摘要 |
Pourable rubber powders comprising particles having an average diameter of from 0.01 to 10 mm which contain, polymerized thereon, a 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, and the core rubber is a latex polymer, the latex particles of which are composed of a core polymer and a sheath polymer, the core and sheath differing in their chemical composition and at least the sheath polymer being a diene or acrylate rubber having glass transition temperatures of below 0 DEG C., and a process for the preparation of such rubber powders, wherein a latex of an approximate rubber is completely broken with the formation of an aqueous suspension of the rubber; from 2 to 20% by weight, based on the rubber, of one or more vinyl monomers which form polymers having glass transition temperatures of above 25 DEG C. are then introduced into the suspension; and the monomer(s) is/are polymerized, optionally after adding a radical-forming catalyst.
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