Most of the bulk of lipstick is usually a solid waxy material mixed with a nonvolatile oil, so it can be spread easily but remains stiff in the tube. Common compositions use beeswax and castor oil, or carnuba wax. A recently patented composition uses a solid silicone material with polyethylene solidifier, and silicone oil.
Many different pigments are used. The dyes have to be insoluble in water, so the color will last. Soluble dyes are first 'laked', that is, converted to insoluble particles by treatment with metal oxides. Eosin is a commonly used red dye in lipsticks:
|Eosin, the red pigment in lipsticks.|
Gray=Carbon, Red=Oxygen, Brown=Bromine.
Click the image for a 3D Chime model.
It becomes an intense red when it reacts with NH2 groups in proteins on the surface of the skin. The pigment is masked in the tube by a laked green or blue dye, and the color change when the lipstick is applied to the skin is sharp.
Many other ingredients insure that the lipstick has the proper texture and melting point. For example, esters of fatty acids (myristates) are sometimes added to give the lipstick 'stickiness'.
Author: Fred Senese firstname.lastname@example.org
Copyright © 1997-2010 by Fred Senese
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Last Revised 08/17/15.URL: http://antoine.frostburg.edu/chem/senese/101/consumer/faq/print-lipstick-composition.shtml