Abstract: Catalytic system which can be used for the polymerisation of .alpha.-olefins comprising:a solid based on complexed titanium trichloride of .delta. crystalline form;an organoaluminium compound;an organic oxygenated silicon compound; characterised in that the organoaluminium compound is a non-halogenated compound.

Abstract: Catalytic system which can be used for the polymerization of .alpha.-olefins comprising:a solid based on complexed titanium trichloride of .delta. crystalline form;an organoaluminium compound;an organic oxygenated silicon compound;characterized in that the organoaluminium compound is a non-halogenated compound.

Abstract: Catalyst systems comprising, on the one hand, a catalytic solid based on complexed titanium trichloride and, on the other hand, a nonhalogenated organoaluminium activator. When employed in gas phase olefin polymerisation processes, these catalyst systems make it possible to manufacture a wide range of homopolymers and copolymers (random and block) with an isotacticity index which can be adjusted to very low values and with excellent pourability, even in the case of copolymers of high comonomer content. In the absence of transfer agents they also make it possible to synthesize polymers of very high molecular masses, with an increased activity. These polymerization processes yield particularly advantageous results in the case of propylene.

Abstract: Catalyst systems comprising, on the one hand, a catalytic solid based on complexed titanium trichloride and, on the other hand, a nonhalogenated organolauminium activator.When employed in gas phase olefin polymerization processes, these catalyst systems make it possible to manufacture a wide range of homopolymers and copolymers (random and block) with an isotacticity index which can be adjusted to very low values and with excellent pourability, even in the case of copolymers of high comonomer content.In the absence of transfer agents they also make it possible to synthesise polymers of very high molecular masses, with an increased activity.These polymerization processes yield particularly advantageous results in the case of propylene.

Abstract: Catalyst systems comprising, on the one hand, a catalytic solid based on complexed titanium trichloride and, on the other hand, a nonhalogenated organoaluminium activator. When employed in gas phase olefin polymerization processes, these catalyst systems make it possible to manufacture a wide range of homopolymers and copolymers (random and block) with an isotacticity index which can be adjusted to very low values and with excellent pourability, even in the case of copolymers of high comonomer content. In the absence of transfer agents they also make it possible to synthesize polymers of very high molecular masses, with an increased activity. These polymerization processes yield particularly advantageous results in the case of propylene.

Abstract: Catalytic solids based on titanium trichloride complex, usable for the stereospecific polymerisation of alpha-olefins, obtained by heat treatment, in the presence of a halogenated activating agent, of the liquid material resulting from bringing TiCl.sub.4, pretreated with an electron-donor compound, into contact with a composition (C) corresponding to the general formulaAlR.sub.p (Y).sub.q X.sub.3-(p+q)in whichR represents a hydrocarbon radical or a hydrogen atom;Y represents a group chosen from --OR', --SR' and --NR'R", in which R' and R" each represent a hydrocarbon radical or a hydrogen atom;X represents a halogen;p is an arbitrary number such that 0<p<3; andq is an arbitrary number such that 0<q<3;the sum (p+q) being such that 0<(p+q).ltoreq.3.These catalytic solids of controllable porosity permit the production of a wide range of propylene polymers, in particular the propylene and ethylene copolymers known as "block" copolymers.

Abstract: Catalytic composition which may be used for the polymerization of alpha-olefins, comprising:(a) a solid catalyst comprising on titanium trichloride (TiCl.sub.3),(b) a non-halogen-containing cocatalyst comprising at least one non-halogen-containing organoaluminium compound,characterized in that the non-halogen-containing cocatalyst additionally contains at least one aminoalane containing no active hydrogen.Such a catalytic system may additionally contain a tertiary constituent chosen from oxygenated organosilicon compounds.

Abstract: Catalytic solids based on titanium trichloride complex, usable for the stereospecific polymerization of alpha-olefins, obtained by heat treatment, in the presence of a halogenated activating agent, of the liquid material resulting from bringing TiCl.sub.4, pretreated with an electron-donor compound, into contact with a composition (C) corresponding to the general formulaAlR.sub.p (Y) .sub.q X .sub.3-(p+q)in whichR represents a hydrocarbon radical or a hydrogen atom;Y represents a group chosen from --OR', --SR' and --NR'R", in which R' and R" each represent a hydrocarbon radical or a hydrogen atom;X represents a halogen;p is an arbitrary number such that 0<p<3; andq is an arbitrary number such that 0<q<3; the sum (p+q) being such that 0<(p+q).ltoreq.3.These catalytic solids of controllable porosity permit the production of a wide range of propylene polymers, in particular the propylene and ethylene copolymers known as "block" copolymers.