JPH0258284B

Free-flowing rubber powders of particles having an average diameter of from 0.01 to 10 mm which contain a grafted-on shell of the polymer or copolymer of one or more vinyl monomers in a quantity of from 2 to 20% by weight, based on the rubber, which rubber is a latex polymer of which the latex particles consist essentially of from 99 to 80% by weight of acrylate rubber having glass transition temperatures below 0 DEG C. and from 1 to 20% by weight of polymer having glass transition temperatures above 0 DEG C. grafted thereon, and a process for their production, wherein the latex of the rubber is completely broken to form an aqueous suspension of the rubber, after which from 2 to 20% by weight, based on the rubber, of one or more vinyl monomers which form polymers having glass transition temperatures above 25 DEG C. are introduced into the suspension and the monomer(s) is/are polymerized, optionally after the addition of a radical-forming catalyst.