Abstract: Process for the preparation of copolymers of ethylene and an alpha-olefin having six carbon atoms comprising hexene-1 or 4-methyl-pentene-1 with a density comprised between 0.910 and 0.940, involving a copolymerization of ethylene and an alpha-olefin having six carbon atoms comprising hexene-1 or 4-methyl-pentene-1 in the gas phase by means of a fluidized bed, in the presence of a catalyst system comprising on the one hand a co-catalyst consisting of at least one organo-metallic compound of a metal of Groups, II and III of the Periodic Table of Elements and on the other hand a supported catalyst comprising a special support based essentially on magnesium chloride and optionally aluminum chloride, on which support there has been precipitated a derivative of a transition metal of Groups IV, V and VI of the Periodic Table of Elements.

Abstract: Process for the preparation of copolymers of ethylene and an alpha-olefin having 6 carbon atoms with a density comprised between 0.910 and 0.940, involving a copolymerization of ethylene and an alpha-olefin having 6 carbon atoms in the gas phase by means of a fluidized bed, in the presence of a catalyst system comprising on the one hand a co-catalyst consisting of at least one organo-metallic compound of a metal of Groups II and III of the Periodic Table of Elements and on the other hand a supported catalyst comprising a special support based essentially on magnesium chloride and optionally aluminium chloride, on which support there has been precipitated a derivative of a transition metal of Groups IV, V and VI of the Periodic Table of elements.

Abstract: Process for the preparation of addition products of epoxides and hydroxylated compounds, characterized by the fact that it comprises the reaction of an epoxide and a hydroxylated compound in the homogeneous liquid phase, in the presence, as catalyst, of a salt of trifluoromethanesulphonic acid.

Abstract: The present invention relates to catalysts which can be used for the polymerization and copolymerization of propylene with other alpha-olefins, characterized in that they comprise a support containing essentially magnesium chloride and possibly a chlorinated aluminium derivative, and occurring in the form of spheroidal particles having a mean diameter by mass comprised between 10 and 100 microns and a particle size distribution such that the ratio of the mean diameter by mass to the mean diameter by number is less than or equal to 3, which support has been treated by an electron donor compound chosen from among the aromatic ethers and aromatic acid esters and which when impregnated with titanium tetrachloride comprises 0.5 to 3% of atoms of titanium per atom of magnesium, and process for utilizing the said catalyst.

Abstract: The present invention relates to catalysts for the polymerization and copolymerization of ethylene, characterized in that they comprise a support based on magnesium chloride and possibly on aluminium chloride, of spheroidal shape, having a mean diameter by mass comprised between 10 and 100 microns and with a narrow particle size distribution, such that the ratio of the mean diameter by mass to the mean diameter by number is less than or equal to 3, on which support there has been precipitated a derivative of a transition metal of groups IV, V and VI of the Periodic Table of Elements, and a polymerization process utilizing the said catalysts.

Abstract: The invention relates to a device and process permitting of the bottom drainage of a fluid-bed polymerization reactor (1) comprising a fluidization plate (2), a gas inlet (3) located between the said plate and the bottom of the reactor and a side pipe (4) located above the said plate and permitting of the evacuation of the fluidized particles, the said device consisting:of a vertical pipe (5) having a top opening at the level of the plate and a bottom end located outside and underneath the bottom of the reactor, which is occluded by a cock (6),and a gas intake tube (7) in the said vertical piping, leading out into the immediate vicinity of the said cock (6).

Abstract: The present invention relates to catalyst supports for the polymerization and co-polymerization of alpha-olefins, especially ethylene and propylene, consisting essentially of magnesium chloride, characterized in that these supports occur in the form of spheroidal particles with a mean particle size by mass comprised between 10 and 100 microns and having a narrow particle size distribution, which can be controlled, such that the ratio of the mean diameter by mass to the mean diameter by number of the particles is less than or equal to 3.0, and the process for the preparation of the said supports.