| 摘要 |
<p>The present invention provides a binder for printing ink based on rosin-modified phenolic resin, whose pigment dispersity is excellent, and which can enhance the flowability of the printing ink and obtain a print having gloss excellence. The afore-mentioned binder for printing ink is made of the rosin-modified phenolic resin with a polydispersity (Mw/Mn) of 7 to 10 (Mw represents the weight-average molecular weight and Mn represents the number-average molecular weight). The rosin-modified phenolic resin is obtained by carrying out the reaction of a rosin ester (B) and a condensate (C) of phenol and formaldehyde, and the rosin ester (B) is obtained by esterifying, in the presence of ingredient (A) at a use amount of 0.05 to 5.0 weight% relative to the (b-1) ingredient by, rosin (b-1) and polyol (b-2), wherein the ingredient (A) represents an organic phosphate compound represented by the general formula (1): (R-O-)3-P (in the formula, R represents an alkyl group with the number of carbon being 1 to 12 or a phenyl group with the alkyl group containing 1 to 12 carbons).</p> |
