| 摘要 |
<p>PURPOSE:To obtain a water-base ink compsn. for writing utensil wherein the pigment dispersion is long stable by compounding a pigment, a specific heteropolysaccharide, water, a water-sol. org. solvent, and an aq. medium contg. a specified amt. of water. CONSTITUTION:The compsn. comprises a pigment (e.g. carbon black), an org.- acid-modified heteropolysaccharide which consists of basic units derived from glucose/galactose/pyruvic acid (salt)/succinic acid (salt)/acetic acid in a molar ratio of (5-8)/(1-2)/(0.5-2)/(0.5-2)/(0.5-1) and has an average mol.wt. of about 1,000,000-8,000,000, water, a water-sol. org. solvent (e.g. diethylene glycol), and an aq. medium contg. at least 50wt.% water.</p> |
