Fiber reinforced plastic molding

Abstract

[Problem] The present invention addresses the problem of providing a fiber-reinforced resin molded body having excellent dielectric properties, light weight, and high strength. [Solution] A fiber-reinforced resin molded body according to the present invention comprises polyimide fibers and a resin. The fiber-reinforced resin molded body has a dielectric constant of 4.0 or less at a frequency in a range of 5-80 GHz, and has a dielectric loss tangent of 0.02 or less at the same frequency. Note that the fiber-reinforced resin molded body preferably has a tensile strength in the range of 0.5-2.5 GPa, and preferably has a tensile modulus in the range of 25-120 GPa.

Description

[Technical field]

[0001] The present invention relates to a fiber-reinforced resin molding having excellent dielectric properties. [Background technology]

[0002] In recent years, with the further advancement of functionality, speed, and miniaturization of electronic devices such as semiconductor elements and mobile communication devices, the speed of electric signal transmission and reception and the high-density wiring are being promoted. As a result, the band of electric signals in electronic components and information and communication devices such as semiconductor substrates, printed circuit boards, EMC (Epoxy Molding Compound), etc. tend to become higher. The transmission loss of an electric signal is proportional to the dielectric loss tangent of an insulating material and the frequency of the electric signal. Therefore, the higher the frequency of the electric signal, the greater the transmission loss, resulting in attenuation of the electric signal and a decrease in the transmission reliability of the electric signal. In addition, the problem of heat generation due to the conversion of the transmission loss to heat may occur. Therefore, in the high frequency range, an insulating material with a very small dielectric loss tangent is required.

[0003] For example, JP 2016-166347 A proposes a prepreg having a woven fabric and / or nonwoven fabric and a semi-cured product of a resin composition containing an epoxy resin, a curing agent, and a fluororesin filler, which is filled into the woven fabric and / or nonwoven fabric and covers the surface thereof, with the objective of providing a high-frequency circuit board with excellent dielectric properties. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2016-166347 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, in recent years, there has been a demand for even faster transmission speeds of electrical signals, and there is a demand for resin molded articles that not only have a low dielectric constant but also a dielectric loss tangent for reducing transmission loss.

[0006] The present invention has been made in view of the above background, and has an object to provide a fiber-reinforced resin molding that is excellent in dielectric properties, has high strength, and is lightweight. [Means for solving the problem]

[0007] A fiber-reinforced resin molding according to a first aspect of the present invention includes polyimide fibers and a resin. The fiber-reinforced resin molding has a dielectric constant of 4.0 or less in a frequency band of 5 GHz or more and 80 GHz or less, and a dielectric loss tangent of 0.02 or less in the same frequency band.

[0008] In the fiber-reinforced resin molding according to the first aspect of the present invention, it is preferable that the tensile strength is in the range of 0.5 GPa to 2.5 GPa and the tensile modulus is in the range of 25 GPa to 120 GPa.

[0009] In the fiber-reinforced resin molding according to the first aspect of the present invention, the polyimide fibers are preferably obtained by a polymerization reaction between an aromatic tetracarboxylic dianhydride and an aromatic diamine, where the aromatic tetracarboxylic dianhydride is at least one of pyromellitic dianhydride and 3,3',4,4'-biphenyltetracarboxylic dianhydride, and the aromatic diamine is at least one of 4,4'-diaminodiphenyl ether and paraphenylenediamine.

[0010] In the fiber-reinforced resin molding according to the first aspect of the present invention, the tensile modulus of the polyimide fibers is preferably within a range of 100 GPa or more and 170 GPa or less.

[0011] A prepreg according to a second aspect of the present invention is used for producing the above-mentioned fiber-reinforced resin molding. The prepreg includes polyimide fibers and a resin or a resin precursor. The "resin precursor" here refers to a monomer composition (which may contain a crosslinking agent, etc.) before curing, a polymer precursor, etc. Effect of the Invention

[0012] According to the present invention, it is possible to provide a fiber-reinforced resin molding that has excellent dielectric properties, high strength, and is lightweight. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] <Configuration of fiber-reinforced resin molded body according to an embodiment of the present invention> The fiber-reinforced resin molding according to the embodiment of the present invention is mainly made of polyimide fibers and resin.

[0014] The polyimide fiber is preferably obtained by a polymerization reaction between an aromatic tetracarboxylic dianhydride and an aromatic diamine. The aromatic tetracarboxylic dianhydride is preferably at least one of pyromellitic dianhydride and 3,3',4,4'-biphenyltetracarboxylic dianhydride. The aromatic diamine is preferably at least one of 4,4'-diaminodiphenyl ether and paraphenylenediamine.

[0015] In addition, the polyimide fiber may be used in combination with glass fiber, aramid fiber, (liquid crystal) polyester fiber, polyacrylic fiber, carbon fiber, etc., within the scope of the present invention. However, from the viewpoint of dielectric properties such as dielectric constant and dielectric loss tangent in the fiber reinforced resin molding, it is preferable to use only polyimide fiber.

[0016] The above-mentioned polyimide fiber has a tensile modulus of elasticity in the range of preferably 100 GPa or more and 170 GPa or less, and more preferably in the range of 110 GPa or more and 150 GPa or less.

[0017] In addition, in order to increase the strength of the fiber reinforced resin molding according to the embodiment of the present invention, the fiber diameter of the polyimide fiber is preferably in the range of 10 μm to 18 μm. By setting the fiber diameter of the polyimide fiber within this range, the manufacturability of the polyimide fiber can be maintained well, and the rigidity of the polyimide fiber can be made good, and thus the handleability can be maintained, which is preferable. In addition, the volume content of the polyimide fiber in the fiber reinforced resin molding is preferably in the range of 40 volume % to 70 volume %. By setting the volume content of the polyimide fiber within this range, the high strength and high elasticity of the polyimide fiber can be expressed in the fiber reinforced resin molding, and the adhesive performance between the resin and the fiber can be maintained well, and thus the voids can be reduced, which is preferable. In addition, the volume content of the polyimide fiber is more preferably in the range of 45 volume % to 65 volume %.

[0018] Examples of the resins mentioned above include thermosetting resins such as epoxy resins, phenol resins, polyimide resins, unsaturated polyester resins, and polyphenylene ether resins, and thermoplastic resins such as polyimide resins, polyphenylene ether resins, polysulfone resins, fluorine resins such as polytetrafluoroethylene resins and perfluoroalkoxy fluorine resins. Among these resins, epoxy resins and polyimide resins are more preferable because they have a good balance between electrical properties and adhesiveness.

[0019] Examples of the epoxy resins include bisphenol A type epoxy resins, bisphenol F type epoxy resins, bisphenol S type epoxy resins, phenol novolac type epoxy resins, bisphenol A novolac type epoxy resins, cresol novolac type epoxy resins, diaminodiphenylmethane type epoxy resins, and epoxy resins flame-retarded by halogenating some of the hydrogen atoms in the epoxy resin structures, etc. Examples of the curing agents for the epoxy resins include amide-based curing agents such as dicyandiamide and aliphatic polyamide, amine-based curing agents such as diaminodiphenylmethane and triethylenediamine, phenol-based curing agents such as phenol novolac resins and bisphenol A type novolac resins, acid anhydride-based compounds, mercaptan-based compounds, phenol resins, amino resins, etc.

[0020] Moreover, the above-mentioned polyimide resin may be, for example, a polyimide resin made of an aromatic tetracarboxylic dianhydride and an aromatic diamine.Examples of aromatic tetracarboxylic dianhydrides include pyromellitic dianhydride, 1,2,5,6-naphthalenetetracarboxylic dianhydride, 1,4,5,8-naphthalenetetracarboxylic dianhydride, 2,3,6,7-naphthalenetetracarboxylic dianhydride, 2,2',3,3'-biphenyltetracarboxylic dianhydride, 2,3,3'4'-biphenyltetracarboxylic dianhydride, 3,3',4,4'-biphenyltetracarboxylic dianhydride (BPDA), 2,2',3,3'-benzophenonetetracarboxylic dianhydride, 2,3,3',4 '-Benzophenonetetracarboxylic dianhydride, 3,3',4,4'-benzophenonetetracarboxylic dianhydride (BTDA), bis(3,4-dicarboxyphenyl)sulfone dianhydride, bis(2,3-dicarboxyphenyl)methane dianhydride, bis(3,4-dicarboxyphenyl)methane dianhydride, 1,1-bis(2,3-dicarboxyphenyl)ethane dianhydride, 1,1-bis(3,4-dicarboxyphenyl)ethane dianhydride, 2,2-bis[3,4-(dicarboxyphenoxy)phenyl]propane dianhydride (BPA) DA), 4,4'-(hexafluoroisopropylidene)diphthalic anhydride, oxydiphthalic anhydride (ODPA), bis(3,4-dicarboxyphenyl)sulfone dianhydride, bis(3,4-dicarboxyphenyl)sulfoxide dianhydride, thiodiphthalic dianhydride, 3,4,9,10-perylenetetracarboxylic dianhydride, 2,3,6,7-anthracenetetracarboxylic dianhydride, 1,2,7,8-phenanthrenetetracarboxylic dianhydride, 9,9-bis(3,4-dicarboxyphenyl)fluorene dianhydride, and 9,9- Examples of the aromatic tetracarboxylic dianhydride include bis[4-(3,4'-dicarboxyphenoxy)phenyl]fluorene dianhydride, etc., cyclobutane tetracarboxylic dianhydride, 1,2,3,4-cyclopentane tetracarboxylic dianhydride, 2,3,4,5-tetrahydrofuran tetracarboxylic dianhydride, 1,2,4,5-cyclohexane tetracarboxylic dianhydride, 3,4-dicarboxy-1-cyclohexyl succinic dianhydride, and 3,4-dicarboxy-1,2,3,4-tetrahydro-1-naphthalene succinic dianhydride.Examples of aromatic diamines include 4,4'-diaminodiphenyl ether, paraphenylenediamine (PPD), metaphenylenediamine (MPDA), 2,5-diaminotoluene, 2,6-diaminotoluene, 4,4'-diaminobiphenyl, 3,3'-dimethyl-4,4'-diaminobiphenyl, 3,3'-dimethoxy-4,4'-diaminobiphenyl, and 2,2-bis(trifluoromethyl)-4,4'-diaminobiphenyl. , 3,3'-diaminodiphenylmethane, 4,4'-diaminodiphenylmethane (MDA), 2,2-bis-(4-aminophenyl)propane, 3,3'-diaminodiphenyl sulfone (33DDS), 4,4'-diaminodiphenyl sulfone (44DDS), 3,3'-diaminodiphenyl sulfide, 4,4'-diaminodiphenyl sulfide, 3,3'-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether ( 34ODA), 1,5-diaminonaphthalene, 4,4'-diaminodiphenyldiethylsilane, 4,4'-diaminodiphenylsilane, 4,4'-diaminodiphenylethylphosphine oxide, 1,3-bis(3-aminophenoxy)benzene (133APB), 1,3-bis(4-aminophenoxy)benzene (134APB), 1,4-bis(4-aminophenoxy)benzene, bis[4-(3-aminophenoxy)phenyl ]sulfone (BAPSM), bis[4-(4-aminophenoxy)phenyl]sulfone (BAPS), 2,2-bis[4-(4-aminophenoxy)phenyl]propane (BAPP), 2,2-bis(3-aminophenyl)1,1,1,3,3,3-hexafluoropropane, 2,2-bis(4-aminophenyl)1,1,1,3,3,3-hexafluoropropane, 9,9-bis(4-aminophenyl)fluorene, and the like.

[0021] The fiber-reinforced resin molding according to the embodiment of the present invention has a dielectric constant of 4.0 or less and a dielectric loss tangent of 0.02 or less in a frequency band of 5 GHz or more and 80 GHz or less. The dielectric constant is preferably in the range of 1.0 to 4.0 and the dielectric loss tangent is preferably in the range of 0 to 0.02. The dielectric constant is more preferably in the range of 1.0 to 3.5 and the dielectric loss tangent is more preferably in the range of 0 to 0.015. This is because the transmission speed can be increased.

[0022] The fiber-reinforced resin molding according to the embodiment of the present invention has a dielectric constant and dielectric tangent that are independent of frequency, even in a wide frequency band of 5 GHz or more and 80 GHz or less. Therefore, it is not necessary to adjust the dielectric constant, etc., and the molding can be suitably used in fields such as housings or parts for satellite mobile phones and next-generation mobile phones (1.0 GHz to 2.5 GHz), housings or parts for network-compatible terminals (personal computers, mobile phones, portable games, tablets, portable music players), housings or parts for wireless LAN (5 GHz to 60 GHz), and housings or parts for wireless communication: AWA (22 GHz to 45 GHz).

[0023] In addition, the tensile strength and tensile modulus of the fiber reinforced resin molded body according to the embodiment of the present invention depend on the fiber direction and fiber volume content contained in the fiber reinforced resin molded body. Therefore, in order to adjust the tensile strength and tensile modulus of the fiber reinforced resin molded body, it is necessary to appropriately adjust the fiber direction and fiber volume content contained in the fiber reinforced resin molded body. For example, if the orientation directions of the fibers in the fiber reinforced resin molded body are all in the same direction, the tensile strength of the fiber reinforced resin molded body in the fiber direction (longitudinal direction of the fibers) is preferably in the range of 0.5 GPa to 2.5 GPa, more preferably in the range of 0.75 GPa to 2.5 GPa, and even more preferably in the range of 1.0 GPa to 2.5 GPa. Under the same conditions, the tensile modulus of the fiber reinforced resin molded body is preferably in the range of 25 GPa to 120 GPa, more preferably in the range of 30 GPa to 120 GPa, and even more preferably in the range of 35 GPa to 120 GPa.

[0024] <Method of manufacturing a fiber-reinforced resin molding according to an embodiment of the present invention> The fiber-reinforced resin molded body according to the embodiment of the present invention can be molded by either a method that uses a prepreg or a method that does not use a prepreg. The polyimide fiber may be a long fiber or a short fiber cut to an arbitrary length. As a method that uses a prepreg, for example, a method in which a plurality of prepregs in which a fiber base material made of the above-mentioned fibers is impregnated with a resin is laminated, and then the laminate is heated and pressurized to harden it, etc. In such a method, as the form of the fiber base material, a so-called UD sheet in which fibers are arranged in one direction, or a woven or knitted product of a long fiber filament yarn can be preferably used. Examples of the woven fabric include a bidirectional woven fabric, a multiaxial woven fabric such as a triaxial woven fabric, etc. Examples of the knitted fabric include a weft knitting machine such as a circular knitting machine, and a warp knitting machine such as a tricot knitting machine, a raschel knitting machine, or a Milanese knitting machine. Examples of methods that do not involve the use of a prepreg include a method in which a varnish containing the above-mentioned resin is prepared, the varnish is impregnated into a fiber substrate, and then the fiber substrate is cured by heating and pressurization. Specifically, examples of such methods include the hand lay-up method, the filament winding method, and the pultrusion method.

[0025] <Examples and Comparative Examples> Examples and comparative examples are described below in detail, but the present invention is not limited to these examples. EXAMPLES

[0026] 1. Preparation of Polyimide Fibers 136g of paraphenylenediamine (PPD) and 2,224g of N-methylpyrrolidone were charged into a reaction vessel, and PPD was dissolved in N-methylpyrrolidone. Next, 259.0g of 3,3',4,4'-biphenyltetracarboxylic dianhydride (BPDA) and 82.30g of pyromellitic dianhydride (PMDA) were charged into the reaction vessel, and PMDA and PPD were polymerized at room temperature. As a result, a polyimide precursor solution with a concentration of 17.7% by weight was obtained. Next, a solution in which 21.41g of 1,3-diazole was dissolved in 40.41g of N-methylpyrrolidone was added to this polyimide precursor solution to prepare a polyimide precursor solution for spinning. Next, using a spinning discharger, this polyimide precursor solution for spinning was discharged into a coagulation bath containing water as the main component to obtain a polyimide precursor fiber. Next, this polyimide precursor fiber was washed with water, stretched, and heated to obtain a polyimide fiber.

[0027] The fiber diameter and tensile properties of the obtained polyimide fiber were measured by the following methods.

[0028] (1) Fiber diameter The fineness of the polyimide fiber obtained as described above was measured using an auto-blow type fineness measuring instrument DC21 manufactured by Search Co., Ltd. The fiber diameter of the polyimide fiber was calculated from the measured fineness and the specific gravity of the polyimide fiber, and the value was 14 μm.

[0029] (2) Tensile properties The tensile modulus (cN / dtex) and tensile strength (cN / dtex) of the polyimide fiber obtained as described above were measured using a method in accordance with "JISR7606." The tensile modulus (GPa) of the polyimide fiber was calculated using the conversion formula of modulus (cN / dtex) x specific gravity ÷ 10. Meanwhile, the tensile strength (GPa) of the polyimide fiber was calculated using the conversion formula of strength (cN / dtex) x specific gravity ÷ 10. As a result, the tensile modulus of the polyimide fiber was 137 GPa, and the tensile strength was 3.1 GPa.

[0030] 2. Fabrication of Fiber-Reinforced Plastic Moldings The polyimide fiber obtained as described above had a fiber weight of 56 g / m 2 After the fibers were aligned in a certain direction, the aligned polyimide fibers were impregnated with an epoxy resin composition containing 100% by weight of an epoxy base agent (JER828 manufactured by Mitsubishi Chemical Corporation) and 8% by weight of a curing agent (ADEKA Hardener EH-3636AS manufactured by ADEKA Corporation), and the composition-impregnated polyimide fibers were heated at 120°C for 30 minutes in a thermostatic chamber to produce a UD prepreg. Next, the obtained UD prepreg was sandwiched between a plate-shaped mold and bagged, and then the UD prepreg was heated and pressurized at 130°C for 90 minutes in an autoclave at 6 atm to obtain a fiber-reinforced resin molded body. At this time, the temperature rise and fall rate of the autoclave was 2°C / min. The thickness of the obtained fiber-reinforced resin molded body was 65 μm, and the volume content of the polyimide fiber was 56%.

[0031] The volume fraction Vf of the polyimide fiber was calculated by the following formula (1). Vf = Faw / ρ / T × 100 (1) Here, Faw is the basis weight of the polyimide fiber (g / m 2 ) and ρ is the density of the polyimide fiber (g / cm 3 ) and T is the thickness (μm) of the fiber-reinforced resin molding. Here, the density of the polyimide fiber is 1.5 g / cm 3 It is.

[0032] The dielectric constant, dielectric tangent and tensile properties of the obtained fiber-reinforced resin molding were measured by the following methods.

[0033] (1) Measurement of dielectric constant and dielectric loss tangent in the frequency range from 5GHz to 80GHz The dielectric constant (ε) and dielectric loss tangent of the fiber-reinforced resin compact in the frequency band of 5 GHz to 80 GHz were measured using a vector network analyzer (Vector Network Analyzer N5290A manufactured by Keysight Technologies), a split post resonator (manufactured by Keysight Technologies), and a split cylinder resonator (manufactured by EM Labs, Inc.). The dielectric constant at a frequency of 5 GHz was 3.35, the dielectric constant at a frequency of 10 GHz was 3.38, the dielectric constant at a frequency of 20 GHz was 3.42, the dielectric constant at a frequency of 28 GHz was 3.38, the dielectric constant at a frequency of 40 GHz was 3.36, the dielectric constant at a frequency of 60 GHz was 3.33, and the dielectric constant at a frequency of 80 GHz was 3.30. In addition, the dielectric tangent at a frequency of 5 GHz was 0.0123, the dielectric tangent at a frequency of 10 GHz was 0.0130, the dielectric tangent at a frequency of 20 GHz was 0.0143, the dielectric tangent at a frequency of 28 GHz was 0.0137, the dielectric tangent at a frequency of 40 GHz was 0.0140, the dielectric tangent at a frequency of 60 GHz was 0.0139, and the dielectric tangent at a frequency of 80 GHz was 0.0132.

[0034] (2) Tensile properties Using a precision universal testing machine (AGS-10kNG, manufactured by Shimadzu Corporation), the obtained fiber-reinforced resin molding was pulled in the fiber direction (longitudinal direction of the fibers) of the fiber-reinforced resin molding at a pulling speed of 2 mm / min to measure the tensile modulus and tensile strength of the fiber-reinforced resin molding. The tensile strength of the fiber-reinforced resin molding was 1.45 GPa and the tensile modulus of elasticity was 41.8 GPa. EXAMPLES

[0035] A fiber-reinforced resin molding was obtained in the same manner as in Example 1, except that the fiber-reinforced resin molding was produced so that the volume content of polyimide fibers was 60%.

[0036] The thickness of the obtained fiber reinforced resin molding was 62 μm. In addition, the dielectric constant and dielectric loss tangent of the fiber reinforced resin molding in the frequency band of 5 GHz to 80 GHz and the tensile properties of the fiber reinforced resin molding were measured by the same method as that described in Example 1. The dielectric constant at a frequency of 5 GHz was 3.48, the dielectric constant at a frequency of 10 GHz was 3.48, the dielectric constant at a frequency of 20 GHz was 3.46, the dielectric constant at a frequency of 28 GHz was 3.47, the dielectric constant at a frequency of 40 GHz was 3.42, the dielectric constant at a frequency of 60 GHz was 3.39, and the dielectric constant at a frequency of 80 GHz was 3.38. The dielectric loss tangent at a frequency of 5 GHz was 0.0120, the dielectric loss tangent at a frequency of 10 GHz was 0.0127, the dielectric loss tangent at a frequency of 20 GHz was 0.0129, the dielectric loss tangent at a frequency of 28 GHz was 0.0125, the dielectric loss tangent at a frequency of 40 GHz was 0.0124, the dielectric loss tangent at a frequency of 60 GHz was 0.0127, and the dielectric loss tangent at a frequency of 80 GHz was 0.0114. The tensile strength of the fiber-reinforced resin molding was 1.55 GPa, and the tensile modulus was 44.8 GPa. EXAMPLES

[0037] A fiber-reinforced resin molding was obtained in the same manner as in Example 1, except that the fiber-reinforced resin molding was produced so that the volume content of polyimide fibers was 40%.

[0038] The thickness of the obtained fiber reinforced resin molding was 93 μm. In addition, the dielectric constant and dielectric loss tangent of the fiber reinforced resin molding in the frequency band of 5 GHz to 80 GHz and the tensile properties of the fiber reinforced resin molding were measured by the same method as that described in Example 1, and the dielectric constant at 5 GHz was 3.32, the dielectric constant at a frequency of 10 GHz was 3.34, the dielectric constant at a frequency of 20 GHz was 3.31, the dielectric constant at a frequency of 28 GHz was 3.18, the dielectric constant at a frequency of 40 GHz was 3.22, the dielectric constant at a frequency of 60 GHz was 3.20, and the dielectric constant at a frequency of 80 GHz was 3.12. The dielectric loss tangent at a frequency of 5 GHz was 0.0198, the dielectric loss tangent at a frequency of 10 GHz was 0.0189, the dielectric loss tangent at a frequency of 20 GHz was 0.0197, the dielectric loss tangent at a frequency of 28 GHz was 0.0194, the dielectric loss tangent at a frequency of 40 GHz was 0.0174, the dielectric loss tangent at a frequency of 60 GHz was 0.0165, and the dielectric loss tangent at a frequency of 80 GHz was 0.0194. The tensile strength of the fiber-reinforced resin molding was 0.60 GPa, and the tensile modulus was 29.8 GPa. EXAMPLES

[0039] A fiber-reinforced resin molding was obtained in the same manner as in Example 1, except that the fiber-reinforced resin molding was produced so that the volume content of polyimide fibers was 58%.

[0040] The thickness of the obtained fiber reinforced resin molding was 64 μm. In addition, the dielectric constant and dielectric loss tangent of the fiber reinforced resin molding in the frequency band of 5 GHz to 80 GHz and the tensile properties of the fiber reinforced resin molding were measured by the same method as that described in Example 1, and the dielectric constant at a frequency of 5 GHz was 3.47, the dielectric constant at a frequency of 10 GHz was 3.46, the dielectric constant at a frequency of 20 GHz was 3.45, the dielectric constant at a frequency of 28 GHz was 3.45, the dielectric constant at a frequency of 40 GHz was 3.43, the dielectric constant at a frequency of 60 GHz was 3.40, and the dielectric constant at a frequency of 80 GHz was 3.39. The dielectric loss tangent at a frequency of 5 GHz was 0.0137, the dielectric loss tangent at a frequency of 10 GHz was 0.0138, the dielectric loss tangent at a frequency of 20 GHz was 0.0138, the dielectric loss tangent at a frequency of 28 GHz was 0.0134, the dielectric loss tangent at a frequency of 40 GHz was 0.0137, the dielectric loss tangent at a frequency of 60 GHz was 0.0155, and the dielectric loss tangent at a frequency of 80 GHz was 0.0133. The tensile strength of the fiber-reinforced resin molding was 1.50 GPa, and the tensile modulus was 43.1 GPa. EXAMPLES

[0041] A fiber-reinforced resin molding was obtained in the same manner as in Example 1, except that the fiber-reinforced resin molding was produced so that the volume content of polyimide fibers was 45%.

[0042] The thickness of the obtained fiber reinforced resin molding was 83 μm. In addition, the dielectric constant and dielectric loss tangent of the fiber reinforced resin molding in the frequency band of 5 GHz to 80 GHz and the tensile properties of the fiber reinforced resin molding were measured by the same method as that described in Example 1. The dielectric constant at a frequency of 5 GHz was 3.34, the dielectric constant at a frequency of 10 GHz was 3.33, the dielectric constant at a frequency of 20 GHz was 3.35, the dielectric constant at a frequency of 28 GHz was 3.25, the dielectric constant at a frequency of 40 GHz was 3.27, the dielectric constant at a frequency of 60 GHz was 3.25, and the dielectric constant at a frequency of 80 GHz was 3.19. The dielectric loss tangent at a frequency of 5 GHz was 0.0193, the dielectric loss tangent at a frequency of 10 GHz was 0.0195, the dielectric loss tangent at a frequency of 20 GHz was 0.0182, the dielectric loss tangent at a frequency of 28 GHz was 0.0179, the dielectric loss tangent at a frequency of 40 GHz was 0.0190, the dielectric loss tangent at a frequency of 60 GHz was 0.0154, and the dielectric loss tangent at a frequency of 80 GHz was 0.0169. The tensile strength of the fiber-reinforced resin molding was 0.75 GPa, and the tensile modulus was 32.1 GPa.

[0043] Comparative Example 1 The polyimide fiber was replaced with aramid fiber (Kevlar (registered trademark) 49 manufactured by Toray DuPont Co., Ltd., fiber diameter: 12 μm, tensile strength: 3.0 GPa, tensile modulus: 112 GPa) and the fiber basis weight was increased to 54 g / m 2 A fiber-reinforced resin molding was obtained in the same manner as in Example 1, except that the above-mentioned was used.

[0044] The thickness of the obtained fiber reinforced resin molded body was 62 μm, and the volume content of the aramid fiber was 56.3%. In addition, the dielectric constant and dielectric tangent of the fiber reinforced resin molded body in the frequency band of 5 GHz to 80 GHz and the tensile properties of the fiber reinforced resin molded body were measured by the same method as that described in Example 1. The dielectric constant at a frequency of 5 GHz was 3.63, the dielectric constant at a frequency of 10 GHz was 3.63, the dielectric constant at a frequency of 20 GHz was 3.58, and the dielectric constant at a frequency of 28 GHz was 3.56. In addition, the dielectric tangent at a frequency of 5 GHz was 0.0201, the dielectric tangent at a frequency of 10 GHz was 0.0210, the dielectric tangent at a frequency of 20 GHz was 0.0226, and the dielectric tangent at a frequency of 28 GHz was 0.0223. The dielectric constant and dielectric tangent in the frequency band of 40 GHz or more could not be measured due to large loss. The fiber reinforced resin molding had a tensile strength of 1.53 GPa and a tensile modulus of elasticity of 54.1 GPa.

[0045] Comparative Example 2 A fiber-reinforced resin molding was obtained in the same manner as in Example 1, except that the polyimide fiber was replaced with glass fiber (ECG150 1 / 0 manufactured by Nitto Boseki Co., Ltd.).

[0046] The thickness of the obtained fiber reinforced resin molded body was 70 μm, and the volume content of the glass fiber was 55.7%. In addition, the dielectric constant and dielectric tangent of the fiber reinforced resin molded body in the frequency band of 5 GHz to 80 GHz and the tensile properties of the fiber reinforced resin molded body were measured by the same method as that described in Example 1. The dielectric constant at a frequency of 5 GHz was 4.85, the dielectric constant at a frequency of 10 GHz was 5.03, the dielectric constant at a frequency of 20 GHz was 4.77, the dielectric constant at a frequency of 28 GHz was 4.78, and the dielectric constant at a frequency of 40 GHz was 4.74. In addition, the dielectric tangent at a frequency of 5 GHz was 0.0148, the dielectric tangent at a frequency of 10 GHz was 0.0162, the dielectric tangent at a frequency of 20 GHz was 0.0199, the dielectric tangent at a frequency of 28 GHz was 0.0238, and the dielectric tangent at a frequency of 40 GHz was 0.0221. In addition, the dielectric constant and dielectric loss tangent could not be measured in the frequency band above 60 GHz due to the large loss. The tensile strength of the fiber-reinforced resin molding was 1.42 GPa, and the tensile modulus of elasticity was 33.2 GPa.

[0047] Comparative Example 3 A fiber-reinforced resin molding was obtained in the same manner as in Example 1, except that the UD prepreg was replaced with a unidirectional carbon fiber prepreg (P3252S-10 manufactured by Toray Industries, Inc.).

[0048] The thickness of the obtained fiber reinforced resin molding was 94 μm, and the volume content of the carbon fiber was 59%. In addition, an attempt was made to measure the dielectric constant and dielectric loss tangent of the fiber reinforced resin molding in the frequency band of 5 GHz to 80 GHz by the same method as that described in Example 1, but since the fiber reinforced resin molding was a conductor, the dielectric constant and dielectric loss tangent could not be measured. In addition, when the tensile properties of the fiber reinforced resin molding were measured by the same method as that described in Example 1, the tensile strength was 2.46 GPa and the tensile modulus was 117.2 GPa.

Claims

1. A non-thermoplastic polyimide fiber obtained by a polymerization reaction of pyromellitic dianhydride, 3,3',4,4'-biphenyltetracarboxylic dianhydride, and paraphenylenediamine, and having a volume content in the range of 56 volume % to 70 volume %, Thermosetting resin and Equipped with The dielectric constant in the frequency band of 5 GHz or more and 80 GHz or less is 3.5 or less, The dielectric loss tangent in the above frequency band is 0.015 or less. Fiber reinforced resin molding.

2. The tensile strength is in the range of 0.5 GPa to 2.5 GPa, The tensile modulus is in the range of 25 GPa or more and 120 GPa or less. The fiber-reinforced resin molding according to claim 1.

3. The tensile modulus of the polyimide fiber is in the range of 100 GPa to 170 GPa. The fiber-reinforced resin molding according to claim 1 or 2.

4. The fiber diameter of the polyimide fiber is in the range of 10 μm to 18 μm. The fiber-reinforced resin molding according to any one of claims 1 to 3.

5. A prepreg used for producing the fiber-reinforced resin molding according to any one of claims 1 to 4, a non-thermoplastic polyimide fiber obtained by a polymerization reaction of pyromellitic dianhydride, 3,3',4,4'-biphenyltetracarboxylic dianhydride, and paraphenylenediamine, the volume content of which is in the range of 56 volume % or more and 70 volume % or less; Precursors of thermosetting resins A prepreg comprising: