METHOD OF PREPARING ISOPRENE PRODUCTION CATALYST Russian patent published in 1999 - IPC

FIELD: catalysts for organic syntheses. SUBSTANCE: catalyst for production of isoprene via 4,4-dimethyl-1,3-dioxane cleavage is prepared by interaction of calcium salts with phosphoric acid in aqueous medium followed by ripening resultant suspension for 10 to 120 min, treating it with phosphoric acid, filtration, washing away chloride ions, extruding catalyst paste, preliminarily drying extrudates at 20-40 C for 2 to 12, subsequent drying at 125-130 C for 2 to 10 , and final drying at 140-150 C for the same time. Dried extrudates are treated with water steam or its mixture with inert gas at 400-600 C in presence of mixture of phosphoric and boric acids (at molar proportion from 1: 100 to 10:1). EFFECT: increased catalyst strength and dimethyldioxane conversion. 1 tbl, 2 ex