PROCESS FOR POLYMERISING OLEFINS HAVING NARROW PARTICLE SIZE DISTRIBUTION

The disclosure relates to process for polymerising olefins, the process comprising polymerising ethylene, optionally in the presence of at least one other alpha olefin comonomer, preferably C4-C10 alpha olefin comonomer, preferably in a multi-stage polymerisation configuration, in the presence of a single-site polymerisation catalyst to produce a polymer component; to produce a polyethylene polymer or a polyethylene copolymer having a particle size distribution of the resulting a polyethylene polymer powder or a polyethylene copolymer powder described by a lognormal distribution having a scale parameter less than 0.5, preferably less than 0.45, in particular from 0.1 to 0.45, more preferably from 0.15 to 0.4. The disclosure further relates to a single-site10 polymerisation catalyst, comprising (i) a transition metal complex; (ii) a cocatalyst; and optionally (iii) a support, preferably a silica support; wherein the single-site polymerisation catalyst is characterised by a compressive strength of at least 5 MPa, preferably at least 5.5 MPa, in particular from 6 to 25 MPa, more preferably from 7 to 20 MPa, even more preferably from 7 to 15 MPa. The disclosure further relates to use of the single-site polymerisation catalyst in the preparation of a polyethylene polymer component, a polyethylene polymer, or a polyethylene copolymer and to a polyethylene polymer or a polyethylene copolymer having a particle size distribution of the polyethylene polymer or the polyethylene copolymer in powder form described by a lognormal distribution having a scale parameter less than 0.5, preferably less than 0.45, in particular from 0.1 to 0.45, more preferably from 0.15 to 0.4, preferably obtained by the present process.