1987 Volume 44 Issue 10 Pages 753-760
UV-and EB-curing properties of various polyol polyacrylates were investigated by the measurements of surface-hardening and conversion of acryloyloxy groups and by ESR spectra. Surface-curability was different for each polyol polyacrylates when the UV-curing process was carried out in air. This behavior was caused by the inhibition effect of oxygen at the surface of polyol polyacrylate layer, which was assumed to be related with the structure of polyols. Especially polyol polyacrylates with the skeleton of pentaerythritol were superior in surface-curability to those with the skeleton of trimethylolpropane. On the other hand, there was almost no difference in surface-curability for EB-curing among the polyol polyacrylates. About 0.4 Mrad dosage caused the surface of the polyol polyacrylate layer to harden. By ESR apectoscopic analysis, it was confirmed that the accumulation of stable radicals and the formation of polymer networks progressed simultaneously.
