Browse Prior Art Database

Carrier Coating in an Electrophotographic Developer Composition

IP.com Disclosure Number: IPCOM000102737D
Original Publication Date: 1990-Jan-01
Included in the Prior Art Database: 2005-Mar-17
Document File: 1 page(s) / 53K

Publishing Venue

IBM

Related People

Beede, AE: AUTHOR [+4]

Abstract

A coating composition for carrier beads, with an appropriate toner, for use in developing a latent image in an electrophotographic reproduction process, is disclosed. The electrophotographic process requires a predefined toner/carrier charge polarity and magnitude in order to achieve the proper development of the latent image. The two component developer composition comprises relatively small toner particles, having at least a polymer and a colorant in each particle. The carrier beads may be either spherical or irregular shaped iron or steel powders. The carrier beads are coated with a water-based, crosslinkable polymer that is selected to achieve the predefined toner/carrier charge polarity in a resistive developer system. A crosslinking component is provided in the carrier coating.

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Carrier Coating in an Electrophotographic Developer Composition

      A coating composition for carrier beads, with an appropriate
toner, for use in developing a latent image in an electrophotographic
reproduction process, is disclosed.  The electrophotographic process
requires a predefined toner/carrier charge polarity and magnitude in
order to achieve the proper development of the latent image.  The two
component developer composition comprises relatively small toner
particles, having at least a polymer and a colorant in each particle.
The carrier beads may be either spherical or irregular shaped iron or
steel powders.  The carrier beads are coated with a water-based,
crosslinkable polymer that is selected to achieve the predefined
toner/carrier charge polarity in a resistive developer system.  A
crosslinking component is provided in the carrier coating.  The
water-based crosslinkable polymer and the crosslinking component is a
copolymer of methyl methacrylate and acrylic acid and a bisphenol-A
epoxy crosslinker.

      A low surface energy fluoropolymer is also provided in the
coating composition.  A conductive carbon black particle may also be
included in the coating composition to provide a conductive substrate
for use with toners that contain charge control agents in their
composition.

      The coating provides a long lasting, durable film on the
carrier surface.  The coating may be applied via fluidized bed or
some other suitable coating device.

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