A process for the preparation of an oil-extended rubber by polymerization

Abstract

The application provides a method for preparing oil-extended rubber by polymerization, which comprises the following steps: introducing monomer, filling oil, main catalyst, benzene electron donor, cocatalyst and hydrogen into a reaction kettle to perform polymerization, and obtaining oil-extended rubber; the main catalyst comprises titanium halide and magnesium compound, and the mass of the benzene electron donor is 0.05-5.0 wt% of the mass of the catalyst. The benzene substance is used as the electron donor to participate in the oil-extended polymerization, so that the catalyst can be uniformly dispersed, and there is no agglomeration at the bottom of the reaction kettle; the catalyst activity is improved, the polymerization efficiency is improved, and the polymerization time is shortened; meanwhile, the filling oil is also helpful for the dispersion of the catalyst in the re-polymerization system, and the rubber processing performance of the polymerization product is improved, the product flex fatigue resistance is improved, the product polymerization cost is reduced, and a new product brand is developed.

Description

Technical Field

[0001] This invention belongs to the field of rubber preparation technology, and particularly relates to a method for preparing oil-extended rubber by polymerization reaction. Background Technology

[0002] Oil-extended rubber refers to a mixture of rubber with a certain amount of mineral oil added. Adding oil to rubber can reduce the Mooney viscosity of raw rubber, thereby improving its processing performance. It can also improve the rubber's physical and mechanical properties, such as its wet skid resistance and low-temperature resistance, to some extent, while simultaneously reducing the production cost of rubber.

[0003] There are three main methods for adding rubber filler oil: dry compounding, polymerization reaction, and wet compounding. Dry compounding and wet compounding methods cannot achieve good and uniform dispersion of the filler oil in the rubber compound, and the processes are complex. Polymerization reaction, on the other hand, not only disperses the filler oil evenly but also simplifies the operation, reducing the number of steps. A single polymerization reaction can yield a uniformly dispersed oil-extended trans-butadiene rubber. Polymerization reaction is advantageous for industrial production due to its simple operation and mild reaction conditions. Furthermore, the addition of filler oil improves catalyst dispersibility to some extent, further enhancing the mechanical properties of the rubber.

[0004] However, currently, the catalysts used in diene polymer polymerization are in powder form, resulting in uneven dispersion or agglomeration during addition or participation in the polymerization reaction. Furthermore, the catalyst activity limits the polymerization process and conversion rate, making it difficult to obtain ideal polymerization results and polymer products. Summary of the Invention

[0005] The purpose of this invention is to provide a method for preparing oil-extended rubber by polymerization reaction. The catalyst used in this invention has high activity, high polymerization conversion rate, and good catalyst dispersibility, which can effectively improve the overall performance of the product.

[0006] This invention provides a method for preparing oil-extended rubber by polymerization reaction, wherein monomers, filler oil, main catalyst, benzene electron donor, co-catalyst and hydrogen are introduced into a reaction vessel to carry out polymerization reaction to obtain oil-extended rubber;

[0007] The main catalyst includes titanium halides and magnesium compounds, and the filler oil includes one or more of aromatic oil, white oil, paraffin oil and naphthenic oil;

[0008] The benzene-based electron donor includes one or more of toluene, xylene, m-xylene, p-xylene, o-xylene, trimethylbenzene, and dodecylbenzene, and the mass of the benzene-based electron donor is 0.05 to 5.0 wt% of the catalyst mass.

[0009] Preferably, the benzene-based electron donor participates in the polymerization reaction as an internal electron donor and / or an external electron donor, thereby improving the catalytic efficiency and catalyst dispersibility of the polymerization reaction.

[0010] Preferably, when the benzene-based electron donor is used as an internal electron donor, the main catalyst, the benzene-based electron donor, and the dispersant are mixed before participating in the polymerization reaction;

[0011] When the benzene-based electron donor is used as an external electron donor, the benzene-based electron donor, titanium halide, and magnesium compound are ball-milled and mixed, and then mixed with a dispersant to participate in the polymerization reaction.

[0012] Preferably, the dispersant comprises one or more of cyclohexane, n-hexane, n-heptane, white oil, and liquid paraffin.

[0013] Preferably, the mass ratio of the filler oil to the monomer is 1:(10-100).

[0014] Preferably, the titanium halide includes one or more of titanium tetrachloride, titanium dibromide, titanium tribromide, titanium tetrabromide, titanium diiodide, titanium triiodide, and titanium tetraiodide; the magnesium compound includes one or more of magnesium hydroxide, anhydrous magnesium chloride, basic magnesium chloride, magnesium ethoxylate, and anhydrous magnesium bromide.

[0015] The titanium content in the main catalyst is 0.1–2.0 wt%.

[0016] Preferably, the co-catalyst is one of triisobutylaluminum, trimethylaluminum, triethylaluminum, triisobutylaluminum, trihexylaluminum, and trioctylaluminum; the alkylaluminum chloride is one of diethylaluminum chloride, diisobutylaluminum chloride, dihexylaluminum chloride, and dioctylaluminum chloride; and the alkylaluminum hydride is one or more of diethylaluminum hydride, diisobutylaluminum hydride, dihexylaluminum hydride, and dioctylaluminum hydride.

[0017] The molar ratio of Al to monomer in the co-catalyst is (0.5~200)×10 -3 :1.

[0018] Preferably, the molar ratio of Ti to monomer in the main catalyst is (1-5)×10⁻⁶. -5 The molar ratio of Al in the co-catalyst to Ti in the main catalyst is (10-400):1.

[0019] Preferably, the polymerization reaction temperature is 30–50°C, the polymerization reaction time is 0–12 hours, the polymerization reaction pressure is 0.05–2.0 MPa, and the stirring speed is 10–500 rpm.

[0020] Preferably, after the polymerization reaction is completed, an antioxidant and a terminator are added, and the product is dried to constant weight to obtain oil-extended rubber.

[0021] This invention provides a method for preparing oil-extended rubber via polymerization. The method involves introducing monomers, filler oil, a main catalyst, a benzene-based electron donor, a co-catalyst, and hydrogen into a reactor to carry out a polymerization reaction, thereby obtaining oil-extended rubber. The main catalyst includes titanium halides and magnesium compounds. The filler oil includes one or more of aromatic oils, white oils, paraffinic oils, and naphthenic oils. The benzene-based electron donor includes one or more of toluene, xylene, m-xylene, p-xylene, o-xylene, trimethylbenzene, and dodecylbenzene, with the mass of the benzene-based electron donor being 0.05–5.0 wt% of the catalyst mass. This invention uses benzene-based substances as electron donors in the oil-filled polymerization reaction, which ensures uniform catalyst dispersion and prevents clumping at the bottom of the reactor. Furthermore, it improves catalyst activity, increases polymerization efficiency, and shortens polymerization time. Simultaneously, the filler oil also aids in the dispersion of the catalyst in the polymerization system, improves the processing performance of the polymerized rubber, enhances the product's flexural fatigue resistance, reduces polymerization costs, and facilitates the development of new product grades. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0023] Figure 1 The state of the synthesized product obtained in the comparative case of using a common catalyst in this invention (catalyst agglomeration at the bottom of the reactor);

[0024] Figure 2 The state of the synthesized product obtained in Example 3 of the present invention (the product has low viscosity and no catalyst agglomeration at the bottom);

[0025] Figure 3 These are photos of the catalyst of this invention blended with an external electron donor for 0 hours (left image, yellowish color) and 48 hours (right image, dark brown color).

[0026] Figure 4 This is the state of the product obtained by the polymerization of aromatic oil rubber in Example 4 of the present invention. Detailed Implementation

[0027] This invention provides a method for preparing oil-extended rubber by polymerization reaction, wherein monomers, filler oil, main catalyst, benzene electron donor, co-catalyst and hydrogen are introduced into a reaction vessel to carry out polymerization reaction to obtain oil-extended rubber;

[0028] The main catalyst includes titanium halides and magnesium compounds, and the filler oil includes one or more of aromatic oil, white oil, paraffin oil and naphthenic oil;

[0029] The benzene-based electron donor includes one or more of toluene, xylene, m-xylene, p-xylene, o-xylene, trimethylbenzene, and dodecylbenzene. The mass of the benzene-based electron donor is preferably 0.05 to 5.0 wt% of the catalyst mass, more preferably 0.1 to 4 wt%, such as 0.05 wt%, 0.1 wt%, 0.5 wt%, 1 wt%, 1.5 wt%, 2 wt%, 2.5 wt%, 3 wt%, 3.5 wt%, 4 wt%, 4.5 wt%, 5 wt%, preferably a range of values ​​with any of the above values ​​as the upper or lower limit.

[0030] In this invention, the reactor is preferably evacuated and purged with nitrogen several times to bring it into a vacuum state before the above-mentioned raw materials are added to carry out the polymerization reaction.

[0031] In this invention, the monomer is preferably a diene monomer. In the embodiments of this invention, isoprene and butadiene are used as polymerization monomers.

[0032] In this invention, the filler oil preferably includes one or more of aromatic oil, white oil, paraffin oil and naphthenic oil. The mass ratio of the filler oil to the monomer is preferably 1:(10-100), more preferably 1:(20-80), such as 1:10, 1:15, 1:20, 1:25, 1:30, 1:35, 1:40, 1:45, 1:50, 1:55, 1:60, 1:65, 1:70, 1:75, 1:80, 1:85, 1:90, 1:95, 1:100, preferably a range of values ​​with any of the above values ​​as the upper or lower limit.

[0033] In this invention, the filler oil is preferably heated in a water bath at 45±5℃ and evacuated, and then purged with nitrogen multiple times to remove oxygen from the filler oil. After being mixed evenly with the monomer, the oil is added to the reactor for polymerization reaction.

[0034] In this invention, the main catalyst is a supported titanium-based catalyst, comprising titanium halides and magnesium compounds. The titanium halides include one or more of titanium tetrachloride, titanium dibromide, titanium tribromide, titanium tetrabromide, titanium diiodide, titanium triiodide, and titanium tetraiodide. The titanium content in the main catalyst is preferably 0.1–2.0 wt%, more preferably 0.5–1.5 wt%, such as 0.1 wt%, 0.2 wt%, 0.3 wt%, 0.4 wt%, 0.5 wt%, 0.6 wt%, 0.7 wt%, 0.8 wt%, 0. The magnesium content is preferably within the range of 0.9 wt%, 1 wt%, 1.1 wt%, 1.2 wt%, 1.3 wt%, 1.4 wt%, 1.5 wt%, 1.6 wt%, 1.7 wt%, 1.8 wt%, 1.9 wt%, and 2.0 wt%, with any of the above values ​​as the upper or lower limit; the magnesium compound includes one or more of magnesium hydroxide, anhydrous magnesium chloride, basic magnesium chloride, magnesium ethoxylate, and anhydrous magnesium bromide; the magnesium content in the main catalyst is preferably 20-25 wt%, more preferably 22-23 wt%.

[0035] In this invention, benzene compounds are used as electron donors to participate in the polymerization reaction. The electron donor is preferably an alkylbenzene, and more preferably one or more of toluene, xylene, m-xylene, p-xylene, o-xylene, trimethylbenzene, and dodecylbenzene. The amount of the electron donor is preferably 0.05 to 5.0 wt%.

[0036] In this invention, the phenyl group, as a functional group, has an inductive effect (due to the influence of substituents with different electronegativity, the bonding electron cloud density in the whole molecule shifts in a certain direction, causing the molecule to become polarized) and a conjugation effect (an electronic effect in which the distribution of π electrons in a conjugated system changes due to the mutual influence between atoms).

[0037] In this invention, the benzene-based electron donor can participate in the polymerization reaction as an internal electron donor and / or an external electron donor.

[0038] When the benzene-based electron donor is added during the catalyst preparation process, it acts as an internal electron donor, stabilizing the primary magnesium chloride crystals, controlling the quantity and distribution of TiCl4 in magnesium chloride, adsorbing on the magnesium chloride surface that supports TiCl4 to form isotactic stereoregular groups, thus avoiding the formation of isotactic stereoregular groups; and participating in the formation of hyperisoregular groups, thus preventing the agglomeration of magnesium chloride particles during the grinding process, which leads to an increase in the effective surface area.

[0039] In this invention, the benzene electron donor, titanium halide and magnesium compound are ball-milled and mixed during catalyst grinding, and then mixed with the dispersant.

[0040] In this invention, the catalyst containing an internal electron donor can be scaled up for use in actual production. The catalyst and internal electron donor are mixed in a pressure vessel for a certain time (0-30 min) to activate the active centers of the catalyst and promote the polymerization reaction. A dispersant is then injected into the catalyst mixture to make it more uniformly dispersed. In the reactor, the monomer, catalyst, and co-catalyst are added together through pipes. The amount of each component added is controlled by changes in current and temperature, accompanied by stirring with a stirring paddle.

[0041] In this invention, the dispersant is preferably one or more of cyclohexane, n-hexane, n-heptane, white oil, and liquid paraffin. The mass ratio of the dispersant to the catalyst is preferably (1-50):1, more preferably (10-40):1, such as 1:1, 5:1, 10:1, 15:1, 20:1, 25:1, 30:1, 35:1, 40:1, 45:1, 50:1, and preferably a range of values ​​with any of the above values ​​as the upper or lower limit.

[0042] When the benzene-based electron donor is added during olefin polymerization, it acts as an external electron donor, capable of deactivating random centers; activating regular active centers; preventing the extraction of internal electron donors; or replacing internal electron donors to form higher isotactic groups. It can also convert isotactic active groups into higher isotactic groups and increase the reactivity of isotactic groups.

[0043] In practical production, the catalyst and external electron donor are mixed in a pressure vessel for a certain period of time (0-30 min) to activate the active centers of the catalyst and promote the polymerization reaction. Then, a dispersant is injected into the catalyst mixture to make it more uniformly dispersed. The monomer, catalyst, and co-catalyst are then added to the reactor through pipes. The amount of each component added is controlled by changes in current and temperature, accompanied by stirring with a paddle.

[0044] In this invention, the dispersant is preferably one or more of cyclohexane, n-hexane, n-heptane, white oil, and liquid paraffin. The mass ratio of the dispersant to the catalyst is preferably (1-50):1, more preferably (10-40):1, such as 1:1, 5:1, 10:1, 15:1, 20:1, 25:1, 30:1, 35:1, 40:1, 45:1, 50:1, and preferably a range of values ​​with any of the above values ​​as the upper or lower limit.

[0045] In this invention, the co-catalyst is preferably an alkylaluminum compound, more preferably one of triisobutylaluminum, trimethylaluminum, triethylaluminum, triisobutylaluminum, trihexylaluminum, and trioctylaluminum; the alkylaluminum chloride is one of diethylaluminum chloride, diisobutylaluminum chloride, dihexylaluminum chloride, and dioctylaluminum chloride; the alkylaluminum hydride is one or more of diethylaluminum hydride, diisobutylaluminum hydride, dihexylaluminum hydride, and dioctylaluminum hydride; the molar ratio of Al to monomer in the co-catalyst is preferably (0.5–200) × 10⁻⁶. -3 :1, more preferably (10~180)×10 -3 : 1, such as 0.5×10 -3 1,5×10 -3 : 1, 10×10 -3 : 1,50×10 -3 : 1,100×10 -3 : 1,150×10 -3 : 1,200×10 -3 :1, preferably a range of values ​​with any of the above values ​​as the upper or lower limit.

[0046] In this invention, the pressure inside the reactor after the addition of hydrogen increases from about -0.05 kPa to 0.02 to 0.03 kPa.

[0047] In this invention, the preferred molar ratio of Ti to monomer in the main catalyst is (1-5)×10⁻⁶. -5 More preferably, it is (2-4)×10 -5 , such as 1×10 -5 1.5×10 -5 2×10 -5 2.5×10 -5 3×10 -5 3.5×10 -5 4×10 -5 4.5×10 -5 5×10 -5 Preferably, the values ​​are within the range of any of the above values ​​as the upper or lower limit; the molar ratio of Al in the co-catalyst to Ti in the main catalyst is preferably (10-400):1, more preferably (50-300):1, such as 10:1, 50:1, 100:1, 150:1, 200:1, 250:1, 300:1, 350:1, 400:1, and preferably within the range of any of the above values ​​as the upper or lower limit.

[0048] In this invention, the polymerization temperature is preferably 30–50°C, more preferably 35–45°C, such as 30°C, 35°C, 40°C, 45°C, 50°C, and preferably within the range of any of the above values ​​as the upper or lower limit; the polymerization time is preferably 0–12 hours, more preferably 3–10 hours, and most preferably 5–8 hours; the polymerization pressure is preferably 0.05–2.0 MPa, more preferably 0.1–1.5 MPa, such as 0.05 MPa, 0.1 MPa, 0.5 MPa, 0.8 MPa, 1.0 MPa, 1.2 MPa, 1.5 MPa, 1.8 MPa, 2.0 MPa, and preferably within the range of any of the above values ​​as the upper or lower limit; the polymerization reaction is carried out under stirring conditions, and the stirring speed is preferably 10–500 rpm, more preferably 50–400 rpm, and most preferably 100–300 rpm.

[0049] After the polymerization reaction is complete, an antioxidant and a terminator are added, and the product is dried to constant weight to obtain oil-extended rubber.

[0050] In this invention, the antioxidant is preferably antioxidant 1035; the mass of the antioxidant is preferably 1 to 5% of the mass of the polymerization product, more preferably 2 to 4%, such as 1%, 2%, 3%, 4%, 5%, preferably within the range of any of the above values ​​as the upper or lower limit; the terminator is preferably ethanol; the amount of the terminator is preferably 0.1 to 10% of the mass of the polymerization product, more preferably 1 to 8%, such as 0.1%, 0.5%, 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, preferably within the range of any of the above values ​​as the upper or lower limit.

[0051] The method in this invention is applicable to homopolymerization and copolymerization of dienes, copolymerization of α-olefins, and other processes in laboratory pilot-scale and large-scale production, and is applicable to bulk polymerization, solution polymerization, and other processes.

[0052] This invention provides a method for preparing oil-extended rubber via polymerization. The method involves introducing monomers, filler oil, a main catalyst, a benzene-based electron donor, a co-catalyst, and hydrogen into a reactor to carry out a polymerization reaction, thereby obtaining oil-extended rubber. The main catalyst comprises titanium halides and magnesium compounds. The filler oil comprises one or more of aromatic oils, white oils, paraffin oils, and naphthenic oils. The benzene-based electron donor comprises one or more of toluene, xylene, m-xylene, p-xylene, o-xylene, trimethylbenzene, and dodecylbenzene, with the mass of the benzene-based electron donor being 0.05–5.0 wt% of the catalyst mass. This invention uses benzene-based substances as electron donors in the oil-filled polymerization reaction, which ensures uniform catalyst dispersion and prevents clumping at the bottom of the reactor. Furthermore, it improves catalyst activity, increases polymerization efficiency, and shortens polymerization time. Simultaneously, the filler oil also aids in the dispersion of the catalyst in the polymerization system, improves the processing performance of the polymerized rubber, enhances the product's flexural fatigue resistance, reduces polymerization costs, and facilitates the development of new product grades.

[0053] To further illustrate the present invention, the following detailed description of a method for preparing oil-extended rubber by polymerization reaction provided by the present invention is provided in conjunction with embodiments, but it should not be construed as limiting the scope of protection of the present invention.

[0054] In the following examples, "monomer ratio" refers to the isoprene / butadiene mass ratio (Ip / Bd).

[0055] Example 1: Benzene-based substances as external electron donors

[0056] The oil bath of the 1L reactor was heated to 150℃, and the reactor was filled with nitrogen and evacuated three times to achieve a vacuum state.

[0057] The oil bath temperature of the 1L reactor is lowered to 0℃ and kept at a low temperature for later use (keeping the reactor at a low temperature makes it easier to introduce monomers).

[0058] 198.67 g of isoprene was introduced into a round-bottom flask using a double needle, followed by the addition of 5 mL of triisobutylaluminum-hexane solution using a syringe. The mixture was thoroughly mixed and ready for polymerization.

[0059] Weigh out 12g of butadiene, then place it in an ice-water mixture for low-temperature storage until polymerization is used;

[0060] Add isoprene-triisobutylaluminum mixture, hydrogen, and butadiene separately. Heat the oil bath to 50°C. When the temperature inside the reactor reaches about 45°C, inject the catalyst (0.03g TiCl4 + 0.32g MgCl2, 2.5g xylene, and 2g n-hexane) using a syringe. Then, cool the oil bath to 48°C (there is a temperature difference between the oil bath and the reactor). Record the polymerization time and start polymerization.

[0061] After polymerization, the oil bath was cooled to -20°C, and antioxidant 1035 and terminator ethanol were injected into the syringe. The mixture was stirred until the temperature of the reactor was around 25-26°C.

[0062] After cooling, open the reactor, remove the polymerization product, place it in a fume hood to air dry, and then dry it in a vacuum oven at 45°C until constant weight.

[0063] Table 1. Details of the polymerization reaction in Example 1

[0064]

[0065] Examples 2-4

[0066] The oil bath of the 1L reactor was heated to 150℃, and the reactor was filled with nitrogen and evacuated three times to achieve a vacuum state.

[0067] The oil bath temperature of the 1L reactor is lowered to 0℃ and kept at a low temperature for later use (keeping the reactor at a low temperature makes it easier to introduce monomers).

[0068] 225.11 g of isoprene was introduced into a round-bottom flask using a double needle, followed by the addition of 5 mL of triisobutylaluminum-hexane solution using a syringe. The mixture was thoroughly mixed and ready for polymerization.

[0069] Weigh out 13.43g of butadiene, then place it in an ice-water mixture for low-temperature storage until it is used for polymerization;

[0070] Add isoprene-triisobutylaluminum mixture, hydrogen, and butadiene separately. Heat the oil bath to 50°C. When the temperature inside the reactor reaches about 45°C, inject the catalyst (0.03g TiCl4 + 0.32g MgCl2, 2.5g xylene, and 2g n-hexane) using a syringe. Then, cool the oil bath to 48°C (there is a temperature difference between the oil bath and the reactor). Record the polymerization time and start polymerization.

[0071] After polymerization, the oil bath was cooled to -20°C, and antioxidant 1035 and terminator ethanol were injected into the syringe. The mixture was stirred until the temperature of the reactor was around 25-26°C.

[0072] After cooling, open the reactor, remove the polymerization product, place it in a fume hood to air dry, and then dry it in a vacuum oven at 45°C until constant weight.

[0073] Table 2. Details of polymerization reactions in Examples 2-4

[0074]

[0075] In the comparative cases in Table 2, the catalyst used was a mixture of catalyst and n-hexane without the addition of alkylbenzene electron donors.

[0076] Example 4 uses a high-efficiency catalyst (a mixture of catalyst and hexane + external electron donor), and adds aromatic oil to the system to polymerize and obtain TBIR products. An appropriate amount of aromatic oil helps disperse the catalyst in the polymerization system, improves the rubber processing properties of the polymerized product, enhances the product's flexural fatigue resistance, reduces polymerization costs, and facilitates the development of new product grades.

[0077] As shown in Table 2, under the same conditions of controlling the polymerization process, the change in torque during the polymerization process is the same. Using an electron-donating catalyst to participate in the polymerization reaction significantly increases the catalytic efficiency, the polymerization rate and product conversion rate, and greatly shortens the reaction time.

[0078] Processing of polymer products

[0079] The compounding formula is shown in Table 3, and the compounding process adopts the following standard compounding process:

[0080] Farrel internal mixer filling factor: 75%, initial temperature: sidewall temperature 70℃, rotor temperature 70℃, speed 70rpm.

[0081] A secret rehearsing:

[0082] Raw rubber → 30s → sequentially add minor ingredients and carbon black (oil) → 160s clean the top plug → 240s discharge rubber; first stage masterbatch rubber 2.0mm;

[0083] Fold the sheet 5 times on an open mill (50℃) and let it stand at room temperature for at least 1 hour.

[0084] Second stage of secret refining:

[0085] Add a section of mixed rubber compound, lower the top bolt, and discharge the rubber in 3 minutes.

[0086] The second-stage masterbatch rubber is folded 5 times on a 2.0mm open mill (50℃) and then sheeted out, and left at room temperature for at least 1 hour.

[0087] Three-stage mixing: (Side wall temperature 50℃, rotor temperature 50℃, speed: 50rpm)

[0088] Add the vulcanization system and the corresponding weight of the two-stage compound, lower the top bolt, mix the compound, and unload the compound. The compound is 1.5mm thick.

[0089] The sheets are rolled 6 times on an open mill (50℃, 22:20rpm) and then cut into pieces.

[0090] Table 3. Mixing and processing formula (parts by mass, phr)

[0091]

[0092] Synthetic products ①②③④ correspond to the synthetic products of comparative cases and implementation cases 2 / 3 / 4 in Table 2, respectively.

[0093] illustrate:

[0094] Synthetic product ①: Polymerization product that participates in the polymerization reaction using a common catalyst, hexane solution (catalytic synthesis product before preparation of a high-efficiency catalyst);

[0095] Synthetic product ②: After vacuum drying with a high-efficiency catalyst (catalyst + external electron donor), the aged powder was blended with n-hexane and polymerized to obtain the TBIR product.

[0096] Synthetic product ③: Polymerization product obtained by using a highly efficient catalyst (TiCl4 + MgCl2 + external electron donor) in hexane solution.

[0097] Synthetic product ④: The polymer product obtained by using a highly efficient catalyst (TiCl4 + MgCl2 + external electron donor) in hexane solution and adding aromatic oil.

[0098] After testing the vulcanization characteristics, the vulcanization time was obtained. Vulcanization was carried out at 150℃ * vulcanization time. After vulcanization, the samples were left to stand for 24 hours before performance testing.

[0099] Table 4 Physical and Mechanical Properties

[0100]

[0101] Experimental results show that, compared with the basic formulation, the fatigue resistance (level 1 and level 6) of the control case increased by 20-30%, while the tensile strength of implementation cases 1 and 2 decreased slightly; the loss factor and DIN wear performance were improved, the flexural fatigue resistance (level 1 and level 6) was significantly improved, and the fatigue resistance of level 6 was improved by more than 78%; the fatigue resistance of implementation case 3 and the flexural fatigue resistance of level 6 were improved by 52%.

[0102] Table 5 Flexural fatigue resistance after aging

[0103]

[0104] Aging conditions: 100℃*48h.

[0105] Experimental results show that, compared with the basic formula NR, the fatigue performance of Comparative Example 1 is improved by about 20% after aging. The fatigue performance of Implementation Cases 1 and 2 samples is significantly improved after aging, regardless of whether it is a level 1 crack, a level 6 crack, or a 15mm crack. The fatigue performance of Implementation Case 3 is improved by 49% after aging, with resistance to level 6 flexural fatigue.

[0106] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for preparing oil-extended rubber by polymerization reaction, characterized in that, Monomer, filler oil, main catalyst, benzene electron donor, co-catalyst and hydrogen are introduced into the reactor to carry out a polymerization reaction to obtain oil-extended rubber. The main catalyst includes titanium halides and magnesium compounds, and the filler oil includes one or more of aromatic oil, white oil, paraffin oil and naphthenic oil; The benzene-based electron donor participates in the polymerization reaction as an external electron donor to improve the catalytic efficiency and catalyst dispersibility of the polymerization reaction. When the benzene-based electron donor is used as an external electron donor, the benzene-based electron donor, titanium halide and magnesium compound are ball-milled and mixed, and then mixed with a dispersant to participate in the polymerization reaction. The benzene-based electron donor includes one or more of toluene, xylene, trimethylbenzene, and dodecylbenzene, and the mass of the benzene-based electron donor is 0.05 to 5.0 wt% of the catalyst mass.

2. The method according to claim 1, characterized in that, The dispersant includes one or more of cyclohexane, n-hexane, n-heptane, white oil, and liquid paraffin.

3. The method according to claim 1, characterized in that, The mass ratio of the filler oil to the monomer is 1:(10~100).

4. The method according to claim 1, characterized in that, The titanium halide includes one or more of titanium tetrachloride, titanium dibromide, titanium tribromide, titanium tetrabromide, titanium diiodide, titanium triiodide, and titanium tetraiodide; the magnesium compound includes one or more of magnesium hydroxide, anhydrous magnesium chloride, basic magnesium chloride, magnesium ethoxylate, and anhydrous magnesium bromide. The titanium content in the main catalyst is 0.1~2.0 wt%.

5. The method according to claim 1, characterized in that, The co-catalyst is one or more of the following: triisobutylaluminum, trimethylaluminum, triethylaluminum, triisobutylaluminum, trihexylaluminum, trioctylaluminum, diethylaluminum chloride, diisobutylaluminum chloride, dihexylaluminum chloride, dioctylaluminum chloride, diethylaluminum hydride, diisobutylaluminum hydride, dihexylaluminum hydride, and dioctylaluminum hydride. The molar ratio of Al to monomer in the co-catalyst is (0.5~200)×10 -3 :

1.

6. The method according to claim 1, characterized in that, The molar ratio of Ti to monomer in the main catalyst is (1~5)×10. -5 The molar ratio of Al in the co-catalyst to Ti in the main catalyst is (10~400):

1.

7. The method according to claim 1, characterized in that, The polymerization reaction is carried out at a temperature of 30~50℃, for a time of 0~12 hours, at a pressure of 0.05~2.0MPa, and at a stirring speed of 10~500rpm.

8. The method according to any one of claims 1 to 7, characterized in that, After the polymerization reaction is completed, an antioxidant and a terminator are added, and the product is dried to constant weight to obtain oil-extended rubber.

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