Fiberglass

Abstract

The glass fiber of the present invention contains: SiO2, Al2O3, and MgO forming a glass skeleton; and the glass fiber has crack resistance.

Description

Fiberglass This invention relates to glass fiber, glass fiber materials using the same, and resin-impregnated fiber materials. Glass fiber has a high modulus of elasticity, so it can be used in a variety of fields, such as sometimes for the regeneration of existing pipes as shown in Patent Document 1. Prior Art Documents Patent Document 1: Japanese Patent Application Publication No. 2021-11904 The glass fiber described in this invention is used not only in the construction of the aforementioned tubes but also in various other applications, such as windmill blades and other frequently moving objects. These moving objects are sometimes subjected to impacts from other objects, which can cause cracks. However, research on crack resistance is insufficient, and a glass fiber with high crack resistance is desired. This invention was made to solve this problem, and its object is to provide glass fiber, glass fiber materials, and resin-impregnated fiber materials with high crack resistance. Item 1. A glass fiber containing: SiO₂ forming a glass framework. 2; Al 2O 3; and MgO; and the glass fiber has crack resistance. Item 2. Glass fiber as in Item 1, wherein SiO The content of 2 is above 55 mol%. Item 3. Glass fiber as described in Item 1 or 2, wherein the aforementioned MgO content is less than 30 mol%. Item 4. The glass fiber of any one of Items 1 to 3 has an elastic modulus of 90 GPa or higher. Item 5. The glass fiber of any of Items 1 to 4 further contains rare earth compounds. Item 6. The glass fiber of any of Items 1 to 5 has a crack load resistance of 400g or more. Item 7. A glass fiber material formed from any one of the glass fibers described in Items 1 to 6, wherein the glass fiber material is any one of plied yarn, spun yarn, yarn, and roving. Item 8. A resin-impregnated fiber material comprising: a glass fiber material formed from glass fibers as described in any one of items 1 to 6, wherein the glass fiber material is in the form of woven or nonwoven fabric; and a resin impregnated in the aforementioned glass fiber material. Item 9. As described in Item 8, the resin-impregnated fiber material is used as the blades of wind turbines for wind power generation, the blades of helicopters, the blades of drones, or the structure of high-voltage troughs. According to the present invention, high crack resistance can be achieved. This invention illustrates various embodiments of the glass fiber used to implement the invention. The glass fiber of this invention contains at least SiO₂. 2. Al 2O 3. And elastic modulus adjusting components used to improve the elastic modulus. These will be explained in detail below. Unless otherwise specified, the symbols % representing the glass composition content are in moles. <1. Glass fiber composition> <1-1. SiO2> 2> SiO 2 is the main component of glass fiber, that is, the component that forms the glass skeleton, and its content is set in the range of, for example, 50-70%. SiO The content of 2 should ideally be above 55%, more preferably above 60%, and especially above 62%. SiO 2. If the content of SiO is too low, the crack resistance and acid resistance may decrease. On the other hand, if the SiO content is too low... If the content of 2 is too high, the elastic modulus (e.g., Young's modulus) will decrease. Therefore, SiO 2. The content should be below 67%, more preferably below 65% or 63%, and especially below 60%. <1-2.Al 2O 3> Al 2O 3. It helps maintain the heat resistance and water resistance of glass components, and is also a component that affects devitrification temperature and viscosity. In particular, Al 2O 3. This helps increase the crack resistance load, which will be discussed later. Therefore, Al 2O 3. The content is set in the range of 10-26%. Al 2O 3. The content should ideally be above 10%, more preferably above 12%, especially above 15%, and depending on the situation, above 16%, and even above 17%. If Al 2O If the content of 3 is too high, the liquid phase temperature will rise significantly, leading to manufacturing defects. Therefore, Al 2O 3. The content should be below 24%, more preferably below 22%, and depending on the situation, it can also be below 20%, and even further below 19%. Especially considering mass production, the devitrification temperature of the glass composition should be sufficiently lower than the liquidus temperature. To ensure the devitrification temperature is sufficiently lower than the liquidus temperature, a suitable Al... 2O The content of 3 is 11-15%, further 11-14%, and 11.5-13.5% is particularly suitable. As will be discussed later, in order to lower the devitrification temperature sufficiently below the liquidus temperature, an appropriate amount of Li can be added. 2O and / or B 2O 3. <1-3. Components for Improving the Modulus of Elasticity> The glass fiber of the present invention contains MgO as an elastic modulus adjusting component to improve the elastic modulus. In addition, it may further contain, for example, alkaline earth metal compounds and rare earth compounds as other elastic modulus adjusting components. Examples of alkaline earth metal compounds include MgO and CaO. Examples of rare earth compounds include Y... 2O 3. La 2O 3. CeO 2. Furthermore, the elastic modulus adjusting component only needs to contain at least one component, but may also contain two or more components. This will be explained below. (MgO) MgO helps to increase the elastic modulus (e.g., Young's modulus) and is also a component that affects devitrification temperature, viscosity, etc. Furthermore, MgO helps to increase the crack load resistance described later. Therefore, the MgO content can be set in the range of, for example, 15-30%. The MgO content should preferably be 17% or higher, more preferably 18% or higher, especially preferably 20% or higher, and may also be 21% or higher, and further may be 22% or higher. If the MgO content is too high, there will be a significant increase in the liquidus temperature. Therefore, the MgO content should preferably be 35% or lower, more preferably 30% or lower, and may also be 28% or lower, and further may be 25% or lower. In order to make the devitrification temperature sufficiently lower than the liquidus temperature, the appropriate MgO content is 18-30%, and more preferably 20-28%. (CaO) CaO is an arbitrary component that, in addition to adjusting the elastic modulus (e.g., Young's modulus), helps maintain water resistance and affects devitrification temperature and viscosity. The CaO content can be set in a range of, for example, 0-8%. Adding an appropriate amount of CaO is beneficial from the perspective of lowering the liquidus temperature. Therefore, it is advisable to add CaO (content greater than 0%), preferably 0.1% or higher, more preferably 0.12% or higher, and depending on the situation, 2% or higher, and even further, 3% or higher. However, excessive CaO can sometimes reduce Young's modulus and acid resistance. Therefore, the CaO content should preferably be below 7%, more preferably below 5%. For improving Young's modulus and crack load resistance, a CaO content of less than 1% is particularly suitable. (Total content of MgO and CaO) The total content of MgO and CaO should be set at 18-35%, preferably in the range of 20-30%. (Al 2O 3 / (MgO+CaO)) Al 2O 3. The molar ratio relative to the combined content of MgO and CaO can be set to less than 1. This makes it easier to balance a high Young's modulus with a liquidus temperature that is not excessively high. (Molar ratio Al) 2O The molar ratio of 3 / (MgO+CaO) should preferably be 0.3~0.9, especially 0.35~0.85, and can also be 0.4~0.7 depending on the situation, and further can be in the range of 0.4~0.6. However, the molar ratio of Al is particularly suitable for improving crack load resistance. 2O The ratio of 3 / (MgO+CaO) is 0.7 or higher and less than 1, and is even more suitable if it is 0.7 or higher and less than 0.9, and especially suitable if it is 0.8 or higher and less than 0.9. (MgO / RO (total amount of alkaline earth metal compounds)) It is known that increasing the MgO / RO ratio improves acid resistance. For example, the MgO / RO ratio should ideally be 0.5 or higher, and even more preferably 0.7 or higher. (Rare Earth Compounds) As previously mentioned, rare earth compounds can be exemplified by Y... 2O 3. La 2O 3. CeO 2. The content of rare earth elements (REEs) can be set in the range of, for example, 0% to 8%. The content should ideally be above 0.1%, more preferably above 1%, and especially above 3%. If the REE content is too high, acid resistance will decrease and batch costs will increase. Therefore, the REE content should ideally be below 8%, and more preferably below 6%. <1-4. Other Components> In addition to the above-mentioned components, the following components may also be added to the glass fiber of the present invention as needed. However, it is not limited to the following components, and other components may also be added appropriately. (ZrO 2) ZrO 2-series components used to improve acid resistance. ZrO 2. The content can be set to, for example, a range of 0.1% to 3%. ZrO 2. The content should ideally be above 0.1%, more preferably above 0.3%, and especially above 0.5%. If ZrO If the content of ZrO is too high, the glass is prone to crystallization, resulting in devitrification. Therefore, ZrO 2. The content should be below 3%, and even more preferably below 1.5%. (TiO 2) TiO TiO₂ is a component used to improve acid resistance. 2. The content can be set to, for example, a range of 0.1% to 3%. TiO The content of TiO2 should ideally be 0.1% to 3% or higher, more preferably 0.3% or higher, and especially preferably 0.5% or higher. If the TiO2 content is too high, the glass will lose its homogeneity, and in this case, devitrification may sometimes occur. Therefore, TiO2... 2. The content should be below 3%, and even more preferably below 1.5%. (B 2O 3) B 2O 3-series components form the framework of glass and affect properties such as devitrification temperature and viscosity. B 2O 3. The content is set within the range of 0-3%. Add trace amounts of B. 2O 3. Sometimes it helps to lower the devitrification temperature. Therefore, B can also be added. 2O 3 (content greater than 0%), B added 2O At level 3, its content should ideally be above 0.1%, especially above 0.3%, and depending on the circumstances, above 0.5%, and even above 0.7%. However, excessive B... 2O 3. Sometimes this will reduce Young's modulus. B 2O 3. The content should ideally be below 2.5%, more preferably below 2%, especially below 1.8%, and depending on the circumstances, below 1.6%, and even further below 1.5%. B 2O 3. One of the preferred ranges for the content is 0.1% to 1.6%. (Li 2O) Li 2O is a component that modifies the glass framework and can be any component that affects properties such as liquidus temperature, devitrification temperature, and viscosity. Li The O2 content is set within the range of 0-3%. Li within this range is then added. O₂ can effectively reduce the devitrification temperature. Therefore, Li₂ can also be added. 2O (content greater than 0%), with added Li When the content of 2O is present, it should be above 0.1%, more preferably above 0.2%, especially above 0.3%, and depending on the circumstances, it can also be above 0.5%, and further above 0.7%. If Li If the content of 2O is too high, the Young's modulus will decrease. Therefore, Li The content of 2O should preferably be below 2.5%, more preferably below 2%, especially below 1.8%, and depending on the circumstances, it can also be below 1.6%, and further below 1.5%. Li One preferred range for the O2 content is 0.2% to 2.5%, which is higher than that of Na. The range with a higher content of 2O. (Na 2O) Na 2O and Li O₂ can also be any component that affects properties such as liquidus temperature, devitrification temperature, and viscosity. However, due to Na... 2O compared to Li O₂ has a greater effect on reducing Young's modulus, therefore its content is set in the range of 0-0.2%. While it is generally desirable to have no Na present. 2O, but for the purpose of clarifying the glass melt, it is advisable to add it within a limit of 0.2%, and even more so within a limit of 0.15%, for example, it is advisable to add it within a range of greater than 0% and less than 0.1%. Furthermore, in this specification, the glass fiber contains oxides of transition elements (ZrO) with several valences. 2. Y 2O 3. La 2O 3. CeO The content of (2, etc.) is calculated based on the oxide with the highest oxidation number of the metal. (Total of the components described above) The components described above (SiO2) 2. Al 2O 3. The total content of MgO should be above 95%, more preferably above 97%, especially above 98%, and particularly preferably above 99%. Depending on the circumstances, it can also be 99.5%, and further above 99.9%, or even 100%. <2. Characteristics of Glass Fibers> <2-1. Modulus of Elasticity> In one embodiment of the present invention, the modulus of elasticity of the glass fiber can be determined using Young's modulus. The Young's modulus is preferably 90 GPa or higher, more preferably 95 GPa or higher, and especially preferably 100 GPa or higher. There is no particular upper limit to the Young's modulus, and it can also be 110 GPa or lower. The Young's modulus is not determined using glass fiber, but rather using bulk glass with the same composition as follows. Young's modulus was determined according to the ultrasonic pulse method described in Japanese Industrial Standard (JIS) R1602-1995. Each test piece was a cuboid measuring 5 mm × 25 mm × 35 mm. The measurements were conducted at room temperature and in atmospheric conditions using a Panametrics Model 25 DL Plus. Furthermore, it is known that in glass fibers and bulk glass composed of the same glass composition, glass fibers typically have a relatively low modulus of elasticity. This can be attributed to the rapid and significant cooling of glass fibers during the forming process from molten glass. However, there is a positive correlation between the modulus of elasticity of glass fibers and that of bulk glass (as measured by the aforementioned JIS standard). Therefore, it is appropriate to use the measured values ​​obtained according to the aforementioned JIS standard to evaluate the properties of glass fibers or glass compositions used to make glass fibers. <2-2. Crack Resistance Load> In this invention, the resistance to cracking when subjected to external impact was evaluated, i.e., crack resistance. Crack resistance load can be used as an indicator of crack resistance. Specifically, the crack resistance load of the glass fiber is, for example, 300g or more, preferably 400g or more, and more preferably 500g or more. Surprisingly, according to one embodiment of the invention, a glass composition with particularly high crack resistance load can also be provided, for example, 900g or more, further 1000g or more, and particularly 1200g or more. The upper limit of the crack resistance load is not particularly limited and may be 2000g or less. The crack load test is conducted by pressing a Vickers indenter against a mirror-polished glass sample surface. The apparatus used is a Vickers hardness tester manufactured by Akashi Corporation. The sample glass is processed into a plate shape with parallel planes. Furthermore, a suspension of cerium oxide abrasive is used to polish the plane to which the indenter is pressed to a mirror finish. The Vickers indenter is pressed against this mirror-polished surface for 15 seconds, then unloaded for 5 minutes. The square indentation remaining on the sample glass surface is then examined to determine if a crack has formed at the apex of the indentation. The presence of a crack is determined by observation using a microscope integrated into the Vickers hardness tester. The microscope has a magnification of 100x. This test is performed 10 times, and the probability of crack formation, P, is calculated by dividing the number of apexes with crack formation by the total number of measured apexes (40). The above measurements were repeated by changing the load in the order of 50g, 100g, 200g, 300g, 500g, 1000g, and 2000g until P=100%, and the probability of crack initiation P under each load was calculated. Following this method, two adjacent loads WH and WL across P=50% were obtained, along with the crack initiation probabilities PH and PL (PH < 50% < PL). The load and crack initiation probability were plotted on the horizontal and vertical axes, respectively, and a straight line was drawn through the two points (WH, PH) and (WL, PL). The load at P=50% was defined as the crack-resistant load. Crack resistance can be mainly divided into two factors. One is impact resistance. Impact resistance refers to the ease with which glass fibers are damaged. This also depends on the shape of the glass fibers, the shape of the strands formed by the glass fibers, and the manufacturing process of the glass fibers and strands. The other factor is fracture toughness. Fracture toughness refers to the resistance of a material to fracture when a mechanical load is applied to a material with crack-like defects. In other words, the greater the fracture toughness, the higher the crack resistance. In this invention, the relationship between crack resistance and fracture toughness is particularly focused on the relationship between crack resistance and glass composition. <2-3.Acid Resistance> In one embodiment of the present invention, the acid resistance of glass fibers can, for example, be evaluated according to the method of JOGIS J06-1999. Also, the specific gravity grams of the pulverized fiberglass was placed in a platinum vessel, immersed in 80 ml of sulfuric acid solution with a specific gravity of 1.2 in a flask, and heated at 99°C for 60 minutes, after which it was dried at 120°C and weighed to determine its reduction rate. As a result, a reduction rate of less than 0.2% is more ideal. <3. Method of Manufacture of Fiberglass> The above-mentioned glass fibers are manufactured by allowing the glass melt with a controlled viscosity to flow out from the nozzle and by means of a curling machine. The continuous fibers can be cut into appropriate lengths when in use. Glass short fibers can be manufactured by spraying glass melt with high pressure air, centrifugal force, etc. <4. Fiberglass Materials> The glass fibers of the present invention may be applied to various forms of fiberglass materials. For example, strands made of clusters of multiple fiberglass can be formed. Each strand may be constructed of, for example, 100~10000 fiberglass, typically 200~4000 fiberglass. Additionally, cut strands formed by cutting the strand line into a predetermined length may also be formed. There is no special limit to the length of the strands. For example, it can be set to 1~25mm, preferably 2~11mm, preferably 3~6mm. Also, a yarn can be formed, which is made by adding a plurality of fiberglass strips to a composite yarn. Alternatively, coarse yarns made of clustered multiple strips of fiberglass can be formed. Further multiple strips of fiberglass can be utilized to form woven fabrics. In this case, flat weave, diagonal weave, gauze weave, braided cloth and other braiding methods can be applied. Alternatively, multiple strips of fiberglass can be utilized to form nonwoven fabrics. In addition, a blanket with voids formed by the random aggregation of glass fibers can be formed. <5.Resin-impregnated fiber materials> The above-mentioned glass fibers can be applied to resin-impregnated fiber sheets. Resin-impregnated fiber sheets are sheets made by using the above-mentioned glass fibers to form woven fabrics, nonwoven fabrics, or fiber bundles, and then infiltrating the resin into them. The resin impregnated into the resin-impregnated fiber sheet is not particularly limited, for example, thermohardening resins, thermoplastic resins, or photohardening resins may be used. Thermohardening resins may be, for example: amine ester resins, vinyl ester resins, epoxy resins and other resins. Thermoplastic resins may be, for example,: polyethylene resins, polypropylene resins, polypropylene copolymers, nylon resins, polymethacrylic resins, polyvinyl chloride resins and polycarbonate resins. Photohardening resins may be exemplified: UV-hardened resins that can be hardened by irradiation of UV rays. Resins impregnated into resin-impregnated fiber sheets may be used using only 1 such resin, or multiple resins may be mixed. There is no particular limitation on the thickness of the resin-impregnated fiber sheet; for example, it can be set to 1~10mm. In addition to being made into sheets, it can also be made into various shapes such as blocks by laminating multiple sheets. <6. Applications of Resin-Impregnated Fiber Materials> <6-1. Blade Components> As blade components, they can be used in applications such as wind turbine blades for wind power generation, helicopter propeller blades, and drone propeller blades. For the applications listed here, in addition to requiring a high modulus of elasticity, these components are subject to frequent movement and impact from foreign objects, thus requiring crack resistance. As shown in Figure 1, the blade component 5 includes: a mounting portion 51 for mounting on a rotating shaft, and a blade body 52 extending from the mounting portion 5. The blade body 52 is formed by an outer skin 521 and a core material 522, the core material 522 being disposed in an internal space surrounded by the outer skin 521. The outer skin 521 is formed by at least one layer of resin-impregnated fiber sheet. In addition to materials containing glass fibers, the resin-impregnated fiber sheet can also be made of materials containing carbon fibers, aramid fibers, etc. For example, the outer skin 521 can be formed by laminating at least one layer of resin-impregnated glass fiber sheet and at least one layer of resin-impregnated carbon fiber sheet. In this case, by placing the resin-impregnated carbon fiber sheet on the inner side and the resin-impregnated glass fiber sheet on the outer side, the impact resistance to external impacts can be improved. Alternatively, the outer skin 521 can be formed solely of resin-impregnated glass fiber sheet. The composition of the core material 522 is not particularly limited. For example, it can be composed of a truss extended into a rod shape and foam material disposed around the truss. By forming the outer skin 521 in the manner described above, the following effects can be achieved. For example, if only resin-impregnated carbon fiber sheets are used to form the outer skin, although the high elasticity of the carbon fibers can ensure strength under load, there will be a problem of weakness in impact resistance. Furthermore, conventional resin-impregnated glass fiber sheets have the problem of low impact resistance. Therefore, if resin-impregnated glass fiber sheets are formed using glass fiber strands that are impact-resistant and highly elastic as described above, strength under load can be ensured, and impact resistance can be obtained, thus making it effective as a blade component. In addition, if the elastic modulus of glass fiber is high, the resin impregnation of carbon fiber sheets can be made thinner, thereby reducing costs. In particular, the outer skin 521 of the blade component 5 is becoming increasingly thinner in order to reduce weight. Therefore, in order to prevent deformation caused by its own weight or centrifugal force, a higher modulus of elasticity is required. Moreover, this component is usually used outdoors, so in order to maintain strength against impacts from foreign objects such as birds, it must be equipped with high crack resistance (impact resistance). Thus, the above-mentioned blade component can balance strength and impact resistance. <6-2. High-Pressure Tank> The high-pressure gas tank is used to store high-pressure gases such as compressed hydrogen and compressed natural gas. For example, as shown in Figure 2, the high-pressure gas tank is cylindrical and has nozzles 63 at both ends in the axial direction. The outer wall of the high-pressure gas tank has a lining 61 made of a resin material such as polyamide, and a reinforcing layer 62 is formed on the inner side of the lining 61. The reinforcing layer 62 is formed by laminating multiple resin-impregnated fiber sheets, or it can be formed by laminating, for example, at least one layer of resin-impregnated glass fiber sheet and at least one layer of resin-impregnated carbon fiber sheet. In this case, the resin-containing carbon fiber sheet is placed on the inner side to ensure strength against the internal pressure of the tank. On the other hand, the resin-impregnated glass fiber sheet is placed on the outer side to protect the inside of the tank from impacts applied to the surface of the tank from the outside. Alternatively, the reinforcing layer 62 can be formed solely of resin-impregnated glass fiber sheet. In particular, when storing compressed hydrogen, it is more advantageous to use glass fiber with excellent low-temperature resistance. <6-3. Other> The resin-impregnated glass fiber sheet of this invention can be applied not only to the aforementioned propeller components and high-pressure air tanks, but also to the shells of transportation equipment such as helicopters and drones. Within the shell, the resin-impregnated glass fiber sheet is particularly suitable for the portion corresponding to the floor. <7. Features> As described above, the glass fiber of the present invention is made of SiO2. 2. This forms a glass framework, thus achieving high crack resistance. Furthermore, the presence of MgO also contributes to both a high elastic modulus and high crack resistance. However, increasing the MgO content necessitates reducing the SiO content. The content of 2% of SiO2 can lead to a decrease in crack resistance. Therefore, the SiO2 content must be adjusted according to the required crack resistance. 2. Equilibrium with MgO. For example, if SiO By setting the content of 2 to 55% or more and the content of MgO to 30% or less, glass fibers with high elastic modulus and high crack load resistance can be obtained. The following describes embodiments of the present invention. However, the present invention is not limited to the following embodiments. Glass fibers with the compositions shown in Table 1 were fabricated, and their Young's modulus (bulk modulus) and crack load resistance were evaluated. The values ​​for the compositions in Table 1 are in mol%. [Table 1] According to Table 1, increasing the MgO content leads to an increase in Young's modulus. Furthermore, a certain increase in MgO content also increases crack resistance. However, if the SiO content increases with increasing MgO content... A decrease in SiO2 content will reduce the crack resistance load. Especially if the SiO2 content decreases... If the SiO2 content is reduced to less than 55 mol%, the crack resistance load will decrease significantly. Therefore, in order to achieve both high elastic modulus and high crack resistance load, it is advisable to, for example, reduce the SiO2 content to less than 55 mol%. The content of MgO should be set between 55 mol% and 62.5 mol%, and the MgO content should preferably be set between 22.5 mol% and 30 mol%. That is, it can be achieved through SiO₂... A balance between MgO and MgO content is achieved to achieve high elasticity and high crack resistance. On the other hand, the comparative example differs from the examples in that it does not contain MgO. In terms of physical properties, its Young's modulus and crack load are lower than those of the examples, especially its crack load, which is significantly lower than that of the examples. 5: Blade component 51: Mounting part 52: Blade body 521: Outer skin 522: Core material 6: Component 61: Liner 62: Reinforcing layer 63: Nozzle component 64: Component Figure 1 is a cross-sectional view of the blade assembly. Figure 2 is a cross-sectional view of the high-pressure gas tank. (none)

Claims

1. A glass fiber comprising: SiO2 forming a glass skeleton; Al2O3; and MgO; and wherein the glass fiber does not contain rare earth compounds; the SiO2 content is 50-67 mol%; the Al2O3 content is 10-26 mol%; the MgO content is 21-35 mol%; and the glass fiber has a crack load resistance of 300 g or more.

2. A glass fiber comprising: SiO2 forming a glass skeleton; Al2O3; and MgO; wherein the SiO2 content is 50-67 mol%; the Al2O3 content is 10-26 mol%; the MgO content is 25-30 mol%; and the glass fiber has a crack load resistance of 300 g or more.

3. The glass fiber as requested in item 1 or 2, wherein the SiO2 content is 55 mol% or more.

4. The glass fiber of request item 1 or 2 has an elastic modulus of 90 GPa or higher.

5. The glass fiber of claim 2 further contains rare earth compounds.

6. The glass fiber used in request item 1 or 2 has a crack load resistance of 400g or more.

7. The glass fiber, as requested in item 1 or 2, has a crack load resistance of 500g or more.

8. A glass fiber material formed from any one of the glass fibers claimed in claims 1 to 7, wherein the glass fiber material is any one of plied yarn, spun yarn, yarn, and roving.

9. A resin-impregnated fiber material comprising: a glass fiber material formed from any one of the glass fibers claimed in claims 1 to 7, wherein the glass fiber material is in the form of woven or nonwoven fabric; and a resin impregnated in the aforementioned glass fiber material.

10. The resin-impregnated fiber material as requested in item 9 is used as the blade of a wind turbine for wind power generation, the blade of a helicopter, the blade of a drone, or the structure of a high-voltage trough.

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