Olefin polymerization catalyst and process for producing olefin polymer

An olefin polymerization catalyst prepared by contacting (A) with (B) described below:

• (A) a transition metal compound selected from the group consisting of transition metal compounds represented by the general formulas (I), (II) or (III);
• wherein, in the general formula (I), (II) or (III), M represents a transition metal atom of the Group IV of the Periodic Table of the Elements;
• A represents an atom of the Group XVI of the Periodic Table of the Elements;
• J represents an atom of the Group XIV of the Periodic Table of the Elements;
• Cp represents a group having a cyclopentadiene type anion skeleton;
• each of X1, R1, R2, R3, R4, R5 and R6 independently represents a hydrogen atom, a halogen atom, an alkyl group, an aralkyl group, an aryl group, a substituted silyl group, an alkoxy group, an aralkyloxy group, an aryloxy group, a di-substituted amino group, an alkylthio group, an aralkylthio group, an arylthio group, an alkylseleno group, an aralkylseleno group or arylseleno group;
• X2 represents an atom of Group XVI of the Periodic Table of the Elements;
• R1, R2, R3, R4, R5 and R6 may be optionally combined with each other to form a ring;
• and in the general formula (II) or (III), two of M, A, J, Cp, X1, X2, X3, R1, R2, R3, R4, R5 and R6 may be respectively the same or different,
• (B) a modified aluminum oxy compound (B) obtained by reacting (B1) with (B2) described below;
• (B1) an aluminum oxy compound, and
• (B2) a compound having a hydroxyl group.