METHOD FOR RECOVERING UNREACTED ALPHA,BETA-ETHYLENICALLY UNSATURATED NITRILE MONOMER CONTAINED IN LATEX OF CARBOXYL GROUP-CONTAINING NITRILE RUBBER

摘要

A method for recovering an unreacted α,β-ethylenically unsaturated nitrile monomer contained in a latex of a nitrile rubber obtained by emulsion polymerizing a monomer mixture comprising an α,β-ethylenically unsaturated nitrile monomer and a carboxyl group-containing monomer is provided. The method comprises the steps of: adjusting a pH of the latex of the carboxyl group-containing nitrile rubber to 6.5 or more; decompressing the latex of the carboxyl group-containing nitrile rubber having the pH adjusted to 6.5 or more under a heating condition; and recovering a component evaporated by the decompression under the heating condition.