Patent ID: 7381754
Filing Date: 2008-06-03
Classification: C09D

Abstract:
1. A ballpoint pen ink composition comprising coloring materials, a resin, and a non-aqueous solvent comprising 3-methoxy-3-methyl-1-butanol, said coloring materials comprising a combination of an anthraquinone-based pigment and at least one dye represented by the following Formulas 1 or 2 and being free of a metal complex salt dye, said anthraquinone-based pigment having an average particle size of 30-700 nm and occupying 0.5-25 mass % based on the ink composition, wherein 3-methoxy-3-methyl-1-butanol is 40 mass % or more of the entire solvent, said dye dissolving in said non-aqueous solvent to a concentration of at least 20 mass %, said resin comprising polyvinylbutyral: wherein A may be the same or different and is a quaternary ammonium ion group having a saturated hydrocarbon group substituted with a hydroxyl group and being sterically hindered, wherein said dye represented by the chemical structural Formula 1 or 2 is compatible with the other ingredients in said ink composition, and said ink composition has a low temperature aging stability.