TRANSITION METAL COMPOUND, CATALYST FOR POLYMERIZATION OF PROPYLENE AND PREPARATION METHOD OF PROPYLENE POLYMER

摘要

A catalyst comprising a novel transition metal compound is provided to control tacticity through interaction of the catalyst and a co-catalyst without using a catalyst having a complex structure and obtain a propylene polymer having high molecular weight and high tacticity. A transition metal compound is represented by a formula(1), wherein M^1 and M^2 may be the same or different from each other and are selected from the group consisting of groups III to X elements; Cp^1 and Cp2, and Cp^3 and Cp^4 may be the same or different from each other and each of which is a ligand having a cyclopentadienyl skeleton including at least one substituent including a hetero atom; X and Y may be the same or different from each other and are selected from the group consisting of C1-20 alkyl, C3-20 cycloalkyl, C1-20 alkylsilyl, C1-20 silyl alkyl, C6-20 aryl, C6-20 arylalkyl, C6-20 alkylaryl, C6-20 arylsilyl, C6-20 silylaryl, C1-20 alkoxy, C1-20 alkylsiloxy, C6-20 aryloxy, halogen, amine and tetrahydroborate; each a and b is an integer from 1 to 5; p is 0 or 1; and B^1 is a bridge connecting the Cp^1 and Cp^2 and a compound represented by a formula(2). A catalyst for polymerizing propylene comprises: the transition metal compound; and an aluminoxane compound represented by a formula(7) or an organic aluminum compound represented by a formula(8), wherein R^3 is C1-10 alkyl; n is an integer from 1-70; and R^4, R^5 and R^6 may be the same or different from one another and are selected from the group consisting of C1-10 alkyl, alkoxy and halogen, provided that at least one of the R^4, R^5 and R^6 is alkyl. A method for preparing a propylene polymer comprises a step of polymerizing propylene at a temperature of -50 to 200 deg.C in the presence of the catalyst.