PROCESS FOR THE PREPARATION OF METHACRYLIC ACID AND THE ESTERS AND NITRILE THEREOF

摘要

Propionic acid (or the nitrile or an ester thereof) is reacted with methylal at an elevated temperature in the presence of a catalyst comprising zirconium dioxide. The process can be carried out for example at temperatures of at least 200 DEG C, particularly 200 to 350 DEG C. The catalyst may also contain aluminium oxide and/or silicon dioxide. The catalyst is preferably pre-treated with a phosphate and/or subjected to a thermal pre- treatment.