Catalyst components for the polymerization of olefins and catalysts therefrom obtained

Abstract

The invention relates to catalyst components, suiitable for the sprtion of homnopolymats and copolymene of ethylene having a broad molecular weight distribution (MWD), which comprise Ti, Mg, Cl, and are characterized by the following properties: surface area, determined by BET method, of lower than 100 m 2 /g, a total poroslty, measured by the mercury method, of higher than 0.25 cm 3 /g, a pore radius distribution such that at least 45% of the total porosity is due to pores with radius up to 0.1 μm.

1 . Catalyst components for the polymerization of olefins CH 2 =CHR VIII , wherein R RIII  is hydrogen or hydrocarbon radical having 1-12 carbon atoms, comprising Ti, Mg, Cl and optionally OR groups, and characterized by the following properties: 
 surface area, determined by BET method, of lower than 100 m 2 /g,    a total porosity, measured by the mercury method, of higher than 0.25 cm 3 /g and,    a pore radius distribution such that at least 45% of the total porosity is due to pores with radius up to 0.1 μm.    
     
     
         2 . Catalyst components according to  claim 1  in which the catalyst component comprises a Ti compound having at least one Ti-halogen bond supported on magnesium chloride in active form.  
     
     
         3 . Catalyst components according to  claim 1  containing groups different from halogen, in amount lower than 0.3 mole for each mole of titanium.  
     
     
         4 . Catalyst components according to  claim 1  in which the total porosity is between 0.35 and 1.2 cm 3 /g.  
     
     
         5 . Catalyst components according to  claim 4  in which the total porosity is between 0.38 and 0.9.  
     
     
         6 . Catalyst components according to  claim 1  in which the porosity due to pores with radius up to 1 μm is between 0.3 and 1 cm 3 /g.  
     
     
         7 . Catalyst components according to  claim 6  in which the porosity due to pores with radius up to 1 μm is between 0.34 and 0.8.  
     
     
         8 . Catalyst components according to  claim 4  in which the value of the porosity due to pores with radius higher than μm is lower than 25% with respect to the total porosity.  
     
     
         9 . Catalyst components according to  claim 8  in which the value of the porosity due to pores with radius higher than μm is lower than 15% with respect to the total porosity.  
     
     
         10 . Catalyst component according to  claim 1  in which the surface area measured by the B.E.T. method is preferably lower than 80 m 2 /g.  
     
     
         11 . Catalyst component according to  claim 1  in which the surface area is between 30 and 70 m 2 /g.  
     
     
         12 . Catalyst component according to  claim 1  in which the porosity measured by the BET method is generally comprised between 0.1 and 0.5 cm 3 /g.  
     
     
         13 . Catalyst component according to  claim 12  in which the porosity is from 0.15 to 0.4 cm 3 /g.  
     
     
         14 . Catalyst component according to  claim 1  in which more than 50% of the total porosity is due to pores with radius up to 0.1 μm.  
     
     
         15 . Catalyst component according to  claim 1  in which more than 65% of the total porosity is due to pores with radius up to 0.1 μm.  
     
     
         16 . Catalyst components according to  claim 1  in which the average pore radius value, for porosity due to pores up to 1 μm, is lower than 0.09μm.  
     
     
         17 . Catalyst components according to  claim 16  in which the average pore radius value, for porosity due to pores up to 1 μm, is lower than 0.08μm.  
     
     
         18 . Catalyst components according to  claim 17  in which the average pore radius value, for porosity due to pores up to 1 μm, is lower than 0.07μm.  
     
     
         19 . Catalyst components according to  claim 1  in which the titanium compound has the formula Ti(OR V ) n X y-n , wherein n is a number comprised between 0 and 0.5 inclusive, y is the valence of titanium, R V  is an alkyl, cycloalkyl or aryl radical having 2-8 carbon atoms and X is chlorine.  
     
     
         20 . Catalyst components according to  claim 19  in which y is 3 or 4, and n is 0.  
     
     
         21 . A process for the preparation of the catalyst components of  claim 1  comprising the following steps: 
 (a) reacting a compound MgCl 2 mR VI OH, wherein 0.3 ≦m ≦1.7 and R VI  is an alkyl, cycloalkyl or aryl radical having 1-12 carbon atoms, with a titanium compound of the formula Ti(OR V ) n X y-n , in which n is comprised between 0 and 0,5, y is the valence of titanium, X is halogen and R V  is an alkyl radical having 2-8 carbon atoms;  
 (b) reacting the product obtained from (a) with An Al-alkyl compound and  
 (c) reacting the product obtained from (b) with a titanium compound of the formula Ti(OR V ) n X y-n , in which n is comprised between 0 and 0,5, y is the valence of titanium, X is halogen and R V  is an alkyl radical having 2-8 carbon atoms.  
 
     
     
         22 . Process according to  claim 21  in which he compound MgCl 2 mR VI OH is prepared by thermal dealcoholation of adducts MgCl 2 ·pR VI OH, wherein p is a number higher than 2.  
     
     
         23 . Process according to  claim 21  in which the titanium compound used in step (a) and (c) is TiCl 4 .  
     
     
         24 . Process according to  claim 21  and  22  in which R VI  is ethyl.  
     
     
         25 . Process according to  claim 21  in which the aluminum alkyl compound of step (b) is selected from those of formula R z AlX 3-z  in which R is a C 1 -C 20  hydrocarbon group, z is an integer ranging from 1 to 3 and X is chlorine.  
     
     
         26 . Process according to  claim 25  in which the aluminum alkyl compound is a trialkyl aluminum compounds selected from the group consisting of triethylaluminum, triisobutylaluminum, tri-n-butylaluminum, tri-n-hexylaluminum, tri-n-octylaluminum.  
     
     
         27 . Process according to  claim 26  in which the aluminum alk-yl compound is tri-n-octylaluminum.  
     
     
         28 . Catalysts for the polymerization of olefins comprising the product of the reaction between an aluminum alkyl compound and a catalyst component according to one or more of the claims  1 - 20 .  
     
     
         29 . Pre-polymerized catalyst for the polymerization of olefins obtained by pre-polymerizing ethylene or mixtures thereof containing one or more α-olefins, with a catalyst according to  claim 28  and thereby forming amounts of polymer from 0.1 up to 1000 g per gram of solid catalyst component.  
     
     
         30 . Process for the polymerization of olefins CH 2 =CHR VIII , wherein R VIII  is hydrogen or hydrocarbon radical having 1-12 carbon atoms, carried out in the presence of a catalyst according to any of the claims  28 - 29 .  
     
     
         31 . Process for the preparation of broad molecular weight distribution ethylene polymers having a F/E ratio higher than 100 characterized in that it is carried out in the presence of a catalyst according to claims  28 - 29 .  
     
     
         32 . Process according to  claim 31  in which the F/E ratio is higher than 120.  
     
     
         33 . Process according to  claim 31  characterized by the fact that it is carried out more than one step working under different polymerization conditions.  
     
     
         34 . Polymer products obtainable from the processes according to any of the claims  30 - 33 .