Browse Prior Art Database

Spherical Toner

IP.com Disclosure Number: IPCOM000053057D
Original Publication Date: 1981-Aug-01
Included in the Prior Art Database: 2005-Feb-12
Document File: 1 page(s) / 11K

Publishing Venue

IBM

Related People

Kitze, PT: AUTHOR [+2]

Abstract

Spherical toner is produced by a direct polymerization process utilizing ultraviolet light.

This text was extracted from a PDF file.
This is the abbreviated version, containing approximately 100% of the total text.

Page 1 of 1

Spherical Toner

Spherical toner is produced by a direct polymerization process utilizing ultraviolet light.

A pigment or dye, for example, carbon black, is mechanically dispersed in a liquid monomer or oligomer of resins conventionally used in xerographic toners. A photoinitiator which is sensitive to ultraviolet light is then added to this liquid suspension. Examples of such a photoinitiator are benzophenone, an -onium salt and a complex metal halide.

This liquid suspension is then sprayed into a gas stream, preferably an oxygen-free gas stream, and is thereby carried into a chamber which is illuminated with ultraviolet light. As a result, the individual droplets are polymerized to form spherical toner particles.

The polymerized toner is then recovered from the gas stream by the use of a cyclone and filter arrangement or, alternatively, an electrostatic precipitator. If electrostatic precipitation is used, the toner may be charged either before or after polymerization, as desired. If the charge is applied prior to polymerization, the application of the charge will affect the toner"s xerographic properties by virtue of a control of the molecular orientation within the liquid droplets. Moreover, the charged droplets will repel, and agglomeration into larger droplets will be avoided prior to polymerization.

1