Abstract: The invention relates to a process for the sulphurization of catalysts for the hydrotreating of hydrocarbon feedstocks. According to the invention, a small amount of at least one orthophthalic acid ester is added to the sulphurization agent used to sulphurize the catalyst. The catalysts thus sulphurized prove to be more active than conventionally sulphurized catalysts.

Abstract: Method of manufacturing a tubular capsule comprising fiber (11) having a wall delimiting internal compartments (11b) that are isolated from one another, the wall being made from a solution of at least one polymer and the compartments (11b) being full of a biologically active medium, the method comprising the steps of: coextruding the solution of at least one polymer and the biologically active medium by simultaneously injecting the polymer solution and the biologically active medium through a die (7) of determined dimensions; interrupting the injection of the biologically active medium at determined points in time to form in the fiber (11) successive compartments (11b) full of the biologically active medium and separated by a solid partition section (11a) consisting only of the polymer solution; immersing the fiber (11) in a coagulation liquid as it leaves the die (7) so as to initiate early coagulation of the polymer solution around the outside of the fiber (11); and simultaneously driving the fiber (11)

Abstract: Porous particles of MgCl2 having the form of essentially regular polyhedrons with six or eight faces in which the paired symmetrically opposite faces are essentially parallel, two of which faces are large and elongated and form the too face and the bottom face of a polyhedron such that on each of them the longest diagonal (D) is larger than the shortest distance (d) separating two opposite sides, which large elongated faces are surrounded essentially perpendicularly by the other essentially rectangular faces that form the sides of the said polyhedron, the length of the smaller side (e) of each of the said essentially rectangular faces being less than the shortest distance (d) separating the two opposite sides of the large elongated faces, catalytic components supported on the particles, catalyst systems utilizing the catalytic products, process for making the particles, and polyolefins obtained utilizing the catalytic systems.

Abstract: The invention relates to alkoxysilacycloalkanes, to the process for their preparation and to their use in the polymerization of olefins. The introduction of these alkoxysilacycloalkanes into the olefin polymerization environment makes it possible to raise the heptane-insolubles content of the polymer finally formed.

Abstract: The present invention relates to a process for the manufacture of particles comprising magnesium chloride, which may serve as a support for a catalytic component for the polymerization of olefins, this process comprising a step of placing in contact between solid particles, an organomagnesium derivative and a chlorinating agent for the organomagnesium derivative. The process affords excellent control over the morphology of the support particles, particles of catalytic component and polymer particles.

Abstract: The process according to the invention consists in bringing the substrate to be coated into contact with a solution of a catalyst of olefin polymerization and in then polymerizing at least one olefin in gaseous phase in the presence of the said substrate. The invention also relates to the use of an item including a coating made of polymer for coming into contact with polyolefin particles, the polymer forming the coating including chain sequences of formula --CH.sub.2 --CHR--.

Abstract: Crystalline MgCl.sub.2 particulates, exhibiting the morphology of substantially regular polyhedra having an even number of from 10 to 18 face surfaces, are well suited as support substrate for olefin polymerization catalysts.

Abstract: A stable, long-lived catalyst composition, well suited for the polymerization of olefins, e.g., of ethylene, comprises intimate admixture of particulates of an olefin prepolymer and a catalytically effective amount of particles of a metallic olefin polymerization catalyst, such olefin prepolymer particulates having a particle size distribution narrower than the particle size distribution of the metallic catalyst particles.

Abstract: Crystalline MgCl.sub.2 particulates, exhibiting the morphology of substantially regular polyhedra having an even number of from 10 to 18 face surfaces, are well suited as support substrate for olefin polymerization catalysts.

Abstract: A process for the manufacture of MgCl.sub.2.MgO with narrow granulometric distribution by treatment of hydrated MgCl.sub.2 with an alcohol followed by heat treatment after partial elimination of the alcohol, characterized in that the hydrated MgCl.sub.2 is suspended in the alcohol, and that the molar ratio of the alcohol to the hydrated MgCl.sub.2 is lower than the solutility ratio of these two substances at the temperature of the suspension. The resultant MgCl.sub.2.MgO can be employed as a support in catalytic components for the polymerization of olefins.

Abstract: The method of forming a catalytic component for use in the polymerization of ethylene or a copolymer of ethylene and a C.sub.3 to C.sub.12 alpha olefin in a gas-phase comprising impregnating a porous metal oxide support with at least one titanium compound, magnesium compound, and chlorine compound, and prepolymerizing ethylene or a copolymer of ethylene and a C.sub.3 to C.sub.12 alpha olefin, a least partially in suspension, in the presence of said porous metal oxide support and at least one alkylaluminum compound until a degree of prepolymerization is reached which is suitable for the subsequent gas-phase of fluidized bed polymerization, and the method of polymerizing olefins utilizing the catalysts formed by the prepolymerization.

Abstract: Porous particles of MgCl.sub.2 having the form of essentially regular polyhedrons with six or eight faces in which the paired symmetrically opposite faces are essentially parallel, two of which faces are large and elongated and form the top face and the bottom face of a polyhedron such that on each of them the longest diagonal (D) is larger than the shortest distance (d) separating two opposite sides, which large elongated faces are surrounded essentially perpendicularly by the other essentially rectangular faces that form the sides of the said polyhedron, the length of the smaller side (e) of each of the said essentially rectangular faces being less than the shortest distance (d) separating the two opposite sides of the large elongated faces, catalytic components supported on the particles, catalyst systems utilizing the catalytic products, process for making the particles, and polyolefins obtained utilizing the catalytic systems.

Abstract: A magnetic drive system in a reactor generates rotational and translational motion of the agitator. The magnetic drive system includes a tubular shaft having one end attached to the agitator, and another end. A magnetic annular weight is fitted to the another end. A guide column has an end supported by the reactor body and a free end, the guide column further having a cylindrical bore in which an intermediate part of the tubular shaft slides in a fluid tight manner. A cylindrical guide cap is fluid tightly mounted to the free end of the guide column, the guide cap covering the magnetic annular weight and incorporating a cylindrical guide shaft integral with a bottom of the cap, the tubular shaft sliding coaxially and fluid tightly on the guide shaft.

Abstract: A process is provided for the synthesis of a solid Ziegler catalyst or of a transition metal solid constituent thereof, which entails preparing the solid catalyst or constituent thereof as a suspension in an inert liquid medium by contacting precursors or ingredients of the catalyst or of the constituent in the inert liquid medium in one or more steps, and drying the suspension, and collecting the catalyst or constituent thereof; and wherein the process is conducted in a single multi-function reactor having a longitudinal axis and which can pivot around an axis which intersects perpendicularly with this axis.

Abstract: An asymmetric semipermeable membrane and processes for the manufacture thereof are disclosed. The membrane comprises at least one hydrophobic polymer and at least one copolymer based on acrylonitrile, at least one sulphonic monomer which is optionally salified, and optionally at least one non-ionic, ionizable, olefinically unsaturated monomer. The membrane is useful in the treatment of biological fluids such as plasma or blood, especially using plasmapheresis, or with the aid of an artificial kidney using hemodialysis and/or ultrafiltration.

Abstract: The method of forming a catalytic component for use in the polymerization of ethylene or a copolymer of ethylene and a C.sub.3 to C.sub.12 alpha olefin in a gas-phase comprising impregnating a porous metal oxide support with at least one titanium compound, magnesium compound, and chlorine compound, and prepolymerizing ethylene or a copolymer of ethylene and a C.sub.3 to C.sub.12 alpha olefin, a least partially in suspension, in the presence of said porous metal oxide support and at least one alkylaluminum compound until a degree of prepolymerization is reached which is suitable for the subsequent gas-phase of fluidized bed polymerization, and the method of polymerizing olefins utilizing the catalysts formed by the prepolymerization.

Abstract: A process for preparing a transition metal component for a catalyst system wherein a specified aluminosiloxane derivative is reacted with a monohalopenated, alkylated, or alkoxylated compound of magnesium and the reaction product is chlorinated and reacted with a transition metal; a catalyst system comprising such transition metal component and a cocatalyst selected from organometallic compounds of a metal of Groups I through III of the Periodic Table; and the process of synthesizing olefin homopolymers and copolymers utilizing such catalyst system.

Abstract: A process for the manufacture of a linear polyethylene with narrow molecular-weight distribution comprising polymerizing ethylene alone or a mixture of ethylene and an alpha-olefin in which ethylene represents at least about 70% by weight of the total monomers involved, in a gas-phase polymerization medium in the presence of a catalytic component containing at least one transition metal, magnesium, and a halogen, a co-catalyst comprising an alkylaluminum compound, and a monoether, the monoether having the general formula R'OR", wherein R' and R" are the same or different and each is a C.sub.1 to C.sub.8 linear or branched hydrocarbon radical or being a cyclic monoether with the oxygen forming a ring having 4 to 12 carbon atoms.

Abstract: A process is provided for the polymerization of olefins in the gas phase wherein olefins are contacted with a catalyst system consisting of an active solid hydrocarbon having been prepared by forming a pulverulent composition by mixing a transition metal component, a porous organic or inorganic solid support and an organometallic compound of the organo-Al, organo-Mg or organo-Zn type, and polymerizing a controlled amount of one or more C.sub.2 to C.sub.12 olefins in the gas phase in contact with the pulverulent composition with a specific hourly conversion of the olefins to produce the active solid hydrocarbon.

Abstract: Process for the preparation of an active solid hydrocarbon which can be used to polymerize olefines.This process comprises forming a pulverulent composition by mixing a transition metal component, a porous organic or inorganic solid support and an organometallic compound of the organo-Al, organo-Mg or organo-Zn type, and polymerizing a controlled amount of one or more C.sub.2 to C.sub.12 olefines in the gas phase in contact with the pulverulent composition with a specific hourly conversion of the olefines to produce the active solid hydrocarbon.The above active solid hydrocarbon can be used, by itself or together with an organometallic cocatalyst, as a catalytic system for polymerization of olefines, in particular in the gas phase.