Abstract: Process for preparing polyolefins having high molecular weights in the presence of a catalyst comprising an organic transition metal compound in a gas-phase fluidized-bed reactor, where the polyolefins prepared have a melt flow rate at 2.16 kg and 190° C. in accordance with ISO 1133 of less than 4 g/10 min. According to the present invention, a start-up phase during which a polyolefin having an increased melt flow rate of above 4 g/10 min is produced for a transitional period is provided. In this way, trouble-free start-up of the reactor is ensured even in the case of polymer products having a high molecular weight and a melt flow rate below 4 g/10 min and even when using catalysts based on organic transition metal compounds, in particular metallocene catalysts.

Abstract: The invention relates to a process for preparing a supported catalyst, in particular for the polymerization and/or copolymerization of olefins, which comprises: a) preparing a hydrogel; b) milling the hydrogel to give a finely particulate hydrogel; c) producing a slurry based on the finely particulate hydrogel; d) drying the slurry comprising the finely particulate hydrogel to give the support for catalysts; e) producing the supported catalyst by applying at least one transition metal and/or at least one transition metal compound to the support for catalysts and, if appropriate, activating the applied metal and/or compound, wherein a finely particulate hydrogel in which at least 5% by volume of the particles, based on the total volume of the particles, have a particle size in the range from >0 ?m to ?3 ?m; and/or at least 40% by volume of the particles, based on the total volume of the particles, have a particle size in the range from >0 ?m to ?12 ?m, and/or at least 75% by volume of the particles, base

Abstract: Process for preparing polyolefins having high molecular weights in the presence of a catalyst comprising an organic transition metal compound in a gas-phase fluidized-bed reactor, where the polyolefins prepared have a melt flow rate at 2.16 kg and 190° C. in accordance with ISO 1133 of less than 4 g/10 min. According to the present invention, a start-up hase during which a polyolefin having an increased melt flow rate of above 4 g/10 min is produced for a transitional period is provided. In this way, trouble-free start-up of the reactor is ensured even in the case of polymer products having a high molecular weight and a melt flow rate below 4 g/10 min and even when using catalysts based on organic transition metal compounds, in particular metallocene catalysts.

Abstract: Metallocene having two cyclic dienyl groups connected by a single carbon having an aryl substituent and a terminally unsaturated hydrocarbyl substituent, olefin polymerization catalyst systems prepared therefrom, and the use of such catalyst systems are disclosed.

Abstract: Metallocene having two cyclic dienyl groups connected by a single carbon having an aryl substituent and a terminally unsaturated hydrocarbyl substituent, olefin polymerization catalyst systems prepared therefrom, and the use of such catalyst systems are disclosed.

Abstract: Metallocene having two cyclic dienyl groups connected by a single carbon having an aryl substituent and a terminally unsaturated hydrocarbyl substituent, olefin polymerization catalyst systems prepared therefrom, and the use of such catalyst systems are disclosed.

Abstract: Metallocenes having a 9-fluorenyl group and another cyclic dienyl group connected by a single carbon having a terminally unsaturated hydrocarbyl substituent wherein the 9-fluorenyl group has a hydrocarbyl substituent in the 4 position, olefin polymerization catalyst systems prepared therefrom, and the use of such catalyst systems are disclosed.

Abstract: The invention relates to particles comprises of organopolysiloxane microgel particles having a diameter of 5 to 200 nm and organo-aluminum compounds immobilized thereon. The particles can be used as cocatalysts together with metal compounds of the 4, 5, 6 and 8-10 sub-groups of the periodic table for oligomerization, cyclization of polymerization of olefins.

Abstract: Metallocenes having a 9-fluorenyl group and another cyclic dienyl group connected by a single carbon having a terminally unsaturated hydrocarbyl substituent wherein the 9-fluorenyl group has a hydrocarbyl substituent in the 4 position, olefin polymerization catalyst systems prepared therefrom, and the use of such catalyst systems are disclosed.

Abstract: Metallocenes having a 9-fluorenyl group and another cyclic dienyl group connected by a single carbon having a terminally unsaturated hydrocarbyl substituent wherein the 9-fluorenyl group has a hydrocarbyl substituent in the 4 position, olefin polymerization catalyst systems prepared therefrom, and the use of such catalyst systems are disclosed.

Abstract: A solid cocatalyst is prepared by reacting a suitable support base with an organoaluminum compound and then reacting that product with an activity promoting amount of water. The solid cocatalyst can be combined with a polymerization catalyst to form a catalyst system useful for the polymerization of olefins.

Abstract: Metallocene having two cyclic dienyl groups connected by a single carbon having an aryl substituent and a terminally unsaturated hydrocarbyl substituent, olefin polymerization catalyst systems prepared therefrom, and the use of such catalyst systems are disclosed.

Abstract: Novel catalyst systems which comprise 2-pyridine carboxaldimine nickel dihalide complexes can be used with an organoaluminum cocatalyst in slurry oligomerization or polymerization processes to oligomerize or polymerize mono-1-olefins and, optionally a higher alpha-olefin comonomer, to produce low molecular weight polymers or synthetic oils.

Abstract: A prepolymerized solid catalyst is prepared by reacting a suitable support base with an organoaluminum compound and then reacting that product with an activity promoting amount of water and then reacting the resulting solid cocatalyst with a metallocene and then subjecting that product to prepolymerization in the presence of hydrogen. The prepolymerized solid catalyst is useful in the polymerization of olefins.

Abstract: A solid cocatalyst is prepared by combining (1) a first material capable of affixing an organoaluminum compound with (2) an organic liquid and then adding an organoaluminum compound and then contacting that product with water dispersed in an inert gas. Further catalyst compositions prepared from that cocatalyst and the use of such catalyst compositions to polymerize olefins is disclosed.

Abstract: Novel catalyst systems which comprise 2-pyridine carboxaldimine nickel dihalide complexes can be used with an organoaluminum cocatalyst in slurry oligomerization or polymerization processes to oligomerize or polymerize mono-1-olefins and, optionally a higher alpha-olefin comonomer, to produce low molecular weight polymers or synthetic oils.