| 摘要 |
<p>RUBBER POWDERS 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.degree.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.degree.C are then introduced into the suspension; and the monomer(s) is/are polymerized, optionally after adding a radical-forming catalyst.</p> |
