STAIN PREVENTING AGENT AND STAIN PREVENTING METHOD

摘要

PROBLEM TO BE SOLVED: To provide a stain preventing agent capable of being used in a recovery process where a reaction product is recovered by using an aqueous medium after gas-phase catalytic oxidation, when (1) an unsaturated aldehyde and an unsaturated carboxylic acid are produced by the gas-phase catalytic oxidation of a 3-4C monoolefin or alcohol in the presence of a catalyst or when (2) an unsaturated nitrile compound is produced by the gas-phase catalytic oxidation of the 3-4C monoolefin in the presence of ammonia, and to provide a stain preventing method using the agent. SOLUTION: This stain preventing agent is used in the recovery process, wherein the agent has such action as to reduce adhesion of the stain derived from by-products contained in a gas formed by the oxidation, and further the agent contains at least one kind of a melamine resin acid colloid or a melamine-urea resin acid colloid for being added to the aqueous medium as an active ingredient. The stain preventing method uses the agent. COPYRIGHT: (C)2006,JPO&NCIPI