Preparation and characterisation of pigmented UV curable coating based on cresol novalac epoxy acrylate resins.

UV curable systems have found wide applications in clear coatings. However, coatings containing pigment showed a degree of curing inhibition due to the absorption, scattering and reflection of the UV radiation caused by the presence of pigments in the coating film. This results in poor through-cure and consequently in poor adhesion. Thus, pigments used in the UV curable coating systems should not absorb radiation in the same region as the photo-initiators. One of the solutions to such a problem, reported in this paper, was to develop more reactive, alcohol soluble, non-heat reactive, low molecular weight cresol based, pigmented novolac epoxy acrylate systems, which have a lower absorption in the UV region. In addition, the effects of several photoinitiators having absorption in the longer wavelength region of the UV spectrum were investigated. [ABSTRACT FROM AUTHOR]