Montell North America Inc.

Montell Technology Company Bv

Montedison S.p.a.

Basell Technology Company B.v.

Basell Poliolefine Italia S.r.l.

Himont Incorporated

Roberto Rinaldi

Gabriele Govoni

Massimo Covezzi

Paolo Galli

Adolfo Brusaferro

Albert A Hummel

Gianfranco Biglione

Giovanni Di Drusco

Giuseppe Cigna

Francesco Visani

Antonio Gala

Process for gas-phase polymerization carried out in two interconnected polymerization zones, to which one or more &agr;-olefins CH &boxH;CHR are fed in the presence of catalyst under reaction conditions and from which the polymer product is discharged. The process is characterized in that the growing polymer flows through a first polymerization zone under fast fluidization conditions, leaves said first zone and enters a second polymerization zone through which it flows in a densified form under the action of gravity, leaves said second zone and is reintroduced into the first polymerization zone, thus establishing a circulation of polymer around the two polymerization zones. The novel process allows olefins to be polymerized in the gas phase with high productivity per unit volume of the reactor without incurring the problems of the fluidized-bed technologies of the known state of the art.

Process and apparatus for the gas-phase polymerization of &agr;-olefins

Process for the gas-phase polymerization of olefins

A gas phase process for producing olefin polymer graft copolymers, including providing a reaction apparatus having first and second reaction zones operatively connected to each other into which particles of an olefin polymer and a free-radical polymerizable monomer are fed while maintaining free-radical polymerization conditions and a substantial non-oxidizing environment in said zones and from which the grafted copolymer product is discharged. An apparatus suitable for practicing this process is also disclosed.

Apparatus for producing polyolefin grafted copolymers

Process for the gas-phase polymerization of ethylene and ethylene mixtures with .alpha.-olefins CH.sub.2 .dbd.CHR in the presence of a high activity catalyst comprising a titanium compound containing at least one Ti-halogen bond, supported on magnesium dichloride in active form said process comprising the steps of: (a) contacting the catalyst component; (b) prepolymerizing ethylene or ethylene mixtures with .alpha.-olefins in order to produce a polymer amount of from approximately 5 g per g of solid component, up to an amount corresponding to about 10% of the final catalyst yield; (c) polymerizing ethylene or ethylene mixtures with .alpha.-olefins in the gas-phase, in the presence of the prepolymer-catalyst system obtained in (b), while maintaining in the gas phase a molar concentration concentration of the alkane comprised between 20 and 90% with respect to the total gases.

Gas-phase process for the preparation of polymers and copolymers of olefins CH.sub.2 .dbd.CHR, carried out in at least 2 fluidized or mechanically agitated bed gas-phase reactors operating under different reaction conditions so as to obtain different polymers in the different reactors; the process is characterized in that the polymer is at least partially recycled among the different reactors by using ratios of the flow rate of circulation among the different reactors to the discharge flow rate comprised between 2 and 6.

Process and apparatus for the gas-phase polymerization of olefins

Process for gas-phase polymerization carried out in two interconnected polymerization zones, to which one or more .alpha.-olefins CH.sub.2 .dbd.CHR are fed in the presence of catalyst under reaction conditions and from which the polymer product is discharged. The process is characterized in that the growing polymer flows through a first polymerization zone under fast fluidization conditions, leaves said first zone and enters a second polymerization zone through which it flows in a densified form under the action of gravity, leaves said second zone and is reintroduced into the first polymerization zone, thus establishing a circulation of polymer around the two polymerization zones. The novel process allows olefins to be polymerized in the gas phase with high productivity per unit volume of the reactor without incurring the problems of the fluidized-bed technologies of the known state of the art.

Process and apparatus for the gas-phase polymerization of .alpha.-olefins

Process for producing polyolefin grafted copolymers

Process for the gas phase polymerization of alpha-olefins

A process for the production of expandable granules of thermoplastic polymers comprising: (a) the extrusion of the polymer in which an expanding agent is incorporated, through a die-head in order to obtain an expandable polymer; (b) immediate cooling of this polymer in water, kept at a temperature at which the polymer remains in the non-expanded state, but not lower than the Tg of the expandable polymer; (c) cutting of the polymer to granules in water immediately at the outlet of the die-head, and (d) annealing of the thus obtained granules, by slow cooling in a temperature range comprised between at least +5.degree. C. and at least -5.degree. C. the Tg of the expandable polymer, wherein the cooling and the cutting of the polymer to granules and the annealing thereof are carried out under pressure. The apparatus comprises an extruder; a means for injecting the expanding agent into the extruder; a die-head; a chamber fastened to said die-head and provided with cutter and pipes for feeding water under pressure; a tower for the annealing of the granules and a means for maintaining the pressure in the chamber and in the tower.

Process for the production of expandable granules of thermoplastic

The halogen and organic substances content of the catalyst residues in alpha-olefin crystalline (co)-polymers prepared with catalysts obtained by reacting:

Process for treating olefinic polymers with steam

Organic-solvent solutions of polycarbonates containing impurities, e.g., sodium chloride and sodium carbonate formed during the preparation of the polycarbonates, and/or catalysts, are purified by sending aqueous emulsions of polycarbonates in water-immiscible organic solvents, in particular the aqueous emulsions coming from the various purification phases of the organic polycarbonate solutions obtained in the synthesis, through a layer of fibers in which the dispersed droplets of the emulsion coalesce, with the formation of two layers each consisting essentially of one of the two separate phases of the emulsion.

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Mantova, Italy

Roberto Rinaldi