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. 03, 1976
Filed:
Sep. 13, 1974
Kurt Halcour, Leverkusen, DT;
Paul Losacker, Leichlingen, DT;
Wulf Schwerdtel, Leverkusen-Steinbuechel, DT;
Wolfgang Swodenk, Odenthal-Gloebusch, DT;
Bayer Aktiengesellschaft, Leverkusen, DT;
Abstract
In the preparation of isoprene by reacting isobutene with formaldehyde to produce 4,4-dimethyl-m-dioxane in a first stage, and decomposing the dioxane to isoprene and formaldehyde in a second stage, formaldehyde in the effluent streams of either or both of said stages is recovered. The formaldehyde-containing liquids are distilled to separate high boilers; the overhead, which is formaldehyde-rich, is extracted with isobutene feed to the process, whereby the isobutene extracts low boilers from the formaldehyde-containing liquid; and the formaldehyde-containing liquid, having at some point after said distillation been treated with an alkaline material, is subjected to rectification to produce as head product, the recovered formaldehyde.