Browse Prior Art Database

Security Paper

IP.com Disclosure Number: IPCOM000061768D
Original Publication Date: 1986-Sep-01
Included in the Prior Art Database: 2005-Mar-09
Document File: 2 page(s) / 31K

Publishing Venue

IBM

Related People

Kobayashi, M: AUTHOR [+3]

Abstract

Inadvertent or fraudulent copying of a confidential "don't copy" document can be detected by coating the document with a dye that reacts with the intense imaging light of copier. Most copying machines on the market have a halogen lamp as the source of light. Others use a fluorescent lamp or flush-type light source. To project an image from the document, those lights illuminate the document at a high level of intensity that is much higher than room light. Dyes reactive to intense light are coated or impregnated on all or port of document surface in one of the following processes: 1) A dye dispersed in a binder is activated by the light energy and initiates coloring. 2) A dye dispersed in a binder with a photochemical reaction agent is activated by the agent that transfers light energy to the dye and initiates coloring.

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Security Paper

Inadvertent or fraudulent copying of a confidential "don't copy" document can be detected by coating the document with a dye that reacts with the intense imaging light of copier. Most copying machines on the market have a halogen lamp as the source of light. Others use a fluorescent lamp or flush-type light source. To project an image from the document, those lights illuminate the document at a high level of intensity that is much higher than room light. Dyes reactive to intense light are coated or impregnated on all or port of document surface in one of the following processes: 1) A dye dispersed in a binder is activated by the light energy and initiates coloring. 2) A dye dispersed in a binder with a photochemical reaction agent is activated by the agent that transfers light energy to the dye and initiates coloring. 3) A dye dispersed in a binder with a color developer is colored by the developer that absorbs light energy and then reacts with the dye by chemical reaction. The coloring of the dye on the paper indicates that the paper has been exposed to the intense light of the copier. A precaution not to expose to sunlight must be taken, unless the dye distinguishes the copier light from sunlight. Two chemical formulae of dyes that can be employed for the abovementioned purpose are illustrated. Shown on the previous page is a dye consisting of a squarylium nucleus with thiopyrilium end-groups (SQS), and this page illustrates tetradimethyl aminoph...