Polyurethane acrylate is another important light-curing oligomer, which is synthesized by two-step reaction of polyisocyanate, long-chain diol and hydroxy acrylate. Since polyisocyanates and long-chain diols have multiple structures to choose from, they can synthesize oligomers with set properties through molecular design. Therefore, they are currently the most oligomers of product grades and are widely used in light-curing coatings, inks, and adhesives.