Polybutadiene rubber and preparation method thereof, rubber compound and automobile tire product

Abstract

The invention relates to polybutadiene rubber and a preparation method thereof, a rubber compound and an automobile tire product. The preparation method of the polybutadiene rubber comprises the following steps: providing a basic rubber solution, wherein the Mooney viscosity of dry rubber in the basic rubber solution is 20-60MU; filling oil into the basic glue solution to prepare an oil-filled glue solution; and coupling the oil-filled rubber solution to prepare the polybutadiene rubber. According to the preparation method of the polybutadiene rubber, the polybutadiene rubber with relatively high Mooney viscosity can be obtained, the conversion rate can be increased, and the energy consumption can be reduced.

Description

Technical Field

[0001] The present application relates to the field of rubber, and in particular to a polybutadiene rubber and a preparation method thereof, a rubber compound and an automobile tire product. Background Art

[0002] Polybutadiene rubber (PBR) is the second-largest synthetic rubber in terms of production volume after styrene-butadiene rubber (SBR). It is widely used in various rubber products, including automobile tires. Oil-extending PBR improves its wet-slip resistance and plasticity, making it easier to mix.

[0003] However, the current oil-extended polybutadiene rubber still has the following problems: when preparing high Mooney viscosity rubber, the viscosity of the rubber solution is high, which causes problems such as difficulty in transporting the rubber solution and high energy consumption. Summary of the Invention

[0004] Based on this, some embodiments of the present application provide a method for preparing polybutadiene rubber, which can obtain polybutadiene rubber with a higher Mooney viscosity, and is beneficial for improving the conversion rate and reducing energy consumption.

[0005] In addition, other embodiments of the present application also provide a polybutadiene rubber, a rubber compound and an automobile tire product.

[0006] A method for preparing polybutadiene rubber comprises the following steps:

[0007] Providing a basic glue solution, wherein the Mooney viscosity of the dry glue in the basic glue solution is 20MU~60MU;

[0008] Filling the base adhesive with oil to prepare an oil-filled adhesive;

[0009] The oil-extended rubber solution is coupled to prepare polybutadiene rubber.

[0010] In some embodiments, in the step of coupling the oil-extended adhesive, the mass of the coupling agent used is 0.01% to 5% of the mass of the dry adhesive in the oil-extended adhesive;

[0011] and / or, in the step of coupling the oil-extended adhesive, the coupling agent used includes one or more of a silane coupling agent, a halide, a sulfide, an isocyanate, an azo compound, and a peroxide;

[0012] And / or, in the step of coupling the oil-extended adhesive, the coupling temperature is 60° C. to 110° C., and the coupling time is 5 min to 60 min.

[0013] In some embodiments, the mass of the coupling agent is 0.1% to 1% of the mass of the dry glue in the oil-filled glue solution;

[0014] And / or, the coupling agent includes hexamethylcyclotrisiloxane, octamethylcyclotetrasiloxane, divinyldimethylsilane, vinyltrimethoxysilane, vinyltriethoxysilane, tetraethoxysilane, tetramethoxysilane, tetrapropoxysilane, dicyclopentadienyldimethylsilane, divinylbis(2,4-pentadienyl)silane, silicon tetrachloride, trichlorosilane, dimethylsilyldichloride, thionyl chloride, sulfur dichloride, disulfur dichloride, diallyl disulfide, difurfuryl disulfide , carbon tetrachloride, methyltrichloromethane, dibromoethane, 1,2,3-tribromopropane, germanium tetrachloride, n-butylgermanium trichloride, tin tetrachloride, hydrogenated tin trichloride, di-n-butyltin dichloride, phosphorus trichloride, phosphorus pentachloride, 4,4'-diphenylmethane diisocyanate, 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, isophorone diisocyanate, hexamethylene diisocyanate, azobisisobutyronitrile, dilauroyl peroxide and dicumyl peroxide. One or more of the following:

[0015] In some embodiments, the Mooney viscosity of the dry glue in the oil-filled glue solution is 15MU~30MU;

[0016] And / or, the Mooney viscosity of the polybutadiene rubber is 25MU~50MU; optionally, the Mooney viscosity of the polybutadiene rubber is 30MU~45MU.

[0017] In some embodiments, in the step of oil-filling the base adhesive, the oil-filling temperature is 60° C. to 110° C., and the time is 30 min to 300 min;

[0018] And / or, in the step of oil-filling the base rubber solution, the filler oil used includes one or more of aromatic rubber oil, cycloalkyl rubber oil and paraffin rubber oil.

[0019] In some embodiments, the step of filling the basic glue liquid with oil includes: filling the basic glue liquid with oil according to the mass percentage of the dry glue in the basic glue liquid, and the mass of the filling oil is 20% to 40% of the mass of the dry glue in the basic glue liquid.

[0020] In some embodiments, before the step of oil-filling the base glue according to the mass percentage of dry glue in the base glue, the step further includes:

[0021] Establish the corresponding relationship between the viscosity of the glue solution and the percentage of dry glue mass;

[0022] The mass percentage of the dry glue in the basic glue solution is determined according to the corresponding relationship and the viscosity of the basic glue solution.

[0023] In some embodiments, the step of establishing a corresponding relationship between the viscosity of the glue solution and the mass percentage of the dry glue comprises:

[0024] Provide multiple standard glue solutions with different dry glue mass percentages;

[0025] Testing the viscosity of each of the plurality of standard glues;

[0026] According to the viscosity of each of the plurality of standard glue solutions and the corresponding dry glue mass percentage, a corresponding relationship between the glue solution viscosity and the dry glue mass percentage is established.

[0027] In some embodiments, the base adhesive is prepared by the following steps: mixing butadiene monomer, a catalyst and a solvent, and performing a polymerization reaction to prepare the base adhesive;

[0028] Wherein, the catalyst is a rare earth catalyst, and the base rubber liquid is butadiene rubber liquid;

[0029] Optionally, the catalyst comprises component A, component B, component C and component D; component A comprises a neodymium carboxylate compound, component B comprises one or more of an alkylaluminum compound, an alkylaluminum hydride compound and an organoaluminoxane, component C comprises a conjugated diene, and component D comprises one or more of an alkylaluminum chloride, a chloroalkane, a chloroester and a chlorosilane;

[0030] Optionally, the molar ratio of the component A, the component B, the component C and the component D is 1:(5-100):(10-60):(1-10).

[0031] In some embodiments, in the step of mixing the butadiene monomer, the catalyst and the solvent, the molar ratio of the component A in the catalyst to the butadiene monomer is (1×10 -5 ~2×10 -4 ):1;

[0032] And / or, the mass of the butadiene monomer accounts for 6% to 18% of the total mass of the butadiene monomer and the solvent;

[0033] And / or, the polymerization reaction temperature is 0°C to 100°C, and the time is 30min to 180min;

[0034] And / or, after the step of mixing the butadiene monomer, the catalyst and the solvent and performing a polymerization reaction, the method further comprises: removing unreacted butadiene monomer from the base adhesive after the polymerization reaction.

[0035] A polybutadiene rubber, comprising a rubber matrix and a filler oil filled in the rubber matrix, wherein at least a portion of the rubber matrix is coupled, and the polybutadiene rubber has a Mooney viscosity of 25MU to 50MU;

[0036] Optionally, the polybutadiene rubber is prepared by the above-mentioned preparation method.

[0037] A rubber compound comprises the above-mentioned polybutadiene rubber.

[0038] An automobile tire product comprises the above-mentioned polybutadiene rubber or the above-mentioned rubber mixture.

[0039] Compared with polybutadiene rubber with low Mooney viscosity, polybutadiene rubber with high Mooney viscosity has better mechanical and other properties. The traditional method for preparing polybutadiene rubber with high Mooney viscosity is to first prepare a base rubber solution with high Mooney viscosity, then perform oil filling and coagulation to obtain polybutadiene rubber with high Mooney viscosity. However, the above method still has the following problems: the preparation of the base rubber solution with high Mooney viscosity is time-consuming and has low conversion rate, and the viscosity of the rubber solution is high and difficult to transport. The subsequent oil filling process requires long-term stirring, which consumes a lot of energy. Based on this, some embodiments of the present application provide a preparation method that can obtain polybutadiene rubber with high Mooney viscosity, low energy consumption, and easy transportation. Specifically, the preparation method of polybutadiene rubber in some embodiments of the present application includes: oil filling a base rubber solution with a Mooney viscosity of 20MU to 60MU. On the one hand, the synthesis conversion rate of the base rubber solution with medium and low Mooney viscosity is high, the time consumption is short, and it is easy to transport and not easy to clog pipelines. On the other hand, the oil filling process is easy to fill with oil, the dispersion uniformity is good, and it is conducive to reducing energy consumption. The oil-filled rubber is then mixed with a coupling agent for modification. The coupling modification is beneficial to improving the Mooney viscosity and mechanical properties, thereby obtaining a high Mooney viscosity polybutadiene rubber, which has performance comparable to or even better than that of the high Mooney viscosity polybutadiene rubber prepared by traditional methods.

[0040] Therefore, the preparation method of polybutadiene rubber in some embodiments of the present application can obtain polybutadiene rubber with a higher Mooney viscosity, and is beneficial to improving the conversion rate and reducing energy consumption. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0042] Figure 1 A schematic diagram of a process flow of a method for preparing polybutadiene rubber according to some embodiments of the present application;

[0043] Figure 2 A schematic diagram of a process flow for preparing polybutadiene rubber according to other embodiments of the present application. DETAILED DESCRIPTION

[0044] To facilitate understanding of the present application, the present application will be described more fully below in conjunction with the specific embodiments. Preferred embodiments of the present application are provided in the specific embodiments. However, the present application can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosure of the present application more thorough and comprehensive.

[0045] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this application pertains. The terms used herein in the specification of this application are for the purpose of describing specific embodiments only and are not intended to limit this application. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0046] Unless otherwise specified or incompatible therewith, terms and phrases used in this application shall have the following meanings:

[0047] In this application, the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of technical features indicated. Therefore, a feature specified as "first" or "second" may explicitly or implicitly include at least one of the features.

[0048] In the description of the present application, “a plurality of” means at least two, for example, two, three, etc., unless otherwise clearly and specifically defined.

[0049] In this application, "one or several" refers to any one, any two, or any two or more of the listed items. Among them, "several" refers to any two or any two or more.

[0050] In this application, the percentage concentration involved, unless otherwise specified, refers to the final concentration. The final concentration refers to the percentage of the added component in the system after the addition of the component.

[0051] In this application, the terms "further," "further," "particularly," "for example," "such as," "example," and "for example" are used for descriptive purposes to indicate that the preceding and following technical solutions are related in terms of their coverage, but should not be construed as limiting the preceding technical solution or the scope of protection of this document. In this document, unless otherwise specified, "A (such as B)" means that B is a non-limiting example of A, and it is understood that A is not limited to B.

[0052] In this application, "optionally", "optional", and "optional" mean optional, that is, any one of the two parallel options of "with" or "without". If multiple "optional" appear in a technical solution, unless otherwise specified and there is no contradiction or mutual restriction, each "optional" is independent. In this application, descriptions such as "optionally contain" and "optionally include" mean "containing or not containing". "Optional component X" means the presence or absence of component X, or means containing or not containing component X.

[0053] When a numerical range is disclosed in this application, the range is considered continuous and includes the minimum and maximum values of the range, as well as every value between such minimum and maximum values. Further, when a range refers to an integer, every integer between the minimum and maximum values of the range is included. In addition, when multiple ranges are provided to describe a feature or characteristic, the ranges can be combined. In other words, unless otherwise indicated, all ranges disclosed in this application should be understood to include any and all subranges subsumed therein.

[0054] In this application, the technical features described in an open manner include closed technical solutions composed of the listed features, and also include open technical solutions containing the listed features.

[0055] The terms "including," "having," and any variations thereof in the embodiments of the present application are intended to cover non-exclusive inclusions. For example, a process, method, system, product, or apparatus comprising a series of steps or units is not limited to the listed steps or units but may optionally include steps or units not listed, or may optionally include other steps or components inherent to the process, method, product, or apparatus.

[0056] References to "embodiments" in this application mean that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment of the application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described in this application may be combined with other embodiments.

[0057] In the flowchart of the present application, although the various steps are displayed in sequence as indicated by the arrows, these steps are not necessarily performed in the order indicated by the arrows. Unless otherwise specified in the text, there is no strict order restriction for the execution of these steps, and they can be performed in other orders. Moreover, at least part of the steps in the figure may include multiple sub-steps or multiple stages. These sub-steps or stages are not necessarily performed at the same time, but can be performed at different times. Their execution order is not necessarily sequential, but can be performed in turn or alternately with other steps or at least part of other sub-steps or stages.

[0058] In this application, unless otherwise specified, Mooney viscosity values are expressed as ML1+4(100), where "M" stands for Mooney, "L" indicates the use of a large rotor for testing, "100" represents a test temperature of 100°C, and "1+4" indicates a 4-minute test after a 1-minute preheating period. A higher Mooney viscosity value indicates a higher molecular weight of the rubber, making it difficult to mix and extrude uniformly during processing; conversely, a lower Mooney viscosity value indicates a lower molecular weight of the rubber.

[0059] As described in the background, the traditional preparation of high-Mooney viscosity polybutadiene rubber suffers from low conversion rates and high viscosity, resulting in difficult transport of the rubber and high energy consumption. Therefore, some embodiments of the present application provide a method for preparing polybutadiene rubber that can produce polybutadiene rubber with a relatively high Mooney viscosity, while also improving conversion rates and reducing energy consumption.

[0060] In the first aspect, the present application provides a method for preparing polybutadiene rubber. Figure 1 , including the following steps S110, S120, and S130:

[0061] Step S110: providing a basic glue solution, wherein the Mooney viscosity of the dry glue in the basic glue solution is 20MU-60MU.

[0062] Step S120: Filling the base adhesive with oil to prepare an oil-filled adhesive.

[0063] Step S130: coupling the oil-extended rubber solution to prepare polybutadiene rubber.

[0064] Compared with polybutadiene rubber with low Mooney viscosity, polybutadiene rubber with high Mooney viscosity has better mechanical and other properties. The traditional method for preparing polybutadiene rubber with high Mooney viscosity is to first prepare a base rubber solution with high Mooney viscosity, then perform oil filling and coagulation to obtain polybutadiene rubber with high Mooney viscosity. However, the above method still has the following problems: the preparation of the base rubber solution with high Mooney viscosity is time-consuming and has low conversion rate, and the viscosity of the rubber solution is high and difficult to transport. The subsequent oil filling process requires long-term stirring, which consumes a lot of energy. Based on this, some embodiments of the present application provide a preparation method that can obtain polybutadiene rubber with high Mooney viscosity, low energy consumption, and easy transportation. Specifically, the preparation method of polybutadiene rubber in some embodiments of the present application includes: oil filling a base rubber solution with a Mooney viscosity of 20MU to 60MU. On the one hand, the synthesis conversion rate of the base rubber solution with medium and low Mooney viscosity is high, the time consumption is short, and it is easy to transport and not easy to clog pipelines. On the other hand, the oil filling process is easy to fill with oil, the dispersion uniformity is good, and it is conducive to reducing energy consumption. The oil-filled rubber is then mixed with a coupling agent for modification. The coupling modification is beneficial to improving the Mooney viscosity and mechanical properties, thereby obtaining a high Mooney viscosity polybutadiene rubber, which has performance comparable to or even better than that of the high Mooney viscosity polybutadiene rubber prepared by traditional methods.

[0065] Therefore, the preparation method of polybutadiene rubber in some embodiments of the present application can obtain polybutadiene rubber with a higher Mooney viscosity, and is beneficial to improving the conversion rate and reducing energy consumption.

[0066] In some embodiments, the base adhesive is prepared by the following steps: mixing butadiene monomer, a catalyst, and a solvent, and performing a polymerization reaction to prepare the base adhesive.

[0067] Polybutadiene rubber is typically produced using catalysts based on nickel, cobalt, titanium, lithium, rare earth, molybdenum, and iron. Different catalysts can produce polybutadiene rubbers with varying structures, such as cis-1,4-polybutadiene rubber, syndiotactic 1,2-polybutadiene rubber, low-cis polybutadiene rubber, high-vinyl polybutadiene rubber, and liquid polybutadiene rubber.

[0068] In some embodiments, the catalyst is a rare earth catalyst. Compared to other catalysts, such as nickel-based and lithium-based catalysts, the polybutadiene rubber produced using rare earth catalysts exhibits higher molecular weight, structural regularity, high linearity, narrow molecular weight distribution, and adjustable Mooney viscosity. This results in excellent flexural and abrasion resistance, low rolling resistance, and improved green strength and vulcanized properties, enabling it to meet the high-speed driving requirements of automobiles. It is widely used in tire treads and sidewalls, and is a key rubber type for the production of high-performance green tires. Furthermore, the base rubber prepared using rare earth catalysts exhibits improved oil-filling properties.

[0069] In some embodiments, the base rubber is a cis-1,4-polybutadiene rubber. The use of rare earth catalysts facilitates the production of cis-1,4-polybutadiene rubber. Cis-1,4-polybutadiene rubber (C1,4-polybutadiene) has a regular structure, excellent flexural strength, wear resistance, low rolling resistance, and good green strength and vulcanized properties. It can withstand high-speed driving requirements of automobiles and is widely used in tire treads and sidewalls, making it a key rubber for the production of high-performance green tires. However, C1,4-polybutadiene rubber still suffers from poor wet skid resistance and processing difficulties. Researchers have oil-filled C1,4-polybutadiene rubber, achieving enhanced wet skid resistance and fatigue resistance while maintaining the original advantages of C1,4-polybutadiene rubber. This results in superior traction and wear resistance for tire treads. Oil-filling also increases the plasticity of C1,4-polybutadiene rubber, making it easier to mix. Furthermore, the addition of inexpensive petroleum distillates increases production and reduces costs.

[0070] In one example, the catalyst is a neodymium-based catalyst, which has higher catalytic activity among rare earth catalysts.

[0071] Furthermore, the catalyst is a homogeneous rare earth catalyst. Homogeneous catalysis refers to a catalytic reaction system in which the catalyst is indistinguishable from the reaction medium, forming a uniform phase with other components in the medium. Homogeneous catalysis is commonly used in liquid-phase reactions. In the materials undergoing the catalytic reaction, both the starting materials and the catalyst are dissolved in the reaction medium and dispersed as independent molecules. A catalyst capable of homogeneous catalysis is called a homogeneous catalyst.

[0072] In some embodiments, the catalyst includes component A, component B, component C, and component D;

[0073] Among them, component A includes a neodymium carboxylate compound, component B includes one or more of an alkyl aluminum compound, an alkyl aluminum hydride compound and an organic aluminoxane, component C includes a conjugated diene, and component D includes one or more of an alkyl aluminum chloride, a chloroalkane, a chloroester and a chlorosilane.

[0074] Specifically, neodymium carboxylate compounds include C1~C 10 For example, neodymium carboxylates include neodymium naphthenate, neodymium n-octanoate, neodymium isooctanoate, neodymium decanoate, neodymium neodecanoate, and the like.

[0075] Specifically, the alkylaluminum compounds include trimethylaluminum, triethylaluminum, tripropylaluminum, tributylaluminum, tripentylaluminum, etc. The alkylaluminum hydride compounds include diethylaluminum hydride, dipropylaluminum hydride, dibutylaluminum hydride, dipentylaluminum hydride, etc. The organoaluminoxanes include methylaluminoxane, etc.

[0076] Specifically, the conjugated diene includes one or more of butadiene and isoprene.

[0077] Specifically, the alkylaluminum chloride includes one or more of butylaluminum chloride or ethylaluminum chloride. The chlorinated alkanes include one or more of dichloromethane, chloroform, 1,1-dichloroethane, 1,2-dichloroethane, 1,1,1-trichloroethane, 1,1,2-trichloroethane, tetrachloroethane, dichloropropane, chloroisoctane and triphenylmethane. The chlorinated esters include one or more of methyl chloroformate, ethyl chloroformate, methyl chloropropionate, bis(2,4-dichlorophenyl)chlorophosphate and dimethyl chloromalonate. The chlorinated silanes include one or more of trichlorosilane, dimethyl-3-chloropropylchlorosilane, diisopropylchlorosilane and trimethylchlorosilane.

[0078] In some embodiments, the molar ratio of component A, component B, component C, and component D is 1:(5-100):(10-60):(1-10).

[0079] For example, the molar ratio of component A to component B can be, but is not limited to, 1:5, 1:10, 1:20, 1:30, 1:40, 1:50, 1:60, 1:70, 1:80, 1:90, 1:100, or a range consisting of any two of these values. Alternatively, the molar ratio of component A to component B is 1:(10-30).

[0080] Illustratively, the molar ratio of component A to component C is 1:10, 1:15, 1:20, 1:25, 1:30, 1:35, 1:40, 1:45, 1:50, 1:55, 1:60, or a range consisting of any two of these values. Alternatively, the molar ratio of component A to component C is 1:(10-30).

[0081] Illustratively, the molar ratio of component A to component D is 1:1, 1:2, 1:3, 1:4, 1:5, 1:6, 1:7, 1:8, 1:9, 1:10, or a range consisting of any two of these values.

[0082] In some embodiments, the catalyst is prepared as follows: Under nitrogen protection, component A, component B, component C, and component D are mixed uniformly at room temperature, and the temperature is raised to 30°C to 100°C and aged for 10 minutes to 180 minutes to obtain a catalyst. The room temperature can be, but is not limited to, 10°C to 30°C.

[0083] For example, the aging temperature may be, but is not limited to, 30° C., 40° C., 50° C., 60° C., 70° C., 80° C., 90° C., 100° C., or a range consisting of any two of these values. The aging time may be, but is not limited to, 10 min, 20 min, 30 min, 40 min, 50 min, 60 min, 90 min, 120 min, 150 min, 180 min, or a range consisting of any two of these values.

[0084] It can be understood that the catalyst referred to in this application is a homogeneous rare earth aging liquid.

[0085] In some embodiments, in the step of mixing the butadiene monomer, the catalyst, and the solvent, the mass percentage of the butadiene monomer to the total mass of the butadiene monomer and the solvent is 6% to 18%. For example, the mass percentage of the butadiene monomer to the total mass of the butadiene monomer and the solvent can be, but is not limited to, 6%, 7%, 8%, 9%, 10%, 12%, 14%, 15%, 16%, 18%, or a range consisting of any two of these values.

[0086] In some embodiments, the solvent is an inert organic solvent. An inert solvent refers to a solvent that does not directly participate in the chemical reaction of the system. Specifically, the solvent includes an inert organic solvent of the alkane class. Further, the solvent includes any one or a mixture of n-hexane, cyclohexane, cyclopentane, n-pentane, n-hexane, and n-heptane.

[0087] In some embodiments, the step of mixing the butadiene monomer, the catalyst, and the solvent comprises: mixing the butadiene monomer and the solvent, and then adding the catalyst and continuing to mix.

[0088] In some embodiments, the molar ratio of component A to butadiene monomer is (1×10 -5 ~2×10 -4 ) : 1. For example, the molar ratio of component A to butadiene monomer in the catalyst can be, but is not limited to, 1×10 -5 :1, 2×10 -5 :1, 4×10 -5 :1, 6×10 -5 :1, 8×10 -5 :1, 1×10 -4 :1, 1.2×10 -4 :1, 1.4×10 -4 :1, 1.6×10 -4 :1, 1.8×10 -4 :1, 2×10 -4 :1 or a range consisting of any two of these values.

[0089] In some embodiments, the polymerization reaction temperature is 0°C to 100°C, and the polymerization time is 30 min to 180 min. For example, the polymerization reaction temperature may be, but is not limited to, 0°C, 10°C, 20°C, 30°C, 40°C, 50°C, 60°C, 70°C, 80°C, 90°C, 100°C, or a range consisting of any two of these values. The polymerization reaction time may be, but is not limited to, 30 min, 40 min, 50 min, 60 min, 80 min, 90 min, 100 min, 120 min, 140 min, 150 min, 160 min, 180 min, or a range consisting of any two of these values.

[0090] In one example, the polymerization reaction is carried out in a polymerization kettle. Specifically, there may be multiple polymerization kettles, which are connected in series. Providing multiple polymerization kettles can help extend the polymerization reaction time and improve the polymerization conversion rate. It is understood that in other embodiments, there may also be a single polymerization kettle.

[0091] In some embodiments, after the step of mixing butadiene monomer, catalyst, and solvent and performing a polymerization reaction, the method further includes removing unreacted butadiene monomer from the base adhesive after the polymerization reaction. In some embodiments, the unreacted butadiene monomer is removed by flash evaporation. Specifically, the base adhesive delivered from the polymerization reactor is first passed into a flash tank to remove unreacted butadiene monomer. This step removes unreacted butadiene monomer, reduces interference with subsequent viscosity testing, and further improves test accuracy.

[0092] In some embodiments, the Mooney viscosity ML of the dry glue in the base glue solution is 20MU to 60MU. For example, the Mooney viscosity ML can be, but is not limited to, 20MU, 25MU, 30MU, 35MU, 40MU, 45MU, 50MU, 55MU, 60MU, or a range consisting of any two of these values.

[0093] In some embodiments, the preparation step of the base adhesive comprises: mixing an inert organic solvent, a butadiene monomer, and a catalyst, reacting at 0°C to 100°C for 30 minutes to 180 minutes, and obtaining a base adhesive having a dry adhesive Mooney viscosity of 20MU to 60MU. The mass of the butadiene monomer accounts for 6% to 18% of the total mass of the butadiene monomer and the solvent, and the molar ratio of component A to the butadiene monomer in the catalyst is (1×10 -5 ~ 2×10 -4 ) :1.

[0094] In some embodiments, the oil filling temperature is 60°C to 110°C, and the filling time is 30 minutes to 300 minutes. For example, the oil filling temperature may be, but is not limited to, 60°C, 70°C, 80°C, 90°C, 100°C, 110°C, or a range consisting of any two of these values. The oil filling time may be, but is not limited to, 30 minutes, 40 minutes, 50 minutes, 60 minutes, 80 minutes, 90 minutes, 100 minutes, 120 minutes, 140 minutes, 150 minutes, 160 minutes, 180 minutes, 210 minutes, 240 minutes, 270 minutes, 300 minutes, or a range consisting of any two of these values.

[0095] In some embodiments, in the step of extending the base rubber solution with oil, the extending oil used includes one or more of aromatic rubber oil, cycloalkyl rubber oil and paraffin rubber oil.

[0096] In some embodiments, the step of filling the base glue liquid with oil includes: filling the base glue liquid with oil according to the mass percentage of the dry glue in the base glue liquid, and the mass of the filling oil is 20% to 40% of the mass of the dry glue in the base glue liquid.

[0097] For example, the mass of the filling oil is 20%, 22%, 24%, 26%, 28%, 30%, 32%, 34%, 36%, 38%, 40% of the mass of the dry glue in the base glue solution, or a range consisting of any two of these values.

[0098] In some embodiments, before the step of oil-filling the base glue according to the mass percentage of the dry glue in the base glue, the method further comprises:

[0099] Establish the corresponding relationship between the viscosity of the glue solution and the percentage of dry glue mass;

[0100] The mass percentage of dry glue in the basic glue solution is determined based on the corresponding relationship and the viscosity of the basic glue solution.

[0101] Specifically, the steps of establishing the corresponding relationship between the viscosity of the glue solution and the mass percentage of the dry glue include:

[0102] Provide multiple standard glue solutions with different dry glue mass percentages;

[0103] Test the viscosity of multiple standard glues;

[0104] According to the viscosity of each of a plurality of standard glue solutions and the corresponding dry glue mass percentage, a corresponding relationship between the glue solution viscosity and the dry glue mass percentage is established.

[0105] The above steps are helpful to improve the accuracy of the dry glue mass content test. In the traditional method, after the polymerization reaction is completed, a small amount of glue liquid is taken, and the mass of the glue liquid and the mass of the dry glue after the glue liquid is dried are measured to calculate the mass percentage of the dry glue. However, the present application found that the above method still has the problems of low accuracy of the dry glue mass percentage, poor stability of the direct oil filling experiment, and large fluctuations in the oil filling amount; and the success rate of one-time oil filling is low, and the use of secondary oil filling has low efficiency and high production costs. In some embodiments of the present application, the dry glue mass percentage is obtained according to the corresponding relationship between the viscosity of the glue liquid and the dry glue mass percentage and the viscosity of the basic glue liquid, which improves the test accuracy, solves the problem of fluctuations in the oil filling amount caused by fluctuations in the mass of the dry glue in the glue liquid, and improves the qualified rate of oil filling.

[0106] It should be understood that the correspondence between the viscosity of the rubber solution and the percentage of dry rubber by mass refers to the correspondence between the viscosity of the rubber solution and the percentage of dry rubber by mass after monomer removal. If the rubber solution is not monomer-removed, the conversion rate and monomer content may vary from one run to the next, affecting subsequent viscosity measurements. Therefore, removing unreacted monomer from the rubber solution before testing its viscosity can help improve the accuracy and stability of viscosity testing.

[0107] In one example, an online viscosity monitor provides real-time feedback on the viscosity of the base glue.

[0108] In some embodiments, step S120 includes: filling the base glue liquid with oil according to the mass percentage of the dry glue in the base glue liquid, the mass of the filling oil is 20%~40% of the mass of the dry glue in the base glue liquid, the oil filling temperature is 60℃~110℃, the time is 30min~300min, and the oil-filled glue liquid with a dry glue Mooney viscosity of 15MU~30MU is obtained.

[0109] In some embodiments, the Mooney viscosity ML of the dry adhesive in the oil-filled adhesive solution is 15MU to 30MU. For example, the Mooney viscosity ML of the dry adhesive in the oil-filled adhesive solution can be, but is not limited to, 15MU, 16MU, 18MU, 20MU, 22MU, 24MU, 25MU, 26MU, 28MU, 30MU, or a range consisting of any two of these values.

[0110] In some embodiments, oil filling is performed in an oil filling kettle. Specifically, a base adhesive solution with a known dry adhesive mass content is metered by a first metering device and then introduced into the oil filling kettle, and a filler oil at a mass of 20% to 40% of the dry adhesive mass is metered by a second metering device and then introduced into the oil filling kettle.

[0111] In one example, the first metering device and the second metering device may be flow meters.

[0112] In traditional technology, the production of oil-filled polybutadiene rubber mainly adopts dry oil-filling process or wet oil-filling process. The dry oil-filling process is to mix the filler oil and rubber in a mixer, and disperse the filler oil in the rubber through mechanical hybrid power. This method has high energy consumption and must be oil-filled in batches. The wet oil-filling process is to first prepare a polymer glue, then mix the filler oil and the glue evenly before coagulation, and then coagulate the glue to obtain oil-filled rubber. In order to make the filler oil and the base glue with high Mooney viscosity mix evenly, it is usually necessary to prepare the filler oil as an oil emulsion, or to stir the mixture of the filler oil and the glue for a long time. In some embodiments of the present application, although the wet oil-filling process is adopted, due to the low Mooney viscosity of the dry glue in the base glue, it is more conducive to uniform mixing with the filler oil compared to the traditional wet oil-filling process, and it takes less time and has lower energy consumption.

[0113] In other related technologies, butadiene, isoprene, a saturated hydrocarbon solvent, and an extender oil are mixed to form a solution to be polymerized, and then a rare earth catalyst is added for polymerization to directly produce an oil-extended rubber. This preparation method is simple, easy to operate, and suitable for industrial production. However, conventional extender oils have complex compositions and contain a large number of polar substances. Mixing them with rare earth catalysts for polymerization can poison the catalyst and hinder its effectiveness. In some embodiments of the present application, however, by first polymerizing butadiene under the action of a catalyst and then adding the extender oil, the catalyst activity is not impaired.

[0114] In some embodiments, during the step of coupling the oil-extended adhesive, the mass of the coupling agent used is 0.01% to 5% of the mass of the dry adhesive in the oil-extended adhesive. For example, the mass of the coupling agent is 0.01%, 0.05%, 0.1%, 0.2%, 0.4%, 0.5%, 0.6%, 0.8%, 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5% of the mass of the oil-extended adhesive, or a range consisting of any two of these values. Alternatively, the mass of the coupling agent is 0.1% to 1% of the mass of the dry adhesive in the oil-extended adhesive.

[0115] In some embodiments, during the step of coupling the oil-extended adhesive, the coupling temperature is 60°C to 110°C, and the coupling time is 5 minutes to 60 minutes. For example, the coupling temperature may be, but is not limited to, 60°C, 70°C, 80°C, 90°C, 100°C, 110°C, or a range consisting of any two of these values. The coupling time may be, but is not limited to, 5 minutes, 10 minutes, 20 minutes, 30 minutes, 40 minutes, 50 minutes, 60 minutes, or a range consisting of any two of these values. Optionally, the coupling time is 20 minutes to 40 minutes.

[0116] The low Mooney oil-filled rubber solution is further treated with a coupling agent to further improve the Mooney viscosity and mechanical properties, thereby obtaining a high-performance modified oil-filled rubber.

[0117] In some embodiments, the coupling agent includes one or more of a silane coupling agent, a halide, a sulfide, an isocyanate, an azo compound, and a peroxide.

[0118] Among them, the silane coupling agent includes one or more of hexamethylcyclotrisiloxane, octamethylcyclotetrasiloxane, divinyldimethylsilane, vinyltrimethoxysilane, vinyltriethoxysilane, tetraethoxysilane, tetramethoxysilane, tetrapropoxysilane, dicyclopentadienyldimethylsilane, divinylbis(2,4-pentadienyl)silane, and the halide includes silicon tetrachloride, trichlorosilane, dimethylsilicon dichloride, carbon tetrachloride, methyltrichloromethane, dibromoethane, 1,2,3-tribromopropane, germanium tetrachloride, n-butylgermanium trichloride, tin tetrachloride, trichlorosilane ... One or more of tin chloride, di-n-butyltin dichloride, phosphorus trichloride, and phosphorus pentachloride; sulfides include one or more of thionyl chloride, sulfur dichloride, disulfur dichloride, diallyl disulfide, and difurfuryl disulfide; isocyanates include one or more of 4,4'-diphenylmethane diisocyanate, 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, isophorone diisocyanate, and hexamethylene diisocyanate; azo compounds include azobisisobutyronitrile; and peroxides include one or more of dilauroyl peroxide and dicumyl peroxide.

[0119] In some embodiments, the coupling agent includes hexamethylcyclotrisiloxane, octamethylcyclotetrasiloxane, divinyldimethylsilane, vinyltrimethoxysilane, vinyltriethoxysilane, tetraethoxysilane, tetramethoxysilane, tetrapropoxysilane, dicyclopentadienyldimethylsilane, divinylbis(2,4-pentadienyl)silane, silicon tetrachloride, trichlorosilane, dimethylsilyldichloride, thionyl chloride, sulfur dichloride, disulfur dichloride, diallyl disulfide, difurfuryl disulfide One or more of the following: compounds, carbon tetrachloride, methyltrichloromethane, dibromoethane, 1,2,3-tribromopropane, germanium tetrachloride, n-butylgermanium trichloride, tin tetrachloride, hydridotin trichloride, di-n-butyltin dichloride, phosphorus trichloride, phosphorus pentachloride, 4,4'-diphenylmethane diisocyanate, 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, isophorone diisocyanate, hexamethylene diisocyanate, azobisisobutyronitrile, dilauroyl peroxide and dicumyl peroxide.

[0120] In some embodiments, the Mooney viscosity ML of the polybutadiene rubber is 25MU to 50MU. For example, the Mooney viscosity ML of the polybutadiene rubber can be, but is not limited to, 25MU, 26MU, 28MU, 30MU, 32MU, 34MU, 35MU, 36MU, 38MU, 40MU, 42MU, 44MU, 45MU, 48MU, 48MU, 50MU, or a range consisting of any two of these values. Alternatively, the Mooney viscosity ML of the polybutadiene rubber is 30MU to 45MU.

[0121] In some embodiments, step S130 is performed in a coupling modification reactor.

[0122] In some embodiments, step S130 includes: mixing the oil-filled rubber liquid with a coupling agent, wherein the mass of the coupling agent is 0.01% to 5% of the mass of the dry rubber in the oil-filled rubber liquid, and reacting at 60° C. to 110° C. for 5 min to 60 min to prepare a polybutadiene rubber with a Mooney viscosity of 30MU to 45MU.

[0123] In some embodiments, after the step of coupling the oil-extended rubber solution, the method further comprises: coagulating the coupled rubber solution to precipitate polybutadiene rubber particles.

[0124] In some embodiments, the coagulation step can be a commonly used method in the art. For example, the coagulation adopts the hydrolysis method, which uses the principle of steam distillation, that is, the rubber liquid is evaporated and separated from the rubber under the action of hot water, steam and mechanical stirring in the coagulation kettle, and the rubber is suspended in hot water in the form of particles and transported to the finished product workshop.

[0125] In some embodiments, the coagulation step adopts a three-kettle coagulation principle, including a first coagulation kettle, a middle coagulation kettle and a last coagulation kettle connected in sequence.

[0126] In some embodiments, after the coagulation step, a post-processing step is further included. Specifically, the post-processing step includes drying, extrusion, etc., which are commonly used in the art and will not be described in detail here.

[0127] In some embodiments, see Figure 2 , the preparation method of polybutadiene rubber comprises the following steps:

[0128] Step S210: mixing butadiene monomer, catalyst and solvent, and performing polymerization reaction to obtain a base adhesive solution with a dry adhesive Mooney viscosity of 20MU to 60MU.

[0129] Step S220: removing unreacted butadiene monomer in the base glue solution.

[0130] Step S230: constructing a corresponding relationship between the viscosity of the glue solution and the mass percentage of the dry glue, and determining the mass percentage of the dry glue in the basic glue solution according to the corresponding relationship and the viscosity of the basic glue solution.

[0131] Step S240: Filling the base glue solution with oil according to the mass percentage of the dry glue in the base glue solution. The mass of the filling oil is 20% to 40% of the mass of the dry glue in the base glue solution. The oil filling temperature is 60°C to 110°C and the filling time is 30 minutes to 300 minutes to obtain an oil-filled glue solution with a dry glue Mooney viscosity of 15MU to 30MU.

[0132] Step S250: mixing the oil-filled adhesive liquid with a coupling agent, wherein the mass of the coupling agent is 0.01% to 5% of the mass of the dry adhesive in the oil-filled adhesive liquid, and coupling is performed at 60° C. to 110° C. for 5 min to 60 min to obtain a modified adhesive liquid with a dry adhesive Mooney viscosity of 25MU to 50MU.

[0133] Step S260: coagulating the modified rubber solution to prepare polybutadiene rubber.

[0134] In a second aspect, the present application provides a polybutadiene rubber, comprising a rubber matrix and an extender oil filled in the rubber matrix, wherein at least a portion of the rubber matrix is coupled, and the polybutadiene rubber has a Mooney viscosity of 25 MU to 50 MU. Optionally, the Mooney viscosity of the polybutadiene rubber is 30 MU to 45 MU.

[0135] Specifically, the polybutadiene rubber is prepared by the preparation method of the first aspect.

[0136] In a third aspect, the present application provides a rubber compound comprising the polybutadiene rubber according to the second aspect.

[0137] Among them, rubber mix refers to the rubber material obtained by mixing raw rubber and compounding agents in a rubber mixer, which is the raw material for manufacturing rubber products. Compounding agents can be, but are not limited to, vulcanizing agents, accelerators, reinforcing fillers, antioxidants, etc.

[0138] In a fourth aspect, the present application provides an automobile tire product, comprising the polybutadiene rubber of the second aspect or the rubber compound of the third aspect.

[0139] The polybutadiene rubber or compounded rubber has excellent flexural resistance, wear resistance, low rolling resistance, better raw rubber strength and vulcanized rubber performance, can meet the high-speed driving requirements of automobiles, and can be used in tire treads and sidewall rubbers.

[0140] In order to make the purpose and advantages of the present application clearer, the polybutadiene rubber, preparation method and effects of the present application are further described in detail below with reference to specific examples. It should be understood that the specific examples described herein are only used to explain the present application and shall not be used to limit the present application. The following examples do not include other components except for unavoidable impurities unless otherwise specified. The drugs and instruments used in the examples are conventionally selected in the art unless otherwise specified. The experimental methods for which specific conditions are not specified in the examples are implemented according to conventional conditions, such as the conditions described in the literature, books or the methods recommended by the manufacturer.

[0141] Example 1

[0142] This embodiment provides a polybutadiene rubber, the preparation method of which includes the following steps:

[0143] (1) Under nitrogen protection, components A, B, C, and D were mixed uniformly at 30°C, heated to 45°C, and aged for 120 minutes to obtain a homogeneous rare earth catalyst. Component A is neodymium isooctanoate, component B is triisobutylaluminum, component C is isoprene, and component D is chloroform. The molar ratio of components A, B, C, and D is 1:20:10:1.

[0144] (2) An inert organic solvent, butadiene monomer, and catalyst were mixed in a polymerization reactor and reacted at 60°C for 120 min to obtain a base glue with a Mooney viscosity of 40 MU. The mass of butadiene monomer accounted for 12% of the total mass of butadiene monomer and solvent, and the molar ratio of component A in the catalyst to butadiene monomer was 1:10,000.

[0145] (3) The base glue solution is passed into a flash tank for flash evaporation to remove unreacted butadiene monomer. The viscosity of the base glue solution flowing out of the flash tank is 260cp according to the online viscosity monitor. According to the viscosity, the mass percentage of dry glue in the base glue solution after flash evaporation is 10.5%. The base glue solution with a known mass percentage of dry glue is measured by the first flow meter and then enters the oil filling kettle. The filling oil is measured by the second flow meter at 27% of the mass of dry glue and then enters the oil filling kettle. The oil filling is carried out at 80℃ for 60 minutes to obtain an oil-filled glue solution with a Mooney viscosity of 26MU.

[0146] (4) The oil-filled rubber liquid is metered by the third flow meter and then fed into the coupling modification kettle. The coupling agent (disulfur dichloride) is metered by the fourth flow meter at a ratio of 0.8% of the mass of the oil-filled rubber liquid dry rubber and then fed into the coupling reaction kettle. The reaction is carried out at 80°C for 40 minutes to obtain a modified rubber liquid with a Mooney viscosity of 37.5MU.

[0147] (5) The modified rubber solution is coagulated to obtain polybutadiene rubber.

[0148] Example 2

[0149] This embodiment provides a polybutadiene rubber, and its preparation method is similar to that of Example 1, except that step (4) is different. In this embodiment, step (4) is as follows:

[0150] The oil-filled rubber liquid is measured by the third flow meter and then input into the coupling modification kettle. The coupling agent (silicon tetrachloride) is measured by the fourth flow meter at a ratio of 0.8% of the mass of the oil-filled rubber liquid and then enters the coupling reaction kettle. The reaction is carried out at 80°C for 40 minutes to obtain a modified rubber liquid with a Mooney viscosity of 30MU.

[0151] Example 3

[0152] This embodiment provides a polybutadiene rubber, and its preparation method is similar to that of Example 1, except that step (4) is different. In this embodiment, step (4) is as follows:

[0153] The oil-filled rubber liquid is measured by the third flow meter and then input into the coupling modification kettle. The coupling agent (disulfur dichloride) is measured by the fourth flow meter at a ratio of 1.5% of the mass of the oil-filled rubber liquid and then enters the coupling reaction kettle. The reaction is carried out at 80°C for 40 minutes to obtain a modified rubber liquid with a Mooney viscosity of 50MU.

[0154] Example 4

[0155] This embodiment provides a polybutadiene rubber, and its preparation method is similar to that of Example 1, except that step (3) is different. In this embodiment, step (3) is as follows:

[0156] (3) The viscosity of the base glue liquid was measured by an online viscosity monitor to be 238 cp. Based on the viscosity, the mass percentage of dry glue in the base glue liquid after flash evaporation was 9.3%. The base glue liquid with a known mass percentage of dry glue was measured by a first flow meter and then entered the oil filling kettle. The filling oil was measured by a second flow meter at 27% of the mass of dry glue and then entered the oil filling kettle. The oil filling was carried out at 80°C for 60 minutes to obtain an oil-filled glue liquid with a Mooney viscosity of 43 MU.

[0157] Example 5

[0158] This embodiment provides a polybutadiene rubber, and its preparation method is similar to that of Example 1, except that step (3) is different. In this embodiment, step (3) is as follows:

[0159] (3) A portion of the base adhesive solution flowing out of the final polymerization kettle was taken and its mass and the mass after drying were measured. The mass percentage of dry adhesive in the base adhesive solution was 13.7%. The base adhesive solution with a known mass percentage of dry adhesive was metered by the first flowmeter and then entered the oil-filling kettle. The filling oil was metered by the second flowmeter at 27% of the mass of dry adhesive and then entered the oil-filling kettle. The oil filling was carried out at 80°C for 60 minutes to obtain an oil-filled adhesive solution with a Mooney viscosity of 30.5MU.

[0160] Comparative Example 1

[0161] Comparative Example 1 provides a polybutadiene rubber, the preparation method of which comprises the following steps:

[0162] (1) Under nitrogen protection, components A, B, C, and D were mixed uniformly at 30°C, heated to 45°C, and aged for 120 minutes to obtain a homogeneous rare earth catalyst. Component A is neodymium isooctanoate, component B is triisobutylaluminum, component C is isoprene, and component D is chloroform. The molar ratio of components A, B, C, and D is 1:20:10:1.

[0163] (2) An inert organic solvent, butadiene monomer, and catalyst were mixed in a polymerization reactor and reacted at 60°C for 300 min to obtain a base glue solution with a Mooney viscosity of 90 MU. The mass of butadiene monomer accounted for 6% of the total mass of butadiene monomer and solvent, and the molar ratio of component A in the catalyst to butadiene monomer was 1:20,000.

[0164] (3) A portion of the base adhesive solution was taken to determine the conversion rate (partial replacement of the whole). Based on the conversion rate, the mass percentage of dry adhesive in the base adhesive solution was 5.3%. The base adhesive solution with a known mass percentage of dry adhesive was transferred to an oil-filling kettle. The filling oil was measured by a second flow meter at 27% of the mass of the dry adhesive and then entered the oil-filling kettle. The oil filling was carried out at 80°C for 240 minutes to obtain an oil-filled adhesive solution with a Mooney viscosity of 45MU.

[0165] (5) The oil-filled rubber solution is coagulated to obtain polybutadiene rubber.

[0166] The polybutadiene rubber prepared in the above-mentioned embodiments and comparative examples was subjected to the following tests, and the results shown in Table 1 were obtained. The Mooney viscosity is expressed as ML1+4(100) and is measured by a Mooney viscometer; the stress relaxation time is measured by a Mooney viscometer as follows; the number average molecular weight is measured by gel permeation chromatography (GPC); the intrinsic viscosity is measured by the following method or the test equipment used is as follows: the intrinsic viscosity is measured by a fully automatic Ubbelohde viscometer IV6000 produced by Hangzhou Zhuoxiang Technology Co., Ltd.

[0167] The test method for gel content is as follows:

[0168] (1) According to the provisions of GB / T 19187, take approximately 5 g of butadiene rubber sample and cut it into thin strips (1 × 1 × 3) mm using scissors. Place a small stainless steel basket rinsed with distilled water in a drying oven at (120 ± 2) °C and dry it for 1 h. Remove it and place it in a desiccator, cool it to room temperature, and weigh it. Place it in a drying oven and dry it for 30 min. Remove it and place it in a desiccator, cool it to room temperature, and weigh it. Repeat this step until the difference between two consecutive weighings is no more than 0.0003 g, which is a constant weight.

[0169] (2) Weigh 0.25 g (accurate to 0.01 g) of the sample that has been cut into thin strips and spread it flat in a small stainless steel basket with constant weight, without the strips connecting to each other.

[0170] (3) Use a graduated cylinder to take 50 mL of toluene and add it to the sample bottle. Suspend a small stainless steel basket in the sample bottle so that the strip is completely immersed in the toluene. Close the bottle cap tightly and place the sample bottle in a dark place in a fume hood at (23 ± 5) °C for approximately 24 h. Note: The height of the small basket should be appropriate. There should be a gap between the bottom of the basket and the bottom of the bottle, and the top of the small basket should be at least 2 mm above the liquid surface.

[0171] (4) After the sample is dissolved, remove the stainless steel basket from the toluene with tweezers. Use a pipette to carefully rinse the dissolved material in the basket at least three times with (1.5-2) mL of toluene to remove any residual sol. Place the basket on filter paper in a fume hood for approximately 20 minutes. Once the toluene has essentially evaporated, place the basket in a drying oven at (120 ± 2)°C for 1 hour. Dry to constant weight according to the procedures in 7.1.

[0172] (5) Calculation

[0173] The mass fraction X of gel in butadiene rubber raw rubber is calculated according to the following formula: X = (m2-m1) / m×100%;

[0174] Where: m represents the mass of the sample, in g; m1 represents the mass of the stainless steel basket, in g; m2 represents the mass of the stainless steel basket plus gel, in g.

[0175] The test method for oil filling volume is as follows: Based on the national standard SH / T1718-2015.

[0176] Table 1

[0177]

[0178] From Table 1 above, we can see that:

[0179] (1) Compared with the traditional method, the process of first filling with oil and then coupling can ensure the stability of the oil filling amount and improve the success rate of oil filling under more energy-saving conditions;

[0180] (2) Compared with the traditional process of calculating the conversion rate, the use of an online viscosity monitor can more accurately determine the actual content of dry glue in the glue solution. Online detection saves time and is more conducive to controlling the reaction process of the basic glue solution preparation;

[0181] (3) The oil-filled adhesive obtained by the coupling process has a low intrinsic viscosity, which is conducive to the transportation of the adhesive. The traditional process has a high Mooney viscosity, which may cause pipeline blockage. This limits the preparation of the basic adhesive at a low monomer concentration or the use of solvent dilution after polymerization, resulting in increased energy consumption.

[0182] (4) By adjusting the coupling agent, the Mooney viscosity and stress relaxation time of the oil-filled rubber can be controlled to meet different needs;

[0183] (5) Different coupling agents have different coupling effects. By changing the type of coupling agent, the Mooney viscosity and stress relaxation time of the oil-filled rubber can be controlled.

[0184] The polybutadiene rubber prepared in the above examples and comparative examples was mixed to prepare a rubber compound. The specific method is as follows: refer to the oil-extended rubber formula in GBT8660-2018, as shown in Table 2 below.

[0185] Table 2 Standard test formula

[0186]

[0187] The mechanical properties of the rubber mix were tested in accordance with GBT528-2009, Determination of tensile stress-strain properties of vulcanized rubber or thermoplastic rubber. The tensile strength, modulus of tensile stress and elongation at break of the rubber mix were tested using an INSTRON3300 electronic universal material testing machine from Instron Corporation of the United States.

[0188] Tensile strength: measured using INSTRON 3300 electronic universal material testing machine.

[0189] Elongation at break: measured using INSTRON 3300 electronic universal material testing machine.

[0190] 300% modulus of elongation: measured by INSTRON3300 electronic universal materials testing machine.

[0191] Hardness: Measured using a Shore A hardness tester.

[0192] The performance test methods of the prepared rubber mix include the rubber mix Mooney viscosity, hardness, tensile strength, elongation at break and 300% modulus of elongation. The test results are shown in Table 3 below:

[0193] Table 3 Performance test results of rubber compounds

[0194]

[0195] As can be seen from Table 3 above, the performance of the rubber mixes prepared by the polybutadiene rubber preparation method of some embodiments of the present application and the polybutadiene rubber prepared by the traditional process is not much different.

[0196] The technical features of the above-mentioned embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the technical features in the above-mentioned embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0197] The embodiments described above only express several implementation methods of the present application, which are convenient for understanding the technical solutions of the present application in a specific and detailed manner, but they cannot be understood as limiting the scope of protection of the invention patent. It should be pointed out that for ordinary technicians in this field, without departing from the concept of the present application, several variations and improvements can be made, which all fall within the scope of protection of the present application. It should be understood that the technical solutions obtained by those skilled in the art through logical analysis, reasoning or limited experiments on the basis of the technical solutions provided in the present application are all within the scope of protection of the claims attached to the present application. Therefore, the scope of protection of the patent of this application shall be based on the content of the attached claims, and the description and drawings can be used to interpret the content of the claims.

Claims

1. A method for preparing polybutadiene rubber, characterized in that: The steps include: Providing a basic glue solution, wherein the Mooney viscosity of the dry glue in the basic glue solution is 20MU~60MU; Filling the base adhesive with oil to prepare an oil-filled adhesive; The oil-extended rubber solution is coupled to prepare polybutadiene rubber.

2. The method for preparing polybutadiene rubber according to claim 1, wherein In the step of coupling the oil-extended adhesive, the mass of the coupling agent used is 0.01% to 5% of the mass of the dry adhesive in the oil-extended adhesive; and / or, in the step of coupling the oil-extended adhesive, the coupling agent used includes one or more of a silane coupling agent, a halide, a sulfide, an isocyanate, an azo compound, and a peroxide; And / or, in the step of coupling the oil-extended adhesive, the coupling temperature is 60° C. to 110° C., and the coupling time is 5 min to 60 min.

3. The method for preparing polybutadiene rubber according to claim 2, wherein: The mass of the coupling agent is 0.1% to 1% of the mass of the dry glue in the oil-filled glue solution; And / or, the coupling agent includes hexamethylcyclotrisiloxane, octamethylcyclotetrasiloxane, divinyldimethylsilane, vinyltrimethoxysilane, vinyltriethoxysilane, tetraethoxysilane, tetramethoxysilane, tetrapropoxysilane, dicyclopentadienyldimethylsilane, divinylbis(2,4-pentadienyl)silane, silicon tetrachloride, trichlorosilane, dimethylsilyldichloride, thionyl chloride, sulfur dichloride, disulfur dichloride, diallyl disulfide, difurfuryl disulfide , carbon tetrachloride, methyltrichloromethane, dibromoethane, 1,2,3-tribromopropane, germanium tetrachloride, n-butylgermanium trichloride, tin tetrachloride, hydrogenated tin trichloride, di-n-butyltin dichloride, phosphorus trichloride, phosphorus pentachloride, 4,4'-diphenylmethane diisocyanate, 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, isophorone diisocyanate, hexamethylene diisocyanate, azobisisobutyronitrile, dilauroyl peroxide and dicumyl peroxide. One or more of the following:

4. The method for preparing polybutadiene rubber according to claim 1, wherein: The Mooney viscosity of the dry glue in the oil-filled glue solution is 15MU~30MU; And / or, the Mooney viscosity of the polybutadiene rubber is 25MU~50MU; optionally, the Mooney viscosity of the polybutadiene rubber is 30MU~45MU.

5. The method for preparing polybutadiene rubber according to claim 1, wherein In the step of oil-filling the base adhesive, the oil-filling temperature is 60° C. to 110° C., and the time is 30 min to 300 min; And / or, in the step of oil-filling the base rubber solution, the filler oil used includes one or more of aromatic rubber oil, cycloalkyl rubber oil and paraffin rubber oil.

6. The method for preparing polybutadiene rubber according to claim 1 or 5, characterized in that: The step of filling the basic glue liquid with oil includes: filling the basic glue liquid with oil according to the mass percentage of the dry glue in the basic glue liquid, and the mass of the filling oil is 20% to 40% of the mass of the dry glue in the basic glue liquid.

7. The method for preparing polybutadiene rubber according to claim 6, wherein: Before the step of oil-filling the base glue according to the mass percentage of dry glue in the base glue, the method further comprises: Establish the corresponding relationship between the viscosity of the glue solution and the percentage of dry glue mass; The mass percentage of the dry glue in the basic glue solution is determined according to the corresponding relationship and the viscosity of the basic glue solution.

8. The method for preparing polybutadiene rubber according to claim 7, characterized in that: The steps of establishing the corresponding relationship between the viscosity of the glue solution and the mass percentage of the dry glue include: Provide multiple standard glue solutions with different dry glue mass percentages; Testing the viscosity of each of the plurality of standard glues; According to the viscosity of each of the plurality of standard glue solutions and the corresponding dry glue mass percentage, a corresponding relationship between the glue solution viscosity and the dry glue mass percentage is established.

9. The method for preparing polybutadiene rubber according to any one of claims 1 to 5 and 7 to 8, characterized in that: The base glue is prepared by the following steps: mixing butadiene monomer, catalyst and solvent, and performing polymerization reaction to prepare the base glue; Wherein, the catalyst is a rare earth catalyst, and the base rubber liquid is butadiene rubber liquid; Optionally, the catalyst comprises component A, component B, component C and component D; component A comprises a neodymium carboxylate compound, component B comprises one or more of an alkylaluminum compound, an alkylaluminum hydride compound and an organoaluminoxane, component C comprises a conjugated diene, and component D comprises one or more of an alkylaluminum chloride, a chloroalkane, a chloroester and a chlorosilane; Optionally, the molar ratio of the component A, the component B, the component C and the component D is 1:(5-100):(10-60):(1-10).

10. The method for preparing polybutadiene rubber according to claim 9, characterized in that: In the step of mixing the butadiene monomer, the catalyst and the solvent, the molar ratio of the component A in the catalyst to the butadiene monomer is (1×10 -5 ~2×10 -4 ):1; And / or, the mass of the butadiene monomer accounts for 6% to 18% of the total mass of the butadiene monomer and the solvent; And / or, the polymerization reaction temperature is 0°C to 100°C, and the time is 30min to 180min; And / or, after the step of mixing the butadiene monomer, the catalyst and the solvent and performing a polymerization reaction, the method further comprises: removing unreacted butadiene monomer from the base adhesive after the polymerization reaction.

11. A polybutadiene rubber, characterized in that: The polybutadiene rubber comprises a rubber matrix and a filler oil filled in the rubber matrix, at least a portion of the rubber matrix is coupled, and the Mooney viscosity of the polybutadiene rubber is 25MU to 50MU; Optionally, the polybutadiene rubber is prepared by the preparation method according to any one of claims 1 to 10.

12. A rubber mix, characterized in that: Including the polybutadiene rubber according to claim 11.

13. An automobile tire product, characterized in that: Including the polybutadiene rubber according to claim 11 or the rubber compound according to claim 12.

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