| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a rollerball pen which can suppress causing disfigurement without infiltration of an adjustor to a body for preventing the reverse flow of liquid ink from a contacting interface even when a dye containing the adjustor is used as a colorant for writing ink of a direct-coupled type. <P>SOLUTION: The rollerball pen is structured by incorporating a water-based ink composition containing the dye and water in an ink housing tube, and closely arranging the liquid ink reverse flow preventing body, which follows in accordance with consumption of the ink, on a rear end of the ink. The water-based ink composition contains an H-acid derivative and thiadiazoles expressed by the general formula (1) in the ink. (In the formula, R is a substituent group of either of CH<SB POS="POST">3</SB>, NH<SB POS="POST">2</SB>, or SM; and M is either of hydrogen, alkaline metal, ammonium, alkanolamine, cyclohexylamine, or cyclohexyl alkanolamine). <P>COPYRIGHT: (C)2012,JPO&INPIT |
