Modified conjugated diene-based polymer and rubber composition including the same

A modified conjugated diene-based polymer, comprising:

• a functional group derived from a modification initiator at one terminal;
• and
• a functional group derived from a modifier represented by the following Formula 2 or Formula 3 at the other terminal,
• wherein the modification initiator is a reaction product of a compound represented by the following Formula 1 and an organometal compound:
• in Formula 1,
• R1 to R3 are each independently hydrogen;
• an alkyl group of 1 to 30 carbon atoms;
• an alkenyl group of 2 to 30 carbon atoms;
• an alkynyl group of 2 to 30 carbon atoms;
• a heteroalkyl group of 1 to 30 carbon atoms, a heteroalkenyl group of 2 to 30 carbon atoms;
• a heteroalkynyl group of 2 to 30 carbon atoms;
• a cycloalkyl group of 5 to 30 carbon atoms;
• an aryl group of 6 to 30 carbon atoms;
• or a heterocyclic group of 3 to 30 carbon atoms,
• R4 is a single bond;
• a substituted or unsubstituted alkylene group of 1 to 20 carbon atoms with a substituent;
• a substituted or unsubstituted cycloalkylene group of 5 to 20 carbon atoms with a substituent;
• or a substituted or unsubstituted arylene group of 5 to 20 carbon atoms with a substituent, wherein the substituent is an alkyl group of 1 to 10 carbon atoms, a cycloalkyl group of 5 to 10 carbon atoms, or an aryl group of 6 to 20 carbon atoms,
• R5 is an alkyl group of 1 to 30 carbon atoms;
• an alkenyl group of 2 to 30 carbon atoms;
• an alkynyl group of 2 to 30 carbon atoms;
• a heteroalkyl group of 1 to 30 carbon atoms;
• a heteroalkenyl group of 2 to 30 carbon atoms;
• a heteroalkynyl group of 2 to 30 carbon atoms;
• a cycloalkyl group of 5 to 30 carbon atoms;
• an aryl group of 6 to 30 carbon atoms;
• a heterocyclic group of 3 to 30 carbon atoms;
• or a functional group represented by the following Formula 1a or Formula 1b, and
• n is an integer of 1 to 5, and at least one of R5 groups is a functional group represented by the following Formula 1a or Formula 1b, in case where n is an integer of 2 to 5, a plurality of R5 groups may be the same or different,
• in Formula 1a,
• R6 is a substituted or unsubstituted alkylene group of 1 to 20 carbon atoms with a substituent;
• a substituted or unsubstituted cycloalkylene group of 5 to 20 carbon atoms with a substituent;
• or a substituted or unsubstituted arylene group of 6 to 20 carbon atoms with a substituent, wherein the substituent is an alkyl group of 1 to 10 carbon atoms, a cycloalkyl group of 5 to 10 carbon atoms, or an aryl group of 6 to 20 carbon atoms,
• R7 and R8 are each independently a substituted or unsubstituted alkylene group of 1 to 20 carbon atoms with an alkyl group of 1 to 10 carbon atoms, a cycloalkyl group of 5 to 10 carbon atoms, or an aryl group of 6 to 20 carbon atoms,
• R9 is hydrogen;
• an alkyl group of 1 to 30 carbon atoms, an alkenyl group of 2 to 30 carbon atoms;
• an alkynyl group of 2 to 30 carbon atoms;
• a heteroalkyl group of 1 to 30 carbon atoms;
• a heteroalkenyl group of 2 to 30 carbon atoms;
• a heteroalkynyl group of 2 to 30 carbon atoms;
• a cycloalkyl group of 5 to 30 carbon atoms;
• an aryl group of 6 to 30 carbon atoms;
• or a heterocyclic group of 3 to 30 carbon atoms, and
• X is an N, O or S atom, in case where X is O or S, R9 is not present,
• in Formula 1b,
• Rio is a substituted or unsubstituted alkylene group of 1 to 20 carbon atoms with a substituent;
• a substituted or unsubstituted cycloalkylene group of 5 to 20 carbon atoms with a substituent;
• or a substituted or unsubstituted arylene group of 6 to 20 carbon atoms with a substituent, wherein the substituent is an alkyl group of 1 to 10 carbon atoms, a cycloalkyl group of 5 to 10 carbon atoms, or an aryl group of 6 to 20 carbon atoms, and
• R11 and R12 are each independently an alkyl group of 1 to 30 carbon atoms;
• an alkenyl group of 2 to 30 carbon atoms;
• an alkynyl group of 2 to 30 carbon atoms;
• a heteroalkyl group of 1 to 30 carbon atoms;
• a heteroalkenyl group of 2 to 30 carbon atoms;
• a heteroalkynyl group of 2 to 30 carbon atoms;
• a cycloalkyl group of 5 to 30 carbon atoms;
• an aryl group of 6 to 30 carbon atoms;
• or a heterocyclic group of 3 to 30 carbon atoms,
• in Formula 2,
• R20 is a single bond, or an alkylene group of 1 to 10 carbon atoms,
• R21 and R22 are each independently an alkyl group of 1 to 10 carbon atoms,
• R23 is a single bond or an alkylene group of 1 to 10 carbon atoms,
• R24 is hydrogen, an alkyl group of 1 to 10 carbon atoms or a substituted divalent, trivalent or tetravalent alkylsilyl group with an alkyl group of 1 to 10 carbon atoms,
• a is an integer of 2 or 3,
• c is an integer of 1 to 3, and b is an integer of 0 to 2, where b+c=3,
• in Formula 3,
• A1 and A2 are each independently an alkylene group of 1 to 20 carbon atoms,
• R25 to R28 are each independently an alkyl group of 1 to 20 carbon atoms, and
• L1 to L4 are each independently a substituted divalent, trivalent or tetravalent alkylsilyl group with an alkyl group of 1 to 10 carbon atoms, or an alkyl group of 1 to 20 carbon atoms,
• wherein the modified conjugated diene-based polymer having a unimodal molecular weight distribution, and a polydispersity index of 1.0 to less than 1.7.