PRODUCTION METHOD OF FINE PARTICLE OF INFRARED SHIELDING MATERIAL, PRODUCTION METHOD OF FINE PARTICLE DISPERSION LIQUID OF INFRARED SHIELDING MATERIAL, FINE PARTICLE OF INFRARED SHIELDING MATERIAL, FINE PARTICLE POWDER OF INFRARED SHIELDING MATERIAL, FINE PARTICLE DISPERSION LIQUID OF INFRARED SHIELDING MATERIAL, FINE PARTICLE DISPERSION OF INFRARED SHIELDING MATERIAL, AND COATED SUBSTRATE

摘要

PROBLEM TO BE SOLVED: To provide a method for achieving a good recovery rate and good workability in the producing of fine particles of an infrared shielding material, which are Nb-doped oxide titanium fine particles and sufficiently develop functions as an infrared shielding material.SOLUTION: A method is provided, which includes: a hydrolysis step of heating a solution that contains a Ti complex obtained by reacting a Ti-containing compound with a complexing agent (A), a Nb complex obtained by reacting a Nb-containing compound with a complexing agent (B), water, and a reductive compound used as a solvent, so as to induce hydrolysis in each complex; a recovery step of recovering fine particles of an infrared shielding material as a precipitate after the hydrolysis step; and a heat treatment step of heating the recovered fine particles of the infrared shielding material in a hydrogen atmosphere. The hydrolysis step includes: a gelation step of gelling the aqueous solution by progressing the hydrolysis; and a solation step of solating the gelled aqueous solution in the gelation step by progressing the hydrolysis. The heating temperature in the heat treatment step is controlled to 500°C or higher and 700°C or lower.