Method for producing heat-sensitive reversible discoloration type (heat-sensitive reversible change type) printing ink and vehicle

摘要

The extender is produced by heating the mixt. of 10% reactive dyestuff, 20% phenol cpd. and 70% temp.-controlling material at 130 deg.C for 60 min to obtain a thermal reversible discolorating material (A), first-reacting the material (A) with 40% petroleum resin, 14% phenol resin and 40% aliphatic hydrocarbon solvent at 200 deg.C for 60 min, and second-reacting the reactant with 6% phenol cpd. at 220 deg.C for 30 min to obtain the varmishy extender (B). The printing ink is produced by mixing 38-40% (A) and 50-54% (B) with 8-10% aliphatic hydorcarbon solvent in the three roll mill. The ink has a good water- and light- resistance.