Applications of Novel Photo-Curing Oligomer Resins: Generation Two
Recently published papers1,2 have discussed novel self-initiating resins that UV-cure with no or very little added photoinitiator. These resins contain a unique chromophore that becomes part of the resin/oligomer structure through the Michael addition reaction between b-diketones, b-ketoesters and/or b-ketoanilides with common acrylates. During the reaction, new covalent bonds are formed between the activated methylene carbon of the Michael donor and the terminal carbons of the acrylate double bonds. The new product molecule features a ketone moiety attached to a fully substituted carbon atom. This bond is inherently photolabile and provides the unique photosensitivity of this class of resins. An example of the Michael addition oligomer resin is depicted in Figure 1.
Claims about the versatility of this new technology are based on the experience of creating many, many unique materials. While the methodology to synthesize these novel resins has been refined to create robust ‘products' from almost any raw materials, distinct trends in structure-property relationships have been gleaned from a substantial database of new materials. Novel, self-initiating acrylic oligomer resins have been created from every class of starting material - epoxies, urethanes, polyesters, melamines, silicones, fluorocarbon acrylates, etc.