DE1592828C - Process for the production of a phosphor based on alkaline earth phosphates and zinc silicate - Google Patents

Description

The change in the spectral energy distribution of the emission with increasing concentration of manganese can be seen from the curves in the accompanying figure. Curve A shows the energy distribution of the emission of a sample which was produced according to example 1, curve B a sample according to example 2 with a higher concentration of manganese.

The brightest luminescence is obtained when the mixture is heated in a steam atmosphere at temperatures of 750-1200 ° C, in particular between 900 and HOO ⁰ C. In the preferred method, the mixture is ^{heated to a temperature between 900 and HOO 0} C in a closed vessel, cooled, ground and reheated to a temperature within the same range in a steam atmosphere.

The starting materials for the halophosphate portion of the mixture can be an alkaline earth phosphate and be a carbonate or halide, and ammonium chloride; the manganese can be used, for example, as a halide, for example as manganese chloride and / or fluoride or as another compound, for example as carbonate or phosphate may be present. The zinc silicate content can be due to ingredients such as zinc oxide and silicon dioxide be given.

Due to the wide range of possible compositions and the lack of a single distinctive X-ray diffraction patterns are not possible for those made in accordance with the invention To characterize phosphors better than has been done above.

example 1

36.6 g of SrHPO ₄

14.7 g of SrCO ₃
16.2 g of ZnO

6.0 g SiO ₂

6.93 g of MnCl ₂ 4H ₂ O

6.95 g NH ₄ Cl

These substances are ground together and then kept at 1000 ° C. for 2 hours in a closed melting crucible made of SiO _2. After cooling, the material is ground to a fine powder and heated again for a further half hour at 1000 ⁰ C in a steam atmosphere. After cooling, the product shows a pink fluorescence when excited by short-wave ultraviolet light with a peak at 6100 Å and a second peak at 5300 Å.

Example 2

If the procedure of Example 1 is modified by omitting the SrCO ₃ , increasing the amount of ZnO to 24.3 g and the amount of MnCl ₂ · 4H ₂ O to 12.87 g, and reducing the amount of NH ₄ Cl to 3.75 g then the product shows orange fluorescence with peaks at substantially the same wavelengths as in Example 1, but with an increase in relative energy at wavelengths below about 6100 Å.

Example 3

When the method of Example 2 is _{modified by using 12 g of SiO 2} , the product shows green fluorescence.

Example 4

Mixtures according to the following table are prepared and heated as in the previous examples. The color of the fluorescence of the product is given at the end of the table.

Mixture A
G Mixture B
G Mixture C
G CaHPO ₄
CaCO, .... 50.0
11.5
7.0
28.0
9.0
5.94
5.0
green 50.0
7.0
6.2
28.0
9.0
16.83
1 8
J, 8
yellow 50.0
10.0
3.5
28.0
9.0
17.82
7.0
pink CaF, ZnO SiO ₂ MnCl ₂ -4 H, 0
NH ₄ Cl Color of
fluorescence

Example 5

36.6 g of SrHPO ₄
24.3 grams of ZnO

6.0 g SiO ₂

8.91 g of MnCl ₂ -4H ₂ O

1.86 g MnF ₂

3.75 g NH ₄ Cl

These substances are ground together and then heated in a closed melting crucible made of SiO ₂ at 900 ^° C. for one hour. After cooling, the substance is ground to a fine powder, and it is heated again for 1 hour in steam at 900 ^° C. After cooling, the product shows a pink fluorescence when it is excited by short-wave ultraviolet (2537 Å).

Example 6

36.6 g of SrHPO ₄

⁴ S 24.3 g ZnO

6.0 g SiO ₂
4.95 g MnCl ₂ -4H ₂ O 3.72 g MnF ₂

3.75 g NH ₄ Cl

These and the following samples are treated as in Example 5, except for the temperature the heating in Examples 10 to 15.

The product shows green fluorescence on Erre

with the same short wavelength as in example 5.

Example 7

36.6 g of SrHPO ₄

24.3 grams of ZnO

6.0 g SiO ₂

7.5 g MnCl ₂ -4H ₂ O

8.0 g NH ₄ Cl

The product shows yellow fluorescence.

Example 8

36.6 g SrHPO ₄ 10.29 g SrCO ₃ 16.2 g ZnO

5.95 g MnCl ₂ -4H ₂ O

6.0 g SiO ₂

4.05 g NH ₄ Cl

The product shows yellow fluorescence.

Example 9

27.2 g CaHPO ₄

24.3 g ZnO 6.0 g SiO ₂

15.0g MnCl ₂ -4H ₂ O 4.05 g NH ₄ Cl

The product shows yellow fluorescence. Example 10

50, Og CaHPO ₄

13.0 g CaCO ₃

3.9 g CaF ₂

28.0 grams of ZnO

10.3 g NH ₄ Cl 10.89 g MnCl ₂ -4H ₂ O

9.0 g SiO ₂

This sample and the following are heated to HOO ⁰ C. The product shows a yellow-green fluorescence.

Example 11

50.0 g CaHPO ₄

13.0 g CaCO ₃

1.2 g CaF ₂

28.0 grams of ZnO

10.3 g NH ₄ Cl 17.82 g MnCl ₂ -4H ₂ O

9.0 g SiO ₂

30th

40

45

This product shows orange fluorescence.

Example 12

50.0 g CaHPO ₄ 11.0 g CaCO ₃ 1.17 g CaF ₂

55 16.83 g MnCl ₂ -4H ₂ O

27.2 g ZnO 9.0 g SiO ₂ 4.28 g NH ₄ Cl

This product shows yellow fluorescence.

example

67.3 g SrHPO ₄ 16.2 g SrCO ₃ 27.2 g ZnO

8.75 g of SrF ₂

5.94 g of MnCl ₂ -4H ₂ O

9.0 g SiO ₂

4.28 g NH ₄ Cl

This product shows green fluorescence. example

50.0 g CaHPO ₄ 16.2 g SrCO ₃

3.75 g SrF ₂ 27.2 g ZnO

9.0 g SiO ₂ 13.86 g MnCl ₂ -4H ₂ O

4.28 g NH ₄ Cl

This product shows yellow fluorescence.

A fabric prepared according to this example gives an initial brightness of 42 lumens per watt with color coordinates of χ - 0.374, y = 0.473 when used in 40 watt fluorescent lamps with a length of 1.2 m.

example

50.0 g CaHPO ₄ 16.2 g SrCO ₃

1.87 g SrF ₂ 27.2 g ZnO

9.0 g SiO ₂ 16.83 g MnCl ₂ -4H ₂ O

4.28 g NH ₄ Cl

This product shows orange fluorescence.

A fabric prepared according to this example gives an initial brightness of 31 lumens per watt with color coordinates of χ - 0.416, y = 0.449 when used in 40 watt fluorescent lamps with a length of 1.2 m.

1 sheet of drawings

Claims (8)

1 2 alkali metal halophosphates and zinc silicate so proceed, claims: that a mixture of starting materials for the produc- tion of an alkaline earth phosphate, a manganese 1. Process for the production of a phosphor compound and zinc silicate or starting materials for based on alkaline earth phosphates and 5 the production of zinc silicate under conditions er zinc silicate, characterized in that they are heated, which give a phosphor. It has that a mixture of starting materials to produce is shown that in this way according to the invention Creation of an alkaline earth phosphate, a new range of phosphors with a luminescent manganese compound and zinc silicate or from the properties at which raw materials for the production of zinc silicate, no other activating metal than manganese for the be heated under conditions that require a halophosphate. With a loose Result in phosphor. Mixing in the absence of a "primary activator" 2. The method according to claim 1, characterized in that there would be no luminescence of the halophosphate, that the zinc silicate or the ingredients result in components. ; instead 10 to 80 percent by weight of the 15 mentioned. The process products are thus due to manganese Make a mix. activated phosphors based on alkaline earth! 3. The method according to claim 1 and 2, characterized in metal-zinc silicon halophosphates. The co- ■ characterized that the mixture of zinc oxide and composition of these new phosphors can by far j Contains silicon dioxide. The range can be varied and neither the zinc silicate! 4. Process according to one or more of the anao proportion nor the halophosphate proportion must stoichiose 1 to 3, characterized in that they are metric. The preferred alkaline earths im Mixture of manganese chloride and / or manganese fluoride ■ Halogen phosphate components are calcium, strontium or i contains. a mixture of these. In the case of the halophosphate / ^ I ^ 5. The method according to one or more of the, the halogen is preferably fluorine or chlorine or V! Claims 1 to 4, characterized in that 35 both. i the mixture in a steam atmosphere between the valuable phosphors according to the invention 750 and 1200 ⁰ C is heated. are made from an initial mix of ingredients j 6. The method according to one or more of the prepares, the zinc silicate or the components therefor in i claims 1 to 5, characterized in that it contains a proportion of 10 to 80 percent by weight. | An initial heating to a temperature of 30 If less than 10% zinc silicate constituents are used from 900 to 1100 ⁰ C in a closed vessel, then the brightness of the finished phosphor is achieved, that the mixture is then cooled, ground very low, and the brightest substances result when and subsequently in a steam atmosphere to the zinc silicate constituents 20% or more of the initial temperature of 900 to 1100 ⁰ C is heated. borrowed mix make up. Does the initial 7. The method according to one or more of the mixture of more than 80 percent by weight zinc claims 1 to 6, characterized in that silicate components, then the finished phosphor the halophosphate components have a calcium - practically the luminescent properties (e.g. and / or contain a strontium compound. the color) of the well-known willemite form 8. The method according to claim 7, characterized in that the zinc silicate phosphor is identified. The brightest phosphors, characterized by the fact that the mixture 0.002 to 0.4 g-atom 40, the emissions of which are different from those of willemite, are manganese per g-atom of zinc, calcium and stron, when the zinc silicate components contain tium together. Make up 65 percent by weight or less of the starting mixture, so that the preferred proportion of zinc silicate components between 20 and 65 percent by weight ^ 45 percent of the mixture is. \ J Luminescent substances arise over a wide range of manganese concentrations. The pre- The invention relates to a method of manufacturing the lower limit of manganese is 0.002 atoms Mn of a phosphor based on alkaline earth halogen per atom (Zn + Ca + Sr), and the upper limit phosphates and zinc silicate. 50 is 0.4 atoms Mn per atom (Zn + Ca + Sr), Synthetic willemite (zinc silicate) is considered to be more valuable during the most useful range of manganese concentrations luminescent substance with green fluorescence generalization 0.005 to 0.25 atoms per atom (Zn + Ca + Sr) my known. Also known are luminescent is. Substances based on alkaline earth metal halogens - Depending on their composition, the phosphates in which the base material (host crystal) 55 new substances show X-ray diffraction patterns that have the apatite structure and an activating metal, characteristic of willemite or apatite or both, for example antimony, Arsenic, bismuth, or cerium are, however, differentiated by the absence of the previously silver, contains. Where such a primary "activator" necessary "primary activator" is available from the usual halophosphate, luminescent substances with an apatite structure can also be used.
May be added and the result is a 60 The new substances show a range of emissions; a wider range of substances. Manganese on its own can have singe colors, which in steady succession from green to act as an activator for apatite-halogen (characteristic of willemite) via yellow and pink phosphates. extends to a reddish color. You speak up More finely, mixtures are known, the calcium halogen short-wave ultraviolet radiation (for example phosphate with manganese-antimony activation and 65 2537 A) and can be used for the production of Contains Mn-activated zinc silicate. Fluorescent lamps can be used. In less According to the invention, in a method for degrees, they are now also by long-wave ultraviolet Production of a phosphor based on earth and cathode rays excited.