UV supportive raw materials for food packaging applications

In recent years, there has been enormous progress on new commercially available raw materials for cationic UV/EB curing. New photoinitiators like thioxanthonium salts (Omnicat 550, ICM, NL), an odour and benzene-free photoinitiator, are particularly suited to food packaging applications. New cycloaliphatic epoxides demonstrating superior toughness are also available. 

Monomer diluents are primarily used to lower the viscosity of uncured materials and facilitate application. They are usually low molecular weight, monofunctional materials that chemically incorporate into the cured adhesive rather than volatilise into the atmosphere, as is common with solvent diluents. 

Monomer diluents provide good solvency, effectively reducing the viscosity of the oligomer without significantly retarding the cure rate. Generally, they produce soft, thermoplastic films because of their linear and unaoss-linked nature. Representative monomeric diluents include 2- 2-ethyoxyethoxy) ethyl acrylate, tetrahydrofurfuryl methacrylate and 2-phenoxyethyl acrylate. 

---