| 摘要 |
PROBLEM TO BE SOLVED: To provide a rosin polyhydric alcohol ester resin capable of suppressing printing troubles by suitably adjusting emulsification suitability of inks, and to provide a varnish for offset printing ink and an ink composition for offset printing which contain the same.SOLUTION: A rosin polyhydric alcohol ester resin is obtained by polycondensing rosins (A) and polyhydric alcohols (B), and uses a compound (B1) represented by formula 1 as the polyhydric alcohols (B), and has a percentage of the compound (B1) represented by the formula 1 in the polyhydric alcohols (B), of 10 to 100 mass%, and a reaction ratio of the rosins (A) to the polyhydric alcohols (B) is 2 mol to 6 mol in terms of hydroxyl groups of the polyhydric alcohols (B) based on 1 mol of acid groups of (A). Formula 1: H-(CHOH)-H, where n is an integer of 4 or more. |
