Called photopolymerization, the photochemical UV curing process relies on liquid monomers and oligomers that, when mixed with a small percentage of materials called photoinitiators and exposed to UV light, harden instantly to become tough clear coatings, decorative inks, and adhesives.
Ciba’s research priority today is developing photoinitiators for colored UV coatings, which are receiving increasing attention for indoor and outdoor applications. To this point, experience with UV-cured colored systems for outdoor applications has been fairly limited. Colored prints with a film thickness of a few micrometers have cured well, but the through-curing of thicker coatings has, historically, been difficult.