Dry developer for electrostatic copying

Abstract

Abstract A DEVELOPER MIX FOR ELECTROSTATIC IMAGES CONSISTING ESSENTIALLY OF A TONER AND CARRIER OF IRON PARTICLES, SAID TONER CONSISTING ESSENTIALLY OF A POWDER REACTION PRODUCT OF (1) ETHYL CELLULOSE, POLYSTYRENE OR MIXTURES THEREOF (2) CARBON BLACK OR AZO OIL BLACK AND (3) SULFUR. ALSO PROVIDED IS AN ELECTROSTATIC PRINTING PROCESS FOR DEVELOPING A LATENT ELECTROSTATIC IMAGE TO YIELD AN ELECTROSTATICALLY-ADHERING IMAGE OF ELECTROSTATICALLY-ATTRACTABLE POWDER COMPRISING MAGNETICALLY TRANSPORTING ACROSS THE LATENT ELECTROSTATIC IMAGE A DRY ELECTROSCOPIC DEVELOPER MIXTURE COMPRISING A TONER CONSISTING OF LOOSE MOVABLE PARTICLES OF ELECTROSTATICALLY-ATTRACTABLE POWDER AND A CARRIER COMPRISING SEPARATE MAGNETICALLY ATTRACTABLE GRANULES, THE MAGNETICALLY-ATTRACTABLE GRANULES AND POWDER HAVING A TRIBOELECTRIC RELATIONSHIP OF OPPOSITE POLARITY, THE POWDER PARTICLES THEREBY BEING ELECTROSTATICALLY CHARGED THROUGH TRIBOELECTRIC ACTION BY CONTACT WITH THE MAGNETICALLY-ATTRACTABLE GRANULES TO ADHERE ELECTROSTATICALLY TO THE SURFACE OF THE MAGNETICALLY-ATTRACTABLE GRANULES AND BEING ATTRACTABLE BY CHARGED AREAS OF THE LATENT ELECTROSTATIC IMAGE WHEN MOVED THEREACROSS, AND THE MAGNETICALLY ATTRACTABLE GRANULES BEING CORRESPONDINGLY ELECTROSTATICALLY CHARGED TO OPPOSITE POLARITY AND THUS ADAPTED TO ATTRACT THE CHARGED PARTICLES AND REMOVE THEM FROM UNCHARGED AREAS OF THE LATENT ELECTROSTATIC IMAGE WHEN MOVED THEREACROSS, THE ELECTROSTATICALLY-ATTRACTABLE POWDER COMPRISING A MIXTURE OF THERMOPLASTIC RESINS, PIGMENTS AND DYES HAVING ABOUT 1 TO 60 WEIGHT PERCENT OF SULFUR INCORPORATED THEREIN.

Inventors

• 👤 Peter Steiner

Bibliographic Details