| 摘要 |
<p>PURPOSE:To provide a low-cost dry lithographic printing ink excellent in shelf stability, scumming resistance, the gloss of printed matter, etc., by using a specified rosin-modified phenolic resin as its varnish component to form a W/O emulsion. CONSTITUTION:In manufacturing a rosin-modified phenolic resin by reacting a rosin with a phenolic resin, a resol phenolic resin comprising a part of the phenolic resin is reacted with the double bonds of the rosin, and the remaining resol phenolic resin and/or a novolak phenolic resin is reacted with the carboxyl groups of the rosin for esterification, thus producing a rosin-modified phenolic resin having an acid value of 60 or lower. The rosin-modified phenolic resin is used as vanish component, which is mixed with necessary pigment, solvent, emulsification accelerator, water, etc. A W/O emulsion is formed from this mixture by using, e.g. a high-speed mixer, thus producing a dry lithographic printing ink.</p> |
