9. The preparation method according to claim 4, characterized in that: A second solvent and / or a basic catalyst are added to the reaction in step (2), wherein the second solvent is one or more of tetrahydrofuran, dichloromethane, chloroform, acetone, ethyl acetate and acetonitrile, and the basic catalyst is one or more of triethylamine, tert-butylamine, pyridine, diisopropylethylamine and hexamethyldisilazane.

10. The preparation method according to claim 4, characterized in that: In step (3), the acylated product obtained in step (2) is subjected to a deprotection reaction of the alcoholic hydroxyl group with a C1-C5 alcohol or an acid solution.

11. The preparation method according to claim 10, characterized in that: In step (3), the C1-C5 alcohol is one or more of methanol, ethanol, propanol, isopropanol, butanol and pentanol; and the acid solution is an aqueous solution of an inorganic acid.

12. The preparation method according to claim 10, characterized in that: In step (3), the molar concentration of the acylated product obtained in step (2) in the solution formed by the C1-C5 alcohol, the acid solution and the acylated product obtained in step (2) is 0.5-5 mol / L; the acid solution is prepared by mixing H + The molar ratio of the acylated product obtained in step (2) to the acid solution is 1:0.01-1; the reaction temperature is 20-80°C, and the reaction time is 1-48 hours.

13. The preparation method according to claim 4, characterized in that: In step (4), the dihydroxy product obtained in step (3) is reacted with R 2 COX', R 3 The molar ratio of COX' is 1:0.8-1.5:0.8-1.5; the reaction temperature is 0-80°C, and the reaction time is 1-48 hours.

14. The preparation method according to claim 13, characterized in that: In step (4), a carbodiimide condensation reagent and / or an activator is added, wherein the carbodiimide condensation reagent is one or more of 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride, dicyclohexylcarbodiimide and N,N'-diisopropylcarbodiimide, and the activator is one or more of 4-dimethylaminopyridine, 1-hydroxybenzotriazole and 1-hydroxy-7-azabenzotriazole.

15. Use of the trimethylolpropane ester composition according to any one of claims 1 to 3 or the trimethylolpropane ester composition prepared by the preparation method according to any one of claims 4 to 14 as a lubricating oil base oil.

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