| 摘要 |
PURPOSE:To ensure flowability of ink by a method wherein an ink reservoir part is molded by adding a surfactant in a specific ratio composed mainly of a polymer of an alkyl ester of an acrylic acid or methacrylic acid containing carboxylic groups or sulfonic groups as a hydrophilic part to a thermoplastic elastomer resin, such as a polypropylene. CONSTITUTION:In a writing utensil for low-viscosity liquid ink, an ink reservoir part is molded by adding 0.01-1% surfactant composed mainly of a polymer of an alkyl ester of an acrylic acid or methacrylic acid containing carboxylic groups or sulfonic groups as a hydrophilic part to a thermoplastic elastomer resin, such as a polypropylene, a polyethylene, a polyvinyl chloride, a styrene- butadiene copolymer, ethylene-butadience-styrene block copolymer, an acryl- butadiene-styrene copolymer, or an ethylene-vinyl acetate copolymer. As a result, flowability of ink is ensured in the ink reservoir part, and a shortage of ink suppy to a writing tip caused by a defective ink flow is prevented. |
