Preparation of goldless green phosphor

Abstract

The invention relates to a manufacture method of barren green fluorescent powder. In the method, a latent solvent system consisting of barium iodide, zinc iodide, potassium iodide and strontium bromide is adopted; activated aluminum Gamma-Al2O3 is used as the leading-in matter of a coactivator Al; copper nitrate is used as the leading-in matter of an activator Cu; the led-in Cu is used to replace the heavy metal gold which belongs to the same main group of the Cu, thus realizing to manufacture the barren green powder the chroma X value of which is between 0.293 and 0.305 and extensively reducing the manufacture cost of the fluorescent powder; besides, the brightness of the fluorescent powder is improved by 2 percent; the color of the fluorescent powder is purer and plumper.

Description

technical field [0001] The invention belongs to the technical field of cathode ray tube manufacture, and relates to a method for manufacturing fluorescent powder for cathode ray tubes, in particular to a method for manufacturing a gold-free green fluorescent powder. Background technique [0002] Green phosphors for cathode ray tubes can be divided into two types of phosphors according to their composition, namely ZnS: Cu·Al type gold-free green powder and ZnS: Cu·Al·Au type gold-containing green powder, according to the current manufacturing method , the former ZnS: Cu·Al formula gold-free green powder has a chromaticity X value of 0.280~0.292, while the latter ZnS: Cu·Al·Au formula gold-containing green powder has a chromaticity X value of 0.293~0.305. Among the green phosphors used in cathode ray tubes, Cu and Al can increase the chromaticity X value of the green powder, but the existing method can only reach 0.292, which can meet the requirements of some cathode ray tubes...

AI Technical Summary

Problems solved by technology

Because the bismuth iodide in the co-solvent changes from solid to gas during the high-temperature firing process, but due to the temperature drop during the discharge process, bismuth will precipitate and attach to the surface of the phosphor powder, making the phosphor gray, making the phosphor The chromaticity and brightness of the phosphor are reduced, and because the bismuth iodide and antimony iodide in the co-solvent are relatively high in impurities, it will affect the diffusion of Cu, Al, and Au activators in the ZnS lattice, making the chromaticity of the phosphor and brightness reduction (the more sufficient the diffusion of Cu, Al, Au activators in the ZnS lattice, the higher the chromaticity and brightness of the phosphor

); although the barium iodide co-solvent can reduce the consumption of Au in addition, since there is only one co-solvent, Au must also be added

In addition, because the existing co-activator Al uses aluminum nitrate, the luminescent performance of the phosphor fired product is poor, showing low brightness and impure body color, which increases the amount of co-activator chloroauric acid, resulting in phosphor powder Manufacturing costs have risen sharply

[0003] Overall, there are disadvantages in the existing technology: for large-scale production of green phosphors with a chromaticity X value of 0.293 to 0.305, one is the high cost of green powder manufacturing due to the addition of gold, and the other is the luminous performance of the fired phosphors. Poor, manifested as low brightness and impure body color

These are not conducive to product quality and cost