SURFACE-MODIFIED HEAVY CALCIUM CARBONATE AND ITS PRODUCTION AND AQUEOUS COATING COMPOSITION

摘要

PROBLEM TO BE SOLVED: To obtain the subject compound excellent in defoamability on production and coating and capable of imparting a mirror luster to a coating film without deteriorating the physical properties of the coating by treating the surface of heavy calcium carbonate with a fatty acid sorbitan ester. SOLUTION: The surface of (A) heavy calcium carbonate (e.g. that having an average particle diameter of 0.4-10μm and a specific surface area of 7000-50000cm<2> /g by an air permeation method) is treated with (B) a fatty acid sorbitan ester e.g. by a method comprising adding the component B to the component A and subsequently stirring the mixture at 40-210 deg.C. The component B is preferably added in an amount of 0.1-5.0 pts.wt. per 10000cm<2> /g of the specific surface area and per 100 pts.wt. of the component A.