Organic pigments, surface properties

Pigments Aftertreatments. The surfaces of pigment particles can have different properties and composition than the particle centers. This disparity can be caused by the absorption of ions during wet milling, eg, the —OH groups, on the surface. In some cases, surfaces are modified intentionaHy to improve the pigments appHcation properties, interaction with the organic matrix, and weather resistance. 

It seems reasonable to conclude that experimentally determined specific surface areas can only qualitatively relate to the physical characteristics of organic pigments. Instead, their value emerges in combination with other physical or physico-chemical parameters or in the context of application properties such as oil absorption [16] or wettability (Sec. 1.6.5). 

P.O.5 is one of the most significant organic pigments. Two product lines with different particle sizes are available which differ considerably in their coloristic properties. The varieties with coarser particle sizes and specific surface areas between ca. 10 and 12 m2/g are much more reddish and duller than the types with somewhat finer particle sizes and specific surface areas between 15 and 25 m2/g. 

Organic pigments are used for colored paints. Carbon blacks are classed as organic and come in a variety of properties which depend on the method of production. Metallic powders and flakes are often used especially for hot surfaces. Aluminum, copper, and bronze powders also serve as decorative coatings. 

Determination of the influence of surface coating and particle size on flow properties of organic pigment powders... 

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