Abstract: A catalyst for polymerization of conjugated diene is provided, which facilitates manufacture of a conjugated diene polymer with a high 1,4-cis structure content, leaves less aluminum residue on polymerization, and has high activity. A method of manufacturing conjugated diene polymers using the catalyst is also provided. A catalyst for polymerization of conjugated diene comprises (A) an yttrium compound; (B) an ionic compound including a non-coordinate anion and a cation; and (C) an organometallic compound including an element selected from the groups 2, 12 and 13 of the periodic table.

Abstract: A rubber composition comprises a rubber component. The rubber component contains (A) 1-70 weight parts of polybutadiene rubber having a Mooney viscosity (ML) of 35-50 and composed of (a) 1-9 weight % of a boiled n-hexane insoluble fraction having a melting point of 180° C. or higher and (b) 99-91 weight % of a boiled n-hexane soluble fraction. The rubber component also contains (B) 99-30 weight parts of diene-based rubber other than (A). A crosslinking coagent (C) is mixed in the rubber component.

Abstract: A catalyst for polymerization of conjugated diene comprises (A) an yttrium compound; (B) an ionic compound including a non-coordinate anion and a cation; and (C) an organometallic compound including an element selected from the groups 2, 12 and 13 of the periodic table.

Abstract: [Subject] A catalyst for polymerization of conjugated diene is provided, which facilitates manufacture of a conjugated diene polymer with a high 1,4-cis structure content, leaves less aluminum residue on polymerization, and has high activity. A method of manufacturing conjugated diene polymers using the catalyst is also provided. [Solution] A catalyst for polymerization of conjugated diene comprises (A) an yttrium compound; (B) an ionic compound including a non-coordinate anion and a cation; and (C) an organometallic compound including an element selected from the groups 2, 12 and 13 of the periodic table.

Abstract: A rubber composition comprises a rubber component. The rubber component contains (A) 1-70 weight parts of polybutadiene rubber having a Mooney viscosity (ML) of 35-50 and composed of (a) 1-9 weight % of a boiled n-hexane insoluble fraction having a melting point of 180° C. or higher and (b) 99-91 weight % of a boiled n-hexane soluble fraction. The rubber component also contains (B) 99-30 weight parts of diene-based rubber other than (A). A crosslinking coagent (C) is mixed in the rubber component.

Abstract: [Subject] a catalyst for polymerization of conjugated diene is provided, which facilitates manufacture of a conjugated diene polymer with a high 1,4-cis structure content, leaves less aluminum residue on polymerization, and has high activity. A method of manufacturing conjugated diene polymers using the catalyst is also provided. [Solution] A catalyst for polymerization of conjugated diene comprises (A) an yttrium compound; (B) an ionic compound including a non-coordinate anion and a cation; and (C) an organometallic compound including an element selected from the groups 2, 12 and 13 of the periodic table.

Abstract: A rubber composition for golf balls, comprises a base polymer consisted of (A) 20-99 weight parts of high cis polybutadiene synthesized in the presence of a cobalt-based catalyst and having a Mooney viscosity of 50-70 and a molecular weight distribution (Weight average molecular weight (Mw)/ Number average molecular weight (Nw)) of 2.5-3.8, and (B) 80-1 weight part(s) of high cis polybutadiene synthesized in the presence of a non-cobalt-based catalyst and having a Mooney viscosity of 30-70; and a crosslinking coagent.