| 摘要 |
Provided is a polymerization catalyst composition that makes it possible to efficiently synthesize a polyisoprene having a high molecular weight. The isoprene polymerization catalyst composition is characterized by comprising: a rare earth element compound (component (a)) having a rare earth element-oxygen bond or a rare earth element-sulfur bond; an ionic compound (component (b)); and at least one compound (component (c)) selected from the group consisting of the compound that is represented by formula (X) and compounds comprising the repeating unit that is represented by formula (Y) (Formula (X): YR1 aR2 bR3 c. Formula (Y): (-Y(R1)O-). In the formulas, Y is a metal selected from among group 1, group 2, group 12, and group 13 elements of the period table, R1 and R2 are each a hydrocarbon group having a carbon number of 1-10 or a hydrogen atom, and R3 is a hydrocarbon group having a carbon number of 1-10. R1, R2, and R3 may be the same as or different from each other. When Y is a metal that is selected from among group 1 elements of the periodic table, a is 1 and b and c are 0. When Y is a metal that is selected from among group 2 and group 12 elements of the periodic table, a and b are 1 and c is 0. When Y is a metal that is selected from among group 13 elements of the periodic table, a, b, and c are 1.). |
