Abstract: Preactivated unsupported catalyst compositions methods of using them are disclosed whereby the compositions have a concentration of preactivated catalyst of at least about 0.04 mmol of preactivated catalyst per liter of solution when using aliphatic or alicyclic hydrocarbon solvents, and a concentration of less than about 0.80 mmol/liter when using aromatic or halogen-substituted solvents. In the method, an unsupported catalyst precursor first is contacted with an activator, or co-catalyst, in a suitable reaction medium, and then the resulting mixture is contacted with additional solvent to form a preactivated unsupported olefin polymerization catalyst composition that can be fed to a gas phase polymerization reactor without plugging the catalyst injection nozzle.

Abstract: The present invention teaches the use of particular soluble metallocene catalyst to produce stereo-regular polymers in gas phase polymerizations wherein the catalysts are fed into a particle lean zone in the react. The metallocenes catalysts are bridged bis-(substituted indenyl) compounds.

Abstract: The present invention teaches the use of particular soluble metallocene catalysts to produce stereoregular polymers in gas phase polymerizations wherein the catalysts are fed into a particle lean zone in the reactor. The metallocenes catalysts are bridged bis-(substituted indenyl) compounds.

Abstract: Preactivated unsupported catalyst compositions methods of using them are disclosed whereby the compositions have a concentration of preactivated catalyst of at least about 0.04 mmol of preactivated catalyst per liter of solution when using aliphatic or alicyclic hydrocarbon solvents, and a concentration of less than about 0.80 mmol/liter when using aromatic or halogen-substituted solvents. In the method, an unsupported catalyst precursor first is contacted with an activator, or co-catalyst, in a suitable reaction medium, and then the resulting mixture is contacted with additional solvent to form a preactivated unsupported olefin polymerization catalyst composition that can be fed to a gas phase polymerization reactor without plugging the catalyst injection nozzle.

Abstract: The present invention teaches the use of particular soluble metallocene catalysts to produce stereoregular polymers in gas phase polymerizations wherein the catalysts are fed into a particular lean zone in the reactor. The metallocene catalysts are bridged bis(substituted indenyl) compounds.