| 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:A rosin is thermally reacted with a phenol in the presence of an acid catalyst. The reaction product, if necessary together with an alkylphenol containing 4-12C alkyl, is reacted with formaldehyde in the presence of an acid catalyst to give a novolak. If necessary, a polyhydric alcohol in an amount of at most 10wt.% based on the novolak is used to esterify the novolak, thus giving a rosin-modified phenolic resin. This resin is used as varnish 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> |
