| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a tarnishable ball-point pen, which has excellent initial writing-out properties, can get a dark holograph by a light writing touch and satisfy the drying properties of the holograph and is excellent in practicality and convenience by tarnishing or decolorizing the holograph and a writing utensil set using the tarnishable ball-point pen. <P>SOLUTION: This tarnishable ball-point pen formed by directly charging an ink and an ink anti-backflowing body in an ink housing tube equipped with a ball-point pen tip. The ink is made of water and a dye, which is tarnished or decolorized by a reducing agent and has a viscosity of 3-160 mPa s measured at 20°C by a E type rotational viscometer at 100 rpm and, at the same time, is a shear-thinning tarnishable ink having a shear-thinning index of 0.6-0.99 or a non-shear-thinning tarnishable ink having the viscosity of 1-50 mPa s and has pH of 1-6. Further, the writing utensil set employing the tarnishable ball-point pen is dealt. <P>COPYRIGHT: (C)2006,JPO&NCIPI |
