Glass fiber and glass fiber reinforced resin molded article

Abstract

This invention provides glass fiber and glass fiber reinforced resin molded articles. It exhibits excellent long-term manufacturing stability, and when glass fiber is made into glass fiber reinforced resin molded articles, the coefficient of linear expansion in the MD direction can be reduced and anisotropy can be decreased. The glass fiber comprises multiple glass filaments, and contains 60.0–69.0% by mass of SiO2, 18.0–26.0% by mass of Al2O3, 8.0–14.0% by mass of MgO, and 0.0–4.9% by mass of CaO. The total content of SiO2, Al2O3, MgO, and CaO is 95.0% by mass or more. The glass filaments have a flat cross-sectional shape and the ratio of the major diameter to the minor diameter (major diameter / minor diameter) is in the range of 1.2–5.5. The content of SiO2 (S), Al2O3 (A), MgO (M), CaO (C), and the ratio of the major diameter to the minor diameter of the glass filaments, i.e., major diameter / minor diameter (D), satisfy the following formula (1): 228.9 ≤ (S / A) × (C + M) 2 / D 1 / 4 ≤588.9 … (1).

Description

Technical Field

[0001] This invention relates to glass fiber and glass fiber reinforced resin molded articles. Background Technology

[0002] In recent years, with portable electronic devices as the main focus, efforts have been made to reduce the number of parts and lower costs by appropriately using dissimilar materials such as iron, other metals, resins, and fiber-reinforced resins in relevant parts based on their properties.

[0003] For example, glass fiber reinforced resin molded articles containing flat-section glass fibers not only have excellent dimensional stability, but also have higher mechanical strength than glass fiber reinforced resin molded articles containing round-section glass fibers. Therefore, they are considered to be suitable for use in metal composites by integral molding with metal.

[0004] It should be noted that in this specification, glass filaments having a flat cross-sectional shape are sometimes referred to as "flat cross-sectional glass filaments," and glass fibers containing such flat cross-sectional glass filaments are sometimes referred to as "flat cross-sectional glass fibers." Additionally, glass filaments having a generally circular cross-sectional shape are sometimes referred to as "circular cross-sectional glass filaments," and glass fibers substantially composed solely of such circular cross-sectional glass filaments are sometimes referred to as "circular cross-sectional glass fibers."

[0005] On the other hand, the coefficient of linear expansion of glass fiber reinforced resin molded articles is generally larger than that of metals. Therefore, due to the difference in deformation, the bonding with metals may be weakened. Furthermore, the coefficient of linear expansion of glass fiber reinforced resin molded articles is generally greater in the TD direction than in the MD direction. Therefore, if anisotropy increases, bonding with metals will be unfavorable. The aforementioned MD direction is the direction in which the resin composition flows during the manufacture of glass fiber reinforced resin molded articles, and the aforementioned TD direction is the direction orthogonal to the direction of resin composition flow. In addition, anisotropy refers to the difference between the coefficient of linear expansion in the TD direction and the coefficient of linear expansion in the MD direction, and is evaluated as the ratio of the coefficient of linear expansion in the MD direction to the coefficient of linear expansion in the TD direction (coefficient of linear expansion in the MD direction / coefficient of linear expansion in the TD direction).

[0006] As a type of glass fiber capable of imparting an extremely low coefficient of linear expansion to the aforementioned glass fiber reinforced resin molded articles, glass fibers with an S-glass composition (S-glass fiber) are known. The aforementioned S-glass composition refers to a composition containing, relative to the total amount of glass fibers, 64.0 to 66.0% by mass of SiO2, 24.0 to 26.0% by mass of Al2O3, and 9.0 to 11.0% by mass of MgO.

[0007] However, the glass composition having the above-mentioned S glass composition (S glass composition) has the following problems: since the operating temperature range calculated from the difference between the 1000 poise temperature of the molten glass and the liquidus temperature is narrow, the spinning of glass fibers may not be easy, and since the crystallization rate of the molten glass is fast, the long-term manufacturing stability of the glass fibers is poor.

[0008] When the crystallization rate of the molten glass is relatively fast, such as in the spinning of flat-section glass fibers, which requires a lower spinning temperature than round-section glass fibers, prolonged continuous glass fiber manufacturing (spinning) can lead to crystallization of the molten glass cooled by the external gas around the nozzle. Once crystallization occurs, it can trigger a chain reaction, even causing crystallization within the nozzle itself. If crystallization occurs inside the nozzle, it is necessary to remove the crystals to continue manufacturing glass fibers, requiring a prolonged halt to glass fiber production. Consequently, the long-term manufacturing stability of glass fibers obtained from the molten glass is poor.

[0009] To address the issue that spinning glass fibers using the aforementioned S-glass composition may not be easy, a glass composition is proposed that, relative to the total amount of glass fibers, contains 57.0–62.0% by mass of SiO2, 15.0–20.0% by mass of Al2O3, 7.5–12.0% by mass of MgO, and 9.0–16.5% by mass of CaO, and the total content of SiO2, Al2O3, MgO, and CaO is 98.0% by mass or more (see Patent Document 1). Furthermore, a glass composition is proposed that, relative to the total amount of glass fibers, contains 57.0–63.0% by mass of SiO2, 19.0–23.0% by mass of Al2O3, 10.0–15.0% by mass of MgO, and 4.0–11.0% by mass of CaO, and the total content of SiO2, Al2O3, MgO, and CaO is 99.5% by mass or more (see Patent Document 2).

[0010] Existing technical documents Patent documents Patent Document 1: International Publication No. 2017 / 033245 Patent Document 2: International Publication No. 2011 / 155362 Summary of the Invention

[0011] The problem that the invention aims to solve However, the glass fibers obtained from the glass compositions described in the aforementioned Patent Documents 1 and 2 have the following disadvantages: while reducing the coefficient of linear expansion in the MD direction of the glass fiber reinforced resin molded article containing the glass fiber, it is not possible to sufficiently obtain the effect of reducing the anisotropy of the coefficient of linear expansion of the glass fiber reinforced resin molded article.

[0012] The object of the present invention is to eliminate the above-mentioned disadvantages and provide a glass fiber that can achieve excellent long-term manufacturing stability, and when it is made into a glass fiber reinforced resin molded article, can reduce the coefficient of linear expansion of the glass fiber reinforced resin molded article in the MD direction, and can also reduce the anisotropy of the coefficient of linear expansion of the glass fiber reinforced resin molded article.

[0013] Methods for solving problems To achieve the above objectives, the glass fiber of the present invention has the following technical features: it comprises multiple glass filaments, characterized in that, relative to the total amount of the glass fiber, it comprises 60.0 to 69.0% by mass of SiO2, 18.0 to 26.0% by mass of Al2O3, 8.0 to 14.0% by mass of MgO, and 0.0 to 4.9% by mass of CaO, and the total content of SiO2, Al2O3, MgO, and CaO is 95.0% by mass or more; the glass filaments have a flat cross-sectional shape; the ratio of the major diameter to the minor diameter (major diameter / minor diameter) of the glass filaments is in the range of 1.2 to 5.5; when the content of SiO2 is set as S, the content of Al2O3 as A, the content of MgO as M, the content of CaO as C, and the ratio of the major diameter to the minor diameter (major diameter / minor diameter) of the glass filaments is set as D, S, A, M, C, and D satisfy the following formula (1). 228.9≤(S / A)×(C+M) 2 / D 1 / 4 ≤588.9 … (1).

[0014] According to the flat-section glass fiber of the present invention comprising the above-mentioned flat-section glass filament, excellent long-term manufacturing stability can be obtained. When it is made into a glass fiber reinforced resin molded article, the coefficient of linear expansion in the MD direction of the glass fiber reinforced resin molded article can be reduced, and the anisotropy of the coefficient of linear expansion of the glass fiber reinforced resin molded article can be reduced.

[0015] Among them, the ability to obtain excellent long-term manufacturing stability means that, in the spinning process described later, when the flat cross-section glass fiber of the present invention is spun for 8 hours, the molten glass does not crystallize inside the nozzle within a time range of 30 minutes, and there is no need to spend more than 4 hours of operation downtime to remove the crystals generated.

[0016] Furthermore, reducing the linear expansion coefficient in the MD direction of the glass fiber reinforced resin molded article means that, for a glass fiber reinforced resin molded article containing the flat-section glass fibers of the present invention and obtained by the method described later, its linear expansion coefficient in the MD direction, measured according to JIS K7197:2012, is 2.10 ppm or less. Furthermore, reducing the anisotropy of the linear expansion coefficient of the glass fiber reinforced resin molded article means that, for a glass fiber reinforced resin molded article containing the flat-section glass fibers of the present invention and obtained by the method described later, the ratio of the linear expansion coefficient in the MD direction to the linear expansion coefficient in the TD direction (linear expansion coefficient in the MD direction / linear expansion coefficient in the TD direction), measured according to JIS K 7197:2012, is 0.60 or more.

[0017] In addition, the flat cross-section glass fiber of the present invention preferably has S, A, M, C and D satisfying the following formula (2). 303.1≤(S / A)×(C+M) 2 / D 1 / 4 ≤588.9 … (2).

[0018] According to the present invention, by making the S, A, M, C and D satisfy formula (2), it is possible to obtain better long-term manufacturing stability, and when it is made into a glass fiber reinforced resin molded article, it is possible to reduce the coefficient of linear expansion in the MD direction of the glass fiber reinforced resin molded article, and to reduce the anisotropy of the coefficient of linear expansion of the glass fiber reinforced resin molded article.

[0019] Among them, achieving better long-term manufacturing stability means that, in the spinning process described later, when the flat cross-section glass fiber of the present invention is spun for 8 hours, crystallization of molten glass will not occur inside the nozzle within a time range of 8 hours, and the downtime during glass fiber cutting can be less than 1.5 hours.

[0020] In addition, the flat cross-section glass fiber of the present invention preferably has S, A, M, C and D satisfying the following formula (3).

[0021] 454.0≤(S / A)×(C+M) 2 / D 1 / 4 ≤535.2 … (3) According to the present invention, by making the S, A, M, C and D satisfy formula (3), it is possible to obtain better long-term manufacturing stability. When it is made into a glass fiber reinforced resin molded article, the linear expansion coefficient in the MD direction of the glass fiber reinforced resin molded article can be further reduced, and the anisotropy of the linear expansion coefficient of the glass fiber reinforced resin molded article can be reduced.

[0022] Among them, the ability to obtain better long-term manufacturing stability means that, in the spinning process described later, when the flat cross-section glass fiber of the present invention is spun for 8 hours, the crystallization of molten glass does not occur inside the nozzle within a time range of 8 hours, and the downtime during the cutting of glass fiber is less than 30 minutes.

[0023] Furthermore, further reducing the linear expansion coefficient in the MD direction of glass fiber reinforced resin molded articles means that, for glass fiber reinforced resin molded articles containing the flat cross-section glass fibers of the present invention and obtained by the method described later, the linear expansion coefficient in the MD direction measured according to JIS K 7197:2012 is 2.05 ppm or less.

[0024] Furthermore, the glass fiber reinforced resin molded article of the present invention is characterized by containing the flat cross-section glass fiber of the present invention. Detailed Implementation

[0025] Next, the embodiments of the present invention will be described in further detail.

[0026] The flat-section glass fiber of this embodiment comprises multiple glass filaments. The flat-section glass fiber, relative to the total amount of the glass fiber, contains 60.0–69.0% by mass of SiO2, 18.0–26.0% by mass of Al2O3, 8.0–14.0% by mass of MgO, and 0.0–4.9% by mass of CaO. The total content of SiO2, Al2O3, MgO, and CaO is 95.0% by mass or more. The glass filaments have… It has a flat cross-sectional shape, and the ratio of the major diameter to the minor diameter of the glass filament (major diameter / minor diameter) is in the range of 1.2 to 5.5. When the content of SiO2 is set as S, the content of Al2O3 is set as A, the content of MgO is set as M, the content of CaO is set as C, and the ratio of the major diameter to the minor diameter of the glass filament (major diameter / minor diameter) is set as D, S, A, M, C and D satisfy the following formula (1), and preferably satisfy the following formula (2), and even more preferably satisfy the following formula (3).

[0027] 228.9≤(S / A)×(C+M) 2 / D 1 / 4 ≤588.9 … (1) 303.1≤(S / A)×(C+M) 2 / D 1 / 4 ≤588.9 … (2) 454.0≤(S / A)×(C+M) 2 / D 1 / 4 ≤535.2 … (3) In the flat-section glass fiber of this embodiment, if the content of SiO2 relative to the total amount of glass fiber is less than 60.0% by mass, the mechanical strength of the glass fiber decreases. On the other hand, if the content of SiO2 relative to the total amount of glass fiber exceeds 69.0% by mass, the 1000 poise temperature and liquidus temperature become higher, making the manufacture of the glass fiber more difficult.

[0028] In the flat-section glass fiber of this embodiment, the content of SiO2 relative to the total amount of glass fiber is preferably in the range of 60.6 to 67.9% by mass, more preferably in the range of 61.1 to 67.4% by mass, further preferably in the range of 61.6 to 66.9% by mass, particularly preferably in the range of 62.1 to 65.8% by mass, extremely preferably in the range of 62.6 to 64.8% by mass, and most preferably in the range of 63.1 to 63.8% by mass.

[0029] Furthermore, in the flat-section glass fiber of this embodiment, if the content of Al2O3 relative to the total amount of glass fiber is less than 18.00% by mass, the mechanical strength of the glass fiber decreases. On the other hand, if the content of Al2O3 relative to the total amount of glass fiber exceeds 26.00% by mass, the liquidus temperature increases, making fiber manufacturing difficult.

[0030] In the flat-section glass fiber of this embodiment, the content of Al2O3 relative to the total amount of glass fiber is preferably in the range of 19.1 to 24.9% by mass, more preferably in the range of 19.6 to 24.5% by mass, further preferably in the range of 20.1 to 24.2% by mass, particularly preferably in the range of 20.3 to 23.9% by mass, extremely preferably in the range of 20.6 to 23.4% by mass, and most preferably in the range of 20.9 to 22.9% by mass.

[0031] Furthermore, in the flat-section glass fiber of this embodiment, if the content of MgO relative to the total amount of glass fiber is less than 8.00% by mass, the crystal formation rate is accelerated, and the long-term manufacturing stability deteriorates. On the other hand, when the content of MgO relative to the total amount of glass fiber exceeds 14.00% by mass, the mechanical strength of the glass fiber decreases.

[0032] In the flat-section glass fiber of this embodiment, the content of MgO relative to the total amount of glass fiber is preferably in the range of 8.6 to 13.7% by mass, more preferably in the range of 9.1 to 13.4% by mass, even more preferably in the range of 9.4 to 13.2% by mass, particularly preferably in the range of 9.8 to 12.9% by mass, extremely preferably in the range of 10.3 to 12.7% by mass, and most preferably in the range of 11.1 to 12.4% by mass.

[0033] Furthermore, in the flat-section glass fiber of this embodiment, if the content of CaO relative to the total amount of glass fiber exceeds 4.9% by mass, the coefficient of linear expansion of the glass fiber reinforced resin molded article when it is made into a glass fiber reinforced resin molded article will deteriorate.

[0034] In the flat-section glass fiber of this embodiment, the content of CaO relative to the total amount of glass fiber is preferably in the range of 3.9% by mass or less, more preferably in the range of 3.4% by mass or less, further preferably in the range of 0.01 to 2.9% by mass, particularly preferably in the range of 0.03 to 2.9% by mass, and most preferably in the range of 0.05 to 2.9% by mass.

[0035] In the flat-section glass fiber of this embodiment, if the total content of SiO2, Al2O3, MgO and CaO relative to the total amount of glass fiber is less than 95.0% by mass, the content of other impurity components will be relatively higher, resulting in poorer spinnability or lower mechanical strength of the obtained glass fiber.

[0036] In the flat-section glass fiber of this embodiment, the total content of SiO2, Al2O3, MgO and CaO relative to the total amount of glass fiber is preferably in the range of 98.0% by mass or more, more preferably in the range of 99.0% by mass or more, and even more preferably in the range of 99.5% by mass or more.

[0037] The flat-section glass fiber of this embodiment may contain Fe2O3. In this case, the content of Fe2O3 relative to the total amount of glass fiber is, for example, in the range of 0.05 to 0.50% by mass, preferably in the range of 0.10 to 0.45% by mass, more preferably in the range of 0.15 to 0.45% by mass, and even more preferably in the range of 0.18 to 0.40% by mass. In the flat-section glass fiber of this embodiment, by keeping the content of Fe2O3 relative to the total amount of glass fiber within the above range, the coloring of the glass fiber can be suppressed, and the defoaming property of the molten glass can be improved, thereby improving the manufacturability of the glass fiber.

[0038] Furthermore, the flat-section glass fiber of this embodiment may contain B2O3. In this case, the content of B2O3 relative to the total amount of glass fiber is, for example, less than 5.0% by mass, preferably less than 3.0% by mass, more preferably less than 1.0% by mass, and even more preferably less than 0.6% by mass. In the flat-section glass fiber of this embodiment, by keeping the content of B2O3 relative to the total amount of glass fiber within the above-mentioned range, the manufacturability of the glass fiber can be improved without deteriorating the mechanical properties of the glass fiber.

[0039] Furthermore, the flat-section glass fiber of this embodiment may contain Li₂O, K₂O, and Na₂O. In this case, the total content of Li₂O, K₂O, and Na₂O relative to the total amount of glass fiber is, for example, less than 5.0% by mass, preferably less than 3.0% by mass, more preferably less than 1.0% by mass, even more preferably less than 0.3% by mass, and particularly preferably less than 0.1% by mass. In the flat-section glass fiber of this embodiment, by keeping the content of Li₂O, K₂O, and Na₂O relative to the total amount of glass fiber within the above-mentioned range, the manufacturability of the glass fiber can be improved without deteriorating its mechanical properties.

[0040] Furthermore, the flat-section glass fiber of this embodiment may contain ZrO2 in a range of 0.1% by mass or less relative to the total amount of glass fiber. In the flat-section glass fiber of this embodiment, by keeping the content of ZrO2 relative to the total amount of glass fiber within the above range, the coefficient of linear expansion of the glass fiber can be maintained at a low level, and the melt viscosity of the molten glass can be reduced, thereby improving the manufacturability of the glass fiber.

[0041] Furthermore, the flat-section glass fiber of this embodiment preferably does not substantially contain F2 and Cl2, and more preferably does not contain F2 and Cl2 at all. In this embodiment, the flat-section glass fiber not substantially containing F2 and Cl2 means that the total content of F2 and Cl2 relative to the total amount of glass fiber is less than 0.1% by mass; completely not containing F2 and Cl2 means that the total content of F2 and Cl2 relative to the total amount of glass fiber is 0%.

[0042] When the flat-section glass fiber of this embodiment contains F2 and Cl2, there is a concern that the mechanical properties of the glass fiber may deteriorate.

[0043] In the flat-section glass fiber of this embodiment, oxides of Ba, Sr, P, Ti, Cr, Mn, Co, Ni, Cu, Zn, Mo, W, Ce, Y, La, Bi, Gd, Pr, Sc or Yb may be contained as impurities derived from the raw materials in a range of less than 1.00% by mass relative to the total amount of glass fiber. In particular, when the flat-section glass fiber of this embodiment contains BaO, SrO, P2O5, TiO2, Cr2O3, NiO, CuO, ZnO, MoO3, CeO2, Y2O3, La2O3, Bi2O3, Gd2O3, Pr2O3, Sc2O3 or Yb2O3 as impurities, the content of each of these impurities relative to the total amount of glass fiber is preferably less than 1.00% by mass, more preferably less than 0.50% by mass, further preferably less than 0.10% by mass, particularly preferably less than 0.05% by mass, extremely preferably less than 0.01% by mass, and most preferably less than 0.005% by mass.

[0044] In the flat-section glass fiber of this embodiment, if the ratio of the major diameter to the minor diameter (major diameter / minor diameter) D of the flat-section glass filament constituting the glass fiber is less than 1.2, the anisotropy of the coefficient of linear expansion when producing glass fiber reinforced resin molded articles cannot be sufficiently reduced. Furthermore, if the ratio of the major diameter to the minor diameter (major diameter / minor diameter) D of the aforementioned flat-section glass filament exceeds 5.5, the molten glass inside the nozzle is prone to crystallization during the glass fiber manufacturing process, making it impossible to stably manufacture glass fibers.

[0045] In the flat-section glass fiber of this embodiment, the ratio of the major diameter to the minor diameter (major diameter / minor diameter) D of the flat-section glass filament constituting the flat-section glass fiber is preferably in the range of 1.4 to 4.5, more preferably in the range of 1.6 to 3.8, even more preferably in the range of 1.8 to 3.3, and particularly preferably in the range of 2.1 to 2.9.

[0046] In the flat-section glass fiber of this embodiment, the short diameter of the flat-section glass filament constituting the flat-section glass fiber is, for example, in the range of 3.5 to 25.0 μm, preferably in the range of 4.0 to 20.0 μm, more preferably in the range of 5.1 to 16.0 μm, even more preferably in the range of 5.6 to 14.0 μm, particularly preferably in the range of 6.1 to 12.0 μm, especially preferably in the range of 7.8 to 11.4 μm, extremely preferably in the range of 8.5 to 11.0 μm, and most preferably in the range of 8.8 to 10.5 μm.

[0047] In the flat-section glass fiber of this embodiment, the major diameter of the flat-section glass filament constituting the flat-section glass fiber is, for example, in the range of 12.0 to 94.5 μm, preferably in the range of 14.0 to 84.0 μm, more preferably in the range of 16.1 to 60.0 μm, even more preferably in the range of 17.0 to 55.0 μm, particularly preferably in the range of 17.8 to 50.0 μm, especially preferably in the range of 18.3 to 45.0 μm, extremely preferably in the range of 19.3 to 24.8 μm, and most preferably in the range of 20.1 to 23.8 μm.

[0048] Furthermore, from the viewpoint of achieving excellent long-term manufacturing stability, reducing the coefficient of linear expansion in the MD direction of the glass fiber reinforced resin molded article containing the flat cross-section glass fiber, and reducing the anisotropy of the coefficient of linear expansion of the glass fiber reinforced resin molded article, the content of SiO2 S, Al2O3 A, MgO M, CaO C, and the ratio of the major diameter to the minor diameter (major diameter / minor diameter) D of the flat cross-section glass fiber in this embodiment satisfy the above formula (1), and preferably satisfy the above formula (2), and even more preferably satisfy the above formula (3).

[0049] In formulas (1) to (3) above, S / A represents the ratio of the content of SiO2 and Al2O3, which form the glass network. When the content of Al2O3, which is more difficult to form a glass network than SiO2, increases, the molten glass is more likely to crystallize during the manufacture of the flat cross-section glass fiber of this embodiment. In addition, in formulas (1) to (3) above, C+M represents the total content of CaO and MgO. When the total content of CaO and MgO increases, the viscosity of the molten glass decreases, and there is a tendency for the spinnability to be more stable.

[0050] On the other hand, when D in the above formulas (1) to (3) becomes larger, the anisotropy of the glass fiber reinforced resin molded article containing flat cross-section glass fiber in this embodiment decreases, the mechanical properties of the glass fiber reinforced resin molded article are improved, but the long-term manufacturing stability of the flat cross-section glass fiber in this embodiment deteriorates.

[0051] Based on the above content, it can be considered that the above formulas (1) to (3) embody a balance between the long-term manufacturing stability of the flat cross-section glass fiber of this embodiment and the anisotropy and mechanical properties of the glass fiber reinforced resin molded article of this embodiment.

[0052] Regarding the determination of the content of each of the aforementioned components in the flat cross-section glass fiber of this embodiment, an ICP emission spectrophotometer can be used to determine Li as a light element, and a wavelength dispersive X-ray fluorescence analyzer can be used to determine the content of other elements.

[0053] As a method for determination, the following approach can be adopted. First, a glass batch or glass fiber mixed with glass raw materials is placed in a platinum crucible. The glass batch is then melted in an electric furnace at a temperature of 1500–1650°C for 6 hours while being stirred. Alternatively, the glass fiber is melted in an electric furnace at a temperature of 1450–1600°C for 6 hours while being stirred, thereby obtaining a homogeneous molten glass. Furthermore, if organic matter adheres to the surface of the glass fiber, or if the glass fiber is mainly contained within organic matter (resin) as a reinforcing material, the organic matter is removed, for example, by heating in a muffle furnace at 300–650°C for approximately 0.5–24 hours before use. Next, the obtained molten glass is poured onto a carbon plate to form glass shavings. These shavings are then pulverized and powdered to form glass powder. For the determination of Li, a light element, the glass powder is decomposed by heating with acid, and then quantitative analysis is performed using an ICP-based luminescence spectrophotometer. For the determination of other elements, after the glass powder was formed into a disc shape using a press, quantitative analysis was performed using a wavelength dispersive X-ray fluorescence analyzer. The quantitative analysis using the wavelength dispersive X-ray fluorescence analyzer was specifically carried out as follows: First, the content of each component in the sample used for testing was determined using the parameter method. Then, based on the determination results, at least three standard curve samples were prepared, and analysis was performed using the standard curve method. It should be noted that the content of each component in the standard curve samples could be quantitatively analyzed using an ICP emission spectrophotometer. Next, oxide conversion was performed on these quantitative analysis results to calculate the content and total amount of each component, and the content rate (mass%) of each component could be determined based on these values.

[0054] The flat-section glass fiber of this embodiment can be manufactured in the following manner. First, a glass raw material (glass batch) prepared in a manner that can form a glass composition suitable for use in the flat-section glass fiber of this embodiment is supplied to a melting furnace based on the composition and content of the ore used as glass raw material, waste glass fibers generated in the glass fiber manufacturing process, or commercial waste glass, as well as the amount of each component volatilized during the melting process. For example, it is melted at a temperature range of 1500 to 1650°C. Next, the molten glass batch (molten glass) is drawn out from 1 to 20,000 nozzles of a sleeve controlled at a specified temperature and quenched. At this time, the nozzles have a non-circular shape and have protrusions or notches for quenching the molten glass. By controlling the temperature conditions, flat-section glass filaments with flat cross-sectional shapes such as elliptical or oblong can be obtained.

[0055] Next, a bundling agent or adhesive is applied to the glass filaments formed in the above manner using a coater, which is a coating device, and while bundling 1 to 20,000 glass filaments together, a winding machine is used to wind them onto a tube at high speed, thereby obtaining flat-section glass fibers.

[0056] In the flat-section glass fiber of this embodiment, more than 50% of the glass filaments constituting the flat-section glass fiber are the aforementioned flat-section glass filaments, and preferably more than 80% of the glass filaments are the aforementioned flat-section glass filaments, more preferably more than 90% of the glass filaments are the aforementioned flat-section glass filaments, and even more preferably more than 100% of the glass filaments are the aforementioned flat-section glass filaments.

[0057] It should be noted that the spinning process is as follows: the glass batch is melted and fiberized to obtain flat cross-section glass filaments, and then multiple glass filaments containing flat cross-section glass filaments are bundled together to obtain flat cross-section glass fiber filaments.

[0058] The short and long diameters of the flat-section glass filaments contained in the flat-section glass fiber of this embodiment can be adjusted by adjusting the long and short diameters of the nozzle head, the winding speed, and the temperature conditions. For example, by increasing the winding speed, the short and long diameters can be reduced, and by slowing down the winding speed, the short and long diameters can be increased.

[0059] For example, the major and minor diameters of the flat-section glass filaments in the flat-section glass fiber of this embodiment can be measured in the following manner.

[0060] First, when the glass fiber reinforced resin molded article does not contain the flat cross-section glass fiber of this embodiment, the flat cross-section glass fiber is embedded in a resin such as epoxy resin and the resin is cured. Then, the cured resin is cut, and its cross-section is ground. Next, the cross-section of the cured resin is observed using an electron microscope. Then, for all or more of the flat cross-section glass filaments exposed on the cross-section of the cured resin, the longest side passing through the approximate center of the flat cross-section glass filament is taken as the major axis, and the side orthogonal to the approximate center of the flat cross-section glass filament is taken as the minor axis, and their lengths are measured respectively.

[0061] Furthermore, when the glass fiber reinforced resin molded article contains the aforementioned flat-section glass fibers, the glass fiber reinforced resin molded article is cut and its cross-section is ground. Then, the cross-section of the resin is observed using an electron microscope. Then, for more than 200 of the aforementioned flat-section glass filaments exposed from the cross-section of the resin, the longest side passing through approximately the center of the flat-section glass filament is taken as the major axis, and the side orthogonal to the longest side at approximately the center of the flat-section glass filament is taken as the minor axis, and their lengths are measured respectively.

[0062] In either the case where the glass fiber reinforced resin molded article does not contain the aforementioned flat cross-section glass fiber, or in the case where the glass fiber reinforced resin molded article contains the aforementioned flat cross-section glass fiber, the major and minor axes of the aforementioned cross-section can be determined by image processing of the image obtained by the electron microscope using an automatic analysis device.

[0063] Then, based on the lengths of the major and minor diameters of the flat-section glass filament of this embodiment, as measured by the aforementioned method, the ratio of the major diameter to the minor diameter (major diameter / minor diameter) D of the flat-section glass filament of this embodiment is calculated.

[0064] To improve the bundled properties of glass filaments, the adhesion between flat-section glass fibers and resins, and the uniform dispersion of flat-section glass fibers in mixtures of flat-section glass fibers with resins or inorganic materials, an organic material can be coated onto the surface of the flat-section glass fibers in this embodiment. Examples of such organic materials include starch, polyurethane resin, epoxy resin, vinyl acetate resin, acrylic resin, modified polypropylene, particularly carboxylic acid-modified polypropylene, (poly)carboxylic acid, and copolymers of maleic acid and unsaturated monomers. In addition to being coated with these resins, the flat-section glass fibers of this embodiment can also be coated with a resin composition including silane coupling agents, lubricants, and surfactants. Furthermore, the flat-section glass fibers of this embodiment can also be coated with a treatment agent composition containing silane coupling agents, surfactants, etc., instead of the aforementioned resins. Based on the mass of the flat-section glass fibers of this embodiment in their uncoated state, the resin composition or treatment agent composition coats the flat-section glass fibers in a proportion ranging from 0.03% to 2.0% by mass. It should be noted that the processing of coating organic matter onto flat cross-section glass fibers can be carried out, for example, by coating a resin solution or resin composition solution onto the flat cross-section glass fibers using a known method such as a roller coater during the manufacturing process of the flat cross-section glass fibers, and then drying the flat cross-section glass fibers coated with the resin solution or resin composition solution. Alternatively, drying can be carried out by immersing the flat cross-section glass fibers of this embodiment, which are in the form of a fabric, in a treatment agent composition solution, and then drying the flat cross-section glass fibers with the treatment agent composition attached.

[0065] Examples of silane coupling agents include: aminosilanes, ureosilanes, chlorosilanes, epoxysilanes, mercaptosilanes, vinylsilanes, (meth)acryloyloxysilanes, phenylsilanes, styrylsilanes, and isocyanate silanes. In this embodiment, the above-mentioned silane coupling agents can be used alone or in combination of two or more.

[0066] Examples of aminosilanes include: γ-aminopropyltriethoxysilane, N-β-(aminoethyl)-γ-aminopropyltrimethoxysilane, N-β-(aminoethyl)-N'-β-(aminoethyl)-γ-aminopropyltrimethoxysilane, and γ-anilinepropyltrimethoxysilane.

[0067] Examples of ureosilanes include γ-ureopropyltriethoxysilane.

[0068] Examples of chlorosilanes include γ-chloropropyltrimethoxysilane.

[0069] Examples of epoxy silanes include β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane and γ-epoxypropoxypropyltrimethoxysilane.

[0070] Examples of mercaptosilanes include γ-mercaptotrimethoxysilane and γ-mercaptopropyltrimethoxysilane.

[0071] Examples of vinyl silanes include vinyltrimethoxysilane, N-β-(N-vinylbenzylaminoethyl)-γ-aminopropyltrimethoxysilane, and N-benzyl-β-aminoethyl-γ-aminopropyltrimethoxysilane.

[0072] Examples of (meth)acryloyloxysilanes include γ-acryloyloxypropyltrimethoxysilane and γ-methacryloyloxypropyltrimethoxysilane.

[0073] Examples of phenylsilanes include phenyltrimethoxysilane.

[0074] p-Styryltrimethoxysilane is an example of a styrylsilane.

[0075] Examples of isocyanate silanes include γ-isocyanate propyltriethoxysilane.

[0076] Examples of lubricants include: modified silicone oils, animal oils and their hydrogenated additives, vegetable oils and their hydrogenated additives, animal waxes, vegetable waxes, mineral waxes, condensates of higher saturated fatty acids and higher saturated alcohols, polyethyleneimine, polyalkyl polyamine alkylamine derivatives, fatty acid amides, and quaternary ammonium salts. In this embodiment, the above-mentioned lubricants can be used alone or in combination of two or more.

[0077] Examples of animal fats include beef tallow.

[0078] Examples of vegetable oils include soybean oil, coconut oil, rapeseed oil, palm oil, and castor oil.

[0079] Examples of animal-derived waxes include beeswax and lanolin.

[0080] Examples of plant-based waxes include candelilla wax and carnauba wax.

[0081] Examples of mineral waxes include paraffin wax and lignite wax.

[0082] Examples of stearates, such as lauryl stearate, are condensations of higher saturated fatty acids and higher saturated alcohols.

[0083] Examples of fatty acid amides include dehydration condensates of polyethylene polyamines such as diethylenetriamine, triethylenetetramine, and tetraethylenepentamine with fatty acids such as lauric acid, myristic acid, palmitic acid, and stearic acid.

[0084] Examples of quaternary ammonium salts include alkyl trimethylammonium salts such as lauryltrimethylammonium chloride.

[0085] Examples of surfactants include nonionic surfactants, cationic surfactants, anionic surfactants, and amphoteric surfactants. In this embodiment, the above-mentioned surfactants can be used alone or in combination of two or more.

[0086] Examples of nonionic surfactants include: ethylene oxide and propylene oxide alkyl ethers, polyoxyethylene alkyl ethers, polyoxyethylene-polyoxypropylene-block copolymer ethers, alkyl polyoxyethylene-polyoxypropylene-block copolymer ethers, polyoxyethylene fatty acid esters, polyoxyethylene fatty acid monoesters, polyoxyethylene fatty acid diesters, polyoxyethylene sorbitan fatty acid esters, glycerol fatty acid ester ethylene oxide adducts, polyoxyethylene propylene oxide alkyl ethers, hydrogenated castor oil ethylene oxide adducts, alkylamine ethylene oxide adducts, fatty acid amide ethylene oxide adducts, glycerol fatty acid esters, polyglycerol fatty acid esters, pentaerythritol fatty acid esters, sorbitol fatty acid esters, sorbitan fatty acid esters, sucrose fatty acid esters, polyol alkyl ethers, fatty acid alkanolamides, acetylenol, ethylene oxide adducts of acetylenol, and ethylene oxide adducts of acetylenol.

[0087] Examples of cationic surfactants include: alkyl dimethyl benzyl ammonium chloride, alkyl trimethyl ammonium chloride, alkyl dimethyl ethyl ammonium ethyl sulfate, higher alkylamine salts (acetates, hydrochlorides, etc.), ethylene oxide adducts of higher alkylamines, condensates of higher fatty acids and polyalkylene polyamines, salts of esters of higher fatty acids and alkanolamines, salts of higher fatty acid amides, imidazoline-type cationic surfactants, and alkylpyridinium salts.

[0088] Examples of anionic surfactants include: higher alcohol sulfates, higher alkyl ether sulfates, α-olefin sulfates, alkylbenzene sulfonates, α-olefin sulfonates, reaction products of fatty acid halides and N-methyl taurine, dialkyl sulfosuccinates, higher alcohol phosphates, and phosphates of higher alcohol ethylene oxide adducts.

[0089] Examples of amphoteric surfactants include: amino acid-type amphoteric surfactants such as alkali metal salts of alkylaminopropionic acid, betaine-type amphoteric surfactants such as alkyl dimethyl betaine, and imidazoline-type amphoteric surfactants.

[0090] Examples of flat-section glass fibers in this embodiment include: fabrics (glass cloth), knitted fabrics, yarns, chopped strands, rovings, chopped strand mats, paper, meshes, woven fabrics, and ground fibers, but chopped strands, rovings, and fabrics (glass cloth) are preferred, and fabrics (glass cloth) are even more preferred.

[0091] For example, when the flat-section glass fiber in this embodiment is a chopped filament, the number of glass filaments constituting the flat-section glass fiber in this embodiment is, for example, 10 to 20,000, preferably 50 to 10,000, and more preferably 1,000 to 8,000. Furthermore, the length of the chopped filaments of the flat-section glass fiber in this embodiment is, for example, 1.0 to 100.0 mm, preferably 1.2 to 51.0 mm, more preferably 1.5 to 30.0 mm, further preferably 2.0 to 15.0 mm, and particularly preferably 2.3 to 7.8 mm.

[0092] In the case where the flat-section glass fiber in this embodiment is a roving, the number of glass filaments constituting the flat-section glass fiber in this embodiment is, for example, 200 to 30,000. In addition, the roving of the flat-section glass fiber in this embodiment has a mass per unit length of 0.5 to 10,000 tex (g / 1000m).

[0093] In the case where the flat-section glass fiber of this embodiment is a glass fabric, the glass fabric can be obtained by weaving the flat-section glass fiber of this embodiment as warp and weft yarns using a known loom. Examples of such looms include jet looms such as air-jet looms or water-jet looms, shuttle looms, and rapier looms. Furthermore, examples of weaving methods using such looms include plain weave, satin weave, and twill weave; from the viewpoint of manufacturing efficiency, plain weave is preferred.

[0094] The aforementioned fiberglass fabrics can also undergo degreasing, surface treatment, and fiber opening treatment after weaving.

[0095] As a degreasing treatment, the following treatment can be cited: placing the glass fiber fabric in a heating furnace at an atmosphere temperature of 350°C to 400°C for 40 to 80 hours, and heating and decomposing the organic matter attached to the glass fiber.

[0096] As a surface treatment, the following treatment can be used: the glass fiber fabric is impregnated in a solution containing the above-mentioned silane coupling agent or in a solution containing the above-mentioned silane coupling agent and the above-mentioned surfactant, and after squeezing out the excess water, it is heated and dried in a temperature range of 80 to 180°C for 1 to 30 minutes.

[0097] As a fiber opening process, examples include the following: while applying a tension of 20 to 200 N to the warp yarns of the glass fiber fabric, fiber opening is performed using water pressure, high-frequency vibration using a liquid as a medium, pressure of a fluid with surface pressure, or pressure of a roller, etc., to expand the width of the warp and weft yarns.

[0098] Furthermore, the glass fiber fabric of this embodiment has a strength of 5.0 to 220 g / m². 2 The quality ranges from 4.0 to 200.0 μm, and preferably the thickness ranges from 4.0 to 200.0 μm.

[0099] Furthermore, the glass fiber fabric of this embodiment may have a surface treatment layer comprising the aforementioned silane coupling agent or a surface treatment layer comprising the aforementioned silane coupling agent and the aforementioned surfactant. When the glass fiber fabric of this embodiment comprises the surface treatment layer, the surface treatment layer has a mass relative to the total amount of the glass fiber fabric comprising the surface treatment layer, for example, in the range of 0.03 to 1.50% by mass.

[0100] The glass fiber reinforced resin molded article of this embodiment is formed from a glass fiber reinforced resin composition containing the glass fibers described in this embodiment. Specifically, in the glass fiber reinforced resin composition comprising resin (thermoplastic resin or thermosetting resin), flat-section glass fibers, and other additives, the glass fiber reinforced resin composition contains flat-section glass fibers in an amount of 10 to 90% by mass relative to the total amount of the glass fiber reinforced resin composition. Furthermore, the glass fiber reinforced resin composition contains resin in an amount of 90 to 10% by mass relative to the total amount of the glass fiber reinforced resin composition, and contains other additives in an amount of 0 to 40% by mass.

[0101] Examples of thermoplastic resins include: polyethylene, polypropylene, polystyrene, styrene / maleic anhydride resin, styrene / maleimide resin, polyacrylonitrile, acrylonitrile / styrene (AS) resin, acrylonitrile / butadiene / styrene (ABS) resin, chlorinated polyethylene / acrylonitrile / styrene (ACS) resin, acrylonitrile / ethylene / styrene (AES) resin, acrylonitrile / styrene / methyl acrylate (ASA) resin, styrene / acrylonitrile (SAN) resin, methacrylic acid resin, polyvinyl chloride (PVC), polyvinylidene chloride (PVDC), polyamide, polyacetal, polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polypropylene terephthalate (PTT), polycarbonate, polyaryl sulfide, polyethersulfone (PES), and polyphenylene sulfone (PPS). Poly(phenylene oxide), polyphenylene ether (PPE), modified polyphenylene ether (m-PPE), polyaryl ether ketone, liquid crystal polymer (LCP), fluoropolymers, polyetherimide (PEI), polyarylate (PAR), polysulfone (PSF), polyamide imide (PAI), polyaminobismaleimide (PABM), thermoplastic polyimide (TPI), polyethylene naphthalate (PEN), ethylene / vinyl acetate (EVA) resin, ionomer (IO) resin, polybutadiene, styrene / butadiene resin, polybutene, polymethylpentene, olefin / vinyl alcohol resin, cyclic olefin resin, cellulose resin, polylactic acid, polyvinyl alcohol (PVA), polyglycolic acid (PGA), polybutylene succinate (PBS), polybutylene adipate succinate (PBSA), polybutylene terephthalate (PBAT), etc.

[0102] Specifically, examples of polyethylene include: high-density polyethylene (HDPE), medium-density polyethylene, low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), and ultra-high molecular weight polyethylene.

[0103] Examples of polypropylene include isotactic polypropylene, atactic polypropylene, syndiotactic polypropylene, and mixtures thereof.

[0104] Examples of polystyrene include general-purpose polystyrene (GPPS), which is a random stereostructured polystyrene; impact-resistant polystyrene (HIPS), which incorporates rubber components into GPPS; and syndiotactic polystyrene, which has a syndiotactic structure.

[0105] Examples of methacrylic resins include polymers homopolymerized from one of the following methacrylic resins: acrylic acid, methacrylic acid, styrene, methyl acrylate, ethyl acrylate, ethyl methacrylate, butyl acrylate, butyl methacrylate, and ethylene fatty acid esters; and polymers copolymerized from two or more of the above-mentioned methacrylic resins.

[0106] Examples of polyvinyl chloride include: homopolymers of vinyl chloride polymerized using existing known methods such as emulsion polymerization, suspension polymerization, micro-suspension polymerization, and bulk polymerization; copolymers of monomers that can copolymerize with vinyl chloride monomers; and graft copolymers formed by grafting vinyl chloride monomers onto polymers.

[0107] Examples of polyamides include: polycaprolactam (Nylon 6), polyhexamethylene adipamide (Nylon 66), polybutylene adipamide (Nylon 46), polybutylene decanedamide (Nylon 410), polypentylene adipamide (Nylon 56), polydecanoyl diamine (Nylon 510), polyhexamethylene decanedamide (Nylon 610), polydodecyl hexamethylene diamine (Nylon 612), polydemoethylene adipamide (Nylon 106), and polydecanoyl decyl diamine (Nylon 610). Nylon 1010, polydodecanoyl decylamine (Nylon 1012), polyundecylamide (Nylon 11), polyhexamethylene adipamide (Nylon 116), polydodecylamide (Nylon 12), polyxylene hexamethylenediamine (Nylon XD6), polyxylene sebacamide (Nylon XD10), polyadipamide m-phenylene adipate (Nylon MXD6), polyadipamide m-phenylene adipate (Nylon PXD6), polyterephthalamide (Nylon 4T), polyterephthalamide (Nylon 4T), polyterephthalamide (Nylon 4T), polyterephthalamide (Nylon 1010), polydodecyl decylamine (Nylon 11), polyhexamethylene adipate (Nylon 116), polydodecylamide (Nylon 12), polyxylene adipate (Nylon 1012), polyhexamethylene adipate (Nylon 1 ... Diphenyl terephthalamide (Nylon 5T), Poly(hexamethylene terephthalamide) (Nylon 6T), Poly(hexamethylene isophthalamide) (Nylon 6I), Poly(nonadiamine terephthalamide) (Nylon 9T), Poly(decyl terephthalamide) (Nylon 10T), Poly(undecanthoxy) terephthalamide (Nylon 11T), Poly(dodecyl terephthalamide) (Nylon 12T), Polytetramethylene polyphthalamide (Nylon 4I), Poly(3-methyl-4-aminohexyl) The following are considered as one component or a copolymer of two or more components: methane terephthalamide (Nylon PACMT), poly(3-methyl-4-aminohexyl)methane isophthalamide (Nylon PACMI), poly(3-methyl-4-aminohexyl)methane dodecylamide (Nylon PACM12), and poly(3-methyl-4-aminohexyl)methane tetradecylamide (Nylon PACM14).

[0108] Examples of polyacetals include homopolymers with oxymethylene units as the main repeating units and copolymers of oxyalkylene units having 2 to 8 adjacent carbon atoms in the main chain, which mainly contain oxymethylene units.

[0109] Polyethylene terephthalate can be exemplified by polymers obtained by polycondensation of terephthalic acid or its derivatives with ethylene glycol.

[0110] Polybutylene terephthalate can be exemplified by polymers obtained by polycondensation of terephthalic acid or its derivatives with 1,4-butanediol.

[0111] Examples of polypropylene terephthalate include polymers obtained by polycondensation of terephthalic acid or its derivatives with 1,3-propanediol.

[0112] Examples of polycarbonates include polymers obtained by transesterification, which involves reacting a dihydroxy aryl compound with a carbonate such as diphenyl carbonate in the molten state, and polymers obtained by phosgene reaction, which involves reacting a dihydroxy aryl compound with phosgene.

[0113] Examples of polyaryl sulfides include linear polyphenylene sulfides, cross-linked polyphenylene sulfides that achieve high molecular weight through a curing reaction after polymerization, polyphenylene sulfide sulfone, polyphenylene sulfide ether, and polyphenylene sulfide ketone.

[0114] Examples of polyphenylene ethers include: poly(2,3-dimethyl-6-ethyl-1,4-phenylene ether), poly(2-methyl-6-chloromethyl-1,4-phenylene ether), poly(2-methyl-6-hydroxyethyl-1,4-phenylene ether), poly(2-methyl-6-n-butyl-1,4-phenylene ether), poly(2-ethyl-6-isopropyl-1,4-phenylene ether), poly(2-ethyl-6-n-propyl-1,4-phenylene ether), poly(2,3,6-trimethyl-1,4-phenylene ether), poly[2-(4'-methylphenyl)-1,4-phenylene ether], poly(2-bromo-6-phenyl-1,4-phenylene ether), poly(2-methyl-6-phenyl-1,4-phenylene ether), poly(2-phenyl-1... Poly(2-chloro-1,4-phenylene ether), poly(2-methyl-1,4-phenylene ether), poly(2-chloro-6-ethyl-1,4-phenylene ether), poly(2-chloro-6-bromo-1,4-phenylene ether), poly(2,6-dipropyl-1,4-phenylene ether), poly(2-methyl-6-isopropyl-1,4-phenylene ether), poly(2-chloro-6-methyl-1,4-phenylene ether), poly(2-methyl-6-ethyl-1,4-phenylene ether), poly(2,6-dibromo-1,4-phenylene ether), poly(2,6-dichloro-1,4-phenylene ether), poly(2,6-diethyl-1,4-phenylene ether), poly(2,6-dimethyl-1,4-phenylene ether), etc.

[0115] Examples of modified polyphenylene ethers include: polymer alloys of poly(2,6-dimethyl-1,4-phenylene) ether and polystyrene; polymer alloys of poly(2,6-dimethyl-1,4-phenylene) ether and styrene / butadiene copolymer; polymer alloys of poly(2,6-dimethyl-1,4-phenylene) ether and styrene / maleic anhydride copolymer; polymer alloys of poly(2,6-dimethyl-1,4-phenylene) ether and polyamide; polymer alloys of poly(2,6-dimethyl-1,4-phenylene) ether and styrene / butadiene / acrylonitrile copolymer; modified polyphenylene ethers in which functional groups such as amino, epoxy, carboxyl, and styrene groups are introduced at the polymer chain ends of the above-mentioned polyphenylene ethers; and modified polyphenylene ethers in which functional groups such as amino, epoxy, carboxyl, styrene, and methacryloyl groups are introduced into the side chains of the polymer chains of the above-mentioned polyphenylene ethers.

[0116] Examples of polyaryletherketones include: polyetherketone (PEK), polyetheretherketone (PEEK), polyetherketoneketone (PEKK), and polyetheretherketoneketone (PEEKK).

[0117] Examples of liquid crystal polymers (LCPs) include (co)polymers composed of one or more structural units selected from the following components: aromatic hydroxy carbonyl units, aromatic dihydroxy units, aromatic dicarbonyl units, aliphatic dihydroxy units, aliphatic dicarbonyl units, etc., which are thermotropic liquid crystal polyesters.

[0118] Examples of fluoropolymers include: polytetrafluoroethylene (PTFE), perfluoroalkoxy resin (PFA), fluorinated ethylene propylene resin (FEP), fluorinated ethylene tetrafluoroethylene resin (ETFE), polyethylene fluoride (PVF), polyvinylidene fluoride (PVDF), polychlorotrifluoroethylene (PCTFE), and ethylene / chlorotrifluoroethylene resin (ECTFE).

[0119] Examples of ionomer (IO) resins include copolymers of olefins or styrene with unsaturated carboxylic acids, where a portion of the carboxyl group is neutralized with metal ions.

[0120] Examples of olefin / vinyl alcohol resins include: ethylene / vinyl alcohol copolymers, propylene / vinyl alcohol copolymers, ethylene / vinyl acetate copolymer saponifications, and propylene / vinyl acetate copolymer saponifications.

[0121] Examples of cyclic olefin resins include: monocyclic resins such as cyclohexene, polycyclic resins such as tetracyclopentadiene, and polymers of cyclic olefin monomers.

[0122] Examples of polylactic acid include: poly-L-lactic acid as a homopolymer of the L-body, poly-D-lactic acid as a homopolymer of the D-body, or stereocomposite polylactic acid as a mixture thereof.

[0123] Examples of cellulose resins include: methylcellulose, ethylcellulose, hydroxycellulose, hydroxymethylcellulose, hydroxyethylcellulose, hydroxyethylmethylcellulose, hydroxypropylmethylcellulose, cellulose acetate, cellulose propionate, and cellulose butyrate.

[0124] In addition, examples of the aforementioned thermosetting resins include: unsaturated polyester resins, vinyl ester resins, epoxy (EP) resins, melamine (MF) resins, phenolic resins (PF), polyurethane resins (PU), polyisocyanates, polyisocyanurates, modified polyimide (PI) resins, urea-formaldehyde (UF) resins, silicone (SI) resins, furan (FR) resins, benzoguanamine (BR) resins, alkyd resins, xylene resins, bismaleimide triazine (BT) resins, diallyl phthalate resins (PDAP), etc.

[0125] Specifically, as an example of an unsaturated polyester resin, a resin obtained by esterification of an aliphatic unsaturated dicarboxylic acid with an aliphatic diol can be cited.

[0126] Examples of vinyl ester resins include: divinyl ester resins and phenolic varnish-based vinyl ester resins.

[0127] Examples of epoxy resins include: bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol E type epoxy resin, bisphenol S type epoxy resin, bisphenol M type epoxy resin (4,4'-(1,3-phenylene diisopropylidene) bisphenol type epoxy resin), bisphenol P type epoxy resin (4,4'-(1,4-phenylene diisopropylidene) bisphenol type epoxy resin), bisphenol Z type epoxy resin (4,4'-cyclohexylene diphenol type epoxy resin), phenolic varnish type epoxy resin, cresol phenolic varnish type epoxy resin, and tetraphenolic ethane type epoxy resin. Aldehyde-based varnish epoxy resins, phenolic varnish epoxy resins with fused ring aromatic hydrocarbon structures, biphenyl-based epoxy resins, xylene-based epoxy resins or phenylarylene-based epoxy resins and other aralkyl-based epoxy resins, naphthylene ether-based epoxy resins, naphthol-based epoxy resins, naphthiol-based epoxy resins, 2 to 4 functional epoxy naphthalene resins, binatyl-based epoxy resins, naphthylaralkyl-based epoxy resins, anthracene-based epoxy resins, phenoxy-based epoxy resins, dicyclopentadiene-based epoxy resins, norbornene-based epoxy resins, adamantane-based epoxy resins, fluorene-based epoxy resins, etc.

[0128] Examples of melamine resins include polymers formed by the condensation polymerization of melamine (2,4,6-triamino-1,3,5-triazine) and formaldehyde.

[0129] Examples of phenolic resins include: phenolic varnish resins such as phenolic varnish resins, cresol varnish resins, and bisphenol A varnish resins; methyl phenolic resins such as hydroxymethyl methyl phenolic resins and dimethylene ether methyl phenolic resins; and arylalkylene phenolic resins, etc., or phenolic resins composed of one or more of the above-mentioned resins.

[0130] Examples of urea-formaldehyde resins include those obtained by the condensation of urea-formaldehyde and formaldehyde.

[0131] The above-mentioned thermoplastic resin or thermosetting resin can be used alone or in combination of two or more.

[0132] Other additives mentioned above include, for example, reinforcing fibers other than glass fibers such as carbon fiber and metal fiber; fillers other than glass fibers such as glass powder, talc, and mica; flame retardants; ultraviolet absorbers; heat stabilizers; antioxidants; antistatic agents; flow modifiers; anti-blocking agents; lubricants; nucleating agents; antibacterial agents; and pigments.

[0133] The aforementioned glass fiber reinforced resin composition can be a prepreg prepared by impregnating the aforementioned glass fiber fabric with the aforementioned resin and allowing it to semi-cured by a method that is known in itself.

[0134] The glass fiber reinforced resin composition described above can be molded using known molding methods to obtain various glass fiber reinforced resin molded articles of this embodiment. Examples of the known molding methods include: injection molding, injection compression molding, two-color molding, hollow molding, foaming molding including supercritical fluids, insert molding, in-mold coating molding, autoclave molding, extrusion molding, sheet molding, thermoforming, rotational molding, lamination molding, compression molding, blow molding, stamping, resin introduction, hand lay-up molding, spraying, low-pressure reactive injection molding, resin transfer molding, sheet molding compound molding, bulk molding compound molding, pultrusion molding, and fiber winding molding. Furthermore, the glass fiber reinforced resin molded articles of this embodiment can also be obtained by curing the aforementioned prepreg.

[0135] For glass fiber reinforced resin molded articles containing the flat-section glass fiber of this embodiment and obtained by the method described later, the coefficient of linear expansion in the TD direction, as measured according to JIS K 7197:2012, is, for example, 3.00 ppm or less, preferably 2.90 ppm or less, and more preferably 2.80 ppm or less.

[0136] For glass fiber reinforced resin molded articles containing the flat-section glass fibers of this embodiment and obtained by the method described later, the ratio of the linear expansion coefficient in the MD direction to the linear expansion coefficient in the TD direction (linear expansion coefficient in the MD direction / linear expansion coefficient in the TD direction), as measured according to JIS K 7197:2012, is 0.60 or more, preferably 0.65 or more, and more preferably 0.70 or more. Furthermore, the upper limit of the above-mentioned ratio of the linear expansion coefficient in the MD direction to the linear expansion coefficient in the TD direction (linear expansion coefficient in the MD direction / linear expansion coefficient in the TD direction) is not particularly limited, for example, it is 1.40 or less, preferably 1.20 or less, and more preferably 1.10 or less.

[0137] Examples of applications for the glass fiber reinforced resin molded articles of this embodiment include: printed circuit boards, electronic components such as connectors, housings of electronic devices, interior parts of vehicles, exterior parts of vehicles, housings of electronic devices such as antennas and radars, and separators for fuel cells.

[0138] The following are embodiments and comparative examples of the present invention.

[0139] Example (Examples 1-5 and Comparative Examples 1-5) Glass raw materials prepared in a manner consistent with the compositions of Examples 1-5 and Comparative Examples 1-5 shown in Table 1 were melted, and the molten glass obtained was drawn from a sleeve equipped with 200 nozzles to obtain multiple flat-section glass filaments. Next, the obtained flat-section glass filaments were bundled to obtain the flat-section glass fibers of Examples 1-5 and Comparative Examples 1-5.

[0140] The nozzle head includes: an orifice having a flat cross-sectional shape, the flat cross-sectional shape having a major diameter and a minor diameter within a specified range; and a wall having a notch for cooling the molten glass. In this case, the minor diameter of the orifice is adjusted to a length range of 0.2 to 2.0 mm, the ratio of the length of the major diameter to the length of the minor diameter of the nozzle is adjusted to a range of 1.3 to 5.5, and the flow rate of the molten glass through each nozzle is adjusted to a range of 0.1 to 3.0 g / min.

[0141] Next, the major and minor diameters of the flat-section glass filaments of Examples 1-5 and Comparative Examples 1-5 were measured, and the ratio of the major diameter to the minor diameter (major diameter / minor diameter) D was calculated. Then, (S / A) × (C + M) was obtained. 2 / D 1 / 4 The value of .

[0142] In addition, the long-term manufacturing stability of the flat-section glass fibers of Examples 1-5 and Comparative Examples 1-5 was evaluated using the methods shown below, and the coefficient of linear expansion was measured. The results are shown in Table 1.

[0143] (Long-term manufacturing stability) After 8 hours of continuous production of each flat section glass fiber in Examples 1-5 and Comparative Examples 1-5, the flat section glass fibers that did not crystallize inside the nozzle during the 8-hour period and had a shutdown period of less than 30 minutes when cut were evaluated as "A"; the flat section glass fibers that did not crystallize inside the nozzle and had a shutdown period of more than 30 minutes but less than 1.5 hours when cut were evaluated as "B"; the flat section glass fibers that crystallized inside the nozzle during a period of more than 30 minutes but less than 8 hours and required a shutdown period of more than 1.5 hours but less than 4 hours to remove the crystals were evaluated as "C"; and the flat section glass fibers that crystallized inside the nozzle during a period of less than 30 minutes and required a shutdown period of more than 4 hours to remove the crystals were evaluated as "D".

[0144] (Coefficient of linear expansion) The surface of each flat-section glass fiber from Examples 1-5 and Comparative Examples 1-5 was coated with a composition containing a silane coupling agent, and then cut into 3 mm lengths to obtain chopped filaments. Next, using a biaxial mixing mill (manufactured by Shibaura Machinery Co., Ltd., trade name: TEM-26SS), the chopped filaments from Examples 1-5 and Comparative Examples 1-5 were separately mixed with polyamide 6 resin (manufactured by Ube Industries, Ltd., trade name: UBE1015B) at a screw speed of 100 rpm and a temperature of 270°C to obtain resin particles with a glass fiber content of 30% by mass. Then, using the resin particles from Examples 1-5 and Comparative Examples 1-5, glass fiber reinforced resin molded articles were produced by injection molding using an injection molding machine (manufactured by Nissei Resin Kogyo Co., Ltd., trade name: NEX80) at a mold temperature of 80°C and an injection temperature of 270°C.

[0145] Next, in accordance with JIS K 7197:2012, the coefficients of linear expansion of the resin composition in the direction of resin composition flow (MD direction) and the direction orthogonal to the direction of resin composition flow (TD direction) of each glass fiber reinforced resin molded article of Examples 1 to 5 and Comparative Examples 1 to 5 were measured under the conditions of a measurement temperature range of 50 to 150°C and a heating rate of 2°C / min.

[0146] (Table 1) As shown in Table 1, the flat-section glass fibers of Examples 1 to 5 can achieve excellent long-term manufacturing stability. Furthermore, when they are made into glass fiber reinforced resin molded articles, the linear expansion coefficient in the MD direction of the glass fiber reinforced resin molded articles can be reduced, and the anisotropy can also be reduced.

[0147] On the other hand, it can be seen that (S / A) × (C + M) 2 / D 1 / 4 A value less than 228.9 indicates that the flat-section glass fibers in Comparative Examples 1, 2, and 4, which fall outside the range of Equation (1) above, exhibit poor long-term manufacturing stability. Additionally, (S / A) × (C + M) 2 / D 1 / 4 The value exceeding 588.9 is outside the range of the above formula (1). When the flat section glass fiber of Comparative Example 3 is made into a glass fiber reinforced resin molded body, the ratio of the linear expansion coefficient in the MD direction to the linear expansion coefficient in the TD direction (MD / TD ratio) is 0.55, which cannot be sufficiently close to 1. When the flat section glass fiber of Comparative Example 5 is made into a glass fiber reinforced resin molded body, the linear expansion coefficient in the MD direction is 2.16ppm, which exceeds 2.10ppm, so it is impossible to reduce the linear expansion coefficient in the MD direction of the glass fiber reinforced resin molded body.

Claims

1. A glass fiber comprising a plurality of glass filaments, characterized in that, The glass fibers contain 60.0–69.0% by mass of SiO2, 18.0–26.0% by mass of Al2O3, 8.0–14.0% by mass of MgO, and 0.0–4.9% by mass of CaO, with a total content of SiO2, Al2O3, MgO, and CaO of 95.0% by mass or more. The glass filament has a flat cross-sectional shape, and the ratio of its major diameter to its minor diameter, i.e., major diameter / minor diameter, is in the range of 1.2 to 5.

5. When the content of SiO2 is set as S, the content of Al2O3 is set as A, the content of MgO is set as M, the content of CaO is set as C, and the ratio of the major diameter to the minor diameter of the glass filament, i.e., major diameter / minor diameter, is set as D, S, A, M, C and D satisfy the following formula (1). 228.9≤(S / A)×(C+M) 2 / D 1 / 4 ≤588.9 … (1)。 2. The glass fiber according to claim 1, characterized in that, S, A, M, C and D satisfy the following equation (2). 303.1≤(S / A)×(C+M) 2 / D 1 / 4 ≤588.9 … (2)。 3. The glass fiber according to claim 1, characterized in that, The S, A, M, C and D satisfy the following formula (3). 454.0≤(S / A)×(C+M) 2 / D 1 / 4 ≤535.2 … (3)。 4. A glass fiber reinforced resin molded article, characterized in that, It comprises glass fiber as described in any one of claims 1 to 3.

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