PRODUCTION OF METHACRYLIC ACID

摘要

PURPOSE:To obtain the objective compound by producing acetone cyanohydrin from hydrocyanic acid and acetone, hydrating the product to obtain alpha- hydroxyisobutyramide, producing methyl alpha-hydroxyisobutyrate from the above butyramide and methyl formate and hydrolyzing and then dehydrating the obtained ester. CONSTITUTION:Hydrocyanic acid is made to react with acetone at about 10 deg.C and the obtained acetone cyanohydrin is hydrated at 40-100 deg.C in the presence of a catalyst such as manganese oxide to obtain alpha-hydroxyisobutyramide. The product is made to react with methyl formate or methanol and CO in the presence of a catalyst such as alkali metal alcoholate and a solvent such as methanol at 20-100 deg.C to produce methyl alpha-hydroxyisobutyrate and formaldehyde. The methyl alpha-hydroxyisobutyrate is hydrolyzed to obtain alpha-hydroxyisobutyric acid, which is dehydrated to obtain methacrylic acid. The formaldehyde is dehydrated and the produced hydrocyanic acid is recycled to the production system.