Glass fiber reinforced resin plate

Abstract

Provided is a glass fiber-reinforced resin plate including a glass fiber which has an improved elastic modulus in the TD direction and has a flat cross-sectional shape. The glass fiber-reinforced resin plate includes: a glass fiber having a flat cross-sectional shape; and a resin, wherein the glass fiber having a flat cross-sectional shape has a minor diameter of 4.5-10.5 μm, and a major diameter of 22.0-80.0 μm. A ratio R of the major diameter to the minor diameter (major diameter / minor diameter) falls within the range of 4.5-10.0, a glass fiber content C is 5.0-75.0 mass%, and the thickness H falls within the range of 0.5 mm to 10.0 mm (exclusive of 0.5 mm). C and H satisfy expression (1).　(1): 30.0≤HxC≤120.0.

Description

[Technical field]

[0001] The present invention relates to a glass fiber reinforced resin plate. [Background technology]

[0002] Glass fiber reinforced resin molded products containing glass fibers with a flat cross-sectional shape are less susceptible to warping and have better dimensional stability than glass fiber reinforced resin molded products containing glass fibers with a circular cross-section, and are therefore widely used as light, thin, short and small materials for the housings of portable electronic devices and the like (see, for example, Patent Document 1).

[0003] Meanwhile, in recent years, composite materials of metals and plate-shaped fiber-reinforced resin molded products have been attracting attention, mainly for automotive applications (see, for example, Patent Document 2). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2010-84007 A [Patent Document 2] International Publication No. 2018 / 182038 Summary of the Invention [Problem to be solved by the invention]

[0005] A glass fiber reinforced resin plate containing glass fibers with a flat cross-sectional shape is excellent in dimensional stability and has higher mechanical strength than a glass fiber reinforced resin plate containing glass fibers with a circular cross-section, and is therefore considered to be usable in composite material applications with metals.

[0006] However, when a glass fiber reinforced resin plate containing glass fibers having a flat cross-sectional shape is used as a composite material of a metal and a fiber reinforced resin molded product, which is thicker than the light, thin, short and small materials that have been conventionally used for the housings of portable electronic devices, etc., there is an inconvenience that the elastic modulus of the glass fiber reinforced resin plate in the TD direction is insufficient.

[0007] If the elastic modulus of the glass fiber reinforced resin plate in the TD direction is insufficient, an imbalance occurs between the elastic modulus in the TD direction and the elastic modulus in the MD direction, and due to this imbalance, the adhesion between the metal and the glass fiber reinforced resin plate is reduced. The TD direction refers to the direction perpendicular to the direction in which the resin composition flows when a resin composition containing glass fibers is molded to produce a glass fiber reinforced resin plate. The MD direction refers to the direction in which the resin composition flows when a resin composition containing glass fibers is molded to produce a glass fiber reinforced resin plate.

[0008] Therefore, the present invention aims to eliminate such inconveniences and provide a glass fiber reinforced resin plate containing glass fibers having a flat cross-sectional shape and having an improved elastic modulus in the TD direction. [Means for solving the problem]

[0009] In order to achieve this object, the present invention provides a glass fiber reinforced resin plate comprising glass fibers having a flat cross-sectional shape and a resin, wherein the glass fibers having the flat cross-sectional shape have a minor axis in the range of 4.5 to 10.5 μm, a major axis in the range of 22.0 to 80.0 μm, and a ratio R of the major axis to the minor axis (major axis / minor axis) in the range of 4.5 to 10.0, The resin is a crystalline thermoplastic resin, The glass fiber reinforced resin plate has a glass fiber content C in the range of 5.0 to 75.0 mass%, a thickness H of the glass fiber reinforced resin plate in the range of more than 0.5 mm and not more than 10.0 mm, and C and H satisfy the following formula (1):

[0010] 30.0≦H×C≦120.0 (1) The glass fiber reinforced resin plate of the present invention includes glass fibers having a flat cross-sectional shape and a resin, wherein the glass fibers having a flat cross-sectional shape have a minor axis in the range of 4.5 to 10.5 μm, a major axis in the range of 22.0 to 80.0 μm, and a ratio of the major axis to the minor axis (major axis / minor axis) R in the range of 4.5 to 10.0.

[0011] In a glass fiber reinforced resin plate containing glass fibers having the above-mentioned flat cross-sectional shape, the elastic modulus in the TD direction is insufficient, resulting in an imbalance between the elastic modulus in the TD direction and the elastic modulus in the MD direction, and there is a concern that this imbalance may cause a decrease in adhesion to metal.

[0012] However, the glass fiber reinforced resin plate of the present invention has a glass fiber content C in the range of 5.0 to 75.0 mass%, a thickness H in the range of more than 0.5 mm and 10.0 mm or less, and C and H satisfy the following formula (1), thereby enabling the elastic modulus in the TD direction to be improved. Here, the term "capable of improving the elastic modulus in the TD direction" means that the elastic modulus in the TD direction of the glass fiber reinforced resin plate of the present invention is improved by 5.0% or more compared to the elastic modulus in the TD direction of the comparative glass fiber reinforced resin plate. The comparative glass fiber reinforced resin plate is a glass fiber reinforced resin plate manufactured under the same molding conditions as the glass fiber reinforced resin plate of the present invention, using glass fibers having the same cross-sectional area as the glass fibers used in the glass fiber reinforced resin plate of the present invention and having a flat cross-sectional shape with a ratio of the major axis to the minor axis (major axis / minor axis) R of 4.0, with the same glass fiber content C and thickness H as the glass fiber reinforced resin plate of the present invention.

[0013] 30.0≦H×C≦120.0 (1) In the glass fiber reinforced resin plate of the present invention, when the glass fiber content C and thickness H are within the above ranges, if the product of C and H is less than 30.0 or exceeds 120.0, the elastic modulus in the TD direction cannot be improved.

[0014] In the glass fiber reinforced resin plate of the present invention, it is preferable that the glass fiber content C is in the range of 20.0 to 60.0 mass%, the thickness H of the glass fiber reinforced resin plate is in the range of 0.8 to 8.0 mm, and C and H satisfy the following formula (2). In the glass fiber reinforced resin plate of the present invention, C and H are in the above-mentioned range and satisfy the following formula (2), so that the elastic modulus in the TD direction can be further improved. Here, being able to further improve the elastic modulus in the TD direction means that the elastic modulus in the TD direction of the glass fiber reinforced resin plate of the present invention is improved by 10.0% or more when comparing the elastic modulus in the TD direction of the glass fiber reinforced resin plate of the present invention with the elastic modulus in the TD direction of the comparative glass fiber reinforced resin plate.

[0015] 45.0≦H×C≦80.0 (2) In order to further improve the elastic modulus in the TD direction, it is more preferable that the glass fiber content C of the glass fiber reinforced resin plate of the present invention is in the range of 20.0 to 40.0 mass %, the thickness H of the glass fiber reinforced resin plate is in the range of 1.6 to 5.0 mm, and C and H satisfy the following formula (3):

[0016] 55.0≦H×C≦74.5 (3) In addition, in order to improve the elastic modulus in the TD direction, the resin contained in the glass fiber reinforced resin plate of the present invention is , Po It is a reamide I like I wish. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] Next, the embodiment of the present invention will be described in more detail.

[0018] The glass fiber reinforced resin plate of this embodiment is a molded product containing glass fibers having a flat cross-sectional shape and resin.

[0019] In the glass fiber reinforced resin plate of the present embodiment, the glass composition of the glass forming the glass fiber is not particularly limited. In the glass fiber reinforced resin plate of the present embodiment, the glass composition that the glass fiber can have can be the most general-purpose E glass composition, a high strength and high elastic modulus glass composition, a high elastic modulus easy-to-manufacture glass composition, and a low dielectric constant and low dielectric loss tangent glass composition.

[0020] The E-glass composition is a composition containing SiO2 in the range of 52.0 to 56.0 mass%, Al2O3 in the range of 12.0 to 16.0 mass%, MgO and CaO in the range of 20.0 to 25.0 mass%, and B2O3 in the range of 5.0 to 10.0 mass%, based on the total amount of glass fibers.

[0021] The high-strength, high-elasticity glass composition contains, relative to the total amount of the glass fibers, SiO2 in the range of 60.0 to 70.0 mass%, Al2O3 in the range of 20.0 to 30.0 mass%, MgO in the range of 5.0 to 15.0 mass%, Fe2O3 in the range of 0 to 1.5 mass%, and Na2O, K2O, and Li2O in the range of 0 to 0.2 mass% in total.

[0022] The high elastic modulus, easily manufacturable glass composition contains, relative to the total amount of glass fibers, SiO2 in the range of 57.0 to 60.0 mass%, Al2O3 in the range of 17.5 to 20.0 mass%, MgO in the range of 8.5 to 12.0 mass%, CaO in the range of 10.0 to 13.0 mass%, and B2O3 in the range of 0.5 to 1.5 mass%, and the total amount of SiO2, Al2O3, MgO and CaO is 98.0 mass% or more.

[0023] The low dielectric constant and low dielectric tangent glass composition contains, relative to the total amount of the glass fibers, SiO2 in the range of 48.0 to 62.0 mass%, B2O3 in the range of 17.0 to 26.0 mass%, Al2O3 in the range of 9.0 to 18.0 mass%, CaO in the range of 0.1 to 9.0 mass%, MgO in the range of 0 to 6.0 mass%, Na2O, K2O, and Li2O in a total range of 0.05 to 0.5 mass%, TiO2 in the range of 0 to 5.0 mass%, SrO in the range of 0 to 6.0 mass%, F2 and Cl2 in a total range of 0 to 3.0 mass%, and P2O5 in the range of 0 to 6.0 mass%.

[0024] From the viewpoint of improving the strength of the glass fiber reinforced resin plate, the glass composition of the glass fiber is preferably the high-strength, high-elasticity glass composition or the high-elasticity, easily manufacturable glass composition. Also, from the viewpoint of lowering the dielectric constant and dielectric loss tangent of the glass fiber reinforced resin plate and reducing the transmission loss of high-frequency signals passing through the glass fiber reinforced resin plate, the glass composition of the glass fiber is preferably the low-dielectric, low-dielectric loss tangent glass composition.

[0025] The content of each component in the above-mentioned glass composition can be measured using an ICP optical emission spectrometer for the light element Li, and a wavelength dispersive X-ray fluorescence analyzer for the other elements. The measurement methods are as follows.

[0026] First, the glass fibers are cut to an appropriate size, then placed in a platinum crucible and melted in an electric furnace at 1550°C for 6 hours while stirring to obtain homogeneous molten glass. The molten glass obtained is then poured onto a carbon plate to produce glass cullet, which is then crushed and powdered to obtain glass powder.

[0027] The light element Li is quantitatively analyzed using an ICP emission spectrometer after the glass powder is thermally decomposed with acid. The other elements are quantitatively analyzed using a wavelength dispersive X-ray fluorescence analyzer after the glass powder is molded into a disk shape using a press. The results of these quantitative analyses are converted into oxides to calculate the content and total amount of each component, and the content (mass%) of each of the above-mentioned components can be calculated from these values.

[0028] When organic matter is attached to the surface of the glass fiber, or when the glass fiber is contained mainly as a reinforcing material in an organic matter (resin), the glass fiber is used after removing the organic matter, for example, by heating in a muffle furnace at 300 to 650°C for about 2 to 24 hours.

[0029] The glass fiber having the above-mentioned glass composition can be manufactured as follows. First, a glass raw material (glass batch) prepared to have the above-mentioned composition is supplied to a melting furnace and melted at a temperature in the range of, for example, 1450 to 1550°C. Next, the molten glass batch (molten glass) is drawn out from 1 to 30,000 nozzle tips of a bushing controlled at a predetermined temperature and quenched to form glass filaments. Next, a sizing agent or binder is applied to the formed glass filaments using an applicator, which is a coating device, and 1 to 30,000 glass filaments are bundled using a bundling shoe, while being wound at high speed around a tube using a winding machine, to obtain glass fibers.

[0030] Here, the glass fiber having a flat cross-sectional shape used in the glass fiber reinforced resin plate of this embodiment can be obtained by making the nozzle tip have a non-circular shape and a protrusion or a notch for quenching the molten glass, and by controlling the temperature conditions. In addition, the minor and major diameters of the glass fiber can be adjusted by adjusting the diameter of the nozzle tip, the winding speed, the temperature conditions, and the like. For example, the minor and major diameters can be made smaller by increasing the winding speed, and the minor and major diameters can be made larger by decreasing the winding speed.

[0031] The glass fibers having a flat cross-sectional shape used in the glass fiber reinforced resin plate of this embodiment have a short diameter in the range of 4.5 to 10.5 μm, preferably 5.0 to 8.0 μm, and more preferably 5.0 to 6.4 μm, a long diameter in the range of 22.0 to 80.0 μm, preferably 28.5 to 70.0 μm, more preferably 29.5 to 65.0 μm, even more preferably 32.5 to 60.0 μm, and particularly preferably 32.5 to 50.0 μm, and the ratio of the long diameter to the short diameter (long diameter / short diameter) R is in the range of 4.5 to 10.0, preferably 5.0 to 7.9, more preferably 5.0 to 6.7, and even more preferably 5.5 to 6.5. The flat cross-sectional shape is preferably an elliptical shape or an oval shape, and more preferably an oval shape. The oval shape is a shape in which a semicircular shape is added to both ends of a rectangle, or a shape similar thereto.

[0032] The equivalent fiber diameter of the glass fiber having a flat cross-sectional shape used in the glass fiber reinforced resin plate of this embodiment is in the range of 11.0 to 32.0 μm, preferably in the range of 12.0 to 22.0 μm, more preferably in the range of 12.5 to 20.0 μm, and further preferably in the range of 13.5 to 18.0 μm. Here, the equivalent fiber diameter means the diameter of a glass fiber having a circular cross-sectional area that is the same as the cross-sectional area of ​​the glass fiber having a flat cross-sectional shape.

[0033] The minor axis and major axis of the glass fiber having a flat cross-sectional shape in the glass fiber reinforced resin plate of this embodiment can be calculated, for example, as follows.

[0034] First, the cross section of the glass fiber reinforced resin plate is polished. Next, using an electron microscope, the longest side passing through the approximate center of the cross section of the glass filament is taken as the major axis, and the side perpendicular to the major axis at the approximate center of the cross section of the glass filament is taken as the minor axis, and the lengths of each are measured for 100 or more glass filaments. Then, the minor axis and major axis of the glass fiber can be calculated by averaging the measured lengths of the minor axis and major axis.

[0035] In addition, glass fibers are usually formed by bundling multiple glass filaments, but in a glass fiber reinforced resin plate, the bundling is released through the molding process, and the glass filaments are present in a dispersed state in the glass fiber reinforced resin plate.

[0036] Here, a preferred form that the glass fiber having a flat cross-sectional shape in the glass fiber reinforced resin plate of this embodiment takes before molding is a chopped strand in which the number of glass filaments (bundled number) constituting the glass fiber is preferably in the range of 1 to 20,000, more preferably 50 to 10,000, and even more preferably 1,000 to 8,000, and the length of the glass fiber (also called glass fiber bundle or glass strand) is preferably cut to a range of 1.0 to 100.0 mm, more preferably 1.2 to 51.0 mm, even more preferably 1.5 to 30.0 mm, particularly preferably 2.0 to 15.0 mm, and most preferably 2.3 to 7.8 mm. In addition, in the glass fiber reinforced resin plate of this embodiment, examples of the form that the glass fiber having a flat cross-sectional shape can take before molding include, in addition to chopped strands, roving in which the number of glass filaments constituting the glass fiber is in the range of 10 to 30,000 and is not cut, and cut fibers in which the number of glass filaments constituting the glass fiber is in the range of 1 to 20,000 and which have been pulverized to a length of 0.001 to 0.900 mm by a known method such as a ball mill or a Henschel mixer.

[0037] In the glass fiber reinforced resin plate of this embodiment, the glass fiber may be coated with an organic material on its surface for the purpose of improving the adhesion between the glass fiber and the resin, improving the uniform dispersion of the glass fiber in a mixture of the glass fiber and the resin or the inorganic material, etc. Examples of such organic materials include a resin or a silane coupling agent, and a composition containing a lubricant, a surfactant, etc. in addition to these. Here, the composition may contain a resin and a silane coupling agent.

[0038] Such a composition coats the glass fibers at a ratio in the range of 0.1 to 2.0 mass % based on the mass of the glass fibers in a state where they are not coated with the composition.

[0039] Examples of the resin include urethane resin, epoxy resin, vinyl acetate resin, acrylic resin, modified polypropylene, particularly carboxylic acid modified polypropylene, (poly)carboxylic acid, particularly a copolymer of maleic acid and an unsaturated monomer, and the like.

[0040] The coating of glass fibers with an organic substance can be carried out, for example, in a glass fiber manufacturing process by applying the composition, the resin, or the sizing agent or binder containing a solution of the silane coupling agent to the glass fibers using a known method such as a roller-type applicator, and then drying the glass fibers to which the resin, the silane coupling agent, or the composition has been applied.

[0041] Here, examples of the silane coupling agent include aminosilane, chlorosilane, epoxysilane, mercaptosilane, vinylsilane, acrylicsilane, and cationic silane. The silane coupling agent may be used alone or in combination of two or more of these compounds.

[0042] Examples of the aminosilane include γ-aminopropyltriethoxysilane, N-β-(aminoethyl)-γ-aminopropyltrimethoxysilane, N-β-(aminoethyl)-N'-β-(aminoethyl)-γ-aminopropyltrimethoxysilane, and γ-anilinopropyltrimethoxysilane.

[0043] Moreover, the chlorosilane may include γ-chloropropyltrimethoxysilane.

[0044] Examples of the epoxy silane include γ-glycidoxypropyltrimethoxysilane and β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane.

[0045] Moreover, the mercaptosilane may include γ-mercaptotrimethoxysilane.

[0046] Examples of the vinyl silane include vinyl trimethoxy silane and N-β-(N-vinyl benzyl amino ethyl)-γ-amino propyl trimethoxy silane.

[0047] Moreover, the acrylsilane may include γ-methacryloxypropyltrimethoxysilane.

[0048] Examples of the cationic silane include N-(vinylbenzyl)-2-aminoethyl-3-aminopropyltrimethoxysilane hydrochloride, and N-phenyl-3-aminopropyltrimethoxysilane hydrochloride.

[0049] 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. The lubricants can be used alone or in combination of two or more kinds.

[0050] The animal oil may include beef tallow.

[0051] Examples of the vegetable oil include soybean oil, coconut oil, rapeseed oil, palm oil, castor oil, etc. Examples of the animal wax include beeswax, lanolin, etc. Examples of the vegetable wax include candelilla wax, carnauba wax, etc.

[0052] Examples of the mineral wax include paraffin wax, montan wax, etc. Examples of the condensation products of higher saturated fatty acids and higher saturated alcohols include stearic acid esters such as lauryl stearate.

[0053] Examples of the fatty acid amide 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.

[0054] Examples of the quaternary ammonium salt include alkyltrimethylammonium salts such as lauryltrimethylammonium chloride.

[0055] Examples of the surfactant include nonionic surfactants, cationic surfactants, anionic surfactants, and amphoteric surfactants. The surfactants may be used alone or in combination of two or more kinds.

[0056] 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.

[0057] Examples of cationic surfactants include alkyl dimethyl benzyl ammonium chloride, alkyl trimethyl ammonium chloride, alkyl dimethyl ethyl ammonium ethyl sulfate, higher alkyl amine salts (acetates, hydrochlorides, etc.), ethylene oxide adducts of higher alkyl amines, 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 alkyl pyridinium salts.

[0058] 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.

[0059] Examples of the amphoteric surfactant include amino acid type amphoteric surfactants such as alkali metal salts of alkylaminopropionic acid, betaine type such as alkyldimethylbetaine, and imidazoline type amphoteric surfactants.

[0060] Moreover, examples of the resin used in the glass fiber reinforced resin plate of this embodiment include thermoplastic resins.

[0061] 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, ester, polyarylene sulfide, polyethersulfone (PES), polyphenylsulfone (PPSU), 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, and the like.

[0062] 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.

[0063] Examples of polypropylene include isotactic polypropylene, atactic polypropylene, syndiotactic polypropylene, and mixtures thereof.

[0064] 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.

[0065] Examples of the methacrylic resin 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.

[0066] 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 monomers copolymerizable therewith; and graft copolymers in which vinyl chloride monomers are graft-polymerized onto a polymer.

[0067] Polyamides include polycaproamide (polyamide 6), polyhexamethylene adipamide (polyamide 66), polytetramethylene adipamide (polyamide 46), polytetramethylene sebacamide (polyamide 410), polypentamethylene adipamide (polyamide 56), polypentamethylene sebacamide (polyamide 510), polyhexamethylene sebacamide (polyamide 610), polyhexamethylene dodecamide (polyamide 612), polydecamethylene adipamide (polyamide 106), polydeca Methylene sebacamide (Polyamide 1010), Polydecamethylene dodecamide (Polyamide 1012), Polyundecane amide (Polyamide 11), Polyundecamethylene adipamide (Polyamide 116), Polydodecanamide (Polyamide 12), Polyxylene adipamide (Polyamide XD6), Polyxylene sebacamide (Polyamide XD10), Polymeta-xylylene adipamide (Polyamide MXD6), Polypara-xylylene adipamide (Polyamide PXD6), Polytetramethylene terephthalamide (Poly Polyamide 4T), Polypentamethylene terephthalamide (Polyamide 5T), Polyhexamethylene terephthalamide (Polyamide 6T), Polyhexamethylene isophthalamide (Polyamide 6I), Polynonamethylene terephthalamide (Polyamide 9T), Polydecamethylene terephthalamide (Polyamide 10T), Polyundecamethylene terephthalamide (Polyamide 11T), Polydodecamethylene terephthalamide (Polyamide 12T), Polytetramethylene isophthalamide (Polyamide 4I), Polybi Examples of the polybis(3-methyl-4-aminohexyl)methane terephthalamide (polyamide PACMT), polybis(3-methyl-4-aminohexyl)methane isophthalamide (polyamide PACMI), polybis(3-methyl-4-aminohexyl)methanendodecamide (polyamide PACM12), polybis(3-methyl-4-aminohexyl)methane tetradecamide (polyamide PACM14), etc., may be used alone or as a copolymer of two or more of these components, or as a mixture of these components.

[0068] Examples of polyacetals include homopolymers having oxymethylene units as the main repeating units, and copolymers mainly composed of oxymethylene units and containing oxyalkylene units having 2 to 8 adjacent carbon atoms in the main chain.

[0069] Examples of polyethylene terephthalate include a polymer obtained by polycondensing terephthalic acid or a derivative thereof with ethylene glycol.

[0070] Examples of polybutylene terephthalate include a polymer obtained by polycondensation of terephthalic acid or a derivative thereof with 1,4-butanediol.

[0071] Examples of polytrimethylene terephthalate include polymers obtained by polycondensation of terephthalic acid or a derivative thereof with 1,3-propanediol.

[0072] Examples of polycarbonates include polymers obtained 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 obtained by a phosgene method in which a dihydroxyaryl compound is reacted with phosgene.

[0073] Examples of polyarylene sulfide include linear polyphenylene sulfide, crosslinked polyphenylene sulfide which has been polymerized and then cured, polyphenylene sulfide sulfone, polyphenylene sulfide ether, and polyphenylene sulfide ketone.

[0074] Examples of polyphenylene ether 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), Examples of such poly(2-chloro-1,4-phenylene ether) include 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), and poly(2,6-dimethyl-1,4-phenylene ether).

[0075] Examples of modified polyphenylene ethers include a polymer alloy of poly(2,6-dimethyl-1,4-phenylene) ether and polystyrene, a polymer alloy of poly(2,6-dimethyl-1,4-phenylene) ether and a styrene / butadiene copolymer, a polymer alloy of poly(2,6-dimethyl-1,4-phenylene) ether and a styrene / maleic anhydride copolymer, a polymer alloy of poly(2,6-dimethyl-1,4-phenylene) ether and a polyamide, a polymer alloy of poly(2,6-dimethyl-1,4-phenylene) ether and a styrene / butadiene / acrylonitrile copolymer, the polyphenylene ether having a functional group such as an amino group, an epoxy group, a carboxy group, or a styryl group introduced at the polymer chain end, and the polyphenylene ether having a functional group such as an amino group, an epoxy group, a carboxy group, a styryl group, or a methacryl group introduced at the polymer chain side chain.

[0076] Examples of polyaryletherketones include polyetherketone (PEK), polyetheretherketone (PEEK), polyetherketoneketone (PEKK), and polyetheretherketoneketone (PEEKK).

[0077] Examples of liquid crystal polymers (LCPs) include thermotropic liquid crystal polyesters, such as (co)polymers composed of one or more structural units selected from aromatic hydroxycarbonyl units, aromatic dihydroxy units, aromatic dicarbonyl units, aliphatic dihydroxy units, aliphatic dicarbonyl units, and the like.

[0078] 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).

[0079] 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.

[0080] 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.

[0081] Examples of the cyclic olefin resin include monocyclic compounds such as cyclohexene, polycyclic compounds such as tetracyclopentadiene, and polymers of cyclic olefin monomers.

[0082] 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.

[0083] Examples of the cellulose resin include methyl cellulose, ethyl cellulose, hydroxy cellulose, hydroxy methyl cellulose, hydroxy ethyl cellulose, hydroxy ethyl methyl cellulose, hydroxy propyl methyl cellulose, cellulose acetate, cellulose propionate, and cellulose butyrate.

[0084] The resin used in the glass fiber reinforced resin plate of this embodiment is preferably a crystalline thermoplastic resin because it has a large effect of improving the elastic modulus in the TD direction. Examples of the crystalline thermoplastic resin include polyamide, polybutylene terephthalate, polyphenylene sulfide, polyether ether ketone, polyethylene, and polypropylene, and more preferably polyamide, and particularly preferably polyamide 6.

[0085] Moreover, when the resin used in the glass fiber reinforced resin plate of the present embodiment is a crystalline thermoplastic resin, it is preferable that it does not contain an amorphous thermoplastic resin.

[0086] When the resin used in the glass fiber reinforced resin plate of this embodiment is a transparent resin, the glass fiber reinforced resin plate of this embodiment can improve the light transmittance of visible light, ultraviolet light, infrared light, laser light, etc., compared to the comparative glass fiber reinforced resin plate. The comparative glass fiber reinforced resin plate is a glass fiber reinforced resin plate manufactured under the same molding conditions as the glass fiber reinforced resin plate of this embodiment, using glass fibers having a flat cross-sectional shape with the same cross-sectional area as the glass fiber used in the glass fiber reinforced resin plate of this embodiment and a ratio of the major axis to the minor axis (major axis / minor axis) R of 4.0, with the glass fiber content C and thickness H being the same as those of the glass fiber reinforced resin plate of this embodiment. Here, examples of the transparent resin include polystyrene, ABS resin, (meth)acrylic resin, polyacetal, polyethylene terephthalate, polycarbonate, and polyarylate.

[0087] The glass fiber reinforced resin plate of this embodiment can be obtained, for example, by kneading chopped strands having a predetermined length, which are formed by bundling glass filaments of glass fibers having the flat cross-sectional shape, with the resin in a twin-screw kneader, and performing injection molding using the obtained resin pellets. The glass fiber reinforced resin plate of this embodiment can also be obtained using known molding methods such as injection compression molding, two-color molding, hollow molding, foam molding (including supercritical fluid foam molding), insert molding, in-mold coating molding, extrusion molding, sheet molding, thermoforming, rotational molding, lamination molding, press molding, blow molding, stamping molding, infusion, hand layup, spray-up, resin transfer molding, sheet molding compound method, bulk molding compound method, pultrusion method, and filament winding method. The shape of the glass fiber reinforced resin plate of the present embodiment obtained as described above may be a flat plate, a flat plate having holes or irregularities, or a plate having a curved surface or bends. Here, examples of the plate having a curved surface or bends include a hollow cylinder, a hollow polygonal prism, and a box.

[0088] The glass fiber reinforced resin plate of the present embodiment has a glass fiber content C in the range of 5.0 to 75.0 mass % and a thickness H in the range of more than 0.5 mm and not more than 10.0 mm, and C and H satisfy the following formula (1), thereby enabling the elastic modulus in the TD direction to be improved.

[0089] 30.0≦H×C≦120.0 (1) In the glass fiber reinforced resin plate of this embodiment, the glass fiber content C is preferably in the range of 20.0 to 60.0 mass%, more preferably 20.0 to 40.0 mass%, and more preferably 21.0 to 38.0 mass%. In the glass fiber reinforced resin plate of this embodiment, the thickness H of the glass fiber reinforced resin plate is preferably in the range of 0.8 to 8.0 mm, more preferably 1.6 to 5.0 mm, even more preferably 1.6 to 3.4 mm, and particularly preferably 1.6 to 2.4 mm. In the glass fiber reinforced resin plate of this embodiment, the C and H preferably satisfy the following formula (2), more preferably satisfy the following formula (3), even more preferably satisfy the following formula (4), particularly preferably satisfy the following formula (5), particularly preferably satisfy the following formula (6), and most preferably satisfy the following formula (7).

[0090] 45.0≦H×C≦80.0 (2) 55.0≦H×C≦74.5 (3) 59.0≦H×C≦72.0 (4) 59.0≦H×C≦69.0 (5) 59.0≦H×C≦66.0 (6) 59.0≦H×C≦64.0 (7) The number average fiber length L of the glass fibers contained in the glass fiber reinforced resin plate of this embodiment is in the range of 100 to 700 μm, preferably 150 to 450 μm, more preferably 200 to 400 μm, and further preferably 220 to 380 μm.

[0091] Here, the number average fiber length L of the glass fibers contained in the glass fiber reinforced resin plate of this embodiment can be controlled, for example, by adjusting the length of the chopped strands fed into the twin-screw kneader and the screw rotation speed of the twin-screw kneader when the glass fiber reinforced resin plate of this embodiment is obtained by injection molding. For example, the length of the chopped strands fed into the twin-screw kneader can be increased in the range of 1.0 to 100.0 mm, and the length of the chopped strands can be decreased, thereby shortening the L. In addition, the screw rotation speed during twin-screw kneading can be decreased in the range of 10 to 1000 rpm, and the screw rotation speed can be increased, thereby shortening the L.

[0092] Here, the glass fiber content C, the thickness H of the glass fiber reinforced resin plate, and the number average fiber length L of the glass fibers preferably satisfy the following formula (a), more preferably satisfy the following formula (b), even more preferably satisfy the following formula (c), particularly preferably satisfy the following formula (d), and most preferably satisfy the following formula (e).

[0093] 0.31≦(C / L) (1 / 2) ×H≦1.01 (a) 0.41≦(C / L) (1 / 2) ×H≦0.71 (b) 0.46≦(C / L) (1 / 2) ×H≦0.71 (c) 0.51≦(C / L) (1 / 2) ×H≦0.71 (d) 0.56≦(C / L) (1 / 2) ×H≦0.66 (e) The applications of the glass fiber reinforced resin plate of this embodiment include, but are not limited to, a substitute material for plate-shaped metal in automobiles, and a composite material of metal and plate-shaped fiber reinforced resin molded products for automobiles. The glass fiber reinforced resin plate of this embodiment can be preferably used for, for example, automobile exterior parts such as front fenders and door panels, automobile interior parts such as trim and glove boxes, automobile gear parts such as cylinder head covers and radiator tanks, etc.

[0094] Next, examples, comparative examples and reference examples of the present invention will be described. EXAMPLES

[0095] Example 1 In this example, a chopped strand having a length of 50 mm and having an oval cross-sectional shape with a long diameter of 34.1 μm, a short diameter of 5.7 μm, a long diameter / short diameter R of 6.0, and an equivalent fiber diameter of 15.4 μm, which is made of E-glass composition, glass filaments are bundled and coated with a silane coupling agent composition, and polyamide 6 (manufactured by Ube Industries, Ltd., product name: UBE Nylon 1015B, described as PA in Table 1) was kneaded in a twin-screw kneader (manufactured by Shibaura Machine Co., Ltd., product name: TEM-26SS) at a screw rotation speed of 100 rpm to produce a resin pellet with a glass content C of 40 mass%.

[0096] Next, the resin pellets obtained in this example were used to perform injection molding using an injection molding machine (manufactured by Nissei Plastics Industrial Co., Ltd., product name: NEX80) at a mold temperature of 90°C and an injection temperature of 270°C to produce a glass fiber reinforced resin plate (flat plate) with dimensions of 80 mm in length x 60 mm in width and a thickness H of 1.0 mm.

[0097] Next, the glass fiber reinforced resin plate (flat plate) produced in this example was measured for flexural modulus in the TD direction and flexural modulus in the MD direction by the method described below, and the number average fiber length L of the glass fibers in the glass fiber reinforced resin plate was calculated. The results are shown in Table 1.

[0098] [TD bending modulus] A test piece was obtained by processing the glass fiber reinforced resin plate to a width of 25 mm x length of 20 mm so that the length direction of the test piece corresponds to the TD direction of the glass fiber reinforced resin plate and the width direction of the test piece corresponds to the MD direction of the glass fiber reinforced resin plate. Next, a static bending test was performed on the obtained test piece in accordance with JIS K 7171:2016 using a precision universal testing machine (manufactured by Shimadzu Corporation, product name: Autograph AG-XPlus) at a test temperature of 23°C to measure the TD bending modulus.

[0099] [MD bending modulus] A test piece was obtained by processing the glass fiber reinforced resin plate to a width of 25 mm x length of 20 mm so that the length direction of the test piece corresponds to the MD direction of the glass fiber reinforced resin plate and the width direction of the test piece corresponds to the TD direction of the glass fiber reinforced resin plate. Next, a static bending test was performed on the obtained test piece in accordance with JIS K 7171:2016 using a precision universal testing machine (manufactured by Shimadzu Corporation, product name: Autograph AG-XPlus) at a test temperature of 23°C to measure the MD bending modulus.

[0100] [Number average fiber length of glass fibers L] The number average fiber length L of the glass fibers in the glass fiber reinforced resin plate was calculated by the following method. First, the glass fiber reinforced resin plate was heated in a muffle furnace at 650°C for 0.5 to 24 hours to decompose the organic matter. Next, the remaining glass fibers were transferred to a glass petri dish, and the glass fibers were dispersed on the surface of the petri dish using acetone. Next, the fiber lengths of 1000 or more glass fibers dispersed on the surface of the petri dish were measured using a stereomicroscope, and the average was calculated to calculate the number average fiber length L of the glass fibers. In Tables 1 to 3, the number average fiber length L of the glass fibers is referred to as "number average fiber length L".

[0101] In Tables 1 to 3, the TD bending modulus improvement rate (%) and the MD bending modulus improvement rate (%) are improvement rates relative to the TD bending modulus (GPa) and MD bending modulus (GPa) of the corresponding Reference Example, respectively, and the anisotropy improvement rate (%) is improvement rate relative to the anisotropy of the corresponding Reference Example. In Tables 1 to 3, the difference between the TD bending modulus improvement rate and the MD bending modulus improvement rate (TD bending modulus improvement rate - MD bending modulus improvement rate) is indicated as "bending modulus improvement rate difference".

[0102] [Reference example 1] This reference example corresponds to Example 1, and resin pellets having a glass content C of 40% by mass were produced in exactly the same manner as in Example 1, except that chopped strands formed by bundling glass filaments were used, which had an oval cross-sectional shape with a major axis of 28.0 μm, a minor axis of 7.0 μm, a major axis / minor axis R of 4.0, and an equivalent fiber diameter of 15.4 μm.

[0103] Next, a glass fiber reinforced resin plate (flat plate) was produced in exactly the same manner as in Example 1, except that the resin pellets obtained in this Reference Example were used.

[0104] Next, the TD bending modulus and MD bending modulus of the glass fiber reinforced resin plate (flat plate) produced in this Reference Example were measured exactly in the same manner as in Example 1, and the number average fiber length L of the glass fibers in the glass fiber reinforced resin plate was calculated. The results are shown in Table 1.

[0105] Example 2 In this example, except that the glass content C was set to 50 mass%, resin pellets were produced in exactly the same manner as in Example 1. Next, a glass fiber reinforced resin plate (flat plate) having dimensions of 20 mm length × 25 mm width and a thickness H of 1.0 mm was produced in exactly the same manner as in Example 1, except that the resin pellets obtained in this example were used.

[0106] Next, the TD bending modulus and MD bending modulus of the glass fiber reinforced resin plate (flat plate) produced in this example were measured exactly in the same manner as in Example 1, and the number average fiber length L of the glass fibers in the glass fiber reinforced resin plate was calculated. The results are shown in Table 1.

[0107] [Reference example 2] This Reference Example corresponds to Example 2, and resin pellets were produced in exactly the same manner as in Reference Example 1, except that the glass content C was 50 mass%. Next, a glass fiber reinforced resin plate (flat plate) having dimensions of 20 mm length × 25 mm width and a thickness H of 1.0 mm was produced in exactly the same manner as in Example 1, except that the resin pellets obtained in this Reference Example were used.

[0108] Next, the TD bending modulus and MD bending modulus of the glass fiber reinforced resin plate (flat plate) produced in this Reference Example were measured exactly in the same manner as in Example 1, and the number average fiber length L of the glass fibers in the glass fiber reinforced resin plate was calculated. The results are shown in Table 1.

[0109] Example 3 In this example, except that the glass content C was set to 30 mass%, resin pellets were produced in exactly the same manner as in Example 1. Next, a glass fiber reinforced resin plate (flat plate) having dimensions of 40 mm length × 25 mm width and a thickness H of 2.0 mm was produced in exactly the same manner as in Example 1, except that the resin pellets obtained in this example were used.

[0110] Next, the TD bending modulus and MD bending modulus of the glass fiber reinforced resin plate (flat plate) produced in this example were measured exactly in the same manner as in Example 1, and the number average fiber length L of the glass fibers in the glass fiber reinforced resin plate was calculated. The results are shown in Table 1.

[0111] [Reference example 3] This Reference Example corresponds to Example 3, and resin pellets were produced in exactly the same manner as in Reference Example 1, except that the glass content C was 30 mass%. Next, a glass fiber reinforced resin plate (flat plate) having dimensions of 40 mm length × 25 mm width and a thickness H of 2.0 mm was produced in exactly the same manner as in Example 1, except that the resin pellets obtained in this Reference Example were used.

[0112] Next, the TD bending modulus and MD bending modulus of the glass fiber reinforced resin plate (flat plate) produced in this Reference Example were measured exactly in the same manner as in Example 1, and the number average fiber length L of the glass fibers in the glass fiber reinforced resin plate was calculated. The results are shown in Table 1.

[0113] Example 4 In this example, except that the glass content C was set to 50 mass%, resin pellets were produced in exactly the same manner as in Example 1. Next, a glass fiber reinforced resin plate (flat plate) having dimensions of 40 mm length × 25 mm width and a thickness H of 2.0 mm was produced in exactly the same manner as in Example 1, except that the resin pellets obtained in this example were used.

[0114] Next, the TD bending modulus and MD bending modulus of the glass fiber reinforced resin plate (flat plate) produced in this example were measured exactly in the same manner as in Example 1, and the number average fiber length L of the glass fibers in the glass fiber reinforced resin plate was calculated. The results are shown in Table 2.

[0115] [Reference example 4] This Reference Example corresponds to Example 4, and resin pellets were produced in exactly the same manner as in Reference Example 1, except that the glass content C was 50 mass%. Next, a glass fiber reinforced resin plate (flat plate) having dimensions of 40 mm length × 25 mm width and a thickness H of 2.0 mm was produced in exactly the same manner as in Example 1, except that the resin pellets obtained in this Reference Example were used.

[0116] Next, the TD bending modulus and MD bending modulus of the glass fiber reinforced resin plate (flat plate) produced in this Reference Example were measured exactly in the same manner as in Example 1, and the number average fiber length L of the glass fibers in the glass fiber reinforced resin plate was calculated. The results are shown in Table 2.

[0117] Example 5 In this example, polybutylene terephthalate (manufactured by Polyplastics Co., Ltd., product name: DURANEX 2000, described as PBT in Table 2) was used, and resin pellets were produced in exactly the same manner as in Example 1, except that the glass content C was 30 mass%. Next, using the resin pellets obtained in this example, a glass fiber reinforced resin plate (flat plate) having dimensions of 40 mm length × 25 mm width and a thickness H of 2.0 mm was produced in exactly the same manner as in Example 1, except that the mold temperature was 90°C and the injection temperature was 250°C.

[0118] Next, the TD bending modulus and MD bending modulus of the glass fiber reinforced resin plate (flat plate) produced in this example were measured exactly in the same manner as in Example 1, and the number average fiber length L of the glass fibers in the glass fiber reinforced resin plate was calculated. The results are shown in Table 2.

[0119] [Reference example 5] This Reference Example corresponds to Example 5, and polybutylene terephthalate (manufactured by Polyplastics Co., Ltd., product name: DURANEX 2000, described as PBT in Table 2) was used, and resin pellets were produced in exactly the same manner as in Reference Example 1, except that the glass content C was 30 mass%. Next, using the resin pellets obtained in this example, a glass fiber reinforced resin plate (flat plate) having dimensions of 40 mm length × 25 mm width and thickness H of 2.0 mm was produced in exactly the same manner as in Example 1, except that the mold temperature was 90°C and the injection temperature was 250°C.

[0120] Next, the TD bending modulus and MD bending modulus of the glass fiber reinforced resin plate (flat plate) produced in this Reference Example were measured exactly in the same manner as in Example 1, and the number average fiber length L of the glass fibers in the glass fiber reinforced resin plate was calculated. The results are shown in Table 2.

[0121] Example 6 In this example, polyphenylene sulfide (manufactured by Kureha Corporation, product name: Fortron KPS W203A, described as PPS in Table 2) was used, and resin pellets were produced in exactly the same manner as in Example 1, except that the glass content C was 40 mass%. Next, using the resin pellets obtained in this example, a glass fiber reinforced resin plate (flat plate) having dimensions of 20 mm length x 25 mm width and a thickness H of 1.0 mm was produced in exactly the same manner as in Example 1, except that the mold temperature was 140°C and the injection temperature was 310°C.

[0122] Next, the TD bending modulus and MD bending modulus of the glass fiber reinforced resin plate (flat plate) produced in this example were measured exactly in the same manner as in Example 1, and the number average fiber length L of the glass fibers in the glass fiber reinforced resin plate was calculated. The results are shown in Table 2.

[0123] [Reference example 6] This Reference Example corresponds to Example 6, and polyphenylene sulfide (manufactured by Kureha Corporation, product name: Fortron KPS W203A, described as PPS in Table 2) was used, and resin pellets were produced in exactly the same manner as in Reference Example 1, except that the glass content C was 40 mass%. Next, a glass fiber reinforced resin plate (flat plate) having dimensions of 20 mm length × 25 mm width and a thickness H of 1.0 mm was produced in exactly the same manner as in Example 1, except that the resin pellets obtained in this Reference Example were used.

[0124] Next, the TD bending modulus and MD bending modulus of the glass fiber reinforced resin plate (flat plate) produced in this Reference Example were measured exactly in the same manner as in Example 1, and the number average fiber length L of the glass fibers in the glass fiber reinforced resin plate was calculated. The results are shown in Table 2.

[0125] Comparative Example 1 In this comparative example, except that the glass content C was set to 30 mass%, resin pellets were produced in exactly the same manner as in Example 1. Next, a glass fiber reinforced resin plate (flat plate) having dimensions of 20 mm length × 25 mm width and a thickness H of 0.8 mm was produced in exactly the same manner as in Example 1, except that the resin pellets obtained in this comparative example were used.

[0126] Next, the TD bending modulus and MD bending modulus of the glass fiber reinforced resin plate (flat plate) produced in this comparative example were measured exactly in the same manner as in Example 1, and the number average fiber length L of the glass fibers in the glass fiber reinforced resin plate was calculated. The results are shown in Table 3.

[0127] [Reference example 7] This Reference Example corresponds to Comparative Example 1, and resin pellets were produced in exactly the same manner as Reference Example 1, except that the glass content C was set to 30 mass%. Next, a glass fiber reinforced resin plate (flat plate) having dimensions of 20 mm length × 25 mm width and a thickness H of 0.8 mm was produced in exactly the same manner as Example 1, except that the resin pellets obtained in this Reference Example were used.

[0128] Next, the TD bending modulus and MD bending modulus of the glass fiber reinforced resin plate (flat plate) produced in this Reference Example were measured exactly in the same manner as in Example 1, and the number average fiber length L of the glass fibers in the glass fiber reinforced resin plate was calculated. The results are shown in Table 3.

[0129] Comparative Example 2 In this comparative example, except that the glass content C was 10 mass%, resin pellets were produced in exactly the same manner as in Example 1. Next, a glass fiber reinforced resin plate (flat plate) having dimensions of 40 mm length × 25 mm width and a thickness H of 2.0 mm was produced in exactly the same manner as in Example 1, except that the resin pellets obtained in this comparative example were used.

[0130] Next, the TD bending modulus and MD bending modulus of the glass fiber reinforced resin plate (flat plate) produced in this comparative example were measured exactly in the same manner as in Example 1, and the number average fiber length L of the glass fibers in the glass fiber reinforced resin plate was calculated. The results are shown in Table 3.

[0131] [Reference example 8] This Reference Example corresponds to Comparative Example 2, and resin pellets were produced in exactly the same manner as Reference Example 1, except that the glass content C was 10 mass%. Next, a glass fiber reinforced resin plate (flat plate) having dimensions of 40 mm length × 25 mm width and a thickness H of 2.0 mm was produced in exactly the same manner as Example 1, except that the resin pellets obtained in this Reference Example were used.

[0132] Next, the TD bending modulus and MD bending modulus of the glass fiber reinforced resin plate (flat plate) produced in this Reference Example were measured exactly in the same manner as in Example 1, and the number average fiber length L of the glass fibers in the glass fiber reinforced resin plate was calculated. The results are shown in Table 3.

[0133] Comparative Example 3 In this comparative example, except that the glass content C was set to 70 mass%, resin pellets were produced in exactly the same manner as in Example 1. Next, a glass fiber reinforced resin plate (flat plate) having dimensions of 40 mm length × 25 mm width and a thickness H of 2.0 mm was produced in exactly the same manner as in Example 1, except that the resin pellets obtained in this comparative example were used.

[0134] Next, the TD bending modulus and MD bending modulus of the glass fiber reinforced resin plate (flat plate) produced in this comparative example were measured exactly in the same manner as in Example 1, and the number average fiber length L of the glass fibers in the glass fiber reinforced resin plate was calculated. The results are shown in Table 3.

[0135] [Reference example 9] This Reference Example corresponds to Comparative Example 3, and resin pellets were produced in exactly the same manner as Reference Example 1, except that the glass content C was 70 mass%. Next, a glass fiber reinforced resin plate (flat plate) having dimensions of 40 mm length × 25 mm width and a thickness H of 2.0 mm was produced in exactly the same manner as Example 1, except that the resin pellets obtained in this Reference Example were used.

[0136] Next, the TD bending modulus and MD bending modulus of the glass fiber reinforced resin plate (flat plate) produced in this Reference Example were measured exactly in the same manner as in Example 1, and the number average fiber length L of the glass fibers in the glass fiber reinforced resin plate was calculated. The results are shown in Table 3.

[0137] Comparative Example 4 In this comparative example, polycarbonate (manufactured by Teijin Limited, product name: Panlite L-1250Y, indicated as PC in Table 3) was used, and resin pellets were produced in exactly the same manner as in Example 1, except that the glass content C was 30 mass%. Next, using the resin pellets obtained in this comparative example, a glass fiber reinforced resin plate (flat plate) having dimensions of 20 mm length × 25 mm width and thickness H of 0.8 mm was produced in exactly the same manner as in Example 1, except that the mold temperature was 110°C and the injection temperature was 290°C.

[0138] Next, the glass fiber reinforced resin plate (flat plate) produced in this comparative example was subjected to measurement of the TD bending modulus and MD bending modulus in exactly the same manner as in Example 1, and the number average fiber length L of the glass fibers in the glass fiber reinforced resin plate was calculated. In addition, the total light transmittance was measured by the method described below. The results are shown in Table 3.

[0139] [Total light transmittance] The glass fiber reinforced resin plate was processed to a width of 30 mm and a length of 30 mm to obtain a test piece. The total light transmittance of the obtained test piece was then measured using a spectrophotometer (manufactured by Hitachi High-Tech Science Corporation, product name: Spectrophotometer U-3900) in accordance with JIS K 7375:2008.

[0140] [Reference example 10] This Reference Example corresponds to Comparative Example 4, and polycarbonate PC (manufactured by Teijin Limited, product name: Panlite L-1250Y, described as PC in Table 3) was used, and resin pellets were produced in exactly the same manner as Reference Example 1, except that the glass content C was 20 mass%. Next, using the resin pellets obtained in this Reference Example, a glass fiber reinforced resin plate (flat plate) having dimensions of 20 mm length × 25 mm width and thickness H of 1.0 mm was produced in exactly the same manner as Example 1, except that the mold temperature was 110°C and the injection temperature was 290°C.

[0141] Next, for the glass fiber reinforced resin plate (flat plate) produced in this Reference Example, the TD bending modulus, MD bending modulus, and total light transmittance were measured in exactly the same manner as in Comparative Example 4, and the number average fiber length L of the glass fibers in the glass fiber reinforced resin plate was calculated. The results are shown in Table 3.

[0142] [Table 1]

[0143] [Table 2]

[0144] [Table 3] From Tables 1 to 3, it is clear that the glass fiber reinforced resin plates of Examples 1 to 6 in which the product (H×C) of the glass fiber content C and the thickness H in the glass fiber reinforced resin plate satisfies the above formula (1) have an improvement rate of the TD bending modulus relative to the TD bending modulus of the corresponding Reference Examples of 5.2 to 22.3%, and the modulus of elasticity in the TD direction can be improved.

[0145] On the other hand, from Tables 1 to 3, in the glass fiber reinforced resin plates of Comparative Examples 1, 2, and 4 in which the product (H×C) of the glass fiber content C and the thickness H in the glass fiber reinforced resin plate is less than the range of the above formula (1), and in the glass fiber reinforced resin plate of Comparative Example 3 in which the product (H×C) of the glass fiber content C and the thickness H in the glass fiber reinforced resin plate is greater than the range of the above formula (1), the improvement rate of the TD bending modulus relative to the TD bending modulus (GPa) of the corresponding Reference Example is 0.2 to 3.8%, which makes it clear that the modulus in the TD cannot be improved as compared to the glass fiber reinforced resin plates of Examples 1 to 6.

Claims

1. A glass fiber reinforced resin plate including glass fibers having a flat cross-sectional shape and a resin, the glass fiber having a flat cross-sectional shape has a minor axis in the range of 4.5 to 10.5 μm, a major axis in the range of 22.0 to 80.0 μm, and a ratio R of the major axis to the minor axis (major axis / minor axis) in the range of 4.5 to 10.0; the resin is a crystalline thermoplastic resin; The glass fiber content C in the glass fiber reinforced resin plate is in the range of 5.0 to 75.0 mass%, The thickness H of the glass fiber reinforced resin plate is in the range of more than 0.5 mm and not more than 10.0 mm, A glass fiber reinforced resin plate, characterized in that C and H satisfy the following formula (1). 30.0≦H×C≦120.0 (1)

2. In the glass fiber reinforced resin plate according to claim 1, the glass fiber content C is in the range of 20.0 to 60.0 mass%, the thickness H of the glass fiber reinforced resin plate is in the range of 0.8 to 8.0 mm, and the C and H satisfy the following formula (2). A glass fiber reinforced resin plate. 45.0≦H×C≦80.0 (2)

3. In the glass fiber reinforced resin plate according to claim 1 or 2, the glass fiber content C is in the range of 20.0 to 40.0 mass%, the thickness H of the glass fiber reinforced resin plate is in the range of 1.6 to 5.0 mm, and the C and H satisfy the following formula (3). A glass fiber reinforced resin plate. 55.0≦H×C≦74.5 ... (3)

4. The glass fiber reinforced resin plate according to any one of claims 1 to 3, wherein the resin contained in the glass fiber reinforced resin plate is polyamide.

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