RU2767539C1 - Block copolymer composition and method for its preparation - Google Patents

Abstract

FIELD: chemical or physical processes.

SUBSTANCE: invention relates to a block-copolymer composition used in polymer-bitumen binders, adhesive compositions, hot melt adhesives, etc. Present invention also relates to a method of producing a block copolymer composition, comprising polymerising a vinyl aromatic hydrocarbon and a conjugated diene, taken in ratio (30–32):(68–70), wt. %, respectively, in a medium of a hydrocarbon solvent, in the presence of an electron-donor additive, an organolithium initiator, post-polymerisation cross-linking using at least two coupling agents of different nature, according to the invention, said at least two coupling agents are selected from silicon-containing compounds of formula R₂SiHal₂, where R is C₁-C₂₀-aliphatic or C₆-C₂₀-aromatic groups, and sulfur-containing compounds having polysulphide groups (-S-)_n in their structure, where n=1–8, and a linker group (-Y-) capable of being substituted with active Li atoms in the polymer chain, selected from C₁-C₂₀-alkyl,C₃-C₂₀-alicyclic, C₃-C₂₀-heterocyclic, C₆-C₂₀-aromatic groups, to obtain a block copolymer composition. In addition, the present invention relates to the obtained block copolymer composition for polymer-bitumen binders, which contains (i) from 8 to 16 wt. % of non-cross-linked block copolymer AB, (ii) from 34 to 87 wt. % of a block copolymer cross-linked with a silicon-containing coupling agent, (iii) from 5 to 50 wt. % of a block copolymer cross-linked with a sulfur-containing coupling agent, and (iv), optionally, functional additives, where A is a monovinyl aromatic hydrocarbon block, B is a conjugated diene block, wherein the content of the bound monovinyl aromatic monomer ranges from 30 to 32 wt. %, conjugated diene — from 68 to 70 wt. %, content of 1,2-vinyl links ranges from 10 to 43 wt. %.

EFFECT: obtaining a block copolymer composition characterized by high content of high molecular weight fraction (Mw), expanded polydispersity, as a result, the obtained block copolymer composition is characterized by improved processability; based on the block copolymer composition, a polymer-bitumen binder (PBB) is obtained, characterized by improved affinity of the polymer to bitumen, an improved set of properties, namely, increased extensibility and maximum tensile force, improved elasticity and increased stability of PBB during thermal aging.

17 cl, 2 tbl

Description

The field of technology to which the invention belongs

The invention relates to a method for producing a block copolymer composition used in the composition of polymer-bitumen binders (PBV), adhesive compositions, hot melt adhesives, etc.

The technical result consists in obtaining a block copolymer composition characterized by a high content of high molecular weight fraction (M _w ), expanded polydispersity, as a result, the resulting block copolymer composition is characterized by improved processability; on the basis of the block copolymer composition, a polymer-bitumen binder (PBB) is obtained, characterized by an improved affinity of the polymer for bitumen, an improved set of properties, namely, increased extensibility and maximum tensile force, improved elasticity and increased stability of PBB during thermal aging.

State of the art

Bitumens are among the most common organic binders and are a complex mixture of numerous and chemically diverse liquid and solid saturated, unsaturated, aromatic and polyaromatic hydrocarbons and their oxidized oxygen-containing derivatives, insoluble in water, but soluble in carbon disulfide, chloroform and others. organic solvents. Bitumens are widely used in roofing and road construction. Road surfaces using bitumen are durable and safe, and also cost 2-2.5 times cheaper than concrete road surfaces. Common to most pavements is their combination of mineral fillers and bitumen, with bitumen being used as a strong watertight bonding medium. Often, the physical, physico-mechanical and rheological characteristics of natural and industrial bitumen do not fully satisfy the requirements. To impart the required properties to bitumen, the practice of modifying bitumen with various polymeric materials is widespread. Among the modifier polymers used, block copolymers of vinyl aromatic hydrocarbons and conjugated dienes are widely used. The block molecular structure of such copolymers leads to the appearance in the polymer phase of a matrix of thermoplastic domains from aggregated polyviniaromatic blocks, which are interconnected by elastic polydiene blocks. This matrix is retained when bitumen is modified with such copolymers, which leads to an increase in the strength characteristics of the polymer-bitumen binder (PBM) with a simultaneous decrease in the brittleness temperature of PBV (increase in frost resistance), and an increase in elasticity and extensibility. Elasticity (along with other characteristics such as softening point and index of needle penetration, penetration) determines the ability of unmodified bitumen and PMB to reduce cyclic loads, thereby increasing the resistance of the road surface to rutting. The ability of bitumen and PMB to interact with the polymer, filler and road base is improved, which leads to an increase in extensibility and maximum tensile force, and durability of the road surface. Thus, the development of formulations of polymer-bitumen binders for road pavement is the subject of ongoing scientific and practical research and is widely described in the scientific literature and patent documentation.

Patent US7220798 (KRATON CORPORATION, May 22, 2007) describes a method for producing block copolymers of a conjugated diene (blocks B) and one or more alkenyl arenes (blocks A), where diblock copolymers of the A-B structure with a “living” lithium active center are crosslinked into the final polymer silanes of the formula R _x -Si-(OR') _y (x=0.1; y+x=4), R and R' are alkyl groups of various structures. In addition, a composition is described consisting of block copolymers of structures (A-B) ₄ X (0-5%), (A-B) ₃ X (0-60%), (A-B) ₂ X (40- 95%) and AB (2-10%), where A is a polymer block of a monoalkenyl arene and B is a polymer block of a conjugated diene, X is the remainder of the alkoxysilane coupling agent. The scope of the block copolymer composition is not specified.

The disadvantage of this invention is the presence in the polymer of block structures that differ significantly from each other in molecular weights, which can lead to uneven distribution of the block copolymer composition in bitumen, as a result of reduced strength of the polymer network and irregularity of properties in the material of polymer-bitumen binders.

From the patent US8357735 (KRATON POLYMERS US LLC (US), January 22, 2013) a method is known for producing a composition of a polymer-bitumen binder modified with styrene-butadiene block copolymer. The polymer-bitumen binder composition includes 90-98 wt.% bitumen and 2-10 wt.% block copolymer composition. In one of the embodiments of the invention, the polymer-bitumen binder composition includes a block copolymer composition containing (i) a block copolymer obtained by a coupling reaction having a plurality of beams, including at least two blocks of a monovinyl aromatic hydrocarbon placed at least on at least two of the plurality of arms, and at least one conjugated diene block located on at least one of the plurality of arms, and (ii) one or more block copolymers comprising at least one block a monovinyl aromatic hydrocarbon and at least one conjugated diene block. The ratio (i):(ii) in the copolymer compositions is more than 1:1.

The use of a polymer-bitumen binder modified with a block copolymer composition according to the invention in the lower layer of the road surface makes it possible to improve fatigue characteristics, provide increased resistance to irreversible deformations, and increase the cost-effectiveness of road construction and operation. The use of non-polar cross-linking agents - silanes does not allow to fully ensure the required affinity of the polymer for the polar particles of the filler and bitumen and, as a result, the required bonding strength of the polymer-bitumen binder and filler in the road surface and the durability of road surfaces based on such polymer-bitumen binders.

Application WO9525136 A1 (EXXON RESEARCH ENGINEERING CO (US), Sept. 21, 1995) discloses sulfonated non-hydrogenated styrene-butadiene copolymers and a process for their preparation. Block copolymers according to the invention correspond to the formula A-B-A, where A is a polyvinyl arene block, B is a conjugated diene block. Sulfo groups are introduced into the finished polymer by reaction with acyl sulfates (based on acetic or propionic acid), both ready-made and obtained in situ. These block copolymers are used to improve the performance of PMB, in particular to increase the resistance to delamination.

The disadvantage of this method is the use of aggressive reagents (carboxylic and sulfuric acids) to obtain the polymer, which requires additional reactor equipment and separate stages of polymer preparation and polymer modification.

From patent CN101316730 (DOW GLOBAL TECHNOLOGIES INC (US), November 10, 2010), elastomeric polymers modified at the ends of the chains with silanes and sulfides, as well as a method for their preparation, are known. Such functionalized polymers are intended for use in vulcanizable compositions, in particular for tires, the use of these modifiers provides a decrease in rolling resistance (tg δ index at 60 °C), while maintaining good processability and physical and mechanical properties.

However, the above polymers do not have a block structure and are not applicable in the composition of polymer-bitumen mixtures.

Patent CN106496467 (SHANGHAI RES INST CHEMICAL IND, March 15, 2017) proposes a functionalized block copolymer for modifying road bitumen. After the steps of polymerization and neutralization of the active site, the resulting polymer is functionalized in the presence of a radical reaction initiator and a thiol with polar groups at the end: thiolbenzoic acid, and the like. The functionalization of the polymer leads to an increase in the affinity of the block copolymer of the structure to bitumen particles and to an improvement in the distribution of the polymer in bitumen and the stability of polymer-bitumen binders with increasing temperature.

It should be noted that, in this case, the result of the invention is achieved due to the presence of polar groups in the polymer. The thiol group plays no role in the interaction with the bitumen particles, but is used only as a link between the polymer molecule and the polar group.

The disadvantage of this invention is the complexity of the radical reaction, which is difficult to manage and, as a consequence, to control the final result. In addition, the reagents used are commercially difficult to obtain.

From the patent US9328235 (LG CHEM LTD (KR), 05/03/2016), the structure and method for producing a polymeric bitumen modifier is known, which is a triblock copolymer and which is synthesized by anionic block copolymerization of a vinyl aromatic hydrocarbon and a diene hydrocarbon with conjugated double bonds using an organic anionic initiator in a reactor containing a hydrocarbon solvent. The step of obtaining a block copolymer includes forming a vinyl aromatic block by adding a vinyl aromatic hydrocarbon to a reactor containing a hydrocarbon solvent, and then introducing an organic anionic initiator into it; forming a conjugated diene block attached to the end of the vinyl aromatic block by adding a conjugated diene compound to the reactor; introducing a functional additive selected from the group consisting of compounds represented by formula 1 into the reactor; and obtaining an asphalt modifier composition comprising a block copolymer and a functional additive by removing the hydrocarbon solvent. In formula 1, the sum of n+m+m' is up to 35, n is an integer from 1 to 5, each of m and m' is an integer equal to at least 1, and X is an ester group [-C (=O)O-]. The invention also relates to a method for the composition of the bitumen modifier and the composition of the polymer-bitumen binder.

Formula 1

It should be noted that compounds containing polar carboxylate groups are used as a cross-linking agent, which, in turn, can reduce the affinity for non-polar particles of the modified bitumen. It is also shown that the invention does not lead to an increase in the softening temperature in the resulting polymer-bitumen binder.

In patent US6025418 (FINA RESEARCH (BE), Feb. 15, 2002), a method for producing bitumen-polymer compositions in the presence of new vulcanizing agents for better control of the vulcanization reaction is known. The bituminous composition contains, parts by weight: bitumen with a penetration index of 20-320 - 80-90; butadiene polymer or butadiene-styrene block copolymer - 1-20; sulfur and sulfur-containing additive - 0.01-0.15. The method of obtaining bitumen-polymer compositions is carried out by mixing the components at 150-170°C. The styrene-butadiene block copolymer is a linear, radial or star-shaped copolymer with a molecular weight of 120,000-280,000. The invention relates to the field of modification of hydrocarbon binders such as bitumen, asphalts, tars.

The combined use of a vulcanizing system and sulfur has made it possible to prepare bituminous binders with improved crack resistance properties. However, the disadvantage is the low selectivity of the modification reaction with sulfur and sulfur-containing vulcanizing agents, which leads to uneven distribution of the cross-linked polymer network, therefore, to a decrease in its strength and the occurrence of irregular properties in the material of the polymer-bitumen binder. Also in the examples, there was no improvement in the strength of adhesion and adhesion of bitumen particles with the filler in the polymer-bitumen binder, and its stability to aging.

From application US6087420 (ELF ANTAR FRANCE (FR), 07/11/2000) a method for producing bitumen-polymer compositions with improved physical and mechanical properties for road surfaces, bituminous mixtures or waterproof lining is known. The method also relates to the mother liquor of the polymer, which can be used to prepare from these compositions. According to the proposed embodiment of the preparation of polymer-bitumen compositions, bitumen or a mixture of bitumens and a copolymer of styrene and butadiene of a linear or branched structure, having a total content of butadiene in the range from 50 to 95 wt.% and 1,2-units in the range from 12 to 50 wt. .%, maintained under stirring at temperatures from 100 to 230°C. To form a polymer-bitumen composition that contains at least one cross-linking agent selected from the group formed by (i) sulfur-donor coupling agents, (ii) functionalizing agents selected from carboxylic acids or esters containing thiol or disulfide groups, and (iii) peroxide compounds that generate free radicals at temperatures from 100°C to 230°C. Sulfur is preferably used as a binding agent.

It is known that peroxide compounds initiate the destruction and destruction of the polymer. Thus, the use of these compounds leads to a rapid deterioration of the properties of polymer-bitumen binders.

The closest in technical essence and the achieved result is a method for modifying a polymer-bitumen binder, disclosed in patent US5508112 (ARR-MAZ PRODUCTS, L.P., FLORIDA, 04/16/1996). In this patent, the method for preparing PVB involves homogenizing a mixture of bitumen and a block copolymer of styrene and a conjugated diene at an elevated temperature for a certain period of time. Then, a mixture of sulfur is added to the homogeneous polymer-bitumen composition with heating and prolonged stirring as a cross-linking agent and a cross-linking accelerator, selected from mono- and dithiuramsulfide, morpholine disulfide, caprolactam N,N'-disulfide, with the addition of alkyl disulfides, benzothiazolsulfonamides, metal dithiocarbamates (bismuth , zinc, copper, sodium), guanidine, fatty acids. The polymer is a di- or triblock copolymer of styrene with butadiene or isoprene or carboxylated isoprene or chloroprene or carboxylated butadiene. The polymer and the crosslinking agent are introduced into the bitumen simultaneously in the form of a solution in oil, mixing is carried out at 100-230°C for at least 10 minutes, preferably from 10 to 60 minutes.

The disadvantages of this method include the use of sulfur, which carries environmental risks, as well as the fact that mixing separately the polymer in bitumen and a mixture of a sulfur-containing coupling agent and a crosslinking accelerator does not allow them to be homogeneously distributed in the polymer-bitumen structure, which can lead to deterioration of the characteristics of the polymer-bitumen binder and the low quality of the road surface based on it.

Disclosure of the Invention

The technical objective of the present invention is the creation of a block copolymer composition that improves extensibility, maximum tensile strength and elasticity of polymer-bitumen binders (PBV); improving the stability of PBB under thermal exposure.

The present invention relates to a method for producing a block copolymer composition by polymerization of a vinyl aromatic hydrocarbon and a conjugated diene, taken in the ratios (30-32): (68-70) wt.%, respectively, in a hydrocarbon solvent medium, in the presence of an electron donor additive, an organolithium initiator, a post-polymerization treatment with at least two coupling agents, degassing, squeezing, isolation and drying, each of the coupling agents being independently selected from silicon-containing compounds of formula R ₂ SiHal ₂ , where R is C ₁ -C ₂₀ alkyl or C ₅ -C ₂₀ aryl groups, and sulfur-containing compounds having in their structure polysulfide groups (-S-) _n , where n=1-8, and a linker group (-Y-) selected from C ₁ -C ₂₀ -alkyl, C ₃ -C ₂₀ -alicyclic, C ₃ -C ₂₀ -heterocyclic, C ₅ -C ₂₀ -aromatic groups.

The present invention also relates to a method for producing polymer-bitumen binders by obtaining the above-described block copolymer composition by polymerizing a vinyl aromatic hydrocarbon, post-polymerization treatment using at least two coupling agents, degassing, pressing, isolating and drying, each of the coupling agents being independently selected from silicon-containing compounds of the formula R ₂ SiHal ₂ , where R represents C ₁ -C ₂₀ alkyl or C ₅ -C ₂₀ aryl groups, and sulfur-containing compounds having polysulfide groups (-S-) _n in their structure, where n=1-8 , and a linker group (-Y-) selected from C ₁ -C ₂₀ -alkyl, C ₃ -C ₂₀ -alicyclic, C ₃ -C ₂₀ -heterocyclic, C ₅ -C ₂₀ -aromatic groups, and adding the resulting block -copolymer composition into bitumen.

In addition, the present invention relates to a block copolymer composition for polymer-bitumen binders, comprising

(i) 8 to 16 wt. % uncrosslinked diblock block copolymer AB;

(ii) from 34 to 87 wt. % triblock block copolymer obtained using a silicon-containing coupling agent;

(iii) from 5 to 50 wt. % triblock block copolymer obtained using a sulfur-containing coupling agent and

(iv) optionally, functional additives,

where A is a monovinyl aromatic hydrocarbon block, B is a conjugated diene block,

moreover, the content of the bound monovinyl aromatic monomer is from 30 to 32 wt.%, the conjugated diene is from 68 to 70 wt.%, the content of 1,2-vinyl units is from 10 to 43 wt.% based on 100 wt.% block copolymer compositions.

The block copolymer composition is characterized by the content of bound monovinyl aromatic monomer from 30 to 32 wt.%, the content of 1,2 units from 10 to 43 wt.% per polymer block of conjugated diene, the content of diblock copolymer from 8 to 16 wt.%, weight average molecular weight from 75,000 to 115,000 amu and polydispersity from 1.3 to 1.6.

The present invention also relates to a polymer-bitumen binder for road construction, which is a mixture consisting of 95.0-98.0 wt. % bitumen and 2.0-5.0 wt. % block copolymer composition according to the invention.

The technical result of the present invention is to obtain a block copolymer composition characterized by a high content of high molecular weight fraction (M _w ), expanded polydispersity (from 1.3 to 1.6), as a result, the block copolymer composition according to the invention is characterized by improved processability; The polymer-bitumen binder (PBB) obtained on the basis of the block copolymer composition is characterized by improved affinity of the polymer to bitumen, an improved set of properties, namely, increased extensibility and maximum tensile force, improved elasticity and increased stability of PBB during thermal aging.

Block copolymer composition for polymer-bitumen binders in accordance with the invention is a mixture of block copolymers (i)-(iii) as defined above, with the addition, if necessary, functional additives (iv), conventional in this field.

The presence of 8 to 16 wt. % block copolymer AB (i) in the composition gives increased adhesion of the block copolymer composition to bitumen particles due to intermolecular physical and chemical contacts, being in fact a regulator of the viscosity and distribution rate of the polymer in bitumen. When the content of non-crosslinked block copolymer AB (i) is below 8 wt. %, the mixing rate of the block copolymer with bitumen decreases, thereby not achieving complete distribution of the block copolymer in PBB. When the content of the block copolymer AB (i) more than 16 wt. %, the softening temperature of PMB decreases, the value of the penetration index (needle penetration depth) increases, which negatively affects the performance of the road surface.

The presence of 34 to 87 wt. % block copolymer cross-linked with a silicon-containing coupling agent (ii) in the composition according to the invention ensures the formation in PMB of a strong thermoplastic network of polystyrene domains connected by elastic polybutadiene blocks.

The presence of 5 to 50 wt. % block copolymer crosslinked with a sulfur-containing coupling agent (iii) provides strong adhesion between the particles of the block copolymer composition and bitumen due to the formation of chemical bonds through sulfur atoms. When the content of the block copolymer (iii) is below 5 wt. % improvement of PMB properties is not observed. When the content of the block copolymer (iii) above 50 wt. %, the strength of the polymer mesh in PMB decreases, which negatively affects all the key performance characteristics of the road surface: durability, resistance to cracking and rutting, frost and heat resistance.

In accordance with the present invention, block A in the composition of block copolymers is a block of monovinyl aromatic hydrocarbon. As monovinyl aromatic hydrocarbons, styrene or α-methylstyrene is preferably used, most preferably styrene is used. The content of monovinyl aromatic hydrocarbons in the final block copolymer is from 30 to 32 wt.% of the total weight of the block copolymer.

In accordance with the present invention, the B block in the block copolymers is a conjugated diene block. The conjugated dienes are preferably 1,3-butadiene or isoprene, most preferably 1,3-butadiene. The content of the conjugated diene in the final block copolymer is from 68 to 70 wt.% of the total weight of the block copolymer.

As a coupling agent, a combination of silicon and sulfur-containing compounds is used.

As silicon-containing coupling agent, halogen-substituted silanes of the general formula R ₂ SiHal ₂ are preferably used, where R represents C ₁ -C ₂₀ alkyl or C ₅ -C ₂₀ aryl groups. The most preferred silicon-containing coupling agents are dimethyldichlorosilane (DMDCS) and diphenyldichlorosilane (DPDCS).

The amount of silicon-containing coupling agent used is calculated on the amount of lithium in the initiator, while according to the invention, the molar ratio of halogen to lithium is in the range from 0.34 to 0.84. The specified range provides the desired degree of branching of the block copolymer, since when using a smaller amount of silicon-containing coupling agent, the content of the diblock copolymer exceeds 16 wt.% in the composition of the block copolymer, and the dosage of the silicon-containing coupling agent above the specified range will lead to the content of the block (ii) in the composition will exceed 87 wt. %.

As sulfur-containing coupling agents, which act as cross-linking agents and further as cross-linking accelerators in the preparation of polymer-bitumen compositions, compounds are used that have polysulfide groups (-S-) _n in their structure, where n=1-8, preferably n= 1-4, most preferably n=2 or n=4. Moreover, in the composition of sulfur-containing coupling agents there are linker groups (-Y-), which are able to react with active Li atoms in the polymer chain and attach these polymer chains. As linker groups (-Y-), C ₁ -C ₂₀ - alkyl, C ₃ -C ₂₀ - alicyclic, C ₃ -C ₂₀ -heterocyclic, C ₅ -C ₂₀ -aromatic group groups can be used; preferred alkyl group-linkers structure -(CH ₂ ) _n - where n=3 or more, most preferred alkyl linkers -(CH ₂ ) _n - where n=3, since such compounds are commercially available.

Preferably, di(1-methylethyl) thioperoxydicarboxylic acid ester, 4,4'-dinitrodiphenyl disulfide, bis(triethoxysilylpropyl)disulfide, bis[3-(triethoxysilyl)propyl]tetrasulfide, tetra-n-butylthiuramdisulfide are used as the sulfur-containing coupling agent.

Most preferably, bis[3-(triethoxysilyl)propyl]disulfide, bis[3-(triethoxysilyl)propyl]tetrasulfide and tetra-n-butylthiuramdisulfide are used.

The amount of sulfur-containing coupling agent used is calculated on the amount of lithium, while according to the invention, the molar ratio of the sulfur-containing agent to lithium is in the range from 0.025 to 0.25. This range provides the content of the sulfur-containing block copolymer required by the present invention in the composition.

The term "alkyl group" means a saturated hydrocarbon substituent with a straight or branched chain, usually containing from 1 to 20 carbon atoms, for example, from 1 to 10, from 1 to 8, from 1 to 6 or from 1 to 4 carbon atoms. Examples of such substituents include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, t-butyl, branched and unbranched pentyl, hexyl, heptyl, octyl, nonyl and decyl.

The term "alkenyl group" means a straight or branched hydrocarbon substituent containing one or more double bonds and typically 2 to 20 carbon atoms; for example, 2 to 10, 2 to 8, 2 to 6, or 2 to 4 carbon atoms. Examples of such substituents include ethenyl (vinyl), 2-propenyl, 3-propenyl, 1,4-pentadienyl, 1,4-butadienyl, 1-butenyl, 2-butenyl, 3-butenyl, pentenyl, and hexenyl.

The term "alkynyl group" (by itself or in combination with other term(s)) means a straight or branched hydrocarbon substituent containing one or more triple bonds and typically 2 to 15 carbon atoms; for example, 2 to 10, 2 to 8, 2 to 6, or 2 to 4 carbon atoms. Examples of such substituents include ethynyl, 2-propynyl, 3-propynyl, 2-butynyl and 3-butynyl.

The term "cycloalkyl group" means a saturated cyclic hydrocarbon substituent containing from 3 to 14 carbon atoms in the ring. Cycloalkyl may have one carbon cycle, which typically contains 3 to 8 ring carbon atoms, and more typically 3 to 6 ring atoms.

The term "aryl group" means an aromatic carbocycle containing 6 to 14 ring carbon atoms, or 3 to 8, 3 to 6 or 5 to 6 ring carbon atoms. Aryl may be monocyclic or polycyclic (ie may have more than one cycle). In the case of polycyclic aromatic rings, only one ring in the polycyclic system must be unsaturated, while the remaining rings may be saturated, partially saturated or unsaturated. Examples of aryl groups include phenyl, naphthyl.

The term "heterocyclic group" means a saturated, partially unsaturated or aromatic ring structure containing a total of 3 to 14 ring atoms, where at least one of the ring atoms is a heteroatom (for example, an oxygen, nitrogen or sulfur atom), and the remaining ring atoms are carbon atoms. The heterocyclyl group may, for example, contain one, two, three, four or five heteroatoms.

Examples of heterocyclyls include furanyl, pyrazolyl, morpholinyl, indolizinyl, pyranopyrrolyl, pyridyl, pyrimidinyl.

As used herein, an "aliphatic group" is a chemical group that contains at least one chain of carbon atoms that is at least 20 carbon atoms in length.

The aromatic group may be a carbocyclic aryl group with from 6 to 10 carbon atoms in the ring, which may be unsubstituted or substituted with at least one substituent group selected from the group consisting of substituent groups C below; nitro groups; as well as a carboxyl group; said substituent C groups are selected from the group consisting of C 1 to C 6 alkyl groups; alkoxy groups with 1 to 6 carbon atoms; hydroxyl groups; halogen atoms; amino groups; alkylamino groups with 1 to 6 carbon atoms.

As the hydrocarbon solvent of the present invention, aliphatic and aromatic hydrocarbon solvents or mixtures thereof are used. In accordance with the invention, hexane, toluene, cyclohexane can be used. It is most preferable to use a hydrocarbon solvent, which is a mixture of cyclohexane and nefras in the ratio (65-75):(30-35), where nefras is a hexane-heptane fraction of paraffinic hydrocarbons of dearomatized catalytic reforming gasolines with boiling point limits of 65-75°C.

As the electron donor additive (ED) of the present invention, compounds selected from the class of ethers such as diethyl ether, di-n-butyl ether, ethylene glycol diethyl ether, diethylene glycol dimethyl ether, propylene glycol dimethyl ether, propylene glycol diethyl ether, propylene glycol dibutyl ether, ethyl tert-butyl ether of ethylene glycol; from the class of alkyltetrahydrofuryl ethers such as methyltetrahydrofuryl ether, ethyltetrahydrofuryl ether, propyltetrahydrofuryl ether, butyltetrahydrofuryl ether, hexyltetrahydrofuryl ether, octyltetrahydrofuryl ether, tetrahydrofuran, 2,2-di(tetrahydrofuryl)propane (DTHFP), tetrahydrofuryl alcohol methyl ether, butyl ether or tetrahydrofuryl alcohol from the class of amines such as triethylamine butyl ether, pyridine, N,N,N',N'-tetramethylethylenediamine (TMEDA), triethylamine, tripropylamine, ethylenetriamine, dipiperidinoethane.

As the most preferred electron donor additive in accordance with the present invention, ethylene glycol ethyl tert-butyl ether and tetrahydrofuran (THF) or mixtures thereof are used.

The amount of electron donor additive (ED) used is calculated as a molar ratio to lithium and varies in the range from 0.010 to 1.000 depending on the required microstructure of the block copolymer and the electron donor additive used: the higher the dosage of the electron donor additive used, the higher the content of 1,2-units in the resulting block copolymer.

Ethyllithium, isopropyllithium, n-butyllithium, sec-butyllithium, tert-butyllithium, phenyllithium, ethyllithium, methyllithium, dimethylaminopropyllithium, α-methylstyryldilithium, lithium pyrrolidide, tert-butyldimethylsiloxypropyllithium, 2-naphthyllithium, 4 -phenylbutyllithium, propyllithium, isopropyllithium. Most preferably, n-butyllithium is used.

The amount of initiator used is in the range from 20.0 to 25.0 mmol per 1 kg of monomers. More or less initiator will not allow you to get a polymer with the desired molecular weights of the polymer.

In one of the embodiments of the invention, the process of obtaining a composition of a block copolymer of a conjugated diene and a monovinyl aromatic monomer is carried out by anionic copolymerization in a reactor, in a hydrocarbon solvent medium, in the presence of an electron donor additive, an organolithium initiator and at least two coupling agents selected from silicon-containing and sulfur-containing coupling agents. Polymerization is initiated by adding an initiator solution to a reactor solution of a vinyl aromatic hydrocarbon in a hydrocarbon solvent over a temperature range of 35 to 60° C., forming a polyvinyl aromatic polymer block A with active lithium at the end. After complete conversion (10-30 minutes) of the vinylaromatic monomer, the conjugated diene is added in the temperature range from 45 to 55°C, and at the second stage of the process, polymer synthesis is continued by the formation of a polydiene block in the temperature range of 45-95°C, for 10-20 minutes. In this way, a diblock non-crosslinked copolymer of structure AB (i) is obtained.

To obtain a triblock structure crosslinked with a silicon-containing coupling agent copolymer (ii), at the final stage of polymerization, the resulting diblock block copolymer is cross-linked with a calculated amount of a silicon-containing coupling agent. Crosslinking is carried out for 5-10 minutes at a temperature of 90 to 115°C. Then, after crosslinking with a silicon-containing coupling agent, a calculated amount of a sulfur-containing coupling agent is added to obtain a block copolymer crosslinked with a sulfur-containing agent (iii). After cross-linking for 5-10 minutes at a temperature of 90 to 115°C, the residual active lithium is neutralized with a stopper. Compounds with active hydrogen are used as a stopper: alcohols, acids, water, etc.

The crosslinking process can be carried out by introducing combining agents in any sequence or simultaneously.

Alternatively, the non-crosslinked AB diblock copolymer and the triblock block copolymers crosslinked with appropriate coupling agents are each synthesized in a separate reactor and then mixed, for example, in a blender, in such proportions as to meet the requirements of the present invention.

After deactivation of the active sites prior to degassing, the polymerizate is stabilized with any suitable antioxidant. Most preferably, a mixture of phenolic, amine and sulfur containing antioxidants is used. The dosage of the antioxidant, as a rule, is 0.4-0.6 wt.% on the polymer. This dosage is necessary and sufficient for effective stabilization of the polymer.

Then the block copolymer composition is subjected to water-steam degassing to remove the solvent and subsequent drying.

The block copolymer composition obtained in accordance with the present invention has the following characteristics: the content of the bound monovinyl aromatic monomer is from 30 to 32 wt.%, the conjugated diene is from 68 to 70 wt.%, the content of 1,2-vinyl units is from 10 up to 43 wt.%, the weight average molecular weight of the block copolymer composition is in the range from 75,000 to 115,000 a.m.u. and polydispersity from 1.3 to 1.6.

On the basis of the obtained block copolymer composition, by adding it to the bitumen, a polymer-bitumen binder (PBB) for road construction is obtained, which is a mixture consisting of (A) 95.0-98.0 wt. % bitumen and (B) 2.0-5.0 wt. % block copolymer composition.

The PMB preparation process is typically carried out as follows: the calculated amount of the block copolymer composition is introduced into the bitumen heated to a temperature of at least 175±5°C. Mixing is carried out for 120±5 minutes at a constantly maintained temperature of 185±5°C and a stirring speed of 3000±250 rpm.

The bitumen used in the method according to the present invention is selected from any bitumen, both natural and artificial, obtained from the processing of oil, fossil fuels, bituminous rocks. In addition, petroleum and coal tars obtained by cracking can be used as a component of the polymer-bitumen composition. It is also permissible to use mixtures of different bituminous materials. Examples of suitable bitumen include straight run bitumen, precipitated bitumen, oxidized bitumen or mixtures thereof. It is also possible to use mixtures of one or more of these bitumens with fillers such as petroleum extracts, for example aromatic extracts.

Suitable bitumens are those having penetration values ranging from about 25 to about 400 dmm at 25° C., preferably from 80 to about 160 dmm, most preferably bitumens having a penetration of from about 80 to about 140 dmm.

The share of bitumen in the composition of PMB is 95-98 wt.%. Increasing the amount of bitumen above the specified range leads to a decrease in the characteristics of the road surface: resistance to rutting, resistance to cracking, heat resistance and frost resistance. Reducing the amount of bitumen will lead to an increase in viscosity (deterioration in processability) of PBB.

The share of the block copolymer composition in the composition of PBB is from 2 to 5 wt.%. It should be noted that an increase in the content of the block copolymer composition above the specified range will increase the viscosity of PMB, and a decrease in it will lead to the fact that the viscosity of PMB will meet the technological requirements, but at the same time the softening temperature will decrease and the penetration depth of the needle will increase.

The obtained PMB has the following characteristics: extensibility at 25°C in the range from about 60 to about 91 cm; maximum tensile force at 0°C from 130.0 to 159.5 N; change in penetration after aging (70 minutes at 163°C) from about 73% to about 86%; change in elasticity (at 25°C) after aging (70 minutes at 163°C) from 87.6 to 97.9%. At the same time, other key characteristics of PMB, such as softening point, needle penetration depth, Brookfield dynamic viscosity, remain unchanged.

Implementation of the Invention

Next, embodiments of the present invention will be described. Specialists in this field will be clear that it is not limited only to the examples presented, and the same effect can be achieved in other embodiments that do not go beyond the essence of the claimed invention.

The following describes the test methods used to evaluate the properties of the block copolymer composition and polymer-bitumen binder obtained by the claimed method.

1) The molecular weight characteristics of the samples of the block copolymer composition were determined by gel permeation chromatography according to an internal method. The measurements were carried out on a Gel-Permeation Chromatography Agilent 1260 Infinity II gel chromatograph with columns connected in series: 1) PLgel MIXED-C 300 × 7.5 mm; 2) PLgel MIXED-C 300 × 7.5 mm; 3) PLgel MIXED-C 300 × 7.5 mm, as well as on a Breeze gel chromatograph (Waters) with a refractive index detector. Samples of the block copolymer composition were dissolved in freshly distilled tetrahydrofuran, the mass concentration of the polymer in the solution was 2 mg/mm, universal calibration according to polystyrene standards. The calculation was carried out using the Mark-Kuhn-Houwink constants (for block copolymers containing a monovinyl aromatic hydrocarbon and a conjugated diene K=0.00041, α=0.693). Definition conditions:

- a bank of 4 columns with high resolution (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 × 107 amu ;

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

- temperature of column thermostat and refractometer – 30°C.

2) Determination of the microstructure of samples of the block copolymer composition was carried out according to an internal method, which is based on recording the IR spectrum of the analyzed sample on an infrared Fourier spectrometer using the MATRT attachment (multiple frustrated total internal reflection) and further measuring the optical density maxima of the analytical absorption bands in the ranges :

- for 1,4-trans links from 960 cm ^-1 to 980 cm ^-1 ;

- for 1,2-links from 900 cm ^-1 to 920 cm ^-1 ;

- for bound styrene from 690 cm ^-1 to 710 cm ^-1 .

3) The softening point (K&S) of PBB is determined according to GOST 11506-73.

4) Determination of the needle penetration depth (Penetration) PBB is determined according to GOST 11501-78.

5) Determination of the dynamic viscosity of PMB is determined according to GOST 33142-2014.

6) The extensibility of PMB was determined in accordance with GOST R 33138-2014.

7) The determination of the maximum tensile force was carried out in accordance with GOST R 33138-2014.

8) Determination of the elasticity index after aging for 70 minutes at a temperature of 163°C in accordance with GOST 33140-2014 and GOST R 52056-2003.

The essence of the proposed technical solution is illustrated by the following examples of specific performance, which illustrate, but do not limit the scope of the claims of this invention. Those skilled in the art will appreciate that it is not limited to them and that the same effect can be achieved by applying equivalent formulas.

Example 1 ( prototype method, which does not include the addition of a sulfur-containing coupling agent at the stage of obtaining a block copolymer composition)

a) The synthesis of styrene-butadiene block copolymers was carried out in a metal reactor with a working volume of 5 l, equipped with a stirrer, thermostat jacket, fittings and special removable metal dispensers for reagent supply. The temperature in the jacket and the reactor was controlled through the automated process control system of the thermostat. The rotation speed of the stirrer during the entire synthesis was 300 rpm. The loading of a mixture of 3 liters of solvent with 147.5 ml of styrene and 7.42 ml of THF (as an electron donor additive) was carried out in a stream of nitrogen through a vessel with a siphon feed system. The initiator (n-BuLi) in the amount of 8.46 ml (8.71 mmol) was fed into the reactor at a temperature of 40°C. The polymerization of the polystyrene block was carried out for 20 minutes, recording the temperature increase. Then, 298.0 g of butadiene was fed into the reactor and, by forced heating, the temperature of the reaction mass was raised to 85°C (the ratio of styrene/butadiene is 30/70). Upon reaching the set temperature, the heating of the reactor was turned off. The formation of the polybutadiene part of the diblock copolymer was carried out for 30 minutes. The synthesis time of the polybutadiene block was counted from the moment 85°C was reached until the temperature began to decrease from the maximum reached point. Next, a silicon-containing coupling agent, dimethyldichlorosilane (DMDCS), was fed into the reactor in an amount of 7.69 ml, after which forced heating was turned on to maintain a constant temperature of 85°C in the reactor. The crosslinking step into the triblock copolymer was carried out for 5 minutes.

The finished product was isolated in a laboratory degasser by distilling off the solvent with live steam. The crude sample was cut into small pieces, which were dried in an oven at 90°C for 2 hours.

b) Then the preparation of the PMB composition was carried out in accordance with the recipe.

At the first stage, 3.0 wt.% of the block copolymer synthesized using a silicon-containing coupling agent in stage a) was added to the heated bitumen in the amount of 96.9 wt.%, and then mixing was carried out for 3 hours and 10 minutes using the IKA mixing system Werke Ultraturrax using a G45G high shear tip at a constant temperature of 170°C and 3000 rpm. Then, 0.1 wt. % crystalline sulfur as a crosslinking agent was added in a mixture with 0.02 wt.

The properties of the resulting block copolymer composition are presented in Table 1.

The properties of the resulting PMB are presented in Table 2.

Example 2 (comparative)

Receipt block copolymer composition was carried out analogously to example 1 with the difference that at the stage of preparation of PBB, 4.0 wt.% of the block copolymer composition synthesized using a silicon-containing coupling agent. The mixing of the block copolymer composition with bitumen was carried out for 120 minutes without adding sulfur, at a constantly maintained temperature of 185°C.

The properties of the resulting block copolymer composition are presented in Table 1.

The properties of the resulting PMB are presented in Table 2.

Example 3

Receipt The butadiene-styrene block copolymer composition was carried out analogously to example 1 with the difference that at the stage of polymer synthesis, after supplying the calculated amount of a silicon-containing coupling agent, a sulfur-containing coupling agent, bis[3-(triethoxysilyl)propyl] disulfide, was introduced in an amount of 0.34 mmol.

The preparation of PBB was carried out in the same way as in example 2.

The properties of the resulting block copolymer composition are presented in Table 1.

The properties of the resulting PMB are presented in Table 2.

Example 4

Receipt block copolymer composition was carried out analogously to example 3 with the difference that isoprene was used as the conjugated diene in the amount of 298.0 g, and the amount of sulfur-containing coupling agent was 1.70 mmol. Diphenyldichlorosilane was used as the silicon-containing coupling agent in an amount of 7.69 ml.

The preparation of PMB was carried out in the same way as in example 2 with the difference that the amount of bitumen was 95 wt.%, the amount of polymer - 5 wt.%.

The properties of the resulting block copolymer composition are presented in Table 1.

The properties of the resulting PMB are presented in Table 2.

Example 5

Receipt butadiene-styrene block copolymer composition was carried out analogously to example 4 with the difference that the amount of styrene 152.2 ml, the amount of butadiene 293.7 g (the ratio of styrene/butadiene was 32/68), the amount of sulfur-containing coupling agent 3.40 mmol was applied directly for synthesis after filing the calculated amount of silicon-containing coupling agent.

The preparation of PMB was carried out in the same way as in example 2, with the difference that the amount of bitumen was 98 wt.%, the amount of polymer - 2 wt.%.

The properties of the resulting block copolymer composition are presented in Table 1.

The properties of the resulting PMB are presented in Table 2.

Example 6 (comparative)

The synthesis of a butadiene-styrene block copolymer composition with a content of 1,2-vinyl units increased to 40% (of the polybutadiene part) was carried out in accordance with example 2, with the difference that ethyl tert-butyl ether of ethylene glycol was used as an electron donor additive in the amount 3.96 mol.

The preparation of PBB was carried out in the same way as in example 2.

The properties of the resulting block copolymer composition are presented in Table 1.

The properties of the resulting PMB are presented in Table 2.

Example 7

Receipt block copolymer composition was carried out analogously to example 6, with the difference that isoprene was used as the conjugated diene. Bis[3-(triethoxysilyl)propyl]tetrasulfide was used as a sulfur-containing coupling agent in an amount of 0.25 mmol. The sulfur-containing coupling agent was fed directly after the formation of the diblock copolymer at the stage of synthesis of the block copolymer composition.

The preparation of PBB was carried out in the same way as in example 2.

The properties of the resulting block copolymer composition are presented in Table 1.

The properties of the resulting PMB are presented in Table 2.

Example 8

Receipt butadiene-styrene block copolymer composition was carried out analogously to example 7 with the difference that tetra-n-butylthiuram disulfide was used as a sulfur-containing coupling agent in an amount of 0.27 mmol. The sulfur-containing coupling agent was fed directly after the formation of the diblock copolymer at the stage of synthesis of the block copolymer composition. Diphenyldichlorosilane was used as the silicon-containing coupling agent.

The preparation of PBB was carried out in the same way as in example 4.

The properties of the resulting block copolymer composition are presented in Table 1.

The properties of the resulting PMB are presented in Table 2.

Example 9

Receipt styrene-butadiene block copolymer composition was carried out analogously to example 8 with the difference that the amount of sulfur-containing coupling agent was 1.20 mmol, it was supplied immediately after the formation of the diblock copolymer at the stage of synthesis of the block copolymer composition. Dimethyldichlorosilane (DMDCS) was used as the silicon-containing coupling agent.

The preparation of PBB was carried out in the same way as in example 5.

The properties of the resulting block copolymer composition are presented in Table 1.

The properties of the resulting PMB are presented in Table 2.

Example 10

Receipt butadiene-styrene block copolymer composition was carried out analogously to example 9 with the difference that di-(1-methylethyl) ester of thioperoxydicarboxylic acid was used as a sulfur-containing coupling agent in an amount of 0.27 mmol. Silicon-containing and sulfur-containing coupling agents were supplied in combination in one solution immediately after the formation of the diblock copolymer at the stage of synthesis of the block copolymer composition. Dimethyldichlorosilane was used as the silicon-containing coupling agent.

The preparation of PBB was carried out in the same way as in example 8.

The properties of the resulting block copolymer composition are presented in Table 1.

The properties of the obtained PMB are presented in Table 2.

Table 1

Molecular Weight Characteristics and Microstructure of Block Copolymer Composition (BCC)

No. Monomers SA(Si) ^* SA(S) ^** Content in the block copolymer composition M_w×10³, a.u.m. Polydispersity (i), wt. % (ii), wt. % (iii), wt. % Content of bound MM ^*** , % Content of 1,2 units, % 1 (P) Styrene Butadiene-1,3 DMDHS - 16.0 84.0 - thirty 10 85 1.3 2 (C) Styrene Butadiene-1,3 DMDHS - 16.0 84.0 - thirty 10 85 1.3 3 Styrene Butadiene-1,3 DMDHS SA(S) ₁ 15.9 79.1 five thirty 10 99 1.4 4 Styrene Isoprene DFDHS SA(S) ₁ 15.0 60.0 25 thirty 10 109 1.5 five Styrene Butadiene-1,3 DFDHS SA(S) ₁ 15.7 34.3 fifty 32 10 115 1.6 6 (C) Styrene Butadiene-1,3 DMDHS - 8.0 92.0 - thirty 40 75 1.2 7 Styrene Isoprene DMDHS SA(S) ₂ 9.7 84.3 6 thirty 43 79 1.3 8 Styrene Butadiene-1,3 DFDHS SA(S) ₃ 10.5 82.5 7 thirty 40.5 84 1.3 nine Styrene Butadiene-1,3 DMDHS SA(S) ₃ 16.0 51.0 33 thirty 40.8 91 1.4 10 Styrene Butadiene-1,3 DMDHS SA(S) ₄ 10.3 81.7 8 thirty 40.3 86 1.3

Note

SA(Si) ^* – silicon-containing coupling agent

DMDCS - dimethyldichlorosilane

DFDHS - diphenyldichlorosilane

SA(S) ^** - sulfur-containing coupling agent - crosslinking accelerator in the preparation of polymer-bitumen compositions

SA(S) ₁ - bis[3-(triethoxysilyl)propyl]disulfide

SA(S) ₂ - bis[3-(triethoxysilyl)propyl]tetrasulfide

CA(S) ₃ - tetra-n-butylthiuram disulfide

CA(S) ₄ - di(1-methylethyl) ester of thioperoxydicarboxylic acid

MM ^*** - monovinyl aromatic monomer

In accordance with the data in Table 1, it is obvious that the block copolymer composition according to the invention is characterized by an increased content of high molecular weight fraction (Mw), expanded polydispersity, as a result, the resulting block copolymer composition is characterized by improved processability.

From Table 2 it is obvious that PMBs based on the block copolymer composition according to the invention are distinguished by an improved set of properties, namely increased extensibility and maximum tensile force, improved elasticity and increased stability of PMBs during thermal aging.

The improvements achieved are especially noticeable against the background of comparative examples (examples 2 and 6), in which PMB was prepared on the basis of a block copolymer obtained without the use of a sulfur-containing coupling agent.

Claims (24)

1. The method of obtaining a block copolymer composition, including the polymerization of monovinyl aromatic hydrocarbon and conjugated diene, taken in the ratios (30-32):(68-70), wt. %, respectively, in a hydrocarbon solvent medium, in the presence of an electron donor additive, an organolithium initiator, post-polymerization treatment with at least two coupling agents, degassing, pressing, isolation and drying, each of the coupling agents being independently selected from silicon-containing compounds of the formula R ₂ SiHal ₂ , where R represents C ₁ -C ₂₀ -alkyl or C ₆ -C ₂₀ -aryl groups, in a molar ratio of halogen to lithium in the range from 0.34 to 0.84, and sulfur-containing compounds having polysulfide groups in their structure (-S -)n, where n=1-8, and a linker group (-Y-) selected from C ₁ -C ₂₀ -alkyl, C ₃ -C ₂₀ -alicyclic, C ₃ -C ₂₀ -heterocyclic, C ₆ - With ₂₀ -aromatic groups, in a molar ratio to lithium in the range from 0.025 to 0.25. 2. The method according to p. 1, characterized in that these combining agents are added simultaneously or sequentially in any sequence. 3. The method according to claim 1, characterized in that dimethyldichlorosilane and diphenyldichlorosilane are used as a silicon-containing coupling agent. 4. The method according to p. 1, characterized in that as a sulfur-containing coupling agent, compounds are used that have polysulfide groups (-S-) _n in their structure, where n=1-4, preferably n=2 or n=4. 5. The method according to claim 1, characterized in that di-(1-methylethyl ether of thioperoxydicarboxylic acid, 4,4'-dinitrodiphenyl disulfide, bis(triethoxysilylpropyl) disulfide, bis[3-(triethoxysilyl)propyl] is used as a sulfur-containing coupling agent tetrasulfide, tetra-n-butylthiuram disulfide; most preferably bis[3-(triethoxysilyl)propyl]disulfide, bis[3-(triethoxysilyl)propyl]tetrasulfide and tetra-n-butylthiuramdisulfide. 6. The method according to claim 1, characterized in that compounds selected from the class of ethers, such as diethyl ether, di-n-butyl ether, ethylene glycol diethyl ether, diethylene glycol dimethyl ether, propylene glycol dimethyl ether, diethyl ether are used as an electron donor additive. propylene glycol, propylene glycol dibutyl ether, ethylene glycol ethyl tert-butyl ether; from the class of alkyltetrahydrofuryl ethers such as methyltetrahydrofuryl ether, ethyltetrahydrofuryl ether, propyltetrahydrofuryl ether, butyltetrahydrofuryl ether, hexyltetrahydrofuryl ether, octyltetrahydrofuryl ether, tetrahydrofuran, 2,2-di(tetrahydrofuryl)propane (DTHFP), tetrahydrofuryl alcohol methyl ether, tetrahydrofuryl alcohol butyl ether or from the class of amines such as triethylamine butyl ether, pyridine, N,N,N',N'-tetramethylethylenediamine (TMEDA), triethylamine, tripropylamine, ethylenetriamine, dipiperidinoethane; most preferably, ethylene glycol ethyl tert-butyl ether and tetrahydrofuran (THF) or mixtures thereof are used as the electron donor additive. 7. The method according to claim 1, characterized in that ethyl lithium, isopropyl lithium, n-butyl lithium, sec-butyl lithium, tert-butyl lithium, phenyl lithium, ethyl lithium, methyl lithium, dimethylaminopropyl lithium, butyldimethylsiloxypropyllithium, 2-naphthyllithium, 4-phenylbutyllithium, propyllithium, isopropyllithium; most preferably n-butyllithium is used. 8. The method according to p. 1, characterized in that as a hydrocarbon solvent used aliphatic or aromatic hydrocarbon solvents, or mixtures thereof; preferably the solvent is selected from hexane, toluene, cyclohexane; most preferably, a hydrocarbon solvent is used, which is a mixture of cyclohexane and nefras in the ratio (65-75):(30-35), where nefras is a hexane-heptane fraction of paraffinic hydrocarbons of dearomatized catalytic reforming gasolines with boiling point limits of 65-75°C. 9. The method according to claim 1, characterized in that styrene or α-methylstyrene, most preferably styrene, is used as monovinyl aromatic hydrocarbons. 10. Process according to claim 1, characterized in that the conjugated dienes are 1,3-butadiene or isoprene, most preferably 1,3-butadiene. 11. Block copolymer composition for polymer-bitumen binders, obtained according to any one of paragraphs. 1-10. 12. Block copolymer composition as an additive of polymer-bitumen binders, including (i) from 8 to 16 wt. % uncrosslinked diblock block copolymer AB, (ii) from 34 to 87 wt. % of a triblock block copolymer obtained using a silicon-containing coupling agent, which is a halogen-substituted silane with the general formula R ₂ SiHal ₂ , where R represents C ₁ -C ₂₀ -alkyl or C ₆ -C ₂₀ -aryl groups, (iii) from 5 to 50 wt. % of a triblock block copolymer obtained using a sulfur-containing coupling agent, which is a compound having in its structure polysulfide groups (-S-) n, where n = 1-8, and a linker group (-Y-) selected from C ₁ -C ₂₀ -alkyl, C ₃ -C ₂₀ -alicyclic, C ₃ -C ₂₀ -heterocyclic, C ₆ -C ₂₀ -aromatic groups, and (iv) optionally, functional additives, where A is a monovinyl aromatic hydrocarbon block, B is a conjugated diene block, moreover, the content of the associated monovinyl aromatic monomer is from 30 to 32 wt. %, conjugated diene - from 68 to 70 wt. %, the content of 1,2-vinyl units - from 10 to 43 wt. % based on 100 wt. % block copolymer composition. 13. Block copolymer composition according to claim 11 or 12, characterized by a weight average molecular weight (M _w ) from 75,000 to 115,000 amu. 14. Block copolymer composition according to any one of paragraphs. 11-13, characterized by polydispersity from 1.3 to 1.6. 15. Polymer-bitumen binder for road construction, including a block copolymer composition according to any one of paragraphs. 11-14. 16. Polymer-bitumen binder according to claim 15, including 95.0-98.0 wt. % bitumen and 2.0-5.0 wt. % block copolymer composition according to any one of paragraphs. 11-14. 17. Polymer-bitumen binder according to any one of paragraphs. 15, 16, which has the following characteristics: extensibility at 25°C in the range of from about 60 to about 91 cm; maximum tensile force at 0°C from 130.0 to 159.5 N; change in penetration after aging (70 minutes at 163° C.) from about 73% to about 86%; change in elasticity (at 25°C) after aging (70 min at 163°C) from 87.6 to 97.9%.