Glass fibers and glass fiber–reinforced resin molded article

Abstract

The present invention provides glass fibers that make it possible to achieve excellent long-term production stability and that, when used in a glass fiber–reinforced resin molded article, can reduce the linear expansion coefficient in the MD direction and thereby reduce anisotropy. Glass fibers according to the present invention include a plurality of glass filaments. Relative to the total mass thereof, the glass fibers include 60.0–69.0 mass% of SiO2, 18.0–26.0 mass% of Al2O3, 8.0–14.0 mass% of MgO, and 0.0–4.9 mass% of CaO, the total SiO2, Al2O3, MgO, and CaO content being at least 95.0 mass%. The glass filaments have a flat cross-sectional shape, the ratio (major axis / minor axis) of the major axis to the minor axis is 1.2–5.5, and the SiO2 content S, the Al2O3 content A, the MgO content M, the CaO content C, and the ratio (major axis / minor axis) D of the major axis to the minor axis satisfy expression (1).　(1) 228.9≤(S / A)×(C+M)2 / D1 / 4≤588.9

Description

Glass fiber and glass fiber reinforced resin moldings

[0001] The present invention relates to a glass fiber and a glass fiber reinforced resin molded product.

[0002] In recent years, particularly in the field of portable electronic devices, the use of different materials such as iron, other metals, resins, and fiber-reinforced resins in appropriate locations according to their properties has been considered in order to reduce the number of parts and lower costs.

[0003] For example, glass fiber reinforced resin molded products containing flat cross-section glass fibers not only have excellent dimensional stability but also have higher mechanical strength than glass fiber reinforced resin molded products containing circular cross-section glass fibers, and are therefore thought to be usable in applications where they are integrally molded with metal to form composite materials with metal.

[0004] In this specification, glass filaments having a flat cross-sectional shape are sometimes referred to as "flat cross-section glass filaments," and glass fibers containing such flat cross-section glass filaments are sometimes referred to as "flat cross-section glass fibers." Furthermore, glass filaments having a substantially circular cross-sectional shape are sometimes referred to as "circular cross-section glass filaments," and glass fibers consisting essentially of such circular cross-section glass filaments are sometimes referred to as "circular cross-section glass fibers."

[0005] On the other hand, glass fiber reinforced resin molded products generally have a higher linear expansion coefficient than metals, which may weaken the bond with metals due to differences in deformation. Furthermore, glass fiber reinforced resin molded products generally have a higher linear expansion coefficient in the TD direction than in the MD direction, so increased anisotropy is disadvantageous for bonding with metals. The MD direction is the direction in which the resin composition flows when producing a glass fiber reinforced resin molded product, and the TD direction is the direction perpendicular to the direction in which the resin composition flows. Anisotropy refers to the difference between the linear expansion coefficient in the TD direction and the linear expansion coefficient in the MD direction, and is evaluated by 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).

[0006] Glass fibers having an S-glass composition (S-glass fibers) are known as glass fibers that can impart an extremely low linear expansion coefficient to the glass fiber reinforced resin molded product. The S-glass composition is a glass fiber containing 64.0 to 66.0 mass % of SiO2 relative to the total amount of glass fibers. ２ and Al in the range of 24.0 to 26.0 mass% ２ O ３ and 9.0 to 11.0 mass % MgO.

[0007] However, a glass composition having the above-mentioned S-glass composition (S-glass composition) has a narrow working temperature range, calculated as the difference between the 1000 poise temperature and the liquidus temperature of the molten glass, and therefore spinning of glass fibers is not necessarily easy. Furthermore, the crystallization rate of the molten glass is fast, and therefore there are problems in that the long-term production stability of the glass fiber is poor.

[0008] If the crystallization rate of the molten glass is fast, for example, when spinning flat cross-section glass fibers, which need to be spun at a lower temperature than circular cross-section glass fibers, there is a problem that if the production (spinning) of glass fibers is continued for a long time, the molten glass cooled by the outside air around the nozzle may crystallize. Once the molten glass crystallizes, the crystallization proceeds in a chain reaction, and even the molten glass inside the nozzle crystallizes. If the molten glass crystallizes inside the nozzle, the crystals inside the nozzle must be removed in order to continue the production of glass fibers, and the production of glass fibers must be stopped for a long time to remove the crystals. As a result, the glass fibers obtained from the molten glass have poor long-term production stability.

[0009] In order to solve the problem that the spinning of glass fibers in the S-glass composition is not necessarily easy, SiO in the range of 57.0 to 62.0 mass % based on the total amount of glass fibers is ２ and Al in the range of 15.0 to 20.0 mass% ２ O ３ 7.5 to 12.0% by mass of MgO, 9.0 to 16.5% by mass of CaO, and SiO ２ , Al ２ O ３A glass composition having a total content of SiO in the range of 57.0 to 63.0 mass % relative to the total amount of glass fibers has been proposed (see Patent Document 1). ２ and Al in the range of 19.0 to 23.0 mass% ２ O ３ 10.0 to 15.0% by mass of MgO, 4.0 to 11.0% by mass of CaO, and SiO ２ , Al ２ O ３ A glass composition in which the total content of MgO and CaO is 99.5 mass % or more has been proposed (see Patent Document 2).

[0010] International Publication No. 2017 / 033245 International Publication No. 2011 / 155362

[0011] However, the glass fibers obtained from the glass compositions described in Patent Documents 1 and 2 have the disadvantage that they are unable to sufficiently obtain the effect of reducing the anisotropy of the linear expansion coefficient of a glass fiber reinforced resin molded product containing the glass fibers while reducing the linear expansion coefficient in the MD direction of the glass fiber reinforced resin molded product.

[0012] The present invention aims to provide a glass fiber that can eliminate such inconveniences, achieve excellent long-term production stability, and, when made into a glass fiber-reinforced resin molded article, reduce the linear expansion coefficient of the glass fiber-reinforced resin molded article in the MD direction, and reduce the anisotropy of the linear expansion coefficient of the glass fiber-reinforced resin molded article.

[0013] In order to achieve this object, the glass fiber of the present invention is a glass fiber containing a plurality of glass filaments, and the glass fiber contains SiO in the range of 60.0 to 69.0 mass % relative to the total amount of the glass fiber. ２ and Al in the range of 18.0 to 26.0 mass% ２ O ３ 8.0 to 14.0% by mass of MgO and 0.0 to 4.9% by mass of CaO, and SiO ２ , Al ２ O ３The total content of MgO and CaO is 95.0 mass % or more, the glass filaments have a flat cross-sectional shape, and the ratio of the major axis to the minor axis of the glass filaments (major axis / minor axis) is in the range of 1.2 to 5.5, and SiO ２ The content of S and Al ２ O ３ The glass filament is characterized in that, when the content of S is A, the content of MgO is M, the content of CaO is C, and the ratio of the major axis to the minor axis of the glass filament (major axis / minor axis) is D, the 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] The flat cross section glass fiber of the present invention containing the flat cross section glass filaments can provide excellent long-term manufacturing stability, and when made into a glass fiber reinforced resin molded product, the linear expansion coefficient of the glass fiber reinforced resin molded product in the MD direction can be reduced, and the anisotropy of the linear expansion coefficient of the glass fiber reinforced resin molded product can be reduced.

[0015] Here, being able to obtain excellent long-term production stability means that when the flat cross section glass fiber of the present invention is spun for 8 hours in the spinning process described below, crystallization of the molten glass does not occur inside the nozzle within a time range of 30 minutes or less, and no operation shutdown period of 4 hours or more is required to remove the generated crystals.

[0016] "Reducing the linear expansion coefficient in the MD direction of a glass fiber reinforced resin molded product" means that the linear expansion coefficient in the MD direction of a glass fiber reinforced resin molded product containing the flat cross section glass fiber of the present invention and obtained by the method described below, as measured in accordance with JIS K 7197: 2012, is 2.10 ppm or less. "Reducing the anisotropy of the linear expansion coefficient of a glass fiber reinforced resin molded product" means that the ratio of the linear expansion coefficient in the MD direction to the linear expansion coefficient in the TD direction, as measured in accordance with JIS K 7197: 2012, 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 0.60 or more.

[0017] In addition, in the flat cross section glass fiber of the present invention, it is preferable that the S, A, M, C, and D satisfy the following formula (2): 303.1≦(S / A)×(C+M). ２ / D １／４ ≦588.9 ... (2)

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

[0019] Here, being able to obtain better long-term production stability means that when the flat cross section glass fiber of the present invention is spun for 8 hours in the spinning process described below, crystallization of the molten glass does not occur inside the nozzle within a time range of 8 hours or less, and the operation shutdown period when the glass fiber is cut can be set to a time range of less than 1.5 hours.

[0020] In addition, in the flat cross section glass fiber of the present invention, it is preferable 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)

[0021] According to the flat cross section glass fiber of the present invention, when S, A, M, C and D satisfy the formula (3), even better long-term manufacturing stability can be obtained, and when a glass fiber reinforced resin molded product is made, the linear expansion coefficient of the glass fiber reinforced resin molded product in the MD direction can be further reduced, and the anisotropy of the linear expansion coefficient of the glass fiber reinforced resin molded product can be reduced.

[0022] Here, being able to obtain even better long-term production stability means that when the flat cross section glass fiber of the present invention is spun for 8 hours in the spinning process described below, crystallization of the molten glass does not occur inside the nozzle within a time range of 8 hours or less, and the operation shutdown period when the glass fiber is cut can be set to a time range of less than 30 minutes.

[0023] Further reducing the linear expansion coefficient in the MD direction of a glass fiber reinforced resin molded product means that the linear expansion coefficient in the MD direction of a glass fiber reinforced resin molded product containing the flat cross section glass fiber of the present invention and obtained by the method described below, as measured in accordance with JIS K 7197:2012, is 2.05 ppm or less.

[0024] The glass fiber reinforced resin molded product of the present invention is characterized by containing the flat cross section glass fiber of the present invention.

[0025] Next, the embodiment of the present invention will be described in more detail.

[0026] The flat cross section glass fiber of this embodiment is a glass fiber containing a plurality of glass filaments, and has SiO in the range of 60.0 to 69.0 mass % relative to the total amount of the glass fiber. ２ and Al in the range of 18.0 to 26.0 mass% ２ O ３ 8.0 to 14.0% by mass of MgO and 0.0 to 4.9% by mass of CaO, and SiO ２ , Al ２ O ３ The total content of MgO and CaO is 95.0 mass % or more, the glass filaments have a flat cross-sectional shape, and the ratio of the major axis to the minor axis of the glass filaments (major axis / minor axis) is in the range of 1.2 to 5.5, and SiO ２ The content of S and Al ２ O ３ When the content of S is A, the content of MgO is M, the content of CaO is C, and the ratio of the major axis to the minor axis of the glass filament (major axis / minor axis) is D, the S, A, M, C, and D satisfy the following formula (1), preferably the following formula (2), and more preferably the following formula (3): 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)

[0027] In the flat cross section glass fiber of this embodiment, SiO ２ If the content of SiO is less than 60.0 mass %, the mechanical strength of the glass fiber is reduced. ２ If the content exceeds 69.0 mass %, the 1000 poise temperature and the liquidus temperature become high, making it difficult to produce the glass fiber.

[0028] In the flat cross section glass fiber of this embodiment, SiO ２ The content is preferably in the range of 60.6 to 67.9 mass%, more preferably in the range of 61.1 to 67.4 mass%, even more preferably in the range of 61.6 to 66.9 mass%, particularly preferably in the range of 62.1 to 65.8 mass%, particularly preferably in the range of 62.6 to 64.8 mass%, and most preferably in the range of 63.1 to 63.8 mass%.

[0029] In addition, in the flat cross section glass fiber of this embodiment, Al relative to the total amount of glass fiber ２ O ３ If the content of Al is less than 18.00 mass %, the mechanical strength of the glass fiber will decrease. ２ O ３ If the content exceeds 26.00 mass %, the liquidus temperature becomes high, making it difficult to produce fibers.

[0030] In the flat cross section glass fiber of this embodiment, Al relative to the total amount of glass fiber ２ O ３ The content is preferably in the range of 19.1 to 24.9 mass%, more preferably in the range of 19.6 to 24.5 mass%, even more preferably in the range of 20.1 to 24.2 mass%, particularly preferably in the range of 20.3 to 23.9 mass%, particularly preferably in the range of 20.6 to 23.4 mass%, and most preferably in the range of 20.9 to 22.9 mass%.

[0031] In addition, in the flat cross section glass fiber of this embodiment, if the content of MgO relative to the total amount of glass fiber is less than 8.00 mass%, the crystal growth rate increases and long-term manufacturing stability deteriorates. On the other hand, if the content of MgO relative to the total amount of glass fiber is more than 14.00 mass%, the mechanical strength of the glass fiber decreases.

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

[0033] Furthermore, in the flat cross section glass fiber of this embodiment, if the CaO content relative to the total amount of glass fiber exceeds 4.9 mass %, the linear expansion coefficient of the glass fiber reinforced resin molded product when made into a glass fiber reinforced resin molded product will be deteriorated.

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

[0035] In the flat cross section glass fiber of this embodiment, SiO ２ , Al ２ O ３ If the total content of MgO and CaO is less than 95.0 mass %, the content of other impurity components becomes relatively large, resulting in poor spinnability or poor mechanical strength of the obtained glass fiber.

[0036] In the flat cross section glass fiber of this embodiment, SiO ２ , Al ２ O ３The total content of MgO and CaO is preferably in the range of 98.0 mass % or more, more preferably in the range of 99.0 mass % or more, and even more preferably in the range of 99.5 mass % or more.

[0037] The flat cross section glass fiber of this embodiment is Fe ２ O ３ In this case, the ratio of Fe to the total amount of glass fibers may be ２ O ３ The content of Fe is, for example, in the range of 0.05 to 0.50 mass%, preferably in the range of 0.10 to 0.45 mass%, more preferably in the range of 0.15 to 0.45 mass%, and even more preferably in the range of 0.18 to 0.40 mass%. ２ O ３ When the content is within the above range, it is possible to improve the degassing property of the molten glass while suppressing coloration of the glass fiber, thereby improving the productivity of the glass fiber.

[0038] In addition, the flat cross section glass fiber of this embodiment is B ２ O ３ In that case, B relative to the total amount of glass fibers may be contained. ２ O ３ The content of B is, for example, in the range of less than 5.0 mass%, preferably in the range of less than 3.0 mass%, more preferably in the range of less than 1.0 mass%, and even more preferably in the range of less than 0.6 mass%. ２ O ３ When the content is within the above range, the productivity of the glass fiber can be improved without deteriorating the mechanical properties of the glass fiber.

[0039] In addition, the flat cross section glass fiber of this embodiment is Li ２ O.K. ２ O and Na ２ In that case, the amount of Li relative to the total amount of glass fibers may be ２ O.K. ２ O and Na ２The total content of O is, for example, in the range of less than 5.0 mass%, preferably less than 3.0 mass%, more preferably less than 1.0 mass%, even more preferably less than 0.3 mass%, and particularly preferably 0.1 mass% or less. ２ O.K. ２ O and Na ２ When the O content is within the above range, the productivity of the glass fiber can be improved without deteriorating the mechanical properties of the glass fiber.

[0040] In addition, the flat cross section glass fiber of this embodiment has a ZrO ２ The flat cross section glass fiber of the present embodiment may contain ZrO in an amount of 0.1 mass % or less relative to the total amount of the glass fiber. ２ When the content is within the above range, the linear expansion coefficient of the glass fiber can be maintained low, while the melt viscosity of the molten glass can be reduced, thereby improving the productivity of the glass fiber.

[0041] In addition, the flat cross section glass fiber of this embodiment is F ２ and Cl ２ Preferably, the flat cross section glass fiber of this embodiment is substantially free of F, more preferably completely free of F. ２ and Cl ２ The term "substantially free of F" refers to the amount of F relative to the total amount of glass fibers. ２ and Cl ２ and F means that the total content of ２ and Cl ２ The term "not containing any glass fiber" means that the amount of F relative to the total amount of glass fiber is ２ and Cl ２ This means that the total content of

[0042] The flat cross section glass fiber of this embodiment is F ２ and Cl ２ If it contains, there is a concern that the mechanical properties of the glass fiber may deteriorate.

[0043] The flat cross section glass fiber of this embodiment may contain, as impurities derived from raw materials, oxides of Ba, Sr, P, Ti, Cr, Mn, Co, Ni, Cu, Zn, Mo, W, Ce, Y, La, Bi, Gd, Pr, Sc, or Yb in a total amount of less than 1.00 mass% relative to the total amount of the glass fiber. In particular, the flat cross section glass fiber of this embodiment may contain, as impurities, BaO, SrO, P ２ O ５ , TiO ２ , Cr ２ O ３ , NiO, CuO, ZnO, MoO ３ , CeO ２ , Y ２ O ３ , La ２ O ３ , Bi ２ O ３ , Gd ２ O ３ , Pr ２ O ３ , Sc ２ O ３ , or Yb ２ O ３ When the glass fiber composition contains the above components, the content thereof relative to the total amount of glass fibers is preferably in the range of less than 1.00 mass%, more preferably in the range of less than 0.50 mass%, even more preferably in the range of less than 0.10 mass%, particularly preferably in the range of less than 0.05 mass%, particularly preferably in the range of less than 0.01 mass%, and most preferably in the range of less than 0.005 mass%.

[0044] In the flat cross section glass fiber of this embodiment, if the ratio D of the major axis to the minor axis of the flat cross section glass filaments constituting the flat cross section glass fiber (major axis / minor axis) is less than 1.2, the anisotropy of the linear expansion coefficient when the flat cross section glass fiber is formed into a glass fiber reinforced resin molded product cannot be sufficiently reduced. Also, if the ratio D of the major axis to the minor axis of the flat cross section glass filaments (major axis / minor axis) is more than 5.5, crystals are likely to form in the molten glass inside the nozzle during the production of the glass fiber, making it impossible to stably produce the glass fiber.

[0045] In the flat cross section glass fiber of this embodiment, the ratio D of the major axis to the minor axis of the flat cross section glass filaments constituting the flat cross section glass fiber (major axis / minor axis) 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 cross section glass fiber of this embodiment, the minor diameter of the flat cross section glass filaments constituting the flat cross 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, particularly preferably in the range of 7.8 to 11.4 μm, especially 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 cross section glass fiber of this embodiment, the major diameter of the flat cross section glass filaments constituting the flat cross 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, particularly preferably in the range of 18.3 to 45.0 μm, particularly 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, the flat cross section glass fiber of this embodiment can obtain excellent long-term production stability, can reduce the linear expansion coefficient in the MD direction of a glass fiber reinforced resin molded product containing the flat cross section glass fiber, and can reduce the anisotropy of the linear expansion coefficient of the glass fiber reinforced resin molded product. ２ Contents of S and Al ２ O ３The content A of MgO, the content M of CaO, the content C of CaO, and the ratio D of the major axis to the minor axis of the glass filament (major axis / minor axis) satisfy the formula (1), preferably the formula (2), and more preferably the formula (3).

[0049] In the formulas (1) to (3), S / A is a network-forming oxide that forms a glass network, SiO ２ and Al ２ O ３ and SiO ２ Compared to Al, it is difficult to form a glass network. ２ O ３ When the content of CaO increases, the molten glass tends to crystallize easily when producing the flat cross section glass fiber of this embodiment. In addition, in the formulas (1) to (3), C+M is the total content of CaO and MgO, and when the total content of CaO and MgO increases, the viscosity of the molten glass tends to decrease, and spinnability tends to become more stable.

[0050] On the other hand, in the formulas (1) to (3), when D is large, the anisotropy of the glass fiber reinforced resin molded product containing the flat cross section glass fiber of this embodiment is reduced, and the mechanical properties of the glass fiber reinforced resin molded product are improved, but the long-term manufacturing stability of the flat cross section glass fiber of this embodiment is deteriorated.

[0051] From the above, it is believed that the above formulas (1) to (3) represent the 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 product of this embodiment.

[0052] In the flat cross section glass fiber of this embodiment, the content of each of the above-mentioned components can be measured using an ICP optical emission spectrometer for the light element Li, and using a wavelength dispersive X-ray fluorescence analyzer for the other elements.

[0053] The measurement method involves first placing a glass batch or glass fiber prepared by mixing glass raw materials in a platinum crucible and melting it in an electric furnace at a temperature of 1500 to 1650°C for the glass batch or 1450 to 1600°C for the glass fiber for 6 hours while stirring, thereby obtaining a homogeneous molten glass. If organic matter is attached to the glass fiber surface or if the glass fiber is contained primarily as a reinforcing material in an organic material such as a resin, the organic matter is removed by, for example, heating in a muffle furnace at 300 to 650°C for 0.5 to 24 hours before use. Next, the resulting molten glass is poured onto a carbon plate to produce glass cullet, which is then crushed and powdered to obtain glass powder. The light element Li is quantitatively analyzed for Li after the glass powder is thermally decomposed with acid using an ICP optical emission spectrometer. Other elements are quantitatively analyzed for Li after the glass powder is formed into a disk shape using a press and then quantitatively analyzed using a wavelength-dispersive X-ray fluorescence spectrometer. Quantitative analysis using a wavelength-dispersive X-ray fluorescence analyzer can be performed by the following method. First, the content of each component in a measurement sample is measured using the fundamental parameter method. Next, based on the measurement results, at least three calibration curve samples are prepared and analyzed using the calibration curve method. The content of each component in the calibration curve samples can be quantitatively analyzed using an ICP optical emission spectrometer. Next, these quantitative analysis results are converted into oxides to calculate the content and total amount of each component, and the content (mass %) of each component described above can be determined from these values.

[0054] The flat cross section glass fiber of this embodiment can be produced as follows. First, a glass raw material (glass batch) is prepared to have the composition of the glass composition used for the flat cross section glass fiber of this embodiment, based on the components and content of each component contained in the ore, waste glass fiber generated during the glass fiber manufacturing process, or commercially waste glass that serves as the glass raw material, and the amount of volatilization of each component during the melting process. The glass raw material is supplied to a melting furnace and melted at a temperature in the range of 1500 to 1650°C, for example. Next, the molten glass batch (molten glass) is withdrawn from 1 to 20,000 nozzle tips of a bushing controlled at a predetermined temperature and quenched. At this time, the nozzle tips have a non-circular shape and have protrusions or notches that quench the molten glass. By controlling the temperature conditions, flat cross section glass filaments having a flat cross section such as an ellipse or oval can be obtained.

[0055] Next, a sizing agent or binder is applied to the formed glass filaments using an applicator, which is a coating device, and 1 to 20,000 glass filaments are bundled using a bundling shoe, and then wound at high speed onto a tube using a winder, thereby obtaining flat cross-section glass fibers.

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

[0057] The process of melting a glass batch, fiberizing it to obtain flat cross-section glass filaments, and then bundling a plurality of glass filaments including the flat cross-section glass filaments to obtain a flat cross-section glass fiber yarn is called the spinning process.

[0058] The flat cross section glass filaments contained in the flat cross section glass fiber of this embodiment can have their minor and major diameters adjusted by adjusting the major and minor diameters of the nozzle tip, the winding speed, temperature conditions, etc. For example, by increasing the winding speed, the minor and major diameters can be made smaller, and by decreasing the winding speed, the minor and major diameters can be made larger.

[0059] In the flat cross section glass fiber of this embodiment, the major axis and minor axis of the flat cross section glass filament can be measured, for example, as follows.

[0060] First, when the flat cross section glass fiber of this embodiment is not contained in a glass fiber reinforced resin molded product, the flat cross section glass fiber is embedded in a resin such as an epoxy resin, the resin is cured, the cured resin is cut and its cross section is polished, and then the cross section of the cured resin is observed using an electron microscope. Then, for all or 200 or more of the flat cross section glass filaments exposed in the cross section of the cured resin, the longest side passing through approximately the center of the flat cross section glass filament is defined as the major axis, and the side perpendicular to the longest side at approximately the center of the flat cross section glass filament is defined as the minor axis, and their lengths are measured.

[0061] When the flat cross section glass fiber is contained in a glass fiber reinforced resin molded product, the glass fiber reinforced resin molded product is cut and the cross section is polished, and then the cross section of the resin is observed using an electron microscope. Then, for 200 or more of the flat cross section glass filaments exposed in the cross section of the resin, the longest side passing through approximately the center of the flat cross section glass filament is taken as the major axis, and the side perpendicular to the longest side at approximately the center of the flat cross section glass filament is taken as the minor axis, and their lengths are measured.

[0062] Here, in either the case where the flat cross section glass fiber is not contained in the glass fiber reinforced resin molded product or the case where the flat cross section glass fiber is contained in the glass fiber reinforced resin molded product, the major axis and minor axis of the cross section can also be measured by image processing of an image obtained from an electron microscope using an automatic analysis device.

[0063] Then, from the lengths of the major axis and the minor axis of the flat cross section glass filament of this embodiment measured as described above, the ratio D of the major axis to the minor axis of the flat cross section glass filament of this embodiment (major axis / minor axis) is calculated.

[0064] The flat cross-section glass fiber of this embodiment may be coated on its surface with an organic substance for the purposes of improving the bundling of glass filaments, improving the adhesion between the flat cross-section glass fiber and resin, and improving the uniform dispersion of the flat cross-section glass fiber in a mixture of the flat cross-section glass fiber and resin or inorganic material. Examples of such organic substances include starch, urethane resin, epoxy resin, vinyl acetate resin, acrylic resin, modified polypropylene, particularly carboxylic acid-modified polypropylene, and copolymers of (poly)carboxylic acid, particularly maleic acid and an unsaturated monomer. The flat cross-section glass fiber of this embodiment may also be coated with a resin composition containing, in addition to these resins, a silane coupling agent, a lubricant, a surfactant, and the like. The flat cross-section glass fiber of this embodiment may also be coated with a treatment composition containing, without the resin, a silane coupling agent, a surfactant, and the like. Such a resin composition or treatment composition coats the flat cross-section glass fiber in a range of 0.03 to 2.0 mass % based on the mass of the flat cross-section glass fiber of this embodiment in a state where it is not coated with the resin composition or treatment composition. The coating of the flat cross section glass fiber with an organic substance can be carried out, for example, by applying a resin solution or a resin composition solution to the flat cross section glass fiber using a known method such as a roller applicator in the process of producing the flat cross section glass fiber, and then drying the flat cross section glass fiber to which the resin solution or the resin composition solution has been applied. Alternatively, the coating can be carried out by immersing the flat cross section glass fiber of this embodiment in the form of a woven fabric in a treatment composition solution, and then drying the flat cross section glass fiber to which the treatment composition has been applied.

[0065] Examples of the silane coupling agent include aminosilane, ureidosilane, chlorosilane, epoxysilane, mercaptosilane, vinylsilane, (meth)acrylicsilane, phenylsilane, styrylsilane, and isocyanatesilane. In this embodiment, the silane coupling agent may 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-anilinopropyltrimethoxysilane.

[0067] Examples of ureidosilane include γ-ureidopropyltriethoxysilane.

[0068] Examples of chlorosilanes include γ-chloropropyltrimethoxysilane.

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

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

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

[0072] Examples of the (meth)acrylic silane include γ-acryloxypropyltrimethoxysilane and γ-methacryloxypropyltrimethoxysilane.

[0073] Examples of phenylsilane include phenyltrimethoxysilane.

[0074] The styrylsilane may include p-styryltrimethoxysilane.

[0075] Examples of isocyanate silanes include γ-isocyanate propyl triethoxy silane.

[0076] Examples of lubricants include modified silicone oils, animal oils and their hydrogenated products, vegetable oils and their hydrogenated products, animal waxes, vegetable waxes, mineral waxes, condensates of higher saturated fatty acids and higher saturated alcohols, polyethyleneimines, polyalkylpolyamine alkylamide derivatives, fatty acid amides, and quaternary ammonium salts. In this embodiment, the lubricants may be used alone or in combination of two or more.

[0077] Examples of animal oils include beef tallow.

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

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

[0080] Examples of vegetable waxes include candelilla wax and carnauba wax.

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

[0082] Examples of the condensation products of higher saturated fatty acids and higher saturated alcohols include stearic acid esters such as lauryl stearate.

[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 the quaternary ammonium salt include alkyltrimethylammonium salts such as lauryltrimethylammonium chloride.

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

[0086] Examples of nonionic surfactants include ethylene oxide propylene oxide alkyl ethers, polyoxyethylene alkyl ethers, polyoxyethylene-polyoxypropylene block copolymers, 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 castor oil ethers, hydrogenated castor oil ethylene oxide adducts, alkylamine ethylene oxide adducts, fatty acid amide ethylene oxide adducts, glycerol fatty acid esters, polyglycerin fatty acid esters, pentaerythritol fatty acid esters, sorbitol fatty acid esters, sorbitan fatty acid esters, sucrose fatty acid esters, polyhydric alcohol alkyl ethers, fatty acid alkanolamides, acetylene glycol, acetylene alcohol, ethylene oxide adducts of acetylene glycol, and ethylene oxide adducts of acetylene alcohol.

[0087] Examples of cationic surfactants include alkyldimethylbenzylammonium chloride, alkyltrimethylammonium chloride, alkyldimethylethylammonium ethyl sulfate, higher alkylamine salts (acetates, hydrochlorides, etc.), ethylene oxide adducts of higher alkylamines, condensates of higher fatty acids and polyalkylenepolyamines, 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-methyltaurine, dialkyl sulfosuccinates, higher alcohol phosphates, and phosphate salts 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 alkyldimethylbetaine, and imidazoline type amphoteric surfactants.

[0090] Examples of the form of the flat cross section glass fiber of this embodiment include woven fabric (glass cloth), knitted fabric, yarn, chopped strand, roving, chopped strand mat, paper, mesh, braided fabric, milled fiber, etc., but chopped strand, roving, and woven fabric (glass cloth) are preferred, and woven fabric (glass cloth) is more preferred.

[0091] For example, when the flat cross section glass fiber of this embodiment is a chopped strand, the number of glass filaments constituting the flat cross section glass fiber of this embodiment is, for example, 10 to 20,000, preferably 50 to 10,000, and more preferably 1,000 to 8,000. The length of the chopped strand, which is the flat cross section glass fiber of 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, even more preferably 2.0 to 15.0 mm, and particularly preferably 2.3 to 7.8 mm.

[0092] When the flat cross section glass fiber of this embodiment is a roving, the number of glass filaments constituting the flat cross section glass fiber of this embodiment is, for example, 200 to 30000. Furthermore, the roving, which is the flat cross section glass fiber of this embodiment, has a mass per unit length of 0.5 to 10000 tex (g / 1000 m).

[0093] When the flat cross section glass fiber of this embodiment is a glass fabric, the glass fabric can be obtained by weaving the flat cross section glass fiber of this embodiment as warp and weft using a known loom. Examples of the loom include a jet loom such as an air jet or water jet loom, a shuttle loom, and a rapier loom. Examples of the weaving method used with the loom include plain weave, satin weave, sash weave, and twill weave, with plain weave being preferred from the viewpoint of production efficiency.

[0094] After being woven, the glass fiber fabric may be subjected to a de-oiling treatment, a surface treatment, and a fiber-opening treatment.

[0095] The deoiling treatment may involve placing the glass fiber fabric in a heating furnace at an atmospheric temperature of 350° C. to 400° C. for 40 to 80 hours to thermally decompose organic matter adhering to the glass fibers.

[0096] The surface treatment may include a treatment in which a glass fiber fabric is immersed in the silane coupling agent or in a solution containing the silane coupling agent and the surfactant, excess water is squeezed out, and the fabric is then heated and dried at a temperature in the range of 80 to 180°C for 1 to 30 minutes.

[0097] Examples of the opening treatment include a process in which the warp and weft widths are widened by applying a tension of 20 to 200 N to the warp yarns of a glass fiber fabric while performing opening by water jet pressure, opening by high-frequency vibration using a liquid as a medium, opening by pressure of a fluid having a surface pressure, opening by pressure using a roll, or the like.

[0098] The glass fiber fabric of this embodiment has a fiber density of 5.0 to 220 g / m ２ and a thickness in the range of 4.0 to 200.0 μm.

[0099] The glass fiber fabric of the present embodiment may also have a surface treatment layer containing the silane coupling agent, or the silane coupling agent and the surfactant. When the glass fiber fabric of the present embodiment includes the surface treatment layer, the surface treatment layer may have a mass of, for example, 0.03 to 1.50 mass% relative to the total mass of the glass fiber fabric including the surface treatment layer.

[0100] The glass fiber reinforced resin molded article of this embodiment is made from a glass fiber reinforced resin composition containing the glass fiber of this embodiment. Specifically, the glass fiber reinforced resin composition contains a resin (thermoplastic resin or thermosetting resin), flat cross section glass fibers, and other additives, and the glass fiber reinforced resin composition contains 10 to 90 mass% of the flat cross section glass fibers based on the total amount of the glass fiber reinforced resin composition. Furthermore, the glass fiber reinforced resin composition contains 90 to 10 mass% of the resin based on the total amount of the glass fiber reinforced resin composition, and contains other additives in the range of 0 to 40 mass%.

[0101] Examples of the thermoplastic resin 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 resin, polyvinyl chloride (PVC), polyvinylidene chloride (PVDC), polyamide, polyacetal, polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polytrimethylene terephthalate (PTT), polycarbonate, polyarylene sulfide, polyethersulfone (PES), polyphenylsulfone (PPS), and the like. U), polyphenylene ether (PPE), modified polyphenylene ether (m-PPE), polyaryletherketone, liquid crystal polymer (LCP), fluororesin, polyetherimide (PEI), polyarylate (PAR), polysulfone (PSF), polyamideimide (PAI), polyaminobismaleimide (PABM), thermoplastic polyimide (TPI), polyethylene naphthalate (PEN), ethylene / vinyl acetate (EVA) resin, ionomer (IO) resin, polybutadiene, styrene / butadiene resin, polybutylene, polymethylpentene, olefin / vinyl alcohol resin, cyclic olefin resin, cellulose resin, polylactic acid, polyvinyl alcohol (PVA), polyglycolic acid (PGA), polybutylene succinate (PBS), polybutylene succinate adipate (PBSA), polybutylene adipate terephthalate (PBAT), and the like.

[0102] Specific 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 an atactic polystyrene having an atactic structure, high impact polystyrene (HIPS), which is GPPS with a rubber component added, and syndiotactic polystyrene having a syndiotactic structure.

[0105] Examples of methacrylic resins include a homopolymer of one of acrylic acid, methacrylic acid, styrene, methyl acrylate, ethyl acrylate, ethyl methacrylate, butyl acrylate, butyl methacrylate, and a fatty acid vinyl ester, or a copolymer of two or more of them.

[0106] Examples of polyvinyl chloride include vinyl chloride homopolymers polymerized by conventional methods such as emulsion polymerization, suspension polymerization, microsuspension polymerization, and bulk polymerization; copolymers of vinyl chloride monomers with copolymerizable monomers; and graft copolymers obtained by graft-polymerizing vinyl chloride monomers onto polymers.

[0107] Examples of polyamides include polycaproamide (nylon 6), polyhexamethylene adipamide (nylon 66), polytetramethylene adipamide (nylon 46), polytetramethylene sebacamide (nylon 410), polypentamethylene adipamide (nylon 56), polypentamethylene sebacamide (nylon 510), polyhexamethylene sebacamide (nylon 610), polyhexamethylene dodecamide (nylon 612), polydecamethylene adipamide (nylon 106), and polydecamethylene adipamide (nylon 410). Polyethylene sebacamide (Nylon 1010), polydecamethylene dodecamide (Nylon 1012), polyundecane amide (Nylon 11), polyundecamethylene adipamide (Nylon 116), polydodecanamide (Nylon 12), polyxylene adipamide (Nylon XD6), polyxylene sebacamide (Nylon XD10), polymeta-xylylene adipamide (Nylon MXD6), polypara-xylylene adipamide (Nylon PXD6), polytetramethylene terephthalamide (Nylon 4T), polypentamethylene terephthalamide (nylon 5T), polyhexamethylene terephthalamide (nylon 6T), polyhexamethylene isophthalamide (nylon 6I), polynonamethylene terephthalamide (nylon 9T), polydecamethylene terephthalamide (nylon 10T), polyundecamethylene terephthalamide (nylon 11T), polydodecamethylene terephthalamide (nylon 12T), polytetramethylene isophthalamide (nylon 4I), polybis( Examples of the copolymer include one or a copolymer of two or more of the following components: polybis(3-methyl-4-aminohexyl)methane terephthalamide (nylon PACMT), polybis(3-methyl-4-aminohexyl)methane isophthalamide (nylon PACMI), polybis(3-methyl-4-aminohexyl)methaneandodecamide (nylon PACM12), polybis(3-methyl-4-aminohexyl)methane tetradecamide (nylon PACM14), and the like, as well as mixtures thereof.

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

[0109] Examples of polyethylene terephthalate include polymers obtainable by polycondensing terephthalic acid or a derivative thereof with ethylene glycol.

[0110] Examples of polybutylene terephthalate include polymers obtainable by polycondensation of terephthalic acid or a derivative thereof with 1,4-butanediol.

[0111] Examples of polytrimethylene terephthalate include polymers obtainable by polycondensation of terephthalic acid or a derivative thereof with 1,3-propanediol.

[0112] Examples of polycarbonates include polymers obtainable by a transesterification method in which a dihydroxydiaryl compound is reacted with a carbonate ester such as diphenyl carbonate in a molten state, and polymers obtainable by a phosgene method in which a dihydroxyaryl compound is reacted with phosgene.

[0113] Examples of polyarylene sulfide include linear polyphenylene sulfide, crosslinked polyphenylene sulfide which has been polymerized and then subjected to a curing reaction to increase the molecular weight, 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-1,4-phenylene ether), 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-di-n-propyl-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), and the like.

[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, the polyphenylene ethers in which functional groups such as amino groups, epoxy groups, carboxy groups, and styryl groups have been introduced into the polymer chain terminals, and the polyphenylene ethers in which functional groups such as amino groups, epoxy groups, carboxy groups, styryl groups, and methacrylic groups have been introduced into the polymer chain side chains.

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

[0117] Examples of the liquid crystal polymer (LCP) include a (co)polymer, which is a thermotropic liquid crystal polyester, comprising one or more structural units selected from an aromatic hydroxycarbonyl unit, an aromatic dihydroxy unit, an aromatic dicarbonyl unit, an aliphatic dihydroxy unit, an aliphatic dicarbonyl unit, and the like.

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

[0119] Examples of ionomer (IO) resins include copolymers of olefin or styrene with unsaturated carboxylic acid, in which a portion of the carboxyl groups is neutralized with metal ions.

[0120] Examples of the olefin / vinyl alcohol resin include an ethylene / vinyl alcohol copolymer, a propylene / vinyl alcohol copolymer, a saponified ethylene / vinyl acetate copolymer, and a saponified propylene / vinyl acetate copolymer.

[0121] Examples of the cyclic olefin resin include monocyclic compounds such as cyclohexene, polycyclic compounds such as tetracyclopentadiene, and polymers of cyclic olefin monomers.

[0122] Examples of polylactic acid include poly-L-lactic acid, which is a homopolymer of the L-form, poly-D-lactic acid, which is a homopolymer of the D-form, and stereocomplex polylactic acid, which is a mixture thereof.

[0123] Examples of the cellulose resin include methyl cellulose, ethyl cellulose, hydroxy cellulose, hydroxymethyl cellulose, hydroxyethyl cellulose, hydroxyethyl methyl cellulose, hydroxypropyl methyl cellulose, cellulose acetate, cellulose propionate, and cellulose butyrate.

[0124] Examples of the thermosetting resin include unsaturated polyester resin, vinyl ester resin, epoxy (EP) resin, melamine (MF) resin, phenolic resin (PF), urethane resin (PU), polyisocyanate, polyisocyanurate, modified polyimide (PI) resin, urea (UF) resin, silicone (SI) resin, furan (FR) resin, benzoguanamine (BR) resin, alkyd resin, xylene resin, bismaleimide triazine (BT) resin, and diallyl phthalate resin (PDAP).

[0125] Specifically, the unsaturated polyester resin may be a resin obtainable by esterifying an aliphatic unsaturated dicarboxylic acid with an aliphatic diol.

[0126] Examples of vinyl ester resins include bis-based vinyl ester resins and novolac-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-phenylenediisopridiene)bisphenol type epoxy resin), bisphenol P type epoxy resin (4,4'-(1,4-phenylenediisopridiene)bisphenol type epoxy resin), bisphenol Z type epoxy resin (4,4'-cyclohexidienebisphenol type epoxy resin), phenol novolac type epoxy resin, cresol novolac type epoxy resin, tetraphenol group ethane type novolac type epoxy resin, and the like. Examples of epoxy resins include epoxy resins, novolac-type epoxy resins having a condensed ring aromatic hydrocarbon structure, biphenyl-type epoxy resins, aralkyl-type epoxy resins such as xylylene-type epoxy resins and phenylaralkyl-type epoxy resins, naphthylene ether-type epoxy resins, naphthol-type epoxy resins, naphthalenediol-type epoxy resins, difunctional to tetrafunctional epoxy-type naphthalene resins, binaphthyl-type epoxy resins, naphthalenearalkyl-type epoxy resins, anthracene-type epoxy resins, phenoxy-type epoxy resins, dicyclopentadiene-type epoxy resins, norbornene-type epoxy resins, adamantane-type epoxy resins, and fluorene-type epoxy resins.

[0128] The melamine resin may be a polymer obtained by polycondensation of melamine (2,4,6-triamino-1,3,5-triazine) and formaldehyde.

[0129] Examples of the phenolic resin include novolac-type phenolic resins such as phenol novolac resin, cresol novolac resin, and bisphenol A-type novolac resin; resole-type phenolic resins such as methylol-type resole resin and dimethylene ether-type resole resin; and aryl alkylene-type phenolic resins, and examples thereof include one or a combination of two or more of these.

[0130] Examples of urea resins include resins obtainable by condensation of urea and formaldehyde.

[0131] The thermoplastic resins or thermosetting resins may be used alone or in combination of two or more.

[0132] Examples of the other additives include reinforcing fibers other than glass fibers, such as carbon fibers and metal fibers; fillers other than glass fibers, such as glass powder, talc, and mica; flame retardants, ultraviolet absorbers, heat stabilizers, antioxidants, antistatic agents, flow improvers, antiblocking agents, lubricants, nucleating agents, antibacterial agents, and pigments.

[0133] The glass fiber reinforced resin composition may be a prepreg obtained by impregnating the glass fiber fabric with the resin by a method known per se and semi-curing the impregnated glass fiber fabric.

[0134] The glass fiber reinforced resin composition can be molded by a known molding method to obtain various glass fiber reinforced resin molded articles of this embodiment. Examples of known molding methods include injection molding, injection compression molding, two-color molding, blow molding, foam molding using a supercritical fluid, insert molding, in-mold coating molding, autoclave molding, extrusion molding, sheet molding, thermoforming, rotational molding, laminate molding, press molding, blow molding, stamping molding, infusion molding, hand layup, spray-up, low-pressure RIM molding, resin transfer molding, sheet molding compounding, bulk molding compounding, pultrusion, and filament winding. Alternatively, the glass fiber reinforced resin molded article of this embodiment can be obtained by curing the prepreg.

[0135] For a glass fiber reinforced resin molded article containing the flat cross section glass fiber of this embodiment and obtained by the method described below, the linear expansion coefficient in the TD direction measured in accordance with 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 a glass fiber reinforced resin molded article containing the flat cross section glass fiber of this embodiment and obtained by the method described below, the ratio of the linear expansion coefficient in the MD direction to the linear expansion coefficient in the TD direction measured in accordance with JIS K 7197:2012 (linear expansion coefficient in the MD direction / linear expansion coefficient in the TD direction) is 0.60 or more, preferably 0.65 or more, more preferably 0.70 or more. The upper limit of 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) is not particularly limited, but is, for example, 1.40 or less, preferably 1.20 or less, more preferably 1.10 or less.

[0137] Examples of uses of the glass fiber reinforced resin molded product of this embodiment include electronic components such as printed wiring boards and connectors, housings for electronic devices, vehicle interior materials, vehicle exterior materials, housings for electronic devices such as antennas and radars, and separators for fuel cells.

[0138] Next, examples of the present invention and comparative examples will be described.

[0139] [Examples 1 to 5 and Comparative Examples 1 to 5] Glass raw materials prepared to have the compositions of Examples 1 to 5 and Comparative Examples 1 to 5 shown in Table 1 were melted, and the resulting molten glass was drawn out from a bushing equipped with 200 nozzle tips to obtain a plurality of flat cross section glass filaments. Next, the obtained flat cross section glass filaments were bundled to obtain the flat cross section glass fibers of Examples 1 to 5 and Comparative Examples 1 to 5.

[0140] The nozzle tip was provided with a hole having a flat cross-sectional shape with a major axis and a minor axis within a predetermined range, and a wall portion provided with a notch for cooling the molten glass. The minor axis of the hole was adjusted within a range of 0.2 to 2.0 mm, the ratio of the major axis to the minor axis of the nozzle was adjusted within a range of 1.3 to 5.5, and the flow rate of the molten glass passing through each nozzle was adjusted within a range of 0.1 to 3.0 g / min, so as to achieve the minor axis and major axis values ​​of Examples 1 to 5 and Comparative Examples 1 to 5 shown in Table 1.

[0141] Next, for the flat cross section glass fibers of Examples 1 to 5 and Comparative Examples 1 to 5, the major axis and minor axis of the flat cross section glass filament were measured, and the ratio of the major axis to the minor axis (major axis / minor axis) D was calculated, and the ratio was calculated by (S / A) x (C+M). ２ / D １／４ The value of was calculated.

[0142] Furthermore, the long-term manufacturing stability was evaluated and the linear expansion coefficient was measured for the flat cross section glass fibers of Examples 1 to 5 and Comparative Examples 1 to 5 by the following method. The results are shown in Table 1.

[0143] [Long-term manufacturing stability] When each of the flat cross section glass fibers of Examples 1 to 5 and Comparative Examples 1 to 5 was continuously produced for 8 hours, those in which no crystallization occurred inside the nozzle during the 8 hours and the operation shutdown period during cutting could be kept to less than 30 minutes were evaluated as "A." Those in which no crystallization occurred inside the nozzle during the 8 hours and the operation shutdown period during cutting could be kept to 30 minutes or more and less than 1.5 hours were evaluated as "B." Those in which crystallization occurred inside the nozzle for a period of more than 30 minutes but less than 8 hours, and an operation shutdown period of 1.5 hours or more but less than 4 hours was required to remove the crystals were evaluated as "C." Those in which crystallization occurred inside the nozzle within a period of 30 minutes or less, and an operation shutdown period of 4 hours or more was required to remove the crystals were evaluated as "D."

[0144] [Linear expansion coefficient] The surface of each flat cross-section glass fiber of Examples 1 to 5 and Comparative Examples 1 to 5 was coated with a composition containing a silane coupling agent and cut to a length of 3 mm to form chopped strands. Next, each chopped strand of Examples 1 to 5 and Comparative Examples 1 to 5 and polyamide 6 resin (manufactured by Ube Industries, Ltd., product name: UBE1015B) was mixed at a screw rotation speed of 100 rpm and a temperature of 270 ° C. in a twin-screw mixer (manufactured by Shibaura Machine Co., Ltd., product name: TEM-26SS) to produce resin pellets with a glass fiber content of 30% by mass. Next, each resin pellet of Examples 1 to 5 and Comparative Examples 1 to 5 was injection molded at a mold temperature of 80 ° C. and an injection temperature of 270 ° C. using an injection molding machine (manufactured by Nissei Plastic Industrial Co., Ltd., product name: NEX80) to produce glass fiber-reinforced resin molded products.

[0145] Next, for each of the glass fiber reinforced resin molded products of Examples 1 to 5 and Comparative Examples 1 to 5, the linear expansion coefficient in the direction in which the resin composition flows (MD direction) and in the direction perpendicular to the direction in which the resin composition flows (TD direction) was measured in accordance with JIS K 7197:2012 under conditions of a measurement temperature range of 50 to 150 ° C. and a temperature rise rate of 2 ° C. / min.

[0146]

[0147] From Table 1, it is clear that the flat cross section glass fibers of Examples 1 to 5 can obtain excellent long-term manufacturing stability, and when made into a glass fiber reinforced resin molded body, the linear expansion coefficient in the MD direction of the glass fiber reinforced resin molded body can be reduced, and anisotropy can be reduced.

[0148] On the other hand, (S / A)×(C+M) ２ / D １／４ It is clear that the flat cross section glass fibers of Comparative Examples 1, 2 and 4, which have a value of less than 228.9 and are outside the range of the formula (1), are inferior in long-term production stability. ２ / D １／４ The flat cross section glass fiber of Comparative Example 3, in which the value of (x) exceeds 588.9 and is outside the range of the formula (1), when made into a glass fiber reinforced resin molding, has a ratio of the linear expansion coefficient in the MD direction to the linear expansion coefficient in the TD direction (MD / TD ratio) of 0.55, which cannot be sufficiently close to 1. The flat cross section glass fiber of Comparative Example 5, when made into a glass fiber reinforced resin molding, has a linear expansion coefficient in the MD direction of 2.16 ppm, which is more than 2.10 ppm, and it is not possible to reduce the linear expansion coefficient in the MD direction of the glass fiber reinforced resin molding.

Claims

1. A glass fiber containing a plurality of glass filaments, wherein SiO is in the range of 60.0 to 69.0% by mass based on the total amount of the glass fiber. ２ And Al in the range of 18.0 to 26.0% by mass. ２ O ３ And MgO in the range of 8.0 to 14.0% by mass, and CaO in the range of 0.0 to 4.9% by mass, and the total content of SiO ２ , Al ２ O ３ , MgO and CaO is 95.0% by mass or more. The glass filament has a flat cross-sectional shape, and the ratio of the major axis to the minor axis (major axis / minor axis) of the glass filament is in the range of 1.2 to 5.

5. When the content of SiO ２ is S, the content of Al ２ O ３ is A, the content of MgO is M, the content of CaO is C, and the ratio of the major axis to the minor axis (major axis / minor axis) of the glass filament is D, the glass fiber is characterized in that 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, wherein S, A, M, C and D satisfy the following formula (2): 303.1 ≤ (S / A) × (C + M) ２ / D １／４ ≤ 588.9 ··· (2) 3. The glass fiber according to claim 1, wherein 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 by containing the glass fiber according to any one of claims 1 to 3.

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