阅读说明：本技术 一种具有多孔隙光通道结构的超高亮度蓄光陶瓷及其应用 (Ultrahigh-brightness light-storing ceramic with porous light channel structure and application thereof ) 是由 张乐 杨顺顺 陈东顺 邵岑 康健 李明 周天元 李延彬 陈浩 于 2020-07-20 设计创作，主要内容包括：本发明公开了一种具有多孔隙光通道结构的超高亮度蓄光陶瓷及其应用,所述蓄光陶瓷内部具有相互连通的三维孔道结构,孔道直径为200～800微米,孔隙率为55～75％,可应用于消防指示领域。本发明提供的超高亮度蓄光陶瓷,经过20min蓄光,可实现15小时(>0.32mcd/m<Sup>2</Sup>)的持续发光,初始1min强度>4500mcd/m<Sup>2</Sup>；60min强度>35mcd/m<Sup>2</Sup>(室外阳光直射20min,日光灯30min,紫外线5min,室温25℃测试),相较于现有的蓄光陶瓷材料,本发明产品前置光提取效率明显提高25-40％,同时其多孔结构还能提高陶瓷韧性及减轻陶瓷重量。(The invention discloses an ultra-high brightness light-storing ceramic with a porous light channel structure and application thereof, wherein the light-storing ceramic is internally provided with a three-dimensional pore channel structure which is communicated with each other, the diameter of the pore channel is 200-800 micrometers, the porosity is 55-75%, and the light-storing ceramic can be applied to the field of fire-fighting indication. The ultra-high brightness light-storing ceramic provided by the invention can realize 15 hours after light storage for 20min>0.32mcd/m 2 ) Continuous luminescence, initial 1min intensity>4500mcd/m 2 (ii) a Strength at 60min>35mcd/m 2 (the outdoor sunlight is directly irradiated for 20min, the daylight lamp is used for 30min, the ultraviolet ray is used for 5min, and the room temperature is tested at 25 ℃), compared with the existing light-storing ceramic material, the preposed light extraction efficiency of the product is obviously improved by 25-40%, and meanwhile, the porous structure of the product can also improve the toughness of the ceramic and reduce the weight of the ceramic.)

1. The ultra-high brightness light-storing ceramic with the porous light channel structure is characterized in that the light-storing ceramic is internally provided with a three-dimensional pore channel structure which is communicated with each other, the diameter of each pore channel is 200-800 micrometers, and the porosity is 55-75%.

2. The ultra-high brightness light-storing ceramic with a porous light channel structure according to claim 1, which is prepared by the following steps:

(1.1) weighing: respectively weighing 50-55% of 10-30 mesh quartz raw material, 25-29% of 50-100 mesh quartz raw material, 6-15% of 150-250 mesh quartz raw material and the balance of raw material powder for preparing europium and dysprosium co-doped strontium aluminate long afterglow fluorescent powder, wherein the total mass of the raw material powder is 100%; and weighing a pore-forming agent accounting for 35-55% of the total mass of the raw material powder, wherein the pore-forming agent is ammonium bicarbonate, starch, and the mass ratio of ammonium bicarbonate to starch is 1: 3-6;

(1.2) mixing materials: putting the powder raw materials weighed in the step (1) into a ball milling tank, and simultaneously adding grinding balls and deionized water for ball milling and mixing;

(1.3) forming: carrying out vacuum defoaming treatment on the slurry subjected to ball milling in the step (2), and then injecting the defoamed slurry into a mold for molding to obtain a biscuit;

(1.4) drying: standing the biscuit obtained in the step (3) for 7-12 hours, demolding, and then drying in a drying oven;

(1.5) sintering: and (4) calcining the biscuit dried in the step (4) at high temperature in a reducing atmosphere, wherein the calcining temperature is 800-1200 ℃, the heat preservation time is 3-6 h, and then cooling to room temperature along with the furnace to obtain the light-storing ceramic material.

3. The ultra-high brightness light-storing ceramic with a porous light channel structure as claimed in claim 2, wherein in step (1.1), the raw material powder for preparing europium and dysprosium co-doped strontium aluminate long afterglow phosphor is SrCO₃、Al₂O₃、Eu₂O₃And Dy₂O₃According to the formula SrAl₂O₄:Eu²⁺,Dy³⁺The stoichiometric ratio of each element in the formula (I) is obtained by weighing.

4. The ultra-high brightness light-storing ceramic with the porous light channel structure according to claim 2, wherein in step (1.2), the mass ratio of the grinding balls to the total mass of the raw material powder is 1.5-3: 1, the addition amount of the deionized water is 12-17% of the total mass of the raw material powder.

5. The ultra-high brightness light-storing ceramic with the porous light channel structure as claimed in claim 2, wherein in step (1.2), the rotation speed of the ball milling is 160-300 r/min, and the ball milling time is 20-25 h.

6. The ultra-high brightness light-storing ceramic with a porous light channel structure according to claim 2, wherein in step (1.3), the vacuum degree of vacuum defoaming is-10 to-30 kpa, and the defoaming time is 30 to 50 min.

7. The ultra-high brightness light-storing ceramic with a porous light channel structure according to claim 2, wherein in step (1.4), the drying temperature is 60-100 ℃ and the drying time is 15-24 h.

8. The ultra-high brightness light-storing ceramic with a porous light channel structure according to claim 1, which is prepared by the following steps:

(2.1) putting the glass substrate raw material, the long afterglow light-storing powder, the dispersing agent and the alumina powder into a granulator, adding deionized water doped with a pore-forming agent, directly mechanically stirring for granulation, adding a plasticizer after stirring for 4-8 hours, and continuously stirring for 1-3 hours to obtain a mixed material; the stirring speed in the whole stirring process is 100-300 rad/min; the glass matrix raw material is colorless glass powder, and the particle size of the glass matrix raw material is 10-400 microns; the particle size of the long afterglow light storage powder is 10-500 microns; the particle size of the alumina is 10-500 nanometers; the dispersing agent is sodium tripolyphosphate; the pore-forming agent is natural organic fine powder; the plasticizer is methyl cellulose; the mass ratio of the glass matrix raw material to the long afterglow light-storing powder is 9-49: 1; the additive amount of the dispersing agent is 0.1-0.9% of the total mass of the glass substrate raw material and the long afterglow light-storing powder, the additive amount of the plasticizer is 0.1-0.9% of the total mass of the glass substrate raw material and the long afterglow light-storing powder, the additive amount of the pore-forming agent is 35-55% of the total mass of the glass substrate raw material and the long afterglow light-storing powder, the additive amount of the alumina powder is 0.1-0.4% of the total mass of the glass substrate raw material and the long afterglow light-storing powder, and the additive amount of the deionized water is 20-50% of the total mass of the glass substrate raw material and the long afterglow light-storing powder;

(2.2) filling the mixed material obtained in the step (1) into a die, and tabletting by using an automatic tabletting machine; the shape of the mould is required by the product requirement, the pressure is 5-40 MPa, the pressure maintaining time is 5-20 s, and then the mould is demoulded and sent into a kiln for drying and firing;

(2.3) the temperature rising system of the kiln is as follows: the temperature is between room temperature and 200 ℃, the speed is 2-5 ℃/min, and the temperature is kept for 10-30 min; then, continuously heating to 400-900 ℃, and keeping the temperature for 60-120 min; then cooling the quartz ceramic to be below 100 ℃ along with the furnace and taking out the quartz ceramic to obtain the light-storing self-luminous quartz ceramic.

9. The ultra-high brightness light-storing ceramic with a porous light channel structure as claimed in claim 8, wherein the raw material used in step (2.1) further comprises a pigment which is used for beautifying or meeting the special requirements of the product and is in luminescent cooperation with the long afterglow light-storing powder, and the mass ratio of the pigment to the long afterglow light-storing powder is less than 3.5.

10. The use of the ultra-high brightness light-storing ceramic with a porous light channel structure in the fire-fighting indication field according to claim 1.

Technical Field

The invention relates to light storage ceramic, in particular to ultrahigh brightness light storage ceramic with a porous light channel structure and application thereof, belonging to the field of inorganic non-metallic materials.

Background

The light-storing ceramic integrates the advantages of light-storing materials and ceramics, is different from the structures of 'luminous coating + matrix', 'layered composite' and 'simple cladding' of the light-storing product for fire indication at present, and further improves the performance of the light-storing material product by adopting an integrated forming mode. In the prior art, for example, patent CN110240472A and other patents propose that "one-piece" light-storing ceramic is prepared by weighing, mixing, molding, drying and sintering the long-afterglow light-storing powder and quartz ceramic raw material powder. The advantages of this configuration are: (1) the light storage function of the long afterglow material is combined with the light permeable ceramic matrix phase, so that the whole ceramic body can emit light to meet the requirement of high light efficiency; (2) the cracking of the glaze layer caused by different expansion coefficients of the luminous glaze layer and the ceramic substrate is avoided; (3) the semi-transparent ceramic substrate has the advantages of high acid-base corrosion resistance and thermal shock resistance, low thermal expansion coefficient, high volume stability and the like, and can be used as a substrate to realize the light storage performance.

However, although the advantage of this solution is obvious, the birefringence phenomenon inevitably occurs in the ceramic due to the difference of the medium refractive index (e.g. refractive index of quartz-based light-storing ceramic: aluminate phosphor is-1.6, refractive index of quartz-based ceramic is 1.45-1.50), which results in scattering loss of the excitation light and fluorescence, and reduction of the whole transmittance. And the larger refractive index difference between the light-storing ceramic (the refractive index is more than 1.45) and the air (the refractive index is 1.0) is added, so that the total emission effect can be generated when fluorescence is generated after the excitation of external energy and is emitted from the upper surface of the ceramic, the total reflection critical angle is calculated to be 44 degrees, namely only 24.4 percent of the fluorescence can be emitted from the upper surface of the ceramic, and the rest of the fluorescence is limited by the total reflection effect and is transmitted in the ceramic in a waveguide effect mode until the fluorescence is completely lost. In order to realize the wider application of the integrated light-storing ceramic in the fields of fire-fighting indication, gardening landscape and the like, the light absorption and extraction efficiency is further improved. A fluorescent ceramic with characteristic microstructure is prepared through introducing pore-forming agent (starch, polyvinyl alcohol, dextrin, etc) to make fluorescent light be incident to pores and then be diffused in the interior of ceramic in scattering or reflecting mode to increase light extraction rate and absorption rate (CN 109467453A and CN 110204321A). The scattering source of the optical path in the ceramic mainly comprises air holes, a second phase, impurities and the like. These scattering points generally follow the principle of Mie scattering (Mie scattering). As shown in fig. 1, in the preparation process of the light-storing ceramic, the scattering points are actively introduced, so that the mean free path of photon propagation is increased, and the light-emitting ions can fully absorb natural light; and the waveguide effect and the total reflection effect of the fluorescence are effectively weakened, so that the extraction efficiency and the emergent efficiency of the fluorescence are improved.

However, the pore-forming agent is decomposed at a high temperature to generate a gas, but the pore-forming agent is often accompanied by a severe oxidation-reduction reaction or pyrolysis reaction, resulting in a case where the pore shape deviates from a normal spherical shape or the pore size is not uniform. Therefore, in order to prepare the light-storing ceramic with the micro-characteristic structure, a pore-forming agent and specific other additives need to be accurately selected according to the characteristics of raw materials and the requirements of products, and a specific ball milling and sintering process and the like are also needed. This will undoubtedly put forth a very high demand on workers in the field, and finally result in unstable luminous efficiency of the product.

Disclosure of Invention

The invention aims to provide an ultra-high brightness light-storing ceramic with a porous light channel structure.

The invention also aims to provide the application of the ultrahigh-brightness light-storing ceramic with the porous light channel structure.

In order to achieve the purpose, the invention provides the ultra-high brightness light-storing ceramic with the porous light channel structure, wherein the light-storing ceramic is internally provided with a three-dimensional pore channel structure which is communicated with each other, the diameter of the pore channel is 200-800 micrometers, and the porosity is 55-75%. When the aperture is less than 200 microns, the pore channels are difficult to communicate, the structure can return to the previous large pore structure to become a scattering center for reducing the light effect, and the overall local defect of the ceramic is larger due to more local pores, so that the yield is influenced; when the pore diameter is larger than 800 micrometers, the ceramic can generate local cavities, which affects the appearance and strength of the ceramic.

It is worth mentioning that:

structurally, the "porous structure" referred to in the present invention is different from the "pores" in the prior art, and the microstructure design of the prior fluorescent ceramic or light-storing ceramic only involves generating closed pores by a trace pore-forming agent and controlling the appearance and size of the pores to increase the scattering of light in the ceramic matrix. As shown in the figure 2, the product of the invention has a structure diagram, and different from closed pores, the invention forms a communicated pore structure in the ceramic through a large amount of pore-forming agents. The structure can be used as a light transmission channel, the specific surface area of the ceramic is increased, and the light efficiency of the light-storing ceramic is improved.

In theory, in the prior art, after the fluorescence is incident into the ceramic and meets pores or other two phases, the fluorescence can be transmitted in the ceramic in a scattering or reflecting mode, and the appearance and the size of the pores are controlled through a proper process. However, the pore-forming agent often reacts violently during the sintering process, and the morphology and distribution of pores are difficult to control, which easily causes a great amount of loss of the optical path in the ceramic. The total reflection critical angle is calculated to be 44 degrees, namely only 24.4 percent of fluorescence can be emitted from the upper surface of the ceramic, and the rest of fluorescence is limited by the total reflection effect and is transmitted in the ceramic in a waveguide effect mode until the fluorescence is completely lost. In the invention, the light path can be reflected for multiple times in the channel and projected to be close to the ceramic, and the low-refractive-index medium (compared with light-storing powder and a ceramic substrate) in the light channel can play a part of waveguide effect, and simultaneously can avoid a large amount of scattering loss of the light path in the ceramic, so that the structure of the light channel combined with the ceramic substrate can bring more photons emitted from the luminescent center in the ceramic to reach the surface of the ceramic, and the absorption and the emissivity of the light are greatly improved.

Further, the ultra-high brightness light-storing ceramic with the porous light channel structure can be prepared by the following steps:

(1.1) weighing: respectively weighing 50-55% of 10-30 mesh quartz raw material, 25-29% of 50-100 mesh quartz raw material, 6-15% of 150-250 mesh quartz raw material and the balance of raw material powder for preparing europium and dysprosium co-doped strontium aluminate long afterglow fluorescent powder, wherein the total mass of the raw material powder is 100%; and weighing a pore-forming agent accounting for 35-55% of the total mass of the raw material powder, wherein the pore-forming agent is ammonium bicarbonate, starch, and the mass ratio of ammonium bicarbonate to starch is 1: 3-6;

(1.2) mixing materials: putting the powder raw materials weighed in the step (1) into a ball milling tank, and simultaneously adding grinding balls and deionized water for ball milling and mixing;

(1.3) forming: carrying out vacuum defoaming treatment on the slurry subjected to ball milling in the step (2), and then injecting the defoamed slurry into a mold for molding to obtain a biscuit;

(1.4) drying: standing the biscuit obtained in the step (3) for 7-12 hours, demolding, and then drying in a drying oven;

(1.5) sintering: and (4) calcining the biscuit dried in the step (4) at high temperature in a reducing atmosphere, wherein the calcining temperature is 800-1200 ℃, the heat preservation time is 3-6 h, and then cooling to room temperature along with the furnace to obtain the light-storing ceramic material.

Preferably, in the step (1.1), the raw material powder for preparing the europium and dysprosium co-doped strontium aluminate long afterglow phosphor is SrCO₃、Al₂O₃、Eu₂O₃And Dy₂O₃According to the formula SrAl₂O₄:Eu²⁺,Dy³⁺The stoichiometric ratio of each element in the formula (I) is obtained by weighing.

Preferably, in the step (1.2), the mass ratio of the grinding balls to the total mass of the raw material powder is 1.5-3: 1, the addition amount of the deionized water is 12-17% of the total mass of the raw material powder.

Preferably, in the step (1.2), the rotation speed of the ball milling is 160-300 r/min, and the ball milling time is 20-25 h.

Preferably, in the step (1.3), the vacuum degree of the vacuum defoaming is-10 to-30 kpa, and the defoaming time is 30 to 50 min.

Preferably, in the step (1.4), the drying temperature is 60-100 ℃, and the drying time is 15-24 hours.

Further, the ultra-high brightness light-storing ceramic with the porous light channel structure can be prepared by the following steps:

(2.1) putting the glass substrate raw material, the long afterglow light-storing powder, the dispersing agent and the alumina powder into a granulator, adding deionized water doped with a pore-forming agent, directly mechanically stirring for granulation, adding a plasticizer after stirring for 4-8 hours, and continuously stirring for 1-3 hours to obtain a mixed material; the stirring speed in the whole stirring process is 100-300 rad/min; the glass matrix raw material is colorless glass powder, and the particle size of the glass matrix raw material is 10-400 microns; the particle size of the long afterglow light storage powder is 10-500 microns; the particle size of the alumina is 10-500 nanometers; the dispersing agent is sodium tripolyphosphate; the pore-forming agent is natural organic fine powder; the plasticizer is methyl cellulose; the mass ratio of the glass matrix raw material to the long afterglow light-storing powder is 9-49: 1; the additive amount of the dispersing agent is 0.1-0.9% of the total mass of the glass substrate raw material and the long afterglow light-storing powder, the additive amount of the plasticizer is 0.1-0.9% of the total mass of the glass substrate raw material and the long afterglow light-storing powder, the additive amount of the pore-forming agent is 35-55% of the total mass of the glass substrate raw material and the long afterglow light-storing powder, the additive amount of the alumina powder is 0.1-0.4% of the total mass of the glass substrate raw material and the long afterglow light-storing powder, and the additive amount of the deionized water is 20-50% of the total mass of the glass substrate raw material and the long afterglow light-storing powder;

(2.2) filling the mixed material obtained in the step (1) into a die, and tabletting by using an automatic tabletting machine; the shape of the mould is required by the product requirement, the pressure is 5-40 MPa, the pressure maintaining time is 5-20 s, and then the mould is demoulded and sent into a kiln for drying and firing;

(2.3) the temperature rising system of the kiln is as follows: the temperature is between room temperature and 200 ℃, the speed is 2-5 ℃/min, and the temperature is kept for 10-30 min; then, continuously heating to 400-900 ℃, and keeping the temperature for 60-120 min; then cooling the quartz ceramic to be below 100 ℃ along with the furnace and taking out the quartz ceramic to obtain the light-storing self-luminous quartz ceramic.

Preferably, in step (2.1), the light-storing powder is selected from one or more of yellow, yellow-green, blue-green, orange-red and other colors, such as blue-purple light emitting europium and neodymium-activated CaAl₃O₄: eu, Nb, blue-green europium, dysprosium activated Sr₄Al₁₄O₂₅: eu, Dy, yellow-green europium and dysprosium activated SrAl₂O₄: eu, Dy and other aluminate systems; silicate systems such as Eu and Dy activated pyrosilicate blue powder, Mg activated orthosilicate white luminescent powder and the like; yellow-green ZnS: cu series, blue CaS: bi series, red CaS: and Eu series sulfide systems.

Preferably, the raw materials used in step (2.1) further comprise a pigment which is used for beautifying or meeting the special requirements of products and is matched with the long afterglow light-storing powder in a luminescent way, and the mass ratio of the pigment to the long afterglow light-storing powder is less than 3.5.

The invention also provides application of the ultrahigh-brightness light-storing ceramic with the porous light channel structure in the field of fire-fighting indication.

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

1. the ultra-high brightness light-storing ceramic provided by the invention can realize 15 hours after light storage for 20min>0.32 mcd/m²) Continuous luminescence, initial 1min intensity>4500mcd/m²(ii) a Strength at 60min>35mcd/m²(direct outdoor sunlight for 20min, fluorescent lamp for 30min, ultraviolet ray for 5min, room temperature 25 deg.C).

2. Compared with the existing light-storing ceramic material, the ultra-high brightness light-storing ceramic material provided by the invention has the advantages that the size of pores in the product is within the range of 200-800 microns, and the porosity is 55-75%. The extraction efficiency of the preposed light is obviously improved by 25-40%. Besides improving the light efficiency, the porous structure can also improve the toughness of the ceramic and bring the portability.

3. The three-dimensional porous light channel structure provided by the invention breaks through the technical bias, is different from the prior art that pores are reduced as much as possible or pores are intentionally introduced to carry out morphology and distribution control, forms a new light-storing ceramic characteristic structure simply by adding excessive pore-forming agents, obtains obvious light-emitting effect and provides a new idea for related personnel in the field.

Drawings

FIG. 1 is a model diagram of optical path propagation after introduction of a pore-forming agent micro-morphology into a second phase in the prior art;

FIG. 2 is a schematic diagram of the optical path propagation of the light accumulating ceramic product of the present invention;

fig. 3 is an X-ray diffraction pattern of the samples prepared in example 1 and example 4.

Detailed Description

The invention is described in further detail below with reference to the figures and specific examples.

In the examples below, unless otherwise indicated, the experimental procedures described are generally carried out according to conventional conditions or conditions recommended by the manufacturer; all raw materials and reagents can be obtained by a commercially available method.

To prepare 100g of the target product, the formulation is shown in Table 1 and Table 2.

Table 1 examples 1-3 ingredient tables