Production method of environment-friendly rubber plasticizer

Abstract

A production method of an environment-friendly rubber plasticizer is characterized in that a solvent extraction method is adopted, a first solvent comprises one of phenol, furfural, N-methyl pyrrolidone and dimethyl sulfoxide and enters the upper portion of a second extraction tower, a second solvent is alkane and / or cycloalkane with the carbon number of 6-20 and enters the lower portions of the two extraction towers, raw material oil is extract oil, and the extract oil enters the lower portion of the second extraction tower. Raw oil enters from a middle feed port of the first extraction tower; raffinate flowing out of the top of the first extraction tower enters a middle feed port of the second extraction tower after part of the solvent is recovered; evaporating secondary raffinate flowing out from the top of the second extraction tower to recover the solvent, thereby obtaining the environment-friendly rubber plasticizer. Heating materials flowing out from the bottom of the second extraction tower and pumping the heated materials into an upper feed port of the primary extraction tower; and evaporating the effluent extract at the bottom of the first extraction tower to recover the solvent to obtain primary extract oil.

Description

Technical Field

[0001] This invention belongs to the field of petroleum fraction refining, specifically relating to a method for producing an environmentally friendly rubber plasticizer. The patent classification number is C10G. Background Technology

[0002] Rubber is a highly elastic, tough, and strong polymer with wide applications in modern society. From transportation industries such as automobiles, aviation, and shipping, to construction, cutting-edge technology, medicine and healthcare, and daily life, rubber is indispensable. Therefore, rubber plays an immeasurable role in promoting national economic development and improving people's living standards. Rubber plasticizers (also known as rubber oils) are essential raw materials for rubber production. Adding a certain amount of rubber plasticizer to rubber compounds can improve the elasticity, flexibility, processability, and mixing properties of rubber, playing a crucial role in improving the performance of rubber products and the overall rubber production process.

[0003] Based on their basic properties, rubber plasticizers can be classified into aromatic, cycloalkane, and alkyl types. Among them, aromatic rubber plasticizers have a high aromatic carbon content (C... A Aromatic rubber plasticizers possess advantages such as high density, high viscosity, excellent processing performance, and good compatibility with rubber, while also imparting good anti-skid properties to tires, thus gaining widespread application. However, typical aromatic rubber plasticizers usually contain 10% to 30% polycyclic aromatic hydrocarbons (PCA). With in-depth research, the environmental and health hazards of aromatic rubber plasticizers have been formally raised and confirmed. In 1994, the European Union's Chemical Classification and Labelling Authority (CMAC) classified aromatic rubber plasticizers with a PCA content greater than 3% as carcinogens and toxic substances. The EU Directive 2005 / 69 / EC, signed in 2005, explicitly limits the total content of eight carcinogenic polycyclic aromatic hydrocarbons (PAHs), including benzo[a]pyrene, in tire rubber plasticizers to less than 10 μg / g, with the benzo[a]pyrene content to less than 1 μg / g. Aromatic rubber plasticizers that meet these environmental standards are called environmentally friendly aromatic rubber plasticizers. Rubber plasticizers that do not meet the above environmental standards cannot be placed on the EU market or used in the production of tires and related products. Furthermore, my country has also standardized the production of rubber plasticizers; the national standard GB / T33322—2016 (Rubber Plasticizers Aromatic Mineral Oils) contains the same regulations. Therefore, the production and application of environmentally friendly rubber plasticizers have attracted significant attention from rubber plasticizer manufacturers and tire producers.

[0004] To ensure good compatibility between aromatic mineral oil plasticizers and rubber compounds, and to improve the safety and performance of rubber, environmentally friendly aromatic rubber plasticizers generally require a C... AThe value should be greater than 15%, ideally greater than 20%, especially when dealing with raw oils that are high in density, viscosity, and PCA content, as conventional extraction methods often fail to meet these requirements. Therefore, for these difficult-to-process raw oils, it is crucial to address how to improve the C content of rubber plasticizers. A The challenge in producing aromatic mineral oils for rubber plasticizers is to simultaneously reduce PCA and PAH content while maintaining the yield of rubber plasticizers. Currently, both domestically and internationally, the traditional solvent refining process is mainly used to produce rubber plasticizers. This process involves countercurrent contact between a single solvent such as furfural, phenol, or N-methylpyrrolidone and a feedstock such as vacuum distillate oil in an extraction tower. The polycyclic aromatic hydrocarbons (PAHs) in the feedstock oil are dissolved in the solvent and automatically settle to the bottom of the extraction tower. The extracted feedstock oil automatically rises to the top of the tower and is separated by the solvent to obtain the rubber plasticizer. Although this method controls the PAH content to below 3% and meets the requirements of the EU Directive 2005 / 69 / EC for the content of the eight carcinogenic PAHs, the aromatic carbon content is also relatively low, limiting the application of rubber plasticizers in rubber preparation. As an improvement on traditional processes, some researchers use heavy solvent extract oil refined from lubricating oil solvents as raw material. This oil is first mixed with additives, and then extracted in an extraction tower. The additives used are elemental hydrocarbons or light hydrocarbon oils with low density, low viscosity, and boiling points in the range of 80–300℃. This process has increased the aromatic carbon content of rubber plasticizers to 19.0%, but further adjustments to the solvent-to-oil ratio or operating temperature make it difficult to increase the aromatic carbon content further. Furthermore, this method suffers from low yield of environmentally friendly rubber plasticizers. Patents ZL2017107034337 and ZL2017107034341 employ dual solvents and a special extraction tower, using vacuum distillate oil as raw material, which can improve the yield and aromatic carbon content of rubber plasticizers (environmentally friendly rubber oils). Patent 2025102384894 employs a dual-solvent and dual-extraction tower extraction method, using extracted oil from vacuum distillate or deasphalted oil as raw material to produce rubber plasticizers (environmentally friendly rubber oils). While this method achieves a high yield, there is room for further improvement. Furthermore, this method has a high total solvent-to-oil ratio and high energy consumption for solvent recovery. This patent, based on this patent, provides a method for producing environmentally friendly rubber plasticizers. It aims to increase the aromatic carbon content while further improving the yield of rubber plasticizers, reducing the content of polycyclic aromatic hydrocarbons (PAHs) and eight carcinogenic PAHs, meeting the requirements of EU Directive 2005 / 69 / EC and national standard GB / T 33322—2016 (Rubber Plasticizers Aromatic Mineral Oils), while also reducing energy consumption and production costs. Summary of the Invention

[0005] To improve the yield of rubber plasticizers, this invention provides a newer, environmentally friendly method for producing rubber plasticizers. The method employs a dual-solvent, dual-extraction tower refining process, resulting in a rubber plasticizer with a higher aromatic carbon content and lower levels of polycyclic aromatic hydrocarbons (PAHs) and eight carcinogenic PAHs. This meets the requirements of EU Directive 2005 / 69 / EC and Chinese National Standard GB / T 33322—2016 (Rubber Plasticizers, Aromatic Mineral Oils). Furthermore, it improves the yield of rubber plasticizers while reducing energy consumption and production costs.

[0006] 1. A method for producing an environmentally friendly rubber plasticizer, characterized by using a solvent extraction method, employing a dual-solvent dual-extraction tower, wherein the main solvent includes one of phenol, furfural, N-methylpyrrolidone, and dimethyl sulfoxide, the co-solvent is an alkane and / or cycloalkanes with 6-20 carbon atoms in the molecule, and the feed oil is the extract oil obtained by extraction and refining of wax oil or deasphalted oil with a distillation range of 350-600℃. This method further includes the following steps and features:

[0007] (1) The first extraction tower and the second extraction tower have three feed inlets, located at the top (first feed inlet), middle (third feed inlet) and bottom (second feed inlet) of the extraction tower respectively. Each extraction tower has at least two outlets, located at the top and bottom of the extraction tower respectively. The extraction tower is filled with packing or trays.

[0008] (2) The main solvent enters from the first inlet of the second extraction tower, the raw material oil enters from the third inlet of the first extraction tower, and the co-solvent enters from the second inlet at the bottom of the first extraction tower and the second extraction tower respectively. The extract at the bottom of the second extraction tower is heated to 60-80℃ and then enters the first inlet of the first extraction tower.

[0009] (3) The raffinate flowing out from the top of the first extraction tower enters the solvent recovery tower to recover part of the solvent and obtains primary raffinate oil; the primary extract flowing out from the bottom of the first extraction tower is heated and evaporated to recover the solvent and obtain primary extract oil.

[0010] (4) The residual oil from the first extraction enters the third feed inlet of the second extraction tower;

[0011] (5) The secondary raffinate flows out from the top of the second extraction tower. The solvent is recovered by evaporation of the secondary raffinate to obtain the rubber plasticizer.

[0012] 2. The method for producing a rubber plasticizer according to 1, characterized in that the mass ratio of the co-solvent to the feed oil in the first extraction tower is (0.2-1.0):1; the mass ratio of the main solvent to the primary raffinate oil in the second extraction tower is (3-6):1, and the mass ratio of the co-solvent to the primary raffinate oil is (0.3-0.8):1.

[0013] 3. The method for producing a rubber plasticizer according to 1, characterized in that the temperature of the first extraction section between the first inlet and the third inlet of the first extraction tower is 50-80°C, and the temperature of the second extraction section between the third inlet and the second inlet is 40-60°C.

[0014] 4. The method for producing a rubber plasticizer according to claim 1, characterized in that the temperature of the first extraction section between the first inlet and the third inlet of the second extraction tower is 50-80°C, and the temperature of the second extraction section between the third inlet and the second inlet is 40-60°C.

[0015] The inventors discovered that, for certain high-viscosity, high-polycyclic aromatic hydrocarbon (PCA) content, and high-density extracted oil feedstocks, compared to patent application 2025102384894, which also uses dual-solvent, dual-tower extraction, the refining process provided by this invention can effectively remove polycyclic aromatic hydrocarbons (PCA) and eight specific carcinogenic PCAs from the feedstock oil, while retaining oligocyclic aromatic hydrocarbon components to the maximum extent. Therefore, the resulting rubber plasticizer not only meets the requirements of EU Directive 2005 / 69 / EC but also has a higher aromatic carbon content, and the yield of the rubber plasticizer is significantly improved. Compared to patent 202510677742.6, the agent-to-oil ratio is reduced, and energy consumption is lowered.

[0016] The method of the present invention can be applied to the production of raw material oils commonly used in rubber plasticizers by traditional solvent refining processes. For example, it can be extracted oil produced by extracting wax oil or deasphalted oil with a distillation range of 400-600℃ using a polar solvent. The polar solvent can be one or more of furfural, dimethyl sulfoxide, N-methylpyrrolidone, and phenol.

[0017] The operating temperature during solvent extraction affects the solubility of aromatics in the solvent and the selectivity of the solvent for aromatics. In actual production, the temperature at the bottom of the first extraction section is typically controlled to be lower than the temperature at the top; the temperature at the bottom of the second extraction section is controlled to be lower than the temperature at the top; and the temperature at the bottom of the first extraction section is controlled to be no lower than the temperature at the top of the second extraction section. This creates an operating temperature difference from top to bottom within the extraction tower, which is more conducive to the selective solubility of aromatics in the solvent. Strictly controlling the operating temperature is beneficial for ensuring the quality and yield of rubber plasticizers. In the specific implementation of this invention, the temperature difference between the top of the first extraction section and the bottom of the second extraction section is typically controlled to not exceed 30°C. For example, the temperature at the top of the first extraction section is 10°C to 30°C higher than the temperature at the bottom of the second extraction section.

[0018] The third inlet of the first and second extraction towers is located between the first and second inlets. This invention does not impose a specific limitation on the location of the third inlet; for example, it can be located in the middle, upper middle, or lower middle of the extraction tower. In specific implementations of this invention, the height of the first extraction section is typically controlled to be 1 / 3 to 2 / 3 of the total height of the extraction tower (i.e., the distance between the first and second inlets). In specific implementations of this invention, the third inlet is located in the lower middle part of the extraction tower, meaning the height of the first extraction section is greater than 1 / 2 of the total height of the extraction tower. Of course, while increasing the height of any extraction section will not negatively impact the extraction effect, it will increase equipment costs and operating expenses, provided that extraction accuracy is met. Therefore, the heights of the first and second extraction sections can be reasonably set according to actual production needs. Meanwhile, the theoretical number of the first and second extraction stages is usually no less than 3. Generally speaking, the higher the theoretical number, the better the solvent extraction effect, but it will also increase the investment and operating costs accordingly. Therefore, the theoretical number is usually controlled between 3 and 5.

[0019] The cosolvent used in this invention may contain C6 to C6. 20 Alkanes (including C6-C6) 20 Straight-chain alkanes and C6-C6 hydrocarbons 20 It may contain one or more of the following: branched alkanes, or C6 to C6: 20 It contains one or more of the cycloalkanes, and may also contain C6 to C6. 20 Alkanes and C6-C 20 Cycloalkanes, such as a mixture of n-dodecane and methylcyclohexane, can be used as a co-solvent. Alternatively, solvent oils or kerosene / diesel fractions with a boiling range of 60–350°C, containing C6–C6, can be selected. 20 Alkanes and C6-C 20 It includes various cycloalkanes. In actual production, solvent oils with boiling ranges of 60–90℃, 90–120℃, 120–160℃, 160–200℃, 180–300℃, and 200–350℃, as well as other wide-boiling-range solvent oils obtained by blending these solvent oils, are usually selected as co-solvents. The sources of these solvent oils are more extensive, and they can effectively reduce production costs.

[0020] This invention does not impose specific limitations on the particular process for separating the solvent from the raffinate; conventional solvent separation processes in the art, such as atmospheric distillation and vacuum distillation, can be used. In the specific implementation of this invention, the raffinate is typically heated and evaporated or distilled under atmospheric or vacuum conditions to recover the solvent and obtain the rubber plasticizer. This invention also does not impose specific limitations on the specific heating temperature, which can be reasonably set according to the boiling point of the solvent.

[0021] This invention provides a method for producing a rubber plasticizer. By employing a dual-extraction tower and dual-solvent refining process, the resulting rubber plasticizer exhibits a high aromatic carbon content and a low polycyclic aromatic hydrocarbon (PAH) content. Specifically, the PAH content is below 3.0%, the sum of the contents of eight carcinogenic PAHs does not exceed 5 μg / g, and the content of each carcinogen is less than 1 μg / g, far exceeding the requirements of EU Directive 2005 / 69 / EC. Furthermore, the aromatic carbon content can reach over 24%. Therefore, when this rubber plasticizer is used as a rubber raw material, it not only exhibits excellent compatibility with rubber compounds but also improves the safety and performance of rubber products. Simultaneously, the yield of the rubber plasticizer is increased, energy consumption is reduced, and production efficiency is improved. Attached Figure Description

[0022] Appendix Figure 1 This is a schematic diagram of the process flow of the present invention.

[0023] Explanation of reference numerals in the attached figures:

[0024] 1-Solubilizer tank; 2. Raw material oil tank; 3. Main solvent tank; 4, 5, 6, 12 - Pumps; 7, 8-cosolvent; 9-First extraction tower; 10 - Heater; 11 - Evaporation tower for primary residual liquid; 13-Recover the solvent; 14-Second extraction tower; 17-Extractant solvent recovery unit; 19-Primary raffinate oil 15 - Secondary raffinate solvent recovery unit; 20 - Extracted liquid 16-Rubber plasticizer; 18-Oil extracted in one pass; 21-Residual liquid extracted in one pass. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0026] Example 1

[0027] This embodiment provides a method for producing an environmentally friendly rubber plasticizer. (See attached...) Figure 1 As shown, the main solvent in the main solvent storage tank 3 enters through the first inlet at the top of the second extraction tower 14 via pump 4; the feed oil enters through the first inlet at the top of the first extraction tower 9 via pump 5; the auxiliary agent enters the first extraction tower through the second inlet at the bottom of the first extraction tower 9 via pump 6; the auxiliary agent enters the second extraction tower through the second inlet at the bottom of the second extraction tower 14 via pump 6; the effluent from the bottom of the second extraction tower enters the first inlet at the top of the first extraction tower. The raffinate 21 at the top of the first extraction tower enters the heater 10 and is heated to 160-230°C before entering the primary raffinate evaporator 11. The primary raffinate oil at the bottom of the primary raffinate evaporator 11 is pumped through pump 12 into the third inlet in the middle of the second extraction tower. The top of the primary raffinate evaporator 11 contains the distilled-off recovered solvent. The temperature of the first extraction tower is controlled from bottom to top at 50-70°C; the temperature of the second extraction tower is controlled from bottom to top at 60-80°C.

[0028] The first extraction tower 1 described above is a small extraction tower commonly used in laboratories, with an inner diameter of 33 mm and filled with wire mesh packing. The distance between the first inlet 2 and the third inlet 3 (i.e., the height of the first extraction section) is 2 m, and the distance between the second inlet 4 and the third inlet 3 (i.e., the height of the second extraction section) is 1 m. The structure of the second extraction tower is the same as that of the first extraction tower.

[0029] The feedstock used in this embodiment is the extract oil obtained by furfural extraction from the reduced-pressure fourth fraction of oil produced by a certain refinery. Its PCA content is 26 wt% and its density is 0.985 g / cm³. 3 The total content of eight carcinogenic polycyclic aromatic hydrocarbons was 428 μg / g, of which benzo[a]pyrene content was 12 μg / g; the main solvent was N-methylpyrrolidone; the co-solvent was a solvent oil with a boiling range of 80-120℃. The solvent ratio was: first extraction tower: feed oil: co-solvent = 1:0.5 (mass ratio); second extraction tower: main solvent: primary raffinate oil: co-solvent = 4:1:0.5 (mass ratio). The solvent was recovered by evaporation of the secondary raffinate to obtain rubber plasticizer 16.

[0030] Tests showed that the rubber plasticizer had an aromatic carbon content of 25.4%, a PCA content of 2.8%, and a total content of eight carcinogenic polycyclic aromatic hydrocarbons of 3.1 μg / g, of which the content of benzo[a]pyrene was 0 μg / g, and the content of other carcinogenic aromatic hydrocarbons was also less than 1 μg / g, meeting the requirements of EU Directive 2005 / 69 / EC and national standard GB / T 33322—2016 (Rubber Plasticizer Aromatic Mineral Oil).

[0031] The yield of the rubber plasticizer (mass of rubber plasticizer / mass of raw oil × 100%, the same below) is calculated to be 58.0%.

[0032] Example 2

[0033] This embodiment provides a method for preparing a rubber plasticizer, the process flow and process parameters of which are basically the same as those in Example 1, the difference being:

[0034] (1) Solvent ratio: First extraction tower: First extraction tower: Raw material oil: Co-solvent = 1:0.3 (mass ratio); Second extraction tower: Main solvent: Primary raffinate oil: Co-solvent = 3:1:0.3 (mass ratio).

[0035] (2) Temperature gradient. The temperature of the first extraction tower is 40-65℃ from bottom to top. The temperature of the second extraction tower is 50-70℃ from bottom to top.

[0036] The tested rubber plasticizer had an aromatic carbon content of 25.6%, a PCA content of 2.9%, and a total content of eight carcinogenic polycyclic aromatic hydrocarbons of 2.30 μg / g. Among them, the content of benzo[a]pyrene was 0 μg / g, and the content of other carcinogenic aromatic hydrocarbons was less than 1 μg / g. This met the environmental protection standards for environmentally friendly rubber oils proposed by the EU and the national standard GB / T 33322—2016 (Rubber Plasticizer Aromatic Mineral Oil).

[0037] The yield of the rubber plasticizer was calculated to be 60.0%.

[0038] Example 3

[0039] This embodiment provides a method for preparing a rubber plasticizer, the process flow and process parameters of which are basically the same as those in Example 1, the difference being:

[0040] The primary solvent is phenol. The co-solvent is a solvent oil with a boiling range of 70–250°C, containing 82 wt% alkanes, 15 wt% cycloalkanes, and 1 wt% aromatics.

[0041] Tests showed that the rubber plasticizer had an aromatic carbon content of 24.6%, a PCA content of 2.7%, and a total content of 5.1 μg / g of eight carcinogenic polycyclic aromatic hydrocarbons, of which benzo[a]pyrene content was 0 μg / g and the contents of other carcinogenic aromatic hydrocarbons were all less than 1 μg / g, meeting the environmental standards for environmentally friendly rubber oils set by the European Union.

[0042] The yield of the rubber plasticizer was calculated to be 62.2%.

[0043] Example 4

[0044] This embodiment provides a method for preparing a rubber plasticizer, the process flow and process parameters of which are basically the same as those in Example 2, the difference being:

[0045] The main solvent is furfural. The co-solvent is a solvent oil with a boiling range of 130–200°C and an aromatic hydrocarbon content of 0.01 wt%.

[0046] Tests showed that the rubber plasticizer had an aromatic carbon content of 25.4%, a PCA content of 2.4%, and a total content of 5.50 μg / g of eight carcinogenic polycyclic aromatic hydrocarbons, of which benzo[a]pyrene content was 0 μg / g and the contents of other carcinogenic aromatic hydrocarbons were all less than 1 μg / g, meeting the environmental standards for environmentally friendly rubber oils set by the European Union.

[0047] The yield of the rubber plasticizer was calculated to be 64.3%.

[0048] Example 5

[0049] This embodiment provides a method for preparing a rubber plasticizer, the process flow and process parameters of which are basically the same as those in Example 2, the difference being:

[0050] The primary solvent is dimethyl sulfoxide. The co-solvent is a solvent oil with a boiling range of 150–200°C and an aromatic hydrocarbon content of 0.01 wt%.

[0051] Tests showed that the rubber plasticizer had an aromatic carbon content of 26.3%, a PCA content of 2.6%, and a total content of eight carcinogenic polycyclic aromatic hydrocarbons of 6.50 μg / g, of which benzo[a]pyrene content was 0.2 μg / g, and the contents of other carcinogenic aromatic hydrocarbons were all less than 1 μg / g, meeting the environmental standards for environmentally friendly rubber oils set by the European Union.

[0052] The yield of the rubber plasticizer was calculated to be 62.6%.

[0053] As can be seen from the examples, for feedstock oils with high density and high PCA content, the method provided by this invention patent can further increase the yield by 3-10% compared with the method of patent ZL2025102384894, and the quality meets the requirements of EU and national standard GB / T33322-2016 (rubber plasticizer aromatic mineral oil).

[0054] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for producing an environmentally friendly rubber plasticizer, characterized in that... The solvent extraction method uses a dual-solvent dual-extraction tower. The main solvent includes one of phenol, furfural, N-methylpyrrolidone, and dimethyl sulfoxide. The co-solvent is an alkane and / or cycloalkanes with 6-20 carbon atoms in their molecules. The feed oil is the extract oil obtained by extraction and refining wax oil or deasphalted oil with a distillation range of 350-600℃. This method also includes the following steps and features: (1) The first extraction tower and the second extraction tower have three feed inlets, located at the top (first feed inlet), middle (third feed inlet) and bottom (second feed inlet) of the extraction tower respectively. Each extraction tower has at least two outlets, located at the top and bottom of the extraction tower respectively. The extraction tower is filled with packing or trays. (2) The main solvent enters from the first inlet of the second extraction tower, the raw material oil enters from the third inlet of the first extraction tower, and the co-solvent enters from the second inlet at the bottom of the first extraction tower and the second extraction tower respectively. The extract at the bottom of the second extraction tower is heated to 60-80℃ and then enters the first inlet of the first extraction tower. (3) The raffinate flowing out from the top of the first extraction tower enters the solvent recovery tower to recover part of the solvent and obtains primary raffinate oil; the primary extract flowing out from the bottom of the first extraction tower is heated and evaporated to recover the solvent and obtain primary extract oil. (4) The residual oil from the first extraction enters the third feed inlet of the second extraction tower; (5) The secondary raffinate flows out from the top of the second extraction tower. The solvent is recovered by evaporation of the secondary raffinate to obtain the rubber plasticizer.

2. The method for producing an environmentally friendly rubber plasticizer according to claim 1, characterized in that the mass ratio of the co-solvent to the raw material oil in the first extraction tower is (0.2-1.0):1; the mass ratio of the main solvent to the primary raffinate oil in the second extraction tower is (3-6):1, and the mass ratio of the co-solvent to the primary raffinate oil is (0.3-0.8):

1.

3. The production method of an environmentally friendly rubber plasticizer according to claim 1, characterized in that the temperature of the first extraction tower from bottom to top is 40-80°C.

4. The method for producing an environmentally friendly rubber plasticizer according to claim 1, characterized in that the temperature of the second extraction tower from bottom to top is 50-80°C.

Images