PROBLEM TO BE SOLVED: To provide an efficient method of producing a colored polyamide fine particle which, in reduction of chloroauric acid tetrahydrate in a solution dispersed with a polyamide fine particle in a solvent and in the coexistence of a nitrogen-containing polymer, nearly all of a gold ingredient used is adsorbed on the surface of the polyamide surface and no gold fine particles, a coloring ingredient, are left in the filtrate, and the redness of red coloring is within the range of 5-15 in terms of the redness index a* of the L*a*b* color system of Commission Internationale de lEclairage(CIE).SOLUTION: A production method of a colored polyamide fine particle comprises reducing chloroauric acid tetrahydrate in a solution in which the polyamide fine particle is dispersed in the isopropanol solvent and in the coexistence of a nitrogen-containing polymer. In the above solution, the redness of red coloring is within the range of 5-15 in terms of the redness index a* of the L*a*b* color system of Commission Internationale de lEclairage(CIE).COPYRIGHT: (C)2015,JPO&INPIT【課題】ポリアミド微粒子を溶媒に分散させた溶液中で、含窒素高分子の共存下に塩化金酸4水和物を還元する製法において、仕込みの金成分がほぼ全てポリアミド微粒子の表面に吸着され、ろ液中に着色成分である金微粒子が残存しない、かつ赤色発色の赤みが、国際照明委員会(CIE)のL*a*b*表色系の赤み指標a*の値で5~15の範囲であることを特徴とする着色ポリアミド微粒子の効率的な製造方法を提供する。【解決手段】ポリアミド微粒子をイソプロパノール溶媒に分散させた溶液中で、含窒素高分子の共存下に塩化金酸4水和物を還元し、赤色発色の赤みが、国際照明委員会(CIE)のL*a*b*表色系の赤み指標a*の値で5~15の範囲であることを特徴とする着色ポリアミド微粒子の製造方法。【選択図】図1
