Method for covering silicon dioxide film on aluminate series long afterglow fluorescent powder surface

A long-lasting phosphor and silicon dioxide technology, which is applied in chemical instruments and methods, luminescent materials, etc., can solve the problems of changing the composition and performance of luminescent materials, incomplete surface coating, and performance degradation, etc., to achieve low cost and long-lasting afterglow. Long time, the effect of inhibiting hydrolysis

Inactive Publication Date: 2002-10-02
TSINGHUA UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

Although this method can inhibit the hydrolysis of the luminescent material to a certain extent, the process is complicated. More importantly, the encapsulation material is easy to chemically react with the matrix powder of the luminescent material during the secondary calcination process, thereby changing the composition and performance of the luminescent material. And after calcination, the pulverization destroys the surface of the luminescent material powder particles, making the surface coating layer incomplete, thereby reducing the performance

Method used

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  • Method for covering silicon dioxide film on aluminate series long afterglow fluorescent powder surface
  • Method for covering silicon dioxide film on aluminate series long afterglow fluorescent powder surface
  • Method for covering silicon dioxide film on aluminate series long afterglow fluorescent powder surface

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Embodiment 1

[0016] Weigh 20 grams of strontium aluminate yellow-green long-lasting phosphor, 2 0.70 g of tetraethyl orthosilicate is weighed to account for 1% by mass of the phosphor powder. According to tetraethyl orthosilicate: ethanol: deionized water = 1:6:10 (volume ratio), measure ethanol and deionized water, place them in a beaker, and adjust the pH value of the solution to 6 with nitric acid. Heated in a water bath at 90°C with constant stirring for 3 minutes to turn the solution into a sol. Pour the phosphor powder into the sol, and stir while heating at 100°C. After the phosphor powder expands loosely and the sol completely turns into a gel, put the beaker in an oven and keep it at 100°C for 2 hours to dry. Put the dried coated powder in a sintering furnace, keep it warm at 500°C for 1 hour, and take it out after cooling.

[0017] After coating, the phosphor powder will not be hydrolyzed after soaking in water for 24 hours, the initial brightness will be significantly higher t...

Embodiment 2

[0019] Weigh 20 grams of calcium aluminate series purple long-lasting phosphor, 2 Accounting for 3% by mass of the phosphor powder, weigh 2.08 grams of tetraethyl orthosilicate. According to tetraethyl orthosilicate: ethanol: deionized water = 1:3:4 (volume ratio), measure ethanol and deionized water, place them in a beaker, and adjust the pH value of the solution to 4 with nitric acid. Heated in a water bath at 80°C with constant stirring for 5 minutes to turn the solution into a sol. Pour the phosphor powder into the sol, and stir while heating at 80°C. After the phosphor powder expands loosely and the sol completely turns into a gel, put the beaker in an oven, keep it warm at 60°C for 13 hours, and dry at °C. Put the dried coated powder in a sintering furnace, keep it warm at 400°C for 2 hours, and take it out after cooling.

[0020] After coating, there is a layer of transparent silicon dioxide film on the surface of the phosphor powder, such as figure 1 shown. After c...

Embodiment 3

[0022] Weigh 30 grams of strontium aluminate blue long-lasting phosphor, 2 Accounting for 5% by mass of the phosphor powder, weigh 5.21 grams of ethyl orthosilicate. According to tetraethyl orthosilicate: ethanol: deionized water = 1:4:5 (volume ratio), measure ethanol and deionized water, place them in a beaker, and adjust the pH value of the solution to 3 with nitric acid. Heated in a water bath at 70°C and stirred continuously for 8 minutes to turn the solution into a sol. Pour the phosphor powder into the sol, and stir while heating at 50°C. After the phosphor powder expands loosely and the sol completely turns into a gel, put the beaker in an oven, and first heat it at 70°C for 10 hours to dry. Put the dried coated powder in a sintering furnace, keep it warm at 450°C for 1.5 hours, and take it out after cooling.

[0023] After coating, the phosphor powder will not be hydrolyzed after soaking in water for 24 hours, the initial brightness will be significantly higher than...

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Abstract

The ethyl metasilicate is dissolved in ethyl alcohol and deionized water, heated in hot water bath with 50-90 deg.c to hydrolyze solution into transparent ethyl metasilicate sol; the long-persistencephosphor powder is immersed in the ethyl metasilicate sol, heated to 50-100 deg.c, the sol can be completely changed into gel; the covered mixture is placed in oven, oven-dried at 50-100 deg.c, and the over-dried covered powder is placed in sintering furnace, heat-insulated for 1-5 hr, at 300-500 deg.c and cooled so as to implement said invention which can obviously raise water-resisting propertyof long-persistence phosphor powder.

Description

technical field [0001] The invention relates to a method for coating a film on the surface of a long-lasting phosphor, in particular to a method for coating a layer of water-resistant silicon dioxide film on the surface of an alkaline-earth aluminate long-lasting phosphor. Background technique [0002] Rare earth-doped alkaline earth metal aluminate phosphor is an excellent long-lasting phosphor with high initial brightness and long afterglow time. It has been widely used in luminous paint, luminous paint, luminous ink, luminous clocks, instruments, and meters. Luminous display of dials, electrical appliances, etc. However, in practical applications, this phosphor is easily hydrolyzed when soaked in water, forming a white mixture that does not emit light, thereby drastically reducing the luminous intensity. Therefore, its application in water-containing environments such as water-based coatings is greatly limited. The improvement of water resistance can greatly expand the ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C09K11/02
Inventor 张中太张俊英彭劲松唐子龙
Owner TSINGHUA UNIV
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