Use of modifiers based on ethylene or amorphous elastomers to reduce the surface tack of amorphous polypropylene

An ethylene homo or copolymer or olefin elastomer is useful as a modifying agent to reduce the surface stickiness of high grade amorphous polypropylene. The use of a modifying agent (I) as an additive to a high grade amorphous polypropylene base polymer (II) having a melt enthalpy of upto 40 J/g and a melt flow index of 0.1-50 g/10 min to reduce surface stickiness is claimed. (I) comprises: (a) homopolymers of ethylene copolymers with a higher alpha -olefins having an ethylene content of at least 90 mol.% and a density of no more than 0.92 g/cm (LDPE) (b) copolymers of ethylene with high alpha -olefins produced in a low pressure process using catalyst, having an ethylene content of at least 75 mol.% and a density of no more than 0.93 g/cm (LLDPE), (c) high grade amorphous olefin elastomers having a melt enthalpy of no more than 15 J/g consisting of copolymers of ethylene and propylene (EPR) or of terpolymers of ethylene, propylene and dienes (EPDM) having a density of no more than 0.88 g/cm as well as mixtures of the olefin elastomers with polyethylene or isotactic polypropylene, whereby the olefin elastomer content is greater than 50 wt.%. (II) is a propylene or copolymer with one or more alpha -olefins having a propylene content of at least 80 wt.%. An Independent claim is included for a process to reduce the surface stickiness of (II) by the addition of (I).