Conjugated diene based polymer, and polymer composition containing the polymer
The present invention relates to a conjugated diene based polymer comprising a monomer unit derived from at least one conjugated diene selected from 1,3-butadiene and isoprene and a monomer unit derived from a compound represented by Formula (1): wherein n represents an integer of 0 to 5; R 11 , R 12 and R 13 each independently represent an alkyl group having 1 to 10 carbon atoms.
1. A conjugated diene based polymer comprising a monomer unit derived from at least one conjugated diene selected from 1,3-butadiene and isoprene, and a monomer unit derived from a compound represented by Formula (1):
wherein n represents an integer of 0 to 5; R 11 , R 12 and R 13 each independently represent an alkyl group having 1 to 10 carbon atoms, and wherein the conjugated diene based polymer is modified with a group containing a nitrogen atom.
2. The conjugated diene based polymer according to claim 1 , wherein the content of the monomer unit derived from the compound represented by Formula (1) is not less than 0.01% by weight and not more than 30% by weight where the total amount of the monomer units contained in the conjugated diene based polymer is taken as 100% by weight.
3. The conjugated diene based polymer according to claim 1 , wherein the compound represented by Formula (1) is 1-methyl-4-isopropyl-1,3-cyclohexadiene.
4. A polymer composition comprising the conjugated diene based polymer according to claim 1 and a reinforcing agent, wherein the content of the reinforcing agent is not less than 10 parts by weight and not more than 150 parts by weight per 100 parts by weight of the conjugated diene based polymer.
5. A method for producing a conjugated diene based polymer, wherein the method comprises:
(a) a step of polymerizing monomer components comprising at least one conjugated diene selected from 1,3-butadiene and isoprene, and a compound represented by Formula (1):
in a solvent to form a conjugated diene based polymer, a step of adding a compound having a group containing a nitrogen atom to the solvent, and reacting an active terminal of the conjugated diene based polymer with the compound having a group containing a nitrogen atom; or
(b) a step of polymerizing monomer components comprising the at least one conjugated diene and the compound represented by Formula (1) using an organic alkali metal compound having a group containing a nitrogen atom; or
(c) a step of polymerizing monomer components comprising the at least one conjugated diene and the compound represented by Formula (1) using a secondary amine and an organic alkali metal compound; or
(d) a step of polymerizing monomer components comprising the at least one conjugated diene, the compound represented by Formula (1), and a vinyl based monomer having a group containing a nitrogen atom,
wherein n represents an integer of 0 to 5; R 11 , R 12 and R 13 each independently represent an alkyl group having 1 to 10 carbon atoms.
6. The method according to claim 5 , wherein the supplied amount of the compound represented by Formula (1) is not less than 0.01% by weight and not more than 30% by weight where the total supplied amount of the monomer components is taken as 100% by weight.