| 摘要 |
PROBLEM TO BE SOLVED: To obtain an oil-base ballpoint ink which does not undergo any degradation in writing performance even when a ballpoint pen contg. the ink is left uncapped by selecting an oil-base ballpoint ink contg. a specific org. solvent, a colorant, and a flocculant and having a specified viscosity. SOLUTION: This ink contains an org. solvent having a vapor pressure of 0.2mmHg or lower at 20 deg.C, a colorant, and a flocculant and has a non- Newtonian viscosity index of 0.2-0.5 and a viscosity of 200mPa.s or lower at 25 deg.C and 50rpm. Examples of the solvent are benzyl alcohol, dipropylene glycol, propylene glycol monophenyl ether, triethylene glycol monobutyl ether, and tripropylene glycol monomethyl ether. |
