SPHERICAL CALCIUM CARBONATE PARTICLES

摘要

Disclosed are spherical calcium carbonate particles that have an average diameter ranging from 0.05 .mu.m to 2.0 .mu.m and a maximum water content of 5.0 percent by weight relative to the total weight thereof. Said calcium ca rbonate particles are preferably obtained by reacting calcium chloride with dialkyl carbonate in the presence of an alkali metal hydroxide in aqueous so lution. The components are advantageously used at the following concentratio ns: a) CaCl2: >10 mmol/l to 50 mmol/l; b) dialkyl carbonate: >10 mmol/ l to 50 mmol/l; c) alkali metal hydroxide: 20 mmol/l to 100 mmol/l. The disc losed particles are particularly suitable as an additive or modifying agent in paper, paints, plastics, inks, adhesives, and pharmaceuticals.