Fiber-reinforced resin composition and molded body

Abstract

To provide a fiber-reinforced resin composition which remarkably improves an impact resistance of a molded body and which does not reduce strength of the molded body so much even when the composition contains an elastomer.SOLUTION: A fiber-reinforced resin composition contains an unmodified polyolefin (A), a modified polyolefin (B), a styrenic elastomer (D) having a butylene block, and a reinforced fiber (E), in which the content of the unmodified polyolefin (A) is 20 mass% or more and 70 mass% or less, the content of the modified polyolefin (B) is 1 mass% or more and 20 mass% or less, the content of the styrenic elastomer (D) is 10 mass% or more and 30 mass% or less, the content of the reinforced fiber (E) is 10 mass% or more and 50 mass% or less, and the styrenic elastomer (D) is an elastomer having the content of styrene of 30 mass% or more and 60 mass% or less.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a fiber-reinforced resin composition and a molded article. [Background technology]

[0002] BACKGROUND ART Fiber-reinforced resin compositions, which are resin compositions containing reinforcing fibers, are used in a variety of applications because they can be used to mold lightweight, high-strength molded articles.

[0003] As an example of such a fiber-reinforced resin composition, Patent Document 1 describes a fiber-reinforced resin composition having a resin component composed of a phase-separated polyolefin and polyamide. In the fiber-reinforced resin composition described in Patent Document 1, the total cross-sectional area of the dispersed phase (one of the polyolefin and polyamide phases) having a cross-sectional area equal to or less than the average cross-sectional area of the reinforcing fibers is 10% or less by area of the total cross-sectional area of all dispersed phases. This results in a molded article that is less susceptible to brittle fracture by suppressing the initiation and progression of cracks due to the dispersed phase. Patent Document 2 also describes a reinforced fiber composite resin containing reinforcing fibers and a matrix portion made of a resin, in which the matrix portion is composed of two incompatible phases, a first resin and a second resin, the first resin being a thermoplastic resin, and the second resin having a glass transition temperature (Tg) of −50 to 30°C. Patent Document 2 also describes a reinforced fiber composite resin that, due to the above-described configuration, can achieve both high rigidity and high energy absorbency. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2019-210379 [Patent Document 2] International Publication No. 2019 / 208823 Summary of the Invention [Problem to be solved by the invention]

[0005] Patent Document 1 describes that by using a fiber-reinforced resin composition in which polyolefin and polyamide are phase-separated, a molded article that is resistant to brittle fracture can be obtained. On the other hand, depending on the application of the molded article, a molded article with high impact resistance that is resistant to breakage due to instantaneous impact is required. Furthermore, Patent Document 2 describes that by using a reinforced fiber composite resin in which the matrix portion is composed of two types of resin, a first resin and a second resin, and the two resins are incompatible with each other, the first resin is a thermoplastic resin, and the second resin has a glass transition temperature (Tg) of -50 to 30°C, both high rigidity and high energy absorbency can be achieved. On the other hand, although a certain degree of strength can be ensured, the impact resistance remains unsatisfactory.

[0006] In view of the above circumstances, an object of the present invention is to provide a fiber-reinforced resin composition that significantly improves the impact resistance of a molded body and does not significantly reduce the strength of the molded body even when it contains an elastomer, and a molded body obtained by molding the fiber-reinforced resin composition. [Means for solving the problem]

[0007] One aspect of the present invention for solving the above problems relates to the following fiber-reinforced resin compositions [1] to [5].

[0008] [1] An unmodified polyolefin (A); a modified polyolefin (B); a styrene-based elastomer (D) having a butylene block; A fiber reinforced resin composition containing reinforcing fibers (E), Relative to the total mass of the fiber reinforced resin composition the content of the unmodified polyolefin (A) is 20% by mass or more and 70% by mass or less, The content of the modified polyolefin (B) is 1% by mass or more and 20% by mass or less, the content of the styrene-based elastomer (D) is 10% by mass or more and 30% by mass or less, The content of the reinforcing fiber (E) is 10% by mass or more and 50% by mass or less, The styrene elastomer (D) is an elastomer having a styrene content of 30% by mass or more and 60% by mass or less. Fiber-reinforced resin composition.

[0009] [2] The fiber-reinforced resin composition further contains a polyamide (C) having a structural unit derived from a monomer having 10 or more carbon atoms, and the content of the polyamide (C) is 1% by mass or more and 20% by mass or less relative to the total amount of the fiber-reinforced resin composition. [1] The fiber-reinforced resin composition according to the present invention.

[0010] [3] The polyamide (C) is polyamide 12. [2] The fiber-reinforced resin composition according to [2].

[0011] [4] The polyolefin (A) is polypropylene. The fiber-reinforced resin composition according to any one of [1] to [3].

[0012] [5] The reinforcing fiber (E) is a glass fiber or a carbon fiber. The fiber-reinforced resin composition according to any one of [1] to [4].

[0013] Another aspect of the present invention for solving the above problems relates to the following molded article [6] [7].

[0014] [6] A molded article obtained by molding the fiber-reinforced resin composition according to any one of [1] to [5].

[0015] [7] The molded article according to [6], which is a sports and leisure product. [Effects of the Invention]

[0016] According to the present invention, there are provided a fiber-reinforced resin composition that significantly improves the impact resistance of a molded body and does not significantly reduce the strength of the molded body even when it contains an elastomer, and a molded body obtained by molding the fiber-reinforced resin composition. DETAILED DESCRIPTION OF THE INVENTION

[0017] 1. Fiber-reinforced resin composition One embodiment of the present invention relates to a fiber-reinforced resin composition containing a polyolefin as a resin component, which contains an unmodified polyolefin (A), a modified polyolefin (B), a butylene block-containing styrene-based elastomer (D), and reinforcing fibers (E).

[0018] 1-1. Polyolefin (A) The polyolefin (A) is an unmodified polyolefin.

[0019] The type of polyolefin (A) is not limited, and a wide range of polymers, such as α-olefins, cyclic olefins, non-conjugated dienes, and aromatic olefins, can be used. Among these, polymers containing α-olefins as the main component are preferred. A polymer containing α-olefins as the main component means a polymer in which the proportion of structural units derived from α-olefins to all structural units constituting the polymer is 50 mol% or more and 100 mol% or less. The proportion of structural units derived from α-olefins to all structural units constituting the polyolefin (A) is preferably 60 mol% or more and 100 mol% or less, more preferably 70 mol% or more and 100 mol% or less. The proportion of each structural unit constituting the polyolefin (A) is 13 The carbon content can be measured by C-NMR. The monomer constituting the polyolefin (A) may be derived from a fossil fuel, may be derived from a biomass raw material, or may be a mixture thereof.

[0020] The α-olefin preferably has 2 or more and 20 or less carbon atoms, more preferably 2 or more and 10 or less carbon atoms, and even more preferably 2 or more and 8 or less carbon atoms. Examples of such α-olefins include ethylene, propylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 3-methyl-1-butene, and 4-methyl-1-pentene. These α-olefins may be used alone, or two or more types may be used in combination to form a copolymer.

[0021] Examples of polyolefin (A) include polyethylene, which is an ethylene homopolymer or a copolymer of ethylene and another α-olefin, and polypropylene, which is a propylene homopolymer or a copolymer of propylene and another α-olefin. In these polyethylenes and polypropylenes, the ratio of ethylene-derived structural units to all structural units, and the ratio of propylene-derived structural units to all structural units, are preferably 50 mol% or more and 100 mol% or less, more preferably 70 mol% or more and 100 mol% or less, and even more preferably 90 mol% or more and 100 mol% or less. As polyolefin (A), only one of these polyolefins may be used, or two or more may be used in combination.

[0022] The polyolefin (A) is preferably polypropylene, more preferably propylene homopolymer, from the viewpoint of improving mechanical properties, heat resistance, and water resistance.

[0023] The polypropylene preferably has a melting point of 130°C or higher and 180°C or lower, more preferably 140°C or higher and 170°C or lower, as measured by a differential scanning calorimeter (DSC) at a temperature rise rate of 10°C / min.

[0024] From the viewpoint of enhancing impregnation into the reinforcing fibers (E), the polyolefin (A) preferably has a melt flow rate (MFR) measured under a load of 2.16 kg in accordance with JIS K 7210-1:2014 of 0.01 g / 10 min to 300 g / 10 min, more preferably 0.1 g / 10 min to 300 g / 10 min, even more preferably 1 g / 10 min to 300 g / 10 min, still more preferably 10 g / 10 min to 300 g / 10 min, and particularly preferably 50 g / 10 min to 300 g / 10 min. The MFR is a value measured at 190°C for polyethylene and 230°C for polypropylene.

[0025] 1-2. Modified polyolefin (B) Since the modified polyolefin (B) contains a modified portion, it tends to have a high affinity with the reinforcing fibers (E). By forming an interfacial resin layer at the interface between the polyolefin (A) and the reinforcing fibers (E), adhesion is improved, peeling at the interface between the polyolefin (A) and the reinforcing fibers (E) is unlikely to occur, and crack propagation occurring in impact resistance tests, strength tests, etc. is likely to be suppressed, thereby improving the mechanical properties (e.g., strength such as flexural strength, and impact resistance) of molded articles molded from the fiber-reinforced resin composition. The modified polyolefin (B) may be used alone or in combination of two or more types. The monomer constituting the modified polyolefin (B) may be derived from a fossil fuel, may be derived from a biomass raw material, or may be a mixture thereof.

[0026] The modified polyolefin (B) is preferably a resin obtained by modifying an unmodified polyolefin with an unsaturated carboxylic acid or a derivative thereof.

[0027] The unmodified polyolefin may be any of the various polyolefins exemplified as polyolefin (A). In this case, it is preferable that the polyolefin (A) and the unmodified polyolefin used as the raw material for the modified polyolefin (B) are the same type of resin. This is because the affinity between the polyolefin (A) and the modified polyolefin (B) is increased, facilitating adhesion, which makes it easier to improve the impact resistance of the molded article. For example, when the polyolefin (A) is polyethylene, the unmodified polyolefin used as the raw material for the modified polyolefin (B) is also preferably polyethylene, and when the polyolefin (A) is polypropylene, the unmodified polyolefin used as the raw material for the modified polyolefin (B) is also preferably polypropylene. These unmodified polyolefins may be used alone or in combination of two or more.

[0028] Examples of unsaturated carboxylic acids used for the modification include unsaturated monocarboxylic acids such as acrylic acid, methacrylic acid, crotonic acid, sorbic acid, and angelic acid, and unsaturated dicarboxylic acids such as maleic acid, fumaric acid, itaconic acid, citraconic acid, mesaconic acid, tetrahydrophthalic acid, norbornene dicarboxylic acid, and bicyclo[2.2.1]hept-2-ene-5,6-dicarboxylic acid.

[0029] Examples of the unsaturated carboxylic acid derivatives used for modification include acid anhydrides, acid halides, esters, amidates, imides, and metal salts of the above-mentioned unsaturated carboxylic acids. Specific examples of the unsaturated carboxylic acid derivatives include unsaturated dicarboxylic acid anhydrides such as maleic anhydride, itaconic anhydride, citraconic anhydride, tetrahydrophthalic anhydride, and bicyclo[2.2.1]hept-2-ene-5,6-dicarboxylic anhydride; unsaturated dicarboxylic acid halides such as malenyl chloride; acrylic acid esters such as methyl acrylate, ethyl acrylate, propyl acrylate, and butyl acrylate; methacrylic acid esters such as methyl methacrylate and glycidyl methacrylate; maleic acid esters such as monomethyl maleate, monoethyl maleate, dimethyl maleate, and diethyl maleate; other esters such as diethyl fumarate, dimethyl itaconate, diethyl citraconic acid, dimethyl tetrahydrophthalate, and dimethyl bicyclo[2.2.1]hept-2-ene-5,6-dicarboxylate; acrylamide, maleic acid amide, maleimide, sodium acrylate; and sodium methacrylate.

[0030] Among these, unsaturated dicarboxylic acids or derivatives thereof are preferred, unsaturated dicarboxylic acids or anhydrides thereof are more preferred, and maleic acid or maleic anhydride is even more preferred. Alternatively, the unsaturated dicarboxylic acid or derivatives thereof may be modified by combining an acrylic acid ester with glycidyl methacrylate. These unsaturated carboxylic acids or derivatives thereof may be used alone or in combination of two or more.

[0031] The modified polyolefin (B) may have an unsaturated dicarboxylic acid or a derivative thereof grafted to the side chain, or may have an unsaturated dicarboxylic acid or a derivative thereof copolymerized in the main chain.

[0032] In the modified polyolefin (B), the proportion of the structural units derived from unsaturated carboxylic acids or their derivatives is preferably 0.1% by mass or more and 5% by mass or less, and more preferably 0.2% by mass or more and 1% by mass or less, relative to the total mass of the modified polyolefin (B). The proportion of the structural units derived from unsaturated carboxylic acids or their derivatives can be measured by infrared absorption spectroscopy or the like.

[0033] 1-3.Polyamide (C) The fiber-reinforced resin composition according to this embodiment may contain a polyamide (C) having a structural unit derived from a monomer having a carbon number of 10 or more. The amount added can be selected appropriately depending on the performance required for the molded article.

[0034] The type of polyamide (C) is not limited, and a wide variety of compounds having amino and carboxy groups in the molecule (amino acid monomers) or polymers of their dehydration condensates, copolymers of diamines and dicarboxylic acids, and copolymers thereof can be used. The monomers constituting the polyamide (C) may be derived from fossil fuels, biomass raw materials, or a mixture thereof.

[0035] The polyamide (C) has a structural unit derived from a monomer having 10 or more carbon atoms. This increases the affinity between the polyolefin (A) and the polyamide (C), making it less likely that interfacial peeling will occur between them. From the above viewpoint, the polyamide (C) preferably has a structural unit derived from a monomer having a linear or branched alkyl group having 10 or more carbon atoms, and more preferably has a structural unit derived from a monomer having a linear or branched alkyl group having 10 or more carbon atoms.

[0036] Furthermore, in the polyamide (C), the proportion of the structural units derived from the above-mentioned monomers having 10 or more carbon atoms relative to all structural units constituting the polyamide (C) is preferably 60 mol% or more and 100 mol% or less, more preferably 70 mol% or more and 100 mol% or less, and even more preferably 90 mol% or more and 100 mol% or less.

[0037] Examples of the amino acid monomer having 10 or more carbon atoms include amino acids such as aminoundecanoic acid and aminododecanoic acid, and lactams such as undecane lactam and ω-lauryllactam. These amino acid monomers may be used alone or in combination to form a copolymer of two or more types.

[0038] Examples of the diamine, which is a monomer having 10 or more carbon atoms, include aliphatic diamines such as 1,10-diaminodecane, 1,11-diaminoundecane, 1,12-diaminododecane, 1,13-diaminotridecane, 1,14-diaminotetradecane, 1,15-diaminopentadecane, 1,16-diaminohexadecane, 1,17-diaminoheptadecane, 1,18-diaminooctadecane, 1,19-diaminononadecane, and 1,20-diaminoeicosane, as well as alicyclic diamines such as bis(4-aminocyclohexyl)methane. These diamines may be used alone, or two or more may be used in combination to form a copolymer.

[0039] Examples of the dicarboxylic acid monomer having 10 or more carbon atoms include aliphatic dicarboxylic acids such as sebacic acid, undecanedioic acid, dodecanedioic acid, brassicic acid, tetradecanedioic acid, pentadecanedioic acid, and octadecanedioic acid, as well as aromatic dicarboxylic acids such as naphthalenedicarboxylic acid. These dicarboxylic acids may be used alone or in combination to form a copolymer of two or more types.

[0040] The polyamide (C) may be a copolymer of any of these monomers having 10 or more carbon atoms with a monomer having 9 or less carbon atoms. Examples of amino acid monomers having 9 or less carbon atoms include amino acids such as aminocaproic acid and paraaminomethylbenzoic acid, and lactams such as ε-caprolactam. Examples of diamines having 9 or less carbon atoms include aliphatic diamines such as ethylenediamine, 1,3-diaminopropane, 1,4-diaminobutane, 1,6-diaminohexane, 1,7-diaminoheptane, 1,8-diaminooctane, 1,9-diaminononane, 2-methyl-1,5-diaminopentane (2M-5), and 2-methyl-1,8-diaminooctane (2M-8), alicyclic diamines such as cyclohexanediamine, and aromatic diamines such as p-phenylenediamine, m-phenylenediamine, p-xylylenediamine, and m-xylylenediamine. Examples of dicarboxylic acids that are monomers having 9 or less carbon atoms include aliphatic dicarboxylic acids such as oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, and azelaic acid, alicyclic dicarboxylic acids such as cyclohexanedicarboxylic acid, and aromatic dicarboxylic acids such as phthalic acid, terephthalic acid, and isophthalic acid. These monomers having 9 or less carbon atoms may be used alone or in combination of two or more.

[0041] Specific examples of polyamide (C) include polyamide 6 / 10, polyamide 6 / 12, polyamide 6 / 14, polyamide 11, polyamide 12, polyamide 10 / 10, polyamide 10 / 12, polyamide 10 / T, etc. Among these, polyamide 12 is preferred from the viewpoint of improving water resistance. These polyamides may be used alone or in combination of two or more.

[0042] From the viewpoint of improving the impregnation property into the reinforcing fiber (E), the polyamide (C) preferably has a melt flow rate (MFR) measured under a load of 2.16 kg in accordance with JIS K 7210-1:2014 of 1 g / 10 min to 500 g / 10 min, more preferably 5 g / 10 min to 500 g / 10 min, even more preferably 10 g / 10 min to 300 g / 10 min, still more preferably 20 g / 10 min to 300 g / 10 min, and particularly preferably 60 g / 10 min to 100 g / 10 min. The MFR for PA12 is a value measured at 200°C.

[0043] From the viewpoint of improving the impregnation property into the reinforcing fibers (E), the polyamide (C) preferably has a melting point of 160°C or more and 260°C or less, more preferably 170°C or more and 220°C or less, as measured by a differential scanning calorimeter (DSC) at a heating rate of 10°C / min.

[0044] 1-4. Styrene-based elastomer (D) The styrene-based elastomer (D) is a styrene-based elastomer having a butylene block. The styrene-based elastomer (D) significantly improves the impact resistance of a molded article formed from the fiber-reinforced resin composition. On the other hand, the styrene-based elastomer (D) does not significantly reduce the strength (e.g., flexural strength) of the molded article.

[0045] According to the findings of the present inventors, the use of other elastomers (e.g., ethylene-butylene rubber copolymer (EBR)) as impact modifiers does not significantly improve the impact resistance of molded articles, but the use of styrene-based elastomers can efficiently increase the impact resistance of molded articles. This is thought to be because styrene-based elastomers have the property that, at room temperature, the hard segments aggregate to form domains (pseudo-crosslinking) and disperse, suppressing the propagation of cracks that occur when an impact is applied.

[0046] Furthermore, the styrene-based elastomer (D) contains a butylene block. Because of the butylene block, these styrene-based elastomers (D) tend to enhance the impact resistance of molded articles. This is thought to be because the butylene block has excellent affinity with the unmodified polyolefin (A) and the modified polyolefin (B), provides a high degree of freedom in deformation, and has the property of easily absorbing impact.

[0047] Furthermore, since the styrene content of the styrene-based elastomer (D) is 30% by mass or more and 60% by mass or less, the impact resistance of the molded article can be improved while preventing a decrease in strength (e.g., bending strength). When the styrene content is 30% by mass or more, the hard segment portion, which is a structural unit containing styrene, does not have too high an affinity with the unmodified polyolefin (A) and the modified polyolefin (B), and does not inhibit the interfacial adhesion between the unmodified polyolefin (A) and the modified polyolefin and the reinforcing fiber (E), which tends to increase the strength (e.g., bending strength) of the molded article. When the styrene content is 60% by mass or less, the butylene block, which has excellent affinity with the unmodified polyolefin (A) and the modified polyolefin (B), tends to exhibit an impact resistance-improving effect.

[0048] As described above, the styrene elastomer (D) having a styrene content of 30% by mass or more and 60% by mass or less is considered to significantly improve the impact resistance of the molded body because it combines the suppression of crack propagation due to the pseudo-crosslinking described above with the impact absorption properties of the butylene blocks.

[0049] The type of styrene-based elastomer (D) is not particularly limited as long as it has a butylene block, and may be a styrene-butadiene-styrene copolymer (SBS), a styrene-ethylene / butylene-styrene copolymer (SEBS), or the like. These elastomers may be derived from fossil fuels, biomass raw materials, or mixtures thereof. In particular, from the viewpoint of improving the impact resistance of molded articles, it is preferable that the styrene-based elastomer (D) be a styrene-ethylene / butylene-styrene copolymer (SEBS).

[0050] Furthermore, the styrene elastomer (D) preferably has a content of 40% by mass or more and 55% by mass or less. When the styrene content is 40% by mass or more, it is possible to make it more difficult for the strength (e.g., bending strength) of the molded article to decrease. When the styrene content is 55% by mass or less, it is possible to more significantly increase the impact resistance. Therefore, by using a styrene elastomer (D) having a styrene content within this range, it is possible to obtain a molded article that combines high strength and high impact resistance. The styrene content refers to the ratio of structural units derived from monomers containing a styrene structure to all structural units constituting the styrene elastomer (D), and is a value obtained by measurement using an NMR method.

[0051] 1-5. Reinforced fiber (E) The type of reinforcing fiber (E) is not limited and may be inorganic or organic. Examples of inorganic fibers include metal fibers such as glass fibers, carbon fibers, aluminum fibers, aluminum alloy fibers, copper fibers, brass fibers, steel fibers, stainless steel fibers, and titanium fibers, as well as ceramic fibers such as silicon carbide fibers, silicon nitride fibers, alumina fibers, and zirconia fibers. Examples of organic fibers include synthetic fibers made of synthetic resins such as wholly aromatic polyamides (e.g., aramids), wholly aromatic polyesters, wholly aromatic polyesteramides, wholly aromatic polyethers, wholly aromatic polycarbonates, wholly aromatic polyazomethines, polyphenylene sulfides, polyparaphenylene benzobisoxazoles, poly(para-phenylene benzobisthiazoles), polybenzimidazoles, polyether ether ketones, polyamideimides, polyimides, polytetrafluoroethylene, polyvinyl alcohols, polyolefins, polyarylates, and fluorine-based polymers, as well as natural fibers such as cotton fibers, silk fibers, wood fibers, and cellulose fibers. Among these, glass fiber and carbon fiber are preferred, and glass fiber is more preferred from the viewpoint of reducing production costs, and carbon fiber is more preferred from the viewpoint of improving the mechanical strength and rigidity of the molded article. As the reinforcing fiber (E), only one of these may be used, or two or more may be used in combination.

[0052] Examples of glass fibers include glass fibers having compositions such as A-glass, C-glass, D-glass, E-glass, and S-glass. Among these, glass fibers having a composition of E-glass (alkali-free glass) are preferred. These glass fibers may be used alone or in combination of two or more types.

[0053] The glass fibers may be fibers having a length of 10 mm or more, chopped strands cut to a length of 1 mm or more and 10 mm or less, or milled fibers pulverized to a length of 10 μm or more and 500 μm or less.

[0054] The carbon fiber may be any carbon fiber such as polyacrylonitrile-based, rayon-based, pitch-based, polyvinyl alcohol-based, regenerated cellulose-based, or pitch-based produced from mesophase pitch. The carbon fiber may be a general-purpose fiber or a high-strength fiber. The carbon fiber may also be a recycled fiber. A plurality of carbon fibers may be bundled together using a sizing agent.

[0055] The natural fibers are preferably cellulose fibers, such as cellulose nanofibers, lignocellulose nanofibers, and cellulose microfibers.

[0056] The reinforcing fiber (E) may be a short fiber having a weight-average fiber length of less than 1.0 mm, or a long fiber having a weight-average fiber length of 1.0 mm or more. When the reinforcing fiber (E) is a short fiber, it may be a chopped fiber (cut fiber) without fibrils (microfibers split in the axial direction and divided into smaller pieces), or a pulp-like fiber having fibrils. The reinforcing fiber (E) may be a single fiber or a twisted yarn formed by twisting together a plurality of single fibers. From the viewpoint of fiber dispersion in the molded body, the reinforcing fiber (E) preferably contains short fibers. On the other hand, from the viewpoint of mechanical strength and rigidity, the reinforcing fiber (E) preferably contains long fibers. The weight-average fiber length of the reinforcing fiber (E) in the fiber-reinforced resin composition is a value measured by the following method. The resin portion of the molded body was heated and removed, and the mixture was stirred in an aqueous PVA solution to obtain a dispersion. The prepared dispersion was applied to a glass slide, covered with a cover glass, and heated and dried in a vacuum dryer to volatilize the water, thereby preparing a prepared sample for fiber length observation. The observation sample is photographed under a microscope, and the lengths of 500 reinforcing fibers (E) randomly selected from the photograph of the reinforcing fibers (E) are measured and calculated by weight averaging these lengths.

[0057] The weight-average fiber length of the reinforcing fibers (E) is preferably 0.01 mm or more and 100 mm or less, more preferably 0.1 mm or more and 50 mm or less, and even more preferably 1 mm or more and 30 mm or less. When the weight-average fiber length is within the above range, the mechanical strength of the molded body is easily increased, and from the viewpoint of suppressing the generation of dry fibers due to detachment of relatively short reinforcing fibers from the fiber-reinforced resin composition, it is preferable that the ratio of the number of reinforcing fibers having a fiber length of less than 0.1 mm to the number of all reinforcing fibers of the reinforcing fibers (E) is 18% or less.

[0058] The average fiber diameter of the reinforcing fibers (E) is preferably 1 μm or more and 30 μm or less, more preferably 5 μm or more and 20 μm or less. When the average fiber diameter is within the above range, the mechanical strength (particularly impact resistance and rigidity) and heat resistance of the molded article are easily increased, and the appearance of the molded article is improved. Furthermore, when the average fiber diameter is within the above range, the reinforcing fibers (E) are easily impregnated with the resin component.

[0059] The average fiber diameter can be determined, for example, by measuring the diameters of 100 reinforcing fibers (E) randomly selected from a photograph of the reinforcing fibers (E) taken with an optical microscope, and calculating the arithmetic mean of these diameters.

[0060] The reinforcing fibers (E) may be bundled using a sizing agent. The sizing agent may be any of polyolefin-based sizing agents, acrylic-based sizing agents, urethane-based sizing agents, acid copolymer-based sizing agents, polyamide-based sizing agents, and epoxy-based sizing agents. Among these, acrylic-based sizing agents and polyamide-based sizing agents are preferred, with acrylic-based sizing agents being more preferred, from the viewpoint of improving the flexural modulus, flexural strength, and impact resistance of the molded article. These sizing agents are highly reactive with polyamide (C) and modified polyolefin (B), and are therefore thought to facilitate adhesion of the reinforcing fibers (E) bundled with these sizing agents to other resin components. Furthermore, when the reinforcing fibers (E) are long fibers (especially long glass fibers), acrylic-based sizing agents are preferred because they provide good impregnation with the resin component.

[0061] Furthermore, the mass ratio (loss on ignition) of the sizing agent to the reinforcing fibers (E) is preferably 0.1% by mass or more and 3.5% by mass or less. When the loss on ignition is 0.1% by mass or more, the interface between the polyamide (C) and the reinforcing fibers (E) is stabilized, and the heat resistance of the molded body is likely to be improved. When the loss on ignition is 3.5% by mass or less, the heat resistance of the molded body is less likely to be reduced by the sizing agent. The mass ratio (loss on ignition) of the sizing agent is a value measured on the fibers obtained by applying the sizing agent to the reinforcing fibers with an applicator or the like and drying the fibers to completely volatilize the volatile substances, in accordance with JIS R 3420:2006 7.3.2.

[0062] 1-6.Other ingredients The fiber-reinforced resin composition may contain components other than the above-mentioned components (A) to (E). Examples of other components include polyamides other than component (C), thermoplastic resins other than components (A), (B), and (D), flame retardants, flame retardant auxiliaries, fillers, colorants, antibacterial agents, and antistatic agents. These components may be used alone or in combination of two or more.

[0063] Examples of polyamides other than component (C) include polyamide 6, polyamide 66, polyamide 6T, polyamide 6I, polyamide 9T, polyamide M5T, polyamide MXD6, polyamide 6T / 66, polyamide 6T / 6I, polyamide 6T / 6I / 66, polyamide 6T / 2M-5T, and polyamide 9T / 2M-8T.

[0064] Examples of the flame retardant include halogen-based flame retardants such as halogenated aromatic compounds, phosphorus-based flame retardants such as nitrogen-containing phosphate compounds and phosphoric acid esters, nitrogen-based flame retardants such as guanidine, triazine, melamine and derivatives thereof, inorganic flame retardants such as metal hydroxides, boron-based flame retardants, silicone-based flame retardants, sulfur-based flame retardants, and red phosphorus-based flame retardants.

[0065] Examples of the flame retardant synergist include antimony compounds, metal compounds containing zinc, metal compounds containing bismuth, magnesium hydroxide, and clay silicates.

[0066] Examples of fillers include glass components such as glass beads and glass flakes, silica compounds such as silica, graphite, calcium silicate, aluminum silicate, kaolin, talc, and clay, metal oxides such as iron oxide, titanium oxide, zinc oxide, antimony oxide, and alumina, calcium, magnesium, and metal carbonates or sulfates.

[0067] Examples of colorants include pigments and dyes.

[0068] 1-7. Mixing ratio The content of polyolefin (A) relative to the total mass of the fiber-reinforced resin composition is 20% by mass or more and 70% by mass or less, more preferably 30% by mass or more and 70% by mass or less, more preferably 35% by mass or more and 55% by mass or less, and even more preferably 40% by mass or more and 55% by mass or less. When the proportion of component (A) is 20% by mass or more, it is easy to make the molded body lightweight. When the proportion of component (A) is 70% by mass or less, other components can be sufficiently blended.

[0069] The content of the modified polyolefin (B) relative to the total mass of the fiber-reinforced resin composition is 1% by mass or more and 20% by mass or less, preferably 3% by mass or more and 18% by mass or less, more preferably 4% by mass or more and 14% by mass or less, and even more preferably 4% by mass or more and 10% by mass or less. When the proportion of the (B) component is 1% by mass or more, the impregnation of the resin component into the reinforcing fibers (E) is good, and cracks in the molded article due to reinforcing fibers (E) not impregnated with the resin component (dry fibers), exposure of the reinforcing fibers (E) on the surface of the molded article, and retention (bridging) of the fiber-reinforced resin composition during injection molding are less likely to occur. In addition, good impregnation properties make it easier to reduce the tensile creep strain of the molded article.

[0070] From the viewpoint of reducing the tensile creep strain of the molded article, the content of polyamide (C) relative to the total mass of the fiber-reinforced resin composition is preferably 1% by mass or more and 20% by mass or less, more preferably 3% by mass or more and 15% by mass or less, and even more preferably 3% by mass or more and 10% by mass or less. When the proportion of the (C) component is 1% by mass or more, the tensile creep strain of the molded article is more likely to be reduced. When the proportion of the (C) component is 20% by mass or less, the impregnation of the resin component into the reinforcing fibers (E) is improved, and cracks of the molded article due to reinforcing fibers (E) not impregnated with the resin component (dry fibers), exposure of the reinforcing fibers (E) on the surface of the molded article, and retention (bridging) of the fiber-reinforced resin composition during injection molding are less likely to occur. Furthermore, good impregnation properties make it easier to reduce the tensile creep strain of the molded article.

[0071] From the viewpoint of facilitating an increase in the strength (e.g., bending strength) of the molded article, the content of polyamide (C) relative to the total mass of the fiber-reinforced resin composition is preferably 0% by mass or more and 10% by mass or less, more preferably 0% by mass or more and 1% by mass or less, and even more preferably no polyamide (C) is contained. When the proportion of the (C) component is 10% by mass or less, the strength (e.g., bending strength) of the molded article is likely to be increased.

[0072] The content of the styrene-based elastomer (D) relative to the total mass of the fiber-reinforced resin composition is 10% by mass or more and 30% by mass or less, preferably 5% by mass or more and 25% by mass or less, and more preferably 10% by mass or more and 20% by mass or less. When the proportion of the (D) component is 10% by mass or more, the impact resistance of the molded article is sufficiently increased.

[0073] The content of the reinforcing fiber (E) relative to the total mass of the fiber-reinforced resin composition is 10% by mass or more and 50% by mass or less, preferably 10% by mass or more and 40% by mass or less, and more preferably 20% by mass or more and 30% by mass or less. When the proportion of the (E) component is 10% by mass or more, the bending strength and tensile strength of the molded article are easily increased. Furthermore, when the proportion of the (E) component is increased, the bending modulus, bending strength, tensile modulus, and tensile strength of the molded article are further increased.

[0074] The total content of the polyolefin (A), the modified polyolefin (B), the polyamide (C), the styrene-based elastomer (D), and the reinforcing fibers (E) relative to the total mass of the fiber-reinforced resin composition is preferably 70% by mass or more and 100% by mass or less, more preferably 80% by mass or more and 100% by mass or less, and even more preferably 90% by mass or more and 100% by mass or less.

[0075] 1-8.Form The form of the fiber-reinforced resin composition is not particularly limited, and may be a composition in a molten state (fluid state) containing each heated and melted resin material, the reinforcing fiber (E), and other components, or the resin material may be cooled and in a solid state such as in the form of pellets or a sheet.

[0076] The reinforcing fibers (E) may be dispersed in a random orientation in the fiber-reinforced resin composition, or may be aligned in one direction. For example, the fiber-reinforced resin composition may be a thin-film fiber-reinforced resin (UD sheet) in which a plurality of reinforcing fibers (E) aligned in one direction are impregnated with a resin component, a thin-film fiber-reinforced resin (cross sheet) in which a woven fabric of a plurality of reinforcing fibers aligned in one direction is impregnated with a resin component, or a pellet-shaped resin composition in which a plurality of reinforcing fibers (E) aligned in one direction are impregnated with a resin component (long fiber thermoplastics: LFT). Of these, LFT is preferred because it is applicable to mechanical injection molding and has high moldability.

[0077] For example, the LFT can be a cylindrical pellet having a length in the stretching direction of the reinforcing fibers (E) of 3 mm to 100 mm, preferably 5 mm to 50 mm. The average fiber length of the reinforcing fibers (E) contained in the LFT is approximately the same as the length of the pellet, and specifically, is preferably 80% to 100%, more preferably 90% to 100% of the length of the pellet.

[0078] 2. Manufacturing method The fiber-reinforced resin composition may be prepared by melt-kneading the above-mentioned components, or by impregnating reinforcing fibers (E) oriented in one direction with a resin component and other components.

[0079] For example, when the reinforcing fibers (E) are short fibers, the above-mentioned components can be melt-kneaded to obtain a fiber-reinforced resin composition in which the reinforcing fibers (E) are randomly oriented and dispersed. The melt-kneading temperature is preferably 5°C to 100°C higher than the melting point of the resin with the highest melting point among the resin components, and more preferably 10°C to 60°C higher. The melt-kneading time is preferably 30 seconds to 15 minutes, and more preferably 1 minute to 10 minutes.

[0080] For example, the above-mentioned components may be melt-kneaded using a melt-kneader such as a roll mill, a Banbury mixer, or a kneader. Alternatively, the components may be dry-blended using a kneader such as a tumbler blender, a Henschel mixer, or a ribbon mixer, and then melt-kneaded and extruded using an extruder such as a single-screw extruder or a twin-screw extruder. The melt-kneaded fiber-reinforced resin composition in a molten state may be directly injected into a molding machine and molded, or the extruded fiber-reinforced resin composition may be processed into a predetermined shape (e.g., pellets) to form a solid fiber-reinforced resin composition.

[0081] When the reinforcing fibers (E) are long fibers, the reinforcing fibers (E) are oriented in one direction and then impregnated with a molten resin component and other components to produce a fiber-reinforced resin composition such as a UD sheet, cross sheet, or LFT. The temperature of the molten resin is preferably 5°C to 120°C higher, and more preferably 10°C to 80°C higher, than the melting point of the resin with the highest melting point among the resin components.

[0082] For example, the reinforcing fibers (E) aligned in one direction can be run through an impregnation roll or an impregnation die, and brought into contact with the molten resin component and other components in the impregnation roll or the impregnation die, thereby impregnating them. After impregnation, the resin component is cooled and solidified, and then processed into a predetermined shape (for example, a sheet or pellet) to obtain a solid fiber-reinforced resin composition.

[0083] 3.Applications The fiber-reinforced resin composition can be processed into a molded article by a known molding method such as injection molding, extrusion molding, or press molding.

[0084] The molded article can be used in a wide range of applications, from household goods such as daily necessities and recreational uses, sports and leisure goods, to general industrial applications and industrial goods. Examples of applications for the molded article include home appliance material parts, communication equipment parts, electrical parts, electronic parts, automobile parts, parts for vehicles other than automobiles, ships, aircraft materials, machine mechanism parts, building materials, civil engineering materials, agricultural materials, power tool parts, food containers, films, sheets, and fibers. Among these, the molded article is particularly suitable for sports and leisure goods, which require high impact resistance.

[0085] Examples of sports and leisure goods include skis, rackets, bicycles, fishing tackle, snowboard bindings, camera lens housings, and the like.

[0086] Examples of automotive parts that can be used in various locations include powertrain parts due to improved heat resistance, mechanical parts due to improved tensile creep resistance, and exterior panel parts due to improved bending properties, but the material can also be applied to other locations.Examples of automotive parts include intake manifolds, oil pans, cylinder heads, cylinder head covers, engine covers, shrouds, mirror brackets, interior consoles, sunroofs, sunroof frames, front doors, back doors, sliding doors, front-end modules, door modules, fenders, wheel caps, gas tanks, belts, ceiling linings, convertible tops, armrests, door trim, rear package trays, sun visors, wheel covers, mattress covers, airbags, insulation materials, wire coverings, electrical insulation materials, covering materials, flooring materials, corner walls, deck panels, covers, plywood, ceiling boards, partition boards, side walls, wallpaper, wall coverings, exterior materials, interior materials, roofing materials, soundproofing boards, and heat insulation boards.

[0087] Examples of home appliance material parts, communication equipment parts, electrical parts, and electronic parts include battery pack parts (covers, trays, module cases), office and OA equipment such as printers, personal computers, word processors, keyboards, personal digital assistants (PDAs), headphone stereos, mobile phones, telephones, facsimiles, copiers, electronic cash registers (ECRs), calculators, electronic organizers, electronic dictionaries, cards, holders, and stationery; home appliances such as washing machines, refrigerators, vacuum cleaners, microwave ovens, lighting fixtures, game consoles, irons, and kotatsu tables; audio-visual equipment such as televisions, video players, video cameras, boomboxes, tape recorders, minidiscs, CD players, speakers, and liquid crystal displays; connectors, relays, capacitors, switches, printed circuit boards, coil bobbins, semiconductor encapsulating materials, electric wires, cables, transformers, deflection yokes, distribution boards, and clocks.

[0088] Examples of everyday items include plywood, synthetic boards, buckets, containers, bags, cases, goggles, tents, and lifestyle and sporting goods such as musical instruments. [Example]

[0089] The present invention will be described in more detail below with reference to examples, but the scope of the present invention is not limited to the descriptions in the examples.

[0090] 1. Prepare ingredients The following materials were prepared:

[0091] 1-1. Unmodified polyolefin (A) Polypropylene (PP) Prime Polymer J13B, MFR (JIS K7210:2014 compliant, 230°C, 2.16 kg load): 220 g / 10 min

[0092] 1-2. Modified polyolefin (B) Maleic acid modified polyolefin (modified PP) Modified PP obtained by the following synthesis method 100 parts by mass of polypropylene (manufactured by Prime Polymer Co., Ltd., product name J106G, MFR (230°C, 2.16 kg): 15 g / 10 min) was premixed with 1 part by mass of dialkyl peroxide (manufactured by NOF Corporation, Perhexa 25B ("Perhexa" is a registered trademark of the company)) and 3 parts by mass of powdered maleic anhydride (manufactured by NOF Corporation, CRYSTAL MAN ("CRYSTAL MAN" is a registered trademark of the company)). This mixture was fed into a 30 mm diameter twin-screw extruder temperature-controlled at 190°C and melt-kneaded at 200 rpm. The resulting strand was cooled in a water bath to obtain maleic anhydride-modified polypropylene. To remove residual unmodified maleic anhydride, the maleic anhydride-modified polypropylene was vacuum-dried at 40°C for 2 hours. The maleic acid content of the resulting maleic anhydride-modified polypropylene was 2.5% by mass and the MFR (230°C, 2.16 kg) was 800 g / 10 min.

[0093] 1-3.Polyamide (C) Polyamide 12 (PA12) UBE Corporation 3012U, MFR (JIS K7210 compliant, 200°C, 2.16 kg load): 26 g / 10 min

[0094] 1-4-1. Styrene-based elastomers with butylene blocks (D) Elastomer 1 Styrene-based thermoplastic elastomer: SEBS (styrene-ethylene-butylene-styrene copolymer) Asahi Kasei H1043, MFR (JIS K7210:2014 compliant, 230°C, 2.16 kg load): 2 g / 10 min, styrene content 67% by mass Elastomer 2 Styrene-based thermoplastic elastomer: SEBS (styrene-ethylene-butylene-styrene copolymer) Eneos Material 9901, MFR (JIS K7210:2014 compliant, 230°C, 2.16 kg load): 3 g / 10 min, styrene content 53% by mass Elastomer 3 Styrene-based thermoplastic elastomer: SEBS (styrene-ethylene-butylene-styrene copolymer) Asahi Kasei H1041, MFR (JIS K7210:2014 compliant, 230°C, 2.16 kg load): 4 g / 10 min, styrene content 30% by mass Elastomer 4 Styrene-based thermoplastic elastomer: SEBS (styrene-ethylene-butylene-styrene copolymer) Asahi Kasei H1062, MFR (JIS K7210:2014 compliant, 230°C, 2.16 kg load): 4 g / 10 min, styrene content 18% by mass Elastomer 5 Styrene-based thermoplastic elastomer: SEBS (styrene-ethylene-butylene-styrene copolymer) Eneos material 8600P, MFR (JIS K7210:2014 compliant, 230°C, 2.16 kg load): 30 g / 10 min, styrene content 15% by mass

[0095] 1-4-2. Other elastomers (D') Elastomer 6 Styrene-based thermoplastic elastomer: SEPS (styrene-ethylene-propylene-styrene copolymer) Kuraray Co., Ltd. 2004F, MFR (JIS K7210:2014 compliant, 230°C, 2.16 kg load): 5 g / 10 min, styrene content 18% by mass Elastomer 7 Ethylene-based thermoplastic elastomer: EBR (ethylene-butylene rubber copolymer) Mitsui Chemicals DF7350, MFR (JIS K7210:2014 compliant, 230°C, 2.16 kg load): 65 g / 10 min, styrene content 0%

[0096] 1-5. Reinforced fiber (E) Carbon fiber (CF) 1 Chopped carbon fiber surface treated with epoxy sizing Mitsubishi Chemical Corporation, TR066AB4E (cut length 6 mm, filament diameter 7 μm) Carbon fiber (CF) 2 Long carbon fiber roving surface treated with epoxy sizing Mitsubishi Chemical Corporation, TR50S15L (TEX number 15000, filament diameter 7 μm)

[0097] 2. Preparation of fiber-reinforced resin composition and test specimens 2-1. Preparation of test piece 1 in which reinforcing fiber (E) is short fiber (Examples 1-1 to 1-5, Comparative Examples 1-6 to 1-9) The polyolefin (A), modified polyolefin (B), styrene-based elastomer (D) having butylene blocks, and polyamide (C) shown in Table 1 were blended in the proportions (units: mass%) shown in Table 1 and charged into the hopper of a twin-screw melt kneading extruder (HK-25D, manufactured by Parker Corporation, L / D = 41, D = 25 mm) whose temperature was adjusted to 230°C. Furthermore, the reinforcing fiber (E) shown in Table 1 was charged into the twin-screw melt kneading extruder from a side feeder so that the proportion of the reinforcing fiber (E) in the resulting fiber-reinforced resin composition would be the amount shown in Table 1. The extruded resin component was then cooled and solidified, and cut with a strand cutter to obtain a pellet-shaped fiber-reinforced resin composition (fiber-reinforced resin composition 1).

[0098] This fiber reinforced resin composition 1 was injection molded using an injection molding machine (manufactured by The Japan Steel Works, Ltd., J100ADS-180U) under injection conditions of a set temperature of 230°C and a mold temperature of 80°C to form dumbbell-shaped test pieces for evaluation tests (conforming to JIS K7139:2009 (ISO 3176:1993)) (these test pieces are referred to as test pieces 1). The weight average fiber length of the reinforcing fibers (E) in test piece 1 was less than 1.0 mm.

[0099] 2-2. Preparation of test piece 2 in which reinforcing fiber (E) is long fiber (Example 2-1, Comparative Examples 2-1 to 2-8) The polyolefin (A), modified polyolefin (B), styrene-based elastomer (D) or other elastomer (D') having butylene blocks, and polyamide (C) shown in Table 2 were blended in the proportions (unit: mass%) shown in Table 2 and charged into the hopper of a twin-screw melt-kneading extruder (TEX30α, manufactured by JSW, L / D = 63, D = 30 mm) temperature-controlled at 290°C. The reinforcing fiber (E) shown in Table 2 was expanded and introduced into the impregnation die. The melted resin components (i.e., a mixture of polyolefin (A), modified polyolefin (B), polyamide (C), and styrene-based elastomer (D) or other elastomer (D')) were fed into the impregnation die, and the reinforcing fiber (E) was impregnated with the resin components inside the impregnation die. The moving speed of the reinforcing fiber (E) was adjusted so that the proportion of the reinforcing fiber (E) in the resulting fiber-reinforced resin composition was the amount shown in Table 1. Thereafter, the resin component impregnated into the reinforcing fibers (E) was cooled and solidified, and the reinforcing fibers (E) and the resin component were cut into pellets 9 mm long with a strand cutter to obtain a pellet-shaped fiber-reinforced resin composition (fiber-reinforced resin composition 2).

[0100] This fiber reinforced resin composition 2 was injection molded using an injection molding machine (manufactured by The Japan Steel Works, Ltd., J100ADS-180U) under injection conditions of a set temperature of 250°C and a mold temperature of 60°C, and molded into dumbbell-shaped test pieces for evaluation tests (conforming to JIS K7139:2009 (ISO 3176:1993)) (these test pieces are referred to as test pieces 2). The weight average fiber length of the reinforcing fibers (E) in test piece 2 was 1.0 mm or more.

[0101] 3. Evaluation The above test pieces were used to carry out the following evaluations.

[0102] 3-1. Bending test A bending test was performed at 23°C using dumbbell-shaped test pieces for evaluation testing in accordance with JIS K7171:2022. The flexural modulus FM (GPa) and flexural strength FS (MPa) were determined from the stress-strain curve obtained from the bending test at a test speed of 2 mm / min.

[0103] 3-2. Charpy impact resistance test The dumbbell-shaped test specimen for evaluation test was processed into a shape (Type 1) with a V-shaped notch in accordance with JIS K7111-1:2012, and the impact resistance value (KJ / m) was measured at 23°C with a hammer capacity of 4J in accordance with the 1eA standard. 2 ) was sought.

[0104] 3-3. Impact resistance and bending strength pass / fail judgment From the impact resistance and flexural strength values of each test piece, the increase in impact resistance and decrease in flexural strength were calculated relative to a blank test piece containing no elastomer. Specifically, for resin composition 1, the increase in impact resistance and decrease in flexural strength of each test piece relative to Comparative Example 1-6 (Blank 1) were calculated. Furthermore, for resin composition 2, the increase in impact resistance and decrease in flexural strength of each test piece relative to Comparative Example 2-2 (Blank 2) were calculated. An increase in impact resistance of 25% or more was evaluated as "pass" (○), and an increase in impact resistance of less than 25% was evaluated as "fail" (×). A decrease in flexural strength of 35% or less was evaluated as "pass" (○), and an increase in flexural strength of more than 35% was evaluated as "fail" (×).

[0105] 4.Results Tables 1 and 2 show the composition of the fiber-reinforced resin composition and the evaluation results of the test specimens prepared in each experiment.

[0106] [Table 1]

[0107] [Table 2]

[0108] As is clear from Tables 1 and 2, a fiber-reinforced resin composition containing unmodified polyolefin (A), modified polyolefin (B), styrene-based elastomer (D) having butylene blocks, and reinforcing fiber (E), wherein the content of unmodified polyolefin (A) is 20% by mass or more and 70% by mass or less, the content of modified polyolefin (B) is 1% by mass or more and 20% by mass or less, the content of styrene-based elastomer (D) is 10% by mass or more and 30% by mass or less, and the content of reinforcing fiber (E) is 10% by mass or more and 50% by mass or less, and the styrene-based elastomer (D) is an elastomer with a styrene content of 30% by mass or more and 60% by mass or less, significantly improved impact resistance, and molded articles could be produced that did not suffer a significant decrease in strength even when the elastomer was included. [Industrial Applicability]

[0109] According to the present invention, it is possible to produce a molded article which has significantly improved impact resistance and in which the strength of the molded article is not significantly reduced even when it contains an elastomer.

Claims

1. an unmodified polyolefin (A); A modified polyolefin (B), a styrene-based elastomer (D) having a butylene block; A fiber reinforced resin composition containing reinforcing fibers (E), Relative to the total mass of the fiber reinforced resin composition the content of the unmodified polyolefin (A) is 20% by mass or more and 70% by mass or less, The content of the modified polyolefin (B) is 1% by mass or more and 20% by mass or less, the content of the styrene-based elastomer (D) is 10% by mass or more and 30% by mass or less, The content of the reinforcing fiber (E) is 10% by mass or more and 50% by mass or less, The styrene-based elastomer (D) is an elastomer having a styrene content of 30% by mass or more and 60% by mass or less. Fiber-reinforced resin composition.

2. The fiber-reinforced resin composition further contains a polyamide (C) having a structural unit derived from a monomer having 10 or more carbon atoms, and the content of the polyamide (C) is 1% by mass or more and 20% by mass or less relative to the total amount of the fiber-reinforced resin composition. The fiber-reinforced resin composition according to claim 1.

3. The polyamide (C) is polyamide 12. The fiber-reinforced resin composition according to claim 2.

4. The polyolefin (A) is polypropylene. The fiber-reinforced resin composition according to claim 1.

5. The reinforcing fiber (E) is a glass fiber or a carbon fiber. The fiber-reinforced resin composition according to claim 1.

6. A molded article obtained by molding the fiber-reinforced resin composition according to any one of claims 1 to 5.

7. The molded article according to claim 6, which is a sports and leisure product.

Images