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Correction Technique for Azo Dye Inks

IP.com Disclosure Number: IPCOM000051220D
Original Publication Date: 1982-Aug-01
Included in the Prior Art Database: 2005-Feb-10
Document File: 1 page(s) / 11K

Publishing Venue

IBM

Related People

Aviram, A: AUTHOR [+3]

Abstract

Azo dye inks can be erased by reductive bleaching using a reducing agent and heat.

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This is the abbreviated version, containing approximately 100% of the total text.

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Correction Technique for Azo Dye Inks

Azo dye inks can be erased by reductive bleaching using a reducing agent and heat.

Azo dyes such as Direct Black 19 (constitution number CI 35255) are used in printing inks (e.g., ink jet). These inks can be erased from the paper by reducing agents such as stannous chloride in hydrochloric acid solution. Stannous chloride reduces azo groups. When these azo groups are part of the chromophore, bleaching of the dye occurs. While this reaction can take place at room temperature, increased temperature shortens the reaction time on paper, as shown below: Temperature Time/sec

40 degrees C 20

50 10

60 6

70 4.

This erasing solution can be incorporated into a printer in the form of a felt tip pen and a heater at the back of the paper, or by a heated felt tip pen.

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