Composite pigmentary material

摘要

A structured composite pigmentary material comprises composite particles consisting of an association of at least one titanium dioxide particle and at least one non-film-forming organic polymer particle wherein the particles are held in association as a result of a positive surface charge on the titanium dioxide particles and a negative surface charge on the polymeric particles, the composition of the composite being such that the ratio by volume of polymeric particles to titanium dioxide particles is in the range 0.3:1 to 0.6:1. An aqueous paint composition and a method of preparing the structured composite pigmentary material are described.