Olefin polymerization catalyst and method for producing olefin polymer

An olefin polymerization catalyst comprising:

• (I) as a solid catalyst component for olefin polymerization, (a) a solid catalyst component for olefin polymerization containing at least magnesium, titanium, halogen, and as an internal electron-donating compound, at least one or more compounds selected from succinate diester compounds represented by the following general formula (1):
• in the formula, R1 and R2 each, which are optionally identical or different from each other, independently represent a linear alkyl group having the carbon number of 1 to 12, a branched alkyl group having the carbon number of 3 to 12, a cycloalkyl group having the carbon number of 3 to 12, a cycloalkenyl group having the carbon number of 3 to 12, or an aromatic hydrocarbon group having the carbon number of 6 to 20;
• R3, R4, R5, and R6 each, all of which are optionally identical or different from each other, independently represent an atom or a group selected from a hydrogen atom, a halogen atom, a linear alkyl group having the carbon number of 1 to 12, a branched alkyl group having the carbon number of 3 to 12, a vinyl group, a linear or a branched alkenyl group having the carbon number of 3 to 12, a linear or a branched halogen-substituted alkyl group having the carbon number of 2 to 12, a cycloalkyl group having the carbon number of 3 to 12, a cycloalkenyl group having the carbon number of 3 to 12, an aromatic hydrocarbon group having the carbon number of 6 to 20, a nitrogen-containing group, a phosphorus-containing group, and a silicon-containing group, and
• (b) a solid catalyst component for olefin polymerization containing at least magnesium, titanium, halogen, and as an internal electron-donating compound, at least one or more compounds selected from phthalate diester compounds represented by the following general formula (2):
• in the formula, R7 represents an alkyl group having the carbon number of 1 to 8 or a halogen atom, R8 and R9, which are optionally identical or different from each other, represent an alkyl group having the carbon number of 1 to 12, and the number n of a substituent R7 represents 0, 1 or 2, in which when n is 2, R7 is optionally identical or different from each other;
• (II) an organoaluminum compound;
• and
• (III) as an external electron-donating compound, at least one or more compounds selected from alkoxysilane compounds represented by the following general formula (3):
• in the formula, R10, R11, R12, and R13, all of which are optionally identical or different from each other, represent a linear alkyl group having the carbon number of 1 to 8 or a branched alkyl group having the carbon number of 3 to 8, and
• one or more compound selected from (alkylamino)alkylsilane compounds represented by the following general formula (4):
• in the formula, R14 and R15, which are optionally identical or different from each other, represent a linear alkyl group having the carbon number of 1 to 8, a branched alkyl group having the carbon number of 3 to 12, a cycloalkyl group having the carbon number of 3 to 12, a cycloalkenyl group having the carbon number of 3 to 12, or an aromatic hydrocarbon group having the carbon number of 6 to 20;
• and R16 and R17, which are optionally identical or different from each other, represent an alkyl group having the carbon number of 1 to 8.