Processes for producing polyolefin composition
US6472484B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 26, 2001 |
| Grant date | Oct 29, 2002 |
| Priority date | — |
| Expiry date | Sep 26, 2021 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S526/901
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
The present invention provides a method for producing a polyolefin composition having a narrow composition distribution and is characterized in that when at least two olefins are copolymerized in the presence of a transition metal compound catalyst using at least two gas phase fluidized bed reactors, a saturated aliphatic hydrocarbon is allowed to exist in each reactor in a concentration from 0.1 to 30 mol %, and the ratio of the concentration (C2) of a saturated aliphatic hydrocarbon in a reactor of a second stage to the concentration (C1) of a saturated aliphatic hydrocarbon in a reactor of a first stage (C2/C1) is 0.13 or more. Further, the present invention provides a method for producing a polyolefin composition by multi-stage polymerization, which can prevent sheeting in the reactor and can give a polyolefin composition stably with high productivity, and is characterized in that a saturated aliphatic hydrocarbon is allowed to exist in a transport line for transporting a polymer particle extracted from a fluidized bed reactor in the previous stage to a fluidized bed reactor in the subsequent stage at a concentration from 0.1 to 30 mol %.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.