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:
Aug. 04, 1998
Filed:
Jan. 15, 1997
Geoffrey Chapman, Sausset-Les-Pins, FR;
Stephen Kevin Lee, London, GB;
Michael Bernard Power, London, GB;
Bruno Grenouiller, Martigues, FR;
BP Chemicals Limited, , GB;
Abstract
The present invention relates to a process for continuously manufacturing ethylene (co-)polymer in a gaseous phase in a polymerization zone through which passes an essentially gaseous reaction mixture comprising the (co-)monomers(s). In addition the process comprises transferring a mixture (A) formed by the gaseous reaction mixture and the solid (co-)polymer in a depressurization zone, and separating the mixture (A) into a solid phase (B) and a gaseous phase (C) returned into the polymerization zone. The solid phase (B) is subjected to (1) at least one non-deactivating flushing with respect to the active catalytic residues, and subsequently (2) a deactivating flushing with a gaseous mixture of nitrogen, water and oxygen. The (co-)polymer thus obtained has very low contents of unreacted (co-)monomer(s) and volatile organic compounds, and exhibits a high whiteness index and a long thermal stability with time.