Rosin modified phenolic resin, gel varnish using the same, printing ink, printing method, and method for producing rosin modified phenolic resin

摘要

The present invention provides a rosin modified phenolic resin having a weight average molecular weight of 3,000 to 400,000, which is obtained by reacting a monoester with a polyhydric alcohol and a phenol formaldehyde initial condensate, said monoester being prepared by partially esterifying a rosin and an animal and vegetable oil fatty acid with a monoalcohol, and a method for producing the same. Also the present invention provides a gel varnish comprising the resin, an animal and vegetable oil component, and a gelling agent, and a printing ink comprising the gel varnish. Printing is conducted using the printing ink.