Butadiene rubber alloy as well as preparation method and application thereof

Abstract

The invention relates to a butadiene rubber alloy and a preparation method and application thereof.The preparation method of the butadiene rubber alloy comprises the following steps that rare earth butadiene rubber and nickel butadiene rubber are coupled to obtain composite butadiene rubber, the mass of the rare earth butadiene rubber is larger than that of the nickel butadiene rubber, and the mass of the nickel butadiene rubber is larger than that of the nickel butadiene rubber. The Mooney viscosity of the composite butadiene rubber is 35 MU to 55 MU, and the branching factor of the composite butadiene rubber is 3.0 to 7.1; syndiotactic 1, 2-polybutadiene is prepared in situ in the composite butadiene rubber solution, and a polymerized rubber solution is obtained; and condensing and drying the polymerized rubber solution to obtain the butadiene rubber alloy. The butadiene rubber alloy prepared by the preparation method not only has excellent wet skid resistance, tensile strength and tear strength, but also has good processability and cold flow resistance, so that the requirements of tires on high strength and high modulus can be better met.

Description

Technical Field

[0001] The invention relates to the technical field of synthetic rubber, in particular to a butadiene rubber alloy and a preparation method and application thereof. Background Art

[0002] At present, most of the existing technologies use rare earth cis-1,4-dimethyl-1-butadiene rubber or nickel cis-1,4-dimethyl-1-butadiene rubber as the rubber for preparing tires. However, when the existing rare earth cis-1,4-dimethyl-1-butadiene rubber or nickel cis-1,4-dimethyl-1-butadiene rubber is applied to the tire sidewall, it needs to be reinforced to meet the requirements of high strength and high modulus for the tire sidewall. Most of the traditional processes use the method of adding inorganic fillers or increasing the degree of crosslinking to increase the modulus of the sidewall, but such methods will lead to undesirable results such as high internal friction, high heat generation, and poor aging performance.

[0003] Although there is a method in the market to prepare rubber alloys by in-situ introduction of syndiotactic 1,2-polybutadiene into rare earth butadiene rubber or nickel-based butadiene rubber to improve the reinforcement effect and reduce tire internal friction, the rubber alloys prepared in this way still have problems such as poor processing performance, poor wet skid resistance, and low tensile strength and tear strength, making it difficult to meet the tire's requirements for high strength and high modulus. Summary of the invention

[0004] Based on this, it is necessary to provide a butadiene rubber alloy and its preparation method and application for the above problems. The butadiene rubber alloy prepared by the preparation method not only has excellent wet skid resistance, tensile strength and tear strength, but also has good processing performance and cold flow resistance, so as to better meet the requirements of tires for high strength and high modulus.

[0005] A method for preparing a butadiene rubber alloy comprises the following steps:

[0006] Couple rare earth cis-1,1-butadiene rubber and nickel cis-1,1-butadiene rubber to obtain composite cis-1,1-butadiene rubber, wherein the mass of the rare earth cis-1,1-butadiene rubber is greater than the mass of the nickel cis-1,1-butadiene rubber, and the Mooney viscosity of the composite cis-1,1-butadiene rubber is 35MU-55MU, and the branching factor is 3.0-7.1;

[0007] In-situ preparation of syndiotactic 1,2-polybutadiene in composite butadiene rubber solution to obtain polymeric solution;

[0008] The polymerized rubber solution is coagulated and dried to obtain a butadiene rubber alloy.

[0009] In one embodiment, the step of coupling rare earth cis-1,1-butadiene rubber and nickel cis-1,1-butadiene rubber to obtain composite cis-1,1-butadiene rubber further satisfies at least one of the following conditions:

[0010] (1) The Mooney viscosity of the rare earth cis-1,1-butadiene rubber is 30MU-50MU, the branching factor is 1.5-2.0, the number average molecular weight is 8.0kg / mol-10.0kg / mol, the weight average molecular weight is 16.0kg / mol-30.0kg / mol, the molecular weight distribution is 2.0-3.0, and the mass fraction of the cis-1,4-structure in the rare earth cis-1,1-butadiene rubber is greater than or equal to 98%;

[0011] (2) The Mooney viscosity of the nickel-based butadiene rubber is 30MU-50MU, the branching factor is 15-20, the number average molecular weight is 7.0kg / mol-9.5kg / mol, the weight average molecular weight is 21.5kg / mol-34.2kg / mol, the molecular weight distribution is 3.2-3.6, and the mass fraction of the cis-1,4-structure in the nickel-based butadiene rubber is greater than 96%;

[0012] (3) The number average molecular weight of the composite butadiene rubber is 7.8 kg / mol-9.6 kg / mol, the weight average molecular weight is 22.0 kg / mol-31.7 kg / mol, the molecular weight distribution is 2.8-3.3, and the mass fraction of the cis-1,4-structure in the composite butadiene rubber is greater than or equal to 96%;

[0013] (4) The rare earth butadiene rubber is selected from neodymium butadiene rubber;

[0014] (5) The rare earth butadiene rubber, the nickel-based butadiene rubber, a coupling agent and an organic solvent are mixed and coupled to separate and obtain the composite butadiene rubber.

[0015] In one embodiment, in the step of mixing and coupling the rare earth butadiene rubber, the nickel-based butadiene rubber, the coupling agent and the organic solvent, at least one of the following conditions must be met:

[0016] (1) The mass ratio of the rare earth butadiene rubber to the nickel-based butadiene rubber is 4:1-19:1;

[0017] (2) The mass ratio of the rare earth butadiene rubber to the coupling agent is 125:1-1000:1;

[0018] (3) The coupling agent is at least one selected from divinyldimethylsilane, triethoxysilane, 3-chloropropyltriethoxysilane, 4-chloropropylmethyldimethoxysilane, 3-chloropropylmethyldiethoxysilane, bis-[Y-(triethoxysilyl)propyl]tetrasulfide, n-propyltrichlorosilane, silicon tetrachloride, tin tetrachloride, and disulfide dichloride.

[0019] In one embodiment, in the step of in-situ preparation of syndiotactic 1,2-polybutadiene in a composite butadiene rubber solution, the composite butadiene rubber solution and a butadiene monomer solution are mixed in the presence of an iron-based catalyst or a cobalt-based catalyst and subjected to an in-situ polymerization reaction.

[0020] In one embodiment, in the step of mixing the composite butadiene rubber solution and the butadiene monomer solution and performing an in-situ polymerization reaction, at least one of the following conditions must be met:

[0021] (1) the molar ratio of the composite butadiene rubber in the composite butadiene rubber solution to the butadiene monomer in the butadiene monomer solution is 3:2-19:1;

[0022] (2) The polymerization temperature is 30°C-50°C, and the polymerization time is 30min-60min.

[0023] In one embodiment, when the composite butadiene rubber solution and the butadiene monomer solution are mixed and subjected to in-situ polymerization in the presence of an iron-based catalyst, at least one of the following conditions must be met:

[0024] (1) The molar ratio of the butadiene monomer in the butadiene monomer solution to the iron element in the iron-based catalyst is 5000:1-40000:1;

[0025] (2) The iron-based catalyst comprises an iron compound, a phosphine-containing compound and an alkyl aluminum, wherein a molar ratio of the iron compound, the phosphine-containing compound and the alkyl aluminum is 1:3:10-1:20:50.

[0026] In one embodiment, when the composite butadiene rubber solution and the butadiene monomer solution are mixed and subjected to in-situ polymerization in the presence of a cobalt-based catalyst, at least one of the following conditions must be met:

[0027] (1) The molar ratio of butadiene monomer in the butadiene monomer solution to cobalt element in the cobalt-based catalyst is 5000:1-40000:1;

[0028] (2) The cobalt-based catalyst comprises a soluble cobalt compound, an alkyl aluminum and carbon disulfide, wherein a molar ratio of the soluble cobalt compound, the alkyl aluminum and the carbon disulfide is 1:10:2-1:100:20.

[0029] A butadiene rubber alloy prepared by the method for preparing the butadiene rubber alloy as described above, wherein the butadiene rubber alloy comprises a composite butadiene rubber and syndiotactic 1,2-polybutadiene dispersed in the composite butadiene rubber.

[0030] In one embodiment, the Mooney viscosity of the butadiene rubber alloy is 39MU-85MU, the branching factor is 3.5-8.5, the melting point is 196°C-203°C, the mass fraction of 1,2-polybutadiene in the butadiene rubber alloy is 3.5%-30%, and the mass fraction of 1,4-structure in the butadiene rubber alloy is 69%-95.5%.

[0031] An application of the butadiene rubber alloy as described above in tires.

[0032] In the preparation method of the cis-1,4-butadiene rubber alloy of the present invention, the composite cis-1,4-butadiene rubber obtained by coupling rare earth cis-1,4-butadiene rubber and nickel cis-1,4-butadiene rubber is used as the base rubber, and the amount ratio of the rare earth cis-1,4-butadiene rubber and the nickel cis-1,4-butadiene rubber is limited, so that the composite cis-1,4-butadiene rubber can have the excellent properties of both rare earth cis-1,4-butadiene rubber and nickel cis-1,4-butadiene rubber, that is, it has excellent processing performance and mechanical properties. Meanwhile, by controlling the Mooney viscosity and branching factor of the composite cis-1,4-butadiene rubber, not only can the problem of a sudden increase in Mooney viscosity caused by the introduction of syndiotactic 1,2-polybutadiene be effectively avoided, so that the prepared rubber alloy has better processing performance and cold flow resistance, better wet-slip resistance, tensile strength and tear strength, but also is more conducive to the uniform dispersion of syndiotactic 1,2-polybutadiene in the composite cis-1,4-butadiene rubber, further enhances the interaction between syndiotactic 1,2-polybutadiene and the composite cis-1,4-butadiene rubber, can better improve the reinforcement effect, and thus further improve the tensile strength, tear strength and modulus and bending crack propagation resistance of the cis-1,4-butadiene rubber alloy.

[0033] Therefore, the butadiene rubber alloy prepared by the preparation method of the present invention not only has excellent wet skid resistance, tensile strength and tear strength, but also has good processing performance and cold flow resistance, thereby being able to better meet the requirements of tires for high strength and high modulus. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0035] Figure 1 This is an infrared spectrum of the butadiene rubber alloy prepared in Example 1 of the present invention;

[0036] Figure 2 The differential scanning calorimetry curve of the butadiene rubber alloy prepared in Example 1 of the present invention is shown in FIG. 1 , wherein Tc represents the crystallization temperature and Tm represents the melting point temperature. DETAILED DESCRIPTION

[0037] For ease of understanding of the present invention, the present invention will be described in more detail below. However, it should be understood that the present invention can be implemented in many different forms and is not limited to the embodiments or examples described herein. On the contrary, the purpose of providing these embodiments or examples is to make the understanding of the disclosure of the present invention more thorough and comprehensive.

[0038] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those generally understood by those skilled in the art of the present invention. The terms used herein in the specification of the present invention are only for the purpose of describing specific implementation methods or embodiments, and are not intended to limit the present invention. The optional scope of the term "and / or" used herein includes any one of two or more related listed items, and also includes any and all combinations of related listed items, and the combinations include any two related listed items, any more related listed items, or all related listed items.

[0039] The preparation method of the butadiene rubber alloy provided by the present invention comprises the following steps:

[0040] S1, coupling rare earth cis-1,1-butadiene rubber and nickel cis-1,1-butadiene rubber to obtain composite cis-1,1-butadiene rubber, wherein the mass of the rare earth cis-1,1-butadiene rubber is greater than the mass of the nickel cis-1,1-butadiene rubber, and the Mooney viscosity of the composite cis-1,1-butadiene rubber is 35MU-55MU, and the branching factor is 3.0-7.1;

[0041] S2, in situ preparing syndiotactic 1,2-polybutadiene in the composite butadiene rubber solution to obtain a polymerized solution;

[0042] S3, coagulating and drying the polymerized rubber solution to obtain a butadiene rubber alloy.

[0043] Rare earth cis-1,4-butadiene rubber has excellent wear resistance, anti-slip properties, low heat storage, low rolling properties and high bending fatigue resistance, but pure rare earth cis-1,4-butadiene rubber has poor cold flow resistance and poor processing performance, and its sulfide has relatively low tensile strength, tear strength and modulus and bending crack propagation resistance. Therefore, in the present invention, rare earth cis-1,4-butadiene rubber is used as the main material, and nickel-based cis-1,4-butadiene rubber is used as the auxiliary material for coupling, so that the prepared composite cis-1,4-butadiene rubber not only has the excellent properties of rare earth cis-1,4-butadiene rubber, but also has the easy processing performance, extrusion performance and good cold flow resistance of nickel-based cis-1,4-butadiene rubber, that is, it has both mechanical properties and processing performance, and can effectively avoid the problem of a sudden increase in Mooney viscosity caused by the introduction of syndiotactic 1,2-polybutadiene (sPB), so that the prepared rubber alloy has excellent anti-slip properties, tensile strength and tear strength, and has good processing performance and cold flow resistance.

[0044] Furthermore, controlling the Mooney viscosity of the composite butadiene rubber to be 35MU-55MU and the branching factor to be 3.0-7.1 can not only further improve the processing performance and mechanical properties of the rubber alloy, but also be more conducive to the uniform dispersion of syndiotactic 1,2-polybutadiene in the composite butadiene rubber, further enhance the interaction between syndiotactic 1,2-polybutadiene and the composite butadiene rubber, and better improve the reinforcement effect, thereby further improving the tensile strength, tear strength and modulus of the butadiene rubber alloy and the resistance to bending crack propagation.

[0045] Therefore, the butadiene rubber alloy prepared by the preparation method of the present invention not only has excellent wet skid resistance, tensile strength and tear strength, but also has good processing performance and cold flow resistance, thereby improving the bending fatigue resistance, flexural resistance, crack propagation resistance and weather resistance of its sulfide, and thus can better meet the requirements of tires for high strength and high modulus.

[0046] In addition, the viscosity of the composite butadiene rubber solution in the present invention is relatively low. When syndiotactic 1,2-polybutadiene is introduced in situ, it is more conducive to the dispersion of syndiotactic 1,2-polybutadiene in the composite butadiene rubber matrix, thereby further improving the reinforcement effect and better avoiding the problems of high internal friction, high heat generation, poor aging performance, etc. caused by traditional processes (increasing the sidewall modulus by adding inorganic fillers or increasing the degree of crosslinking).

[0047] It should be noted that, in the present invention, rare earth cis-1, ...

[0048] In step S1, the rare earth butadiene rubber, the nickel-based butadiene rubber, a coupling agent and an organic solvent are mixed and coupled, and the composite butadiene rubber is separated.

[0049] Specifically, the rare earth cis-1,1-butadiene rubber and the nickel cis-1,1-butadiene rubber are first dissolved in an organic solvent, a coupling agent is then added and mixed, and then filtered to remove impurities to obtain a composite cis-1,1-butadiene rubber. In this process, by adding the coupling agent, the rare earth cis-1,1-butadiene rubber and the nickel cis-1,1-butadiene rubber are connected to each other by covalent bonds, so that the linear rare earth cis-1,1-butadiene rubber has a long-chain branched structure.

[0050] Optionally, the mass ratio of the rare earth cis-1,4-butadiene rubber to the nickel cis-1,4-butadiene rubber is 4: 1-19: 1. Such an arrangement can better bring into play the synergistic effect of the excellent properties of the rare earth cis-1,4-butadiene rubber and the nickel cis-1,4-butadiene rubber, and at the same time better balance the relationship between the mechanical properties and processing properties of the composite cis-1,4-butadiene rubber, and further improve the mechanical properties and processing properties of the composite cis-1,4-butadiene rubber.

[0051] Optionally, the mass ratio of the rare earth cis-1,2-butadiene rubber to the coupling agent is 125: 1-1000: 1. Such a configuration is conducive to better improving the coupling effect of the rare earth cis-1,2-butadiene rubber and the nickel-based cis-1,2-butadiene rubber, further improving the dispersion effect of syndiotactic 1,2-polybutadiene in the composite cis-1,2-butadiene rubber, thereby improving the reinforcement effect, and at the same time, it is also conducive to improving the compatibility of the cis-1,2-butadiene rubber alloy with other fillers or rubbers during vulcanization, thereby better meeting the modulus and mechanical strength of the cis-1,2-butadiene rubber alloy when applied to tires.

[0052] Optionally, the coupling agent is selected from at least one of divinyldimethylsilane, triethoxysilane, 3-chloropropyltriethoxysilane, 4-chloropropylmethyldimethoxysilane, 3-chloropropylmethyldiethoxysilane, bis-[Y-(triethoxysilyl)propyl]tetrasulfide, n-propyltrichlorosilane, silicon tetrachloride, tin tetrachloride, and disulfide dichloride.

[0053] In one embodiment, the organic solvent is selected from at least one of n-hexane, cyclohexane, cyclopentane and n-heptane.

[0054] Optionally, the Mooney viscosity of the rare earth butadiene rubber is 30MU-50MU, the branching factor is 1.5-2.0, the number average molecular weight (Mn) is 8.0kg / mol-10.0kg / mol, the weight average molecular weight (Mw) is 16.0kg / mol-30.0kg / mol, the molecular weight distribution (PDI) is 2.0-3.0, and the mass fraction of cis-1,4-structure in the rare earth butadiene rubber is greater than or equal to 98%.

[0055] Optionally, the Mooney viscosity of the nickel-based butadiene rubber is 30MU-50MU, the branching factor is 15-20, the number average molecular weight (Mn) is 7.0kg / mol-9.5kg / mol, the weight average molecular weight (Mw) is 21.5kg / mol-34.2kg / mol, the molecular weight distribution (PDI) is 3.2-3.6, and the mass fraction of cis-1,4-structure in the nickel-based butadiene rubber is greater than 96%.

[0056] In the present invention, by controlling various performance parameters of rare earth butadiene rubber and nickel butadiene rubber, the performance of the composite butadiene rubber can be better controlled, and the mechanical properties and processing properties of the composite butadiene rubber can be further improved.

[0057] Optionally, the number average molecular weight (Mn) of the composite butadiene rubber is 7.8kg / mol-9.6kg / mol, the weight average molecular weight (Mw) is 22.0kg / mol-31.7kg / mol, the molecular weight distribution (PDI) is 2.8-3.3, and the mass fraction of the cis-1,4-structure in the composite butadiene rubber is greater than or equal to 96%, preferably 96%-98%. Such an arrangement can make the composite butadiene rubber have better processing performance and mechanical properties, while better reducing its glue viscosity, further improving its compatibility with syndiotactic 1,2-polybutadiene, which is conducive to further improving the reinforcement effect.

[0058] Optionally, the rare earth butadiene rubber is selected from neodymium butadiene rubber, wherein the neodymium butadiene rubber is selected from branched neodymium butadiene rubber. Such an arrangement can further improve the processing performance of the composite butadiene rubber while ensuring that the composite butadiene rubber has excellent mechanical properties, thereby making the prepared butadiene rubber alloy have better mechanical properties and processing properties.

[0059] In step S2, the composite butadiene rubber solution can be obtained by the following two methods:

[0060] The first method is to directly use the rubber solution obtained in the process of preparing the composite butadiene rubber in step S1 as the composite butadiene rubber solution;

[0061] The second method is to dissolve the composite butadiene rubber obtained in step S1 in an organic solvent to obtain a composite butadiene rubber solution, wherein the organic solvent is selected from at least one of n-hexane, cyclohexane, cyclopentane and n-heptane.

[0062] Considering that the impurity components present in the rubber solution obtained during the preparation of the composite butadiene rubber in step S1 may affect the subsequent in-situ polymerization reaction, the second method is preferred in the present invention.

[0063] In step S2, in the presence of an iron-based catalyst or a cobalt-based catalyst, the composite butadiene rubber solution and the butadiene monomer solution are mixed and subjected to an in-situ polymerization reaction.

[0064] Specifically, the composite butadiene rubber solution and the butadiene monomer solution are mixed evenly, and then an iron-based catalyst or a cobalt-based catalyst is added to mix and an in-situ polymerization reaction is initiated to obtain a polymerized solution.

[0065] Optionally, the molar ratio of the composite butadiene rubber in the composite butadiene rubber solution to the butadiene monomer in the butadiene monomer solution is 3: 2-19: 1. Such a configuration is conducive to better controlling the Mooney viscosity, branching degree, molecular weight distribution and other performance parameters of the butadiene rubber alloy, and better improving the mechanical properties and processing properties of the butadiene rubber alloy.

[0066] Optionally, the polymerization temperature is 30° C.-50° C., and the polymerization time is 30 min-60 min. Such an arrangement is conducive to a sufficient polymerization reaction between the components.

[0067] It is understood that the catalyst system for the polymerization reaction of the composite butadiene rubber and the butadiene monomer in the present invention can be an iron catalyst or a cobalt catalyst. The present invention is preferably a cobalt catalyst, under which the polymerization time can be effectively reduced, and the required polymerization temperature is low, which is conducive to energy saving and consumption reduction in production.

[0068] Specifically, when an iron-based catalyst is used, the molar ratio of the butadiene monomer in the butadiene monomer solution to the iron element in the iron-based catalyst is 5000: 1-40000: 1. This arrangement can better promote the efficiency of the in-situ polymerization reaction.

[0069] The iron-based catalyst comprises an iron compound, a phosphine-containing compound and an alkyl aluminum, wherein the molar ratio of the iron compound, the phosphine-containing compound and the alkyl aluminum is 1:3:10-1:20:50. Such a configuration can improve the catalytic efficiency.

[0070] Furthermore, the iron compound is selected from organic iron compounds, and the organic iron compound is selected from organic acid iron containing 1-20 carbon atoms, preferably at least one of iron benzoate, iron acetate, iron cyclopentaneate, iron octanoate, iron neodecanoate, iron palmitate, iron stearate, iron acetylacetonate, and iron salicylate.

[0071] The phosphine-containing compound is selected from phosphite compounds or phosphate compounds, preferably at least one of dimethyl phosphite, diethyl phosphite, dibutyl phosphite, diisooctyl phosphite, diphenyl phosphite, trimethyl phosphate, triethyl phosphate, tributyl phosphate, triphenyl phosphate, and triphenyl phosphine, and more preferably at least one of diethyl phosphite, diisooctyl phosphite, and triphenyl phosphate.

[0072] The alkylaluminum is selected from any one of trialkylaluminum or methylaluminoxane, preferably trimethylaluminum, triethylaluminum, triisobutylaluminum, trioctylaluminum, more preferably at least one of triethylaluminum and triisobutylaluminum.

[0073] When a cobalt-based catalyst is used, the molar ratio of the butadiene monomer in the butadiene monomer solution to the cobalt element in the cobalt-based catalyst is 5000: 1-40000: 1. This arrangement is conducive to increasing the polymerization reaction rate, reducing the polymerization time, and the polymerization temperature is relatively low, which is conducive to reducing energy consumption.

[0074] The cobalt-based catalyst comprises a soluble cobalt compound, an alkyl aluminum and carbon disulfide, wherein the molar ratio of the soluble cobalt compound, the alkyl aluminum and the carbon disulfide is 1:10:2-1:100:20. Such a configuration can improve the catalytic activity and better improve the catalytic efficiency.

[0075] Furthermore, the soluble cobalt compound is selected from organic acid cobalt, and the organic acid cobalt is selected from at least one of cobalt isooctanoate, cobalt cyclohexaneate, cobalt neodecanoate, and cobalt stearate, preferably cobalt isooctanoate.

[0076] The alkylaluminum is selected from at least one of triethylaluminum, trimethylaluminum, triisobutylaluminum, diethylaluminum chloride, and diisobutylaluminum chloride, preferably triethylaluminum.

[0077] In the present invention, before the polymerized glue is condensed, that is, after the in-situ polymerization reaction is completed, a terminator is added to the polymerized glue to terminate the reaction, wherein the terminator is an antioxidant / ethanol solution, and the antioxidant is selected from at least one of antioxidant 1076, antioxidant 1520, antioxidant B7802 and antioxidant 264.

[0078] Specifically, in step S3, an antioxidant solution is added to the polymerized rubber solution to terminate the reaction, and then ethanol or water is added to condense the polymerized rubber solution, and then the polymerized rubber solution is placed in a vacuum drying oven for drying to obtain a butadiene rubber alloy.

[0079] At the same time, the present invention also provides a butadiene rubber alloy prepared by the above-mentioned preparation method of butadiene rubber alloy, wherein the butadiene rubber alloy comprises composite butadiene rubber and syndiotactic 1,2-polybutadiene dispersed in the composite butadiene rubber.

[0080] The Mooney viscosity of the butadiene rubber alloy is 39MU-85MU, the branching factor is 3.5-8.5, the melting point is 196°C-203°C, the mass fraction of 1,2-polybutadiene in the butadiene rubber alloy is 3.5%-30%, and the mass fraction of 1,4-structure in the butadiene rubber alloy is 69%-95.5%.

[0081] Therefore, the butadiene rubber alloy not only has excellent wet skid resistance, tensile strength and tear strength, but also has good processing performance and cold flow resistance, so as to better meet the requirements of tires for high strength and high modulus.

[0082] In addition, the present invention also provides a use of the butadiene rubber alloy as described above in a tire.

[0083] Specifically, the cis-1,4-butadiene rubber alloy of the present invention is mixed with polyisoprene rubber as the sidewall rubber of the tire and used in the preparation of the tire sidewall. During the preparation process, not only the compatibility of the components in the rubber material can be improved, the dispersibility of carbon black can be improved, thereby improving the dynamic fatigue performance, crack propagation resistance and weather resistance of the tire sidewall, but also the internal friction and heat generation of the tire sidewall can be reduced, thereby improving the service life of the tire sidewall.

[0084] In one embodiment, the butadiene rubber alloy is used in the preparation of tire treads.

[0085] Below, the cis-1,1-butadiene rubber alloy and its preparation method and application will be further described by the following specific examples. However, it will be appreciated by those skilled in the art that the following examples are only used to illustrate the present invention and should not be considered as limiting the scope of the present invention. In the examples, if specific conditions are not specified, the conditions are carried out according to normal conditions or manufacturer recommendations. If the reagents or instruments used do not specify the manufacturer, they are all conventional products that can be obtained commercially.

[0086] It should be noted that the number average molecular weight (Mn), weight average molecular weight (Mw), and molecular weight distribution (PDI) of the neodymium butadiene rubber, nickel butadiene rubber, composite butadiene rubber, and butadiene rubber alloy involved in the embodiments and comparative examples of the present invention are all measured by gel permeation chromatography (GPC); the Mooney viscosity of the neodymium butadiene rubber, nickel butadiene rubber, composite butadiene rubber, and butadiene rubber alloy is measured by using the American ALPHA MV 2000 Mooney viscometer; and the branching factor of the neodymium butadiene rubber, nickel butadiene rubber, composite butadiene rubber, and butadiene rubber alloy is measured by using the RPA rubber processing analyzer. In addition, the melting point of the butadiene rubber alloy is measured by using TA-Q200.

[0087] Example 1

[0088] Under nitrogen atmosphere, neodymium-based butadiene rubber (Mooney viscosity of 40MU, branching factor of 1.8, Mn of 8.9kg / mol, Mw of 23.1kg / mol, PDI of 2.6, and the mass fraction of cis-1,4-structure of 98%) and nickel-based butadiene rubber (Mooney viscosity of 30, branching factor of 16, Mn of 7.0kg / mol, Mw of 23.1kg / mol, PDI of 3.3, and the mass fraction of cis-1,4-structure of 96%) were dissolved in The n-hexane solution is then added with a dichlorodisulfide coupling agent, mixed evenly, and then separated to obtain a composite butadiene rubber, wherein the mass ratio of the neodymium butadiene rubber to the nickel butadiene rubber is 9:1, the mass ratio of the neodymium butadiene rubber to the dichlorodisulfide coupling agent is 200:1, the Mooney viscosity of the composite butadiene rubber is 38MU, the branching factor is 5.5, the Mn is 8.6kg / mol, the Mw is 24.1kg / mol, the PDI is 2.8, and the mass fraction of the cis-1,4-structure is 97.8%.

[0089] The composite butadiene rubber obtained above is dissolved in a n-hexane solution to obtain a composite butadiene rubber glue solution; then, a butadiene hexane solution, cobalt isooctanoate, triethyl aluminum and carbon disulfide are added to the composite butadiene rubber glue solution and stirred evenly, and a polymerization reaction is carried out at 40° C. for 30 minutes to obtain a polymerized glue solution, wherein the molar ratio of the composite butadiene rubber in the composite butadiene rubber glue solution to butadiene in the butadiene hexane solution is 100:22, the molar ratio of butadiene in the butadiene hexane solution to the cobalt element in cobalt isooctanoate is 15000:1, and the molar ratio of the cobalt isooctanoate, triethyl aluminum and carbon disulfide is 1:70:10; then, an antioxidant B7802 / ethanol solution is added to the polymerized glue solution to terminate, and an ethanol solution is used for condensation, and finally the solution is placed in a vacuum drying oven for drying to obtain a butadiene rubber alloy. The Mooney viscosity of the butadiene rubber alloy is 48MU, the branching factor is 5.8, the melting point is 202°C, the mass fraction of 1,2-polybutadiene in the butadiene rubber alloy is 12%, and the mass fraction of 1,4-structure in the butadiene rubber alloy is 87%.

[0090] The structure of the polybutadiene rubber alloy of this embodiment was detected by Fourier transform infrared spectrometer. The detection results are as follows: Figure 1 As shown, from Figure 1 It can be seen that the structure of the butadiene rubber alloy described in this embodiment has characteristic peaks of polybutadiene segments, among which 738cm -1 The characteristic peak corresponding to the cis-1,4-structure is 911 cm -1 The characteristic peak corresponding to -1,2 structure is 967cm -1 Corresponding to the characteristic peak of trans 1,4-structure.

[0091] At the same time, from Figure 2It can be seen that the melting point of the butadiene rubber alloy described in this embodiment is 197°C.

[0092] Example 2

[0093] Under nitrogen atmosphere, neodymium-based butadiene rubber (Mooney viscosity of 35MU, branching factor of 1.8, Mn of 8.5kg / mol, Mw of 21.25kg / mol, PDI of 2.5, and the mass fraction of cis-1,4-structure of 98%) and nickel-based butadiene rubber (Mooney viscosity of 30MU, branching factor of 16, Mn of 7.0kg / mol, Mw of 22.54kg / mol, PDI of 3.22, and the mass fraction of cis-1,4-structure of 96%) were dissolved in The n-hexane solution is then added with a dichlorodisulfide coupling agent, mixed evenly, and then separated to obtain a composite butadiene rubber, wherein the mass ratio of the neodymium butadiene rubber to the nickel butadiene rubber is 19:1, the mass ratio of the neodymium butadiene rubber to the dichlorodisulfide coupling agent is 1000:1, the Mooney viscosity of the composite butadiene rubber is 34.2MU, the branching factor is 3.0, the Mn is 8.3kg / mol, the Mw is 23.8kg / mol, the PDI is 2.87, and the mass fraction of the cis-1,4-structure is 97.9%.

[0094] The composite butadiene rubber obtained above is dissolved in a n-hexane solution to obtain a composite butadiene rubber glue solution; then, a butadiene hexane solution, cobalt isooctanoate, triethylaluminum and carbon disulfide are added to the composite butadiene rubber glue solution and stirred evenly, and a polymerization reaction is carried out at 40° C. for 30 minutes to obtain a polymerized glue solution, wherein the molar ratio of the composite butadiene rubber in the composite butadiene rubber glue solution to butadiene in the butadiene hexane solution is 100:7, the molar ratio of butadiene in the butadiene hexane solution to the cobalt element in cobalt isooctanoate is 20000:1, and the molar ratio of the cobalt isooctanoate, triethylaluminum and carbon disulfide is 1:30:20; then, an antioxidant B7802 / ethanol solution is added to the polymerized glue solution to terminate, and an ethanol solution is used for condensation, and finally the solution is placed in a vacuum drying oven for drying to obtain a butadiene rubber alloy. The Mooney viscosity of the butadiene rubber alloy is 39MU, the branching factor is 3.1, the melting point is 197°C, the mass fraction of 1,2-polybutadiene in the butadiene rubber alloy is 3.5%, and the mass fraction of 1,4-structure in the butadiene rubber alloy is 95.5%.

[0095] Example 3

[0096] Under nitrogen atmosphere, neodymium-based butadiene rubber (Mooney viscosity of 50MU, branching factor of 1.7, Mn of 9.6kg / mol, Mw of 24kg / mol, PDI of 2.5, and the mass fraction of cis-1,4-structure of 98%) and nickel-based butadiene rubber (Mooney viscosity of 45MU, branching factor of 16, Mn of 9.0kg / mol, Mw of 30.6kg / mol, PDI of 3.4, and the mass fraction of cis-1,4-structure of 96%) were dissolved in The n-hexane solution is then added with a dichlorodisulfide coupling agent, mixed evenly, and then separated to obtain a composite butadiene rubber, wherein the mass ratio of the neodymium butadiene rubber to the nickel butadiene rubber is 4:1, the mass ratio of the neodymium butadiene rubber to the dichlorodisulfide coupling agent is 125:1, the Mooney viscosity of the composite butadiene rubber is 48MU, the branching factor is 7.1, the Mn is 9.4kg / mol, the Mw is 28.2kg / mol, the PDI is 3.0, and the mass fraction of the cis-1,4-structure is 97.6%.

[0097] The composite butadiene rubber obtained above is dissolved in a n-hexane solution to obtain a composite butadiene rubber glue solution; then, a butadiene hexane solution, cobalt isooctanoate, triethylaluminum and carbon disulfide are added to the composite butadiene rubber glue solution and stirred evenly, and a polymerization reaction is carried out at 50° C. for 30 minutes to obtain a polymerized glue solution, wherein the molar ratio of the composite butadiene rubber in the composite butadiene rubber glue solution to butadiene in the butadiene hexane solution is 100:39, the molar ratio of butadiene in the butadiene hexane solution to the cobalt element in cobalt isooctanoate is 10000:1, and the molar ratio of the cobalt isooctanoate, triethylaluminum and carbon disulfide is 1:70:10; then, an antioxidant B7802 / ethanol solution is added to the polymerized glue solution to terminate, and an ethanol solution is used for condensation, and finally the solution is placed in a vacuum drying oven for drying to obtain a butadiene rubber alloy. The Mooney viscosity of the butadiene rubber alloy is 63MU, the branching factor is 7.5, the melting point is 202°C, the mass fraction of 1,2-polybutadiene in the butadiene rubber alloy is 20%, and the mass fraction of 1,4-structure in the butadiene rubber alloy is 79%.

[0098] Example 4

[0099] Compared with Example 1, Example 4 differs only in that, in the step of preparing the composite butadiene rubber, the mass ratio of the neodymium-based butadiene rubber to the nickel-based butadiene rubber is 3:2, the Mooney viscosity of the composite butadiene rubber is 36MU, the branching factor is 20.8, the Mn is 7.6kg / mol, the Mw is 23.7kg / mol, the PDI is 3.1, the mass fraction of the cis-1,4-structure is 97.2%, and the other conditions are the same, and a butadiene rubber alloy is obtained, wherein the Mooney viscosity of the butadiene rubber alloy is 47MU, the branching factor is 12.5, the melting point is 197°C, the mass fraction of 1,2-polybutadiene in the butadiene rubber alloy is 12%, and the mass fraction of the cis-1,4-structure in the butadiene rubber alloy is 87%.

[0100] Example 5

[0101] Example 5 is different from Example 1 only in that, in the step of preparing the composite butadiene rubber, a branched neodymium butadiene rubber (Mooney viscosity is 40MU, branching factor is 5.0, Mn is 9.1kg / mol, Mw is 23.66kg / mol, PDI is 2.6, and the mass fraction of cis-1,4-structure is 98%) is used to replace the neodymium butadiene rubber, and a tin tetrachloride coupling agent is used to mention a dichlorodisulfide coupling agent. The mass ratio of the branched neodymium butadiene rubber to the nickel butadiene rubber is 9:1, and the mass ratio of the branched neodymium butadiene rubber to the tin tetrachloride coupling agent is 5:1. 00:1, the Mooney viscosity of the composite butadiene rubber is 36MU, the branching factor is 7.1, the Mn is 8.2kg / mol, the Mw is 23.3kg / mol, the PDI is 2.85, the mass fraction of the cis-1,4-structure is 97.8%, and the other conditions are the same to obtain a butadiene rubber alloy, wherein the Mooney viscosity of the butadiene rubber alloy is 44MU, the branching factor is 8.5, the melting point is 198°C, the mass fraction of 1,2-polybutadiene in the butadiene rubber alloy is 12%, and the mass fraction of the cis-1,4-structure in the butadiene rubber alloy is 87%.

[0102] Example 6

[0103] Compared with Example 1, Example 6 differs only in that the molar ratio of the composite butadiene rubber in the composite butadiene rubber solution and the butadiene in the butadiene hexane solution is 1:1, the Mooney viscosity of the composite butadiene rubber is 38MU, the branching factor is 5.5, the Mn is 8.6kg / mol, the Mw is 24.1kg / mol, the PDI is 2.8, the mass fraction of the cis-1,4-structure is 97.8%, and the other conditions are the same, and a butadiene rubber alloy is obtained, wherein the Mooney viscosity of the butadiene rubber alloy is 85MU, the branching factor is 8.5, the melting point is 197°C, the mass fraction of 1,2-polybutadiene in the butadiene rubber alloy is 30%, and the mass fraction of the cis-1,4-structure in the butadiene rubber alloy is 70.3%.

[0104] Example 7

[0105] Example 7 is compared with Example 1, except that butadiene hexane solution, ferric isooctanoate, diethyl phosphite and triethylaluminum are added to the composite butadiene rubber solution and stirred evenly, wherein the molar ratio of butadiene in the butadiene hexane solution and the iron element in ferric isooctanoate is 10000:1, the molar ratio of ferric isooctanoate, diethyl phosphite and triethylaluminum is 1:6:30, and the other conditions are the same, to obtain a butadiene rubber alloy, wherein the Mooney viscosity of the butadiene rubber alloy is 45MU, the branching factor is 5.3, the melting point is 163°C, the mass fraction of 1,2-polybutadiene in the butadiene rubber alloy is 10%, and the mass fraction of cis-1,4-structure in the butadiene rubber alloy is 87%.

[0106] Comparative Example 1

[0107] Comparative Example 1 is compared with Example 1, except that, in the step of preparing the composite butadiene rubber, no dichlorodisulfide coupling agent is added, the Mooney viscosity of the composite butadiene rubber is 39.6MU, the branching factor is 4, Mn is 8.8kg / mol, Mw is 25.6kg / mol, PDI is 2.91, and the mass fraction of cis-1,4-structure is 97.8%, and the other conditions are the same, and a butadiene rubber alloy is obtained, wherein the Mooney viscosity of the butadiene rubber alloy is 52MU, the branching factor is 4.7, the melting point is 197°C, the mass fraction of 1,2-polybutadiene in the butadiene rubber alloy is 12%, and the mass fraction of cis-1,4-structure in the butadiene rubber alloy is 87%.

[0108] Comparative Example 2

[0109] Compared with Example 1, Comparative Example 2 differs only in that, in the step of preparing the composite butadiene rubber, the mass ratio of the neodymium-based butadiene rubber to the nickel-based butadiene rubber is 1:1, the Mooney viscosity of the composite butadiene rubber is 36MU, the branching factor is 11, the Mn is 7.5kg / mol, the Mw is 23.7kg / mol, the PDI is 3.16, the mass fraction of the cis-1,4-structure is 97%, and the other conditions are the same, and a butadiene rubber alloy is obtained, wherein the Mooney viscosity of the butadiene rubber alloy is 45MU, the branching factor is 12, the melting point is 197°C, the mass fraction of 1,2-polybutadiene in the butadiene rubber alloy is 12%, and the mass fraction of the cis-1,4-structure in the butadiene rubber alloy is 87%.

[0110] Comparative Example 3

[0111] Compared with Example 1, Comparative Example 3 differs only in that, in the step of preparing the composite butadiene rubber, the mass ratio of the neodymium-based butadiene rubber to the nickel-based butadiene rubber is 2:3, the Mooney viscosity of the composite butadiene rubber is 34MU, the branching factor is 15, the Mn is 7.5kg / mol, the Mw is 24.2kg / mol, the PDI is 3.22, the mass fraction of the cis-1,4-structure is 96.8%, and the other conditions are the same, and a butadiene rubber alloy is obtained, wherein the Mooney viscosity of the butadiene rubber alloy is 44MU, the branching factor is 16, the melting point is 200°C, the mass fraction of 1,2-polybutadiene in the butadiene rubber alloy is 12%, and the mass fraction of the cis-1,4-structure in the butadiene rubber alloy is 87%.

[0112] Comparative Example 4

[0113] Comparative Example 4 is compared with Example 1, except that, in the step of preparing the composite butadiene rubber, the nickel-based butadiene rubber of equal mass in Example 1 is used to replace the neodymium-based butadiene rubber, that is, only the nickel-based butadiene rubber is contained, the Mooney viscosity of the composite butadiene rubber is 42MU, the branching factor is 20, the Mn is 8.9kg / mol, the Mw is 31.15kg / mol, the PDI is 3.5, the mass fraction of the cis-1,4-structure is 96.8%, and the other conditions are the same, and a butadiene rubber alloy is obtained, wherein the Mooney viscosity of the butadiene rubber alloy is 52MU, the branching factor is 21.2, the melting point is 196°C, the mass fraction of 1,2-polybutadiene in the butadiene rubber alloy is 12%, and the mass fraction of the cis-1,4-structure in the butadiene rubber alloy is 87%.

[0114] Comparative Example 5

[0115] Comparative Example 5 is compared with Example 1, except that, in the step of preparing the composite butadiene rubber, the neodymium butadiene rubber of equal mass in Example 1 is used to replace the nickel butadiene rubber, that is, only the neodymium butadiene rubber is contained, the Mooney viscosity of the composite butadiene rubber is 58MU, the branching factor is 6.2, the Mn is 9.9kg / mol, the Mw is 31.18kg / mol, the PDI is 3.15, the mass fraction of the cis-1,4-structure is 98%, and the other conditions are the same, and a butadiene rubber alloy is obtained, wherein the Mooney viscosity of the butadiene rubber alloy is 69MU, the branching factor is 9.6, the melting point is 197°C, the mass fraction of 1,2-polybutadiene in the butadiene rubber alloy is 12%, and the mass fraction of the cis-1,4-structure in the butadiene rubber alloy is 87%.

[0116] Comparative Example 6

[0117] Compared with Example 1, Comparative Example 6 differs only in that, in the step of preparing the composite butadiene rubber, an equal mass of natural rubber is used to replace the neodymium butadiene rubber, the Mooney viscosity of the composite butadiene rubber is 65MU, the branching factor is 6.5, Mn is 20.7kg / mol, Mw is 57.7kg / mol, PDI is 2.78, the mass fraction of cis-1,4-structure is 97%, and the other conditions are the same, and a butadiene rubber alloy is obtained, wherein the Mooney viscosity of the butadiene rubber alloy is 70MU, the branching factor is 7.9, the melting point is 197°C, the mass fraction of 1,2-polybutadiene in the butadiene rubber alloy is 12%, and the mass fraction of cis-1,4-structure in the butadiene rubber alloy is 87%.

[0118] The butadiene rubber alloys prepared in Examples 1-7 and Comparative Examples 1-6 were respectively prepared into mixed rubbers, and the specific preparation methods were as follows:

[0119] 100 parts by weight of butadiene rubber alloy are added to a rubber mixing device and kneaded for 2 minutes. Then, 2 parts by weight of stearic acid and 3 parts by weight of zinc oxide are added. After kneading for 2 minutes, 30 parts by weight of carbon black and 30 parts by weight of are added. After kneading for 16 minutes, 30 parts by weight of carbon black are added continuously and kneaded for 11 minutes. Finally, 0.9 parts by weight of vulcanization accelerator TBBS and 1.5 parts by weight of sulfur are added and kneaded for 5 minutes to obtain a mixed rubber. The mixed rubber is then pressed into a film. The film is then cut to obtain a 12 mm × 12 mm film. The obtained film is then vulcanized to obtain a 12 mm × 12 mm vulcanized sheet. Finally, the vulcanized sheet is made into a dumbbell-shaped sample, i.e., a mixed rubber, wherein the dumbbell-shaped sample has a width of 6 mm and a thickness of 2 mm.

[0120] At the same time, the dynamic mechanical analyzer (DMA) Q800 of TA Company of the United States was used to measure the Mooney viscosity of the above-obtained rubber mix, wherein the Mooney change value is used to characterize the processing performance of the rubber mix. The larger the Mooney change value, the worse the processing performance of the rubber mix. The Mooney change value is the difference between the Mooney viscosity of the rubber mix and the Mooney viscosity of the butadiene rubber alloy. The measurement results are shown in Table 1.

[0121] Table 1

[0122]

[0123]

[0124] In addition, the performance test of the obtained rubber compound was carried out, wherein the tensile strength, elongation at break and 300% elongation were used to characterize the mechanical properties of the rubber compound, 60°C tanδ was used to characterize the rolling resistance of the rubber compound, the smaller the 60°C tanδ value, the smaller the rolling resistance of the rubber compound, 0°C tanδ was used to characterize the anti-slip performance of the rubber compound, the larger the 0°C tanδ value, the better the anti-slip performance of the rubber compound, and 60°C loss modulus was used to characterize the heat resistance of the rubber compound, the smaller the 60°C loss modulus, the better the anti-slip performance of the rubber compound, the test results are shown in Table 2-3, wherein the specific test method is as follows:

[0125] Tensile strength: in accordance with GBT528-2009 standard;

[0126] Elongation at break: in accordance with GBT528-2009 standard;

[0127] 300% fixed elongation: in accordance with GBT528-2009 standard.

[0128] Table 2

[0129]

[0130] Table 3

[0131]

[0132] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described 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.

[0133] The above-mentioned embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A method for preparing a butadiene rubber alloy, characterized in that: The following steps are involved: Couple rare earth cis-1,1-butadiene rubber and nickel cis-1,1-butadiene rubber to obtain composite cis-1,1-butadiene rubber, wherein the mass of the rare earth cis-1,1-butadiene rubber is greater than the mass of the nickel cis-1,1-butadiene rubber, and the Mooney viscosity of the composite cis-1,1-butadiene rubber is 35MU-55MU, and the branching factor is 3.0-7.1; In-situ preparation of syndiotactic 1,2-polybutadiene in composite butadiene rubber solution to obtain polymeric solution; The polymerized rubber solution is coagulated and dried to obtain a butadiene rubber alloy.

2. The method for preparing butadiene rubber alloy according to claim 1, characterized in that: In the step of coupling rare earth cis-1,1-butadiene rubber and nickel cis-1,1-butadiene rubber to obtain composite cis-1,1-butadiene rubber, at least one of the following conditions is also satisfied: (1) The Mooney viscosity of the rare earth cis-1,1-butadiene rubber is 30MU-50MU, the branching factor is 1.5-2.0, the number average molecular weight is 8.0kg / mol-10.0kg / mol, the weight average molecular weight is 16.0kg / mol-30.0kg / mol, the molecular weight distribution is 2.0-3.0, and the mass fraction of the cis-1,4-structure in the rare earth cis-1,1-butadiene rubber is greater than or equal to 98%; (2) The Mooney viscosity of the nickel-based butadiene rubber is 30MU-50MU, the branching factor is 15-20, the number average molecular weight is 7.0kg / mol-9.5kg / mol, the weight average molecular weight is 21.5kg / mol-34.2kg / mol, the molecular weight distribution is 3.2-3.6, and the mass fraction of the cis-1,4-structure in the nickel-based butadiene rubber is greater than 96%; (3) The number average molecular weight of the composite butadiene rubber is 7.8 kg / mol-9.6 kg / mol, the weight average molecular weight is 22.0 kg / mol-31.7 kg / mol, the molecular weight distribution is 2.8-3.3, and the mass fraction of the cis-1,4-structure in the composite butadiene rubber is greater than or equal to 96%; (4) The rare earth butadiene rubber is selected from neodymium butadiene rubber; (5) The rare earth butadiene rubber, the nickel-based butadiene rubber, a coupling agent and an organic solvent are mixed and coupled to separate and obtain the composite butadiene rubber.

3. The method for preparing butadiene rubber alloy according to claim 2, characterized in that: In the step of mixing and coupling the rare earth butadiene rubber, the nickel-based butadiene rubber, the coupling agent and the organic solvent, at least one of the following conditions must be met: (1) The mass ratio of the rare earth butadiene rubber to the nickel-based butadiene rubber is 4:1-19:1; (2) The mass ratio of the rare earth butadiene rubber to the coupling agent is 125:1-1000:1; (3) The coupling agent is at least one selected from divinyldimethylsilane, triethoxysilane, 3-chloropropyltriethoxysilane, 4-chloropropylmethyldimethoxysilane, 3-chloropropylmethyldiethoxysilane, bis-[Y-(triethoxysilyl)propyl]tetrasulfide, n-propyltrichlorosilane, silicon tetrachloride, tin tetrachloride, and disulfide dichloride.

4. The method for preparing the butadiene rubber alloy according to any one of claims 1 to 3, characterized in that: In the step of in-situ preparing syndiotactic 1,2-polybutadiene in the composite butadiene rubber solution, the composite butadiene rubber solution and the butadiene monomer solution are mixed in the presence of an iron-based catalyst or a cobalt-based catalyst and subjected to an in-situ polymerization reaction.

5. The method for preparing butadiene rubber alloy according to claim 4, characterized in that: In the step of mixing the composite cis-1,2-butadiene rubber solution and the butadiene monomer solution and performing an in-situ polymerization reaction, at least one of the following conditions must be met: (1) the molar ratio of the composite butadiene rubber in the composite butadiene rubber solution to the butadiene monomer in the butadiene monomer solution is 3:2-19:1; (2) The polymerization temperature is 30°C-50°C, and the polymerization time is 30min-60min.

6. The method for preparing butadiene rubber alloy according to claim 5, characterized in that: When the composite butadiene rubber solution and the butadiene monomer solution are mixed and subjected to in-situ polymerization in the presence of an iron-based catalyst, at least one of the following conditions must be met: (1) The molar ratio of the butadiene monomer in the butadiene monomer solution to the iron element in the iron-based catalyst is 5000:1-40000:1; (2) The iron-based catalyst comprises an iron compound, a phosphine-containing compound and an alkyl aluminum, wherein a molar ratio of the iron compound, the phosphine-containing compound and the alkyl aluminum is 1:3:10-1:20:

50.

7. The method for preparing butadiene rubber alloy according to claim 5, characterized in that: When the composite butadiene rubber solution and the butadiene monomer solution are mixed and subjected to in-situ polymerization in the presence of a cobalt-based catalyst, at least one of the following conditions must be met: (1) The molar ratio of butadiene monomer in the butadiene monomer solution to cobalt element in the cobalt-based catalyst is 5000:1-40000:1; (2) The cobalt-based catalyst comprises a soluble cobalt compound, an alkyl aluminum and carbon disulfide, wherein a molar ratio of the soluble cobalt compound, the alkyl aluminum and the carbon disulfide is 1:10:2-1:100:

20.

8. A butadiene rubber alloy prepared by the method for preparing butadiene rubber alloy according to any one of claims 1 to 7, characterized in that: The butadiene rubber alloy comprises composite butadiene rubber and syndiotactic 1,2-polybutadiene dispersed in the composite butadiene rubber.

9. The butadiene rubber alloy according to claim 8, characterized in that: The Mooney viscosity of the butadiene rubber alloy is 39MU-85MU, the branching factor is 3.5-8.5, the melting point is 196°C-203°C, the mass fraction of 1,2-polybutadiene in the butadiene rubber alloy is 3.5%-30%, and the mass fraction of 1,4-structure in the butadiene rubber alloy is 69%-95.5%.

10. Use of the butadiene rubber alloy according to claim 8 or claim 9 in a tire.

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