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:
May. 14, 2019
Filed:
Jun. 09, 2014
Borealis Ag, Vienna, AT;
BOREALIS AG, Vienna, AT;
Abstract
A process for the preparation of a propylene polymer in a multistage polymerisation process in the presence of a single site catalyst, said process comprising: (I) in a prepolymerisation step prepolymerising a single site catalyst in the presence of propylene and optionally at least one C2-10 alpha olefin comonomer and in the presence of hydrogen or in the absence of hydrogen; (II) in a slurry polymerisation step, polymerising propylene and optionally at least one C2-10 alpha olefin comonomer, with the pre-polymerised catalyst of step (I) in the presence of hydrogen; and subsequently (III) in a gas polymerisation step polymerising propylene and optionally at least one C2-10 alpha olefin comonomer, in the presence of catalyst and polymer from step (II) and optionally in the presence of hydrogen so as to form a propylene homopolymer or copolymer; wherein the amount of hydrogen fed to the pre-polymerisation step (I) is at most 15% of the total amount of hydrogen fed to steps (I) and (II) of the polymerisation process.