Abstract: An oil-based ball-point pen refill includes a ball-point pen tip in which a ball is held, in which the ball-point pen tip is mounted on a leading end of an ink housing cylinder, an ink composition including a coloring agent consisting of a dye, an organic solvent, and polyvinyl butyral resin is housed in the ink housing cylinder, the arithmetic mean roughness of a surface of the ball is 0.1 to 15 nm, the content of the polyvinyl butyral resin is 50 mass % or more based on the total mass of the whole resin, and an ink viscosity is 5000 to 50000 mPa·s. In an oil-based ball-point pen, the refill is disposed in a barrel cylinder. An oil-based ball-point pen ink composition including a specific salt-forming dye, polyvinyl butyral resin, and an aromatic alcohol can be utilized in the refill.

Abstract: [Problem to be Solved] Provided are: an oil-based ball-point pen refill having the excellent concentration of a written trace, excellent performance against ink dripping, and an excellent feeling of writing; an oil-based ball-point pen using the oil-based ball-point pen refill; and an ink composition that is preferably used in the oil-based ball-point pen refill and the oil-based ball-point pen. [Solution] An oil-based ball-point pen refill includes a ball-point pen tip in which a ball is held, in which the ball-point pen tip is mounted on a leading end of an ink housing cylinder, an ink composition including a coloring agent consisting of a dye, an organic solvent, and polyvinyl butyral resin is housed in the ink housing cylinder, the arithmetic mean roughness of a surface of the ball is 0.1 to 15 nm, the content of the polyvinyl butyral resin is 50 mass % or more based on the total mass of the whole resin, and an ink viscosity is 5000 to 50000 mPa·s.

Abstract: Disclosed is a water based ink composition for a rollerball pen that includes at a least colorant, a water-soluble organic solvent, water, a shear thinning viscosity property-providing agent, a lubricant, and a bubble suppressant. The ink composition includes a phosphate-ester based surfactant having a structure of general formula 1 as the lubricant, and an erythorbic acid or a derivative thereof as the bubble suppressant (n represents an integer of 1 or more, R represents an alkyl group having carbon numbers of 12 to 15, and R? represents H or R—(C2H4O)n—).

Abstract: Disclosed is a water based ink composition for a rollerball pen that includes at a least colorant, a water-soluble organic solvent, water, a shear thinning viscosity property-providing agent, a lubricant, and a bubble suppressant. The ink composition includes a phosphate-ester based surfactant having a structure of general formula 1 as the lubricant, and an erythorbic acid or a derivative thereof as the bubble suppressant (n represents an integer of 1 or more, R represents an alkyl group having carbon numbers of 12 to 15, and R? represents H or R—(C2H4O)n—).

Abstract: A ballpoint pen contains an aqueous ink composition into which ink is directly filled. The pen is free from ink dripping and has improved writing performance. The aqueous ink composition is directly filled into an ink reservoir tube equipped with a ballpoint pen tip. The aqueous ink composition includes (a) an aqueous medium, (b) a pigment and (c) a carboxyl group-containing crosslinked hydrophilic polymer. The hydrophilic polymer swells and disperses in a gel state in the form of particles having a particle diameter of 0.5 to 10 .mu.m. The polymer is crosslinked with a crosslinkable monomer having at least two polymerizable unsaturated groups in an amount of 0.5 mol % or more based on the total of a carboxyl group-containing monomer and a copolymerizable monoethylenic monomer used together, if desired. The ink reservoir tube tip has a clearance between a ball and a ball receiver in the range of 10 to 40 .mu.m.

Abstract: A water-resistant ink composition containing water, an anionic dye and a water-resistance modifier which contains as an effective component a sparingly water-soluble compound comprising at least one oleophilic group selected from the group consisting of an aromatic ring and an aliphatic hydrocarbon having 6-12 carbon atoms, and at least one hydrophilic group having at least one of O, N and S atoms.

Abstract: A method of refining beet juice containing a colorant wherein the beet juice is contacted with an adsorbent composed of a dehydrated solid of a coprecipitated substance formed by insolubilizing metallic compounds in an aqueous solution. The adsorbent contains either a calcium or magnesium compound and also either an aluminum or iron compound. The process is conducted in a temperature range of 40.degree.-100.degree. C.