Olefin polymer, films or sheets made therefrom, and process for the production of olefin polymer

A method for producing an olefin polymer, comprising the step of homopolymerizing an olefin or copolymerizing two or more olefins at a temperature of at least 130° C. under a pressure of at least 300 kg/cm2G with a catalyst for olefin polymerization, comprising the following (A), (B) and (C);

• (A) and (B);
• or (A) and (C):
• (A) a transition metal complex represented by the following general formula (I):
• wherein M1 represents a transition metal atom of Group IV of the Periodic Table of the Elements;
• A representsents an atom of Group XVI of the Periodic Table of the Elements;
• J represents an atom of Group XIV of the Periodic Table of the Elements;
• Cp1 represents a group having a cyclopentadiene anion skeleton;
• X1, X2, R1, R2, R3, R4, R5 and R6 independently represent 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 or a di-substituted amino group;
• and R1, R2, R3, R4, R5 and R6 may be optionally combined with each other to form a ring;
• (B) at least one aluminum compound selected from the following (B1) to (B3):
• (B1) an organoaluminum compound represented by the general formula E1aAlZ3−a;
• (B2) a cyclic aluminoxane having a structure represented by the general formula (Al(E2)—O—)b;
• and
• (B3) a linear aluminoaxe having a structure represented by the general formula E3(—Al(E3)—O—)cAlE32,
• wherein E1, E2 an E3 respectively represents a hydrocarbon group, all of E1, E2 and E3 may be the same or different, Z represents a hydrogen atom or a halogen atom, and all of Z may be the same or different, a represents a numeral of 0 to 3, b represents an integer of not less than 2, and c represents an integer of not less than 1, and
• (C) a boron compound of any one of the following (C1) to (C3):
• (C1) a boron compound represented by the general formula BQ1Q2Q3;
• (C2) a boron compound represented by the general formula G+(BQ1Q2Q3Q4)−;
• and
• (C3) a boron compound represented by the general formula (L—H)+(BQ1Q2Q3Q4)−,
• wherein B represents a boron atom in the trivalent valence state, Q1 to Q4 may be the same or different and represent a halogen atom, a hydrocarbon group, a halogenated hydrocarbon group, a substituted silyl group, an alkoxy group or a di-substituted amino group, G+ represents an inorganic or organic cation, L represents a neutral Lewis base, and (L—H)+ represents a Brønsted acid.