| abstract |
(57) [Problem] To provide latex particles colored in a sufficiently dark color. SOLUTION: A copolymer latex particle (for example, comprising styrene and at least one selected from the group consisting of a polymerizable unsaturated carboxylic acid and a polymerizable unsaturated sulfonic acid) Styrene-methacrylic acid copolymer) is a colored particle obtained by immersing a dye solution in which an oil-soluble dye is dissolved, adsorbing the dye to latex particles, and then replacing the dye solution with water, The solvent of the dye is made of a water-soluble dye (eg, methanol), and the oil-soluble dye is made of a water-insoluble water (eg, solvent blue). Colored particles having a negative charge of more than 0.5 meq / g and not more than 5.0 meq / g. |