Novel Propylene Polymer Compositions

Abstract

The invention relates to propylene polymer compositions comprising 50-70 wt % of a propylene homo- or copolymer, 5-20 wt % of a first elastomeric ethylene-propylene copolymer, 5-25 wt % of a second elastomeric ethylene-propylene copolymer and 5-30 wt % of an ethylene polymer. The propylene polymer compositions are suitable for moulding and they have low haze and a good impact strength/stiffness balance with good impact strengths at low temperatures.

1 . A polypropylene composition for moulding having an MFR (230° C./2.16 kg)≧8 g/10 min comprising 
 A) 50-70 wt % of a propylene polymer comprising a propylene homopolymer and/or a propylene copolymer with up to 5 wt % ethylene and/or one or more C 4 -C 8  α-olefins and having an intrinsic viscosity IV A  1.00-2.20 dl/g,    B) 5-20 wt % of a first elastomeric ethylene-propylene copolymer having an intrinsic viscosity IV B  1.65-2.50 dl/g and an ethylene content of 20-40 wt %, with IV B >IV A ,    C) 5-25 wt % of a second elastomeric ethylene-propylene copolymer having an intrinsic viscosity IV C  of 0.90-1.60 dl/g and an ethylene content of 45-85 wt %,    D) 5-30 wt % of an ethylene polymer having an ethylene content of at least 80 mol % and having a melt index MI (190° C., 2.16 kg) of at least 5 g/10 min and a density of 905-925 kg/m 3 .    
     
     
         2 . Polypropylene composition according to  claim 1 , wherein the first elastomeric ethylene-propylene copolymer has an intrinsic viscosity IV B  of 1.80-2.25 dl/g.  
     
     
         3 . Polypropylene composition according to  claim 1  or  2 , wherein the second elastomeric ethylene-propylene copolymer has an intrinsic viscosity IV C  of 0.90-1.50 dl/g.  
     
     
         4 . Polypropylene composition, according to  claim 1  or  2 , wherein IV B −IV C ≧0.2 dl/g.  
     
     
         5 . Polypropylene composition according to  claim 1  or  2 , it contains further comprising, based on the total weight of A to D, 0.01-2 wt % of α-nucleating agents.  
     
     
         6 . Polypropylene composition according to  claim 1  or  2 , wherein the ratio (B+C)/D of the amounts of elastomeric copolymers (B+C) to the amount of ethylene polymer D is from 0.3:1 to 2.5:1.  
     
     
         7 . Process for producing a polypropylene composition of  claim 1  or  2 , comprising mixing 
 A) 50-70 wt % of a propylene polymer comprising a propylene homopolymer and/or a propylene copolymer with up to 5 wt % ethylene and/or one or more C 4 -C 8  α-olefins and having an intrinsic viscosity IV A  1.00-2.20 dl/g,    B) 5-20 wt % of a first elastomeric ethylene-propylene copolymer having an intrinsic viscosity IV B  1.65-2.50 dl/g and an ethylene content of 20-40 wt %, with IV B >IV A ,    C) 5-25 wt % of a second elastomeric ethylene-propylene copolymer having an intrinsic viscosity IV C  of 0.90-1.60 dl/g and an ethylene content of 45-85 wt %,    D) 5-30 wt % of an ethylene polymer having an ethylene content of at least 80 mol % and having a melt index MI (190° C., 2.16 kg) of at least 5 g/10 min and a density of 905-925 kg/m 3 .    melting and homogenising and    cooling and pelletising the mixture.    
     
     
         8 . (canceled)  
     
     
         9 . Polypropylene composition, according to  claim 1  or  2 , wherein IV B −IV C ≧0.4 dl/g.  
     
     
         10 . A method of producing a shaped article, comprising injection molding a composition of  claim 1  or  2 .  
     
     
         11 . A method of producing packaging, comprising injection molding a composition of  claim 1  or  2 .  
     
     
         12 . A method of producing this wall packaging, comprising injection molding a composition of  claim 1  or  2 .  
     
     
         13 . A shape article produced by the method of  claim 9 .  
     
     
         14 . A shape article produced by the method of  claim 10 .  
     
     
         15 . A shape article produced by the method of  claim 11.