PELLETS AV NEDBRUTT PROPYLENHOMOPOLYMER ELLER KOPOLYMER AV PROPYLEN MED MINST ET ANNET ALFA-OLEFIN, FREMGANGSMAATE FOR FREMSTILLING AV SLIKE PELLETS SAMT AV FORMEDE GJENSTANDER

摘要

The present invention relates to a process for the manufacture of propylene homopolymer or copolymer pellets in the presence of free radical generators so as to obtain non-sticky pellets with excellent reproducibility and to increase the melt index of the polymer during the pelletisation and of the subsequent conversion of the pellets into finished articles. The invention consists particularly in adding to the polymer two free radical generators, G1 and G2, the half-life of G2 being at least 20 times longer than that of G1 at the pelletisation temperature and in pelletising the polymer to which such addition has been made under conditions such that at least 80% by weight of G2 and not more than 20% by weight of G1 remain intact in the pellets and available for a subsequent decomposition during the conversion of the pellets into finished articles.