CN112083521A - Preparation method of diffuse reflection device and diffuse reflection device - Google Patents

Abstract

The invention provides a preparation method of a diffuse reflection device and the diffuse reflection device, wherein the preparation method of the diffuse reflection device comprises the following steps: s1: after mixing the diffuse reflection particles and an organic carrier into slurry, coating the slurry on a heat conduction substrate layer and pre-drying the slurry at a first temperature; s2: sintering the slurry coated on the heat-conducting substrate layer into a diffuse reflection powder layer at a second temperature; s3: and sintering the diffuse reflection powder layer soaked by the water glass into a diffuse reflection layer at a third temperature. According to the invention, high-fluidity water glass is used as a binder to fill the gaps among the particles, and a compact film layer is formed after curing, and meanwhile, high-strength bonding can be formed with the heat-conducting substrate layer, so that higher reflectivity and lower thermal resistance are realized, and the efficiency of the diffuse reflection device is higher.

Description

Preparation method of diffuse reflection device and diffuse reflection device

technical field

The invention relates to a preparation method of a diffuse reflection device and a diffuse reflection device, and belongs to the technical field of optical materials.

Background technique

At present, the diffuse reflection layer of mainstream diffuse reflection devices is formed by mixing and sintering white diffuse reflection particles and glass frit. In order to ensure a higher reflectivity, a diffuse reflection layer with a higher content of diffuse reflection particles is generally used, or a thicker diffuse reflection layer is used. However, when the content of diffuse reflection particles is high, the adhesion between the diffuse reflection layer and the thermally conductive substrate is poor, and the reliability is low; and the thermal resistance of the thicker diffuse reflection layer is higher, so the current diffuse reflection layer structure of the diffuse reflection device It is difficult to have the characteristics of high reflection and low thermal resistance at the same time, which is not conducive to the improvement of the efficiency of the diffuse reflection device.

In order to make the diffuse reflection layer have high reflection characteristics relative to visible light, the particle size of the white diffuse reflection particles is generally required to be in the submicron range of 0.1μm-0.5μm, and the glass powder used as a binder, due to process limitations, can only be Provide particles with a particle size close to 1 μm, the original particles are larger, and the larger particle size of the bonded particles will affect the distribution of the white diffuse reflection particles during the sintering process, and the bonded white diffuse reflection particles are difficult to form a close-packed structure. It is difficult to further improve the reflectivity of the reflective layer. Figure 1 is a partial SEM image of the diffuse reflection layer in the prior art. As shown in Figure 1, the glass powder does not form a completely molten flow state after sintering, and basically maintains its original particle size, with a size of about 1 μm, and the particle size is The white diffuse reflection particles of 0.1μm-0.5μm adhere to the glass particles. Due to the spacing effect of the large glass particles, the white diffuse reflection particles cannot completely cover the glass particles, leaving more holes and poor bonding strength. If the thickness of the diffuse reflection layer is high, the thickness of the prepared diffuse reflection layer is relatively thick and the thermal resistance is high, making it difficult for the diffuse reflection layer to meet the requirements of high reflectivity and low thermal resistance.

SUMMARY OF THE INVENTION

The technical problem to be solved by the present invention is to provide a preparation method of a diffuse reflection device and a diffuse reflection device in view of the deficiencies of the prior art. The gaps between particles are filled with high-fluidity water glass as a binder, and a dense film is formed after curing. At the same time, it can also form high-strength bonding with the thermally conductive substrate layer, so as to achieve higher reflectivity and lower thermal resistance, so that the efficiency of the diffuse reflection device is higher; and the potassium water glass used in the present invention and the thermally conductive substrate layer It has high adhesion and can also be modified by silicon phosphate to significantly improve its water resistance and reliability.

The technical problem to be solved by the present invention is achieved through the following technical solutions:

The present invention provides a preparation method of a diffuse reflection device. The preparation method includes the following steps: S1: after mixing the diffuse reflection particles and an organic carrier into a slurry, coat it on a thermally conductive substrate layer and pre-dry it at a first temperature; S2: Sinter the slurry coated on the thermally conductive substrate layer at the second temperature to form a diffuse reflection powder layer; S3: Sinter the diffuse reflection powder layer infiltrated with water glass into a diffuse reflection powder layer at a third temperature Floor.

Preferably, the diffusely reflective particles include first white diffusely reflective particles and second white diffusely reflective particles, and the first white diffusely reflective particles include one or more of titanium oxide, zinc oxide, yttrium oxide and zirconium oxide, The second white diffusely reflective particles include one or more of aluminum oxide, barium sulfate and aluminum silicate.

Preferably, the first white diffuse reflection particles are titanium oxide with a rutile structure.

In order to make the diffuse reflection layer have high reflection characteristics relative to visible light, the average particle diameters of the first white diffuse reflection particles and the second white diffuse reflection particles are both 0.1 μm-0.5 μm.

Preferably, the first temperature is 60°C-150°C, the second temperature is 400°C-600°C, and the third temperature is 100°C-300°C.

In order to make the water glass fully infiltrate the diffuse reflection powder layer, in S3, the infiltration method includes: spraying the water glass on the diffuse reflection powder layer, and dropping the water glass on the diffuse reflection powder layer. On the reflective powder layer or the diffuse reflection powder layer is immersed in the water glass for a preset time and taken out.

In order to further improve the adhesive force between the diffuse reflection layer and the thermally conductive substrate layer, the water glass is potassium water glass, and the modulus of the potassium water glass is 3-7.

In order to improve the water resistance of the diffuse reflection device, the potassium water glass is potassium water glass modified by silicon phosphate or potassium water glass modified by sodium fluorosilicate.

Preferably, the mass fraction of the silicon phosphate is 5%-20%, and the mass fraction of the sodium fluorosilicate is less than or equal to 5%.

The present invention also provides a diffuse reflection device, comprising a thermally conductive substrate layer and a diffuse reflection layer disposed on the thermally conductive substrate layer, wherein the diffuse reflection layer is prepared by the above-mentioned preparation method of a diffuse reflection device.

In order to avoid cracking while ensuring the reflectivity of the diffuse reflection device, the thickness of the diffuse reflection layer is 40 μm-90 μm.

To sum up, the present invention uses water glass with high fluidity as a binder to fill the gaps between particles, and forms a dense film layer after curing, and can also form a high-strength bond with the thermally conductive substrate layer, thereby achieving higher reflectivity. and lower thermal resistance, so that the efficiency of the diffuse reflection device is higher; and the potassium water glass used in the present invention has high adhesion to the thermally conductive substrate layer, and can also be modified by silicon phosphate to significantly improve its water resistance and reliability. .

The technical solutions of the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

Description of drawings

Fig. 1 is the partial SEM image of the diffuse reflection layer in the prior art;

Fig. 2 is the partial SEM image of the diffuse reflection layer of the present invention;

3 is a schematic structural diagram of a diffuse reflection device of the present invention;

FIG. 4 is a schematic diagram of the production process of the diffuse reflection device of the present invention.

Detailed ways

All the raw materials of the present invention, their sources are not particularly limited, can be purchased in the market or prepared according to conventional methods well known to those skilled in the art.

FIG. 2 is a partial SEM image of the diffuse reflection layer 10 of the present invention; FIG. 3 is a schematic structural diagram of the diffuse reflection device of the present invention. As shown in FIG. 2 and FIG. 3 , the present invention provides a diffuse reflection device, the diffuse reflection device includes a thermally conductive substrate layer 20 and a diffused reflection layer 10 disposed on the thermally conductive substrate layer 20 .

The material of the thermally conductive substrate layer 20 is alumina ceramics, sapphire crystals, aluminum nitride ceramics, silicon carbide ceramics, silicon nitride ceramics or boron nitride ceramics with thermal conductivity higher than 10 W/m·K. In addition, in order to reduce the cost and enhance the adhesion between the thermally conductive substrate layer 20 and the diffuse reflection layer 10 , the material of the thermally conductive substrate layer 20 may also be aluminum.

The diffuse reflection layer 10 includes diffuse reflection particles and water glass 13, and the diffuse reflection particles preferably include first white diffuse reflection particles 11 and second white diffuse reflection particles 12, wherein the first white diffuse reflection particles 11 and The average particle diameters of the second white diffusely reflective particles 12 are both 0.1 μm-0.5 μm, and the bulk densities of the first and second white diffusely reflective particles 11 preferably reach the tap density. The first white diffuse reflection particles 11 include one or more of titanium oxide, zinc oxide, yttrium oxide and zirconium oxide. When the first white diffuse reflection particles 11 include titanium oxide, titanium oxide with a rutile structure is preferred. The second white diffusely reflective particles 12 include one or more of aluminum oxide, barium sulfate and aluminum silicate.

Since the existing diffuse reflection layer 10 is mixed and sintered on the thermally conductive substrate with glass frit and diffuse reflection particles, the diffuse reflection particles cannot be densely packed, and the high temperature fluidity of the glass liquid is poor. Easy to bond is not strong. In the present invention, the diffuse reflection powder layer 10 ′ without glass powder adhesive is first prepared, and the diffuse reflection particles can basically realize a close-packed structure. to fill the gaps between the diffusely reflective particles, which together with the first white diffusely reflective particles 11 and the second white diffusely reflective particles 12 form a dense diffusely reflective layer 10 after curing. At the same time of the bonding strength between 20, high diffuse reflection particle content is achieved, so that the diffuse reflection device has higher reflectivity and lower thermal resistance, thereby improving the efficiency of the diffuse reflection device.

In order to further improve the adhesive force between the diffuse reflection layer 10 and the thermally conductive substrate layer 20 , the water glass 13 is preferably potassium water glass, and the modulus of the potassium water glass is preferably 3-7. More preferably, potassium water glass modified by silicon phosphate or potassium water glass modified by sodium fluorosilicate is used. When potassium water glass modified by silicon phosphate is used, the water resistance of the diffuse reflection device can be significantly improved. Preferably, the mass fraction of the silicon phosphate is 5%-20%, and the mass fraction of the sodium fluorosilicate is less than or equal to 5%.

Preferably, when the thickness of the diffuse reflection layer 10 is greater than 90 μm, the reflectivity of the diffuse reflection layer 10 will no longer increase and it is easy to crack, and when the thickness is less than 40 μm, the reflectivity decreases seriously. Therefore, in the present invention, the diffuse reflection layer 10 The thickness is 40μm-90μm.

FIG. 4 is a schematic diagram of the production process of the diffuse reflection device of the present invention. As shown in FIG. 4 , the present invention also provides a preparation method of the above-mentioned diffuse reflection device, and the preparation method is as follows:

S1: after mixing the first white diffusely reflective particles 11 and the second white diffusely reflective particles 12 with an organic carrier into a slurry, coat it on the thermally conductive substrate layer 20 and pre-dry it at a first temperature;

S2: sintering the slurry coated on the thermally conductive substrate layer 20 into a diffuse reflection powder layer 10' at a second temperature;

S3: The diffuse reflection powder layer 10' soaked with water glass 13 is sintered at a third temperature to form a diffuse reflection layer.

In S1, the organic carrier includes but is not limited to phenyl, methyl and other systems of silicone oil, ethanol, ethylene glycol, xylene, ethyl cellulose, acetyl tributyl citrate, terpineol, butyl One or more mixtures of carbitol, butyl carbitol acetate, polyvinyl alcohol (PVA), polyvinyl butyral (PVB), polyacrylic acid (PAA), polyethylene glycol (PEG) body. The pre-drying temperature (first temperature) is preferably 60°C-150°C, and the pre-drying time is preferably 0.5-4 hours, so as to shape the slurry. It should be added that, in order to make the slurry uniform, it can be left for a period of time before pre-drying, preferably for 1-3 hours.

It should be added that the coating in S1 can be carried out in a variety of ways, such as dip coating, spray coating or deposition, etc. Since the deposition method is used to coat the diffuse reflection device prepared by coating the first white diffuse reflection particles and the second white diffuse reflection particles The reflectivity is low, preferably dip coating or spray coating.

In S2, the sintering temperature (second temperature) is preferably 400° C.-600° C., and the sintering time is preferably 0.5-3 hours, so that the organic carrier is decomposed and excluded during the sintering process, reducing its effect on diffuse reflection. Influenced by the layer 10 , only the diffuse reflection powder layer 10 ′ consisting of the first white diffuse reflection particles 11 and the second white diffuse reflection particles 12 remains on the thermally conductive substrate layer 20 .

In S3, the sintering temperature (third temperature) is preferably 100°C-300°C, and the sintering time is preferably 0.5-3 hours. There are many ways to infiltrate the diffuse reflection powder layer 10' and the water glass 13. The present invention does not limit the specific way of mixing. Those skilled in the art can choose according to actual needs. For example, spraying, dipping or The water glass 13 is soaked in the diffuse reflection powder layer 10 ′ by dropping or the like. Specifically, the water glass 13 can be sprayed on the diffuse reflection powder layer 10 ′, the water glass 13 can be dripped on the diffuse reflection powder layer 10 ′, or the diffuse reflection powder layer 10 ′ can be immersed in the water glass 13 beforehand. Take out after setting the time, and the preset time is preferably 0.5-12 hours.

In order to accelerate the infiltration of the water glass 13 into the diffuse reflection powder layer 10', the water glass 13 may be heated, thereby shortening the infiltration time.

Alternatively, water glass 13 can also be added dropwise on the diffuse reflection powder layer 10 ′, thereby infiltrating the diffuse reflection powder layer 10 ′; Diffuse reflection powder layer 10 ′ wetted by water glass 13 .

The following preparation methods are used to prepare diffuse reflection layers with different thicknesses (sample 1, sample 2, sample 3, sample 4), and glass frit sintering adhesive is used to prepare diffuse reflection layers with different thicknesses (inorganic diffuse reflection 1, inorganic diffuse reflection Reflection 2), using organic silica gel adhesive to prepare diffuse reflection layers of different thicknesses (organic diffuse reflection 1, organic diffuse reflection 2), and take SRS-010 Bluefield standard whiteboard as a reference, the relative reflection of different diffuse reflection layers The relationship between the ratio and the thickness is shown in Table 1.

Table 1

Thickness/μm Relative reflectivity Sample 1 65-64 102.0% Sample 2 69-70 103.3% Sample 3 57-60 102.8% Sample 4 70-73 103.4% Inorganic Diffuse 1 63-60 100.4% Inorganic Diffuse 2 59-58 100.3% Organic Diffuse 1 50-55 100.8% Organic Diffuse 2 70-76 101.1%

It can be seen from Table 1 that, compared with the relative reflectivity test of the diffuse reflection layer sintered with inorganic glass powder and bonded with organic silica gel, the relative reflectivity of the diffuse reflection layer prepared by the present invention is higher than that of the glass powder sintered adhesive. Diffuse reflective layer with silicone adhesive.

To sum up, the present invention uses water glass with high fluidity as a binder to fill the gaps between particles, and forms a dense film layer after curing, and can also form a high-strength bond with the thermally conductive substrate layer, thereby achieving higher reflectivity. and lower thermal resistance, so that the efficiency of the diffuse reflection device is higher; and the potassium water glass used in the present invention has high adhesion to the thermally conductive substrate layer, and can also be modified by silicon phosphate to significantly improve its water resistance and reliability. .

Claims (10)

1. A method for preparing a diffuse reflection device, the method comprising:

s1: after mixing the diffuse reflection particles and an organic carrier into slurry, coating the slurry on a heat conduction substrate layer and pre-drying the slurry at a first temperature;

s2: sintering the slurry coated on the heat-conducting substrate layer into a diffuse reflection powder layer at a second temperature;

s3: and sintering the diffuse reflection powder layer soaked by the water glass into a diffuse reflection layer at a third temperature.

2. The method of claim 1, wherein the diffuse reflection particles comprise first white diffuse reflection particles comprising one or more of titanium oxide, zinc oxide, yttrium oxide, and zirconium oxide, and second white diffuse reflection particles comprising one or more of aluminum oxide, barium sulfate, and aluminum silicate.

3. The method of manufacturing a diffuse reflection apparatus according to claim 2, wherein said first white diffuse reflection particles are titanium oxide of a rutile structure.

4. The method of manufacturing a diffuse reflection apparatus according to claim 2, wherein the first white diffuse reflection particles and the second white diffuse reflection particles each have an average particle diameter of 0.1 μm to 0.5 μm.

5. The method of making a diffuse reflective device according to claim 1, wherein said first temperature is in the range of 60 ℃ to 150 ℃, said second temperature is in the range of 400 ℃ to 600 ℃, and said third temperature is in the range of 100 ℃ to 300 ℃.

6. The method of claim 1, wherein in S3, the wetting comprises: spraying the water glass on the diffuse reflection powder layer, dropwise adding the water glass on the diffuse reflection powder layer or immersing the diffuse reflection powder layer in the water glass for a preset time and then taking out the water glass.

7. The method of making a diffuse reflective device according to claim 1, wherein said water glass is a potash water glass having a modulus of 3 to 7.

8. The method of making a diffuse reflective device according to claim 7, wherein said potash water glass is a silicon phosphate modified potash water glass or a sodium fluorosilicate modified potash water glass.

9. The method for producing a diffuse reflection device according to claim 8, wherein the silicon phosphate is 5 to 20% by mass, and the sodium fluorosilicate is 5% by mass or less.

10. A diffuse reflective device comprising a thermally conductive substrate layer and a diffuse reflective layer disposed on said thermally conductive substrate layer, wherein said diffuse reflective layer is produced using the method of producing a diffuse reflective device according to any one of claims 1-9.

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