Process for preparing polyolefin blends in a device for continuously physically melting and blending the blends

摘要

A process for preparing a polyolefin product can include providing a first high molecular weight (HMW) polyolefin resin having an HLMI of between 0.01 and 5 g/10 min, and separately providing a second low molecular weight (LMW) polyolefin resin having an MI2 of between 1 and 150 g/10 min. A device can be used to continuously physically melt and blend the first HMW polyolefin resin and the second LMW polyolefin resin to produce the polyolefin product. The device can include at least two feeding zones spatially separated and operably connected to each other. At least a art of the first HMW polyolefin resin is introduced in a first feeding zone, and at least a part of the second LMW polyolefin is introduced in a second feeding zone different from the first zone.

主权项

1. A process for preparing a polyolefin product, said process comprising:
(a) providing a first high molecular weight (HMW) polyolefin resin having a High Load Melt Index (HLMI), measured at 190° C. under a 21.6 kg load according ASTM D-1238, of between 0.01 and 5 g/10 min; (b) separately providing a second low molecular weight (LMW) polyolefin resin having a Melt Index (MI2), measured at 190° C. under a 2.16 kg load according ASTM D-1238, of between 1 and 150 g/10 min; and (c) using a device for physically melting and blending said first HMW polyolefin resin and said second LMW polyolefin resin to produce a polyolefin product;
characterized in that said device comprises at least two feeding zones spatially separated and operably connected to each other, wherein at least part of the first HMW polyolefin resin is introduced in a first feeding zone, and at least part and up to 90% by weight of the second LMW polyolefin resin is introduced in a second feeding zone different from the first feeding zone, wherein a remainder of the second LMW polyolefin resin in introduced in the first feeding zone;wherein the second feeding zone is located downstream of the first feeding zone, and wherein polyolefin resin is moved from the first feeding zone, through a first melting and blending zone, to the second feeding zone, and through a second melting and blending zone; andwherein a ratio the first HMW polyolefin resin/the second LMW polyolefin resin of the polyolefin product decreases as a function of residence time in the device.