Method for reducing the migration of photoinitiators and their degradation products in UV curable coatings

摘要

The invention relates to a method for reducing the concentration of migratable substances having molecular weights of less than 1000 Da from UV-cured prints and coatings, in which migratable photoinitiator degradation products and unreacted photoinitiators produced in the UV curing process are irradiated in a secondary reaction by irradiation with (UVC-enhanced -) Hg medium-pressure lamps, which have a greatly increased emission intensity at wavelengths <230 nm, degraded and the reaction products are chemically incorporated into the resulting polymeric network and thus immobilized against migration.