Copolymer, rubber composition, crosslinked rubber composition, and tire
Provided is a copolymer of a conjugated diene compound and a non-conjugated olefin, the copolymer being a block copolymer, the conjugated diene compound unit having 1,2 adduct (including 3,4 adduct) content of 5% or less or the conjugated diene compound unit having a cis-1,4 bond content of more than 92%, in which preferred examples of the conjugated diene compound include 1,3-butadiene and isoprene, and preferred examples of the non-conjugated olefin include ethylene, propylene, and 1-butene.
1. A copolymer of a conjugated diene compound and a non-conjugated olefin,
wherein the copolymer is a block copolymer,
wherein the conjugated diene compound unit has a 1,2 adduct (including 3,4 adduct) content of 5% or less, and the conjugated diene compound unit has a cis-1,4 bond content of more than 92%, and
wherein the block copolymer has either one of the structures of A-(B-A) x and B-(A-B) x , where A represents a block sequence including monomer units of the non-conjugated olefin, B represents a block sequence including monomer units of the conjugated diene compound, and x represents an integer of at least 1.
2. The copolymer according to claim 1 , wherein the copolymer contains the non-conjugated olefin by more than 0 mol % and less than 100 mol %.
3. The copolymer according to claim 2 , wherein the copolymer contains the non-conjugated olefin by more than 0 mol % and less than 50 mol %.
4. The copolymer according to claim 1 , comprising a copolymer having a polystyrene-equivalent average-weight molecular weight of 10,000 to 10/000,000.
5. The copolymer according to claim 1 , comprising a copolymer having a molecular weight distribution (Mw/Mn) of 10 or less.
6. The copolymer according to claim 1 , wherein the non-conjugated olefin is an acyclic olefin.
7. The copolymer according to claim 1 , wherein the non-conjugated olefin has 2 to 10 carbon atoms.
8. The copolymer according to claim 6 , wherein the non-conjugated olefin is at least one selected from a group consisting of ethylene, propylene, and 1-butene.
9. The copolymer according to claim 8 , wherein the non-conjugated olefin is ethylene.
10. The copolymer according to claim 1 , wherein the conjugated diene compound is at least one selected from a group consisting of 1,3-butadiene and isoprene.
11. A rubber composition comprising the copolymer according to claim 1 .
12. The rubber composition according to claim 11 comprising the copolymer in a rubber component.
13. The rubber composition according to claim 12 , comprising, with respect to 100 parts by mass of the rubber component, a reinforcing filler by 5 parts by mass to 200 parts by mass and a crosslinking agent by 0.1 parts by mass to 20 parts by mass.
14. A crosslinked rubber composition obtained by crosslinking the rubber composition according to claim 11 .
15. A tire manufactured by using the rubber composition according to claim 11 .
16. A tire manufactured by using the crosslinked rubber composition according to claim 14 .