Verfahren zum Spalten von 4,4-Dimethyl-m-Dioxan zu Isopren

摘要

1,226,266. Isoprene catalyst. FARBENFABRIKEN BAYER A.G. 18 June, 1969 [29 Nov., 1968], No. 30817/69. Heading B1E. [Also in Division C5] A catalyst for the preparation of isoprene by the gaseous phase decomposition of 4, 4- dimethyl m dioxane is prepared by suspending a silicic acid filter of specific surface 30- 200 m2/g together with a kaolinite montmorillonite or atupulgite clay in an aqueous stable silicic acid sol (specific area 150-400 m2g); adding to the suspension on any suspension of MgO to set the suspension into beads; drying and heating the beads to 500-1000‹C for at least 10 minutes; adding thereto 5-30% phosphoric acid and further heating to 300- 650‹C.