Olefin polymerization catalyst component, its preparation and use

Abstract

A catalyst having high activity independent of the hydrogen concentration and low gel productivity in the polymerization of ethylene has been prepared. The preparation comprises the steps of reacting: a support comprising a magnesium halide compound having the formula (1): RO 2-n MgX n   (1)  wherein R is a C 1 -C 20 alkyl, a C 7 -C 26 aralkyl, a C 1 -C 20 alkoxy or a C 7 -C 26 aralkoxy, each same or different X is a halogen, and n is an integer 1 or 2, an alkyl metal halide compound having the formula (2): R 1 n 1 M m 1 X 1 (3m 1 -n 1 )   (2)  wherein M is B or Al, each same or different R 1 is a C 1 -C 10 alkyl, each same or different X 1 is a halogen, m 1 is 1 or 2, n 1 is 1 or 2 when m 1 is 1 and n 1 is an integer from 1 to 5 when m 1 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): R 2 n 2 (R 3 O) 2-n 2 Mg  (3)  wherein each same or different R 2 is a C 1 -C 20 alkyl, each same or different R 3 is a C 1 -C 20 alkyl, n 2 is between 0.01 and 1.99, and a titanium halide compound having the formula (4): (R 4 O) n 3 TiX 2 4-n 3   (4)  wherein each same or different R 4 is a C 1 -C 20 alkyl, each same or different X 2 is a halogen, n 3 is 0 or an integer 1-3, and Ti is quadrivalent titanium.

1 . A polyethylene composition produced in at least two polymerization stages using a catalyst prepared by reacting a support comprising a magnesium halide compound having the formula (1):  
       (RO) 2-n MgX n   (1)  
       wherein R is a C 1 -C 20  alkyl or a C 7 -C 26  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):  
 R 1   n   1 M m   1 X 1 ( 3m   1   -n   1 )  (2)  
  wherein M is B or Al, each same or different R 1  is a C 1 -C 10  alkyl, each same or different X 1  is a halogen, m 1  is 1 or 2, n 1  is 1 or 2 when m 1  is 1 and n 1  is an integer from 1 to 5 when m 1  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):  
 R 2   n   2 (R 3 O) 2-n   2 Mg  (3)  
  wherein each same or different R 2  is a C 1 -C 20  alkyl, each same or different R 3  is a C 1 -C 20  alkyl, n 2  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):  
 (R 4 O) n   3 TiX 2   4-n   3   (4)  
  wherein each same or different R 4  is a C 1 -C 2 , alkyl, each same or different X 2  is a halogen, and n 3  is 0 or an integer 1-3; and having an SHI 5/300  higher than 60, and having a low gel level.  
 
     
     
         2 . A film produced from a composition according to  claim 1 , wherein the number of gels in size class 0.3-0.7 mm and >0.7 mm are <20 and 0 respectively.  
     
     
         3 . 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-n MgX n   (1)     wherein R is a C 1 -C 20  alkyl or a C 7 -C 26  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):    R 1   n   1 M m   1 X 1 ( 3m   1   -n   1 )  (2)     wherein M is B or Al, each same or different R 1  is a C 1  C 10  alkyl, each same or different X 1  is a halogen, m 1  is 1 or 2, n 1  is 1 or 2 when m 1  is 1 and n 1  is an integer from 1 to 5 when m 1  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):    R 2   n   2 (R 3 O) 2-n   2 Mg  (3)     wherein each same or different R 2  is a C 1 -C 20  alkyl, each same or different R 3  is a C 1 -C 20  alkyl, n 2  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):    (R 4 O) n   3 TiX 2   4-n   3   (4)     wherein each same or different R 4  is a C 1 -C 20  alkyl, each same or different X 2  is a halogen, and n 3  is 0 or an integer 1-3; and having an MF21 between 5 and 15 and an SHI 2.7/210  higher than 40, characterized in that when compounded with a carbon black additive, the resulting compound has a low dispersion value.    
     
     
         4 . A polyethylene composition according to  claim 3 , having a dispersion (ISO-rating) lower than 5.