Low gloss UV-curable coatings
UV-curable coatings are attractive for a wide range of applications due to several advantages, including rapid polymerization rates, increased production rate, and low environmental impact (from limited use of volatile organic compounds).
In the present work, UV-curable formulations were prepared from various acrylate oligomers and monomers and modified silica as a matting agent. To improve compatibility between the acrylate-based coating and silica, the surface of the silica particles was modified in two steps. First, to introduce amino-reactive groups to the surface, (3-aminopropyl) triethoxysilane (APTES) was grafted onto the silica. Subsequently, the second step consisted of grafting an acrylate monomer, dipropylene glycol diacrylate (DPGDA), via the aza-Michael reaction.
Coatings with low gloss levels
The functionalisation with acrylate chains promotes compatibility with the acrylate-based coating formulation and results in a very low gloss surface. This silica modification allows the formation of coatings with low gloss levels at loadings as low as 10% wt modified silica.
The study has been published in Progress in Organic Coatings, Volume 158, September 2021.