glass fibers

Abstract

The present invention provides a glass fiber having low spinning temperature and low dielectric constant and dielectric loss tangent. A glass fiber, as a glass composition, contains 40 to 80% of SiO2, 0 to 20% of Al2O3, 10 to 30% of B2O3, and at least one selected from MgO, CaO, SrO, BaO, Li2O, Na2O, K2O, ZrO2, Fe2O3, SnO2, F and Cl, the total amount of MOO3, Cr2O3, Pt and Rh is 0.01 to 500 ppm, and the value of TiO2 (mass%) x MoO3 (ppm) is 3100 or less.

Description

TECHNICAL FIELD

[0001] The present application relates to a glass fiber suitable as a reinforcing material for a resin member that requires low dielectric constant and low dielectric loss tangent characteristics as a member for high-speed communication equipment, a radar for a vehicle, and the like. BACKGROUND

[0002] With the development of various electronic devices that support information industries, remarkable progress has been made in technologies related to mobile phones, portable information terminals, and the like. For circuit members for electronic devices that have been developed in high density and high speed processing, in order to minimize signal propagation delay caused by dielectric loss, further concomitant mobile loss, conduction loss, deformation loss, vibration loss, and the like, and to prevent heating of a substrate caused by thermal loss, low dielectric constant and low dielectric loss tangent characteristics are required. As examples of these circuit substrates for electronic devices, printed wiring substrates, and low-temperature fired substrates can be cited. A printed wiring substrate is a composite material in which glass fibers are mixed as a reinforcing material in a resin and formed into a sheet shape, and a low-temperature fired substrate is formed by firing a green sheet of a composite powder in which a filler (filler) such as silica is mixed in a powder glass containing a large amount of SiO2, B2O3 (for example, see Patent Document 1).

[0003] In addition, in addition to the above, with the miniaturization of electronic devices and the high speed of communication, in recent years, the demand for low dielectric properties of resins around circuit substrates, resins used in members for communication equipment, and electronic device housings has increased, and for glass fibers used as reinforcing materials therefor, low dielectric constant and low dielectric loss tangent are also required. Furthermore, in the automobile industry, with the development of autonomous driving systems, it is considered that the demand for glass fiber reinforced resins having high strength, light weight, and low dielectric constant and low dielectric loss tangent characteristics as members used in radars and cameras for vehicles has increased.

[0004] PRIOR ART DOCUMENTS

[0005] PATENT DOCUMENTS

[0006] Patent Document 1: Japanese Patent Application Laid-Open No. 63-2831 SUMMARY

[0007] PROBLEMS TO BE SOLVED BY THE INVENTION

[0008] As a glass fiber for printed wiring substrates and resin reinforcement, in general, E glass (dielectric constant ε at a frequency of 2.45 MHz at room temperature (25°C) is 6.9, and dielectric loss tangent tan δ is 46 x 10 -4), but the E glass has a problem that it does not satisfy the requirements of the above-mentioned low dielectric constant and low dielectric loss tangent. Therefore, in Patent Document 1, a glass called D glass is disclosed, which is characterized by a lower dielectric constant and dielectric loss tangent than the E glass. For the D glass, for example, the dielectric constant ε at a frequency of 2.45 GHz at room temperature is 4.2, and the dielectric loss tangent tan δ is 15 x 10 -4 .

[0009] In addition, a radar for vehicle, an electronic device housing, and the like are often used outdoors, and are exposed to severe environments such as ultraviolet rays contained in sunlight, changes in weather and air temperature. In particular, degradation of the resin caused by ultraviolet rays is significant, and has a large impact on the life of the material.

[0010] In view of the above, an object of the present application is to provide a glass fiber which, by suppressing degradation of the resin caused by ultraviolet rays and suppressing coloring, does not easily change the color tone of a composite material, and has a low dielectric constant and a low dielectric loss tangent.

[0011] Means for solving the problem

[0012] The glass fiber of the present application is characterized in that, as a glass composition, it contains, in mass %, 40 to 80% of SiO2, 0 to 20% of Al2O3, and 10 to 30% of B2O3, and contains at least one kind selected from MgO, CaO, SrO, BaO, Li2O, Na2O, K2O, ZrO2, Fe2O3, SnO2, F, and Cl, the total amount of MoO3, Cr2O3, Pt, and Rh is 0.01 to 500 ppm, and the value of TiO2 (mass %) x MoO3 (ppm) is 3100 or less. Thereby, when compounded with a resin, degradation of the resin caused by ultraviolet rays can be suppressed, and the color tone of the composite material does not easily change, and a low dielectric constant and a low dielectric loss tangent characteristic can be achieved. Note that, in the present specification, a material in which a resin is compounded with a glass fiber is sometimes referred to simply as a "composite material".

[0013] For the glass fiber of the present application, it is preferable that the total light transmittance at a wavelength of 300 nm be 70% or less and the minimum total light transmittance in the range of wavelengths of 400 to 800 nm be 50% or more at a thickness of 1 mm. Thereby, when compounded with a resin, the glass fiber easily absorbs ultraviolet rays in sunlight, and the ultraviolet rays irradiated to the resin can be reduced, and thus degradation of the resin can be suppressed. In addition, since the degree of coloring of the glass fiber itself is low, the color tone of the composite material does not easily change when compounded with a resin.

[0014] For the glass fiber of the present application, it is preferable that the dielectric constant at 25°C, 40GHz be 6 or less and the dielectric loss tangent be 0.011 or less. Thereby, the transmission loss of a member obtained by compounding with a resin can be reduced.

[0015] For the glass fiber of the present application, it is preferable that the spinning temperature be 1450°C or less. Thereby, the deformation of the bushing equipment is less, and long-term operation is possible. In addition, the elution of noble metal elements from the bushing equipment can be suppressed, and the phase separation of the glass caused by the noble metal elements can be suppressed, so that the reduction in water resistance is less likely to occur. Note that, in the present application, the "spinning temperature" refers to the temperature at which the viscosity of the glass reaches 10 3.0 dPa-s.

[0016] The glass fiber of another aspect of the present application is characterized in that, as the glass composition, it contains, in mass%, 40 to 80% of SiO2, 0 to 20% of Al2O3, 10 to 30% of B2O3, 0 to 0.15% of Fe2O3, 0.01 to 100 ppm of Pt, and at least one selected from MgO, CaO, SrO, BaO, Na2O, and K2O, and at least one selected from Li2O, ZrO2, TiO2, Fe2O3, MoO3, Cr2O3, SnO2, F, Cl, and Rh.

[0017] The glass fiber of still another aspect of the present application is characterized in that, as the glass composition, it contains, in mass%, 55 to 80% of SiO2, 0 to 15% of Al2O3, 10 to 30% of B2O3, and at least one selected from MgO, CaO, SrO, BaO, Li2O, Na2O, K2O, Fe2O3, SnO2, F, and Cl, the total amount of MoO3, Cr2O3, Pt, and Rh is 0.01 to 500 ppm, and the value of TiO2 (mass%) x MoO3 (ppm) is 3100 or less.

[0018] Effects of the Invention

[0019] With the present application, a glass fiber which is less likely to change the color tone as a composite material by suppressing the resin deterioration caused by ultraviolet rays and suppressing coloring, and which has the characteristics of low dielectric constant and low dielectric loss tangent, can be provided. DETAILED DESCRIPTION

[0020] The glass fiber of the present application is characterized in that, as a glass composition, it contains 40 to 80% of SiO2, 0 to 20% of Al2O3, and 10 to 30% of B2O3, in mass%, and contains at least one kind selected from the group consisting of MgO, CaO, SrO, BaO, Li2O, Na2O, K2O, ZrO2, Fe2O3, SnO2, F, and Cl, the total amount of MoO3, Cr2O3, Pt, and Rh is 0.01 to 500 ppm, and the value of TiO2 (mass%) x MoO3 (ppm) is 3100 or less. The reason for thus limiting the glass composition will be described in detail below. Note that, in the present application, % means mass% unless otherwise specified.

[0021] SiO2is a component that forms the skeleton of the network structure in the glass structure, and is a component that lowers the dielectric constant and the dielectric loss tangent. If the content of SiO2is too small, it is difficult to obtain the above-mentioned effects. On the other hand, if the content of SiO2is too large, the melting property of the raw material decreases, and it is difficult to obtain a homogeneous glass. In addition, the spinning temperature becomes high, and the productivity decreases. Therefore, the suitable lower limit range of SiO2is 40% or more, 45% or more, 50% or more, 54% or more, 55% or more, 60% or more, 64% or more, 65% or more, 67% or more, 70% or more, and most preferably 73% or more, and the suitable upper limit range is 80% or less, less than 80%, 79% or less, 78% or less, and most preferably 76% or less.

[0022] Al2O3is a component that forms the skeleton of the glass and stabilizes the glass by suppressing phase separation. However, if the content of Al2O3is too large, the dielectric constant and the dielectric loss tangent easily become high. Therefore, the suitable upper limit range is 20% or less, 19% or less, 18% or less, 17% or less, 16% or less, 15% or less, 13% or less, 10% or less, less than 10%, 8% or less, 5% or less, 3% or less, 2% or less, 1% or less, less than 1%, 0.9% or less, 0.8% or less, less than 0.5%, less than 0.4%, less than 0.2%, 0.1% or less, and particularly less than 0.1%. Note that the lower limit range of Al2O3is not particularly limited, and is 0% or more, and in order to obtain the above-mentioned effects, it is preferably 0.01% or more, and particularly preferably 0.015% or more.

[0023] B2O3 is also a component that forms a glass skeleton together with SiO2, and is a component that lowers the dielectric constant and dielectric loss tangent. If the content of B2O3 is too small, it is difficult to obtain the above effects. On the other hand, if the content of B2O3 is too large, the glass is likely to phase separate, and the productivity can decrease. Therefore, the suitable lower limit range of B2O3 is 10% or more, 12% or more, 13% or more, 15% or more, 16% or more, 17% or more, particularly 18% or more, and the suitable upper limit range is 30% or less, 28% or less, 26% or less, 25% or less, 24% or less, particularly 23% or less.

[0024] MgO is a component that lowers the viscosity of the glass, and is a component that is less likely to increase the dielectric constant and dielectric loss tangent than alkali metal components such as Li2O, Na2O, and K2O. Note that MgO has an effect of suppressing dielectric loss caused by movement of alkali metal ions by coexisting with the alkali metal elements. However, if the content of MgO is too large, phase separation can be promoted. This tendency is particularly significant in a glass composition system having a small content of Al2O3. Therefore, the suitable upper limit range of the content of MgO is 8% or less, 7% or less, 6% or less, 5% or less, 4% or less, 3% or less, 2% or less, 1.5% or less, particularly 1% or less. Note that the lower limit range of MgO is not particularly limited, and is 0% or more, and in order to obtain the above effects, it is preferable to be 0.01% or more, 0.05% or more, 0.07% or more, particularly preferably 0.1% or more.

[0025] CaO is also a component that lowers the viscosity of the glass, like MgO, and is a component that is less likely to increase the dielectric constant and dielectric loss tangent than alkali metal components such as Li2O, Na2O, and K2O. Note that CaO has an effect of suppressing movement of alkali metal ions by coexisting with the alkali metal elements. However, if the content of CaO is too large, phase separation can be promoted. This tendency is particularly significant in a glass composition system having a small content of Al2O3. Therefore, the suitable upper limit range of the content of CaO is 8% or less, 7% or less, 6% or less, 5% or less, 4% or less, 3% or less, 2% or less, 1.5% or less, particularly 1% or less. Note that the lower limit range of CaO is not particularly limited, and is 0% or more, and in order to obtain the above effects, it is preferable to be 0.01% or more, 0.05% or more, 0.07% or more, particularly preferably 0.1% or more.

[0026] SrO is, like MgO and CaO, a component that lowers the viscosity of the glass and is a component that is less likely to increase the dielectric constant and the dielectric loss tangent than alkali metal components such as Li20, Na20, and K20. Note that SrO has an effect of suppressing the movement of alkali metal ions by coexisting with alkali metal elements. However, if the content of SrO is too large, phase separation can be promoted. This tendency is particularly significant in a glass composition system in which the content of Al203is small. Thus, the upper limit of the content of SrO is preferably 8% or less, 7% or less, 6% or less, 5% or less, 4% or less, 3% or less, 2% or less, 1.5% or less, and particularly 1% or less. From the viewpoint of suppressing phase separation, the content of SrO can also be set to 0%. Note that the lower limit of the content of SrO is not particularly limited and is preferably 0.01% or more, 0.05% or more, 0.07% or more, and particularly 0.1% or more in order to obtain the above-described effect.

[0027] BaO is, like MgO and CaO, a component that lowers the viscosity of the glass and is a component that is less likely to increase the dielectric constant and the dielectric loss tangent than alkali metal components such as Li20, Na20, and K20. Note that BaO has an effect of suppressing the movement of alkali metal ions by coexisting with alkali metal elements. However, if the content of BaO is too large, phase separation can be promoted. This tendency is particularly significant in a glass composition system in which the content of Al203is small. Thus, the upper limit of the content of BaO is preferably 8% or less, 7% or less, 6% or less, 5% or less, 4% or less, 3% or less, 2% or less, 1.5% or less, and particularly 1% or less. From the viewpoint of suppressing phase separation, the content of BaO can also be set to 0%. Note that the lower limit of the content of BaO is not particularly limited and is preferably 0.01% or more, 0.05% or more, 0.07% or more, and particularly 0.1% or more in order to obtain the above-described effect.

[0028] Li2O is a component that can reduce the manufacturing cost by lowering the viscosity of the glass and lowering the spinning temperature, but if the content thereof is too much, the dielectric constant and the dielectric loss tangent tend to be high. In addition, if the composite material of the glass fiber and the resin is exposed to a high-temperature and high-humidity environment, Li2O is eluted from the glass, and thus the adhesion of the glass fiber to the resin tends to be reduced, the fiber diameter tends to be reduced due to the erosion of the glass fiber, and as a result, the mechanical strength of the composite material tends to be reduced. Therefore, the appropriate upper limit range is 2% or less, 1.5% or less, 1.4% or less, particularly 1.3% or less. On the other hand, the lower limit range of Li2O is not particularly limited, and is 0% or more, and in order to obtain the above effects, it is preferable to be 0.001% or more, 0.005% or more, 0.01% or more, 0.02% or more, 0.05% or more, 0.08% or more, 0.1% or more, particularly preferably 0.15% or more.

[0029] Na2O is a component that can reduce the manufacturing cost by lowering the viscosity of the glass and lowering the spinning temperature, like Li2O, but if the content thereof is too much, the dielectric constant and the dielectric loss tangent tend to be high. In addition, if the composite material of the glass fiber and the resin is exposed to a high-temperature and high-humidity environment, Na2O is eluted from the glass, and thus the adhesion of the glass fiber to the resin tends to be reduced, the fiber diameter tends to be reduced due to the erosion of the glass fiber, and as a result, the mechanical strength of the composite material tends to be reduced. Therefore, the appropriate upper limit range is 3% or less, 2.4% or less, particularly 2.3% or less. On the other hand, the lower limit range of Na2O is not particularly limited, and is 0% or more, and in order to obtain the above effects, it is preferable to be 0.01% or more, 0.05% or more, 0.08% or more, 0.1% or more, 0.5% or more, 0.8% or more, particularly preferably 1% or more.

[0030] K2O is a component that can reduce the manufacturing cost by lowering the viscosity of the glass and lowering the spinning temperature, like Li2O and Na2O, but if the content thereof is too much, the dielectric constant and the dielectric loss tangent tend to be high. In addition, if the composite material of the glass fiber and the resin is exposed to a high-temperature and high-humidity environment, K2O is eluted from the glass, and thus the adhesion of the glass fiber to the resin tends to be reduced, the fiber diameter tends to be reduced due to the erosion of the glass fiber, and as a result, the mechanical strength of the composite material tends to be reduced. Therefore, the appropriate upper limit range is 3% or less, 2.4% or less, 2.3% or less, particularly 2% or less. On the other hand, the lower limit range of K2O is not particularly limited, and is 0% or more, and in order to obtain the above effects, it is preferable to be 0.01% or more, 0.05% or more, 0.08% or more, 0.1% or more, 0.5% or more, 0.8% or more, particularly preferably 1% or more.

[0031] If Li2O + Na2O + K2O (total amount of Li2O, Na2O and K2O) is too much, the dielectric constant and dielectric loss tangent tend to increase. In addition, if the glass fiber composite is exposed to a high temperature and high humidity environment, Li2O, Na2O and / or K2O are eluted from the glass, and thus the adhesion of the glass fiber to the resin tends to decrease, and the fiber diameter tends to decrease due to erosion of the glass fiber, and as a result, the mechanical strength of the composite tends to decrease. Therefore, the upper limit range is preferably 7.5% or less, 7.4% or less, 7% or less, and particularly preferably 6.5% or less. On the other hand, the lower limit range of Li2O + Na2O + K2O is not particularly limited, and is preferably 0% or more, and in order to obtain the above-mentioned effects, it is preferably 0.1% or more, 0.3% or more, 0.5% or more, and particularly preferably 1% or more. Note that Li2O, Na2O and K2O are components that tend to be eluted from the glass, but by coexisting these components, the movement in the glass can be inhibited, and elution can be suppressed. Therefore, it is preferable to mix two or three of these components.

[0032] ZrO2is a component that improves the chemical durability of the glass. However, if the content of ZrO2is too much, the liquidus temperature becomes high, devitrification occurs during spinning, and the production efficiency can decrease. Therefore, the upper limit range is preferably 1.5% or less, 1.3% or less, 1.2% or less, 1% or less, 0.5% or less, 0.2% or less, and particularly preferably less than 0.2%. If the content of ZrO2is too little, the above-mentioned effects can not be obtained. On the other hand, the lower limit range of ZrO2is not particularly limited, and is preferably 0% or more, and in order to obtain the above-mentioned effects, it is preferably 0.001% or more, 0.005% or more, 0.01% or more, 0.05% or more, 0.08% or more, and particularly preferably 0.1% or more.

[0033] Fe2O3is a component that has a refining effect. In addition, it is a component that can absorb ultraviolet rays and suppress degradation of the resin. However, if the content of Fe2O3is too much, the dielectric constant and dielectric loss tangent can increase. In addition, not only in the ultraviolet region, but also in the visible region, absorption occurs, the glass is colored, and the color tone of the composite can change. Therefore, the upper limit range is preferably 0.5% or less, 0.4% or less, 0.3% or less, less than 0.2%, 0.15% or less, 0.1% or less, 0.09% or less, and particularly preferably 0.08% or less. On the other hand, the lower limit range of Fe2O3is not particularly limited, and is preferably 0% or more, and in order to obtain the above-mentioned effects, it is preferably 0.0001% or more, 0.0005% or more, 0.001% or more, 0.005% or more, and particularly preferably 0.01% or more.

[0034] Sn02is also a component having a refining effect. Specifically, the valence number of Sn changes depending on the temperature of the molten glass, whereby oxygen is released at 1500°C or higher. In addition, it is a component capable of absorbing ultraviolet rays and suppressing deterioration of the resin. However, if the content thereof is large, light absorption in the visible region becomes large, and the glass can possibly be colored. Therefore, the appropriate upper limit range is 0.5% or less, 0.45% or less, 0.4% or less, 0.35% or less, particularly 0.3% or less. From the viewpoint of suppressing coloring of the glass, the content of Sn02may also be set to 0%. On the other hand, the lower limit range of the content of Sn02is not particularly limited, and is 0% or more, and in order to obtain the above-mentioned effects, in order to obtain a sufficient refining effect, the appropriate lower limit range is 0% or more, 0.01% or more, 0.02% or more, 0.05% or more. Note that in the case where the content of alkali metal components such as Li20, Na20, and K20 is small, the melting temperature tends to be high. SO3, which also has a refining effect, decomposes at 1400°C or higher to release SO2gas, and if the gas is released in a state where the viscosity of the molten glass is high, a sufficient defoaming effect cannot be expected. In such a case, it is preferable to use Sn02as a refining agent.

[0035] F is also a component having a refining effect. In addition, it also has an effect of reducing the viscosity of the molten glass. However, if the content thereof is large, it can possibly increase the environmental load or corrode the melting equipment. Therefore, the appropriate upper limit range is 0.5% or less, 0.3% or less, 0.2% or less, particularly 0.1% or less. On the other hand, the lower limit range of the content of F is not particularly limited, and is 0% or more, and in order to obtain the above-mentioned effects, it is preferable to be 0.01% or more, 0.02% or more, 0.05% or more.

[0036] Cl is also a component having a refining effect. In addition, it also has an effect of reducing the viscosity of the molten glass. However, if the content thereof is large, it can possibly increase the environmental load or corrode the melting equipment. Therefore, the appropriate upper limit range is 0.5% or less, 0.3% or less, 0.2% or less, particularly 0.1% or less. On the other hand, the lower limit range of the content of Cl is not particularly limited, and is 0% or more, and in order to obtain the above-mentioned effects, it is preferable to be 0.01% or more, 0.02% or more, 0.05% or more.

[0037] MoO3may be added as an ultraviolet absorber as well as Fe2O3. However, if the content thereof is too much, the absorption in the visible region becomes strong, and the glass is easily colored. Therefore, the upper limit range is preferably 500 ppm or less, 300 ppm or less, 200 ppm or less, 100 ppm or less, 50 ppm or less, particularly 20 ppm or less. On the other hand, the lower limit range of the content of MoO3is not particularly limited, and is preferably 0.01 ppm or more, 0.02 ppm or more, particularly 0.03 ppm or more, in order to obtain the above-mentioned effects.

[0038] Note that if MoO3is used in combination with TiO2, it is easily reduced, and therefore the glass can be colored. Therefore, the value of the content of TiO2(mass %) x the content of MoO3(ppm) is preferably 3100 or less, 3000 or less, 2900 or less, 2800 or less, 2500 or less, 2000 or less, 1500 or less, 1000 or less, 500 or less, 100 or less, 50 or less, 20 or less, particularly 10 or less. The lower limit is not particularly limited, and can be 0 or more, and is preferably 0.01 or more, 0.1 or more, particularly 1 or more.

[0039] TiO2is a component that lowers the viscosity of the glass and easily absorbs ultraviolet rays. In addition, there is a tendency that the dielectric constant easily increases, but the dielectric loss tangent does not easily change. If the content of TiO2is too much, the liquidus temperature becomes high, devitrification occurs at the time of spinning, and the production efficiency can be lowered. In addition, the absorption in the visible region becomes strong, and the glass is easily colored. Therefore, the upper limit range is preferably 7% or less, 6.5% or less, 6% or less, 5.5% or less, 4% or less, 3% or less, 2% or less, 1% or less, 0.5% or less, 0.2% or less, particularly less than 0.2%. On the other hand, the lower limit range of the content of TiO2is not particularly limited, and a prescribed amount can be contained in order to obtain the above-mentioned effects. In addition, TiO2is often contained as an impurity of a natural raw material, and if a high-purity raw material is used, the production cost is increased. Therefore, from the viewpoint of reducing the production cost, a prescribed amount can also be contained. In view of the above, the lower limit range of the content of TiO2may also be 0% or more, 0.01% or more, 0.05% or more, 0.1% or more, particularly 0.2% or more.

[0040] Cr2O3may also be added as an ultraviolet absorber as well as Fe2O3, MoO3. However, if the content thereof is too much, the absorption in the visible region becomes strong, and coloring easily occurs. Therefore, a suitable upper limit range is 500 ppm or less, 300 ppm or less, 200 ppm or less, 100 ppm or less, 50 ppm or less, 20 ppm or less, 10 ppm or less, 5 ppm or less, 1 ppm or less, 0.5 ppm or less, particularly less than 0.2 ppm. On the other hand, the lower limit range of the content of Cr2O3is not particularly limited, and is 0 ppm or more, and in order to obtain the above-mentioned effect, it can be set to 0.01 ppm or more, 0.1 ppm or more, 0.5 ppm or more, particularly 1 ppm or more.

[0041] Pt can also be added as an ultraviolet absorber as well as Fe2O3, MoO3. However, if the content thereof is too much, the absorption in the visible region becomes strong, and coloring easily occurs. Therefore, a suitable upper limit range is 100 ppm or less, 90 ppm or less, 70 ppm or less, 50 ppm or less, 30 ppm or less, 10 ppm or less, 5 ppm or less, 1 ppm or less, 0.5 ppm or less, particularly less than 0.2 ppm. On the other hand, the lower limit range of the content of Pt is not particularly limited, and is 0 ppm or more, and in order to obtain the above-mentioned effect, it is preferably 0.01 ppm or more, 0.02 ppm or more, particularly preferably 0.03 ppm or more.

[0042] Rh can also be added as an ultraviolet absorber as well as Fe2O3, MoO3. However, if the content thereof is too much, the absorption in the visible region becomes strong, and coloring easily occurs. Therefore, a suitable upper limit range is 100 ppm or less, 90 ppm or less, 70 ppm or less, 50 ppm or less, 30 ppm or less, 10 ppm or less, 5 ppm or less, 1 ppm or less, 0.5 ppm or less, particularly less than 0.2 ppm. On the other hand, the lower limit range of the content of Rh is not particularly limited, and is 0 ppm or more, and in order to obtain the above-mentioned effect, it is preferably 0.01 ppm or more, 0.02 ppm or more, particularly preferably 0.03 ppm or more.

[0043] Note that, in order to sufficiently obtain the ultraviolet absorption ability, it is preferable that the total amount of MoO3, Cr2O3, Pt and Rh be 0.01 ppm or more, 0.02 ppm or more, and particularly preferably 0.03 ppm or more. However, if the content of these components is too much, the absorption of the visible region becomes strong, and coloring easily occurs, and therefore the total amount of MoO3, Cr2O3, Pt and Rh is preferably 500 ppm or less, 300 ppm or less, 200 ppm or less, 100 ppm or less, 90 ppm or less, 70 ppm or less, 50 ppm or less, 30 ppm or less, 25 ppm or less, and particularly preferably 20 ppm or less.

[0044] Among the ultraviolet absorbers, Pt and Rh are less likely to color the glass and can efficiently absorb ultraviolet rays. Therefore, by appropriately adjusting the content ratio of Pt and Rh in the ultraviolet absorber, it is possible to efficiently impart ultraviolet absorption effects. Therefore, the appropriate lower limit range of the content ratio of Pt and Rh calculated from {(Pt + Rh) / (Pt + Rh + MoO3+ Cr2O3)} x 100 (%) is 0.01% or more, 0.02% or more, 0.05% or more, 0.1% or more. On the other hand, the appropriate upper limit range is 100% or less, 99% or less, 98% or less, 80% or less, 70% or less, 60% or less, 50% or less, 40% or less, 30% or less, 20% or less, 10% or less. Note that, ({(Pt + Rh) / (Pt + Rh + MoO3+ Cr2O3)} x 100 (%)) is a value obtained by dividing the total amount of the contents (ppm) of Pt and Rh by the total amount of the contents (ppm) of Pt, Rh, MoO3and Cr2O3and multiplying by 100.

[0045] Note that, the upper limit of the value of the product of the transmittance at a wavelength of 300 nm (%T at 300 nm) and the ratio of Pt to the sum of Pt and Rh (Pt / (Pt + Rh)) ((%T at 300 nm) x (Pt / (Pt + Rh))) is preferably 50 or less, 40 or less, and particularly preferably 30 or less. In this way, it is possible to efficiently have ultraviolet absorption effects.

[0046] The ultraviolet absorbers such as Pt, Rh, Cr2O3, MoO3, Fe2O3, SnO2may also be added in small amounts as raw materials, or can be mixed into the glass from a melting device such as a melting furnace. In the latter case, the content can be controlled by adjusting the output of the electrode (Japanese original: output), the power of the bushing (Japanese original: power) of the melting furnace, and the like.

[0047] The glass fiber of the present application can contain the following components in addition to the above components.

[0048] ZnO is, like MgO and CaO, a component that lowers the viscosity of the glass, and is a component that is less likely to increase the dielectric constant and the dielectric loss tangent than alkali metal components such as Li20, Na20, and K20. Note that ZnO has an effect of suppressing the movement of alkali metal ions by coexisting with alkali metal elements. However, if the content of ZnO is too high, it can promote phase separation. This tendency is particularly significant in a glass composition system having a small content of Al203. Therefore, the upper limit of the content of ZnO is preferably 8% or less, 7% or less, 6% or less, 5% or less, 4% or less, 3% or less, 2% or less, 1.5% or less, and particularly 1% or less. From the viewpoint of suppressing phase separation, the content of ZnO can also be set to 0%. Note that the lower limit of the content of ZnO is not particularly limited, and is 0% or more, and in order to obtain the above effect, it is preferably 0.01% or more, 0.05% or more, 0.07% or more, and particularly preferably 0.1% or more.

[0049] SO3 is a component that functions as a fining agent. Specifically, SO3 releases SO2 gas in molten glass at 1400°C or higher, and brings about a fining effect. However, if the content thereof is too high, the molten glass is easily reduced, and transition metals in the molten glass are reduced, and thus, it can cause undesirable coloring. Therefore, the upper limit is preferably 0.1% or less, less than 0.1%, 0.05% or less, and particularly 0.03% or less. On the other hand, the lower limit of the content of SO3 is not particularly limited, and is 0% or more, and in order to obtain the above effect, it is preferably 0.0005% or more, 0.0010% or more, 0.0050% or more, more than 0.0050%, 0.0051% or more, 0.0053% or more, 0.0055% or more, and particularly preferably 0.0057% or more.

[0050] In addition to SO3, as a fining agent, or in order to reduce the viscosity of the molten glass, Sb2O3, As2O3, CeO2, etc. can be contained. However, if the content of these components is too much, there are concerns about environmental load, corrosion of equipment, etc. The upper limit range of the content of these fining agents is 0.5% or less, 0.3% or less, 0.2% or less, particularly 0.1% or less. In view of the above concerns, the content of Sb2O3, As2O3, and CeO2 can also be set to 0%. On the other hand, the lower limit range of the content of these fining agents is not particularly limited, and is 0% or more, and in order to obtain the above effects, 0.0005% or more, 0.0010% or more, particularly 0.0050% or more is preferable. Note that these fining agents can be used alone, or two or more can be used in combination. In the case of using two or more in combination, the upper limit range of the total amount of these is preferably 0.5% or less, 0.3% or less, 0.2% or less, particularly 0.1% or less, and the lower limit range is preferably 0% or more, 0.0005% or more, 0.0010% or more, particularly 0.0050% or more.

[0051] The glass fiber of another aspect of the present application is characterized in that, as the glass composition, it contains 40 to 80% of SiO2, 0 to 20% of Al2O3, 10 to 30% of B2O3, 0 to 0.15% of Fe2O3, 0.01 to 100 ppm of Pt, and contains at least one selected from the group consisting of MgO, CaO, SrO, BaO, Na2O, and K2O, and contains at least one selected from the group consisting of Li2O, ZrO2, TiO2, Fe2O3, MoO3, Cr2O3, SnO2, F, Cl, and Rh, in mass%.

[0052] The glass fiber of still another aspect of the present application is characterized in that, as the glass composition, it contains 55 to 80% of SiO2, 0 to 15% of Al2O3, 10 to 30% of B2O3, and contains at least one selected from the group consisting of MgO, CaO, SrO, BaO, Li2O, Na2O, K2O, Fe2O3, SnO2, F, and Cl, the total amount of MoO3, Cr2O3, Pt, and Rh is 0.01 to 500 ppm, and the value of TiO2 (mass%) x MoO3 (ppm) is 3100 or less.

[0053] In the glass fiber of another aspect of the present application and the glass fiber of still another aspect of the present application, the preferable range of the content of each component and the reason therefor are the same as described above, and thus the description is omitted here.

[0054] Next, the characteristics of the glass fiber of the present application are described below.

[0055] In order to protect the resin in the composite material from the ultraviolet rays in sunlight, the transmittance at 300 nm, at which the resin is most susceptible to deterioration, becomes important. Therefore, the total light transmittance at 300 nm of the glass fiber of the present application is preferably 70% or less, 69% or less, 68% or less, 67% or less, 66% or less, 65% or less, at a thickness of 1 mm.

[0056] In addition, in order to not cause an inappropriate change in the color tone of the composite material, the coloring (transmittance in the visible region) of the glass fiber also becomes important. Therefore, the minimum total light transmittance in the range of 400 to 800 nm of the glass fiber of the present application is preferably 50% or more, 55% or more, 60% or more, 65% or more, 70% or more, 75% or more, 80% or more, 85% or more, 86% or more, 88% or more, 90% or more, at a thickness of 1 mm.

[0057] If the dielectric constant and the dielectric loss tangent are low, the dielectric loss becomes small. Therefore, the dielectric constant of the glass fiber of the present application at 25°C, 40 GHz is preferably 6 or less, 5.5 or less, 5 or less, 4.8 or less, particularly preferably 4.7 or less. The lower limit is not particularly limited, and in reality, it is 1 or more. In addition, the dielectric loss tangent at 25°C, 40 GHz is preferably 0.01 or less, 0.009 or less, 0.008 or less, 0.007 or less, particularly preferably 0.006 or less. Thereby, it is suitable as a glass fiber used in a resin reinforcing material in a use requiring low dielectric properties, such as a printed wiring board, a communication device component, and the like.

[0058] The spinning temperature is a temperature at which the viscosity is 10 3.0 If the spinning temperature is high, the damage to the bushing becomes large, and the bushing life becomes short. In addition, the frequency of bushing replacement, the energy cost increases, and the production cost becomes high. Therefore, the spinning temperature of the glass fiber of the present application is preferably 1450°C or less, 1420°C or less, particularly preferably 1380°C or less.

[0059] If the liquidus temperature is high, it is difficult to perform stable production. Therefore, the liquidus temperature of the glass fiber of the present application is preferably 1350°C or less, 1300°C or less, 1250°C or less, 1200°C or less, 1150°C or less, 1100°C or less, 1010°C or less, particularly preferably 1000°C or less.

[0060] In addition, the greater the difference between the liquidus temperature and the spinning temperature, the more difficult the crystallization to flow out at the time of spinning, and the less the cutting of the filaments, and therefore the productivity improves. Therefore, the difference (ΔT) between the liquidus temperature and the spinning temperature is preferably 50°C or more, 60°C or more, 70°C or more, 90°C or more, 100°C or more, 110°C or more, 125°C or more, particularly preferably 180°C or more.

[0061] Density is a property that affects the weight of the composite material of the resin and the glass fiber. If the density of the glass fiber becomes high, the weight of the composite material becomes large, and it becomes difficult to reduce the weight. Therefore, the density of the glass fiber is preferably 2.55 g / cm 3 2.45 g / cm 3 Hereinafter, 2.4 g / cm 3 Hereinafter, the lower limit value is not particularly limited, and in reality, 2 g / cm 3 Hereinafter, the upper limit value is not particularly limited, and in reality, 3.0 g / cm

[0062] Young's modulus is a property that affects the strength of the composite material of the resin and the glass fiber. If the Young's modulus of the glass fiber is too low, it is difficult to obtain a composite material of sufficient strength. On the other hand, if the Young's modulus of the glass fiber is too high, the composite material loses flexibility and it is difficult to process. Therefore, the suitable lower limit range of the Young's modulus is 40 GPa or more, 45 GPa or more, and particularly 50 GPa or more, and the suitable upper limit range is 90 GPa or less, and particularly 85 GPa or less.

[0063] The water content in the glass affects the dielectric properties. The water content in the glass can be evaluated by the "β-OH value". The β-OH value refers to a value calculated by measuring the transmittance using FT-IR and by the following formula.

[0064] β-OH value = (1 / t) x log 10 (T1 / T2)

[0065] t: thickness of the glass (mm)

[0066] T1: transmittance (%) at a reference wavelength of 3846 cm -1 (2600 nm)

[0067] T2: minimum transmittance (%) near a hydroxyl absorption wavelength of 3600 cm -1 (2800 nm)

[0068] If the β-OH value is too large, the network in the glass is cut, and non-crosslinking oxygen easily becomes large. Thus, it is possible that polarization is locally generated, and the dielectric constant and the dielectric loss tangent become high. Therefore, the upper limit of the β-OH value is preferably 0.9 / mm or less, 0.88 / mm or less, 0.85 / mm or less, 0.8 / mm or less, 0.75 / mm or less, 0.7 / mm or less, 0.6 / mm or less, 0.55 / mm or less, less than 0.55 / mm, 0.54 / mm or less, 0.53 / mm or less, less than 0.53 / mm, 0.52 / mm or less, 0.51 / mm or less, 0.5 / mm or less, 0.48 / mm or less, 0.46 / mm or less, 0.44 / mm or less, 0.42 / mm or less, and particularly 0.4 / mm or less. On the other hand, if the β-OH value is too small, the meltability easily decreases. Therefore, the lower limit of the β-OH value is preferably 0.3 / mm or more, and particularly 0.35 / mm or more.

[0069] Note that adjustment of the β-OH value can be performed by use of a water-containing raw material, a melting method, a melting temperature, adjustment of a glass flow, or the like.

[0070] Next, a method for producing the glass fiber of the present application will be described. Note that in the following description, a direct melting method (DM method) and an indirect forming method (MM method: Marble Melt method, glass ball melting method) are described as examples, but the method for producing the glass fiber of the present application is not limited to the following methods, and other methods can also be used.

[0071] First, a raw material batch is prepared so as to have the above composition. Note that a part or all of the glass raw material can be a cullet.

[0072] Next, the prepared raw material batch is put into a glass melting furnace, and glassification, melting, and homogenization are performed. The melting temperature is preferably about 1500 to 1600°C.

[0073] Next, the obtained molten glass is continuously drawn from a bushing to be formed into a fiber shape, and a glass fiber is obtained (DM method). Alternatively, the obtained molten glass is temporarily formed into a glass ball shape, and then remelted, and the obtained molten glass is continuously drawn from a bushing to be formed into a fiber shape, and a glass fiber is obtained (MM method).

[0074] If necessary, a coating agent for imparting a desired physical and chemical property can be applied to the surface of the glass fiber. Specifically, a polyurethane resin, an epoxy resin, an acid copolymer, a modified polypropylene resin, a polyester resin, an antistatic agent, a surfactant, an antioxidant, a coupling agent, or a lubricant can be used.

[0075] Note that examples of coupling agents that can be used in the surface treatment of the glass fibers include γ-aminopropyltriethoxysilane, N-phenyl-Y-aminopropyltrimethoxysilane, Y- glycidoxypropyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-(2-aminoethyl) aminopropyltrimethoxysilane, β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, N-β-(N- vinylbenzylaminoethyl)-Y-aminopropyltrimethoxysilane hydrochloride, γ-chloropropyltrimethoxysilane, Y-mercaptopropyltrimethoxysilane, and vinyltriethoxysilane. These can be appropriately selected depending on the type of the resin to be compounded.

[0076] The glass fibers of the present application can be processed into any glass fiber product, in addition to being used as chopped strands for resin reinforcement, such as yarns, glass cloth, glass fillers, glass fiber chopped strands, glass paper, nonwoven fabric, continuous strand mat, knitted fabric, glass roving, milled fiber, and the like.

[0077] The glass fibers of the present application can be used in combination with fibers other than those of the present application, provided that the combination does not interfere with the objects of the present application. Examples of such fibers include glass fibers such as E glass fibers and S glass fibers, and inorganic fibers other than glass fibers such as carbon fibers and metal fibers.

[0078] [Examples]

[0079] The present application will be described below based on examples. The present application is not limited to these examples, however.

[0080] Examples 1 to 6 of the present application are shown in Table 1, Examples 7 to 12 are shown in Table 2, and Comparative Examples 1 to 3 are shown in Table 3.

[0081] [Table 1]

[0082]

[0083] [Table 2]

[0084]

[0085] [Table 3]

[0086]

[0087] Each of the samples described in Tables 1 to 3 was produced as follows.

[0088] First, various glass raw materials such as natural raw materials, chemically synthesized raw materials, etc. were weighed so that the total would be 500 g, and were prepared in a manner such that the glass composition after melting would be the glass composition shown in Tables 1 to 3. Next, the obtained raw material mixture was crushed and mixed (Japanese original: crushed and mixed) for 20 minutes. Next, the crushed (Japanese original: crushed) raw material mixture was put into a 300 cc platinum-rhodium crucible, and a molten glass was produced by heating in an indirect heating electric furnace in an atmosphere at about 1450 to 1650°C for 6 hours. The obtained molten glass was flowed onto a carbon plate, and was roll-formed in a manner such that the thickness would be 5 mm, and was left to cool to room temperature.

[0089] Note that, for Example 7 of Table 2 and Comparative Example 3 of Table 3, the following procedure was followed to melt and obtain the evaluation sample. Various glass raw materials such as natural raw materials, chemically synthesized raw materials, etc. were weighed so that the total would be 300 g, and were prepared in a manner such that the glass composition after melting would be the glass composition shown in Tables 2 and 3. For Example 7, 0.135 g of MoO3 was added to the obtained raw material mixture. The raw material mixture to which MoO3 was added was crushed and mixed for 20 minutes. For Comparative Example 3, no MoO3 was added. Next, the crushed (Japanese original: crushed) raw material mixture was put into a 300 cc quartz glass crucible, and a molten glass was produced by heating in an indirect heating electric furnace in an atmosphere at about 1450 to 1650°C for 6 hours. The obtained molten glass was flowed onto a carbon plate, and was roll-formed in a manner such that the thickness would be 5 mm, and was left to cool to room temperature.

[0090] The following characteristics were measured for each of the obtained samples.

[0091] The dielectric constant ε and the dielectric loss tangent tan δ at a frequency of 40 GHz were measured as follows. The glass sample obtained by the above method was processed to a size of 30 mm x 40 mm x 0.15 mm t. The two main faces were mirror finished by polishing and grinding. The obtained sample was subjected to annealing treatment. The measurement was performed by the split cylinder method using a resonator for 40 GHz and a vector analyzer. In addition, the measurement was performed at room temperature (25°C).

[0092] Note that the annealing treatment was performed using an annealing furnace according to the following temperature schedule. The sample was set in the annealing furnace, and was heated at 1°C / min from room temperature to 580 to 600°C, was held at 580 to 600°C for 30 minutes, was cooled at 3°C / min to 400 to 420°C, and was then left to cool to room temperature in the annealing furnace.

[0093] The transmittance was measured as follows. The glass sample obtained by the above method was processed to a size of 25 mm x 30 mm x 1 mm. The two main faces were mirror finished by polishing grinding. The obtained sample was subjected to annealing treatment under the above conditions. The measurement was performed using a spectrophotometer V-670 (Nippon Denshoku Industries Co., Ltd.). The measurement wavelength was set to 200 to 800 nm, the scanning speed was set to 200 nm / min, the sampling interval was set to 1 nm, and the measurement was performed at room temperature. Note that, in the table, "%T at 300 nm" means the total light transmittance at a wavelength of 300 nm, and "min %T 400-800 nm" means the minimum total light transmittance in the range of wavelengths of 400 to 800 nm.

[0094] Temperature at 10 dPa s, high temperature viscosity 4 Temperature at 10 dPa s, high temperature viscosity 3 Temperature at 10 dPa s, high temperature viscosity 2.5 Temperature at 10 dPa s, high temperature viscosity 2 The temperature at 10 dPa s (indicated as "10 4 ", "10 3 ", "10 2.5 ", and "10 2 " in the table, respectively) was measured as follows. A part of the glass sample obtained by the above method was broken into an appropriate size in advance, and was put into a platinum crucible, and then was heated to a molten state, and was measured by a platinum ball pulling method.

[0095] Liquidus temperature T L The measurement was performed as follows. The glass sample obtained by the above method was pulverized, and the powder that was equivalent to 10 times the weight of the density was collected by sieving through a 500-μm mesh. The collected glass powder was filled into a platinum boat having an internal size of about 120 x 20 x 10 mm, and was put into an electric furnace having a linear temperature gradient for 24 hours. Then, the glass was taken out of the platinum boat, and after being cooled to room temperature, the crystallization precipitation site was observed and determined by a microscope. The temperature corresponding to the crystallization precipitation site was calculated from the temperature gradient chart of the electric furnace, and was taken as the liquidus temperature.

[0096] With respect to the density p, about 10 g of the glass sample obtained by the above method was cut out, and was measured by the Archimedes method. Note that, before the measurement, annealing treatment was performed by the above method.

[0097] The Young's modulus was measured as follows. The glass sample obtained by the above method was processed to 40 x 20 x 2 mm. The two main faces of the obtained sample were polished with a polishing liquid prepared by dissolving 1200-grade alumina powder in water. The sample was subjected to the annealing treatment described above before the measurement to remove strain. In addition, on the surface of the sample, a layer of a protective film having a thickness of 100 nm was formed by sputtering. Gold was deposited in the above manner. The free resonance type elastic modulus measuring device (JE-RT3 manufactured by Nihon Techno-Plus Co., Ltd.) was used to measure the elastic modulus.

[0098] The β-OH value was measured by the following procedure. The glass sample obtained by the above procedure was processed into a 20 mm x 30 mm x 1 mm sample. The two major surfaces of the sample were mirror finished. The sample was annealed to remove strain before measurement. The β-OH value was measured by the above procedure using the sample.

[0099] Note that, for each of the above properties, a bulk glass sample can be prepared from a glass fiber sample or a glass bead sample by the following procedure, and the bulk glass sample can be used for measurement. The glass fiber sample or the glass bead sample was melted in a quartz container in an electric furnace set to a temperature corresponding to a high-temperature viscosity of 10 3 The melting time is preferably about 15 minutes to 5 hours, although it depends on the weight of the glass. If the sample is added to the molten glass, the quartz container can be damaged by thermal shock, so the sample is preferably added to the quartz container at one time. Note that, in the case of a glass fiber sample, the sample was preferably heat-treated at 400 to 500°C for 6 to 12 hours in the quartz container to remove the binder coated on the surface, and then added to the quartz container.

[0100] After confirming that the bubbles in the molten glass had disappeared, the sample was removed from the electric furnace and cast onto a carbon plate to form a glass sheet having a thickness of 5 mm. The obtained glass sheet was cooled to room temperature. In the case where the amount of glass was insufficient to cast the molten glass, the molten glass was cooled by pressing it with an iron plate. In the case where strain was removed before measurement, the sample was annealed by the above procedure. Note that, in the case where the amount of glass was so small that it could not be cast, the sample was annealed in the quartz container in an annealing furnace.

[0101] As shown in Tables 1 and 2, the dielectric constant of the glass of Examples 1 to 12 at 40 GHz was 4.9 or less, and the dielectric loss tangent was as low as 0.0105 or less. In addition, since the total light transmittance at 300 nm was as low as 63% or less, the glass was easily colored by ultraviolet light. Furthermore, since the minimum total light transmittance in the range of 400 to 800 nm was as high as 51% or more, the glass was less colored and the color tone as a composite material was less likely to change.

[0102] On the other hand, as shown in Table 3, the B2O3 of Comparative Example 1 is small, and the dielectric constant is as high as 6.6. In Comparative Example 2, the value of TiO2 x MoO3 is as large as 3150, and thus the glass is strongly colored, and the minimum total light transmittance in the wavelength range of 400 to 800 nm is 9% or less. In Comparative Example 3, since all of MoO3, Cr2O3, Pt, and Rh are not contained, the transmittance at a wavelength of 300 nm is as high as 72%.

[0103] Industrial applicability

[0104] For the glass fiber of the present application, as a fiber-reinforced resin molded article, in addition to being suitable for use as a housing and a member of a portable electronic device such as a smartphone, a tablet, a notebook computer, a portable music player, and a portable game machine, it can also be suitable for use as a communication member used in a millimeter wave band, such as a vehicle-mounted millimeter wave radar, a vehicle exterior member, a vehicle interior member, a vehicle engine surrounding member, an electronic device housing, an electronic component, and the like.

Claims

1. A glass fiber, wherein, As the glass composition, 55 to 80% of SiO2, 0% or more and less than 10% of Al2O3, 18 to 25% of B2O3, 0 to 4% of MgO, 0 to 5% of CaO, 0 to 1% of SrO, 0 to 2% of Li2O, 0 to 3% of Na2O, 0 to 3% of K2O, 1 to 3.8% of Li2O + Na2O + K2O, 0 to 0.2% of ZrO2, 0 to 0.5% of Fe2O3, 0 to 0.5% of SnO2, 0.01 to 6% of TiO2, 0.01 ppm to 500 ppm of MoO3, 0.01 ppm to 500 ppm of MoO3, Cr2O3, Pt, and Rh, and the total amount of MoO3, Cr2O3, Pt, and Rh is 0.01 ppm to 500 ppm, and The value of the TiO2 content in mass% x the MoO3 content in ppm is 3100 or less, The β-OH value is less than 0.55 / mm.

2. The glass fiber according to claim 1, having a total light transmittance of 70% or less at a wavelength of 300 nm and a minimum total light transmittance of 50% or more in a wavelength range of 400 to 800 nm at a thickness of 1 mm.

3. The glass fiber according to claim 1 or 2, having a dielectric constant of 6 or less and a dielectric loss tangent of 0.011 or less at 25°C and 40 GHz.

4. The glass fiber according to claim 1 or 2, having a spinning temperature of 1450°C or less. As the glass composition, 0 to 0.15% of Fe2O3, 0.01 ppm to 100 ppm of Pt in mass%.

5. The glass fiber of claim 1 or 2, wherein, ​

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