Abstract: Zirconocene compounds with two indenyl ligands linked in the 2 position by means of a two-carbon-atoms divalent bridging group can be suitably used as components of catalysts for the polymerization of olefins. Particularly it is possible to prepare, with high yields, ethylene (co)polymers having low molecular weights and narrow molecular weight distributions, without the need of using considerable amounts of molecular weight regulators, such as hydrogen.

Abstract: A multi-stage process for preparing ethylene (co)polymers having broad molecular weight distributions is disclosed, said process comprising: (A) a first polymerization stage in which, in the presence of a Ti or V catalyst, a first ethylene polymer is prepared; (B) a treatment stage in which the catalyst used in the first stage is deactivated and in which a bridged bis-2-indenyl zirconocene is supported on the ethylene polymer produced in stage (A), optionally in the presence of a suitable cocatalyst; and (C) a second polymerization stage in which ethylene is polymerized in the presence of the product obtained from stage (B). Furthermore, polyethylene obtainable by the above process is disclosed, having intrinsic viscosity ranging from 0.5 to 6 dl/g, Mw/Mn>8 and cold xylene solubility<1.2 % wt.

Abstract: Metallocene compounds with two indenyl-type ligands linked in the 4 position by means of a divalent bridging group can be suitably used as components of catalysts for the polymerization of olefins. In particular, it is possible to prepare saturated or unsaturated elastomeric copolymers of ethylene characterized by valuable properties, such as low ash content and uniform distribution of the comonomers in the polymer chain.

Abstract: Zirconocene compounds with two indenyl ligands linked in the 2 position by means of a two-carbon-atoms divalent bridging group can be suitably used as components of catalysts for the polymerization of olefins. Particularly it is possible to prepare, with high yields, ethylene (co)polymers having low molecular weights and narrow molecular weight distributions, without the need of using considerable amounts of molecular weight regulators, such as hydrogen.

Abstract: Zirconocene compounds with two indenyl ligands linked in the 2 position by means of a two-carbon-atoms divalent bridging group can be suitably used as components of catalysts for the polymerization of olefins. Particularly it is possible to prepare, with high yields, ethylene (co)polymers having low molecular weights and narrow molecular weight distributions, without the need of using considerable amounts of molecular weight regulators, such as hydrogen.

Abstract: Zirconocene compounds with two indenyl ligands linked in the 2 position by means of a two-carbon-atoms divalent bridging group can be suitably used as components of catalysts for the polymerization of olefins. Particularly it is possible to prepare, with high yields, ethylene (co)polymers having low molecular weights and narrow molecular weight distributions, without the need of using considerable amounts of molecular weight regulators, such as hydrogen.

Abstract: A multi-stage process for preparing ethylene (co)polymers having broad molecular weight distributions is disclosed, said process comprising: (A) a first polymerization stage in which, in the presence of a Ti or V catalyst, a first ethylene polymer is prepared; (B) a treatment stage in which the catalyst used in the first stage is deactivated and in which a bridged bis-2-indenyl zirconocene is supported on the ethylene polymer produced in stage (A), optionally in the presence of a suitable cocatalyst; and (C) a second polymerization stage in which ethylene is polymerized in the presence of the product obtained from stage (B). Furthermore, polyethylene obtainable by the above process is disclosed, having intrinsic viscosity ranging from 0.5 to 6 dl/g, Mw/Mn>8 and cold xylene solubility<1.2% wt.

Abstract: Zirconocene compounds with two indenyl ligands linked in the 2 position by means of a two-carbon-atoms divalent bridging group can be suitably used as components of catalysts for the polymerization of olefins. Particularly it is possible to prepare, with high yields, ethylene (co)polymers having low molecular weights and narrow molecular weight distributions, without the need of using considerable amounts of molecular weight regulators, such as hydrogen.