| 摘要 |
<p>PURPOSE:To provide printing ink which has excellent dryness, offset printability and workability, hardly causes thickening and environmental pollution under low-temperature conditions and gives prints of good quality, by using varnish obtd. by dissolving a resin obtd. by reacting rosin (derivative) with a phenolic resin in a specified solvent. CONSTITUTION:Rosin (derivative) such as gum rosin, polymerized rosin, etc. is reacted with a phenolic resin such as a novolak or resol type phenolic resin in the presence of a catalyst such as p-toluene-sulfonic acid, sulfuric acid, etc. and optionally, a reducing agent such as hypophosphorus acid at 150 deg.C or above to obtain a resin (A) having an acid value of 40 or below and a m.p. of 120 deg.C or above. 30-60wt% component A and optionally, 1-30wt% drying oil (C) (e.g., linseed oil) are dissolved in a solvent (B) having an aniline point of 55-85 deg.C and a b.p. of 200 deg.C or above, composed of an arom. hydrocarbon mainly composed of 13-14C naphthene having a pour point of -10 deg.C or below and contg. not more than 10wt% 13-14C n- or isoparaffin, e.g., at 180 deg.C.</p> |
