METHOD FOR WET PULVERIZATION OF ORGANIC SOLID SUBSTANCE AND RECORDING MATERIAL COATED WITH AQUEOUS DISPERSION OF FINE PARTICLE OF ORGANIC SOLID SUBSTANCE

摘要

PURPOSE:To enhance pulverization efficiency by continuously grinding an aqueous dispersion of an org. solid substance using a plurality of sand mills constituted so that the diameter of the grinding media used in the sand mill of a later stage is made smaller than that of the grinding media used in the sand mill used in an earlier stage. CONSTITUTION:A plurality of sand mills constituted so that the diameter of the grinding media used in the sand mill of a later stage is made smaller than that of the grinding media used in the sand mill of an early stage are arranged. An aqueous dispersion of org. solid substances such as org. pigment, an org. dye, an org. coupler or an org. heat-meltable substance is continuously subjected to wet pulverization using a plurality of the sand mills. The diameter of the opening part of a separation mechanism part separating the aqueous dispersion and grinding media in each of the sand mills is pref. 3/5-2/5 the diameter of the grinding media. The aqueous dispersion containing the fine particles of pulverized org. solid substances is applied to a support and dried to form a thermal recording material.