| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a water-soluble gel ball-point pen for which the preservation stability of an ink has sufficiently been increased especially when a needle type ball-point tip is adopted. <P>SOLUTION: This water-soluble gel ball-point pen has an ink housing tube which houses a water-soluble gel ink containing a pigment as a coloring agent, and a ball-point pen tip. In this case, the ball-point pen tip has a ball which is rotatably held on the distal end. At the same time, on the ball-point pen tip, an ink flowing hole is formed in such a manner that the water-soluble gel ink may flow to the ball from the ink housing tube. In the water-soluble gel ball-point pen 1, an ink flowing hole diameter r (unit: mm) of the ball-point pen tip, and the storage elasticity G' (unit: Pa) of the water-soluble gel ink at 20°C satisfy conditions represented by equations (1) and (2). (1) 0.24≤r≤0.64, and (2) 1.3≤G'≤16r-3.2. <P>COPYRIGHT: (C)2009,JPO&INPIT |
