FIELD: chemistry.
SUBSTANCE: invention discloses a method of obtaining a modified polymer, involving: performing a modification reaction for an alkali metal-containing active terminal group of a conjugated diene polymer under the effect of an alkoxysilane compound, where the conjugated diene polymer is obtained as a result of performing for a diene monomer or diene monomer and a monomer different from the diene monomer amine polymerisation in a hydrocarbon solvent using an alkali metal-based initiator; and conducting a condensation reaction of the obtained product in the presence of a condensation accelerator, which contains a compound of at least one element selected from group 4A elements (except Ti), group 3B elements and group 5B elements; in which the alkoxysilane compound is at least one alkoxysilane compound selected from alkoxysilane compounds of the following general formula (I), and/or incomplete condensates thereof, where R1 and R2 separately denote a monovalent aliphatic hydrocarbon group containing 1-20 carbon atoms or a monovalent aromatic hydrocarbon group containing 6-18 carbon atoms, and a is a whole number from 0 to 2 under the condition that, in the presence of several OR2, said OR2 can be identical or different, and an active proton is not included in the molecule, and alkoxysilane compounds of the following general formula (II), and/or incomplete condensates thereof, where A1 denotes a monovalent group having at least one functional group selected from an imine group, a cyclic tertiary amino group, a non-cyclic tertiary amino group, a pyridine group, a silazane group and a bisulphide group, R3 denotes a single bond or a divalent hydrocarbon group, R4 and R5 separately denote a monovalent aliphatic hydrocarbon group containing 1-20 carbon atoms, or a monovalent aromatic hydrocarbon group containing 6-18 carbon atoms, and b is a whole number from 0 to 2 under the condition that, in the presence of several OR5, several OR5 can be identical or different, and an active proton is not included in the molecule. The invention also discloses a modified polymer obtained using the method described above, a rubber composition for tyres which contains said modified polymer. The invention also describes a rubber composition for tyres, which contains 100 pts.wt rubber component and 20-120 pts.wt silicon dioxide and/or technical carbon, where the rubber component contains said modified polymer in amount of 20 wt % or higher.
EFFECT: obtaining a modified polymer, characterised by low rolling resistance, high skid resistance on a wet road surface and excellent wear resistance.
11 cl, 9 tbl, 24 ex
