Abstract: A desensitizing ink for printing by wet or dry offset, flexographic or typographic printing is disclosed and claimed. This ink contains at least one desensitizing agent, at least one ink binder which is polymerizable or crosslinkable by UV light or electron beam radiations and, if necessary, an initiator system. Thus, the drying time of the printings is greatly reduced. The ink is free from vaporizable ink solvents.

Abstract: New nucleophilic urethanes are described and claimed, which are the reaction product of a monoisocyanate, a diisocyanate or a polyisocyanate with a basic alkoxylated amine whose hydroxyl functionality has been adjusted to a value of 0.5 to 2 by etherification, esterification and/or reaction with a monoisocyanate. These compounds are particularly used, individually or as a mixture, as neutralizing nucleophilic compositions in desensitizing inks for the printing by dry or humid offset, typographic, or flexographic methods, destined to locally neutralize the electrophilic layer of a chemical pressure sensitive copying set. The disclosed compounds have a better neutralizing power which allows to reduce the weight per surface unit of the desensitizing printing by at least a third.