Browse Prior Art Database

IMPROVEMENTS IN ELECTROMARKING MATERIAL

IP.com Disclosure Number: IPCOM000022957D
Original Publication Date: 1976-May-31
Included in the Prior Art Database: 2004-Mar-27
Document File: 2 page(s) / 191K

Publishing Venue

Xerox Disclosure Journal

Abstract

The present method of writing in the ioncolor proceâs consists of passing a small current through a porous belt, e.g. cellulose soaked with a conductive solution containing a pH indicator such as phenolphthalein. Passage of the current, with subsequent slight electro~~ lysis of the solution, results in a change in color in the pH indicator due to the formation of OH~and H+ ions, thus forming a visible mark, Problems have been encountered because of leaching of the indicator from the belt due to continual wetting and evaporation. This is the case since most indicators do not bond firmly to cellulose,

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XEROX DISCLOSURE JOURNAL

IMPROVEMENTS IN ELECTROMARKING Proposed Classification
MATERIAL U.S. Cl. 96/38,4
ID. K, Burrell mt. Cl. G03c 5/00

The present method of writing in the ioncolor proceâs
consists of passing a small current through a porous
belt, e.g. cellulose soaked with a conductive solution
containing a pH indicator such as phenolphthalein.
Passage of the current, with subsequent slight electro~~
lysis of the solution, results in a change in color in
the pH indicator due to the formation of OH~and H+ ions,
thus forming a visible mark, Problems have been encountered
because of leaching of the indicator from the belt due to
continual wetting and evaporation. This is the case since
most indicators do not bond firmly to cellulose,

The present disclosure involves a compound prepared
from the sulfuric acid ester of~B-(aminophenylsulfonyl)~
ethanol which, when diazotized and coupled with~-naphthol,
forms a water soluble dye which can be permanently bonded
to cellulose, This dye is pH sensitive, and, when a
filter is treated with the dye, the resultant light purple
material turns colorless with the application of voltage
via a positive platinum electrode, Furthermore, the
dye cannot be leached out of the filter by washing with
water,

Volume 1 Number 5 May 1976 19

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20 XEROX DISCLOSURE JOURLThIJ volume 1 Number 5 May 1976

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