Magnetic and heat conductive film glass etching agent, its preparation method and application

Abstract

The application discloses a kind of magnetic film glass etchant and its preparation method and application, the chemical composition of glass etchant is: Li2O 0~2wt%, Na2O 1.5~2.5wt%, K2O 2~4wt%, MgO 2.5~4.5wt%, B2O38~12wt%, SiO210~20wt%, TiO21.5~5wt%, Al2O30.4~1.2wt%, Bi2O320~30wt%, V2O535~45wt%, Nb2O50.5~2.5wt%.The melting temperature of the glass etchant of the application is low, the expansion coefficient is low, the surface tension is small, the high-temperature viscosity is low, can penetrate to ceramic or glass surface through metal powder layer at high temperature, play the role of etching ceramic or glass surface, thereby increase the roughness and surface area of ceramic or glass surface, make metal layer and ceramic or glass bond firm, and will not increase the resistance of metal layer, effectively improve the heating efficiency, thereby be favorable to promote the technical progress and development of electromagnetic induction furnace magnetic heating material industry.

Description

Technical Field

[0001] This invention relates to the field of glass materials technology, and in particular to a magnetically and thermally conductive film glass etchant, its preparation method, and its application. Background Technology

[0002] Induction cookers heat food using a physical principle called "electromagnetic induction." When an electromagnetic induction coil is energized, it generates a strong magnetic field. When this magnetic field passes through the iron cookware placed on the induction cooker, it induces eddy currents within the cookware. These eddy currents generate heat, thus heating the cookware and transferring the heat to the food. Induction cookers are characterized by their rapid heating and high efficiency, and are widely used in modern kitchens.

[0003] Since the magnetic heating materials in electromagnetic induction furnaces can only be iron or graphite, and ceramics and glass cannot generate eddy current heating, a metal film must be coated onto the bottom of the ceramic or glass furnace to enable its use in the electromagnetic induction furnace. Glass powder must be added to the metal film to firmly bond the metal to the ceramic or glass surface. Currently, existing technology mainly involves mixing metal powder and ordinary low-melting-point glass powder, coating the ceramic or glass surface, and then sintering at high temperature to fix the metal powder to the surface. However, this glass powder remains dispersed within the metal powder after high-temperature sintering. While this solves the problem of metal powder adhesion to the ceramic or glass surface, it also increases the resistance of the metal powder, resulting in low heating efficiency. Furthermore, it reduces the elasticity of the metal powder, making it prone to breakage during temperature fluctuations and causing failure. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of existing technologies and provide a magnetically conductive and thermally conductive film glass etchant with low melting temperature, low coefficient of expansion, low surface tension, and low high-temperature viscosity. This glass etchant can penetrate the ceramic or glass surface through a metal powder layer at high temperatures, etching the ceramic or glass surface, thereby increasing the surface roughness and surface area, resulting in a strong bond between the metal layer and the ceramic or glass, without increasing the resistance of the metal layer. This effectively improves heating efficiency, thus promoting technological progress and development in the electromagnetic induction furnace magnetic heating material industry. Another objective of this invention is to provide a method for preparing the aforementioned magnetically conductive and thermally conductive film glass etchant and its applications.

[0005] The objective of this invention is achieved through the following technical solution:

[0006] The present invention provides a magnetically and thermally conductive film glass etchant with the following chemical composition: Li2O 0-2wt%, Na2O 1.5-2.5wt%, K2O 2-4wt%, MgO 2.5-4.5wt%, B2O3 8-12wt%, SiO2 10-20wt%, TiO2 1.5-5wt%, Al2O3 0.4-1.2wt%, Bi2O3 20-30wt%, V2O5 35-45wt%, and Nb2O5 0.5-2.5wt%.

[0007] Another objective of this invention is achieved through the following technical solution:

[0008] The method for preparing the above-mentioned magnetic and thermal conductive film glass etchant provided by the present invention includes the following steps:

[0009] (1) The components in the chemical composition are introduced from the corresponding oxides, nitrates, carbonates and sulfates as raw materials;

[0010] (2) After weighing and mixing the raw materials according to the formula, the glass etchant is obtained by dry ball milling, sieving, melting, air cooling, graded ball milling, drying and grinding.

[0011] In the above scheme, in the chemical composition of the present invention, Li2O is introduced by lithium carbonate, Na2O is introduced by sodium nitrate, sodium carbonate or sodium sulfate, K2O is introduced by potassium nitrate, potassium carbonate or potassium sulfate, B2O3 is introduced by boric acid or borax, Al2O3 is introduced by aluminum hydroxide, and the remaining components are introduced by the corresponding oxides.

[0012] Furthermore, in step (2) of the preparation method of the present invention, the melting temperature is 1000-1050℃; the graded ball milling is performed by first dry milling to a particle size ≤20μm, and then wet milling to a particle size of 1-3μm.

[0013] The application of the above-mentioned magnetic and thermal conductive film glass etchant provided by the present invention involves mixing and dispersing the glass etchant, metal powder, and ink oil in a mass ratio of glass etchant: metal powder: ink oil = 100:4~6:40~50. The mixture is then applied to the surface of ceramics or glass using screen printing, or it can be made into decals and applied to the surface of ceramics or glass. Finally, it is baked at 800~900℃ for 3~4 hours to obtain the magnetic and thermal conductive film coating.

[0014] The present invention has the following beneficial effects:

[0015] (1) The magnetic and thermal conductive film coating formed by the glass etchant of the present invention is firmly bonded to ceramics or glass, has good adhesion performance (adhesion level 0) and is not easy to scratch.

[0016] (2) The glass etchant of the present invention melts after baking. Due to its low surface tension, it can quickly spread on the solid surface. Under the action of gravity, it penetrates through the metal powder layer and spreads to the surface of ceramic or glass without increasing the resistance of the metal powder layer, effectively improving the heating efficiency of the coating (96.2-99.2%). At the same time, it also has a good wetting effect.

[0017] (3) The glass etchant of the present invention has a low coefficient of thermal expansion (4.6 to 5.8 × 10⁻⁶). -6 ( / ℃), which can prevent the metal coating from peeling off during alternating hot and cold temperatures.

[0018] (4) The preparation method of the present invention is simple, has low production cost, high production efficiency, low energy consumption, and is economical and environmentally friendly. It can well meet the actual production and application needs of enterprises and is conducive to promoting the technological progress and application development of this glass etchant. Attached Figure Description

[0019] The present invention will now be described in further detail with reference to the embodiments and accompanying drawings:

[0020] Figure 1 This is a SEM image of the magnetically and thermally conductive film coating prepared according to the embodiments of the present invention;

[0021] Figure 2 This is a mapping diagram of the magnetic and thermal conductive film coating prepared in the embodiments of the present invention. Detailed Implementation

[0022] This invention discloses a magnetically and thermally conductive film glass etchant with the following chemical composition: Li₂O 0-2wt%, Na₂O 1.5-2.5wt%, K₂O 2-4wt%, MgO 2.5-4.5wt%, B₂O₃ 8-12wt%, SiO₂ 10-20wt%, TiO₂ 1.5-5wt%, Al₂O₃ 0.4-1.2wt%, Bi₂O₃ 20-30wt%, V₂O₅ 35-45wt%, and Nb₂O₅ 0.5-2.5wt%. The chemical compositions of each embodiment are shown in Table 1.

[0023] Table 1. Chemical composition of the etchant for the magnetic and thermally conductive film glass in the embodiments of the present invention.

[0024] Chemical composition (wt%) of the examples Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 <![CDATA[Li2O]]> 1.5 1.5 1.5 1.5 2 2 <![CDATA[Na2O]]> 1.5 1.5 1.5 1.5 2.5 1.5 <![CDATA[K2O]]> 3.5 2.5 3.5 3.5 2 4 MgO 3.0 3.0 3.0 3.0 3.0 2.5 <![CDATA[B2O3]]> 11 8 11 11 11 11 <![CDATA[SiO2]]> 18 18 10 18 18 10 <![CDATA[TiO2]]> 4.5 3.5 2.5 4.5 4.5 4 <![CDATA[Al2O3]]> 0.4 0.4 0.4 0.4 0.4 0.4 <![CDATA[Bi2O3]]> 21.1 21.1 21.1 21.1 21.1 29.1 <![CDATA[V2O5]]> 35 40 45 35 35 35 <![CDATA[Nb2O5]]> 0.5 0.5 0.5 0.5 0.5 0.5

[0025] The preparation method of the magnetic and thermal conductive film glass etchant according to an embodiment of the present invention comprises the following steps:

[0026] (1) The components in the above chemical composition are introduced from the corresponding oxides, nitrates, carbonates and sulfates as raw materials; among them, Li2O is introduced from lithium carbonate, Na2O is introduced from sodium nitrate, sodium carbonate or sodium sulfate, K2O is introduced from potassium nitrate, potassium carbonate or potassium sulfate, B2O3 is introduced from boric acid or borax, Al2O3 is introduced from aluminum hydroxide, and the remaining components are introduced from the corresponding oxides.

[0027] (2) The raw materials were weighed and proportioned according to the above formula, mixed by dry ball milling, sieved, melted at a high temperature of 1000-1050℃, air-cooled, dried, and then subjected to graded ball milling, i.e., first dry milling to a particle size ≤20μm, then wet milling to a particle size of 1-3μm, and then dried and powdered to obtain the glass etchant. The melting temperature of the preparation methods of each embodiment is shown in Table 2.

[0028] The application of the magnetic and thermal conductive film glass etchant in this embodiment of the invention is as follows: the glass etchant: metal powder: ink oil is mixed and dispersed evenly with the metal powder (using metallic silver) and ink oil according to the mass ratio of glass etchant: metal powder: ink oil = 100: 4~6: 40~50. The coating is then applied to the ceramic or glass surface by screen printing or by making decals and baking at 800~900℃ for 3~4 hours to obtain the magnetic and thermal conductive film coating.

[0029] The process parameters used in each embodiment are shown in Table 2.

[0030] Table 2. Melting temperature and process parameters in the preparation methods of various embodiments of the present invention.

[0031] Example Process Parameters Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Melting temperature (°C) 1050 1010 1020 1040 1000 1040 Glass etchant: Metal powder: Ink oil 100∶6∶50 100∶5∶45 100∶4.5∶45 100∶5∶50 100∶5.5∶50 100∶4.5∶40 Baking temperature (°C) 800 820 860 850 900 880 Baking time (h) 4 4 3.5 3.5 3 3

[0032] Note: 1) The coefficient of thermal expansion was tested using a CSI-771 thermal expansion coefficient tester.

[0033] 2) Adhesion is measured using a cross-cut adhesion tester.

[0034] 3) The ratio of glass etchant to metal powder to ink is by mass.

[0035] like Figure 1 and Figure 2 As shown, the magnetically and thermally conductive film coating obtained in the application of this embodiment of the invention consists of a silver metal layer and an etchant layer. The silver metal layer is on the outer layer, while the etchant layer penetrates through the silver metal layer to the ceramic or glass surface and is located in the inner layer, contacting the ceramic or glass surface. This not only ensures a strong bond between the metal layer and the ceramic or glass but also avoids increasing the resistance of the metal layer, effectively improving the heating efficiency.

[0036] The performance indicators of the magnetic and thermal conductive film coatings obtained in each embodiment are shown in Table 3.

[0037] Table 3 Performance indicators of the magnetic and thermal conductive film coatings obtained in the applications of various embodiments of the present invention

[0038] Example Performance Indicators Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 <![CDATA[Coefficient of expansion (×10 -6 / °C)]]> 4.6 5.2 4.8 5.2 5.8 5.1 Adhesion Level 0 Level 0 Level 0 Level 0 Level 0 Level 0 Heating efficiency (%) 96.2 98.8 99.1 97.6 97.1 99.2

[0039] Note: The heating efficiency is the ratio of output power to input power × 100%.

Claims

1. A magnetic and thermal conductive film glass etching agent, characterized by The chemical composition comprises: Li2O 0-2wt%, Na2O 1.5-2.5wt%, K2O 2-4wt%, MgO 2.5-4.5wt%, B2O3 8-12wt%, SiO2 10-20wt%, TiO2 1.5-5wt%, Al2O3 0.4-1.2wt%, Bi2O3 20-30wt%, V2O5 35-45wt%, Nb2O5 0.5-2.5wt%.

2. The method of claim 1, wherein the etchant for the magnetically and thermally conductive film glass is prepared by the steps of: The method comprises the following steps: ​ (1) the components in the chemical composition are introduced by corresponding oxides, nitrates, carbonates, sulfates as raw materials; (2) the raw materials are weighed and mixed according to the formula, then sieved, melted, air-cooled, classified ball-milled, dried and powdered, so that the glass etching agent is obtained.

3. The method for preparing the magnetically and thermally conductive film glass etchant according to claim 2, characterized in that: Li2O in the chemical composition is introduced by lithium carbonate, Na2O is introduced by sodium nitrate, sodium carbonate or sodium sulfate, K2O is introduced by potassium nitrate, potassium carbonate or potassium sulfate, B2O3 is introduced by boric acid or borax, Al2O3 is introduced by aluminum hydroxide, and the rest of the components are introduced by corresponding oxides.

4. The method for preparing the magnetically and thermally conductive film glass etchant according to claim 2, characterized in that: The melting temperature in the step (2) is 1000-1050℃.

5. The method for preparing the magnetically and thermally conductive film glass etchant according to claim 2, characterized in that: The classified ball-milling in the step (2) is dry-milling to a particle size of ≤20μm, and then wet-milling to a particle size of 1-3μm.

6. The use of the etchant of claim 1, wherein the etchant is used for etching a glass film having a magnetic permeability and a thermal conductivity. The glass etching agent, metal powder and ink adjusting oil are mixed and dispersed uniformly according to the mass ratio of glass etching agent:metal powder:ink adjusting oil=100:4-6:40-50, then coated on the surface of ceramic or glass by silk screen printing, or made into a decal paper and pasted on the surface of ceramic or glass, and then baked at a temperature of 800-900℃ for 3-4h, so that the magnetic and heat conductive film coating is obtained.

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