Glass composition, glass fiber and method for producing the same

Abstract

Provided is a glass composition that contains the following components, indicated in mass%: 45 ≤ SiO2 ≤ 80, 10 ≤ B2O3 ≤ 40, 0.1 ≤ Al2O3 ≤ 20, 0.1 ≤ (MgO + CaO) ≤ 10, 0 ≤ (Li2O + Na2O + K2O) ≤ 5, and 0.1 ≤ T-SnO2 ≤ 2 (where T-SnO2 is the total tin oxide as SnO2), wherein 0 ≤ MgO / (MgO + CaO) ≤ 0.50 on a mass basis is established. The glass composition is suitable for the stable production of low-dielectric-constant glass fiber.

Description

[Technical Field]

[0001] The present invention relates to a glass composition, a glass fiber formed from the composition, and a method for producing the glass fiber. [Background technology]

[0002] Resin compositions are widely used as electrical insulating materials and mechanical components in various electronic components. Examples of electrical insulating materials include connector housings used in SMT (surface mount technology), FPC (flexible printed circuits), board-to-board connections, CPU (central processing unit) sockets, memory cards, card edges, optical connectors, etc., LCD (liquid crystal display) backlights, coils, flats, transformers, reactance bobbins used in magnetic heads, etc., relay cases, relay base switches, reflow DIP switches, tact switches, etc., switches, sensor cases, capacitor casings, volume casings, and trimmer casings. Examples of mechanical components include lens holders and pickup bases for optical pickups, insulators and terminals for micromotors, and laser printer drums. Resin compositions are also used as films, such as base films for FPCs and copper-clad laminates. In addition, substrates made of resin compositions are also used as a type of printed circuit board (PC) used in electronic components. Printed wiring boards, before electronic components are mounted, also include substrates made of resin compositions. Hereinafter, in this specification, both printed circuit boards and printed wiring boards will be referred to as "printed boards."

[0003] The resin composition contains a thermoplastic resin and glass fiber, and optionally further contains a curing agent, a modifier, etc. The printed circuit board may further contain an inorganic filler. A glass filler may be used as the inorganic filler. In recent years, to meet the demands for miniaturization of electronic devices and for thinner devices for higher functionality, resin compositions are required to have a low dielectric constant, and accordingly, the constituent materials thereof are also required to have a low dielectric constant. Patent Document 1 discloses glass fiber composed of a glass composition with a low dielectric constant. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 62-226839 Summary of the Invention [Problem to be solved by the invention]

[0005] Glass compositions are required to have properties suitable for mass production. For example, long glass fibers are obtained by spinning a glass melt in a refractory kiln. In such a glass fiber manufacturing method, the glass fibers are prone to breakage due to bubbles present in the glass melt. In particular, glass compositions with low dielectric constants have a relatively high viscosity, and bubbles generated during melting of the glass raw materials are likely to remain in the glass melt. There is room for improvement in the technology for manufacturing glass fibers composed of glass compositions with low dielectric constants.

[0006] An object of the present invention is to provide a glass composition that can be stably produced as a glass fiber having a low dielectric constant. [Means for solving the problem]

[0007] The inventors have discovered that such a glass composition can be obtained by using tin oxide as a fining agent and by specifying the range of the T-SnO2 content (T-SnO2 is the total tin oxide converted to SnO2).

[0008] The glass composition of the present invention comprises, expressed in mass %, 45≦SiO2≦80, 10≦B2O3≦40, 0.1≦Al2O3≦20, 0.1≦(MgO+CaO)≦10, 0≦(Li2O+Na2O+K2O)≦5, 0.1≦T-SnO2≦2, (However, T-SnO2 is total tin oxide converted to SnO2) Contains the ingredients of By mass, 0≦MgO / (MgO+CaO)≦0.50 holds true.

[0009] The glass fiber of the present invention is a glass fiber composed of the above-mentioned glass composition.

[0010] The method for producing a glass fiber of the present invention is a method for producing a glass fiber, comprising the steps of melting the glass composition of the present invention and forming the molten glass composition into a glass fiber. [Effects of the Invention]

[0011] According to the present invention, a glass composition is obtained that can stably produce glass fibers with a low dielectric constant. Furthermore, a glass composition that emits light upon irradiation with ultraviolet light is obtained. The light emission upon irradiation with ultraviolet light is useful for applications such as pigments, sensor materials, lighting materials, and building materials. DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, embodiments of the present invention will be described, but the following description is not intended to limit the present invention to specific embodiments. Hereinafter, "substantially free" means a content of less than 0.1% by mass, preferably less than 0.05% by mass, more preferably less than 0.01% by mass, even more preferably less than 0.005% by mass, particularly preferably less than 0.003% by mass, and most preferably less than 0.001% by mass. "Substantially composed" means that components other than the listed components, such as impurities inevitably mixed in from industrial raw materials, manufacturing equipment, etc., are allowed within a range that can be considered "substantially free." The preferred ranges for the content, characteristics, and other aspects of each component can be understood by arbitrarily combining the upper and lower limits individually described below.

[0013] [Glass composition] <Glass composition> (SiO2) Silicon dioxide (SiO2) is a component that forms the skeleton of glass and is the main component (the component with the highest content) of the glass composition. SiO2 also adjusts the devitrification temperature and viscosity during glass formation and has the effect of lowering the dielectric constant. When the SiO2 content is 45% by mass or more and 80% by mass or less, the increase in the devitrification temperature of the glass is suppressed, the melting point of the glass does not become excessively high, and uniformity is improved when melting raw materials. The lower limit of the SiO2 content is preferably 48% by mass or more, more preferably 50% by mass or more, and may be 51% by mass or more, 52% by mass or more, 53% by mass or more, 54% by mass or more, or even 55% by mass or more. The upper limit of the SiO2 content is preferably 75% by mass or less, more preferably 70% by mass or less, even more preferably 65% ​​by mass or less, particularly preferably 60% by mass or less, and most preferably 58% by mass or less. The SiO2 content may be 48% by mass or more and 55% by mass or less.

[0014] (B2O3) Diboron trioxide (BO) is a component that forms the glass skeleton. It also adjusts the devitrification temperature and viscosity during glass formation and has the effect of lowering the dielectric constant. However, BO is prone to volatilization during the melting of a glass composition, and an excessive BO content makes it difficult to obtain sufficient homogeneity in the glass composition. Furthermore, excessive BO reduces the water resistance of the glass. A BO content of 10% by mass or more and 40% by mass or less suppresses an increase in the devitrification temperature of the glass, prevents the glass melting point from becoming excessively high, and improves uniformity during melting of the raw materials. Furthermore, within this range, the water resistance of the glass is improved. The lower limit of the BO content is preferably 15% by mass or more, more preferably 20% by mass or more, even more preferably 24% by mass or more, particularly preferably 25% by mass or more, and most preferably greater than 26% by mass. The upper limit of the B2O3 content is preferably 35% by mass or less, more preferably 32% by mass or less, even more preferably 30% by mass or less, particularly preferably 29% by mass or less, and may be 28% by mass or less. In some cases, the B2O3 content may be 29% by mass or more.

[0015] (Al2O3) Aluminum oxide (Al2O3) is a component that forms the skeleton of glass. Al2O3 also adjusts the devitrification temperature and viscosity during glass formation, improving the water resistance of the glass. Furthermore, Al2O3 adjusts the dielectric constant of the glass. When the Al2O3 content is 0.1% by mass or more and 20% by mass or less, the increase in the devitrification temperature of the glass is suppressed, and the water resistance of the glass is enhanced. Furthermore, the melting point of the glass does not become excessively high, improving uniformity during melting of the raw materials. The lower limit of the Al2O3 content is preferably 1% by mass or more, more preferably 5% by mass or more, even more preferably 8% by mass or more, particularly preferably 10% by mass or more, and most preferably 12% by mass or more. The upper limit of the Al2O3 content is preferably 18% by mass or less, more preferably 16% by mass or less, even more preferably 15% by mass or less, and may be 14% by mass or less, or even 13% by mass or less.

[0016] (MgO, CaO) Magnesium oxide (MgO) and calcium oxide (CaO) are components that adjust the devitrification temperature and viscosity during glass formation while maintaining the heat resistance of the glass. MgO and CaO also improve the water resistance of the glass. Furthermore, MgO and CaO are components that adjust the dielectric constant of the glass.

[0017] When the dielectric constant and water resistance of a glass composition are important, the sum of the contents of MgO and CaO (MgO + CaO), which are components that adjust the dielectric constant and water resistance of the glass, is important. When the sum of the contents of MgO and CaO (MgO + CaO) is 0.1% by mass or more and 10% by mass or less, the increase in the devitrification temperature of the glass is suppressed, the melting point of the glass does not become excessively high, and uniformity is improved when melting the raw materials. Furthermore, within this range, the water resistance of the glass is improved. The lower limit of the sum of the contents of MgO and CaO (MgO + CaO) is preferably 1% by mass or more, more preferably 1.5% by mass or more, even more preferably 2% by mass or more, particularly preferably 2.5% by mass or more, and most preferably 3% by mass or more. The upper limit of the sum of the contents of MgO and CaO (MgO+CaO) is preferably 8% by mass or less, and may be 7% by mass or less, 6% by mass or less, less than 5% by mass, or even 4.5% by mass or less.

[0018] The addition of MgO and CaO can achieve similar effects, but from the viewpoint of further reducing the dielectric constant, the addition of MgO is more advantageous than the addition of CaO. Furthermore, from the viewpoint of further improving water resistance, the addition of MgO is more advantageous than the addition of CaO. However, from the viewpoint of suppressing the occurrence of glass phase separation, the addition of CaO may be more advantageous than the addition of MgO in the case of glass fibers with a low dielectric constant. The occurrence of phase separation in the glass can impair the homogeneity of the glass and make spinning of the glass fiber difficult. When this point is important, it is preferable to add MgO and CaO so that, by mass, 0≦MgO / (MgO+CaO)≦0.50, preferably 0≦MgO / (MgO+CaO)≦0.25, particularly 0≦MgO / (MgO+CaO)<0.21, and in some cases 0≦MgO / (MgO+CaO)≦0.2 is satisfied.

[0019] MgO is a component that adjusts the devitrification temperature and viscosity during glass formation while maintaining the heat resistance of the glass. MgO also improves the water resistance of the glass. Furthermore, MgO adjusts the dielectric constant of the glass. MgO also suppresses phase separation in the glass. However, excessive MgO content increases the dielectric constant of the glass. Therefore, the lower limit of the MgO content may be 0.1% by mass or more, 0.5% by mass or more, 1% by mass or more, 1.5% by mass or more, 2% by mass or more, or 2.5% by mass or more. The upper limit of the MgO content may be 10% by mass or less, 8% by mass or less, 6% by mass or less, less than 5% by mass, 4.5% by mass or less, 4% by mass or less, or even 3% by mass or less.

[0020] CaO is a component that adjusts the devitrification temperature and viscosity during glass formation while maintaining the heat resistance of the glass. CaO also improves the water resistance of the glass. CaO also adjusts the dielectric constant of the glass. CaO also suppresses phase separation in the glass. On the other hand, excessive CaO content increases the dielectric constant of the glass. Therefore, the lower limit of the CaO content may be 0.1% by mass or more, 0.5% by mass or more, 1% by mass or more, 2% by mass or more, 3% by mass or more, or 4% by mass or more. The upper limit of the CaO content may be 10% by mass or less, 8% by mass or less, 6% by mass or less, or even less than 5% by mass. When adjusting the dielectric constant of the glass composition is particularly important, the upper limit of the CaO content may be less than 4% by mass, less than 2% by mass, or even less than 1% by mass.

[0021] (SrO) The glass composition may further contain strontium oxide (SrO). SrO is a component that adjusts the devitrification temperature and viscosity during glass formation. SrO also suppresses phase separation of the glass. However, excessive SrO content increases the dielectric constant of the glass. Therefore, the upper limit of the SrO content may be 5% by mass or less, or may be 3% by mass or less, 2% by mass or less, 1% by mass or less, 0.5% by mass or less, or even less than 0.1% by mass. SrO may be substantially absent. However, in certain embodiments, particularly those in which MgO is 1% by mass or less, surprisingly, the inclusion of an appropriate amount of SrO unexpectedly reduces the dielectric constant. This effect is significantly observed at SrO contents of 1% by mass or more, or 2% by mass or more.

[0022] (BaO) The glass composition may further contain barium oxide (BaO). BaO is a component that adjusts the devitrification temperature and viscosity during glass formation. BaO also suppresses phase separation of the glass. However, excessive BaO content increases the dielectric constant of the glass. Therefore, the upper limit of the BaO content may be 5% by mass or less, 2% by mass or less, 1% by mass or less, 0.5% by mass or less, or even less than 0.1% by mass. BaO may not be substantially present. When particular importance is attached to uniform melting of the glass raw materials and stable production of the glass composition, the lower limit of the BaO content may be 0.05% by mass or more, 0.1% by mass or more, for example, 0.1% by mass or more but less than 1% by mass, or even 0.2% by mass or more but less than 1% by mass.

[0023] (ZnO) The glass composition may further contain zinc oxide (ZnO). ZnO is a component that adjusts the devitrification temperature and viscosity during glass formation. ZnO also adjusts the dielectric constant of the glass. However, excessive ZnO content increases the dielectric constant of the glass. Therefore, the upper limit of the ZnO content may be 5% by mass or less, 2% by mass or less, 1% by mass or less, 0.5% by mass or less, or even less than 0.1% by mass. ZnO need not be substantially present.

[0024] (Li2O, Na2O, K2O) Alkali metal oxides (Li2O, Na2O, K2O) are components that adjust the devitrification temperature and viscosity during glass formation while maintaining the heat resistance of the glass.

[0025] Li2O is a component that adjusts the devitrification temperature and viscosity during glass formation. However, excessive Li2O content increases the dielectric constant of the glass. Furthermore, excessive Li2O content reduces the water resistance of the glass. Therefore, the lower limit of the Li2O content may be 0.1% by mass or more, 0.2% by mass or more, 0.3% by mass or more, 0.4% by mass or more, or even 0.5% by mass or more. The upper limit of the Li2O content may be 5% by mass or less, 4% by mass or less, 3% by mass or less, 2% by mass or less, 1.5% by mass or less, or even 1% by mass or less.

[0026] Na2O is a component that adjusts the devitrification temperature and viscosity during glass formation. However, excessive Na2O content increases the dielectric constant of the glass. Furthermore, excessive Na2O content reduces the water resistance of the glass. Therefore, the upper limit of the Na2O content can be 4% by mass or less, 2% by mass or less, 1.5% by mass or less, 1% by mass or less, 0.5% by mass or less, or even 0.2% by mass or less.

[0027] K2O is a component that adjusts the devitrification temperature and viscosity during glass formation. However, excessive K2O content increases the dielectric constant of the glass. Furthermore, excessive K2O content reduces the water resistance of the glass. Therefore, the upper limit of the K2O content can be 4% by mass or less, 2% by mass or less, 1% by mass or less, 0.5% by mass or less, 0.2% by mass or less, or even less than 0.1% by mass. K2O need not be substantially present.

[0028] The lower limit of the total alkali metal oxide content (Li2O + Na2O + K2O) may be 0.1 mass% or more, 0.2 mass% or more, 0.3 mass% or more, 0.4 mass% or more, or even 0.5 mass% or more. The upper limit of (Li2O + Na2O + K2O) may be 5 mass% or less, 4 mass% or less, 3 mass% or less, 2 mass% or less, 1.5 mass% or less, or even 1 mass% or less. Alkali metal oxides (Li2O + Na2O + K2O) may not be substantially present. However, when uniform melting of glass raw materials and stable production of glass compositions are particularly important, (Li2O + Na2O + K2O) may be 1 mass% or more.

[0029] The lower limit of the ratio of alkali metal oxide contents, Li2O / (Li2O + Na2O), expressed in mass%, can be 0.01 or greater, 0.02 or greater, or 0.05 or greater. The upper limit of Li2O / (Li2O + Na2O) can be 0.9 or less, 0.8 or less, or 0.6 or less. When this ratio is within these ranges, the operating temperature is significantly reduced, resulting in advantages in operability and equipment design. This effect is considered to be known as the mixed alkali effect, but the known mixed alkali effect applies when the alkali metal oxide content exceeds, for example, 10 mass%, and is not known when the alkali metal oxide content is 5 mass% or less. It is also noteworthy that the mixed alkali effect at such low alkalinity becomes particularly pronounced when this ratio changes from 0 to 0.01.

[0030] (TiO2) The glass composition may further contain titanium oxide (TiO2). TiO2 is a component that improves the meltability and chemical durability of glass and improves the ultraviolet absorption characteristics of glass. On the other hand, excessive TiO2 content increases the dielectric constant of glass. The lower limit of the TiO2 content may be 0.1 mass% or more. The upper limit of the TiO2 content may be 5 mass% or less, or 2 mass% or less, less than 1 mass%, less than 0.5 mass%, or 0.2 mass% or less. Within these upper limit ranges, the increase in devitrification temperature due to the inclusion of TiO2 can be suppressed. The upper limit of the TiO2 content may be less than 0.1 mass%. TiO2 may be substantially absent.

[0031] (ZrO2) The glass composition may further contain zirconium oxide (ZrO2). ZrO2 is a component that adjusts the devitrification temperature and viscosity during glass formation. However, excessive ZrO2 content increases the dielectric constant of the glass. The upper limit of the ZrO2 content may be 5% by mass or less, or may be 2% by mass or less, less than 1% by mass, less than 0.5% by mass, 0.2% by mass or less, or even less than 0.1% by mass. Within these upper limit ranges, the inclusion of ZrO2 can prevent an increase in the devitrification temperature of the molten glass that would affect the production of the glass composition. ZrO2 need not be substantially present.

[0032] (T-Fe2O3) The glass composition may further contain iron oxide. The iron (Fe) contained in the glass composition is usually Fe 2+ or Fe 3+ It exists in the state of Fe 3+ is a component that enhances the ultraviolet absorption properties of the glass composition, and Fe 2+is a component that enhances the heat absorption properties of a glass composition. Even if not intentionally included, Fe may be unavoidably mixed in with industrial raw materials. A low Fe content can prevent coloration of the glass composition. The upper limit of the Fe content, expressed as T-Fe2O3 (T-Fe2O3 is total iron oxide converted to Fe2O3), can be 5% by mass or less, 2% by mass or less, less than 1% by mass, less than 0.5% by mass, or even 0.2% by mass or less. T-Fe2O3 may be 0.1% by mass or more. Depending on the glass composition, T-Fe2O3 may reinforce the fining effect of T-SnO2. Specifically, a glass composition containing 0.1% or more of T-Fe2O3, for example, 0.1% to 1% by mass, and satisfying 0≦MgO / (MgO+CaO)≦0.2, or even 0≦MgO / (MgO+CaO)≦0.15, is particularly suitable for stable production. In this particularly suitable glass composition, the T-SnO2 content may be 0.15% or more by mass, or even 0.2% or more by mass. Due to the reinforcing effect of T-Fe2O3, stable production is possible even when the T-SnO2 content is less than 0.5% by mass.

[0033] (T-SnO2) The glass composition of this embodiment contains tin oxide. Sn in the glass is usually Sn 2+ and / or Sn 4+ SnO2 exists in the following state. SnO2 is a component that defoams bubbles present in the glass matrix. It also improves the water resistance of glass. Furthermore, Sn in glass is a component that emits light when irradiated with ultraviolet light. In the glass composition, the content of tin oxide, T-SnO2 (total tin oxide converted to SnO2), is set to be in the range of 0.1 mass% to 2 mass%. If the T-SnO2 content is less than 0.1 mass%, the tin oxide does not have a sufficient effect of clarifying the glass composition. If the T-SnO2 content exceeds 2 mass%, the devitrification temperature of the glass composition increases, or the glass becomes more susceptible to phase separation.

[0034] The lower limit of the T-SnO2 content is preferably 0.1 mass% or more, and may be 0.2 mass% or more, 0.22 mass% or more, 0.25 mass% or more, 0.3 mass% or more, 0.35 mass% or more, 0.4 mass% or more, or even 0.5 mass% or more. The lower limit of the T-SnO2 content is 0.6 mass% or more, further 0.65 mass% or more, and in some cases may be 0.8 mass% or more. The upper limit of the T-SnO2 content is preferably 1.8 mass% or less, more preferably 1.6 mass% or less, even more preferably 1.4 mass% or less, 1.3 mass% or less, or less than 1.2 mass%, particularly preferably 1.0 mass% or less, 0.8 mass% or less, and most preferably 0.5 mass% or less, or 0.3 mass% or less.

[0035] An example of a glass composition suitable for stable production of low-dielectric-constant glass fibers has a T-SnO2 content of 0.5 mass% or more, and 0≦MgO / (MgO+CaO)≦0.2. This example of a glass composition may contain T-Fe2O3 in the above range, but may not contain it substantially. Examples of this glass composition will be described later. CeO 2 may be included within the range described below, but it does not have to be substantially included.

[0036] Another example of a glass composition suitable for stable production of low-dielectric-constant glass fibers has a T-SnO2 content of 0.3 mass % or more, and even 0.4 mass % or more, and is substantially free of MgO. This example of a glass composition may also contain T-Fe2O3 in the above range, but may not be substantially free of it. This example of a glass composition will also be described later. CeO 2 may be included within the range described below, but it does not have to be substantially included.

[0037] Another example of a glass composition suitable for stable production of low-dielectric-constant glass fibers has a T-SnO2 content of 0.6 mass% or more, preferably 0.65 mass% or more, particularly 0.7 mass% or more, and in some cases 0.8 mass% or more, and (Li2O + Na2O + K2O) in the range of 0.3 mass% or more, further 0.35 mass% or more. This example of a glass composition may also contain T-Fe2O3 in the above range, but may not be substantially contained. This example of a glass composition will also be described later. CeO 2 may be included within the range described below, but it does not have to be substantially included.

[0038] For stable production of glass fibers with a low dielectric constant, a larger ΔT, as described below, is preferable. In one example of a glass composition suitable for ensuring a large ΔT, the following formulas are satisfied on a mass basis: 0.1≦T-SnO2≦0.5 0.1≦(T-Fe2O3+T-SnO2)≦0.6 0.1≦(Li2O+Na2O+K2O)≦1 A glass composition satisfying the above formulas is suitable for achieving properties such as a dielectric constant of 5.0 or less, preferably 4.8 or less at 1 GHz, and a ΔT of 100°C or more, preferably 140°C or more.

[0039] Components not shown in the above formulas also affect ΔT. However, within the range where the above three formulas are true, even if a low dielectric constant contains undesirable components, for example, when the following fourth formula is also true along with the above three formulas, a low dielectric constant and a high ΔT can be achieved simultaneously. 0.1≦(SrO+BaO)≦5

[0040] (CeO2) The glass composition may further contain cerium oxide (CeO2). CeO2 is a fining component. A low CeO2 content can prevent coloration of the glass composition. Therefore, the lower limit of the CeO2 content may be 0.1 mass% or more. The upper limit of the CeO2 content may be 5 mass% or less, 2 mass% or less, 1 mass% or less, or less than 0.5 mass%. The upper limit of the CeO2 content may be less than 0.1 mass%. CeO2 may be substantially absent.

[0041] (F2, Cl2) The glass composition may further contain fluorine and / or chlorine. Fluorine and chlorine may be present as molecules (F2 and Cl2, respectively) or as anions (F - and Cl - ) may be contained as fluorine or chlorine. In this specification, fluorine and chlorine contained in the form of molecules or anions may be collectively referred to as F2 and Cl2, respectively. Their contents are expressed as mass percentages converted to molecules. Fluorine (F2) is easily volatile, which may cause it to scatter during melting, and there is also the problem that its content in the glass is difficult to control. The upper limit of the F2 content may be 5% by mass or less, or 2% by mass or less, 1% by mass or less, 0.5% by mass or less, 0.2% by mass or less, or even less than 0.1% by mass. F2 may be substantially absent. Chlorine (Cl2) is easily volatile, which may cause it to scatter during melting, and there is also the problem that its content in the glass is difficult to control. The upper limit of the Cl2 content may be 5% by mass or less, or 2% by mass or less, 1% by mass or less, 0.5% by mass or less, 0.2% by mass or less, or even less than 0.1% by mass. It is not necessary for Cl2 to be substantially contained.

[0042] (P2O5) The glass composition may further contain diphosphorus pentoxide (P2O5). Diphosphorus pentoxide is a component that forms the glass framework and also adjusts the devitrification temperature and viscosity during glass formation. P2O5 also adjusts the dielectric constant of the glass. Generally, if the P2O5 content exceeds 2% by mass, the furnace walls of melting furnaces and regenerative furnaces may be corroded during glass melting, significantly shortening the furnace life. The upper limit of the P2O5 content may be 5% by mass or less, or may be 2% by mass or less, less than 1% by mass, less than 0.5% by mass, 0.2% by mass or less, or even less than 0.1% by mass. P2O5 may be substantially absent.

[0043] (Other ingredients) The glass composition may contain at least one other component selected from La2O3, WO3, Nb2O5, Y2O3, MoO3, Ta2O5, MnO2, Cr2O3, CuO, and CoO, each in a content of 0% to 5% by mass. The allowable content of each of these components may be less than 2% by mass, less than 1% by mass, less than 0.5% by mass, or even less than 0.1% by mass. The allowable total content of these components may be 5% by mass or less, less than 2%, less than 1%, less than 0.5%, or even less than 0.1% by mass. However, each of the above other components may not necessarily be substantially present.

[0044] The glass composition may contain at least one additive selected from Br2, I2, As2O3, and Sb2O3, each in a content of 0% by mass or more and 1% by mass or less. The allowable content of each of these components may be less than 0.5% by mass, less than 0.2% by mass, or even less than 0.1% by mass. The allowable total content of these components may be less than 1% by mass, less than 0.5%, less than 0.2%, or even less than 0.1% by mass. However, the above other components may not be substantially present.

[0045] The glass composition may contain HO, OH, H, CO, CO, He, Ne, Ar, and N at a content of 0% by mass or more and 0.1% by mass or less, respectively. The allowable content of each of these components may be less than 0.05% by mass, less than 0.03% by mass, or even less than 0.01% by mass. The allowable total content of these components may be less than 0.1% by mass, less than 0.05% by mass, less than 0.03% by mass, or even less than 0.01% by mass. However, the above other components may not be substantially present.

[0046] The glass composition may contain trace amounts of precious metal elements. For example, precious metal elements such as Pt, Rh, Au, and Os may be contained in a content of 0% by mass or more and 0.1% by mass or less, respectively. The allowable content of each of these components may be less than 0.1% by mass, less than 0.05% by mass, less than 0.03% by mass, or even less than 0.01% by mass. The allowable total content of these components may be 0.1% by mass or less, less than 0.05% by mass, less than 0.03% by mass, or even less than 0.01% by mass. However, the above other components may not be substantially present.

[0047] <Characteristics> The properties that the glass composition of this embodiment can have will be described below. (melting characteristics) The temperature at which the viscosity of molten glass reaches 1000 dPa·sec (1000 poise) is called the working temperature of the glass, and is the temperature most suitable for forming the glass. When producing glass fibers, if the working temperature of the glass is 1100°C or higher, the variation in glass fiber diameter can be reduced. If the working temperature is 1450°C or lower, the fuel cost for melting the glass can be reduced, glass manufacturing equipment is less susceptible to thermal corrosion, and the equipment life can be extended. The lower limit of the working temperature can be 1100°C or higher, 1150°C or higher, 1200°C or higher, 1250°C or higher, or even 1300°C or higher. The upper limit of the working temperature can be 1450°C or lower, 1420°C or lower, 1400°C or lower, 1380°C or lower, or even lower than 1350°C.

[0048] The larger the temperature difference ΔT, which is the working temperature minus the devitrification temperature, the less likely devitrification occurs during glass molding, and the higher the yield of homogeneous glass that can be produced. Therefore, ΔT can be 0°C or higher, 10°C or higher, 20°C or higher, 30°C or higher, 40°C or higher, 50°C or higher, and in some cases, 100°C or higher, or even 140°C or higher. On the other hand, if ΔT is 500°C or lower, it becomes easier to adjust the glass composition. ΔT can be 500°C or lower, 400°C or lower, 300°C or lower, or even 200°C or lower.

[0049] (Dielectric constant) The glass composition of this embodiment may have a low dielectric constant. The dielectric constant at a measurement frequency of 1 GHz is 5.5 or less, 5.2 or less, 5.0 or less, 4.9 or less, 4.8 or less, 4.7 or less, 4.6 or less, or even 4.5 or less, and in some cases 4.4 or less. Strictly speaking, the dielectric constant refers to the relative permittivity, but in this specification, it is simply referred to as the dielectric constant in accordance with conventional practice. The dielectric constant is a value at room temperature (25°C).

[0050] [Glass fiber, etc.] <Glass fiber> The glass fiber of the present embodiment is composed of the above-mentioned glass composition. According to the present embodiment, even when the fiber diameter is small, the occurrence of devitrification and the inclusion of bubbles in the glass fiber can be further suppressed, and therefore the glass fiber of the present embodiment can be a glass fiber with a small fiber diameter.

[0051] The average fiber diameter of the glass fibers is, for example, 1 to 6 μm. The average fiber diameter may be 3 μm or more, 4.6 μm or less, or even 4.3 μm or less. A glass composition having a characteristic temperature suitable for mass production is suitable for stable production as thin glass fibers. In a preferred embodiment, the average fiber diameter is even thinner, for example, 3.9 μm or less, or even 3.5 μm or less. The glass fibers are, for example, long glass fibers (filaments).

[0052] A preferred application of the glass fiber of this embodiment is a printed circuit board. Glass fibers with a low dielectric constant and a small fiber diameter are suitable for use in printed circuit boards. However, the application is not limited to printed circuit boards.

[0053] The glass fiber may be a glass yarn. The glass yarn of this embodiment may contain glass fibers other than the glass fiber of this embodiment, but may also be composed only of the glass fiber of this embodiment, specifically, long glass fibers. This glass yarn is highly productive because it is less susceptible to defects such as thread breakage and fluffing of the glass fiber.

[0054] The number of long glass fibers (filament count) contained in the glass yarn is, for example, 30 to 200. When used in a printed circuit board, the number of filaments may be, for example, 30 to 100, 30 to 70, or even 30 to 60. An appropriate number is advantageous for more easily and reliably forming a glass cloth and for achieving a thinner printed circuit board. However, the configuration and uses of the glass yarn are not limited to these examples.

[0055] The glass yarn containing glass fibers may have a count of 1 to 6 tex, or even 1 to 3 tex. An appropriate count is advantageous in that it makes it easier and more reliable to form a thin glass cloth, thereby enabling a thinner printed circuit board to be produced.

[0056] The glass yarn may have a strength of 0.4 N / tex or more, further 0.6 N / tex or more, particularly 0.7 N / tex or more.

[0057] The glass fiber of this embodiment can be produced by applying a known method. For example, when producing glass fibers having an average fiber diameter of about 1 to 6 μm, the following example method can be used. That is, a glass composition is charged into a glass melting furnace and melted to form molten glass. The molten glass is then drawn out from a number of spinning nozzles attached to the bottom of a heat-resistant bushing in a spinning furnace and formed into a filament. This method produces glass fibers. The glass fibers can be long glass fibers (filaments). The melting temperature in the melting furnace is, for example, 1300 to 1700°C, preferably 1400 to 1700°C, and more preferably 1500 to 1700°C. In these cases, even when the fiber diameter of the formed glass fiber is small, the occurrence of minute devitrification and the inclusion of bubbles in the glass fiber can be further suppressed, and an excessively high spinning tension can be prevented, thereby reliably ensuring the properties (e.g., strength) and quality of the obtained glass fiber.

[0058] To produce glass fibers with a small fiber diameter, methods such as increasing the drawing speed of molten glass from a spinning furnace or lowering the temperature of the spinning nozzle can be considered. However, the former method may not provide enough time to promote degassing of the molten glass in the spinning furnace. This can lead to thread breakage during spinning due to the inclusion of bubbles, a decrease in fiber strength, and other problems. In addition, the tension generated in the fiber during spinning (spinning tension) increases with an increase in spinning speed, which can also lead to thread breakage during spinning, a decrease in fiber strength, and a decrease in fiber quality. Typically, a winding rotor device called a collet is used to wind glass fibers. However, if the spinning tension increases excessively, the wound glass fibers will develop a kink due to the recesses between the fingers, leading to a decrease in the quality of the glass fiber. The collet is a device equipped with multiple fingers on the outer periphery of the collet body that move radially outward during rotation and sink into the collet body when stopped. The deterioration of the quality of the glass fibers may lead to, for example, poor appearance and / or poor opening of the glass cloth. On the other hand, the latter method requires lowering the melting temperature in the melting furnace, which brings the melting temperature close to the devitrification temperature of the glass composition, increasing the viscosity of the molten glass and making it impossible to perform sufficient degassing. The increase in viscosity also increases the spinning tension, which may cause the above-mentioned problems.

[0059] The above-mentioned problems can be alleviated by using the glass composition of the present embodiment and melting it in the above-mentioned temperature range. The improved quality of the glass fibers also improves the appearance and / or openability of the glass cloth using the glass fibers.

[0060] A glass strand can be formed by applying a sizing agent to the surface of the glass fiber formed by spinning and bundling a plurality of glass fibers, for example, 10 to 120 glass fibers. This strand includes the glass fiber of this embodiment. The strand is wound onto a tube (for example, a cardboard tube) on a collet rotating at high speed to form a cake, and then the strand is unwound from the outer layer of the cake, air-dried while being twisted, and then rewound onto a bobbin or the like and twisted to form a glass yarn.

[0061] [Glass cloth] The glass cloth of this embodiment is made of the above-mentioned glass fibers. The glass cloth of this embodiment may also have the above-mentioned properties, such as a low dielectric constant, of the glass composition of this embodiment. The weave of the glass cloth of this embodiment is, for example, a plain weave, a satin weave, a twill weave, a basket weave, or a rib weave, and is preferably a plain weave. However, the weave is not limited to these examples. The glass yarn may contain glass fibers other than the glass fiber of this embodiment, but may be made only of the glass fiber of this embodiment, specifically, long glass fibers. The glass cloth of this embodiment is suppressed in occurrence of defects such as thread breakage and fluffing of the glass fiber, and has high productivity.

[0062] In a preferred embodiment, the thickness of the glass cloth is 20 μm or less, 7 to 20 μm, or even 8 to 15 μm, as measured in accordance with the provisions of Item 7.10.1 of JIS R3420: 2013. This preferred embodiment of the glass cloth is suitable for thinning printed circuit boards.

[0063] In a preferred embodiment, the mass of the glass cloth is 20 g / m 2, expressed by the cloth mass measured in accordance with the provisions of JIS R3420:2013, item 7.2. 2 Below 8~20g / m 2 , and even 8 to 13 g / m 2 This preferred form of glass cloth is suitable for use in thin printed circuit boards.

[0064] In a preferred embodiment, the number of glass fibers (weave density) per unit length (25 mm) of the glass cloth is, for example, 80 to 130, 80 to 110, or even 90 to 110 per 25 mm of both warp and weft. The glass cloth of this preferred embodiment is suitable for reducing the thickness and increasing the number of intertwining points of the warp and weft, thereby making the glass cloth less prone to twisting and suppressing the occurrence of pinholes when impregnated with a resin.

[0065] In a preferred embodiment, the air permeability of the glass cloth is 200 cm 3 / (cm 2 ·seconds) or less, 50~200cm 3 / (cm 2 seconds), and even 50-150cm 3 / (cm 2 sec). The glass cloth of this preferred embodiment is suitable for reducing its thickness and suppressing the occurrence of the above-mentioned pinholes. In order to open the glass cloth so that it has the above-mentioned level of air permeability, it is advisable to obtain glass fibers by subjecting the glass composition of this embodiment or a glass raw material prepared to obtain the glass composition of this embodiment to the above-mentioned melting temperature, i.e., 1400°C or higher, preferably 1400 to 1650°C.

[0066] The glass cloth of this embodiment can be produced by a known method using the glass fiber of this embodiment. One example of a production method is a method in which a glass yarn is subjected to a warping process and a sizing process, and then the warp yarn is used to drive a glass yarn weft. Various looms, such as a jet loom, a Sulzer loom, or a rapier loom, can be used to drive the weft. Specific examples of jet looms include an air jet loom and a water jet loom. However, the looms used to produce the glass cloth are not limited to these.

[0067] The glass cloth of this embodiment may be subjected to an opening treatment. The opening treatment is advantageous for thinning the glass cloth. The specific method of the opening treatment is not particularly limited, and for example, opening by the pressure of a water flow, opening by high-frequency vibration using water or the like as a medium, and opening by pressure using a roll or the like can be applied. Note that, as the water used as the opening medium, deaerated water, ion-exchanged water, deionized water, electrolytic cation water, electrolytic anion water, etc. can be used. The opening treatment may be carried out simultaneously with or after weaving of the glass cloth. Furthermore, the opening treatment may be carried out simultaneously with or after various treatments such as heat cleaning and surface treatment.

[0068] If a substance such as a sizing agent is attached to the woven glass cloth, a removal treatment of the substance, typically a heat cleaning treatment, may be further carried out. When the glass cloth that has undergone the removal treatment is used for a printed circuit board, it will have excellent impregnation with a matrix resin and excellent adhesion to the resin. After the removal treatment, or separately from the removal treatment, the woven glass cloth may be surface-treated with a silane coupling agent or the like. The surface treatment can be carried out by known means, specifically, by impregnating, coating, or spraying the silane coupling agent into the glass cloth.

[0069] The glass cloth of this embodiment is suitable for printed circuit boards. When used in printed circuit boards, the glass cloth can effectively utilize its characteristics of having a low dielectric constant and being made of glass fibers with a small fiber diameter. However, its use is not limited to printed circuit boards.

[0070] [Prepreg] The prepreg of this embodiment may be made of the glass cloth of this embodiment. The prepreg of this embodiment may also have the above-mentioned properties, such as a low dielectric constant, of the glass composition of this embodiment. The method for manufacturing the prepreg of this embodiment is not particularly limited, and any conventionally known manufacturing method may be used. The resin impregnated into the prepreg of this embodiment is not particularly limited as long as it is a synthetic resin that can be compounded with the glass cloth of this embodiment, and examples thereof include thermosetting resins, thermoplastic resins, and composite resins thereof. It is desirable to use a resin having a low dielectric constant that matches the glass cloth of this embodiment, which has a low dielectric constant.

[0071] [Printed circuit board] The printed circuit board of this embodiment may be made of the glass cloth of this embodiment. The printed circuit board of this embodiment may also have the above-mentioned properties, such as a low dielectric constant, of the glass composition of this embodiment. The method for manufacturing the substrate of this embodiment is not particularly limited, and any conventionally known manufacturing method may be used. For example, a method may be used in which a prepreg containing a resin impregnated in a glass cloth is manufactured and then cured.

[0072] (Examples 1 to 21 and Comparative Examples 1 to 5) Conventional glass raw materials such as silica sand were mixed to obtain the compositions shown in Tables 1 to 3, and batches of glass raw materials were prepared for each of the Examples and Comparative Examples. Each batch was heated to 1550 to 1600°C in an electric furnace to melt it, and maintained at this temperature for approximately 4 hours until the composition became uniform. After that, a portion of the molten glass (glass melt) was poured onto an iron plate and slowly cooled to room temperature in the electric furnace to obtain a bulk glass composition (plate-shaped product, glass sample).

[0073] The relationship between viscosity and temperature of the obtained glass composition was investigated by the conventional platinum sphere pulling method, and the working temperature was determined from the results. Here, the platinum sphere pulling method is a method of measuring viscosity by applying the relationship between the load (resistance) applied when immersing a platinum sphere in molten glass and pulling the platinum sphere up at a uniform speed, and the gravity and buoyancy acting on the platinum sphere, to Stokes' law, which shows the relationship between the viscosity and the falling speed of microparticles when they sink in a fluid.

[0074] The glass composition, crushed to particles with a diameter of 1.0 to 2.8 mm, was placed in a platinum boat and held in an electric furnace with a temperature gradient (800 to 1400°C) for 2 hours. The devitrification temperature was determined from the maximum temperature of the electric furnace corresponding to the position where crystals appeared. When the glass became cloudy and crystals could not be observed, the maximum temperature of the electric furnace corresponding to the position where cloudiness appeared was taken as the devitrification temperature. Here, the particle diameter is a value measured by a sieving method. The temperature (temperature distribution within the electric furnace), which varies depending on the location within the electric furnace, was measured in advance, and the glass composition placed in a predetermined location within the electric furnace was heated at the temperature of the predetermined location. The temperature difference ΔT is the temperature difference obtained by subtracting the devitrification temperature from the working temperature.

[0075] The dielectric constant at a frequency of 1 GHz was measured using a dielectric constant measurement device using a cavity resonator perturbation method. The measurement temperature was 25°C, and the dimensions of the measurement sample were a rectangular parallelepiped with a height of 100 mm and a square base with sides of 1.5 mm.

[0076] The bubble count was determined as follows. Conventional glass raw materials, such as silica sand, were blended to prepare batches of glass raw materials for each example and comparative example. Each 150 g batch was heated to the test temperature of 1,600°C using an electric furnace to melt the material, and the temperature was maintained for two hours until the composition became uniform. A portion of the molten glass (glass melt) was then poured onto an iron plate and slowly cooled to room temperature in the electric furnace to obtain a glass sample. The number of bubbles in this glass sample was observed using an optical microscope, and the number of bubbles per 100 g of glass was calculated. Glass samples with fewer than 2,000 bubbles per 100 g were graded A, those with 2,000 to 5,000 bubbles were graded B, those with 5,000 to 10,000 bubbles were graded C, and those with 10,000 or more bubbles were graded D.

[0077] Furthermore, when the glass composition was irradiated with an ultraviolet lamp with a wavelength of 254 nm, the presence or absence of light emission and the color were visually observed.

[0078] The results of these measurements are shown in Tables 1 to 3.

[0079] [Table 1]

[0080] [Table 2]

[0081] [Table 3]

[0082] The temperature difference ΔT (working temperature - devitrification temperature) of the glass compositions obtained in Examples 1 to 21 was 7°C to 285°C. The dielectric constant at a frequency of 1 GHz of the glass compositions obtained in Examples 1 to 21 was 4.4 to 5.0. The bubble count of the glass compositions obtained in Examples 1 to 21 was A to C. Luminescence by ultraviolet light was observed in all of the glass compositions obtained in Examples 1 to 21.

[0083] On the other hand, the glass composition obtained in Comparative Example 1 had a T-SnO2 content outside the composition range specified in the present invention. Therefore, the bubble count of the glass composition obtained in Comparative Example 1 was D, which was larger than the bubble counts of the glass compositions obtained in Examples 1 to 21. Furthermore, the glass composition obtained in Comparative Example 1 did not emit light due to ultraviolet light.

[0084] The glass composition obtained in Comparative Example 2 had a T-SnO2 content outside the composition range specified in the present invention. Therefore, the bubble count of the glass composition obtained in Comparative Example 2 was D, which was larger than the bubble counts of the glass compositions obtained in Examples 1 to 21. Furthermore, the glass composition obtained in Comparative Example 2 did not emit light due to ultraviolet light.

[0085] The glass composition obtained in Comparative Example 3 had a T-SnO2 content outside the composition range specified in the present invention. Therefore, the bubble count of the glass composition obtained in Comparative Example 3 was D, which was larger than the bubble counts of the glass compositions obtained in Examples 1 to 21. Furthermore, the glass composition obtained in Comparative Example 3 did not emit light due to ultraviolet light.

[0086] The glass composition obtained in Comparative Example 4 had a T-SnO2 content outside the composition range specified in the present invention. Therefore, the ΔT of the glass composition obtained in Comparative Example 4 was less than 0°C, which was smaller than the ΔT of the glass compositions obtained in Examples 1 to 21.

[0087] The glass composition obtained in Comparative Example 5 had a T-SnO2 content outside the composition range specified in the present invention. Therefore, the bubble count of the glass composition obtained in Comparative Example 5 was D, which was larger than the bubble counts of the glass compositions obtained in Examples 1 to 21.

Claims

1. Expressed in mass %, 45≦SiO 2 ≦60、 26<B 2 O 3 ≦40、 8≦Al 2 O 3 ≦20 0.1≦(MgO+CaO)≦10, 0≦(L) 2 O+1 2 O+K 2 O)≦5、 1≦SrO≦3, 0.05≦BaO≦1, 0.1≦T-SnO 2 ≦2、 (However, T-SnO 2 is SnO 2 (This is the total tin oxide converted to Contains the ingredients of By mass, 0≦MgO / (MgO+CaO)≦0.50 is established, When the temperature at which the viscosity is 1000 dPa sec is defined as the working temperature, the working temperature is 1420°C or less; Glass composition.

2. Expressed in mass %, 45≦SiO 2 ≦55、 26<B 2 O 3 ≦40、 0.1≦Al 2 O 3 ≦20 0.1≦(MgO+CaO)≦10, 0≦(L) 2 O+1 2 O+K 2 O)≦5、 1≦SrO≦3, 0.05≦BaO≦1, 0.1≦T-SnO 2 ≦2、 (However, T-SnO 2 is SnO 2 (This is the total tin oxide converted to Contains the ingredients of By mass, 0≦MgO / (MgO+CaO)≦0.50 is established, When the temperature at which the viscosity is 1000 dPa sec is defined as the working temperature, the working temperature is 1420°C or less; Glass composition.

3. A glass fiber made from the glass composition according to claim 1 or 2.

4. A method for producing a glass fiber, comprising: melting the glass composition according to claim 1 or 2; and forming the molten glass composition into glass fibers. Glass fiber manufacturing method.

5. Expressed in mass %, 45≦SiO 2 ≦70、 26<B 2 O 3 ≦40、 0.1≦Al 2 O 3 ≦20 0.1≦(MgO+CaO)≦10, 0≦(L) 2 O+1 2 O+K 2 O)≦5、 0.3≦T-SnO 2 ≦2、 (However, T-SnO 2 is SnO 2 (This is the total tin oxide converted to Contains the ingredients of Substantially free of MgO, By mass, 0≦MgO / (MgO+CaO)≦0.50 A glass fiber made of a glass composition in which:

6. Expressed in mass %, 45≦SiO 2 ≦70、 26<B 2 O 3 ≦40、 0.1≦Al 2 O 3 ≦20 0.1≦(MgO+CaO)≦10, 0≦(L) 2 O+1 2 O+K 2 O)≦5、 0.1≦T-SnO 2 ≦2、 (However, T-SnO 2 is SnO 2 (This is the total tin oxide converted to 0.12≦F 2 ≦5、 Contains the ingredients of By mass, 0≦MgO / (MgO+CaO)≦0.50 A glass fiber made of a glass composition in which:

7. Expressed in mass %, 45≦SiO 2 ≦70、 24 ≦ B 2 O 3 ≦40 0.1≦Al 2 O 3 ≦20 0.1≦(MgO+CaO)≦10, 0≦(L) 2 O+1 2 O+K 2 O)≦5、 0.3≦T-SnO 2 ≦2、 (However, T-SnO 2 is SnO 2 (This is the total tin oxide converted to 0 ≦ P 2 O 5 ≦0.2 Contains the ingredients of MgO and TiO 2 Substantially free of By mass, 0≦MgO / (MgO+CaO)≦0.50 A glass fiber made of a glass composition in which:

8. Expressed in mass %, 45≦SiO 2 ≦70、 24 ≦ B 2 O 3 ≦40 0.1≦Al 2 O 3 ≦20 0.1≦(MgO+CaO)≦10, 0≦(L) 2 O+1 2 O+K 2 O)≦5、 0.1≦T-SnO 2 ≦2、 (However, T-SnO 2 is SnO 2 (This is the total tin oxide converted to 0 ≦ P 2 O 5 ≦0.2 0.12≦F 2 ≦5、 Contains the ingredients of TiO 2 Substantially free of By mass, 0≦MgO / (MgO+CaO)≦0.50 A glass fiber made of a glass composition in which:

9. A step of melting the glass composition according to any one of claims 5 to 8; forming the molten glass composition into glass fibers. Glass fiber manufacturing method.

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