UV-Light Sensitives (LS) Urethane Acrylate Oligomers

A new type of urethane acrylate oligomers, which have grafted photoinitiators (PIs), is described. Commercially available PIs with hydroxylalkyl substituents were grafted in a level 0.5-5.0 wt.% to oligomers during oligomers syntheses. These oligomers got a name of UV-light sensitive (LS®) oligomers. Coating formulations containing LS® oligomers do not need an addition of an extra P1, because the oligomer has a chemically tethered P1 in its structure already. Rates and efficiency of cure of oligomers are similar to those of corresponding oligomers with a dissolved same P1 in the same level. Benefits of grafting P1 to oligomers vs. dissolution of P1 are discussed.