Dispersant of Inorganic Pigments

Titanium dioxide is the principal white pigment for paints owing to its high refractive index [64]. However, the available resources of this metal oxide are scarce and it is important to disperse the titania particles as much as possible to maximize their hiding power and reflectance [65]. 

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The colloidal stability and pigment surface modification of aqueous dispersions of inorganic pigments Ti02 (rutile) and Fe203 (red) as well as organic pigment copper phthalocyanine CuPc (blue) treated in an ultrasonic field in the presence of water-soluble polymers and surfactants was studied. 

Effect of Ultrasonic Treatment on Stability of Aqueous Dispersions of Inorganic Pigments TiC>2 and FezCh. 

For over thirty years it has been known that particles of inorganic pigments dispersed in hydrocarbons develop appreciable electric potentials. The early studies of van der Minne and... 

In principle, electrostatic stabilization can be achieved by either anionic or cationic pigment dispersants. In order to be compatible with the other components of a paint formulation, in particular the latex which is almost always negatively charged, anionic dispersants are usually employed. A good dispersant for inorganic pigments for water-borne paints should... 

Polyphosphates are versatile inorganic polyelectrolytes that at relatively low concentrations disperse a variety of inorganic pigments. Table 6.1 shows some common polyphosphates used as pigment dispersants. Polyphosphates are suitable as pigment dispersants on two accounts. First, the polyphosphoric acids are relatively strong acids, i.e. the first p/faS are low, and... 

The Tg of PAA has been variously reported as 75,106, and 126°C, depending on the mode of measurement. However, the highest value is probably the most accurate. Solid polymers are hard, clear, brittle materials. In aqueous solutions, viscosity increases with increasing molecular weight. PAA imdergoes a munber of reactions in solution, ie, hydrolysis, esterification, dehydration, and complex formation with polyethers. PAA is an excellent thickener for lattices. PAA has been used in oil recovery, as a dispersant for inorganic pigments, as a flocculant, and as an adhesive. 

Other applieations are examination of porous and pigmented or filled polymers (size, shape, distribution and orientation of pores or dispersed components), and the study of multicomponent and weathered materials. Examples are the determination of the distribution of rubber particles in ABS, the distribution of inorganic pigments or fillers in the surfaee (produetion of specks, irregular gloss) or in the layer proximate to the surface (haze) [135], The method is also suitable for quantitative eharacteri-sation of reinforeed composites. Mills et al. [151]... 

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