GB832505A - Process for the continuous production of polyolefines of uniform molecular weight - Google Patents

Abstract

A Ziegler catalyst for use in the continuous production of polyolefines, is stabilized by using in an initial polymerization at about 20-60 DEG C. and for a short residence time in a pre-reactor before continuously introducing into the main reactor which is at a higher temperature, e.g. about 80 DEG C. In an example the catalyst is formed by mixing aluminium diethyl chloride and titanium tetrachloride in cyclohexane.ALSO:Polyolefines of uniform molecular weight are obtained by a continuous process using Ziegler catalysts, characterized in that the catalyst is used in an initial polymerization at about 20-60 DEG C. and for a short residence time in a pre-reactor, and is then continuously introduced into the main reactor which is at a temperature above that of the pre-reactor, e.g. at about 80 DEG C. In the example ethylene is polymerized with cyclohexane as diluent and with a catalyst formed from aluminium diethyl chloride and titanium tetrachloride. The apparatus used consists of 3 reaction columns through which the reaction components flow. In the first column the catalyst components and diluent are mixed and then flow into the second column, at 20 DEG to 60 DEG C., into which ethylene is also introduced. The residence time in this pre-reactor is 10 minutes and the catalyst and reaction medium containing some polymer then passes into the third column into which further ethylene and cyclohexane are also introduced. The residence time in the third column is 3 hours.