Abstract: The present invention provides a process for the preparation of a multimodal polyethylene comprising: (i) polymerising ethylene and optionally an ?-olefin comonomer in a first polymerisation stage to produce a first ethylene polymer; and (ii) polymerising ethylene and optionally an ?-olefin comonomer, in the presence of said first ethylene polymer, in a second polymerisation stage, wherein the first and second polymerisation stages are carried out in the presence of an unsupported metallocene catalyst and each polymerisation stage produces at least 5% wt of the multimodal polyethylene, and the multimodal polyethylene has a multimodal molecular weight distribution, a molecular weight of at least 50,000 g/mol and a bulk density of at least 250 g/dm3, and wherein a solution of the unsupported metallocene catalyst in a solvent is employed.

Abstract: The present invention provides a process for the preparation of a multimodal polyethylene comprising: (i) polymerising ethylene and optionally an ?-olefin comonomer in a first polymerisation stage to produce a first ethylene polymer; and (ii) polymerising ethylene and optionally an ?-olefin comonomer, in the presence of said first ethylene polymer, in a second polymerisation stage, wherein the first and second polymerisation stages are carried out in the presence of an unsupported metallocene catalyst and each polymerisation stage produces at least 5% wt of the multimodal polyethylene, and the multimodal polyethylene has a multimodal molecular weight distribution, a molecular weight of at least 50,000 g/mol and a bulk density of at least 250 g/dm3, and wherein a solution of the unsupported metallocene catalyst in a solvent is employed.

Abstract: The present invention provides a process for the preparation of a multimodal polyethylene comprising: (i) polymerizing ethylene and optionally an ?-olefin comonomer in a first polymerization stage to produce a first ethylene polymer; and (ii) polymerizing ethylene and optionally an ?-olefin comonomer, in the presence of said first ethylene polymer, in a second polymerization stage, wherein the first and second polymerization stages are carried out in the presence of an unsupported metallocene catalyst and each polymerization stage produces at least 5% wt of the multimodal polyethylene, and the multimodal polyethylene has a multimodal molecular weight distribution, a molecular weight of at least 50,000 g/mol and a bulk density of at least 250 g/dm3, and wherein a solution of the unsupported metallocene catalyst in a solvent is employed.

Abstract: The present invention provides a process for the preparation of a multimodal polyethylene, said multimodal polyethylene preferably having a bimodal or trimodal M.W. distribution, comprising: (i) polymerizing ethylene and optionally an ?-olefin comonomer in a first polymerization stage to produce a first ethylene polymer; and (ii) polymerizing ethylene and optionally an ?-olefin comonomer, in the presence of said first ethylene polymer, in a second polymerization stage, wherein said first and second polymerization stages are carried out in the presence of an unsupported metallocene catalyst, which is a complex of a group 4-10 metal having at least two ligands, wherein at least one of the ligands is persubstituted and comprises a delocalized pi system of electrons, each polymerization stage produces at least 5% wt of said multimodal polyethylene, and said multimodal polyethylene has a multimodal M.W. distribution, a M.W. of at least 50,000 g/mol and a bulk density of at least 250 g/dm3.

Abstract: The present invention provides a process for the preparation of a multimodal polyethylene comprising: (i) polymerising ethylene and optionally an ?-olefin comonomer in a first polymerisation stage to produce a first ethylene polymer; and (ii) polymerising ethylene and optionally an ?-olefin comonomer, in the presence of said first ethylene polymer, in a second polymerisation stage, wherein the first and second polymerisation stages are carried out in the presence of an unsupported metallocene catalyst and each polymerisation stage produces at least 5% wt of the multimodal polyethylene, and the multimodal polyethylene has a multimodal molecular weight distribution, a molecular weight of at least 50,000 g/mol and a bulk density of at least 250 g/dm3, and wherein a solution of the unsupported metallocene catalyst in a solvent is employed.

Abstract: An alkene interpolymer is prepared by polymerizing at least one 3-substituted C4-10 alkene and at least one C2-8 alkene in a slurry polymerization using a particulate catalyst system containing a single site catalyst.

Abstract: This application relates to an ethylene polymer having a weight average molecular weight of at least 120,000 including 1-50 tertiary double bonds per 10,000 carbon atoms.

Abstract: Method for the production of a thermostable crosslinked PVC copolymer where the crosslinking is carried out in the presence of humidity and after processing of the polymer. The copolymer is a copolymer of vinyl chloride and 0.05-10 weight % of a vinyl containing alkoxysilane compound. Preferably methacryloxy-propyltrimethoxy-silane or methacryloxy-propyltriethoxysilane is used as comonomer. The crosslinking can be carried out independent of the type of stabilizer. A condensation catalyst and also an inhibitor can be used to prevent too early crosslinking.