Process for the production of films from polypropylene by calendering

摘要

A process for the production of films by calendering at temperatures above the crystallite melting point, in particular above 180 DEG C, from a composition containing, per 100 parts by weight of homopolymer and/or copolymer of propylene having an MFI (230 DEG C/21.6 N) of 0.2-1.0 g/10 min, 0.1-0.5 parts by weight of a stabiliser based on phenolic antioxidants, 0.5-3.0 parts by weight of processing aids based on polymers such as dimethyl siloxane polymers, polyoctenamers or the like and/or optionally metal salts of carboxylic acids, which comprises mixing the components while warming them to a temperature of 180 to 190 DEG C and thus plastifying the mixture, then sheeting out the plastified composition at a temperature of from 185 to 200 DEG C, and subsequently calendering the sheeted-out compound at maximum temperatures of from 220 to 230 DEG C, to give films having a thickness of from 0.2 to 0.75 mm.