SURFACE-MODIFIED AND PYROGENICALLY PRODUCED TITANIUM DIOXIDE, ITS PRODUCTION AND USE THEREOF

摘要

PROBLEM TO BE SOLVED: To improve the dispersibility in a lipophilic medium and a hydrophilic medium by treating titanium dioxide with at least one ammonium functional silane. SOLUTION: A surface-modified titanium dioxide is produced as follows: A solution of a silane or a silane mixture is sprayed on a pyrogenically prepared titanium dioxide, as necessary, in the presence of water or a dilute acid in a mixing unit for carrying out vigorous mixing. The resultant mixture is further stirred for about 10-30 min and then heated at 100-400 deg.C for 0.5-6 h. The resultant titanium dioxide has the following physicochemical properties: 15-100 m2/g BET specific surface area, 150-700 g/L bulk density, 2.5-8.5 value of pH, 0.1-2.0 mass % loss on drying, 0.3-13.0 mass % ignition loss, 0.3-12.0 mass % carbon content and 0-50 mass % wettability with methanol.