| 摘要 |
<p>PROBLEM TO BE SOLVED: To obtain an aqueous ink composition enabling writing with smooth pen touch and handwriting free from blotting on paper surface by compounding a water-soluble dye, xanthan gum, a water-soluble organic solvent and water as essential components. SOLUTION: This aqueous ink composition for marking pen is obtained by compounding (A) a water-soluble dye preferably in an amount of 1-10wt.% in the ink composition, (B) xanthan gum in an amount of 0.01-0.1wt.% based on the total weight of the ink, (C) an water-soluble organic solvent preferably in an amount of 5-30wt.% in the ink composition and (D) water, as essential components. Further, the ink composition has preferably a viscosity in the range of 2-25mPa.S (measuring conditions: at 20-25 deg.C; a measuring equipment, a BL-type rotary viscometer; a number of revolutions of a rotor, 6r.p.m.). Furthermore, the ink is produced by placing specified amounts of water and all other components in a container, stirring the mixture at 60-70 deg.C for about 1hr under heating to obtain a homogeneous solution, subsequently cooling down to the ambient temperature, adjusting the state of the liquid by adding water and treating the liquid with a filter.</p> |
