Process for the polymerization olefins

A process for polymerizing an olefin comprising polymerizing or copolymerizing an olefin at a polymerization reaction temperature of 50 to 170° C. in the presence of an olefin polymerization catalyst consisting essentially of:

• (A) a transition metal compound represented by the following formula (I),
• (B-1) an organoaluminum compound having reducing ability which reacts with the transition metal compound (A) to convert an imine structure moiety to a metal amide structure, and
• (B-2) a compound which reacts with the transition metal compound (A) to form an ion pair;
• wherein said transition metal compound is represented by the following formula (I)
• wherein M is a transition metal atom of Groups 4 and 5 of the periodic table,
• m is an integer of 1 to 6,
• Y is an oxygen atom, a sulfur atom or a selenium atom, or a nitrogen atom having a substituent R7,
• R1 to R7 may be the same or different, and are each a hydrogen atom, a halogen atom, a hydrocarbon group, an oxygen-containing group, a nitrogen-containing group, a boron-containing group, a sulfur-containing group, a phosphorus-containing group, a heterocyclic compound residual group, a silicon-containing group, a germanium-containing group or a tin-containing group, two or more of R1 to R7 may be bonded to each other to form a ring except for the case where R1 and R5 or R1 and R6 are bonded to each other to form an aromatic ring, and when m is 2 or greater, one group of R1 to R7 contained in one ligand and one group of R1 to R7 contained in other ligands may be bonded, and R1s, R2s, R3s, R4s, R5s, R6s and R7s may be the same or different,
• n is a number satisfying a valence of M, and
• X is a hydrogen atom, a halogen atom, a hydrocarbon group, an oxygen-containing group, a nitrogen-containing group, a boron-containing group, a sulfur-containing group, a phosphorus-containing group, a halogen-containing group, an aluminum-containing group, a heterocyclic compound residual group, a silicon-containing group, a germanium-containing group or a tin-containing group, and when n is 2 or greater, plural groups indicated by X may be the same or different, and plural groups indicated by X may be bonded to each other to form a ring, and
• wherein the catalyst activity is at least 1000 kg polyolefin/mole transition metal atom hr.