METHOD FOR INHIBITING POLYMERIZATION OF VINYL COMPOUNDS

摘要

A method for inhibiting the polymerization of vinyl compounds by using N-nitrosophenylhydroxylamine or salts thereof, wherein further use is made of either a copper salt or a combination of a metal dialkyldithiocarbamate with at least one member selected among inorganic acids, salts thereof, and water. In a distillation system in a process for preparing vinyl compounds, particularly acrylic or methacrylic acid, the method can effectively inhibit the polymerization of the above compounds, optionally while preventing the corrosion of the equipment, thus permitting a stable continuous operation for a long period of time.