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Photoconductor Overcoat

IP.com Disclosure Number: IPCOM000101122D
Original Publication Date: 1990-Jun-01
Included in the Prior Art Database: 2005-Mar-16
Document File: 1 page(s) / 49K

Publishing Venue

IBM

Related People

Merten, RA: AUTHOR [+4]

Abstract

Disclosed is a unique coating application for elimination of low-density image or total loss-of-print condition on copies, which result from photoreceptor degradation caused by an acidic environment. This technique uses a dip coating process to coat photoconductor drums without attacking the transport layer or extracting any of its components, while providing an acid and moisture resistant barrier film.

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This is the abbreviated version, containing approximately 65% of the total text.

Photoconductor Overcoat

       Disclosed is a unique coating application for elimination
of low-density image or total loss-of-print condition on copies,
which result from photoreceptor degradation caused by an acidic
environment.  This technique uses a dip coating process to coat
photoconductor drums without attacking the transport layer or
extracting any of its components, while providing an acid and
moisture resistant barrier film.

      A low-density or loss-of-print condition develops when the
photoconductor drum in a printer or copier cartridge is exposed to a
strong acid environment resulting from decomposition of air adjacent
to the corona [*].  Oxides of nitrogen develop over extended periods
of running and are absorbed by the corona housing and shield.  During
long shut-off periods, these highly acidic materials gradually desorb
onto the photoconductor drum, react with and decompose the charge
transport agent, reducing its capability.  The result is especially
severe after a photoreceptor has been cycled (fatigued), and when
printing single-pel patterns.

      Overcoating of web-type photoreceptors has been used in the
past as a method of protecting the photoconductor surface from
various harmful conditions.  However, overcoating drums is
considerably more difficult to accomplish than webs because of the
immersion dip-coating process which is necessary in order to obtain
uniform, thin films.  The overcoating polymer must be soluble in a
solven...