Nemoto & Co. Ltd., Japan is a leading world manufacturer of inorganic phosphorescent pigments and UV fluorescent pigments with fine particle size and high efficiency. They are considered to be special effect pigments.
Phosphorescent pigments are charged by UV light. They store and re-emit energy in the form of visible light over a period after the removal of the light source. They are not radioactive. They all exhibit initial fluorescent emission followed by an afterglow or phosphorescent emission (or decay). The combination of the fluorescent and phosphorescent emissions gives a photoluminescent result. They may be split into two categories:
GSS phosphorescent pigments
LumiNova® phosphorescent pigments
UV fluorescent pigments are also mainly charged by UV light but only re-emit energy in the form of visible light in a range of emission colours as a fluorescent emission in milliseconds.
Security pigments include inorganic fine particle size pigments with special characteristics under specific light sources.
GSS Phosphorescent Pigments
The GSS series of phosphorescent pigments are based on Zinc Sulphide crystals doped with copper which exhibit high initial brightness and typically phosphoresce for 2-4 hours. These low-cost glow in the dark pigments have a light yellow green body colour with a yellowish green emission colour. Fine particle sized and orange emission colour versions are also available. GSS may be used in water-based or solvent-based paint and in screen ink formulations as well as in a range of polymers. End applications include safety items, screen inks and paint systems.
LumiNova® Phosphorescent Pigments
The LumiNova® series of phosphorescent pigments are based on Strontium Aluminate doped with rare earth elements with an afterglow in excess of 12 hours. These are high performance pigments with excellent chemical, temperature and UV stability. The main body and emission colour is yellow green but there are also blue green and violet emission colours. Special very fine particle sized versions are available for fine printing applications. LumiNova® may be used in solvent based and water-based paint and ink formulations as well as in a range of polymers. End applications include non-electrical photoluminescent safety evacuation systems and promotional inks.
UV Fluorescent Pigments
These are inorganic neutral body colour pigments with fine particle size and a range of colour emissions under UV light which disappear almost immediately after removal of the light source. Most are excited by long wave UV (365nm) and short wave UV (254nm) but some are only excited by short wave UV sources. Fine particle size combined with good chemical resistance and UV stability make these pigments highly suitable for security printing, anti-counterfeit, brand protection and product verification applications.
This range includes luminescent, UV fluorescent, infrared and anti-stokes pigments. We also offer a confidential service to our customers to develop security pigments with bespoke characteristics to ensure they maintain the integrity of their security product. End applications include currency and high security documents. We follow a strict policy of supply only to accredited companies involved in the security market.
Support and Services
To support new developments Nemoto offer a free technical service to our customers for luminance measurement of products using their phosphorescent pigments according to DIN 67510 or other international standards. As a European manufacturer Nemoto comply with all European requirements for Health & Safety, Materials Handling and Transport regulations including REACh registration where applicable.