DESENSITIZING INK FOR PRESSURE-SENSITIVE COPYING PAPER

PURPOSE:To obtain a photo-setting desensitizing ink for pressure-sensitive copying paper reduced in thickening properties with time, shortened in setting time by light irradiation, and improved in offset printability by incorporating a photo- setting compound having ethylenic nnsatd. double bonds and a reactive product obtained by adding glycidyl ester or glycidyl ether to piperazines. CONSTITUTION:A desensitizer contained in a desensitizing ink is a reactive product obtained by adding glycidyl ester or glycidyl ether to piperazines. As a photo-setting compound having at least one ethylenic unsatd. double bond, a prepolymer, such as polyester acrylate, a monofunctional acrylate, such as lauryl acrylate, a bifunctional monomer, such as diethylene glycol diacrylate, a multifunctional monomer, such as a trimethylol propane triacrylate, and the like are used in combination.