Abstract: A polyethylene for IM having excellent processing properties in terms of spiral flow testing is devised.

Abstract: A process for introducing a catalyst powder based on a titanium compound supported on magnesium halide into a gas-phase olefin polymerization reactor, characterized in that it comprises: (a) storing the catalyst powder under an atmosphere of a liquid C3-C12 alkane; (b) withdrawing from step (a) a measured amount of said catalyst powder by means of a rotary valve; (c) transferring said metered amount of catalyst powder to a catalyst activation section by a continuous pick-up flow of a liquid C3-C12 alkane; (d) contacting the catalyst powder with a liquid phase comprising an organo-aluminum compound and optionally an external donor compound, at a temperature ranging from ?20° C. to 60° C.; (e) introducing the activated catalyst powder in one or more gas-phase olefin polymerization reactors, where a gaseous mixture comprising at least one alpha-olefin is subjected to polymerization.

Abstract: A process for introducing a catalyst powder based on a titanium compound supported on magnesium halide into a gas-phase olefin polymerization reactor, characterized in that it comprises: (a) storing the catalyst powder under an atmosphere of a liquid C3-C12 alkane; (b) withdrawing from step (a) a measured amount of said catalyst powder by means of a rotary valve; (c) transferring said metered amount of catalyst powder to a catalyst activation section by a continuous pick-up flow of a liquid C3-C12 alkane; (d) contacting the catalyst powder with a liquid phase comprising an organo-aluminum compound and optionally an external donor compound, at a temperature ranging from ?20° C. to 60° C.; (e) introducing the activated catalyst powder in one or more gas-phase olefin polymerization reactors, where a gaseous mixture comprising at least one alpha-olefin is subjected to polymerization.

Abstract: A polyethylene for IM having excellent processing properties in terms of spiral flow testing is devised.

Abstract: A process for preparing supported, titanized chromium catalysts is disclosed. The process comprises A) bringing a support material into contact with a protic medium comprising a titanium compound and a chromium compound; B) optionally removing the solvent; C) optionally calcining the precatalyst obtained after step B); and D) optionally activating the precatalyst obtained after step B) or C) in an oxygen-containing atmosphere at from 400° C. to 1100° C.

Abstract: Catalyst for the polymerization and/or copolymerization of olefins which is obtainable by application to a finely divided inorganic support and concluding calcination at temperatures of from 350 to 1050° C. and has a chromium content of from 0.1 to 5% by weight and a zirconium content of from 0.5 to 10% by weight, in each case based on the element in the finished catalyst, with the molar ratio of zirconium to chromium being from 0.6 to 5.

Abstract: Process for preparing a supported catalyst for the polymerization and/or copolymerization of olefins which has a chromium content of from 0.01 to 5% by weight, based on the element, which comprises (a) preparing a homogeneous solution comprising an organic or inorganic chromium compound and at least one further organic or inorganic compound of elements selected from among Mg, Ca, Sr, B, Al, Si, P, Bi, Sc, V, Mn, Fe, Co, Ni, Cu, Zn, Zr, Nb, Mo, Ru, Rh, Pd, Hf, Ta, W in a protic or aprotic polar solvent, (b) bringing the solution from a) into contact with a finely divided inorganic support to form a catalyst precursor, (c) if appropriate, removing the solvent from the catalyst precursor and (d) calcining the catalyst precursor at temperatures of from 350 to 950° C., preferably 400 to 900° C., under oxidative conditions.

Abstract: The invention relates to a process for preparing an essentially spherical support for olefin polymerization catalysts, which comprises the steps: preparation of a hydrogel comprising a cogel of silicon oxide and at least one further metal oxide, if appropriate, washing of the hydrogel until the content of alkali metal ions is less than 0.1% by weight, based on the weight of solids, extraction of the water from the hydrogel until the water content is less than 5% by weight, based on the total content of liquid, and drying of the hydrogel to form a xerogel. According to the invention, the extraction step comprises at least one batchwise extraction with an organic solvent which is at least partially miscible with water down to a water content of less than 50% by weight, followed by at least one continuous extraction with an organic solvent which is at least partially miscible with water.

Abstract: The invention relates to a process for preparing an essentially spherical support for olefin polymerization catalysts, which comprises the steps: preparation of a hydrogel comprising a cogel of silicon oxide and at least one further metal oxide, if appropriate, washing of the hydrogel until the content of alkali metal ions is less than 0.1% by weight, based on the weight of solids, extraction of the water from the hydrogel until the water content is less than 5% by weight, based on the total content of liquid, and drying of the hydrogel to form a xerogel. According to the invention, the extraction step comprises at least one first extraction with a first organic solvent which is at least partially miscible with water down to a water content of 50% by weight, followed by at least one second extraction with a second organic solvent which is at least partially miscible with water.

Abstract: The invention relates to a process for preparing an essentially spherical support for olefin polymerization catalysts, which comprises the steps: preparation of a hydrogel comprising a cogel of silicon oxide and at least one further metal oxide, if appropriate, washing of the hydrogel until the content of alkali metal ions is less than 0.1% by weight, based on the weight of solids, extraction of the water from the hydrogel until the water content is less than 5% by weight, based on the total content of liquid, and drying of the hydrogel to form a xerogel. According to the invention, the extraction step comprises at least one first extraction with a first organic solvent which is at least partially miscible with water down to a water content of 50% by weight, followed by at least one second extraction with a second organic solvent which is at least partially miscible with water.

Abstract: Catalyst for the polymerization and/or copolymerization of olefins which is obtainable by application to a finely divided inorganic support and concluding calcination at temperatures of from 350 to 1050° C. and has a chromium content of from 0.1 to 5% by weight and a zirconium content of from 0.5 to 10% by weight, in each case based on the element in the finished catalyst, with the molar ratio of zirconium to chromium being from 0.6 to 5.

Abstract: Process for preparing a supported catalyst for the polymerization and/or copolymerization of olefins which has a chromium content of from 0.01 to 5% by weight, based on the element, which comprises (a) preparing a homogeneous solution comprising an organic or inorganic chromium compound and at least one further organic or inorganic compound of elements selected from among Mg, Ca, Sr, B, Al, Si, P, Bi, Sc, V, Mn, Fe, Co, Ni, Cu, Zn, Zr, Nb, Mo, Ru, Rh, Pd, Hf, Ta, W in a protic or aprotic polar solvent, (b) bringing the solution from a) into contact with a finely divided inorganic support to form a catalyst precursor, (c) if appropriate, removing the solvent from the catalyst precursor and (d) calcining the catalyst precursor at temperatures of from 350 to 950° C., preferably 400 to 900° C., under oxidative conditions.

Abstract: Process for preparing supported, titanized chromium catalysts, which comprises the following steps: A) bringing a support material into contact with a protic medium comprising a titanium compound and a chromium compound, B) optionally removing the solvent, C) optionally calcining the precatalyst obtained after step B) and D) optionally activating the precatalyst obtained after step B) or C) in an oxygen-containing atmosphere at from 400° C. to 1100° C.

Abstract: A method for production of catalytic systems of the Ziegler-Natta type is characterised in comprising the following steps: A) bringing an inorganic metal oxide and a magnesium compound of formula MgRnX2-n into contact, where X=independently, fluorine, chlorine, bromine, iodine, hydrogen, NR2, OR, SR, SO3R or OC(O)R and R=independently, C1-C20 linear, branched, or cyclic alkyl, a C2-C10 alkenyl, an alkylaryl with 1-10 C atoms in the alkyl group and 6-20 C atoms in the aryl group, or a C6-C18 aryl and n=1 or 2, then, B) bringing the intermediate product obtained in step A) into contact with a halogenating reagent, C) bringing the intermediate product obtained in step B) into contact with a) a tetravalent titanium compound, b) a metallo-organic compound of group 3 of the periodic system and c) optionally, an electron-donor compound and D) washing the product obtained in step C) with an aprotic solvent.

Abstract: In a process for producing Phillips catalysts in which an oxidic support material is treated in suspension with a chromium salt solution and subsequently, after removing the solvent, calcined in an oxygen-containing atmosphere at above 300° C., the oxidic support material and/or the catalyst after calcination are/is, according to the present invention, comminuted until a mean particle size of <100 &mgr;m has been reached and the proportion of particles having a size of <50 &mgr;m is at least 30%, preferably in the range from 40 to 80%. A process for preparing homopolymers or copolymers of ethene in a loop reactor at from 30 to 150° C. under a pressure in the range from 0.2 to 15 MPa in the presence of a catalyst produced by the process of the present invention is also provided.

Abstract: The invention relates to a catalyst support and to a method for the production of the catalyst support comprising the following steps: a) production of a silicic acid hydrogel having a solids content of from 10 to 25% by weight (calculated as SiO2) whose particles are substantially spherical, b) extraction of the hydrogel particles with an alcohol until at least 60% of the water present in the hydrogel has been removed, c) drying of the resultant hydrogel until the residual alcohol content is less than 10% by weight (xerogel formation) at temperatures of ≧160° C. at atmospheric pressure using an inert entraining gas, d) setting of the desired particle size of the resultant xerogel, in which the hydrogel particles have a particle size of ≧8 mm before the extraction, and to a catalyst and to a method for the production of the catalyst by loading the catalyst support with a chromium compound. The invention also relates to a method for the production of polyolefins using the catalyst.

Abstract: The invention relates to a method for producing supported chromium catalysts for the polymerisation of olefins by loading a xerogel support with chromium by adding to the xerogel support a volume of a 0.025 to 15% by weight solution of a chromium compound or a volume of a solution comprising from 0.025 to 7.8% by weight of Cr which is essentially converted into a chromium(VI) compound on heating in a water-free stream of gas under oxidizing conditions at temperatures in the range from 300 to 1100° C. for a period of from 10 to 1000 minutes in a solvent which comprises a maximum of 20% by weight of water, and subsequently evaporating the solvent, where the volume of the chromium salt solution employed is smaller than the pore volume of the xerogel support.

Abstract: A process for preparing stabilized olefin polymers which have a low cold heptane extractables content by polymerization of olefins with Ziegler or Phillips catalysts, wherein the polymer is, immediately after leaving the polymerization reactor, brought into contact with an involatile phenol derivative.

Abstract: In a low-odor polyethylene blend made from a high-molecular-weight ethylene copolymer obtainable by polymerization in the presence of a Ziegler catalyst and from a low-molecular-weight ethylene homopolymer or ethylene copolymer obtainable by polymerization in the presence of a chromocene catalyst on an oxidic support, the Al content of the high-molecular-weight component is from 5 to 60 mg/kg, the Al content of the low-molecular-weight component is from 0 to 5 mg/kg and the Al content of the blend is from 1 to 55 mg/kg. Processes are described for preparing blends of this type. Their use is described for producing moldings, in particular hollow articles and pipes. Moldings, in particular hollow articles and pipes, are produced from low-odor polyethylene blends.

Abstract: The invention relates to a catalyst support and to a method for the production of the catalyst support comprising the following steps: