Inorganic pigment particles

Special substrate pigments include the aftertreated pigments and the core pigments. To produce aftertreated pigments the inorganic pigment particles are covered... 

But higher loadings can reduce mechanical properties, and hard, abrasive inorganic pigment particles such as titanium dioxide can damage the reinforcing glass fibers [9-1, 9-37],... 

Opacifiers are fine inorganic powders, usually white, that are used to reduce the transparency of ceramic gla2es and porcelain enamels. The coating becomes opaque because the particles of the opacifter scatter and reflect the incident light. When inorganic pigments are combined with white opacifiers, pastel colors are obtained. 

Inorganics are denser and usually of a larger particle size. Common inorganic pigments include iron oxides in buff colors, titanium dioxide in white, lead and zinc... 

Chemical Composition. With few exceptions, inorganic pigments are oxides, sulfides, oxide hydroxides, silicates, sulfates, or carbonates (see Tables 3 and 4), and normally consist of single-component particles (e.g., red iron oxide, a-Fe203) with well defined crystal structures. However, mixed and substrate pigments consist of nonuniform or multicomponent particles. 

X-ray investigation of inorganic pigments yields information on the structure, fine structure, state of stress, and lattice defects of the smallest coherent regions that are capable of existence (i.e., crystallites) and on their size. This information cannot be obtained in any other way. Crystallite size need not be identical with particle size as measured by the electron microscope, and can, for example, be closely related to the magnetic properties of the pigment. 

Particle Size. The important physical data for inorganic pigments comprise not only optical constants, but also geometric data mean particle size, particle size distribution, and particle shape [1.8]. The standards used for the terms that are used in this section are listed in Table 1 ( Particle size analysis ). 

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