Olefin polymerization catalyst component, its preparation and use

A polyethylene composition produced in at least two polymerization stages using a catalyst component prepared by reacting;

• a support comprising a magnesium halide compound having the formula (1):
• (RO)2-nMgXn (1)
• wherein R is a C1-C20 alkyl or a C7-C26 aralkyl, each the same or different, X is a halogen, and n is an integer 1 or 2 which further comprises an inorganic oxide;
• a compound having the formula (2):
• R1n1Mm1X1(3m1-n1) (2)
• wherein M is B or Al, each same or different R1 is a C1 C10 alkyl, each same or different X1 is a halogen, m1 is 1 or 2, n1 is 1 or 2 when m1 is 1 and n1 is an integer from 1 to 5 when m1 is 2;
• a magnesium composition containing magnesium bonded to a hydrocarbyl and magnesium bonded to a hydrocarbyl oxide, said magnesium composition having the empirical formula (3):
• R2n2(R3O)2-n2Mg (3)
• wherein each same or different R2 is a C1-C20 alkyl, each same or different R3 is a C1-C20 alkyl, n2 is between 0.01 and 1.99 which is the contact product of a dialkyl magnesium and an alcohol in a molar ratio of alcohol to dialkyl magnesium of 1.8-1.98 mol/mol, and;
• a titanium halide compound having the formula (4):
• (R4O)n3TiX24-n3 (4)
• wherein each same or different R4 is a C1-C20 alkyl, each same or different X2 is a halogen, and n3 is 0 or an integer 1-3;
• and having an MF21 between 5 and 15 and an SHI2.7/210 higher than 40, characterized in that when compounded with a carbon black additive, the resulting compound has a low dispersion value.