RU2815816C1 - Method for producing branched polydiene - Google Patents

Abstract

FIELD: production of synthetic rubbers.

SUBSTANCE: invention relates to the production of synthetic rubbers used in the manufacture of tires and tire parts, rubber products, golf balls and other similar products. In particular, the present invention relates to a method for producing branched polydiene by polymerization of conjugated diene in a hydrocarbon solvent medium in the presence of a catalytic system comprising a lanthanide compound, an organoaluminium compound, conjugated diene and a halogen-containing component, by introducing a branching agent at the end of polymerization, selected from a group of chlorine-containing compounds consisting of methylene trichloride, dimethylene dichloride, ethylene trichloride, diethylol dichloride, n-butylol trichloride, di-n-butylol dichloride, phenylolol trichloride, diphenylol dichloride, 2,4,6-trichloro-2,4,6-tri(phenoxy)-1,3,5-triase-2,4,6-triphosphorine, hexachlorocyclotriphosphazene or mixtures thereof, or compounds containing at least two maleic fragments, wherein the hydrocarbon solvent is a mixture of an aliphatic solvent (A) selected from heptane, nephras or cycloaliphatic solvents - cyclohexane, cycloheptan - or mixtures thereof, and low-boiling hydrocarbons C5-C6 (B) taken in the mass ratio (A):(B)=(80-91):(9-20)%. In addition, the present invention relates to branched polydiene obtained by the method described above, as well as to a rubber compound for rubber products based on the specified polydiene.

EFFECT: technical result of the invention consists in increasing the productivity of the polydiene production process, reducing the dynamic viscosity of the polymerizate solution, improving recyclability, increasing the branching index of the polymer, characterized by a decrease in the tangent of the angle of mechanical losses tgδ (1200%), reducing cold flow and improving elastoplastic properties.

19 cl, 3 tbl, 24 ex

Description

Field of technology to which the invention relates

The invention relates to the production of synthetic rubbers used in the production of tires and tire parts, rubber products, golf balls, etc. In particular, the present invention relates to a method for producing branched polydiene by polymerization of a conjugated diene in a hydrocarbon solvent in the presence of a catalytic system , including a lanthanide compound, an organoaluminum compound, a conjugated diene and a halogen-containing component, and the introduction at the end of polymerization of a branching agent selected from the group of chlorine-containing compounds or compounds containing at least two maleic fragments, and the hydrocarbon solvent used at the stage Diene polymerization is a mixture of an aliphatic solvent (A) and low-boiling hydrocarbons C ₅ -C ₆ (B), taken in the percentage ratio (A): (B) = (50-93): (7-50). In addition, the invention relates to rubber compounds containing branched polydiene obtained in this way, which are used, in particular, in the manufacture of tires and rubber products.

State of the art

Typically, aromatic hydrocarbons or their mixtures with aliphatic hydrocarbons are used as solvents for the polymerization of butadiene. In industry, benzene, toluene or their mixtures with cyclohexane or hexane are predominantly used (Bashkatov T.V., Zhigalin Ya.L. Technology of synthetic rubbers: Textbook for technical schools. 2nd ed., revised. L.: Chemistry, 1987. 360 p., p.170, [1]).

It is also known that to ensure high rates of polymerization of butadiene under the influence of an iodine-containing titanium catalytic system, as well as to obtain polybutadiene with the required microstructure and molecular parameters, it is necessary to carry out the process in an aromatic solvent or its mixture with a small amount of aliphatic hydrocarbon (Murachev V.B., Aksenov V. .I., etc. The influence of the composition of a mixed solvent (toluene-hexane) on the viscosity of polybutadiene solutions and the activity of titanium catalytic // M.: TsNIITEneftekhim, handwritten Dep. - 12 pp. - 1987. - 87RZHKH 10S470, [2]). An increase in the proportion of the aliphatic component leads to a decrease in the yield of the polymer and a violation of many other properties of the final product.

At the same time, the use of a mixture of aromatic and aliphatic solvents helps to reduce the viscosity of the polymer in comparison with the viscosity of the polymer obtained under the same conditions only in an aromatic solvent.

There is a known method for carrying out solution polymerization of ethylene-alpha-olefin copolymer (CN103880999, UNIV ZHEJIANG, 06/15/2016, [3]). According to the known method, a mixed organic solvent is used for polymerization, which reduces the viscosity of the polymer system, thereby facilitating the separation and purification of the solvent, and therefore, the known method is characterized by reduced energy consumption.

In patent RU2523799 (CHINA PETROLEUM & CHEMICAL CORP. INC. (CN), BEIJING UNIVERSITY OF CHEMICAL TECHNOLOGY (CN), 07/27/2014, [4]) to reduce the viscosity of a polymer solution, a complex additive consisting of a higher carboxylic acid, alcohol ( C ₁ -C ₁₀ alcohols), ammonium/alkali or alkaline earth metal salts (carboxylates, sulfates, sulfonates or phosphates), and also in some cases water. This additive is introduced into the polymer solution after the polymerization reaction in an amount of 0.7-6.0 wt.% based on the total weight of the polymer. The interaction time of the additive with the polymer solution is 0.5-30 minutes at 100-110°C. The result of using this additive is a reduction in the viscosity of the polymer solution by 31-85%, depending on the composition of the additive and the type of rubber obtained.

The disadvantage of the known invention is the multicomponent nature of the additive, which leads to complications in the hardware design of the process.

In the method described in the patent US6177603B1 (BRIDGESTONE CORP (US), 01/23/2001, [5]) the viscosity of the polymer is reduced by introducing diethylzinc into the reaction mass at the polymerization stage in a molar ratio of Zn/Nd = 3.8-20. Polymerization is carried out in the presence a catalytic system including neodymium versatate (neodecanoate) or neodymium dibutylmagnesium tris(bis(2-ethylhexyl)phosphate). The authors of the invention [5] note that the use of diethylzinc as an additive makes it possible to prevent gelation and significantly reduce the viscosity of the polymer.

However, when using diethylzinc in the molar ratio Zn/Nd=3.8-20, the yield of polydiene does not exceed 72%.

From patents RU2510402 (LANXESS AG (DE), 03/27/2014, [6]) and RU2622648 (SAUDI ARABIAN OIL COMPANY (SAUDI ARAMCO), 06/19/2017, [7]) a method of polymerization in a mixed aliphatic hydrocarbon solvent containing components is known with a boiling point below 45°C at a pressure of 1013 hPa, as well as components with a boiling point in the range from 45°C to 80°C at a pressure of 1013 hPa, in particular isopentane and cyclopentane. According to the data presented, this reduces the viscosity of the polymerizate of the butyl rubber solution, and in addition, the use of these additives makes it possible to increase the solid content in the solution to 16-18 wt.%.

The main disadvantage of existing methods is the presence in the reaction mass of aromatic solvents, which, when polymerization is carried out on lanthanide catalytic systems, occupy vacant coordination sites in the complex, thereby suppressing polymerization. In addition, these patents do not indicate any changes/improvement in the properties of the polymer itself due to the use of viscosity-reducing additives.

The closest in technical essence and achieved result is the method for producing rubber described in US patent 5397851 (LANXESS INC. (CA), 03/14/1995, [8]), chosen as the prototype of the present invention. According to the data presented in [8], the polymerization of butadiene is carried out on a catalytic system including cobalt dioctoate, tributylaluminum and diethylaluminum chloride in a mixed hydrocarbon solvent, including hexane, butene-1 and/or benzene. The resulting samples are characterized by a high content of 1,4-cis units (no less than 97.4 wt.%).

However, in this prior art source there is no indication of the influence of the solvent composition on the viscosity of the polymer solution and the properties of the resulting rubbers.

The essence of the invention

The technical objective of the present invention is to increase productivity, reduce the viscosity of the polymer solution and reduce energy consumption in the production of polydiene rubbers.

The technical result of the invention is to increase the productivity of the polydiene production process, reduce the dynamic viscosity of the polymer solution and the consumption rates of the branching agent, improve processability, increase the branching index of rubber (characterized by a decrease in the mechanical loss tangent tgδ (1200%)), as well as a decrease in cold flow and improvement of plasticity. elastic properties.

The specified technical result is achieved by the method of polymerization of a conjugated diene in a hydrocarbon solvent in the presence of a catalytic system, including a lanthanide compound, an organoaluminum compound, a conjugated diene and a halogen-containing component, by introducing a branching agent at the end of polymerization, selected from the group of chlorine-containing compounds or compounds containing in its composition, at least two maleic fragments, and the hydrocarbon solvent is a mixture of an aliphatic solvent (A) and low-boiling hydrocarbons C ₅ -C ₆ (B), taken in the mass ratio (A): (B) = (50-90): ( 10-50).

DESCRIPTION OF THE INVENTION

The present invention relates to a method for producing a branched polydiene by polymerization of a conjugated diene in a hydrocarbon solvent, in the presence of a catalytic system including a lanthanide compound, an organoaluminum compound, a conjugated diene and a halogen-containing component, by introducing at the end of the polymerization a branching agent selected from the group of chlorine-containing compounds or compounds containing contains at least two maleic fragments, and the hydrocarbon solvent is a mixture of an aliphatic solvent (A) and low-boiling hydrocarbons C ₅ -C ₆ (B), taken in the mass ratio (A): (B) = (50- 90):(10-50).

To improve the technological properties of rubbers based on the resulting polymers, various branching agents (BAs) are used, due to which the formation of branched polymer molecules occurs. This factor influences such characteristics as the orderliness of the arrangement of chain fragments relative to each other, plasto-elastic properties, melt viscosity, etc., which makes it possible to obtain new materials with improved properties.

In the present invention, various chlorine-containing compounds are used as branching agents, such as tin tetrachloride, methyl tin trichloride, dimethyl tin dichloride, ethyl tin trichloride, diethyl tin dichloride, n-butyl tin trichloride, di-n-butyl tin trichloride, phenyl tin trichloride, diphenyl tin dichloride, silicon tetrachloride, 2,4,6-tri chloro- 2,4,6-tri(phenoxy)-1,3,5-triaza-2,4,6-triphosphorine, hexachlorocyclotriphosphazene, or mixtures thereof.

It is preferable to use tin tetrachloride, silicon tetrachloride or hexachlorocyclotriphosphazene. Most preferred is tin tetrachloride.

The branching agent is used in the form of a 1-20 wt.% solution in an aliphatic solvent. The branching agent solution is prepared in advance or immediately before use.

The molar ratio of the chlorine-containing PA used according to the invention to neodymium ranges from 0.1:1 to 4:1. This ratio ensures the production of polydiene with optimal plasto-elastic properties, a mechanical loss tangent tgδ (1200%) of no more than 6.5 and a high content of 1,4-cis units - no less than 97 wt.%.

The preferred molar ratio of chlorine-containing PA: neodymium is from 0.2:1 to 3:1.

The most preferred molar ratio of chlorine-containing PA: neodymium is from 1:1 to 2.5:1.

In another embodiment of the present invention, compounds containing at least two maleic fragments are used as a branching agent. One maleic fragment gives a lower degree of branching, and therefore, it is noted that the processability of rubber compounds will be worse in comparison with a polymer modified with the use of two or more maleic fragments. As a compound containing maleic moieties, maleated polydienes, in particular maleated polybutadiene and maleated polyisoprene rubbers, in one embodiment, maleated polybutadiene and maleated polyisoprene low molecular weight rubbers, are widely available and commercially available.

The molar ratio of the branching agent used according to the invention, containing at least two maleic fragments, to neodymium is from 0.1:1 to 5:1. This ratio makes it possible to obtain polydiene with optimal plasto-elastic properties, a mechanical loss tangent tgδ (1200%) of no more than 6.5 and a high content of 1,4-cis units - no less than 97 wt. %.

The preferred molar ratio of maleated PA: neodymium is from 0.5:1 to 2:1.

Most preferably, the maleated PA: neodymium molar ratio is from 0.8:1 to 1.0:1.

Increasing the molar dosage of the branching agent above the presented range leads to a sharp jump in Mooney viscosity, which negatively affects the plasto-elastic properties, and problems arise with the release of the polymer and its processing. Reducing the molar dosage of the branching agent below the specified ranges is not effective.

According to the claimed method, for the polymerization of the conjugated diene, the calculated part of the aliphatic solvent (A) is replaced with low-boiling hydrocarbons C ₅ -C ₆ (B) with boiling points at atmospheric pressure in the range of 25-65 ° C, preferably 35-60 ° C, the most preferably 40-50°C. As such hydrocarbons (B), aliphatic hydrocarbons are used, in particular such as pentane, isopentane, hexane, 2-methylpentane (isohexane), 3-methylpentane, 2,2-dimethylbutane (neohexane), 2,3-dimethylbutane, individually or in mixtures with each other, and/or alicyclic hydrocarbons selected from the group consisting of cyclopentane, methylcyclobutane, ethylcyclopropane.

Preferably, isopentane, cyclopentane, hexane, most preferably cyclopentane, hexane, or mixtures thereof, are used as low-boiling hydrocarbons (B).

The present inventors have discovered that the use of hydrocarbons with a boiling point below 25° C. is undesirable because higher pressure would have to be used to maintain the system in a liquid state. The use of hydrocarbons with a boiling point above 65°C will reduce the processability of rubber isolation at the degassing stage.

According to the present invention, the proportion of low boiling hydrocarbons (B) is from 7 wt.% to 50 wt.% based on the total mass of the solvent, preferably from 9 wt.% to 20 wt.%, most preferably from 10 wt.% to 15 wt. .%. The present inventors have found that when the content of low-boiling hydrocarbons is less than 7 wt.%, the decrease in the viscosity of the polymer solution will be too small and the presence of low-boiling C ₅ -C ₆ hydrocarbons will not affect the properties of the final rubber. The content of low-boiling hydrocarbons C ₅ -C ₆ above 50 wt.% in the total volume of the solvent will lead to a sharp increase in pressure in the reactor due to the low boiling point of these hydrocarbons, and in addition, will lead to the accelerated formation of high-molecular polymer deposits on the internal surfaces of the equipment.

The aliphatic solvent (A) for polymerization is an inert organic solvent, which is selected, for example, from heptane, nefras, as well as cycloaliphatic solvents, in particular cyclohexane, cycloheptane or mixtures thereof.

In the context of the present invention, nefras is a hexane-heptane fraction of paraffinic hydrocarbons of dearomatized catalytic reforming gasoline with a boiling point temperature range of 65-75°C.

Preferably, cyclohexane or mixtures of cyclohexane and nefras are used as the aliphatic solvent.

Most preferably, a mixture of cyclohexane and nefras is used as the aliphatic solvent in a mass ratio of 65:35 to 70:30, respectively.

The authors of the present invention found that due to the lower viscosity of low-boiling C ₅ -C ₆ hydrocarbons compared to the viscosity of other aliphatic solvents, the use of low-boiling hydrocarbons as an additive reduces the final viscosity of the polydiene solution by 16-51%, which in turn increases the content monomer in the reaction mixture and thus increases the productivity of the polymer production process. In addition, it was unexpectedly discovered that the presence of low-boiling C ₅ -C ₆ hydrocarbons in the polymerization solvent significantly increases the efficiency of using the branching agent (RA), and also reduces the mechanical loss tangent tgδ (1200%) by 3-25%, which indicates obtaining more branched polymers, characterized by good processability and plasto-elastic properties, using less branching agent.

Since the degree of branching of polydiene rubber increases with a decrease in the mechanical loss tangent tgδ (1200%) with an increase in the content of low-boiling hydrocarbons, to achieve optimal properties of the polymer and the best manufacturability of its production, the most preferred ratio of components in a mixed solvent is an aliphatic solvent (A) and lower low-boiling hydrocarbons (B) is 90:10 wt.%.

The method for producing diene copolymers in accordance with the present invention includes several stages, in particular: preparation of a catalytic complex, polymerization of the diene using the above complex, introduction of a branching agent upon achieving at least 96% conversion of the diene, modification, stoppering, degassing, isolation and polymer drying.

The invention uses a catalytic system comprising a lanthanide compound, an organoaluminum compound and a halogen-containing component. As lanthanide compounds, compounds are used that include at least one lanthanide atom selected from neodymium, lanthanum, cerium, praseodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutetium. Preferably neodymium compounds are used.

Lanthanide-containing compounds include, but are not limited to, carboxylates, organophosphates (particularly alkylphosphates and arylphosphates), organophosphonates (particularly alkylphosphonates and arylphosphonates), organophosphinates (particularly alkylphosphinates and arylphosphinates), carbamates, dithiocarbamates, lanthanides xanthates, β-diketonates, halides, oxyhalides, alcoholates.

Neodymium carboxylates include neodymium formate, neodymium acetate, neodymium acrylate, neodymium methacrylate, neodymium valerate, neodymium gluconate, neodymium citrate, neodymium fumarate, neodymium lactate, neodymium maleate, neodymium oxalate, neodymium 2-ethylhexanoate, neodymium neodecanoate, neodymium naphthenate, neodymium stearate ma, neodymium oleate, neodymium benzoate and neodymium picolinate.

Neodymium organophosphates include neodymium dibutyl phosphate, neodymium diphenyl phosphate, neodymium dihexyl phosphate, neodymium diheptyl phosphate, neodymium dioctyl phosphate, neodymium bis-(1-methylheptyl) phosphate, neodymium bis-(2-ethylhexyl) phosphate, neodymium didecyl phosphate, neodymium didodecyl phosphate, neodymium dioctadecyl phosphate, bis-( Neodymium n-nonylphenyl)phosphate, neodymium butyl (2-ethylhexyl)phosphate, neodymium (1-methylphenyl)(2-ethylhexyl)phosphate and neodymium (2-ethylhexyl)(n-nonylphenyl)phosphate.

Neodymium organophosphonates include neodymium butylphosphonate, neodymium pentylphosphonate, neodymium hexylphosphonate, neodymium heptylphosphonate, neodymium octylphosphonate, neodymium (1-methylheptyl)phosphonate, neodymium (2-ethylhexyl)phosphonate, neodymium decylphosphonate, neodymium dodecylphosphonate, neodymium octadecylphosphonate, neodymium oleylphosphonate, phenyl neodymium phosphonate, ( Neodymium n-nonylphenylphosphonate, neodymium butyl(butylphosphonate), neodymium pentyl(pentylphosphonate), neodymium hexyl(hexylphosphonate), neodymium heptyl(heptylphosphonate), neodymium octyl(octylphosphonate), (1-methylheptyl)((1-methylheptyl)phosphonate) neodymium, (2-ethylhexyl)((2-ethylhexyl)phosphonate) neodymium, decyl(decylphosphonate) neodymium, dodecyl(dodecylphosphonate) neodymium, octadecyl(octadecylphosphonate) neodymium, oleyl(oleylphosphonate) neodymium, phenyl(phenylphosphonate) neodymium, (n- neodymium nonylphenyl)((n-nonylphenyl)phosphonate, neodymium butyl((2-ethylhexyl)phosphonate), neodymium (2-ethylhexyl)(butylphosphonate), neodymium (1-methylheptyl)((2-ethylhexyl)phosphonate), (2 -ethylhexyl)((1-methylheptyl)phosphonate) of neodymium, (2-ethylhexyl)((n-nonylphenyl)phosphonate) of neodymium and (p-nonylphenyl)((2-ethylhexyl)phosphonate) of neodymium.

Neodymium organophosphinates include neodymium butylphosphinate, neodymium pentylphosphinate, neodymium hexylphosphinate, neodymium heptylphosphinate, neodymium octylphosphinate, neodymium (1-methylheptyl)phosphinate, neodymium (2-ethylhexyl)phosphinate, neodymium decylphosphinate, neodymium dodecylphosphinate, octadecyl neodymium phosphinate, neodymium oleylphosphinate, neodymium phenylphosphinate, ( Neodymium n-nonylphenyl)phosphinate, neodymium dibutylphosphinate, neodymium dipentylphosphinate, neodymium dihexylphosphinate, neodymium diheptylphosphinate, neodymium dioctylphosphinate, neodymium bis-(1-methylheptyl)phosphinate, neodymium bis-(2-ethylhexyl)phosphinate, tris-[bis-(2- neodymium ethylhexyl)phosphate, neodymium didecylphosphinate, neodymium didodecylphosphinate, neodymium dioctadecylphosphinate; neodymium dioleylphosphinate, neodymium diphenylphosphinate, neodymium bis-(n-nonylphenyl)phosphinate, neodymium butyl(2-ethylhexyl)phosphinate, neodymium (1-methylheptyl)(2-ethylhexyl)phosphinate and neodymium (2-ethylhexyl)(n-nonylphenyl)phosphinate .

The use of neoacid carboxylates is most preferable due to their faster and more complete alkylation, which leads to the production of more active catalytic compounds.

Most preferably, the use of neodymium neodecanoate, neodymium tris-[bis-(2-ethylhexyl)phosphate] or mixtures thereof.

In the present invention, the organoaluminum compound used is trialkylaluminum, triphenylaluminum or dialkylaluminum hydrides, alkylaluminum dihydrides, in particular, trimethylaluminum, triethylaluminum, tri-n-propylaluminum, triisopropylaluminum, tri-n-butylaluminum, triisobutylaluminum, tritertbutylaluminum, triphenylaluminum, trihexylaluminum, tricyclohexylaluminum ium, trioctylaluminum, diethylaluminum hydride, di-n-propylaluminum hydride, di-n-butylaluminum hydride, diisobutylaluminum hydride, dihexylaluminum hydride, diisohexylaluminum hydride, dioctylaluminum hydride, diisoactylaluminum hydride, phenylethylaluminum hydride, phenyl-n-propylaluminum hydride, phenylisopropylaluminum hydride, phenyl-n-butylaluminum hydride, phenylyse butylaluminum hydride, benzylethylaluminum hydride, benzyl-n-butylaluminum hydride, benzyl isobutylaluminum hydride, benzylisopropylaluminum hydride and the like.

Preferably, aluminum alkyls or aluminum alkyl hydrides or mixtures thereof are used. Most preferably, the use of triethylaluminum, triisobutylaluminum, diisobutylaluminum hydride or mixtures thereof.

The conjugated dienes used in the method according to the invention are 1,3-butadiene, isoprene, 2,3-dimethyl-1,3-butadiene, piperylene, 2-methyl-3-ethyl-1,3-butadiene, 3-methyl-1 ,3-pentadiene, 2-methyl-3-ethyl-1,3-pentadiene, 3-methyl-1,3-pentadiene, 1,3-hexadiene, 2-methyl-1,3-hexadiene, 1,3-heptadiene , 3-methyl-1,3-heptadiene, 1,3-octadiene, 3-butyl-1,3-octadiene, 3,4-dimethyl-1,3-hexadiene, 4,5-diethyl-1,3-octadiene , phenyl-1,3-butadiene, 2,3-diethyl-1,3-butadiene, 2,3-di-n-propyl-1,3-butadiene, 2-methyl-3-isopropyl-1,3-butadiene .

It is most preferable to use 1,3-butadiene and isoprene as conjugated dienes.

As the halogen-containing compound, organohalogen compounds of aluminum can be used, in particular, such as dimethylaluminum chloride, diethylaluminum chloride, diisobutylaluminum chloride, dimethylaluminum bromide, diethylaluminum bromide, diisobutylaluminum bromide, dimethylaluminum fluoride, diethylaluminum fluoride, diisobutylaluminum fluoride, dimethylaluminum iodide, diethyl aluminum iodide, diisobutylaluminum iodide, methylaluminum dichloride, ethylaluminum dichloride, methylaluminum dibromide, ethylaluminum dibromide, methylaluminum difluoride, ethylaluminum difluoride , methylaluminum sesquichloride, ethylaluminum sesquichloride, isobutylaluminum sesquichloride or mixtures thereof.

Preferably, ethyl aluminum sesquichloride is used as the halogen-containing compound.

In accordance with the present invention, a catalyst system comprising (i) a lanthanide compound, (ii) a conjugated diene, (iii) an organoaluminum compound, and (iv) a halogen-containing component, taken in the molar ratio (i):(ii): (iii):(iv) equal to 1:(5-30):(8-30):(1.5-4.5).

The preferred molar ratio of the components of the catalytic system is (i):(ii):(iii):(iv)=1:(5-20):(8-20):(1.8-4.0).

The most preferred molar ratio of the components of the catalytic system is (i):(ii):(iii):(iv)=1:(10-15):(10-15):(2.1-3.5).

According to one embodiment of the invention, the above catalytic system is used to produce a branched polydiene by polymerizing a conjugated diene in a mixed hydrocarbon solvent.

According to this invention, a mixed polymerization solvent is prepared by mixing specified amounts of an aliphatic solvent and low-boiling hydrocarbons at room temperature under a nitrogen atmosphere or air, followed by bubbling nitrogen through the resulting solvent for at least 30 minutes. It is possible to use a mixed solvent both at the polymerization stage and at the stage of preparing the catalytic complex.

A diene copolymer is produced in a batch or continuous manner in a hydrocarbon solvent by feeding into a polymerization vessel (reactor or autoclave) a prepared solvent, including a low-boiling hydrocarbon, a monomer, and a catalytic complex pre-mixed with the solvent, consisting of a lanthanide compound, a conjugated diene, an organoaluminum compound and a halogen-containing organic compound. The concentration of monomer in the solvent is typically 7-15 wt.%, the preferred concentration is 11-13 wt.%. A concentration below 7 wt.% leads to a decrease in the energy efficiency of the process, a concentration above 13 wt.% leads to an increase in the viscosity of the polymer, and, as a consequence, an increase in energy consumption during the isolation and drying of rubber.

The catalyst system is prepared by introducing into a solution of a conjugated diene (most preferably 1,3-butadiene) in an aliphatic solvent (most preferably a nefras/cyclohexane mixture or a cyclohexane/n-hexane mixture) an organoaluminum compound (most preferably triisobutylaluminum, triethylaluminum, diisobutylaluminum hydride or a mixture thereof ), a lanthanide compound (most preferably a carboxylate, in particular neodymium neodecanoate), maintaining the resulting mixture for 2 to 20 hours at a temperature of 23±2°C, followed by the addition of a halogen-containing compound (most preferably ethylaluminum sesquichloride, ethylaluminum dichloride, diethylaluminum chloride or mixtures thereof) , with the molar ratio of the components of the catalytic system: (i) lanthanide compound, (ii) conjugated diene (iii) organoaluminum compound and (iv) halogen-containing component (i):(ii):(iii):(iv) equal to 1:(5 -30):(8-30):(1.5-3.0).

The duration of polymerization ranges from 0.5 to 3 hours. Monomer conversion reaches 96-99%.

Once the above conversion is achieved, a branching agent is introduced into the polymer. Next, the resulting mixture is thoroughly mixed for 15 minutes to 6 hours at a temperature of 60-90°C. The mixing time, and consequently the modification, is preferably from 15 minutes to 5 hours, most preferably from 20 minutes to 2 hours. At temperatures below 60°C, the viscosity of the polymer will increase, which is undesirable because difficulties are inevitable in its isolation and processing. At the same time, the terminal groups of the polymer chain tend to lose their activity at temperatures above 90°C, as a result of which the degree of modification of the polymer will decrease.

At the end of the modification process, the polymer is stopped with softened water, or ethyl or isopropyl alcohol, and stabilized with an antioxidant solution taken in an amount of 0.2-0.6 wt.%. Next, the rubber is isolated using known methods, such as water-steam degassing and roller drying.

The branched polydiene obtained by the method described above has a Mooney viscosity from 39 to 52 arb. units Mooney after modification, the polydispersity coefficient of the obtained diene copolymers corresponds to the range from 2.4 to 2.8, the content of 1,4-cis units is more than 97 wt.%, the mechanical loss tangent tanδ (1200%) is in the range from 6. 41 to 2.87, plasticity from 0.41 to 0.56, cold flow from 17.4 to 35.8 mm/hour, elastic recovery from 0.99 to 2.17 mm.

The present invention also relates to rubber mixtures based on polydienes obtained by this method, and such mixtures are used for the manufacture of tires and rubber products. The composition of the components of the rubber mixture is determined by the purpose, operating conditions and technical requirements for the product, production technology and other aspects.

The technology for producing rubber includes mixing rubber with ingredients in special mixers or on rollers, cutting and cutting semi-finished rubber products (shapes and sizes depend on the planned further use of the resulting rubber, in particular, on the planned test method) and vulcanization of the resulting semi-finished products in special devices (presses , autoclaves, formers-vulcanizers, etc.).

Rubber mixtures based on the obtained polydienes are prepared according to standard recipes (for example, according to ASTM 3189).

Examples of implementation of the invention

Next, embodiments of the present invention will be described. It is necessary to clarify that the invention is not limited only to the examples presented and the same effect can be achieved in other embodiments that do not go beyond the scope of the claimed invention.

The test methods used to evaluate the properties of polymers obtained by the claimed method are described.

1. The percentage of conversion is determined by the method of precipitating the polymer from the polymerizate with ethyl alcohol and drying the isolated polymer.

2. The microstructure of polymer chains was determined by IR spectroscopy according to ISO 12965 using a multiple attenuated total internal reflection (MATR) attachment with a diamond crystal or using a single attenuated total internal reflection (ATR) attachment with a ZnSe crystal, recording the IR spectrum of the sample in the range from 4000 to 400 cm ^-1 with a resolution of 2 cm ^-1 , number of scans 32.

3. The molecular mass characteristics of rubbers were determined by gel permeation chromatography using an internal method using a Breeze gel chromatography system from Waters with a refractometric detector. Rubber samples were dissolved in freshly distilled tetrahydrofuran, the mass concentration of the polymer in the solution was 2 mg/ml, the calculation was carried out using universal calibration using polystyrene standards and Mark-Kuhn-Houwink constants for polybutadiene (K = 0.000457, α = 0.693). Definition conditions:

- a bank of 4 high-resolution columns (length 300 mm, diameter 7.8 mm), filled with styrogel, HR3, HR4, HR5, HR6, allowing the analysis of polymers with a molecular weight from 500 to 1 * 10 ⁷ a.u. m.;

- tetrahydrofuran solvent, flow rate - 1 cm ³ /min;

- temperature of the column thermostat and refractometer is 30°C.

4. Determination of the mechanical loss tangent (tgδ (1200%)) was carried out on an RPA-2000 device from Alpha Technologies with a variable shear amplitude: amplitude range from 0 to 1200%, frequency 0.1 Hz, temperature 100°C.

5. The viscosity of the polymer solution was determined using a Brookfield DV2T viscometer according to GOST 25271-93.

6. Determination of plasto-elastic properties of rubbers (plasticity, cold flow) was carried out according to GOST 19920.17 and GOST 19920.18 on a compression plastometer with a thermostat, model GT7060SA.

7. Mooney viscosity index was determined according to ASTM D 1646.

8. The elastic component of the complex dynamic shear modulus G' (kPa), which makes it possible to evaluate the distribution of the filler in rubber compounds and the silanization of the filler, was determined on an RPA-2000 rubber processability analyzer from Alpha Technologies at 0.1 Hz and 100°C in the deformation range from 1 to 450%. The difference in storage moduli at a deformation amplitude of 1% and 50% - ΔG'=(G'1% - G'43%) - Payne effect.

9. Abrasion resistance when sliding on a renewable surface was assessed according to GOST 23509 (method B) using an ABRASION CHECK “Gibitre Instruments” abrasion meter.

Example 1 (based on prototype)

Prepare a mixture of diethylaluminum chloride and tributylaluminum by mixing 1 molar solution of diethylaluminum chloride in hexane (80 ml, 0.08 mol) with a 25 wt.% solution of tributylaluminum in heptane (15.87 g, 0.02 mol) under a nitrogen atmosphere.

To carry out polymerization, 150.0 g of cyclohexane, 84.0 g of 1-butene, 0.24 ml (1.22 mmol) of water, 4.0 ml of 1.5-octadiene are loaded into a glass reactor, which is a 1-liter bottle. and 72.0 g (1.33 mol) of 1,3-butadiene (butadiene content was 23 wt.% of the total mass of the solution), and then the mixture was stirred by shaking in a water bath at 20° C. for 10 minutes. Then a mixture of diethylaluminum chloride and tributylaluminum (3.5 mmol) is added to the solution, followed by stirring the resulting solution in a water bath at 20°C for 10 minutes. Then 0.22 ml (0.0067 mol) of a 0.87 wt.% solution of cobalt dioctoate in hexane is added. Polymerization is carried out for 30 minutes at 20°C, after which a mixture of water and methanol is added to deactivate the catalyst and precipitate polybutadiene. Next, the polymer is dried in a vacuum oven at 60°C for 24 hours.

The properties of the resulting polymer are presented in Table 1.

Example 2 (comparative)

At the first stage, a catalytic system of neodymium neodecanoate - butadiene (BD) - diisobutylaluminum hydride (DIBAH) - ethylaluminum sesquichloride (EASQ) with a molar ratio of components of 1:10:13:2.5 (by substance) is obtained. The maturation time of the complex is 22 hours at a temperature of 23°C.

In a Schlenk vessel with a volume of 150 ml, 0.87 g (0.522 mmol) of neodymium neodecanoate salt with a concentration of 8.7% is placed in the form of a solution in hexane, 40 ml of an aliphatic solvent and stirred on a magnetic stirrer for 10 minutes at a temperature of 23°C. Then 0.28 g of butadiene (BD) is introduced into the vessel in the form of a solution with a concentration of 17.8 wt.%, which corresponds to 5.2 mmol of butadiene. Molar ratio of butadiene/Nd=10.

After 15 minutes of stirring the contents at 23°C, 6.3 ml of DIBAG solution with a concentration of 1.07 mol/l is added and stirred for 30 minutes. Molar ratio DIBAG/Nd=13. Next, 2.0 ml of EASC solution with a concentration of 0.66 mol/l was introduced, molar ratio Cl/Nd=2.5. Then the solvent is introduced into the system to a solution volume of 100 ml, stirred for 10 minutes and left to form at 20-23°C for 22 hours.

Polymerization is carried out in a 5-liter reactor equipped with a mixing device and a jacket for heat removal. Solvent (A) is used as a medium, which is a mixture of cyclohexane/nefras in a mass ratio of 73: 27. The monomer content in the reaction mass is 11.5 wt.%. The polymerization reaction temperature is 90°C. The duration of the process is 2 hours.

Then a branching agent, tin tetrachloride, is fed into the reactor in the form of a solution with a concentration of 0.91 mol/l at the rate of 2.5 mol to 1 mol Nd. The modification process is carried out with constant stirring for 30 minutes at a temperature of 75°C, after which an antioxidant is introduced (mass fraction 0.2-0.4%). The resulting polymer is degassed and dried on rollers, physical and mechanical properties and molecular weight characteristics are determined (see table No. 1).

The properties of the resulting polymer are presented in Table 1. The sample was also tested according to the ASTM 3189 rubber compound formulation (Table 2), the test results are presented in Table 3.

Example 3 (according to the invention)

At the first stage, a catalytic system of neodymium neodecanoate - butadiene (BD) - diisobutylaluminum hydride (DIBAH) - ethylaluminum sesquichloride (EASQ) with a molar ratio of components of 1:10:13:2.5 (by substance) is obtained. The maturation time of the complex is 22 hours at a temperature of 23°C.

In a Schlenk vessel with a volume of 150 ml, 0.87 g (0.522 mmol) of neodymium neodecanoate salt with a concentration of 8.7% is placed in the form of a solution in hexane, 40 ml of solvent (A) and stirred on a magnetic stirrer for 10 minutes at a temperature of 23°C. Then 0.28 g of butadiene (BD) is introduced into the vessel in the form of a solution with a concentration of 17.8 wt.%, which corresponds to 5.2 mmol of butadiene. Molar ratio of butadiene/Nd=10.

After 15 minutes of stirring the contents at 23°C, 6.3 ml of DIBAG solution with a concentration of 1.07 mol/l is added and stirred for 30 minutes. Molar ratio DIBAG/Nd=13. Next, 2.0 ml of EASC solution with a concentration of 0.66 mol/l is introduced, molar ratio Cl/Nd=2.5. Then the solvent is introduced into the system to a solution volume of 100 ml, stirred for 10 minutes and left to form at 20-23°C for 22 hours.

Polymerization is carried out in a 5-liter reactor equipped with a mixing device and a jacket for heat removal. The medium used is a mixed solvent obtained by mixing 1702 g of solvent (A), which is a mixture of cyclohexane/nefras in a mass ratio of 73: 27, with 434 g of solvent (B), which is isopentane, thus the content of solvent (B) in the solvent polymerization is 10 wt.%. The monomer content in the reaction mass is 11 wt.%. Polymerization reaction temperature 90°C. The duration of the process is 1 hour.

Then a branching agent, tin tetrachloride, is fed into the reactor in the form of a solution in hexane with a concentration of 0.93 mol/l with a dosage of 2.5 mol relative to Nd. The modification process is carried out with constant stirring for 30 minutes at a temperature of 75°C, after which an antioxidant is introduced (mass fraction 0.2-0.4%). The resulting polymer is degassed and dried on rollers, and the physical and mechanical properties and molecular weight characteristics are determined.

The properties of the resulting polymer are presented in Table 1.

Example 4

Similar to example 3 with the difference that the content of solvent (B) in the polymerization solvent is 20 wt.%.

The properties of the resulting polymer are presented in Table 1. The sample was also tested according to the ASTM 3189 rubber compound formulation (Table 2), the test results are presented in Table 3.

Example 5

Similar to example 3 with the difference that isoprene is used as a monomer, its content in the reaction mass is 13.0 wt.% and the molar ratio of SnCl ₄ to Nd is 0.2.

The properties of the resulting polymer are presented in Table 1.

Example 6

Similar to example 5 with the difference that the content of solvent (B) in the polymerization solvent is 20 wt.%.

The properties of the resulting polymer are presented in Table 1. The sample was also tested according to the ASTM 3189 rubber compound formulation (Table 2), the test results are presented in Table 3.

Example 7

Similar to example 3 with the difference that cyclopentane is used as solvent (B).

The properties of the resulting polymer are presented in Table 1.

Example 8

Similar to example 7 with the difference that the solvent content (B) in the polymerization solvent is 20 wt.%, and the molar ratio of SnCl ₄ to Nd is 0.1.

The properties of the resulting polymer are presented in Table 1.

Example 9

Similar to example 7 with the difference that the content of solvent (B) in the polymerization solvent is 15 wt.%.

The properties of the resulting polymer are presented in Table 1.

Example 10

Similar to example 7 with the difference that isoprene is used as a monomer and SiCl ₄ is used as a branching agent in the form of a solution in hexane with a concentration of 0.83 mol/l with a dosage of 2.5 mol to Nd.

The properties of the resulting polymer are presented in Table 1. The sample was also tested according to the ASTM 3189 rubber compound formulation (Table 2), the test results are presented in Table 3.

Example 11

Similar to example 10 with the difference that 2,2,4,4,6,6-hexachloro-1,3,5-triaza-2,4,6-triphosphorine is used as a branching agent in the form of a solution in toluene with a concentration of 0 .5 mol/l with a dosage of 1.5 mol to Nd.

The properties of the resulting polymer are presented in Table 1. The sample was also tested according to the ASTM 3189 rubber compound formulation (Table 2), the test results are presented in Table 3.

Example 12

Similar to example 7 with the difference that maleinated polybutadiene (MPB) with a maleic anhydride content of 8% and a molecular weight of 2700 g/mol is used as a branching agent. The molar ratio of maleic groups to neodymium is 0.8.

The properties of the resulting polymer are presented in Table 1.

Example 13

Similar to example 10 with the difference that neodymium tris-[bis-(2-ethylhexyl)phosphate] is used as a compound containing a lanthanide, isopentane is chosen as solvent B, the content of low-boiling hydrocarbon in solvent (B) is 20%, in SnCl ₄ is used as a branching agent in the form of a solution in hexane with a concentration of 0.9 mol/l with a molar dosage of Nd 2.0.

The properties of the resulting polymer are presented in Table 1. The sample was also tested according to the ASTM 3189 rubber compound formulation (Table 2), the test results are presented in Table 3.

Example 14

Similar to example 7 with the difference that neodymium tris-[bis-(2-ethylhexyl)phosphate] is used as a lanthanide-containing compound.

The properties of the resulting polymer are presented in Table 1.

Example 15

Similar to example 3 with the difference that cyclohexane is used as a solvent (A), and n-hexane is used as a solvent (B), the content of n-hexane in the total volume of the polymerization solvent is 20 wt.%.

The properties of the resulting polymer are presented in Table 1. The sample was also tested according to the ASTM 3189 rubber compound formulation (Table 2), the test results are presented in Table 3.

Example 16

Similar to example 15 with the difference that the content of solvent (B) in the polymerization solvent is 30 wt.%.

The properties of the resulting polymer are presented in Table 1.

Example 17

Similar to example 15 with the difference that the solvent content (B) in the polymerization solvent is 50 wt.% and the monomer content is 11.6 wt.%.

The properties of the resulting polymer are presented in Table 1.

Example 18

Similar to example 15 with the difference that the solvent content (B) in the polymerization solvent is 50 wt.% and the monomer content is 13 wt.%.

The properties of the resulting polymer are presented in Table 1.

Example 19

Similar to example 14 with the difference that cyclohexane is used as a solvent (A), n-hexane is used as a solvent (B), the percentage ratio (A): (B) is 80:20. 2,4,6-trichloro-2,4,6-triphenoxycyclotriphosphazene is used as a branching agent in the form of a solution in nefras with a concentration of 0.5 mol/l, the dosage to Nd was 1.0 mol.

The properties of the resulting polymer are presented in Table 1.

Example 20

Similar to example 3 with the difference that gadolinium versatate (GdV ₃ ) is used as the lanthanide compound, isoprene is used as the monomer, 2,4,6-trichloro-2,4,6-triphenoxycyclotriphosphazene in the form of a solution is used as a branching agent in nefras with a concentration of 0.5 mol/l. The molar ratio of branching agent to Gd is 1.5.

The properties of the resulting polymer are presented in Table 1.

Example 21

Similar to example 19, characterized in that tin tetrachloride is used as a branching agent, in the form of a solution with a concentration of 0.91 mol/l with a dosage of 3.0 mol relative to Nd. The monomer content was 13 wt.%.

The properties of the resulting polymer are presented in Table 1.

Example 22

Similar to example 15 with the difference that GdV ₃ is used as the lanthanide compound used, the molar ratio of tin tetrachloride to neodymium is 4.0.

The properties of the resulting polymer are presented in Table 1.

Example 23

Similar to example 12 with the difference that maleated polyisoprene (MPI) with a maleic anhydride content of 10% and a molecular weight of 30,000 g/mol is used as a branching agent. The molar ratio of maleic groups to neodymium is 0.1.

The properties of the resulting polymer are presented in Table 1.

Example 24

Similar to example 12 with the difference that the molar ratio of maleic groups to neodymium is 5.

The properties of the resulting polymer are presented in Table 1.

The rubber samples obtained in Examples 4, 6, 13, 10, 11, 15 were tested in the ASTM 3189 rubber compound formulation (see Table 2). Test results are presented in Table 3.

Table 1
Preparation mode and properties of copolymers Size unit Example number 1 (prototype) 2 (comparative) 3 4 5 6 Lanthanide compound NdV ₃ NdV ₃ NdV ₃ NdV ₃ NdV ₃ Monomer butadiene butadiene butadiene butadiene isoprene isoprene Monomer concentration in the charge, wt.% 23.0 11.0 11.0 11.0 13.0 13.0 Solvent A Cyclohexane Cyclohexane: Nefras Cyclohexane: Nefras Cyclohexane: Nefras Cyclohexane: Nefras Cyclohexane: Nefras Solvent B Butene-1 - Isopentane Isopentane Isopentane Isopentane Mass ratio of solvents A:B 64.1 : 35.9 100.0 : 0.0 90.0 : 10.0 80.0 : 20.0 90.0 : 10.0 80.0 : 20.0 RA, type, dosage in mole - SnCl ₄
2.5/Nd SnCl ₄
2.5/Nd SnCl ₄
2.5/Nd SnCl ₄
0.2/Nd SnCl ₄
2.5/Nd Viscosity of the polymer solution, mPa*s at 25°C - 4236 3528 2125 6225 3948 Polymer properties Mooney viscosity ML1+4 (100°С), conventional units. Mooney 32.4 47.3 43.7 43.0 42.0 47.3 Area under the relaxation curve A, conventional units. Muni * sec. - 230 347 217 203 546 Plastic - 0.56 0.49 0.51 0.47 0.48 Elastic recovery, mm - 0.99 1.76 1.70 1.71 1.80 Cold flow, mm/h - 35.8 30.4 31.6 33.7 20.5 _Mw / _Mn 3.7 2.65 2.51 2.8 2.53 2.7 1,4-cis units, % 97.4 98.4 97.6 98.1 97.7 98.2 Mechanical loss tangent (tgδ 1200%) - 6.12 4.00 4.58 5.8 2.99

Table 1. Continued Size unit Example number 7 8 9 10 eleven 12 Lanthanide compound NdV ₃ NdV ₃ NdV ₃ NdV ₃ NdV ₃ NdV ₃ Monomer butadiene butadiene butadiene isoprene isoprene butadiene Monomer concentration in the charge, wt.% 11.0 11.0 11.0 11.0 11.0 11.0 Solvent A Cyclohexane: Nefras Cyclohexane: Nefras Cyclohexane: Nefras Cyclohexane: Nefras Cyclohexane: Nefras Cyclohexane: Nefras Solvent B Cyclopentane Cyclopentane Cyclopentane Cyclopentane Cyclopentane Cyclopentane Mass ratio of solvents A:B 90.0 : 10.0 80.0 : 20.0 85.0 : 15.0 90.0 : 10.0 90.0 : 10.0 90.0 : 10.0 RA, type, dosage in mole SnCl ₄
2.5/Nd SnCl ₄
0.1/Nd SnCl ₄
2.5/Nd _SiCl4
2.5/Nd GHF
1.5/Nd MPB
0.8/Nd Viscosity of the polymer solution, mPa*s, at 25°C 2509.0 2161.0 2363.0 2674.0 2453.0 2726.0 Polymer properties Mooney viscosity ML1+4 (100°С), conventional units. Mooney 49.8 44.0 50.4 50.5 51.8 50.3 Area under the relaxation curve A, conventional units. Muni * sec. 310 165 573 216 295 159 Plastic 0.48 0.54 0.43 0.53 0.45 0.58 Elastic recovery, mm 1.43 1.92 1.99 1.29 1.89 1.16 Cold flow, mm/h 32.8 33.5 25.7 34.2 29.5 35.6 _Mw / _Mn 2.42 2.73 2.45 2.48 2.38 2.35 1,4-cis units, % 98.1 98.6 97.0 97.7 97.9 97.1 Mechanical loss tangent (tgδ 1200%) 4.83 6.1 2.87 5.67 4.36 6.41

Table 1. Continued Size unit Example number 13 14 15 16 17 18 Lanthanide compound NDP ₃ NDP ₃ NdV ₃ NdV ₃ NdV ₃ NdV ₃ Monomer isoprene butadiene butadiene butadiene butadiene butadiene Monomer concentration in the charge, wt.% 11.0 11.0 11.0 11.0 11.0 13.0 Solvent A Cyclohexane: Nefras Cyclohexane: Nefras Cyclohexane Cyclohexane Cyclohexane Cyclohexane Solvent B Isopentane Cyclopentane N-hexane N-hexane N-hexane N-hexane Mass ratio of solvents A:B 80.0 : 20.0 90.0 : 10.0 80.0 : 20.0 70.0 : 30.0 50.0 : 50.0 50.0 : 50.0 RA, type, dosage in mole SnCl ₄
2.0/Nd SnCl ₄
2.5/Nd SnCl ₄
2.5/Nd SnCl ₄
2.5/Nd SnCl ₄
2.5/Nd SnCl ₄
2.5/Nd Viscosity of the polymer solution, mPa*s, at 25°C 2023.0 2476.0 3400.0 2568.0 2250 4056 Polymer properties Mooney viscosity ML1+4 (100°С), conventional units. Mooney 43.2 45.4 45.8 51.4 48.3 41.6 Area under the relaxation curve A, conventional units. Muni * sec. 271 315 267 417 360 328 Plastic 0.43 0.47 0.49 0.43 0.46 0.53 Elastic recovery, mm 1.63 1.95 1.57 2.17 1.97 1.29 Cold flow, mm/h 35.7 25.4 28.75 17.4 26.25 45.5 _Mw / _Mn 2.40 2.47 2.39 2.51 2.51 2.3 1,4-cis units, % 96.6 96.5 97.7 97.65 97.8 97.1 Mechanical loss tangent (tgδ 1200%) 5.97 4.75 4.91 3.55 3.8 3.28

Table 1. Continued Size unit Example number 19 20 21 22 23 24 Lanthanide compound NDP ₃ GdV3 NDP ₃ GdV3 NdV ₃ NdV ₃ Monomer butadiene isoprene butadiene butadiene butadiene butadiene Monomer concentration in the charge, wt.% 11.0 11.0 13.0 11.0 11.0 11.0 Solvent A Cyclohexane Cyclohexane: Nefras Cyclohexane Cyclohexane Cyclohexane: Nefras Cyclohexane: Nefras Solvent B N-hexane Isopentane N-hexane N-hexane Cyclopentane Cyclopentane Mass ratio of solvents A:B 80.0 : 20.0 90.0 : 10.0 80.0 : 20.0 80.0 : 20.0 90.0 : 10.0 90.0 : 10.0 RA, type, dosage in mole THF 1.0/Nd THF 1.5/Nd SnCl ₄
3.0/Nd SnCl ₄
4.0/Nd MPI
0.1/Nd MPB
5/Nd Viscosity of the polymer solution, mPa*s, at 25°C 3580 2476 6114 3123 3641 2918 Polymer properties Mooney viscosity ML1+4 (100°С), conventional units. Mooney 39.7 42.6 44.7 42.1 43.8 47.6 Area under the relaxation curve A, conventional units. Muni * sec. 218 278 371 449 119 250 Plastic 0.41 0.46 0.48 0.47 0.59 0.48 Elastic recovery, mm 1.69 1.81 1.91 1.89 1.21 1.10 Cold flow, mm/h 34.9 28.3 27.3 22.3 34.8 31.2 _Mw / _Mn 2.64 2.75 2.68 2.71 2.59 2.64 1,4-cis units, % 97.5 96.9 96.1 96.0 96.3 96.6 Mechanical loss tangent (tgδ 1200%) 4.98 4.31 4.27 3.87 6.91 3.74

List of abbreviations given in Table 1:

RA - branching agent;

BD - butadiene;

NdP3 - neodymium tris-[bis-(2-ethylhexyl)phosphate]

NdV3 - neodymium neodecanoate

GdV3 - gadolinium versatate

HCP - 2,2,4,4,6,6-hexachloro-1,3,5-triaza-2,4,6-triphosphorine;

TCP - 2,4,6-trichloro-2,4,6-triphenoxycyclotriphosphazene;

MPB - maleinated polybutadiene

MPI - maleinated polyisoprene

table 2
Formulation of rubber compounds (ASTM 3189) Name of ingredients Mass parts Butadiene rubber 100.0 Carbon black N330 (IRB 8) 60.0 Zinc whitewash 3.0 Technical stearic acid 2.0 Naphthenic oil 15.0 Gas sulfur 1.5 Sulfenamide T 0.9 Total: 182.40

Table 3
Characteristics of rubber compounds Indicator name Example number 2 4 6 10 eleven 13 15 Solvent Nefras Nefras: Isopentane
90/10 Nefras: Isopentane
80/20 Nefras: Cyclopentane
90/10 Nefras: Cyclopentane
90/10 Cyclohexane: hexane 80/20 Cyclohexane: hexane 50/50 Mooney viscosity ML ₍₁₊₄₎ , units. Mooney 76.1 62.6 58.8 72.8 73.9 68.5 67.3 Area under the relaxation curve, Mooney units*sec 498 362 363 473 439 399 429 Payne effect Δ (G'1% - G'50%), kPa 228 227 224 163 176 172 224 Tear resistance, kN/m 39 44 49 43 48 54 45

As can be seen from Table 1, when using a mixture of an aliphatic solvent (A) and low-boiling hydrocarbons C ₅ -C ₆ (B) as a solvent, taken in different percentages, the branching index of the polydiene increases, as evidenced by the low value of the mechanical loss angle tgδ ( 1200%), the viscosity of the polymer solution decreases, and cold flowability decreases. In comparison with the prototype, a significant improvement in polydispersity was noted in all samples obtained according to the present invention.

According to the results of testing rubber compounds (Table 3) based on samples obtained according to the invention, there is an improvement in processability, expressed in a reduced Mooney viscosity of the rubber mixture, an improvement in the interaction of the filler with the polymer matrix, which is manifested in a decrease in the Payne effect index, as well as an improvement ( increase) tear resistance.

Claims (24)

1. A method for producing branched polydiene, including the stages: providing a catalyst system comprising (i) a lanthanide compound, (ii) an organoaluminum compound, (iii) a conjugated diene, and (iv) a halogen-containing component; polymerization of a conjugated diene in a hydrocarbon solvent in the presence of said catalyst system; introducing a branching agent; carrying out modification, stopping, degassing, isolation and drying of the polymer, characterized in that upon reaching at least 96% conversion of the conjugated diene, a branching agent is introduced selected from the group of chlorine-containing compounds consisting of methyltin trichloride, dimethyltin dichloride, ethyltin trichloride, diethyltin dichloride, n-butyltin trichloride, di-n-butyltin dichloride, phenyltin trichloride, diphenyltin dichloride, 2,4,6-trichloro-2,4,6-tri(phenoxy)-1,3,5-triaza-2,4,6-triphosphorine, hexachlorocyclotriphosphazene or mixtures thereof, or compounds containing at least two maleic fragments, and the hydrocarbon solvent is a mixture of an aliphatic solvent (A) selected from heptane, nefras or cycloaliphatic solvents - cyclohexane, cycloheptane - or mixtures thereof, and low boiling hydrocarbons C₅-WITH₆ (B), taken in the mass ratio (A): (B) = (80-91): (9-20). 2. The method according to claim 1, characterized in that the lanthanide compounds used are compounds that include at least one lanthanide atom selected from the group of neodymium, lanthanum, cerium, praseodymium, promethium, samarium, europium, gadolinium, terbium , dysprosium, holmium, erbium, thulium, ytterbium, lutetium. 3. The method according to claim 2, characterized in that neodymium compounds are used as lanthanide compounds. 4. The method according to claim 1, characterized in that the chlorine-containing branching agent is used in the form of a 1-20 wt.% solution in an aliphatic solvent. 5. The method according to claim 1, characterized in that the molar ratio of the chlorine-containing branching agent used to lanthanide is from 0.1:1 to 4:1. 6. The method according to claim 5, characterized in that the preferred molar ratio of chlorine-containing branching agent to lanthanide is from 0.2:1 to 3:1. 7. The method according to claim 6, characterized in that the most preferred molar ratio of chlorine-containing branching agent to lanthanide is from 1:1 to 2.5:1. 8. The method according to claim 1, characterized in that maleated polydienes, in particular maleized polybutadiene and maleized polyisoprene rubbers, are used as a branching agent containing at least two maleic fragments. 9. The method according to claim 1, characterized in that the molar ratio of the branching agent (RA) containing at least two maleic fragments to lanthanide is from 0.1:1 to 5:1. 10. The method according to claim 9, characterized in that the preferred molar ratio of maleated branching agent: lanthanide is from 0.5:1 to 2:1. 11. The method according to claim 10, characterized in that the most preferred molar ratio of maleated branching agent: lanthanide is from 0.8:1 to 1:1. 12. The method according to claim 1, characterized in that aliphatic hydrocarbons selected from the group containing pentane, isopentane, hexane, 2-methylpentane ( isohexane), 3-methylpentane, 2,2-dimethylbutane (neohexane), 2,3-dimethylbutane, alicyclic hydrocarbons, in particular cyclopentane, methylcyclobutane, ethylcyclopropane. 13. The method according to claim 12, characterized in that isopentane, cyclopentane, hexane, or mixtures thereof are used as the solvent (B). 14. The method according to claim 13, characterized in that cyclopentane, hexane, or mixtures thereof are most preferably used as solvent (B). 15. The method according to claim 1, characterized in that the proportion of solvent (B) is most preferably from 10 wt.% to 15 wt.% based on the total mass of the solvent. 16. The method according to claim 1, characterized in that a mixture of cyclohexane and nefras is most preferably used as a solvent (A) in a mass ratio of 65:35 to 70:30, respectively. 17. Branched polydiene obtained by the method according to paragraphs. 1-16, characterized by a Mooney viscosity index from 39 to 52 arb. units Mooney after modification, polydispersity coefficient obtained in the range from 2.4 to 2.8, content of 1,4-cis units - more than 97 wt.%, mechanical loss tangent tanδ 1200%, corresponding to the range from 6.41 to 2, 87, plasticity from 0.41 to 0.56, cold flow from 17.4 to 35.8 mm/hour and elastic recovery from 0.99 to 2.17 mm. 18. Rubber mixture for rubber products, in particular tires, based on polydiene according to claim 17, also containing additional ingredients. 19. Rubber mixture according to claim 18, in which the additional ingredients are carbon black and gas sulfur.