Patent ID: 6998457
Filing Date: 2006-02-14
Classification: C08F,Y10S

Abstract:
1. A process for preparing an atactic, substantially amorphous, tacky polypropylene or propylene-ethylene copolymer, which comprises the steps of: (a) introducing into a pressurized reactor, maintained at about 180° to 450° F. and at about 450 to 5000 psig, monomer(s) selected from the group consisting of (i) liquefied propylene and (ii) liquefied propylene and liquefied ethylene, with the propylene being present in an amount of at least about 65% by weight and with the ethylene being present in an amount of up to about 35% by weight, with the weight percentages totaling 100%.; (b) introducing a metallocene catalyst consisting essentially of a soluble sandwich compound of a titanium halide into the reactor; (c) allowing the liquefied monomer(s) to vaporize in the reactor; (d) polymerizing the vaporized monomer(s) in the reactor; (e) discharging a mixture of gaseous monomer(s) and molten polymer or copolymer from the reactor; and (f) separating the gaseous monomer(s) from the molten polymer or copolymer.