| abstract |
A stable colored liquid developer and method for making such are described wherein an improved optical density resulting from a colored dye being imbibed into a thermoplastic resin core occurs. In particular, the liquid developer comprises a marking particle dispersed in an aliphatic dispersion medium, the marking particle comprises a thermoplastic resin core having an amphipathic block or graft copolymeric steric stabilizer irreversibly chemically or physically anchored to the thermoplastic resin core with the dye being imbibed in the resin core and being soluble therein and insoluble in the dispersion medium. The stable colored liquid developer is preferably made by first preparing a graft or block copolymer amphipathic steric stabilizer, anchoring said stabilizer to a thermoplastic resin core, and to the aliphatic disperion of said particle adding a solution of a dye dissolved in a polar solvent, preferrably methanol, the dye being soluble in the thermoplastic resin core to enable it to be imbibed therein and substantially insoluble in the dispersion medium. |