Polymer/CaCO.sub.3 composite core/sheath particulates and hollow . CaCO. sub3 microbeads prepared therefrom

摘要

Composite core/sheath particulates comprising an organic polymer core at least partly coated with calcium carbonate, these core/sheath particulates having a mean particle size not exceeding 5 m, well suited for reinforcing plastic/elastomer substrates, are conveniently converted, e.g., via calcination, into hollow calcium carbonate microbeads which comprise CaCO.sub.3 shells having a mean particle size not exceeding 5 m; such hollow microbeads are themselves well suited for enhancing the low-temperature flexibility of elastomer substrates, notably vehicle tires.