Electrostatic method for multicolor imaging from a single toner bath comprising double-encapsulated toner particles

Claim 1

A color imaging method which comprises the steps of: (a) forming a latent image on a photoconductive or dielectric substrate, (b) electrostatically depositing a blended toner composition onto a charged or uncharged surface of said substrate to form a toned image which is a positive or reverse image as compared to said latent image, said blended toner composition comprising at least two different toners, each of said toners comprising a color precursor contained in photo-sensitive double-encapsulated toner particles, (c) selectively photohardening or photosoftening at least a portion of said toner particles by imagewise exposure to appropriate wavelengths of radiation to provide harder toner particles and softer, rupturable toner particles, (d) transferring said harder toner particles and said rupturable toner particles to a copy surface, (e) rupturing at least a portion of said toner particles on said copy surface to release color precursor(s) from said rupturable toner particles, and (f) contacting said released color precursor(s) on said copy surface with a developer to form a color image on said copy surface, said double-encapsulated toner particles being fabricated by carrying out the steps of: (1) forming a first, inner microcapsule by encapsulating a solution of color precursor in a spreading oil; (2) encapsulating said first, inner microcapsule in a second, outer microcapsule and enclosing at least a radiation-sensitive composition in an annular region between an outside wall of said inner microcapsule and an inside wall of said outer microcapsule.