Method for producing dispersion, dispersion, coating material, coating film, and film

A method for producing a dispersion, comprising,

• in a wet ball mill including
• a vessel (p) filled with a medium,
• a rotational shaft (q),
• a stirring impeller (r) that has a rotational axis coaxial with the rotational shaft (q) and that is rotated by rotation of the rotational shaft,
• a slurry supply port (s) provided in the vessel (p),
• a slurry discharge port (t) provided in the vessel (p), and
• a shaft seal device (u) disposed in a portion where the rotational shaft penetrates the vessel, the shaft seal device (u) including two mechanical seal units in which seal portions of the two mechanical seal units are sealed with an external sealing liquid,
• supplying a slurry through the supply port (s) into the vessel (p), the slurry containing as essential components an active-energy-ray-curable compound (A), an active-energy-ray-curable compound (B), and inorganic fine particles (C), the active-energy-ray-curable compound (A) having a weight-average molecular weight (Mw) in a range of 3,000 to 100,000, having a (meth)acryloyl group in a molecular structure, and having a (meth)acryloyl equivalent in a range of 100 g/eq to 600 g/eq, the active-energy-ray-curable compound (B) having 3 to 6 (meth)acryloyl groups in a molecular structure and having a molecular weight in a range of 100 to 600;
• rotating the rotational shaft (q) and the stirring impeller (r) in the vessel (p) to stir the medium and the slurry so that the inorganic fine particles (C) in the slurry are pulverized and the inorganic fine particles (C) are dispersed in the active-energy-ray-curable compound (A) and the active-energy-ray-curable compound (B);
• and subsequently discharging the slurry through the discharge port.