METHOD FOR PRODUCING HOLLOW PARTICLE, HOLLOW PARTICLE, ANTIREFLECTION FILM, AND OPTICAL ELEMENT

摘要

PROBLEM TO BE SOLVED: To provide a hollow particle excellent in shell strength by forming a shell made of magnesium fluoride as a continuous layer and a method for producing the same.SOLUTION: Inside a shell comprising a continuous layer composed of magnesium fluoride, hollow particles have a hollow core at least a part of which is hollow. There is provided a method for producing hollow particles including the steps of: adding an aqueous solution containing an aqueous solution of a magnesium salt and fluorine ions into an aqueous dispersion containing fine particles to be cores at a temperature of 10°C or more and 30°C or less, and heating the mixed solution at a temperature of 50°C or more and 80°C or less to obtain core-shell fine particles in which a shell comprising continuous layer composed of the magnesium fluoride around the cores made of the fine particles is formed; and forming the hollow core by removing at least a part of the fine particles from the core-shell particles.