Characteristics of Pigments

While the properties of (soluble) dyes are determined almost exclusively by their chemical constitution, application characteristics of pigments—which are by definition insoluble in the medium in which they are applied (see Sec. 1.1) — are largely controlled by their crystalline constitution, i.e., by their physical characteristics. This is discussed in the next chapter. 

DIN ISO 8780-1-1990 Dispersion characteristics of pigments and extenders - Methods of dispersion. 

As a result of the physical and chemical characteristics of pigments, pigments and dyes differ in their application when a dye is applied, it penetrates the substrate in a SOLUBLE form after which it may or may not become insoluble. When a... 

It provides both crock resistance and resistance to laundering while retaining the light-fastness characteristics of pigment colors. The film is comparatively soft, thus producing a satisfactory hand. 

The impact of the extraction conditions using various solvents on the recoveries has never been studied in detail, and the results have never been compared. The introduction of modern extraction methods, such as microwave-assisted extraction, supercritical fluid extraction, and solid-phase extraction, probably will improve the efficiency of extraction, even in the instance of unstable pigments and pigment mixtures. The majority of TLC separations were carried out on traditional silica layers. As the chemical structures and, consequently, the retention characteristics of pigments are highly different, a wide variety of eluent systems has been employed for their separation, consisting of light petroleum, ethyl formate, ethyl acetate, benzene, toluene, chloroform, methanol, n-butanol, formic or acetic acid, and so forth. 

Table 12.3 Characteristics of Pigments for Metai Protective Paints... 

Not all colored insoluble products synthesized are commercial pigments. To qualify as a pigment, a product needs to demonstrate various characteristics that are not covered in the definition alone, but are important from an application standpoint. Some important properties and characteristics of pigments are briefly discussed below. 

Kousik G., Pitchumani S. and Renganathan N. G. (2001), Investigation of the Corrosion Resistance Characteristics of Pigments in Alkyd Coatings on Steel. Prog Org Coat, 43, 286-91. 

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