Photochromic pigments change color when exposed to UV light or sunlight. Once removed from the UV light or sunlight, the pigment fades back to its normal color after a minute or so. Lifespan of the pigments is about 400,000 Lux-Hours and a shelf life of 12 months (Bue Wool Index = 1) which means the usefulness of the pigment is somewhat limited.
The pigments can also used in line with PU, PE, PVC, PS and PP for plastic injection. Heat can be applied for less than 10 minutes if the temperatures do not exceed 230 degrees Celsius. Please avoid prolonged exposure of temperature if it exceeds 75 degrees Celsius.
The pigments are not soluble but you can make suspensions or dispersions with them using a clear coat, lacquer, varnish, etc. Please test the pigments for your application before making any quantity production runs.
Below are pictures of the pigments in their natural color and with a center spot exposed to UV light from a flashlight.