Isoprene polymerization catalyst composition, method for producing synthetic polyisoprene, and synthetic polyisoprene

摘要

An isoprene polymerization catalyst composition includes: Component (a): a rare earth element compound having a rare earth element-oxygen bond or a rare earth element-sulfur bond; Component (b): an ionic compound; and Component (c): at least one compound selected from the group consisting of a compound of formula (X): YR¹_aR²_bR³_c and a compound having a repeating unit of formula (Y): (—Y(R¹)O—) (where Y is a metal selected from groups 1, 2, 12 and 13 in a periodic table, R¹ and R² are C1-10 hydrocarbon groups or hydrogen atoms and R³is a C1-10 hydrocarbon group).