Method of preparing coated pigment and water-based ink composition containing coated pigment prepared thereby

Abstract

Proposed are a method of preparing a coated pigment, which includes: preparing a pigment dispersion by mixing and dispersing first and second surfactants with a pigment in water; and coating the pigment by adding an emulsion obtained by mixing and emulsifying a polymerizable surfactant and first and second monomers that differ in glass transition point, to the pigment dispersion, a water-based ink composition containing a thickener and the coated pigment prepared thereby, and a water-based writing instrument including the ink composition. When preparing the coated pigment by the above method, there are advantages of improving pigment dispersion stability and adsorption stability of a coating layer while controlling hardness and flexibility due to the glass transition point difference. In addition, when using the coated pigment as an ink pigment, adhesiveness and lubricity can be improved while providing a better writing experience.

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