PROBLEM TO BE SOLVED: To provide a manufacturing method of a dispersion in which hardly soluble material in a dispersant is dispersed with nano-order particle diameter without using an organic solvent high in toxicity as the dispersant.SOLUTION: There is provided a method for manufacturing a dispersion in which a hardly soluble material in a dispersant containing a surfactant is dispersed with a nano-order particle diameter as a medium in the dispersant, including preparing a solution in which the hardly soluble material and the surfactant are dissolved in a good solvent, quickly cooling the solution to a temperature at which the hardly soluble material is crystallized in the solution at a temperature decrease rate of 100 to 4000°C/sec. to generate hardly soluble material-containing ultrafine particle with nano-order level particle diameter in the good solvent, and (i) separating the good solvent from a mixture of the solution and dispersant after mixing the dispersant with the solution, or (ii) mixing the dispersant after separating the good solvent from the solution.SELECTED DRAWING: NoneCOPYRIGHT: (C)2020,JPO&INPIT【課題】分散媒として毒性の高い有機溶媒を使用せず、分散媒に難溶解性の物質がナノオーダーの粒子径で分散した分散液の製造方法の提供。【解決手段】界面活性剤を含む分散媒中に、媒質として、前記分散媒に難溶性の物質がナノオーダーの粒子径で分散した分散液を製造する方法であって、良溶媒に前記難溶性物質および界面活性剤を溶解した溶液を準備し、前記溶液を、１００～４０００℃／秒の降温速度にて、前記難溶性物質が溶液中で析出する温度まで急冷して、前記良溶媒中に粒子径がナノオーダーレベルの難溶性物質含有超微粒子を生成させ、（ｉ）前記溶液に分散媒を混合した後に前記溶液と分散媒との混合液から前記良溶媒を分離するか、または、（ｉｉ）前記溶液から前記良溶媒を分離した後に分散媒を混合することを含む方法とする。【選択図】なし
