Performances of an acrylated dendritic polyester in a UV coating formulation

Dendritic, polymers are,a new' ciass of polymer, characterised by: a'den'sely branched backbone and a large number of reaetive groups. 2 main characteristics of such a structure is the lack of entanglements and the low hydrodynamic volume resulting in a lower viscosity than Iinear 'or branched analogues: De.ndritic polymers have already shown specific properties " enhancemerits ina wide range of applications (as processing aid, toughening agent, and . promoting agent).' New application areas are still discovered, showing the high potentialof such a technology. In Rad-cure applications, trÊmds towards' highly reactive formulation allowing higher productivity and/or lower photo-initiator level (printing inks) are becoming more and more stringent. The, high molecular weight, the high crosslinking density and the high number of functionality combined with a low viscosity compared to conventional system seem to be a valuable solution to achieve these goals. The high reactivity of using dendritic polyester acrylates (curing without photoinitiator is possible in air and with a low lamp intensity) has already been reported. Here are presented the performances of ,a 16, acrylate functionality aliphatic polyester dendritic oligomer
(Mw=2600g/mol) in a UV formulation. High reactivity, deèp and homogenous curing depth; low curl, high chemical resistance, better scratch resistanceand low extractable are someef the multiple advántages of using dendritic polyester in a UV formulation. This new kind of oligomer is an opportunity to open and extend new applications for Rad-cure technology as for example food packaging printing inks (Iow photo-initiator concentration as weil as low extractable) or electronic applications (deep and homogenous curing depth).