摘要 |
PROBLEM TO BE SOLVED: To provide a polymer composition excellent in low heat build-up.SOLUTION: There are used a first constituent which is a rare-earth element containing compound and contains a rare-earth element compound or a reactant of the rare-earth element compound and a Lewis base, a second constituent containing a compound represented by formula (X) below, and a third constituent containing silica. A method for producing a polymer composition includes a step for mixing and aging the second constituent and the third constituent followed by addition of the first constituent for reaction and polymerizing at least one of a conjugated diene compound and a non-conjugated olefin in the presence of an obtained polymerization catalyst composition to form a polymer component. (In the formula (X), Y is a metal selected from the groups-I, II, XXII and XXIII of the periodic table; Rand Rare a C1-C10 hydrocarbon group or a hydrogen atom; Ris a C1-C10 hydrocarbon group; R, Rand Rmay be the same or different; when Y is a metal selected from the group-I of the periodic table, a is 1, and b and c are 0; when Y is a metal selected from the groups-II and XXII of the periodic table, a and b are 1, and c is 0; and when Y is a metal selected from the group-XXIII of the periodic table, a, b and c are 1.) |