Ethylene polymerization process

摘要

Novel catalysts are provided for the polymerization of olefins such as ethylene. The catalysts consist essentially of a chromium compound supported upon an inorganic carrier containing aluminum and phosphorus moieties, at least a portion of the chromium having a valence of less than 6. The inorganic carrier is an amorphous precipitate of aluminum phosphate or an amorphous precipitate containing aluminum and phosphorus moieties in an atomic ratio in the range of about 5:1 to 1:1. The catalysts are particularly useful for polymerizing ethylene in a Particle Form Process in that the catalyst has essentially no polymerization induction period and provides ethylene polymers having a desirably broad molecular weight distribution and a desirably high melt flow shear ratio.