Abstract: A process for the gas-phase (co-)polymerization of olefins in a fluidised bed reactor using a Ziegler-Natta type catalyst characterised in that the polymerisation is performed in the presence of an additive having the formula R—Cl where R is an alkyl group of 2 to 7 carbon atoms.

Abstract: The present invention relates to a process for the gas-phase (co-)polymerisation of olefins in a fluidised bed reactor using a Ziegler-Natta type catalyst characterised in that the polymerisation is performed in the presence of an additive.

Abstract: A catalyst composition for polymerising ethylene with a superior activity, productivity, and giving, in particular, copolymers with an improved narrower short chain branching distribution, and especially an improved cling development in PIB formulated films. The catalyst composition for the (co-)polymerisation of ethylene, optionally with an alpha olefin of 3 to 10 carbon atoms, has a catalyst precursor and an organoaluminium cocatalyst, wherein the catalyst precursor has i) a catalyst carrier material, having from 0.3 to 1.2 mmoles of OH groups per gram of catalyst carrier; ii) a dialkylmagnesium compound of the formula RMgR1, where R and R1 are the same or different C2-C12 alkyl groups, in an amount between 1.1 and 2.4 mmoles of diakylmagnesium per gram of catalyst carrier; iii) a tetraalkyl orthosilicate, in which the alkyl group contains from 2 to 6 carbon atoms, in an amount between 0.4 and 1.