A novel liquid phase polymerization process for preparing a polyolefin product
having preselected properties is disclosed. The process includes the steps of providing
a liquid feedstock which contains an olefinic component and a catalyst composition
consisting of a stable complex of BF3 and a complexing agent therefor.
The feedstock may comprise any one or more of a number of olefins including branched
olefins such as isobutylene, C3 to C15 linear alpha olefins
and C4 to C15 reactive non-alpha olefins. The feedstock and
the catalyst composition are introduced into a residual reaction mixture recirculating
in a loop reactor reaction zone provided in the tube side of a shell and tube heat
exchanger at a recirculation rate sufficient to cause intimate intermixing of the
residual reaction mixture, the added feedstock and the added catalyst composition.
The heat of the polymerization reaction is removed from the recirculating intimately
intermixed reaction admixture at a rate calculated to provide a substantially constant
reaction temperature therein while the same is recirculating in said reaction zone.
The conditions in the reactor are appropriate for causing olefinic components introduced
in said feedstock to undergo polymerization to form the desired polyolefin product
in the presence of the catalyst composition. A product stream containing the desired
polyolefin product is withdrawn from the reaction zone. The introduction of the
feedstock into the reaction zone and the withdrawal of the product stream from
the reaction zone are controlled such that the residence time of the olefinic components
undergoing polymerization in the reaction zone is appropriate for production of
the desired polyolefin product.
