Glass composition, glass filler, method for producing the same, and resin composition containing the glass filler

Abstract

The glass composition provided by the present invention contains, in mass %, 50 ≤ SiO2 ≤ 65, 20 ≤ B2O3 ≤ 30, 5 ≤ Al2O3 ≤ 20, further contains at least one selected from MgO and CaO, and at least one selected from Li2O, Na2O, and K2O. In the glass composition, 0.1 ≤ (MgO + CaO) < 5, 0 ≤ (Li2O + Na2O + K2O) ≤ 4, and 0.50 < MgO / (MgO + CaO) ≤ 1.00 are satisfied. The glass composition is suitable for manufacturing glass fillers with a low dielectric constant and excellent water resistance.

Description

Technical Field

[0001] The present invention relates to a glass composition. Further, the present invention relates to a glass filler, a method for manufacturing the glass filler, and a resin composition containing the glass filler. Background Art

[0002] Among various components included in electronic devices, resin compositions are widely used as electrical insulating components and mechanical components. Examples of electrical insulating components are: connector housings used in SMT (surface mount technology), FPC (flexible printed circuits), board-to-board connectors, CPU (central processing unit) sockets, memory cards, card edges, optical connectors, etc.; reactance bobbins used in LCD (liquid crystal display) backlights, coils, flats, transformers, magnetic heads, etc.; switches used in relay housings, relay base switches, reflow dip switches, tactile switches, etc.; sensor housings, condenser housings, potentiometer casings (volume casings), trimmer housings. Examples of mechanical components are: lens holders and picker bases for optical pickups, insulators and terminals for micro motors, and drums for laser printers. Resin compositions are also used as films such as base films for FPCs and base films for copper-clad laminates. Further, among printed circuit boards included in electronic devices, there is also a substrate made of a resin composition. Among printed wiring boards before mounting electronic components, there is also a substrate made of a resin composition. Hereinafter, in the present specification, both the printed circuit board and the printed wiring board are collectively referred to as "printed board".

[0003] The above resin composition generally contains a thermoplastic resin and an inorganic filler, and may also contain a curing agent, a modifier, etc. as needed. As the inorganic filler, glass fillers are sometimes used. A representative glass filler is flaky glass. In recent years, in order to meet the requirements for miniaturization of electronic devices and the requirements for thinning for the purpose of high performance, a lower dielectric constant is required for resin compositions and their constituent materials.

[0004] Printed boards sometimes also contain glass fibers. A lower dielectric constant is also required for the glass fibers. In Patent Documents 1 to 3, glass fibers made of a glass composition having a low dielectric constant are disclosed.

[0005] Prior Art Documents

[0006] Patent Document

[0007] Patent Document 1: Japanese Unexamined Patent Application Publication No. 62-226839

[0008] Patent Document 2: International Publication No. 2017 / 187471

[0009] Patent Document 3: International Publication No. 2018 / 216637 Summary of the Invention

[0010] Problems to be Solved by the Invention

[0011] For glass fillers used as inorganic filler materials, low dielectric constant and excellent water resistance are required. However, for glass compositions with low dielectric constant, it is not easy to improve water resistance. In addition, water resistance is not considered in Patent Documents 1 to 3.

[0012] In view of the above, an object of the present invention is to provide a glass composition suitable for manufacturing a glass filler having a low dielectric constant and capable of exhibiting excellent water resistance.

[0013] Means for Solving the Problems

[0014] The present invention provides a glass composition comprising, in mass %:

[0015] 50 ≤ SiO 2 ≤ 65

[0016] 20 ≤ B 2 O 3 ≤ 30

[0017] 5 ≤ Al 2 O 3 ≤ 20,

[0018] further comprising:

[0019] at least one selected from MgO and CaO, and

[0020] at least one selected from Li 2 O, Na 2 O, and K 2 O,

[0021] 0.1 ≤ (MgO + CaO) < 5

[0022] 0 ≤ (Li 2 O + Na 2 O + K 2 O) ≤ 4, and

[0023] 0.50 < MgO / (MgO + CaO) ≤ 1.00 holds.

[0024] From another aspect, the present invention provides a glass filler comprising the glass composition of the present invention described above.

[0025] From another aspect, the present invention provides a resin composition comprising the glass filler of the present invention described above and a thermoplastic resin.

[0026] From another aspect, the present invention provides a method for manufacturing a glass filler, which includes a step of melting the glass composition of the present invention described above; and a step of forming the melted glass composition into a glass filler.

[0027] Advantages of the Invention

[0028] According to the present invention, a glass composition suitable for manufacturing a glass filler having a low dielectric constant and excellent water resistance can be provided. With the glass composition of the present invention, a glass filler can be manufactured which, for example, can lower the dielectric constant of a resin composition while being suitable for improving various properties of the resin composition by compounding. The improvement of the above-mentioned various properties includes, for example, an increase in strength, heat resistance, and dimensional stability; a decrease in the linear thermal expansion coefficient and anisotropy; and a decrease in the anisotropy of the shrinkage rate during molding. Description of the Drawings

[0029] Figure 1A FIG. is a perspective view schematically showing an example of a flaky glass as a kind of the glass filler of the present invention.

[0030] Figure 1B is a plan view of the flaky glass observed from above Figure 1A of the flaky glass.

[0031] Figure 2 FIG. is a schematic view for explaining an example of an apparatus and a method for manufacturing the flaky glass.

[0032] Figure 3 FIG. is a schematic view for explaining another example of an apparatus and a method for manufacturing the flaky glass.

[0033] Figure 4 FIG. is a schematic view for explaining an example of a spinning apparatus that can be used in the manufacture of chopped strands.

[0034] Figure 5 is for explaining Figure 4 an example of an apparatus for manufacturing chopped strands from a bobbin of rovings obtained by the spinning apparatus.

[0035] Figure 6 FIG. is a perspective view showing an example of a flat fiber.

[0036] Figure 7 FIG. is a perspective view showing another example of a flat fiber. Detailed Embodiments

[0037] All "% " expressions indicating the content ratio of each component hereinafter are by mass %. "Substantially free of" means that the content ratio is less than 0.1% by mass, preferably less than 0.07% by mass, more preferably less than 0.05% by mass, particularly preferably less than 0.01% by mass, and most preferably less than 0.005% by mass. "Substantially" in the above text means that impurities inevitably mixed from industrial raw materials, glass manufacturing equipment, glass forming body manufacturing equipment, etc. are allowed within the above range. The content ratio, characteristics, and other preferred ranges of each component can be understood as arbitrarily combining the upper and lower limits separately described below.

[0038] Strictly speaking, the dielectric constant refers to the relative dielectric constant, but in this specification, it is only denoted as the dielectric constant according to custom. The dielectric constant is the value at room temperature (25 °C).

[0039] The following description is not intended to limit the present invention, but is presented to show its preferred embodiments.

[0040] [Components of the Glass Composition]

[0041] (SiO 2 )

[0042] SiO 2 is a component that forms the framework of the glass and is the main component (the component with the largest content ratio). SiO 2 has the function of adjusting the devitrification temperature and viscosity during glass formation, and has the function of reducing the dielectric constant of the glass. When the content ratio of SiO 2 is 50% or more and 65% or less, an increase in the devitrification temperature that makes it difficult to manufacture the glass filler can be suppressed, and the dielectric constant can be adjusted to a range suitable for compounding with the resin composition. In addition, within the above range, the melting point of the glass does not become excessively high, and the uniformity during melting of the raw materials is increased. The lower limit of the content ratio of SiO 2 can be 51% or more, 52% or more, 53% or more, 54% or more, 55% or more, and can further exceed 55%. The upper limit of the content ratio of SiO 2 can be less than 64%, 63% or less, 62% or less, less than 62%, 61% or less, 60% or less, 59% or less, and can further be 58% or less.

[0043] (B 2 O 3 )

[0044] B 2 O 3 is a component that forms the framework of the glass. B 2 O 3It has the function of adjusting the devitrification temperature and viscosity during glass formation and has the function of reducing the dielectric constant of the glass. On the other hand, B 2 O 3 is easily volatilized during the melting of the glass. If its content rate becomes too large, it is difficult to obtain sufficient homogeneity as the glass. In addition, excessive B 2 O 3 content reduces the water resistance of the glass. When the content rate of B 2 O 3 is 20% or more and 30% or less, it is possible to suppress the rise in the devitrification temperature of the glass that makes the production of the glass filler difficult, and it is possible to adjust the dielectric constant to a range suitable for compounding with the resin composition. In addition, within the above range, the melting point of the glass does not become excessively high, and the uniformity during melting of the raw materials is increased. Furthermore, within the above range, the water resistance of the glass becomes high. The lower limit of the content rate of B 2 O 3 can be more than 20%, 21% or more, 22% or more, 23% or more, 24% or more, 25% or more, 26% or more, and further can be more than 26%. The upper limit of the content rate of B 2 O 3 can be less than 30%, 29.5% or less, 29% or less, 28.5% or less, and further can be 28% or less.

[0045] (SiO 2 -B 2 O 3 )

[0046] In order to obtain a glass composition with a lower dielectric constant and higher water resistance, the value obtained by subtracting the content rate of B 2 from the content rate of SiO 2 O 3 , that is, SiO 2 -B 2 O 3 can be adjusted to 26% or more, 27% or more, 28% or more, 29% or more, and further can be adjusted to 30% or more.

[0047] (Al 2 O 3 )

[0048] Al 2 O 3 is a component that forms the framework of the glass. Al 2 O 3 has the function of adjusting the devitrification temperature and viscosity during glass formation and has the function of improving the water resistance of the glass. In addition, Al 2 O 3 is a component that adjusts the dielectric constant of the glass. Al 2 O3 When the content rate is 5% or more and 20% or less, it is possible to suppress an increase in the devitrification temperature of the glass that makes the production of the glass filler difficult, and the water resistance of the glass becomes high. In addition, within the above range, the melting point of the glass does not become excessively high, and the uniformity during melting of the raw materials increases. Al 2 O 3 The lower limit of the content rate of can be 6% or more, 8% or more, 9% or more, and further can be 10% or more. Al 2 O 3 The upper limit of the content rate of can be 18% or less, 16% or less, 15.5% or less, 15.3% or less, 15% or less, 14.5% or less, 14% or less, 13.5% or less, and further can be 13% or less. When it is desired to lower the devitrification temperature, or when it is desired to reliably increase the temperature difference ΔT between the operating temperature and the devitrification temperature, the content rate of Al 2 O 3 is 13% or less. It should be noted that the larger the temperature difference ΔT, the more the formability of the glass filler is improved.

[0049] (MgO, CaO)

[0050] MgO and CaO have the function of maintaining the heat resistance of the glass and adjusting the devitrification temperature and viscosity during glass formation. In addition, MgO and CaO are components that have the function of improving the water resistance of the glass and adjusting the dielectric constant of the glass.

[0051] When importance is attached to the control of the dielectric constant and water resistance of the glass filler, the sum of the content rates of MgO and CaO, that is, MgO + CaO, is important. When MgO + CaO is 0.1% or more and less than 5%, it is possible to suppress an increase in the devitrification temperature of the glass that makes the production of the glass filler difficult, and the dielectric constant can be adjusted to a range suitable for compounding into the resin composition. In addition, within the above range, the melting point of the glass does not become excessively high, and the uniformity during melting of the raw materials increases. Furthermore, within the above range, the water resistance of the glass becomes high. The lower limit of MgO + CaO can be 0.5% or more, 1% or more, 1.5% or more, 2% or more, 2.2% or more, 2.4% or more, 2.5% or more, 2.8% or more, 2.9% or more, 3% or more, 3.2% or more, 3.5% or more, and further can exceed 3.5%. The upper limit of MgO + CaO can be 4.5% or less, and further can be 4% or less.

[0052] From the viewpoint of reducing the dielectric constant, the addition of MgO is advantageous compared to CaO. Also, from the viewpoint of improving water resistance, the addition of MgO is advantageous compared to CaO. Therefore, the ratio of MgO to MgO + CaO (by mass), i.e., MgO / (MgO + CaO), is set to be more than 0.50 and 1.00 or less. When MgO / (MgO + CaO) exceeds 0.50, it is possible to suppress the rise in the devitrification temperature of the glass that makes it difficult to manufacture the glass filler, and the dielectric constant can be adjusted to a range suitable for compounding into the resin composition. Also, within the above range, the melting point of the glass does not become excessively high, and the uniformity during melting of the raw materials increases. In addition, within the above range, the water resistance of the glass becomes higher. The lower limit of MgO / (MgO + CaO) can be 0.55 or more, 0.60 or more, 0.65 or more, 0.70 or more, 0.75 or more, 0.80 or more, and further can be 0.85 or more. The upper limit of MgO / (MgO + CaO) can be 0.99 or less, and further can be 0.95 or less. In the case of reliably improving the water resistance of the glass while maintaining a low dielectric constant, the suitable range of MgO / (MgO + CaO) is 0.85 or more, and can be 0.90 or more.

[0053] For MgO, excessive content will increase the dielectric constant of the glass. The content rate of MgO is, for example, 0.1% or more and less than 5%. Within the above range, it is possible to more reliably suppress the rise in the devitrification temperature of the glass that makes it difficult to manufacture the glass filler, and it becomes more reliable to adjust the dielectric constant to a range suitable for compounding into the resin composition. Also, within the above range, it is possible to suppress the excessive increase in the melting point of the glass, and it is possible to more reliably improve the uniformity during melting of the raw materials. In addition, within the above range, it is possible to more reliably improve the water resistance of the glass. The lower limit of the content rate of MgO can be 1% or more, 1.5% or more, 1.8% or more, 2% or more, 2.1% or more, 2.3% or more, 2.5% or more, 2.7% or more, and further can be 3% or more. The upper limit of the content rate of MgO can be 4.5% or less, 4% or less, and further can be 3.5% or less.

[0054] For CaO, excessive content will increase the dielectric constant of the glass. The lower limit of the content rate of CaO can be 0.1% or more, and further can be 0.2% or more. The upper limit of the content rate of CaO can be less than 2.5%, 2% or less, 1.5% or less, 1.2% or less, 1% or less, 0.75% or less, 0.7% or less, and further can be 0.5% or less. The suitable content rate of CaO for reliably improving the water resistance of the glass while maintaining a low dielectric constant is 0.5% or less.

[0055] (SrO)

[0056] The glass composition may contain SrO. SrO can function to adjust the devitrification temperature and viscosity during glass formation. On the other hand, the inclusion of excessive SrO increases the dielectric constant of the glass. The upper limit of the content rate of SrO can be 5% or less, 3.5% or less, 2% or less, 1.5% or less, 1% or less, 0.5% or less, less than 0.5%, and further can be 0.1% or less. SrO may be substantially absent.

[0057] (BaO)

[0058] The glass composition may contain BaO. BaO can function to adjust the devitrification temperature and viscosity during glass formation. On the other hand, the inclusion of excessive BaO increases the dielectric constant of the glass. The upper limit of the content rate of BaO can be 5% or less, 2% or less, 1% or less, less than 1%, 0.5% or less, and further can be 0.1% or less. BaO may be substantially absent. In the case where particular importance is attached to the uniform melting of the glass raw materials and the stable production of the glass composition, the lower limit of the content rate of BaO can be set to 0.1% or more.

[0059] (ZnO)

[0060] The glass composition may contain ZnO. ZnO can function to adjust the devitrification temperature and viscosity during glass formation. In addition, ZnO can function to adjust the dielectric constant of the glass. On the other hand, the inclusion of excessive ZnO increases the dielectric constant of the glass. The lower limit of the content rate of ZnO can be 0.1% or more. The upper limit of the content rate of ZnO can be 5% or less, 4% or less, 3.5% or less, 3% or less, 2% or less, 1.5% or less, 1% or less, less than 1%, 0.5% or less, and further can be 0.1% or less. ZnO may be substantially absent.

[0061] (MgO + CaO + ZnO)

[0062] In the case of containing ZnO, from the viewpoint of paying attention to the dielectric constant of the glass filler, the total content of MgO, CaO, and ZnO, that is, MgO + CaO + ZnO, can be controlled. MgO + CaO + ZnO can be 0.1% or more and 6% or less. Within the above range, it is possible to more reliably suppress the increase in the devitrification temperature of the glass that makes the production of the glass filler difficult, and it becomes more reliable to adjust the dielectric constant to a range suitable for blending with the resin composition. In addition, within the above range, it is possible to suppress the melting point of the glass from becoming excessively high, and it is possible to more reliably improve the uniformity when melting the raw materials. The lower limit of MgO + CaO + ZnO can be 1% or more, 1.5% or more, 2% or more, 2.5% or more, 2.8% or more, 2.9% or more, 3% or more, 3.2% or more, 3.3% or more, and further can be 3.5% or more. The upper limit of MgO + CaO + ZnO can be 6% or less, 5.5% or less, less than 5%, 4.5% or less, and further can be 4% or less.

[0063] (Li 2 O, Na 2 O, K 2 O)

[0064] As the alkali metal oxides, Li 2 O, Na 2 O, and K 2 O have the function of adjusting the devitrification temperature and viscosity during glass formation while maintaining the heat resistance of the glass. On the other hand, excessive content of alkali metal oxides will increase the dielectric constant of the glass and reduce the water resistance. Therefore, the total content of the alkali metal oxides, Li 2 O + Na 2 O + K 2 O, is set to be 0% or more and 4% or less. The lower limit of Li 2 O + Na 2 O + K 2 O can be 0.1% or more, 0.2% or more, 0.3% or more, 0.4% or more, 0.5% or more, more than 0.5%, 0.6% or more, 0.7% or more, and further can be more than 0.7%. The upper limit of Li 2 O + Na 2 O + K 2 O can be 4% or less, 3% or less, 2% or less, 1.5% or less, 1% or less, and further can be 0.9% or less.

[0065] For Li 2 O, excessive content will increase the dielectric constant of the glass and reduce the water resistance. The lower limit of the content of Li 2 O can be 0.1% or more, 0.2% or more, 0.3% or more, 0.4% or more, and further can be 0.5% or more. Li2 The upper limit of the content rate of O can be 4% or less, 3% or less, 2% or less, 1.5% or less, 1% or less, and further can be 0.9% or less.

[0066] For Na 2 O, excessive content will increase the dielectric constant of the glass and reduce the water resistance. In addition, the increase in the dielectric constant caused by Na 2 O is larger than that caused by Li 2 O. The upper limit of the content rate of Na 2 O can be 4% or less, 2% or less, 1.5% or less, 1% or less, 0.5% or less, 0.3% or less, and further can be 0.2% or less.

[0067] For K 2 O, excessive content will increase the dielectric constant of the glass and reduce the water resistance. In addition, the increase in the dielectric constant caused by K 2 O is larger than that caused by Li 2 O. The upper limit of the content rate of K 2 O can be 4% or less, 2% or less, 1% or less, 0.5% or less, 0.2% or less, and further can be less than 0.1%. K 2 O can be substantially free.

[0068] (TiO 2 )

[0069] The glass composition may contain TiO 2 . TiO 2 can have the effects of improving the meltability and chemical durability of the glass and improving the ultraviolet absorption characteristics of the glass. On the other hand, excessive content will increase the dielectric constant of the glass. The lower limit of the content rate of TiO 2 can be 0.1% or more. The upper limit of the content rate of TiO 2 can be 5% or less, 2% or less, less than 1%, 0.9% or less, 0.8% or less, 0.7% or less, less than 0.5%, 0.4% or less, 0.3% or less, 0.2% or less, and further can be 0.1% or less. Within the above range, it is possible to suppress the increase in the devitrification temperature of the molten glass that affects the manufacture of the glass filler due to the content of TiO 2 . TiO 2 can be substantially free.

[0070] (ZrO 2 )

[0071] The glass composition may contain ZrO 2 . ZrO 2It can function to adjust the devitrification temperature and viscosity during glass formation. On the other hand, excessive inclusion will increase the dielectric constant of the glass. The inclusion of ZrO 2 The upper limit of the inclusion rate can be 5% or less, 2% or less, less than 1%, less than 0.5%, 0.2% or less, and further can be 0.1% or less. Within the above range, it is possible to suppress the increase in the devitrification temperature of the molten glass that affects the manufacture of glass fillers due to the inclusion of ZrO 2 . The lower limit of the inclusion rate of ZrO 2 can be 0.1% or more, and further can be 0.15% or more. ZrO 2 can be substantially free of.

[0072] (Fe)

[0073] The glass composition may contain Fe. Fe in the glass usually exists in the state of Fe 2+ and / or Fe 3+ . Fe 3+ can function to improve the ultraviolet absorption characteristics of the glass. Fe 2+ can function to improve the infrared absorption characteristics of the glass. Even if Fe is not intentionally included, it sometimes inevitably mixes in through industrial raw materials. If the inclusion of Fe is small, coloring of the glass can be prevented. The upper limit of the inclusion rate of Fe is represented by T-Fe 2 O 3 (T-Fe 2 O 3 is the total iron oxide converted to Fe 2 O 3 ), and can be 5% or less, 2% or less, less than 1.8%, 1.5% or less, less than 1%, less than 0.5%, and further can be 0.2% or less. The lower limit of the inclusion rate of Fe is represented by T-Fe 2 O 3 , and can be 0.1% or more. Fe is represented by T-Fe 2 O 3 and can be substantially free of.

[0074] (P 2 O 5 )

[0075] The glass composition may contain P 2 O 5 . P 2 O 5 is a component that forms the framework of the glass and can function to adjust the devitrification temperature and viscosity during glass formation. In addition, P 2 O 5 can function to adjust the dielectric constant of the glass. However, generally speaking, if P 2 O5 If the content ratio exceeds 2%, the furnace walls of the melting furnace and regenerator will be eroded when the glass is melted, and the life of the furnace will be significantly reduced. P 2 O 5 The upper limit of the content ratio can be 5% or less, 2% or less, less than 1%, less than 0.5%, 0.3% or less, 0.2% or less, and further can be less than 0.1%. P 2 O 5 It may be substantially free of.

[0076] (F 2 , Cl 2 )

[0077] The glass composition may contain F 2 and / or Cl 2 . F 2 and Cl 2 By including in the glass composition, the melting point of the glass will not be excessively increased, and the uniformity of the glass during melting of the raw materials will be improved. However, F 2 and Cl 2 are volatile, so they may fly off during melting, and there is also a problem of difficulty in controlling the content ratio in the glass. F 2 The upper limit of the content ratio can be 5% or less, 2% or less, 1% or less, 0.5% or less, 0.2% or less, and further can be 0.1% or less. F 2 It may be substantially free of. Cl 2 The upper limit of the content ratio can be 5% or less, 2% or less, 1% or less, 0.5% or less, 0.2% or less, and further can be 0.1% or less. Cl 2 It may be substantially free of.

[0078] (Other components)

[0079] The glass composition may contain, in the range of 0% or more and 5% or less respectively, selected from La 2 O 3 , WO 3 , Nb 2 O 5 , Y 2 O 3 , MoO 3 , Ta 2 O 5 , MnO 2 and Cr 2 O 3at least one of the following as other components. The upper limit of the allowable content rate for each component can be less than 2%, less than 1%, less than 0.5%, and further can be 0.1% or less. The upper limit of the allowable total content rate for each component can be 5% or less, less than 2%, less than 1%, less than 0.5%, and further can be 0.1% or less. Any one component selected from the above group may be substantially free. In addition, two or more components selected from the above group may be substantially free in any combination.

[0080] The glass composition may contain, respectively, in the range of 0% or more and 1% or less, at least one selected from Br 2 , I 2 , SnO 2 , CeO 2 , As 2 O 3 and Sb 2 O 3 as additives. The upper limit of the allowable content rate for each component can be less than 0.5%, less than 0.2%, and further can be less than 0.1%. The upper limit of the allowable total content rate for each component can be 1% or less, less than 0.5%, less than 0.2%, and further can be less than 0.1%. Any one component selected from the above group may be substantially free. In addition, two or more components selected from the above group may be substantially free in any combination.

[0081] The glass composition may contain, respectively, in the range of 0% or more and 0.1% or less, at least one selected from H 2 O, OH, H 2 , CO 2 , CO, He, Ne, Ar and N 2 In. The upper limit of the allowable content rate for each component can be less than 0.05%, less than 0.03%, and further can be less than 0.01%. The upper limit of the allowable total content rate for each component can be 0.1% or less, less than 0.05%, less than 0.03%, and further can be less than 0.01%. Any one component selected from the above group may be substantially free. In addition, two or more components selected from the above group may be substantially free in any combination.

[0082] The glass composition may contain trace amounts of noble metal elements. Examples of noble metal elements are Pt, Rh, Au, and Os. The content rates of noble metal elements are 0% or more and 0.1% or less, respectively. The upper limit of the allowable content rate for each component can be less than 0.1%, less than 0.05%, less than 0.03%, and further can be less than 0.01%. The upper limit of the allowable total content rate for each component can be less than 0.1%, less than 0.05%, less than 0.03%, and further can be less than 0.01%. Each component may be substantially free.

[0083] The glass composition may consist essentially of any combination of the above-described components and content ratios. The "essentially" in "consist essentially of" is intended to allow for the inclusion of impurities having a content ratio of less than 0.1% by mass, preferably less than 0.07% by mass, more preferably less than 0.05% by mass, particularly preferably less than 0.01% by mass, and most preferably less than 0.005% by mass.

[0084] (Examples of Preferred Compositions)

[0085] The glass composition in a preferred embodiment contains, in mass %:

[0086] 55 ≤ SiO 2 ≤ 65

[0087] 20 ≤ B 2 O 3 ≤ 30

[0088] 5 ≤ Al 2 O 3 ≤ 20,

[0089] 0.1 ≤ (MgO + CaO) < 5

[0090] 0 ≤ (Li 2 O + Na 2 O + K 2 O) ≤ 4, and

[0091] 0.75 ≤ MgO / (MgO + CaO) ≤ 1.00 holds.

[0092] The glass composition in another preferred embodiment contains, in mass %:

[0093] 50 ≤ SiO 2 ≤ 65

[0094] 20 ≤ B 2 O 3 ≤ 30

[0095] 5 ≤ Al 2 O 3 ≤ 20

[0096] 0 ≤ F 2 ≤ 0.5,

[0097] 0.1 ≤ (MgO + CaO) < 5

[0098] 0.1 ≤ (Li 2 O + Na 2 O + K 2 O) ≤ 4, and

[0099] 0.50 < MgO / (MgO + CaO) ≤ 1.00 holds.

[0100] Another preferred glass composition contains, in mass %,

[0101] 50 ≤ SiO 2 ≤ 65

[0102] 20 ≤ B 2 O 3 ≤ 30

[0103] 5 ≤ Al 2 O 3 ≤ 15,

[0104] 0.1 ≤ (MgO + CaO) < 5

[0105] 0 ≤ (Li 2 O + Na 2 O + K 2 O) ≤ 4, and

[0106] 0.50 < MgO / (MgO + CaO) ≤ 1.00 holds.

[0107] Another preferred glass composition contains, in mass %,

[0108] 50 ≤ SiO 2 ≤ 65

[0109] 20 ≤ B 2 O 3 ≤ 30

[0110] 5 ≤ Al 2 O 3 ≤ 20

[0111] 0.1 ≤ TiO 2 ≤ 5,

[0112] 0.1 ≤ (MgO + CaO) < 5

[0113] 0.1 ≤ (MgO + CaO + ZnO) ≤ 6

[0114] 0 ≤ (Li 2 O + Na 2 O + K 2 O) ≤ 4, and

[0115] 0.50 < MgO / (MgO + CaO) ≤ 1.00 holds.

[0116] Another preferred glass composition contains 0.1 ≤ Li 2O ≤ 4. The glass composition of this solution can be the glass composition of each of the above-preferred solutions.

[0117] In another preferred solution, the glass composition further contains 0 ≤ P 2 O 5 ≤ 5. The glass composition of this solution can be the glass composition of each of the above-preferred solutions.

[0118] In another preferred solution, the glass composition is substantially free of F 2 . The glass composition of this solution can be the glass composition of each of the above-preferred solutions.

[0119] In another preferred solution, the glass composition further contains 0 ≤ ZnO ≤ 5 in terms of mass%. The glass composition of this solution can be the glass composition of each of the above-preferred solutions.

[0120] In another preferred solution, the glass composition further contains 0 ≤ BaO ≤ 5 in terms of mass%. The glass composition of this solution can be the glass composition of each of the above-preferred solutions.

[0121] In another preferred solution, the glass composition further contains 0 ≤ SrO ≤ 5 in terms of mass%. The glass composition of this solution can be the glass composition of each of the above-preferred solutions.

[0122] In another preferred solution, the glass composition further contains 0 ≤ ZrO 2 ≤ 5. The glass composition of this solution can be the glass composition of each of the above-preferred solutions.

[0123] [Properties of the glass composition]

[0124] The properties obtainable for the glass composition of the present invention are described. The glass filler containing the glass composition of the present invention can have the following respective properties.

[0125] (Dielectric constant)

[0126] When the glass filler is incorporated into the resin composition, if the dielectric constant of the glass composition constituting the glass filler at a frequency of 1 GHz is 4.6 or less, the loss of the dielectric properties of the resin composition can be suppressed. In a preferred solution, the dielectric constant of the glass composition at a frequency of 1 GHz can be 4.6 or less, 4.5 or less, 4.4 or less, and further can be 4.3 or less. The lower limit of the dielectric constant at a frequency of 1 GHz can be 3.5 or more, 3.8 or more, 3.9 or more, and further can be 4.0 or more. If the dielectric constant at a frequency of 1 GHz is 3.5 or more, the adjustment of the glass composition becomes easier.

[0127] (Melting characteristics)

[0128] The temperature at which the viscosity of molten glass becomes 1000 dPa·sec (1000 poise) is called the working temperature, which is the most suitable temperature for glass forming. When manufacturing flaky glass or glass fibers as glass fillers, if the working temperature of the glass is 1100 °C or higher, the deviation in the thickness of the flaky glass or the diameter of the glass fibers can be reduced. If the working temperature is 1450 °C or lower, the fuel cost for melting the glass can be reduced, the glass manufacturing apparatus is less likely to be corroded by heat, and the apparatus life is extended. In a preferred embodiment, the lower limit of the working temperature of the glass composition can be 1100 °C or higher, 1150 °C or higher, 1200 °C or higher, 1250 °C or higher, 1300 °C or higher, and further can be 1320 °C or higher. The upper limit of the working temperature can be 1450 °C or lower, 1420 °C or lower, 1410 °C or lower, 1400 °C or lower, 1390 °C or lower, and further can be 1380 °C or lower.

[0129] The larger the temperature difference ΔT obtained by subtracting the devitrification temperature from the working temperature, the less likely devitrification occurs during glass forming, and homogeneous glass fillers can be manufactured with a high yield. In other words, the larger the temperature difference ΔT, the higher the formability (mass productivity) of the glass fillers. In a preferred embodiment, ΔT of the glass composition can be 0 °C or higher, 17 °C or higher, 20 °C or higher, 30 °C or higher, 40 °C or higher, 50 °C or higher, 60 °C or higher, 70 °C or higher, 75 °C or higher, 80 °C or higher, 90 °C or higher, 100 °C or higher, 125 °C or higher, 150 °C or higher, 170 °C or higher, 190 °C or higher, and further can be 200 °C or higher. On the other hand, if ΔT is 500 °C or lower, the adjustment of the glass composition becomes easier. ΔT can be 500 °C or lower, 400 °C or lower, 300 °C or lower, 250 °C or lower, and further can be 200 °C or lower.

[0130] (Water resistance)

[0131] The alkali dissolution amount can be used as an index of water resistance. The smaller the alkali dissolution amount, the higher the water resistance of the glass. When the glass filler is incorporated into the resin composition, if the alkali dissolution amount of the glass composition is 0.40 mg or less, the reduction in the strength of the resin composition caused by water is suppressed. In a preferred embodiment, the upper limit of the alkali dissolution amount of the glass composition can be 0.40 mg or less, 0.37 mg or less, 0.35 mg or less, 0.34 mg or less, and further can be 0.33 mg or less. The lower limit of the alkali dissolution amount is usually about 0.001 mg, and can be 0.01 mg or higher, and further can be 0.03 mg or higher.

[0132] [Glass filler]

[0133] The glass filler of the present invention comprises the glass composition of the present invention. Examples of the form of the glass filler are at least one selected from scaly glass, chopped strands, milled fibers, glass powder, glass beads, flat fibers, and flakes. However, the form of the glass filler is not limited to the above examples. In addition, the above forms are not strictly distinguished from each other. Two or more glass fillers having different forms can be combined and used as a filler. For example, a mixture can be used as a filler. Hereinafter, each form will be described.

[0134] Typically, scaly glass is a flaky particle having an average thickness t of 0.1 μm or more and 15 μm or less, an average particle size a of 0.2 μm or more and 15000 μm or less, and an aspect ratio (average particle size a / average thickness t) of 2 or more and 1000 or less (see Figure 1A and Figure 1B ; Figure 1A and Figure 1B , which shows an example of scaly glass 1). Regarding the average thickness t of scaly glass, at least 100 pieces of scaly glass can be extracted, and for each of the extracted scaly glasses, the thickness can be measured using a magnifying observation device such as a scanning electron microscope (SEM), and the average value of the measured thicknesses can be calculated for evaluation. The average particle size a of scaly glass can be determined by the particle size (D50) corresponding to a cumulative volume percentage of 50% in the particle size distribution measured by the laser diffraction scattering method.

[0135] Scaly glass can be obtained by a known blowing method, cup method, etc. The manufacturing apparatus using the blowing method is shown in Figure 2 . In this apparatus, a glass blank 11 having a predetermined composition melted in a refractory kiln tank 12 expands into a balloon shape due to the gas blown to a blow nozzle 15 and becomes a hollow glass film 16. By crushing this hollow glass film 16 with a pair of pressing rollers 17, scaly glass 1 is obtained.

[0136] The manufacturing apparatus using the cup method is shown in Figure 3 . In this apparatus, the molten glass blank 11 flowing into a rotating cup 22 from a nozzle 21 flows out radially from the upper edge portion of the rotating cup 22 due to the centrifugal force generated by the rotation of the rotating cup 22. The flowing-out blank 11 passes through the upper and lower annular disks 23, 23, is attracted by an air stream, and is introduced into an annular cyclone type collector 24. During the passage through the annular disks 23, 23, the glass is cooled and solidified into a thin film, and further crushed into fine pieces to obtain scaly glass 1.

[0137] The chopped strand has a shape in which the glass fiber is cut relatively short. The fiber diameter of the chopped strand is, for example, 1 to 50 μm, and its aspect ratio is, for example, 2 to 1000. The shape of the cross section of the chopped strand may be circular, or may be, for example, a flat cross section. The fiber diameter of the chopped strand is defined as the diameter of a circle having the same area as the cross section of the strand. The aspect ratio of the chopped strand can be obtained by dividing the fiber length by the fiber diameter. The chopped strand can be used, for example Figure 4 and Figure 5 shown in the device to manufacture.

[0138] As Figure 4 shown, the glass blank that is melted in the refractory kiln trough and has a specified composition is drawn out from a spinneret 30 having a plurality of (for example, 2400) nozzles at the bottom, in the form of a large number of glass filaments 31. After spraying cooling water on the glass filaments 31, an adhesive (sizing agent) 34 is coated by a coating roller 33 of an adhesive feeder 32. A large number of glass filaments 31 coated with the adhesive 34 are bundled by a reinforcing pad 35 into 3 strands of filaments 36 each containing, for example, about 800 glass filaments 31. Each strand of filament 36 is wound around a cylindrical tube 39 that is oscillated by a traversing finger 37 and inserted into a collet 38. The cylindrical tube 39 wound with the strand of filament 36 is removed from the collet 38 to obtain a cake of yarn (a bobbin of filament) 40.

[0139] Next, as Figure 5 shown, the cake of yarn 40 is stored in a creel 41, the strand of filament 36 is drawn out from the cake of yarn 40, and is bundled into a filament bundle 43 through a bundling guide 42. Water or a treatment liquid is sprayed onto the filament bundle 43 by a spraying device 44. The filament bundle 43 is cut by a rotary knife 46 of a cutting device 45 to obtain chopped strands 47.

[0140] The ground fiber has a shape in which the glass fiber is cut into a powdery form. The fiber diameter of the ground fiber is, for example, 1 to 50 μm, and the aspect ratio is, for example, 2 to 500. The shape of the cross section of the ground fiber may or may not be circular, and may be, for example, a flat cross section. The fiber diameter of the ground fiber is defined as the diameter of a circle having the same area as the cross section of the strand. The aspect ratio of the ground fiber can be obtained by dividing the fiber length by the fiber diameter. The ground fiber can be obtained by a known method.

[0141] The glass powder can be manufactured by pulverizing glass. The average particle diameter of the glass powder is, for example, 1 to 500 μm. The particle diameter of the glass powder is defined as the diameter of a sphere having the same volume as the particle of the glass powder. The average particle diameter of the glass powder can be determined by D50 (the particle diameter at which the cumulative volume percentage is equivalent to 50%) evaluated by measuring the particle size distribution of at least 0.1 g of the glass powder based on the laser diffraction scattering method. The glass powder can be obtained by a known method.

[0142] The glass beads have a spherical or substantially spherical shape. The average particle diameter of the glass beads is, for example, 1 to 500 μm. The particle diameter of the glass beads is defined as the diameter of a sphere having the same volume as the particles of the glass beads. The average particle diameter of the glass beads is determined by D50 (the particle diameter at which the cumulative volume percentage is 50%) evaluated by measuring the particle size distribution of at least 0.1 g of the glass beads based on the laser diffraction scattering method. The glass beads can be obtained by a known method.

[0143] The flat fibers have a shape obtained by cutting glass fibers having a flat cross-section such as an ellipse. As Figure 6 shown, with respect to the minor axis D1 of the cross-section of the flat fiber 50, the major axis D2 is large, and D2 / D1 is, for example, 1.2 or more. The minor axis D1 is, for example, 0.5 to 25 μm. The major axis D2 is, for example, 0.6 to 300 μm. The length L of the flat fiber is, for example, 10 to 1000 μm. As Figure 7 shown, the cross-section of the flat fiber 60 can be a shape that is concave in the center. In other words, the cross-sectional shape of the flat fiber 60 can have a concave shape in which the surface extending along the major axis D2 recedes at the center compared to the ends. The cross-section is a substantially gourd-shaped or substantially hourglass-shaped in which the central portion in the direction of the major axis D2 recedes from both sides.

[0144] The fine flakes are scaly glass with a thin thickness. The fine flakes can be composed of scaly glass having an average thickness of 0.1 to 2.0 μm, and can contain, for example, scaly glass having a thickness in the range of 0.01 to 2.0 μm at a proportion of 90 mass% or more. The fine flakes with such a thin average thickness and a small deviation in thickness have a high effect of reinforcing the resin and are also excellent in the effect of reducing the molding shrinkage rate of the resin. The fine flakes can be obtained by the above method.

[0145] The glass filler can be manufactured by a method including a step of melting the above-described glass composition and a step of forming the molten glass composition into a desired glass filler. The temperature for melting the glass composition is, for example, 1400 °C or higher.

[0146] [Granulation of Glass Filler]

[0147] At least a part of the glass filler can be granulated. Granulation is a process of subjecting the glass filler to an adhesive treatment and granulating by bonding each glass filler to each other with an adhesive. The granular glass filler has excellent operability due to its low scattering property and is also excellent in dispersibility in the resin. If granular glass filler is used, the feeding property is improved, and more reliable quantitative feeding can be achieved. Hereinafter, the adhesive used for granulation will be described.

[0148] The binder preferably contains a surfactant and a binding component. The surfactant can be any surfactant among anionic, cationic, amphoteric, and nonionic surfactants. Among them, when the binding component contains an epoxy resin or a polyurethane resin, a nonionic surfactant is preferably used. This is because it can inhibit the aggregation of the binder and stabilize it. Examples of anionic surfactants are sodium dioctyl sulfosuccinate, fatty acid salts, alkyl sulfates, alkyl sulfonates, alkyl aryl sulfonates, alkyl naphthalene sulfonates, alkyl sulfosuccinates, alkyl diphenyl ether disulfonates, alkyl phosphates, polyoxyethylene alkyl sulfates, polyoxyethylene alkyl allyl sulfates, and sulfosuccinates. Examples of cationic surfactants are higher amine halides, halogenated alkyl pyridinium salts, and quaternary ammonium salts. Examples of amphoteric surfactants are lauryl aminopropionate and lauryl dimethyl betaine. Examples of nonionic surfactants are polyoxyethylene lauryl ethers, polyoxyethylene higher alcohol ethers, polyoxyethylene octyl phenyl ethers and other polyoxyethylene glycol alkyl ethers, polyethylene glycol fatty acid esters such as polyethylene glycol monostearate, sorbitan monolaurate, sorbitan fatty acid esters such as polyoxyethylene sorbitan monolaurate, glycol fatty acid esters such as glycol monostearate, and fatty acid monoglycerides. Two or more of these can also be used in combination.

[0149] The binding component of the binder is not particularly limited, and organic or inorganic components can be used. Examples of organic binding components are methyl cellulose, carboxymethyl cellulose, starch, carboxymethyl starch, hydroxyethyl cellulose, hydroxypropyl cellulose, polyvinyl alcohol, silane coupling agents, acrylic resins, epoxy resins, phenolic resins, vinyl acetate, polyurethane resins, etc. Examples of inorganic binding components are sodium silicate, colloidal silica, colloidal alumina, amino silanes, etc. The binding component preferably contains at least one selected from silane coupling agents, epoxy resins, and polyurethane resins. The silane coupling agent has two or more reactive groups in the molecule, one of which reacts with the surface of the glass filler and the other reacts with the organic binding component and the thermoplastic resin, thus improving the fusion of the glass filler and the thermoplastic resin. The epoxy resin and the polyurethane resin have good fusion with the silane coupling agent and the thermoplastic resin.

[0150] For the binder, water or alcohol is preferably used as a solvent, and its concentration is adjusted so that each component can uniformly exist on the surface of the glass filler. The concentration of the binder, expressed as the total solid component concentration, is preferably 1 to 10% by mass. The binder can be manufactured, for example, by appropriately adding a binding component, a surfactant, etc. to a solvent at normal temperature and atmospheric pressure and stirring until it becomes uniform.

[0151] The ratio of the binder in the granulated glass filler, in other words, the adhesion rate of the binder, is, for example, 0.1 to 2% by mass based on the solid component mass ratio. An adhesion rate of 0.1% by mass or more is suitable for sufficiently suppressing the scattering property of the glass filler. An adhesion rate of 2% by mass or less is suitable for suppressing the generation of gas during the extrusion molding of the resin composition and the discoloration of the resin composition.

[0152] The method for granulating the glass filler is not particularly limited. For example, a stirring granulation method, a fluidized bed granulation method, a spray granulation method, a rotary granulation method, etc. can be used. Specifically, the following method can be used: A glass filler to which an appropriate amount of binder is attached by spraying or the like is spread in a drum or on a vibrating tray, heated to evaporate the solvent, and granulated at the same time. By appropriately adjusting the rotation speed of the drum or the vibration frequency of the vibrating tray, and further appropriately adjusting the evaporation rate of the solvent, glass filler in the form of granules of a desired size can be manufactured.

[0153] The glass filler can be a product whose surface has been treated with a surface treatment agent. Sometimes, the reinforcing effect of the glass filler is improved by this treatment. Examples of the surface treatment agent include silane coupling agents such as γ-aminopropyltriethoxysilane, vinyltriethoxysilane, γ-methacryloxypropyltrimethoxysilane, and titanium coupling agents. The usage amount of the surface treatment agent is, for example, 0.05 to 0.20% by mass of the glass filler.

[0154] [Resin composition]

[0155] The resin composition according to the present invention contains the glass filler according to the present invention and a thermoplastic resin. The thermoplastic resin is not particularly limited. For example, it is polyvinyl chloride, polypropylene, polyethylene, polystyrene, polyester, polyamide, polycarbonate, polybutene, polybutylene terephthalate, copolymers thereof, etc. If polybutylene terephthalate is used, the effect of suppressing warping of the molded product and improving dimensional stability brought about by mixing with the glass filler becomes greater.

[0156] The content rate of the glass filler such as flaky glass in the resin composition is preferably 5 to 70% by mass. By setting it to 5% by mass or more, it is easy to fully exhibit the function of the reinforcing material as the glass filler. By setting it to 70% by mass or less, it is easy to uniformly disperse the glass filler in the resin composition. In order to sufficiently suppress the molding shrinkage rate, it is more preferable to set the content rate of the glass filler to 30% by mass or more.

[0157] In the resin composition, a reinforcing material other than the glass filler can be appropriately contained. For example, in applications requiring high strength, glass fibers can be contained. In this case, the glass fibers can be added at a content rate equivalent to that of the glass filler.

[0158] Scaly glass, flat fibers, and flakes have a relatively large specific surface area and are suitable for ensuring the bonding force with thermoplastic resins. From this perspective, Figure 7 The flat fibers shown in Figure 7 are preferred because the concave surface shape helps to increase the specific surface area.

[0159] The resin composition according to the present invention has a low dielectric constant and is suitable for improving various properties such as strength, heat resistance, dimensional stability, reduction of linear thermal expansion coefficient, reduction of anisotropy, and reduction of anisotropy of shrinkage rate during molding.

[0160] Examples

[0161] Hereinafter, the present invention will be described in more detail by way of examples. The present invention is not limited to the following examples.

[0162] (Examples 1 to 53 and Comparative Examples 1 to 6)

[0163] General glass raw materials such as silica sand were weighed so as to have the respective compositions shown in Tables 1 to 12 (the unit of the content of the components is mass%), and mixed so as to be in a homogeneous state to prepare a glass raw material mixture. Then, the prepared mixture was melted using an electric furnace at 1500 to 1600 °C and maintained for about 4 hours until the composition became uniform. Thereafter, a part of the obtained molten glass (glass melt) was poured out onto an iron plate and slowly cooled to room temperature in the electric furnace to obtain a block-shaped glass composition sample (plate-shaped) for evaluation.

[0164] For the glass sample thus prepared, the operating temperature, devitrification temperature, temperature difference ΔT, alkali dissolution amount, and dielectric constant at a frequency of 1 GHz were evaluated. The evaluation methods are as follows.

[0165] [Operating temperature]

[0166] The viscosity was measured by the platinum ball pulling method, and the temperature at which the measured viscosity became 1000 dPa·sec was taken as the operating temperature. The platinum ball pulling method is a method of measuring the viscosity of molten glass by substituting the relationship between the load (resistance) when a platinum ball is immersed in molten glass and the immersed platinum ball is pulled at a constant speed, and the gravity and buoyancy acting on the platinum ball, etc., into the Stokes' law representing the relationship between the viscosity and the falling speed when a minute particle settles in a fluid.

[0167] [Devitrification temperature and temperature difference ΔT]

[0168] Place 25 g of a glass sample crushed to a particle size of 1.0 to 2.8 mm in a platinum boat (a rectangular and lidless platinum vessel), hold it in an electric furnace with a temperature gradient (800 to 1400 °C) for 2 hours, and then remove it from the furnace. The maximum temperature of the electric furnace corresponding to the position where crystallization is observed inside the glass is taken as the devitrification temperature. The above particle size range is determined by the sieving method. Specifically, crush the glass sample and sieve the particles that pass through a sieve with a mesh size of 2.8 mm (wire mesh sieve, the same applies to sieves below) and remain on a sieve with a mesh size of 1.0 mm. Take the value obtained by subtracting the devitrification temperature from the operating temperature as the temperature difference ΔT.

[0169] [Alkali dissolution amount]

[0170] According to the alkali dissolution test specified in JIS R3502:1995 "Test Methods for Glass Apparatus for Chemical Analysis", measure the alkali dissolution amount. Specifically, as follows. Crush the glass sample and sieve the particles that pass through a sieve with a mesh size of 420 μm and remain on a sieve with a mesh size of 250 μm. Then, weigh out particles with a mass equal to the specific gravity of the glass sample from the sieved particles. Immerse the weighed particles in 50 mL of distilled water at 100 °C for 1 hour, and then titrate the alkali components contained in the water after immersion with sulfuric acid with a concentration of 0.01 N. Multiply the number of milliliters of sulfuric acid required for titration by 0.31 to obtain the milligrams of alkali components converted to Na 2 O, and take it as the alkali dissolution amount. The smaller the alkali dissolution amount, the higher the water resistance of the glass sample.

[0171] [Dielectric constant]

[0172] The dielectric constant at a frequency of 1 GHz is measured using a dielectric constant measuring device based on the cavity resonator perturbation method. The measurement temperature is 25 °C, and the size of the sample for measurement is set as a cuboid with a square bottom with a side length of 1.5 mm and a height of 100 mm.

[0173] Show the evaluation results in Tables 1 to 12.

[0174]

Table 1

[0175] Composition (mass %) or physical property Example 1 Example 2 Example 3 Example 4 Example 5 <![CDATA[SiO 2 > 57.51 55.49 56.19 57.20 56.49 <![CDATA[B 2 O 3 > 27.30 26.78 27.12 26.08 25.75 <![CDATA[Al 2 O 3 > 10.72 13.65 12.24 12.26 13.67 <![CDATA[P 2 O 5 > - - - - - MgO 3.43 3.06 3.41 3.42 3.07 CaO 0.24 0.74 0.24 0.24 0.74 SrO - - - - - BaO - - - - - ZnO - - - - - MgO + CaO 3.67 3.80 3.65 3.66 3.81 MgO / (MgO + CaO) 0.93 0.81 0.93 0.93 0.81 MgO + CaO + ZnO 3.67 3.80 3.65 3.66 3.81 <![CDATA[Li 2 O]]> 0.70 0.18 0.70 0.70 0.18 <![CDATA[Sodium 2 O]]> 0.10 0.10 0.10 0.10 0.10 <![CDATA[K 2 O]]> - - - - - <![CDATA[Li 2 O + Na 2 O + K 2 O]]> 0.80 0.28 0.80 0.80 0.28 <![CDATA[TiO 2 > - - - - - <![CDATA[ZrO 2 > - - - - - <![CDATA[Fe 2 O 3 > - - - - - <![CDATA[F 2 > - - - - - Devitrification temperature [°C] 1107 1325 1207 1203 1324 Operating temperature [°C] 1405 1380 1380 1396 1395 ΔT [°C] 298 55 173 193 71 Alkali dissolution amount [mg] 0.23 0.15 0.16 0.13 0.11 Dielectric constant 4.3 4.3 4.4 4.4 4.3

[0176]

Table 2

[0177] Composition (mass %) or physical property Example 6 Example 7 Example 8 Example 9 Example 10 <![CDATA[SiO 2 > 61.31 56.56 56.64 59.90 57.01 <![CDATA[B 2 O 3 > 21.86 23.64 27.96 26.44 26.03 <![CDATA[Al 2 O 3 > 12.33 15.27 12.13 9.20 12.23 <![CDATA[P 2 O 5 > - - - - 0.22 MgO 1.69 3.07 2.99 3.46 3.10 CaO 1.26 0.67 - 0.24 0.67 SrO - - - - - BaO - - - - - ZnO - - - - - MgO + CaO 2.95 3.74 2.99 3.70 3.77 MgO / (MgO + CaO) 0.57 0.82 1.00 0.94 0.82 MgO + CaO + ZnO 2.95 3.74 2.99 3.70 3.77 <![CDATA[Li 2 O]]> 1.45 0.69 0.18 0.76 0.74 <![CDATA[Sodium 2 O]]> 0.10 0.10 0.10 - - <![CDATA[K 2 O]]> - - - - - <![CDATA[Li 2 O + Na 2 O + K 2 O]]> 1.55 0.79 0.28 0.76 0.74 <![CDATA[TiO 2 > - - - - - <![CDATA[ZrO 2 > - - - - - <![CDATA[Fe 2 O 3 > - - - - - <![CDATA[F 2 > - - - - - Devitrification temperature [°C] 1111 1321 1258 1033 1179 Operating temperature [°C] 1409 1380 1413 1441 1396 ΔT [°C] 298 59 155 408 217 Alkali dissolution amount [mg] 0.28 0.03 0.33 0.26 0.18 Dielectric constant 4.5 4.5 4.1 4.2 4.4

[0178]

Table 3

[0179] Composition (mass %) or physical property Example 11 Example 12 Example 13 Example 14 Example 15 <![CDATA[SiO 2 > 55.63 55.46 55.12 56.37 56.92 <![CDATA[B 2 O 3 > 27.38 28.07 27.90 26.13 27.03 <![CDATA[Al 2 O 3 > 12.90 12.18 12.89 12.28 12.20 <![CDATA[P 2 O 5 > - - - - - MgO 3.07 3.76 3.07 4.89 2.67 CaO 0.74 0.24 0.74 0.04 0.38 SrO - - - - - BaO - - - - - ZnO - - - - - MgO + CaO 3.81 4.00 3.81 4.93 3.05 MgO / (MgO + CaO) 0.81 0.94 0.81 0.99 0.88 MgO + CaO + ZnO 3.81 4.00 3.81 4.93 3.05 <![CDATA[Li 2 O]]> 0.18 0.19 0.18 0.19 0.70 <![CDATA[Sodium 2 O]]> 0.10 0.10 0.10 0.10 0.10 <![CDATA[K 2 O]]> - - - - - <![CDATA[Li 2 O + Na 2 O + K 2 O]]> 0.28 0.29 0.28 0.29 0.80 <![CDATA[TiO 2 > - - - - - <![CDATA[ZrO 2 > - - - - - <![CDATA[Fe 2 O 3 > - - - - - <![CDATA[F 2 > - - - - - Devitrification temperature [°C] 1287 1244 1282 1318 1179 Operating temperature [°C] 1387 1382 1379 1380 1382 ΔT [°C] 100 138 97 62 203 Alkali dissolution amount [mg] 0.24 0.24 0.26 0.08 0.27 Dielectric constant 4.3 4.2 4.3 4.3 4.3

[0180]

Table 4

[0181] Composition (mass %) or physical property Example 16 Example 17 Example 18 Example 19 Example 20 <![CDATA[SiO 2 > 55.29 55.62 55.12 56.03 54.12 <![CDATA[B 2 O 3 > 27.75 27.16 27.67 26.39 27.40 <![CDATA[Al 2 O 3 > 12.04 12.79 12.78 11.91 12.66 <![CDATA[P 2 O 5 > - - - - - MgO 2.74 2.50 2.50 1.80 2.10 CaO 0.31 0.38 0.38 0.73 0.31 SrO 1.59 1.27 1.27 3.14 3.14 BaO - - - - - ZnO - - - - - MgO + CaO 3.05 2.88 2.88 2.53 2.41 MgO / (MgO + CaO) 0.90 0.87 0.87 0.71 0.87 MgO + CaO + ZnO 3.05 2.88 2.88 2.53 2.41 <![CDATA[Li 2 O]]> 0.18 0.18 0.18 - 0.18 <![CDATA[Sodium 2 O]]> 0.10 0.09 0.09 - 0.09 <![CDATA[K 2 O]]> - - - - - <![CDATA[Li 2 O+Na 2 O+K 2 O]]> 0.28 0.27 0.27 - 0.27 <![CDATA[TiO 2 > - - - - - <![CDATA[ZrO 2 > - - - - - <![CDATA[Fe 2 O 3 > - - - - - <![CDATA[F 2 > - - - - - Devitrification temperature [°C] 1250 1329 1332 1264 1249 Operating temperature [°C] 1392 1397 1390 1418 1379 ΔT [°C] 142 68 58 154 130 Alkali dissolution amount [mg] 0.32 0.24 0.29 0.18 0.28 Dielectric constant 4.3 4.3 4.3 4.3 4.4

[0182]

Table 5

[0183] Composition (mass %) or physical property Example 21 Example 22 Example 23 Example 24 Example 25 <![CDATA[SiO 2 > 57.23 56.20 56.43 56.88 56.03 <![CDATA[B 2 O 3 > 27.17 25.62 25.72 27.00 27.05 <![CDATA[Al 2 O 3 > 10.67 13.60 13.66 12.18 12.20 <![CDATA[P 2 O 5 > - - - - - MgO 3.10 2.74 3.34 2.66 4.19 CaO 0.24 0.31 0.09 0.38 0.53 SrO - - - - - BaO - - - - - ZnO 0.64 1.25 - - - MgO + CaO 3.34 3.05 3.43 3.04 4.72 MgO / (MgO + CaO) 0.93 0.90 0.97 0.88 0.89 MgO + CaO + ZnO 3.98 4.30 3.43 3.04 4.72 <![CDATA[Li 2 O]]> 0.56 0.18 - 0.65 - <![CDATA[Sodium 2 O]]> 0.39 0.10 0.76 0.10 - <![CDATA[K 2 O]]> - - - 0.15 - <![CDATA[Li 2 O + Na 2 O + K 2 O]]> 0.95 0.28 0.76 0.90 - <![CDATA[TiO 2 > - - - - - <![CDATA[ZrO 2 > - - - - - <![CDATA[Fe 2 O 3 > - - - - - <![CDATA[F 2 > - - - - - Devitrification temperature [°C] 1092 1311 1348 1184 1298 Operating temperature [°C] 1403 1384 1395 1400 1387 ΔT [°C] 311 73 47 216 89 Alkali dissolution amount [mg] 0.25 0.11 0.13 0.22 0.10 Dielectric constant 4.3 4.3 4.4 4.3 4.2

[0184]

Table 6

[0185] Composition (mass %) or physical property Example 26 Example 27 Example 28 Example 29 Example 30 <![CDATA[SiO 2 > 55.32 55.39 55.04 56.19 55.76 <![CDATA[B 2 O 3 > 27.46 28.04 27.86 26.90 27.99 <![CDATA[Al 2 O 3 > 12.94 12.16 12.87 12.93 12.14 <![CDATA[P 2 O 5 > - - - - - MgO 4.12 3.81 3.12 3.39 3.08 CaO 0.16 0.60 1.11 0.31 0.75 SrO - - - - - BaO - - - - - ZnO - - - - - MgO + CaO 4.28 4.41 4.23 3.70 3.83 MgO / (MgO + CaO) 0.96 0.86 0.74 0.92 0.80 MgO + CaO + ZnO 4.28 4.41 4.23 3.70 3.83 <![CDATA[Li 2 O]]> - - - 0.18 0.18 <![CDATA[Sodium 2 O]]> - - - 0.10 0.10 <![CDATA[K 2 O]]> - - - - - <![CDATA[Li 2 O + Na 2 O + K 2 O]]> - - - - - <![CDATA[TiO 2 > - - - - - <![CDATA[ZrO 2 > - - - - - <![CDATA[Fe 2 O 3 > - - - - - <![CDATA[F 2 > - - - - - Devitrification temperature [°C] 1339 1283 1290 1315 1264 Operating temperature [°C] 1378 1383 1380 1394 1392 ΔT [°C] 39 100 90 79 128 Alkali dissolution amount [mg] 0.10 0.16 0.17 0.16 0.31 Dielectric constant 4.2 4.2 4.2 4.3 4.2

[0186]

Table 7

[0187] Composition (mass %) or physical property Example 31 Example 32 Example 33 Example 34 Example 35 <![CDATA[SiO 2 > 55.90 57.08 55.49 55.23 55.54 <![CDATA[B 2 O 3 > 28.06 27.64 27.85 27.97 27.88 <![CDATA[Al 2 O 3 > 12.18 11.43 12.87 12.92 12.88 <![CDATA[P 2 O 5 > - - - - - MgO 3.02 2.67 2.70 3.36 2.68 CaO 0.23 0.38 0.81 0.10 0.60 SrO - - - - - BaO - - - - - ZnO - - - - - MgO + CaO 3.25 3.05 3.51 3.46 3.28 MgO / (MgO + CaO) 0.93 0.88 0.77 0.97 0.82 MgO + CaO + ZnO 3.25 3.05 3.51 3.46 3.28 <![CDATA[Li 2 O]]> 0.51 0.70 0.18 0.32 0.32 <![CDATA[Na 2 O]]> 0.10 0.10 0.10 0.10 0.10 <![CDATA[K 2 O]]> - - - - - <![CDATA[Li 2 O + Na 2 O + K 2 O]]> - - - - - <![CDATA[TiO 2 > - - - - - <![CDATA[ZrO 2 > - - - - - <![CDATA[Fe 2 O 3 > - - - - - <![CDATA[F 2 > - - - - - Devitrification temperature [°C] 1258 1208 1335 1309 1341 Operating temperature [°C] 1389 1402 1390 1379 1389 ΔT [°C] 131 194 55 70 48 Alkali dissolution amount [mg] 0.18 0.31 0.29 0.09 0.11 Dielectric constant 4.3 4.3 4.2 4.3 4.3

[0188]

Table 8

[0189] Composition (mass %) or physical property Example 36 Example 37 Example 38 Example 39 Example 40 <![CDATA[SiO 2 > 56.34 56.65 56.44 56.23 56.55 <![CDATA[B 2 O 3 > 25.76 26.04 26.88 25.83 25.77 <![CDATA[Al 2 O 3 > 13.68 12.24 12.13 12.14 13.69 <![CDATA[P 2 O 5 > - - - - - MgO 3.38 3.41 3.08 2.76 3.38 CaO 0.31 0.24 0.31 0.23 0.31 SrO - - - - - BaO - - - - - ZnO - - 0.63 1.26 - MgO + CaO 3.69 3.65 3.39 2.99 3.69 MgO / (MgO + CaO) 0.92 0.93 0.91 0.92 0.92 MgO + CaO + ZnO 3.69 3.65 4.02 4.25 3.69 <![CDATA[Li 2 O]]> 0.18 0.70 0.18 0.55 0.18 <![CDATA[Sodium 2 O]]> 0.10 0.10 0.10 0.38 0.10 <![CDATA[K 2 O]]> - - - - - <![CDATA[Li 2 O + Na 2 O + K 2 O]]> 0.28 0.80 0.28 0.93 0.28 <![CDATA[TiO 2 > 0.25 0.62 0.25 0.62 - <![CDATA[ZrO 2 > - - - - - <![CDATA[Fe 2 O 3 > - - - - 0.02 <![CDATA[F 2 > - - - - - Devitrification temperature [°C] 1340 1200 1251 1165 1342 Operating temperature [°C] 1393 1390 1399 1382 1401 ΔT [°C] 53 190 148 217 59 Alkali dissolution amount [mg] 0.09 0.11 0.21 0.15 0.10 Dielectric constant 4.3 4.4 4.3 4.4 4.3

[0190]

Table 9

[0191] Composition (mass %) or physical property Example 41 Example 42 Example 43 Example 44 Example 45 <![CDATA[SiO 2 > 56.13 57.74 56.54 55.63 56.92 <![CDATA[B 2 O 3 > 27.10 26.97 27.93 27.92 27.02 <![CDATA[Al 2 O 3 > 12.23 12.17 12.12 12.90 12.19 <![CDATA[P 2 O 5 > - - - - - MgO 3.73 2.13 2.32 2.64 3.02 CaO 0.10 0.08 0.67 0.30 0.24 SrO - - - - - BaO - - - - - ZnO - - - - - MgO + CaO 3.83 2.21 2.99 2.94 3.26 MgO / (MgO + CaO) 0.97 0.96 0.78 0.90 0.93 MgO + CaO + ZnO 3.83 2.21 2.99 2.94 3.26 <![CDATA[Li 2 O]]> 0.51 0.69 0.32 0.51 0.51 <![CDATA[Sodium 2 O]]> 0.10 0.10 0.10 0.10 0.10 <![CDATA[K 2 O]]> - - - - - <![CDATA[Li 2 O+Na 2 O+K 2 O]]> 0.61 0.79 0.42 0.61 0.61 <![CDATA[TiO 2 > - - - - - <![CDATA[ZrO 2 > - - - - - <![CDATA[Fe 2 O 3 > 0.10 - - - - <![CDATA[F 2 > - 0.12 - - - Devitrification temperature [°C] 1203 1168 1341 1333 1255 Operating temperature [°C] 1386 1412 1410 1386 1404 ΔT [°C] 183 244 69 53 149 Alkali dissolution amount [mg] 0.12 0.26 0.18 0.15 0.13 Dielectric constant 4.3 4.2 4.2 4.3 4.3

[0192]

Table 10

[0193] Composition (mass %) or physical property Example 46 Example 47 Example 48 Example 49 Example 50 <![CDATA[SiO 2 > 55.68 55.62 55.16 55.54 54.90 <![CDATA[B 2 O 3 > 27.42 26.85 28.17 27.26 26.95 <![CDATA[Al 2 O 3 > 12.92 13.69 12.22 12.68 13.74 <![CDATA[P 2 O 5 > - - - - - MgO 2.70 3.00 3.41 3.38 3.39 CaO 0.67 0.23 0.24 0.24 0.23 SrO - - - - - BaO - - - - - ZnO - - - - - MgO + CaO 3.37 3.23 3.65 3.62 3.62 MgO / (MgO + CaO) 0.80 0.93 0.93 0.93 0.94 MgO + CaO + ZnO 3.37 3.23 3.65 3.62 3.62 <![CDATA[Li 2 O]]> 0.51 0.51 0.70 0.70 0.69 <![CDATA[Sodium 2 O]]> 0.10 0.10 0.10 0.10 0.10 <![CDATA[K 2 O]]> - - - - - <![CDATA[Li 2 O + Na 2 O + K 2 O]]> 0.61 0.61 0.80 0.80 0.79 <![CDATA[TiO 2 > - - - - - <![CDATA[ZrO 2 > - - - - - <![CDATA[Fe 2 O 3 > - - - 0.10 - <![CDATA[F 2 > - - - - - Devitrification temperature [°C] 1294 1339 1194 1202 1271 Operating temperature [°C] 1383 1381 1365 1340 1361 ΔT [°C] 89 42 171 138 90 Alkali dissolution amount [mg] 0.13 0.08 0.21 0.15 0.10 Dielectric constant 4.3 4.3 4.4 4.4 4.4

[0194]

Table 11

[0195] Composition (mass %) or physical property Example 51 Example 52 Example 53 <![CDATA[SiO 2 > 56.65 56.77 57.05 <![CDATA[B 2 O 3 > 26.90 26.95 26.01 <![CDATA[Al 2 O 3 > 12.14 12.16 12.22 <![CDATA[P 2 O 5 > - - - MgO 2.59 3.33 3.34 CaO 0.64 0.31 0.24 SrO - - - BaO 0.47 - - ZnO - - - MgO + CaO 3.23 3.64 3.58 MgO / (MgO + CaO) 0.80 0.91 0.93 MgO + CaO + ZnO 3.23 3.64 3.58 <![CDATA[Li 2 O]]> 0.51 0.19 0.56 <![CDATA[Sodium 2 O]]> 0.10 0.10 0.39 <![CDATA[K 2 O]]> - - - <![CDATA[Li 2 O+Na 2 O+K 2 O]]> 0.61 0.29 0.95 <![CDATA[TiO 2 > - - - <![CDATA[ZrO 2 > - 0.19 0.19 <![CDATA[Fe 2 O 3 > - - - <![CDATA[F 2 > - - - Devitrification temperature [°C] 1236 1276 1204 Operating temperature [°C] 1400 1407 1398 ΔT [°C] 164 131 194 Alkali dissolution amount [mg] 0.15 0.19 0.13 Dielectric constant 4.3 4.2 4.4

[0196]

Table 12

[0197] Composition (mass %) or physical property Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 Comparative Example 6 <![CDATA[SiO 2 > 54.83 74.20 49.25 61.74 56.12 56.42 <![CDATA[B 2 O 3 > 5.95 22.00 35.52 26.81 28.18 25.72 <![CDATA[Al 2 O 3 > 14.52 0.30 10.56 10.52 10.64 12.09 <![CDATA[P 2 O 5 > - - - - - - MgO 0.38 - 3.07 - 1.84 1.50 CaO 22.80 0.50 0.67 - 2.42 0.08 SrO - - - - - - BaO - - - - - - ZnO - - - - - - MgO + CaO 23.18 0.50 3.74 - 4.26 1.58 MgO / (MgO + CaO) 0.02 - 0.82 - 0.43 0.95 MgO + CaO + ZnO 23.18 0.50 3.74 - 4.26 1.58 <![CDATA[Li 2 O]]> - 0.50 0.55 0.55 0.70 0.37 <![CDATA[Na 2 O]]> 0.49 1.00 0.38 0.38 0.10 3.82 <![CDATA[K 2 O]]> 0.30 1.50 - - - - <![CDATA[Li 2 O + Na 2 O + K 2 O]]> 0.79 3.00 0.93 0.93 0.80 4.19 <![CDATA[TiO 2 > - - - - - - <![CDATA[ZrO 2 > - - - - - - <![CDATA[Fe 2 O 3 > 0.25 - - - - - <![CDATA[F 2 > 0.48 - - - - - Devitrification temperature [°C] 1090 - 1078 - 1018 1133 Operating temperature [°C] 1205 - 1274 - 1372 1381 ΔT [°C] 115 - 196 - 354 248 Alkali dissolution amount [mg] 0.12 0.45 ＞1.0 ＞1.0 0.47 ＞1.0 Dielectric constant ＞6.0 4.1 - - 4.4 -

[0198] For Examples 1 to 53, the operating temperature was 1340 to 1441 °C, the temperature difference ΔT (= operating temperature - devitrification temperature) was 39 to 408 °C, the alkali dissolution amount was 0.03 to 0.33 mg, and the dielectric constant at a frequency of 1 GHz was 4.1 to 4.5.

[0199] In contrast, Comparative Example 1 having a glass composition equivalent to that of conventional E glass showed a high dielectric constant exceeding 6.0.

[0200] Comparative Example 2 having a glass composition equivalent to that of conventional D glass showed a high alkali dissolution amount as compared with Examples 1 to 53.

[0201] In Comparative Example 3, the content of SiO 2 and B 2 O 3 was outside the range defined in the present invention. Comparative Example 3 showed a high alkali dissolution amount exceeding 1.0 mg.

[0202] Comparative Example 4 did not contain MgO and CaO and showed a high alkali dissolution amount exceeding 1.0 mg.

[0203] In Comparative Example 5, MgO / (MgO + CaO) is outside the range defined in the present invention. Comparative Example 5 shows a high alkali dissolution amount compared with Examples 1 to 53.

[0204] In Comparative Example 6, Li 2 O + Na 2 O + K 2 O is outside the range defined in the present invention. Comparative Example 6 shows a high alkali dissolution amount exceeding 1.0 mg.

[0205] (Examples 54 to 106)

[0206] Using each of the glass compositions prepared in Examples 1 to 53, flaky glass was produced. Specifically, each glass composition was remelted in an electric furnace and formed into particles while cooling. The obtained particles were put into a melting furnace to produce flaky glass with an average thickness of 1 to 2 μm and an average particle diameter of 100 to 500 μm.

[0207] (Examples 107 to 159)

[0208] Using each of the glass compositions prepared in Examples 1 to 53, chopped strands that can be used as glass fillers were produced. Specifically, each glass composition was remelted in an electric furnace and formed into particles while cooling. The obtained particles were put into Figure 4 and Figure 5 the manufacturing apparatus shown, and chopped strands with an average fiber diameter of 10 to 20 μm and a length of 3 mm were produced.

[0209] (Examples 160 to 212)

[0210] Using the chopped strands prepared in Examples 107 to 159, ground fibers were produced. Specifically, the chopped strands with an average fiber diameter of 10 to 20 μm and a length of 3 mm were pulverized with an alumina ball mill to produce ground fibers with an average fiber diameter of 10 to 20 μm and an average length of 50 to 100 μm.

[0211] (Examples 213 to 265)

[0212] Using each of the glass compositions prepared in Examples 1 to 53, thin flakes were produced. Specifically, each glass composition was remelted in an electric furnace and formed into particles while cooling. The obtained particles were put into a melting furnace to produce thin flakes with an average thickness of 0.5 to 1 μm and an average particle diameter of 100 to 300 °C m.

[0213] Industrial Applicability

[0214] The glass composition of the present invention can be used, for example, for manufacturing glass fillers. The glass fillers of the present invention can be used for the same uses as conventional glass fillers.

Claims

1. A glass composition, comprising, in mass %: 50 ≤ SiO 2 ≤ 65、 20 ≤ B 2 O 3 ≤ 30、 10.67 ≤ Al 2 O 3 ≤ 12.68、 0 ≤ T - Fe 2 O 3 ≤ 1.5, Further comprising: At least one selected from MgO and CaO, and Selected from Li 2 O, Na 2 O and K 2 O, at least one of The glass composition substantially does not contain TiO 2 , And the following formula holds: 0.1 ≤ (MgO + CaO) ≤ 4 0 ≤ (Li 2 O + Na 2 O + K 2 O) ≤ 4, and 0.80 ≤ MgO / (MgO + CaO) ≤ 1.00, Wherein, T-Fe 2 O 3 is the converted Fe 2 O 3 total iron oxide.

2. The glass composition according to claim 1, Wherein, The glass composition comprises, in mass %: 55 ≤ SiO 2 ≤ 65, 20 ≤ B 2 O 3 ≤ 30, 10.67 ≤ Al 2 O 3 ≤ 12.68、 0 ≤ T - Fe 2 O 3 ≤ 1.5, The glass composition substantially does not contain TiO 2 , And the following formula holds: 0.1 ≤ (MgO + CaO) ≤ 4 0 ≤ (Li 2 O + Na 2 O + K 2 O) ≤ 4, and 0.80 ≤ MgO / (MgO + CaO) ≤ 1.

00.

3. The glass composition according to claim 1, Wherein, The glass composition comprises, in mass %: 50 ≤ SiO 2 ≤ 65, 20 ≤ B 2 O 3 ≤ 30、 10.67 ≤ Al 2 O 3 ≤ 12.68, 0 ≤ F 2 ≤ 0.5, 0 ≤ T - Fe 2 O 3 ≤ 1.5, The glass composition substantially does not contain TiO 2 , And the following formula holds: 0.1 ≤ (MgO + CaO) ≤ 4 0.1 ≤ (Li 2 O + Na 2 O + K 2 O) ≤ 4, and 0.80 ≤ MgO / (MgO + CaO) ≤ 1.

00.

4. The glass composition according to claim 1, Wherein, The glass composition comprises, in mass %: 50 ≤ SiO 2 ≤ 65, 20 ≤ B 2 O 3 ≤ 30, 10.67≤Al 2 O 3 ≤12.68、 0 ≤ T - Fe 2 O 3 ≤ 1.5, The glass composition substantially does not contain TiO 2 , And the following formula holds: 0.1 ≤ (MgO + CaO) ≤ 4 0.6 ≤ (Li 2 O + Na 2 O + K 2 O) ≤ 4, and 0.80 ≤ MgO / (MgO + CaO) ≤ 1.

00.

5. The glass composition according to claim 1, Wherein, The glass composition contains 0.1 ≤ Li 2 O ≤ 4 in terms of mass%.

6. The glass composition according to claim 1, Wherein, The glass composition further contains 0 ≤ P 2 O 5 ≤ 5 in terms of mass%.

7. The glass composition according to claim 1, Wherein, The glass composition substantially does not contain F 2 .

8. The glass composition according to claim 1, Wherein, The glass composition further comprises 0 ≤ ZnO ≤ 5 in mass %.

9. The glass composition according to claim 1, Wherein, The glass composition further comprises 0 ≤ BaO ≤ 5 in mass %.

10. The glass composition according to claim 1, Wherein, The glass composition further comprises 0 ≤ SrO ≤ 5 in mass %.

11. The glass composition according to claim 1, Wherein, The glass composition further contains 0 ≤ ZrO 2 ≤ 5 in terms of mass%.

12. The glass composition according to claim 1, Wherein, The dielectric constant of the glass composition at a frequency of 1 GHz is 4.4 or less.

13. The glass composition according to claim 1, Wherein, The operating temperature of the glass composition is 1413 °C or less, Wherein the operating temperature is the temperature at which the viscosity of the glass composition becomes 1000 dPa·sec.

14. The glass composition according to claim 1, Wherein, For the glass composition, the temperature difference ΔT between the operating temperature and the devitrification temperature is 125 °C or more, Wherein the operating temperature is the temperature at which the viscosity of the glass composition becomes 1000 dPa·sec.

15. The glass composition according to claim 1, Wherein, The alkali dissolution amount of the glass composition measured according to the alkali dissolution test specified in JIS R3502:1995 is 0.001 mg to 0.40 mg.

16. A glass filler, comprising the glass composition according to any one of claims 1 to 15.

17. The glass filler according to claim 16, which is at least one selected from flaky glass, chopped rovings, milled fibers, glass powder, glass beads, and flat fibers.

18. The glass filler according to claim 17, which is flaky glass.

19. The glass filler according to claim 17, which is chopped strand.

20. The glass filler according to claim 17, which is milled fiber.

21. The glass filler according to claim 16, which is a thin flake.

22. A resin composition comprising the glass filler according to claim 16 and a thermoplastic resin.

23. A method for manufacturing a glass filler, which comprises: a step of melting the glass composition according to any one of claims 1 to 15; and a step of forming the molten glass composition into a glass filler.

Images