Process for the preparation of ethylene copolymers

摘要

A polymerization process comprising contacting under polymerization conditions ethylene and at least one alpha olefin of formula CH2=CHA wherein A is a C2-C20 alkyl radical to obtain a copolymer containing from 95% by mol to 50% by mol of ethylene derived units in the presence of a catalyst system obtainable by contacting:
b) at least a metallocene compound of formula (I);b) alumoxane or a compound capable of forming an alkyl metallocene cation; and optionallyc) an organo aluminum compound;wherein the groups R1-R4, L, M and W are described in the text.

主权项

1. A polymerization process comprising contacting under polymerization conditions ethylene and at least one alpha olefin of formula CH2=CHA, wherein A is a C2-C20 alkyl radical, to obtain a copolymer comprising from 95% by mol to 75% by mol of ethylene derived units in presence of a catalyst system obtained by contacting:
a) at least a metallocene compound of formula (I) and b) alumoxane or a compound capable of forming an alkyl metallocene cation;
wherein:M is an atom of a transition metal selected from group 3, 4, or the lanthanide or actinide groups in the Periodic Table of Elements;X equal to or different from each other, is hydrogen, halogen, R, OR, OR′O, OSO2CF3, OCOR, SR, NR2 or PR2;R is a linear or branched, cyclic or acyclic, C1-C40-alkyl, C2-C40 alkenyl, C2-C40 alkynyl, C6-C40-aryl, C7-C40-alkylaryl or C7-C40-arylalkyl radical, optionally comprising at least one heteroatom belonging to groups 13-17 of the Periodic Table of Elements;R′ is a C1-C20-alkylidene, C6-C20-arylidene, C7-C20-alkylarylidene, or C7-C20-arylalkylidene radical;L is a divalent bridging group selected from C1-C20 alkylidene, C3-C20 cycloalkylidene, C6-C20 arylidene, C7-C20 alkylarylidene, or C7-C20 arylalkylidene radicals, optionally comprising at least one heteroatom belonging to groups 13-17 of the Periodic Table of Elements, or a silylidene radical comprising up to 5 silicon atoms;R1 is a linear C1-C40 hydrocarbon radical optionally comprising at least one heteroatom belonging to groups 13-17 of the Periodic Table of Elements;R2 and R3 are part of 4-7 membered ring condensed to the benzene ring of the indenyl moiety, the ring optionally comprising at least one heteroatom belonging to groups 13-16 of the Periodic Table of Elements, wherein the valence of each atom forming the ring being filled with R18 radicals;R18 equal to or different from each other, are hydrogen or C1-C40 hydrocarbon radicals;R4 is hydrogen;W is an aromatic 5 or 6 membered ring optionally comprising at least one heteroatom belonging to groups 13-16 of the Periodic Table of Elements, wherein the valence of each atom of the ring is substituted with hydrogen or is optionally substituted with at least one R5 group; andR5 equal to or different from each other, are C1-C40 hydrocarbon radicals optionally comprising at least one heteroatom belonging to groups 13-17 of the Periodic Table of Elements.