Patent ID: 7780777
Filing Date: 2010-08-24
Classification: B82Y,C01P,C03C,C04B,C09C,C09D

Abstract:
1. A process for the preparation of an aqueous dispersion, said process comprising: placing producing a pre-dispersion by introduction of energy in an amount of less than 1000 kJ/m dividing the pre-dispersion into at least two partial streams, placing said partial streams under a pressure of at least 500 bar in a high-energy mill, venting said partials streams via a nozzle, allowing said partial streams to come together in a gas-or liquid-filled reaction space, and optionally adding a preservative; wherein said aggregated titanium dioxide powder has a specific surface area of from 20 to 150 m wherein said at least one amino alcohol has from 1 to 6 carbon atoms, wherein said at least one carboxylic acid is selected from the group consisting of a dibasic carboxylic acid having from 2 to 6 carbon atoms, a hydroxycarboxylic acid having from 2 to 6 carbon atoms, and mixtures thereof, wherein, in said dispersion, the aggregated titanium dioxide powder has a mean, volume-related aggregate diameter of less than 150 nm, wherein said dispersion comprises the amino alcohol in an amount of from 2.5 to 7.0 μmol/m wherein said dispersion comprises the carboxylic acid in an amount of from 1.0 to 3.5 μmol/m