Properties of UV-Curable Hyperbranched Urethane-Acrylate Modified Acrylic Monomer Coatings

In this work it is suggested to modify trimethylolpropane ethoxylate triacrylate (TMPETA) with solvent born difunctional urethane acrylate oligomer (UA) of hyperbranched structure and high molecular weight. In this case the photopolymer composition initial UV-precuring was replaced by thermal action. Under heating at 70 °C temperature solvent (butyl acetate) evaporates and layer with proper deformation properties for microrelief embossing was obtained. After microrelief embossing UV-curing of photopolymer follows and photoinitiator initiated radical photopolymerization of TMPETA monomer and UA oligomer proceeds. The goal of this work - to investigate the influence of the acrylic composition on the UV-cured coating mechanical properties and on the geometrical parameters and optical properties of replicated microrelief. It was defined that coatings with UA oligomer possess higher deformation and mechanical properties due to the increase in layer flexibility. The replicated microrelief of geometrical parameters and diffraction efficiency close to those of master matrix to be used was obtained using compositions containing  30 wt. % - 40 wt. % of  UA.http://dx.doi.org/10.5755/j01.ms.17.4.772