Modified conjugated diene-based polymer and method for preparing the same

A modified conjugated diene-based polymer comprising a repeating unit derived from a conjugated diene-based monomer, comprising a compound represented by the following Formula 1 at one terminal, and comprising a functional group derived from a modification initiator which comprises a compound represented by the following Formula 2 at the other terminal:

• in Formula 1,
• X1 and X2 are each a N atom,
• R1 to R4 are each independently a divalent hydrocarbon group of 1 to 30 carbon atoms, or a heteroalkylene group of 1 to 30 carbon atoms, which comprises one or more heteroatoms selected from the group consisting of N, O and S atoms,
• R5 and R6 are each independently a monovalent hydrocarbon group of 1 to 30 carbon atoms, a heteroalkyl group of 1 to 30 carbon atoms, which comprises one or more heteroatoms selected from the group consisting of N, O and S atoms, or a heterocycle of 1 to 30 carbon atoms, which comprises one or more heteroatoms selected from the group consisting of N, O and S atoms,
• n is 0-3, and
• R7 is a hydrogen atom, a monovalent hydrocarbon group of 1 to 30 carbon atoms, a heteroalkyl group of 1 to 30 carbon atoms, which comprises one or more heteroatoms selected from the group consisting of N, O and S atoms, or a heterocycle of 1 to 30 carbon atoms, which comprises one or more heteroatoms selected from the group consisting of N, O and S atoms,
• in Formula 2,
• R8 and R9 are each independently one selected from the group consisting of an alkyl group of 1 to 20 carbon atoms, a cycloalkyl group of 3 to 20 carbon atoms, and an aralkyl group of 5 to 20 carbon atoms, or R8 and R9 are combined with each other to form a saturated or unsaturated cyclic structure of 5 to 20 carbon atoms together with an adjacent N atoms, where if R8 and R9 form a cyclic structure, a branched structure may be obtained,
• R10 is a single bond, an alkylene group of 1 to 20 carbon atoms, or one linker selected from the group consisting of the following Formula 3 to Formula 5, and
• M is an alkali metal:

A method for preparing a modified conjugated diene-based polymer, the method comprising:

• polymerizing conjugated diene-based monomers, or an aromatic vinyl-based monomer and a conjugated diene-based monomer, in a hydrocarbon solvent which comprises an organometal compound, to prepare an active polymer which is coupled with an organometal (S1);
• and
• reacting the active polymer and a modifier which comprises a compound represented by the following Formula 1 (S2):
• in Formula 1,
• X1 and X2 are each a N atom,
• R1 to R4 are each independently a divalent hydrocarbon group of 1 to 30 carbon atoms, or a heteroalkylene group of 1 to 30 carbon atoms, which comprises one or more heteroatoms selected from the group consisting of N, O and S atoms,
• R5 and R6 are each independently a monovalent hydrocarbon group of 1 to 30 carbon atoms, a heteroalkyl group of 1 to 30 carbon atoms, which comprises one or more heteroatoms selected from the group consisting of N, O and S atoms, or a heterocycle of 1 to 30 carbon atoms, which comprises one or more heteroatoms selected from the group consisting of N, O and S atoms,
• n is 0-3, and
• R7 is a hydrogen atom, a monovalent hydrocarbon group of 1 to 30 carbon atoms, a heteroalkyl group of 1 to 30 carbon atoms, which comprises one or more heteroatoms selected from the group consisting of N, O and S atoms, or a heterocycle of 1 to 30 carbon atoms, which comprises one or more heteroatoms selected from the group consisting of N, O and S atoms.

A modifier comprising a compound represented by the following Formula 1:

• in Formula 1,
• X1 and X2 are each a N atom,
• R1 to R4 are each independently a divalent hydrocarbon group of 1 to 30 carbon atoms, or a heteroalkylene group of 1 to 30 carbon atoms, which comprises one or more heteroatoms selected from the group consisting of N, O and S atoms,
• R5 and R6 are each independently a monovalent hydrocarbon group of 1 to 30 carbon atoms, a heteroalkyl group of 1 to 30 carbon atoms, which comprises one or more heteroatoms selected from the group consisting of N, O and S atoms, or a heterocycle of 1 to 30 carbon atoms, which comprises one or more heteroatoms selected from the group consisting of N, O and S atoms,
• n is 0-3, and
• R7 is a hydrogen atom, a monovalent hydrocarbon group of 1 to 30 carbon atoms, a heteroalkyl group of 1 to 30 carbon atoms, which comprises one or more heteroatoms selected from the group consisting of N, O and S atoms, or a heterocycle of 1 to 30 carbon atoms, which comprises one or more heteroatoms selected from the group consisting of N, O and S atoms.