Fiber-reinforced resin molding material and molded article

Abstract

Provided is a fiber-reinforced resin molding material containing a carbon fiber (A) and a thermoplastic resin (B). The fiber-reinforced resin molding material contains 10-40 parts by weight of the carbon fiber (A) and 60-90 parts by weight of the thermoplastic resin (B) with respect to 100 parts by weight in total of the carbon fiber (A) and the thermoplastic resin (B). The carbon fiber (A) contains carbon fibers having a fiber length of 3-10 mm and oriented in the longitudinal direction of a molding material. The fiber-reinforced resin molding material contains a compound (C) filling the spaces between the carbon fibers. The thermoplastic resin (B) contains a recycled resin. The molding material of the present invention has excellent fluidity during molding while having a recycled resin, and can easily produce a molded article having excellent mechanical properties, and thus can be applied to a wide range of molding methods.

Description

Fiber-reinforced resin molding materials and molded products

[0001] The present invention relates to a molding material containing carbon fibers as reinforcing fibers and a thermoplastic resin, and to a molded article containing carbon fibers and a thermoplastic resin.

[0002] Fiber-reinforced resins, which are made from reinforcing fibers and thermoplastic resins, are widely used in various industrial applications due to their light weight and excellent mechanical properties. In particular, molded products made from pelletized molding materials using economical and productive molding methods such as injection molding and stamping molding are frequently used for parts and housings of electrical and electronic devices such as automobile parts, personal computers, office automation (OA) equipment, audiovisual (AV) equipment, mobile phones, telephones, home appliances, and toys.

[0003] In particular, fiber-reinforced resins that use carbon fiber as the reinforcing fiber are frequently used when high levels of lightness and mechanical properties are required, because the excellent specific strength of carbon fiber allows them to exhibit high tensile strength and elastic modulus despite their light weight.

[0004] Patent Document 1 discloses that a molded article with excellent mechanical properties can be obtained by injection molding a molding material composed of reinforcing fibers and a thermoplastic resin. Patent Document 2 discloses that a molded article with improved mechanical properties and appearance quality can be obtained by injection molding thermoplastic resin pellets that combine two types of reinforcing fibers, one having a long fiber length and the other having a short fiber length, with a thermoplastic resin. Patent Document 3 further discloses that a molded article with excellent mechanical properties can be obtained by injection molding a molding material that combines carbon fiber as the reinforcing fiber with a recycled resin.

[0005] International Publication No. 2021 / 124726 Japanese Patent Application Laid-Open No. 2006-181776 Japanese Patent Application Laid-Open No. 2001-113528

[0006] However, in recent years, molded products have become smaller, thinner, and more complex, requiring molding materials to have high moldability. At the same time, growing environmental awareness has led to a demand for the use of recycled raw materials, such as recycled resins, while maintaining mechanical properties.

[0007] In the past, there has been a movement to utilize recycled resins by mixing them with fiber-reinforced resin materials, but recycled resins have inferior physical properties compared to virgin resins, making it difficult to use them in large quantities.In addition, although material recycled resins are made by sorting the recovered raw materials, their properties are affected by factors such as the usage history of the raw materials, and even when used in fiber-reinforced resin molding materials, they do not exhibit stable mechanical properties, making it difficult to use recycled resins in large quantities.

[0008] In view of the above problems and needs, an object of the present invention is to provide a fiber-reinforced resin molding material that contains recycled resin and has excellent moldability and mechanical properties.

[0009] In order to solve the above problems, the present invention has the following configuration: (1) A fiber-reinforced resin molding material containing carbon fibers (A) and a thermoplastic resin (B), the material containing 10 to 40 parts by weight of carbon fibers (A) and 60 to 90 parts by weight of thermoplastic resin (B) relative to a total of 100 parts by weight of the carbon fibers (A) and the thermoplastic resin (B), the carbon fibers (A) having a fiber length of 3 mm or more and 10 mm or less and including carbon fibers oriented in the longitudinal direction of the molding material, the fiber-reinforced resin molding material containing a compound (C) present in a state of filling the spaces between the carbon fibers, and the thermoplastic resin (B) including a recycled resin. (2) The fiber-reinforced resin molding material according to (1), characterized in that the carbon fiber (A) comprises a carbon fiber (A-1) and a carbon fiber (A-2), the carbon fiber (A-1) having a fiber length of 3 mm or more and 10 mm or less and being oriented in the longitudinal direction of the molding material, and the carbon fiber (A-2) having a fiber length of 0.1 mm or more and 0.4 mm or less. (3) The fiber-reinforced resin molding material according to (2), characterized in that the fiber-reinforced resin molding material comprises a long-fiber-reinforced resin molding material (X) and a short-fiber-reinforced resin molding material (Y), the long-fiber-reinforced resin molding material (X) comprising the carbon fiber (A-1), a thermoplastic resin (B-1), and a flame retardant (D), and the compound (C) present in a state of filling the spaces between the carbon fibers (A-1), the short-fiber-reinforced resin molding material (Y) comprising the carbon fiber (A-2), a thermoplastic resin (B-2), and a flame retardant (D), and the thermoplastic resin (B-2) comprising a recycled resin. (4) The fiber-reinforced resin molding material according to (3), characterized in that the short fiber-reinforced resin molding material (Y) contains a polytetrafluoroethylene resin. (5) The fiber-reinforced resin molding material according to any one of (2) to (4), characterized in that the carbon fiber (A-2) contains recycled carbon fiber. (6) The fiber-reinforced resin molding material according to any one of (3) to (5), characterized in that the flame retardant (D) is a condensed phosphate ester. (7) The fiber-reinforced resin molding material according to any one of (1) to (6), characterized in that the thermoplastic resin (B) contains a polycarbonate resin. (8) The fiber-reinforced resin molding material according to any one of (1) to (6), characterized in that the thermoplastic resin (B) contains a polyamide resin.(9) The fiber-reinforced resin molding material according to any one of (1) to (8), wherein the compound (C) has a lower melt viscosity than the thermoplastic resin (B). (10) The fiber-reinforced resin molding material according to any one of (3) to (9), wherein the long-fiber-reinforced resin molding material (X) contains a sulfur-based antioxidant and a hindered phenol-based antioxidant. (11) The fiber-reinforced resin molding material according to any one of (7), (9), and (10), wherein the polycarbonate resin is a recycled polycarbonate resin. (12) The fiber-reinforced resin molding material according to (11), wherein the recycled polycarbonate resin is a mixture of a polycarbonate resin having a weight-average molecular weight of 28,000 to 45,000 and a polycarbonate resin having a weight-average molecular weight of 50,000 to 60,000. (13) The fiber-reinforced resin molding material according to (12), wherein the recycled polycarbonate resin is a mixture of a polycarbonate resin having a weight-average molecular weight of 28,000 to 45,000 and a polycarbonate resin having a weight-average molecular weight of 50,000 to 60,000, in a weight ratio of 5 / 95 to 40 / 60. (14) A molded product obtained by molding the fiber-reinforced resin molding material according to any one of (1) to (13).

[0010] The molding material of the present invention contains recycled resin, yet has excellent fluidity during molding processing, and can easily produce molded articles with excellent mechanical properties. Therefore, it can be applied not only to molding methods such as injection molding, transfer molding, blow molding, and insert molding, but also to a wide range of molding methods such as plunger molding, press molding, and stamping molding.

[0011] The molded articles of the present invention have excellent flowability during molding and maintain mechanical properties despite containing recycled resins, and can be used for automotive parts such as thrust washers, oil filters, seals, bearings, gears, cylinder head covers, bearing retainers, intake manifolds, and pedals; semiconductor and liquid crystal manufacturing equipment parts such as silicon wafer carriers, IC chip trays, electrolytic capacitor trays, and insulating films; industrial machinery parts such as compressor parts and aircraft cabin interior parts; medical equipment parts such as sterilization instruments, columns, and piping; food and beverage manufacturing equipment parts; and electrical and electronic equipment parts and housings for personal computers, office automation equipment, audiovisual equipment, mobile phones, telephones, home appliances, and toys. Using the molding material of the present invention, thin-walled molded articles of 0.5 to 2 mm can be obtained relatively easily, and the carbon fibers used as reinforcing fibers are conductive, which can impart electromagnetic wave shielding properties, making them suitable for electrical and electronic equipment parts and housings.

[0012] DETAILED DESCRIPTION OF THE INVENTION The fiber-reinforced resin molding material of the present invention (hereinafter, sometimes simply referred to as "molding material") is a molding material that satisfies the following requirements.

[0013] The molding material of the present invention is a molding material containing at least carbon fiber (A) and thermoplastic resin (B), and contains 10 to 40 parts by weight of carbon fiber (A) and 60 to 90 parts by weight of thermoplastic resin (B) relative to a total of 100 parts by weight of carbon fiber (A) and thermoplastic resin (B), the carbon fiber (A) has a fiber length of 3 mm or more and 10 mm or less and contains carbon fibers oriented in the longitudinal direction of the molding material, the fiber-reinforced resin molding material contains compound (C) present in a state of filling the spaces between the carbon fibers, and the thermoplastic resin (B) contains recycled resin.

[0014] By including the carbon fiber (A), the fiber length of the carbon fiber can be kept long while maintaining fluidity, and a molded article exhibiting mechanical properties equivalent to those of virgin resin can be obtained.

[0015] [Carbon Fiber (A)] The carbon fiber (A) of the present invention will be described. The type of carbon fiber (A) of the present invention is not particularly limited, and carbon fibers such as PAN (polyacrylonitrile), pitch, and rayon are preferably used. In particular, from the viewpoint of high strength, carbon fibers having a tensile strength of 3,000 MPa or more are preferred, more preferably 4,000 MPa or more. From the viewpoint of high modulus of elasticity, carbon fibers having a tensile modulus of 200 GPa or more are preferred, more preferably 300 GPa or more. The fiber diameter of the carbon fiber (A) is preferably 3 to 20 μm, more preferably 4 to 15 μm, and even more preferably 4.2 to 13 μm. If the fiber diameter is less than 3 μm, the number of fiber entanglements in the molded article will increase significantly, reducing fluidity and impairing the thinness and surface appearance of the molded article. Furthermore, recycled carbon fibers are preferably used from the viewpoints of the economic efficiency and environmental impact of the resulting molded article. Here, recycled carbon fibers are carbon fibers that are recovered and reused from molded articles containing used carbon fibers, or from process waste materials of resin compositions or molded articles containing carbon fibers.

[0016] It is preferable that a sizing agent is attached to the carbon fiber (A). By attaching the sizing agent to the carbon fiber (A), it is possible to improve the handleability during transport of the carbon fiber, the processability during the production of the molding material, and the mechanical properties and appearance properties of the molded product. There are no particular limitations on the type of sizing agent, but one or more types of sizing agents such as epoxy resins, urethane resins, acrylic resins, and various thermoplastic resins can be used in combination.

[0017] The amount of carbon fiber (A) is preferably 10 to 40 parts by weight per 100 parts by weight of the total of carbon fiber (A) and thermoplastic resin (B), more preferably 10 to 35 parts by weight, and even more preferably 10 to 30 parts by weight. If the amount is less than 10 parts by weight, the mechanical properties may be insufficient, while if the amount is more than 40 parts by weight, the flowability during molding may be insufficient and the carbon fiber (A) may fall off during cutting, resulting in a deterioration in the surface appearance.

[0018] The carbon fibers (A) in the molding material preferably have a fiber length of 3 mm or more and 10 mm or less and contain carbon fibers oriented in the longitudinal direction of the molding material, and more preferably contain fibers having a length of 5 to 9 mm.

[0019] The carbon fiber (A) may include two types of carbon fiber, namely, carbon fiber (A-1) and carbon fiber (A-2). Examples of the types of carbon fiber (A-1) and carbon fiber (A-2) include the carbon fibers described in the description of carbon fiber (A).

[0020] The carbon fiber (A-1) is preferably aligned in the longitudinal direction of the molding material, and the length of the carbon fiber is preferably 3 mm or more and 10 mm or less. Furthermore, it is preferable that the length of the carbon fiber (A-1) is substantially the same as the length of the molding material. "Aligned in the longitudinal direction of the molding material" here refers to a state in which the longitudinal axis of the carbon fiber (A-1) and the longitudinal axis of the molding material are oriented in the same direction, and the angular deviation between the axes is preferably 20° or less, more preferably 10° or less, and even more preferably 5° or less. Furthermore, "substantially the same length" means, for example, that in a pellet-shaped molding material, the carbon fiber (A-1) is not cut midway inside the pellet, and carbon fiber (A-1) significantly shorter than the total length of the pellet is not substantially contained. The total length of the pellet refers to the length in the orientation direction of the carbon fiber (A-1) in the pellet. By having the carbon fiber (A-1) have substantially the same length as the molding material, the carbon fiber length in the molded product can be increased, resulting in excellent mechanical properties and dimensional accuracy.

[0021] The carbon fiber (A-2) preferably has a fiber length of 0.1 mm or more and 0.4 mm or less, more preferably 0.2 to 0.4 mm. If the fiber length of the carbon fiber (A-2) is less than 0.1 mm, the mechanical properties of the molded article may be insufficient. On the other hand, if the fiber length of the carbon fiber (A-2) is 0.4 mm or more, the flowability during molding may be insufficient.

[0022] Here, the "fiber length of carbon fibers" in the present invention refers to the number average fiber length calculated from the following formula 1: Fiber length of carbon fibers = Σ(Li) / 1,000 (Formula 1), where Li is the length of each carbon fiber (mm).

[0023] The fiber length of the carbon fibers can be measured by the following method. Using an optical microscope equipped with a hot stage, appropriate test pieces are extracted from the molding material, and heated while sandwiched between glass plates on a hot stage appropriately set at 150 to 500°C, matching the melting temperature of the thermoplastic resin (B) used. The carbon fibers (A) are uniformly dispersed in a film-like form, and the thermoplastic resin (B) is observed in a molten state using an optical microscope (50 to 200 magnification). The fiber lengths of 1,000 randomly selected carbon fibers are measured, and the fiber length is calculated using the above formula 1. Alternatively, test pieces extracted from the molding material are placed in a solvent that dissolves the thermoplastic resin (B), and appropriately heated to prepare a solution in which the carbon fibers are uniformly dispersed. The solution is then filtered, and the carbon fibers dispersed on the filter paper are observed using an optical microscope (50 to 200 magnification). The fiber lengths of 1,000 randomly selected carbon fibers are measured, and the fiber length is calculated using the above formula 1. The filter paper used here may be quantitative filter paper (model number: No. 5C) manufactured by Advantec Co., Ltd.

[0024] From the viewpoint of reducing waste, it is preferable to use recycled carbon fiber for the carbon fiber (A-2) out of the carbon fiber (A-1) and the carbon fiber (A-2). As the recycled carbon fiber, fibers produced by a known manufacturing method can be used, and for example, a method of obtaining recycled carbon fiber by carrying out the following steps (a) to (c) can be mentioned. (a) A crushing step of crushing a fiber-reinforced resin waste material to prepare crushed pieces having a predetermined fiber length; (b) A pyrolysis treatment step of heating the crushed pieces while supplying them to a pyrolysis furnace in a fixed amount, removing the matrix resin component, and obtaining a pyrolyzed product; and (c) A classification step of classifying the pyrolyzed product according to fiber length to obtain recycled carbon fiber.

[0025] A sizing agent may be added to the recycled carbon fibers after the classification step.

[0026] The recycled carbon fibers are preferably contained in an amount of 10 to 80 parts by weight, more preferably 15 to 70 parts by weight, per 100 parts by weight of the carbon fibers (A).

[0027] The carbon fiber (A-2) may be in a dispersed state of single filaments or may partially contain bundled fibers. The inclusion of bundled fibers increases the impact strength of molded articles compared to dispersed single filaments, but the carbon fibers may fall off during cutting, resulting in poor surface appearance. The dispersed state of single filaments is preferred, which, compared to the case where bundled fibers are included, results in slightly improved impact strength, but excellent surface appearance and mechanical properties of molded articles.

[0028] Preferably, the carbon fiber (A-1) is a carbon fiber contained in a molding material (X) described later, and the carbon fiber (A-2) is a carbon fiber contained in a molding material (Y) described later.

[0029] [Thermoplastic Resin (B)] In the present invention, the thermoplastic resin (B) preferably has a molding temperature (melting temperature) of 200 to 450°C, and examples thereof include polyolefin resins, polystyrene resins, polyamide resins, halogenated vinyl resins, polyacetal resins, saturated polyester resins, polycarbonate resins, polyarylsulfone resins, polyarylketone resins, polyphenylene ether resins, polyphenylene sulfide resins, polyaryletherketone resins, polyethersulfone resins, polyphenylene sulfide sulfone resins, and polyarylate resins, and two or more of these can also be used. Among the thermoplastic resins, polyolefin resins, polyamide resins, polycarbonate resins, and polyarylene sulfide resins are more preferred because they are lightweight and have an excellent balance of mechanical properties and moldability.

[0030] From the viewpoint of reducing waste, the thermoplastic resin (B) preferably contains a recycled resin obtained through material recycling or chemical recycling, and from the viewpoint of environmental load, it is more preferable that the thermoplastic resin (B) contains a recycled resin obtained through material recycling.

[0031] The term "polyolefin resin" as used herein includes both unmodified and modified polyolefins. For example, an unmodified polypropylene resin is specifically a propylene homopolymer or a copolymer of propylene with at least one α-olefin, conjugated diene, non-conjugated diene, or the like. Examples of α-olefins include α-olefins having 2 to 12 carbon atoms (excluding propylene), such as ethylene, 1-butene, 3-methyl-1-butene, 4-methyl-1-pentene, 3-methyl-1-pentene, 4-methyl-1-hexene, 4,4-dimethyl-1-hexene, 1-nonene, 1-octene, 1-heptene, 1-hexene, 1-decene, 1-undecene, and 1-dodecene. Examples of conjugated dienes and non-conjugated dienes include butadiene, ethylidene norbornene, dicyclopentadiene, and 1,5-hexadiene. Two or more of these may be used. Examples of the skeletal structure of unmodified polypropylene resin include a propylene homopolymer, a random or block copolymer of propylene and the other monomers mentioned above, and a random or block copolymer of propylene and other thermoplastic monomers. Suitable examples include polypropylene, ethylene-propylene copolymer, propylene-1-butene copolymer, and ethylene-propylene-1-butene copolymer. A propylene homopolymer is preferred from the viewpoint of further improving the rigidity of molded articles, and a random or block copolymer of propylene and the other monomers mentioned above is preferred from the viewpoint of further improving the impact strength of molded articles.

[0032] Furthermore, the modified polypropylene resin is preferably an acid-modified polypropylene resin, and more preferably a polypropylene resin having a carboxylic acid and / or a salt thereof bound to the polymer chain. The acid-modified polypropylene resin can be obtained by various methods, for example, by graft polymerizing a polypropylene resin with a monomer having a neutralized or unneutralized carboxylic acid group and / or a monomer having a saponified or unsaponified carboxylic acid ester. Examples of the monomer having a neutralized or unneutralized carboxylic acid group or the monomer having a saponified or unsaponified carboxylic acid ester group include ethylenically unsaturated carboxylic acids, their anhydrides, and esters thereof. Furthermore, compounds having unsaturated vinyl groups other than olefins may also be used.

[0033] Examples of ethylenically unsaturated carboxylic acids include (meth)acrylic acid, maleic acid, fumaric acid, tetrahydrophthalic acid, itaconic acid, citraconic acid, crotonic acid, and isocrotonic acid, and examples of their anhydrides include Nadic acid™ (endo-cis-bicyclo[2,2,1]hept-5-ene-2,3-dicarboxylic acid), maleic anhydride, and citraconic anhydride.

[0034] Examples of esters of ethylenically unsaturated carboxylic acids include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, n-butyl (meth)acrylate, iso-butyl (meth)acrylate, tert-butyl (meth)acrylate, n-amyl (meth)acrylate, isoamyl (meth)acrylate, n-hexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, octyl (meth)acrylate, and decyl (meth)acrylate. Acrylate, dodecyl (meth)acrylate, octadecyl (meth)acrylate, stearyl (meth)acrylate, tridecyl (meth)acrylate, lauroyl (meth)acrylate, cyclohexyl (meth)acrylate, benzyl (meth)acrylate, phenyl (meth)acrylate, isobornyl (meth)acrylate, dicyclopentanyl (meth)acrylate, dicyclopentenyl (meth)acrylate, dimethylaminoethyl (meth)acrylate, di Examples of the hydroxyl group-containing (meth)acrylic acid esters include ethylaminoethyl (meth)acrylate, hydroxyethyl acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 4-hydroxybutyl acrylate, lactone-modified hydroxyethyl (meth)acrylate, and 2-hydroxy-3-phenoxypropyl acrylate, and examples of the hydroxyl group-containing (meth)acrylic acid esters include glycidyl (meth)acrylate and methyl glycidyl (meth)acrylate, and examples of the aminoalkyl (meth)acrylates include N,N-dimethylaminoethyl (meth)acrylate, N,N-diethylaminoethyl (meth)acrylate, N,N-dimethylaminopropyl (meth)acrylate, N,N-dipropylaminoethyl (meth)acrylate, N,N-dibutylaminoethyl (meth)acrylate, and N,N-dihydroxyethylaminoethyl (meth)acrylate.

[0035] Examples of the monomer having an unsaturated vinyl group other than olefins include isocyanate group-containing vinyls such as vinyl isocyanate and isopropenyl isocyanate, aromatic vinyls such as styrene, α-methylstyrene, vinyltoluene and t-butylstyrene, amide group-containing vinyls such as acrylamide, methacrylamide, N-methylol methacrylamide, N-methylol acrylamide, diacetone acrylamide and maleic acid amide, vinyl esters such as vinyl acetate and vinyl propionate, unsaturated sulfonic acids such as styrene sulfonic acid, sodium styrene sulfonate and 2-acrylamido-2-methylpropane sulfonic acid, and unsaturated phosphoric acids such as mono(2-methacryloyloxyethyl) acid phosphate and mono(2-acryloyloxyethyl) acid phosphate.

[0036] Two or more of these may be used. Among these, ethylenically unsaturated carboxylic acid anhydrides are preferred, with maleic anhydride being more preferred.

[0037] In order to improve the bending strength and tensile strength of the molded article, it is preferable to use both unmodified and modified polypropylene resins, and from the viewpoint of the balance between flame retardancy and mechanical properties in particular, it is preferable to use the unmodified and modified polypropylene resins in a weight ratio of 95 / 5 to 75 / 25, more preferably 95 / 5 to 80 / 20, and even more preferably 90 / 10 to 80 / 20.

[0038] The polyolefin resin used in the present invention may be one obtained by polymerization as described above, but it is preferable to use a polyolefin resin obtained through material recycling.

[0039] The polyolefin resins used in material recycling are sourced from process scraps, containers and packaging, electrical and electronic components, and other polyolefin-based materials. Material recycling can further separate the collected and sorted raw materials into polyolefin resins and other materials (metals, lint, paper, film, and other resin waste, etc.) using vibration or wind sorting, water gravity separation in a water tank (floating / sedimentation), electrostatic separation, or near-infrared separation.

[0040] Polyamide resins are resins whose main raw materials are amino acids, lactams, or diamines and dicarboxylic acids. Typical examples of the main raw materials include amino acids such as 6-aminocaproic acid, 11-aminoundecanoic acid, 12-aminododecanoic acid, and para-aminomethylbenzoic acid, lactams such as ε-caprolactam and ω-laurolactam, aliphatic diamines such as tetramethylenediamine, hexamethylenediamine, 2-methylpentamethylenediamine, nonamethylenediamine, undecamethylenediamine, dodecamethylenediamine, 2,2,4- / 2,4,4-trimethylhexamethylenediamine, and 5-methylnonamethylenediamine, aromatic diamines such as metaxylylenediamine and paraxylylenediamine, 1,3-bis(aminomethyl)cyclohexane, 1,4-bis(aminomethyl)cyclohexane, and 1-amino-3-aminomethyl-3,5,5-trimethylcyclohexane. Alicyclic diamines such as hexane, bis(4-aminocyclohexyl)methane, bis(3-methyl-4-aminocyclohexyl)methane, 2,2-bis(4-aminocyclohexyl)propane, bis(aminopropyl)piperazine, and aminoethylpiperazine; aliphatic dicarboxylic acids such as adipic acid, suberic acid, azelaic acid, sebacic acid, and dodecanedioic acid; aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, 2-chloroterephthalic acid, 2-methylterephthalic acid, 5-methylisophthalic acid, 5-sodiumsulfoisophthalic acid, hexahydroterephthalic acid, and hexahydroisophthalic acid; and alicyclic dicarboxylic acids such as 1,4-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, and 1,2-cyclohexanedicarboxylic acid. Two or more of these may be used.

[0041] In the present invention, polyamide resins having a melting point of 170° C. or higher are particularly useful because of their excellent heat resistance and strength. Specific examples thereof include polycaproamide (nylon 6), polyhexamethylene adipamide (nylon 66), polycaproamide / polyhexamethylene adipamide copolymer (nylon 6 / 66), polytetramethylene adipamide (nylon 46), polyhexamethylene sebacamide (nylon 610), polyhexamethylene dodecamide (nylon 612), polydecamethylene decamide (nylon 1010), polydecamethylene dodecamide (nylon 1012), polydodecamethylene dodecamide (nylon 1212), polyundecaneamide (nylon 11), polydodecanamide (nylon 12), polyhexamethylene terephthalamide / polycaproamide copolymer (nylon 6T / 6), polyhexamethylene adipamide / polyhexamethylene terephthalamide copolymer (nylon 6T / 6), Examples of such a copolymer include polyhexamethylene adipamide / polyhexamethylene isophthalamide copolymer (nylon 66 / 6I), polyhexamethylene adipamide / polyhexamethylene terephthalamide / polyhexamethylene isophthalamide copolymer (nylon 66 / 6T / 6I), polyhexamethylene terephthalamide / polyhexamethylene isophthalamide copolymer (nylon 6T / 6I), polyhexamethylene terephthalamide / polydodecanamide copolymer (nylon 6T / 12), polyhexamethylene terephthalamide / poly(2-methylpentamethylene) terephthalamide copolymer (nylon 6T / M5T), polyxylylene adipamide (nylon XD6), polynonamethylene terephthalamide (nylon 9T), and copolymers thereof. Two or more of these may be used. Among these, nylon 6, nylon 66, nylon 610, nylon 11, nylon 12 and nylon 9T are more preferred.

[0042] There are no particular restrictions on the degree of polymerization of these polyamide resins, and the relative viscosity of a solution obtained by dissolving 0.25 g of polyamide resin in 25 ml of 98% concentrated sulfuric acid, measured at 25°C, is preferably in the range of 1.5 to 5.0, and more preferably in the range of 2.0 to 3.5.

[0043] The polyamide resin used in the present invention may be one obtained by polymerization as described above, but preferably includes recycled resin obtained through material recycling or chemical recycling, and from the viewpoint of environmental load, it is more preferable to use polyamide resin obtained through material recycling.

[0044] The polyamide resin for material recycling is selected and used from polyamide-based components such as automobile parts and electrical and electronic components, as well as process scraps generated during the manufacturing process of each component. Material recycling can be carried out by further separating the collected and selected raw materials into polyamide resin and other materials (metals, lint, paper, film, and other resin waste) using vibration or wind sorting, water gravity separation in a water tank (floating / sedimentation), electrostatic separation, or near-infrared separation.

[0045] The polycarbonate resin is obtained by reacting a dihydric phenol with a carbonate precursor. It may also be a copolymer obtained using two or more dihydric phenols or two or more carbonate precursors. Examples of reaction methods include interfacial polymerization, melt transesterification, solid-phase transesterification of carbonate prepolymers, and ring-opening polymerization of cyclic carbonate compounds. Such polycarbonate resins are known per se, and the polycarbonate resins described in JP-A-2002-129027, for example, can be used.

[0046] Examples of dihydric phenols include 1,1-bis(4-hydroxyphenyl)-3,3,5-trimethylcyclohexane, bis(4-hydroxyphenyl)alkanes (such as bisphenol A), 2,2-bis{(4-hydroxy-3-methyl)phenyl}propane, α,α'-bis(4-hydroxyphenyl)-m-diisopropylbenzene, and 9,9-bis(4-hydroxy-3-methylphenyl)fluorene. Two or more of these may be used. Among these, bisphenol A is preferred, as it allows the production of polycarbonate resins with superior impact resistance. On the other hand, copolymers obtained using bisphenol A and other dihydric phenols are excellent in terms of high heat resistance and low water absorption.

[0047] As the carbonate precursor, for example, a carbonyl halide, a carbonic acid diester, or a haloformate may be used, and specific examples thereof include phosgene, diphenyl carbonate, or a dihaloformate of a dihydric phenol.

[0048] In producing the polycarbonate resin from the dihydric phenol and carbonate precursor, a catalyst, a terminal stopper, an antioxidant for preventing oxidation of the dihydric phenol, and the like may be used as needed.

[0049] The polycarbonate resins of the present invention include branched polycarbonate resins copolymerized with trifunctional or higher polyfunctional aromatic compounds, polyester carbonate resins copolymerized with aromatic or aliphatic (including alicyclic) bifunctional carboxylic acids, copolymer polycarbonate resins copolymerized with bifunctional alcohols (including alicyclic), and polyester carbonate resins copolymerized with such bifunctional carboxylic acids and bifunctional alcohols. These polycarbonate resins are also known. Two or more of these polycarbonate resins may be used.

[0050] The polycarbonate resin is preferably a resin obtained by mixing a polycarbonate resin having a weight average molecular weight of 28,000 to 45,000 with a polycarbonate resin having a weight average molecular weight of 50,000 to 60,000 in a weight ratio of 5 / 95 to 40 / 60. A weight ratio of 5 / 95 to 45 / 65 is more preferred. By achieving a weight ratio in this range, a molded product can be obtained that is excellent in mechanical properties and surface appearance, as well as in flame retardancy.

[0051] The polycarbonate resin used in the present invention may be one obtained by polymerization as described above, but it is preferable to use a polycarbonate resin obtained through material recycling.

[0052] Sources of polycarbonate resin for material recycling include information media discs such as CDs and DVDs, materials sorted and used for water bottles such as gallon bottles, semiconductor trays, headlights, process offcuts generated in various manufacturing processes, etc. Material recycling can employ methods such as further separating the collected and sorted raw materials into polycarbonate resin and other materials (metals, lint, paper scraps, film scraps, other resin scraps, etc.) using vibration / wind sorting, water gravity difference sorting in a water tank (floating / sedimentation), electrostatic sorting, or near-infrared sorting.

[0053] Polycarbonate resins with a weight average molecular weight of 28,000 to 45,000 are easily obtained from information medium disks such as CDs and DVDs, and polycarbonate resins with a weight average molecular weight of 50,000 to 60,000 are easily obtained from water bottles such as gallon bottles.

[0054] In order to eliminate the influence of low molecular weight substances, in the present invention, the weight average molecular weight means a value determined for components having a polystyrene-equivalent molecular weight of 3,000 or more (however, in the case where an alkyl ester-based unsaturated carboxylic acid monomer is used, a polymethyl methacrylate-equivalent molecular weight).

[0055] In the present invention, examples of polyarylene sulfide resins include polyphenylene sulfide (PPS) resins, polyphenylene sulfone resins, polyphenylene sulfide ketone resins, and random or block copolymers thereof. Two or more of these may be used. Among these, polyphenylene sulfide resins are particularly preferred.

[0056] The polyarylene sulfide resin can be produced by any method, such as the method for obtaining a polymer having a relatively small molecular weight described in JP-B-45-3368, or the method for obtaining a polymer having a relatively large molecular weight described in JP-B-52-12240 or JP-A-61-7332.

[0057] The obtained polyarylene sulfide resin may be subjected to various treatments such as crosslinking / polymerization by heating in air, heat treatment in an inert gas atmosphere such as nitrogen or under reduced pressure, washing with an organic solvent, hot water, an acid aqueous solution, or the like, or activation with a functional group-containing compound such as an acid anhydride, an amine, an isocyanate, or a functional group-containing disulfide compound.

[0058] The melt viscosity of the polyarylene sulfide resin is preferably 80 Pa·s or less, and more preferably 20 Pa·s or less, under conditions of 310°C and a shear rate of 1,000 / sec. There is no particular lower limit, but it is preferably 5 Pa·s or more. Two or more polyarylene sulfide resins with different melt viscosities may be used in combination. The melt viscosity can be measured using a Capilograph (manufactured by Toyo Seiki Co., Ltd.) device under conditions of a die length of 10 mm and a die hole diameter of 0.5 to 1.0 mm.

[0059] As the polyarylene sulfide resin, polyphenylene sulfide resins commercially available as "TORELINA" (registered trademark) manufactured by Toray Industries, Inc., "DIC.PPS" (registered trademark) manufactured by DIC Corporation, "DURAFIDE" (registered trademark) manufactured by Polyplastics Co., Ltd., etc. can also be used.

[0060] The polyarylene sulfide resin used in the present invention may be one obtained by polymerization as described above, but it is preferable to use a polyarylene sulfide resin obtained through material recycling.

[0061] The polyarylene sulfide resin for material recycling is selected and used from components that use polyarylene sulfide, such as automobile parts, electrical and electronic parts, and plumbing components, as well as process scraps generated in various manufacturing processes. Material recycling can employ methods such as further separating the recovered and selected raw materials into polyarylene sulfide resin and other materials (metals, lint, paper scraps, film scraps, other resin scraps, etc.) using vibration / wind sorting, water specific gravity difference sorting in a water tank (floating / sedimentation), electrostatic sorting, or near-infrared sorting.

[0062] [Compound (C)] In the present invention, the molding material contains, in addition to carbon fibers (A) and thermoplastic resin (B), a compound (C) different from the thermoplastic resin (B) that is present in a state of filling the spaces between the carbon fibers (A). It is preferable that the compound (C) is present in a state of filling the spaces between the carbon fibers (A-1). The presence of compound (C) in a state of filling the spaces between the carbon fibers can improve fiber dispersion during molding and also suppress fiber breakage during molding.

[0063] The compound (C) preferably has a lower melt viscosity than the thermoplastic resin (B). Because the melt viscosity of the compound (C) is lower than that of the thermoplastic resin (B), the fluidity of the compound (C) is high when molding the molding material, which can further improve the dispersion of the carbon fiber (A) in the thermoplastic resin (B) and suppress fiber breakage. Furthermore, the compound (C) preferably has a high affinity with the thermoplastic resin (B). By selecting a compound with a high affinity with the thermoplastic resin (B), it is possible to efficiently dissolve the compound with the thermoplastic resin (B) during molding, thereby further improving the dispersibility of the carbon fiber. The compound (C) is preferably a resin selected from the group consisting of epoxy resins, phenolic resins, terpene resins, and rosin resins, and examples thereof include homopolymers and reaction products with other components. Pre-impregnating the carbon fiber (A-1) with the compound (C) can efficiently improve dispersibility during molding, and is therefore preferably used.

[0064] The number average molecular weight of compound (C) is preferably 200 to 5,000. If the number average molecular weight is 200 or more, the bending strength and tensile strength of the molded article can be further improved. The number average molecular weight is more preferably 1,000 or more. Furthermore, if the number average molecular weight is 5,000 or less, the viscosity of the compound is appropriately low, so that the impregnation ability into carbon fiber (A-1) is excellent and the dispersibility of carbon fiber in the molded article can be further improved. The number average molecular weight is more preferably 3,000 or less. The number average molecular weight of such a compound can be measured using gel permeation chromatography (GPC).

[0065] The amount of compound (C) is preferably 0.1 to 20 parts by weight, more preferably 1 to 10 parts by weight, relative to 100 parts by weight of molding material (X). By adjusting the amount within this range, a molding material with excellent moldability and handleability can be obtained.

[0066] [Flame retardant (D)] In the present invention, the molding material preferably contains a flame retardant (D) in addition to the carbon fiber (A), the thermoplastic resin (B), and the compound (C). The flame retardant (D) preferably has a heat loss of 5% or less when heated at 300°C for 10 minutes under nitrogen. If the heat loss is 5% or less, the amount of gas generated when the resin melts during molding is reduced, which is preferable because gas burning can be suppressed.

[0067] The type of flame retardant (D) is not particularly limited, and known flame retardants can be used, for example, halogen-based flame retardants, phosphorus-based flame retardants, metal hydroxide-based flame retardants such as aluminum hydroxide and magnesium hydroxide, organic sulfonic acid-based flame retardants such as sodium styrene sulfonate, potassium styrene sulfonate and calcium styrene sulfonate, zinc borate, antimony trioxide, antimony pentoxide, melamine, melamine cyanurate, and silicone-based flame retardants.

[0068] [Correction based on Rule 91 09.05.2025] Representative halogenated flame retardants include decabromodiphenyl ether, tetrabromobisphenol A, tetrabromobisphenol S, 1,2-bis(2',3',4',5',6'-pentabromophenyl)ethane, 1,2-bis(2,4,6-tribromophenoxy)ethane, 2,4,6-tris(2,4,6-tribromophenoxy)-1,3,5-triazine, 2,6-(or 2,4-)dibromophenol, brominated polystyrene, ethylenebistetrabromophthalimide, hexabromocyclododecane, hexabromobenzene, pentabromobenzyl acrylate, and the like. brominated flame retardants containing bromine-containing compounds such as bis(3,5-dibromo-2,4-dibromopropoxyphenyl)sulfone, 2,2-bis[4'-(2",3"-dibromopropoxy)-3',5'-dibromophenyl]-propane, bis(3,5-dibromo-2,4-dibromopropoxyphenyl)sulfone, and tris(2,3-dibromopropyl)isocyanurate; and chlorinated flame retardants containing chlorine-containing compounds such as chlorinated paraffin, chlorinated polyethylene, chlorinated polypropylene, perchloropentacyclodecane, dodecachlorododecahydrodimethanodibenzocyclooctene, and dodecachlorooctahydrodimethanodibenzofuran.

[0069] Representative examples of phosphorus-based flame retardants include phosphate ester-based flame retardants such as triphenyl phosphate, tricresyl phosphate, trimethyl phosphate, triethyl phosphate, cresyl diphenyl phosphate, xylenyl diphenyl phosphate, 2-ethylhexyl diphenyl phosphate, and other aromatic phosphate esters; halogen-containing phosphate ester-based flame retardants such as trisdichloropropyl phosphate, trischloroethyl phosphate, and trischloropropyl phosphate; condensed phosphate ester-based flame retardants such as resorcinol bis-diphenyl phosphate, resorcinol bis-dixylenyl phosphate, bisphenol A bis-diphenyl phosphate, and biphenyl bisdiphenyl phosphate; phosphate flame retardants such as ammonium polyphosphate and melamine polyphosphate; phosphinic acid metal salt-based flame retardants such as aluminum phosphinate and magnesium phosphinate; phosphazene-based flame retardants such as phosphonitrile acid phenyl ester; and red phosphorus-based flame retardants. Phosphorus-based flame retardants and red phosphorus-based flame retardants are preferably used because they accelerate dehydration and carbonization, forming dense char on the surface of molded articles, blocking heat and oxygen and preventing flame propagation. They also exhibit flame retardancy by stabilizing active H and OH radicals in the combustion field through their radical trapping effect against the radical chain reaction during thermal decomposition.

[0070] The phosphorus concentration of the phosphorus-based flame retardant is preferably 5 to 50%. The phosphorus concentration refers to the weight of phosphorus in the phosphorus-based flame retardant. If the phosphorus concentration is 5% or more, dense char is easily formed, improving flame retardancy. 7% or more is preferred, and 9% or more is even more preferred. If the phosphorus concentration is 50% or less, compatibility with thermoplastic resins is improved, resulting in high flame retardancy, which is preferable.

[0071] From the viewpoint of high flame retardancy, halogen-based flame retardants, halogen-based flame retardants, phosphorus-based flame retardants, and organic sulfonic acid-based flame retardants are preferred, and among them, from the viewpoint of safety and environmental load, flame retardants selected from red phosphorus-based flame retardants, phosphate ester-based flame retardants, condensed phosphate ester-based flame retardants, metal phosphinate-based flame retardants, and phosphazene-based flame retardants are more preferred. Furthermore, from the viewpoint of compatibility with the thermoplastic resin, when the thermoplastic resin (B) is a polycarbonate resin, it is particularly preferred to use a condensed phosphate ester-based flame retardant, and when the thermoplastic resin (B) is a polyamide resin, it is particularly preferred to use a metal phosphinate-based flame retardant.

[0072] Such flame retardants may be used alone or in combination of two or more.

[0073] [Molding material (X)] This is a long-fiber reinforced resin molding material containing carbon fibers (A-1) having a fiber length of 3 mm or more and 10 mm or less and oriented in the longitudinal direction of the molding material, a thermoplastic resin (B-1), and a flame retardant (D), and also containing a compound (C) present in a state of filling the spaces between the carbon fibers (A-1). The type of thermoplastic resin (B-1) is not particularly limited, and examples thereof include the thermoplastic resins described above in the description of the thermoplastic resin (B).

[0074] The flame retardant (D) has high compatibility with thermoplastic resins, and the mixture exhibits excellent flame retardancy and fluidity. The flame retardant (D) is preferably compatible with the thermoplastic resin (B). Higher compatibility is preferable because it results in higher flame retardancy. Compatibility can be confirmed by a change in the glass transition temperature of the thermoplastic resin (B). The glass transition temperature of the mixture can be measured using a differential scanning calorimeter (DSC) at a heating rate of 20°C / min in accordance with JIS K7121.

[0075] In the present invention, the flame retardant (D) may be contained in any of the raw materials used as the molding material (X) during molding. Specific examples of the flame retardant (D) contained in any of the raw materials include, for example, a resin composition obtained by melt-kneading a thermoplastic resin and a flame retardant, which is contained in a resin that coats the reinforcing fibers, or the flame retardant may be pre-impregnated into a reinforcing fiber bundle in the process of obtaining the reinforcing fibers.

[0076] The molding material (X) of the present invention preferably contains an antioxidant, and as the antioxidant, it is preferable to use a hindered phenol-based, hydroquinone-based, phosphorus-based, phosphite-based, amine-based, sulfur-based, or substituted derivatives thereof.

[0077] Specific examples of the phosphorus-based and phosphite-based antioxidants include tetrakis(2,4-di-t-butylphenyl)-4,4'-biphenylene phosphonite, bis(2,6-di-t-butyl-4-methylphenyl)pentaerythritol-diphosphite, 2,2-methylenebis(4,6-di-t-butylphenyl)octyl phosphite, triphenyl phosphite, tris(2,4-di-t-butylphenyl)phosphite, diphenylisodecyl phosphite, phenyldiisodecyl phosphite, 4,4-butylidene-bis(3-methyl-6-t-butylphenyl-di-tridecyl)phosphite, cyclic ne Examples of the phosphate phosphite include neopentanetetraylbis(octadecyl phosphite), cyclic neopentanetetraylbis(2,6-di-t-butyl-4-methylphenyl)phosphite, tris(nonyl phenyl)phosphite, diisodecylpentaerythritol diphosphite, 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 10-(3,5-di-t-butyl-4-hydroxybenzyl)-9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 10-decyloxy-9,10-dihydro-9-oxa-10-phosphaphenanthrene, and mixtures thereof.

[0078] Examples of the hindered phenol antioxidant include triethylene glycol-bis[3-(3-t-butyl-5-methyl-4-hydroxyphenyl)propionate, 4,4'-butylidenebis(3-methyl-6-t-butylphenol), 1,6-hexanediol-bis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate, 2,4-bis-(n-octylthio)-6-(4-hydroxy-3,5-di-t-butylanilino)-1,3,5-triazine, pentaerythrityl-tetrakis[3-(3,5-di-t-butyl octadecyl-3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate], 2,2-thio-diethylenebis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate], octadecyl-3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate, 2,2-thiobis(4-methyl-6-t-butylphenol), N,N'-hexamethylenebis(3,5-di-t-butyl-4-hydroxy-hydrocinnamamide), 3,5-di-t-butyl-4-hydroxy-benzylphosphonate-diethyl ester, 1,3,5-trimethyl-2, 4,6-tris(3,5-di-t-butyl-4-hydroxybenzyl)benzene, bis(3,5-di-t-butyl-4-hydroxybenzylsulfonate ethyl calcium, tris-(3,5-di-t-butyl-4-hydroxybenzyl)-isocyanurate, 2,6-di-t-butyl-p-cresol, butylated hydroxyanisole, 2,6-di-t-butyl-4-ethylphenol, stearyl-β-(3,5-di-t-butyl-4-hydroxyphenyl)propionate, 2,2'-methylenebis-(4-methyl-6-t-butylphenol), 2 , 2'-methylene-bis-(4-ethyl-6-t-butylphenol), 4,4'-thiobis-(3-methyl-6-t-butylphenol), octylated diphenylamine, 2,4-bis[(octylthio)methyl]-o-cresol, isooctyl-3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate, 4,4'-butylidenebis(3-methyl-6-t-butylphenol, 3,9-bis[1,1-dimethyl-2-[β-(3-t-butyl-4-hydroxy-5-methylphenyl)propionyloxy]ethyl]2,4,8,10-Tetraoxaspiro[5,5]undecane, benzenepropanoic acid, 3-(1,1-dimethylethyl)-4-hydroxy-5-methyl-2,4,8,10-tetraoxaspiro[5.5]undecane-3,9-diylbis(2,2-dimethyl-2,1-ethanediyl)ester, 1,1,3-tris(2-methyl-4-hydroxy-5-t-butylphenyl)butane, 1,3,5-trimethyl-2,4,6-tris(3,5-di-t-butyl-4-hydroxybenzyl)benzene, bis[3,3'-bis-(4'-hydroxy Examples include 1,3,5-tris(3',5'-di-t-butyl-4'-hydroxybenzyl)-sec-triazine-2,4,6-(1H,3H,5H)trione, d-α-tocopherol, 3,9-bis(2-(3-(3-tert-butyl-4-hydroxy-5-methylphenyl)propionyloxy)-1,1-dimethylethyl)-2,4,8,10-tetraoxaspiro[5.5]undecane, and mixtures thereof.

[0079] [Correction based on Rule 91 09.05.2025] Examples of amine antioxidants include polycondensates of dimethyl succinate-1-(2-hydroxyethyl)-4-hydroxy-2,2,6,6-tetramethylpiperidine, poly[{6-(1,1,3,3-tetramethylbutyl)amino-1,3,5-triazine-2,4-diyl}{(2,2,6,6-tetramethyl-4-piperidyl)imino}hexamethylene{(2,2,6,6-tetramethyl-4-piperidyl)imino}], bis(1,2,2,6,6-pentamethyl-4-piperidyl)-2-n-butylmalonate, tetrakis(2,2,6,6-tetramethyl-4-piperidyl)-2-(3,5-di-t-butyl-4-hydroxybenzyl)-2-n-butylmalonate, and tetrakis(2,2,6,6-tetramethyl-4-piperidyl)-2-n-butylmalonate. bis(1,2,3,4-pentamethyl-4-piperidyl)sebacate, methyl(1,2,2,6,6-pentamethyl-4-piperidyl)sebacate, 1-[2-[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionyloxy]ethyl]-4-[3-(3,5-t-butyl-hydroxyphenyl)propionyloxy]2,2,6,6-tetramethylpiperidine, 4-benzoyloxy-2,2,6,6-tetramethylpiperidine, and the like, or a mixture thereof, can be exemplified.

[0080] Examples of sulfur-based antioxidants include 4,4'-thiobis(6-t-butyl-3-methylphenol), dialkyl(C12-18)3,3'-thiodipropionate, pentaerythrityl tetrakis(3-laurylthiopropionate), and mixtures thereof. It is preferable to use antioxidants and heat stabilizers (hindered phenols, hydroquinones, phosphorus compounds, phosphites, amines, sulfur compounds, and their substituted derivatives).

[0081] From the viewpoint of inhibiting decomposition, sulfur-based antioxidants, hindered phenol-based antioxidants, or mixtures thereof are preferably used.

[0082] The content of the antioxidant is preferably 1 part by weight or more relative to 100 parts by weight of the molding material (X). When 1 part by weight or more is contained, decomposition of the components of the molding material during molding and heating is suppressed, resulting in excellent surface appearance. The upper limit is preferably 2 parts by weight or less. When 2 parts by weight or less, gas burning due to decomposition of the antioxidant itself is suppressed, resulting in excellent surface appearance.

[0083] [Molding material (Y)] The molding material (Y) comprises carbon fibers (A-2) having a fiber length of 0.1 mm or more and 0.4 mm or less, a thermoplastic resin (B-2), and a flame retardant (D), wherein the thermoplastic resin (B-2) comprises a recycled resin. The type of the thermoplastic resin (B-1) is not particularly limited, and examples thereof include the thermoplastic resins described in the description of the thermoplastic resin (B).

[0084] Furthermore, in the present invention, the molding material (Y) preferably contains polytetrafluoroethylene. Hereinafter, polytetrafluoroethylene may be referred to as PTFE. PTFE with fibril-forming ability is more preferred. PTFE with fibril-forming ability has an extremely high molecular weight and tends to bond PTFE molecules together to form fibers under external influences such as shear force. Its molecular weight, in terms of number average molecular weight used based on standard specific gravity, is 1 million to 10 million, more preferably 2 million to 9 million. Furthermore, such fibril-forming PTFE can be used in a mixed form with other resins to improve dispersibility in resins and obtain even better flame retardancy and impact resistance. Acrylic resin-tetrafluoroethylene polymers are particularly preferred because of their excellent dispersibility in the thermoplastic resin (B).

[0085] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to the descriptions in these examples. First, the evaluation methods for each property used in these examples will be described.

[0086] (1) Fiber Length of Carbon Fiber A test piece extracted from the molding material was placed in a solvent that dissolved the thermoplastic resin (B) used in each Example and Comparative Example, and appropriately heated to obtain a solution in which the carbon fibers were uniformly dispersed. The solution was then filtered using quantitative filter paper (No. 5C) manufactured by Advantec Co., Ltd., and the carbon fibers (A) dispersed on the filter paper were observed under an optical microscope (50 to 200 magnifications). The fiber lengths of 1,000 randomly selected carbon fibers (A) were measured, and the fiber length of the carbon fibers was calculated using the following formula 1: Fiber Length of Carbon Fiber = Σ(Li) / 1,000 (Formula 1), where Li is the length of each carbon fiber (mm).

[0087] (2) Fluidity of Molding Material The molding material was injection molded using an injection molding machine (J110AD manufactured by The Japan Steel Works, Ltd.) using a mold having a width of 10 mm, a length of 125 mm, and a thickness of 1 mm under the following conditions: injection speed 30 mm / s, back pressure 10 MPa, dwell pressure 60 MPa, cylinder temperature 280°C, and mold temperature 80°C. The cylinder peak pressure when producing a molded product was used as an index of fluidity. The cylinder pressure was the average value of 20 shots, and this average value was used for evaluation of each example and comparative example.

[0088] (3) Surface Appearance of Molded Articles A parallel section was cut out from the ISO dumbbell test specimens obtained in each Example and Comparative Example, and the cut cross section and the surface of the test specimen were observed under an optical microscope (10 to 50 magnifications). Each observed surface was evaluated according to the following criteria: A: Neither fallen nor unopened fibers were found in the carbon fibers on the observed surface. B: Either fallen or unopened fibers were found in the carbon fibers on the observed surface. C: Both fallen and unopened fibers were found in the carbon fibers on the observed surface.

[0089] (4) Measurement of Charpy impact strength of molded product The molding material was injection molded using an injection molding machine (J110AD manufactured by The Japan Steel Works, Ltd.) under the following conditions: injection speed: 30 mm / s, back pressure: 10 MPa, dwell pressure: 85 MPa, dwell time: 10 seconds, cylinder temperature: 280°C, mold temperature: 80°C, to produce an ISO dumbbell test piece as a molded product. A parallel portion of the ISO dumbbell test piece was cut out, and a V-notched Charpy impact test was carried out in accordance with ISO179 using a C1-4-01 model testing machine manufactured by Tokyo Testing Machine Co., Ltd., to measure the impact strength (kJ / cm ２ ) was calculated.

[0090] (5) Flame Retardancy of Molded Articles The flame retardancy of the 1.0 mm thick test pieces for evaluating flame retardancy obtained in each of the Examples and Comparative Examples was evaluated in the V test below in accordance with the evaluation criteria defined in UL94.

[0091] [V Test Method] The flame of a gas burner is applied to the lower end of a vertically held test specimen for 10 seconds. If the burning stops within 30 seconds, the flame is applied for another 10 seconds. This test is performed on five test specimens. The evaluation criteria are as follows:

[0092] V-0: No specimen continues to burn for more than 10 seconds after any application of flame. The total burning time for 10 applications of flame to 5 specimens does not exceed 50 seconds. No specimen burns to the position of the fixing clamp. No specimen drops burning particles that ignite the absorbent cotton placed below the specimen. No specimen continues to glow red for more than 30 seconds after the second application of flame.

[0093] V-1: No specimen continues to burn for more than 30 seconds after any application of flame. The total burning time for 10 applications of flame to 5 specimens does not exceed 250 seconds. No specimen burns to the position of the fixing clamp. No specimen drops burning particles that ignite the absorbent cotton placed below the specimen. No specimen remains red-hot for more than 60 seconds after the second application of flame.

[0094] [Correction under Rule 91 09.05.2025] V-2: No specimen continues to burn for more than 30 seconds after any application of flame. The total burning time for 10 applications of flame to 5 specimens does not exceed 250 seconds. No specimen burns to the level of the fixing clamp. Fall of burning particles is permitted, igniting the absorbent cotton placed below the specimen. No specimen remains red-hot for more than 30 seconds after the second application of flame.

[0095] Reference Example 1 [Preparation of Carbon Fiber (A-1)] A sizing agent mother solution was prepared by dissolving glycerol polyglycidyl ether as a polyfunctional compound in water to 2% by weight for carbon fiber "TORAYCA" (registered trademark) T700S-24000 manufactured by Toray Industries, Inc. (total number of single fibers: 24,000, single fiber diameter: 7 μm), and the sizing agent was applied to the carbon fiber by a dipping method, followed by drying at 230° C. The amount of sizing agent attached to the carbon fiber thus obtained was 1.0% by weight.

[0096] Reference Example 2 [Preparation of Carbon Fiber (A-2)-(1)] For carbon fiber "TORAYCA" (registered trademark) T700S-24000 manufactured by Toray Industries, Inc. (total number of single fibers: 24,000, single fiber diameter: 7 μm), a sizing agent mother solution was prepared by dissolving glycerol polyglycidyl ether as a polyfunctional compound in water to a concentration of 2% by weight, and the sizing agent was applied to the carbon fiber by an immersion method, followed by drying at 230 ° C. The amount of sizing agent attached to the obtained carbon fiber was 1.0% by weight. The carbon fiber thus obtained was cut with a cartridge cutter to obtain carbon fiber chopped yarns with a chopped length of 6 mm.

[0097] Reference Example 3 [Preparation of Carbon Fiber (A-2)-(2)] Carbon fiber "TORAYCA" (registered trademark) Toray Industries, Inc. prepreg P2252S-12 (single fiber diameter 5 μm) was used. A carbon fiber reinforced plastic (CFRP) molded product was prepared by applying a pressure of 0.6 MPa in a press and heating at 160 ° C. for 2 hours. The resulting CFRP was crushed and classified to obtain waste CFRP pieces. The waste CFRP pieces were uniformly spread in a metal tub and placed in an electric muffle furnace with an internal volume of 59 liters. While introducing nitrogen gas into the furnace, the treatment temperature was maintained at 500 ° C. and heat-treated for 3.5 hours. Thereafter, similarly, while introducing air into the furnace, the treatment temperature was maintained at a predetermined temperature (300 ° C.) and heat-treated for 2 hours to obtain recycled carbon fiber chopped yarn.

[0098] [Correction based on Rule 91 09.05.2025] <Thermoplastic resin (B)> (B-i) Polycarbonate resin ("Iupilon" (registered trademark) S-3000 manufactured by Mitsubishi Engineering Plastics Corporation) (B-ii) Polycarbonate resin ("Iupilon" (registered trademark) S-2000 manufactured by Mitsubishi Engineering Plastics Corporation) (B-iii) Recycled polycarbonate with a weight-average molecular weight of 32,300, sourced from information media discs such as CDs and DVDs. (B-iv) Material recycled polycarbonate resin with a weight average molecular weight of 54,000, sourced from water bottles; (B-v) Material recycled polycarbonate resin with a weight average molecular weight of 46,000, sourced from transparent polycarbonate sheets; (B-vi) Polyamide 6 resin ("Amilan" (registered trademark) CM1007, manufactured by Toray Industries, Inc.); (B-vii) Material recycled polyamide 6 resin sourced from discarded fishing nets.

[0099] <Compound (C)> (C-1) Terpene phenol resin (YS Polystar N125, manufactured by Yasuhara Chemical Co., Ltd.) (C-2) Bisphenol A epoxy resin (jER (registered trademark) 1004AF, manufactured by Mitsubishi Chemical Corporation)

[0100] <Flame Retardant (D)> (D) Condensed phosphate ester flame retardant ("PX-200" manufactured by Daihachi Chemical Industry Co., Ltd.)

[0101] <Antioxidant> (E) A 2 / 1 weight ratio mixture of hindered phenol ("Irganox (registered trademark) 1010" manufactured by BASF Japan Ltd.) and thioether ("Adekastab (registered trademark) AO-412S" manufactured by Adeka Corporation)

[0102] <PTFE> (F) Acrylic resin / tetrafluoroethylene polymer ("A3800" manufactured by Mitsubishi Chemical Corporation)

[0103] <Method of producing long fiber reinforced resin molding material (X)> A long fiber reinforced resin pellet manufacturing apparatus was used, equipped with a coating die for electrical wire resin coating at the tip of a TEX-30α type twin-screw extruder (screw diameter 30 mm, L / D = 32) manufactured by The Japan Steel Works, Ltd. The extruder cylinder temperature was set to 280 ° C. The thermoplastic resin (B), flame retardant (D), and antioxidant (E) shown above were fed from the main hopper and melt-kneaded at a screw rotation speed of 200 rpm. The compound (C) was heated and melted at 250 ° C. The discharge rate was adjusted so that the ratios shown in Tables 1 to 3 were obtained relative to a total of 100 parts by weight of carbon fiber (A-1), thermoplastic resin (B), flame retardant (D), and antioxidant (E). Thereafter, the compound (C) was discharged and impregnated into a fiber bundle made of carbon fiber (A-1). The fiber bundle of carbon fiber (A-1) to which the compound (C) had been applied was then supplied to a die hole (diameter 3 mm) through which the molten thermoplastic resin (B) was discharged. The fiber bundle was continuously arranged so that the thermoplastic resin (B) covered the periphery of the carbon fiber (A-1). At this time, the internal cross section of the fiber bundle showed that at least a portion of the carbon fiber (A-1) was in contact with the thermoplastic resin (B). The resulting strand was cooled and then cut into pellets 7 mm long with a cutter to obtain a long fiber reinforced resin molding material (X). At this time, the take-up speed was adjusted so that the proportion of carbon fiber (A-1) relative to a total of 100 parts by weight of the long fiber reinforced resin molding material was as shown in Tables 1 to 3. The length of the carbon fiber (A-1) in the obtained fiber reinforced resin molding material (X) was substantially the same as the pellet length, and the carbon fiber bundles were aligned parallel to the axial direction of the molding material.

[0104] <Method for producing short fiber reinforced resin molding material (Y)> After raw materials except for carbon fiber (A-2) were supplied to the main hopper of a TEX-30α type twin-screw extruder (screw diameter 30 mm, L / D = 32) manufactured by The Japan Steel Works, Ltd., carbon fiber (A-2) was supplied from a side feeder to the molten resin, and the screw rotation speed was set to 200 rpm. The strand discharged from the die was cooled in water, cut into 3.0 mm lengths with a strand cutter, and pelletized to obtain short fiber reinforced resin molding material (Y).

[0105] <Method for producing fiber-reinforced resin molding material> The long fiber-reinforced resin molding material (X) and the short fiber-reinforced resin molding material (Y) obtained by the method for producing the long fiber-reinforced resin molding material (X) and the short fiber-reinforced resin molding material (Y) described above were dry-blended in the proportions shown in Tables 1 to 3 to obtain fiber-reinforced resin molding materials.

[0106] (Examples 1 to 15, Comparative Examples 1 to 10) Molding materials and molded articles were obtained using the method for producing the long fiber reinforced resin molding material (X), the method for producing the short fiber reinforced resin molding material (Y), and the method for producing the fiber reinforced resin molding material, so as to achieve the ratios of components shown in Tables 1 to 3. The evaluation results of the molded articles are shown in Tables 1 to 3.

[0107]

[0108]

[0109]

[0110] Examples 1 to 4 and Examples 7, 10, and 11 all exhibited excellent fluidity, mechanical properties, surface appearance, and flame retardancy, and also had a high recycling rate. Examples 5 and 6 differed from Examples 1 and 2 in the proportion of recycled polycarbonate resin, and while they were slightly inferior in various properties, they exhibited excellent properties. Examples 8 and 9 did not contain short fiber-reinforced resin molding material, and therefore were inferior in fluidity and surface appearance, but exhibited excellent mechanical properties. Example 12 differed from Example 1 in the type of recycled polycarbonate resin, and while they were slightly inferior in various properties, they exhibited excellent properties.

[0111] On the other hand, Comparative Examples 1 and 2 were excellent in all of fluidity, mechanical properties, surface appearance, and flame retardancy, but did not contain recycled raw materials, resulting in a high environmental impact.Comparative Example 3 did not contain compound (C) compared to Example 1, resulting in insufficient fiber dispersion and inferior surface appearance and flame retardancy.Comparative Examples 4 to 8 did not use carbon fibers having a fiber length of 3 mm or more and 10 mm or less, resulting in inferior mechanical properties.

[0112] Examples 13 and 14 were excellent in fluidity, mechanical properties, and surface appearance, and also had a high recycling rate. Example 15, which did not contain a short fiber reinforced resin molding material, was inferior in fluidity and surface appearance, but showed excellent mechanical properties.

[0113] On the other hand, Comparative Examples 9 and 10 did not use carbon fibers having a fiber length of 3 mm or more and 10 mm or less, and therefore the mechanical properties were inferior.

Claims

1. A fiber-reinforced resin molding material comprising carbon fiber (A) and thermoplastic resin (B), wherein the material contains 10 to 40 parts by weight of carbon fiber (A) and 60 to 90 parts by weight of thermoplastic resin (B) relative to a total of 100 parts by weight of the carbon fiber (A) and the thermoplastic resin (B), the carbon fiber (A) has a fiber length of 3 mm or more and 10 mm or less and includes carbon fibers oriented in the longitudinal direction of the molding material, the fiber-reinforced resin molding material contains a compound (C) that exists in a state where it fills the spaces between the carbon fibers, and the thermoplastic resin (B) includes a recycled resin.

2. The fiber-reinforced resin molding material according to claim 1, characterized in that the carbon fiber (A) comprises carbon fiber (A-1) and carbon fiber (A-2), the carbon fiber (A-1) having a fiber length of 3 mm or more and 10 mm or less and oriented in the longitudinal direction of the molding material, and the carbon fiber (A-2) having a fiber length of 0.1 mm or more and 0.4 mm or less.

3. The fiber reinforced resin molding material according to claim 2, characterized in that the fiber reinforced resin molding material comprises a long fiber reinforced resin molding material (X) and a short fiber reinforced resin molding material (Y), the long fiber reinforced resin molding material (X) comprises the carbon fiber (A-1), a thermoplastic resin (B-1) and a flame retardant (D), and comprises a compound (C) present in a state of filling the spaces between the carbon fibers (A-1), the short fiber reinforced resin molding material (Y) comprises the carbon fiber (A-2), a thermoplastic resin (B-2) and a flame retardant (D), and the thermoplastic resin (B-2) comprises a recycled resin.

4. The fiber-reinforced resin molding material according to claim 3, characterized in that the short fiber-reinforced resin molding material (Y) contains polytetrafluoroethylene resin.

5. The fiber-reinforced resin molding material according to claim 2, characterized in that the carbon fiber (A-2) contains recycled carbon fiber.

6. A fiber-reinforced resin molding material according to claim 3, wherein the flame retardant (D) is a condensed phosphate ester.

7. The fiber-reinforced resin molding material according to claim 1, characterized in that the thermoplastic resin (B) contains a polycarbonate resin.

8. The fiber-reinforced resin molding material according to claim 1, characterized in that the thermoplastic resin (B) contains a polyamide resin.

9. The fiber-reinforced resin molding material according to claim 1, characterized in that the compound (C) has a lower melt viscosity than the thermoplastic resin (B).

10. The fiber-reinforced resin molding material according to claim 3, characterized in that the long-fiber-reinforced resin molding material (X) contains a sulfur-based antioxidant and a hindered phenol-based antioxidant.

11. The fiber-reinforced resin molding material according to claim 7, wherein the polycarbonate resin is a recycled polycarbonate resin.

12. The fiber-reinforced resin molding material according to claim 11, wherein the recycled polycarbonate resin is a mixture of a recycled polycarbonate resin having a weight-average molecular weight of 28,000 to 45,000 and a recycled polycarbonate resin having a weight-average molecular weight of 50,000 to 60,000.

13. The fiber-reinforced resin molding material according to claim 12, wherein the recycled polycarbonate resin is a mixture of a recycled polycarbonate resin having a weight-average molecular weight of 28,000 to 45,000 and a recycled polycarbonate resin having a weight-average molecular weight of 50,000 to 60,000, with the weight ratio between them being in the range of 5 / 95 to 40 / 60.

14. A molded product obtained by molding the fiber-reinforced resin molding material according to any one of claims 1 to 13.

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