| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an ink composition for an aqueous ballpoint pen that is excellent in rub resistance, resistance to blobbing and dotting and resistance to hand sebum and to provide an aqueous ballpoint pen using the ink composition. <P>SOLUTION: In an ink composition for an aqueous ballpoint pen including at least water, a coloring agent and a pseudoplasticity-imparting agent, the ink composition for an aqueous ballpoint pen to which a rotary shearing of a shear rate of 500 (s<SP POS="POST">-1</SP>) has been applied in an environment of 20°C is such that when an ink viscosity at a shear rate of 0.1 (s<SP POS="POST">-1</SP>) after the elapsed time A (s) is represented by V<SB POS="POST">A</SB>(Pa s) and an ink viscosity at a shear rate of 0.1 (s<SP POS="POST">-1</SP>) after the elapsed time B (s) is represented by V<SB POS="POST">B</SB>(Pa s) in the case of the time at starting point of measurement of an ink viscosity at a shear rate of 0.1 (s<SP POS="POST">-1</SP>) in an environment of 20°C being set at 0, the relationship between the elapsed time and the ink viscosity is 0.01≤(V<SB POS="POST">B</SB>-V<SB POS="POST">A</SB>/B-A)≤1.0 and the ink viscosity V<SB POS="POST">A</SB>(Pa s) and the ink viscosity V<SB POS="POST">B</SB>(Pa s) are each independently 6 to 30 (Pa s) (in the formula, A and B are integers; A<B; and 0<A, B≤10). <P>COPYRIGHT: (C)2013,JPO&INPIT |
