Inorganically treated barium sulphate, useful as filler in polymers

摘要

Inorganically-treated BaSO4 (I) contains 0.1-10 wt.% P2O5, 0.1-15 wt.% SiO2 and 0.1-20 wt.% Al2O3. Also claimed is a process for the prodn. of (I) by treating an aq. suspension of BaSO4 in succession with phosphate, Na silicate and a water-soluble Al cpd., and isolating the solid.