Abstract: An ethylene homo- or copolymer composition is stabilized by suitable stabilizers conferring improved resistance against thermo-oxidative degradation, which occurs in the presence of liquid fuels comprising biodiesel, such as vegetable oil esters, in combination with oxygen. The stabilizers comprise a combination of at least two sterically hindered amine compounds or N-hydroxy- or N-oxylderivatives thereof in an amount of from 100 to 10 000 ppm. Such ethylene homo- or copolymer composition is highly suitable for articles of plastic and components for the transport and storage of liquid fuels comprising biodiesel, such as vegetable oil esters, preferably for plastic fuel tanks for automotive vehicles.

Abstract: Method of changing from a polymerization using a first catalyst to a polymerization using a second catalyst which is incompatible with the first catalyst in a gas-phase reactor, which comprises the steps a) stopping of the polymerization reaction using the first catalyst, b) flushing of the reactor under polymerization conditions with at least one deactivating agent comprising a volatile constituent and a nonvolatile constituent in a weight ratio of from 0.1 to 1000, c) introduction of the second catalyst into the reactor and d) continuation of the polymerization using the second catalyst.

Abstract: The present invention refers to a process for overcoming the problem of formation of oligomeric-polymeric complexes during preparation of cyclopentadienyl metallocenes comprising ligands bridged by at least three carbon atoms. According to the invention a process is presented comprising the steps of deprotonating a biscyclopentadienyl ligand bridged by a chain having a backbone of at least three carbon atoms by a base and reacting the deprotonated ligand with at least one alkali or alkaline earth metal alkylating agent and a salt of a transition metal belonging to group 3, 4, 5, 6 or to the lanthanide or actinide groups of the Periodic Table of the Elements.

Abstract: The present invention relates to a process for recycling cyclopentadienyl derivatives of the formulae (I) and (I?), a process for preparing metallocenes of the formula (III) from cyclopentadienyl derivatives of the formulae (I) and (I?) or from bridged biscyclopentadienyl derivatives of the formula (II), in which the cyclopentadienyl derivatives of the formulae (I), (I?) or (II) which are used have been at least partly recovered and purified by means of liquid-solid chromatography, and the use of liquid-solid chromatography for purifying substituted, recovered cyclopentadienyl derivatives of the formulae (I), (I?) or (II).

Abstract: A process for preparing a polymer containing derived units of one or more alpha olefins of formula CH2?CHW wherein W is a C3-C10 hydrocarbon radical and optionally from 0 to 81% by mol of derived units of propylene or 1-butene, comprising contacting under polymerization conditions one or more alpha olefins of formula CH2?CHW and optionally propylene or 1-butene in the presence of a catalyst system obtainable by contacting: a) a metallocene compound of formula (I) wherein M, X, L, T1, T2, T3 and R1 are described in the text; and (b) an alumoxane or a compound capable of forming an alkyl metallocene cation.

Abstract: Polyethylene which comprises ethylene homopolymers and/or copolymers of ethylene with 1-alkenes and has a molar mass distribution width Mw/Mn of from 3 to 30, a density of from 0.945 to 0.965 g/cm3, a weight average molar mass Mw of from 50 000 g/mol to 200 000 g/mol, a HLMI of from 10 to 300 g/10 min and has from 0.1 to 15 branches/1000 carbon atoms, wherein the 1 to 15% by weight of the polyethylene having the highest molar masses have a degree of branching of more than 1 branch of side chains larger than CH3/1000 carbon atoms, a process for its preparation, catalysts suitable for its preparation and also injection moldings in which this polyethylene is present.

Abstract: A novel adhesive composition suitable for composing multilayered coatings onto large, industrial equipment such as pipeline tubes is devised. The composition is a blend based on a polyethylene which determines the blend's favorable properties, which polyethylene itself can be used further in coating cables and for producing mouldings, especially rotomoulded articles.

Abstract: The invention relates to a glass fiber-reinforced molding composition composed of an olefin polymer, in particular a propylene polymer. The molding composition comprises an olefin polymer which contains 5-50% by weight of glass fibers which are bonded to the olefin polymer by means of a compatibilizer, and from 10?4 to 1% by weight, preferably from 10?3 to 1031 1% by weight, of a phthalocyanine pigment as the nucleating agent. The low costs and the fact that even a very small fraction of the phthalocyanine pigment in the polymer leads to sufficient nucleation ensures extremely inexpensive production. The nucleation with the phthalocyanine pigment leads to an improvement in the impact strength, and also in the yield stress and tensile strain at break of the molding composition.

Abstract: Method of determining the melt mass flow rate of an ethylene polymer in the polymerization of ethylene or of ethylene with further comonomers, which is carried out at temperatures of from 140° C. to 350° C. and pressures of from 40 MPa to 350 MPa in a reactor to form the ethylene polymer and the ethylene polymer is subsequently cooled in a heat exchanger, which comprises: a) establishment of a correlation between the thermal conductivity of the ethylene polymer in the heat exchanger and the melt mass flow rate of the ethylene polymer, with the individual measurements each being carried out at an essentially constant melt mass flow rate, b) measurement of the thermal conductivity of an ethylene polymer in the heat exchanger c) calculation of the melt mass flow rate from the thermal conductivity measured in b) and the correlation established in a).

Abstract: The invention relates to a polyethylene molding composition which has a multimodal molar mass distribution and is particularly suitable for producing protective coatings on steel pipes. The molding composition has a density at a temperature of 23° C. in the range from 0.94 to 0.95 g/cm3 and an MFI190/5 in the range from 1.2 to 2.1 dg/min. It comprises from 45 to 55% by weight of a low molecular weight ethylene homopolymer A, from 30 to 40% by weight of a high molecular weight copolymer B of ethylene and another olefin having from 4 to 8 carbon atoms and from 10 to 20% by weight of an ultra high molecular weight ethylene copolymer C.

Abstract: The present invention relates to transition metal compounds of the formula (I), a process for preparing polyolefins by polymerization or copolymerization of at least one olefin in the presence of at least one olefin in the presence of at least one of the catalyst systems according to the invention and the use of the ligand systems according to the invention for preparing transition metal compounds.

Abstract: A multistage process for the homo or copolymerization of ethylene carried out in the presence of a catalyst system comprising at least one polymerization catalyst (A) based on a late transition metal component having a tridentate ligand which bears at least two ortho.ortho-disubstituted aryl radicals, at least one Ziegler polymerization catalyst (B), and at least a Lewis acid activating compound (C), wherein the molar ratio of the metal of the activating compound (C) to the late transition metal of catalyst (A) is different in the two polymerizations steps. Catalysts (A) and (B) may be selectively controlled by varying the amount of activating compound (C).

Abstract: A continuous gas-phase process for the polymerization of alpha-olefins, in particular ethylene, comprising passing an alpha-olefin monomer stream through an oil filter in order to reduce the amount of oil to less than 8 ppm, and polymerizing the thus purified monomer feed in gas-phase reactor; the reduction of the amount of oil improves the operability of the plant over time.

Abstract: A bridged metallocene compound of formula (I) wherein: M is an atom of a transition metal selected from those belonging to group 3, 4, or to the lanthanide or actinide groups in the Periodic Table of the Elements; X, equal to or different from each other, is a hydrogen atom, a halogen atom, a R, OR, OSO2CF3, OCOR, SR, NR2 or PR2 group; L is a divalent bridging group; R1 and R2, equal to each other, are C1-C40 hydrocarbon radical; R3 is hydrogen or a are C1-C40 hydrocarbon radical and W is an aromatic 5 or 6 membered ring.

Abstract: A process for obtaining thermoformed articles, comprising the following steps: a) forming a sheet comprising a propylene resin; b) thermoforming the sheet obtained in step a); wherein said propylene resin has the following characteristics: a) distribution of molecular weight Mw/Mn lower than 4; preferably lower than 3; b) 2,1 insertions measured with by 13C-NMR lower than 0.50%; preferably lower than 0.40%; c) eta* and the frequency ? meet the following relation for ? comprised between 0.1 ad 1: eta*>3700?(?0 13) d) melt flow rate (MFR) (ISO 1133) lower than 5; preferably lower than 4; more preferably lower than 3; wherein the polypropylene resin comprises: (i) from 10 to 100% by weight of a propylene homopolymer or a propylene copolymer containing from 0.1% to 10% by mol of derived units of ethylene or an alpha-olefin of formula CH2?CHZ wherein Z is a linear or branched C2-C20 radical; and (ii) from 0 to 90% by weight of a propylene copolymer containing from 0.

Abstract: Process for preparation of ethylene homopolymers or copolymers, comprising the steps of a) polymerization of ethylene or of ethylene with one or more other 1-olefins in the presence of a chromium catalyst at temperatures of from 20 to 200° C. and at pressures of from 0.1 to 20 MPa, where the chromium catalyst can be prepared via application of one or more chromium compounds to a silicate support and subsequent thermal activation under oxidative conditions at temperatures of from 620 to 900° C.; b) mixing of the polyethylene in the melt in the presence of from 1000 to 2000 ppm of an antioxidant comprising at least one sterically hindered phenol and comprising at least one phosphite in a mixing ratio of from 1:5 to 5:1, with specific energy input of at least 0.17 kWh/kg.

Abstract: A new class of heterocyclic metallocenes, a catalytic system containing them and a process for polymerizing addition polymerizable monomers using the catalytic system are disclosed; the heterocyclic metallocenes correspond to the formula (I): YjR?iZjjMeQkPl wherein Y is a coordinating group containing a six ? electron central radical directly coordinating Me, to which are associated one or more radicals containing at least one non-carbon atom selected from B, N, O, Al, Si, P, S, Ga, Ge, As, Se, In, Sn, Sb and Te; R? is a divalent bridge between the Y and Z groups; Z is a coordinating group, optionally being equal to Y; Me is a transition metal; Q is halogen or hydrocarbon substituents; P is a counterion; i is 0 or 1; j is 1-3; jj is 0-2; k is 1-3; and l is 0-2.

Abstract: The present invention relates to a process for preparing transition metal compounds, in particular ansa-bisindenyl-metallocenes having nitrogen, phosphor, sulfur or oxygen comprising substituents, the corresponding transition metal compounds themselves and their use in the preparation of catalyst systems and also the use of the catalyst systems in the polymerization and copolymerization of olefins.

Abstract: Polyethylene which comprises ethylene homopolymers and copolymers of ethylene with ?-olefins and has a molar mass distribution width Mw/Mn of from 6 to 100, a density of from 0.89 to 0.97 g/cm3, a weight average molar mass Mw of from 5000 g/mol to 700 000 g/mol and has from 0.01 to 20 branches/1000 carbon atoms and at least 0.5 vinyl groups/1000 carbon atoms, wherein the 5-50% by weight of the polyethylene having the lowest molar masses have a degree of branching of less than 10 branches/1000 carbon atoms and the 5-50% by weight of the polyethylene having the highest molar masses have a degree of branching of more than 2 branches/1000 carbon atoms, a process for its preparation, catalysts suitable for its preparation and also fibers, moldings, films or polymer blends in which this polyethylene is present.

Abstract: The present invention relates to a polyethylene molding composition which has a multimodal molar mass distribution and is particularly suitable for thermoforming to produce fuel containers having a capacity in the range from 20 to 200 I. The molding composition has a density at a temperature of 23° C. in the range from 0.948 to 0.953 g/cm3 and an MFR190/21.6 in the range from 4.5 to 6 g/10 min. It comprises from 40 to 50% by weight of a low molecular weight ethylene homopolymer A, from 35 to 45% by weight of a high molecular weight copolymer B of ethylene and another olefin having from 4 to 8 carbon atoms and from 10 to 25% by weight of an ultrahigh molecular weight ethylene copolymer C.