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Process for preparing magnesium barium silicate green fluorescent powder

A technology of green fluorescent powder and barium magnesium silicate, which is applied in the direction of chemical instruments and methods, luminescent materials, etc., can solve the problems of fluorescent powder over-sintering, high reaction temperature, long reaction cycle, etc., and achieve uniform and small particle size distribution , reduce the reaction temperature, improve the effect of synthesis efficiency

Inactive Publication Date: 2006-10-04
NINGXIA UNIVERSITY
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, at present, the preparation of phosphors such as silicate mostly adopts high-temperature solid-phase method and sol-gel method. The so-called high-temperature solid-phase method directly uses SiO 2 Mixing and grinding with other alkaline earth carbonates or oxides, this method is difficult to achieve the mixing of substances at the molecular level, so it is not easy to obtain a pure phase after high temperature solid phase, there are defects such as large particles and easy sintering, high reaction temperature, and long time. Such as the U.S. patent "Phosphors for light generation from light emitting semiconductors" (US.6,255,670.B1.Jul.3, 2001), the synthesis process of this patent adopts the traditional high-temperature solid-phase method, which not only has the synthesis temperature of If the temperature is above 1300 degrees, the product is easy to vitrify, and the excessively high synthesis temperature has high requirements on the industrialization process, and the energy waste is large, and the waste heat and waste gas generated in the production are not conducive to environmental protection. At the same time, high temperature solid phase synthesis is easy to cause Phosphor powder is over-sintered, and the particles are coarse and uneven, which is not conducive to subsequent powder coating and other processes. This is obviously not practical for commercial applications that pursue low cost and high output value.
Generally speaking, the phase obtained by the sol-gel method is purer, and the reaction temperature is much lower than that of the high-temperature solid phase, but its luminous brightness is obviously not as good as that of the traditional high-temperature solid phase, and the reaction cycle is longer.
[0004] In addition, previous research and patents have also studied its application too narrowly, only limited to phosphors used in traditional artificial light sources, and did not further study its application value in other aspects
[0005] Although scintillation crystals have been commercialized and used in high-energy ray detection equipment such as x-rays, due to their high price and short lifespan, there is still a huge market for phosphors used in x-ray intensifying screens now and in the future prospects, therefore, it is of great significance to develop phosphors that can be applied in this field

Method used

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  • Process for preparing magnesium barium silicate green fluorescent powder

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0021] Analytical pure Na 2 SiO 3 .9H 2 O and Ba(NO 3 ) 2 Dissolve them in deionized water at a ratio of 1:1 (molar ratio), and then mix the two to produce a large amount of white BaSiO 3 The precipitate was stirred evenly with a glass rod, filtered and washed, and dried at 70°C for 12h. The obtained barium silicate powder is mixed with MgO in a ratio (molar ratio) of 2:1, and 0.02molEu 2 o 3 Grind evenly in an agate mortar. Put the mixed sample into a corundum crucible, burn it in an activated carbon reducing atmosphere at 900°C for 2-3h, and then cool it down to room temperature with the furnace.

[0022] Take out the corundum crucible from the furnace, open the cover and use tweezers to remove the activated carbon ash wrapped in quartz wool, take out the product and grind it again with a mortar to get the required phosphor.

Embodiment 2

[0024] Analytical pure Na 2 SiO 3 .9H 2 O and BaCl 2 Dissolve them in deionized water at a ratio of 1:1 (molar ratio), and then mix the two to produce a large amount of white BaSiO 3 The precipitate was stirred evenly with a glass rod, washed by suction filtration, and dried at 100°C for 10h. Gained barium silicate powder and MgCO 3 At the same time, 0.04molEu(NO 3 ) 3 Grind well in an agate mortar. Put the mixed sample into a corundum crucible, burn it in an activated carbon reducing atmosphere at 950°C for 2-3h, and then cool it down to room temperature with the furnace.

[0025] Take out the corundum crucible from the furnace, open the cover and use tweezers to remove the activated carbon ash wrapped in quartz wool, take out the product and grind it again with a mortar to get the required phosphor.

Embodiment 3

[0027] Analytical pure K 2 SiO 3 and Ba(NO 3 ) 2 Dissolve them in deionized water at a ratio of 1:1 (molar ratio), and then mix the two to produce a large amount of white BaSiO 3 Precipitate, stir with a glass rod. Suction-filtered and washed, dried at 90°C for 12h. Gained barium silicate powder and analytically pure (MgCO 3 ) 4 ·Mg(OH) 2 ·5H 2 O (calculated as MgO) is simultaneously mixed with 0.02molEu at a ratio of 2:1 (molar ratio) 2 o 3 Grind well in an agate mortar. Put the mixed sample into a corundum crucible, burn it in an activated carbon reducing atmosphere at 950°C for 2.5h, and then cool it to room temperature with the furnace.

[0028] Take out the corundum crucible from the furnace, open the cover and use tweezers to remove the activated carbon ash wrapped in quartz wool, take out the product and grind it again with a mortar to get the required phosphor.

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Abstract

The present invention relates to the preparation process of barium magnesium silicate as green phosphor. Reaction precursor BaSiO3 is first obtained via precipitation process, and then mixed with MgO and dopent Eu2O3 and ground, and the mixture powder is burnt at 900 deg.c for 2 hr to obtain required material. The precipitation process can obtain fine and pure precursor powder, and the whole technological process has low reaction temperature, short reaction period, low power consumption and high synthesis efficiency. The product has fine and homogeneously distributed grain size, may be used in coating after slight grinding and has no vitrification and sintering.

Description

technical field [0001] The invention relates to the technical field of chemical synthesis, in particular to a preparation method of barium magnesium silicate green fluorescent powder. Background technique [0002] As we all know, phosphors used in artificial light sources such as neon lights, signal lights, imitating natural white light sources, and display equipment such as x-ray intensifying screens for hospitals and home TV displays are one of the foundations for the prosperity of modern civilization. New fluorescent materials or improvements to existing fluorescent materials have always been valued by the chemical and material industries of various countries because of their huge market development prospects and social benefits. [0003] In the existing research on phosphors, doped silicate compounds, especially alkaline earth and alkaline earth metal silicates, have the advantages of better moisture resistance than aluminate, and their application value in luminescent m...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C09K11/59
Inventor 徐崇福雷芳
Owner NINGXIA UNIVERSITY