Polyolefin masterbatch and composition suitable for injection molding

Abstract

A masterbatch composition comprising: 70-90% wt of a component (A) being a propylene homopolymer or copolymer of propylene with ethylene or C 4 -C 10 alpha olefins, having a MFR A according to ISO 1133 (230° C./2.16 Kg) ranging from 15 to 70 g/10 min; and 10-30% wt of a component B) being a propylene-ethylene copolymer comprising 25-45% wt of ethylene derived units and having a value of the intrinsic viscosity [η] of the fraction soluble in xylene at room temperature ranging from 5 to 9 dl/g, said masterbatch composition having a total MFR higher than 4 g/10 min, and a value of the flexural modulus measured according to ISO method 178 ranging from 950 to 2000 MPa.

What is claimed is: 
     
         1 . A masterbatch composition comprising:
 70-90 wt % of a component (A) being a propylene homopolymer or a copolymer of propylene with ethylene or C 4 -C 10  alpha olefins, having a MFR A  according to ISO 1133 (230° C./2.16 Kg) ranging from 15 to 70 g/10 min; and   10-30 wt % of a component B) being a propylene-ethylene copolymer comprising 25-45 wt % of ethylene derived units and having a value of the intrinsic viscosity [η] of the fraction soluble in xylene at room temperature ranging from 5 to 9 dl/g,   
       the masterbatch composition having a total MFR higher than 4 g/10 min, and a value of the flexural modulus measured according to ISO method 178 ranging from 950 to 2000 MPa,
 wherein the masterbatch composition is suitable to form an injection molded article having a tiger stripes ratio less than 0.638 cm/cm. 
 
     
     
         2 . The masterbatch composition of  claim 1  in which the amount of component (A) ranges from 74 to 86 wt %, and the amount of component (B) ranges from 14 to 26%, said component B) having a content of ethylene derived units ranging from 30 to 42wt %. 
     
     
         3 . The masterbatch composition of  claim 1  in which the intrinsic viscosity [η] of the component (B) ranges from 6.5 to 8 dl/g. 
     
     
         4 . The masterbatch composition of  claim 1  in which the MFR A  of component (A) ranges from 20 to 60 g/10 min, while the MFR of the total composition ranges from 4 to 15 g/10 min. 
     
     
         5 . The masterbatch composition of  claim 1  having a flexural modulus, measured according to ISO method 178, ranging from 1000 to 1700 MPa. 
     
     
         6 . The masterbatch composition of  claim 1  in which the P.I. (Polydispersity Index) of component (A) ranges from 5 to 10. 
     
     
         7 . A thermoplastic polyolefin composition comprising the masterbatch composition of  claim 1  and a polyolefin. 
     
     
         8 . (canceled) 
     
     
         9 . The masterbatch composition of  claim 1 , wherein the masterbatch composition is suitable to form the injection molded article, wherein the injection molded article further comprises a polyolefin. 
     
     
         10 . The masterbatch composition of  claim 1 , wherein the masterbatch composition is suitable to form the injection molded article having sporadic medium gels. 
     
     
         11 . The masterbatch composition of  claim 1 , wherein masterbatch composition is suitable to form the injection molded article having no big gels. 
     
     
         12 . The masterbatch composition of  claim 1 , wherein the masterbatch composition is suitable to form the injection molded article comprising from about 8 percent by weight to about 25 percent by weight of the masterbatch composition. 
     
     
         13 . The masterbatch composition of  claim 9 , wherein the polyolefin is selected from the group consisting of propylene homopolymers, random copolymers, and thermoplastic elastomeric polyolefin compositions. 
     
     
         14 . The masterbatch composition of  claim 9 , wherein the masterbatch composition is suitable to form the injection molded article, wherein the article is formed by compounding the masterbatch composition with the polyolefin. 
     
     
         15 . The masterbatch composition of  claim 1 , wherein the masterbatch composition is suitable to form the injection molded article having a tiger stripes ratio less than about 0.605 cm/cm. 
     
     
         16 . The masterbatch composition of  claim 1 , wherein the masterbatch composition is suitable to form the injection molded article having additives selected from the group consisting of mineral fillers, colorants, and stabilizers. 
     
     
         17 . The masterbatch composition of clam  1 , wherein the masterbatch composition is suitable to form the injection molded article, wherein the injection molded article is an automobile bumper. 
     
     
         18 . The masterbatch composition of clam  1 , wherein the masterbatch composition is suitable to form the injection molded article, wherein the injection molded article is an automobile fascia.