Rosin-modified resin and its production method, varnish for active energy ray curable lithographic printing ink, active energy ray curable lithographic printing ink, and printed matter

摘要

A structural unit (ab) derived from a compound obtained by adding an α, β-unsaturated carboxylic acid or an acid anhydride (B) thereof to a conjugated rosin acid (A), and an organic compound excluding the conjugated rosin acid (A). A structural unit (c) derived from a basic acid (C), a structural unit (d) derived from an aliphatic polybasic acid anhydride (D), and a structural unit (e) derived from a polyol (E) A rosin-modified resin having a weight ratio of the structural unit (ab) to the structural unit (c) in the range of 100: 80 to 100: 350.