Method of preparing barium fluoroiodide, iodine-containing barium fluorohalide phosphor, and radiation image conversion panel

A method of preparing an iodine-containing barium fluorohalide phosphor comprising the steps of:

• (a) mixing barium carbonate with an aqueous solution of hydrogen iodide in a molar ratio from 0.5 to 2 of hydrogen iodide to barium carbonate, and concentrating the resultant solution to prepare a suspension having barium iodide dissolved in the solution at a concentration of at least 3.0 mol/l, and activating barium fluoroiodide by mixing with europium or cerium such that a molar ratio thereof to a finally obtained amount of barium fluoroiodide is in the range of about 0.00001 to about 0.01;
• (b) precipitating barium fluoroiodide by adding a total amount of hydrogen fluoride to the suspension to achieve a molar ratio from 0.4 to 0.8 of hydrogen iodide to the barium carbonate, and wherein the hydrogen fluoride is added at a rate to generate 0.001 N/minute to 10 N/minute of barium fluoroiodide precipitate, wherein N is the theoretical amount of barium fluoroiodide precipitate that can be generated based upon the amount of barium carbonate in the suspension;
• and
• (c) separating the precipitate, wherein the barium fluoroiodide has an average particle diameter of 1 to 20 μm.

A method of preparing a radiation image conversion panel comprising the steps of:

• (i) preparing barium fluoroiodide by:
• (a) mixing barium carbonate with an aqueous solution of hydrogen iodide in a molar ratio from 0.5 to 2 of hydrogen iodide to barium carbonate, and concentrating the resultant solution to prepare a suspension having barium iodide dissolved in the solution at a concentration of at least 3.0 mol/l;
• (b) precipitating barium fluoroiodide by adding a total amount of hydrogen fluoride to the suspension to achieve a molar ratio from 0.4 to 0.8 of hydrogen iodide to the barium carbonate, and wherein the hydrogen fluoride is added at a rate to generate 0.001 N/minute to 10 N/minute of barium fluoroiodide precipitate, wherein N is the theoretical amount of barium fluoroiodide precipitate that can be generated based upon the amount of barium carbonate in the suspension;
• and
• (c) separating the precipitate, and
• (ii) coating the barium fluoroiodide prepared in step (i) onto a support.

A method of preparing an iodine-containing barium fluorohalide phosphor comprising mixing:

• (i) a first barium fluorohalide obtained by:
• (a) mixing barium carbonate with an aqueous solution of hydrogen iodide in a molar ratio from 0.5 to 2 of hydrogen iodide to barium carbonate, and concentrating the resultant solution to prepare a suspension having barium iodide dissolved in the solution at a concentration of at least 3.0 mol/l;
• (b) precipitating barium fluoroiodide by adding a total amount of hydrogen fluoride to the suspension to achieve a molar ratio from 0.4 to 0.8 of hydrogen iodide to the barium carbonate, and wherein the hydrogen fluoride is added at a rate to generate 0.001 N/minute to 10 N/minute of barium fluoroiodide precipitate, wherein N is the theoretical amount of barium fluoroiodide precipitate that can be generated based upon the amount of barium carbonate in the suspension;
• and
• (c) separating the precipitate, with
• (ii) a second phosphor material.