Process for preparing polyethylene blend comprising metallocene produced resins and chromium produced resins

摘要

A process for preparing a homogeneous polyethylene product can include producing a first polyethylene resin in the presence of a metallocene catalyst in a reactor. The first polyethylene resin can have a density of from 0.942 to 0.970 g/cm3 and an HLMI of from 0.5 to 150 g/10 min. The process can include separately producing a second polyethylene resin in the presence of a chromium catalyst in a reactor. The process can include physically blending together the first polyethylene resin and the second polyethylene resin to produce the homogeneous polyethylene product. The homogeneous polyethylene product can include at least 25% by weight of the first polyethylene resin.

主权项

1. A process for preparing a polyethylene product, said process comprising:
(a) producing a first polyethylene resin in the presence of a metallocene catalyst in a reactor, said first polyethylene resin having a density of from 0.942 to 0.970 g/cm3 and a High Load Melt Index (HLMI) of from 0.5 to 150 g/10 min, with the HLMI being measured by the procedure of ASTM D-1238 using a temperature of 190° C. and a load of 21.6 kg and with the density being determined with the ASTM D-1505 standardized test at a temperature of 23° C., wherein said first polyethylene resin has a bimodal molecular weight distribution; (b) separately producing a second polyethylene resin in the presence of a chromium catalyst in the reactor, and (c) physically blending together said first polyethylene resin and said second polyethylene resin to produce a polyethylene product; wherein the polyethylene product comprises at least 33% by weight of the first polyethylene resin.