Cross-linked polyester toners and process of making such toners

摘要

Cross-linked toner resin having linear portions and cross-linked portions of high density microgel particles, where the toner resin is an unsaturated polyester resin, is prepared using a liquid chemical initiator such as 1,1-bis(t-butyl peroxy)-3,3,5-trimethylcyclohexane so that the cross-linked resin achieved contains less than 0.20 percent by weight of acids. In particular, the cross-linked toner resin is free of benzoic acid. The method of making the cross-linked toner resin includes (a) spraying the liquid chemical initiator onto the unsaturated polyester resin prior to, during or subsequent to melting of the unsaturated polyester resin to form a polymer melt; and (b) subsequently cross-linking the polymer melt under high shear to form the cross-linked toner resin.