Abstract: The invention relates to a process for preparing a catalyst for the polymerization of olefins, which comprises: a) preparation of a finely divided silica xerogel, b) loading of the xerogel with chromium from a solution of chromium trioxide or a chromium compound which is converted into chromium trioxide under the conditions of step c), and c) activation of the resulting product at from 400 to 1100° C. in a water-free gas stream comprising oxygen in a concentration of above 10% by volume, wherein a fluoride doping with a fluorinating agent is carried out in step b) or in step c). Furthermore, the invention relates to a catalyst for the polymerization of olefins which is obtainable by the process of the invention and to a process for the polymerization of olefins in which an olefin or an olefin mixture is polymerized in the presence of a catalyst according to the invention.

Abstract: The present invention relates to a process for producing hollow plastic articles, encompassing the following steps: a) producing a tubular plastic parison on a blow molding plant or coextrusion blow molding plant b) cutting open the extruded or coextruded plastic parison to give at least one semifinished open-surface product c) thermoforming the resultant semifinished open-surface product to give half-shells d) welding the thermoformed half-shells to give a hollow article.

Abstract: The present invention relates to plastic containers or moldings which have been produced by blow molding and have improved antistatic properties. The containers or moldings have an outer wall and an inner wall and contain webs of electrically conducting material running along the inner wall. The invention also relates to a process for the production of the containers or moldings and to their use.

Abstract: Process for improving the electrical properties of polyethylene, in particular of single- or multilayer polyethylene-containing items, for example hollow articles, in particular of plastic fuel tanks, by introducing a conductivity black with certain specific iodine adsorption prior to optional surface-treatment.

Abstract: The invention relates to a roll stand comprising a crown-variable-control (CVC) roll pair, preferably a CVC working roll pair and a back-up roll pair, which comprise a contact area (bcont) in which a horizontally active torque (M) acts that leads to a twisting of the rolls and thus to axial forces in the roll bearings. In order to keep the axial forces in the roll bearings as small as possible, the torque (M) is minimized by an appropriate CVC grinding.

Abstract: A fuel tank for motor vehicles which is connected to a supplementary tank containing a flame-coloring additive, where a data recorder causes, in the event of a fault signal, the flame-coloring additive to be added to the fuel tank from the supplementary tank, and a process for adding a flame-coloring additive to the fuel in a fuel tank.

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: Ethylene homo- and copolymers stabilized by sterically hindered amines or by N-hydroxy or N-oxyl derivatives are used to produce articles of plastic and components for the storage and transport of vegetable oil esters.

Abstract: Bimodal polyethylene blends are made from a high-molecular-weight ethylene copolymer and a low-molecular-weight ethylene homo- or copolymer and have a melt flow rate MFR 190/21.6 of from 6 to 14 g/10 min, a density of from 0.94 to 0.97 g/cm3, an environmental-stress-cracking resistance ESCR>150 h and a value of less than 3 when the quality of blending in the blend is measured to ISO 13949. A process prepares polyethylene blends of this type by melting and homogenization in a mixing apparatus and discharge via a gear pump. The blends are used to produce moldings, in particular hollow articles and pressure pipes.

Abstract: A multilayer composite plastics material, containing at least one layer (A), which consists, to an extent of least 90 wt %, based on the total weight of this layer, of ethylene homopolymers or copolymers, at least one barrier layer (B), which substantially consists of polybutylene terephthalate, and also, if desired, layers of adhesion promoter (C) serving to improve the adhesion between these layers.

Abstract: The present invention relates to plastic containers or mouldings which have been produced by blow moulding and have improved antistatic properties. The containers or mouldings have an outer wall and an inner wall and contain webs of electrically conducting material running along the inner wall. The invention also relates to a process for the production of the containers or mouldings and to their use.

Abstract: A hollow plastic article with increased fire resistance is described, as are its use and a process for its production. The hollow plastic article has one or more layers made from polymeric material, of which at least one layer comprises flame retardants.

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: A process for increasing the flame resistance of polyethylene-containing, single- or multilayer hollowware, in particular plastic fuel tanks, by heat treating the hollowware at 60-135° C.

Abstract: The present invention relates to a process for producing hollow plastic articles, encompassing the following steps:

Abstract: The inner wall of a solids reactor for carrying out reactions in the gas phase is coated with an antistatic layer having a thickness of 0.1-800 &mgr;m and consisting essentially of a poly-&agr;-olefin and a nonvolatile antistatic agent.

Abstract: Described is the characterization and the use of strong viral promoters for expressing genes, in bacteria and fungi, in particular yeasts. The invention is based on the surprising finding that CFDV DNA (coconut foliar decay virus DNA) and CFDV DNA fragments contain a region which is active as promoter even in bacteria and fungi, in particular yeasts, although they are derived from a virus which infects monocotyledonous plants. The activity of the promoters described in E. coli is distinctly higher than that of the CaMV 35S promoter, which is also active in bacteria.

Abstract: The invention relates to the use of primers or primer pairs for DNA fingerprint analysis, wherein with the primers or primer pairs fingerprints are obtainable from humans as well as from animals as well as from plants as well as from microorganisms. The invention further relates to primers or primer pairs for the above-mentioned use.

Abstract: Catalyst systems which are suitable for the polymerization of olefinically unsaturated hydrocarbons contain, as active components, A) an amidinato metal complex of the general formula A  where M is a metal from group IIIb, IVb, Vb or VIb of the Periodic Table of Elements or a metal from the lanthanide group, X is a negative leaving atom or a negative leaving group, and the radicals X may be identical or different if (n−m)>1, R1, R2 and R3 are each a C-organic or Si-organic radical, n is the valency of M in the metal complex A and m is from 1 to 5, with the proviso that n−m≧0, and, if required, B) an acceptor compound for the substituent X of the component A as an activator.

Abstract: Polyalk-1-enes are prepared by polymerization of alk-1-enes with the aid of the compound bis(cyclopentadienyl)-chromium(II) in which the cyclopentadienyl rings may carry inert organic radicals, said compound being adsorbed on an inorganic oxide carrier, by a process in which the polymerization is carried out in the presence of an organometallic compound of a metal of main groups I to III or of a metal hydride, in particular of n-butyl-lithium.