Permanent vs. Transient Pigment Coating

Posted: January 2, 2007

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The strongest type of bond is achieved with reactive coating. There are two variations; the first is when the coating bonds by reaction with the pigment and the second bonds when the coating penetrates the pigment and reacts with itself to form an interpenetrating network. The first results in a new molecule, and the latter in an encapsulated pigment. This pigment is very tenacious and seldom migrates in a formulation.

There are a number of extraction techniques that allow for the analysis of the type of coating found on the pigment. The formulator should discuss the nature of the coating with the supplier. This will make the selection process more efficient and it is particularly important when formulating lipsticks, makeup or sunscreens.