Abstract: An oil-based ballpoint pen includes: an ink container configured to accommodate an ink composition for the oil-based ballpoint pen, the ink composition containing colorant, alkylene glycol alkyl ether, and polyacrylic resin; and a ballpoint pen tip configured to rotatably hold a ball at one end thereof in an extending direction of the ink container. A ratio of an ink consumption (mg) per writing distance of 100 m to a diameter (mm) of the ball is 30 or more.

Abstract: In order to obtain an ink for oil-based ballpoint pens and an oil-based ballpoint pen which are excellent in handwriting sharpness, handwriting dryness, handwriting and feeling of writing, an ink composition includes an oil-soluble dye, water, an organic solvent whose vapor pressure at 20° C. is 0.5 mmHg 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. A total of these three components is 20 to 75% by mass based on an entire mass of the ink composition. A content of the water is 3.0 to 15.0% by mass based on the entire mass of the ink composition. An ink viscosity at 20° C. is 100 to 5,000 mPa·s. The water and the other components are formulated, mixed and stirred to produce the ink. A ballpoint pen refill with low vapor permeability is used.

Abstract: In order to obtain an ink for oil-based ballpoint pens and an oil-based ballpoint pen which are excellent in handwriting sharpness, handwriting dryness, handwriting and feeling of writing, an ink composition includes an oil-soluble dye, water, an organic solvent whose vapor pressure at 20° C. is 0.5 mmHg 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. A total of these three components is 20 to 75% by mass based on an entire mass of the ink composition. A content of the water is 3.0 to 15.0% by mass based on the entire mass of the ink composition. An ink viscosity at 20° C. is 100 to 5,000 mPa·s. The water and the other components are formulated, mixed and stirred to produce the ink. A ballpoint pen refill with low vapor permeability is used.

Abstract: There is provided a water-based ink comprising: 1-15% by weight of aluminum powder; 10-40% by weight of a humectant; 0.05-0.5% by weight of a chelating agent; 0.1-0.5% by weight of a cross-linkable acrylic acid polymer having a number average molecular weight in the range of 3,000,000-5,000,000; 30-80% by weight of water; 2-8% by weight of a dispersant; and 0.2-1.5% by weight of a anticorrosive lubricant.

Abstract: Disclosed is water based ink having metallic luster adapted for a direct-filling ball-point pen, which is used by being directly filled into the tube, said ink comprising, based on the total amount of the ink composition, 1% to 20% by weight of a metallic color pigment comprising metallic powder and a color pigment adsorbed thereon, 0.1% to 1.0% by weight of a water-soluble or water-dispersible polymer agent which imparts pseudo-plasticity, and water, thereby providing ink satisfactory in beauty and luster and excellent in aging stability and writing properties.