Polycarbonate resin composition and molded article

Abstract

To provide a polycarbonate resin composition and a molding which less generate squeak noise (abnormal sound).SOLUTION: The polycarbonate resin composition contains 3.2-15 pts.mass of an ethylene-α-olefin copolymer (C) having a density of 0.940 g / cm3 or less and MFR (measurement at 190°C and 21.18 N) of 0.9 g / 10 min or more, with respect to 100 pts.mass of the total of 55-90 pts.mass of (A) a polycarbonate resin (A) and 10-45 pts.mass of a graft copolymer (B) containing an aromatic vinyl monomer component (b1), a vinyl cyanide monomer component (b2) and a diene-based rubbery polymer component (b3).SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a polycarbonate resin composition and molded articles, and more specifically, to a polycarbonate resin composition and molded articles that produce less squeaking noise (abnormal noise) and produce less squeaking noise (abnormal noise) even when used for long periods in high-temperature environments as vehicle parts, etc. [Background technology]

[0002] Alloy compositions made by compounding polycarbonate resin with ABS resin exhibit excellent moldability, impact resistance, mechanical strength, and heat resistance, making them suitable for use as parts and components in electrical and electronic equipment such as vehicles, computers, notebook PCs, various mobile terminals, printers, and photocopiers, as well as office automation and information equipment. In particular, polycarbonate resin / ABS resin alloys have long been widely used as interior materials due to their ease of molding and lightweight properties.

[0003] Furthermore, components installed inside automobiles, such as displays, console panels, dashboards, and car navigation systems, are manufactured by fitting together molded resin parts in order to reduce weight. For example, if they are housing structures, typically, two halves of a container-shaped molded part are formed, each with interlocking parts integrally molded in various places. The housing is then manufactured by fitting the outer edges of the upper and lower molded parts together, using screws or other fasteners with little to no use.

[0004] However, when such molded parts are installed in a vehicle, the temperature inside the car is subject to extreme temperature fluctuations from low to high, and the resin molded parts are prone to deformation due to contraction and expansion caused by thermal fluctuations. If even slight deformation occurs in the mating parts, creaking noises are likely to occur due to vibrations during vehicle operation. Creaking noises greatly impair passenger comfort, and since a higher level of interior quietness is required, especially in luxury cars, preventing the occurrence of creaking noises is an extremely important issue.

[0005] However, molded products made of polycarbonate resin / ABS resin alloy are prone to generating creaking noises (abnormal sounds) when the molded products come into dynamic contact with each other, such as during vibration. To reduce these creaking noises, it has been proposed to replace the ABS resin in the polycarbonate resin / ABS resin alloy with AES resin (see Patent Document 1). However, products molded from alloys in which ABS resin is replaced with AES resin may be prone to developing creaking noises when used for extended periods in high-temperature environments. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2018-138680 [Overview of the project] [Problems that the invention aims to solve]

[0007] The object of the present invention is, in view of the problems of the prior art described above, to provide a polycarbonate resin composition and molded article that generates less squeaking noise (abnormal noise) and generates less squeaking noise (abnormal noise) even when used for long periods in high-temperature environments as vehicle parts, etc. [Means for solving the problem]

[0008] In order to achieve the above objectives, the inventors have conducted extensive research and have found that a polycarbonate resin / ABS resin alloy rich in polycarbonate resin has a density of 0.940 g / cm³. 3 The present invention was completed based on the discovery that a polycarbonate resin composition containing a specific amount of ethylene-α-olefin copolymer with an MFR (measured at 190°C, 21.18N) of 0.9 g / 10 min or more generates less squeaking noise (abnormal noise), and even when used for long periods in high-temperature environments as vehicle parts, etc. In other words, the present invention relates to the following polycarbonate resin compositions and molded articles.

[0009] [1] A total of 100 parts by mass of (A) and (B) contains 55 to 90 parts by mass of polycarbonate resin (A) and 10 to 45 parts by mass of graft copolymer (B) containing aromatic vinyl monomer component (b1), vinyl cyanide monomer component (b2), and diene rubber polymer component (b3), with a density of 0.940 g / cm³. 3 The following polycarbonate resin composition is characterized by containing 3.2 to 15 parts by mass of ethylene-α-olefin copolymer (C) with an MFR (measured at 190°C, 21.18N) of 0.9 g / 10 min or more. [2] The polycarbonate resin composition described in [1] above, wherein the noise risk index based on the German Association of the Automotive Industry VDA203-206 is 1 to 3. [3] The polycarbonate resin composition according to [1] or [2] above, wherein the graft copolymer (B) is ABS resin. [4] A molded article obtained by molding a polycarbonate resin composition as described in any of [1] to [3] above. [5] The molded product described in [4] above, wherein the molded product is an automotive interior part. [Effects of the Invention]

[0010] The polycarbonate resin composition of the present invention generates less squeaking noise (abnormal noise), and even when used for long periods in high-temperature environments as vehicle parts, etc., it generates less squeaking noise (abnormal noise). Therefore, molded products made from the polycarbonate resin composition of the present invention can be used particularly suitably as automotive interior parts. [Modes for carrying out the invention]

[0011] The present invention will be described in detail below with reference to embodiments and examples, but the present invention is not limited to the embodiments and examples shown below. In this specification, the symbol "~" is used to mean that the numbers written before and after it include the lower and upper limits, respectively.

[0012] The polycarbonate resin composition of the present invention contains 55 to 90 parts by mass of a polycarbonate resin (A) and 10 to 45 parts by mass of a graft copolymer (B) comprising an aromatic vinyl monomer component (b1), a vinyl cyanide monomer component (b2) and a diene rubbery polymer component (b3), and based on 100 parts by mass of the total of (A) and (B), the density is 0.940 g / cm 3 or less, and 3.2 to 15 parts by mass of an ethylene-α-olefin copolymer (C) having an MFR (measured at 190°C under 21.18 N) of 0.9 g / 10 min or more is contained.

[0013] [Polycarbonate Resin (A)] The type of the polycarbonate resin (A) contained in the polycarbonate resin composition of the present invention is not limited, and only one type may be used, or two or more types may be used in combination at any optional combination and any optional ratio. The polycarbonate resin is a polymer having a basic structure with a carbonate bond represented by the general formula: -[-O-X-O-C(=O)-]-. In the above formula, X is generally a hydrocarbon, but X into which a heteroatom or a hetero bond is introduced may be used for imparting various properties.

[0014] As the polycarbonate resin (A), an aromatic polycarbonate resin is particularly preferred. The aromatic polycarbonate resin refers to a polycarbonate resin in which the carbons directly bonded to the carbonate bond are each an aromatic carbon. Among various polycarbonates, the aromatic polycarbonate is excellent from the viewpoints of heat resistance, mechanical properties, electrical characteristics and the like.

[0015] There are no specific restrictions on the type of aromatic polycarbonate resin, but examples include aromatic polycarbonate polymers obtained by reacting a dihydroxy compound with a carbonate precursor. In this case, polyhydroxy compounds may also be reacted in addition to the dihydroxy compound and carbonate precursor. Alternatively, a method may be used in which carbon dioxide is used as the carbonate precursor and reacted with a cyclic ether. Furthermore, aromatic polycarbonate polymers may be linear or branched. In addition, aromatic polycarbonate polymers may be homopolymers consisting of one type of repeating unit, or copolymers having two or more types of repeating units. In this case, various copolymerization forms such as random copolymers and block copolymers can be selected. Typically, such aromatic polycarbonate polymers are thermoplastic resins.

[0016] Examples of aromatic dihydroxy compounds among the monomers used as raw materials for aromatic polycarbonate resins include: Dihydroxybenzenes such as 1,2-dihydroxybenzene, 1,3-dihydroxybenzene (i.e., resorcinol), and 1,4-dihydroxybenzene;

[0017] Dihydroxybiphenyls such as 2,5-dihydroxybiphenyl, 2,2'-dihydroxybiphenyl, and 4,4'-dihydroxybiphenyl;

[0018] Dihydroxynaphthalene compounds such as 2,2'-dihydroxy-1,1'-binaphthyl, 1,2-dihydroxynaphthalene, 1,3-dihydroxynaphthalene, 2,3-dihydroxynaphthalene, 1,6-dihydroxynaphthalene, 2,6-dihydroxynaphthalene, 1,7-dihydroxynaphthalene, and 2,7-dihydroxynaphthalene;

[0019] Dihydroxydiaryl ethers such as 2,2'-dihydroxydiphenyl ether, 3,3'-dihydroxydiphenyl ether, 4,4'-dihydroxydiphenyl ether, 4,4'-dihydroxy-3,3'-dimethyldiphenyl ether, 1,4-bis(3-hydroxyphenoxy)benzene, and 1,3-bis(4-hydroxyphenoxy)benzene;

[0020] 2,2-bis(4-hydroxyphenyl)propane (i.e., bisphenol A), 1,1-Bis(4-hydroxyphenyl)propane, 2,2-bis(3-methyl-4-hydroxyphenyl)propane, 2,2-bis(3-methoxy-4-hydroxyphenyl)propane, 2-(4-hydroxyphenyl)-2-(3-methoxy-4-hydroxyphenyl)propane, 1,1-Bis(3-tert-butyl-4-hydroxyphenyl)propane, 2,2-bis(3,5-dimethyl-4-hydroxyphenyl)propane, 2,2-Bis(3-cyclohexyl-4-hydroxyphenyl)propane, 2-(4-hydroxyphenyl)-2-(3-cyclohexyl-4-hydroxyphenyl)propane, α,α'-bis(4-hydroxyphenyl)-1,4-diisopropylbenzene, 1,3-bis[2-(4-hydroxyphenyl)-2-propyl]benzene, Bis(4-hydroxyphenyl)methane, Bis(4-hydroxyphenyl)cyclohexylmethane, Bis(4-hydroxyphenyl)phenylmethane, Bis(4-hydroxyphenyl)(4-propenylphenyl)methane, Bis(4-hydroxyphenyl)diphenylmethane, Bis(4-hydroxyphenyl)naphthylmethane, 1,1-bis(4-hydroxyphenyl)ethane, 1,1-bis(4-hydroxyphenyl)-1-phenylethane, 1,1-bis(4-hydroxyphenyl)-1-naphthylethane, 1,1-Bis(4-hydroxyphenyl)butane, 2,2-bis(4-hydroxyphenyl)butane, 2,2-bis(4-hydroxyphenyl)pentane, 1,1-Bis(4-hydroxyphenyl)hexane, 2,2-bis(4-hydroxyphenyl)hexane, 1,1-bis(4-hydroxyphenyl)octane, 2,2-bis(4-hydroxyphenyl)octane, 4,4-bis(4-hydroxyphenyl)heptane, 2,2-bis(4-hydroxyphenyl)nonane, 1,1-bis(4-hydroxyphenyl)decane, 1,1-Bis(4-hydroxyphenyl)dodecane, Bis(hydroxyaryl)alkanes such as;

[0021] 1,1-Bis(4-hydroxyphenyl)cyclopentane, 1,1-Bis(4-hydroxyphenyl)cyclohexane, 1,1-bis(4-hydroxyphenyl)-3,3-dimethylcyclohexane, 1,1-bis(4-hydroxyphenyl)-3,4-dimethylcyclohexane, 1,1-bis(4-hydroxyphenyl)-3,5-dimethylcyclohexane, 1,1-bis(4-hydroxyphenyl)-3,3,5-trimethylcyclohexane, 1,1-Bis(4-hydroxy-3,5-dimethylphenyl)-3,3,5-trimethylcyclohexane, 1,1-Bis(4-hydroxyphenyl)-3-propyl-5-methylcyclohexane, 1,1-Bis(4-hydroxyphenyl)-3-tert-butyl-cyclohexane, 1,1-Bis(4-hydroxyphenyl)-4-tert-butyl-cyclohexane, 1,1-bis(4-hydroxyphenyl)-3-phenylcyclohexane, 1,1-Bis(4-hydroxyphenyl)-4-phenylcyclohexane, Bis(hydroxyaryl)cycloalkanes such as the above;

[0022] 9,9-Bis(4-hydroxyphenyl)fluorene, Bisphenols containing cardo structures, such as 9,9-bis(4-hydroxy-3-methylphenyl)fluorene;

[0023] 4,4'-Dihydroxydiphenyl sulfide, Dihydroxydiaryl sulfides such as 4,4'-dihydroxy-3,3'-dimethyldiphenyl sulfide;

[0024] Dihydroxydiaryl sulfoxides such as 4,4'-dihydroxydiphenyl sulfoxide and 4,4'-dihydroxy-3,3'-dimethyldiphenyl sulfoxide;

[0025] 4,4'-Dihydroxydiphenylsulfone, Dihydroxydiarylsulfones such as 4,4'-dihydroxy-3,3'-dimethyldiphenylsulfone; These are some examples.

[0026] Among these, bis(hydroxyaryl)alkanes are preferred, and bis(4-hydroxyphenyl)alkanes are preferred, with 2,2-bis(4-hydroxyphenyl)propane (i.e., bisphenol A) being particularly preferred in terms of impact resistance and heat resistance. Furthermore, one aromatic dihydroxy compound may be used, or two or more may be used in any combination and ratio.

[0027] Furthermore, to give an example of monomers that are raw materials for aliphatic polycarbonate resins, Alkanediols such as ethane-1,2-diol, propane-1,2-diol, propane-1,3-diol, 2,2-dimethylpropane-1,3-diol, 2-methyl-2-propylpropane-1,3-diol, butane-1,4-diol, pentane-1,5-diol, hexane-1,6-diol, and decane-1,10-diol;

[0028] Cycloalkanediols such as cyclopentane-1,2-diol, cyclohexane-1,2-diol, cyclohexane-1,4-diol, 1,4-cyclohexanedimethanol, 4-(2-hydroxyethyl)cyclohexanol, and 2,2,4,4-tetramethyl-cyclobutane-1,3-diol;

[0029] Glycols such as ethylene glycol, 2,2'-oxydiethanol (i.e., diethylene glycol), triethylene glycol, propylene glycol, and spiroglycol;

[0030] Aralkyldiols such as 1,2-benzenedimethanol, 1,3-benzenedimethanol, 1,4-benzenedimethanol, 1,4-benzenediethanol, 1,3-bis(2-hydroxyethoxy)benzene, 1,4-bis(2-hydroxyethoxy)benzene, 2,3-bis(hydroxymethyl)naphthalene, 1,6-bis(hydroxyethoxy)naphthalene, 4,4'-biphenyldimethanol, 4,4'-biphenyldiethanol, 1,4-bis(2-hydroxyethoxy)biphenyl, bisphenol A bis(2-hydroxyethyl) ether, and bisphenol S bis(2-hydroxyethyl) ether;

[0031] Examples include cyclic ethers such as 1,2-epoxyethane (i.e., ethylene oxide), 1,2-epoxypropane (i.e., propylene oxide), 1,2-epoxycyclopentane, 1,2-epoxycyclohexane, 1,4-epoxycyclohexane, 1-methyl-1,2-epoxycyclohexane, 2,3-epoxynorbornane, and 1,3-epoxypropane.

[0032] Among the monomers used as raw materials for polycarbonate resin, examples of carbonate precursors include carbonyl halides and carbonate esters. Note that one type of carbonate precursor may be used, or two or more types may be used in any combination and ratio.

[0033] Examples of carbonyl halides include, specifically, phosgene; bischloroformates of dihydroxy compounds; monochloroformates of dihydroxy compounds; and other haloformates. Examples of carbonate esters include diaryl carbonates such as diphenyl carbonate and dityl carbonate; dialkyl carbonates such as dimethyl carbonate and diethyl carbonate; and carbonates of dihydroxy compounds such as biscarbonates, monocarbonates, and cyclic carbonates of dihydroxy compounds.

[0034] The method for producing polycarbonate resin is not particularly limited, and any known method can be used. Examples include interfacial polymerization, molten transesterification, pyridine method, ring-opening polymerization of cyclic carbonate compounds, and solid-phase transesterification of prepolymers.

[0035] The molecular weight of the polycarbonate resin (A) is arbitrary and can be selected and determined as appropriate, but it is preferably 10,000 to 40,000 in viscosity-average molecular weight [Mv]. If the viscosity-average molecular weight is less than 10,000, the mechanical strength tends to be insufficient, and if it exceeds 40,000, the fluidity tends to be poor and the moldability tends to be poor. The viscosity-average molecular weight is more preferably 16,000 to 40,000, even more preferably 18,000 to 30,000, and particularly preferably 18,500 to 25,000. The molecular weight can be adjusted to this range by known methods such as controlling the amount of molecular weight adjusting agent as described later.

[0036] Here, viscosity-average molecular weight [Mv] is calculated by using methylene chloride as the solvent, determining the intrinsic viscosity [η] (unit dl / g) at 20°C using an Ubbelohde viscometer, and then using Schnell's viscosity formula, i.e., η = 1.23 × 10⁻⁶ -4 Mv 0.83 This refers to the value calculated from [the formula shown]. Intrinsic viscosity [η] is the value calculated by measuring the specific viscosity [ηsp] at each solution concentration [C] (g / dl) and using the following formula.

number

[0037] Other matters concerning polycarbonate resin The concentration of terminal hydroxyl groups in the polycarbonate resin is arbitrary and can be selected and determined as appropriate, but it is usually 1,000 ppm or less, preferably 800 ppm or less, and more preferably 600 ppm or less. This improves the heat retention stability and color tone of the polycarbonate resin composition. Furthermore, the lower limit is usually 10 ppm or more, preferably 30 ppm or more, and more preferably 40 ppm or more, especially for polycarbonate resins produced by the melt transesterification method. This suppresses the decrease in molecular weight and further improves the mechanical properties of the polycarbonate resin composition. The unit for terminal hydroxyl group concentration is expressed as the mass of terminal hydroxyl groups relative to the mass of polycarbonate resin, expressed in ppm. The measurement method is colorimetric determination using the titanium tetrachloride / acetic acid method (as described in Macromol. Chem. 88 215 (1965)).

[0038] Furthermore, the polycarbonate resin (A) is not limited to a configuration containing only one type of polycarbonate resin; two or more types of polycarbonate resins with different monomer compositions, molecular weights, terminal hydroxyl group concentrations, etc., may be mixed and used. Alternatively, the polycarbonate resin may be used in combination with an alloy (mixture) of other thermoplastic resins.

[0039] Furthermore, for example, to further enhance flame retardancy and impact resistance, the polycarbonate resin may be composed of copolymers mainly consisting of polycarbonate resin, such as copolymers with oligomers or polymers having a siloxane structure; copolymers with monomers, oligomers, or polymers having phosphorus atoms to further improve thermal oxidation stability and flame retardancy; copolymers with monomers, oligomers, or polymers having a dihydroxyanthraquinone structure to improve thermal oxidation stability; copolymers with oligomers or polymers having an olefin-based structure such as polystyrene to improve optical properties; and copolymers with polyester resin oligomers or polymers to improve chemical resistance.

[0040] Furthermore, in order to improve the appearance and fluidity of the molded product, the polycarbonate resin may contain polycarbonate oligomers. The viscosity-average molecular weight [Mv] of these polycarbonate oligomers is usually 1,500 or more, preferably 2,000 or more, and usually 9,500 or less, preferably 9,000 or less. Moreover, it is preferable that the amount of polycarbonate oligomers contained be 30% by mass or less of the polycarbonate resin (including the polycarbonate oligomers).

[0041] Furthermore, the polycarbonate resin may be not only virgin raw material, but also polycarbonate resin recycled from used products (so-called material-recycled polycarbonate resin). Examples of the aforementioned used products include optical recording media such as optical discs; light guide plates; transparent vehicle components such as car windows, car headlamp lenses, and windshields; containers such as water bottles; eyeglass lenses; and building components such as soundproof walls, glass windows, and corrugated sheets. In addition, crushed materials obtained from non-conforming products, sprues, runners, etc., or pellets obtained by melting them can also be used. However, the recycled polycarbonate resin is preferably 80% by mass or less of the polycarbonate resin contained in the polycarbonate resin composition, and more preferably 50% by mass or less. This is because recycled polycarbonate resin is highly likely to have undergone degradation such as thermal degradation or aging degradation, and using more of such polycarbonate resin than the above range may reduce its hue and mechanical properties.

[0042] [Graft copolymer (B) containing aromatic vinyl monomer component (b1), vinyl cyanide monomer component (b2), and diene-based rubber polymer component (b3)] The graft copolymer (B) contained in the polycarbonate resin composition of the present invention is a graft copolymer containing an aromatic vinyl monomer component (b1), a vinyl cyanide monomer component (b2), and a diene-based rubber polymer component (b3). Preferably, the graft copolymer (B) consists of 40 to 80% by mass of the aromatic vinyl monomer component (b1), 10 to 30% by mass of the vinyl cyanide monomer component (b2), and 10 to 50% by mass of the diene-based rubber polymer component (b3), and may also contain 0 to 30% by mass of other monomer components (b4).

[0043] Examples of aromatic vinyl monomer components (b1) in the graft copolymer (B) include styrene, α-methylstyrene, o-methylstyrene, p-methylstyrene, vinylxylene, ethylstyrene, dimethylstyrene, p-tert-butylstyrene, vinylnaphthalene, methoxystyrene, monobromstyrene, dibromstyrene, fluorostyrene, tribromstyrene, etc., with styrene being particularly preferred. The proportion of aromatic vinyl monomer component (b1) in the graft copolymer (B) is preferably in the range of 40 to 80% by mass, more preferably 45% by mass or more, even more preferably 50% by mass or more, particularly preferably 55% by mass or more, more preferably 75% by mass or less, even more preferably 70% by mass or less, and particularly preferably 65% ​​by mass or less, based on 100% by mass of the graft copolymer (B).

[0044] Examples of vinyl cyanide monomer components (b2) in the graft copolymer (B) include acrylonitrile and methacrylonitrile, with acrylonitrile being particularly preferred. The proportion of the vinyl cyanide monomer component (b2) in the graft copolymer (B) is preferably in the range of 10 to 30% by mass, more preferably 12% by mass or more, even more preferably 14% by mass or more, particularly preferably 15% by mass or more, more preferably 28% by mass or less, even more preferably 26% by mass or less, and particularly preferably 25% by mass or less, based on 100% by mass of the graft copolymer (B).

[0045] As the diene-based rubber polymer component (b3) of the graft copolymer (B), for example, rubber components such as polybutadiene, polyisoprene, and styrene-butadiene copolymer can be used, and the proportion of the diene-based rubber polymer component (b3) in the graft copolymer (B) is preferably in the range of 10 to 50% by mass, more preferably 13% by mass or more, even more preferably 14% by mass or more, particularly preferably 15% by mass or more, and more preferably 45% by mass or less, based on 100% by mass of the graft copolymer (B).

[0046] Furthermore, copolymers with other monomer components (b4) that can copolymerize with these may also be used. In this case, examples of other copolymerizable vinyl monomers include maleimide monomers such as maleimide, N-methylmaleimide, N-cyclohexylmaleimide, and N-phenylmaleimide; acrylamide monomers such as acrylamide and N-methylacrylamide; unsaturated anhydrides such as maleic anhydride and itaconic anhydride; unsaturated acids such as acrylic acid and methacrylic acid; glycidyl acrylate, glycidyl methacrylate, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, and methoxypolyethylene glycol methacrylate. The proportion of other monomer components (b4) in the graft copolymer (B) is preferably in the range of 0 to 30% by mass, more preferably 20% by mass or less, even more preferably 10% by mass or less, most preferably 5% by mass or less, especially 3% by mass or less, and most preferably 2% by mass or less, based on 100% by mass of the graft copolymer (B).

[0047] Specific examples of the graft copolymer (B) include acrylonitrile-butadiene-styrene graft copolymer and acrylonitrile-butadiene-styrene-α-methylstyrene graft copolymer, with acrylonitrile-butadiene-styrene graft copolymer and ABS resin being particularly preferred.

[0048] Graft copolymers (B) are typically produced by methods such as bulk polymerization, solution polymerization, suspension polymerization, and emulsion polymerization, and any of these methods can be used.

[0049] The content of graft copolymer (B) is 10 to 45 parts by mass based on 100 parts by mass of the total of polycarbonate resin (A) and graft copolymer (B), preferably 12 parts by mass or more, more preferably 15 parts by mass or more, preferably 42 parts by mass or less, and more preferably 40 parts by mass or less. If the amount of graft copolymer (B) exceeds 45 parts by mass, the heat resistance decreases, and if it is less than 10 parts by mass, the fluidity decreases.

[0050] [Ethylene-α-olefin copolymer (C)] The ethylene-α-olefin copolymer (C) contained in the polycarbonate resin composition of the present invention has a density of 0.940 g / cm³. 3 The following conditions are met: MFR (measured at 190°C and 21.18N) is 0.9 g / 10 min or higher. In this invention, by incorporating an ethylene-α-olefin copolymer (C) having such density and MFR into an alloy of polycarbonate resin (A) and graft copolymer (B), it is possible to create a polycarbonate resin composition that generates less squeaking noise (abnormal noise) and generates less squeaking noise (abnormal noise) even when used for long periods in high-temperature environments as vehicle parts, etc.

[0051] If the density is too high and exceeds 0.940g / cm 3 , the crystallinity increases, resulting in reduced impact resistance. The density is preferably 0.935g / cm 3 or less, more preferably 0.930g / cm 3 or less, further 0.925g / cm 3 or less, particularly 0.920g / cm 3 or less, especially 0.915g / cm 3 or less, particularly 0.910g / cm 3 or less, most preferably 0.908g / cm 3 or less. The lower limit of the density is preferably 0.800g / cm 3 or more, more preferably 0.820g / cm 3 or more, further preferably 0.840g / cm 3 or more, particularly preferably 0.850g / cm 3 or more, especially 0.860g / cm 3 or more, particularly preferably 0.870g / cm 3 or more, most preferably 0.880g / cm 3 or more. The density of the ethylene-α-olefin copolymer (C) is a value measured in accordance with JIS K7112.

[0052] When the MFR is less than 0.9g / 10 min, the impact resistance decreases. In addition, if the MFR is too high, surface layer peeling tends to occur, so the MFR is preferably 75g / 10 min or less, more preferably 50g / 10 min or less, further preferably 40g / 10 min or less, particularly preferably 30g / 10 min or less, and is preferably 1.09g / 10 min or more, further preferably 1.1g / 10 min or more. The MFR is a melt flow rate (MFR) measured at a temperature of 190°C under a load of 21.18N in accordance with JIS K7210 (1995).

[0053] The ethylene-α-olefin copolymer (C) is a copolymer containing monomer units derived from ethylene and monomer units derived from α-olefins. The α-olefin is preferably one having 3 to 20 carbon atoms, such as propylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene, 1-decene, 1-dodecene, 4-methyl-1-pentene, and 4-methyl-1-hexene. The copolymer may contain only one type of monomer unit derived from these α-olefins, or two or more types. The α-olefin is preferably 1-butene, 1-hexene, 4-methyl-1-pentene, or 1-octene, and more preferably 1-butene or 1-hexene.

[0054] Examples of ethylene-α-olefin copolymer (C) include ethylene-1-butene copolymer, ethylene-1-hexene copolymer, ethylene-4-methyl-1-pentene copolymer, ethylene-1-octene copolymer, ethylene-1-butene-1-hexene copolymer, ethylene-1-butene-4-methyl-1-pentene copolymer, ethylene-1-butene-1-octene copolymer, ethylene-1-hexene-1-octene copolymer, and the like. Preferably, it is ethylene-1-butene copolymer, ethylene-1-hexene copolymer, ethylene-4-methyl-1-pentene copolymer, ethylene-1-butene-1-hexene copolymer, ethylene-1-butene-1-octene copolymer, or ethylene-1-hexene-1-octene copolymer, and particularly preferably ethylene-1-butene copolymer or ethylene-1-hexene copolymer.

[0055] In the ethylene-α-olefin copolymer (C), the content of monomer units derived from α-olefin is preferably 1 to 49% by mass, more preferably 5 to 49% by mass, even more preferably 8 to 49% by mass, and particularly preferably 10 to 49% by mass, based on 100% of the total mass of copolymer (C).

[0056] The ethylene-α-olefin copolymer (C) is preferably obtained by polymerization using polymerization catalysts such as Ziegler catalysts, vanadium catalysts, Phillips catalysts, or metallocene catalysts (also called single-site catalysts), or by high-pressure radical polymerization. Polymerization methods include liquid-phase polymerization, slurry polymerization, gas-phase polymerization, and high-pressure ionic polymerization.

[0057] In particular, the ethylene-α-olefin copolymer (C) is preferably a copolymer obtained by copolymerizing ethylene and α-olefin using a Ziegler-Natta catalyst. The Ziegler-Natta catalyst comprises a titanium compound which may be 3- and / or 4-valent and an organoaluminum compound as a co-catalyst, and known catalysts can be used as the Ziegler-Natta catalyst. Polymerization reactions typically occur at a polymerization temperature of 30-300°C and under atmospheric pressure or a pressure of 3000 kg / cm³. 2 The polymerization reaction is carried out under polymerization pressure, in the presence or absence of a solvent, and in a gas-solid, liquid-solid, or homogeneous liquid phase, but preferably the polymerization reaction is carried out at a polymerization temperature of 130-300°C and at a polymerization rate of 300-3000 kg / cm³. 2 It is preferable that this be carried out by a high-pressure bulk method under polymerization pressure.

[0058] The molecular weight-free polymer (MFR) of an ethylene-α-olefin copolymer (C) can be adjusted by polymerizing it with the addition of a molecular weight modifier, such as hydrogen. The amount of hydrogen added varies depending on the catalyst used and the manufacturing conditions. Generally, increasing the amount of hydrogen tends to increase the MFR, so it is preferable to determine the amount of hydrogen added according to the desired MFR. Furthermore, the density of the ethylene-α-olefin copolymer (C) also varies depending on the catalyst used and the manufacturing conditions, as described above, but it can be adjusted by controlling the α-olefin concentration in the ethylene-α-olefin copolymer.

[0059] The content of ethylene-α-olefin copolymer (C) is 3.2 to 15 parts by mass per 100 parts by mass of the total of polycarbonate resin (A) and graft copolymer (B). With this content, a resin composition can be made that produces less squeaking noise (abnormal noise) while maintaining mechanical properties such as impact resistance. The content of ethylene-α-olefin copolymer (C) is preferably 3.5 parts by mass or more, more preferably 4 parts by mass or more, even more preferably 4.5 parts by mass or more, particularly preferably 5 parts by mass or more, preferably 14 parts by mass or less, more preferably 13 parts by mass or less, even more preferably 12 parts by mass or less, and most preferably 11 parts by mass or less, and particularly preferably 10 parts by mass or less.

[0060] [Elastomer (D)] The polycarbonate resin composition of the present invention may further preferably contain elastomer (D). By including elastomer (D) in combination with the above components, the resin composition exhibits excellent impact resistance, particularly at low temperatures, making it particularly suitable for use in automotive interior parts.

[0061] The elastomer used in the present invention is preferably a graft copolymer obtained by graft copolymerizing a rubber component with a monomer component copolymerizable thereto. The graft copolymer may be produced by any of the following methods: bulk polymerization, solution polymerization, suspension polymerization, emulsion polymerization, etc., and the copolymerization method may be single-stage grafting or multi-stage grafting.

[0062] The rubber component has a glass transition temperature of 0°C or lower, preferably -20°C or lower, and more preferably -30°C or lower. Specific examples of rubber components include polybutadiene rubber, polyisoprene rubber, polyalkyl acrylate rubber such as polybutyl acrylate, poly(2-ethylhexyl acrylate), and butyl acrylate-2-ethylhexyl acrylate copolymer, silicone rubber such as polyorganosiloxane rubber, butadiene-acrylic composite rubber, IPN (Interpenetrating Polymer Network) type composite rubber consisting of polyorganosiloxane rubber and polyalkyl acrylate rubber, styrene-butadiene rubber, ethylene-α-olefin rubber such as ethylene-propylene rubber, ethylene-butene rubber, and ethylene-octene rubber, ethylene-acrylic rubber, and fluororubber. These may be used individually or in mixtures of two or more. Among these, polybutadiene rubber, polyalkyl acrylate rubber, polyorganosiloxane rubber, IPN-type composite rubber consisting of polyorganosiloxane rubber and polyalkyl acrylate rubber, and styrene-butadiene rubber are preferred in terms of mechanical properties and surface appearance.

[0063] Specific examples of monomer components that can be graft copolymerized with rubber components include aromatic vinyl compounds, vinyl cyanide compounds, (meth)acrylic acid ester compounds, epoxy group-containing (meth)acrylic acid ester compounds such as glycidyl (meth)acrylate; maleimide compounds such as maleimide, N-methylmaleimide, and N-phenylmaleimide; and α,β-unsaturated carboxylic acid compounds such as maleic acid, phthalic acid, and itaconic acid, and their anhydrides (e.g., maleic anhydride). These monomer components may be used individually or in combination of two or more. Among these, aromatic vinyl compounds, vinyl cyanide compounds, (meth)acrylic acid ester compounds, and (meth)acrylic acid compounds are preferred in terms of mechanical properties and surface appearance, and (meth)acrylic acid ester compounds are more preferred. Specific examples of (meth)acrylic acid ester compounds include methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, cyclohexyl (meth)acrylate, and octyl (meth)acrylate.

[0064] Graft copolymers copolymerized with rubber components are preferably of the core / shell type in terms of impact resistance and surface appearance. Among these, core / shell type graft copolymers are particularly preferred, in which at least one rubber component selected from polybutadiene-containing rubber, polybutyl acrylate-containing rubber, polyorganosiloxane rubber, and IPN-type composite rubber consisting of polyorganosiloxane rubber and polyalkyl acrylate rubber forms the core layer, and a shell layer formed by copolymerizing (meth)acrylic acid ester around it is formed. In the above core / shell type graft copolymer, it is preferable that the rubber component is contained in 40% by mass or more, and more preferably 60% by mass or more. Furthermore, it is preferable that the (meth)acrylic acid is contained in 10% by mass or more.

[0065] Among the above, elastomer (D) is preferably a core / shell type elastomer, and among these, a core / shell type elastomer with a silicone-acrylic composite, acrylic rubber, or butadiene rubber core is preferred, and a core / shell type elastomer with butadiene rubber core is particularly preferred.

[0066] Furthermore, the term "core / shell type" in this invention does not necessarily mean that the core layer and shell layer are clearly distinguishable, and broadly includes compounds obtained by graft polymerization of rubber components around the core portion.

[0067] Preferred specific examples of these core / shell type graft copolymers include methyl methacrylate-butadiene-styrene copolymer (MBS), methyl methacrylate-acrylonitrile-butadiene-styrene copolymer (MABS), methyl methacrylate-butadiene copolymer (MB), methyl methacrylate-acrylic rubber copolymer (MA), methyl methacrylate-acrylic rubber-styrene copolymer (MAS), methyl methacrylate-acrylic / butadiene rubber copolymer, methyl methacrylate-acrylic / butadiene rubber-styrene copolymer, methyl methacrylate-(acrylic / silicone IPN rubber) copolymer, and silicone-acrylic composite rubber containing polyorganosiloxane and polyalkyl (meth)acrylate, with silicone-acrylic composite rubber containing polyorganosiloxane and polyalkyl (meth)acrylate and methyl methacrylate-butadiene copolymer (MB) being particularly preferred. Such rubbery polymers may be used individually or in combination of two or more.

[0068] When elastomer (D) is included, its content is preferably 1 to 25 parts by mass, more preferably 1.5 parts by mass or more, even more preferably 2 parts by mass or more, more preferably 20 parts by mass or less, even more preferably 18 parts by mass or less, and particularly preferably 15 parts by mass or less, based on 100 parts by mass of the total of polycarbonate resin (A) and graft copolymer (B). Elastomer (D) may contain only one type or two or more types. If two or more types are included, the total amount will be within the above range.

[0069] [Stabilizer] The polycarbonate resin composition of the present invention preferably contains a stabilizer, and phosphorus-based stabilizers or phenol-based stabilizers are preferred.

[0070] Any known phosphorus-based stabilizer can be used. Specific examples include phosphoric acid, phosphonic acid, phosphorous acid, phosphinic acid, polyphosphate and other phosphorus oxoacids; acidic pyrophosphate metal salts such as sodium acidic pyrophosphate, potassium acidic pyrophosphate, and calcium acidic pyrophosphate; phosphates of Group 1 or Group 2B metals such as potassium phosphate, sodium phosphate, cesium phosphate, and zinc phosphate; and organic phosphate compounds, organic phosphite compounds, and organic phosphonite compounds, with organic phosphite compounds being particularly preferred.

[0071] Examples of organic phosphite compounds include triphenyl phosphite, tris(mononylphenyl) phosphite, tris(mononyl / dinonylphenyl) phosphite, tris(2,4-di-tert-butylphenyl) phosphite, monooctyldiphenyl phosphite, dioctylmonophenyl phosphite, monodecyldiphenyl phosphite, didecylmonophenyl phosphite, tridecyl phosphite, trilauryl phosphite, tristearyl phosphite, and 2,2-methylenebis(4,6-di-tert-butylphenyl)octyl phosphite. Examples of such organic phosphite compounds include, for example, "ADEKA Stab 1178," "ADEKA Stab 2112," and "ADEKA Stab HP-10" from ADEKA Corporation, "JP-351," "JP-360," and "JP-3CP" from Johoku Chemical Industry Co., Ltd., and "Irgaphos 168" from BASF. Furthermore, the product may contain one type of phosphorus-based stabilizer, or two or more types in any combination and ratio.

[0072] The phosphorus-based stabilizer content is typically 0.001 parts by mass or more, preferably 0.01 parts by mass or more, and more preferably 0.03 parts by mass or more, per 100 parts by mass of the total of the polycarbonate resin (A) and the graft copolymer (B), and is also typically 1 part by mass or less, preferably 0.7 parts by mass or less, and more preferably 0.5 parts by mass or less. If the phosphorus-based stabilizer content is below the lower limit of the above range, the thermal stabilization effect may be insufficient, and if the phosphorus-based stabilizer content exceeds the upper limit of the above range, the effect may plateau and become uneconomical.

[0073] Examples of phenolic stabilizers include hindered phenolic antioxidants. Specific examples include pentaerythritol tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], octadecyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, thiodiethylenebis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], N,N'-hexane-1,6-diylbis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionamide], 2,4-dimethyl-6-(1-methylpentadecyl)phenol, diethyl[[3,5-bis(1,1-dimethylethyl)-4-hydroxyphenyl]methyl]phosphoate, 3,3',3”,5,5',5”-hexa-tert-butyl-a,a',a”-(mesitylene-2,4,6- Examples include triyl)tri-p-cresol, 4,6-bis(octylthiomethyl)-o-cresol, ethylenebis(oxyethylene)bis[3-(5-tert-butyl-4-hydroxy-m-tolyl)propionate], hexamethylenebis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], 1,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione, 2,6-di-tert-butyl-4-(4,6-bis(octylthio)-1,3,5-triazine-2-ylamino)phenol, and 2-[1-(2-hydroxy-3,5-di-tert-pentylphenyl)ethyl]-4,6-di-tert-pentylphenyl acrylate.

[0074] Among these, pentaerythritol tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] and octadecyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate are preferred. Specific examples of such phenolic antioxidants include, for example, BASF's "Irganox 1010" and "Irganox 1076," and ADEKA's "ADEKA Stab AO-50" and "ADEKA Stab AO-60." Furthermore, the product may contain one type of phenolic stabilizer, or two or more types in any combination and ratio.

[0075] The content of the phenolic stabilizer is usually 0.001 parts by mass or more, preferably 0.01 parts by mass or more, and usually 1 part by mass or less, preferably 0.5 parts by mass or less, per 100 parts by mass of the total of the polycarbonate resin (A) and the graft copolymer (B). By setting the content of the phenolic stabilizer to be above the lower limit of the above range, the effect of the phenolic stabilizer can be sufficiently obtained. Furthermore, by setting the content of the phenolic stabilizer to be below the upper limit of the above range, the effect does not plateau, making it economical.

[0076] [Release agent] Furthermore, the polycarbonate resin composition of the present invention preferably contains a mold release agent (lubricant). Examples of mold release agents include aliphatic carboxylic acids, esters of aliphatic carboxylic acids and alcohols, aliphatic hydrocarbon compounds with a number average molecular weight of 200 to 15000, and polysiloxane-based silicone oils.

[0077] Examples of aliphatic carboxylic acids include saturated or unsaturated aliphatic monovalent, divalent, or trivalent carboxylic acids. Here, aliphatic carboxylic acids also include alicyclic carboxylic acids. Among these, preferred aliphatic carboxylic acids are monovalent or divalent carboxylic acids having 6 to 36 carbon atoms, and more preferably aliphatic saturated monovalent carboxylic acids having 6 to 36 carbon atoms. Specific examples of such aliphatic carboxylic acids include palmitic acid, stearic acid, caproic acid, capric acid, lauric acid, arachidic acid, behenic acid, lignoceric acid, cerotic acid, melissic acid, tetrariacontanoic acid, montanic acid, adipic acid, and azelaic acid.

[0078] As the aliphatic carboxylic acid in the ester of an aliphatic carboxylic acid and an alcohol, for example, the same aliphatic carboxylic acid as described above can be used. On the other hand, as the alcohol, for example, saturated or unsaturated monohydric or polyhydric alcohols can be used. These alcohols may have substituents such as fluorine atoms or aryl groups. Among these, monohydric or polyhydric saturated alcohols having 30 or fewer carbon atoms are preferred, and aliphatic saturated monohydric alcohols or aliphatic saturated polyhydric alcohols having 30 or fewer carbon atoms are more preferred. Here, "aliphatic" is used as a term that also includes alicyclic compounds.

[0079] Specific examples of such alcohols include octanol, decanol, dodecanol, stearyl alcohol, behenyl alcohol, ethylene glycol, diethylene glycol, glycerin, pentaerythritol, 2,2-dihydroxyperfluoropropanol, neopentylene glycol, ditrimethylolpropane, and dipentaerythritol.

[0080] Furthermore, the above-mentioned esters may contain aliphatic carboxylic acids and / or alcohols as impurities. Also, the above-mentioned esters may be pure substances or mixtures of multiple compounds. Moreover, the aliphatic carboxylic acids and alcohols that combine to form a single ester may be used individually, or two or more may be used in any combination and ratio.

[0081] Specific examples of esters of aliphatic carboxylic acids and alcohols include beeswax (a mixture mainly composed of myricyl palmitate), stearyl stearate, behenyl behenate, stearyl behenate, glycerin monopalmitate, glycerin monostearate, glycerin distearate, glycerin tristearate, pentaerythritol monopalmitate, pentaerythritol monostearate, pentaerythritol distearate, pentaerythritol tristearate, and pentaerythritol tetrastearate.

[0082] Aliphatic hydrocarbons with a number-average molecular weight of 200 to 15,000 include, for example, liquid paraffin, paraffin wax, microwax, polyethylene wax, Fischer-Tropsch wax, and α-olefin oligomers having 3 to 12 carbon atoms. Note that alicyclic hydrocarbons are also included in the definition of aliphatic hydrocarbons. Furthermore, these hydrocarbons may be partially oxidized. Among these, paraffin wax, polyethylene wax, or partially oxided polyethylene wax are preferred, and paraffin wax and polyethylene wax are more preferred. Furthermore, the number-average molecular weight of the aliphatic hydrocarbon is preferably 5000 or less. Furthermore, while the aliphatic hydrocarbon may be a single substance, it is preferable that the main component is within the above range, even if it is a mixture of substances with various constituent components and molecular weights.

[0083] Examples of polysiloxane-based silicone oils include dimethyl silicone oil, methylphenyl silicone oil, diphenyl silicone oil, and fluorinated alkyl silicone.

[0084] Furthermore, the above-mentioned release agent may contain one type, or two or more types in any combination and ratio.

[0085] The release agent content is typically 0.001 parts by mass or more, preferably 0.01 parts by mass or more, and typically 2 parts by mass or less, preferably 1 part by mass or less, per 100 parts by mass of the total of the polycarbonate resin (A) and the graft copolymer (B). Setting the release agent content above the lower limit of the above range makes it easier to obtain sufficient release properties, and setting the release agent content below the upper limit of the above range provides sufficient hydrolysis resistance and reduces the likelihood of mold contamination during injection molding.

[0086] [Stabilizer] The polycarbonate resin composition of the present invention is preferably further enriched with a stabilizer, as this has the effect of improving thermal stability and preventing deterioration of mechanical strength, transparency, and hue. Phosphorus-based stabilizers and phenol-based stabilizers are preferred as stabilizers. Examples of phosphorus-based stabilizers include phosphorous acid, phosphoric acid, phosphorous acid esters, and phosphate esters, with phosphite and phosphonite being preferred among them.

[0087] Phosphates include, for example, triphenyl phosphite, tris(nonylphenyl) phosphite, dilauryl hydrogen phosphite, triethyl phosphite, tridecyl phosphite, tris(2-ethylhexyl) phosphite, tris(tridecyl) phosphite, tristearyl phosphite, diphenyl monodecyl phosphite, monophenyl didecyl phosphite, diphenyl mono(tridecyl) phosphite, tetraphenyldipropylene glycol diphosphite, tetraphenyltetra(tridecyl)pentaerythritol tetraphosphite, hydrogenated bisphenol A phenol phosphite polymer, diphenyl hydrogen phosphite, 4,4'-butylidene-bis(3-methyl-6-tert-butylphenyl di(tridecyl) phosphite, tetra(tridecyl)4,4'-isopropyl Examples include redenediphenyl diphosphite, bis(tridecyl)pentaerythritol diphosphite, bis(nonylphenyl)pentaerythritol diphosphite, dilaurylpentaerythritol diphosphite, distearylpentaerythritol diphosphite, tris(4-tert-butylphenyl) phosphite, tris(2,4-di-tert-butylphenyl) phosphite, hydrogenated bisphenol A pentaerythritol phosphite polymer, bis(2,4-di-tert-butylphenyl)pentaerythritol diphosphite, bis(2,6-di-tert-butyl-4-methylphenyl)pentaerythritol diphosphite, 2,2'-methylenebis(4,6-di-tert-butylphenyl)octyl phosphite, and bis(2,4-dicumylphenyl)pentaerythritol diphosphite.

[0088] Furthermore, as phosphonates, there are tetrakis(2,4-di-iso-propylphenyl)-4,4'-biphenylenediphosphonite, tetrakis(2,4-di-n-butylphenyl)-4,4'-biphenylenediphosphonite, tetrakis(2,4-di-tert-butylphenyl)-4,4'-biphenylenediphosphonite, tetrakis(2,4-di-tert-butylphenyl)-4,3'-biphenylenediphosphonite, and tetrakis(2,4-di-tert-butylphenyl)-3,3'-biphenylenediphosphonite. Examples include tetrakis(2,6-di-iso-propylphenyl)-4,4'-biphenylenediphosphonite, tetrakis(2,6-di-n-butylphenyl)-4,4'-biphenylenediphosphonite, tetrakis(2,6-di-tert-butylphenyl)-4,4'-biphenylenediphosphonite, tetrakis(2,6-di-tert-butylphenyl)-4,3'-biphenylenediphosphonite, and tetrakis(2,6-di-tert-butylphenyl)-3,3'-biphenylenediphosphonite.

[0089] Furthermore, examples of phosphates include methyl acid phosphate, ethyl acid phosphate, propyl acid phosphate, isopropyl acid phosphate, butyl acid phosphate, butoxyethyl acid phosphate, octyl acid phosphate, 2-ethylhexyl acid phosphate, decyl acid phosphate, lauryl acid phosphate, stearyl acid phosphate, oleyl acid phosphate, behenyl acid phosphate, phenyl acid phosphate, nonylphenyl acid phosphate, cyclohexyl acid phosphate, and Examples include phenoxyethyl acid phosphate, alkoxy polyethylene glycol acid phosphate, bisphenol A acid phosphate, dimethyl acid phosphate, diethyl acid phosphate, dipropyl acid phosphate, diisopropyl acid phosphate, dibutyl acid phosphate, dioctyl acid phosphate, di-2-ethylhexyl acid phosphate, dioctyl acid phosphate, dilauryl acid phosphate, distearyl acid phosphate, diphenyl acid phosphate, and bisnonylphenyl acid phosphate. The phosphorus-based stabilizer may be present in any combination and ratio, or in any combination of two or more types.

[0090] Specific examples of phenolic stabilizers include pentaerythritol tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], octadecyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, thiodiethylenebis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], N,N'-hexane-1,6-diylbis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionamide], 2,4-dimethyl-6-(1-methylpentadecyl)phenol, diethyl[[3,5-bis(1,1-dimethylethyl)-4-hydroxyphenyl]methyl]phosphoate, 3,3',3'',5,5',5 Examples include ''-Hexa-tert-butyl-a,a',a''-(mesitylene-2,4,6-triyl)tri-p-cresol, 4,6-bis(octylthiomethyl)-o-cresol, ethylenebis(oxyethylene)bis[3-(5-tert-butyl-4-hydroxy-m-tolyl)propionate], hexamethylenebis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], 1,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione, 2,6-di-tert-butyl-4-(4,6-bis(octylthio)-1,3,5-triazine-2-ylamino)phenol, etc.

[0091] Among these, pentaerythritol tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] and octadecyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate are preferred. Furthermore, the product may contain one type of phenolic stabilizer, or two or more types in any combination and ratio.

[0092] The stabilizer content is typically 0.001 parts by mass or more, preferably 0.01 parts by mass or more, and typically 1.5 parts by mass or less, preferably 1 part by mass or less, per 100 parts by mass of the total of the polycarbonate resin (A) and the rubber-reinforced styrene resin (B). Below 0.001 parts by mass, the effect of the stabilizer is insufficient, and a decrease in molecular weight and deterioration of color during molding are likely to occur. Above 1.5 parts by mass, it is an excess, and the occurrence of silver and deterioration of color tend to occur even more easily.

[0093] [Other ingredients] The polycarbonate resin composition of the present invention may contain other components as needed, as long as they do not significantly impair the desired physical properties. Examples of other components include polycarbonate resin (A), graft copolymer (B), ethylene-α-olefin copolymer (C), other resins other than elastomer (D), and various resin additives. Note that the other components may be present individually, or two or more in any combination and ratio.

[0094] Other resins include, for example, thermoplastic polyester resins such as polyethylene terephthalate resin, polytrimethylene terephthalate, and polybutylene terephthalate resin; styrene-based resins such as polystyrene resin, high-impact polystyrene resin (HIPS), and acrylonitrile-styrene copolymer (AS resin); polyolefin resins such as polyethylene resin and polypropylene resin; polyamide resin; polyimide resin; polyetherimide resin; polyurethane resin; polyphenylene ether resin; polyphenylene sulfide resin; polysulfone resin; and polymethacrylate resin. Furthermore, the other resins may be present in any combination and ratio, or two or more types may be present.

[0095] Furthermore, if other resins are included besides the polycarbonate resin (A) and the graft copolymer (B), the content of these other resins is preferably 20 parts by mass or less, more preferably 10 parts by mass or less, and even more preferably 5 parts by mass or less, and particularly preferably 3 parts by mass or less, based on 100 parts by mass of the total of the polycarbonate resin (A) and the graft copolymer (B).

[0096] Other resin additives not mentioned above include, for example, ultraviolet absorbers, dyes and pigments (including titanium dioxide and carbon black), antistatic agents, fillers, flame retardants, antifogging agents, lubricants, antiblocking agents, flow improvers, plasticizers, dispersants, and antibacterial agents. Furthermore, the other resin additives may be present in any single form, or in any combination and ratio of two or more forms.

[0097] [Manufacturing of polycarbonate resin compositions] There are no limitations on the method for producing the polycarbonate resin composition of the present invention, and a wide range of known methods for producing polycarbonate resin compositions can be employed. For example, the above-mentioned components (A) to (C), as well as other components added as needed, are pre-mixed using various mixers such as a tumbler or a Henschel mixer, and then melt-kneaded using a mixer such as a Banbury mixer, roll, braver, single-screw extruder, twin-screw extruder, or kneader. The melt-kneading temperature is not particularly limited, but is usually in the range of 240 to 320°C.

[0098] [Molded body] There are no restrictions on the method for producing molded articles from the obtained resin composition pellets, and any molding method commonly used for polycarbonate resin compositions can be arbitrarily adopted. Examples include injection molding, ultra-high-speed injection molding, injection compression molding, two-color molding, hollow molding methods such as gas-assisted molding, molding using insulated molds, molding using rapidly heated molds, foam molding (including supercritical fluids), insert molding, and IMC (in-mold coating) molding. Injection molding and injection compression molding are preferred from the viewpoint of ease of molding and productivity.

[0099] Molded articles made from the polycarbonate resin composition produce less creaking noise (abnormal noise), and even when used for long periods in high-temperature environments, they produce less creaking noise (abnormal noise). Therefore, molded articles made from the polycarbonate resin composition of the present invention can be suitably used as parts that come into contact with other molded articles or other molded articles, such as parts in the automotive, office automation equipment, home appliance, and electrical / electronic fields, and are particularly suitable for use as automotive interior parts. When molded articles of the polycarbonate resin composition of the present invention are used as automotive interior parts, it is possible to significantly reduce the generation of creaking noises when parts come into contact with each other or with other parts due to vibrations of the vehicle. Examples of such automotive interior parts include in-car displays, car navigation systems, car audio systems, dashboards, instrument panels, overhead consoles, door trims, roof trims, switch panels, door linings, decoration panels, indicator panels, pillar garnishes such as front pillar garnishes, center pillar upper garnishes, rear pillar garnishes, cowl side garnishes, front and rear side garnishes, and center pillar lower garnishes, as well as pillar trims, center consoles, console boxes, inner panels, door pockets, armrest bases, grab rails, assist grips, column covers, ventilators, ducts, air conditioners, switch parts, cup holders, sub-trunks, glove boxes, trunk side trims, trunk side linings, tailgate linings, and rear panels. [Examples]

[0100] The present invention will be described below with reference to examples. Examples Reference Example The raw material components used in the comparative examples are shown in Table 1 below.

[0101] [Table 1]

[0102] [Examples 3-4、11-19、22-26, Reference example 1~ 2、5-10、20-21 [Comparative Examples 1-5] Each component listed in Table 1 above was blended in the proportions (mass ratios) shown in Tables 2 to 4 below, and uniformly mixed in a tumbler to obtain a mixture. This mixture was supplied to a twin-screw extruder (Toshiba Machine Co., Ltd. "TEM26SX") and kneaded under the conditions of a screw rotation speed of 150 rpm, a discharge rate of 25 kg / hour, and a barrel temperature of 260°C, and extruded in a strand shape from the tip of the extrusion nozzle. The strand was rapidly cooled in a water bath and cut into pellets using a pelletizer to obtain pellets of polycarbonate resin composition.

[0103] <mvr> The pellets obtained by the above method were dried at 100°C for 5 hours, and then the MVR (Melt Volume Rate, unit: g / 10min) was measured in accordance with ISO 1133 under conditions of a measurement temperature of 250°C and a load of 2.16 kgf.

[0104] <Charpy strength with notch> The pellets obtained by the above method were dried at 100°C for 5 hours, and then injection molded using an injection molding machine (NEX80III, manufactured by Nissei Plastic Industrial Co., Ltd.) under conditions of cylinder temperature of 260°C and mold temperature of 60°C to produce ISO multipurpose test specimens (3mm thick). Using the obtained ISO multipurpose test specimen (3mm thick), the notched Charpy strength (unit: kJ / m²) was measured at a temperature of 23°C, or even -30°C, according to ISO standard 179. 2 ) was measured.

[0105] <Heat resistance DTUL (temperature of deflection under load)> The pellets obtained by the above method were dried at 100°C for 5 hours, and then injection molded using an injection molding machine (NEX80III, manufactured by Nissei Plastic Industrial Co., Ltd.) under the conditions of cylinder temperature 260°C, mold temperature 60°C, and molding cycle of 45 seconds to produce ISO multipurpose test specimens (4 mm thick). Based on ISO 75-1 and ISO 75-2, a constant bending load (1.80 MPa) was applied in the flatwise direction to the center of a 4 mm x 10 mm ISO multipurpose test specimen (4 mm thick), and the temperature was increased at the same rate until the strain in the center reached 0.34 mm (unit: °C).

[0106] <Squeaking noise evaluation (abnormal noise risk index)> The pellets obtained by the above method were injection molded using a Toshiba Machine Co., Ltd. injection molding machine "EC50SXII" under conditions of cylinder temperature 260°C and mold temperature 60°C to obtain a molded product (large test piece) measuring 60 mm in length, 60 mm in width, and 3 mm in thickness. Separately, small test pieces measuring 50 mm in length, 25 mm in width, and 3 mm in thickness were cut from the large test piece using a disc saw. Next, the edges of the test pieces were chamfered with #100 grit sandpaper, and then fine burrs were removed with a utility knife to obtain small test pieces for evaluating squeaking noise.

[0107] The large and small test specimens used for the above evaluation were left (heat-treated) in a constant temperature bath at 85°C for 400 hours, and then cooled at 25°C for 24 hours to obtain evaluation specimens. The obtained large test specimens were set on the movable stage of a Ziegler SSP-04 stick-slip tester, and the small test specimens were set on the fixed stage. Under the conditions of a temperature of 23°C, humidity of 50%RH, and the load (N) and speed (mm / sec) listed in Tables 2-4, the dynamic friction coefficient and static friction coefficient, as well as the noise risk index (also called noise generation risk, RPN), were measured when the two surfaces were rubbed together three times with an amplitude of 20 mm, according to the German Association of the Automotive Industry standard VDA230-206. The noise risk index (RPN) is displayed on a 10-point scale from 1 to 10. A lower RPN value means that squeaking noises are less likely to occur, and a higher value means that squeaking noises are more likely to occur. According to the German Association of the Automotive Industry standard VDA230-206, a noise risk index of 1 to 3 indicates a low risk of creaking noises and is considered acceptable for practical use.

[0108] The obtained abnormal noise risk index (RPN) was used to make a judgment according to the following criteria A to C. A: The highest abnormal noise risk index under the tested conditions is 1-3. B: The highest abnormal noise risk index under the tested conditions is 4-5. C: The highest abnormal noise risk index under the tested conditions is 6-10.

[0109] The evaluation results are shown in Tables 2-4 below. [Table 2]

[0110] [Table 3]

[0111] [Table 4] [Industrial applicability]

[0112] Molded articles made from the polycarbonate resin composition of the present invention produce less squeaking noise (abnormal noise), making them suitable for use as parts that come into contact with other molded articles or other molded articles, such as parts in the automotive, office automation equipment, home appliance, and electrical / electronic fields. They are particularly suitable for use as automotive interior parts and have extremely high industrial value.< / mvr>

Claims

1. The total of 100 parts by mass of (A) and (B) contains 55 to 90 parts by mass of polycarbonate resin (A) and 10 to 45 parts by mass of graft copolymer (B) containing aromatic vinyl monomer component (b1), vinyl cyanide monomer component (b2), and diene-based rubber polymer component (b3), with a density of 0.905 g / cm³ to 0.940 g / cm³. ３ The following polycarbonate resin composition is characterized by containing 3.2 to 15 parts by mass of ethylene-α-olefin copolymer (C) with an MFR (measured at 190°C, 21.18N) of 0.9 g / 10 min or more, and is intended for use in parts that come into contact with other molded products or other molded products formed from the polycarbonate resin composition.

2. The polycarbonate resin composition according to claim 1, wherein the noise risk index based on the German Association of the Automotive Industry's VDA 203-206 is 1 to 3.

3. The polycarbonate resin composition according to claim 1 or 2, wherein the graft copolymer (B) is ABS resin.

4. A molded article obtained by molding a polycarbonate resin composition according to any one of claims 1 to 3.

5. The molded product according to claim 4, wherein the molded product is an automotive interior part.

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