Energy curing of acrylated resins is a well established coating technology gaining further market acceptance for the protection and decoration of surfaces in many applications like furniture, flooring, construction, printing inks and others. Compared to conventional thermally-cured coatings, energy cured coatings offer the additional benefits of low energy consumption, high productivity and also allow to coat heat sensitive substrates while delivering high coating performances (scratch, abrasion, stain and chemical resistances) (1, 2). In that respect, hexa-functional urethane acrylate oligomers are pretty much the state of the art for UV hardcoat applications and various grades can be found on the market. Among the many substrates which can benefit from being coated with UV hardcoats, plastic substrates show a significant growth, whether for consumer electronics devices (mobile phones, displays …), structural uses (panels, sheets) or flexible applications (films, foils) (3).
In the meantime, new challenges have appeared for coating formulators: a growing pressure from the market for considering resins free from tin, including any derivatives achieving higher coating performances (especially scratch and abrasion resistances) applying at low coatweight and/or lower curing energy applications while still achieving high coating properties.
This paper will present the latest developments of Allnex Coating Resins in terms of high performance energy curable resins, namely two new aliphatic urethane acrylate oligomers EXP8602 and EXP8415 with a double bond functionality of 9 and 10 respectively. The evaluation discussed in the paper will document the benefits of these high functionalities for protective coating applications.
2013 Conference Latest Development in Energy Curable Resins for Hardcoat Application