ORGANIC RESIN MICROPARTICLE AND INK COMPOSITION CONTAINING THE SAME

摘要

PROBLEM TO BE SOLVED: To obtain an ink composition made markedly proof against the decomposition of the constituent dye by using organic resin microparticles comprising a surfactant and a polymer dispersant and having a specified particle size. SOLUTION: This microparticle comprises a surfactant and a polymer dispersant and has a mean particle diameter of 20-300nm. The surfactant is desirably a betaine compound (e.g. a compound represented by the formula). The monomer which constitutes the microparticles may be at least one monomer having one radicalpolymerizable unsaturation or a combination thereof with a crosslinking monomer. The polymer dispersant is desirably a polyoxyethylene compound. At least one type of the particles is mixed with a dye, a binder and a water-based solvent to form an ink composition. This composition shows excellent dispersion stability and is made markedly proof against the decomposition of the dye.