Vehicle impact absorbing member

Abstract

To provide a vehicle impact absorbing member made of a resin component using a recycled raw material that has excellent impact energy absorption properties under environmental resistance (low temperature, high temperature and high humidity) required for vehicle components and is capable of complying with European ELV regulations.SOLUTION: A vehicle impact absorbing member made of a thermoplastic resin composition obtained by blending (C) 0.1 to 3.5 pts.wt. of a carbodiimide compound and (D) 1 to 15 pts.wt. of a glycidyl group-containing copolymer having, as a copolymer component, a glycidyl ester of an α-olefin and an α,β-unsaturated acid, with respect to 100 pts.wt. in total of (A) 5 to 48 pts.wt. of polybutylene terephthalate and (B) 52 to 95 pts.wt. of polycarbonate, wherein 10 to 50 wt.% of (B) the polycarbonate is (F) recycled polycarbonate.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a vehicle impact absorbing member, and more particularly to a vehicle impact absorbing member that can exhibit excellent impact energy absorption properties even when made from environmentally friendly recycled raw materials. [Background technology]

[0002] In the case of body frame structures for automobiles and other vehicles, it is known that in order to improve safety in the event of a collision, the strength and rigidity of the frame can be increased and impact energy absorption can be improved by increasing the thickness of the frame plate or by arranging reinforcing plates (reinforcements) within the frame cross section.

[0003] On the other hand, from the viewpoint of improving fuel economy and steering response, further weight reduction is desired, and the conventional frame structures described above result in a significant increase in weight. Therefore, in order to simultaneously maintain or improve fuel economy and improve collision safety, resin impact absorbing components that aim to reduce weight have been proposed.

[0004] However, unlike metal parts such as steel and aluminum, these conventional plastic parts have limitations on the amount of recycled materials they can use. For this reason, the European Commission's proposed regulations on sustainability requirements for automotive design and end-of-life vehicle (ELV) management call for at least 25% of plastics used in vehicles to be PCR (post-consumer recycled: collecting and recycling products from the market) plastics by 2030. Furthermore, 25% of PCR plastics (6.25% of the total) must be made from plastic materials derived from end-of-life vehicles, creating a demand for plastic shock-absorbing components for vehicles made from recycled materials.

[0005] The following proposals have been made as vehicle impact absorbing members that can meet the various demands described above. For example, Patent Document 1 discloses a vehicle impact energy absorbing structure in which an impact absorbing member molded from carbon fiber reinforced resin is housed inside a hollow closed cross section such as a center pillar.

[0006] Furthermore, Patent Document 2 discloses a thermoplastic resin composition that can give molded articles with excellent moist heat resistance and impact resistance, and in particular, discloses its application to automobile exterior parts.

[0007] On the other hand, Patent Document 3 discloses a resin composition that uses recycled raw materials and is environmentally friendly, and that can be laser welded and / or laser marked.

[0008] Furthermore, Patent Document 4 discloses exterior parts for copiers and printers that use a halogen-free flame-retardant resin composition made from recycled raw materials.

[0009] However, these conventional techniques still have problems in using resin parts made from recycled raw materials as impact absorbing components for vehicles. [Prior art documents] [Patent documents]

[0010] [Patent Document 1] Japanese Patent Application Laid-Open No. 2017-19428 [Patent Document 2] Japanese Patent Application Laid-Open No. 2014-189729 [Patent Document 3] Japanese Patent Application Publication No. 2023-114412 [Patent Document 4] Japanese Patent Publication No. 2023-92802 Summary of the Invention [Problem to be solved by the invention]

[0011] Therefore, the object of the present invention is to address the problems in the prior art as described above, and to provide a vehicle impact absorbing component made of resin parts using recycled raw materials that has excellent impact energy absorption properties, particularly under the environmental resistance (low temperature, high temperature and high humidity) required for vehicle parts, and that complies with European ELV regulations. [Means for solving the problem]

[0012] In order to solve the above problems, the vehicle impact absorbing component of the present invention is a vehicle impact absorbing component made from a thermoplastic resin composition obtained by blending 5 to 48 parts by weight of (A) polybutylene terephthalate and 52 to 95 parts by weight of (B) polycarbonate, a total of 100 parts by weight, with 0.1 to 3.5 parts by weight of (C) a carbodiimide compound and 1 to 15 parts by weight of (D) a glycidyl group-containing copolymer having as copolymerization components an α-olefin and a glycidyl ester of an α,β-unsaturated acid, wherein 10 to 50% by weight of the (B) polycarbonate is (F) recycled polycarbonate.

[0013] In the vehicle impact absorbing component according to the present invention, by having ribs extending in a direction along the external load direction of the vehicle impact absorbing component, it is possible to achieve excellent impact energy absorption performance.

[0014] In the impact absorbing component for a vehicle according to the present invention, the thickness of the rib is 2 to 5 mm, there are multiple ribs, and the roundness R (mm) of the corners where the ribs intersect with each other or where the rib intersects with the outer casing of the impact absorbing component is 0.5 times or more the thickness (mm) of the rib, thereby making it possible to achieve excellent impact energy absorption performance.

[0015] Furthermore, in the vehicle impact absorbing component according to the present invention, the thermoplastic resin composition contains (E) a phosphorus-based stabilizer, thereby making it possible to achieve excellent impact energy absorption performance.

[0016] Furthermore, in the impact absorbing component for a vehicle according to the present invention, a notched Charpy test piece is molded in accordance with ISO179-1:2000, and after being treated for 20 hours in an environment of a temperature of 121°C and a humidity of 100% RH, the Charpy impact strength measured in accordance with ISO179 is 25 kJ / m 2 As a result, it is possible to achieve excellent impact energy absorption performance.

[0017] Furthermore, in the vehicle impact absorbing component according to the present invention, the (F) recycled polycarbonate is made from water bottles for water dispensers, which makes it possible to easily secure the required amount of raw material and achieve excellent impact energy absorption performance.

[0018] Furthermore, in the vehicle impact absorbing component according to the present invention, the thermoplastic resin composition is a blend of 5 to 48 parts by weight of (A) polybutylene terephthalate and 52 to 95 parts by weight of (B) polycarbonate, totaling 100 parts by weight, and further containing 10 parts by weight or less of (G) recycled material from crash pad parts derived from end-of-life vehicles, thereby enabling the component to achieve excellent impact energy absorption performance while complying with European ELV regulations.

[0019] The impact absorbing component for a vehicle according to the present invention is useful as a vehicle part that requires resistance to severe environments and as a resin part made from recycled raw materials that complies with European ELV regulations. [Effects of the Invention]

[0020] The vehicle impact absorbing component according to the present invention is a thermoplastic resin composition comprising 100 parts by weight of a total of 5 to 48 parts by weight of (A) polybutylene terephthalate and 52 to 95 parts by weight of (B) polycarbonate, 0.1 to 3.5 parts by weight of (C) carbodiimide compound, and 1 to 15 parts by weight of (D) a glycidyl group-containing copolymer copolymerized with an α-olefin and a glycidyl ester of an α,β-unsaturated acid. Since 10 to 50% by weight of the (B) polycarbonate is recycled polycarbonate (F), the component exhibits excellent impact energy absorption performance even at low temperatures and at high temperatures and high humidity. This component is particularly useful for resin parts made from recycled materials that comply with European ELV regulations. [Brief explanation of the drawings]

[0021] [Figure 1] 1 is a perspective view showing a configuration of an impact absorbing member for a vehicle according to an embodiment of the present invention. [Figure 2] 1 is a perspective view showing a rib thickness of an impact absorbing member for a vehicle according to an embodiment of the present invention; [Figure 3] 1 is a perspective view showing the roundness R of a corner where ribs of a vehicle impact absorbing member according to one embodiment of the present invention intersect. [Figure 4] FIG. 10 is a see-through perspective view showing the periphery of a fastening portion in which three or more ribs are formed radially in an impact absorbing member for a vehicle according to another embodiment of the present invention. [Figure 5] 1 is a perspective view showing an embodiment of a drop weight test of an impact absorbing member for a vehicle according to an embodiment of the present invention; [Figure 6] 3 is a graph showing a load-displacement curve of the impact absorbing member for a vehicle according to the embodiment of the present invention. [Figure 7] 10 is a graph showing a load-displacement curve of an impact absorbing member for a vehicle according to another embodiment of the present invention. [Figure 8] FIG. 10 is a perspective view showing the configuration of a vehicle impact absorbing member according to still another embodiment of the present invention. [Figure 9]FIG. 10 is a perspective view showing an embodiment of a drop weight test of an impact absorbing member for a vehicle according to another embodiment of the present invention. [Figure 10] 3 is a graph showing a load-displacement curve of the impact absorbing member for a vehicle according to the embodiment of the present invention. [Figure 11] 10 is a graph showing a load-displacement curve of a vehicle impact absorbing member including another embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0022] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

[0023] <Thermoplastic resin composition> The thermoplastic resin composition used in the vehicle impact absorbing component of the present invention comprises 100 parts by weight of a total of 5 to 48 parts by weight of (A) polybutylene terephthalate and 52 to 95 parts by weight of (B) polycarbonate, blended with 0.1 to 3.5 parts by weight of (C) a carbodiimide compound, and 1 to 15 parts by weight of (D) a glycidyl group-containing copolymer (hereinafter sometimes abbreviated as glycidyl group-containing copolymer) whose copolymerization components are an α-olefin and a glycidyl ester of an α,β-unsaturated acid. (A) Polybutylene terephthalate is a crystalline thermoplastic resin that exhibits excellent moldability, including high cycle properties, fluidity, and retention stability, in addition to electrical properties, chemical resistance, heat resistance, and dimensional stability. (B) Polycarbonate is an amorphous thermoplastic resin that exhibits excellent impact resistance, flame retardancy, heat resistance, and other properties. By combining specific amounts of the crystalline resin (A) polybutylene terephthalate and the amorphous resin (B) polycarbonate, molded products can exhibit high impact resistance. Although (A) polybutylene terephthalate has the problem of being easily hydrolyzed, this can be suppressed by adding (C) a carbodiimide compound or (D) a glycidyl group-containing copolymer.

[0024] Furthermore, when (A) polybutylene terephthalate and (B) polycarbonate are used in combination, a decrease in retention stability due to an ester exchange reaction between (A) polybutylene terephthalate and (B) polycarbonate can become an issue, but by adding (E) a phosphorus-based stabilizer, this ester exchange reaction can be suppressed.

[0025] <Polybutylene terephthalate> The polybutylene terephthalate (A) used in the present invention is a polymer obtained by a conventional polymerization method such as polycondensation reaction from raw materials containing terephthalic acid or its ester-forming derivative and 1,4-butanediol or its ester-forming derivative as the main components. Other copolymerization components may be copolymerized within a range that does not impair the properties, for example, within a range of about 20% by weight or less of the raw materials. Examples of other copolymerization components include aromatic dicarboxylic acids such as isophthalic acid, phthalic acid, 2,6-naphthalenedicarboxylic acid, 1,5-naphthalenedicarboxylic acid, bis(p-carboxyphenyl)methane, anthracenedicarboxylic acid, 4,4'-diphenyl ether dicarboxylic acid, 5-tetrabutylphosphonium isophthalate, 5-sodium sulfoisophthalic acid, and diphenic acid; aliphatic dicarboxylic acids such as oxalic acid, succinic acid, adipic acid, sebacic acid, azelaic acid, dodecanedioic acid, malonic acid, glutaric acid, and dimer acid; alicyclic dicarboxylic acids such as 1,3-cyclohexanedicarboxylic acid and 1,4-cyclohexanedicarboxylic acid; and ester-forming derivatives thereof. Other examples include aliphatic diols such as aliphatic glycols having 2 to 20 carbon atoms, such as ethylene glycol, propylene glycol, neopentyl glycol, 1,5-pentanediol, 1,6-hexanediol, decamethylene glycol, and dimer diol; long-chain glycols having a molecular weight of 200 to 100,000, such as polyethylene glycol, poly-1,3-propylene glycol, and polytetramethylene glycol; alicyclic diols such as cyclohexanedimethanol and cyclohexanediol; aromatic diols such as 4,4'-dihydroxybiphenyl, hydroquinone, t-butylhydroquinone, bisphenol A, bisphenol S, bisphenol F, and bisphenol-C; and ester-forming derivatives thereof.

[0026] Preferred examples of (A) polybutylene terephthalate include polybutylene terephthalate, polybutylene (terephthalate / isophthalate), polybutylene (terephthalate / adipate), polybutylene (terephthalate / sebacate), polybutylene (terephthalate / decanedicarboxylate), polybutylene (terephthalate / naphthalate), and poly(butylene / ethylene) terephthalate. Here, " / " indicates a copolymer. Two or more of these may be blended.

[0027] The polybutylene terephthalate (A) used in the present invention preferably has an intrinsic viscosity in the range of 0.60 to 1.60 dL / g when measured in an o-chlorophenol solution at 25°C. If the intrinsic viscosity is 0.60 dL / g or higher, molded articles with more excellent mechanical properties such as tensile strength, flexural strength, flexural modulus, and impact resistance can be obtained. 0.80 dL / g or higher is more preferable. On the other hand, if the intrinsic viscosity is 1.60 dL / g or lower, the flowability can be further improved.

[0028] The method for producing the polybutylene terephthalate (A) used in the present invention is not particularly limited, and examples thereof include known polycondensation methods, ring-opening polymerization methods, etc. Either batch polymerization or continuous polymerization may be used, and either transesterification or direct polymerization polycondensation may be applied. However, continuous polymerization is preferred because it can reduce the amount of carboxyl terminal groups and has a greater effect of improving fluidity, and direct polymerization is preferred from the standpoint of cost.

[0029] In order to effectively promote the esterification reaction, transesterification reaction, and polycondensation reaction, it is preferable to add a catalyst during these reactions. Specific examples of catalysts include organic titanium compounds, tin compounds, zirconia compounds, and antimony compounds. Examples of organic titanium compounds include methyl ester, tetra-n-propyl ester, tetra-n-butyl ester, tetraisopropyl ester, tetraisobutyl ester, tetra-tert-butyl ester, cyclohexyl ester, phenyl ester, benzyl ester, tolyl ester, and mixed esters thereof of titanic acid. Examples of tin compounds include dibutyltin oxide, methylphenyltin oxide, tetraethyltin, hexaethylditin oxide, cyclohexahexylditin oxide, didodecyltin oxide, triethyltin hydroxide, triphenyltin hydroxide, triisobutyltin acetate, dibutyltin diacetate, diphenyltin dilaurate, monobutyltin trichloride, dibutyltin dichloride, tributyltin chloride, dibutyltin sulfide, butylhydroxytin oxide, and alkylstannoic acids such as methylstannoic acid, ethylstannoic acid, and butylstannoic acid. Examples of zirconia compounds include zirconium tetra-n-butoxide. Examples of antimony compounds include antimony trioxide and antimony acetate. Two or more of these compounds may be used. Among these, organic titanium compounds and tin compounds are preferred, with tetra-n-propyl ester, tetra-n-butyl ester, and tetraisopropyl ester of titanic acid being more preferred, and tetra-n-butyl ester of titanic acid being particularly preferred. The amount of catalyst added is preferably in the range of 0.005 to 0.5 parts by weight, more preferably 0.01 to 0.2 parts by weight, per 100 parts by weight of the polybutylene terephthalate resin, in terms of mechanical properties, moldability, and color tone.

[0030] The amount of (A) polybutylene terephthalate in the thermoplastic resin composition used in the vehicle impact absorbing component of the present invention is in the range of 5 to 48 parts by weight, relative to 100 parts by weight of the total of (A) polybutylene terephthalate and (B) polycarbonate (described below). If the amount of (A) polybutylene terephthalate is less than 5 parts by weight, the fluidity of the thermoplastic resin composition decreases. 20 parts by weight or more is preferred. On the other hand, if the amount of (A) polybutylene terephthalate is more than 48 parts by weight, the impact resistance of the molded article decreases. 40 parts by weight or less is preferred.

[0031] <Polycarbonate> The polycarbonate (B) used in the present invention is a polymer obtained by reacting raw materials mainly composed of a dihydric phenol and a carbonate precursor such as phosgene or a carbonate ester compound, etc. For example, it is produced by reacting a dihydric phenol with a carbonate precursor such as phosgene in a solvent such as methylene chloride, or by transesterification of a dihydric phenol with a carbonate precursor such as diphenyl carbonate.

[0032] Examples of dihydric phenols include 2,2-bis(4-hydroxyphenyl)propane (bisphenol A), bis(4-hydroxyphenyl)alkane, 1,1-(4-hydroxyphenyl)methane, 1,1-(4-hydroxyphenyl)ethane, hydroquinone, bis(4-hydroxyphenyl)cycloalkane, bis(4-hydroxyphenyl)oxide, bis(4-hydroxyphenyl)sulfide, bis(4-hydroxyphenyl)sulfone, bis(4-hydroxyphenyl)sulfoxide, and bis(4-hydroxyphenyl)ether. Two or more of these may be used. Among these, 2,2-bis(4-hydroxyphenyl)propane (bisphenol A) is preferred.

[0033] Examples of the carbonate ester compound include diaryl carbonates such as diphenyl carbonate, and dialkyl carbonates such as dimethyl carbonate and diethyl carbonate. Two or more of these may be used.

[0034] The polycarbonate (B) used in the present invention preferably has a number-average molecular weight of 10,000 to 60,000. A number-average molecular weight of 10,000 or more further improves the mechanical properties of the molded article, such as tensile strength, flexural strength, flexural modulus, and impact resistance. A number-average molecular weight of 15,000 or more is more preferable. On the other hand, a number-average molecular weight of 60,000 or less further improves the fluidity of the thermoplastic resin composition. A number-average molecular weight of 40,000 or less is more preferable. Polycarbonates having such a number-average molecular weight are available, for example, from Idemitsu Kosan Co., Ltd. under the trade name "Toughlon" (registered trademark) A2600. The number-average molecular weight was measured using GPC (gel permeation chromatography).

[0035] The amount of (B) polycarbonate in the thermoplastic resin composition used in the vehicle impact absorbing component of the present invention is in the range of 52 to 95 parts by weight per 100 parts by weight of the total of (B) polycarbonate and (A) polybutylene terephthalate. If the amount of (B) polycarbonate is less than 52 parts by weight, the impact resistance of the molded article will decrease. It is preferably 60 parts by weight or more. On the other hand, if the amount of (B) polycarbonate is more than 95 parts by weight, the fluidity of the thermoplastic resin composition will decrease. It is preferably 80 parts by weight or less.

[0036] <Carbodiimide compounds> The thermoplastic resin composition used in the vehicle impact absorbing member of the present invention contains a carbodiimide compound (C). The carbodiimide compound (C) inhibits hydrolysis and improves moist heat resistance by bonding with the carboxyl terminal of the polyester resin. Epoxy-based end-capping agents are generally known as compounds that inhibit the hydrolysis of polyester resins, but the carbodiimide compound (C) has a stronger hydrolysis-inhibiting effect than epoxy-based end-capping agents.

[0037] (C) Carbodiimide compound is a compound having at least one carbodiimide group represented by (-N=C=N-) in the molecule. For example, it can be produced by heating an organic isocyanate in the presence of a suitable catalyst to cause a decarboxylation reaction.

[0038] Examples of the (C) carbodiimide compound include N,N'-diphenylcarbodiimide, N,N'-di-cyclohexylcarbodiimide, N,N'-di-2,6-dimethylphenylcarbodiimide, N,N'-diisopropylcarbodiimide, N,N'-dioctyldecylcarbodiimide, N,N'-di-o-toluylcarbodiimide, N,N'-di-p-toluylcarbodiimide, N,N'-di-p-nitrophenylcarbodiimide, N,N'-di-p-aminophenylcarbodiimide, N,N'-di-p-hydroxyphenylcarbodiimide, N,N '-Di-p-chlorophenylcarbodiimide, N,N'-di-o-chlorophenylcarbodiimide, N,N'-di-3,4-dichlorophenylcarbodiimide, N,N'-di-2,5-dichlorophenylcarbodiimide, N,N'-p-phenylene-bis-o-toluylcarbodiimide, N,N'-p-phenylene-bis-dicyclohexylcarbodiimide, N,N'-p-phenylene-bis-di-p-chlorophenylcarbodiimide, N,N'-2,6,2',6'-tetraisopropyldiphenylcarbodiimide, N,N'-hexamethylene-bis -cyclohexylcarbodiimide, N,N'-ethylene-bis-diphenylcarbodiimide, N,N'-ethylene-bis-dicyclohexylcarbodiimide, N-triyl-N'-cyclohexylcarbodiimide, N,N'-di-2,6-diisopropylphenylcarbodiimide, N,N'-di-2,6-di-tert-butylphenylcarbodiimide, N-toluyl-N'-phenylcarbodiimide, N,N'-benzylcarbodiimide, N-octadecyl-N'-phenylcarbodiimide, N-benzyl-N'-phenylcarbodiimide, N-octadecyl-N'-phenylcarbodiimide Tadecyl-N'-tolylcarbodiimide, N-cyclohexyl-N'-tolylcarbodiimide, N-phenyl-N'-tolylcarbodiimide, N-benzyl-N'-tolylcarbodiimide, N,N'-di-o-ethylphenylcarbodiimide, N,N'-di-p-ethylphenylcarbodiimide, N,N'-di-o-isopropylphenylcarbodiimide, N,N'-di-p-isopropylphenylcarbodiimide, N,N'-di-o-isobutylphenylcarbodiimide, N,N'-di-p-isobutylphenylcarbodiimide, N,N'-di-2,Monocarbodiimide compounds such as 6-diethylphenylcarbodiimide, N,N'-di-2-ethyl-6-isopropylphenylcarbodiimide, N,N'-di-2-isobutyl-6-isopropylphenylcarbodiimide, N,N'-di-2,4,6-trimethylphenylcarbodiimide, N,N'-di-2,4,6-triisopropylphenylcarbodiimide, and N,N'-di-2,4,6-triisobutylphenylcarbodiimide; poly(1,6-hexamethylenecarbodiimide), poly(4,4'-methylenebiscyclohexylcarbodiimide), and poly(1,3-cyclohexylenecarbodiimide); Examples of suitable polycarbodiimide compounds include poly(1,4-cyclohexylenecarbodiimide), poly(4,4'-diphenylmethanecarbodiimide), poly(3,3'-dimethyl-4,4'-diphenylmethanecarbodiimide), poly(naphthylenecarbodiimide), poly(p-phenylenecarbodiimide), poly(m-phenylenecarbodiimide), poly(tolylcarbodiimide), poly(diisopropylcarbodiimide), poly(methyl-diisopropylphenylenecarbodiimide), poly(triethylphenylenecarbodiimide), and poly(triisopropylphenylenecarbodiimide). Two or more of these may be blended together. Among these, polycarbodiimide compounds are preferred, and poly(diisopropylphenylcarbodiimide) is more preferred. Poly(diisopropylphenylcarbodiimide) is available, for example, from Rhein Chemie under the trade name "Stavaxol" (registered trademark) P.

[0039] The amount of the (C) carbodiimide compound in the thermoplastic resin composition used in the vehicle impact absorbing component of the present invention is 0.1 to 3.5 parts by weight per 100 parts by weight of the total of the (A) polybutylene terephthalate and the (B) polycarbonate. If the amount of the (C) carbodiimide compound is less than 0.1 part by weight, the impact energy absorption performance of the impact absorbing component at low temperatures or high temperatures and high humidity conditions will decrease. A content of 0.3 parts by weight or more is preferred. On the other hand, if the amount of the (C) carbodiimide compound exceeds 3.5 parts by weight, molding will become difficult due to the generation of mold deposits (gas generated during molding). From the viewpoint of further suppressing mold deposits during molding, a content of 2.0 parts by weight or less is even more preferred.

[0040] <Glycidyl group-containing copolymer> The thermoplastic resin composition used in the vehicle impact absorbing component of the present invention contains (D) a glycidyl group-containing copolymer, which binds to the carboxyl terminal of (A) polybutylene terephthalate, thereby inhibiting hydrolysis and improving the moist heat resistance of the molded article.

[0041] Furthermore, the (D) glycidyl group-containing copolymer has excellent toughness, which has the effect of improving the impact resistance of molded articles. Such (D) glycidyl group-containing copolymer is a copolymer obtained by copolymerizing an α-olefin, a glycidyl ester of an α,β-unsaturated acid, and, if necessary, an unsaturated monomer copolymerizable therewith. It is preferable to use 60% by weight or more of the α-olefin and the glycidyl ester of an α,β-unsaturated acid among all copolymerization components.

[0042] Examples of α-olefins include ethylene, propylene, butene-1, and pentene-1. Two or more of these may be used. Examples of glycidyl esters of α,β-unsaturated acids include glycidyl acrylate, glycidyl methacrylate, glycidyl ethacrylate, and glycidyl itaconate. Two or more of these may be used. Examples of vinyl monomers copolymerizable with the above components include vinyl ethers, vinyl esters such as vinyl acetate and vinyl propionate, acrylic and methacrylic esters such as methyl, ethyl, propyl, and butyl, acrylonitrile, and styrene. Two or more of these may be used.

[0043] Preferred examples of the glycidyl group-containing copolymer (D) in the present invention include ethylene / glycidyl methacrylate copolymer, ethylene / glycidyl methacrylate / vinyl acetate copolymer, ethylene / glycidyl methacrylate / acrylic acid ester copolymer, and ethylene / glycidyl acrylate / vinyl acetate copolymer. Two or more of these may be blended. In particular, ethylene / glycidyl methacrylate / acrylic acid ester copolymer is preferred from the viewpoint of excellent toughness and further improving the moist heat resistance and impact resistance of molded articles. Ethylene / glycidyl methacrylate / methyl acrylate copolymer is particularly preferred, and is available, for example, from Elf Atochem under the trade name "Rotadar" (registered trademark) AX8900.

[0044] The amount of (D) glycidyl group-containing copolymer in the thermoplastic resin composition used in the vehicle impact absorbing component of the present invention is 1 to 15 parts by weight per 100 parts by weight of the total of (A) polybutylene terephthalate and (B) polycarbonate. If the amount of (D) glycidyl group-containing copolymer is less than 1 part by weight, the impact energy absorption performance of the impact absorbing component at low temperatures or high temperatures and high humidity will decrease. 3 parts by weight or more is preferred. On the other hand, if the amount of (D) glycidyl group-containing copolymer exceeds 15 parts by weight, the fluidity of the thermoplastic resin composition will decrease. 10 parts by weight or less is preferred.

[0045] <Phosphorus-based stabilizer> The thermoplastic resin composition of the present invention preferably further contains (E) a phosphorus-based stabilizer, which has the effect of suppressing the transesterification reaction between (A) polybutylene terephthalate and (B) polycarbonate and improving retention stability.

[0046] (E) Examples of the phosphorus-based stabilizer include phosphite-based stabilizers (phosphite compounds) and phosphate-based stabilizers (phosphate compounds). Two or more of these may be used. Among these, phosphate-based stabilizers are preferred because they are more effective in improving the retention stability of the thermoplastic resin composition.

[0047] Examples of the phosphite stabilizer include tetrakis[2-t-butyl-4-thio(2'-methyl-4'-hydroxy-5'-t-butylphenyl)-5-methylphenyl]-1,6-hexamethylene-bis(N-hydroxyethyl-N-methylsemicarbazide)-diphosphite, tetrakis[2-t-butyl-4-thio(2'-methyl-4'-hydroxy-5'-t-butylphenyl)-5-methylphenyl]-1,10-decamethylene-dicarboxylic acid-dihydroxyethylcarbonylhydrazide-diphosphite, tetrakis[2-t-butyl-4-thio(2'-methyl-4'-hydroxy-5'-t-butylphenyl)-5-methylphenyl]-1,10-decamethylene-dicarboxylic acid-dihydroxyethylcarbonylhydrazide-diphosphite, and tetrakis[2-t-butyl-4-thio(2'-methyl-4 tetrakis[2-t-butyl-4-thio(2'-methyl-4'-hydroxy-5'-t-butylphenyl)-5-methylphenyl]-N,N'-bis(hydroxyethyl)oxamide-diphosphite, tetrakis[2-t-butyl-4-thio(2'-methyl-4'-hydroxy-5'-t-butylphenyl)-5-methylphenyl]-N,N'-bis(hydroxyethyl)oxamide-diphosphite, and the like. Those in which at least one PO bond is bonded to an aromatic group are preferred, such as tris(2,4-di-t-butylphenyl)phosphite, tetrakis(2,4-di-t-butylphenyl)4,4'-biphenylenephosphonite, bis(2,4-di-t-butylphenyl)pentaerythritol-diphosphite, bis(2,6-di-t-butyl-4-methylphenyl)pentaerythritol-diphosphite, 2,2-methylenebis(4,6-di-t -butylphenyl)octyl phosphite, 4,4'-butylidene-bis(3-methyl-6-t-butylphenyl-di-tridecyl) phosphite, 1,1,3-tris(2-methyl-4-ditridecyl phosphite-5-t-butyl-phenyl)butane, tris(mixed mono- and di-nonylphenyl) phosphite, tris(nonylphenyl) phosphite, 4,4'-isopropylidenebis(phenyl-dialkyl phosphite), etc. Two or more of these may be combined.Among these, tris(2,4-di-t-butylphenyl)phosphite, 2,2-methylenebis(4,6-di-t-butylphenyl)octylphosphite, bis(2,6-di-t-butyl-4-methylphenyl)pentaerythritol-diphosphite, tetrakis(2,4-di-t-butylphenyl)-4,4'-biphenylenephosphonite, etc. are preferably used. Among these, cyclic neopentanetetraylbis(2,6-di-t-butyl-4-methylphenyl)phosphite is particularly preferred, and is available, for example, from ADEKA Corporation under the trade name "ADEKA STAB" (registered trademark) PEP-36.

[0048] Examples of phosphate stabilizers include monostearyl acid phosphate, distearyl acid phosphate, methyl acid phosphate, isopropyl acid phosphate, butyl acid phosphate, octyl acid phosphate, and isodecyl acid phosphate. Two or more of these may be combined. Among these, monostearyl acid phosphate and distearyl acid phosphate are preferred. A nearly equimolar mixture of these mono- and distearyl acid phosphates is particularly preferred, and is available, for example, under the trade name "ADEKA STAB" (registered trademark) AX-71 manufactured by ADEKA Corporation.

[0049] The amount of (E) phosphorus-based stabilizer is preferably 0.005 to 0.02 parts by weight per 100 parts by weight of the total of (A) polybutylene terephthalate and (B) polycarbonate. When the amount of (E) phosphorus-based stabilizer is 0.005 parts by weight or more, the retention stability of the thermoplastic resin composition is further improved. On the other hand, when the amount of (E) phosphorus-based stabilizer is 0.02 parts by weight or less, the reaction between (C) carbodiimide compound and (D) glycidyl group-containing copolymer is suppressed, and the impact energy absorption performance of the impact absorbing component formed by (C) carbodiimide compound and (D) glycidyl group-containing copolymer at low temperatures and high temperatures and high humidity is fully achieved.

[0050] <Recycled polycarbonate> The thermoplastic resin composition used in the vehicle impact absorbing member of the present invention is made by blending 10 to 50% by weight of the (B) polycarbonate with the (F) recycled polycarbonate.

[0051] The recycled polycarbonate (F) used in the present invention is a polycarbonate resin recovered from molded articles using polycarbonate resin as a base material, and is a material recycled material also known as polycarbonate resin derived from market recovered products, recovered or reclaimed polycarbonate resin. It may be a polycarbonate resin recovered from used molded articles shipped to the market among polycarbonate resin molded articles, or a polycarbonate resin recovered from waste materials, scraps, or defective products generated in the process of manufacturing molded articles.

[0052] It should be noted that so-called chemically recycled products, in which polycarbonate resin is returned to its starting materials and then converted into polycarbonate resin, do not fall under the category of (F) recycled polycarbonate, but rather correspond to virgin (B) polycarbonate. (F) recycled polycarbonate may be used alone or in a mixture of two or more types, but is preferably a polycarbonate resin derived from post-consumer recycled products.

[0053] Preferred types of molded articles from which (F) recycled polycarbonate can be recovered include beverage containers such as water bottles for water dispensers, baby bottles, and thermoses; optical components such as headlamps for automobiles and other vehicles, camera lenses, light guide plates, and transparent covers for electrical components; cases and housings for electronic components in pachinko game machines and the like; sheets; building materials such as corrugated sheets and carport boards; containers for transporting semiconductors; optical recording media such as optical discs like CDs and DVDs; etc. Among these, recycled polycarbonate resin recovered from water bottles for water dispensers and headlamps for automobiles and other vehicles is preferred.

[0054] The blending amount of (F) recycled polycarbonate in the thermoplastic resin composition used in the vehicle impact absorbing component of the present invention is 10 to 50% by weight relative to the (B) polycarbonate. If the blending amount of (F) recycled polycarbonate is less than 10% by weight, it becomes difficult to comply with the European ELV regulations. 20% by weight or more is preferable. On the other hand, if the blending amount of (F) recycled polycarbonate exceeds 50% by weight, the impact energy absorption performance of the impact absorbing component at low temperatures or high temperatures and high humidity conditions decreases. 40% by weight or less is preferable.

[0055] <Crash pad parts> The thermoplastic resin composition used in the vehicle impact absorbing component of the present invention preferably contains 5 to 48 parts by weight of the (A) polybutylene terephthalate and 52 to 95 parts by weight of the (B) polycarbonate (total of 100 parts by weight), and further contains 10 parts by weight or less of (G) recycled material from crash pad parts derived from end-of-life vehicles. If the amount of (G) recycled material from crash pad parts derived from end-of-life vehicles is 10 parts by weight or less, compliance with European ELV regulations becomes easier. On the other hand, if the amount of (G) recycled material from crash pad parts derived from end-of-life vehicles is more than 10 parts by weight, the impact energy absorption performance of the impact absorbing component at low temperatures and high temperatures and high humidity conditions decreases. Preferably, the amount is 7 parts by weight or less.

[0056] The recycled crash pad parts (G) derived from scrapped vehicles used in the present invention are resin parts attached to the front and rear bumper beams of scrapped automobiles and other vehicles or near the impact beams inside the doors, and the ISO notation engraved on the parts preferably includes "PC+PBT," "PC+PBT-I," or "PBT+PC."

[0057] <Other additives> The thermoplastic resin composition used in the vehicle impact absorbing member of the present invention may contain conventional additives such as stabilizers, release agents, and colorants, as well as small amounts of other polymers, provided that the effects of the present invention are not impaired. As stabilizers, any of those used as stabilizers for polyester resin compositions can be used. Examples include antioxidants, light stabilizers, and catalyst deactivators. Two or more of these may be blended. As release agents, any of those used as release agents for polyester resins can be used. Examples include plant-based waxes such as carnauba wax and rice wax, animal-based waxes such as beeswax and lanolin, mineral waxes such as montan wax, petroleum-based waxes such as paraffin wax and polyethylene wax, and oil-based waxes such as castor oil and its derivatives, fatty acids and its derivatives. Two or more of these may be blended. As colorants, for example, organic dyes, organic pigments, and inorganic pigments can be used. Two or more of these may be blended. The other polymer may be any melt-moldable resin, such as AS resin (acrylonitrile / styrene copolymer), hydrogenated or unhydrogenated SBS resin (styrene / butadiene / styrene triblock copolymer), hydrogenated or unhydrogenated SIS resin (styrene / isoprene / styrene triblock copolymer), polyethylene resin, polypropylene resin, polymethylpentene resin, cyclic olefin resin, cellulose resin such as cellulose acetate, polyamide resin, polyacetal resin, polysulfone resin, polyphenylene sulfide resin, polyether ether ketone resin, polyimide resin, polyetherimide resin, etc. Two or more of these may be blended.

[0058] <Manufacturing method> Examples of a method for producing the thermoplastic resin composition used in the vehicle impact absorbing member of the present invention include a method of melt-kneading each component using a known melt-kneader such as a single-screw or twin-screw extruder, a Banbury mixer, a kneader, or a mixing roll. It is preferable to melt-knead each component so that they are uniformly dispersed. The components may be mixed together in advance and then melt-kneaded. The moisture content of each component is preferably low, and it is desirable to dry the components in advance if necessary.

[0059] Furthermore, examples of methods for feeding each component into a melt kneader include a method in which a single-screw or twin-screw extruder is used, and (A) polybutylene terephthalate, (B) polycarbonate, (C) carbodiimide compound, (D) glycidyl group-containing copolymer, (F) recycled polycarbonate, and other components as necessary are fed into a main feeding port located at the base of the screw, followed by melt kneading.

[0060] The thermoplastic resin composition of the present invention can be processed into various molded parts and used by molding it by any known method such as injection molding, extrusion molding, blow molding, press molding, or spinning.

[0061] The vehicle impact-absorbing component of the present invention is produced by molding a thermoplastic resin composition. Molding using a mold is preferred, and various molding methods such as injection molding, extrusion molding, and press molding can be used. Molding using an injection molding machine, in particular, allows for continuous, stable production of molded products. While there are no particular restrictions on injection molding conditions, preferred conditions include an injection time of 0.5 to 10 seconds, a back pressure of 0.1 to 10 MPa, a dwell pressure of 1 to 50 MPa, a dwell time of 1 to 20 seconds, a cylinder temperature of 200 to 340°C, and a mold temperature of 20 to 150°C. Here, the cylinder temperature refers to the temperature of the part of the injection molding machine where the molding material is heated and melted, and the mold temperature refers to the temperature of the mold into which the resin is injected to form the desired shape. By appropriately selecting these conditions, particularly the injection time, injection pressure (back pressure and dwell pressure), and mold temperature, it is possible to appropriately adjust the appearance, sink marks, warpage, and other characteristics of the molded product.

[0062] <Charpy impact strength> The vehicle impact absorbing component of the present invention is prepared by molding a notched Charpy test piece in accordance with ISO179-1:2000, subjecting it to a PCT (Pressure Cooker Test) tester at a temperature of 121°C and a humidity of 100% for 20 hours, and then measuring the Charpy impact strength in accordance with ISO179 to a value of 25 kJ / m. 2 The Charpy impact strength under such conditions represents the toughness after high temperature and high humidity environmental treatment that simulates the conditions under which a vehicle impact absorbing component is used for a long period of time inside an automobile underhood at an accelerated rate. 2 If the impact resistance is 30 kJ / m or more, it can be said that the impact resistance in a high-temperature, high-humidity environment is excellent, and the material can be suitably used as an impact absorbing member. 2 Here, in the present invention, the Charpy impact strength is measured using N=5 test pieces, and the Charpy impact strength is calculated by excluding the maximum and minimum values ​​of each measurement and dividing the average value by the product of the width and thickness of the test piece.

[0063] Furthermore, it is desirable that the Charpy impact strength after the high-temperature, high-humidity treatment should have little change from the Charpy impact strength before the high-temperature, high-humidity treatment. The impact strength retention calculated by the following formula is preferably 45% or more, and more preferably 55% or more. Impact strength retention rate (%) = (impact strength of test piece after 20 hours of high temperature and humidity treatment / impact strength of test piece before high temperature and humidity treatment) x 100

[0064] The impact absorbing component for a vehicle having the above-mentioned properties can be obtained, for example, by using the thermoplastic resin composition used in the impact absorbing component for a vehicle of the present invention as described above.

[0065] <Impact-absorbing components for vehicles> In the present invention, the vehicle impact absorbing component is preferably a component that receives an input impact load, and the component has the function of absorbing the applied impact energy itself and transmitting the applied impact load from the component to other structural components with changes over time. Therefore, preferred examples of the component include an automobile bumper beam, a component installed alongside a side sill, an underhood, or a component installed inside a door panel.

[0066] <Shape of vehicle impact absorbing member> Furthermore, the vehicle impact absorbing component according to the present invention preferably has ribs extending in a direction parallel to the external load direction. Having such ribs allows the component to exert a high resistance to the external load, thereby enabling the vehicle impact absorbing component to exhibit high strength. The direction parallel to the external load direction is not particularly limited, but from the viewpoint of more efficiently bearing the external load, it is preferable that the direction parallel to the external load direction or a direction close to it.

[0067] <Thickness of vehicle impact absorbing member> Furthermore, in the vehicle impact absorbing member according to the present invention, the rib thickness is preferably 2 to 5 mm. Such a rib thickness allows the member to exert high resistance to external loads, thereby enabling the member to exhibit high strength as a vehicle impact absorbing member. If the rib thickness is less than 2 mm, the member will be prone to cracking under external loads (brittle fracture), and the impact energy absorption performance of the impact absorbing member will decrease at low temperatures or high temperatures and humidity. If the thickness exceeds 5 mm, voids (cavities) will be easily generated inside the rib due to the use of recycled materials, and the impact energy absorption performance of the impact absorbing member will decrease. A thickness of 2 to 4 mm is more preferable.

[0068] <Roundness R of the corners of vehicle impact absorbing components> Furthermore, in the vehicle impact absorbing component according to the present invention, it is preferable that the radius R (mm) of the corners where the ribs intersect or where the rib intersects with the outer periphery of the impact absorbing component is 0.5 times or more the thickness (mm) of the rib. Having such a radius R allows the component to exert high resistance to external loads, thereby enabling the vehicle impact absorbing component to exhibit high strength. If the radius R is less than 0.5 times the thickness of the rib, stress will be concentrated at the corners, making the component more susceptible to cracking (brittle fracture), and the impact energy absorption performance of the impact absorbing component at low temperatures or high temperatures and high humidity will be reduced. A radius R of 0.75 times or more is more preferable.

[0069] <Fastening portion of vehicle impact absorbing member> Furthermore, the vehicle impact absorbing component according to the present invention is often used by fastening it to a metal part of the vehicle. For example, it is used by fastening it to a component attached to an automobile bumper beam or side sill, or to a metal part installed inside an underhood or door panel. While bolts, snap fits, pins, etc. are used to fasten it to the metal part, bolt fastening is preferred due to its effectiveness in absorbing impact energy. Furthermore, a shape in which three or more radial ribs are formed around the fastening portion of the vehicle impact absorbing component is preferred because it has a higher impact energy absorption effect, and is also preferred over bolt fastening with a metal collar attached to the fastening portion.

[0070] Specific examples of the configuration (shape) of the impact absorbing member for a vehicle according to the present invention will be described with reference to FIGS. 1 to 4. FIG. FIG. 1 shows the configuration of a vehicle impact absorbing component according to one embodiment of the present invention, where reference numeral 1 indicates the entire vehicle impact absorbing component. Vehicle impact absorbing component 1 comprises an outer shell 2 having a rectangular cross-section with sides of approximately 50 mm and a height of approximately 60 mm, and ribs 3 connected to outer shell 2 and intersecting each other, each having a thickness (wall thickness) of approximately 2 mm. The bottom of the outer shell 2 has a fastening portion 4 for fastening to another vehicle component (e.g., another metal component, not shown), and fastening portion 4 has a bolt hole 5 formed therein. A metal collar (not shown) may be attached to bolt hole 5. Ribs 3 extend in the direction of an external load (from top to bottom in FIG. 1).

[0071] In the above-described vehicle impact absorbing member 1, the thickness (wall thickness) of the outer shell 2 and ribs 3 can be set as desired while taking into consideration the overall strength, rigidity, and total weight of the vehicle impact absorbing member 1 for weight reduction, and can be set to, for example, 1 mm or 6 mm as shown in Figures 2(A) and 2(B). However, as mentioned above, these wall thicknesses are preferably in the range of 2 to 5 mm.

[0072] Furthermore, in the vehicle impact absorbing member according to the present invention, as mentioned above, it is desirable that the radius R (mm) of the corners where the ribs intersect or where the rib intersects with the outer shell of the impact absorbing member is at least 0.5 times, and preferably at least 0.75 times the thickness (mm) of the rib. This corner radius R refers to the radius R of the corners where the ribs 3 intersect with each other or where the rib 3 intersects with the outer shell 2, as shown in Fig. 3, for example, and it is preferable that the radius R of all corners satisfy the above range.

[0073] Furthermore, in the vehicle impact absorbing member according to the present invention, it is preferable that the fastening portion 4 in Fig. 1 has a structure in which three or more ribs 12 are formed radially around the fastening portion (more precisely, the bolt hole of the fastening portion) 11, as shown in Fig. 4. This structure can ensure the desired strength of the fastening portion while minimizing the weight of the entire member. [Example]

[0074] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to the descriptions of these examples. First, the materials used in these examples and the methods for evaluating various properties will be described.

[0075] (1) Resin materials (A) Polybutylene terephthalate (melting point 223°C, Toray Industries, Inc. "Trecon" (registered trademark) 1100M (product name)) (B) Polycarbonate (Idemitsu Kosan Co., Ltd. "Toughlon" (registered trademark) A2600 (product name)) (C) Carbodiimide compound (poly(diisopropylphenylcarbodiimide) ("Stavaxol" (registered trademark) P (trade name) manufactured by Rhein Chemie) (D) Glycidyl group-containing copolymer ethylene / methyl acrylate / glycidyl methacrylate copolymer ("Rotader" (registered trademark) AX8900 (trade name) manufactured by ElfAtochem) (E) Phosphate-based antioxidant (a nearly equimolar mixture of mono- and di-stearyl acid phosphate) (ADEKA Corporation, "ADEKA STAB" (registered trademark) AX-71 (trade name)) (F) Recycled polycarbonate F-1: PCR product derived from water bottles used in water dispensers, manufactured by SunSang, PC110-BL-M (product name) Recycled polycarbonate F-2: Collected automobile headlamps and parts with the ISO mark "PC" are obtained from used car parts manufacturers and crushed into pellets. (G) Crash pad parts: Parts stamped with the ISO notation "PC+PBT" are obtained from a used car scrap parts manufacturer and crushed into pellets.

[0076] (2) Composition for vehicle impact absorbing components (A) to (G) components were fed from the hopper into a twin-screw extruder (ZSK57 manufactured by WERNER & Pfeiderer) with a screw diameter of 57 mm φ and a cylinder temperature set at 260 °C, and melt-kneaded. The strands discharged from the die were cooled in a cooling bath and then pelletized with a strand cutter to obtain a thermoplastic resin composition.

[0077] (3) Vehicle impact-absorbing member molded product The above thermoplastic resin composition was injection-molded to produce the vehicle impact-absorbing member molded products described in FIGS. 1 to 4 and 8. It was carried out at a cylinder temperature of 265 °C and a mold temperature of 80 °C. Also, the injection molding of the general-purpose PP resin was carried out at a cylinder temperature of 210 °C and a mold temperature of 40 °C.

[0078] (4) Drop weight impact test As shown in FIG. 5, the vehicle impact-absorbing member molded product 21 was fastened to the metal plate 22 with bolts 23 (M8), and a drop weight impact test under the following conditions was carried out with a striker 24 (rounding at the tip: R = 15 mm), and the load and displacement amount (load-displacement curve) as shown in FIGS. 6 and 7 were measured.

[0079] <-30 °C drop weight> After the vehicle impact-absorbing member molded product was temperature-controlled in a -40 °C constant temperature bath for 2 hours, it was quickly taken out, and when the surface temperature of the molded product reached -30 °C at room temperature (23 °C) after about 60 seconds, a drop weight impact test was carried out. FIG. 6 shows the drop weight impact test results of Example 2 and Comparative Example 2.

[0080] <Drop weight after PCT treatment> After the vehicle impact-absorbing member molded product was treated in a PCT tester at a temperature of 121 °C and a humidity of 100% RH for 20 hours, a drop weight impact test was carried out at room temperature (23 °C). FIG. 7 shows the drop weight impact test results of the PCT-treated products of Example 4 and Comparative Example 4.

[0081] <Input energy> 100 J: Load 16.2 kg × Impact velocity 3.5 m / s 200 J: Load 16.2 kg × Impact velocity 5.0 m / s 400 J: Load 16.2 kg × Impact velocity 7.0 m / s 600J: Load 16.2kg x Collision speed 8.6m / s 800J: Load 16.2kg x Collision speed 9.9m / s

[0082] <Verdict> Ductile fracture: "Good", partial brittle fracture: "Good", brittle fracture: "Poor".

[0083] (5) Charpy impact strength The thermoplastic resin composition was injection molded into test pieces (80 mm × 10 mm × 4.0 mm) according to ISO 179-1:2000. Five test pieces were notched to leave an 8 mm gap, and the Charpy impact strength was measured according to ISO 179. The Charpy impact strength was determined by dividing the impact strength by the product of the thickness and width of the test piece.

[0084] Five test pieces each molded in the same manner were treated in a PCT tester at a temperature of 121°C and a humidity of 100% for 20 hours, and then the Charpy impact strength of each test piece was measured in the same manner as above, and the impact strength retention rate (%) was calculated using the following formula. Impact strength retention rate (%) = (impact strength of test piece after 20 hours of high temperature and humidity treatment / impact strength of test piece before high temperature and humidity treatment) x 100

[0085] (6) High-load drop weight test As shown in Fig. 8, a vehicle impact absorbing component 1 was molded in a box-shaped test shape having lattice-like ribs 3 inside an outer shell 2, and as shown in Fig. 9, a vehicle impact absorbing component molded product 21 was fastened to a metal plate 22 with bolts 23 (M8), and a drop weight test was performed using a striker 24 (flat plate), measuring the load and displacement (load-displacement curve) as shown in Fig. 10 and Fig. 11. Note that the same reference numerals as those used in Figs. 1 and 5 were used to indicate the various parts in Figs. 8 and 9.

[0086] <Input energy> 1200J: Load 243kg x Collision speed 3.2m / s 1800J: Load 243kg x Collision speed 3.8m / s 2400J: Load 243kg x Collision speed 4.4m / s

[0087] <Verdict> Ductile fracture: "Good", partial brittle fracture: "Good", brittle fracture: "Poor".

[0088] (Examples 1 to 9, Comparative Examples 1 to 4) Thermoplastic resin compositions having the formulations shown in Table 1 were molded and evaluated for drop weight impact strength and Charpy impact strength. The results are shown in Table 1, Fig. 6 (showing the evaluation results of Example 2 and Comparative Example 2), and Fig. 7 (showing the evaluation results of Example 4 and Comparative Example 4). The impact-absorbing component molded product shape was evaluated with a rib thickness of 2 mm, a corner rounding ratio of 0.5, and normal fastening parts (normal means fastening parts with the configuration shown in Figs. 1 to 3, rather than a ribbed fastening part as shown in Fig. 4).

[0089] (Examples 10 to 15) Impact absorbing component molded articles having the test specimen shapes shown in Table 2 were molded and evaluated in a drop weight impact test. The results are summarized in Table 2.

[0090] (Examples 16 and 17) The fastening portion shape was changed as shown in Table 2 (the fastening portion shape of Example 16 was the same as that of Example 14), and a high-energy (input energy: 800 J) drop weight impact test was performed. The results are shown in Table 2.

[0091] [Table 1]

[0092] [Table 2]

[0093] As shown in Table 1, the molded articles of vehicle impact absorbing components according to the examples, which satisfied the requirements of the present invention, maintained ductile fracture even in drop weight impact tests at -30°C and after high-temperature, high-humidity treatment, demonstrating a preferable form for a vehicle impact absorbing component that can efficiently absorb energy with a small amount of displacement. On the other hand, the molded articles of vehicle impact absorbing components according to the comparative examples, which did not satisfy the requirements of the present invention, suffered particularly brittle fracture, resulting in poor energy absorption properties.

[0094] As shown in Table 2, the molded vehicle impact absorbing components according to the examples that met the requirements of the present invention showed some brittle fracture, but were still in a desirable form as vehicle impact absorbing components that could efficiently absorb energy with a small amount of displacement.

[0095] Furthermore, when a large input energy is applied as shown in Example 16, forming radial ribs around the fastening portion is a preferable form that can suppress fracture deformation of the fastening portion and absorb energy.

[0096] (Examples 18 to 20, Comparative Example 5) Using the thermoplastic resin composition having the formulation shown in Table 3, a box-shaped impact absorbing component molded article shown in FIG. 8 was molded and evaluated in the high-load drop weight test shown in FIG. 9. The general-purpose PP resin used in the comparative examples was a resin composition consisting of "PP + talc + elastomer." The results are shown in Table 3, FIG. 10 (showing the evaluation results of Example 18 and Comparative Example 5), and FIG. 11 (showing the evaluation results of Examples 18 to 20). The box-shaped test specimen was evaluated with a rib thickness of 2 mm, a corner rounding ratio of 0.5, and normal fastening.

[0097] [Table 3]

[0098] As shown in Table 3 and Figure 10, the molded vehicle impact absorbing component according to the embodiment that satisfies the requirements of the present invention maintains ductile fracture even in a high-load drop weight test, and can withstand a high load of 110 kN (11 tons), making it suitable for use as an alternative to impact absorbing components made of metals such as aluminum.

[0099] Furthermore, as shown in Fig. 11, even when the input energy is increased, ductile fracture is maintained stably, and large energy can be efficiently absorbed with high load and small displacement, making this a desirable form for a vehicle impact absorbing component that can also withstand automobile collisions.

[0100] On the other hand, the general-purpose PP resin commonly used in automobiles experienced partial brittle fracture, the load value was less than half at 51kN, and the displacement was large, resulting in poor energy absorption characteristics and making it inferior as an impact absorbing material for vehicles. [Industrial Applicability]

[0101] The vehicle impact absorbing component of the present invention is a resin part made from recycled materials that complies with European ELV regulations, and has excellent impact energy absorption properties under environmental resistance (low temperature, high temperature and high humidity), making it suitable for use as a vehicle component. [Explanation of symbols]

[0102] 1. Impact absorbing components for vehicles 2 Outer Wall 3. Ribs 4 Fastening part 5 bolt holes 11 Fastening part 12 Ribs 21 Impact absorbing molded parts for vehicles 22 Metal Plate 23 volts 24 Striker

Claims

1. A vehicle impact absorbing component made from a thermoplastic resin composition obtained by blending 5 to 48 parts by weight of (A) polybutylene terephthalate and 52 to 95 parts by weight of (B) polycarbonate, together for a total of 100 parts by weight, with 0.1 to 3.5 parts by weight of (C) a carbodiimide compound and 1 to 15 parts by weight of (D) a glycidyl group-containing copolymer having as copolymerization components an α-olefin and a glycidyl ester of an α,β-unsaturated acid, wherein 10 to 50% by weight of the (B) polycarbonate is (F) recycled polycarbonate.

2. The vehicle impact absorbing member according to claim 1 , further comprising a rib extending in a direction parallel to the external load direction of the vehicle impact absorbing member.

3. 3. The vehicle impact absorbing member according to claim 2, wherein the rib has a thickness of 2 to 5 mm.

4. 3. The vehicle impact absorbing component according to claim 2, wherein the vehicle impact absorbing component has a plurality of ribs, and the corners where the ribs intersect with each other or where the ribs intersect with the outer periphery of the impact absorbing component have a radius R (mm) of 0.5 times or more the thickness (mm) of the ribs.

5. 3. The impact absorbing component for a vehicle according to claim 1, wherein the thermoplastic resin composition further comprises a phosphorus-based stabilizer (E).

6. Notched Charpy test specimens were molded in accordance with ISO179-1:2000, and after 20 hours of treatment in an environment of 121°C and 100% RH, the Charpy impact strength measured in accordance with ISO179 was 25 kJ / m ２ 3. The vehicle impact absorbing member according to claim 1 or 2.

7. 3. The vehicle impact absorbing component according to claim 1, wherein the recycled polycarbonate (F) is made from water bottles for a water dispenser.

8. 3. The vehicle impact absorbing member according to claim 1 or 2, wherein the thermoplastic resin composition further comprises 10 parts by weight or less of (G) recycled material from crash pad parts derived from scrapped vehicles, for a total of 100 parts by weight of (A) 5 to 48 parts by weight of polybutylene terephthalate and (B) 52 to 95 parts by weight of polycarbonate.

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