Method for synthesizing dibasic acid diester base oil by utilizing dehydrated ricinoleic acid

Abstract

The invention belongs to the technical field of chemical engineering, and particularly discloses a method for synthesizing dibasic acid diester base oil by using dehydrated ricinoleic acid, which comprises the following steps: reacting conjugated linoleic acid and linoleic acid in dehydrated ricinoleic acid with an allyl compound under the closed condition of a high-pressure kettle by using a proper amount of iodine to synthesize the dibasic acid diester base oil. The method comprises the following steps: synthesizing an addition product of dehydrated ricinoleic acid and an allyl compound, carrying out esterification reaction on a mixture of the addition product of the dehydrated ricinoleic acid and fatty acid and unit fatty alcohol, and removing substances such as mono-fatty acid ester and an added catalyst which are generated in the reaction by virtue of decompression vacuum, filtration and washing processes, so as to obtain a dibasic acid diester product. The product prepared by the scheme belongs to green plant-based ester base oil, the cost is low, the biodegradation rate is high, the kinematic viscosity of the product is 30-60mm < 2 > / s, the pour point is-40 to-55 DEG C, the acid value is less than 0.02 mgKOH / g, the dielectric loss is less than 0.02, and the breakdown voltage is greater than 75Kv.

Description

Technical Field

[0001] The invention relates to the technical field of chemical industry, and in particular to a method for synthesizing a dibasic acid diester base oil by utilizing dehydrated ricinoleic acid. Background Art

[0002] As people's awareness of environmental crises grows, they generally realize that a large number of existing mineral-based lubricants cause environmental pollution problems due to penetration, leakage, overflow and improper handling during production, use and discharge. Environmentally friendly lubricants will gradually replace existing mineral-based lubricants.

[0003] Environmentally friendly lubricants are mainly bio-based lubricants, which are modified fatty acid-based oils or lubricants that can be decomposed into water and carbon dioxide by active microorganisms in a relatively short period of time. They have the following characteristics: they have good lubrication properties and can reduce environmental pollution by saving energy; the product itself is non-toxic to the environment and has little impact; the product can be biodegraded and can be decomposed into simple CO2 and water and absorbed by the environment without harm.

[0004] Environmentally friendly lubricants are mainly based on vegetable oils. Compared with traditional mineral lubricants, the natural renewable and biodegradable properties of vegetable oils can provide obvious environmental and economic sustainable development benefits. In addition, vegetable oils also have the advantages of low volatility, high flash point, high viscosity index and excellent lubricity. Therefore, bio-based lubricants with vegetable oil as the main source have become the main force of environmentally friendly lubricants.

[0005] The existing processes all use vegetable oil oleic acid and acrylic acid to synthesize dibasic acid diesters under normal pressure. Only when a large amount of iodine and a high temperature are used can the conjugation and addition reactions proceed smoothly. On the one hand, such a process is prone to self-polymerization of vegetable oil acid, acrylic acid, etc., and also brings a darker chroma, resulting in a poor appearance of the product, affecting the quality and application of the product. On the other hand, due to the normal pressure, the mass transfer between the low-boiling point acrylic acid and the easily sublimated iodine and the material is insufficient, the reaction speed decreases, the energy consumption increases, and the production efficiency is low. Summary of the invention

[0006] The object of the present invention is to provide a method for synthesizing a dibasic acid diester base oil by utilizing dehydrated castor oil acid, so as to solve the problem that the dibasic acid diester prepared by utilizing vegetable oil oleic acid and acrylic acid in the existing process needs to be heated to a higher temperature and more iodine is used to promote the reaction in order to avoid the self-polymerization of vegetable oil oleic acid, acrylic acid and the like during the normal pressure reaction process. Such a process not only makes the cost of the iodine raw material used higher, resulting in poor product color and affecting the product quality, but also requires correspondingly increasing the temperature conditions, resulting in the problem that the process of preparing the dibasic acid diester by the existing process has high energy consumption and low production efficiency.

[0007] To achieve the above object, the basic scheme provided by the present invention is: a method for synthesizing a dibasic acid diester base oil using dehydrated ricinoleic acid, characterized in that it comprises the following steps:

[0008] S1: In an autoclave containing dehydrated ricinoleic acid, a certain amount of iodine is added and nitrogen is introduced, the temperature is raised to 180-240° C., the stirrer is turned on, and the allyl compound is uniformly injected into the autoclave using a high-pressure constant-current pump, and then the reaction is continued for 1-3 hours; after the reaction is completed, a mixture of a Diels-Alder adduct of dehydrated ricinoleic acid, a dibasic acid monoester, a fatty acid and an allyl compound is obtained;

[0009] S2: performing vacuum distillation on the mixture of the reaction products obtained in step S1 to recover the allyl compound that has not participated in the reaction, thereby obtaining a mixture of dibasic acid monoester and fatty acid;

[0010] S3: placing the mixture of the dibasic acid monoester and fatty acid obtained in step S2 into a three-necked flask with a water separator, adding a mono-fatty alcohol in an amount of 0.5 to 3 times the mass of the mixture, using sodium bicarbonate as a catalyst, and subjecting the dibasic acid monoester and fatty acid to an esterification reaction with the fatty alcohol under mechanical stirring conditions, filtering out the catalyst after reacting for 1 to 3 hours, and recovering excess alcohol under reduced pressure and vacuum; washing the substrate with a weak alkaline solution and water for multiple times, and obtaining a mixture of the dibasic acid diester and fatty acid ester after dehydration;

[0011] S4: At 210-230°C, the fatty acid esters are separated by vacuum distillation technology to finally obtain the dibasic acid diester base oil product.

[0012] The principle and beneficial effects of the present invention are as follows: the present invention utilizes conjugated linoleic acid and linoleic acid present in dehydrated ricinoleic acid to react with an allyl compound under the closed condition of an autoclave, uses an appropriate amount of iodine to participate in the reaction, synthesizes an adduct of dehydrated ricinoleic acid and the allyl compound, and after the mixture of the dehydrated ricinoleic acid adduct and fatty acid is esterified with a mono-fatty alcohol, the mono-fatty acid ester produced by the reaction and the added catalyst and other substances are removed through the steps of reduced pressure vacuum, filtration, and washing to obtain a dibasic acid diester product. In the preparation process of the dibasic acid diester, the following beneficial effects are also produced:

[0013] First, the scheme utilizes the closed environment of the autoclave to achieve the addition of dehydrated ricinoleic acid with an allyl compound under high-pressure nitrogen filling conditions, thereby effectively avoiding the self-polymerization of dehydrated ricinoleic acid and promoting the preparation of dibasic acid diesters.

[0014] Second, under the protection of nitrogen, the allyl compound is injected at a uniform speed using a high-pressure constant-flow pump to avoid the self-polymerization of methacrylate or acrylate and improve the utilization rate of the material.

[0015] Third, since the reaction is carried out at a pressure not less than 1 MPa, the utilization rate of easily sublimated iodine is improved, the amount of iodine used is reduced, and the chromaticity of the product is reduced.

[0016] Fourth, under the condition of high-pressure nitrogen filling, it is conducive to the full contact of the allyl compound with a lower boiling point with the dehydrated ricinoleic acid, thereby improving the mass transfer efficiency and reducing the reaction time.

[0017] The product prepared by the process of this scheme has low cost and high biodegradability, and belongs to green plant-based ester base oil. In addition, the kinematic viscosity of the product is tested to be between 30 and 60 mm 2 / s, pour point -40~-55℃, acid value less than 0.02mgKOH / g, dielectric loss less than 0.02, and breakdown voltage greater than 75Kv. Therefore, the product can be used in the field of metalworking fluids, can replace existing anti-wear hydraulic oils, and can also be used as plant-based transformer oil, with good effectiveness.

[0018] Scheme 2, which is a preferred basic scheme, in steps S1 and S2, the allyl compound includes butyl acrylate, isobutyl acrylate, octyl acrylate, isooctyl acrylate, butyl methacrylate, isobutyl methacrylate, octyl methacrylate, isooctyl methacrylate;

[0019] Methacrylate and acrylate are allyl compounds, and any of the above-mentioned methacrylate and acrylate can be used as the reaction material of the dibasic acid diester.

[0020] Scheme 3 is a preferred embodiment of the basic scheme. In step S1, the dehydrated ricinoleic acid is industrial-grade dehydrated ricinoleic acid. The use of industrial-grade dehydrated ricinoleic acid can effectively control costs.

[0021] Scheme 4 is a preferred basic scheme. In step S3, the amount of sodium bicarbonate used is 0.6-1.0%wt of the total material amount. Sodium bicarbonate is an inorganic solid. Using sodium bicarbonate as a catalyst can promote the reaction rate of the esterification reaction.

[0022] Scheme 5 is a preferred embodiment of Scheme 3. In step S1, the iodine added is 0.1-1% (mass fraction) of the total material amount; iodine is used as a conjugation reagent for dehydrated ricinoleic acid and allyl compounds, and iodine plays a certain role in promoting the reaction process when participating in the reaction; if it is less than 0.1%, it will affect the reaction process and cause the reaction to be insufficient. If the amount of iodine used exceeds 1% or even more, the product color will be darker, affecting the appearance of the obtained dibasic acid diester product.

[0023] Scheme 6 is a preferred embodiment of Scheme 5. In step S1, the pressure in the autoclave is maintained at not less than 1.0 MPa. When the pressure is not less than 1 MPa, the reaction can be promoted to occur and proceed faster.

[0024] Scheme 7, which is a preferred embodiment of Scheme 4, wherein the mono-fatty alcohol added in step S3 is butanol, isobutanol, octanol, isooctyl alcohol, etc. 4～12 One of the mono-fatty alcohols; the mono-fatty alcohols containing 4 to 12 carbon elements can be used for esterification with a mixture of dibasic acid mono-fatty acid and fatty acid, and each mono-fatty alcohol is a raw material for the esterification reaction.

[0025] Scheme 8 is a preferred embodiment of Scheme 4, wherein the vacuum degree during the reduced pressure distillation operation is 0.05 MPa to 0.099 MPa; the temperature can be appropriately controlled under the vacuum environment so that fatty acid esters and monofatty alcohols can be extracted from the product dibasic acid diester without heating the temperature to a very high level; when the temperature is lower than 0.05 MPa, it is close to room temperature and cannot play a role in lowering the reaction temperature. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a reaction equation for preparing a dibasic acid diester from dehydrated ricinoleic acid and an allyl compound in a method for synthesizing a dibasic acid diester base oil from dehydrated ricinoleic acid of the present invention;

[0027] Figure 2 The infrared spectrum of the dibasic acid diester in the method for synthesizing the dibasic acid diester base oil by utilizing dehydrated ricinoleic acid is disclosed. DETAILED DESCRIPTION

[0028] The present invention is further described in detail below through specific embodiments:

[0029] like Figure 1 and Figure 2 As shown: A method for synthesizing a dibasic acid diester base oil using dehydrated ricinoleic acid comprises the following specific steps:

[0030] S1: 1000 g of industrial grade dehydrated ricinoleic acid (containing 90% conjugated linoleic acid and linoleic acid) is added to an autoclave. To allow the reaction to be carried out under closed conditions, 0.1-1% of iodine is added to the autoclave and nitrogen is introduced. The temperature is raised to 180-240° C., an agitator is turned on, and an allyl compound is uniformly injected into the autoclave using a high-pressure constant-current pump. The allyl compound is methacrylate and acrylate, specifically including butyl acrylate, isobutyl acrylate, octyl acrylate, isooctyl acrylate, butyl methacrylate, isobutyl methacrylate, octyl methacrylate, isooctyl methacrylate, etc. Any methacrylate or acrylate can be used interchangeably, and each methacrylate or acrylate having the same performance can be used as a reaction raw material.

[0031] Then, the reaction is continued for 1 to 3 hours. After the reaction is completed, a Diels-Alder adduct of dehydrated ricinoleic acid, i.e., a mixture of a dibasic acid monoester, a fatty acid and an allyl compound is obtained.

[0032] S2: performing a reduced pressure vacuum distillation operation on the mixture of the reaction products obtained in step S1 to recover the allyl compound that has not participated in the reaction, thereby obtaining a mixture of dibasic acid monoesters and fatty acids;

[0033] S3: Take a certain amount of the dibasic acid monoester and fatty acid mixture obtained in step S2, place it in a 1000 ml three-necked flask with a water separator, and then add 0.5 to 3 times the mass of the mixture of mono-fatty alcohol, the mono-fatty alcohol is butanol, isobutanol, octanol, isooctyl alcohol, etc. 4～12 One of the mono fatty alcohols, each of which has the same properties and can be used as a raw material; sodium bicarbonate is used as a catalyst, and the amount of sodium bicarbonate used is 0.6-1.0%wt of the total amount of the dibasic acid monoester, the fatty acid mixture and the mono fatty alcohol;

[0034] The temperature in the three-necked flask is heated and the dibasic acid monoester, fatty acid and mono fatty alcohol are subjected to esterification reaction under mechanical stirring. The catalyst is filtered out when the reaction is completed and no water is generated. The excess mono fatty alcohol is recovered by reduced pressure vacuum operation. The vacuum degree during the reduced pressure distillation operation is 0.05MPa-0.099MPa. The substrate after the mono fatty alcohol is recovered is washed with a weak alkaline solution and water for multiple times until the substrate is no longer alkaline, that is, the washing is completed. After dehydration, a mixture of dibasic acid diester and fatty acid ester is obtained;

[0035] S4: At 210-230°C, the fatty acid ester is separated by vacuum distillation technology to finally obtain a dibasic acid diester base oil product; the reaction equation for preparing the dibasic acid diester by using dehydrated ricinoleic acid and an allyl compound is as follows: Figure 1 The infrared spectrum of the finally obtained dibasic acid diester base oil product is shown in Figure 2 shown.

[0036] The technical solution of the present invention is described in more detail below through specific embodiments, but it is not intended to limit the protection scope of the present invention.

[0037] Embodiment 1

[0038] 1000 g of dehydrated ricinoleic acid and 0.15% (mass fraction) of iodine in the amount of dehydrated ricinoleic acid are added to an autoclave, nitrogen is filled into the autoclave, air is exhausted, the autoclave is heated to 220° C. in a sealed state, and the pressure in the autoclave is controlled to be at least 1.0 MPa, and butyl methacrylate in an amount of 1 to 1.5 times (molar ratio) of dehydrated ricinoleic acid is uniformly injected into the autoclave using a high-pressure constant-current pump, and the pressure is then maintained constant for 1 hour. The autoclave is then cooled and decompressed to obtain a mixture of dibasic acid monoesters, fatty acids and butyl methacrylate.

[0039] The obtained mixture of dibasic acid monoester, fatty acid and butyl methacrylate is subjected to reduced pressure vacuum distillation operation to recover butyl methacrylate that has not participated in the reaction, thereby obtaining a mixture of dibasic acid monoester and fatty acid.

[0040] A certain mass of a mixture of a dibasic acid monoester and a fatty acid is added into a 1000 ml three-necked flask with a water separator, 0.5 times the mass of butanol of the mixture is weighed and added into the three-necked flask, and sodium bicarbonate is added into the three-necked flask, wherein the amount of sodium bicarbonate accounts for 0.6% of the total mass of the mixture of the dibasic acid monoester and the fatty acid mixture and the butanol, the three-necked flask is heated to increase the reaction temperature of the mixture and the butanol, and the mixture and the butanol are subjected to an esterification reaction under mechanical stirring, and the reaction ends when no water is generated.

[0041] The sodium bicarbonate catalyst is filtered off, and the excess butanol is recovered under reduced pressure and vacuum, and then washed with alkaline water and purified water for 3 times respectively. The pH test paper test shows that the sodium bicarbonate has been washed clean if it is not alkaline, and a mixture of dibasic acid dibutyl ester and fatty acid butyl ester is obtained after dehydration. The dibasic acid dibutyl ester and fatty acid butyl ester are subjected to reduced pressure distillation operation at 210°C to distill out fatty acid butyl ester, thereby obtaining a dibasic acid diester product.

[0042] After measurement, the kinematic viscosity of the obtained dibasic acid diester product is 30 mm 2 / s, pour point -43℃, acid value 0.02mgKOH / g, breakdown voltage 76Kv, dielectric loss 0.02.

[0043] Embodiment 2

[0044] 1000 g of dehydrated ricinoleic acid and 0.3% (mass fraction) of iodine in the amount of dehydrated ricinoleic acid are added to an autoclave, nitrogen is filled into the autoclave, air is exhausted, the autoclave is heated to 240° C. in a sealed state, and the pressure in the autoclave is controlled to reach at least 1.0 MPa, and 1 to 1.5 times (molar ratio) of isobutyl acrylate is uniformly injected into the autoclave by a high-pressure constant-current pump, and the pressure is then maintained constant for 3 hours. The autoclave is then cooled and decompressed to obtain a mixture of dibasic acid monoesters, fatty acids and isobutyl acrylate.

[0045] The obtained mixture of dibasic acid monoester, fatty acid and isobutyl acrylate is subjected to reduced pressure vacuum distillation operation to recover the isobutyl acrylate that has not participated in the reaction, thereby obtaining a mixture of dibasic acid monoester and fatty acid.

[0046] A certain mass of a mixture of a dibasic acid monoester and a fatty acid is added to a 1000 ml three-necked flask with a water separator, octanol in an amount three times the mass of the mixture is weighed and added to the three-necked flask, and sodium bicarbonate is added to the three-necked flask, wherein the amount of sodium bicarbonate accounts for 1.0% of the total mass of the mixture of the dibasic acid monoester and the fatty acid mixture and octanol, the three-necked flask is heated to increase the reaction temperature of the mixture and octanol, and the mixture and octanol are subjected to an esterification reaction under mechanical stirring, and the reaction is terminated when no water is generated.

[0047] The sodium bicarbonate catalyst is filtered off, and the excess octanol is recovered under reduced pressure and vacuum, and then washed with alkaline water and purified water for 3 times respectively. The pH test paper test shows that the sodium bicarbonate has been washed clean if it is not alkaline, and a mixture of dibasic acid diester and fatty acid octyl ester is obtained after dehydration. The dibasic acid diester and fatty acid octyl ester are subjected to reduced pressure distillation at 230°C to distill out fatty acid octyl ester, thereby obtaining the dibasic acid diester product.

[0048] After measurement, the kinematic viscosity of the obtained dibasic acid diester product is 60 mm 2 / s, pour point -48℃, acid value 0.02mgKOH / g, breakdown voltage 77Kv, dielectric loss 0.015.

[0049] Embodiment 3

[0050] 1000 g of dehydrated ricinoleic acid and 0.5% (mass fraction) of iodine in the amount of dehydrated ricinoleic acid are added to an autoclave, nitrogen is filled into the autoclave, air is exhausted, the autoclave is heated to 230° C. in a sealed state, and the pressure in the autoclave is controlled to be at least 1.0 MPa, and 1 to 1.5 times (molar ratio) of isobutyl methacrylate is uniformly injected into the autoclave by a high-pressure constant flow pump, and the pressure is then maintained constant for 3 hours. The autoclave is then cooled and decompressed to obtain a mixture of dibasic acid monoesters, fatty acids and isobutyl methacrylate.

[0051] The obtained mixture of dibasic acid monoester, fatty acid and isobutyl methacrylate is subjected to reduced pressure vacuum distillation operation to recover the isobutyl methacrylate that has not participated in the reaction, thereby obtaining a mixture of dibasic acid monoester and fatty acid.

[0052] A certain mass of a mixture of a dibasic acid monoester and a fatty acid is added to a 1000 ml three-necked flask with a water separator, octanol twice the mass of the mixture is weighed and added to the three-necked flask, and sodium bicarbonate is added to the three-necked flask, wherein the amount of sodium bicarbonate accounts for 1.0% of the total mass of the mixture of the dibasic acid monoester and the fatty acid mixture and octanol, the three-necked flask is heated to increase the reaction temperature of the mixture and isooctyl alcohol, and the mixture and isooctyl alcohol are subjected to an esterification reaction under mechanical stirring, and the reaction is terminated when no water is generated.

[0053] The sodium bicarbonate catalyst is filtered off, and the excess octanol is recovered under reduced pressure and vacuum, and then washed with alkaline water and purified water for 3 times respectively. The pH test paper test shows that the sodium bicarbonate has been washed clean if it is not alkaline, and a mixture of dibasic acid diester and fatty acid isooctyl ester is obtained after dehydration. The dibasic acid diester and fatty acid isooctyl ester are subjected to reduced pressure distillation at 230°C to distill out fatty acid butyl ester, thereby obtaining the dibasic acid diester product.

[0054] After measurement, the kinematic viscosity of the obtained dibasic acid diester product is 54 mm 2 / s, pour point -55℃, acid value 0.018mgKOH / g, breakdown voltage 79Kv, dielectric loss 0.015.

[0055] Embodiment 4

[0056] 1000 g of dehydrated ricinoleic acid and 0.7% (mass fraction) of iodine in the amount of dehydrated ricinoleic acid are added to an autoclave, nitrogen is filled into the autoclave, air is exhausted, the autoclave is heated to 210° C. in a sealed state, and the pressure in the autoclave is controlled to be at least 1.0 MPa, and 1 to 1.5 times (molar ratio) of octyl acrylate is uniformly injected into the autoclave by a high-pressure constant-current pump, and the pressure is then kept constant for 2 hours. The autoclave is then cooled and decompressed to obtain a mixture of dibasic acid monoesters, fatty acids and octyl acrylate.

[0057] The obtained mixture of dibasic acid monoester, fatty acid and octyl acrylate is subjected to reduced pressure vacuum distillation operation to recover the octyl acrylate that has not participated in the reaction, thereby obtaining a mixture of dibasic acid monoester and fatty acid.

[0058] A certain mass of a mixture of a dibasic acid monoester and a fatty acid is added into a 1000 ml three-necked flask with a water separator, 1.5 times the mass of butanol of the mixture is weighed and added into the three-necked flask, and sodium bicarbonate is added into the three-necked flask, wherein the amount of sodium bicarbonate accounts for 0.7% of the total mass of the mixture of the dibasic acid monoester and the fatty acid mixture and the butanol, the three-necked flask is heated to increase the reaction temperature of the mixture and the butanol, and the mixture and the butanol are subjected to an esterification reaction under mechanical stirring, and the reaction ends when no water is generated.

[0059] The sodium bicarbonate catalyst is filtered off, and the excess butanol is recovered under reduced pressure and vacuum, and then washed with alkaline water and purified water for 3 times respectively. The pH test paper test shows that the sodium bicarbonate has been washed clean if it is not alkaline, and a mixture of dibasic acid diester and fatty acid butyl ester is obtained after dehydration. The dibasic acid diester and fatty acid butyl ester are subjected to reduced pressure distillation operation at 210°C to distill out fatty acid butyl ester, thereby obtaining the dibasic acid diester product.

[0060] After measurement, the kinematic viscosity of the obtained dibasic acid diester product is 50 mm 2 / s, pour point -50℃, acid value 0.015mgKOH / g, breakdown voltage 77Kv, dielectric loss 0.02.

[0061] Embodiment 5

[0062] 1000 g of dehydrated ricinoleic acid and 0.4% (mass fraction) of iodine in the amount of dehydrated ricinoleic acid are added to an autoclave, nitrogen is filled into the autoclave, air is exhausted, the autoclave is heated to 190° C. in a sealed state, and the pressure in the autoclave is controlled to be at least 1.0 MPa, and 1 to 1.5 times (molar ratio) of dehydrated ricinoleic acid is injected into the autoclave at a uniform speed by a high-pressure constant-current pump, and the pressure is then maintained constant for 2.5 hours. The autoclave is then cooled and decompressed to obtain a mixture of dibasic acid monoesters, fatty acids and methacrylate.

[0063] The obtained mixture of dibasic acid monoester, fatty acid and isooctyl methacrylate is subjected to reduced pressure vacuum distillation operation to recover isooctyl methacrylate that has not participated in the reaction, thereby obtaining a mixture of dibasic acid monoester and fatty acid.

[0064] A certain mass of a mixture of a dibasic acid monoester and a fatty acid is added to a 1000 ml three-necked flask with a water separator, 1.5 times the mass of isooctyl alcohol of the mixture is weighed and added to the three-necked flask, and sodium bicarbonate is added to the three-necked flask, wherein the amount of sodium bicarbonate accounts for 0.8% of the total mass of the mixture of the dibasic acid monoester and the fatty acid mixture and the isooctyl alcohol, the three-necked flask is heated to increase the reaction temperature of the mixture and the isooctyl alcohol, and the mixture and the isooctyl alcohol are subjected to an esterification reaction under mechanical stirring, and the reaction is terminated when no water is generated.

[0065] The sodium bicarbonate catalyst is filtered off, and the excess isooctyl alcohol is recovered under reduced pressure and vacuum, and then washed with alkaline water and purified water for 3 times respectively. The pH test paper test shows that the sodium bicarbonate has been washed clean if it is not alkaline, and a mixture of dibasic acid diester and fatty acid isooctyl ester is obtained after dehydration. The dibasic acid diester and fatty acid isooctyl ester are subjected to reduced pressure distillation at 220°C to distill out fatty acid isooctyl ester, thereby obtaining the dibasic acid diester product.

[0066] After measurement, the kinematic viscosity of the obtained dibasic acid diester product is 60 mm 2 / s, pour point -49℃, acid value 0.02mgKOH / g, breakdown voltage 78Kv, dielectric loss 0.02.

[0067] Embodiment 6

[0068] 1000 g of dehydrated ricinoleic acid and 0.1% (mass fraction) of iodine in the amount of dehydrated ricinoleic acid are added to an autoclave, nitrogen is filled into the autoclave, air is exhausted, the autoclave is heated to 200° C. in a sealed state, and the pressure in the autoclave is controlled to be at least 1.0 MPa, and butyl methacrylate in an amount of 1 to 1.5 times (molar ratio) of dehydrated ricinoleic acid is uniformly injected into the autoclave using a high-pressure constant-current pump, and the pressure is then maintained constant for 2 hours. The autoclave is then cooled and decompressed to obtain a mixture of dibasic acid monoesters, fatty acids and butyl methacrylate.

[0069] The obtained mixture of dibasic acid monoester, fatty acid and butyl methacrylate is subjected to reduced pressure vacuum distillation operation to recover butyl methacrylate that has not participated in the reaction, thereby obtaining a mixture of dibasic acid monoester and fatty acid.

[0070] A certain mass of a mixture of a dibasic acid monoester and a fatty acid is added to a 1000 ml three-necked flask with a water separator, isooctyl alcohol in an amount of 1 times the mass of the mixture is weighed and added to the three-necked flask, and sodium bicarbonate is added to the three-necked flask, wherein the amount of sodium bicarbonate accounts for 0.7% of the total mass of the mixture of the dibasic acid monoester and the fatty acid mixture and the isooctyl alcohol, the three-necked flask is heated to increase the reaction temperature of the mixture and the isooctyl alcohol, and the mixture and the isooctyl alcohol are subjected to an esterification reaction under mechanical stirring, and the reaction is terminated when no water is generated.

[0071] The sodium bicarbonate catalyst is filtered off, and the excess isooctyl alcohol is recovered under reduced pressure and vacuum, and then washed with alkaline water and purified water for 3 times respectively. The pH test paper test shows that the sodium bicarbonate has been washed clean if it is not alkaline, and a mixture of dibasic acid diester and fatty acid isooctyl ester is obtained after dehydration. The dibasic acid diester and fatty acid isooctyl ester are subjected to reduced pressure distillation at 220°C to distill out fatty acid isooctyl ester, thereby obtaining the dibasic acid diester product.

[0072] After measurement, the kinematic viscosity of the obtained dibasic acid diester product is 51 mm2 / s, pour point -47℃, acid value 0.016mgKOH / g, breakdown voltage 76Kv, dielectric loss 0.018.

[0073] Embodiment 7

[0074] 1000 g of dehydrated ricinoleic acid and 0.1% (mass fraction) of iodine in the amount of dehydrated ricinoleic acid are added to an autoclave, nitrogen is filled into the autoclave, air is exhausted, the autoclave is heated to 180° C. in a sealed state, and the pressure in the autoclave is controlled to be at least 1.0 MPa, and butyl acrylate in an amount of 1 to 1.5 times (molar ratio) of dehydrated ricinoleic acid is uniformly injected into the autoclave using a high-pressure constant-current pump, and the pressure is then maintained constant for 2 hours. The autoclave is then cooled and decompressed to obtain a mixture of dibasic acid monoesters, fatty acids and butyl acrylate.

[0075] The obtained mixture of dibasic acid monoester, fatty acid and butyl acrylate is subjected to reduced pressure vacuum distillation operation to recover butyl acrylate that has not participated in the reaction, thereby obtaining a mixture of dibasic acid monoester and fatty acid.

[0076] A certain mass of a mixture of a dibasic acid monoester and a fatty acid is added into a 1000 ml three-necked flask with a water separator, isobutanol in an amount of 1 times the mass of the mixture is weighed and added into the three-necked flask, and sodium bicarbonate is added into the three-necked flask, wherein the amount of sodium bicarbonate accounts for 0.8% of the total mass of the mixture of the dibasic acid monoester and the fatty acid and the isobutanol, the three-necked flask is heated to increase the reaction temperature of the mixture and the isobutanol, and the mixture and the isobutanol are subjected to an esterification reaction under mechanical stirring, and the reaction ends when no water is generated.

[0077] The sodium bicarbonate catalyst is filtered off, and the excess isooctyl alcohol is recovered under reduced pressure and vacuum, and then washed with alkaline water and purified water for 3 times respectively. The pH test paper test shows that the sodium bicarbonate has been washed clean if it is not alkaline, and a mixture of dibasic acid diester and fatty acid isobutyl ester is obtained after dehydration. The dibasic acid diester and fatty acid isobutyl ester are subjected to reduced pressure distillation at 220°C to distill out fatty acid isobutyl ester, thereby obtaining the dibasic acid diester product.

[0078] After measurement, the kinematic viscosity of the obtained dibasic acid diester product is 30 mm 2 / s, pour point -45℃, acid value 0.015mgKOH / g, breakdown voltage 75Kv, dielectric loss 0.017.

[0079] Embodiment 8

[0080] 1000 g of dehydrated ricinoleic acid and 0.8% (mass fraction) of iodine in the amount of dehydrated ricinoleic acid are added to an autoclave, nitrogen is filled into the autoclave, air is exhausted, the autoclave is heated to 225° C. in a sealed state, and the pressure in the autoclave is controlled to reach at least 1.0 MPa, and 1 to 1.5 times (molar ratio) of octyl methacrylate is uniformly injected into the autoclave by a high-pressure constant-current pump, and the pressure is then maintained constant for 2.5 hours. The autoclave is then cooled and decompressed to obtain a mixture of dibasic acid monoesters, fatty acids and octyl methacrylate.

[0081] The obtained mixture of dibasic acid monoester, fatty acid and octyl methacrylate is subjected to reduced pressure vacuum distillation operation to recover the octyl methacrylate that has not participated in the reaction, thereby obtaining a mixture of dibasic acid monoester and fatty acid.

[0082] A certain mass of a mixture of a dibasic acid monoester and a fatty acid is added to a 1000 ml three-necked flask with a water separator, isobutanol 2.5 times the mass of the mixture is weighed and added to the three-necked flask, and sodium bicarbonate is added to the three-necked flask, wherein the amount of sodium bicarbonate accounts for 0.9% of the total mass of the mixture of the dibasic acid monoester and the fatty acid and the isobutanol, the three-necked flask is heated to increase the reaction temperature of the mixture and the isobutanol, and the mixture and the isobutanol are subjected to an esterification reaction under mechanical stirring, and the reaction ends when no water is generated.

[0083] The sodium bicarbonate catalyst is filtered off, and the excess isooctyl alcohol is recovered under reduced pressure and vacuum, then washed with alkaline water and purified water for 3 times respectively. The pH test paper shows that the sodium bicarbonate has been washed clean if it is not alkaline, and a mixture of dibasic acid diester and fatty acid isooctyl ester is obtained after dehydration. The dibasic acid diester and fatty acid isobutyl ester are subjected to reduced pressure distillation at 230°C to distill out fatty acid isobutyl ester, thereby obtaining the dibasic acid diester product.

[0084] After measurement, the kinematic viscosity of the obtained dibasic acid diester product is 55 mm 2 / s, pour point -51℃, acid value 0.02mgKOH / g, breakdown voltage 78Kv, dielectric loss 0.02.

[0085] Embodiment 9

[0086] 1000 g of dehydrated ricinoleic acid and 0.9% (mass fraction) of iodine in the amount of dehydrated ricinoleic acid are added to an autoclave, nitrogen is filled into the autoclave, air is exhausted, the autoclave is heated to 225° C. in a sealed state, and the pressure in the autoclave is controlled to reach at least 1.0 MPa, and 1 to 1.5 times (molar ratio) of isooctyl acrylate is injected into the autoclave at a uniform speed by a high-pressure constant-current pump, and the pressure is then maintained constant for 3 hours. The autoclave is then cooled and decompressed to obtain a mixture of dibasic acid monoesters, fatty acids and isooctyl acrylate.

[0087] The obtained mixture of dibasic acid monoester, fatty acid and isooctyl acrylate is subjected to reduced pressure vacuum distillation operation to recover isooctyl acrylate that has not participated in the reaction, thereby obtaining a mixture of dibasic acid monoester and fatty acid.

[0088] A certain mass of a mixture of a dibasic acid monoester and a fatty acid is added to a 1000 ml three-necked flask with a water separator, octanol twice the mass of the mixture is weighed and added to the three-necked flask, and sodium bicarbonate is added to the three-necked flask, wherein the amount of sodium bicarbonate accounts for 0.8% of the total mass of the mixture of the dibasic acid monoester and the fatty acid mixture and octanol. The three-necked flask is heated to increase the reaction temperature of the mixture and octanol, and the mixture and octanol are subjected to an esterification reaction under mechanical stirring, and the reaction is terminated when no water is generated.

[0089] The sodium bicarbonate catalyst is filtered off, and the excess octanol is recovered under reduced pressure and vacuum, and then washed with alkaline water and purified water for 3 times respectively. The pH test paper test shows that the sodium bicarbonate has been washed clean if it is not alkaline, and a mixture of dibasic acid diester and fatty acid octyl ester is obtained after dehydration. The dibasic acid diester and fatty acid octyl ester are subjected to reduced pressure distillation at 215°C to distill out fatty acid octyl ester, thereby obtaining the dibasic acid diester product.

[0090] After measurement, the kinematic viscosity of the obtained dibasic acid diester product is 57 mm 2 / s, pour point -40℃, acid value 0.02mgKOH / g, breakdown voltage 76Kv, dielectric loss 0.02.

[0091] The invention uses nitrogen to create a high-pressure state in an autoclave, uses a relatively small amount of iodine as a catalyst, and uses a high-pressure constant-current pump to uniformly inject an allyl compound into the autoclave, thereby accelerating the mass transfer of iodine and the allyl compound, allowing the conjugated linoleic acid in the dehydrated ricinoleic acid and the linoleic acid and the allyl compound to undergo conjugation and Diels-Alder addition reactions more quickly, thereby obtaining a dibasic acid monoester adduct with a high yield.

[0092] The technical solution has obtained the target product, dibasic acid diester, through a large number of experiments. The invention uses conjugated linoleic acid and linoleic acid present in dehydrated ricinoleic acid and an allyl compound to participate in the reaction under the closed condition of an autoclave, using an appropriate amount of iodine to synthesize an adduct of dehydrated ricinoleic acid and an allyl compound, and after the dehydrated ricinoleic acid adduct has an esterification reaction with a mono-fatty alcohol, the fatty acid ester, the catalyst and other substances produced by the reaction are removed through the steps of reduced pressure vacuum, filtration and washing to obtain a dibasic acid diester product.

[0093] The product obtained through the process of this scheme has low cost and high biodegradability, and belongs to green plant-based ester base oil. In addition, the kinematic viscosity of the product is tested to be between 30 and 60 mm 2 / s, pour point -40~-55℃, acid value less than 0.02mgKOH / g, dielectric loss less than 0.02, and breakdown voltage greater than 75Kv. Therefore, the product can be used in the field of metalworking fluids, can replace existing anti-wear hydraulic oils, and can also be used as plant-based transformer oil, with good effectiveness.

[0094] The above is only an embodiment of the present invention, and the common knowledge such as the known specific structure and characteristics in the scheme is not described in detail here. It should be pointed out that for those skilled in the art, several deformations and improvements can be made without departing from the structure of the present invention, which should also be regarded as the protection scope of the present invention, and these will not affect the effect of the implementation of the present invention and the practicality of the patent. The scope of protection required by this application shall be based on the content of its claims, and the specific implementation methods and other records in the specification can be used to interpret the content of the claims.

Claims

1. A method for synthesizing a dibasic acid diester base oil using dehydrated ricinoleic acid, characterized in that: The steps include: S1: In an autoclave containing dehydrated ricinoleic acid, a certain amount of iodine is added and nitrogen is introduced, the temperature is raised to 180-240° C., the stirrer is turned on, and the allyl compound is uniformly injected into the autoclave using a high-pressure constant-current pump, and then the reaction is continued for 1-3 hours; after the reaction is completed, a mixture of a Diels-Alder adduct of dehydrated ricinoleic acid, a dibasic acid monoester, a fatty acid and an allyl compound is obtained; S2: performing vacuum distillation on the mixture of the reaction products obtained in step S1 to recover the allyl compound that has not participated in the reaction, thereby obtaining a mixture of dibasic acid monoester and fatty acid; S3: placing the mixture of the dibasic acid monoester and fatty acid obtained in step S2 into a three-necked flask with a water separator, adding a mono-fatty alcohol in an amount of 0.5 to 3 times the mass of the mixture, and subjecting the dibasic acid monoester and fatty acid to an esterification reaction with the fatty alcohol using sodium bicarbonate as a catalyst and mechanical stirring. After reacting for 1 to 3 hours, the catalyst is filtered out, and excess alcohol is recovered under reduced pressure and vacuum. The substrate is washed with a weak alkaline solution and water for multiple times, and a mixture of the dibasic acid diester and fatty acid ester is obtained after dehydration. S4: At 210-230°C, the fatty acid esters are separated by vacuum distillation technology to finally obtain the dibasic acid diester base oil product.

2. The method for synthesizing a dibasic acid diester base oil by utilizing dehydrated ricinoleic acid according to claim 1, characterized in that: In steps S1 and S2, the allyl compound includes butyl acrylate, isobutyl acrylate, octyl acrylate, isooctyl acrylate, butyl methacrylate, isobutyl methacrylate, octyl methacrylate, and isooctyl methacrylate.

3. The method for synthesizing dibasic acid diester base oil by utilizing dehydrated ricinoleic acid according to claim 1, characterized in that: In step S1, the dehydrated ricinoleic acid is industrial-grade dehydrated ricinoleic acid.

4. The method for synthesizing a dibasic acid diester base oil by utilizing dehydrated ricinoleic acid according to claim 1, characterized in that: In step S3, the amount of sodium bicarbonate used is 0.6-1.0%wt of the total material amount.

5. The method for synthesizing dibasic acid diester base oil by utilizing dehydrated ricinoleic acid according to claim 3, characterized in that: In step S1, the amount of iodine added is 0.1-1% (mass fraction) of the total material.

6. The method for synthesizing dibasic acid diester base oil by utilizing dehydrated ricinoleic acid according to claim 5, characterized in that: In step S1, the pressure in the autoclave is maintained at not less than 1.0 MPa.

7. The method for synthesizing dibasic acid diester base oil by utilizing dehydrated ricinoleic acid according to claim 4, characterized in that: The mono-fatty alcohol added in step S3 is butanol, isobutanol, octanol, isooctyl alcohol, etc. 4～12 A type of mono-fatty alcohol.

8. The method for synthesizing dibasic acid diester base oil by utilizing dehydrated ricinoleic acid according to claim 4, characterized in that: The vacuum degree during the reduced pressure distillation operation is 0.05MPa to 0.099MPa.

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