GB1344197A - Thermosetting electrostatographic toner powders - Google Patents

Abstract

1344197 Toner composition XEROX CORP 19 April 1971 [4 Feb 1970] 21057/71 Heading G2H [Also in Division C3] An electrostatographic toner powder comprises a finely divided coloured resin, a substantial part of which is a solid free-flowing uncross-linked thermosetting polymer of diallyl phthalate or diallyl isophtalate or a mixture of such polymers. The thermosetting polymerpreferably forms at least 80% by wt. of the total resin. The thermosetting resins have preferred softening ranges which are 55-95‹ C for poly (diallyl isophthalate) and 80-150‹C for poly diallyl phthalate). The resin may include 1-20 wt. per cent of a thermoplastic resin modifier such as PVC polyethylene or polyvinyl butyral. The colouring may be imparted by 1-20 parts by wt. of a pigment and/or dye per 100 parts by wt. of resin and free radical cross-linking agent for the thermosetting resin may also be present . In the examples the particles are prepared by spray drying solution of diallyl (iso) phthalate prepolymers in which finely divided pigments are dispersed. In use, the particles are mixed with a carrier whose particles are shaped to roll across the image-bearing surface e.g. steel beads. When the image has been formed (e.g. on a photo-conductive insulating layer), the resulting image of particles may be transferred to a transfer member, which is then heated to effect cross-linking of the thermosetting polymer to provide a final copy. In the examples, the photoconductive image bearing layer is a flat selenium plate, and the final copy is on a paper substrate.