WO2022239747A1

WO2022239747A1 - Glass fiber, and method for producing same

Info

Publication number: WO2022239747A1
Application number: PCT/JP2022/019716
Authority: WO
Inventors: 美樹木村
Original assignee: 日本電気硝子株式会社
Priority date: 2021-05-13
Filing date: 2022-05-09
Publication date: 2022-11-17
Also published as: JPWO2022239747A1; TW202311192A

Abstract

Provided are: a glass fiber with which both a low spinning temperature, and a low dielectric constant and dielectric loss tangent are achieved; and a method for producing same. A glass fiber according to the present invention is characterized by containing 22.5-45 mass% of SiO2, 0.1-30 mass% of Al2O3, 0-45 mass% of B2O3, 0-60 mass% of P2O5, 0.001-3 mass% of Fe2O3, and 0-9 mass% of Li2O+Na2O+K2O+MgO+CaO+BaO+SrO.

Description

Glass fiber and its manufacturing method

The present invention relates to a glass fiber that is suitable as a reinforcing material for resin members that require low dielectric constant and low dielectric loss tangent characteristics, such as components for high-speed communication equipment and automotive radar, and a manufacturing method thereof.

Along with the development of various electronic devices that support the information industry, technologies related to mobile phones, personal digital assistants, etc. are making remarkable progress. Circuit parts for electronic devices, which are becoming more dense and have higher processing speeds, are designed to minimize signal propagation delay due to dielectric loss (movement loss, conduction loss, deformation loss and vibration loss) and to reduce heat generation in the substrate due to heat loss. To prevent this, low dielectric constant and low dielectric loss tangent properties are required. Examples of these circuit boards for electronic devices include printed wiring boards and low-temperature firing boards. _A _printed wiring board is a sheet _- shaped composite material made by mixing glass fiber as a reinforcing material with a resin. A green sheet of composite powder mixed with is fired.

In addition to the above, along with the miniaturization of electronic devices and the speeding up of communication, in recent years, there has been an increasing demand for low dielectric properties of resin materials used for resin around circuit boards, components for communication devices, and housings of electronic devices. The glass fiber used as the reinforcing material is also required to have a low dielectric constant and a low dielectric loss tangent. Furthermore, in the automotive industry, the demand for high-strength, lightweight, low-dielectric constant, low-dielectric loss tangent glass fiber reinforced resins is expected to increase as components used in automotive radars and cameras as autonomous driving systems develop. there is

Japanese Patent Laid-Open No. 63-2831

As glass fibers for printed wiring boards and resin reinforcement, E glass (for example, dielectric constant ε at room temperature of 2.45 MHz frequency is 6.9 and dielectric loss tangent tan δ is 46×10 ⁻⁴ ) is generally known. However, there is a problem that E-glass does not meet the requirements for a low dielectric constant and a low dielectric loss tangent. Therefore, Patent Document 1 discloses a glass called D-glass characterized by a dielectric constant and a dielectric loss tangent lower than those of E-glass. D-glass has a dielectric constant ε of 4.2 at room temperature and a frequency of 2.45 GHz, and a dielectric loss tangent tan δ of 15×10 ⁻⁴ , for example.

However, D glass has the problem of high spinning temperature and low productivity. Moreover, when a composite material in which D glass and resin are mixed is exposed to a high-temperature and high-humidity environment, there is a problem that the strength of the composite material tends to decrease.

In view of the above situation, the object of the present invention is to provide a glass fiber that achieves both a low spinning temperature, a low dielectric constant and a low dielectric loss tangent, and a method for producing the same.

The glass fiber of the present invention contains, in mass %, SiO ₂ 22.5-45%, Al ₂ O ₃ 0.1-30%, B ₂ O ₃ 0-45%, P ₂ O ₅ 0-60%, Fe ₂ O ₃ 0.001-3% and Li ₂ O+Na ₂ O+K ₂ O+MgO+CaO+BaO+SrO 0-9%. By doing so, a glass fiber having a low dielectric constant and a low dielectric loss tangent and a low spinning temperature can be obtained. Also, the strength of the composite material can be improved. Here, "Li2O ₊ _Na2O ₊ K2O+MgO+CaO+BaO+SrO" is the _total amount of Li2O, _Na2O , _K2O , MgO, CaO, BaO and SrO.

In the glass fiber of the present invention, the average value ΔΧ of the difference in electronegativity between oxygen and elements other than oxygen, which are constituent components of the glass, is preferably 1.4 to 1.8. In the present invention, ΔX is defined by the following formula.

ΔX=Σ{(number of moles of oxide element Z other than oxygen)×(difference in electronegativity between oxygen and oxide element Z other than oxygen)}/(number of moles of oxide element Z other than oxygen) total)

The difference in electronegativity between oxygen and the oxide element Z other than oxygen can be calculated using the value of Pauling's electronegativity. Table 1 shows the representative value of Pauling's electronegativity of each element and the difference in electronegativity ΔΧ between oxygen and each element.

The glass fiber of the present invention preferably has a dielectric constant of 6 or less at 25° C. and 2.45 GHz and a dielectric loss tangent of 45×10 ⁻⁴ or less. Thereby, transmission loss can be reduced.

The glass fiber of the present invention preferably has a dielectric constant of 6 or less at 25° C. and 28 GHz and a dielectric loss tangent of 45×10 ⁻⁴ or less.

The glass fiber of the present invention preferably has a dielectric constant of 6 or less at 25° C. and 40 GHz and a dielectric loss tangent of 50×10 ⁻⁴ or less.

The glass fiber of the present invention preferably has a spinning temperature of 1450° C. or lower. In the present invention, the "spinning temperature" means the temperature at which the viscosity of the glass becomes 10 ^3.0 dPa·s.

The glass fiber of the present invention preferably has a Young's modulus of 40 GPa or more. Thereby, the strength of the composite material produced by kneading with the resin can be improved.

In the glass fiber of the present invention, the molar ratio B ₂ O ₃ /P ₂ O ₅ of the content of B ₂ O ₃ to P ₂ O ₅ is preferably 0-50.

In the glass fiber of the present invention, it is preferable that the molar ratio B ₂ O ₃ /Al ₂ O ₃ of the content of B ₂ O ₃ to Al ₂ O ₃ is 0-20.

In the method for producing the glass fiber of the present invention, the glass composition is 22.5 to 45% by mass of SiO ₂ , 0.1 to 30% by mass of Al ₂ O ₃ , 0 to 45% by mass of B ₂ O ₃ , and P ₂ O. 50-60%, Fe ₂ O ₃ _0.001-3 % and Li ₂ O+Na ₂ O+K ₂ O+MgO+CaO+BaO+SrO 0-9%, comprising: It is characterized by molding into fibrous form.

The glass of the present invention has, as a glass composition, SiO ₂ 22.5 to 45%, Al ₂ O ₃ 0.1 to 30%, B ₂ O ₃ 0 to 45%, and P ₂ O ₅ 0 to 60% by mass. %, Fe ₂ O ₃ 0.001-3%, and Li ₂ O+Na ₂ O+K ₂ O+MgO+CaO+BaO+SrO 0-9%.

The glass fiber of the present invention contains, in mass %, SiO 24-45%, Al ₂ O ₃ 0.1-30%, B ₂ O ₃ 0-45%, P ₂ O ₅ _{5-60%, Fe 2} _O ₃ 0.001-3% and Li ₂ O+Na ₂ O+K ₂ O 0-3%. By doing so, a glass fiber having a low dielectric constant and a low dielectric loss tangent and a low spinning temperature can be obtained. Also, the strength of the composite material can be improved. Here, "Li2O ₊ _Na2O ₊ K2O" is the _total amount of Li2O, _Na2O and _K2O .

According to the present invention, it is possible to provide a glass fiber that achieves both a low spinning temperature, a low dielectric constant and a low dielectric loss tangent, and a method for producing the same.

4 is a graph showing the relationship between the molar ratio B ₂ O ₃ /P ₂ O ₅ and the dielectric loss tangent tan δ at 25° C. and 2.45 GHz. 4 is a graph showing the relationship between the molar ratio B ₂ O ₃ /Al ₂ O ₃ and the dielectric loss tangent tan δ at 25° C. and 2.45 GHz.

The glass fiber of the first aspect of the present invention contains, in mass %, SiO ₂ 22.5-45%, Al ₂ O ₃ 0.1-30%, B ₂ O ₃ 0-45%, P ₂ O ₅ 0 ~60%, Fe ₂ O ₃ 0.001-3% and Li ₂ O + Na ₂ O + K ₂ O + MgO + CaO + BaO + SrO 0-9%. The glass fiber of the second aspect of the present invention contains, in mass %, SiO ₂ 24-45%, Al ₂ O ₃ 0.1-30%, B ₂ O ₃ 0-45%, P ₂ O ₅ 5-60 %, Fe ₂ O ₃ 0.001-3% and Li ₂ O+Na ₂ O+K ₂ O 0-3%. The reasons for limiting the glass composition as described above will be described in detail below. In addition, in the present invention, unless otherwise specified, "%" refers to % by mass.
In this specification, the numerical range indicated using "to" means a range including the numerical values before and after "to" as the minimum and maximum values, respectively.

SiO ₂ is a component that forms the skeleton of the network structure in the glass structure, and is also a component that lowers the dielectric constant and dielectric loss tangent. If the content of SiO ₂ is too small, it is difficult to obtain the above effects. On the other hand, if the content of SiO ₂ is too high, the spinning temperature will increase and the productivity will decrease. Therefore, the preferable lower limit range of _SiO2 in the glass fiber and glass of the first aspect of the present invention is 22.5% or more, 23% or more, 24% or more, 25% or more, 27% or more, 28% or more , 29% or more, particularly 30% or more, and the preferred upper limit range is 45% or less, less than 45%, 43% or less, 42% or less, 41% or less, particularly 40% or less. In the glass fiber and glass of the second aspect of the present invention, the preferred lower range of _SiO2 is 24% or more, 25% or more, 27% or more, 28% or more, 29% or more, especially 30% or more, A preferred upper limit range is 45% or less, less than 45%, 43% or less, 42% or less, 41% or less, particularly 40% or less.

Al ₂ O ₃ is a component that forms the skeleton of the glass and suppresses the phase separation of the glass to stabilize it. If the content of Al ₂ O ₃ is too small, it is difficult to obtain the above effects. On the other hand, if the Al ₂ O ₃ content is too high, the dielectric constant and dielectric loss tangent tend to increase. Therefore, the preferable lower limit range of Al ₂ O ₃ is 0.1% or more, 0.5% or more, 3% or more, 5% or more, 6% or more, 8% or more, 9% or more, particularly 10% or more. Yes, the preferred upper limit range is 30% or less, 29% or less, 28% or less, 27% or less, 26% or less, 25% or less, 24% or less, 23% or less, 20% or less, 17% or less, 16% or less , 15% or less, 13% or less, in particular 12% or less.

B ₂ O ₃ , like SiO ₂ , is a component that forms a skeleton of glass, and is a component that significantly lowers the dielectric constant and dielectric loss tangent. If the content of B ₂ O ₃ is too large, the glass tends to undergo phase separation, which may reduce productivity. Therefore, the preferable lower limit range of B ₂ O ₃ is 0% or more, 0.1% or more, 0.5% or more, 1% or more, 2% or more, 3% or more, 5% or more, 6% or more, 7% or more. % or more, particularly 8% or more. 20% or less, 15% or less, 13% or less, particularly 11% or less.

P ₂ O ₅ is a component that forms a skeleton of glass like SiO ₂ and B ₂ O ₃ and is a component that lowers the dielectric constant and dielectric loss tangent. If the content of P ₂ O ₅ is too small, it will be difficult to obtain the above effects. On the other hand, if the content of P ₂ O ₅ is too large, the glass tends to undergo phase separation, which may reduce productivity. Also, raw material costs may increase. Therefore, the preferable lower limit range of P ₂ O ₅ in the glass fiber and glass of the first aspect of the present invention is 0% or more, 2% or more, 3% or more, 5% or more, 6% or more, 7% or more, 8% or more, 9% or more, 10% or more, 15% or more, particularly 20% or more, the preferred upper limit range is 60% or less, 59% or less, 55% or less, 50% or less, 47% or less, 40% 30% or less, 25% or less, particularly 20% or less. In the glass fiber and glass of the second aspect of the present invention, the preferable lower range of P ₂ O ₅ is 5% or more, 6% or more, 7% or more, 8% or more, 9% or more, 10% or more, 15% Above, especially 20% or more, the preferred upper limit range is 60% or less, 59% or less, 55% or less, 50% or less, 47% or less, 40% or less, 30% or less, 25% or less, especially 20% or less is.

A preferable _lower limit range of the molar ratio _B2O3 / _P2O5 of the content of _B2O3 to P2O5 is ₀ or _more _, 0.01 or more _, 0.05 or more, 0.08 or more, especially 0.1 or more, and the preferred upper limit range is 50 or less, 40 or less, 30 or less, 20 or less, 10 or less, 7 or less, 5.5 or less, 4 or less, 3 or less, 2 or less, particularly 1 or less. If the B ₂ O ₃ /P ₂ O ₅ ratio is too low, the polarity of the unpaired electron pair in P ₂ O ₅ will increase the polarization, and the dielectric loss tangent and dielectric loss will tend to increase. On the other hand, if the value of B ₂ O ₃ /P ₂ O ₅ is too high, there is a possibility that the weather resistance will be remarkably lowered.

A preferable lower limit range of the molar ratio _B2O3 / _Al2O3 of the content of _B2O3 to _Al2O3 is ₀ or _more _, 0.01 or more _, 0.05 or more, 0.1 or more, 0 0.15 or more, especially 0.2 or more. On the other hand, the preferred upper limit range is 20 or less, 10 or less, 9 or less, 8.5 or less, 7 or less, 6 or less, 5 or less, 3 or less, particularly 2 or less. If the B ₂ O ₃ /Al ₂ O ₃ is too low, the dielectric loss tangent and dielectric loss may increase. On the other hand, if the B ₂ O ₃ /Al ₂ O ₃ ratio is too high, the weather resistance and Young's modulus may decrease.

Fe ₂ O ₃ is a component having a refining action. If the amount of Fe ₂ O ₃ is too small, it is difficult to obtain the above effects. On the other hand, if the amount of Fe ₂ O ₃ is too large, the coloration of the glass becomes strong. Therefore, the preferable lower limit range of Fe ₂ O ₃ is 0.001% or more, 0.002% or more, 0.003% or more, 0.005% or more, 0.008% or more, 0.01% or more, 0.01% or more. 02% or more, particularly 0.08% or more, and the preferred upper limit range is 3% or less, 2% or less, and particularly 1% or less.

Li ₂ O, Na ₂ O and K ₂ O are components that lower the viscosity of the glass and lower the spinning temperature, but if Li ₂ O+Na ₂ O+K ₂ O is too much, the dielectric constant and dielectric loss tangent tend to increase. In addition, when a composite material in which glass fibers and resin are mixed is exposed to a high-temperature and high-humidity environment, Li ₂ O, Na ₂ O and/or K ₂ O are eluted from the glass and the strength of the composite material is lowered. becomes easier. Therefore, the preferable upper limit range of Li ₂ O+Na ₂ O+K ₂ O is 3% or less, 2.5% or less, 2% or less, 1.5% or less, 1.3% or less, particularly 1% or less. A preferable lower limit range is 0% or more, 0.001% or more, particularly 0.01% or more.

The preferred upper limits of Li ₂ O, Na ₂ O and K ₂ O are 3% or less, 2.5% or less and 2% or less, and particularly 1.5% or less. Moreover, preferable lower limit ranges are 0% or more, 0.001% or more, and 0.01% or more, respectively.

MgO, like alkali metal oxides, is a component that lowers the viscosity of glass and lowers the spinning temperature. However, if the MgO content is too high, the dielectric constant and dielectric loss tangent tend to increase. In addition, the phase separation of the glass is promoted, and the glass tends to become cloudy. Therefore, the preferable lower limit range of MgO is 0% or more, 0.01% or more, 0.05% or more, 0.1% or more, particularly 0.3% or more, and the preferable upper limit range is 7% or less, 6 % or less, 5.6% or less, 5% or less, 4% or less, 3% or less, particularly 2.5% or less.

CaO, like MgO, is a component that lowers the viscosity of glass and lowers the spinning temperature. However, if the CaO content is too high, the dielectric constant and dielectric loss tangent tend to increase. Therefore, the preferable lower limit range of CaO is 0% or more, 0.01% or more, 0.05% or more, 0.1% or more, 0.3% or more, 0.4% or more, particularly 0.5% or more. A preferable upper limit range is 9% or less, 8.8% or less, 7% or less, particularly 6% or less.

BaO, like MgO and CaO, is a component that lowers the viscosity of the glass and lowers the spinning temperature. However, if the BaO content is too high, the dielectric constant and dielectric loss tangent tend to increase. Therefore, the preferable lower limit range of BaO is 0% or more, 0.01% or more, 0.05% or more, 0.1% or more, 0.3% or more, 0.4% or more, particularly 0.5% or more. A preferable upper limit range is 9% or less, 8.8% or less, 7% or less, particularly 6% or less.

SrO, like MgO and CaO, is a component that lowers the viscosity of glass and lowers the spinning temperature. On the other hand, since the difference in electronegativity with oxygen is large, if the content of SrO is too large, the dielectric constant and dielectric loss tangent tend to increase. Therefore, the preferable lower limit range of SrO is 0% or more, 0.01% or more, 0.05% or more, 0.1% or more, 0.3% or more, 0.4% or more, particularly 0.5% or more. A preferable upper limit range is 9% or less, 8.8% or less, 7% or less, particularly 6% or less.

A preferable upper limit range of Li ₂ O + Na ₂ O + K ₂ O + MgO + CaO + BaO + SrO, which is the total amount of alkali metal oxides and alkaline earth metal oxides, is 9% or less, 7% or less, 5% or less, particularly 3% or less. Moreover, the preferable lower limit range is 0% or more, 0.001% or more, and 0.01% or more. If Li ₂ O+Na ₂ O+K ₂ O+MgO+CaO+BaO+SrO is too large, the dielectric constant and dielectric loss tangent tend to increase. On the other hand, if it is too small, the spinning temperature tends to rise, and the productivity tends to decrease.

In addition to the above components, the glass fiber of the present invention may contain the following components in the glass composition.

_TiO2 is a component that lowers the viscosity of the glass and lowers the spinning temperature. TiO ₂ is more likely than alkali metal oxides and alkaline earth metal oxides to simultaneously lower the spinning temperature and lower the dielectric constant. If the content of TiO ₂ is too small, it is difficult to obtain the above effects. However, if the content of TiO ₂ is too high, devitrification tends to occur, which may reduce productivity. Therefore, the preferred lower range of _TiO2 is 0% or higher, 0.001% or higher, 0.005% or higher, 0.01% or higher, especially 0.05% or higher, and the preferred upper limit range is 5% or lower, 4% or less, 3% or less, 2% or less, 1.5% or less, 1% or less, particularly 0.5% or less.

ZrO ₂ is a component mixed in by elution of the refractory material in the manufacturing kiln. If the content of ZrO ₂ is too high, devitrification tends to occur, and productivity may decrease. Therefore, the content of ZrO ₂ is preferably 1% or less, 0.8% or less, particularly 0.6% or less.

_SnO2 is a component that acts as a refining agent. However, if the SnO2 content is too _high , the glass tends to be colored and the transparency tends to decrease. Therefore, the preferred _lower range of SnO2 is 0% or higher, 0.001% or higher, 0.005% or higher, especially 0.01% or higher, and the preferred upper range is 3% or lower, 2% or lower, 1% below, particularly below 0.5%.

Besides SnO ₂ , SO ₃ , chlorine, fluorine, Sb ₂ O ₃ , As ₂ O ₃ , CeO ₂ and the like can be used as clarifiers other than SnO 2 . However, due to concerns about environmental impact and corrosion of equipment, the total content should be 0.5% or less, 0.3% or less, 0.2% or less, particularly 0.1% or less. preferable.

Next, the relationship between dielectric loss and electronegativity in the glass fiber of the present invention will be described.

When currents of various frequencies are passed through glass, which is a dielectric, dielectric loss occurs for each frequency. Here, dielectric loss refers to movement loss, conduction loss, deformation loss and vibration loss. In the low frequency range, the contributions of transport loss and conduction loss become large. The migration loss is the loss due to the migration of the dipole paired by the alkali ion and the oxygen ion in the glass. Conduction loss is loss due to direct current conduction such as ionic conduction of alkali in glass.

Furthermore, in the high-frequency millimeter wave band, the contribution of deformation loss and vibration loss becomes significant. Deformation loss is loss caused by deformation of the network structure of SiO ₂ due to an AC electric field. Vibrational loss is loss caused by resonance of thermal vibration of ions with an external electric field. Next-generation communications use the millimeter wave band to transmit large amounts of information. Therefore, communication delay due to deformation loss and vibration loss is a problem. In order to reduce these losses, it is effective to suppress the deformation of the network structure or to reduce the polarization in order to suppress the thermal vibration of the ions. When an alkali metal component or an alkaline earth metal component is present in the oxide glass, the Si--O--Si bond is broken and non-bridging oxygen is formed. Furthermore, there is a large electrical difference between non-bridging oxygen and alkali metal ions or alkaline earth ions. In order to reduce the effects of the above-mentioned network structure breakage and the electrical difference (that is, polarization) between oxygen ions and alkali metal ions or alkaline earth metal ions, the electrical Need to reduce the difference.

　ΔX is the electronegativity difference between oxide elements other than oxygen and oxygen, which are constituents of the glass. In the present invention, it has been found that by limiting ΔX to a predetermined range, a glass fiber having a low dielectric constant and a low dielectric loss tangent with suppressed dielectric loss can be obtained. If the value of ΔΧ is too high, the number of ionic bonds increases, and electric bias tends to occur with respect to the electric field, which tends to increase the dielectric constant and dielectric loss tangent. On the other hand, if the value of ΔΧ is too low, the covalent bond becomes strong, which may increase the viscosity of the glass and reduce the productivity. Therefore, the preferable lower limit range of ΔΧ is 1.4 or more, 1.5 or more, particularly 1.55 or more, and the preferable upper limit range is 1.8 or less, 1.79 or less, 1.78 or less, 1.55 or more, and 1.55 or more. 75 or less, 1.7 or less, 1.69 or less, especially 1.67 or less.

Further, the properties of the glass fiber of the present invention are detailed below.

　If the glass fiber spinning temperature is high, the damage to the bushing will increase and the life of the bushing will be shortened. In addition, the frequency of bushing replacement and energy costs increase, resulting in high production costs. Therefore, the spinning temperature of the glass fiber of the present invention is preferably 1450° C. or lower, 1420° C. or lower, particularly 1380° C. or lower.

A high liquidus temperature makes stable production difficult. Therefore, the liquidus temperature is preferably 1200° C. or lower, 1190° C. or lower, 1170° C. or lower, 1160° C. or lower, 1150° C. or lower, 1100° C. or lower, 1010° C. or lower, particularly 1000° C. or lower.

In addition, the larger the difference between the liquidus temperature and the spinning temperature, the more difficult it is for the crystals to flow out during spinning, and the fewer the yarn breaks, the higher the productivity. Therefore, the difference between the liquidus temperature and the spinning temperature is preferably 50°C or higher, 60°C or higher, 70°C or higher, 90°C or higher, 100°C or higher, 110°C or higher, 125°C or higher, particularly 180°C or higher.

Low dielectric constant and loss tangent result in low dielectric loss. Therefore, the dielectric constant of the glass fiber of the present invention at 25° C. and 2.45 GHz is preferably 6 or less, 5.5 or less, 5 or less, particularly 4.7 or less, and the dielectric loss tangent is preferably 45×10 ^{− 4} or less, 40×10 ⁻⁴ or less, 35×10 ⁻⁴ or less, 30×10 ⁻⁴ or less, 25×10 ⁻⁴ or less, 20×10 ⁻⁴ or less, 18×10 ⁻⁴ or less, especially 10×10 ^{− 4} or less. Further, the dielectric constant at 25° C. and 28 GHz is preferably 6 or less, 5.5 or less, 5 or less, particularly 4.7 or less, and the dielectric loss tangent is preferably 45×10 ⁻⁴ or less, 44×10 ⁻⁴ 43×10 ⁻⁴ or less, 42×10 ⁻⁴ or less, particularly 41×10 ⁻⁴ or less. Further, the dielectric constant at 25° C. and 40 GHz is preferably 6 or less, 5.5 or less, 5 or less, particularly 4.7 or less, and the dielectric loss tangent is preferably 50×10 ⁻⁴ or less, 48×10 ⁻⁴ 45×10 ⁻⁴ or less, 44×10 ⁻⁴ or less, 43×10 ⁻⁴ or less, 42×10 ⁻⁴ or less, particularly 41×10 ⁻⁴ or less. When the dielectric loss is small, the glass fiber is suitable for use in applications requiring low dielectric properties, for example, as a resin reinforcing material for printed wiring boards, communication equipment parts, and the like.

Density is a property that affects the weight of composites compounded with resins. As the density of glass fibers increases, the weight of the composite material increases, making it difficult to reduce weight. Therefore, the density is preferably 2.55 g/cm ³ or less, 2.54 g/cm ³ or less, especially 2.53 g/cm ³ or less. Although the lower limit is not particularly limited, it is practically 2.00 g/cm ³ or more.

　Young's modulus is a property that affects the strength of composite materials kneaded with resin. If the Young's modulus is too low, it will be difficult to obtain sufficient strength in the composite material. On the other hand, if the Young's modulus is too high, the composite material loses flexibility and becomes difficult to process. Therefore, the preferred lower limit range of Young's modulus is 40 GPa or higher, 45 GPa or higher, particularly 50 GPa or higher, and the preferred upper limit range is 90 GPa or lower, particularly 85 GPa or lower.

The method for producing the glass fiber of the present invention will be described below. In the following explanation, the direct melt method (DM method) and the indirect molding method (MM method: marble melt method) are described as examples, but the method for producing the glass fiber of the present invention is not limited to the following. Other methods can also be adopted.

First, a raw material batch is prepared so that it has the above composition. Cullet may be used as part or all of the raw material for glass. The reason why the content of each component is set as above is as described above, and the explanation is omitted here.

Next, the mixed raw material batch is put into a glass melting furnace, vitrified, melted, and homogenized. A melting temperature of about 1500 to 1600° C. is suitable.

Subsequently, the obtained molten glass is continuously pulled out from the bushing and formed into fibers to obtain glass fibers (DM method). Alternatively, the obtained molten glass is once molded into a marble shape, and then the remelted molten glass is continuously pulled out from the bushing and molded into fibers to obtain glass fibers (MM method).

If necessary, the surface of the glass fiber may be coated with a coating that imparts desired physicochemical performance. Specifically, polyurethane resin, epoxy resin, acid copolymer, modified polypropylene resin, polyester resin, antistatic agent, surfactant, antioxidant, coupling agent or lubricant may be coated.

Examples of coupling agents that can be used for surface treatment of glass fibers include γ-aminopropyltriethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-methacrylic roxypropyltrimethoxysilane, γ-(2-aminoethyl)aminopropyltrimethoxysilane, β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, N-β-(N-vinylbenzylaminoethyl)-γ- There are aminopropyltrimethoxysilane/hydrochloride, γ-chloropropyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane, vinyltriethoxysilane, and the like, and these may be appropriately selected depending on the type of resin to be combined.

The glass fiber of the present invention is suitable for use as chopped strands for resin reinforcement, and also includes glass cloth, glass filler, glass chopped strands, glass paper, nonwoven fabrics, continuous strand mats, knitted fabrics, glass rovings, milled fibers, and the like. , may be processed into any glass fiber product.

The glass fiber of the present invention can be used by mixing with fibers other than those of the present invention as long as the object of the present invention is not impaired. The fibers include glass fibers such as E-glass fibers and S-glass fibers, and fibers other than glass fibers such as carbon fibers and metal fibers.

The present invention will be described below based on examples.

Examples 1 to 17 of the present invention and Comparative Example 1 are shown in Tables 2 to 4. FIG. 1 is a graph showing the relationship between the molar ratio B ₂ O ₃ /P ₂ O ₅ of Examples 1 to 17 and the dielectric loss tangent tan δ at 25° C. and 2.45 GHz. FIG. 2 is a graph showing the relationship between the molar ratio B ₂ O ₃ /Al ₂ O ₃ of Examples 1 to 15 and the dielectric loss tangent tan δ at 25° C. and 2.45 GHz.

Each sample in Tables 2-4 was prepared as follows.

First, a predetermined amount of various glass raw materials such as natural raw materials and chemical raw materials were weighed to a total of 500 g, and the glass composition obtained after melting was prepared as shown in Tables 2 to 4. Next, the raw material mixed batch thus obtained was charged into a 300 cc platinum-rhodium crucible, and then heated in an indirect heating electric furnace at about 1650° C. for 20 hours in an air atmosphere to form a molten glass. In order to homogenize the molten glass, a heat-resistant stirring rod was used to stir the molten glass 1 hour after the entire batch was put into the crucible and 1 hour before it was poured out. The molten glass thus homogenized was poured into a carbon plate, roll-formed to a thickness of 5 mm, and allowed to cool to room temperature.

The following characteristics were measured for each sample obtained.

The strain point Ps, annealing point Ta and softening point Ts were measured by the fiber elongation method.

Measurement of the temperature at a high temperature viscosity of 10 ^4.0 dPa s, the temperature at a high temperature viscosity of 10 ^3.0 dPa s, the temperature at a high temperature viscosity of 10 ^2.5 dPa s and the temperature at a high temperature viscosity of 10 ^2.0 dPa s , A part of the glass sample obtained by the above method is pre-crushed to an appropriate size, put into a platinum crucible and reheated, heated to a molten state, and then subjected to a platinum ball pulling method. It was measured. The spinning temperature is a temperature corresponding to a viscosity of 10 ^3.0 dPa·s.

For the measurement of the liquidus temperature TL, the glass sample obtained by the above method was pulverized, passed through a sieve with an opening of 500 μm, and the mass of the powder deposited on the 300 μm sieve, which was equivalent to 10 times the density, was collected. A platinum boat of about 120 mm×20 mm×10 mm was filled with the collected glass powder, and placed in an electric furnace having a linear temperature gradient for 24 hours. After that, the glass was taken out from the platinum boat, cooled to room temperature, and then crystal precipitation sites were specified by microscopic observation. The temperature corresponding to the crystal deposition location was calculated from the temperature gradient graph of the electric furnace, and this temperature was defined as the liquidus temperature.

The dielectric constant ε and dielectric loss tangent tan δ at a frequency of 2.45 GHz were measured using a glass sample piece processed to dimensions of 3 mm × 80 mm × 1 mm from the glass sample obtained by the above method. The measurement was performed at a room temperature of 25° C. using a ZVL-3 network analyzer manufactured by Rohde Schwartz and a cavity resonator manufactured by AET. The dielectric constant ε and dielectric loss tangent tan δ at frequencies of 28 GHz and 40 GHz were measured using a glass sample piece of 30 mm×40 mm×0.15 mm processed from the glass sample obtained by the above method. Both sides were polished to a mirror finish. Measurement was performed at room temperature of 25° C. by the split cylinder method using resonators for 28 GHz and 40 GHz and a vector analyzer.

About 10 g of the glass sample obtained by the above method was cut out and the density ρ was measured by the Archimedes method.

The Young's modulus was measured using a sample piece of 40 mm × 20 mm × 2 mm processed from the glass sample obtained by the above method. Both surfaces of this glass sample piece having a thickness of 2 mm were polished with a polishing liquid prepared by dissolving No. 1200 alumina powder in water. This glass sample piece was precision annealed to remove strain before measurement. The samples were deposited with gold (>1500 Å) and the width, length, thickness and weight of the samples were measured. The measurement was performed using a free resonance elastic modulus measuring device JE-RT3 manufactured by Technoplus Japan Co., Ltd.

As can be seen from Tables 2 to 4, the example glasses of the present invention have a ΔX of 1.67 or less, and the dielectric constant at 25° C. and 2.45 GHz compared to Comparative Example 1, which has a large ΔX of 1.94. And the dielectric loss tangent was low, and it had excellent low dielectric properties. Further, the example glasses of the present invention had excellent dielectric properties in the high frequency range of 28 GHz and 40 GHz, but the dielectric constant and dielectric loss tangent in the high frequency range of Comparative Example 1 were too high to be measured. Further, the spinning temperature of all the example glasses of the present invention was as low as 1436° C. or lower.

As can be seen from FIG. 1, in the example glasses of the present invention, the larger the value of B ₂ O ₃ /P ₂ O ₅ is, the smaller the dielectric loss tangent tan δ tends to be.

As can be seen from FIG. 2, in the example glasses of the present invention, the larger the value of B ₂ O ₃ /Al ₂ O ₃ is, the smaller the dielectric loss tangent tan δ tends to be.

The glass fiber of the present invention is used as a fiber-reinforced resin molded product, in addition to housings and members of mobile electronic devices such as smartphones, tablets, laptop computers, mobile music players, and mobile game machines, as well as in-vehicle millimeter wave radars and vehicle exteriors. It can be suitably used as a communication member used in the millimeter wave band, such as a member, a vehicle interior member, a vehicle engine peripheral member, an electronic device housing, and an electronic component. The composition of the glass fiber of the present invention may be applied to the composition of glass substrates, glass tubes, glass containers, and the like.

Claims

The glass composition is SiO 2 22.5 to 45%, Al 2 O 3 0.1 to 30%, B 2 O 3 0 to 45%, P 2 O 5 0 to 60%, and Fe 2 O 3 in mass %. 0.001-3% and Li 2 O+Na 2 O+K 2 O+MgO+CaO+BaO+SrO 0-9%.
The glass fiber according to claim 1, wherein the average value ΔΧ of the difference in electronegativity between oxygen, which is a constituent of the glass, and other oxide elements is 1.4 to 1.8.
3. The glass fiber according to claim 1, wherein the dielectric constant at 25° C. and 2.45 GHz is 6 or less, and the dielectric loss tangent is 45×10 −4 or less.
The glass fiber according to any one of claims 1 to 3, which has a dielectric constant of 6 or less at 25°C and 28 GHz and a dielectric loss tangent of 45×10 -4 or less.
The glass fiber according to any one of claims 1 to 4, which has a dielectric constant of 6 or less at 25°C and 40 GHz and a dielectric loss tangent of 50 × 10 -4 or less.
The glass fiber according to any one of claims 1 to 5, characterized in that the spinning temperature is 1450°C or less.
The glass fiber according to any one of claims 1 to 6, which has a Young's modulus of 40 GPa or more.
The glass fiber according to any one of claims 1 to 7, wherein the molar ratio B 2 O 3 /P 2 O 5 of the content of B 2 O 3 to P 2 O 5 is 0-50.
The glass fiber according to any one of claims 1 to 8, wherein the molar ratio B 2 O 3 /Al 2 O 3 of the content of B 2 O 3 to Al 2 O 3 is 0-20.
The glass composition is SiO 2 22.5 to 45%, Al 2 O 3 0.1 to 30%, B 2 O 3 0 to 45%, P 2 O 5 0 to 60%, and Fe 2 O 3 in mass %. A method for producing glass fibers containing 0.001-3% Li 2 O + Na 2 O + K 2 O + MgO + CaO + BaO + SrO 0-9%, characterized in that molten glass is continuously pulled out from a bushing and formed into fibers. A method for producing glass fibers.
The glass composition is SiO 2 22.5 to 45%, Al 2 O 3 0.1 to 30%, B 2 O 3 0 to 45%, P 2 O 5 0 to 60%, and Fe 2 O 3 in mass %. 0.001-3% and Li 2 O+Na 2 O+K 2 O+MgO+CaO+BaO+SrO 0-9%.
The glass composition is SiO 2 24 to 45%, Al 2 O 3 0.1 to 30%, B 2 O 3 0 to 45%, P 2 O 5 5 to 60%, Fe 2 O 3 0.0%, in mass %. 001-3% and Li 2 O+Na 2 O+K 2 O 0-3%.