SPHERICAL CALCIUM CARBONATE PARTICLES

摘要

Disclosed are spherical calcium carbonate particles that have an average diameter ranging from 0.05 µm to 2.0 µm and a maximum water content of 5.0 percent by weight relative to the total weight thereof. Said calcium carbonate particles are preferably obtained by reacting calcium chloride with dialkyl carbonate in the presence of an alkali metal hydroxide in aqueous solution. The components are advantageously used at the following concentrations: 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 disclosed particles are particularly suitable as an additive or modifying agent in paper, paints, plastics, inks, adhesives, and pharmaceuticals.