Platy pigments
AssigneeThe Mearl Corporation
InventorsHarold A. Miller, Philip Greenberg, Adolph Blum, Wasi Ahmed
Life of this patent
Estimating the term…
Abstract
Platy pigments with good tactile characteristics are obtained by treating such pigments with a compound of the general formula: ##STR1## where m is an even number from 8 to 18 and n is 3 or 4 under defined conditions. N.epsilon.-lauroyl lysine is preferred. The pigments are especially useful in cosmetic compositions such as eye shadow.
Claims36
A process for improving the tactile characteristics of a platy pigment comprising precipitating a compound of the general formula ##STR3## where m is an even number from 8 to 18 and n is 3 or 4, onto the surface of said platy pigment, said precipitation being accomplished by adding an acid or alkaline solution of said compound to an aqueous dispersion of said platy pigment, the amount of said solution being such as to supply said compound in an amount of about 0.5-5.0% by weight of said platy pigment, while maintaining the temperature between about 15.degree. and 80.degree. C., said acid or alkaline solution being added at a rate not exceeding 1.50 mg of said compound per gram of platy pigment per minute, adding alkali or acid as required to bring the pH of the resulting mixture to between 1 and 8, and recovering said platy pigment coated with said compound.
A process as defined in claim 16 wherein said dye or pigment is carmine or a laked dye.
A platy pigment having improved tactile, dispersion, and stability properties, said pigment comprising a substrate of platelets of mica, talc, or a metal oxide coated mica, said substrate being coated with N.epsilon.-lauroyl-L-lysine,
- said platelets having a particle size in the range of about 2-80 microns, with the average particle size in the range of about 5-40 microns,
- the N.epsilon.-lauroyl-L-lysine coating being present on the surface of said platelets in the range of about 0.5% to 5.0% by weight of the platelets, and
- at least 80% of said coating remaining adhered to said substrate after four centrifugations in distilled water, each centrifugation being carried out on a dispersion of 1.00 g. of said platy pigment in 75 ml. of distilled water.
Dependencies are inferred from the claim text.