Heterophasic polypropylene composition with low hexane extractables

Abstract

The invention relates to a polypropylene composition comprising a heterophasic propylene copolymer wherein the heterophasic propylene copolymer consists of: a propylene homopolymer matrix in an amount from 71 to 92 wt %, preferably from 78 to 89 wt %, more preferably from 83 to 87 wt %, based on the heterophasic propylene copolymer and an ethylene-propylene copolymer in an amount from 8 to 29 wt %, preferably from 11 to 22 wt %, more preferably 13 to 17 wt %, based on the heterophasic propylene copolymer, wherein the amount of units derived from ethylene based on the ethylene-propylene copolymer is between 40 to 60 wt %, preferably 42 to 55 wt %, more preferably 43 to 51 wt %, and wherein the polypropylene composition has • an n-hexane extractable content measured by USA FDA 21 CFR § 177.1520; Olefin polymers (measured on film) of less than 5 wt %, wherein the heterophasic propylene copolymer within the polypropylene composition is prepared by visbreaking an intermediate heterophasic propylene copolymer having an initial melt flow rate (MFRinitial) from 1.0 to 25 dg/min, preferably 1.5 to 20 dg/min, as determined according to ISO1133: 2011 using 2.16 kg at 230° C. by contacting said intermediate heterophasic propylene copolymer in a melt mixing process with a peroxide in such an amount that a composition comprising a heterophasic propylene copolymer having the desired final melt flow rate (MFRfinal) from 3 to 45 dg/min as determined according to ISO1133: 2011 using 2.16 kg at 230° C. is obtained.

Dependencies are inferred from the claim text.