PROCESS FOR PREPARING ETHYLENE HOMOPOLYMERS OR COPOLYMERS IN A TUBULAR REACTOR WITH AT LEAST TWO REACTION ZONES HAVING DIFFERENT CONCENTRATIONS OF CHAIN TRANSFER AGENT

摘要

Process for preparing ethylene homopolymers or copolymers in the presence of free-radical polymerization initiator and at least one chain transfer agent at pressures in the range of from 110 MPa to 350 MPa and temperatures in the range of from 100°C to 350°C in a tubular reactor with at least two reaction zones having different concentrations of the chain transfer agent, wherein the concentration of the chain transfer agent in the first reaction zone is less than 70% of the concentration of the chain transfer agent in the reaction zone with the highest concentration of the chain transfer agent, ethylene homopolymers or copolymers obtainable by such a process,the use of the ethylene homopolymers or copolymers for extrusion coating and a process for extrusion coating a substrate selected from the group consisting of paper, paperboard, polymeric film, and metal, with such ethylene homopolymers or copolymers.