Patent ID: 6531255
Filing Date: 2003-03-11
Classification: G03G,Y10T

Abstract:
A particulate composition consisting essentially of resin particles formed of a polyester resin and optionally containing a charge control agent, said resin particles being suitable for making color toner and characterized in that said particles are prepared with a vaporizable plasticizer which is absorbable in the polyester resin and has a boiling point of less than 200Â° C., and wherein the particles containing plasticizer are dispersed in an organic medium in which they are insoluble and the plasticizer is removed from the particles while they are dispersed in the organic medium by maintaining the dispersion at an elevated temperature close to or above the boiling temperature of the vaporizable plasticizer such that the particles are provided with a micro-serrated surface wherein the particles exhibit a surface roughness index of greater than about 1.2, the surface roughness index being determined by the formula:surface roughness index=(&frac16;)&rgr;dvAexp where &rgr; is the density of the polyester resin, dv is the volume average diameter of the resin particles and Aexp is the surface area of 1 gram of the particulate resin composition as determined by nitrogen absorption using the BET isotherm method.