SYNTHETIC RESIN FOR PRINTING INK, PRODUCTION THEREOF, AND PRINTING INK

摘要

PROBLEM TO BE SOLVED: To obtain a printing ink which hardly leaves behind an org. solvent in prints and is excellent in gloss and dryability by using a synthetic resin having a specified molecular structure. SOLUTION: This synthetic resin is represented by formula I and has a number average mol.wt. of 400-5,000. In the formula, M1 is a tri- or tetravalent metal; R1 is at least one kind residue selected from among a rosin-modified phenol resin residue, anα,β-monoethylenically unsatd. carboxylic acid-added rosin residue, and a rosin residue; X is a difunctional group representd by formula II or III (wherein R2 is anα,β-monoethylenically unsatd. carboxylic acid-added rosin residue; R3 is a rosin-modified phenol resin residue; and M2 is a divalent metal); m is 1-30; and n is 3-4. The resin is produced by reacting rosin with anα,β-monoethylenically unsatd. carboxylic acid, mixing the resultant carboxyl- contg. rosin with a rosin-modified phenol resin, and reacting the mixture with a divalent metal compd. and then with a tri- or tetravalent metal compd. (e.g. titanium alcoholate).