TITANIUM PIGMENT DIOXIDE DISPERSITY

Abstract

The criterion for assessing the quality of the pigment may be a detailed characteristic of its dispersion. The dispersion parameters of two grades of pigment titanium dioxide were studied: from an expensive and affordable price range. The method of laser diffraction was used. It has been established that most of the mass (volume) of particles of the studied pigments has sizes outside the effective range from the point of view of scattering power. Pigments have a close number of particles with sizes in the effective range (in the range of 0.19-0.25 microns). The most probable particle size of the cheaper pigment corresponds to the region of the optimum particle size, while that of the expensive pigment is below the optimal values. In both investigated brands of pigment there are nanoparticles with sizes less than 115 nm. Their volumetric (or mass) content is not less than 1.5%; or at least 7% of the total specific surface area of all pigment particles. Studies are needed on the dependences of the durability of pigmented coatings on the presence and content of nanosized particles.