PROBLEM TO BE SOLVED: To provide a more efficient producing method of stained polyamide fine particles having a feature that the degree of red is within a range of 20 to 50 as a value of indicator for red in a* in L*a*b* color model set forth in International Commission on Illumination (CIE) in a method in which chloroauride tetrahydrate is reduced under the co-presence of nitrogen containing macromolecule in a solution in which polyamide fine particles are distributed in a solvent.SOLUTION: There is provided a producing method of stained polyamide fine particles having a feature that the degree of red is within a range of 20 to 50 as a value of indicator for red in a* in L*a*b* color model set forth in International Commission on Illumination (CIE) in which chloroauride tetrahydrate is reduced in a condition where the chloroauride tetrahydrate and nitrogen containing macromolecule is present at 0.2 to 1.6 of weight ratio in a solution in which polyamide fine particles are distributed in a solvent at a concentration of 1 mass% or more.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、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20~50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より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溶媒に1質量%以上の濃度で分散させた溶液中で、塩化金酸4水和物と含窒素高分子との重量比が0.2~1.6である状態で塩化金酸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20~50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】なし
