| 摘要 |
<p>PROBLEM TO BE SOLVED: To obtain a composition which is dissolved in a solvent having a low content of an aromatic component and is suitable for high speed printing by making a mixture of a rosin-modified phenol resin and a solvent react with a resol type phenol-aldehyde resin. SOLUTION: A mixture comprising 20-70 wt.% of a rosin-modified phenol resin (A) having a molecular weight of 70,000-1,000,000, 0-20 wt.% of an unsaturated fatty oil (B1 ) and/or an alkyd resin using an unsaturated fatty oil or an unsaturated fatty acid (B2 ) and 20-70 wt.% of a solvent used for printing ink (C) is dissolved at 180-200 deg.C. To this solution is added 0.1-20 wt.% of a resol type phenol-aldehyde resin (D) to proceed a reaction for one hour while xylene as the above solvent is removed and the viscosity of the obtained solution is adjusted to 1,250 poise at 25 deg.C, whereby a resin composition having not more than 1 wt.% of an aromatic component contained in the solvent is obtained. A printing ink is obtained by mixing 40-80 wt.% of the resin composition, 10-25 wt.% of a pigment and, if necessary, various additives.</p> |
