Process for controlling production of in-situ thermoplastic polyolefins and products

摘要

An improved gas-phase polymerization process for producing in-situ thermoplastic polyolefins in multiple reactors using high activity Ti/Al catalysts is provided. The improvement consists of developing a control parameter derived from eight integrated regions of the copolymer 13C NMR spectrum, defining the limits of the control parameter for the process, and operating the process to maintain the parameter within the defined limits. This is accomplished by adjusting the amount of ethylene fed to the secondary reactor and adjusting other process variables as required. Thermoplastic polyolefins, i.e., modified polypropylenes, having reduced hexane extractables and improved paint adhesion are also disclosed.