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Introduction
Talc is a hydrated magnesium silicate mineral with a laminar structure. Its mineralogical composition is hydrated magnesium silicate. Talc's softness and laminar structure gives it an exceptionally smooth and slippery feel. Talc is considered to be a relatively good electrical and thermal insulator, has high melting point, and offers extraordinary adsorption of oil and grease. It is used in many industrial applications ([11] Streitberger and Kreis, 2008; [4], [5] Ciullo and Robinson, 2002, 2003; [10] Martens, 1974).
Talc is normally self-suspending in paint vehicles and assists in keeping other pigments suspended. When settling does occur, it is generally soft and is readily re-dispersed. Platy talc improves the toughness and general durability of paint films, and upgrades the physical properties of paint. It also provides some resistance to humidity, improves flow behavior, and enhances sanding properties. Good spreading properties help in the use of talc-filled paints as primers, emulsions and exterior undercoats. Talc produces a moisture-resistant finish when emulsion paints are applied ([14] Virta, 2001; [3] Ciullo and Anderson, 2002; [8] Kogel, 2006; [13] Talbert, 2007).
Titanium dioxide is a widely used, nontoxic, stable, synthetic pigment used for both protective and decorative paints. It comes in two different crystalline forms, rutile and anatase. The rutile crystalline is more compact and has a higher specific gravity, greater refractive index, higher stability and enhanced durability. The higher refractive index for titanium dioxide (2.7 for rutile and 2.5 for anatase) enables it to provide a higher degree of opacity in paint films than any other white pigment. Rutile titanium dioxide is photo-chemically inert and thus protects paint films from degradation by scattering absorbed light. In contrast, the anatase is photo-chemically active and paints formulated with this pigment are subjected to heavy chalking. The most widely used form in anticorrosive paints is the rutile form. Being opaque is the reason it can give paints their high gloss and rich depth of color. Its high durability is another important property that is related largely to its lack of photochemical reactivity. Durability also includes chalk resistance, tint retention, gloss retention, and discoloration ([15] Warson and Finch, 2001; [7] Gaumet et al. , 1997; [6] Del Amo et al. , 1999).
The purpose of this investigation was to investigate a new pigment...