CARBOXYLATED NITRILE RUBBER-BASED RUBBER LATEX WITHOUT EMULSIFIER

摘要

PROBLEM TO BE SOLVED: To make it unnecessary to use an emulsifier in synthesizing carboxylated nitrile rubber. ;SOLUTION: When synthesizing carboxylated nitrile rubber, the method of this invention is as follows: (1) initiating the terpolymerization of 1,3-butadiene, acrylonitrile and methacrylic acid in an aqueous polymerization medium by adding potassium persulfate and a co-initiator to potassium persulfate where the terpolymerization is initiated in a reactor in a state filled up to at least 60% of its capacity; (2) making the terpolymerization proceed at ca. 25-80°C until the solid content reaches ca. 20 wt.% to produce seed polymer latex; (3) adding additional 1,3-butadiene, acrylonitrile and potassium persulfate to the seed polymer latex for at least one hour to produce the second polymerization medium; (4) continuing the terpolymerization in the second polymerization medium for at least half an hour to produce carboxylated nitrile rubber latex.;COPYRIGHT: (C)2000,JPO