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:
Nov. 23, 1993
Filed:
Feb. 05, 1993
Ian D Hudson, Freckleton, GB;
Graham J Hutchings, Osmotherley, GB;
Enichem Elastomers Limited, , GB;
Abstract
The invention relates to a process for the preparation of a conjugated diene from the corresponding carbonyl compound having the same number of carbon atoms by dehydration at a temperature of 300.degree. to 450.degree. C. using a catalyst comprising aluminium phosphate having the cristobalite structure. This catalyst is superior to aluminium phosphate having the tridymite structure in the dehydration of carbonyl compounds and has advantages over boron phosphate catalysts. Using the process, isoprene may be prepared from 2-methyl butanal and/or methyl isopropyl ketone in high yields. Unexpectedly aluminium phosphate having the cristobalite structure is markedly superior to boron phosphate in converting methyl isopropyl ketone, which is an intermediate product formed in appreciable amounts in the dehydration of 2-methyl butanal to isoprene. This superiority significantly improves the process economics of the conversion reaction of 2-methyl butanal to isoprene.