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:
Sep. 26, 2006
Filed:
Jul. 10, 2002
Jean-marc Galewski, Noeux-les-Mines, FR;
Jean-Marc Galewski, Noeux-les-Mines, FR;
BP Chemicals Limited, London, GB;
Abstract
The present invention relates to a process and a device for the continuous manufacture of a polymer of an aromatic alkylene monomer e.g. styrene comprising a bulk polymerisation of the monomer and a devolatilization of the resulting polymer in at least two successive steps so as to separate the polymer from the unreacted monomer and the oligomers formed during the polymerisation. The process comprises conveying a first gas stream resulting from the first step of the devolatilization into a first zone Zfor direct condensation and fractionation, removing a gas stream Gcomprising essentially the monomer from the top of Z, and removing a liquid stream Lrich in oligomers from the bottom of Z, a portion of Lbeing taken, cooled and then returned into Z. It also comprises conveying a second gas stream resulting from the second step of the devolatilization into a second zone Zfor direct condensation and fractionation, this zone being also fed with the other portion of L, removing a gas stream Gcomprising the monomer from the top of Z, and removing a liquid stream Lcomprising essentially the oligomers from the bottom of Z. The process and the device are particularly suitable for continuously manufacturing a styrene polymer, a styrene copolymer having a high impact strength modified by grafting onto a rubber, an expandable polystyrene or an expanded polystyrene. The invention is useful for improving the separation of the unreacted monomer from the oligomers and the quality of the polymer when the unreacted monomer thus separated is recycled e.g. to the polymerisation.