Abstract: An aqueous gloss emulsion paint comprises a dispersion of structured composite particles, said structured particles comprising an association of particles of inorganic pigment and polymeric particles. The polymeric particles are formed from a polymer or copolymer having a minimum film forming temperature not greater than 50.degree. C. The component particles of the composite particles are held in association as a result of surface charges on the particles said surface charges on the polymeric particles being of opposite sign to the surface charge on the particles of inorganic pigment. The ratio of polymeric particles to particles of inorganic pigment in the composite particles is from 0.5:1 to 6:1 by volume.

Abstract: 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.

Abstract: A process for preparing a structured composite pigmentary material comprises forming a dispersion of uncoated particles of titanium dioxide at a pH value at which the particles have a surface charge and subjecting the dispersion to cross-flow filtration until the dispersion contains more than 50% by weight titanium dioxide. The concentrated dispersion is mixed with a dispersion of chemically distinct particles having a surface charge of opposite sign under conditions which ensure that the sign of the surface charge on either of the particulate materials is not reversed. In the resultant composite pigmentary material the titanium dioxide particles are held in association with the chemically distinct particles as a result of said surface charges.

Abstract: A process for the production of a structured composite pigmentary material in the form of a dispersion comprises mixing an aqueous dispersion of inorganic pigmentary particles and an aqueous dispersion of polyvinyl chloride (PVC) particles. The inorganic pigment particles carry a positive surface charge and the PVC particles carry a negative surface charge and the particles in the composite are held in association as a result of these charges. The inorganic pigment particles and PVC particles are mixed in the presence of a surfactant system which provides both anionic and steric stabilisation.