RU2706012C1 - Random copolymers of vinyl aromatic compounds and conjugated dienes and a method for production thereof - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: invention relates to a method of producing static copolymers of vinyl aromatic compounds and conjugated dienes in a medium of a hydrocarbon solvent in the presence of an organolithium initiator and an electron-donor additive (ED). ED contains in its structure at least two heteroatoms. ED is fed into reaction medium in two steps. First portion of ED is supplied at the beginning of the process, the amount of the first portion makes 70–90 % of the total amount of ED used. Second portion of ED is fed in conversion of monomers 70–90 %, the amount of the second portion is 10–30 % of the total amount of ED used. Also described is a static copolymer of a vinyl aromatic compound and a conjugated diene and a rubber composition.

EFFECT: technical result is reduction of total number of steps of obtaining a copolymer, low turnover of copolymers at 90 °C by 4–6 times, as well as obtaining random copolymers of vinyl aromatic compounds and conjugated dienes with given polydispersity in range of 1,3–2,3 units and given values of Mooney viscosity and content of 1,2-links.

35 cl, 2 tbl, 35 ex

Description

FIELD OF THE INVENTION

The invention relates to a method for producing random copolymers of vinyl aromatic compounds and conjugated dienes with predetermined values of polydispersity and fluidity at 90 ° C, as well as to the field of statistical copolymers of vinyl aromatic compounds and conjugated dienes used in the manufacture of tires, rubber products, in the electrical and other fields, by anionic copolymerization of vinyl aromatic compounds and conjugated dienes in a hydrocarbon solvent in the presence of organolithium th electron donating initiator and additives.

State of the art

The known patent application RU 94012917 discloses a method for producing low molecular weight polymers of conjugated dienes, in which the polymerization of conjugated dienes is carried out in a hydrocarbon solvent in the presence of a catalyst, which is used a mixture of n-butyllithium in an amount of 0.0035-0.025 mol per 1 mol of the initial amount a monomer with a compound of the general formula

where R is C1 - C4 is a hydrocarbon radical, n is 1.2, Me is sodium or potassium, in an amount of 0.1-1.0 mol per 1 mol of n-butyllithium, and the process is carried out with the initial introduction of a conjugated diene monomer in an amount 20-25% of the mass. of its total amount, followed by portionwise introduction of the remaining monomer and polymerization of it at 60-80 ° C, with each subsequent portion being introduced at a conversion of at least 90% by weight of the monomer, and the process is carried out until the final polymer content in the solution is 60-70% by weight . This technical solution allows to obtain a polymer with the desired microstructure, low molecular weight at low costs of the components of the catalytic system.

The disadvantages of this method include the difficulty of regulating the microstructure and molecular weight distribution, as well as the difficulty of branching / modification of the polymer due to the presence of alkali metal alcoholates, which are used as modifying additives, as well as the poor solubility of these additives in aliphatic hydrocarbons.

Patent RU 2082723 describes a method for producing styrene-butadiene rubber, which is carried out by preparing a mixture of comonomers - butadiene and styrene in a hydrocarbon solvent, copolymerizing in several reactors in the presence of a catalyst - an organolithium compound and a cocatalyst - an organopolymer compound. The mixture is divided into two streams and fed into parallel reactors, the polymerization temperature difference in which is from 10 to 35 ° C, after which the reaction flows are combined and sent to a cascade of series-connected reactors. The method also includes stabilizing, degassing and drying the rubber. The cocatalyst can be introduced in a hydrocarbon solvent or in a mixture with toluene with a toluene content of not more than 5% of the mass. The aim of the invention is to expand the molecular weight distribution of styrene-butadiene rubber and increase the dry residue.

The disadvantage of this method is the use of a pyrophoric potassium-organic compound as a cocatalyst, as well as low-temperature process conditions, difficulties in the hardware design of the process scheme due to the need to separate charge streams.

RU 2200740 describes a method for producing styrene-butadiene rubber, the essence of which is that, as a modifying additive, a compound selected from the group consisting of dimethyl, diethyl, divinyl ether of diethylene glycol, methyl-, ethyl-, dimethrahydrofurfuryl ether and / or sodium tetrahydrofurfurylate, styryl-, nonyl-substituted sodium phenolate, based on the molar ratio to n-butyl lithium in the range of 0.05-0.8, and as a combining agent, divinylbenzene based on the molar ratio to n-butyl lithium 0.1-0.6 to which are fed into the charge, and the copolymerization process is carried out until the conversion of at least 95% at a temperature of 30-80 ° C. If necessary, after reaching a conversion of at least 95%, a compound selected from the group consisting of tin tetrachloride, tributyltin chloride, d-butyltin dichloride, N-methyl-pyrrolidone, 4-nitrosodiphenylamine, N-butylpropionaniline, 2-chloro-4,6- is introduced into the polymerization system bis (diethylamine) simtriazine, 4,4-bis (dibutylamino) benzophenone, 4-diethylaminochlorobenzophenone, based on a molar ratio of n-butyl lithium of 0.1-0.8. The invention allows to obtain rubber with a predominant content of vinyl units (42-61% wt.), Good processability in processing.

A known method for producing random elastomeric conjugated dienes of branched vinyl vinyl arenes of copolymers disclosed in US Pat. No. 6,858,683 includes the following steps: (1) anionic copolymerization in a solution of conjugated diene and vinyl aromatic monomers, in the presence of an agent for converging polymerization constants (randomization agents) and an initiator selected from the group of lithium alkyls, the copolymerization being carried out until the monomers are almost completely consumed; (2) adding to the solution of step (1) lithium alkyl in an equimolar (1 equimole) or excess (up to 4 equimole) molar amount in relation to the amount of lithium alkyl in step (1); (3) adding to the polymer solution in step (2) a compound having the general formula R-Br, with a molar ratio between R-Br and the total amount of lithium alkyl in the range from 0.6 / 1 to 1/1, preferably from 0.7 / 1 to 0.9 / 1, thereby obtaining a branched copolymer.

However, the use of tin chloride as a branching agent (patent RU 2200740) and the use of alkyl bromides and silicon tetrachloride (patent US 6858683) complicates the technological scheme, because appropriate storage and dosage units for the above agents are required.

RU 2382792 describes a method for producing polybutadiene and butadiene-styrene copolymers, according to which polybutadiene and butadiene-styrene copolymers are prepared by continuous polymerization in a hydrocarbon solvent in the presence of a catalyst. The catalyst is an organolithium compound in combination with a modifying additive alkali metal lapramolate, which is obtained by the interaction of lapramol with metallic sodium (potassium) or by the interaction of lapramol with sodium hydroxide (potassium). The method of producing polybutadiene and butadiene copolymers with styrene allows to reduce the consumption of organolithium initiator, to obtain homo- and copolymers with different contents of 1,2-units, with different molecular weight and polydispersity.

The disadvantage of this solution is the difficulty of the process of branching of the polymer due to the content in the reaction medium of alkali metal alkoxides, because sodium (potassium) lapromolate will interact with a branching agent.

Patent RU 2405000 discloses a method for producing butadiene polymers and copolymers of butadiene with styrene by polymerizing the corresponding monomers in a hydrocarbon solvent in the presence of an organolithium initiator and metal alkoxides of groups 1 and 2 of the Periodic Table D.I. Mendeleev as modifiers, including the stages of producing a hydrocarbon solution of a living polymer, branching of a living polymer, characterized in that the stage of branching of a living polymer is carried out by holding the hydrocarbon solution of a living polymer at temperatures of 60-110 ° C for 10- 60 minutes before the formation of a polybutadiene or a copolymer of butadiene with styrene with a given dynamic viscosity of 5.43% solution in toluene from 50 to 250 MPa · s. EFFECT: obtaining polybutadiene or copolymers of butadiene with styrene with a narrow molecular weight distribution and adjustable dynamic viscosity of a 5.43% solution of a polymer or copolymer in toluene at specified Mooney viscosity values.

However, the use of alkali and alkaline earth metal alcoholates as electron donor additives causes difficulties in rubber processing and also limits the possibility of obtaining a branched polymer.

Patent RU 2501816 discloses styrene-butadiene polymers with a styrene gradient and methods for making such, wherein said method comprises: (A) adding less than 60 weight percent of the total amount of butadiene used in the polymerization to a reactor containing all of the styrene used in the polymerization, and a solvent; (B) adding at least one initiator to the reactor, and providing conditions for the reaction to occur during time t; (C) adding the remaining amount of butadiene to the reactor in two or more separate administrations; and, where for each subsequent introduction of butadiene, the amount of butadiene introduced is less than the amount of butadiene added to the reactor immediately before this introduction, or equal to the amount of butadiene added to the reactor immediately before this introduction; moreover, for each introduction of butadiene, butadiene is added over time, t _nc , and after each introduction, the reaction proceeds over time, t _nr , where n is the number of introductions of butadiene, and where the polymer contains polymer chains having a higher styrene content towards the middle of the polymer chains, and lower styrene content at the ends of the chains. EFFECT: obtaining a special rubber structure.

However, this copolymerization method is multi-stage, complicated from the point of view of hardware and requires an increased consumption of initiator - butyl lithium, and also has difficulties in regulating the polymer microstructure.

The well-known patent US 9243099 describes butadiene-styrene polymers with a low content of vinyl units and a method for their preparation. The invention relates to a method for producing a polymer by continuous polymerization of styrene and 1,3-butadiene in the presence of an initiator, which are organolithium compounds, and at least one polar agent. The specified polar agent is selected from compounds represented by the General formula:

,

,

where R ₁ and R ₂ are independently from each other alkyl, preferably C ₁ -C ₄ alkyl; R _3, R _4, R _5, R _6, R ₇ and R ₈ - independently of one another are a radical selected from hydrogen or alkyl, preferably hydrogen or C ₁ -C ₄ alkyl. The resulting polymer is characterized by a molecular weight distribution of 1.5 to 3.0, a number average molecular weight of 70,000 to 500,000 g / mol, and a Mooney viscosity of 30 to 90.

The disadvantage of this method is that with the continuous method of copolymerization of monomers, it is difficult to maintain the ratio of organolithium initiator: electron-donor additive, which ultimately leads to a polymer with a wide variation in the content of 1,2 units.

From patent EP 2495266 styrene-butadiene rubber with a high content of vinyl and styrene and a method for its preparation are known, which is carried out by polymerization of monomers in the presence of an organolithium initiator and a polar agent represented by the general formula:

,

,

where r^oneand R² - independently from each other, represent an alkyl group; R³, R⁴, R⁵, R⁶and R⁷- independently from each other, represent an alkyl group and hydrogen. As the alkyl group, compounds selected from the group consisting of methyl, ethyl, propyl, isopropyl, cyclopropyl, butyl, isobutyl, tert-butyl, sec-butyl, cyclobutyl and others are used.

The polymerization is carried out in a hydrocarbon solvent at a temperature of less than 80 ° C. Styrene is added to the reaction mixture in an amount of more than 40 wt. % of the total monomer content.

In one of the embodiments of the invention, the polymer is obtained in a batch reactor, the molecular weight distribution of such a polymer is 1.05-2.0, preferably 1.1-1.8, more preferably 1.2-1.6. The polymer can also be obtained by continuous polymerization, in this case, the molecular weight distribution of the polymer is 1.5-2.5, preferably 1.6-2.4, more preferably 1.8-2.2. The Mooney viscosity of the obtained polymers is in the range of 20-150.

The disadvantage of this method in the case of a continuous method of implementing the process is the difficulty of regulating the microstructure of the polymer, the high probability of the formation of block styrene, and the periodic method is low productivity.

EP 2495267 describes styrene butadiene rubber with a high content of vinyl and styrene and methods for its preparation by polymerizing monomers in a hydrocarbon solvent at a temperature of 10-80 ° C in the presence of an organolithium initiator and two different polar agents.

The first polar agent is represented by the formula:

;

;

the second polar agent is represented by the following formula:

,

,

where r^one', R^{2 '}, R^{3 '} and R^4' - independently from each other, are compounds selected from the group comprising an alkyl group and hydrogen; Q - contains an alkylene group - (CH₂)_nwhere n = 2-3; R^one and R² - independently from each other, represent an alkyl group, preferably methyl; R³, R⁴, R⁵, R⁶, R⁷ and R⁸- independently from each other, represent an alkyl group and hydrogen.

The polymer obtained according to the present invention has a molecular weight distribution of from 1.05 to 1.8. The polymerization process is characterized by a high conversion of monomers (in some examples, more than 99%) and a short reaction time (in some examples, less than 3 hours).

However, the use of two electron-donating additives simultaneously leads to instability of the polymerization process, which manifests itself in fluctuations in the flow rate of the catalytic system and, as a result, instability of the Mooney viscosity and microstructure in the obtained polymer.

EP 2516410 describes an improved vinyl modifier composition and method for using such a composition. This patent provides a composition based on an oxolanyl compound that contains a certain amount of the meso isomer of one or more oxolanyl compounds selected from the group consisting of compounds of the general formula:

,

,

where R ₁ and R ₂ independently represent hydrogen or an alkyl group, and the total number of carbon atoms in the group —CR ₁ R ₂ - is in the range from 1 to 9; R ₃ , R ₄ and R ₅ independently represent —H or —C _n H _{2n + 1} , where n = 1-6.

The process is carried out at a temperature of 85-120 ° C in the presence of an organolithium initiator.

In addition to diene monomer, vinyl aromatic monomers can also participate in the polymerization. As conjugated dienes use compounds selected from the group including, in particular: 1,3-butadiene, isoprene, 1,3-pentadiene, 2,3-dimethyl-1,3-butadiene, 1,3-hexadiene, 2-methyl -1,3-pentadiene, 3,4-dimethyl-1,3-hexadiene, 4,5-diethyl-1,3-octadiene, 3-butyl-1,3-octadiene, phenyl-1,3-butadiene and their mixture.

Modified polymer compositions are known from WO 2013139378. The application describes a method for producing a modified elastomeric polymer. The claimed method includes the step of polymerizing at least one conjugated diene and, optionally, one or more vinyl aromatic compounds to produce a “living” anionic polymer. The polymerization is carried out in an organic solvent at a temperature of 110 ° C or less in the presence of an anionic initiator and a compound represented by formula (1):

(1),

(one),

where O is oxygen; R ¹ and R ² - independently of one another, represent hydrogen or a C ₁ -C ₄ alkyl group; R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ and R ⁸ independently represent hydrogen or a C ₁ -C ₆ alkyl group, n = 1-4, preferably n = 1. In this case, the molar ratio of the initiator and the above compound (1) is 0.15-10. A suitable compound (1) is di (tetrahydrofuryl) propane or its derivatives. The compound of formula (1), namely di (tetrahydrofuryl) propane or its derivatives, regulates the distribution of the vinyl monomer in the composition as an additional comonomer, and also regulates the distribution and amount of 1,2-polybutadiene units in the polymer and thus acts as an approximation agent polymerization constants (randomization agent). In addition, the polar compound (1) accelerates the polymerization rate.

The method also includes the polymerization of a single conjugated diene, for example, 1,3-butadiene or isoprene with a vinyl aromatic monomer, for example, styrene or 4-methylstyrene; and / or divinylbenzene, to obtain a statistical, block, co or terpolymer.

The disadvantage of the above two methods is the narrow molecular weight distribution of the order of 1.2-1.5 units and, as a result, the poor processability of the resulting rubber. Increased energy costs due to the polymerization process at high temperatures.

The closest in technical essence and the achieved result is a known method for producing styrene-butadiene rubber, disclosed in patent RU 2206581, the essence of which is that the copolymerization process is carried out in several stages, and in the first stage in a mixture with an initial concentration of comonomers 10-20 wt.% with a ratio of butadiene: styrene in the range from 85:15 to 60:40 by weight, n-butyllithium is added at a rate of 20-60 mol per ton of monomers and a modifying additive selected from the group consisting of dimethyl-, diethyls diethylene glycol, methyl, ethyl, di-tetrahydrofurfuryl ether, di-, divinyl, based on the molar ratio of n-butyl lithium in the range of 0.1-0.8, the polymerization process is carried out to a conversion of at least 95%, in the second stage, divinylbenzene, based on the calculation of the molar ratio to n-butyl lithium from 0.1 to 0.6, can withstand at least 2 minutes, in the third stage, the same mixture is additionally fed based on the calculation of the mass ratio to the initial amount in the range from 1: 1 to 6 : 1 and a modifying additive selected from the group comprising tetrahydrofurfurylate Alia stiril- nonilzameschenny or potassium phenolate as a toluene solution of calculating the molar ratio of potassium-lithium of from 0.01 to 0.1, the process is carried out to a conversion of not less than 95%, the temperature of each stage 20-60 ° C. If necessary, in the fourth stage styrene is introduced in an amount of 3-15% wt. of the total number of comonomers fed into the system in the first and third stages, and carry out the process even before the conversion of styrene at least 95%. The method allows to obtain styrene-butadiene rubber with a predominant content of 1,2-units of a statistical or statistic-block structure (if styrene is added at the end), with a wide molecular weight distribution and an increased value of the friction coefficient with a wet surface.

The disadvantage of this method is the branching of the polymer with divinylbenzene, which contributes to an increase in gelation during the polymerization process and can lead to uncontrolled molecular weight growth, which, in turn, negatively affects the equipment and the duration of the process. Also, the method is complicated in technological execution, because is multi-stage (requires four-stage process).

SUMMARY OF THE INVENTION

The technical problem solved by the present invention is to simplify the technology for producing (in comparison with the prototype) a copolymer of vinyl aromatic compounds and conjugated dienes and to improve the process of its isolation, to improve the processability of the resulting rubber.

The problem is achieved using the method of anionic copolymerization of vinyl aromatic compounds and conjugated dienes in a hydrocarbon solvent in the presence of an organolithium initiator and electron-donating additive (hereinafter - ED), which contains at least two heteroatoms in its structure, and ED is fed fractionally into two admission: the first portion of ED is served at the beginning of the process, and the amount of the first portion is from 70 to 90% of the total amount of ED used, and the second portion is fed during conversion onomerov from 70 to 90%, and the amount of the second portion is from 10 to 30% of the applied amount of ED.

In another aspect, the present invention relates to a random copolymer of a vinyl aromatic compound and a conjugated diene, which is obtained by the above method.

The invention also relates to a rubber composition containing such a random copolymer. The rubber composition according to the invention can be used for tires, in particular, tire treads, as well as for rubber products, in the electrical and other fields.

The technical result provided by the present invention is to reduce, compared with the prototype, the total number of stages of obtaining a copolymer, namely the absence of a branching stage (introduction of divinylbenzene), carried out to expand the polydispersity of the copolymer; lack of stages of additional supply of the mixture and styrene; obtaining statistical copolymers of vinyl aromatic compounds and conjugated dienes with specified polydispersity values ranging from 1.3 to 2.3 units and specified Mooney viscosity and 1,2-unit content. The invention provides a reduction in the fluidity of copolymers at 90 ° C by 4-6 times.

Moreover, the properties of rubber mixtures based on the copolymers obtained by the method according to the invention correspond to the technical requirements for the product, in particular ASTM D 3182-89, which is shown by the obtained rolling resistance, physical and mechanical characteristics and volume loss during abrasion.

DETAILED DESCRIPTION OF THE INVENTION

According to the present invention, there is provided a method of anionic copolymerization of vinyl aromatic compounds and conjugated dienes of anionic copolymerization of vinyl aromatic compounds and conjugated dienes in a hydrocarbon solvent in the presence of an organolithium initiator and electron donor additive (ED). In this case, compounds containing at least two heteroatoms in their structure are used as ED. In this case, the supply of ED to the reaction medium is carried out in two stages. The first portion of ED is fed at the beginning of the process, and the second portion is fed when the monomer conversion level is from 70 to 90%. The amount of the first portion is from 70 to 90%, and the amount of the second portion is from 10 to 30% of the total amount of ED used.

Compounds containing at least two heteroatoms in their structure that are bidentant, tridentant, etc., are used as ED in the present invention. ligands and chelating lithium to form reactive complexes. Single heteroatom EDs, which are a monodentant ligand, are coordinated to lithium, forming a less reactive complex. Therefore, it is preferable to use EDs with at least two heteroatoms in their structure in the process of anionic copolymerization of vinyl aromatic compounds and conjugated dienes compared to EDs with one heteroatom. It is well known that bidentant ligands, such as ditetrahydrofurfurylpropane, N, N, N ', N'-tetramethylethylenediamine and tetrahydrofurfuryl esters, are coordinated to lithium by the bidentant mechanism with the formation of reactive complexes (see, in particular, “Are d ⁰ ₆ complexes octahedral? The x-ray structure of trigonal-prismatic [Li (tmed)] ₂ [ZrMe ₆ ]) ”Paige M. Morse, Gregory S. Girolami from J. Am. Chem. Soc., 1989, 111 (11), pp 4114-4116).

In addition, in the case of a lack of electron-donating additives, one ED molecule is coordinated to two LiBu molecules, so that less reactive ED * 2LiBu complexes are formed that initiate the polymerization process. When equimolar amounts of ED are applied to lithium, more reactive complexes of ED * LiBu composition are formed.

As the ED in the method according to the invention, in particular, compounds such as ethylene glycol dimethyl ether (monoglyme), diethylene glycol dimethyl ether (diglyme), ditetrahydrofurfurylpropane (DTGFP), N, N, N ', N'-tetramethylethylenediamine (TM) can be used , methyltetrahydrofurfuryl ether, ethyltetrahydrofurfuryl ether, propyltetrahydrofurfuryl ether, butyltetrahydrofurfuryl ether, isopropyltetrahydrofurfuryl ether, sec-butyltetrahydrofurfurfuryl ether, isobutyltetrahydrofurfurfurofuryl, reels ether pentiltetragidrofurfurilovy ether geksiltetragidrofurfurilovy ether, methyl tert-butyl ether, ethylene glycol ether etiltretbutilovy (ETBEEG) ditetragidrofurfurilovy ether, diethyl ether, dipropyl ether, diisopropyl ether, dibutyl ether, diisobutyl ether, or mixtures thereof.

It is preferable to use DTGFP, TMEDA, methyltetrahydrofurfuryl ether, ethylene glycol dimethyl ether, ethylene glycol ethyl tert-butyl ether, ditetrahydrofurfuryl ether or a mixture thereof.

It is most preferable to use DTHFP, TMEDA, ethylene glycol ethyl tert-butyl ether or mixtures thereof as ED.

The supply of ED according to the invention is carried out fractionally, namely in two steps. The supply of ED in more than two steps leads to an increase in capital and operating costs and the complexity of the technological scheme with the same technical result.

The size of the first portion of the applied ED is from 70 to 90% of the total amount used. Serving in the first batch of ED in an amount of less than 70% is impractical, since the copolymerization process takes place with a lack of ED and, as a result, the resulting copolymer has lower content of 1,2-unit diene, since in this case the conjugated diene polymerization proceeds mainly by 1,4-attachment mechanism. A lower content of bound vinyl aromatic compound is also noted, since part of the vinyl aromatic compound does not enter the copolymerization process and is not included in the structure of the macromolecule. As a result, the microstructure of the copolymer does not meet the requirements of the product specification. Serving in the first portion more than 90% of ED makes it impossible to control the amount of polydispersity, because the process runs on almost the entire amount of ED used.

Preferably, the size of the first serving of ED is from 75 to 90% of the total amount used. In the most preferred embodiment of the invention, the size of the first portion is from 75 to 80% of the total amount of ED used.

The size of the second portion of ED is preferably from 10 to 25% of the total amount used. In the most preferred embodiment, the size of the second portion is from 20 to 25% of the total amount of ED used.

The second portion of ED is served upon reaching a monomer conversion of 70 to 90%. When the second portion is fed at a conversion of less than 70%, it is impossible to obtain a copolymer of the required microstructure, and the second portion is not meaningful after reaching a conversion of more than 90%, because the copolymerization process is almost complete.

It is preferable to serve a second portion of ED after reaching a conversion of monomers from 75 to 85%.

It is most preferable to apply a second portion of ED after reaching a conversion of monomers from 80 to 85%.

Styrene, alpha-methylstyrene, divinylbenzene, diisopropenylbenzene, 1-methyl-2-vinylbenzene, 1-methyl-3-vinylbenzene, 1-methyl-4-vinylbenzene, 1,4-dimethyl- can be used as vinyl aromatic compounds in the method according to the invention. 3-vinylbenzene, 1,3-dimethyl-5-vinylbenzene, 1-ethyl-2-vinylbenzene, 1-ethyl-3-vinylbenzene, 1-ethyl-4-vinylbenzene, 1-ethyl-4-methyl-3-vinylbenzene, 1,4-diethyl-3-vinylbenzene, 1-ethyl-3-methyl-4-vinylbenzene.

It is preferable to use styrene, alpha-methylstyrene, divinylbenzene, diisopropenylbenzene as vinyl aromatic compounds.

Most preferred is the use of styrene and alpha-methylstyrene as vinyl aromatic compounds.

1,3-butadiene, isoprene, 2,3-dimethyl-1,3-butadiene, piperylene, 2-methyl-3-ethyl-1,3-butadiene, 3-methyl can be used as conjugated dienes in the method according to the invention -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.

Most preferably, 1,3-butadiene and isoprene are used as conjugated dienes.

As organolithium initiators in the method according to the invention, ethyl lithium, isopropyl lithium, n-butyl lithium, tert-butyl lithium, phenyl lithium, 2-naphthyl lithium, 4-butyl phenyl lithium, 4-phenyl butyl lithium, cyclohexyl lithium can be used.

Most preferably, n-butyllithium is used as the organolithium initiator.

Aliphatic solvents or mixtures thereof are used as the hydrocarbon solvent.

Preferably, a mixture of cyclohexane and gasoline fractions is used as the hydrocarbon solvent.

It is most preferable to use a mixture of cyclohexane and nefras as a hydrocarbon solvent in the ratio (65-70) :( 30-35), moreover, nefras is a hexane-heptane fraction of paraffinic hydrocarbons of dearomatized catalytic reforming gasolines with a boiling point of 65-75 ° C.

The process of obtaining copolymers of conjugated dienes and vinyl aromatic compounds can be carried out in a continuous or batch mode. The continuous copolymerization process is usually carried out in two or more metal reactors (polymerizers). Preferably, the continuous copolymerization process is carried out in 3-6 metal polymerizers. The batch process is carried out in one steel reactor. All reactors are equipped with mixing devices and jackets for supplying and removing heat. At the beginning of the process, a mixture is fed into the polymerization unit, consisting of the total calculated amount of conjugated diene, the total amount of vinyl aromatic monomer used, and the total volume of the hydrocarbon solvent. In laboratory conditions, the mixture is prepared in advance in a separate apparatus and transferred to the polymerization reactor or obtained in situ in the polymerizer. Similarly, when carrying out polymerization on an industrial scale, the mixture is prepared in a flow-type static mixer in the case of a continuous process or obtained in situ during batch copolymerization by feeding the individual components of the mixture into the reactor and mixing them directly in the polymerization reactor. After the charge, a catalytic system is loaded into the reactor containing the first portion of ED in an amount of 70 to 90% of the total calculated amount and the entire calculated volume of the organolithium initiator. The molar ratio of ED to organolithium initiator is from 0.3 to 2.0. Preferably, the molar ratio of ED to organolithium initiator is from 0.5 to 1.5. It is also possible to download the ED and the initiator separately, but in this case, the loading order is important, namely: you must first submit the ED, and then the initiator. This order is preferable because otherwise, it is highly likely that the polymerization process begins on the organolithium initiator, which will lead to increased microblockness of the copolymer. The temperature of the reaction medium at the beginning of the process is 20-30 ° C. As the copolymerization reaction proceeds, the temperature of the reaction mixture increases to 70-100 ° C due to self-heating of the medium.

Mass ratios of the conjugated diene and vinyl aromatic compounds in the charge according to the proposed method are usually in the range of ratios from 60:40 to 85:15.

Preferred weight ratios of the conjugated diene and vinyl aromatic compound are from 60:40 to 80:20.

The most preferred weight ratios of the conjugated diene and vinyl aromatic compounds according to the proposed method are from 60:40 to 75:25.

Upon reaching the conversion of monomers from 70 to 90%, a second portion of ED is fed into the reaction medium in an amount of from 10 to 30% of the total calculated value. The value of the first and second portion of ED is selected based on the target value of the polydispersity of the copolymer. The lower the value of the first portion of ED, the wider the value of polydispersity. After the second portion of ED is fed, the process is conducted until almost complete conversion, i.e. up to about 98-100% conversion. Upon reaching this conversion, the polymerizate is usually stabilized with an antioxidant, then sent to degassing, and then dried to a moisture content of not more than 0.8% of the mass.

The resulting copolymers are characterized by polydispersity values from 1.3 to 2.3 units, a yield value at 90 ° C of 5 to 50 mm / h and have predetermined Mooney viscosity values ranging from 10 to 200 conv. Mooney units, in a preferred embodiment, from 42 to 65 srvc. Mooney units, and 1.2-unit content required according to the technical specifications for the product.

In a preferred embodiment, the copolymers have a polydispersity of from 1.5 to 2.3 units.

In the most preferred embodiment, the polydispersity of the copolymers is from 1.8 to 2.2 units.

Preferably, the copolymers obtained by the method according to the invention have a fluidity at 90 ° C. of 5 to 40 mm / h.

Most preferably, the fluidity at 90 ° C is from 10 to 25 mm / hour.

At the same time, the yield strength of the copolymer at 90 ° C is optimal, since at a yield below 5 mm / h the copolymer is too rigid, so it is difficult to isolate, and deviations in other key parameters also occur. With a yield value above 50 mm / h, rubber adheres to the mechanical parts of the conveyor dryers, resulting in equipment failure. In addition, briquettes from such a copolymer do not retain their original shape and lose their presentation.

As it was established by the authors of the present invention, the above-described approach used in the polymerization in the method according to the present invention allows to reduce the fluidity at 90 ° C by 4-6 times, as well as adjust the properties of the resulting copolymers - to obtain rubber with a polydispersity value from 1.3 to 2.3 units despite the fact that the Mooney viscosity and the content of 1,2 units are not changed and fully comply with the technical requirements.

In the context of the present invention, the term "rubber" means synthetic elastomeric (co) polymers capable of being processed into rubber by vulcanization. In particular, in the following description and examples, the term "rubbers" may refer to copolymers according to the present invention, (co) polymers used in comparative examples, and the like.

The rubber compounds according to the invention can be obtained, in particular, in accordance with the recipe GOST R 54555-2011. The resulting rubber compounds fully comply with the technical requirements for the product, in particular ASTM D 3182-89.

The compounding of rubber compounds

Name Mass fraction for the recipe, g 1 A 2 A Rubber 100.00 100.00 Zinc oxide 3.0 3.0 Sulfur 1.75 1.75 Stearic acid 1.00 1.00 Petroleum furnace carbon black 50.00 35.00 TBBS (N-tert-butyl-2-benzothiazole sulfenamide) 1.00 1.00 Total: 156.75 141.75 Load factor when mixing on rollers 3.0 3.3 The load factor when mixing in a closed micro mixer:
- with cam type head
- with a Banbury type head 0.47
0.41 0.49
0.46

In the manufacture of mixtures on rollers, rubber and carbon black are weighed to an accuracy of 1.0 g, sulfur and a vulcanization accelerator to an accuracy of 0.02 g, other ingredients to an accuracy of 0.1 g.

In the manufacture of mixtures, a rubber and carbon black are weighed with an accuracy of 0.1 g, a mixture of ingredients with an accuracy of 0.01 g, separately introduced ingredients, if any, with an accuracy of 0.001 g are weighed in a closed micro-mixer.

Examples of carrying out the invention

Next, embodiments of the present invention will be described. Moreover, the invention is not limited to the presented examples only, and it will be clear to those skilled in the art that the same effect can be achieved in other embodiments that do not go beyond the essence of the claimed invention and / or using equivalent features of the invention.

The following describes the test methods used to evaluate the properties of the copolymers obtained by the claimed method.

1) Mooney viscosity of rubbers at 100 ° C (ML (1 + 4) 100 ° C) was determined according to ASTM D 1646-07 on a Mooney viscometer MV2000.

2) The molecular weight characteristics of the rubbers were determined by gel permeation chromatography using an internal method. The measurements were carried out on a Waters Breeze gel chromatograph with a refractometric detector. Determination conditions: a bank of 4 high-resolution columns (300 mm long, 7.8 mm in diameter) filled with styrene (HR3, HR4, HR5, HR6), which allows analyzing polymers with a molecular weight of 500 to 1 * 10 ⁷ a .eat.; the solvent is tetrahydrofuran, the flow rate is 1 cm ³ / min; temperature of the column thermostat and refractometer - 30 ° С; calculation - universal calibration according to polystyrene standards using Mark-Kuhn-Hauwink constants (for styrene-butadiene rubbers K = 0,00041, α = 0,693). Rubber samples were dissolved in freshly distilled tetrahydrofuran, the mass concentration of the polymer in the solution was 2 mg / ml.

3) The mass fraction of bound styrene and 1,2 units in the samples of styrene-butadiene rubbers was determined by the method of an IR spectrometer with a Fourier transform in accordance with the technical specifications TU 38.40387-2007 (Clause 5.8). The method is based on measuring the intensity of the absorption band at 700 cm ^-1 , corresponding to the vibrations of the CH group of the benzene ring in styrene, and also the absorption band at 910 cm ^-1 , corresponding to the vibrations of 1,2-units of polybutadiene. The IR spectrometer is calibrated using a complex of standard samples of the composition and microstructure of styrene-butadiene statistical rubber with known mass fractions of bound styrene and 1,2-units in the butadiene part of the chain, established by NMR spectroscopy.

4) The fluidity of the rubbers was determined on a plastometer model GT-7060-SA at a temperature of 90 ° C. The sample was prepared in accordance with GOST 415-75, then placed in a plastometer preheated to 90 ° C and measured the time during which the sample would be deformed by the compression platforms of the plastometer from 8 mm to 4 mm.

5) The ductility of rubbers was determined according to GOST 415-75 "Rubbers and rubber compounds. Method for determination of plastoelastic properties on a plastometer. "

6) The vulcanization characteristics of the rubber compounds were determined according to ASTM D 5289-07 on the rubber processing analyzer RPA-2000 f. Alpha Technologies: temperature 160 ° С, vibration frequency 1.7 Hz, vibration amplitude 0.5 °, time 30 minutes.

7) Evaluation of the operational properties of rubber compounds - rolling resistance (tg δ at 60 ° C) was carried out on an RPA-2000 rubber processing analyzer f. Alpha Technologies: frequency 10 Hz, shear amplitude 10%, temperature 60 ° C.

8) Physico-mechanical properties of rubbers were determined according to ASTM D 412-06 on a tensile testing machine T 2020.

9) Volume loss during abrasion GOST 23509-79 “Rubber. Method for determining abrasion resistance when sliding on a renewable surface. "

Example 1 (comparative): the prototype.

In a metal reactor with a capacity of 3 liters, equipped with devices for measuring temperature and pressure, loading and unloading, a stirrer and a jacket to maintain temperature, a charge was introduced consisting of 900 g of n-hexane, previously dried and deoxygenated, 85 g of butadiene and 15 g of styrene, methyltetrahydrofurfuryl ether based on the molar ratio to n-butyl lithium = 0.3 in the form of a solution in hexane (concentration 0.4 mol / l), hexane solution of n-butyl lithium (concentration 0.3 mol / l) at the rate of 20 mol per ton monomers and at a temperature of 60 ° C The polymerization process led to 96% conversion. Next, a hexane solution of divinylbenzene (DVB) (concentration 12 g / l) was supplied based on a molar ratio DVB / n-BuLi = 0.1, held for 60 minutes and a charge was applied in an amount of 1000 g containing 900 g of hexane, 85 g of butadiene , 15 g of styrene, into which a toluene solution (concentration of 0.25 mol / L) of styryl substituted potassium phenolate (BC-11, ROK) was previously introduced based on the molar ratio RОК / BuLi = 0.1, and polymerization was carried out at the same temperature to conversions 97%.

Was obtained statistical styrene-butadiene rubber with a Mooney viscosity of 50 srvc. units Mooney, the content of 1,2 units - 55.4% of the mass., The content of bound styrene - 14.2% of the mass, polydispersity - 3.05.

Example 2 (comparative). One-shot ED

The polymerization of butadiene with styrene was carried out periodically in a 3-liter metal polymerizer equipped with a mixing device and a jacket for supplying and removing heat. A pre-prepared styrene-butadiene charge consisting of butadiene-1,3, styrene and the entire used volume of the hydrocarbon solvent was fed into the polymerizer. As a solvent, a mixture of cyclohexane: nephras, taken in a ratio of 65:35, was used. The mass ratio of butadiene and styrene in the mixture is 75:25. After the charge, the catalytic mixture — pre-mixed organolithium initiator and ED — was loaded into the reactor. As the organolithium initiator, n-butyllithium (n-BuLi) was used, the ratio of n-BuLi / 1 kg of monomers was 5 mmol / kg. Diethhydrofurylpropane (DTGFP) was used as the ED, molar ratio ED / n-BuLi = 0.6. Thus, all the applied amount of DTHHP was supplied to the polymerizer in one go. The polymerization temperature was 60 ℃. As a result, a copolymer with a polydispersity of 1.32 units was obtained, the content of 1.2 units was 63.6% by mass, and the fluidity of the copolymer at 90 ° C was 117 mm / h.

Example 3 (comparative). The use of ED with one heteroatom

The process was carried out analogously to example 2 with the difference that tetrahydrofuran (THF) was used as ED. Moreover, the supply of ED was carried out fractionally in two portions. The first portion, which accounted for 75% of the total amount of ED used, was supplied as part of the catalytic mixture, and the second portion, in the amount of 25% of the total amount of ED used, was fed to the polymerizer after reaching 85% of the monomer conversion. As a result, a copolymer with a polydispersity of 1.39 units was obtained, the content of 1.2 units was 52.1% by mass, and the fluidity at 90 ° C was 112 mm / h.

Example 4

The process was carried out analogously to example 3, with the difference that a compound with two heteroatoms, DTGFP, was used as ED. DTHFP was supplied fractionally: the first portion in the amount of 70% was fed into the reactor at the beginning of the process, the remaining 30% of ED were fed upon reaching the conversion of monomers 71%. The result is a copolymer with a polydispersity of 2.12 units, the fluidity of the polymer at 90 ° C was 16 mm / h.

Example 5

The process was carried out analogously to example 4, with the difference that the first portion of DTHHP was 85%, the remaining 15% of ED were filed upon reaching the conversion of monomers 89%. The characteristics of the obtained copolymer are presented in table 1.

Example 6

The process was carried out analogously to example 4, with the difference that diisopropenylbenzene was used as the vinyl aromatic monomer, sec-butyl lithium (sec-LiBu) was used as the initiator of the process. A second portion of ED was introduced into the reaction mixture upon reaching a 90% conversion.

Example 7

The process was carried out analogously to example 5, with the difference that sec-LiBu was used as the initiator of the process, N, N, N ', N'-tetramethylethylenediamine (TMEDA) was used as ED. The second batch of ED was filed upon reaching a monomer conversion of 90%.

Example 8

The process was carried out analogously to example 7, with the difference that n-LiBu was used as the initiator of the process, isoprene was used as the conjugated diene. The first portion of TMEDA was 80%, the remaining 20% was served upon reaching the conversion of monomers 85%.

Example 9

The process was carried out analogously to example 8, with the difference that DTGFP was used as ED. The first portion of DTFPP was 90%, the remaining 10% was filed after reaching a monomer conversion of 85%.

Example 10

The process was carried out analogously to example 9, with the difference that ditetrahydrofurfuryl ether was used as the ED, and the copolymerization of n-BuLi was initiated. The first portion of ED was 70%, the remaining 30% was filed upon reaching the conversion of monomers 90%.

Example 11

The process was carried out analogously to example 5, with the difference that alpha-methylstyrene was used as the vinyl aromatic monomer, tert-butyllithium (tert-LiBu) was used as the initiator of the process. The first portion of ED was 75%, the remaining 25% was filed upon reaching a monomer conversion of 85%.

Example 12

The process was carried out analogously to example 11, with the difference that n-LiBu was used as the initiator of the process. The first portion of ED was 90%, the remaining 10% was filed upon reaching a monomer conversion of 85%.

Example 13

The process was carried out analogously to example 8, with the difference that sec-BuLi was used as an initiator, methyltetrahydrofurfuryl ether was used as an ED. The first portion of ED was 83%, the remaining 17% was filed upon reaching the conversion of monomers 85%.

Example 14

The process was carried out analogously to example 13, with the difference that butadiene was used as the conjugated diene, divinylbenzene was used as the vinyl aromatic monomer. The first portion of ED was 75%, the remaining 25% was filed upon reaching a monomer conversion of 85%.

Example 15

The process was carried out analogously to example 14, with the difference that p-BuLi was used as the initiator, and ethyltetrahydrofurfuryl ether was used as the ED. The first portion of ED was 90%, the remaining 10% was filed upon reaching a monomer conversion of 85%.

Example 16

The process was carried out analogously to example 15, with the difference that piperylene was used as the conjugated diene, and styrene was used as the vinyl aromatic monomer. The first portion of ED was 71%, the remaining 29% was filed upon reaching a monomer conversion of 85%.

Example 17

The process was carried out analogously to example 16, with the difference that DTGFP was used as ED. The first portion of ED was 85%, the remaining 15% was filed upon reaching the conversion of monomers 85%.

Example 18

The process was carried out analogously to example 7, with the difference that DTGFP was used as ED. The first portion of ED was 80%, the remaining 20% was filed upon reaching a monomer conversion of 85%.

Example 19

The process was carried out analogously to example 18, with the difference that ethylene glycol methyl ester (monoglyme) was used as ED, t-BuLi was used as initiator. The first portion of ED was 90%, the remaining 10% was filed after reaching a monomer conversion of 70%.

Example 20

The process was carried out analogously to example 12, with the difference that monoglyme was used as an ED. The first portion of ED was 72%, the remaining 18% was filed upon reaching the conversion of monomers 85%.

Example 21

The process was carried out analogously to example 9, with the difference that tert-BuLi was used as an initiator. The first portion of ED was 90%, the remaining 10% was filed upon reaching a monomer conversion of 85%.

Example 22

The process was carried out analogously to example 5, with the difference that the first portion of ED was 90%, the remaining 10% was filed after reaching a conversion of 80% of the monomers.

Example 23

The process was carried out analogously to example 5, with the difference that ethylene glycol ethyl tert-butyl ether (ETBEG) was used as ED. The first portion of ED was 70%, the remaining 30% was filed upon reaching the conversion of monomers 85%.

Example 24

The process was carried out analogously to example 23, with the difference that isoprene was used as the conjugated diene, and phenyllithium was used as the organolithium initiator. The first portion of ED was 90%, the remaining 10% was filed upon reaching a monomer conversion of 85%.

Example 25

The process was carried out analogously to example 24, with the difference that butadiene was used as the conjugated diene, and TMEDA was used as the ED. The first portion of ED was 80%, the remaining 20% was filed upon reaching the conversion of monomers 90%.

Example 26

The process was carried out analogously to example 20, with the difference that DTGFP was used as ED. The first portion of ED was 85%, the remaining 15% was filed upon reaching the conversion of monomers 90%.

Example 27

The process was carried out analogously to example 22, with the difference that the first portion of ED was 85%, the remaining 15% were filed when the monomer conversion reached 75%.

Example 28

The process was carried out analogously to example 10, with the difference that styrene was used as the vinyl aromatic monomer. The first portion of ED was 85%, the remaining 15% was filed after reaching 80% monomer conversion.

Example 29

The process was carried out analogously to example 28, with the difference that the first portion of ED was 75%, the remaining 25% were filed after reaching a conversion of 80% of the monomers.

Example 30

The process was carried out analogously to example 28, with the difference that diethylene glycol dimethyl ether (diglyme) was used as ED. The first portion of ED was 90%, the remaining 10% was filed after reaching a monomer conversion of 70%.

Example 31

The process was carried out analogously to example 30, with the difference that sec-BuLi was used in the initiator quality. The first portion of ED was 83%, the remaining 17% was filed upon reaching the conversion of monomers 90%.

Example 32

The process was carried out analogously to example 5, with the difference that the first portion of ED was 65%, the remaining 35% were filed after reaching a monomer conversion of 75%.

Example 33

The process was carried out analogously to example 7, with the difference that the first portion of the ED was 93%, the remaining 7% were filed when the monomer conversion reached 85%.

Example 34

The process was carried out analogously to example 7. The first portion of ED was 90%, the remaining 10% was filed after reaching a conversion of 55% of the monomers.

Example 35

The process was carried out analogously to example 19, with the difference that phenyl lithium was used as an initiator. The first portion of ED was 55%, the remaining 45% was filed after reaching a monomer conversion of 70%.

Examples 32-35 illustrate the unattainability of the claimed technical result in the case of experiments on the fractional supply of ED in a portion amount that falls outside the ranges proposed by the invention, or by supplying a second portion of ED in a conversion that is inconsistent with that specified in the invention. So in accordance with examples 33 and 34, the first portion of ED was 93% and 90%, which exceeds the ranges proposed in the present invention. In these cases, copolymers with a narrow polydispersity of 1.23 and 1.12 and high fluidity at 90 ° C, amounting to 113 and 132 mm / h, respectively, were obtained. When feeding the first portion of ED below the established limit (examples 32 and 35), on the contrary, copolymers with wide polydispersity (2.51 and 2.77, respectively) and fluidity at 90 ° C of about 1 mm / h were obtained. In these examples, the resulting copolymers have problems in isolation and processing.

Table 1

Synthesis conditions and properties of copolymers

No. p / p Conjugated diene /
Vinylaro
math compound Mas.
the ratio of comonomers in the mixture,% Organolithium initiator ED ED supply,% Conversion% 1,2 links,% of the mass. Connection. aromatic monomer,% of the mass. Polydispersity Mooney viscosity, conv. units Mooney Fluidity at 90 ° C, mm / h 1 serving Conversion at the time of filing 2 servings of ED,% 2 serving 1 p butadiene: styrene 85:15 n-BuLi methyltetrahydrofurfuryl ether one hundred - - 97 55,4 14.2 3.05 fifty ≤1 2
from butadiene: styrene 75:25 n-BuLi DTGFP one hundred - - 98 63.6 24.1 1.32 60 117 3
from butadiene: styrene 75:25 n-BuLi THF 75 71 25 98 52.1 24.8 1.39 52 112 4 butadiene: styrene 85:15 n-BuLi DTGFP 70 71 thirty 99 44.3 14,4 2.12 51 sixteen 5 butadiene: styrene 85:15 n-BuLi DTGFP 85 89 fifteen 98 67.2 14.9 1.87 54 29th 6 butadiene: diisopropenylbenzene 80:20 sec-BuLi DTGFP 70 90 thirty one hundred 67.8 18.7 2.17 fifty 6 7 butadiene: styrene 60:40 sec-BuLi TMEDA 85 90 fifteen one hundred 39.5 40.1 1.90 fifty twenty 8 isoprene: styrene 80:20 n-BuLi TMEDA 80 85 twenty 99 23.7 20.1 1.85 59 fifteen nine isoprene: styrene 75:25 n-BuLi DTGFP 90 85 10 99 24.1 22.3 1,63 53 25 10 butadiene: diisopropenylbenzene 80:20 n-BuLi Ditetrahydrofurfuryl ether 70 90 thirty one hundred 67.8 18.7 2.17 fifty 7 eleven butadiene: alpha-methylstyrene 75:25 tert-buli DTGFP 75 85 25 99 64,4 26.8 2.01 53 5 12 butadiene: alpha-methylstyrene 75:25 n-BuLi DTGFP 90 85 10 99 63.7 24.9 1.79 58 nineteen thirteen isoprene: styrene 80:20 sec-BuLi Methyltetrahydrofurfuryl Ether 83 85 17 98 23.1 21.5 1,50 58 29th 14 butadiene: divinylbenzene 80:20 sec-BuLi Methyltetrahydrofurfuryl Ether 75 85 25 98 65,4 18.5 2.13 40 6 fifteen butadiene: divinylbenzene 80:20 n-BuLi Ethyl tetrahydrofurfuryl ether 90 85 10 one hundred 64,2 19.1 2.05 46 nine sixteen piperylene: styrene 80:20 n-BuLi Ethyl tetrahydrofurfuryl ether 71 85 29th 98 35.5 18.5 1.55 fifty 33 17 piperylene: styrene 80:20 n-BuLi DTGFP 85 85 fifteen 99 37.0 19,4 1.46 55 43 eighteen butadiene: styrene 60:40 sec-BuLi DTGFP 80 85 twenty 99 38.6 40,2 1.84 fifty 40 nineteen butadiene: styrene 65:35 tert-buli Monoglyme 90 70 10 99 37.9 36.0 1.42 57 23 twenty butadiene: alpha-methylstyrene 80:20 n-BuLi Monoglyme 72 85 eighteen 99 63,2 22.0 2.01 53 7 21 isoprene: styrene 80:20 tert-buli DTGFP 90 85 10 99 22.9 20.6 1.49 60 32 22 butadiene: styrene 60:40 n-BuLi DTGFP 90 80 10 99 55.0 40,2 1,67 48 22 23 butadiene: styrene 80:20 n-BuLi ETBEG 70 85 thirty 98 48.9 21.3 1.70 53 sixteen 24 isoprene: styrene 75:25 phenyl lithium ETBEG 90 85 10 98 24.9 26.8 1.48 52 35 25 butadiene: styrene 80:20 phenyl lithium TMEDA 80 90 twenty one hundred 48.9 19.1 2.22 fifty eleven 26 butadiene: alpha-methylstyrene 80:20 n-BuLi DTGFP 85 90 fifteen one hundred 61,4 20.5 2.12 54 10 27 butadiene: styrene 60:40 n-BuLi DTGFP 85 75 fifteen 99 49.3 40.5 1.77 51 sixteen 28 butadiene: styrene 60:40 n-BuLi Ditetrahydrofurfuryl ether 85 80 fifteen 99 50.1 40.1 1.80 53 14 29th butadiene: styrene 65:35 n-BuLi Ditetrahydrofurfuryl ether 75 80 25 one hundred 38,0 35,4 1,54 58 24 thirty butadiene: styrene 75:25 n-BuLi Diglyme 90 70 10 99 24.8 26.0 1.46 51 32 31 butadiene: styrene 80:20 sec-BuLi Diglyme 83 90 17 98 67.2 19.9 2.10 fifty nine 32 butadiene: styrene 80:20 n-BuLi DTGFP 65 75 35 99 36.6 18.1 2,51 48 ≤1 33 butadiene: styrene 75:25 sec-BuLi TMEDA 93 85 7 98 58.4 23.8 1.23 65 113 34 butadiene: styrene 80:20 sec-BuLi TMEDA 90 55 10 98 60.3 20.7 1.12 42 132 35 butadiene: styrene 80:20 phenyl lithium Monoglyme 55 70 45 98 37,2 18.9 2.77 52 ≤1

From the values given in table 1, it is obvious that the use of compounds containing at least two heteroatoms as ED and the fractional supply of ED in two portions by the method according to the invention allows to obtain copolymers of conjugated dienes and vinyl aromatic compounds with a given polydispersity value, reduces the value of the fluidity of the copolymer at 90 ℃ by 4-6 times, which improves the process of separation of the copolymer and improves its processability. At the same time, the proposed method does not adversely affect such important characteristics of rubber as the microstructure (including the content of the bound vinyl aromatic compound and 1,2 units) and the Mooney viscosity, which makes it possible to obtain copolymers with desired technical characteristics.

The rubber compounds based on the copolymers obtained in some of the above comparative examples and examples according to the invention, were obtained in accordance with the recipe according to GOST R 54555-2011. The characteristics of the obtained rubber compounds are shown in table 2. Moreover, in the first column in the table. 2 shows the number of the example in which the copolymer included in the corresponding rubber composition is obtained.

table 2

Properties of rubber compounds based on copolymers obtained by the method according to the invention

Example No. Rolling resistance
tg δ 60 ° С 10% Time to reach 90% vulcanization (t'90), min Physical and mechanical characteristics Loss of volume during abrasion, mm ³ Conditional tensile strength, MPa Elongation at break,% one 0.166 18.0 15.3 438 180 2 0.165 17.8 15.6 440 109 5 0.157 16.9 18.3 460 136 7 0.131 15.7 19.7 510 140 eighteen 0.129 16.1 19.3 520 141 nineteen 0.136 16,2 19.2 530 115 22 0.133 15.9 19.5 525 122 27 0.152 16.3 18,4 473 133

The test results shown in table 2 of rubber compounds based on copolymers obtained by the method according to the invention confirm the full compliance of the key indicators reflecting the properties of rubbers with the requirements of the technical specifications for the product, in particular ASTM D 3182-89.

The above specific embodiments and examples of implementation should not be construed as limiting the scope of the present invention, which is defined by the following claims.

All documents cited in the present description are included in their entirety in the scope of this application by reference.

Claims (35)

1. The method of anionic copolymerization of vinyl aromatic compounds and conjugated dienes in a hydrocarbon solvent in the presence of an organolithium initiator and electron-donating additive, characterized in that ED, containing at least two heteroatoms in their structure, is used as an electron-donating additive, and the ED is fed into the reaction medium fractionally in two portions: the first portion of ED is served at the beginning of the process, and the amount of the first portion is from 70 to 90% of the total amount of ED used, and the second portion fed at a monomer conversion of from 70 to 90%, and the amount of the second portion is from 10 to 30% of the applied amount of ED. 2. The method according to claim 1, characterized in that as an ED containing at least two heteroatoms in its structure, ethylene glycol dimethyl ether (monoglyme), diethylene glycol dimethyl ether (diglyme), diethhydrofurfurylpropane (DTHFP), N, N, N are used ', N'-tetramethylethylenediamine (TMEDA), methyl tetrahydrofurfuryl ether, ethyl tetrahydrofurfuryl ether, butyl tetrahydrofurfuryl ether, butyl tetrahydrofurfuryl ether, isopropyl tetrahydrofurfuryl ether, sec. tiltetragidrofurfurilovy ether pentiltetragidrofurfurilovy ether geksiltetragidrofurfurilovy ether, methyl tert-butyl ether, ethylene glycol ether etiltretbutilovy, ditetragidrofurfurilovy ether, diethyl ether, dipropyl ether, diisopropyl ether, dibutyl ether, diisobutyl ether, or mixtures thereof. 3. The method according to claim 2, characterized in that as ED containing in their structure at least two heteroatoms, DTGFP, TMEDA, methyltetrahydrofurfuryl ether, ethylene glycol dimethyl ether, ethylene glycol ethyl tert-butyl ether, dietrahydrofurfuryl ether or mixtures thereof are used. 4. The method according to claim 2, characterized in that as ED containing in their structure at least two heteroatoms, DTGFP, TMEDA, ethyl ethylene glycol ethyl tert-butyl ether or mixtures thereof are used. 5. The method according to claim 1, characterized in that the size of the first portion of ED is from 75 to 90% of the total amount used. 6. The method according to claim 5, characterized in that the size of the first portion is from 75 to 80% of the total amount of ED used. 7. The method according to claim 1, characterized in that the size of the second portion of ED is from 10 to 25% of the total amount used. 8. The method according to claim 7, characterized in that the size of the second portion is from 20 to 25% of the total amount of ED used. 9. The method according to claim 1, characterized in that the second portion of the ED is served upon reaching the conversion of monomers from 75 to 85%. 10. The method according to claim 9, characterized in that the second portion of the ED is served upon reaching the conversion of monomers from 80 to 85%. 11. The method according to claim 1, characterized in that 1,3-butadiene, isoprene, 2,3-dimethyl-1,3-butadiene, piperylene, 2-methyl-3-ethyl-1,3 are used as conjugated dienes -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 or 2-methyl-3 isopropyl-1,3-butadiene. 12. The method according to claim 11, characterized in that 1,3-butadiene or isoprene is used as conjugated dienes. 13. The method according to claim 1, characterized in that styrene, alpha-methylstyrene, divinylbenzene, diisopropenylbenzene, 1-methyl-2-vinylbenzene, 1-methyl-3-vinylbenzene, 1-methyl-4-vinylbenzene are used as vinyl aromatic compounds 1,4-dimethyl-3-vinylbenzene, 1,3-dimethyl-5-vinylbenzene, 1-ethyl-2-vinylbenzene, 1-ethyl-3-vinylbenzene, 1-ethyl-4-vinylbenzene, 1-ethyl-4 methyl-3-vinylbenzene, 1,4-diethyl-3-vinylbenzene or 1-ethyl-3-methyl-4-vinylbenzene. 14. The method according to item 13, characterized in that it is preferable to use styrene, alpha-methylstyrene, divinylbenzene, diisopropenylbenzene as the vinyl aromatic compound. 15. The method according to item 13, wherein the styrene or alpha-methylstyrene is used as the vinyl aromatic compound. 16. The method according to claim 1, characterized in that as the organolithium initiators, ethyl lithium, isopropyl lithium, n-butyl lithium, t-butyl lithium, phenyl lithium, 2-naphthyl lithium, 4-butyl phenyl lithium, 4-phenyl butyl lithium, cyclohexyl lithium are used. 17. The method according to clause 16, characterized in that as the organolithium initiator use n-butyl lithium. 18. The method according to claim 1, characterized in that the organolithium initiator and the first portion of ED are fed into the reaction medium together as a catalytic system. 19. The method according to claim 1, characterized in that the organolithium initiator and the first portion of the ED are fed separately to the reaction medium, the first portion of ED being first charged, and then the organolithium initiator. 20. The method according to any one of claims 1 to 19, characterized in that aliphatic solvents or mixtures thereof are used as the hydrocarbon solvent. 21. The method according to claim 20, characterized in that a mixture of cyclohexane and gasoline fractions is used as the hydrocarbon solvent. 22. The method according to claim 20, characterized in that a mixture of cyclohexane and nefras is used as a hydrocarbon solvent in the ratio (65-70) :( 30-35), and nephras is a hexane-heptane fraction of paraffinic hydrocarbons of dearomatized catalytic reforming gasolines with temperature limits of boiling 65-75 ° С. 23. The method according to any one of claims 1 to 22, characterized in that the copolymerization process is carried out in a batch or continuous manner. 24. The method according to any one of claims 1 to 23, characterized in that the mass ratio of the conjugated diene and vinyl aromatic compounds in the charge is in the range (60-85) :( 15-40). 25. The method according to p. 24, characterized in that the mass ratio of the conjugated diene and vinyl aromatic compounds in the charge is in the range (60-80) :( 20-40). 26. The method according to p. 24, characterized in that the mass ratio of the conjugated diene and vinyl aromatic compounds in the mixture comprise the range (60-75) :( 25-40). 27. A statistical copolymer of a vinyl aromatic compound and a conjugated diene used in the manufacture of tires and rubber products, obtained by the method according to any one of claims 1 to 26. 28. The statistical copolymer according to item 27, characterized by a polydispersity value of from 1.3 to 2.3. 29. The statistical copolymer according to item 27, characterized by a polydispersity value of from 1.5 to 2.3. 30. The statistical copolymer according to item 27, characterized by a polydispersity value of from 1.8 to 2.2. 31. The statistical copolymer according to item 27, characterized by a yield value at 90 ° C from 5 to 50 mm / hour. 32. The statistical copolymer according to item 27, characterized by the value of fluidity at 90 ° C from 5 to 40 mm / hour. 33. The statistical copolymer according to item 27, characterized by a yield value at 90 ° C from 10 to 25 mm / hour. 34. The statistical copolymer according to claims 27-33, characterized in that it is a copolymer of 1,3-butadiene and styrene. 35. A rubber composition comprising the random copolymer according to any one of claims 27-34.