Pigment

Name:
Pigment
Detailed information:
Any substance, usually in the form of a dry powder, that imparts color to another substance or mixture. Most pigments are insoluble in organic solvents and water; exceptions are the natural organic pigments, such as chlorophyll, which are generally organosoluble. To qualify as a pigment, a material must have positive colorant value. This definition excludes whiting, barytes, clays, and talc.See Filler.Some pigments (zinc oxide, carbon black) are also reinforcing agents, but the two terms are not synonymous; in the parlance of the paint and rubber industries these distinctions are not always observed.Pigments may be classified as follows:

I. Inorganic

1. (a) Metallic oxides (iron, titanium, zinc, cobalt, chromium)
2. (b) Metal powder suspensions (gold, aluminum)
3. (c) Earth colors (siennas, ochers, umbers)
4. (d) Lead chromates
5. (e) Carbon black

II. Organic

1. (a) Animal (rhodopsin, melanin)
2. (b) Vegetable (chlorophyll, xanthophyll, indigo, flavone, carotene)See Pigment, Plant
3. (c) Synthetic (phthalocyanine, lithos, toluidine, para red, toners, lakes, etc.)See Dye, Natural; Dye, Synthetic.