Patent ID: 7396397
Filing Date: 2008-07-08
Classification: C09D

Abstract:
1. An ink composition for an oil-based ballpoint pen comprising: an oil-soluble dye, water, an organic solvent whose vapor pressure at 20° C. is 0.5 minHg or more and which dissolves the water, and an organic solvent whose vapor pressure at 20° C. is 0.1 mmHg or less and which dissolves the organic solvent whose vapor pressure at 20° C. is 0.5 mmHg or more, wherein a total of the water, the organic solvent whose vapor pressure at 20° C. is 0.5 mmHg or more and which dissolves the water, and the organic solvent whose vapor pressure at 20° C. is 0.1 mmHg or less and which dissolves the organic solvent whose vapor pressure at 20° C. is 0.5 mmHg or more is 20 to 75% by mass based on an entire mass of the ink composition, and a content of the water is 2.0 to 15.0% by mass based on the entire mass of the ink composition, and the ink composition contains the organic solvent whose vapor pressure at 20° C. is 0.5 mmHg or more is 3.0 to 30.0% by mass based on the entire mass of the ink composition.