Method for producing denatured conjugated diene polymer

1. A method for producing a modified conjugated diene polymer, the method comprising polymerizing (i) a monomer comprising a conjugated diene compound, or (ii) a monomer comprising a conjugated diene compound and an aromatic vinyl compound, in the presence of:

at least one compound selected from the group consisting of formulae (1) and (2), and

an alkali metal compound or an alkaline earth metal compound,

to obtain a modified conjugated diene polymer

wherein in the formulae (1) and (2):

A 1 is a functional group which has a hydrocarbylsilyl group in which three hydrogen atoms in a —SiH 3 structure are each substituted by a hydrocarbyl group; has at least one atom selected from the group consisting of N, P and S; and has no active hydrogen and is bound to R 1 by any one atom of the N, P and S;

R 1 and R 2 are hydrocarbylene groups; and

plural R 1 , R 2 and A 1 may each be the same or different.

2. The method according to claim 1 , further comprising contacting and reacting a compound represented by formula (3) with the modified conjugated diene polymer to obtain a modified conjugated diene polymer having a structure represented by formula (6):

wherein in the formula (3):

A 2 is a functional group which has at least one atom selected from the group consisting of N, P and S; has no active hydrogen; and is bound to R 5 by any one atom of the N, P and S;

a part or all of the at least one atom selected from the group consisting of the N, P and S of A 2 may each be protected by a hydrocarbylsilyl group in which three hydrogen atoms in a —SiH 3 structure are each substituted by a hydrocarbyl group;

R 3 and R 4 are hydrocarbyl groups;

n is an integer of 0 to 2;

R 5 is a hydrocarbylene group; and

plural R 3 and R 4 may each be the same or different;

wherein in the formula (6):

A 4 is a functional group which has at least one atom selected from the group consisting of N, P and S and is bound to R 5 by the N, P and S;

a part or all of the at least one atom selected from the group consisting of the N, P and S of A 4 may be protected by a hydrocarbylsilyl group;

R 3 is a hydrocarbyl group;

n is an integer of 0 to 2;

R 5 is a hydrocarbylene group;

R 6 is a hydrogen atom or a hydrocarbyl group; and

plural R 3 and R 6 may each be the same or different.

3. The method according to claim 1 , further comprising reacting the modified conjugated diene polymer with an onium-forming agent.

4. The method according to claim 1 , comprising polymerizing (i) the monomer comprising a conjugated diene compound.

5. The method according to claim 1 , comprising polymerizing (ii) the monomer comprising a conjugated diene compound and an aromatic vinyl compound.

6. The method according to claim 1 , wherein the polymerizing is performed in the presence of the compound of formula (1).

7. The method according to claim 1 , wherein the polymerizing is performed in the presence of the compound of formula (2).

8. The method according to claim 1 , wherein the polymerizing is performed in the presence of both the compound of formula (1) and the compound of formula (2).

9. The method according to claim 2 , further comprising reacting the modified conjugated diene polymer with an onium-forming agent.

10. The method according to claim 2 , comprising polymerizing (i) the monomer comprising a conjugated diene compound.

11. The method according to claim 2 , comprising polymerizing (ii) the monomer comprising a conjugated diene compound and an aromatic vinyl compound.

12. The method according to claim 2 , wherein the polymerizing is performed in the presence of the compound of formula (1).

13. The method according to claim 2 , wherein the polymerizing is performed in the presence of the compound of formula (2).

14. The method according to claim 2 , wherein the polymerizing is performed in the presence of both the compound of formula (1) and the compound of formula (2).