Abstract: A catalyst system is produced by first forming a chromium catalyst on a predominantly silica support, activating in an oxygen-containing ambient and thereafter subjecting the thus activated composition to carbon monoxide reduction. The resulting reduced supported chromium catalyst composition is then precontacted with a cocatalyst selected from trialkyl boron compounds and dialkyl aluminum alkoxide compounds, preferably triethyl borane and thereafer contacted with ethylene. This results in a catalyst system which produces comonomer in situ so as to give tough, flexible ethylene copolymers from an essentially pure ethylene feed.

Abstract: The catalyst system is produced by first forming a chromium catalyst on a predominantly silica support, activating in an oxygen-containing ambient and thereafter subjecting the thus activated composition to carbon monoxide reduction. The resulting reduced supported chromium catalyst composition is then precontacted with a cocatalyst selected from trialkyl boron compounds and dialkyl aluminum alkoxide compounds, preferably triethyl borane and thereafter contacted with ethylene. This results in a catalyst system which produces comonomer in situ so as to give tough, flexible ethylene copolymers from an essentially pure ethylene feed.

Abstract: Olefin polymerization catalysts are described which are based on solid inorganic oxides (such as silica) and polychromium complexes (such as octakis(.mu.-trimethylsilylmethyl) tetrachromium(II)). Linear low density ethylene homopolymers with specific short chain branching as well as polymerization processes to make these polymers using the specific catalyst described are also disclosed.

Abstract: Olefin polymerization catalysts are described which are based on solid inorganic oxides (such as silica) and polychromium complexes (such as octakis(.mu.-trimethylsilylmethyl)tetrachromium(II)). Linear low density ethylene homopolymers with specific short chain branching as well as polymerization processes to make these polymers using the specific catalyst described are also disclosed.

Abstract: A process for copolymerizing ethylene with another monoolefin is described wherein the other monoolefin is incorporated into the polymer at very high efficiencies and in several instances the copolymer produced contains a higher concentration of the comonomer than the gas phase in the polymerization zone. A novel ethylene/1-hexene copolymer having very high relative comonomer dispersities (99% or higher, and even above 100%) is also described.