The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Oct. 29, 2002
Filed:
Sep. 26, 2001
Shinji Abe, Ichihara, JP;
Tomohiro Arase, Ichihara, JP;
Satoru Ohtani, Ichihara, JP;
Shotaro Matsuda, Yamaguchi, JP;
Mitsui Chemicals, Inc., Tokyo, JP;
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 (C ) of a saturated aliphatic hydrocarbon in a reactor of a second stage to the concentration (C ) of a saturated aliphatic hydrocarbon in a reactor of a first stage (C /C ) 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 %.