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. 07, 2010
Filed:
Jun. 22, 2007
Michael Brockelt, Leverkusen, DE;
Ludwig Deibele, Münich, DE;
Manfred Dietrich, Frankfurt, DE;
Markus Hadley, Pulheim, DE;
Jan Thomas Leu, Leichlingen, DE;
Guido Naberfeld, Upper St. Clair, PA (US);
Ralf Dohrn, Bergisch Gladbach, DE;
Michael Brockelt, Leverkusen, DE;
Ludwig Deibele, Münich, DE;
Manfred Dietrich, Frankfurt, DE;
Markus Hadley, Pulheim, DE;
Jan Thomas Leu, Leichlingen, DE;
Guido Naberfeld, Upper St. Clair, PA (US);
Ralf Dohrn, Bergisch Gladbach, DE;
Bayer MaterialScience AG, Leverkusen, DE;
Abstract
The invention provides a process for the purification of polymer polyols that ensures a reduction of acrylonitrile, styrene as well as the residual amounts of optionally used chain regulator, and of occurring recombination products of the initiator when azo initiators are used, to levels of <25 ppm of acrylonitrile, <50 ppm styrene, <50 ppm chain regulator and <280 ppm of recombination products by stripping using packed columns.