PURIFICATION AND PRODUCTION OF METHYL METHACRYLATE

PURPOSE:To efficiently remove water, methanol and low-boiling impurities without accumulation in a process and to obtain the title high-purity substance by distilling a mixture containing water, methanol and methyl methacrylate as main components and methyl acrylate, etc., with hexane. CONSTITUTION:A mixture containing water, methanol and methyl methaacrylate (MMA) as main components and methyl acrylate (MA), methyl propionate (MP), etc., is fed from a conduit 10 to a distillation column 1 and subjected to azeotropic distillation with hexane. A low-boiling fraction comprising water, methanol and hexane as main components and MA and MP is distilled from a conduit 12, condensed by a condenser 3, separated into two layers by a reflux dram 4 and an oil layer consisting essentially of hexane is sent to the distillation column 1 and a water layer consisting essentially of water is discharged to a hydrolysis tank 5. The hydrolyzed water phase 6 is distilled 6 to recover methanol. A high-boiling fraction substantially not containing water, methanol, MA, MP and hexane separated by the azeotropic distillation and comprising MMA as a main component is recovered from the bottom of the distillation column 1.