A high-dielectric hollow glass microsphere of titanosilicate and its preparation method

Abstract

This invention discloses a high-dielectric hollow glass microsphere of titanate and its preparation method. The chemical composition of the microsphere, based on a total mass of 100%, is as follows: SiO2 61.55%–70.26%, TiO2 7.55%–11.65%, B2O3 5.24%–11.44%, Na2O 4.45%–8.5%, CaO 3.15%–8.24%, YO 4.43%–7.56%, Al2O3 0.12%–0.48%, R2O 0%–3%, where Y in YO is at least one of Ba, Sr, Cu, Mg, and Zn, and R in R2O is an alkali metal other than the aforementioned metals. The high-dielectric hollow glass microspheres prepared by this invention not only retain the characteristics of low density and high strength, but also have the characteristics of high dielectric, high light transmittance and corrosion resistance. They can improve the corrosion resistance, insulation, antistatic and electromagnetic shielding and isolation performance of sealing materials for electronic components, and meet the needs of electronic and electrical components in the aerospace and new energy vehicle manufacturing industries.

Description

Technical Field

[0001] This invention belongs to the technical field of dielectric materials and functional glass material preparation, specifically relating to a high-dielectric hollow glass microsphere of titanate and its preparation method. The high-dielectric hollow glass microsphere of titanate prepared using this method can meet the development needs of industries such as aerospace, new energy vehicles, and rail transportation. Background Technology

[0002] When a dielectric material is placed in an applied electric field, it generates induced charges, weakening the electric field. The ratio of the original applied electric field (in vacuum) to the final electric field in the dielectric is called the dielectric constant, also known as the induced charge, and it is frequency-dependent. The dielectric constant is the product of the relative dielectric constant and the absolute dielectric constant in vacuum. If a material with a high dielectric constant is placed in an electric field, the intensity of the electric field will decrease considerably within the dielectric. In other words, a high dielectric constant results in poor conductivity but good insulation properties. High-dielectric materials are widely used in electronic devices and components for anti-static protection, electromagnetic shielding, electromagnetic isolation, and heat-resistant materials.

[0003] With the rapid development of industries such as aerospace, new energy vehicles, and rail transportation, the requirements for sealing and protective materials for electronic components are becoming increasingly stringent. While ensuring high dielectric and high insulation properties, more stringent requirements are being placed on lightweighting, temperature resistance, and thermal insulation. In particular, the aerospace and new energy vehicle sectors have placed even higher demands on the lightweighting of sealing materials, requiring a dielectric constant of no less than 10 F / m and a material density of less than 1.0 g / cm³. 3 High-dielectric fillers generally have a heavier density than resin substrates, typically around 3.0 g / cm³. 3 The above methods cannot meet the requirements for lightweight design. As a core raw material for sealing and protecting electronic components, high-dielectric, lightweight, and high-strength hollow glass microspheres have become an important solution.

[0004] Chinese patent CN115028197A discloses a low-frequency ultra-high dielectric constant material and its preparation method. The high dielectric constant lightweight dielectric substrate is made of high dielectric ceramic powder, hollow microspheres, and polyphenylene ether resin, with a density range of 1.5–2.0 g / cm³. 3 Due to the complexity of its formulation and production process, it is difficult and costly to prepare a uniformly mixed and dispersed ceramic powder and hollow microspheres. At the same time, the properties of high-density, high-dielectric ceramic powder and low-density, low-dielectric hollow microspheres are mutually contradictory, making it difficult to balance their properties, and the performance of the prepared composite material has significant limitations.

[0005] Hollow glass microspheres are mainly composed of silicon dioxide, boron oxide, alkali metals, and alkaline earth metals, with a dielectric constant of 1.0–2.2 F / m and a density of 0.2–0.6 g / cm³. 3While the compressive strength ranges from 3 to 103 MPa, meeting the lightweight requirements of sealing materials in various industries, its dielectric, electrical insulation, and antistatic properties are relatively poor. With the rapid development of aerospace, new energy vehicles, and rail transportation, the comprehensive performance requirements for sealing materials of electronic components—including lightweighting, high dielectric constant, high insulation, electrical breakdown resistance, and antistatic properties—are becoming increasingly stringent. Current hollow glass microspheres can no longer meet the development requirements of modern electronic devices; therefore, developing a high-dielectric hollow glass microsphere is of great significance. Summary of the Invention

[0006] The purpose of this invention is to address the problems of existing high-dielectric materials, such as high density, low strength, poor light transmittance, and poor corrosion resistance, which make it difficult to meet the development needs of industries such as aerospace, new energy vehicles, and rail transportation. The invention provides a titanium silicate high-dielectric hollow glass microsphere. The prepared titanium silicate high-dielectric hollow glass microsphere product not only retains the characteristics of low density and high strength, but also has the characteristics of high dielectric, high light transmittance, and corrosion resistance. It can improve the corrosion resistance, insulation, antistatic, electromagnetic shielding, and isolation performance of sealing materials for electronic components.

[0007] Another object of the present invention is to provide a method for preparing the above-mentioned high-dielectric hollow glass microspheres of titanate silicate.

[0008] To achieve the above-mentioned objectives of this invention, a titanium silicate high-dielectric hollow glass microsphere of this invention has the following chemical composition based on a total mass of 100%:

[0009]

[0010]

[0011] The YO is a metal oxide, and the Y in YO is at least one of Ba, Sr, Cu, Mg, and Zn; the R2O is also a metal oxide, and the R in R2O is an alkali metal other than the metals mentioned above.

[0012] The main function of adding TiO2 in this invention is to improve the strength and rigidity of the hollow glass microsphere shell. The introduction of titanium ions can improve the high-temperature resistance of the glass, making it more stable in high-temperature environments. The TiO2 content is between 7.55% and 11.65%. A content below 7.55% has little impact on the glass properties, while a content above 11.65% results in a higher melting point, making melting difficult, affecting the foaming process, and significantly impacting the final density of the hollow glass microspheres.

[0013] The main function of YO added in this invention is to improve the refractive index and mechanical strength of glass, enhance its gloss and corrosion resistance, and reduce its melting temperature and viscosity.

[0014] The preferred chemical composition, based on a total mass of 100%, is as follows:

[0015]

[0016] This invention discloses a titanium silicate high-dielectric hollow glass microsphere, wherein the proportions of each mineral component in the raw material, based on a total mass of 100%, are as follows:

[0017]

[0018]

[0019] The silica is at least one of the following high-silicon materials: quartz sand, silica powder, quartz sandstone, metamorphic quartzite, siliceous rock, quartz glass, etc., wherein the silica content is ≥95% and the particle size is between 40-120 mesh.

[0020] The boron and its compounds are selected from at least one of boron oxide, sodium tetraborate, boric acid, and metaboric acid.

[0021] The titanate is selected from at least one of barium titanate, barium strontium titanate, magnesium titanate, calcium titanate, calcium copper titanate, and zinc titanate.

[0022] The selected calcium carbonate has a true density range of 2.4–2.8 g / cm³. 3 The sedimentation volume in anhydrous ethanol is 2.0–2.7 mL / g, the effective content of light calcium carbonate is 40–60%, and the mesh size is 1250–1500 mesh.

[0023] This invention discloses a method for preparing high-dielectric hollow glass microspheres of titanate silicate, comprising the following steps:

[0024] (1) Weigh each ingredient accurately according to the formula, and put the prepared ingredients into a homogenizer and mix them evenly.

[0025] (2) The raw materials that are mixed evenly in step (1) are artificially granulated by physical bonding, drying granulation or melt ball milling to obtain precursor particles with an average particle size range of 2 to 500 μm.

[0026] (3) The precursor particles obtained in step (2) are classified to obtain selected precursor particles with an average particle size of 20-40 μm.

[0027] (4) The selected precursor particles prepared in step (3) are fed into a high-temperature vitrification furnace for hollow glass microspheres. The vitrification temperature is controlled at 1300–1500℃, and the vitrification time is 2–5 seconds, to prepare microspheres with a density of 0.2–0.6 g / cm³. 3 High dielectric hollow glass microspheres with compressive strength of 8–130 MPa, average particle size of 25–42 μm, light transmittance >66.5%, and dielectric constant ≥15 F / m.

[0028] The high-dielectric hollow glass microspheres prepared by the method of this invention not only retain the characteristics of low density and high strength, but also have the characteristics of high dielectric, high light transmittance and corrosion resistance. They can improve the corrosion resistance, insulation, antistatic, electromagnetic shielding and isolation performance of sealing materials for electronic components, and meet the development needs of industries such as aerospace, new energy vehicles, and rail transportation.

[0029] Compared with the prior art, the present invention, which discloses a high-dielectric hollow glass microsphere of titanate and its preparation method, has the following beneficial effects after adopting the above technical solution:

[0030] (1) The high dielectric hollow glass microspheres prepared not only retain their low density and high strength characteristics, but also have the characteristics of high dielectric constant. They can endow composite materials with advantages such as lightweight, electrical insulation, antistatic properties and electromagnetic isolation, and meet the needs of electronic and electrical components in the aerospace and new energy vehicle manufacturing industries.

[0031] (2) Compared with conventional hollow glass microsphere granulation methods, the present invention can use a variety of processes for granulation, the equipment is mature and reliable, and the preparation efficiency is greatly improved.

[0032] (3) Titanates can effectively improve the polarization effect of glass and significantly increase the dielectric constant. The titanium silicate hollow glass microspheres prepared by this invention have a dielectric constant ≥15F / m, which is significantly improved compared with the dielectric properties of conventional hollow glass microspheres (dielectric constant 1.0~2.2F / m). This changes the low dielectric constant characteristic of traditional hollow glass microspheres and broadens the application field of hollow glass microspheres.

[0033] (4) The titanate system optimizes the compactness of the glass structure and improves the compressive strength of hollow glass microspheres. Titanates can also reduce the melting temperature and viscosity of the molten glass during the preparation process, thus clarifying the glass, improving the light transmittance of hollow glass microspheres, improving the refractive index of hollow glass microspheres, and enhancing the corrosion resistance of hollow glass microspheres.

[0034] (5) By introducing barite, on the one hand, it acts as an oxygen remover, clarifying agent and flux in the preparation of hollow glass microspheres, reducing air bubbles in the shell of hollow glass microspheres and enhancing the gloss and strength of the shell of hollow glass microspheres; on the other hand, since barite has barium elements with large core mass and barium ions with high dielectric constant, it can not only strengthen the polarization effect of titanium silicate glass and play a role in enhancing and consolidating the dielectric constant of hollow glass microspheres, but also reduce the penetration of rays and weaken electromagnetic waves, thus giving hollow glass microspheres radiation protection performance. Detailed Implementation

[0035] To describe the present invention, the following detailed description, in conjunction with embodiments, provides a method for preparing high-dielectric hollow titanium silicate microspheres. However, the present invention is not limited to these embodiments.

[0036] The silica content is ≥95%, and the particle size is between 40-120 mesh; sodium tetraborate; barium titanate; the true density range is 2.4-2.8 g / cm³. 3 The sedimentation volume in anhydrous ethanol is 2.0-2.7 mL / g, the effective content of light calcium carbonate is 40-60%, and the mesh size is 1250-1500. Sodium feldspar, barite, alunite and spodumene are added to a homogenizer and mixed evenly according to the mass percentages described in Table 1.

[0037] Table 1

[0038]

[0039] The uniformly mixed raw materials are artificially granulated using methods such as physical bonding, drying granulation, or melt ball milling to obtain precursor particles with an average particle size range of 2–500 μm. The obtained precursor particles are then classified using equipment such as an air classifier, fluidized bed, vibrating screen, and ball mill to obtain refined precursor particles with an average particle size of 20–40 μm. These refined precursor particles are then fed into a high-temperature vitrification furnace for hollow glass microspheres, with the vitrification temperature controlled at 1300–1500℃ and the vitrification time at 2–5 seconds, to prepare precursor particles with a density of 0.2–0.6 g / cm³. 3 High-performance hollow glass microspheres with a compressive strength of 8–130 MPa and a dielectric constant ≥15 F / m were developed. The chemical composition of the hollow glass microspheres in each embodiment and comparative example is shown in Table 2.

[0040] Table 2

[0041] <![CDATA[SiO2]]> <![CDATA[TiO2]]> <![CDATA[B2O3]]> <![CDATA[Na2O]]> CaO BaO <![CDATA[Al2O3]]> <![CDATA[R2O]]> Example 1 67.5 8.38 7.63 5.36 4.38 5.33 0.31 1.11 Example 2 67 8.64 7.92 5.31 4.25 5.29 0.39 1.2 Example 3 68.5 8.54 7.29 5.67 4.33 5.31 0.29 0.07 Example 4 64 11.65 6.68 5.25 3.74 7.56 0.32 0.8 Example 5 63 7.55 11.44 6.34 6.24 4.43 0.32 0.68 Example 6 61.55 8.84 7.18 7.08 8.24 5.43 0.48 1.2 Example 7 70.26 8.23 5.24 6.84 3.98 5.29 0.12 0.04 Comparative Example 1 65 0.12 10.32 8.34 14.93 0.92 0.18 0.19 Comparative Example 2 70 0.19 8.04 6.51 14.04 0.94 0.22 0.06 Comparative Example 3 68 0.24 10.63 6.97 12.27 1.33 0.43 0.13

[0042] The hollow glass microspheres prepared in the above examples and comparative examples were tested for density, compressive strength, dielectric constant, light transmittance, and weight loss after immersion in 5% sodium hydroxide for 24 hours. The dielectric constant was tested at a frequency of 1 GHz. Light transmittance was measured by melting the glass microspheres into 30×40×2 mm glass slides and using a transmittance meter. Corrosion resistance was tested by immersing the prepared hollow glass microspheres in a 5% sodium hydroxide solution at room temperature for 24 hours, followed by washing and drying to measure the mass change. The performance test parameters are shown in Table 3.

[0043] Table 3

[0044]

[0045]

[0046] Data from Examples 1-7 and Comparative Examples 1-3 show that the dielectric constant of hollow glass microspheres obtained by the formulation, glass microsphere composition, and preparation method protected by this invention is superior to that of hollow glass microspheres prepared without strictly adhering to the parameter range defined by the scope of protection of this invention, and does not affect the density or particle size of the hollow glass microspheres. Furthermore, the compressive strength of the hollow glass microspheres can be further improved by introducing titanate.

[0047] Analysis of the formulations, components, and test parameters in Tables 1-3, Examples 1-7, and Comparative Examples 1-3 shows that, compared to the dielectric constant of traditional borosilicate hollow glass microspheres (between 1.0 and 2.2 F / m), this invention, by introducing titanate to prepare titanate hollow glass microspheres and controlling the glass powder particle size, can significantly improve the dielectric constant of the hollow glass microspheres to ≥15 F / m, while maintaining low density and high strength. This meets the requirements for electronic and electrical components in the aerospace and new energy vehicle manufacturing industries, and endows the composite material with advantages such as lightweight, electrical insulation, antistatic properties, and electromagnetic isolation.

[0048] Tables 1-3 show the formulations, components, and performance parameters of Examples 1, 4, and 5. It can be seen that the hollow glass microspheres have similar density and particle size. As the amount of titanate added increases, the dielectric constant of the hollow glass microspheres becomes higher. The optimal compressive strength is achieved when the silica content is around 67.5%.

[0049] Tables 1-3 show the formulations, components, and performance parameters of Examples 3, 7, and Comparative Example 2. It can be seen that the introduction of barium titanate not only significantly improves the dielectric constant of hollow glass microspheres, but also, together with the introduced barite, enhances the compressive strength of the glass microspheres and improves their light transmittance and corrosion resistance.

[0050] Unless otherwise specified, the raw materials and equipment used in this invention are all commonly used in the field; unless otherwise specified, the methods used in this invention are all conventional methods in the field.

[0051] The above description is merely an embodiment of the present invention and is not intended to limit the present invention in any way. Any simple modifications, alterations, and equivalent transformations made to the above embodiments based on the technical essence of the present invention shall still fall within the protection scope of the present invention.

[0052] The material ratios, upper and lower limits of process parameters, and range values ​​involved in this invention can all achieve the present invention, and will not be listed one by one here.

Claims

1. A high-dielectric hollow glass microsphere of titanate silicate, characterized in that... The proportions of each mineral component in the raw material, based on a total mass of 100%, are as follows: 55%–65% silica Boron and its compounds 12%–18% Titanate 8%–15% Calcium carbonate 8%–13% Sodium feldspar 3%–5% Barite 0.3-2% Alum stone 0-1.5% spodumene 0-0.5% Others: 0-0.2%; The titanate is selected from at least one of barium titanate, barium strontium titanate, magnesium titanate, calcium titanate, calcium copper titanate, and zinc titanate; the true density of the calcium carbonate is in the range of 2.4–2.8 g / cm³. 3 The sedimentation volume in anhydrous ethanol is 2.0–2.7 mL / g, the effective content of light calcium carbonate is 40–60%, and the mesh size is 1250–1500 mesh. Titanium silicate high-dielectric hollow glass microspheres were prepared using the following steps: (1) Weigh each ingredient accurately according to the formula, and mix the prepared ingredients evenly in a homogenizer; (2) The raw materials that are mixed evenly in step (1) are artificially granulated by physical bonding, drying granulation or melt ball milling to obtain precursor particles with an average particle size range of 2 to 500 μm. (3) The precursor particles obtained in step (2) are classified to obtain selected precursor particles with an average particle size of 20-40 μm; (4) The selected precursor particles prepared in step (3) are fed into a high-temperature vitrification furnace for hollow glass microspheres. The vitrification temperature is controlled at 1300-1500℃ and the vitrification time is 2-5 seconds to prepare microspheres with a density of 0.2-0.6 g / cm³. 3 The high-dielectric hollow glass microspheres have a compressive strength of 8–130 MPa, an average particle size of 25–42 μm, a light transmittance of >66.5%, and a dielectric constant of ≥15 F / m. The dielectric constant is tested at a frequency of 1 GHz. The light transmittance is tested by melting the glass microspheres to form a 30×40×2 mm glass sheet and then measuring it using a light transmittance meter.

2. The titanium silicate high-dielectric hollow glass microspheres as described in claim 1, characterized in that: The silica is at least one of quartz sand, silica powder, quartz sandstone, metamorphic quartzite, siliceous rock, and quartz glass, wherein the silica content is ≥95% and the particle size is between 40-120 mesh.

3. A titanium silicate high-dielectric hollow glass microsphere as described in claim 1 or 2, characterized in that: The boron and its compounds are selected from at least one of boron oxide, sodium tetraborate, boric acid, and metaboric acid.

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