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:
Jul. 11, 2017
Filed:
Jul. 22, 2014
Borealis Ag, Vienna, AT;
BOREALIS AG, Vienna, AT;
Abstract
A process for the preparation of a propylene copolymer, preferably a heterophasic propylene copolymer, in a multistage polymerisation process in the presence of a single site catalyst, said process comprising: (I) in a slurry polymerisation step, polymerising propylene and optionally at least one C2-10 alpha olefin comonomer; and subsequently (II) 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 (I); (III) in a second gas polymerisation step, polymerising propylene and at least one C2-10 alpha olefin comonomer in the presence of the catalyst and polymer from step (II); wherein said catalyst comprises (i) a metallocene complex of a group (IV) metal, said metallocene comprising at least two cyclopentadienyl type ligands; (ii) a boron based cocatalyst; and (iii) an aluminoxane cocatalyst; said catalyst being in solid form, preferably in solid particulate form, and being free from an external carrier.