UV REFLECTING PIGMENTS, AND METHOD OF MAKING AND USING THE SAME

摘要

A pigment is disclosed wherein the pigment includes a platy substrate or uniform platy substrate coated with an odd number of layers of alternating layers of high or low refractive index material, wherein each layer has a refractive index that differs from adjacent layers by at least 0.2; and the pigment has from about 40 to about 100% reflectance of light having a wavelength of 280 nm to 400 nm. Processes for making and using the pigments are also disclosed. These pigments can find application in paints, plastics, cosmetics, glass, printing inks, and glazes.

主权项

1. A pigment, comprising:
a platy substrate, wherein the platy substrate is transparent, has a low refractive index, and is coated with an odd number of layers of from 3 to 23 alternating layers of high or low refractive index material, wherein each layer has a refractive index that differs from adjacent layers by at least 0.2; wherein each layer of high refractive index material has a thickness of 10-40 nm; wherein each layer successively encapsulates the platy substrate and all previous layers such that each layer is applied equally to both sides of the platy substrate; each layer of low refractive index material has a thickness of 20-80 nm; and the pigment has from about 40 to about 100% reflectance of light having a wavelength of 280 nm to 400 nm, and from about 0 to 20% reflectance of light from 450 to 900 nm.