HANR latex was incubated with 0.1 wt% urea in the presence of 1.0 wt% SDS solution for 1 hr. at the ambient temperature. The centrifugation was used to separate the cream fraction, which was redispersed in 1.0 wt% SDS solution. Then, the cream fraction was washed twice with 0.5 and 0.1 wt% SDS solution respectively.