Patent ID: 7534841
Filing Date: 2009-05-19
Classification: C08F,Y10S

Abstract:
1. A process for preparing 1-butene polymers comprising the properties: a) a distribution of molecular weight (Mw/Mn) lower than 3; b) a melt flow rate (MFR) measured according to ISO 1133 (190° C., 2.16 kg) ranging from 200 to 1000; c) an intrinsic viscosity (IV) measured in tetrahydronaphthalene (THN) at 135° C. lower than 0.8 dl/g; d) a melting point higher than 90° C.; e) isotactic pentads (mmmm) measured with f) 4,1 insertions not detectable at a C g) a yellowness index lower than 0; and h) an aluminum content ranging from 2 ppm by weight to 40 ppm by weight, the process comprising polymerizing 1-butene or copolymerizing 1-butene with ethylene, propylene or an alpha-olefin of formula CH (A) a metallocene compound represented by formula (I): wherein: M is an atom of a transition metal selected from those belonging to group 3, 4, or to the lanthanide or actinide groups in the Periodic Table of the Elements; X, equal to or different from each other, is a hydrogen atom, a halogen atom, a R, OR, OR′O, OSO R R (B) an alumoxane or a compound that forms an alkyl metallocene cation; and optionally (C) an organo aluminum compound.