Glass-strengthened resin molded article

Abstract

Provided is a glass-reinforced resin molded article that is anisotropic and has reduced shrinkage in the TD direction. The glass-reinforced resin molded article contains 10.0 to 90.0 mass% of a glass reinforcing material relative to the total amount, and a thermoplastic resin. The glass reinforcing material contains flat-section glass fibers having a flat cross-sectional shape with an aspect ratio of 3.0 to 10.0 relative to a minor axis, the flat-section glass fibers have a content ratio C of 10.0 to 80.0 mass% relative to the total amount, the flat-section glass fibers have an aspect D of 25.0 to 55.0 μm, the proportion P of the glass reinforcing material having a length of 50 to 100 μm relative to the total number of glass reinforcing materials having a length of 50 μm or more in the glass-reinforced resin molded article is 4 to 50%, and the C, D, and P satisfy the following formula (1): 0.46 ≤ P / (C × D) ≤ 0.99 … (1). 1 / 2 ≤0.99 … (1).

Description

Technical Field

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

[0002] Conventionally, as a glass reinforcing material, there are known glass-reinforced resin molded articles containing flat-section glass fibers having a flat cross-sectional shape (for example, see Patent Document 1 and Patent Document 2).

[0003] Glass-reinforced resin molded articles containing flat-section glass fibers as the glass reinforcing material exhibit better resistance to warping and superior dimensional stability compared to glass-reinforced resin molded articles containing circular-section glass fibers. Furthermore, they possess superior mechanical and physical properties and surface smoothness, making them suitable for use in thin and compact components such as housings for portable electronic devices. Here, as described in Patent Documents 1 and 2, in order to improve mechanical and physical properties, an attempt was made to extend the fiber length of the flat-section glass fibers contained in the glass-reinforced resin molded article.

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent Application Publication No. 2015-105359

[0007] Patent Document 2: Japanese Patent Application Publication No. 2010-222486 Summary of the Invention

[0008] The problem that the invention aims to solve

[0009] In recent years, with the further miniaturization of electronic devices, higher dimensional precision is required for glass-reinforced resin molded products used as their components.

[0010] However, in order to achieve such high dimensional precision, the shrinkage rate, expressed by the ratio of the shrinkage rate in the MD direction to the shrinkage rate in the TD direction (hereinafter referred to as the MD direction shrinkage rate), is highly anisotropic in glass-reinforced resin molded articles containing existing flat cross-section glass fibers. In particular, there is a problem that the value of the TD direction shrinkage rate cannot be sufficiently reduced.

[0011] Here, the TD direction mentioned above refers to the direction orthogonal to the flow direction of the resin composition when manufacturing a glass-reinforced resin molded article by molding a resin composition containing a glass reinforcing material. Conversely, the MD direction mentioned above refers to the flow direction of the resin composition when manufacturing a glass-reinforced resin molded article by molding a resin composition containing a glass reinforcing material.

[0012] The purpose of this invention is to solve the above-mentioned problems and provide a glass-reinforced resin molded article that can reduce anisotropy of shrinkage rate and reduce shrinkage rate in the TD direction.

[0013] Methods for solving problems

[0014] The inventors of this invention have conducted in-depth research into the reasons why the anisotropy of shrinkage rate is large in glass-reinforced resin molded articles containing conventional flat-section glass fibers, making it impossible to sufficiently reduce the value of shrinkage rate in the TD direction. As a result, they discovered that, contrary to previous attempts, by shifting the length distribution of the glass reinforcement material in the glass-reinforced resin molded article towards the shorter direction, it is possible to reduce the anisotropy of shrinkage rate and also reduce the shrinkage rate in the TD direction, thus completing this invention.

[0015] That is, the glass-reinforced resin molded article of the present invention comprises a glass reinforcing material in the range of 10.0% to 90.0% by mass and a thermoplastic resin in the range of 90.0% to 10.0% by mass relative to the total amount of the glass-reinforced resin molded article. The glass-reinforced resin molded article is characterized in that the glass reinforcing material comprises flat-section glass fibers having a flat cross-sectional shape with a major-to-minor axis ratio (major axis / minor axis) in the range of 3.0% to 10.0; the content C of the flat-section glass fibers relative to the total amount of the glass-reinforced resin molded article is in the range of 10.0% to 80.0% by mass; the major axis D of the flat-section glass fibers is in the range of 25.0% to 55.0 μm; and the proportion P of the glass reinforcing material having a length in the range of 50% to 100 μm relative to the total number of glass reinforcing materials with a length of 50 μm or more contained in the glass-reinforced resin molded article is in the range of 4% to 50%. C, D, and P satisfy the following formula (1).

[0016] 0.46≤P / (C×D) 1 / 2 ≤0.99…(1).

[0017] The glass-reinforced resin molded article according to the present invention comprises a glass reinforcing material and a thermoplastic resin having the above-mentioned range, wherein the above-mentioned C, D and P are within the above-mentioned range and satisfy formula (1), thereby reducing the anisotropy of shrinkage rate and reducing the shrinkage rate in the TD direction.

[0018] The glass-reinforced resin molded article of the present invention can be obtained, for example, by mixing the above-mentioned glass reinforcing material and the above-mentioned thermoplastic resin using a biaxial mixer, and then using the obtained resin particles for injection molding. It should be noted that, in the case where the glass-reinforced resin molded article of the present invention is obtained by injection molding, the glass-reinforced resin molded article of the present invention can also be described as a glass-reinforced resin injection-molded article. Furthermore, the glass-reinforced resin molded article of this embodiment can also be obtained by other known molding methods, such as injection compression molding, two-color molding, hollow molding, foam molding (including molding methods using supercritical fluids), insert molding, in-mold coating molding, extrusion molding, sheet molding, thermoforming, rotational molding, lamination molding, compression molding, blow molding, stamping molding, melt molding, hand lay-up molding, spraying, resin transfer molding, sheet molding, integral film compression molding, pultrusion molding, filament winding, and other molding methods.

[0019] Here, the shrinkage rates in the MD and TD directions can be obtained using the following methods. The MD shrinkage rate is calculated as follows: When a flat plate is obtained by injection molding using a glass-strengthened resin composition constituting the glass-strengthened resin molded article and a mold with internal dimensions of 80 mm in length, 60 mm in width, and 2.0 mm in depth, the actual length dimension of the flat plate (actual length dimension; unit = mm) is measured using vernier calipers, and the value is calculated using (80 - actual length dimension) / 80 × 100. The TD shrinkage rate is calculated as follows: The actual width dimension of the flat plate (actual width dimension; unit = mm) is measured using vernier calipers, and the value is calculated using (60 - actual width dimension) / 60 × 100.

[0020] Furthermore, reducing the anisotropy of shrinkage rate means that, when a 2mm thick flat glass-reinforced resin molded article is manufactured in the above manner, the ratio of the shrinkage rate in the MD direction to the shrinkage rate in the TD direction (hereinafter referred to as MD direction shrinkage rate / TD direction shrinkage rate) is 0.50 or higher. Additionally, reducing the TD direction shrinkage rate means that, when a 2mm thick flat glass-reinforced resin molded article is manufactured in the above manner, using only glass fibers with a circular cross-section and a fiber diameter of 11.0μm as the glass reinforcement material, setting the screw speed during mixing of the glass reinforcement material and resin to 100rpm, and manufacturing the glass-reinforced resin molded article under identical conditions, the ratio of the TD direction shrinkage rate to the TD direction shrinkage rate (reference shrinkage rate) of the glass-reinforced resin molded article (hereinafter referred to as TD direction shrinkage rate / reference shrinkage rate) is less than 0.70.

[0021] Furthermore, preferably, in the glass-reinforced resin molded article of the present invention, C is in the range of 20.0 to 70.0% by mass, D is in the range of 30.0 to 50.0 μm, and P is in the range of 10 to 40%, and C, D, and P satisfy the following formula (2).

[0022] 0.54≤P / (C×D) 1 / 2 ≤0.72…(2).

[0023] According to the glass-reinforced resin molded article of the present invention, C, D and P are within the above range and satisfy formula (2), thereby reducing the anisotropy of shrinkage rate and further reducing the shrinkage rate in the TD direction.

[0024] Here, the ability to further reduce the shrinkage rate in the TD direction means that, when producing a flat glass-reinforced resin molded product with a thickness of 2 mm, the TD shrinkage rate / reference shrinkage rate is less than 0.60.

[0025] Furthermore, in the glass-reinforced resin molded article of the present invention, it is preferable that the flat cross-section glass fiber has a flat cross-sectional shape in which the ratio of the major diameter to the minor diameter is in the range of 5.0 to 8.0.

[0026] Furthermore, considering the excellent balance of mechanical properties, heat resistance, dimensional accuracy, and material cost, in the glass-reinforced resin molded articles of the present invention, the thermoplastic resin is preferably selected from polycarbonate, polybutylene terephthalate, polyamide, or polyetheretherketone.

[0027] Furthermore, when producing a flat glass-reinforced resin molded article with a thickness of 2 mm, from the perspective of increasing the effect of the present invention when satisfying the above formula (2), the thermoplastic resin is more preferably polycarbonate or polyamide in the glass-reinforced resin molded article of the present invention.

[0028] Furthermore, when producing a flat glass-reinforced resin molded article with a thickness of 2 mm, the shrinkage rate in the MD direction / the shrinkage rate in the TD direction is 0.60 or more, and the shrinkage rate in the TD direction / the reference shrinkage rate is less than 0.50. The effect of the present invention is particularly great. From this perspective, in the glass-reinforced resin molded article of the present invention, the above-mentioned thermoplastic resin is further preferably polyamide. Detailed Implementation

[0029] Next, the embodiments of the present invention will be described in further detail.

[0030] The glass-reinforced resin molded article of this embodiment comprises a glass reinforcing material in the range of 10.0% to 90.0% by mass and a thermoplastic resin in the range of 90.0% to 10.0% by mass relative to the total amount of the glass-reinforced resin molded article. The glass reinforcing material comprises flat cross-section glass fibers having a flat cross-sectional shape with a major diameter to minor diameter ratio (major diameter / minor diameter) in the range of 3.0% to 10.0. The content C of the flat cross-section glass fibers relative to the total amount of the glass-reinforced resin molded article is in the range of 10.0% to 80.0% by mass. The major diameter D of the flat cross-section glass fibers is in the range of 25.0% to 55.0 μm. The proportion P of the glass reinforcing material in the glass-reinforced resin molded article having a length in the range of 50% to 100 μm relative to the total amount of glass reinforcing material having a length of more than 50 μm is in the range of 4% to 50%. C, D and P satisfy the following formula (1).

[0031] 0.46≤P / (C×D) 1 / 2 ≤0.99…(1).

[0032] Here, the larger P is, the lower the anisotropy of the shrinkage rate, but there is a tendency for the absolute value of the shrinkage rate in the TD direction to worsen. Furthermore, the larger C is, the larger the value of P is; on the other hand, although the absolute value of the shrinkage rate in the TD direction decreases, there is a tendency for the anisotropy of the shrinkage rate to worsen. Additionally, there is a tendency for the larger D is, the larger the value of P is; on the other hand, there is a tendency for the anisotropy of the shrinkage rate to decrease, and the absolute value of the shrinkage rate in the TD direction to also decrease. It can be deduced that the above equation (1) reflects these tendencies and embodies a balance between the decrease in the anisotropy of the shrinkage rate and the decrease in the absolute value of the shrinkage rate in the TD direction.

[0033] The glass-reinforced resin molded article of this embodiment can be obtained, for example, by mixing the glass reinforcing material and the thermoplastic resin in a biaxial mixer and then using the mixed resin particles for injection molding to obtain the glass-reinforced resin molded article.

[0034] In the glass-reinforced resin molded article of this embodiment, the glass reinforcing material can be, for example, flat cross-section glass fiber, round cross-section glass fiber, glass flake, glass powder, glass beads, etc.

[0035] The glass composition of the glass forming the aforementioned flat or circular cross-section glass fibers is not particularly limited. In the glass-reinforced resin molded article of this embodiment, the most commonly used glass compositions that can be used for the glass fibers include E-glass compositions, high-strength, high-modulus glass compositions, high-modulus, easily manufacturable glass compositions, and low-dielectric-constant, low-dielectric-loss-tangential glass compositions. From the viewpoint of improving the strength of the glass-reinforced resin molded article, the glass composition of the glass fibers is preferably the aforementioned high-strength, high-modulus glass composition or high-dielectric-constant, easily manufacturable glass composition. From the viewpoint of reducing the dielectric constant and dielectric loss tangential of the glass-reinforced resin molded article, thereby reducing the transmission loss of high-frequency signals through the glass-reinforced resin molded article, the glass composition of the glass fibers is preferably the aforementioned low-dielectric-constant, low-dielectric-loss-tangential glass composition.

[0036] E glass comprises SiO2 in the range of 52.0 to 56.0% by mass relative to the total amount of glass fibers, Al2O3 in the range of 12.0 to 16.0% by mass, MgO and CaO in the range of 20.0 to 25.0% by mass, and B2O3 in the range of 5.0 to 10.0% by mass.

[0037] The high-strength, high-elasticity modulus glass is composed of the following: SiO2 in the range of 60.0 to 70.0% by mass relative to the total amount of glass fibers, Al2O3 in the range of 20.0 to 30.0% by mass, MgO in the range of 5.0 to 15.0% by mass, Fe2O3 in the range of 0 to 1.5% by mass, and Na2O, K2O and Li2O in the range of 0 to 0.2% by mass.

[0038] The high modulus of elasticity easy-to-manufacture glass is composed of the following: SiO2 in the range of 57.0 to 60.0% by mass relative to the total amount of glass fibers, Al2O3 in the range of 17.5 to 20.0% by mass, MgO in the range of 8.5 to 12.0% by mass, CaO in the range of 10.0 to 13.0% by mass, and B2O3 in the range of 0.5 to 1.5% by mass, and the total amount of SiO2, Al2O3, MgO and CaO is 98.0% by mass or more.

[0039] The low dielectric constant and low dielectric loss tangential glass has the following composition: SiO2 in the range of 48.0 to 62.0% by mass relative to the total amount of glass fibers, B2O3 in the range of 17.0 to 26.0% by mass, Al2O3 in the range of 9.0 to 18.0% by mass, CaO in the range of 0.1 to 9.0% by mass, MgO in the range of 0 to 6.0% by mass, Na2O, K2O and Li2O in the range of 0.05 to 0.5% by mass, TiO2 in the range of 0 to 5.0% by mass, SrO in the range of 0 to 6.0% by mass, F2 and Cl2 in the range of 0 to 3.0% by mass, and P2O5 in the range of 0 to 6.0% by mass.

[0040] Regarding the determination of the content of each component in the aforementioned glass composition, the content of Li, as a light element, can be determined using an ICP-based fluorescence spectrophotometer, and the content of other elements can be determined using a wavelength-dispersive X-ray fluorescence analyzer. The method for content determination is as follows: Glass fibers are cut to an appropriate size and placed in a platinum crucible. The crucible is then kept at 1550°C in an electric furnace for 6 hours while stirring until it melts, thereby obtaining a homogeneous molten glass. If organic matter adheres to the surface of the glass fibers during cutting, or if the organic matter (resin) mainly contains glass fibers as a reinforcing material, the organic matter can be removed, for example, by heating in a muffle furnace at 300–650°C for approximately 2–24 hours before use. Next, the obtained molten glass is poured onto a carbon plate to form glass shavings, which are then pulverized to obtain glass powder. For the determination of Li, as a light element, the glass powder is decomposed by heating with acid, and then quantitative analysis is performed using an ICP-based fluorescence spectrophotometer. For the determination of other elements, after the glass powder is formed into a disc shape using a press, quantitative analysis is performed using a wavelength dispersive X-ray fluorescence analyzer. Specifically, quantitative analysis using a wavelength dispersive X-ray fluorescence analyzer can be performed as follows: a standard curve sample is prepared based on the results determined by the basic parameter method, and analysis is performed using the standard curve method. It should be noted that the content of each component in the standard curve sample can be quantitatively analyzed using an ICP emission spectrophotometer. Oxide conversion is performed on these quantitative analysis results to calculate the content and total amount of each component, and the content (mass%) of each component can be determined from these values.

[0041] Glass fibers having the above-described glass composition can be manufactured as follows: First, a glass raw material (glass batch) prepared in the manner described above is fed into a melting furnace and melted, for example, at a temperature range of 1450–1550°C. Next, the molten glass batch (molten glass) is drawn out from 1 to 30,000 nozzles of a sleeve controlled at a specified temperature and quenched to form glass filaments. Then, a bundling agent or binder is applied to the formed glass filaments using a coater, and while bundling 1 to 30,000 glass filaments using a gathering shoe, they are wound at high speed onto a tube using a winding machine, thereby obtaining glass fibers.

[0042] Here, the flat-section glass fibers used in the glass-reinforced resin molded article of this embodiment can be obtained by using the aforementioned nozzle head, which has a non-circular shape and protrusions or notches for quenching molten glass, and by controlling the temperature conditions. Furthermore, the short and long diameters of the glass fibers can be adjusted by changing the nozzle head diameter, winding speed, and temperature conditions. For example, increasing the winding speed can reduce the size of the short and long diameters, while decreasing the winding speed can increase the size of the short and long diameters.

[0043] Furthermore, in the aforementioned flat cross-section glass fibers, the shape of the flat cross-section is preferably rectangular, elliptical, or oblong, and more preferably oblong. Here, the cross-sectional shape refers to the shape of the cross-section formed after cutting the glass fiber on a plane orthogonal to the length direction of the glass fiber. An oblong shape refers to a shape with semi-circular ends at both ends of a rectangle or a similar shape.

[0044] It should be noted that glass fibers are usually formed by bundling multiple glass filaments. However, in glass-reinforced resin molded products, the aforementioned bundled glass filaments are released after molding and exist dispersed in the glass-reinforced resin molded products as glass filaments.

[0045] Here, as the form of the flat-section glass fiber in the glass-reinforced resin molded article of this embodiment before molding, it is preferable to use the following chopped filaments: the number of glass filaments constituting the glass fiber (number of bundled filaments) is preferably in the range of 1 to 20,000, more preferably in the range of 50 to 10,000, and even more preferably in the range of 1,000 to 8,000. The glass fiber (also called glass fiber bundle or glass filament) is preferably cut to a length of 1.0 to 25.0 mm, even more preferably in the range of 1.2 to 10.0 mm, particularly preferably in the range of 1.5 to 6.0 mm, and most preferably in the range of 2.5 to 3.5 mm. In addition, the forms that glass fibers with a flat cross-sectional shape can take before molding processing in the glass-reinforced resin molded article of this embodiment, besides chopped filaments, include, for example, rovings in which the number of glass filaments constituting the glass fiber is in the range of 10 to 30,000 and are not cut; and cut fibers in the range of 0.01 to 1.00 mm in length, which are glass filaments in the range of 1 to 20,000 constituting the glass fiber by known methods such as ball mills or Henschel mixers.

[0046] In the glass-reinforced resin molded article of this embodiment, the glass fibers may be coated with an organic material to improve the adhesion between the glass fibers and the resin, and to improve the uniform dispersion of the glass fibers in a mixture of glass fibers and resin or inorganic materials. Examples of such organic materials include: polyurethane resin, epoxy resin, vinyl acetate resin, acrylic resin, modified polypropylene, especially carboxylic acid modified polypropylene, (poly)carboxylic acid, especially copolymers of maleic acid and unsaturated monomers, or silane coupling agents.

[0047] Furthermore, in the glass-reinforced resin molded article of this embodiment, in addition to being coated by these resins or silane coupling agents, the glass fibers may also be coated by a composition further comprising lubricants, surfactants, etc. This composition coats the glass fibers at a ratio of 0.1 to 2.0% by mass, based on the mass of the glass fibers in their uncoated state.

[0048] It should be noted that, for example, glass fibers can be coated with organic matter in the following manner: In the glass fiber manufacturing process, the above-mentioned bundle agent or adhesive containing a solution of the above-mentioned resin, the above-mentioned silane coupling agent or the above-mentioned composition is coated onto the glass fiber using a known method such as a roller coater, and then the glass fiber coated with the solution of the above-mentioned resin, the above-mentioned silane coupling agent or the above-mentioned composition is dried.

[0049] Examples of silane coupling agents include: aminosilanes, chlorosilanes, epoxysilanes, mercaptosilanes, vinylsilanes, acrylate silanes, and cationic silanes. These silane coupling agents can be silane coupling agents that use only one of these compounds, or silane coupling agents that use two or more of the above compounds in combination.

[0050] Examples of aminosilanes include: γ-aminopropyltriethoxysilane, N-β-(aminoethyl)-γ-aminopropyltrimethoxysilane, N-β-(aminoethyl)-N'-β-(aminoethyl)-γ-aminopropyltrimethoxysilane, and γ-anilinepropyltrimethoxysilane.

[0051] Examples of chlorosilanes include γ-chloropropyltrimethoxysilane.

[0052] Examples of epoxy silanes include γ-epoxypropoxypropyltrimethoxysilane and β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane.

[0053] Examples of mercaptosilanes include γ-mercaptotrimethoxysilane.

[0054] Examples of vinyl silanes include vinyltrimethoxysilane and N-β-(N-vinylbenzylaminoethyl)-γ-aminopropyltrimethoxysilane.

[0055] Examples of acrylic silanes include γ-methacryloyloxypropyltrimethoxysilane.

[0056] Examples of cationic silanes include N-(vinylbenzyl)-2-aminoethyl-3-aminopropyltrimethoxysilane hydrochloride and N-phenyl-3-aminopropyltrimethoxysilane hydrochloride.

[0057] Examples of lubricants include: modified silicone oils, animal oils and their hydrogenated derivatives, vegetable oils and their hydrogenated derivatives, animal waxes, vegetable waxes, mineral waxes, condensates of higher saturated fatty acids and higher saturated alcohols, polyethyleneimine, polyalkyl polyamine alkylamide derivatives, fatty acid amides, and fourth-order ammonium salts. These lubricants can be lubricants that use only one of the above substances, or lubricants that use two or more of the above substances in combination.

[0058] Examples of animal fats include tallow. Examples of vegetable oils include soybean oil, coconut oil, rapeseed oil, palm oil, and castor oil.

[0059] Examples of animal-derived waxes include beeswax and lanolin.

[0060] Examples of plant-based waxes include candelilla wax and carnauba wax.

[0061] Examples of mineral waxes include paraffin wax and lignite wax.

[0062] Examples of condensates of higher saturated fatty acids and higher saturated alcohols include stearates such as lauryl stearate.

[0063] 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.

[0064] Examples of fourth-order ammonium salts include alkyl trimethyl ammonium salts such as lauryltrimethylammonium chloride.

[0065] Examples of surfactants include: nonionic surfactants, cationic surfactants, anionic surfactants, and amphoteric surfactants. These surfactants can be used alone or in combination with two or more of the aforementioned surfactants.

[0066] Examples of nonionic surfactants include: ethylene oxide and 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 acryloyl ethers, hydrogenated castor oil ethylene oxide adducts, alkylamine ethylene oxide adducts, fatty acid amide ethylene oxide adducts, glycerol fatty acid esters, polyglycerol fatty acid esters, pentaerythritol fatty acid esters, sorbitol fatty acid esters, sorbitan fatty acid esters, sucrose fatty acid esters, polyol alkyl ethers, fatty acid alkanolamides, acetylenol, ethylene oxide adducts of acetylenol, and ethylene oxide adducts of acetylenol, etc.

[0067] Examples of cationic surfactants include: alkyl dimethyl benzyl ammonium chloride, alkyl trimethyl ammonium chloride, alkyl dimethyl ethyl ammonium ethyl sulfate, higher alkylamine acetates, higher alkylamine hydrochlorides and other higher alkylamine salts, ethylene oxide adducts of higher alkylamines, condensates of higher fatty acids and polyalkylene polyamines, salts of esters of higher fatty acids and alkanolamines, salts of higher fatty acid amides, imidazoline-type cationic surfactants, and alkylpyridine salts.

[0068] Examples of anionic surfactants include: higher alcohol sulfates, higher alkyl ether sulfates, α-olefin sulfates, alkylbenzene sulfonates, α-olefin sulfonates, reaction products of fatty acid halides and N-methyl taurine, dialkyl sulfosuccinates, higher alcohol phosphates, and phosphates of higher alcohol ethylene oxide adducts.

[0069] Examples of amphoteric surfactants include: amino acid-type amphoteric surfactants such as alkali metal salts of alkylaminopropionic acid, betaine-type surfactants such as alkyl dimethyl betaine, and imidazoline-type amphoteric surfactants.

[0070] The glass flakes used in the glass-strengthened resin molded article of this embodiment can be, for example, scale-like glass flakes with a thickness in the range of 1 to 20 μm and a side length in the range of 0.05 to 1 mm. Furthermore, the glass flakes used in the glass-strengthened resin molded article of this embodiment can be, for example, glass flakes with a volume average particle size in the range of 0.5 to 20 μm. Additionally, the glass beads used in the glass-strengthened resin molded article of this embodiment can be, for example, spherical glass beads with an outer diameter in the range of 10 to 100 μm.

[0071] Furthermore, in the glass-reinforced resin molded article of this embodiment, the following thermoplastic resins can be used as the aforementioned resins: polyethylene, polypropylene, polystyrene, styrene / maleic anhydride resin, styrene / maleimide resin, polyacrylonitrile, acrylonitrile / styrene (AS) resin, acrylonitrile / butadiene / styrene (ABS) resin, chlorinated polyethylene / acrylonitrile / styrene (ACS) resin, acrylonitrile / ethylene / styrene (AES) resin, acrylonitrile / styrene / methyl acrylate (ASA) resin, styrene / acrylonitrile (SAN) resin, methacrylic acid resin, polyvinyl chloride (PVC), polyvinylidene chloride (PVDC), polyamide, polyacetal, polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polypropylene terephthalate (PTT), polycarbonate, polyaryl sulfides, etc. Polyethersulfone (PES), polyphenylsulfone (PPSU), polyphenylene ether (PPE), modified polyphenylene ether (m-PPE), polyaryl ketone, liquid crystal polymer (LCP), fluoropolymer, polyetherimide (PEI), polyaryl ester (PAR), polysulfone (PSF), polyamide-imide (PAI), polyaminobismaleimide (PABM), thermoplastic polyimide (TPI), polyethylene naphthalate (PEN), ethylene / vinyl acetate (EVA) resin, ionomer (IO) resin, polybutadiene, styrene / butadiene resin, polybutene, polymethylpentene, olefin / vinyl alcohol resin, cyclic olefin resin, cellulose resin, polylactic acid, etc., and preferably polyamide, polycarbonate, polybutylene terephthalate or polyaryl ketone, more preferably polyamide or polycarbonate, and even more preferably polyamide.

[0072] Specifically, examples of polyamides include copolymers or mixtures thereof composed of one or more of the following components: polycaprolactam (polyamide 6), polyhexamethylene adipamide (polyamide 66), polybutylene adipamide (polyamide 46), polyhexamethylene sebacamide (polyamide 410), polypentamethylene adipamide (polyamide 56), polypentamethylene sebacamide (polyamide 510), polyhexamethylene sebacamide (polyamide 610), and polyhexamethylene sebacamide (polyamide 610). Methyldodecylamide (polyamide 612), polydexemethylene adipamide (polyamide 106), polydecanoyl decanediamine (polyamide 1010), polydodecanoyl decanediamine (polyamide 1012), polyundecanoamide (polyamide 11), polyhexamethylene adipamide (polyamide 116), polydodecanoamide (polyamide 12), polyadipoxymethyldimethyldiamine (polyamide XD6), polydecanoic acid diamine (polyamide XD10), polyadipoxymethylenedimethylamine (polyamide MXD6) Poly(p-xylenehexadiamide) (polyamide PXD6), poly(p-phthalamide) (polyamide 4T), polypentamethylene terephthalamide (polyamide 5T), polyhexamethylene terephthalamide (polyamide 6T), polyhexamethylene isophthalamide (polyamide 6I), polynonamethylene terephthalamide (polyamide 9T), poly(terephthaloylmethyl terephthalamide) (polyamide 10T), polyundecylmethylene terephthalamide (polyamide 11T), polydodecylmethylene terephthalamide (polyamide 11T). Amine (polyamide 12T), polytetramethylene polyphthalamide (polyamide 4I), polybis(3-methyl-4-aminohexyl)methane terephthalamide (polyamide PACMT), polybis(3-methyl-4-aminohexyl)methane isophthalamide (polyamide PACMI), polybis(3-methyl-4-aminohexyl)methane dodecylamide (polyamide PACM12), polybis(3-methyl-4-aminohexyl)methane tetradecyldiamide (polyamide PACM14), etc.

[0073] Examples of polycarbonates include polymers obtained by transesterification, which involves reacting a dihydroxy aryl compound with a carbonate such as diphenyl carbonate in a molten state, and polymers obtained by phosgene reaction, which involves reacting a dihydroxy aryl compound with phosgene.

[0074] Examples of polybutylene terephthalate include polymers obtained by polycondensation of 1,4-butanediol with terephthalic acid or its derivatives.

[0075] Examples of polyaryl ketones include: polyether ketone (PEK), polyether ether ketone (PEEK), polyether ketone ketone (PEKK), and polyether ether ketone ketone (PEEKK).

[0076] 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.

[0077] Examples of polypropylene include isotactic polypropylene, syndiotactic polypropylene, atactic polypropylene, and mixtures of the above polypropylenes.

[0078] Examples of polystyrene include general-purpose polystyrene (GPPS), which is atactic polystyrene with a random stereostructure; impact-resistant polystyrene (HIPS), which incorporates rubber components into GPPS; and atactic polystyrene with a random stereostructure.

[0079] Examples of methacrylic resins include polymers formed by polymerizing one of the following methacrylic resins: acrylic acid, methacrylic acid, styrene, methyl acrylate, ethyl acrylate, ethyl methacrylate, butyl acrylate, butyl methacrylate, and vinyl fatty acid esters; and polymers formed by copolymerizing two or more of the above-mentioned methacrylic resins.

[0080] Examples of polyvinyl chloride include: homopolymers of vinyl chloride polymerized by existing well-known methods such as emulsion polymerization, suspension polymerization, micro-suspension polymerization, and bulk polymerization; copolymers of vinyl chloride monomers that can copolymerize with vinyl chloride monomers; and graft copolymers of polymers to which vinyl chloride monomers have been grafted.

[0081] Examples of polyacetals include homopolymers with oxymethylene units as the main repeating units, and copolymers mainly composed of oxymethylene units and containing oxyalkylene units with 2 to 8 adjacent carbon atoms in the main chain.

[0082] Examples of polyethylene terephthalate include polymers obtained by polycondensation of ethylene glycol with terephthalic acid or its derivatives.

[0083] Examples of polypropylene terephthalate include polymers obtained by polycondensation of 1,3-propanediol with terephthalic acid or its derivatives.

[0084] Examples of polyaryl sulfides include linear polyphenylene sulfides, cross-linked polyphenylene sulfides that are polymerized by curing after polymerization, polyphenylene sulfide sulfone, polyphenylene sulfide ether, and polyphenylene sulfide ketone.

[0085] 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, and polymer alloys of poly(2,6-dimethyl-1,4-phenylene) ether and styrene / butadiene / acrylonitrile copolymer, etc.

[0086] Examples of liquid crystal polymers (LCPs) include (co)polymers composed of one or more structural units selected from the following components: aromatic hydroxy carbonyl units, aromatic dihydroxy units, aromatic dicarbonyl units, aliphatic dihydroxy units, aliphatic dicarbonyl units, etc., which are thermotropic liquid crystal polyesters.

[0087] Examples of fluoropolymers include: polytetrafluoroethylene (PTFE), perfluoroalkoxy resin (PFA), fluorinated ethylene propylene resin (FEP), fluorinated ethylene tetrafluoroethylene resin (ETFE), polyvinylidene fluoride (PVF), polyvinylidene fluoride (PVDF), polychlorotrifluoroethylene (PCTFE), and ethylene / chlorotrifluoroethylene resin (ECTFE).

[0088] Examples of ionomer (IO) resins include copolymers of olefins or styrene with unsaturated carboxylic acids, where a portion of the carboxyl group is neutralized with metal ions.

[0089] Examples of olefin / vinyl alcohol resins include: ethylene / vinyl alcohol copolymers, propylene / vinyl alcohol copolymers, ethylene / vinyl acetate copolymer saponifications, and propylene / vinyl acetate copolymer saponifications.

[0090] Examples of cyclic olefin resins include: monocyclic resins such as cyclohexene, polycyclic resins such as tetracyclopentadiene, and polymers of cyclic olefin monomers.

[0091] Examples of polylactic acid include: poly-L-lactic acid as a homopolymer of the L-body, poly-D-lactic acid as a homopolymer of the D-body, or stereocomposite polylactic acid as a mixture thereof.

[0092] Examples of cellulose resins include: methylcellulose, ethylcellulose, hydroxycellulose, hydroxymethylcellulose, hydroxyethylcellulose, hydroxyethylmethylcellulose, hydroxypropylmethylcellulose, cellulose acetate, cellulose propionate, and cellulose butyrate.

[0093] In the glass-reinforced resin molded article of this embodiment, the content of glass reinforcing material relative to the total amount of the glass-reinforced resin molded article is preferably in the range of 20.0 to 75.0% by mass, more preferably in the range of 30.0 to 69.5% by mass, even more preferably in the range of 40.0 to 67.0% by mass, particularly preferably in the range of 45.0 to 63.0% by mass, and most preferably in the range of 50.0 to 60.0% by mass.

[0094] In the glass-strengthened resin molded article of this embodiment, the content of glass reinforcing material relative to the total amount of the glass-strengthened resin molded article can be calculated as follows. First, the mass of the glass-strengthened resin molded article (mass before heating) is measured. Next, the glass-strengthened resin molded article is heated in a muffle furnace at 625°C for a period of 0.5 to 24 hours, thereby incinerating the resin component. Next, the mass of the glass material remaining after the resin component is incinerated (mass after heating) is measured. Based on the mass before heating and the mass after heating obtained from the above measurements, the content of glass reinforcing material can be calculated using the formula (mass after heating / mass before heating) × 100. It should be noted that if materials other than glass material are still present after the resin component is incinerated, the glass material can be separated by utilizing the difference in specific gravity of these materials.

[0095] In the glass-reinforced resin molded article of this embodiment, the content of thermoplastic resin relative to the total amount of the glass-reinforced resin molded article is preferably in the range of 80.0 to 25.0% by mass, more preferably in the range of 70.0 to 30.5% by mass, even more preferably in the range of 60.0 to 33.0% by mass, particularly preferably in the range of 55.0 to 37.0% by mass, and most preferably in the range of 50.0 to 40.0% by mass.

[0096] In the glass-reinforced resin molded article of this embodiment, the content of thermoplastic resin relative to the total amount of the glass-reinforced resin molded article can be calculated as follows. First, the mass of the glass-reinforced resin molded article (mass before heating) is measured. Next, the glass-reinforced resin molded article is heated in a muffle furnace at 625°C for a period of 0.5 to 24 hours, thereby incinerating the resin component. Next, the mass of the residue after incineration of the resin component is measured (mass after heating). Based on the mass before heating and the mass after heating obtained from the above measurements, the content of thermoplastic resin can be calculated using the formula ((mass before heating - mass after heating) / mass before heating) × 100.

[0097] In the glass-reinforced resin molded article of this embodiment, the content C of the above-mentioned flat cross-section glass fiber relative to the total amount of the above-mentioned glass-reinforced resin molded article is preferably in the range of 20.0 to 70.0% by mass, more preferably in the range of 30.0 to 67.0% by mass, even more preferably in the range of 40.0 to 65.0% by mass, particularly preferably in the range of 45.0 to 62.0% by mass, and most preferably in the range of 50.0 to 60.0% by mass.

[0098] In the glass-reinforced resin molded article of this embodiment, the content C of the flat cross-section glass fibers relative to the total amount of the glass-reinforced resin molded article can be calculated as follows. First, the cross-section of the glass-reinforced resin molded article is ground, and the cross-sectional shape (the shape of the cross-section after being cut by a plane orthogonal to the length direction) of at least 200 glass materials is observed using a scanning electron microscope (SEM). Here, among all the glass materials whose cross-sectional shape is observed, if the cross-sectional shape is flat, the content of the glass reinforcing material relative to the total amount of the glass-reinforced resin molded article calculated by the above method is set as the content C of the flat cross-section glass fibers. On the other hand, if the glass materials observed in the cross-section include glass materials with circular cross-sectional shapes and glass materials with flat cross-sectional shapes, the cross-sectional area and length of the glass materials of at least 200 glass materials remaining after the resin component is burned are measured using SEM and a stereomicroscope, and the volume ratio of the glass materials with flat cross-sectional shapes to the glass materials with circular cross-sectional shapes is calculated. Then, by allocating the content of the glass reinforcing material according to the calculated volume ratio, the content C of the flat cross-section glass fibers can be calculated. It should be noted that when using SEM to analyze the cross-sectional shape, if materials other than glass are included, the glass material can be separated through compositional analysis (SEM / EDX analysis).

[0099] Furthermore, the ratio of the total content of glass reinforcing materials other than flat cross-section glass fibers to the content C of the aforementioned flat cross-section glass fibers is, for example, in the range of 0 to 0.50, preferably in the range of 0 to 0.30, more preferably in the range of 0 to 0.10, particularly preferably in the range of 0 to 0.05, and most preferably 0.

[0100] The major diameter D of the flat-section glass fibers used in the glass-reinforced resin molded article of this embodiment is preferably in the range of 30.0 to 50.0 μm, more preferably in the range of 30.5 to 45.0 μm, and even more preferably in the range of 31.0 to 43.0 μm. Furthermore, from the viewpoint of improving the flowability of the mixture of the glass reinforcing material and the thermoplastic resin during the manufacture of the glass-reinforced resin molded article, the major diameter D of the flat-section glass fibers used in the glass-reinforced resin molded article of this embodiment is particularly preferably in the range of 31.0 to 35.0 μm, and from the viewpoint of improving the strength of the glass-reinforced resin molded article, it is particularly preferably in the range of 37.0 to 43.0 μm.

[0101] The short diameter of the flat cross-section glass fiber used in the glass-reinforced resin molded article of this embodiment is, for example, in the range of 3.0 to 18.0 μm, preferably in the range of 3.5 to 9.5 μm, more preferably in the range of 3.7 to 8.0 μm, even more preferably in the range of 4.0 to 7.4 μm, particularly preferably in the range of 4.5 to 7.0 μm, and most preferably in the range of 5.0 to 6.4 μm.

[0102] The major diameter D and minor diameter of the flat cross-section glass fiber used in the glass-reinforced resin molded article of this embodiment can be calculated, for example, by the following method: First, the cross-section of the glass-reinforced resin molded article is ground. Then, using an electron microscope, the lengths of the major diameter D and minor diameter of more than 100 glass filaments having a flat cross-section are measured. The longest side passing through the approximate center of the cross-section of the glass filament is defined as the major diameter D, and the side orthogonal to the major diameter D at the approximate center of the cross-section of the glass filament is defined as the minor diameter. The average values ​​of the measured major diameter D and minor diameter are then calculated.

[0103] The ratio of the major diameter to the minor diameter (major diameter / minor diameter) of the flat cross-section glass fiber used in the glass-reinforced resin molded article of this embodiment is preferably in the range of 5.0 to 8.0, more preferably in the range of 5.5 to 7.5, even more preferably in the range of 5.6 to 7.0, and particularly preferably in the range of 5.7 to 6.6.

[0104] In the glass-reinforced resin molded article of this embodiment, the ratio P of the glass reinforcing material having a length in the range of 50 to 100 μm to the total number of glass reinforcing materials having a length of 50 μm or more is preferably in the range of 10 to 40%, more preferably in the range of 15 to 38%, further preferably in the range of 20 to 37%, particularly preferably in the range of 26 to 36%, and most preferably in the range of 27 to 35%. It should be noted that the above ratio P can be determined by the method described in the embodiments described later.

[0105] Furthermore, in the glass-reinforced resin molded article of this embodiment, the proportion of the glass reinforcing material having a length in the range of 300 to 500 μm contained in the glass-reinforced resin molded article to the total number of the glass reinforcing materials having a length of 50 μm or more is preferably less than 7.0%, more preferably less than 5.0%, and even more preferably less than 3.0%.

[0106] Furthermore, in the glass-reinforced resin molded article of this embodiment, the proportion of the glass reinforcing material having a length in the range of 25 to 100 μm to the total number of glass reinforcing materials having a length of 25 μm or more is, for example, in the range of 30 to 60%, preferably in the range of 35 to 55%, and more preferably in the range of 40 to 50%.

[0107] In addition, the glass-reinforced resin molded article of this embodiment preferably has C in the range of 20.0 to 70.0% by mass, D in the range of 30.0 to 50.0 μm, and P in the range of 10 to 40%, wherein C, D and P satisfy the following formula (2).

[0108] 0.54≤P / (C×D) 1 / 2 ≤0.72…(2)

[0109] Furthermore, in the glass-reinforced resin molded article of this embodiment, it is preferable that when the ratio of the major diameter to the minor diameter of the flat cross-section glass fiber (major diameter / minor diameter) is in the range of 5.0 to 8.0, C is in the range of 20.0 to 70.0% by mass, D is in the range of 31.0 to 43.0 μm, and P is in the range of 10 to 40%, C, D and P satisfy the following formula (3).

[0110] 0.59≤P / (C×D) 1 / 2 ≤0.71…(3)

[0111] Furthermore, in the glass-reinforced resin molded article of this embodiment, it is particularly preferred that when the ratio of the major diameter to the minor diameter of the flat cross-section glass fiber (major diameter / minor diameter) is in the range of 5.7 to 6.6, the C is in the range of 20.0 to 70.0% by mass, the D is in the range of 31.0 to 35.0 μm, and the P is in the range of 10 to 40%, the C, D and P satisfy the following formula (4).

[0112] 0.60≤P / (C×D) 1 / 2 ≤0.70…(4)

[0113] The glass-reinforced resin molded articles of this embodiment are preferably used for housings and accessories (motherboards, frames, speakers, antennas, etc.) of portable electronic devices such as smartphones, tablets, laptops, and mobile computers.

[0114] Next, embodiments and comparative examples of the present invention are shown.

[0115] Example

[0116] [Example 1]

[0117] In this embodiment, firstly, flat cross-section glass fibers (30.0% by mass of total weight as glass reinforcement) and polycarbonate (Teijin Corporation, Panlite L1250Y (labeled as PC in Tables 1-2) (70.0% by mass of total thermoplastic resin) are mixed in a twin-screw mixer (manufactured by Shibaura Machinery Co., Ltd., trade name: TEM-26SS) at a screw speed of 110 rpm to obtain resin particles. The aforementioned flat cross-section glass fibers have an E-glass composition, a minor diameter of 5.5 μm, a major diameter D of 33.0 μm, and a major diameter / minor diameter ratio of 6.0.

[0118] Next, using the resin particles obtained in this embodiment, an injection molding machine (manufactured by Nissei Resin Kogyo Co., Ltd., trade name: NEX80) was used to perform injection molding at a mold temperature of 120°C and an injection temperature of 300°C to produce a glass-reinforced resin molded article (glass-reinforced resin injection molded article) with dimensions of 80mm in length × 60mm in width and 2.0mm in thickness.

[0119] Next, the TD shrinkage rate and MD shrinkage rate of the glass-reinforced resin molded article prepared in this embodiment were measured, and the MD shrinkage rate / TD shrinkage rate was calculated. Furthermore, the TD shrinkage rate of the glass-reinforced resin molded article of Reference Example 1 described later was used as the reference shrinkage rate, and the TD shrinkage rate / reference shrinkage rate was calculated.

[0120] Next, using the method described later, the following proportions in the glass-reinforced resin molded article produced in this embodiment are determined: the proportion P of the glass reinforcing material in the glass-reinforced resin molded article having a length in the range of 50 to 100 μm to the total number of the glass reinforcing materials having a length of 50 μm or more, and the proportion of the glass reinforcing material in the glass-reinforced resin molded article having a length in the range of 25 to 100 μm to the total number of the glass reinforcing materials having a length of 25 μm or more.

[0121] Next, based on the content C of the flat cross-section glass fiber relative to the total amount of the glass-reinforced resin molded article, the major diameter D of the flat cross-section glass fiber, and the ratio P of the glass reinforcing material in the glass-reinforced resin molded article having a length in the range of 50 to 100 μm to the total number of glass reinforcing materials having a length of 50 μm or more, P / (C×D) is calculated.1 / 2 The values ​​are shown in Table 1.

[0122] [P is the ratio (of the total number of glass reinforcing materials in a glass-reinforced resin molded article that have a length in the range of 50 to 100 μm to the total number of glass reinforcing materials that have a length of 50 μm or more]

[0123] First, the glass-strengthened resin molded article is heated in a muffle furnace at 650°C for 0.5 to 24 hours to decompose organic matter. Next, the remaining glass material is transferred to a glass dish, and acetone is used to disperse the glass material on the surface of the dish. Then, using a stereomicroscope, the length of more than 1000 pieces of glass material dispersed on the surface of the dish is measured, and the total number of pieces with a length of 50 μm or more and the number of pieces with a length of 50 to 100 μm are counted (object-specific measurements). Next, using a stereomicroscope, the ratio P of the glass reinforcement material with a length in the range of 50 to 100 μm to the total number of glass reinforcement materials with a length of 50 μm or more is calculated as ((number of pieces of glass material with a length of 50 to 100 μm) / (total number of pieces of glass material with a length of 50 μm or more)) × 100.

[0124] [The ratio of the number of glass reinforcing materials in a glass-reinforced resin molded article having a length in the range of 25 to 100 μm to the total number of glass reinforcing materials having a length of 25 μm or more.]

[0125] First, the glass-strengthened resin molded article is heated in a muffle furnace at 650°C for 0.5 to 24 hours to decompose organic matter. Next, the remaining glass material is transferred to a glass dish, and acetone is used to disperse the glass material on the surface of the dish. Then, the length of more than 1000 pieces of glass material dispersed on the surface of the dish is measured using a stereomicroscope, and the total number of glass materials with a length of 25 μm or more and the number of glass materials with a length of 25 to 100 μm are counted (object-specific measurements). Next, ((number of glass materials with a length of 25 to 100 μm) / (total number of glass materials with a length of 25 μm or more)) × 100 is calculated to determine the ratio of the glass reinforcement material with a length in the range of 25 to 100 μm to the total number of glass reinforcement materials with a length of 25 μm or more.

[0126] [Example 2]

[0127] In this embodiment, except that flat cross-section glass fibers with a short diameter of 7.0 μm, a long diameter D of 42.0 μm, and a long diameter / short diameter ratio of 6.0 are used and the mixture is compounded in a biaxial mixer at a screw speed of 100 rpm, the resin particles are obtained in the same manner as in Example 1.

[0128] Next, except for using the resin particles obtained in this embodiment, glass-reinforced resin molded articles were made in exactly the same manner as in Example 1.

[0129] Next, in exactly the same manner as in Example 1, the following values ​​for the glass-reinforced resin molded article produced in this example were determined: MD direction shrinkage rate / TD direction shrinkage rate, TD direction shrinkage rate / reference shrinkage rate, the ratio P of the glass reinforcing material in the glass-reinforced resin molded article having a length in the range of 50 to 100 μm to the total number of glass reinforcing materials having a length of 50 μm or more, and the ratio P of the glass reinforcing material in the glass-reinforced resin molded article having a length in the range of 25 to 100 μm to the total number of glass reinforcing materials having a length of 25 μm or more. Based on the content C of the flat cross-section glass fiber relative to the total amount of the glass-reinforced resin molded article, the major diameter D of the flat cross-section glass fiber, and the ratio P of the glass reinforcing material in the glass-reinforced resin molded article having a length in the range of 50 to 100 μm to the total number of glass reinforcing materials having a length of 50 μm or more, P / (C×D) was calculated. 1 / 2 The values ​​are shown in Table 1.

[0130] [Example 3]

[0131] In this embodiment, resin particles were obtained in exactly the same manner as in Example 1, except that flat cross-section glass fibers with a short diameter of 11.0 μm, a long diameter D of 44.0 μm, and a long diameter / short diameter ratio of 4.0 were used and the mixture was compounded in a biaxial mixer at a screw speed of 200 rpm.

[0132] Next, except for using the resin particles obtained in this embodiment, glass-reinforced resin molded articles were made in exactly the same manner as in Example 1.

[0133] Next, in exactly the same manner as in Example 1, the following values ​​for the glass-reinforced resin molded article produced in this example were determined: MD direction shrinkage rate / TD direction shrinkage rate, TD direction shrinkage rate / reference shrinkage rate, the ratio P of the glass reinforcing material in the glass-reinforced resin molded article having a length in the range of 50 to 100 μm to the total number of glass reinforcing materials having a length of 50 μm or more, and the ratio P of the glass reinforcing material in the glass-reinforced resin molded article having a length in the range of 25 to 100 μm to the total number of glass reinforcing materials having a length of 25 μm or more. Based on the content C of the flat cross-section glass fiber relative to the total amount of the glass-reinforced resin molded article, the major diameter D of the flat cross-section glass fiber, and the ratio P of the glass reinforcing material in the glass-reinforced resin molded article having a length in the range of 50 to 100 μm to the total number of glass reinforcing materials having a length of 50 μm or more, P / (C×D) was calculated. 1 / 2 The values ​​are shown in Table 1.

[0134] [Example 4]

[0135] In this embodiment, firstly, in a twin-screw mixer, 28.0% by mass of flat-section glass fibers (as a glass reinforcement material), 2.0% by mass of glass flakes (as a glass flake material), and 70.0% by mass of polycarbonate (as a thermoplastic resin) are compounded at a screw speed of 110 rpm to obtain resin particles. The aforementioned flat-section glass fibers have an E-glass composition, a minor diameter of 5.5 μm, a major diameter D of 33.0 μm, and a major diameter / minor diameter ratio of 6.0. Furthermore, the aforementioned glass flakes have a thickness of 5 μm and a particle size of 160 μm.

[0136] Next, except for using the resin particles obtained in this embodiment, glass-reinforced resin molded articles were made in exactly the same manner as in Example 1.

[0137] Next, in exactly the same manner as in Example 1, the following values ​​for the glass-reinforced resin molded article produced in this example were determined: MD direction shrinkage rate / TD direction shrinkage rate, TD direction shrinkage rate / reference shrinkage rate, the ratio P of the glass reinforcing material with a length in the range of 50 to 100 μm to the total number of glass reinforcing materials with a length of 50 μm or more contained in the glass-reinforced resin molded article, and the ratio P of the glass reinforcing material with a length in the range of 25 to 100 μm to the total number of glass reinforcing materials with a length of 25 μm or more contained in the glass-reinforced resin molded article. Based on the content C of the flat cross-section glass fiber relative to the total amount of the glass-reinforced resin molded article, the major diameter D of the flat cross-section glass fiber, and the ratio P of the glass reinforcing material with a length in the range of 50 to 100 μm to the total number of glass reinforcing materials with a length of 50 μm or more contained in the glass-reinforced resin molded article, P / (C×D) was calculated. 1 / 2 The values ​​are shown in Table 1.

[0138] [Example 5]

[0139] In this embodiment, the resin particles were obtained in exactly the same manner as in Example 4, except that 24.0% by mass of flat cross-section glass fiber was used as the glass reinforcement material and 6.0% by mass of glass flakes were used.

[0140] Next, except for using the resin particles obtained in this embodiment, glass-reinforced resin molded articles were made in exactly the same manner as in Example 1.

[0141] Next, in exactly the same manner as in Example 1, the following values ​​for the glass-reinforced resin molded article produced in this example were determined: MD direction shrinkage rate / TD direction shrinkage rate, TD direction shrinkage rate / reference shrinkage rate, the ratio P of the glass reinforcing material with a length in the range of 50 to 100 μm to the total number of glass reinforcing materials with a length of 50 μm or more contained in the glass-reinforced resin molded article, and the ratio P of the glass reinforcing material with a length in the range of 25 to 100 μm to the total number of glass reinforcing materials with a length of 25 μm or more contained in the glass-reinforced resin molded article. Based on the content C of the flat cross-section glass fiber relative to the total amount of the glass-reinforced resin molded article, the major diameter D of the flat cross-section glass fiber, and the ratio P of the glass reinforcing material with a length in the range of 50 to 100 μm to the total number of glass reinforcing materials with a length of 50 μm or more contained in the glass-reinforced resin molded article, P / (C×D) was calculated. 1 / 2 The values ​​are shown in Table 1.

[0142] [Comparative Example 1]

[0143] In this comparative example, resin particles were obtained in exactly the same manner as in Example 1, except that flat cross-section glass fibers with a short diameter of 7.0 μm, a major diameter D of 28.0 μm, and a major diameter / short diameter ratio of 4.0 were used and the mixture was compounded in a biaxial mixer at a screw speed of 100 rpm.

[0144] Next, except that the resin particles obtained in this comparative example were used, glass-reinforced resin molded articles were made in exactly the same manner as in Example 1.

[0145] Next, in exactly the same manner as in Example 1, the following values ​​for the glass-reinforced resin molded article produced in this comparative example were determined: MD direction shrinkage rate / TD direction shrinkage rate, TD direction shrinkage rate / reference shrinkage rate, the ratio P of the glass reinforcing material in the glass-reinforced resin molded article having a length in the range of 50 to 100 μm to the total number of glass reinforcing materials having a length of 50 μm or more, and the ratio P of the glass reinforcing material in the glass-reinforced resin molded article having a length in the range of 25 to 100 μm to the total number of glass reinforcing materials having a length of 25 μm or more. Based on the content C of the flat cross-section glass fiber relative to the total amount of the glass-reinforced resin molded article, the major diameter D of the flat cross-section glass fiber, and the ratio P of the glass reinforcing material in the glass-reinforced resin molded article having a length in the range of 50 to 100 μm to the total number of glass reinforcing materials having a length of 50 μm or more, P / (C×D) was calculated. 1 / 2 The values ​​are shown in Table 2.

[0146] [Comparative Example 2]

[0147] In this comparative example, resin particles were obtained in exactly the same manner as in Example 1, except that flat cross-section glass fibers with a short diameter of 11.0 μm, a major diameter D of 44.0 μm, and a major diameter / short diameter ratio of 4.0 were used and the mixture was compounded in a biaxial mixer at a screw speed of 100 rpm.

[0148] Next, except that the resin particles obtained in this comparative example were used, glass-reinforced resin molded articles were made in exactly the same manner as in Example 1.

[0149] Next, in exactly the same manner as in Example 1, the following values ​​for the glass-reinforced resin molded article produced in this comparative example were determined: MD direction shrinkage rate / TD direction shrinkage rate, TD direction shrinkage rate / reference shrinkage rate, the ratio P of the glass reinforcing material in the glass-reinforced resin molded article having a length in the range of 50 to 100 μm to the total number of glass reinforcing materials having a length of 50 μm or more, and the ratio P of the glass reinforcing material in the glass-reinforced resin molded article having a length in the range of 25 to 100 μm to the total number of glass reinforcing materials having a length of 25 μm or more. Based on the content C of the flat cross-section glass fiber relative to the total amount of the glass-reinforced resin molded article, the major diameter D of the flat cross-section glass fiber, and the ratio P of the glass reinforcing material in the glass-reinforced resin molded article having a length in the range of 50 to 100 μm to the total number of glass reinforcing materials having a length of 50 μm or more, P / (C×D) was calculated. 1 / 2 The values ​​are shown in Table 2.

[0150] [Comparative Example 3]

[0151] In this comparative example, firstly, 10.0% by mass of flat-section glass fibers (as a glass reinforcement material), 20.0% by mass of glass flakes (as a glass flake material), and 70.0% by mass of polycarbonate (as a thermoplastic resin) were compounded in a twin-screw mixer at a screw speed of 110 rpm to obtain resin particles. The aforementioned flat-section glass fibers have an E-glass composition, a minor diameter of 5.5 μm, a major diameter D of 33.0 μm, and a major diameter / minor diameter ratio of 6.0. Furthermore, the aforementioned glass flakes have a thickness of 5 μm and a particle size of 160 μm.

[0152] Next, except that the resin particles obtained in this comparative example were used, glass-reinforced resin molded articles were made in exactly the same manner as in Example 1.

[0153] Next, in exactly the same manner as in Example 1, the following values ​​for the glass-reinforced resin molded article produced in this comparative example were determined: MD direction shrinkage rate / TD direction shrinkage rate, TD direction shrinkage rate / reference shrinkage rate, the ratio P of the glass reinforcing material in the glass-reinforced resin molded article having a length in the range of 50 to 100 μm to the total number of glass reinforcing materials having a length of 50 μm or more, and the ratio P of the glass reinforcing material in the glass-reinforced resin molded article having a length in the range of 25 to 100 μm to the total number of glass reinforcing materials having a length of 25 μm or more. Based on the content C of the flat cross-section glass fiber relative to the total amount of the glass-reinforced resin molded article, the major diameter D of the flat cross-section glass fiber, and the ratio P of the glass reinforcing material in the glass-reinforced resin molded article having a length in the range of 50 to 100 μm to the total number of glass reinforcing materials having a length of 50 μm or more, P / (C×D) was calculated. 1 / 2 The values ​​are shown in Table 2.

[0154] [Comparative Example 4]

[0155] In this comparative example, resin particles were obtained in exactly the same manner as in Comparative Example 3, except that flat cross-section glass fibers with a minor diameter of 7.0 μm, a major diameter D of 28.0 μm, and a major diameter / minor diameter ratio of 4.0 were used and the mixture was compounded in a twin-screw mixer at a screw speed of 110 rpm.

[0156] Next, except that the resin particles obtained in this comparative example were used, glass-reinforced resin molded articles were made in exactly the same manner as in Example 1.

[0157] Next, in exactly the same manner as in Example 1, the following values ​​for the glass-reinforced resin molded article produced in this comparative example were determined: MD direction shrinkage rate / TD direction shrinkage rate, TD direction shrinkage rate / reference shrinkage rate, the ratio P of the glass reinforcing material in the glass-reinforced resin molded article having a length in the range of 50 to 100 μm to the total number of glass reinforcing materials having a length of 50 μm or more, and the ratio P of the glass reinforcing material in the glass-reinforced resin molded article having a length in the range of 25 to 100 μm to the total number of glass reinforcing materials having a length of 25 μm or more. Based on the content C of the flat cross-section glass fiber relative to the total amount of the glass-reinforced resin molded article, the major diameter D of the flat cross-section glass fiber, and the ratio P of the glass reinforcing material in the glass-reinforced resin molded article having a length in the range of 50 to 100 μm to the total number of glass reinforcing materials having a length of 50 μm or more, P / (C×D) was calculated. 1 / 2 The values ​​are shown in Table 2.

[0158] [Reference Example 1]

[0159] In this reference example, except that glass fibers with a circular cross-section and a diameter of 11.0 μm were used as the glass reinforcement material and the mixture was mixed in a biaxial mixer at a screw speed of 100 rpm, the resin particles were obtained in exactly the same manner as in Example 1.

[0160] Next, except that the resin particles obtained in this reference example are used, glass-reinforced resin molded articles are made in exactly the same manner as in Example 1.

[0161] Next, in exactly the same manner as in Example 1, the MD direction shrinkage rate, TD direction shrinkage rate, and MD direction shrinkage rate / TD direction shrinkage rate of the glass-reinforced resin molded article prepared in this reference example were determined, and the TD direction shrinkage rate was used as the baseline shrinkage rate for Examples 1 to 5 and Comparative Examples 1 to 4. The results are shown in Tables 1 and 2.

[0162] [Example 6]

[0163] In this embodiment, firstly, 40.0% by mass of flat-section glass fiber as a glass reinforcement material and 60.0% by mass of polycarbonate (Teijin Corporation, trade name: Panlite L1250Y (labeled as PC in Table 3) as a thermoplastic resin were compounded in a twin-screw mixer (manufactured by Shibaura Machinery Co., Ltd., trade name: TEM-26SS) at a screw speed of 110 rpm to obtain resin particles. The aforementioned flat-section glass fiber has an E-glass composition, a minor diameter of 5.5 μm, a major diameter D of 33.0 μm, and a major diameter / minor diameter ratio of 6.0.

[0164] Next, using the resin particles obtained in this embodiment, an injection molding machine (manufactured by Nissei Resin Kogyo Co., Ltd., trade name: NEX80) was used to perform injection molding at a mold temperature of 120°C and an injection temperature of 300°C to produce a glass-reinforced resin molded product with dimensions of 80mm in length × 60mm in width and 2.0mm in thickness.

[0165] Next, the TD and MD shrinkage rates of the glass-reinforced resin molded article prepared in this embodiment were measured, and the MD shrinkage rate / TD shrinkage rate was calculated. Furthermore, the TD shrinkage rate of the glass-reinforced resin molded article of Reference Example 2 (described later) was used as the reference shrinkage rate, and the TD shrinkage rate / reference shrinkage rate was calculated.

[0166] Next, in exactly the same manner as in Example 1, the following values ​​for the glass-reinforced resin molded article produced in this example were determined: the ratio P of the glass reinforcing material having a length in the range of 50 to 100 μm to the total number of glass reinforcing materials having a length of 50 μm or more contained in the glass-reinforced resin molded article; the ratio of the glass reinforcing material having a length in the range of 25 to 100 μm contained in the glass-reinforced resin molded article to the total number of glass reinforcing materials having a length of 25 μm or more contained in the glass-reinforced resin molded article; and P / (C×D) was determined based on the content C of the flat cross-section glass fiber relative to the total amount of the glass-reinforced resin molded article, the major diameter D of the flat cross-section glass fiber, and the ratio P of the glass reinforcing material having a length in the range of 50 to 100 μm contained in the glass-reinforced resin molded article to the total number of glass reinforcing materials having a length of 50 μm or more contained in the glass-reinforced resin molded article. 1 / 2 The values ​​are shown in Table 3.

[0167] [Example 7]

[0168] In this embodiment, except that flat cross-section glass fibers with a short diameter of 7.0 μm, a long diameter D of 42.0 μm, and a long diameter / short diameter ratio of 6.0 are used and the mixture is compounded in a biaxial mixer at a screw speed of 100 rpm, the resin particles are obtained in the same manner as in Example 6.

[0169] Next, except for using the resin particles obtained in this embodiment, glass-reinforced resin molded articles were made in exactly the same manner as in Example 6.

[0170] Next, in exactly the same manner as in Example 6, the following values ​​for the glass-reinforced resin molded article produced in this example were determined: MD direction shrinkage rate / TD direction shrinkage rate, TD direction shrinkage rate / reference shrinkage rate, the ratio P of the glass reinforcing material with a length in the range of 50 to 100 μm to the total number of glass reinforcing materials with a length of 50 μm or more contained in the glass-reinforced resin molded article, and the ratio P of the glass reinforcing material with a length in the range of 25 to 100 μm to the total number of glass reinforcing materials with a length of 25 μm or more contained in the glass-reinforced resin molded article. Based on the content C of the flat cross-section glass fiber relative to the total amount of the glass-reinforced resin molded article, the major diameter D of the flat cross-section glass fiber, and the ratio P of the glass reinforcing material with a length in the range of 50 to 100 μm to the total number of glass reinforcing materials with a length of 50 μm or more contained in the glass-reinforced resin molded article, P / (C×D) was calculated. 1 / 2 The values ​​are shown in Table 3.

[0171] [Reference Example 2]

[0172] In this reference example, resin particles were obtained in exactly the same manner as in Example 6, except that glass fibers with a diameter of 11.0 μm were used as glass reinforcement material and the mixture was compounded in a biaxial mixer at a screw speed of 100 rpm.

[0173] Next, except that the resin particles obtained in this reference example are used, glass-reinforced resin molded articles are made in exactly the same manner as in Example 6.

[0174] Next, in exactly the same manner as in Example 6, the MD direction shrinkage rate, TD direction shrinkage rate, and MD direction shrinkage rate / TD direction shrinkage rate of the glass-reinforced resin molded article prepared in this reference example were calculated, and the TD direction shrinkage rate was used as the baseline shrinkage rate relative to Examples 6 and 7. The results are shown in Table 3.

[0175] [Comparative Example 5]

[0176] In this comparative example, firstly, 20.0% by mass of flat-section glass fibers (as glass reinforcement) and 80.0% by mass of polycarbonate (Teijin Corporation, trade name: Panlite L1250Y (labeled as PC in Table 3)) (as thermoplastic resin) were compounded in a twin-screw mixer (manufactured by Shibaura Machinery Co., Ltd., trade name: TEM-26SS) at a screw speed of 100 rpm to obtain resin particles. The aforementioned flat-section glass fibers had an E-glass composition, a minor diameter of 5.5 μm, a major diameter D of 33.0 μm, and a major diameter / minor diameter ratio of 6.0. The aforementioned flat-section glass fibers also had an E-glass composition, a minor diameter of 7.0 μm, a major diameter D of 28.0 μm, and a major diameter / minor diameter ratio of 4.0.

[0177] Next, using the resin particles obtained in this comparative example, an injection molding machine (manufactured by Nissei Resin Kogyo Co., Ltd., trade name: NEX80) was used to perform injection molding at a mold temperature of 120°C and an injection temperature of 300°C to produce a glass-reinforced resin molded product with dimensions of 80mm in length × 60mm in width and 2.0mm in thickness.

[0178] Next, the TD and MD shrinkage rates of the glass-reinforced resin molded article prepared in this comparative example were measured, and the MD shrinkage rate / TD shrinkage rate was calculated. Furthermore, the TD shrinkage rate of the glass-reinforced resin molded article of Reference Example 3 (described later) was used as the baseline shrinkage rate, and the TD shrinkage rate / baseline shrinkage rate was calculated.

[0179] Next, in exactly the same manner as in Example 1, the following values ​​for the glass-reinforced resin molded article produced in this comparative example were determined: the ratio P of the glass reinforcing material having a length in the range of 50 to 100 μm to the total number of glass reinforcing materials having a length of 50 μm or more contained in the glass-reinforced resin molded article; the ratio of the glass reinforcing material having a length in the range of 25 to 100 μm contained in the glass-reinforced resin molded article to the total number of glass reinforcing materials having a length of 25 μm or more contained in the glass-reinforced resin molded article; and P / (C×D) was determined based on the content C of the flat cross-section glass fiber relative to the total amount of the glass-reinforced resin molded article, the major diameter D of the flat cross-section glass fiber, and the ratio P of the glass reinforcing material having a length in the range of 50 to 100 μm contained in the glass-reinforced resin molded article to the total number of glass reinforcing materials having a length of 50 μm or more contained in the glass-reinforced resin molded article. 1 / 2 The values ​​are shown in Table 3.

[0180] [Comparative Example 6]

[0181] In this comparative example, except that flat cross-section glass fibers with a short diameter of 5.5 μm, a major diameter D of 33.0 μm, and a major diameter / short diameter ratio of 6.0 were used, and the mixture was compounded using a biaxial mixer at a screw speed of 110 rpm, the resin particles were obtained in the same manner as in Comparative Example 5.

[0182] Next, except for using the resin particles obtained in this comparative example, glass-reinforced resin molded articles were made in exactly the same manner as in Comparative Example 5.

[0183] Next, in exactly the same manner as Comparative Example 5, the following values ​​for the glass-reinforced resin molded article produced in this comparative example were calculated: MD direction shrinkage rate / TD direction shrinkage rate, TD direction shrinkage rate / reference shrinkage rate, the ratio P of the glass reinforcing material with a length in the range of 50 to 100 μm to the total number of glass reinforcing materials with a length of 50 μm or more contained in the glass-reinforced resin molded article, and the ratio P of the glass reinforcing material with a length in the range of 25 to 100 μm contained in the glass-reinforced resin molded article to the total number of glass reinforcing materials with a length of 25 μm or more contained in the glass-reinforced resin molded article. Based on the content C of the flat cross-section glass fiber relative to the total amount of the glass-reinforced resin molded article, the major diameter D of the flat cross-section glass fiber, and the ratio P of the glass reinforcing material with a length in the range of 50 to 100 μm contained in the glass-reinforced resin molded article to the total number of glass reinforcing materials with a length of 50 μm or more contained in the glass-reinforced resin molded article, P / (C×D) was calculated. 1 / 2 The values ​​are shown in Table 3.

[0184] [Reference Example 3]

[0185] In this reference example, except that glass fibers with a diameter of 11.0 μm and a circular cross-section were used as glass reinforcement material and the mixture was prepared in a biaxial mixer at a screw speed of 100 rpm, the resin particles were prepared in the same manner as in Comparative Example 5.

[0186] Next, except that the resin particles obtained in this reference example are used, glass-reinforced resin molded articles are made in exactly the same manner as in Comparative Example 5.

[0187] Next, in exactly the same manner as Comparative Example 5, the MD direction shrinkage rate, TD direction shrinkage rate, and MD direction shrinkage rate / TD direction shrinkage rate of the glass-reinforced resin molded article prepared in this reference example were calculated, and the TD direction shrinkage rate was used as the reference shrinkage rate relative to Comparative Examples 5 and 6. The results are shown in Table 3.

[0188] [Example 8]

[0189] In this embodiment, firstly, 30.0% by mass of flat cross-section glass fibers (as glass reinforcement) and 70.0% by mass of polycarbonate (manufactured by Polyplastics Co., Ltd., trade name: DURANEX2000 (labeled as PBT in Table 4) (as thermoplastic resin) were compounded in a twin-screw mixer (manufactured by Shibaura Machinery Co., Ltd., trade name: TEM-26SS) at a screw speed of 110 rpm to obtain resin particles. The aforementioned flat cross-section glass fibers have an E-glass composition, a minor diameter of 5.5 μm, a major diameter D of 33.0 μm, and a major diameter / minor diameter ratio of 6.0.

[0190] Next, using the resin particles obtained in this embodiment, an injection molding machine (manufactured by Nissei Resin Kogyo Co., Ltd., trade name: NEX80) was used to perform injection molding at a mold temperature of 90°C and an injection temperature of 250°C to produce a glass-reinforced resin molded product with dimensions of 80mm in length × 60mm in width and 2.0mm in thickness.

[0191] Next, the TD and MD shrinkage rates of the glass-reinforced resin molded article prepared in this embodiment were measured, and the MD shrinkage rate / TD shrinkage rate was calculated. Furthermore, the TD shrinkage rate of the glass-reinforced resin molded article of Reference Example 4 (described later) was used as the reference shrinkage rate, and the TD shrinkage rate / reference shrinkage rate was calculated.

[0192] Next, in exactly the same manner as in Example 1, the following values ​​for the glass-reinforced resin molded article produced in this example were determined: the ratio P of the glass reinforcing material with a length in the range of 50 to 100 μm to the total number of glass reinforcing materials with a length of 50 μm or more contained in the glass-reinforced resin molded article; the ratio of the glass reinforcing material with a length in the range of 25 to 100 μm contained in the glass-reinforced resin molded article to the total number of glass reinforcing materials with a length of 25 μm or more contained in the glass-reinforced resin molded article; and P based on the content C of the flat cross-section glass fiber to the total amount of the glass-reinforced resin molded article, the major diameter D of the flat cross-section glass fiber, and the ratio P of the glass reinforcing material with a length in the range of 50 to 100 μm contained in the glass-reinforced resin molded article to the total number of glass reinforcing materials with a length of 50 μm or more contained in the glass-reinforced resin molded article, P / (C×D) was determined. 1 / 2 The values ​​are shown in Table 4.

[0193] [Example 9]

[0194] In this embodiment, except that flat cross-section glass fibers with a short diameter of 7.0 μm, a long diameter D of 42.0 μm, and a long diameter / short diameter ratio of 6.0 are used, and the mixture is compounded in a biaxial mixer at a screw speed of 100 rpm, the resin particles are obtained in the same manner as in Example 8.

[0195] Next, except for using the resin particles obtained in this embodiment, glass-reinforced resin molded articles were made in exactly the same manner as in Example 8.

[0196] Next, in exactly the same manner as in Example 8, the following values ​​for the glass-reinforced resin molded article produced in this example were determined: MD direction shrinkage rate / TD direction shrinkage rate, TD direction shrinkage rate / reference shrinkage rate, the ratio P of the glass reinforcing material with a length in the range of 50 to 100 μm to the total number of glass reinforcing materials with a length of 50 μm or more contained in the glass-reinforced resin molded article, and the ratio P of the glass reinforcing material with a length in the range of 25 to 100 μm to the total number of glass reinforcing materials with a length of 25 μm or more contained in the glass-reinforced resin molded article. Based on the content C of the flat cross-section glass fiber relative to the total amount of the glass-reinforced resin molded article, the major diameter D of the flat cross-section glass fiber, and the ratio P of the glass reinforcing material with a length in the range of 50 to 100 μm to the total number of glass reinforcing materials with a length of 50 μm or more contained in the glass-reinforced resin molded article, P / (C×D) was calculated. 1 / 2 The values ​​are shown in Table 4.

[0197] [Example 10]

[0198] In this embodiment, except that flat cross-section glass fibers with a short diameter of 11.0 μm, a long diameter D of 44.0 μm, and a long diameter / short diameter ratio of 4.0 are used and the mixture is compounded in a biaxial mixer at a screw speed of 200 rpm, the resin particles are obtained in the same manner as in Example 8.

[0199] Next, except for using the resin particles obtained in this embodiment, glass-reinforced resin molded articles were made in exactly the same manner as in Example 8.

[0200] Next, in exactly the same manner as in Example 8, the following values ​​for the glass-reinforced resin molded article produced in this example were determined: MD direction shrinkage rate / TD direction shrinkage rate, TD direction shrinkage rate / reference shrinkage rate, the ratio P of the glass reinforcing material with a length in the range of 50 to 100 μm to the total number of glass reinforcing materials with a length of 50 μm or more contained in the glass-reinforced resin molded article, and the ratio P of the glass reinforcing material with a length in the range of 25 to 100 μm to the total number of glass reinforcing materials with a length of 25 μm or more contained in the glass-reinforced resin molded article. Based on the content C of the flat cross-section glass fiber relative to the total amount of the glass-reinforced resin molded article, the major diameter D of the flat cross-section glass fiber, and the ratio P of the glass reinforcing material with a length in the range of 50 to 100 μm to the total number of glass reinforcing materials with a length of 50 μm or more contained in the glass-reinforced resin molded article, P / (C×D) was calculated. 1 / 2 The values ​​are shown in Table 4.

[0201] [Comparative Example 7]

[0202] In this comparative example, resin particles were obtained in exactly the same manner as in Example 8, except that flat cross-section glass fibers with a short diameter of 7.0 μm, a major diameter D of 28.0 μm, and a major diameter / short diameter ratio of 4.0 were used and the mixture was compounded in a biaxial mixer at a screw speed of 100 rpm.

[0203] Next, except that the resin particles obtained in this comparative example were used, glass-reinforced resin molded articles were made in exactly the same manner as in Example 8.

[0204] Next, in exactly the same manner as in Example 8, the following values ​​for the glass-reinforced resin molded article produced in this comparative example were determined: MD direction shrinkage rate / TD direction shrinkage rate, TD direction shrinkage rate / reference shrinkage rate, the ratio P of the glass reinforcing material with a length in the range of 50 to 100 μm to the total number of glass reinforcing materials with a length of 50 μm or more contained in the glass-reinforced resin molded article, and the ratio P of the glass reinforcing material with a length in the range of 25 to 100 μm contained in the glass-reinforced resin molded article to the total number of glass reinforcing materials with a length of 25 μm or more contained in the glass-reinforced resin molded article. Based on the content C of the flat cross-section glass fiber relative to the total amount of the glass-reinforced resin molded article, the major diameter D of the flat cross-section glass fiber, and the ratio P of the glass reinforcing material with a length in the range of 50 to 100 μm to the total number of glass reinforcing materials with a length of 50 μm or more contained in the glass-reinforced resin molded article, P / (C×D) was calculated. 1 / 2 The values ​​are shown in Table 4.

[0205] [Comparative Example 8]

[0206] In this comparative example, resin particles were obtained in exactly the same manner as in Example 8, except that flat cross-section glass fibers with a short diameter of 11.0 μm, a major diameter D of 44.0 μm, and a major diameter / short diameter ratio of 4.0 were used and the mixture was compounded in a biaxial mixer at a screw speed of 100 rpm.

[0207] Next, except that the resin particles obtained in this comparative example were used, glass-reinforced resin molded articles were made in exactly the same manner as in Example 8.

[0208] Next, in exactly the same manner as in Example 8, the following values ​​for the glass-reinforced resin molded article produced in this comparative example were determined: MD direction shrinkage rate / TD direction shrinkage rate, TD direction shrinkage rate / reference shrinkage rate, the ratio P of the glass reinforcing material with a length in the range of 50 to 100 μm to the total number of glass reinforcing materials with a length of 50 μm or more contained in the glass-reinforced resin molded article, and the ratio P of the glass reinforcing material with a length in the range of 25 to 100 μm contained in the glass-reinforced resin molded article to the total number of glass reinforcing materials with a length of 25 μm or more contained in the glass-reinforced resin molded article. Based on the content C of the flat cross-section glass fiber relative to the total amount of the glass-reinforced resin molded article, the major diameter D of the flat cross-section glass fiber, and the ratio P of the glass reinforcing material with a length in the range of 50 to 100 μm to the total number of glass reinforcing materials with a length of 50 μm or more contained in the glass-reinforced resin molded article, P / (C×D) was calculated. 1 / 2 The values ​​are shown in Table 4.

[0209] [Reference Example 4]

[0210] In this reference example, the resin particles were obtained in exactly the same manner as in Example 8, except that glass fibers with a diameter of 11.0 μm were used as the glass reinforcement material and the mixture was mixed in a biaxial mixer at a screw speed of 100 rpm.

[0211] Next, except that the resin particles obtained in this reference example are used, glass-reinforced resin molded articles are made in exactly the same manner as in Example 8.

[0212] Next, the MD direction shrinkage rate, TD direction shrinkage rate, and MD direction shrinkage rate / TD direction shrinkage rate of the glass-reinforced resin molded article prepared in this reference example were determined in exactly the same manner as in Example 8, and the TD direction shrinkage rate was used as the baseline shrinkage rate relative to Examples 8-10 and Comparative Examples 7-8. The results are shown in Table 4.

[0213] [Example 11]

[0214] In this embodiment, firstly, 40.0% by mass of flat-section glass fiber as a glass reinforcement and 60.0% by mass of polycarbonate (manufactured by Polyplastics Co., Ltd., trade name: DURANEX2000 (marked as PBT in Table 5) as a thermoplastic resin were compounded in a twin-screw mixer (manufactured by Shibaura Machinery Co., Ltd., trade name: TEM-26SS) at a screw speed of 110 rpm to obtain resin particles. The aforementioned flat-section glass fiber has an E-glass composition, a minor diameter of 5.5 μm, a major diameter D of 33.0 μm, and a major diameter / minor diameter ratio of 6.0.

[0215] Next, using the resin particles obtained in this embodiment, an injection molding machine (manufactured by Nissei Resin Kogyo Co., Ltd., trade name: NEX80) was used to perform injection molding at a mold temperature of 90°C and an injection temperature of 250°C to produce a glass-reinforced resin molded product with dimensions of 80mm in length × 60mm in width and 2.0mm in thickness.

[0216] Next, the TD and MD shrinkage rates of the glass-reinforced resin molded article obtained in this embodiment were measured, and the MD shrinkage rate / TD shrinkage rate was calculated. Furthermore, the TD shrinkage rate of the glass-reinforced resin molded article of Reference Example 5 (described later) was used as the reference shrinkage rate, and the TD shrinkage rate / reference shrinkage rate was calculated.

[0217] Next, in exactly the same manner as in Example 1, the following values ​​for the glass-reinforced resin molded article produced in this example were determined: the ratio P of the glass reinforcing material having a length in the range of 50 to 100 μm to the total number of glass reinforcing materials having a length of 50 μm or more contained in the glass-reinforced resin molded article; the ratio of the glass reinforcing material having a length in the range of 25 to 100 μm contained in the glass-reinforced resin molded article to the total number of glass reinforcing materials having a length of 25 μm or more contained in the glass-reinforced resin molded article; and P / (C×D) was determined based on the content C of the flat cross-section glass fiber relative to the total amount of the glass-reinforced resin molded article, the major diameter D of the flat cross-section glass fiber, and the ratio P of the glass reinforcing material having a length in the range of 50 to 100 μm contained in the glass-reinforced resin molded article to the total number of glass reinforcing materials having a length of 50 μm or more contained in the glass-reinforced resin molded article. 1 / 2 The values ​​are shown in Table 5.

[0218] [Example 12]

[0219] In this embodiment, except that flat cross-section glass fibers with a short diameter of 7.0 μm, a long diameter D of 42.0 μm, and a long diameter / short diameter ratio of 6.0 are used and the mixture is compounded in a biaxial mixer at a screw speed of 100 rpm, the resin particles are prepared in the same manner as in Example 11.

[0220] Next, except for using the resin particles obtained in this embodiment, glass-reinforced resin molded articles were made in exactly the same manner as in Example 11.

[0221] Next, in exactly the same manner as in Example 11, the following values ​​for the glass-reinforced resin molded article produced in this example were determined: MD direction shrinkage rate / TD direction shrinkage rate, TD direction shrinkage rate / reference shrinkage rate, the ratio P of the glass reinforcing material in the glass-reinforced resin molded article having a length in the range of 50 to 100 μm to the total number of glass reinforcing materials having a length of 50 μm or more, and the ratio P of the glass reinforcing material in the glass-reinforced resin molded article having a length in the range of 25 to 100 μm to the total number of glass reinforcing materials having a length of 25 μm or more. Based on the content C of the flat cross-section glass fiber relative to the total amount of the glass-reinforced resin molded article, the major diameter D of the flat cross-section glass fiber, and the ratio P of the glass reinforcing material in the glass-reinforced resin molded article having a length in the range of 50 to 100 μm to the total number of glass reinforcing materials having a length of 50 μm or more, P / (C×D) was calculated. 1 / 2 The values ​​are shown in Table 5.

[0222] [Comparative Example 9]

[0223] In this comparative example, resin particles were prepared in exactly the same manner as in Example 11, except that flat cross-section glass fibers with a short diameter of 7.0 μm, a major diameter D of 28.0 μm, and a major diameter / short diameter ratio of 4.0 were used and the mixture was compounded in a biaxial mixer at a screw speed of 100 rpm.

[0224] Next, except that the resin particles obtained in this comparative example were used, glass-reinforced resin molded articles were made in exactly the same manner as in Example 11.

[0225] Next, in exactly the same manner as in Example 11, the following values ​​for the glass-reinforced resin molded article produced in this example were determined: MD direction shrinkage rate / TD direction shrinkage rate, TD direction shrinkage rate / reference shrinkage rate, the ratio P of the glass reinforcing material with a length in the range of 50 to 100 μm to the total number of glass reinforcing materials with a length of 50 μm or more contained in the glass-reinforced resin molded article, and the ratio P of the glass reinforcing material with a length in the range of 25 to 100 μm contained in the glass-reinforced resin molded article to the total number of glass reinforcing materials with a length of 25 μm or more contained in the glass-reinforced resin molded article. Based on the content C of the flat cross-section glass fiber relative to the total amount of the glass-reinforced resin molded article, the major diameter D of the flat cross-section glass fiber, and the ratio P of the glass reinforcing material with a length in the range of 50 to 100 μm to the total number of glass reinforcing materials with a length of 50 μm or more contained in the glass-reinforced resin molded article, P / (C×D) was calculated. 1 / 2 The values ​​are shown in Table 5.

[0226] [Reference Example 5]

[0227] In this reference example, resin particles were prepared in exactly the same manner as in Example 11, except that glass fibers with a diameter of 11.0 μm with a circular cross-section were used as the glass reinforcement material and the mixing was carried out in a biaxial mixer at a screw speed of 100 rpm.

[0228] Next, except that the resin particles obtained in this reference example are used, glass-reinforced resin molded articles are made in exactly the same manner as in Example 11.

[0229] Next, the MD direction shrinkage rate, TD direction shrinkage rate, and MD direction shrinkage rate / TD direction shrinkage rate of the glass-reinforced resin molded article prepared in this reference example were determined in exactly the same manner as in Example 11, and the TD direction shrinkage rate was used as the baseline shrinkage rate relative to Examples 11-12 and Comparative Example 9. The results are shown in Table 5.

[0230] [Example 13]

[0231] In this embodiment, firstly, 60.0% by mass of flat-section glass fibers (as glass reinforcement) and 40.0% by mass of polyamide (Ube Industries, Ltd., trade name: UBE1015B (labeled PA in Table 6)) (as thermoplastic resin) were mixed in a twin-screw mixer (manufactured by Shibaura Machinery Co., Ltd., trade name: TEM-26SS) at a screw speed of 100 rpm to obtain resin particles. The aforementioned flat-section glass fibers have an E-glass composition, a minor diameter of 7.0 μm, a major diameter D of 42.0 μm, and a major diameter / minor diameter ratio of 6.0.

[0232] Next, using the resin particles obtained in this embodiment, an injection molding machine (manufactured by Nissei Resin Kogyo Co., Ltd., trade name: NEX80) was used to perform injection molding at a mold temperature of 90°C and an injection temperature of 270°C to produce a glass-reinforced resin molded product with dimensions of 80mm in length × 60mm in width and 2.0mm in thickness.

[0233] Next, the TD and MD shrinkage rates of the glass-reinforced resin molded article prepared in this embodiment were measured, and the MD shrinkage rate / TD shrinkage rate was calculated. Furthermore, the TD shrinkage rate of the glass-reinforced resin molded article of Reference Example 6 (described later) was used as the reference shrinkage rate, and the TD shrinkage rate / reference shrinkage rate was calculated.

[0234] Next, in exactly the same manner as in Example 1, the following values ​​for the glass-reinforced resin molded article produced in this example were determined: the ratio P of the glass reinforcing material having a length in the range of 50 to 100 μm to the total number of glass reinforcing materials having a length of 50 μm or more contained in the glass-reinforced resin molded article; the ratio of the glass reinforcing material having a length in the range of 25 to 100 μm contained in the glass-reinforced resin molded article to the total number of glass reinforcing materials having a length of 25 μm or more contained in the glass-reinforced resin molded article; and P / (C×D) was determined based on the content C of the flat cross-section glass fiber relative to the total amount of the glass-reinforced resin molded article, the major diameter D of the flat cross-section glass fiber, and the ratio P of the glass reinforcing material having a length in the range of 50 to 100 μm contained in the glass-reinforced resin molded article to the total number of glass reinforcing materials having a length of 50 μm or more contained in the glass-reinforced resin molded article. 1 / 2 The values ​​are shown in Table 6.

[0235] [Example 14]

[0236] In this embodiment, except that flat cross-section glass fibers with a short diameter of 5.5 μm, a long diameter D of 33.0 μm, and a long diameter / short diameter ratio of 6.0 are used, and the mixture is compounded in a biaxial mixer at a screw speed of 110 rpm, the resin particles are obtained in the same manner as in Example 13.

[0237] Next, except for using the resin particles obtained in this embodiment, glass-reinforced resin molded articles were made in exactly the same manner as in Example 13.

[0238] Next, in exactly the same manner as in Example 13, the following values ​​for the glass-reinforced resin molded article produced in this example were determined: MD direction shrinkage rate / TD direction shrinkage rate, TD direction shrinkage rate / reference shrinkage rate, the ratio P of the glass reinforcing material with a length in the range of 50 to 100 μm to the total number of glass reinforcing materials with a length of 50 μm or more contained in the glass-reinforced resin molded article, and the ratio P of the glass reinforcing material with a length in the range of 25 to 100 μm to the total number of glass reinforcing materials with a length of 25 μm or more contained in the glass-reinforced resin molded article. Based on the content C of the flat cross-section glass fiber relative to the total amount of the glass-reinforced resin molded article, the major diameter D of the flat cross-section glass fiber, and the ratio P of the glass reinforcing material with a length in the range of 50 to 100 μm to the total number of glass reinforcing materials with a length of 50 μm or more contained in the glass-reinforced resin molded article, P / (C×D) was calculated. 1 / 2 The values ​​are shown in Table 6.

[0239] [Example 15]

[0240] In this embodiment, except that flat cross-section glass fibers with a short diameter of 11.0 μm, a long diameter D of 44.0 μm, and a long diameter / short diameter ratio of 4.0 are used, and the mixture is compounded in a biaxial mixer at a screw speed of 130 rpm, the resin particles are obtained in the same manner as in Example 13.

[0241] Next, except for using the resin particles obtained in this embodiment, glass-reinforced resin molded articles were made in exactly the same manner as in Example 13.

[0242] Next, in exactly the same manner as in Example 13, the following values ​​for the glass-reinforced resin molded article produced in this example were determined: MD direction shrinkage rate / TD direction shrinkage rate, TD direction shrinkage rate / reference shrinkage rate, the ratio P of the glass reinforcing material with a length in the range of 50 to 100 μm to the total number of glass reinforcing materials with a length of 50 μm or more contained in the glass-reinforced resin molded article, and the ratio P of the glass reinforcing material with a length in the range of 25 to 100 μm to the total number of glass reinforcing materials with a length of 25 μm or more contained in the glass-reinforced resin molded article. Based on the content C of the flat cross-section glass fiber relative to the total amount of the glass-reinforced resin molded article, the major diameter D of the flat cross-section glass fiber, and the ratio P of the glass reinforcing material with a length in the range of 50 to 100 μm to the total number of glass reinforcing materials with a length of 50 μm or more contained in the glass-reinforced resin molded article, P / (C×D) was calculated. 1 / 2 The values ​​are shown in Table 6.

[0243] [Reference Example 6]

[0244] In this reference example, resin particles were prepared in exactly the same manner as in Example 13, except that glass fibers with a diameter of 11.0 μm with a circular cross-section were used as the glass reinforcement material and the mixing was carried out in a biaxial mixer at a screw speed of 100 rpm.

[0245] Next, except that the resin particles obtained in this reference example are used, glass-reinforced resin molded articles are made in exactly the same manner as in Example 13.

[0246] Next, in exactly the same manner as in Example 13, the MD direction shrinkage rate, TD direction shrinkage rate, and MD direction shrinkage rate / TD direction shrinkage rate of the glass-reinforced resin molded article prepared in this reference example were determined, and the TD direction shrinkage rate was used as the baseline shrinkage rate relative to Examples 13-15. The results are shown in Table 6.

[0247] [Comparative Example 10]

[0248] In this comparative example, firstly, 30.0% by mass of flat-section glass fibers as glass reinforcement and 70.0% by mass of polyamide (Ube Industries, Ltd., trade name: UBE1015B (labeled PA in Table 7) as thermoplastic resin) were compounded in a twin-screw mixer (manufactured by Shibaura Machinery Co., Ltd., trade name: TEM-26SS) at a screw speed of 100 rpm to obtain resin particles. The aforementioned flat-section glass fibers have an E-glass composition, a minor diameter of 7.0 μm, a major diameter D of 28.0 μm, and a major diameter / minor diameter ratio of 4.0.

[0249] Next, using the resin particles obtained in this comparative example, an injection molding machine (manufactured by Nissei Resin Kogyo Co., Ltd., trade name: NEX80) was used to perform injection molding at a mold temperature of 90°C and an injection temperature of 270°C to produce a glass-reinforced resin molded product with dimensions of 80mm in length × 60mm in width and 2.0mm in thickness.

[0250] Next, the TD and MD shrinkage rates of the glass-reinforced resin molded article prepared in this comparative example were measured, and the MD shrinkage rate / TD shrinkage rate was calculated. Furthermore, the TD shrinkage rate of the glass-reinforced resin molded article of Reference Example 7 (described later) was used as the baseline shrinkage rate, and the TD shrinkage rate / baseline shrinkage rate was calculated.

[0251] Next, in exactly the same manner as in Example 1, the following values ​​for the glass-reinforced resin molded article produced in this example were determined: the ratio P of the glass reinforcing material having a length in the range of 50 to 100 μm to the total number of glass reinforcing materials having a length of 50 μm or more contained in the glass-reinforced resin molded article; the ratio of the glass reinforcing material having a length in the range of 25 to 100 μm contained in the glass-reinforced resin molded article to the total number of glass reinforcing materials having a length of 25 μm or more contained in the glass-reinforced resin molded article; and P / (C×D) was determined based on the content C of the flat cross-section glass fiber relative to the total amount of the glass-reinforced resin molded article, the major diameter D of the flat cross-section glass fiber, and the ratio P of the glass reinforcing material having a length in the range of 50 to 100 μm contained in the glass-reinforced resin molded article to the total number of glass reinforcing materials having a length of 50 μm or more contained in the glass-reinforced resin molded article. 1 / 2 The values ​​are shown in Table 7.

[0252] [Comparative Example 11]

[0253] In this comparative example, resin particles were obtained in exactly the same manner as in Comparative Example 10, except that flat cross-section glass fibers with a short diameter of 5.5 μm, a major diameter D of 33.0 μm, and a major diameter / short diameter ratio of 6.0 were used and the mixture was compounded in a biaxial mixer at a screw speed of 110 rpm.

[0254] Next, except for using the resin particles obtained in this comparative example, glass-reinforced resin molded articles were made in exactly the same manner as in Comparative Example 10.

[0255] Next, in exactly the same manner as Comparative Example 10, the following values ​​for the glass-reinforced resin molded article produced in this embodiment were determined: MD direction shrinkage rate / TD direction shrinkage rate, TD direction shrinkage rate / reference shrinkage rate, the ratio P of the glass reinforcing material with a length in the range of 50 to 100 μm to the total number of glass reinforcing materials with a length of 50 μm or more contained in the glass-reinforced resin molded article, and the ratio P of the glass reinforcing material with a length in the range of 25 to 100 μm contained in the glass-reinforced resin molded article to the total number of glass reinforcing materials with a length of 25 μm or more contained in the glass-reinforced resin molded article. Based on the content C of the flat cross-section glass fiber relative to the total amount of the glass-reinforced resin molded article, the major diameter D of the flat cross-section glass fiber, and the ratio P of the glass reinforcing material with a length in the range of 50 to 100 μm contained in the glass-reinforced resin molded article to the total number of glass reinforcing materials with a length of 50 μm or more contained in the glass-reinforced resin molded article, P / (C×D) was calculated. 1 / 2 The values ​​are shown in Table 7.

[0256] [See Example 7]

[0257] In this reference example, except that glass fibers with a diameter of 11.0 μm and a circular cross-section were used as the glass reinforcement material and the mixture was mixed in a biaxial mixer at a screw speed of 100 rpm, the resin particles were obtained in the same manner as in Comparative Example 10.

[0258] Next, except that the resin particles obtained in this reference example are used, glass-reinforced resin molded articles are made in exactly the same manner as in Comparative Example 10.

[0259] Next, the MD direction shrinkage rate, TD direction shrinkage rate, and MD direction shrinkage rate / TD direction shrinkage rate of the glass-reinforced resin molded article prepared in this reference example were calculated in exactly the same manner as in Comparative Example 10, and the TD direction shrinkage rate was used as the reference shrinkage rate relative to Comparative Examples 10-11. The results are shown in Table 7.

[0260] [Example 16]

[0261] In this embodiment, firstly, 70.0% by mass of flat-section glass fibers (as glass reinforcement) and 30.0% by mass of polyetheretherketone (PEEK) (Daicel-Evonik Co., Ltd., trade name: VESTAKEEP 2000G, labeled as PEEK in Table 8) (as thermoplastic resin) were mixed in a twin-screw mixer (manufactured by Shibaura Machinery Co., Ltd., trade name: TEM-26SS) at a screw speed of 120 rpm to obtain resin particles. The aforementioned flat-section glass fibers have an E-glass composition, a minor diameter of 5.5 μm, a major diameter D of 33.0 μm, and a major diameter / minor diameter ratio of 6.0.

[0262] Next, using the resin particles obtained in this embodiment, an injection molding machine (manufactured by Nissei Resin Kogyo Co., Ltd., trade name: NEX80) was used to perform injection molding at a mold temperature of 200°C and an injection temperature of 410°C to produce a glass-reinforced resin molded product with dimensions of 80mm in length × 60mm in width and 2.0mm in thickness.

[0263] Next, the TD and MD shrinkage rates of the glass-reinforced resin molded article obtained in this embodiment were measured, and the MD shrinkage rate / TD shrinkage rate was calculated. Furthermore, the TD shrinkage rate of the glass-reinforced resin molded article of Reference Example 8 (described later) was used as the reference shrinkage rate, and the TD shrinkage rate / reference shrinkage rate was calculated.

[0264] Next, in exactly the same manner as in Example 1, the following values ​​for the glass-reinforced resin molded article produced in this example were determined: the ratio P of the glass reinforcing material having a length in the range of 50 to 100 μm to the total number of glass reinforcing materials having a length of 50 μm or more contained in the glass-reinforced resin molded article; the ratio of the glass reinforcing material having a length in the range of 25 to 100 μm contained in the glass-reinforced resin molded article to the total number of glass reinforcing materials having a length of 25 μm or more contained in the glass-reinforced resin molded article; and P / (C×D) was determined based on the content C of the flat cross-section glass fiber relative to the total amount of the glass-reinforced resin molded article, the major diameter D of the flat cross-section glass fiber, and the ratio P of the glass reinforcing material having a length in the range of 50 to 100 μm contained in the glass-reinforced resin molded article to the total number of glass reinforcing materials having a length of 50 μm or more contained in the glass-reinforced resin molded article. 1 / 2 The values ​​are shown in Table 8.

[0265] [Comparative Example 12]

[0266] In this comparative example, resin particles were obtained in exactly the same manner as in Example 16, except that flat cross-section glass fibers with a minor diameter of 7.0 μm, a major diameter D of 28.0 μm, and a major diameter / minor diameter ratio of 4.0 were used and the mixture was compounded in a biaxial mixer at a screw speed of 120 rpm.

[0267] Next, except that the resin particles obtained in this comparative example were used, glass-reinforced resin molded articles were made in exactly the same manner as in Example 16.

[0268] Next, in exactly the same manner as in Example 16, the following values ​​for the glass-reinforced resin molded article produced in this example were determined: MD direction shrinkage rate / TD direction shrinkage rate, TD direction shrinkage rate / reference shrinkage rate, the ratio P of the glass reinforcing material with a length in the range of 50 to 100 μm to the total number of glass reinforcing materials with a length of 50 μm or more contained in the glass-reinforced resin molded article, and the ratio P of the glass reinforcing material with a length in the range of 25 to 100 μm contained in the glass-reinforced resin molded article to the total number of glass reinforcing materials with a length of 25 μm or more contained in the glass-reinforced resin molded article. Based on the content C of the flat cross-section glass fiber relative to the total amount of the glass-reinforced resin molded article, the major diameter D of the flat cross-section glass fiber, and the ratio P of the glass reinforcing material with a length in the range of 50 to 100 μm to the total number of glass reinforcing materials with a length of 50 μm or more contained in the glass-reinforced resin molded article, P / (C×D) was calculated. 1 / 2 The values ​​are shown in Table 8.

[0269] [Refer to Example 8]

[0270] In this reference example, resin particles were prepared in exactly the same manner as in Example 16, except that glass fibers with a diameter of 11.0 μm with a circular cross-section were used as the glass reinforcement material and the mixing was carried out in a biaxial mixer at a screw speed of 120 rpm.

[0271] Next, except that the resin particles obtained in this reference example are used, glass-reinforced resin molded articles are made in exactly the same manner as in Example 16.

[0272] Next, in exactly the same manner as in Example 16, the MD direction shrinkage rate, TD direction shrinkage rate, and MD direction shrinkage rate / TD direction shrinkage rate of the glass-reinforced resin molded article prepared in this reference example were determined, and the TD direction shrinkage rate was used as the baseline shrinkage rate relative to Example 16 and Comparative Example 12. The results are shown in Table 8.

[0273] [Table 1]

[0274]

[0275] [Table 2]

[0276]

[0277] [Table 3]

[0278]

[0279] [Table 4]

[0280]

[0281] [Table 5]

[0282]

[0283] [Table 6]

[0284]

[0285] [Table 7]

[0286]

[0287] [Table 8]

[0288]

[0289] As can be clearly seen from Tables 1 to 8, the glass-reinforced resin molded articles according to Examples 1 to 16 have a shrinkage rate in the MD direction of 0.50 or more, which can reduce the anisotropy of the shrinkage rate, and a shrinkage rate in the TD direction of less than 0.70, which can reduce the shrinkage rate in the TD direction.

[0290] On the other hand, it is clear from Tables 1 to 8 that: according to P / (C×D) 1 / 2 For the glass-reinforced resin molded articles of Comparative Examples 1 to 12 with a value less than 0.46 or greater than 0.99, the shrinkage rate in the MD direction / shrinkage rate in the TD direction is less than 0.50, which means that the anisotropy of the shrinkage rate cannot be reduced, or the shrinkage rate in the TD direction / reference shrinkage rate is greater than 0.70, which means that the shrinkage rate in the TD direction cannot be reduced, or neither the anisotropy of the shrinkage rate nor the shrinkage rate in the TD direction can be reduced.

Claims

1. A glass-reinforced resin molded article, characterized by, Contains: glass reinforcing material ranging from 10.0% to 90.0% by mass relative to the total amount of the glass-reinforced resin molded article, and thermoplastic resin. The glass reinforcement material comprises flat-section glass fibers having a flat cross-sectional shape, wherein the ratio of the major axis to the minor axis of the flat cross-section, i.e., major axis / minor axis, is in the range of 3.0 to 10.

0. The content C of the flat cross-section glass fiber relative to the total amount of the glass-reinforced resin molded article is in the range of 10.0% to 80.0% by mass. The major diameter D of the flat cross-section glass fiber is in the range of 30.0 to 55.0 μm. The proportion P of the glass reinforcing material in the glass-reinforced resin molded article having a length in the range of 50 to 100 μm to the total number of glass reinforcing materials having a length of more than 50 μm is in the range of 4% to 50%. C, D, and P satisfy the following equation (1): 0.46 ≤ P / (C x D) 1 / 2 ≤ 0.99... (1).

2. The glass-reinforced resin molded article according to claim 1, characterized in that, The C is in the range of 20.0 to 70.0% by mass, the D is in the range of 30.0 to 50.0 μm, and the P is in the range of 10 to 40%. The C, D, and P satisfy the following formula (2): 0.54 ≤ P / (C x D) 1 / 2 ≤ 0.72... (2).

3. The glass-reinforced resin molded article according to claim 1, characterized in that, The flat cross-section glass fiber has a flat cross-sectional shape in which the ratio of the major diameter to the minor diameter is in the range of 5.0 to 8.

0.

4. The glass-reinforced resin molded article according to any one of claims 1 to 3, characterized in that, The thermoplastic resin is a thermoplastic resin selected from the group consisting of polycarbonate, polybutylene terephthalate, polyetheretherketone, or polyamide.

5. The glass-strengthened resin molded article according to claim 4, characterized by, The thermoplastic resin is polycarbonate or polyamide.

6. The glass-strengthened resin molded article according to claim 5, characterized by, The thermoplastic resin is polyamide.

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