Browse Prior Art Database

PLANOGRAPHIC PRINTING MEMBER

IP.com Disclosure Number: IPCOM000022819D
Original Publication Date: 1976-Feb-29
Included in the Prior Art Database: 2004-Mar-26
Document File: 2 page(s) / 285K

Publishing Venue

Xerox Disclosure Journal

Abstract

Although lithographic printing has been widely recognized and commercialized to a great extent, it has been necessary to employ hydrophilic materials in the non-imaged areas of the lithographic plate which comprise highly hydrated surface layers whose mechanical and electrical properties are therefore inherently humidity-sensitive, In particular these materials which become conductive under humid ambient conditions are not well suited for imaging by electrostatic electrophotography because a material which is highly re- sistive is required for imaging. It is to this problem to which this invention is directed.

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XEROX DISCLOSURE JOURNAL

PLANOGRAPHIC PRINTING NEMBER Proposed Classification
John w. Weigi U.S. Cl, 101/1

mt. CL B41f

Although lithographic printing has been widely recognized
and commercialized to a great extent, it has been necessary
to employ hydrophilic materials in the non-imaged areas
of the lithographic plate which comprise highly hydrated
surface layers whose mechanical and electrical properties
are therefore inherently humidity-sensitive, In particular
these materials which become conductive under humid ambient
conditions are not well suited for imaging by electrostatic
electrophotography because a material which is highly re-
sistive is required for imaging. It is to this problem
to which this invention is directed.

It has now been discovered that a lithographic printing
plate (master) can be employed which is not hydrophilic.
Further, it has been discovered that release fluids other
than water can be employed. This permits the use of a con-
siderably greater variety of inks, different materials for
the printing plate, as well as release fluids than hereto-
fore. Finally, the plate is not significantly adversely
affected by ambient humidity conditions.

More particularly it has been discovered that the aforesaid
advantages can be obtained by the preparation and use of
a planographic printing member comprising non-imaged areas
of a microporous interconnected pore material capable of
admitting and delivering a release fluid to cover the

non-imaged areas, and comprising image a...