PURPOSE: To prevent background staining at the time of wet offset printing and to enhance transfer properties by adding a specific novolac type epoxy resin.
CONSTITUTION: In desensitized ink containing a desensitizing agent, pigment and a binder, as the binder, a novolac type epoxy resin represented by formula (wherein R is a 1-18C alkyl group and n is 2-50) is added. This resin has the wide solubility range with a solvent and has a merit showing good compatibility even when it is combined with a known desensitizing agent. As the resin, a commercial one can be used and, as n of the general formula, 2-30 is pref. from the aspect of the preparation of ink. As the pigment, white pigment such as titanium dioxide is used. This desensitized ink can be prepared only from the above mentioned composition but an org. solvent such as paraffin oil may be used as a diluent and a strike-through preventing agent such as dextrin, an ultraviolet absorber or an oxidation inhibitor can be added.
KIKUCHI SHIGEO