CN101565614B - Orange-red long afterglow Luminescent Material - Google Patents

Abstract

The invention relates to a luminescent material which can emit orange-red light and has a long afterglow after being excited by ultraviolet light or sunlight, and a preparation method of the material. The luminescent material of the present invention has a general formula of Ca _(2-xy) SnO ₄ :Sm _x , an orange-red long-lasting luminescent material of My _y , wherein: M is zinc or cadmium, or a combination of zinc and cadmium; x and y are The molar ratio coefficient of corresponding dopant ions relative to Ca ₂ SnO ₄ , wherein: x=0.001-0.150, y=0-0.150. The preparation method of the luminescent material of the present invention adopts a high-temperature solid-phase method.

Description

An orange-red long-lasting luminescent material

technical field

The invention relates to a luminescent material which can emit orange-red light and has a long afterglow after being excited by ultraviolet light or sunlight, and a preparation method of the material. the

Background technique

Long-lasting luminescent material is a kind of photoluminescent material, which can absorb the energy of external light and store the energy. After the excitation light source is turned off, the stored energy is slowly released in the form of visible light at room temperature. It has the advantages of no pollution, safety, energy saving and economy. Since the 1990s, people have successively invented rare earth ion-doped aluminate system and silicate system long-lasting luminescent materials. The long afterglow materials of the sulfide system have been improved, but the luminous colors of these two types of luminescent materials are generally green, blue, blue-green, etc., which are difficult to meet the needs. Therefore, people turn their attention to the development and research of red light long afterglow materials. Due to the special optical properties of red long afterglow materials, it has a wider range of applications than green or blue long afterglow materials. the

Red long afterglow materials mainly include rare earth activated alkaline earth metal sulfides, sulfur oxides, alkaline earth metal titanate systems and phosphate systems. Sulfur-containing red long-lasting materials have better afterglow and brightness, but their chemical stability is poor, and their applications are limited. The red long afterglow material of alkaline earth titanate system has low luminance and short afterglow time. The cost of red long afterglow materials in phosphate system is low, but most of them need to be protected by reducing atmosphere and the process is complicated. the

Chinese invention patent application 200410017538.X discloses a patent application technology named "La ₂ O ₂ S red long-lasting luminescent material and preparation method". The red long-lasting luminescent material disclosed in this patent uses La ₂ O ₂ S as the matrix, La ₂ O ₃ and S as the matrix raw materials, Eu ³⁺ as the exciter, Mg ²⁺ , Zr ⁴⁺ , Ti ⁴⁺ , Nb ⁵⁺ As co-activator, Na ₂ CO ₃ and Li ₂ CO ₃ as flux. Its preparation method must be under activated carbon reducing atmosphere, burning at 1200 DEG C for 4 hours, cooling out of the furnace, crushing, washing and sieving to obtain the product. After the material is excited, the afterglow is orange-red or red with the naked eye. Although the afterglow performance of this long afterglow material is good, the product and its preparation method have the following disadvantages and shortcomings: sulfur is used as a raw material, and the waste gas produced is very harmful to the human body and the environment; the production process is protected by a reducing atmosphere, The production process is complicated and the production cost is high; the cost of the flux Na ₂ CO ₃ and Li ₂ CO ₃ used is high. In addition to these deficiencies, the raw materials in the prior art are expensive, especially containing expensive rare earth europium, which makes the cost of the product high. Therefore, there is still a need for red and orange-red long afterglow materials with stable properties, good afterglow performance, and low cost.

Contents of the invention

The invention provides a luminescent material that can emit orange-red light and has a long afterglow after being excited by ultraviolet light or sunlight, which overcomes the shortcomings of the prior art. the

The luminescent material of the present invention has a general formula of Ca _(2-xy) SnO ₄ :Sm _x , an orange-red long-lasting luminescent material of My _y , wherein: M is zinc or cadmium, or a combination of zinc and cadmium; x and y are The molar ratio coefficient of corresponding dopant ions relative to Ca ₂ SnO ₄ , wherein: x=0.001-0.150, y=0-0.150.

A specific orange-red long-lasting luminescent material of the present invention has a chemical formula of Ca ₂ SnO ₄ :Sm _0.01 , and the afterglow duration can reach 45-380 minutes.

Another specific orange-red long-lasting luminescent material of the present invention has a chemical formula of Ca ₂ SnO ₄ :Sm _0.01 , Zn _0.01 , and the afterglow can last for 180 minutes.

Another specific orange-red long-lasting luminescent material of the present invention has a chemical formula of Ca ₂ SnO ₄ :Sm _0.01 , Cd _0.01 , and the afterglow can last for 235 minutes.

The preparation method of any orange-red long-lasting luminescent material of the present invention adopts a high-temperature solid-phase method, that is, the oxide or/and carbonate or/and nitrate or/and acetate of the corresponding element is weighed according to the composition of the chemical formula of the material Or/and oxalate, using absolute ethanol or acetone as a dispersant, grinding each raw material to a micron level, sintering at 1100-1300°C, taking it out after cooling down and grinding to obtain the desired material. the

The preferred preparation method of the present invention is to add absolute ethanol or acetone as a dispersant to the raw material at a rate of 3-6ml/(g raw material) during grinding before sintering. the

In the preferred preparation method of the present invention, H ₃ BO ₃ or/and NH ₄ Cl in an amount of 0.5-6% by weight of raw materials can be added as a flux to the raw materials during grinding before sintering. Tests show that adding 0.5-3% of H ₃ BO ₃ and 0.5-3% of NH ₄ Cl into the raw material at the same time has the best effect when grinding before sintering.

In the preferred preparation method of the present invention, two sinterings are adopted, that is, after the raw materials are fully ground and mixed, they are first sintered at 1100-1300°C for 3-6 hours, cooled to room temperature, ground and mixed again, and then sintered at 800-1200°C The second sintering is 1 to 4 hours. the

The material of the invention is based on orthostannate, adding rare earth ions and other ions as activators, and realizes the long afterglow performance of orange-red light emission in the orthostannate, and has ideal effect. the

In the preparation method of the present invention, a certain amount of absolute ethanol or acetone is added as a dispersant during grinding, so that the raw materials can be mixed more uniformly, and at the same time, the time required for grinding can be greatly reduced. The test shows that if the grinding is carried out directly without adding a dispersant, it will take a longer time to grind to achieve the required particle size, and the raw materials will not be mixed uniformly. the

The present invention adds a certain amount of boric acid or/and ammonium chloride as a flux to the raw material, which can not only reduce the impurity phase in the product phase, but also prolong the afterglow time while improving the luminous performance of the material. the

Research also shows that the use of secondary sintering in the preparation process of the present invention can reduce the impurity phase in the product phase. the

The preparation method of the invention is simple, beneficial to large-scale production, low in production cost, easy to grind, stable in property, non-radioactive, and does not cause harm to the environment, and is a long-lasting luminescent material with wide application prospects. the

Description of drawings

Figure 1 is the excitation spectrum of Ca ₂ SnO ₄ :Sm _0.01 .

Figure 2 is the emission spectrum of Ca ₂ SnO ₄ :Sm _0.01 .

Fig. 3 is a logarithmic afterglow decay curve of Ca ₂ SnO ₄ :Sm _0.01 .

Fig. 4 is a powder diffraction standard card 74-1493 (4-1) and X-ray powder diffraction patterns (4-2-4) of products prepared under different conditions. 4-4 are the XRD patterns of Ca ₂ SnO ₄ :Sm _0.01 . In the picture:

1- No flux; 1100-1300 degrees Celsius for 3-6 hours

2-Add boric acid; 1100-1300 degrees Celsius for 3-6 hours

3- Add boric acid and ammonium chloride; 1100-1300 degrees Celsius for 3-6 hours

4- Add boric acid and ammonium chloride; 1100-1300 degrees Celsius for 3-6 hours; 800-1200 degrees Celsius for 1-4 hours

Fig. 5 is the excitation spectrum of Ca ₂ SnO ₄ :Sm _0.01 .

Fig. 6 is an emission spectrum diagram of Ca ₂ SnO ₄ :Sm _0.01 .

Fig. 7 is a double-logarithmic afterglow decay curve of Ca ₂ SnO ₄ :Sm _0.01 .

Fig. 8 is the excitation spectrum of Ca ₂ SnO ₄ :Sm _0.01 .

Fig. 9 is an emission spectrum diagram of Ca ₂ SnO ₄ :Sm _0.01 .

Fig. 10 is the afterglow decay curve of Ca ₂ SnO ₄ :Sm _0.01 .

Fig. 11 is the excitation spectrum of Ca ₂ SnO ₄ :Sm _0.01 , Zn _0.01 .

Fig. 12 is the emission spectrum diagram of Ca ₂ SnO ₄ :Sm _0.01 , Zn _0.01 .

Fig. 13 is a double-logarithmic afterglow decay curve of Ca ₂ SnO ₄ :Sm _0.01 , Zn _0.01 .

Figure 14 is the excitation spectrum of Ca ₂ SnO ₄ :Sm _0.01 , Cd _0.01 .

Figure 15 is the emission spectrum of Ca ₂ SnO ₄ :Sm _0.01 , Cd _0.01 .

Fig. 16 is the log-logarithmic afterglow decay curve of Ca ₂ SnO ₄ :Sm _0.01 , Cd _0.01 .

The following are the preferred embodiments of the present invention. the

Detailed ways

Example 1

According to the chemical formula Ca ₂ SnO ₄ :Sm _0.01 , accurately weigh the oxides or carbonates of the corresponding elements and 2-3% H ₃ BO ₃ , pour the above materials into an agate mortar, and press 3-6ml/( grams of raw material) adding absolute ethanol or acetone as a dispersant, thoroughly ground and mixed, then transferred to a corundum crucible, sintered at 1100-1300°C for 3-6 hours in an air atmosphere, cooled to room temperature, took out the sample and ground it again, and ground it again at 800 Insulate at ~1200°C for 1-4 hours, cool to room temperature, take out the sample and grind it to obtain the example material. The appearance of the material is white, and the XRD test shows that the main phase is Ca ₂ SnO ₄ . The excitation spectrum of this material consists of a series of peaks in the range of 320-575nm, the strongest peak is at 408nm, and other peaks are at 348, 364, 378, 478 and 560nm, see Figure 1. The emission spectrum of this material has 3 strong peaks, the strongest peak is located at 608nm, and the other two peaks are located at 565 and 652nm, see Figure 2. The CIE chromaticity diagram calculates the color coordinates of the emitted light as x=0.53, y=0.47, which is located in the orange-red light emission region. After the material is irradiated by ultraviolet lamp or sunlight, it shows an orange-red afterglow glow in the dark. After being irradiated for 10 minutes under a simulated sunlight light source, the example material can emit light for more than 45 minutes at a luminance (0.32mcd/m ² ) that can be distinguished by the human eye, see Figure 3. The afterglow decay curve conforms to the law of exponential decay.

Example 2

According to the chemical formula Ca ₂ SnO ₄ :Sm _0.01 , accurately weigh the oxides or carbonates of the corresponding elements, 0.5-3% H ₃ BO ₃ and 0.5-3% NH ₄ Cl by weight of the raw materials, and pour the above materials into the agate grinder. In the bowl, add absolute ethanol or acetone as a dispersant according to 3~6ml/(gram of raw material), grind and mix thoroughly, then transfer to a corundum crucible, sinter at 1100~1300°C for 3~6h in an air atmosphere, and cool to At room temperature, take out the sample and grind it again, keep it warm at 800-1200° C. for 1-4 hours, cool to room temperature, take out the sample and grind it to obtain the example material. Accompanying drawing 4 has provided the XRD figure of preparation product under different conditions. The appearance of the material is white, and the XRD test shows that the main phase is Ca ₂ SnO ₄ , see Figure 4-4. The excitation spectrum of this material consists of a series of peaks in the range of 320-575nm, the strongest peak is at 408nm, and other peaks are at 348, 364, 378, 478 and 560nm, see Figure 5. The emission spectrum of this material has 3 strong peaks, the strongest peak is located at 608nm, and the other two peaks are located at 565 and 652nm, see Figure 6. After the material is irradiated by ultraviolet lamp or sunlight, it shows an orange-red afterglow glow in the dark. After being irradiated for 10 minutes under a simulated sunlight light source, the example material can emit light for more than 380 minutes at a luminance that can be distinguished by the human eye (0.32mcd/m ² ), see Figure 7. The afterglow decay curve conforms to the law of exponential decay.

Example 3

According to the chemical formula Ca ₂ SnO ₄ :Sm _0.01 , accurately weigh the oxides or carbonates of the corresponding elements, 1-3% H ₃ BO ₃ and 0.5-3% NH ₄ Cl by weight of the raw materials, and pour the above materials into the agate grinding chamber. In the bowl, add absolute ethanol or acetone as a dispersant according to 3~6ml/(gram of raw material), grind and mix thoroughly, then transfer to a corundum crucible, sinter at 1100~1300°C for 3~6h in an air atmosphere, and cool to At room temperature, take out the sample and grind it again, keep it warm at 800-1200° C. for 1-4 hours, cool to room temperature, take out the sample and grind it to obtain the example material. The appearance of the material is white, and the XRD test shows that the main phase is Ca ₂ SnO ₄ . The excitation spectrum of this material consists of a series of peaks in the range of 320-575nm, the strongest peak is at 408nm, and other peaks are at 348, 364, 378, 478 and 560nm, see Figure 8. The emission spectrum of this material has 3 strong peaks, the strongest peak is located at 608nm, and the other two peaks are located at 565 and 652nm, see Figure 9. The CIE chromaticity diagram calculates the color coordinates of the emitted light as x=0.54, y=0.46, which is located in the orange-red light emission region. After the material is irradiated by ultraviolet lamp or sunlight, it shows an orange-red afterglow glow in the dark. After being irradiated for 10 minutes under the simulated sunlight light source, the example material can emit light for more than 210 minutes at a luminance (0.32mcd/m ² ) that can be distinguished by the human eye, see FIG. 10 . The afterglow decay curve conforms to the law of exponential decay.

Example 4

According to the chemical formula Ca ₂ SnO ₄ : Sm _0.01 , Zn _0.01 , accurately weigh the oxides or carbonates of the corresponding elements, as well as 0.5-3% H ₃ BO ₃ and 0.5-3% NH ₄ Cl by weight of the raw materials, pour the above materials Put it into an agate mortar, then add absolute ethanol or acetone as a dispersant at 3-6ml/(gram of raw material), grind and mix thoroughly, then transfer to a corundum crucible, and sinter at 1100-1300°C for 3-6 hours in an air atmosphere , cooled to room temperature, took out the sample and ground it again, kept it at 800-1200° C. for 1-4 hours, cooled to room temperature, took out the sample and ground it to obtain the example material. The appearance of the material is white, and the XRD test shows that the main phase is Ca ₂ SnO ₄ . The excitation spectrum of this material consists of a series of peaks in the range of 320-575nm, the strongest peak is at 408nm, and other peaks are at 348, 364, 378, 478 and 560nm, see Figure 11. The emission spectrum of this material has 3 strong peaks, the strongest peak is located at 608nm, there is a shoulder at 600nm, and the other two peaks are located at 565 and 652nm, see Figure 12. After the material is irradiated by ultraviolet lamp or sunlight, it shows an orange-red afterglow glow in the dark. After being irradiated for 10 minutes under a simulated sunlight light source, the example material can emit light for more than 180 minutes at a luminance (0.32mcd/m ² ) that can be distinguished by the human eye, see Figure 13. The afterglow decay curve conforms to the law of exponential decay.

Example 5

According to the chemical formula Ca ₂ SnO ₄ : Sm _0.01 , Cd _0.01 , accurately weigh the oxides or carbonates or nitrates of the corresponding elements, as well as 1-3% of H ₃ BO ₃ and 0.5-3% of NH ₄ Cl by weight of raw materials , pour the above materials into an agate mortar, then add absolute ethanol as a dispersant at 3-6ml/(gram of raw material), grind and mix well, then transfer to a corundum crucible, and sinter at 1100-1300°C in an air atmosphere After 3-6 hours, cool to room temperature, take out the sample and grind it again, keep it warm at 800-1200°C for 1-4 hours, cool to room temperature, take out the sample and grind it to obtain the example material. The appearance of the material is white, and the XRD test shows that the main phase is Ca ₂ SnO ₄ . The excitation spectrum of this material consists of a series of peaks in the range of 320-575nm, the strongest peak is at 408nm, and other peaks are at 348, 364, 378, 478 and 560nm, see Figure 14. The emission spectrum of this material has three strong peaks, the strongest peak is located at 608nm, and the other two peaks are located at 565 and 652nm, see Figure 15. After the material is irradiated by ultraviolet lamp or sunlight, it shows an orange-red afterglow glow in the dark. After being irradiated for 10 minutes under the simulated sunlight light source, the example material can emit light for more than 235 minutes at a luminance (0.32mcd/m ² ) that can be distinguished by the human eye, see FIG. 16 . The afterglow decay curve conforms to the law of exponential decay.

Claims (9)

1. a general formula is Ca _(2-x-y)SnO ₄: Sm _x, M _yOrange red long after glow luminous material, wherein: M is zinc or cadmium, or the combination of zinc and cadmium; X, y are that corresponding dopant ion is with respect to Ca ₂SnO ₄The mol ratio coefficient, wherein: x=0.001～0.150, y=0～0.150.

2. orange red long after glow luminous material, its chemical formula is Ca ₂SnO ₄: Sm _0.01

3. orange red long after glow luminous material, its chemical formula is Ca ₂SnO ₄: Sm _0.01, Zn _0.01

4. orange red long after glow luminous material, its chemical formula is Ca ₂SnO ₄: Sm _0.01, Cd _0.01

5. the preparation method of the described arbitrary orange red long after glow luminous material of claim 1 to 4; It is characterized in that composition by the materials chemistry formula take by weighing respective element oxide compound or/and carbonate or/and nitrate salt or/and acetate or/and oxalate; After abundant ground and mixed is even, carry out sintering at 1100～1300 ℃; The cooling back is taken out and is ground, and obtains needed material.

6. preparation method according to claim 5 adds absolute ethyl alcohol or acetone as dispersion agent by 3～6ml/ (gram raw material) when it is characterized in that the grinding before the sintering in raw material.

7. preparation method according to claim 6, the H that in raw material, adds as fusing assistant when it is characterized in that the grinding before the sintering by 0.5～6% of raw material weight ₃BO ₃Or/and NH ₄Cl.

8. preparation method according to claim 7 adds the H of raw material weight 0.5～3% simultaneously in raw material when it is characterized in that the grinding before the sintering ₃BO ₃NH with raw material weight 0.5～3% ₄Cl.

9. according to the described arbitrary preparation method of claim 5 to 8; It is characterized in that raw material through abundant ground and mixed evenly the back first with raw material 1100～1300 ℃ of sintering 3～6 hours; Be cooled to regrinding mixing after the room temperature, carry out sintering 1～4 hour second time at 800～1200 ℃ again.

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