Chemistry

The two UV curable silicone release systems offered by us are both solventless and produce release coatings without the use of heat, but differ in their underlying chemistries. The first is based on silicone acrylate and cures via a free radical mechanism, while the other release system uses epoxy silicones and cures in the presence of a cationic photo catalyst. Standard medium pressure mercury UV lamps (arc lamps) or microwave induced UV lamps (as used in normal UV printing and coating processes) can be used to cure both types of silicones.

The curing mechanism of silicone acrylates is very robust and unaffected by impurities in the substrates. However, the free radical curing reaction requires nitrogen inerting during UV exposure.

The cationic curing mechanism uses a photo catalyst. Generally, cationic photo catalysts are sensitive to impurities in the substrate. The curing is initiated by UV radiation and exhibits some post-cure until the reaction is complete. The reaction continues after the UV exposure (dark reaction). Cationic curing takes place without inerting.