Principle of Color Changing
The photochromic pigment changes colors when exposed to sunlight/UV, and reverts to its original color when the sunlight/UV is dimmed or blocked. After absorbing the energy of sunlight/UV, its molecular structure is changed, which causes its absorbed wavelength to be changed allowing a color to appear. It reverts to the original molecular structure and color when the light stimulus is dimmed or blocked.
Basic Colors
From colorless to colored
Colorless(without UV)
Blue Colored(with UV)
Basic Colors Mixed with Common Pigments
Application
The photochromic pigments are suitable for plastic injection and solvent based ink/paint.
- COATING, like PMMA painting, ABS painting, PVC painting and waterbased painting. Recommend pigments concentration is 10%-30%.
- INK, like fiber, paper, foil and glass printing ink. Recommend pigments concentration is 20%-40%.
- Plastic Injection/Extrusion, like PE masterbatch, PMMA masterbatch, Recommend pigments concentration is 0.8-3%.
Remark
- The photochromic pigment does not react to sunlight/UV and need to be dissolved in a medium(solvent, resin, or polymer) to function. Polarity of the medium is directly related to the color.
- Overexposure to sunlight, acids, free radicals and humidity may cause poor fastness, which could be improved by adding UV absorbing or anti-oxiants.
- Specific formulations of UV absorbents or anti-oxidants should be used depending on the media.Improper formulations speed destroying color fastness and end up destroying the color changing properties.
- Highest heat resistance of photochromic pigment is 250℃
- The photochromic pigments do not contain heavy metals which are harmful to people. They are comply with toy and food packaging standard.