CN113583661A

CN113583661A - Spheroidal fluoride fluorescent powder, preparation method thereof, mixture and light-emitting device

Info

Publication number: CN113583661A
Application number: CN202011368858.5A
Authority: CN
Inventors: 何锦华; 刘晓鹏; 李朝军; 梁超; 符义兵; 徐俊峰
Original assignee: Taizhou Chengruida New Material Co ltd
Current assignee: Jiangsu Borui Photoelectric Co ltd; Taizhou Chengruida New Material Co Ltd
Priority date: 2020-11-30
Filing date: 2020-11-30
Publication date: 2021-11-02

Abstract

The invention provides a sphere-like fluoride fluorescent powder, a preparation method thereof, a mixture and a light-emitting device, wherein the weight specific surface area range of particles of the sphere-like fluoride fluorescent powder is 1273-1785 cm²(ii)/g; the grain size range is 14-40 μm; the chemical structural formula is as follows: a. the_xM_(1‑y)F_z:yMn⁴⁺Wherein A is K, Li, Na, Rb, Cs or NH4⁺M is at least one of Si, Ge, Sn, Ti, Zr or Hf; and 1.6 ≦ x ≦ 2.4, 0<y < 0.18, 5.0 < z < 7.3. The spherical fluoride fluorescent powder is irregular spherical particles, has rough surface, improves the interfacial tension, has strong surface adsorption capacity, and can pass through the preparation processThe addition of the PE balls or the tetrafluoroethylene balls can improve the specific surface area and the sphericity of the particles, easily disperse the particles in media such as colloid and the like, and facilitate the compatibility of the particles with packaging glue when the particles are applied to LED packaging, thereby preventing reflection, improving the light emitting efficiency and improving the anti-aging performance.

Description

Spheroidal fluoride fluorescent powder, preparation method thereof, mixture and light-emitting device

Technical Field

The invention relates to the technical field of luminescent materials, in particular to a spherical fluoride fluorescent powder, a preparation method thereof, a mixture and a luminescent device.

Background

Based on the characteristics of high luminous efficiency, low carbon, environmental protection and energy conservation of the LED, most of LCD televisions and mobile phones on the market adopt the LED as a backlight source. Meanwhile, in order to meet the requirement of high color gamut coverage of an LED backlight source, some new fluorescent materials with narrow half-wave width are receiving attention in recent years, such as fluoride fluorescent powder, wherein an important fluoride fluorescent powder is KSF fluorescent powder, the KSF fluorescent powder belongs to a cubic crystal system, and the fluorescent materials have the outstanding advantages of high luminous efficiency, high color purity, capability of liquid phase synthesis and the like, and have wide commercial prospects in the application of white LEDs and wide color gamut LCD backlight sources because the spectral peak is narrower than that of commercial nitride red fluorescent powder.

In the prior art, patent document CN207993892U discloses an LED lamp, in which an LED light-emitting component includes a support, a blue light chip, a green light chip and a fluorescent colloid, the blue light chip and the green light chip are encapsulated on the support through the fluorescent colloid, and the fluorescent colloid is filled with KSF fluorescent powder, and the scheme of the embodiment of the patent can make the luminous color gamut value reach 105%.

However, the existing fluoride fluorescent powder has smooth surface, small interfacial tension, poor compatibility with organic materials such as packaging glue and the like, so that the fluoride fluorescent powder is difficult to uniformly distribute in the packaging glue and has poor dispersibility, thereby causing the fluorescent powder to settle and agglomerate, further causing the problems of reduced optical consistency of products, increased reject ratio, increased production cost, easy aging of products and the like, and no good solution is available at present.

Disclosure of Invention

One of the objectives of the present invention is to overcome the deficiencies of the prior art and provide a quasi-spherical fluoride phosphor, which is irregular quasi-spherical particles with rough surface, improved interfacial tension, strong surface adsorption capability, reflection prevention, higher light extraction efficiency and better anti-aging performance.

In order to achieve the purpose, the invention adopts the following technical scheme:

the weight specific surface area range of the particles of the globular fluoride fluorescent powder is 1273-1785 cm²/g。

Preferably, the weight specific surface area range of the spheroidal fluoride phosphor particles is: 1482-1699 cm²(ii) in terms of/g. The weight specific surface area range can avoid low light-emitting rate of the spheroidal fluoride fluorescent powder due to smoothness, and can also avoid poor ageing resistance due to unfavorable powder dispersion due to overlarge weight specific surface area; therefore, within the range of the weight specific surface area, the spheroidal fluoride fluorescent powder can ensure better light-emitting rate and dispersibility.

Preferably, the grain size of the spheroidal fluoride phosphor is in a range of 14 to 40 μm. Further preferably, the grain size range of the spheroidal fluoride fluorescent powder is 20-30 μm, and the grain size range can ensure that the powder is uniformly dispersed and the crystallization is complete, so that better aging performance is ensured. The particle size is too large, which is not beneficial to the uniform dispersion of the powder; the crystal structure with the undersize grain diameter is imperfect, and the ageing resistance is poor.

The preparation of the spheroidal fluoride fluorescent powder controls the surface roughness of the fluorescent powder by adding a PE ball or a tetrafluoroethylene ball, and the volume specific surface area range of the PE ball or the tetrafluoroethylene ball is 2.0-10.0 mm²/mm³Preferably 4 to 5.8mm²/mm³. The surface roughness of the fluorescent powder can reach the optimal range by controlling the volume specific surface area of the PE ball or the tetrafluoroethylene ball, so that the spherical fluoride fluorescent powder can ensure better light-emitting rate and dispersibility.

Preferably, the chemical structural formula of the spheroidal fluoride phosphor is as follows: a. the_xM_(1-y)F_z:yMn^4+，Wherein the content of the first and second substances,a is at least one of K, Li, Na, Rb, Cs or NH4+, and M is at least one of Si, Ge, Sn, Ti, Zr or Hf; and 1.6 ≦ x ≦ 2.4, 0<y≦0.18，5.0≦z≦7.3。

Preferably, the chemical structural formula of the spheroidal fluoride phosphor is as follows: a. the_xM_(1-y)F_z:yMn⁴⁺Wherein A is at least one of K, Li, Na, Rb, Cs or NH4+, and M is at least one of Si, Ge, Sn, Ti, Zr or Hf; and x is 2 and z is 6.

Preferably, the chemical structural formula of the spheroidal fluoride phosphor is as follows: a. the_xM_(1-y)F_z:yMn⁴⁺Wherein A is at least one of K, Li, Na, Rb, Cs or NH4+, and M is at least one of Si, Ge, Sn, Ti, Zr or Hf; and 2 x 0.3, y 0.03 y 0.06, z 6.7 7 7.1.

The second purpose of the present invention is to provide a method for preparing the above-mentioned spheroidal fluoride phosphor, wherein during preparation, PE spheres or tetrafluoroethylene spheres with different specifications are added, so as to control the roughness of the surface of the crystal grain, i.e. to improve the specific surface area and sphericity of the particles, to easily disperse the particles in a medium such as a colloid, and to facilitate compatibility with an encapsulation adhesive, to prevent reflection, to improve light extraction efficiency, and to improve anti-aging performance when applied to LED encapsulation. The following technical scheme is adopted specifically:

the preparation method of the spheroidal fluoride fluorescent powder comprises the following steps:

(1) taking fluoride and fluoromanganate of at least one of K, Li, Na, Rb, Cs or NH4+ as raw materials, weighing the required raw materials according to the chemical structural formula and the stoichiometric ratio, and uniformly mixing; dissolving the raw materials in an HF aqueous solution to prepare a first solution;

(2) adding PE balls or tetrafluoroethylene balls into the first solution, stirring, injecting at least one fluoride solution of Si, Ge, Sn, Ti, Zr or Hf into the first solution at the speed of 10-15 mL/min, mixing, heating and stirring, and pouring out the supernatant to obtain a mixed system; the excessively fast dropping speed is not beneficial to the growth of the KSF fluorescent powder crystal, so that the luminous efficiency is excessively low, and the excessively slow dropping speed has no obvious influence on the growth of the crystal, but consumes a great deal of time and cost.

(3) Adding an HF aqueous solution with the mass concentration of 2-5% into the mixed system, stirring and washing for 2 times, and then stirring and washing for 2 times by using absolute ethyl alcohol;

(4) and (3) taking the washed mixed system for blast drying, wherein the temperature of the blast drying is 60-100 ℃, and obtaining the spheroidal fluoride fluorescent powder.

Preferably, the mass concentration of the HF aqueous solution in the step (1) is 30-50%, and the mass concentration of the fluoride solution in the step (2) is 10-15%.

Preferably, in the step (2), the temperature of mixing, heating and stirring is 10-50 ℃, and the time of mixing, heating and stirring is 2-5 hours; the low temperature is not beneficial to the growth of the KSF fluorescent powder crystal, the low luminous efficiency is caused, and the high temperature can cause the Mn in the reaction system⁴⁺The inactivation due to valence instability also leads to low luminous efficiency.

Preferably, the diameter of the PE ball or the tetrafluoroethylene ball is 1-5 mm, and the density of the PE ball or the tetrafluoroethylene ball is 1.1-1.4 mg/mL. The density of the PE balls or tetrafluoroethylene balls is selected to be similar to the concentration of hydrofluoric acid in the system, the dispersion state of the PE balls or tetrafluoroethylene balls is influenced when the density is too large or too small, and the PE balls or tetrafluoroethylene balls have good dispersion state in the density range; the diameter of the PE ball or the tetrafluoroethylene ball is too small, so that the obtained fluorescent powder particles are too fine, the diameter is too large, the KSF fluorescent powder with a rough surface is not prepared, and the fluorescent powder prepared in the diameter range of the PE ball or the tetrafluoroethylene ball is irregular spherical-like particles and has a rough surface.

Preferably, the density of the PE balls or the tetrafluoroethylene balls is 1.25-1.3 mg/mL.

Preferably, the volume specific surface area of the PE balls or the tetrafluoroethylene balls is 2.0-10.0 mm²/mm^3；The volume specific surface area of the PE spheres is correspondingly reduced along with the increase of the diameter of the PE spheres or tetrafluoroethylene spheres; more preferably, the volume specific surface area of the PE balls or tetrafluoroethylene balls is 4.0-5.8 mm²/mm³. The surface roughness of the fluorescent powder can reach the optimal range by controlling the volume specific surface area of the PE ball or the tetrafluoroethylene ball, so that the quasi-spherical fluoride fluorescent powder can be ensuredThe light-emitting rate and the dispersibility are better.

Preferably, the density of the PE or tetrafluoroethylene spheres is controlled by filling sulfuric acid of different concentrations inside the PE or tetrafluoroethylene spheres.

Preferably, the concentration of the sulfuric acid is 10-75%.

The third purpose of the invention is to provide a mixture of two kinds of fluorescent powder containing the spheroidal fluoride fluorescent powder, which is realized by the following technical scheme:

one of the fluorescent powder mixture comprises the spherical fluoride fluorescent powder and one of beta sialon powder, silicate green powder, aluminate fluorescent powder or quantum dot green powder.

Another phosphor mixture comprises the spherical fluoride phosphor and one or more of aluminate phosphor, nitride red phosphor, nitride blue-green phosphor, silicate phosphor, phosphate blue phosphor or magnesium fluorogermanate.

The fourth object of the present invention is to provide a light emitting device at least comprising an LED chip emitting ultraviolet light, violet light or blue light and a phosphor, wherein the phosphor is the above-mentioned spheroidal fluoride phosphor.

Compared with the prior art, the invention has the following beneficial effects:

(1) the spherical fluoride fluorescent powder provided by the invention is irregular spherical particles, has rough surface, improves the interfacial tension and has stronger surface adsorption capacity;

(2) PE balls or tetrafluoroethylene balls with different specifications are added during preparation, so that the specific surface area and the sphericity of the particles can be improved, the particles are easily dispersed in media such as colloid, and the sedimentation rate of powder particles in packaging glue can be effectively reduced in the use process of the fluorescent powder, so that the targeting concentration is greatly improved;

(3) the preparation method is simple and suitable for large-scale batch production;

(4) the spherical fluoride fluorescent powder prepared by the invention is applied to LEDs, is beneficial to being compatible with packaging glue during packaging, prevents reflection, and has higher light emitting efficiency and better anti-aging performance.

Drawings

FIG. 1 is a scanning electron microscope image of a spheroidal fluoride phosphor prepared in example 1 of the present invention;

FIG. 2 is a scanning electron microscope image of a spheroidal fluoride phosphor prepared in example 2 of the present invention;

FIG. 3 is a scanning electron micrograph of a spheroidal fluoride phosphor prepared in example 4 of the present invention;

FIG. 4 is a scanning electron micrograph of a phosphor prepared according to a comparative example of the present invention;

FIG. 5 is a target drawing of a spheroidal fluoride phosphor prepared in example 10 of the present invention;

FIG. 6 is a target drawing of a phosphor prepared according to a comparative example of the present invention;

FIG. 7 is a graph showing an excitation spectrum of a spherical-like fluoride phosphor prepared in example 1 of the present invention;

FIG. 8 is a graph showing an emission spectrum of a spherical-like fluoride phosphor prepared in example 1 of the present invention;

FIG. 9 is a graph showing an excitation spectrum of a fluoride phosphor according to a comparative example of the present invention;

FIG. 10 is a graph showing an emission spectrum of a fluoride phosphor according to a comparative example of the present invention.

Detailed Description

In order to make the objects, technical solutions and effects of the present invention clearer and clearer, the present invention will be described in further detail with reference to the accompanying drawings in conjunction with the detailed description. It should be understood that the detailed description and specific examples, while indicating the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention. The test methods used below are all conventional methods unless otherwise specified; the materials, reagents and the like used are, unless otherwise specified, commercially available reagents and materials.

Example 1

This example provides a spheroidal fluoride phosphor prepared by the following method: weighing K₂MnF₆2.5g，KHF₂25g of the first solution is prepared by dissolving the first solution in 250g of HF aqueous solution with the mass concentration of 30%; in addition, the weight is measuredH in a quantitative concentration of 10%₂SiF₆200g of an aqueous solution as a second solution; adding 100g of PE balls into the prepared first solution, wherein the density of the PE balls is 1.25mg/mL, the diameter of the PE balls is 1.0mm, the concentration of a sulfuric acid medium is 30%, and mechanically stirring the mixture at the stirring temperature of 30 ℃; then, the second solution was injected into the first solution at a rate of 15 mL/min. Stirring the reaction solution for 3h, pouring out the supernatant, adding 3% HF aqueous solution, stirring and washing for 2 times, washing for 2 times with absolute ethyl alcohol, and drying at 60 deg.C under forced air drying condition to obtain spherical Mn⁴⁺Excited fluoride phosphor K_2.11Si_0.95F_6.95:0.05Mn⁴⁺。

Fig. 7 shows an excitation spectrum of the quasi-spherical fluoride phosphor prepared in test example 1, where the excitation spectrum is a change of fluorescence intensity at a certain wavelength measured by the phosphor under the action of excitation lights with different wavelengths, that is, a relative efficiency of the excitation lights with different wavelengths, and it can be seen that the phosphor prepared in example 1 has the strongest fluorescence intensity under the action of the excitation light with a wavelength of about 448 nm; FIG. 8 is an emission spectrum of the phosphor obtained in example 1, which shows the distribution of the fluorescence intensity at different wavelengths under the action of excitation light of a certain fixed wavelength, i.e., the relative intensities of light components of different wavelengths in the fluorescence.

Example 2

This example provides a spheroidal fluoride phosphor prepared by the following method: weighing K₂MnF₆3.0g、KHF₂25g of the first solution is prepared by dissolving the first solution in 250g of HF aqueous solution with the mass concentration of 40%; further, H was weighed to have a mass concentration of 15%₂SiF₆200g of an aqueous solution as a second solution; secondly, adding the prepared first solution into 100g of PE balls, wherein the density of the PE balls is 1.25mg/mL, the diameter of the PE balls is 1.0mm, the concentration of a sulfuric acid medium is 30%, and mechanically stirring the mixture at the stirring temperature of 30 ℃; then, injecting the second solution into the first solution at a speed of 15 mL/min; stirring the reaction solution for 3h, pouring out the supernatant, adding HF aqueous solution with the mass concentration of 3%, stirring and washing for 2 times, and washing for 2 times with absolute ethyl alcoholDrying the mixture under the condition of 60 ℃ blast drying to prepare the spheroidal Mn⁴⁺Excited fluoride phosphor K_2.07Si_0.95F_6.88:0.05Mn⁴⁺。

Example 3

This example provides a spheroidal fluoride phosphor prepared by the following method: weighing K₂MnF₆2.8g、KHF₂28g of the first solution was prepared by dissolving it in 250g of an aqueous HF solution having a mass concentration of 50%; further, H was weighed to have a mass concentration of 15%₂SiF₆150g of an aqueous solution as a second solution; secondly, adding the prepared first solution into 100g of PE balls, wherein the density of the PE balls is 1.25mg/mL, the diameter of the PE balls is 1.0mm, the concentration of a sulfuric acid medium is 30%, and mechanically stirring the mixture at the stirring temperature of 30 ℃. Then, injecting the second solution into the first solution at a speed of 15 mL/min; stirring the reaction solution for 3h, pouring out the supernatant, adding HF aqueous solution with the mass concentration of 3%, stirring and washing for 2 times, washing for 2 times with absolute ethyl alcohol, and drying under the condition of blast drying at 60 ℃ to obtain the spherical Mn⁴⁺Excited fluoride phosphor K_2.15Si_0.94F_6.95:0.06Mn⁴⁺。

Example 4

This example provides a spheroidal fluoride phosphor prepared by the following method: weighing K₂MnF₆3.0g、KHF₂27g of a first solution prepared by dissolving 230g of an aqueous HF solution having a mass concentration of 30%; further, H was weighed to have a mass concentration of 15%₂SiF₆250g of aqueous solution was used as the second solution. Secondly, adding the prepared first solution into 150g of PE balls, wherein the density of the PE balls is 1.25mg/mL, the diameter of the PE balls is 1.0mm, the concentration of a sulfuric acid medium is 30%, and mechanically stirring the mixture at the stirring temperature of 10 ℃; then, injecting the second solution into the first solution at a speed of 10 mL/min; stirring the reaction solution for 2h, pouring out the supernatant, adding HF aqueous solution with the mass concentration of 2%, stirring and washing for 2 times, washing for 2 times with absolute ethyl alcohol, and drying under the condition of blast drying at 60 ℃ to obtain the spherical Mn⁴⁺ExcitationFluoride phosphor K of_2.04Si_0.97F_7.07:0.03Mn⁴⁺。

Example 5

This example provides a spheroidal fluoride phosphor prepared by the following method: weighing K₂MnF₆3.0g、KHF₂27g of a first solution prepared by dissolving 230g of an aqueous HF solution having a mass concentration of 40%; further, H was weighed to have a mass concentration of 15%₂SiF₆250g of aqueous solution was used as the second solution. Secondly, adding 150g of PE balls into the prepared first solution, wherein the density of the PE balls is 1.28mg/mL, the diameter of the PE balls is 2.3mm, the concentration of a sulfuric acid medium is 45%, and mechanically stirring the mixture at the stirring temperature of 10 ℃; then, injecting the second solution into the first solution at a speed of 10 mL/min; stirring the reaction solution for 2h, pouring out the supernatant, adding HF aqueous solution with the mass concentration of 2%, stirring and washing for 2 times, washing for 2 times with absolute ethyl alcohol, and drying under the condition of blast drying at 60 ℃ to obtain the spherical Mn⁴⁺Excited fluoride phosphor K_2.15Si_0.95F_7.10:0.05Mn⁴⁺。

Example 6

This example provides a spheroidal fluoride phosphor prepared by the following method: weighing K₂MnF₆3.0g、KHF₂27g of a first solution prepared by dissolving 230g of an aqueous HF solution having a mass concentration of 50%; further, H was weighed to have a mass concentration of 15%₂SiF₆250g of aqueous solution was used as the second solution. Secondly, adding the prepared first solution into 150g of PE balls, wherein the density of the PE balls is 1.30mg/mL, the diameter of the PE balls is 5.0mm, the concentration of a sulfuric acid medium is 45%, and mechanically stirring the mixture at the stirring temperature of 10 ℃; then, the second solution was injected into the first solution at a rate of 10 mL/min. Stirring the reaction solution for 2h, pouring out the supernatant, adding HF aqueous solution with the mass concentration of 2%, stirring and washing for 2 times, washing for 2 times with absolute ethyl alcohol, and drying under the condition of blast drying at 60 ℃ to obtain the spherical Mn⁴⁺Excited fluoride phosphor K_2.09Si_0.95F_7.10:0.05Mn⁴⁺。

Example 7

This example provides a spheroidal fluoride phosphor prepared by the following method: weighing K₂MnF₆2.8g、KHF₂28g of a first solution prepared by dissolving 200g of 35% HF aqueous solution; further, H was weighed so as to have a mass concentration of 12%₂SiF₆230g of an aqueous solution was used as the second solution. Secondly, adding the prepared first solution into 200g of PE balls, wherein the density of the PE balls is 1.28mg/mL, the diameter of the PE balls is 3.0mm, the concentration of a sulfuric acid medium is 38%, and mechanically stirring at 50 ℃; then, the second solution was injected into the first solution at a rate of 13 mL/min; stirring the reaction solution for 5h, pouring out the supernatant, adding HF aqueous solution with the mass concentration of 5%, stirring and washing for 2 times, washing for 2 times with absolute ethyl alcohol, and drying under the condition of blast drying at 60 ℃ to obtain the spherical Mn⁴⁺Excited fluoride phosphor K_2.13Si_0.95F_6.91:0.05Mn⁴⁺。

Example 8

This example provides a spheroidal fluoride phosphor prepared by the following method: weighing K₂MnF₆2.5g、KHF₂28g of the second solution was dissolved in 200g of an aqueous HF solution having a mass concentration of 50%, to prepare a first solution. Further, H was weighed so as to have a mass concentration of 12%₂SiF₆230g of an aqueous solution as a second solution; secondly, adding the prepared first solution into 200g of PE balls, wherein the density of the PE balls is 1.28mg/mL, the diameter of the PE balls is 5.0mm, the concentration of a sulfuric acid medium is 38%, and mechanically stirring at the temperature of 50 ℃; then, the second solution was injected into the first solution at a rate of 13 mL/min; stirring the reaction solution for 5h, pouring out the supernatant, adding HF aqueous solution with the mass concentration of 5%, stirring and washing for 2 times, washing for 2 times with absolute ethyl alcohol, and drying under the condition of blast drying at 60 ℃ to obtain the spherical Mn⁴⁺Excited fluoride phosphor K_2.09Si_0.95F_7.01:0.05Mn⁴⁺。

Example 9

This embodiment provides a ball-like shapeA fluoride phosphor prepared by the process of: weighing K₂MnF₆2.8g、KHF₂25g of the first solution is prepared by dissolving the first solution in 220g of HF aqueous solution with the mass concentration of 50%; further, H was weighed to have a mass concentration of 15%₂SiF₆200g of an aqueous solution as a second solution; secondly, 130g of PE balls with the density of 1.20mg/mL and the diameter of 2.0mm are added into the prepared first solution, the concentration of a sulfuric acid medium is 30 percent, and the mixture is mechanically stirred at the stirring temperature of 20 ℃. Then, injecting the second solution into the first solution at a speed of 15 mL/min; stirring the reaction solution for 4h, pouring out the supernatant, adding HF aqueous solution with the mass concentration of 3%, stirring and washing for 2 times, washing for 2 times with absolute ethyl alcohol, and drying under the condition of blast drying at 80 ℃ to obtain the spherical Mn⁴⁺Excited fluoride phosphor K_2.11Si_0.95F_6.94:0.05Mn⁴⁺。

Example 10

This example provides a spheroidal fluoride phosphor prepared by the following method: weighing K₂MnF₆2.6g、KHF₂25g of the first solution was prepared by dissolving the first solution in 200g of an aqueous solution of HF having a mass concentration of 30%; further, H was weighed to have a mass concentration of 15%₂SiF₆250g of an aqueous solution as a second solution; secondly, adding the prepared first solution into 150g of PE balls, wherein the density of the PE balls is 1.25mg/mL, the diameter of the PE balls is 1.0mm, the concentration of a sulfuric acid medium is 45%, and mechanically stirring the mixture at the stirring temperature of 50 ℃; then, injecting the second solution into the first solution at a speed of 15 mL/min; stirring the reaction solution for 5h, pouring out the supernatant, adding HF aqueous solution with the mass concentration of 5%, stirring and washing for 2 times, washing for 2 times with absolute ethyl alcohol, and drying under the condition of blast drying at 80 ℃ to obtain the spherical Mn⁴⁺Excited fluoride phosphor K_2.18Si_0.94F_7.02:0.06Mn⁴⁺。

Example 11

This example provides a spheroidal fluoride phosphor prepared by the following method: weighing Na₂MnF₆2.5g、KHF₂25g of the first solution was dissolved in 250g of an aqueous HF solution having a mass concentration of 30%. Further, H was weighed to a mass concentration of 10%₂SiF₆250g of aqueous solution is taken as a second solution; secondly, adding 170g of PE balls into the prepared first solution, wherein the density of the PE balls is 1.25mg/mL, the diameter of the PE balls is 1.0mm, the concentration of a sulfuric acid medium is 45%, and mechanically stirring the mixture at the stirring temperature of 50 ℃; then, injecting the second solution into the first solution at a speed of 10 mL/min; stirring the reaction solution for 5h, pouring out the supernatant, adding HF aqueous solution with the mass concentration of 5%, stirring and washing for 2 times, washing for 2 times with absolute ethyl alcohol, and drying under the condition of blast drying at 80 ℃ to obtain the spherical Mn⁴⁺Excited fluoride phosphor Na_2.16Si_0.94F_6.95:0.06Mn⁴⁺。

Example 12

This example provides a spheroidal fluoride phosphor prepared by the following method: weighing K₂MnF₆2.5g、KHF₂28g, and dissolving the mixture in 250g of an HF aqueous solution with a mass concentration of 40% to prepare a first solution; further, 250g of an aqueous fluoride solution containing 10% by mass of Ti was weighed out as a second solution. Secondly, adding 170g of PE balls into the prepared first solution, wherein the density of the PE balls is 1.25mg/mL, the diameter of the PE balls is 1.25mm, the concentration of a sulfuric acid medium is 50%, and mechanically stirring the mixture at the stirring temperature of 40 ℃; then, injecting the second solution into the first solution at a speed of 10 mL/min; stirring the reaction solution for 5h, pouring out the supernatant, adding HF aqueous solution with the mass concentration of 5%, stirring and washing for 2 times, washing for 2 times with absolute ethyl alcohol, and drying under the condition of blast drying at 80 ℃ to obtain the spherical Mn⁴⁺Excited fluoride phosphor K_2.05Ti_0.94F_7.10:0.06Mn⁴⁺。

Example 13

This example provides a spheroidal fluoride phosphor prepared by the following method: weighing K₂MnF₆2.8g、KHF₂25g of the first solution was dissolved in 220g of an aqueous HF solution having a mass concentration of 50%; further, the weighed mass concentration was 15% of Si in 250g of an aqueous fluoride solution as a second solution. Secondly, adding 170g of PE balls into the prepared first solution, wherein the density of the PE balls is 1.40mg/mL, the diameter of the PE balls is 2mm, the concentration of a sulfuric acid medium is 75%, and mechanically stirring the mixture at the stirring temperature of 40 ℃; then, injecting the second solution into the first solution at a speed of 10 mL/min; stirring the reaction solution for 5h, pouring out the supernatant, adding HF aqueous solution with the mass concentration of 5%, stirring and washing for 2 times, washing for 2 times with absolute ethyl alcohol, and drying under the condition of blast drying at 80 ℃ to obtain the spherical Mn⁴⁺Excited fluoride phosphor K_1.82Si_0.94F_5.8:0.06Mn⁴⁺。

Example 14

This example provides a spheroidal fluoride phosphor prepared by the following method: weighing K₂MnF₆2.8g、KHF₂25g of a first solution prepared by dissolving 200g of an aqueous HF solution having a mass concentration of 30%; further, 250g of an aqueous fluoride solution of Si having a mass concentration of 10% was weighed as a second solution. Secondly, adding 170g of PE balls into the prepared first solution, wherein the density of the PE balls is 1.35mg/mL, the diameter of the PE balls is 1.25mm, the concentration of a sulfuric acid medium is 62%, and mechanically stirring the mixture at the stirring temperature of 50 ℃; then, injecting the second solution into the first solution at a speed of 10 mL/min; stirring the reaction solution for 5h, pouring out the supernatant, adding HF aqueous solution with the mass concentration of 5%, stirring and washing for 2 times, washing for 2 times with absolute ethyl alcohol, and drying under the condition of blast drying at 80 ℃ to obtain the spherical Mn⁴⁺Excited fluoride phosphor K_1.6Si_0.93F_5.0:0.07Mn⁴ ⁺。

Example 15

This example provides a spheroidal fluoride phosphor prepared by the following method: weighing K₂MnF₆2.8g、KHF₂25g of the first solution was dissolved in 250g of an aqueous HF solution having a mass concentration of 50%; further, 250g of an aqueous solution of Si fluoride having a mass concentration of 15% was weighed as a second solution. Secondly, the prepared first solution is added into 190g of PE balls, the density of the PE balls is 1.25mg/mL, and the diameter of the PE balls is1.30mm, adding 50% of sulfuric acid medium, and mechanically stirring at 40 deg.C; then, the second solution is injected into the first solution at the speed of 12 mL/min; stirring the reaction solution for 5h, pouring out the supernatant, adding HF aqueous solution with the mass concentration of 5%, stirring and washing for 2 times, washing for 2 times with absolute ethyl alcohol, and drying under the condition of blast drying at 80 ℃ to obtain the spherical Mn⁴⁺Excited fluoride phosphor K_1.8Si_0.95F_6.22:0.05Mn⁴ ⁺。

Example 16

This example provides a spheroidal fluoride phosphor prepared by the following method: weighing K₂MnF₆2.5g、KHF₂28g, and dissolving the mixture in 210g of 35% by mass HF aqueous solution to prepare a first solution; further, 220g of an aqueous solution of Si fluoride having a mass concentration of 12% was weighed as a second solution. Secondly, adding 180g of tetrafluoroethylene spheres into the prepared first solution, wherein the density of the tetrafluoroethylene spheres is 1.10mg/mL, the diameter of the tetrafluoroethylene spheres is 1.25mm, the concentration of a sulfuric acid medium is 30%, and mechanically stirring the mixture at the stirring temperature of 50 ℃; then, injecting the second solution into the first solution at a speed of 10 mL/min; stirring the reaction solution for 5h, pouring out the supernatant, adding HF aqueous solution with the mass concentration of 5%, stirring and washing for 2 times, washing for 2 times with absolute ethyl alcohol, and drying under the condition of blast drying at 80 ℃ to obtain the spherical Mn⁴⁺Excited fluoride phosphor K₂Si_0.95F_6.49:0.05Mn⁴⁺。

Example 17

The embodiment provides a fluorescent mixture, which comprises a spherical fluoride fluorescent powder and one of beta sialon powder, silicate green powder, aluminate fluorescent powder or quantum dot green powder.

Example 18

This embodiment provides a phosphor mixture, which comprises a spherical fluoride phosphor and one or more of aluminate phosphor, nitride red phosphor, nitride blue-green phosphor, silicate phosphor, phosphate blue phosphor or magnesium fluorogermanate.

Example 19

The present embodiment provides a light emitting device including at least an LED chip emitting ultraviolet light, violet light, or blue light and a quasi-spherical fluoride phosphor.

Comparative example

Comparative example provides a fluoride phosphor prepared by the following method without adding PE beads or tetrafluoroethylene beads: weighing K₂MnF₆Weighing 2.8g of KHF 228 g, and dissolving in 200g of 40% HF aqueous solution to prepare a first solution; further, H was weighed to a mass concentration of 10%₂SiF₆200g of an aqueous solution as a second solution; secondly, injecting the second solution into the first solution at the speed of 10mL/min, stirring for 2h, and reacting at the temperature of 50 ℃; stirring the reaction solution for 2h, pouring out the supernatant, adding HF aqueous solution with the mass concentration of 5%, stirring and washing for 2 times, washing for 2 times with absolute ethyl alcohol, and drying under the condition of blast drying at 60 ℃ to obtain the spherical Mn⁴⁺Excited fluoride phosphor K_2.12Si_0.94F_7.05:0.06Mn⁴⁺。

The excitation spectrum of the spheroidal fluoride phosphor prepared in the comparative example is tested and shown in fig. 9, the excitation spectrum is the change of the fluorescence intensity at a certain wavelength measured by the phosphor under the action of the excitation lights with different wavelengths, namely the relative efficiency of the excitation lights with different wavelengths, and therefore, the phosphor prepared in the comparative example has the strongest fluorescence intensity under the action of the excitation light with the wavelength of about 448 nm; FIG. 10 is an emission spectrum of a phosphor prepared in comparative example, which shows the distribution of the fluorescence intensity at different wavelengths under the action of excitation light of a certain fixed wavelength, that is, the relative intensities of light components of different wavelengths in the fluorescence.

The quasi-spherical fluoride phosphors prepared in the above examples 1 to 19 and the fluoride phosphor prepared in the comparative example were subjected to the tests of luminous intensity, specific surface area, crystal grain size, target concentration and aging property under the following conditions:

(1) and (3) testing the luminous intensity: the size of the chip is 10 x 30mil, the wave band of the chip is 452.5-455.0 nm, the current is 150mA, the power is 0.5W, the powder is beta-sialon, the color temperature is 10000-;

(2) target concentration test: a support 2835, the size of a chip is 10 x 30mil, the wave band of the chip is 452.5-455 nm, the current is 150mA, the power is 0.5W, the color temperature is 2700K, and nitride red powder and silicate green powder are matched;

(3) specific surface area and particle size testing: the nitrogen pressure is more than or equal to 6bar, the environmental humidity is less than 75% RH, and the temperature is 3-35 ℃;

(4) and (3) aging test: uniformly mixing fluoride fluorescent powder and epoxy resin packaging adhesive in a certain proportion, and coating the mixture on a 2835 support, wherein the size of a chip is 10 x 30mil, and the wave band of the chip is 452.5-455 nm; welding the lamp beads on the aluminum substrate radiating platform, placing the aluminum substrate radiating platform on an aging test bench, and adjusting the current to 150mA and the power to 0.5W; placing the aging test bench in an aging box for lighting test under the test condition of 85 ℃/85% RH; and after 48h, the attenuation and color shift of the lamp beads are tested. Wherein the model of the aging test bench is Taishan starlight PCA-F2A-40, and the model of the aging box is WHTH-150L-40-880 produced by Dongguan Vivian British technology Co.

The results obtained are shown in tables 1 and 2.

TABLE 1 test results of inventive examples 1-16 and comparative examples

TABLE 2 test results of the aged light decay Properties of inventive examples 1-16 and comparative examples

As can be seen from the above, the products of examples 1 to 16 of the present inventionThe grain size of the spheroidal fluoride fluorescent powder is between 14 and 40 mu m, and under the condition that the grain size of the spheroidal fluoride fluorescent powder is similar to that of the fluoride fluorescent powder of the comparative example, the weight specific surface area of the spheroidal fluoride fluorescent powder prepared in the embodiments 1 to 16 is far larger than that of the fluoride fluorescent powder of the comparative example; furthermore, the weight specific surface area range of the quasi-spherical fluoride fluorescent powder particles prepared by the invention is 1482-1699 cm²When the voltage is between the voltage and the voltage of the LED lamp, the aging brightness maintenance rate and the color drift data are relatively balanced; when the grain size is between 20 and 30 mu m, the weight specific surface area of the spheroidal fluoride fluorescent powder prepared by the invention is relatively large, and the effect is better. It can be seen from the scanning electron micrographs shown in fig. 1 to 4 that the fluoride phosphor prepared in the example of the present invention is irregular and spheroidal, and has a rough surface with a higher roughness than the fluoride phosphor prepared in the comparative example.

The LED luminous intensity of the spheroidal fluoride fluorescent powder prepared in the embodiments 1-16 of the invention is higher than that of the comparative example; and the target hitting concentration is higher than that of the comparative example, as shown in fig. 5 and fig. 6, the target hitting graphs of the comparative example and the example 10 also show that the LED target hitting concentration of the fluorescent powder prepared by the example 10 of the invention is obviously higher than that of the comparative example.

In addition, the LED aging light decay resistance of the spheroidal fluoride fluorescent powder prepared in the embodiments 1-16 of the invention is better than that of the comparative example.

Descriptions not related to the embodiments of the present invention are well known in the art, and may be implemented by referring to the well-known techniques. The invention obtains satisfactory trial effect through repeated test verification.

The above description is only a preferred embodiment of the present invention, but the scope of the present invention is not limited thereto. Any person skilled in the art should be able to cover the technical scope of the present invention by equivalent or modified solutions and modifications within the technical scope of the present invention.

Claims

1. A spherical fluoride fluorescent powder is characterized in that the weight specific surface area of particles is 1273-1785 cm²/g。

2. The spheroidal fluoride phosphor according to claim 1, wherein the grain size is in the range of 14 to 40 μm.

3. The spheroidal fluoride phosphor as set forth in claim 1, wherein the particles have a weight-specific surface area in the range of 1482 to 1699cm²/g。

4. The spheroidal fluoride phosphor according to claim 2, wherein the grain size is 20 to 30 μm.

5. The spheroidal fluoride phosphor according to any of claims 1 to 4, having a chemical formula: a. the_xM_(1-y)F_z:yMn⁴⁺Wherein, in the step (A),

a is K, Li, Na, Rb, Cs or NH4⁺At least one of (a) and (b),

m is at least one of Si, Ge, Sn, Ti, Zr or Hf; and 1.6 ≦ x ≦ 2.4, 0< y ≦ 0.18, 5.0 ≦ z ≦ 7.3.

6. The spheroidal fluoride phosphor of claim 5 having the chemical formula: a. the_xM_(1-y)F_z:yMn⁴⁺Wherein A is K, Li, Na, Rb, Cs or NH4⁺M is at least one of Si, Ge, Sn, Ti, Zr or Hf; and x is 2 and z is 6.

7. The spheroidal fluoride phosphor of claim 5 having the chemical formula: a. the_xM_(1-y)F_z:yMn⁴⁺Wherein A is K, Li, Na, Rb, Cs or NH4⁺M is at least one of Si, Ge, Sn, Ti, Zr or Hf; and 2 x 0.3, y 0.03 y 0.06, z 6.7 7 7.1.

8. The method for preparing a spheroidal fluoride phosphor according to any of claims 5 to 7, comprising the steps of:

(1) with K, Li, Na, Rb, Cs or NH4⁺At least one fluoride and fluoromanganate in the raw materials are taken as raw materials, the required raw materials are weighed according to the chemical structural formula and the stoichiometric ratio and are uniformly mixed; dissolving the raw materials in an HF aqueous solution to prepare a first solution;

(2) adding PE balls or tetrafluoroethylene balls into the first solution, stirring, injecting at least one fluoride solution of Si, Ge, Sn, Ti, Zr or Hf into the first solution at the speed of 10-15 mL/min, mixing, heating and stirring, and pouring out the supernatant to obtain a mixed system;

9. The method according to claim 8, wherein the HF aqueous solution in the step (1) has a mass concentration of 30 to 50% and the fluoride solution in the step (2) has a mass concentration of 10 to 15%.

10. The preparation method according to claim 8, wherein in the step (2), the temperature of the mixing, heating and stirring is 10-50 ℃, and the time of the mixing, heating and stirring is 2-5 h.

11. The method according to claim 8, wherein the PE pellets have a diameter of 1 to 5mm and a density of 1.1 to 1.4 mg/mL.

12. The method according to claim 10, wherein the PE pellets or tetrafluoroethylene pellets have a density of 1.25 to 1.3 mg/mL.

13. The production method according to claim 11 or 12,characterized in that the volume specific surface area of the PE balls or tetrafluoroethylene balls is 2.0-10.0 mm²/mm³。

14. The production method according to claim 13, wherein the PE pellets or tetrafluoroethylene pellets have a volume specific surface area of 4.0 to 5.8mm²/mm³。

15. The production method according to claim 8, wherein the density of the PE pellets or tetrafluoroethylene pellets is controlled by filling sulfuric acid of different concentrations inside the PE pellets or tetrafluoroethylene pellets.

16. The method according to claim 15, wherein the sulfuric acid concentration is 10 to 75%.

17. A phosphor blend comprising the spheroidal fluoride phosphor of any of claims 1 to 7 and one of a beta sialon, a silicate green, an aluminate phosphor or a quantum dot green.

18. A phosphor blend comprising the spheroidal fluoride phosphor according to any one of claims 1 to 7 in combination with one or more of aluminate phosphor, nitride red phosphor, nitride blue green phosphor, silicate phosphor, phosphate blue phosphor, or magnesium fluorogermanate.

19. A light-emitting device comprising at least an ultraviolet, violet or blue light-emitting LED chip and a phosphor, wherein the phosphor is the spheroidal fluoride phosphor according to any one of claims 1 to 7.