RESIN AND PRINTING INK

摘要

PROBLEM TO BE SOLVED: To improve compatibility with solvents for ink and drying properties by reacting a resin acid, anα,β-ethylenically unsaturated carboxylic acid or its anhydride, a polyol and a fatty acid other than theα,β-ethylenically unsaturated carboxylic acid or its anhydride. SOLUTION: This resin is obtained by reacting (A) a resin acid such as wood resin, (B) anα,β-ethylenically unsaturated carboxylic acid such as fumaric acid or its anhydride, (C) a polyol such as glycerol and (D) a 6-36C fatty acid other than component B such as caproic acid. The components are esterified in the presence of a catalyst such as p-toluenesulfonic acid in a weight ratio of component A/component B of 80/20 to 97/3 and in a mole ratio of carboxylic groups in components (A+B+C)/hydroxy groups in component C of 1/0.5 to 1/1.2 with component D being 5-40 wt.% in the resin. The resultant resin has an acid value of 30 or less, a weight average molecular weight of 10,000-200,000, a solubility in solvents for ink of 130 deg.C or less and a melting point of 100 deg.C or more.