WO2022105185A1

WO2022105185A1 - Low dielectric glass fiber and preparation method therefor, glass fiber product, composite material and application thereof

Info

Publication number: WO2022105185A1
Application number: PCT/CN2021/097748
Authority: WO
Inventors: 郭仁贤; 黄三喜; 黄松林; 祖群
Original assignee: 南京玻璃纤维研究设计院有限公司; 中材科技股份有限公司
Priority date: 2020-11-18
Filing date: 2021-06-01
Publication date: 2022-05-27
Also published as: CN113135666B; CN113135666A

Abstract

Provided are low dielectric glass fiber and a preparation method therefor, a glass fiber product, a composite material and an application thereof. A low-dielectric glass having excellent comprehensive properties such as high mechanical strength, good dielectric properties and a simple melting process can be obtained by reasonably adjusting the proportions of oxides in a glass composition. Specifically, by reasonably configuring a ratio of silicon oxide, aluminum oxide and boron oxide, the glass fiber has a relatively low dielectric constant and dielectric loss, and the glass viscosity is suitably adjusted; meanwhile, with consideration to dielectric properties and mechanical strength, by appropriately setting the amounts of alkaline earth metal oxides, alkali metal oxides, TiO₂, CeO₂ and SnO₂, the melting and clarifying properties of the glass are further improved, the drawing and forming temperature is lower, the stability and yield is higher, the density is lower, and excellent working performance is achieved.

Description

Low dielectric glass fiber and preparation method, glass fiber product, composite material and application

technical field

The application belongs to the technical field of glass fibers, and in particular relates to a low-dielectric glass fiber and a preparation method, glass fiber products, composite materials and applications.

Background technique

Modern electronic devices often include printed circuit boards reinforced with fiberglass. Two types of glass fibers commonly used to strengthen printed circuit boards are E-glass and D-glass. Among them, the alkali-free and low-dielectric E-glass fiber is the most widely used, and the production and preparation are simple, and the price is low. However, at room temperature and a frequency of about 10 GHz, E glass has a relatively high dielectric constant of about 6.1 and a relatively high dissipation factor of about 38×10 ^-4 , which can no longer meet the application requirements in the field of high-performance, high-integrated electronic circuits. Compared with E glass fiber, D glass fiber has excellent dielectric properties, the dielectric constant is less than 4.2, but its production processability is poor due to its high silica content, and the glass has high viscosity, high clarification temperature and Bubble is difficult to eliminate, so there are usually streaks and bubble-like defects, the product performance is unstable, the production cost is high, and the interface with epoxy resin is weak; in addition, quartz glass fiber has the lowest dielectric properties, with a dielectric constant of 3.8 , but the production process is more complicated, the yield is low, and the price is expensive. At present, some manufacturers and researchers use blending methods to obtain good dielectric properties and mechanical properties, such as blending high-strength glass fibers and quartz glass fibers, but this process is complicated and the cost is high and it is not suitable for mass production. . Therefore, adjusting and optimizing the low-dielectric glass fiber formulation to obtain good comprehensive properties has become the main way to solve the problem.

Chinese patent document CN110139841A discloses a low dielectric glass composition, fiber and product, which improves fiber melting by introducing more Al ₂ O ₃ , introducing more SiO ₂ and B ₂ O ₃ and part of P ₂ O ₅ is used to obtain lower dielectric constant and dielectric loss, but due to the large amount of Al ₂ O ₃ , the viscosity during the melting process is too large, the glass is difficult to bubble, and the molding temperature and liquidus temperature are high. This leads to high energy consumption for melting and high operating temperature of the bushing, which leads to the deterioration of the performance of the drawing process and the reduction of the continuous performance of the fiber products.

Chinese patent document CN110171929A discloses a method for preparing low-bubble and low-dielectric glass fibers. The method adds ZrO ₂ , which can reduce the dielectric constant of glass to a certain extent, while avoiding the melting temperature of glass fiber composition and the temperature of fiber forming. increased, and ZrO ₂ improved the water resistance of glass fibers. However, due to the low content of alkaline earth metal oxides and alkali metal oxides and the introduction of ZrO ₂ , the molding temperature is very high >1385 ° C, and the working temperature of the bushing is high, so it is difficult to realize the production of large bushings.

Chinese patent document CN110028249A discloses a low-dielectric glass fiber and its preparation method. The method introduces a small amount of Zr and Ti to improve the water resistance of the glass; a small amount of Bi is introduced to appropriately reduce the degree of network connection of the structure and improve the melting temperature; At the same time, the ratio of CaO\MgO\ZnO is adjusted to strengthen the ternary mixed alkaline earth metal effect to improve the melting effect, reduce the phase separation of the glass and relatively low glass dielectric constant and dielectric loss; however, the metal oxide content is high , and Zn and Bi are transition metal elements, the ionic field strength is low, and the dielectric constant and dielectric loss of glass are high. Zn and Zr, as a nucleating agent, will lead to the growth of crystal nuclei during the drawing process and lead to wire breakage; In addition, the Mg and Ca contents are low, so the mechanical properties of the fibers are poor.

Therefore, although many improvements have been made to the low-dielectric glass fiber formulation in the prior art, it is still difficult to make the glass fiber formulation have the properties of low dielectric constant and dielectric loss, simple melting, and high mechanical strength.

Application content

Therefore, the technical problem to be solved by the present application is to overcome the defects in the prior art that the glass fiber cannot have the properties of low dielectric constant and dielectric loss, simple melting and high mechanical strength at the same time, so as to provide a low dielectric Glass fiber and preparation method, glass fiber product, composite material and application.

To this end, the present application provides a low dielectric glass fiber, comprising the following raw materials by weight:

SiO ₂ : 50-58%;

Al ₂ O ₃ : 10-16%;

B ₂ O ₃ : 20-28%;

MgO: 1-4%;

CaO: 1-4%;

_Li2O : 0.05-0.5%;

Na ₂ O: 0.05-0.6%;

K ₂ O: 0.05-0.8%;

TiO ₂ : 0.2-1.5%;

CeO ₂ : 0-1%;

SnO ₂ : 0.01-1.5%;

Fe ₂ O ₃ ≤ 0.1%.

In the glass structure, SiO ₂ is the main network former, and the irregular network structure formed by silicon-oxygen tetrahedra is used as the structural skeleton of the glass, which affects the performance and other indicators of the glass. When the content of _SiO2 is less than 50%, due to weak glass network connection, poor fiber-forming ability of glass and mechanical properties of fibers, etc., its corrosion resistance will also be reduced, and it will also lead to the dielectric constant and dielectric loss of glass fibers. increase, it is not conducive to the improvement of the dielectric properties of the glass; but when the SiO ₂ content exceeds 58%, the viscosity of the glass increases relatively, so the melting temperature needs to be greatly increased, on the one hand, it will cause the refractory in the production of glass furnaces. The service life is greatly reduced; on the other hand, due to the increase in viscosity, it is difficult to clarify the glass, and the tiny bubbles in the glass melt are difficult to escape and remain in the glass fiber, resulting in increased dielectric loss and unstable performance of the glass fiber, which is not conducive to low Manufacture of dielectric glass fibers. The present application therefore defines the SiO ₂ content to be 50-58%.

B ₂ O ₃ exists as an intermediate in the glass structure. On the one hand, when the network exosomes provide enough free oxygen, a part of [BO ₄ ] tetrahedral structure is formed into the glass silica network structure, which plays a role in reinforcing the network. The BO bond energy is larger than the Si-O bond energy, which can effectively suppress the ion polarization in the glass structure, thereby reducing the dielectric constant and dielectric loss, and at the same time helping to improve the mechanical properties of the glass; on the other hand, in the low dielectric glass The content of B ₂ O ₃ is relatively large, and more B ³⁺ exists in the form of [BO ₃ ] triangle, which is a layered structure, and the coupling of the network structure is weak, so it can reduce the high temperature viscosity of the glass. Helps to clarify glass melting. However, with the increase of B ₂ O ₃ content, the tendency of devitrification of glass increases, resulting in process problems such as difficulty in glass melting and fiber forming. Therefore, the present application defines the B ₂ O ₃ content to be 20-28%.

SiO ₂ and B ₂ O ₃ are the most significant for reducing dielectric constant and dielectric loss and improving dielectric properties. Increasing the proportion of SiO ₂ and B ₂ O ₃ in the glass component can significantly improve the dielectric properties of the glass, but the excessively high content of SiO ₂ and B ₂ O ₃ will cause the viscosity to be too large, making it difficult for bubbles to escape in the glass melt. It is difficult to solve the process problems such as the forming of glass fiber by adjusting the ratio of SiO ₂ and B ₂ O ₃ .

Al ₂ O ₃ also exists in the form of intermediates in the glass structure. On the one hand, a small amount of [AlO ₄ ] tetrahedron enters the glass network structure to strengthen and improve the dielectric and mechanical properties of the glass; on the other hand, it forms [AlO ₅ ] Coordinated with [AlO ₆ ] polyhedron as the outer body structure of the network, which reduces the phase separation tendency of the glass, inhibits the formation of devitrified phase and improves the forming ability of the fiber. The introduction of an appropriate amount of Al ₂ O ₃ not only improves the mechanical properties and dielectric properties of the glass, but also helps to improve the chemical resistance stability; however, excessive introduction of Al 2 O 3 will lead to problems such as difficulty in glass melting, increase in dielectric constant and dielectric loss.

Alkaline earth metal oxides are network exosomes that can provide free oxygen. On the one hand, it reduces the density of the Si-O tetrahedral network structure in the glass network, thereby reducing the viscosity of the glass and helping to improve the melting point of the glass. On the other hand, free oxygen can promote the formation of network intermediates such as B ₂ O ₃ and Al ₂ O ₃ [BO ₄ ]- and [ AlO ₄ ]-tetrahedral structure, so as to complement the network structure of the glass, help to reduce the dielectric constant and dielectric loss, improve the dielectric properties, and also help to improve the modulus and chemical resistance of the glass fiber ; In addition, the ionic polarizability of alkaline earth metal oxides is larger than that of Si/B, and the greater the polarizability is, the more unfavorable the dielectric properties of glass fibers are. Metal oxides such as (Na ₂ O/K ₂ O) have a much lower polarizability. At the same time, the ionic field strength of alkaline earth metal oxides is relatively large, which can play a role in aggregation in the glass network structure, thereby reducing structural breaks and defects, improving the strength and modulus of glass fibers, and helping to improve the chemical corrosion resistance of glass fibers. performance. Moreover, the influence mechanisms of alkaline earth metal ions on the dielectric constant and dielectric loss are different. The weaker the ion field, the easier the ion migration and the slower the influence of polarization. Therefore, the effect on the dielectric constant is more significant than that of the dielectric loss. The field strength is stronger, so the ion force is stronger in the network structure, the ion migration is weaker and the polarization is more sensitive, which has a more significant effect on the dielectric loss. The contribution of alkaline earth metal oxides to the increase in dielectric constant is as follows BaO>SrO>CaO>MgO>BeO, while its contribution to the dielectric loss is opposite. Therefore, how to adjust the dielectric constant and dielectric loss requires reasonable adjustment of the addition amount of each alkaline earth oxide. In addition, the introduction of alkaline earth metal oxides, on the one hand, promotes the transformation of intermediates to formers, thereby enhancing the structure of the glass network; on the other hand, metal ions with high field strength help to improve the polymerization of the network structure, thereby improving the mechanical properties of glass.

In this application, 1-4% MgO, 1-4% CaO ratio and 0.2-1.5% TiO ₂ are set to help improve the dielectric properties and mechanical strength, and at the same time have a certain effect on the glass fiber forming temperature and crystallization temperature. Significant improvement; however, when excessive amounts are introduced, the dielectric constant and dielectric loss will increase significantly, which is not conducive to the production of low-dielectric glass. Compared with the prior art excluding alkaline earth metal oxides, on the premise of obtaining low dielectric properties, the technical solution has higher mechanical strength and excellent melting properties.

Further, in terms of mass ratio, in order to obtain glass fibers with low dielectric constant and dielectric loss, and at the same time have higher mechanical strength and drawing process temperature, SiO ₂ , B ₂ O ₃ , MgO, CaO, TiO ₂ , CeO ₂ Component adjustment has the following designs:

X=[4.31×(a-0.5)/0.1945+4.32×(b-0.2)/0.1945+4.32×(c-0.01)/0.1945+4.37×(d-0.01)/0.1945]×[5.84×(e- 0.002)/0.1945]×(4.62×f/0.1945).

Among them, a is the mass percentage of SiO ₂ in the component formula for preparing glass fibers; if the formula contains 53% SiO ₂ , then a is 0.53;

b is the mass percentage of B ₂ O ₃ in the component formula for preparing glass fiber;

c is the mass percentage of MgO in the component formula for preparing glass fiber;

d is the mass percentage of CaO in the component formula for preparing glass fiber;

e is the mass percentage of TiO ₂ in the component formula for preparing glass fibers;

f is the mass percentage of CeO ₂ in the component formula for preparing glass fiber; when the CeO ₂ content is 0, it should be excluded from the formula.

Calculated according to the above formula, X≤0.15; preferably, when X is less than or equal to 0.09, the glass fiber has low dielectric constant and dielectric loss, and the dielectric constant is less than or equal to 4.40 and the dielectric loss is less than or equal to 4.0 at a frequency of 10MHz ×10 ^-3 , and the temperature range of the wire drawing process is greater than or equal to 30°C, the modulus is greater than or equal to 52GPa, and the single-filament strength is greater than or equal to 2500MPa.

Further, calculated according to the above formula, when X is less than or equal to 0.07, the glass fiber has a lower liquidus temperature, the drawing process range is greater than or equal to 40°C, and the monofilament strength is greater than or equal to 2600MPa.

Further, according to the above formula, when X is less than or equal to 0.025, the glass fiber has better dielectric properties. At a frequency of 10MHz, the dielectric constant is less than or equal to 4.32, the dielectric loss is less than or equal to 3.6×10 ^-3 , and the bubble content is less than or equal to 0.01/g.

Further, the mass ratio of MgO, CaO and TiO ₂ is 3-11:2-10:1. Adjusting the ratio of magnesium oxide, calcium oxide and titanium oxide, on the one hand, the mechanical strength of the glass is significantly improved, and on the other hand, its dielectric constant and dielectric loss are also reduced.

Further, the mass ratio of MgO, CaO and TiO ₂ is 5-9:4-7:1. The magnesium oxide, calcium oxide and titanium oxide in this proportion can further improve the mechanical properties of the glass and improve the drawing temperature and liquidus temperature of the glass.

Further, in terms of mass percentage, the amount of Li ₂ O+Na ₂ O+K ₂ O is 0.3-1.6% of the total amount of raw materials.

More specifically, the glass fiber raw materials include Li ₂ O+Na ₂ O+K ₂ O<1.0%, 0-0.8% CeO ₂ , and 0.2-0.7% SnO ₂ . Improve the dielectric properties of glass under the conditions of making; more optimal, glass fiber raw materials, including Li ₂ O+Na ₂ O+K ₂ O<0.6%, 0-0.6% CeO ₂ , 0.2-0.6% SnO ₂ , the combination can reduce the crystallization temperature and at the same time have a good clarification effect, and obtain a glass component with a low dielectric constant.

In the prior art, in order to ensure excellent dielectric properties, a relatively large amount of SiO ₂ , B ₂ O ₃ and Al ₂ O ₃ are often added, but when the content of these substances is large, the viscosity of the system during melting will increase. Alkaline earth metal oxides, alkali metal oxides and other elements are used for flux clarification, but in order to ensure a lower dielectric constant and dielectric loss, the introduction amount is controlled within a small range, so the viscosity of the glass is still large, and the glass melting It is difficult to manufacture, and a large number of tiny bubbles are difficult to escape during the melting process, resulting in a large number of broken filaments and hollow glass fiber filaments during the glass fiber forming process, resulting in production difficulties and poor quality and performance of subsequent products.

The present application improves the melting and clarifying effect of glass fibers by adding multiple alkali metal oxides for composite melting. Alkali metal oxides have a significant effect on reducing viscosity, but at the same time are not conducive to improving dielectric properties. In this application, a small amount of Li ₂ O+Na ₂ O+K ₂ O is set to be introduced. Due to the mixed alkali effect, the high temperature viscosity of the glass is Significant reduction but little change in dielectric properties. The mixed alkali effect means that, under the premise of the same amount of introduction, the chemical corrosion resistance and dielectric properties of the glass are reduced by the use of mixed alkali metal oxides, which is much weaker than that of a single alkali metal oxide. This is because in the glass network structure, alkali metal ions mainly fill in the gaps of the glass network to neutralize and depolymerize anion groups to achieve charge balance. As the atomic number increases, the ionic radius of alkali metal ions increases gradually, and the ionic polarizability also increases gradually. Using mixed alkali metal ions, due to the significantly different ion radii, the internal structure of the glass is more disordered, and ions with larger radii are filled in the smaller structural gaps, blocking the migration of ions with smaller radii, so that the ions in the glass structure are more disordered. The migration ability is significantly reduced, and the dielectric properties are improved; while the alkali metal with a large ionic radius is simply reused, although the ion migration ability is weakened, its polarizability is significantly increased, and the dielectric properties are also reduced. Therefore, the use of mixed alkali effect to formulate alkali metal ions is of great significance for reducing viscosity and maintaining dielectric properties.

But the mixed alkali effect is not simply a mix and match. The effect of mixed alkali on performance also needs to comprehensively consider the basic composition of glass. The basic composition of glass determines the densification of the glass network structure, the size of network gaps and defects, etc. Therefore, according to the different composition of the glass itself, many experiments are needed to adjust and match, in order to obtain better performance improvement.

When the content of Li ₂ O or Na ₂ O or K ₂ O is less than 0.05%, it has little effect on improving the glass melting and forming properties, and it is very difficult to form textile-grade fibers in particular. When the Li ₂ O content exceeds 0.5% or Na ₂ O exceeds 0.6% or K ₂ O exceeds 0.8% or Li ₂ O+NaO ₂ +K ₂ O exceeds 0.8%, the dielectric constant and dielectric loss of the glass will increase more than big.

At the same time, introducing an appropriate amount of 0-1% CeO ₂ and 0.01-1.5% SnO ₂ into the glass component, CeO ₂ and SnO ₂ can generate oxygen during high temperature heating, on the one hand, adjust the gas partial pressure in the glass melt; On the other hand, it can combine with microbubbles to form large bubbles, thereby promoting the growth and escape of microbubbles in the glass melt.

If too much CeO ₂ and SnO ₂ are introduced, on the one hand, the bubbles in the glass body will not decrease but increase, on the other hand, SnO ₂ will act as a nucleating agent to cause crystallization of the glass, resulting in difficulty in fiber drawing; and CeO ₂ will color the glass and cost are also significantly increased, as well as an increase in dielectric constant and loss. In addition, if the alkali metal oxide is used alone to promote glass melting and clarification, the effect is not good, and the mechanical strength, chemical corrosion resistance and dielectric properties of the glass fiber are also damaged. If you simply introduce a clarifying agent such as CeO ₂ , SnO ₂ , etc., through chemical foam removal, in order to achieve a suitable foam removal effect, the introduction amount will be relatively large, and there will also be adverse effects on the crystallization temperature and coloring of the glass.

In the present application, through the combination of suitable alkali metal oxides and fining agents, better fining effects can be obtained without significantly damaging the mechanical properties, dielectric properties and chemical corrosion resistance of the glass, and significantly reduce the The number of bubbles in the glass melt.

Further, the number of air bubbles in the glass fiber is less than or equal to 0.05/g.

Further, the diameter of the glass fiber is 4-10um.

Further, when the frequency of the glass fiber is 10 GHz at room temperature, the dielectric constant is 4.2-4.5, and the dielectric loss is 2.5×10 ^-3 -4.4×10 ^-3 .

Further, the liquidus temperature of the glass fiber is lower than 1315°C, the temperature at which the viscosity is 1000 poise is lower than 1370°C, and the molding process temperature is higher than 30°C.

Further, the modulus of the glass fiber is 55-62GPa, and the strength is 2500-3100MPa.

The present application also provides a method for preparing a low dielectric glass fiber, comprising the following steps:

The glass fiber raw material is melted, heated to above the liquidus temperature, clarified and homogenized, and then drawn and formed.

Specifically, the glass composition (such as the above-mentioned glass components provided in this application) is transported into a glass melter (such as a furnace equipment), and the composition is heated to a forming temperature above the liquidus temperature through the melting zone, and the clarification is uniform. The molten glass is fiberized by continuous wire drawing through a pulling device, thereby producing glass fibers with low dielectric constant and loss.

The application also provides a glass fiber product, the glass fiber product is a product obtained by grinding, weaving, heat treatment and/or chemical treatment of the glass fiber, such as glass micropowder, woven fabric (electronic cloth, open cloth, etc.) fiber cloth, etc.), non-woven fabric, unidirectional fabric, chopped yarn, 3D fabric, colored glass fiber cloth, pre-treated cloth, post-treated cloth and/or cotton felt, etc.

The present application also provides a composite material comprising the above-mentioned glass fiber product, such as a printed circuit board, an electronic device substrate, and/or an electronic device frame and housing.

The present application also provides an application of the above composite material in electronic devices and systems operating at high frequency and/or high speed, the electronic devices and systems include mobile phones, computers, smart wearable devices and electronic products that use high-frequency signal transmission , intelligent driving and computing equipment, etc.

Although the description of this application mainly describes the application of glass compositions and glass fibers in the fields of electronic equipment and printed circuit boards, but without departing from the spirit and scope of the application, they can also be applied in other fields and obtain beneficial effects. Examples are vehicle exterior and interior components (wheel covers, fenders, bumpers, interior trim, etc.).

The technical solution of the present application has the following advantages:

1. The low dielectric glass fiber provided by the present application includes the following raw materials by weight: SiO ₂ : 50-58%; Al ₂ O ₃ : 10-16%; B ₂ O ₃ : 20-28%; MgO: 1 -4%; CaO: 1-4%; _Li2O : 0.05-0.5%; Na2O: _0.05-0.6 % _; K2O: 0.05-0.8% _; _TiO2 : 0.2-1.5%; CeO2 : 0-1%; SnO ₂ : 0.01-1.5%; Fe ₂ O ₃ ≤ 0.1%, the application can reasonably adjust the proportion of each oxide in the glass component to obtain high mechanical strength, good dielectric properties and melting process Low-dielectric glass with excellent comprehensive properties such as simplicity. Specifically, by setting the ratio of silicon oxide, aluminum oxide and boron oxide reasonably, the glass fiber has lower dielectric constant and dielectric loss, and the glass viscosity is properly adjusted. At the same time, considering the dielectric properties and mechanical strength Under the premise, by reasonably setting the dosage of alkaline earth metal oxide, alkali metal oxide, TiO ₂ , CeO ₂ and SnO ₂ , the melting and clarifying properties of glass are further improved, the wire drawing temperature is lower, and the stability and yield are higher. , the density is smaller, and it has excellent working performance.

2. The low-dielectric glass fiber provided by the present application has fewer defects, and the melting process is optimized by adjusting the components, so that the wire drawing process interval is enlarged, which is beneficial to the wire drawing operation. In the process of glass melting, the escape of micro-bubbles is improved to reduce the residual of bubble defects, and the number of bubbles in the glass body is significantly reduced, so the defects in the glass fiber are lower, and the broken wire caused by the hollow fiber in the glass drawing process is less, and the production efficiency is improved.

3. The low-dielectric glass fiber provided by this application has good water resistance, stable mechanical properties, good compatibility with resins, and excellent processing performance, and is especially suitable for use as a reinforced substrate for aircraft radomes, radomes, and electromagnetic windows.

4. The fiber cloth produced by the low-dielectric glass fiber provided by the present application, the weaving process is due to the breakage caused by the hollow fiber, and the fly wire is reduced. , Strong tensile damage ability, thus reducing the proportion of splicing silk, improving the yield and product quality. The composite material prepared by using the fiber cloth processed and manufactured by the glass fiber described in the present application has strong mechanical properties and large space for resin preparation according to product performance requirements; at the same time, due to the lower defects of micro-bubble, the defects in the subsequent processing of the composite material are relatively low. less, the performance is more stable, and the efficiency and quality of subsequent product use and processing are improved.

Detailed ways

The following examples are provided for a better understanding of the present application, and are not limited to the best embodiments, and do not limit the content and protection scope of the present application. Any product identical or similar to the present application obtained by combining with the features of other prior art shall fall within the protection scope of the present application.

If the specific experimental steps or conditions are not indicated in the examples, it can be carried out according to the operations or conditions of the conventional experimental steps described in the literature in this field. The reagents or instruments used without the manufacturer's indication are all conventional reagent products that can be obtained from the market.

Examples 1-28

Table 1 shows the composition of the low-dielectric glass fiber raw materials in Examples 1-28.

Comparative Examples 1-5

Table 1 shows the composition of the low-dielectric glass fiber raw materials in Comparative Examples 1-5.

Comparative Example 6

Example 1 in patent CN1903767A.

Comparative Example 7

Example D53 in patent CN101594987B.

Comparative Example 8

Example 1 in patent TW450948B.

Comparative Example 9

Example 1 in patent CN110028249A.

Comparative Example 10

Example 9 in patent HK1172603A.

Experimental example

The properties of the glass fibers obtained in the above examples were tested, and the specific testing items included: dielectric properties, bubble content, strength, modulus, liquidus temperature, and forming temperature (drawing temperature). The specific detection method is as follows:

Dielectric properties: The test uses glass block glass, which is prepared into glass batches according to the glass ratio, put into a platinum crucible, heated to 1500-1550 ° C in a resistance furnace, clarified for 24 hours, and then poured into the mold. , for annealing. According to the test requirements, the glass is processed into a sample to be tested with a diameter of 60mm (±0.1mm), a thickness of 3mm (±0.1mm), and the surface is ground and polished. According to the standard GB/T 5597, the dielectric constant and dielectric loss of glass samples were measured by the resonant cavity method at a frequency of 10 GHz.

Determination of bubble content: use glass blocks, prepare glass batches according to the glass composition, put them into platinum crucibles, heat to 1500-1550 ° C in a resistance furnace, clarify for 10 hours, and then pour the glass liquid into the mold (mold size The diameter of the mold is 30-100mm and the thickness is 3-10mm). After the pouring is completed, annealing is carried out. In this experiment, the diameter of the mold is 60mm and the thickness is 3-5mm. Observe the bubbles in the glass sample with a magnifying glass and count the number n, and weigh the weight g of the glass sample. In order to ensure the accuracy of the number of bubbles, it is usually necessary to observe 5 to 10 samples, calculate the bubble content by the formula n/g, and take the average value. Among them, n is the total number of bubbles, and g is the total weight of all samples, wherein the weight of the sample in this example is 40-60 g.

Glass drawing temperature: According to the ASTM-C 965 standard "Standard Practice for Measureing Viscosity of Glass Above Softening Point", measure the temperature corresponding to glass at 1000 poise, which is glass drawing temperature.

Liquidus temperature: According to the ASTM C 829 standard "Standard Pratice for Measurement of Liquidus Temperature of Glass by the Gradient Furnace Method" (Standard Pratice for Measurement of Liquidus Temperature of Glass by the Gradient Furnace Method), the liquidus temperature of glass is determined, namely Crystallization temperature.

The glass fiber drawing process parameters, namely ΔT=drawing temperature-crystallization temperature, are obtained by calculation.

Modulus: The determination of glass fiber modulus requires the preparation of glass fiber thick filaments. The glass batch is prepared according to the glass ratio, put into a platinum crucible, heated to 1500-1550 ℃ in a resistance furnace, and kept for 2 hours. Then use a quartz glass rod to pick the glass melt, pull the glass wire out and collect fibers with a length of 30-40cm. The fiber diameter is from 100-300um at one end to 700-1000um at the other end.

Use the ultrasonic pulse echo method to measure the propagation velocity of sound waves in the glass body (longitudinal wave velocity C _l ), obtain the density p of the glass sample by testing with a true density tester, and calculate the Young's modulus (E) according to the following formula:

E=p× _Cl ² .

Strength: The glass batch is prepared according to the glass ratio, added to the platinum single-hole furnace, heated to near the drawing temperature, about 1280 ℃-1380 ℃, after 30 minutes of heat preservation, the glass filament is extended from the single-hole leak nozzle, and the wire drawing is adjusted by adjusting The pulling rate of the machine is used to prepare glass fiber monofilaments with a diameter of 8-10um. The glass fiber filaments were collected by the sample strips to prepare the strength test samples. The strength of glass fiber filaments is measured on a microstress strength tester, and at least 50 samples of each glass fiber are tested.

The test results are shown in Table 2.

Table 1

Table 2

Obviously, the above-mentioned embodiments are only examples for clear description, and are not intended to limit the implementation manner. For those of ordinary skill in the art, changes or modifications in other different forms can also be made on the basis of the above description. There is no need and cannot be exhaustive of all implementations here. However, the obvious changes or changes derived from this are still within the protection scope created by the present application.

Claims

A low-dielectric glass fiber, characterized in that it comprises the following raw materials by weight:

SiO 2 : 50-58%;

Al 2 O 3 : 10-16%;

B 2 O 3 : 20-28%;

MgO: 1-4%;

CaO: 1-4%;

Li2O : 0.05-0.5%;

Na 2 O: 0.05-0.6%;

K 2 O: 0.05-0.8%;

TiO 2 : 0.2-1.5%;

CeO 2 : 0-1%;

SnO 2 : 0.01-1.5%;

Fe 2 O 3 : 0-0.1%.
The low dielectric glass fiber according to claim 1, wherein the mass ratio of MgO, CaO and TiO 2 is 3-11:2-10:1;

Preferably, the mass ratio of MgO, CaO and TiO 2 is 5-9:4-7:1.
The low-dielectric glass fiber according to claim 1 or 2, characterized in that, in terms of mass percentage, the amount of Li 2 O+Na 2 O+K 2 O is 0.3-1.6% of the total amount of raw materials;

Preferably, in terms of mass percentage, the amount of Li 2 O+Na 2 O+K 2 O is less than 1.0% of the total amount of raw materials.
The low-dielectric glass fiber according to any one of claims 1-3, characterized in that, by mass percentage, the amount of the components of SiO 2 , B 2 O 3 , MgO, CaO, TiO 2 and CeO 2 It conforms to the following formula:

X=[4.31×(a-0.5)/0.1945+4.32×(b-0.2)/0.1945+4.32×(c-0.01)/0.1945+4.37×(d-0.01)/0.1945]×[5.84×(e- 0.002)/0.1945]×(4.62×f/0.1945),

Wherein, a is the mass percentage of SiO2 in the component formula for preparing glass fiber;

b is the mass percentage of B 2 O 3 in the component formula for preparing glass fiber;

c is the mass percentage of MgO in the component formula for preparing glass fiber;

d is the mass percentage of CaO in the component formula for preparing glass fiber;

e is the mass percentage of TiO 2 in the component formula for preparing glass fibers;

f is the mass percentage of CeO 2 in the component formula for preparing glass fiber;

X≤0.15.
The low-dielectric glass fiber according to claim 4, wherein X≤0.09.
The low-dielectric glass fiber according to any one of claims 1-5, wherein the glass fiber has a diameter of 4-10um.
The low-dielectric glass fiber according to any one of claims 1-6, wherein the glass fiber has a dielectric constant of 4.2-4.5 and a dielectric loss of 2.5×10 -3 - at a frequency of 10 GHz at room temperature. 4.4×10 -3 .
The low-dielectric glass fiber according to any one of claims 1-7, characterized in that the liquidus temperature of the glass fiber is lower than 1315°C, and the temperature at which the viscosity is at 1000 poise is lower than 1370°C.
The low dielectric glass fiber according to any one of claims 1-8, wherein the glass fiber has a modulus of 55-62 GPa and a strength of 2500-3100 MPa.
The preparation method of the low-dielectric glass fiber according to any one of claims 1-9, characterized in that, comprising the steps of:

The glass fiber raw material is melted, heated to above the liquidus temperature, and then drawn and formed.
A glass fiber product, characterized in that the glass fiber product is obtained by grinding the glass fiber according to any one of claims 1 to 9 or the glass fiber prepared by the method according to claim 10 through grinding, weaving, Articles obtained by thermal and/or chemical treatment.
The glass fiber product according to claim 11, wherein the glass fiber product is glass micropowder, woven fabric, non-woven fabric, unidirectional fabric, chopped yarn, 3D fabric, colored glass fiber cloth, pre-treated cloth , post-processing cloth or cotton felt.
A composite material, characterized by comprising the glass fiber product of claim 11 or 12.
The composite material according to claim 13, wherein the composite material is a printed circuit board, an electronic device substrate, an electronic device frame or a casing.
Use of the composite material of claim 13 or 14 in electronic devices and systems operating at high frequency and/or high speed.
The application according to claim 14, wherein the electronic device and system are mobile phones, computers, smart wearable devices, smart driving or computing devices.