| 摘要 |
PROBLEM TO BE SOLVED: To provide an ink for ball pens which shows an improved shelf- stability and is erasable with erasers. SOLUTION: The aqueous ink contains water, a dyestuff, a phosphoric ester surfactant, a rubber latex and polyvinylpyrrolidone and has a viscosity of 300 to 2,000 cP. In the rubber latex, the main component (designated as component A) has a particle size of >=500 nm and a glass transition temperature of <=-20 deg.C and accounts for 70 to 95(%) of the total rubber latex, and the secondary component (designated as component B) has a glass transition temperature of >=20 deg.C. |
