Method for preparing surface-coated yellow fluorescent powder

A technology of yellow fluorescent powder and surface coating, applied in chemical instruments and methods, luminescent materials, electrical components, etc., can solve problems such as uneven light emission of white light-emitting diodes, unstable electrical and chemical properties, poor dispersion of phosphor powder, etc. , to achieve the effect of avoiding the decline of luminous performance, improving the light spot and good uniformity

Inactive Publication Date: 2012-02-01
IRICO
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

Due to external factors and the luminescent material itself, untreated phosphors often have powder agglomeration, surface defects, and unstable electrical and chemical properties. The thermal quenching temperature is low, resulting in poor dispersion of phosphors during slurrying. Poor and low luminous efficiency during use, the white light-emitting diodes produced are uneven and easy to be blackened, etc.

Method used

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  • Method for preparing surface-coated yellow fluorescent powder

Examples

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Effect test

Embodiment 1

[0022] A preparation method for surface-coated yellow fluorescent powder, comprising the following steps:

[0023] 1) Weigh 0.298mol of Y 2 o 3 , 0.5mol of Al(OH) 3 , 0.001mol of BaCO 3 , CeO as an activator 4 0.001mol, the four compounds were mixed to form a mixture, and then added a flux of 4.6% by weight and ground for 30 minutes to obtain a phosphor precursor; the flux was prepared by YF 3 , AlF 3 、BaF 2 , CeF 3 Composition by mixing; YF in flux 3 :AlF 3 :BaF 2 : CeF 3 The mass ratio is 1:4:1.6:1;

[0024] 2) Place the phosphor precursor in a planetary ball mill for ball milling, mix thoroughly and evenly, and then put it into a roasting container, put double-layer graphite surface coating blocks inside and outside the container, and put them together at high temperature Heating in the furnace, keeping the temperature at 1000°C for 1 hour, then raising the temperature to 1450°C for 6 hours, and cooling in air after the roasting is completed, to obtain the roas...

Embodiment 2

[0028] A preparation method for surface-coated yellow fluorescent powder, comprising the following steps:

[0029] 1) Weigh 0.295mol of Y 2 o 3 , 0.5mol of Al(OH) 3 , 0.002mol of BaCO 3 , CeO as an activator 4 0.003mol, the four compounds were mixed to form a mixture, and then 8% of the mass of the mixture was added as a flux and ground for 30 minutes to obtain a phosphor precursor; the flux was supplied by YF 3 , AlF 3 、BaF 2 , CeF 3 Composition by mixing; YF in flux 3 :AlF 3 :BaF 2 : CeF 3 The mass ratio is 1:5:2:1.2;

[0030] 2) Place the phosphor powder precursor in a planetary ball mill for ball milling, mix well and evenly, then put it into a roasting container, put carbon powder inside and outside the container, and put it into a high-temperature furnace for heating, 800 ℃ for 1.5h, then heated up to 1300°C and roasted for 10h, after the roasting was completed, cooled in the air to obtain the roasted product;

[0031] 3) Break the roasted product after coo...

Embodiment 3

[0034] The preparation method of yellow fluorescent powder comprises the following steps:

[0035] 1) Weigh 0.29mol of Y 2 o 3 , 0.5mol of Al(OH) 3 , 0.004mol of BaCO 3 , CeO as an activator 4 0.006mol, the four compounds are mixed to form a mixture, and then 1% of the mass of the mixture is added as a flux and ground for 30 minutes to obtain a phosphor precursor; the flux is provided by YF 3 , AlF 3 、BaF 2 , CeF 3 Composition by mixing; YF in flux 3:AlF 3 :BaF 2 : CeF 3 The mass ratio is 1:6:2.2:1.4;

[0036] 2) Place the phosphor precursor in a planetary ball mill for ball milling, mix thoroughly and evenly, then put it into a roasting container, put carbon powder inside and outside the container, and put them together in a high-temperature furnace for heating, 900 ℃ for 1.2h, then heated up to 1550℃ and roasted for 10h, after the roasting was completed, cooled in the air to obtain the roasted product;

[0037] 3) Break the roasted product after cooling, collec...

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Abstract

The invention discloses a method for preparing surface-coated yellow fluorescent powder, which comprises the following steps of: mixing four compounds according to a molar ratio of Y2O3 to Al(OH)3 to BaCO3 to CeO4 of (3-x-y):5:x:y; then adding a fluxing agent of which the mass is 1 percent to 8 percent of the mass of the mixture and grinding for 30 to 40min to obtain a fluorescent powder precursor; carrying out ball milling and uniform mixing on the fluorescent powder precursor; then preserving heat for 1 to 1.5 hours at a temperature of 800 to 1,000 DEG C in the reducing condition; then heating the obtained product to a temperature of 1,300 DEG C to 1,550 DEG C, roasting for 5 to 10 hours and cooling in the air; after cooling, crushing the obtained product, collecting the crushed product and sufficiently washing the crushed product by water; filtering the obtained crushed product to obtain yellow fluorescent powder; coating the obtained yellow fluorescent powder with a mixture of carboxymethyl cellulose sodium, gelatin, polyethylene glycol and sodium silicate; and finally obtaining the surface-coated yellow fluorescent powder. Due to the adoption of the method disclosed by the invention, the aggregation between powder is effectively prevented, so that particles are small and are at the micron level.

Description

【Technical field】 [0001] The invention belongs to the technical field of fluorescent powder for white light emitting diodes, and in particular relates to a preparation method of surface-coated yellow fluorescent powder. 【Background technique】 [0002] White light-emitting diode (w-LED) is a new generation of green and environmentally friendly solid-state lighting green light source. It has the advantages of low energy consumption, long life, small size, stable structure, good directionality, fast response, no radiation, and suitable for harsh environments. In the preparation of white LED devices, phosphor is a very critical material, and its performance directly affects the brightness, color coordinates, color temperature, and color rendering of white LEDs. Due to external factors and the luminescent material itself, untreated phosphors often have powder agglomeration, surface defects, and unstable electrical and chemical properties. The thermal quenching temperature is low,...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C09K11/80C09K11/02H01L33/50
Inventor 毕自贵
Owner IRICO
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