Process for producing bimodal ethylene polymers in tandem reactors

摘要: A process is provided for producing a bimodal ethylene polymer blend comprising contacting in first gas phase, fluidized bed reaction zone under polymerization conditions, gaseous monomeric composition major proportion of and, optionally, hydrogen, with Ziegler-Natta catalyst, the hydrogen/ethylene molar ratio (H₂/C₂ ratio) being no higher than about 0.3 and partial pressure 100 psia, to produce relatively high molecular weight (HMW) associated catalyst particles, transferring HMW particles second into which also fed hydrogen ethylene, conditions including an H₂/C₂ at least 0.9 8.0 times that zone, 1.7 said low (LMW) deposited on within voids polymer/catalyst resulting obtained from having fraction 0.35.