Curing at the Speed of Light

摘要

Acrylate and epoxy-polyol compositions that cure with UV light can be cured by exposure to high-energy electrons commonly referred to as EB curing. The electrons used in the curing process range from 80 to as high as 300 Kv. The higher the voltage, the deeper the electrons penetrate into the coated substrate. In the case of acrylates, no photoinitiator is required for EB curing. However, cationically cured compositions require a small amount of acid-producing photoinitiator. A comparison of UV versus EB curing is shown in Table VI. Table VII provides a comparison of typical UV light sources used in industry. Table VIII provides commercial EB sources for coating applications. In general, UV-curable coatings require a dose or radiant energy density of between 0.5 to 3.0 Joules/cm~2 to achieve full cure at reasonable line speeds. Additional cure may result in embrittlement and/or discoloration of the cured film.