PRODUCTION OF RARE EARTH OXYSULFIDE PHOSPHOR FOR X-RAY INTENSIFYING SCREEN

摘要

PROBLEM TO BE SOLVED: To provide a production process by which a rare earth oxysulfide phosphor used for X-ray intensifying screens and improved in water resistance is produced economically and which is suitable for mass production. ;SOLUTION: In a process for producing a rare earth oxysulfide phosphor comprising an oxysulfide of at least one element selected from among yttrium, lanthanum, and gadolinium (pref. gadolinium oxysulfide) as the matrix and terbium as the activator, a phosphor powder subjected to grinding in advance is brought into contact with an oxidizing agent (pref. H₂O₂) in water to form an oxide layer on the surfaces of phosphor particles and then heated at 200-500°C.;COPYRIGHT: (C)1998,JPO