CH676118

New urethanes of high molecular weight, obtained by reaction of a compound based on alkoxylated amine whose hydroxyl functionality had been adjusted to 0.5 - 2 by etherification, esterification and/or urethanisation, with a mono-, di- or polyisocyanate. These compounds find a particular use as a neutralising nucleophilic substance in desensitising inks for dry or wet offset printing, in letterpress printing or in flexography, intended to neutralise locally the electrophilic layer of a chemical autocopying unit. The compounds described have an increased neutralising power, and this makes it possible to decrease the desensitising imprint in weight per unit area by at least a third.