Abstract: Composition based on a crosslinkable polyethylene comprising from 0.05 to 0.24 hydrolysable silane groups per 100 —CH2— units and having a standard density SD of at least 954 kg/m3 and a melt flow index MI5 of less than 1.5 g/10 min. Pipes for the transportation of fluids under pressure, which can be obtained by extruding this composition and then hydrolysing it.

Abstract: A polyethylene resin comprising a blend of from 35 to 49 wt % of a first polyethylene fraction of high molecular weight and 51 to 65 wt % of a second polyethylene fraction of low molecular weight, the first polyethylene fraction comprising a linear low density polyethylene having a density of up to 0.928 g/cm3, and an HLMI of less than 0.6 g/10 min and the second polyethylene fraction comprising a high density polyethylene having a density of at least 0.969 g/cm3, and an MI2 of greater than 100 g/10 min, and the polyethylene resin, having a density of greater than 0.951 g/cm3 and an HLMI of from 1 to 100 g/10 min.

Abstract: A stabilized polypropylene composition, free or essentially free of any phenolic antioxidant containing: a) 100 parts by weight of a propylene polymer, b) from 0.005 to 0.1 part by weight of an amine oxide having the structural formula wherein R? and R? are groups containing from 1 to 36 carbon atoms, or of a N,N-dialkylhydroxylamine of formula R1R2NOH??(II) wherein R1 and R2 are independent groups of 1 to 36 carbon atoms, c) from 0.1 to 0.5 part by weight of a clarifying agent, and optionally d) from 0.01 to 0.1 part by weight of a sterically hindered amine. Manufacture of shaped object by using said composition and manufactured objects so obtained.

Abstract: A polyethylene resin comprising from 35 to 49 wt. % of a first polyethylene fraction of high molecular weight and from 51 to 65 wt. % of a second polyethylene fraction of low molecular weight, the first polyethylene having a density of up to 0.930 g/cm3, and an HLMI of less than 0.6 g/10 min and the second polyethylene fraction comprising a high density polyethylene having a density of at least 0.969 g/cm3 and an MI2 of greater than 10 g/10 min, and the polyethylene resin, having a density of great 0.946 g/cm3, an HLMI of from 1 to 100 g/10 min, a dynamical viscosity, measured at 0.01 radians/second, greater than 200,000 Pa.s and a ratio of the dynamical viscosities measured at, respectively 0.01 and 1 radians/second greater than 8.

Abstract: Multi-layered pipe comprising a main layer of polyethylene compound having a resistance to stress cracking NPT measured according to ISO 13479 standard of less than 8000 hours and an internal layer of polyethylene compound having a resistance to stress cracking NPT of higher than 8000 hours, the thickness of the internal layer being between 1 and 25% of the total pipe thickness but not less than 0.3 mm.

Abstract: Method of compounding a multimodal polyethylene composition in a compounding device, wherein a) the total residence time of the polyethylene composition in the compounding device is at least 1.5 minutes, b) the total drive specific energy (SEC) applied on the polyethylene composition is from 0.270 to 0.460 kWh/kg, c) optionally, a specific cooling energy (SCC) of at most 0.200 kWh/kg is applied on the polyethylene composition, d) the total specific energy, which is the difference between the total drive specific energy SEC and any specific cooling energy SCC, applied on the polyethylene composition is from 0.220 to 0.330 kWh/kg.

Abstract: The invention concerns a polyethylene based composition comprising 0.05 to 0.5 wt. % of at least a saturated fatty acid amide containing 8 to 30 carbon atoms, 0 to 0.1 wt. % of an auxiliary lubricant selected among fatty acids, fatty acid esters, fatty acid salts, monounsaturated fatty acid amides, polyols containing at least 4 carbon atoms, monoalcohol or polyalcohol monoethers, glycerol esters, paraffins, polysiloxanes, fluorinated polymers and mixtures thereof, and 0 to 5 wt. % of one or more additives selected among the antioxidants, anti-acids, anti-UV stabilizers, coloring agents and antistatic agents.

Abstract: Compositions comprising one or more olefin polymers functionalized by at least one functionalization agent chosen from carboxylic acids, their esters, their anhydrides and their metal salts and one or more stabilizing agents comprising one or more sterically hindered phenol groups and at most one ester functional group. Process for their preparation and use of these compositions for compatibilizing olefin polymers with polymers, fillers and metal substrates which are incompatible with olefin polymers.

Abstract: The invention concerns a method for producing ethylene homopolymers or copolymers comprising at least 90 mol % of units derived from ethylene which consists in: contacting in polymerising conditions, the monomers with a catalytic system including: (a) a catalytic solid comprising a metallocene of a transition metal of groups 4 to 6 of the periodic table containing at least a cyclopentadiene ligand capable of being substituted and a support, (b) at least an organoaluminium compound selected among compounds of general formula (1): AlTx(Y′)yX′z wherein: T is a hydrocarbon group containing 1 to 30 carbon atoms; Y′ is a group selected among —OR′, —SR′ and NR′R″ with R′ and R″ independently representing a hydrocarbon group containing 1 to 30 carbons atoms; X′ is a halogen atom: x verifies the relationship 0<x≦3; y verifies the relationship 0≦y<3; z verifies the relationship 0≦2<3, and x+y+z=3, and (c) at least

Abstract: A complex of a transition metal complying with the general formula (I) in which M is a transition metal of groups 6 to 12, T is the oxidation state of M, each A, which may be identical with or differ from each other, is an atom or an atomic grouping bonded covalently or ionically to the transition metal M, b is the valency of A, each R1, R2, R3, R4 and R5 is independently a hydrogen atom, an unsubstituted or substituted hydrocarbon group, an unsubstituted or substituted heterohydrocarbon group, or an inert functional group, R6 and R7 are, independently of one another, a polynuclear aromatic hydrocarbon group containing at least two condensed benzene nuclei, substituted with at least one hydrocarbon group.

Abstract: Continuous process for manufacturing a polyolefin resin in at least two polymerization reactors connected in series, in which the polymer suspensions leaving the reactors are transferred into hydrocyclone separators in which a flow comprising diluent and polymer particles, on the one hand, and a concentrated suspension of polymer particles, on the other hand, are formed and separated. The flows comprising the polymer particles are recycled into the first polymerization reactor.

Abstract: A device for purging a high-output polymer extruder includes a purge valve for discharging a molten polymer from the extruder. A cutting device is arranged at the output of this purge valve so as to be able to cut a continuous stream of polymer at the output of the purge valve into blocks. A conveying device, preferably hydraulic, is arranged at the output of the cutting device, so as to transport the blocks in a flow of liquid and convey them away from the discharge zone of the purge valve. The hydraulic conveying device preferably includes a chute equipped with a liquid-injection device, and a channel equipped with a device for creating a strong flow of liquid in the channel.

Abstract: Process for manufacturing an olefin polymer composition in at least two polymerization reactors connected in series, in which the suspension of polymer in a diluant, formed in the first reactor, is sent into a hydrocyclone seperator in which, on the one hand, a stream comprising diluant and, on the other hand, a concentrated suspension of polymer particles are formed and separated. The concentrated suspension is then introduced into the subsequent polymerization reactor.

Abstract: Process for the preparation of a catalytic system according to which a mixture of a halogenated neutral metallocene derived from a transition metal chosen from groups IIIB, IVB, VB and VIB of the Periodic Table and of an organoaluminium compound is prepared and an ionising agent is added thereto. (Co)polymerisation process according to which a mixture of a halogenated neutral metallocene as defined above and of an organoaluminium compound is prepared, the olefin is brought into contact with this mixture and an ionising agent is added thereto.

Abstract: Process for polymerizing &agr;-olefins Process for polymerizing x-olefins, in which at least one &agr;-olefin is placed in contact, under polymerizing conditions, with a catalytic system comprising

Abstract: Novel asymmetric silicon-bridged metallocenes useful as catalysts in the polymerization of olefins and process for preparing said metallocenes.

Abstract: Catalyst support containing an &agr;-olefin polymer which is in the form of particles of mean size from 5 to 350 &mgr;m in which the pore volume generated by the pores of radius from 1,000 to 75,000 Å is at least 0.2 cm3/g. Catalyst usable for the polymerization of &agr;-olefins, including a compound containing at least one transition metal belonging to groups IIIb, IVb, IVb and VIb of the Periodic Table, bound in or on this support.

Abstract: A complex of a transition metal complying with the general formula (I) 1

Abstract: Process for polymerizing alpha-olefins, in which at least one alpha-olefin is placed in contact, under polymerizing conditions, with a catalytic system comprising (a) a solid catalyst comprising (i) a compound of a transition metal from groups 4 to 6 of the Periodic Table, containing at least one cyclopentadiene ligand which may be substituted, (ii) an activator chosen from aluminoxanes and ionizing agents, and (iii) a porous polymeric support, and (b) at least one organoaluminium compound corresponding to the general formula R3−nAl(Y′)n in which 0.

Abstract: Process for manufacturing olefin polymers, in which some of the suspension of olefin polymer particles formed in a diluent is drawn off from the polymerization reactor and diluted by means of a liquid before being sent into a hydrocyclone separator in which, on the one hand, a concentrated suspension of polymer particles and, on the other hand, a stream essentially comprising diluent are formed and separated.