| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a water-based pigment ink composition for inner lead type marking pen, highly storable and good in writing property, preventing the pigment from sedimentation in the lead, causing neither handwriting color unevenness even in case of pigment sedimentation in the lead after the lapse of time nor handwriting blur due to cloggings of the ink composition at a nib made of felt chips or plastic molded product or the like. <P>SOLUTION: The water-based pigment ink composition for inner lead type marking pen contains as a thickening agent, at least one thixotropic agent selected from polyacrylic acid, an alkali metal salt thereof, an organic amine salt thereof and a polyol, and has viscosities at 20°C of ≥45 mPa.s and ≤12 mPa.s under stresses of 0.01 Pa and 10 Pa, respectively. <P>COPYRIGHT: (C)2004,JPO |
