DE582401C - Process for the production of phosphors - Google Patents

Description

Process for the production of phosphors Phosphors are known which, without containing radioactive substances, act as light accumulators, d. H. they give their energy after exposure to wave or corpuscular rays in the form of visible and also ultraviolet rays. These usual Phosphors consist of alkaline earth sulfides or alkaline earth halides with a Admixture of metal or rare earths.

The usability of these Sulüdischen phosphors is limited, because they cannot be finely chopped up, because their luminous effect is affected destroyed by pressure. In addition, the sulfidic phosphors are in water Liquids soluble and are attacked by humidity.

It has now been shown that & phosphors, their basis Is silicate or carbonate, is not subject to pressure deterioration, d. H. you can finely to even colloidally comminuted without losing their luminosity. Furthermore, these oxidic phosphors are also not affected by water-containing liquids or humidity attacked.

Rare earths are used as an activating substance - preferably Yttrium, lanthanum, gadolinium, scandium, generally elements with the ordinal numbers 21, 39 and 57 to 71. These phosphors are produced by the most varied types of radiation made to be phosphorescent or fluorescent: by ultraviolet light, X-rays, Cathode rays, alpha rays, radium rays. They have a particularly good luminosity and the particular advantage of emitting blue to ultraviolet light in the main roof.

The production takes place, for example, as & iooo g zinc fluoride, 100 g silica and i g yttrium mixed intimately and in the oven. melted will. The melt is fine to colloidal depending on the intended use crushed and irradiated in a known manner.

The rare earth can be present in the mixture in any concentration even in such small quantities that they can no longer be detected chemically. Embodiments i. o, ooi g gadolinium (as nitrate), 403 g zinc fluoride, 1.56 g of potassium fluoride and i, 8o g of silica are intimately mixed and heated at iioo ° C for 1 hour long annealed. The yield is approximately 2.5 g.

2. 0.007 g praseodymium, 2.06 g zinc fluoride, 1.8 g silica, 1.96 g of barium carbonate are intimately mixed and calcined at i300 ° C. for one hour. the Yield is approximately 3 g.

3. o, ooi g yttrium, o, oi g_ sodium chloride and i g barium carbonate are mixed intimately and calcined at 96o ° C for 20 minutes. The yield is about i g.

q .. 0.00025 g of terbium, 2.06 g of zinc fluoride and 1.2 g of silica intimately mixed and annealed at rioo to iäoo ° C for one hour. f) ie The yield is approximately 2 g.

5. o, oooo2 g of erbium, o, oor g of potassium iodide and i g of barium carbonate intimately mixed and annealed at 100 ° C for 20 minutes. The yield is approx r g.

6. 0.000015 g of gadolinium and rg of barium or calcium silicate are intimately mixed and calcined at 100 ° C. for 1 hour. The yield is approximately i g.

In all examples, the rare earths are in forin-their Nitrates applied. The phosphors according to Examples r to 3 are used for purposes in which it depends on fluorescence, while the embodiments 4 to 6 Provide phosphors with phosphorescence or ultraviolet phosphorescence. Her Usability is very diverse, e.g. B. for fluorescent screens in televisions as well as fluorescent X-ray screens.

Claims (1)

PATENT CLAIM Process for the production of phosphors by melting of carrier substances with rare earths and subsequent comminution, thereby characterized that the rare earths in the presence of silica, silicates or _ alkaline earth carbonates sintered together, finely crushed and optionally be irradiated in a known manner.