Abstract: A process for the gas-phase (co-)polymerization of olefins in a fluidized bed reactor using a metallocene catalyst in that the polymerization is preformed in the presence of a process aid additive selected from at least one of 1) a polysulfone copolymer, 2) a polymeric polyamine, or 3) an oil-soluble sulfonic acid.

Abstract: A process for the gas-phase (co-)polymerisation of olefins in a fluidised bed reactor using a metallocene catalyst. The polymerisation is performed in the presence of a process aid additive.

Abstract: A process for preparing bimodal molecular weight distribution copolymers of ethylene with alpha-olefins having 3 to 20 carbon atoms, said copolymers having: (a) a comonomer distribution wherein the comonomer level at the mid-position of the low molecular weight component is <3 times the level at the mid-position of the high molecular weight component, and (b) a total average comonomer content in the range 0.5-20 short chain branches (SCB)/1000 C atoms characterised in that said process is carried out in the presence of a supported multisite catalyst. The multisite catalyst comprises a metallocene complex and a Ziegler catalyst. The metallocene complex for example is bis(pentamethylcyclopentadienyl) zirconium dichloride.

Abstract: A catalyst composition for preparing polyketones comprises(a) a Group VIII metal compound, containing at least one ligand capable of coordinating to the Group VIII metal and,(b) a compound of the formula BXYZ where at least one of X, Y and Z is a chloro or bromophenyl group preferably B(p-ClC.sub.6 H.sub.4).sub.3. Polyketones having p-chlorophenyl or p-bromophenyl end groups are also disclosed.

Abstract: A catalyst composition comprising at least one metallocene complex of general formula I or II ##STR1## wherein R is a univalent of divalent 1-20c hydrocarbyl, or a 1-20c hydrocarbyl containing substituent oxygen, silicon, phosphorus, nitrogen of sulphur atoms with the proviso that at least one R group contains a lewis base functionality and when there are two or more R groups present they may be the same or different, and when R is divalent it is directly attached to M and replaces a Y ligand, and wherein M is a Group IVA metal,Y is a univalent anionic ligandX is an organic group containing a cyclopentadienyl nucleus and for formula In is an integer of 1 to 10x is either 1 or 2, and for formula II,n, m and l are integers or 0 such that n +m +l .gtoreq.1, p =0-2, andz is a c.sub.1 to c.sub.

Abstract: Catalyst compositions comprising metallocene complexes having Lewis base functionality may be used for the preparation of polyolefins. Preferred complexes are zirconium complexes in which the Lewis base functionality is provided by ether or thioether groups.The catalyst compositions may be supported on inorganic supports or on supports having polymerisation activity eg Ziegler catalysts.

Abstract: Catalyst compositions comprising both metallocene complexes having polymerisable groups and polymerization catalysts eg Ziegler-Natta may be used for the preparation of polyolefins. The catalyst compositions may comprise the metallocene complex in the form of a polymer and may suitably be supported on inorganic supports. Polymers having a wide range of molecular weights and comonomer distributions may be prepared by use of the catalyst compositions. Preferred metallocene complexes are zirconium complexes in which the polymerisable group is vinyl.

Abstract: Catalyst compositions comprising metallocene complexes having polymerisable olefinic groups substituent on an organic group containing a cyclopentadienyl nucleus may be used for the preparation of polyolefins. The catalyst compositions may be in the form of polymers comprising the metallocene complex and may be suitably supported on inorganic supports. Polymers having a broad range of density and melt indices as well as low hexane extractables and excellent powder morphology and flowability may be obtained by use of the catalyst compositions. Preferred metallocene complexes are zirconium complexes in which the polymerisable olefinic group is vinyl.

Abstract: Catalyst compositions comprising metallocene complexes having polymerisable may be used for the preparation of polyolefins.The catalyst compositions may be in the form of polymers comprising the metallocene complex and may be suitably supported on inorganic supports. Polymers having a broad range of density and melt indices as well as low hexane extractables and excellent powder morphology and flowability may be obtained by use of the catalyst compositions. Preferred metallocene complexes are zirconium complexes in which the polymerisable group is vinyl.