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 a molded article thereof, and more particularly to a polycarbonate resin composition and a molded article thereof which generate little creaking noise (abnormal noise) and which generate little creaking noise (abnormal noise) even when used for long periods of time in high-temperature environments as vehicle parts, etc. [Background technology]

[0002] Alloy compositions obtained by blending polycarbonate resin with ABS resin have excellent moldability, impact resistance, mechanical strength, and heat resistance, and are therefore favorably used as parts and components for electric and electronic devices such as vehicles, computers, notebook personal computers, various portable terminals, printers, copiers, and office automation and information devices. In particular, polycarbonate resin / ABS resin alloys have traditionally been widely used as interior materials in automobiles and the like for reasons such as ease of moldability and weight reduction.

[0003] Automobile interior parts, such as displays, console panels, dashboards, car navigation systems, and other products, are manufactured by fitting together and assembling molded resin parts to reduce weight. For example, when these have a housing structure, fitting portions for fitting are usually molded integrally in various locations on upper and lower halves of a container-like molded part, and the housing molded product is manufactured by fitting the outer edges of the upper and lower molded parts together, with little or no use of screws or the like.

[0004] However, when such molded parts are installed in a vehicle, the temperature inside the car changes drastically from low to high, and the resin molded parts are prone to deformation due to contraction and expansion caused by thermal fluctuations, and even slight deformation in the fitting parts makes them prone to generating creaking noises due to vibrations when the car is in motion. Creaking noises significantly reduce passenger comfort, and luxury cars in particular require even greater interior quietness, so preventing creaking noises is an extremely important issue.

[0005] However, molded articles made of polycarbonate resin / ABS resin alloys are prone to generating creaking noises (abnormal noises) when the molded articles come into dynamic contact with each other during vibration, etc. In order to reduce this creaking noise, it has been proposed to use AES resin instead of the ABS resin in the polycarbonate resin / ABS resin alloy (see Patent Document 1). However, products molded from alloys in which ABS resin is replaced with AES resin may be prone to creaking noises when used for long periods of time in high-temperature environments. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Publication No. 2018-138680 Summary of the Invention [Problem to be solved by the invention]

[0007] In view of the above-mentioned problems of the conventional art, an object (purpose) of the present invention is to provide a polycarbonate resin composition and a molded article which generate little creaking noise (abnormal noise) and which generate little creaking noise (abnormal noise) even when used for a long period of time in a high-temperature environment as a vehicle part or the like. [Means for solving the problem]

[0008] The present inventors have conducted extensive research to achieve the above object, and as a result, have found that a polycarbonate resin / ABS resin alloy rich in polycarbonate resin has a density of 0.940 g / cm 3 The inventors have found that a polycarbonate resin composition containing a specific amount of an ethylene-α-olefin copolymer having an MFR (measured at 190°C and 21.18 N) of 0.9 g / 10 min or more generates little creaking noise (unusual noise), even when used for long periods of time in high-temperature environments as vehicle parts, etc., and have completed the present invention. That is, the present invention relates to the following polycarbonate resin composition and molded article.

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

[0010] The polycarbonate resin composition of the present invention generates little creaking noise (unusual noise), and generates little creaking noise (unusual noise) even when used for a long period of time in a high-temperature environment as a vehicle part, etc. Therefore, molded articles molded from the polycarbonate resin composition of the present invention can be particularly suitably used as automobile interior parts. DETAILED DESCRIPTION OF THE INVENTION

[0011] The present invention will be described in detail below by showing embodiments and examples, but the present invention is not limited to the embodiments and examples shown below. In the present specification, the symbol "to" is used to mean that the numerical values ​​before and after it are included as the lower limit and upper limit.

[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) containing an aromatic vinyl monomer component (b1), a vinyl cyanide monomer component (b2), and a diene rubber polymer component (b3). The polycarbonate resin composition has a density of 0.940 g / cm per 100 parts by mass of the total of (A) and (B). 3 The present invention is characterized in that it contains 3.2 to 15 parts by mass of an ethylene-α-olefin copolymer (C) having an MFR (measured at 190° C. and 21.18 N) of 0.9 g / 10 min or more.

[0013] [Polycarbonate resin (A)] The polycarbonate resin (A) contained in the polycarbonate resin composition of the present invention is not limited to its type, and one type may be used alone, or two or more types may be used in any combination and in any ratio. Polycarbonate resin is a polymer with a basic structure having a carbonate bond represented by the general formula: -[-OXOC(=O)-]-. In the above formula, X is generally a hydrocarbon, but X containing a heteroatom or hetero bond may also be used to impart various properties.

[0014] As the polycarbonate resin (A), an aromatic polycarbonate resin is particularly preferred. An aromatic polycarbonate resin is a polycarbonate resin in which each carbon atom bonded directly to a carbonate bond is an aromatic carbon atom. Among various polycarbonates, aromatic polycarbonates are superior in terms of heat resistance, mechanical properties, electrical properties, etc.

[0015] There are no specific limitations 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, a polyhydroxy compound or the like may be reacted in addition to the dihydroxy compound and carbonate precursor. Alternatively, a method of reacting carbon dioxide as a carbonate precursor with a cyclic ether may also be used. The aromatic polycarbonate polymer may be linear or branched. Furthermore, the aromatic polycarbonate polymer may be a homopolymer consisting of one type of repeating unit, or a copolymer 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] Among the monomers that are raw materials for aromatic polycarbonate resins, examples of aromatic dihydroxy compounds 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] dihydroxynaphthalenes 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;

[0022] 9,9-bis(4-hydroxyphenyl)fluorene, Cardo structure-containing bisphenols 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'-dihydroxydiphenyl sulfone, dihydroxydiarylsulfones such as 4,4'-dihydroxy-3,3'-dimethyldiphenylsulfone; etc.

[0026] Of these, bis(hydroxyaryl)alkanes are preferred, and bis(4-hydroxyphenyl)alkanes are particularly preferred, with 2,2-bis(4-hydroxyphenyl)propane (ie, bisphenol A) being particularly preferred from the standpoint of impact resistance and heat resistance. The aromatic dihydroxy compounds may be used alone or in any combination of two or more in any ratio.

[0027] Examples of monomers that can be used as raw materials for aliphatic polycarbonate resin include: 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 that serve as raw materials for polycarbonate resins, examples of carbonate precursors include carbonyl halides, carbonate esters, etc. The carbonate precursors may be used alone or in any combination and ratio of two or more.

[0033] Specific examples of carbonyl halides include phosgene; haloformates such as bischloroformates of dihydroxy compounds and monochloroformates of dihydroxy compounds; and the like. Specific examples of carbonate esters include diaryl carbonates such as diphenyl carbonate and ditolyl carbonate; dialkyl carbonates such as dimethyl carbonate and diethyl carbonate; biscarbonates of dihydroxy compounds, monocarbonates of dihydroxy compounds, and carbonates of dihydroxy compounds such as cyclic carbonates.

[0034] The method for producing the polycarbonate resin is not particularly limited, and any known method can be used, such as interfacial polymerization, melt transesterification, pyridine method, ring-opening polymerization of a cyclic carbonate compound, and solid-phase transesterification of a prepolymer.

[0035] The molecular weight of the polycarbonate resin (A) is optional and may be appropriately selected and determined, but a viscosity-average molecular weight [Mv] of 10,000 to 40,000 is preferred. If the viscosity-average molecular weight is less than 10,000, the mechanical strength tends to be insufficient, while if the viscosity-average molecular weight exceeds 40,000, the flowability and moldability tend 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 18,500 to 25,000. The molecular weight can be adjusted to this range by known methods, such as controlling the amount of a molecular weight regulator, as described below.

[0036] Here, the viscosity average molecular weight [Mv] is determined by using methylene chloride as a solvent and an Ubbelohde viscometer to determine the intrinsic viscosity [η] (unit: dl / g) at a temperature of 20°C, and then using the Schnell viscosity formula, i.e., η = 1.23 × 10 -4 Mv 0.83 The intrinsic viscosity [η] is the value calculated from the following formula after measuring the specific viscosity [ηsp] at each solution concentration [C] (g / dl).

number

[0037] Other matters regarding polycarbonate resin The terminal hydroxyl group concentration of the polycarbonate resin is optional and may be appropriately selected and determined, but is typically 1,000 ppm or less, preferably 800 ppm or less, and more preferably 600 ppm or less. This can further improve the residence heat stability and color tone of the polycarbonate resin composition. The lower limit, particularly for polycarbonate resins produced by the melt transesterification method, is typically 10 ppm or more, preferably 30 ppm or more, and more preferably 40 ppm or more. This can suppress a decrease in molecular weight and further improve the mechanical properties of the polycarbonate resin composition. The terminal hydroxyl group concentration is expressed in ppm as the mass of terminal hydroxyl groups relative to the mass of polycarbonate resin, and is measured by colorimetric determination using the titanium tetrachloride / acetic acid method (the method described in Macromol. Chem. 88 215 (1965)).

[0038] The polycarbonate resin (A) is not limited to an embodiment containing only one type of polycarbonate resin, and may be a mixture of two or more polycarbonate resins differing in monomer composition, molecular weight, terminal hydroxyl group concentration, etc. Also, a polycarbonate resin may be mixed with another thermoplastic resin to be used as an alloy (mixture).

[0039] Furthermore, for example, polycarbonate resin may be constituted as a copolymer mainly composed of polycarbonate resin, such as a copolymer with an oligomer or polymer having a siloxane structure for the purpose of further enhancing flame retardancy and impact resistance; a copolymer with a monomer, oligomer, or polymer having a phosphorus atom for the purpose of further improving thermal oxidation stability and flame retardancy; a copolymer with a monomer, oligomer, or polymer having a dihydroxyanthraquinone structure for the purpose of improving thermal oxidation stability; a copolymer with an oligomer or polymer having an olefin structure such as polystyrene for improving optical properties; or a copolymer with a polyester resin oligomer or polymer for the purpose of improving chemical resistance.

[0040] Furthermore, to improve the appearance and fluidity of molded articles, the polycarbonate resin may contain a polycarbonate oligomer. The viscosity average molecular weight [Mv] of this polycarbonate oligomer is usually 1,500 or more, preferably 2,000 or more, and usually 9,500 or less, preferably 9,000 or less. Furthermore, the polycarbonate oligomer contained is preferably 30% by mass or less of the polycarbonate resin (including the polycarbonate oligomer).

[0041] Furthermore, the polycarbonate resin may be not only virgin raw material but also polycarbonate resin regenerated from used products (so-called material-recycled polycarbonate resin). Examples of the used products include optical recording media such as optical disks; light guide plates; transparent vehicle components such as automobile window glass, automobile headlamp lenses, and windshields; containers such as water bottles; eyeglass lenses; and building components such as soundproof walls, glass windows, and corrugated sheets. Also usable are crushed products obtained from non-conforming products, sprues, runners, etc., and pellets obtained by melting these. However, the recycled polycarbonate resin preferably accounts for 80% by mass or less, and more preferably 50% by mass or less, of the polycarbonate resin contained in the polycarbonate resin composition. This is because recycled polycarbonate resins are likely to have been subjected to degradation such as thermal degradation and aging degradation, and if such polycarbonate resins are used in an amount greater than the above range, the color and mechanical properties may be deteriorated.

[0042] [Graft copolymer (B) containing an aromatic vinyl monomer component (b1), a vinyl cyanide monomer component (b2), and a diene 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 rubber polymer component (b3). The graft copolymer (B) preferably comprises 40 to 80 mass% of the aromatic vinyl monomer component (b1), 10 to 30 mass% of the vinyl cyanide monomer component (b2), and 10 to 50 mass% of the diene rubber polymer component (b3), and may further contain 0 to 30 mass% of another monomer component (b4).

[0043] Examples of the aromatic vinyl monomer component (b1) in the graft copolymer (B) include styrene, α-methylstyrene, o-methylstyrene, p-methylstyrene, vinylxylene, ethylstyrene, dimethylstyrene, p-tert-butylstyrene, vinylnaphthalene, methoxystyrene, monobromostyrene, dibromostyrene, fluorostyrene, and tribromostyrene, with styrene being particularly preferred. The proportion of the 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, and more preferably 75% by mass or less, even more preferably 70% by mass or less, particularly preferably 65% ​​by mass or less, based on 100% by mass of the graft copolymer (B).

[0044] Examples of the vinyl cyanide monomer component (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, and more preferably 28% by mass or less, even more preferably 26% by mass or less, particularly preferably 25% by mass or less, based on 100% by mass of the graft copolymer (B).

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

[0046] Furthermore, copolymers of other monomer components (b4) copolymerizable with these may also be used. In this case, examples of the other copolymerizable vinyl monomers include maleimide-based monomers such as maleimide, N-methylmaleimide, N-cyclohexylmaleimide, and N-phenylmaleimide, acrylamide-based monomers such as acrylamide and N-methylacrylamide, unsaturated acid 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 the other monomer component (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, even more preferably 5% by mass or less, particularly preferably 3% by mass or less, and especially preferably 2% by mass or less, based on 100% by mass of the graft copolymer (B).

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

[0048] The graft copolymer (B) is usually produced by a method such as bulk polymerization, solution polymerization, suspension polymerization, or emulsion polymerization, and any of these methods can be used.

[0049] The content of the graft copolymer (B) is 10 to 45 parts by mass, preferably 12 parts by mass or more, more preferably 15 parts by mass or more, and preferably 42 parts by mass or less, more preferably 40 parts by mass or less, based on 100 parts by mass of the total of the polycarbonate resin (A) and the graft copolymer (B). If the amount of the 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 / cm 3 Hereinafter, the MFR (measured at 190°C and 21.18 N) is 0.9 g / 10 min or more. In the present invention, by incorporating an ethylene-α-olefin copolymer (C) having such a density and MFR into an alloy of a polycarbonate resin (A) and a graft copolymer (B), it is possible to obtain a polycarbonate resin composition that generates little creaking noise (noise) and that generates little creaking noise (noise) even when used for long periods of time in high-temperature environments as vehicle parts, etc.

[0051] The density is too high, 0.940 g / cm 3 If the density exceeds 0.935 g / cm, the crystallinity increases and the impact resistance decreases. 3 or less, more preferably 0.930 g / cm 3 Below that, 0.925g / cm 3 Below, 0.920g / cm 3 Below, especially 0.915 g / cm 3 Below, especially 0.910 g / cm 3 Below 0.908 g / cm, most preferably 0.908 g / cm 3 The following is the result. The upper limit of the density is preferably 0.800 g / cm 3 More preferably, 0.820 g / cm 3 More preferably, 0.840 g / cm 3 Above that, 0.850 g / cm is preferable. 3 Above, especially 0.860 g / cm 3 More preferably, 0.870 g / cm 3 or more, most preferably 0.880 g / cm 3 That's all. The density of the ethylene-α-olefin copolymer (C) is a value measured in accordance with JIS K7112.

[0052] If the MFR is less than 0.9 g / 10 min, the impact resistance decreases. If the MFR is too high, surface peeling is likely to occur, so the MFR is preferably 75 g / 10 min or less, more preferably 50 g / 10 min or less, even more preferably 40 g / 10 min or less, and of these, preferably 30 g / 10 min or less, and is preferably 1.09 g / 10 min or more, and even more preferably 1.1 g / 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 an α-olefin. The α-olefin is preferably an α-olefin having from 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 or more of these α-olefin-derived monomer units. The α-olefin is preferably 1-butene, 1-hexene, 4-methyl-1-pentene, or 1-octene, more preferably 1-butene or 1-hexene.

[0054] Examples of the 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, etc., preferably 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, particularly preferably ethylene-1-butene copolymer, ethylene-1-hexene copolymer.

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

[0056] The ethylene-α-olefin copolymer (C) is preferably an ethylene-α-olefin copolymer obtained by polymerization using a polymerization catalyst such as a Ziegler catalyst, a vanadium catalyst, a Phillips catalyst, or a metallocene catalyst (also called a single-site catalyst), or produced by high-pressure radical polymerization. Examples of the polymerization method 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 an α-olefin using a Ziegler-Natta catalyst, which contains a titanium compound, which may be trivalent and / or tetravalent, and an organoaluminum compound as a cocatalyst, and any known Ziegler-Natta catalyst can be used. The polymerization reaction is usually carried out at a polymerization temperature of 30 to 300°C under atmospheric pressure or 3000 kg / cm 2 The polymerization reaction is carried out under a polymerization pressure of 300 to 3000 kg / cm in the presence or absence of a solvent, in a gas-solid, liquid-solid or homogeneous liquid phase. Preferably, the polymerization reaction is carried out at a polymerization temperature of 130 to 300°C and a polymerization pressure of 300 to 3000 kg / cm. 2 Preferably, the polymerization is carried out in a high-pressure bulk process under a polymerization pressure of 1000 kJ / min.

[0058] The MFR of the ethylene-α-olefin copolymer (C) can be adjusted by adding a molecular weight modifier such as hydrogen during polymerization. The amount of hydrogen added varies depending on the catalyst used and production conditions. In general, increasing the amount of hydrogen added tends to increase the MFR, so it is preferable to determine the amount of hydrogen added depending on the desired MFR. The density of the ethylene-α-olefin copolymer (C) also varies depending on the catalyst used and production conditions, but can be adjusted by the concentration of the α-olefin in the ethylene-α-olefin copolymer.

[0059] The content of the ethylene-α-olefin copolymer (C) is 3.2 to 15 parts by mass per 100 parts by mass of the total of the polycarbonate resin (A) and the graft copolymer (B). This content allows for a resin composition that generates less creaking noise (noise) while maintaining mechanical properties such as impact resistance. The content of the 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, especially 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 preferably further contains an elastomer (D). By containing the elastomer (D) in combination with the above components, the resin composition has excellent impact resistance, particularly low-temperature impact resistance, making it particularly suitable for use in automobile 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 therewith. The graft copolymer may be produced by any of bulk polymerization, solution polymerization, suspension polymerization, emulsion polymerization, etc., and the copolymerization method may be either single-stage grafting or multi-stage grafting.

[0062] The rubber component typically 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 the rubber component include polybutadiene rubber, polyisoprene rubber, polyalkyl acrylate rubbers such as polybutyl acrylate, poly(2-ethylhexyl acrylate), and butyl acrylate-2-ethylhexyl acrylate copolymers, silicone rubbers such as polyorganosiloxane rubber, butadiene-acrylic composite rubber, IPN (Interpenetrating Polymer Network) composite rubbers consisting of polyorganosiloxane rubber and polyalkyl acrylate rubber, styrene-butadiene rubber, ethylene-α-olefin rubbers such as ethylene-propylene rubber, ethylene-butene rubber, and ethylene-octene rubber, ethylene-acrylic rubber, and fluororubber. These may be used alone or in combination. 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 the monomer component graft-copolymerizable with the rubber component include aromatic vinyl compounds, vinyl cyanide compounds, (meth)acrylic acid ester compounds, (meth)acrylic acid compounds, epoxy group-containing (meth)acrylic acid ester compounds such as glycidyl (meth)acrylate; maleimide compounds such as maleimide, N-methylmaleimide, and N-phenylmaleimide; 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 alone 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] The graft copolymer obtained by copolymerizing a rubber component is preferably a core / shell graft copolymer in terms of impact resistance and surface appearance. Among these, a core / shell graft copolymer is particularly preferred, which has a core layer made of at least one rubber component selected from polybutadiene-containing rubber, polybutyl acrylate-containing rubber, polyorganosiloxane rubber, and an IPN-type composite rubber composed of polyorganosiloxane rubber and polyalkyl acrylate rubber, and a shell layer formed by copolymerizing a (meth)acrylic acid ester around the core layer. The core / shell graft copolymer preferably contains 40% by mass or more of the rubber component, more preferably 60% by mass or more. Furthermore, it is preferable that the (meth)acrylic acid content be 10% by mass or more.

[0065] Among the above-mentioned elastomers, the elastomer (D) is preferably a core / shell type elastomer, and more preferably a core / shell type elastomer having a core of a silicone-acrylic composite, an acrylic rubber, or a butadiene rubber, and particularly preferably a core / shell type elastomer having a core of a butadiene rubber.

[0066] In the present invention, the core / shell type does not necessarily mean that the core layer and the shell layer are clearly distinguishable, but rather broadly includes compounds obtained by graft polymerizing a rubber component around the core portion.

[0067] Preferred examples of these core / shell 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. Particularly preferred are silicone-acrylic composite rubber containing polyorganosiloxane and polyalkyl(meth)acrylate, and methyl methacrylate-butadiene copolymer (MB). These rubbery polymers may be used alone or in combination of two or more.

[0068] When the elastomer (D) is contained, the content thereof 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, relative to 100 parts by mass of the total of the polycarbonate resin (A) and the graft copolymer (B). The elastomer (D) may be one type or two or more types, in which case the total amount falls within the above range.

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

[0070] Any known phosphorus stabilizer can be used. Specific examples include phosphorus oxoacids such as phosphoric acid, phosphonic acid, phosphorous acid, phosphinic acid, and polyphosphoric acid; metal acid pyrophosphates such as sodium acid pyrophosphate, potassium acid pyrophosphate, and calcium acid pyrophosphate; phosphates of Group 1 or Group 2B metals such as potassium phosphate, sodium phosphate, cesium phosphate, and zinc phosphate; 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. Specific examples of such organic phosphite compounds include "ADK STAB 1178," "ADK STAB 2112," and "ADK STAB HP-10" manufactured by ADEKA CORPORATION, "JP-351," "JP-360," and "JP-3CP" manufactured by Johoku Chemical Industry Co., Ltd., and "IRGAFOS 168" manufactured by BASF. The phosphorus-based stabilizer may be contained either as one type or as two or more types in any combination and ratio.

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

[0073] Examples of the phenolic stabilizer include hindered phenolic antioxidants. Specific examples thereof 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]phosphate, 3,3',3",5,5',5"-hexa-tert-butyl-a,a',a"-(mesitylene-2,4,6- triyl)tri-p-cresol, 4,6-bis(octylthiomethyl)-o-cresol, ethylene bis(oxyethylene) bis[3-(5-tert-butyl-4-hydroxy-m-tolyl)propionate], hexamethylene bis[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-triazin-2-ylamino)phenol, 2-[1-(2-hydroxy-3,5-di-tert-pentylphenyl)ethyl]-4,6-di-tert-pentylphenyl acrylate, and the like.

[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 "Irganox 1010" and "Irganox 1076" manufactured by BASF, and "Adekastab AO-50" and "Adekastab AO-60" manufactured by ADEKA. The phenolic stabilizer may be contained in one kind or in any combination and ratio of two or more kinds.

[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 the lower limit of the above range or more, the effect as a phenolic stabilizer can be sufficiently obtained. Furthermore, by setting the content of the phenolic stabilizer to the upper limit of the above range or less, the effect does not plateau, which is economical.

[0076] [Release agent] The polycarbonate resin composition of the present invention preferably contains a mold release agent (lubricant). Examples of the mold release agent include aliphatic carboxylic acids, esters of aliphatic carboxylic acids and alcohols, aliphatic hydrocarbon compounds having a number average molecular weight of 200 to 15,000, and polysiloxane-based silicone oils.

[0077] Examples of aliphatic carboxylic acids include saturated or unsaturated aliphatic mono-, di-, or tri-carboxylic acids. Aliphatic carboxylic acids also include alicyclic carboxylic acids. Among these, preferred aliphatic carboxylic acids are mono- or di-carboxylic acids having 6 to 36 carbon atoms, with saturated aliphatic mono-carboxylic acids having 6 to 36 carbon atoms being more preferred. Specific examples of such aliphatic carboxylic acids include palmitic acid, stearic acid, caproic acid, capric acid, lauric acid, arachic acid, behenic acid, lignoceric acid, cerotic acid, melissic acid, tetralinic acid, montanic acid, adipic acid, and azelaic acid.

[0078] The aliphatic carboxylic acid in the ester of an aliphatic carboxylic acid and an alcohol can be, for example, the same as the aliphatic carboxylic acid described above. On the other hand, the alcohol can be, for example, a saturated or unsaturated monohydric or polyhydric alcohol. These alcohols may have a substituent such as a fluorine atom or an aryl group. Among these, a monohydric or polyhydric saturated alcohol having 30 or less carbon atoms is preferred, and an aliphatic saturated monohydric alcohol or an aliphatic saturated polyhydric alcohol having 30 or less carbon atoms is more preferred. Here, the term "aliphatic" is used to include 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] The ester may contain an aliphatic carboxylic acid and / or an alcohol as an impurity. The ester may be a pure substance or a mixture of multiple compounds. The aliphatic carboxylic acid and the alcohol that combine to form an ester may each be used alone or in any combination and ratio of two or more.

[0081] Specific examples of esters of aliphatic carboxylic acids and alcohols include beeswax (a mixture containing myricyl palmitate as a main component), 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] Examples of aliphatic hydrocarbons having a number average molecular weight of 200 to 15,000 include liquid paraffin, paraffin wax, microcrystalline wax, polyethylene wax, Fischer-Tropsch wax, and α-olefin oligomers having 3 to 12 carbon atoms. Aliphatic hydrocarbons also include alicyclic hydrocarbons. These hydrocarbons may also be partially oxidized. Among these, paraffin wax, polyethylene wax, or a partial oxide of polyethylene wax is preferred, and paraffin wax and polyethylene wax are more preferred. The number average molecular weight of the aliphatic hydrocarbon is preferably 5,000 or less. The aliphatic hydrocarbon may be a single substance, but even if it is a mixture of substances with various constituent components and molecular weights, it is preferable that the main component is within the above range.

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

[0084] The above-mentioned release agents may be contained either alone or in any combination and ratio of two or more.

[0085] The content of the release agent is usually 0.001 part by mass or more, preferably 0.01 part by mass or more, and usually 2 parts by mass or less, preferably 1 part by mass or less, relative to 100 parts by mass of the total of the polycarbonate resin (A) and the graft copolymer (B). By setting the content of the release agent to be at least the lower limit of the above range, sufficient releasability effect is easily obtained, and by setting the content of the release agent to be at most the upper limit of the above range, sufficient hydrolysis resistance is obtained and mold contamination during injection molding is less likely to occur.

[0086] [Stabilizer] The polycarbonate resin composition of the present invention preferably further contains a stabilizer, which has the effect of improving thermal stability and preventing deterioration of mechanical strength, transparency, and color. As the stabilizer, phosphorus-based stabilizers and phenol-based stabilizers are preferred. Examples of phosphorus-based stabilizers include phosphorous acid, phosphoric acid, phosphite esters, and phosphate esters, with phosphites and phosphonites being preferred.

[0087] Examples of phosphites include 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, tetraphenyl dipropylene glycol diphosphite, tetraphenyl tetra(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 of the diphosphite include lidenediphenyl diphosphite, bis(tridecyl)pentaerythritol diphosphite, bis(nonylphenyl)pentaerythritol diphosphite, dilauryl pentaerythritol diphosphite, distearyl pentaerythritol 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] Examples of phosphonites include tetrakis(2,4-di-iso-propylphenyl)-4,4'-biphenylene diphosphonite, tetrakis(2,4-di-n-butylphenyl)-4,4'-biphenylene diphosphonite, tetrakis(2,4-di-tert-butylphenyl)-4,4'-biphenylene diphosphonite, tetrakis(2,4-di-tert-butylphenyl)-4,3'-biphenylene diphosphonite, and tetrakis(2,4-di-tert-butylphenyl)-3,3'-biphenylene diphosphonite. tetrakis(2,6-di-iso-propylphenyl)-4,4'-biphenylene diphosphonite, tetrakis(2,6-di-n-butylphenyl)-4,4'-biphenylene diphosphonite, tetrakis(2,6-di-tert-butylphenyl)-4,4'-biphenylene diphosphonite, tetrakis(2,6-di-tert-butylphenyl)-4,3'-biphenylene diphosphonite, and tetrakis(2,6-di-tert-butylphenyl)-3,3'-biphenylene diphosphonite.

[0089] 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, Examples of the acid phosphate 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 contained either as one type or as two or more types in any combination and ratio.

[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]phosphate, 3,3',3'',5,5',5 Examples of such phenols include 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-triazin-2-ylamino)phenol, and the like.

[0091] Of 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. The phenolic stabilizer may be contained in one kind or in any combination and ratio of two or more kinds.

[0092] The content of the stabilizer is usually 0.001 part by mass or more, preferably 0.01 part by mass or more, and usually 1.5 parts by mass or less, preferably 1 part by mass or less, based on 100 parts by mass of the total of the polycarbonate resin (A) and the rubber-reinforced styrene resin (B). If the content is less than 0.001 part by mass, the effect as a stabilizer is insufficient, and a decrease in molecular weight and deterioration in hue during molding tend to occur. If the content exceeds 1.5 parts by mass, the amount becomes excessive, and silver streaks tend to occur and the hue tends to deteriorate more easily.

[0093] [Other ingredients] The polycarbonate resin composition of the present invention may contain other components in addition to those described above, as necessary, as long as the desired physical properties are not significantly impaired. Examples of such other components include other resins other than the polycarbonate resin (A), graft copolymer (B), ethylene-α-olefin copolymer (C), and elastomer (D), various resin additives, etc. One type of such other component may be contained, or two or more types may be contained in any combination and ratio.

[0094] Other resins include, for example, thermoplastic polyester resins such as polyethylene terephthalate resin, polytrimethylene terephthalate resin, 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. The other resins may be contained either alone or in any combination and ratio of two or more.

[0095] When a resin other than the polycarbonate resin (A) and the graft copolymer (B) is contained, the content thereof is preferably 20 parts by mass or less, more preferably 10 parts by mass or less, even more preferably 5 parts by mass or less, and particularly preferably 3 parts by mass or less, per 100 parts by mass of the total of the polycarbonate resin (A) and the graft copolymer (B).

[0096] Examples of resin additives other than those mentioned above include ultraviolet absorbers, dyes and pigments (including titanium oxide and carbon black), antistatic agents, fillers, flame retardants, antifogging agents, lubricants, antiblocking agents, flow improvers, plasticizers, dispersants, and antibacterial agents. The other resin additives may be contained either alone or in any combination and ratio of two or more.

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

[0098] [Molded body] There is no limitation on the method for producing a molded article from the obtained resin composition pellets, and any molding method commonly used for polycarbonate resin compositions can be used. Examples include injection molding, ultra-high speed injection molding, injection compression molding, two-color molding, gas-assisted or other hollow molding methods, molding using an insulated mold, molding using a rapidly heated mold, foam molding (including supercritical fluid), insert molding, and IMC (in-mold coating molding). Injection molding and injection compression molding are preferred from the viewpoints of ease of molding and productivity.

[0099] Molded articles made from the polycarbonate resin composition of the present invention produce little creaking noise (unusual noise), even when used for long periods of time in a high-temperature environment. Therefore, molded articles made from the polycarbonate resin composition of the present invention can be suitably used as parts that come into contact with each other or with 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 a molded article of the polycarbonate resin composition of the present invention is used as an automobile interior part, it is possible to significantly reduce the generation of creaking noise when the parts come into contact with each other or with other parts due to automobile vibration. Examples of such automobile 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, 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. [Example]

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

[0101] [Table 1]

[0102] [Example 24. Reference Examples 1~ 23、25、26, Comparative Examples 1 to 5] The components listed in Table 1 above were blended in the proportions (mass ratios) listed in Tables 2 to 4 below, and the mixture was uniformly mixed in a tumbler to obtain a mixture. This mixture was fed into a twin-screw extruder (Toshiba Machine Co., Ltd., "TEM26SX"), kneaded at a screw rotation speed of 150 rpm, a discharge rate of 25 kg / hour, and a barrel temperature of 260°C, and extruded from the tip of the extrusion nozzle in the form of a strand. The strand was quenched in a water bath and cut and pelletized using a pelletizer to obtain pellets of a 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 / 10 min) was measured in accordance with ISO1133 under conditions of a measurement temperature of 250°C and a load of 2.16 kgf.

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

[0105] <Heat resistance DTUL (deflection temperature under load)> The pellets obtained by the above method were dried at 100°C for 5 hours and then injection-molded into ISO multipurpose test specimens (4 mm thick) using an injection molding machine (NEX80III, manufactured by Nissei Plastic Industrial Co., Ltd.) under conditions of a cylinder temperature of 260°C, a mold temperature of 60°C, and a molding cycle of 45 seconds. Based on ISO75-1 and ISO75-2, 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 piece (4 mmt), and the temperature was raised at the same rate. The temperature (unit: °C) was measured when the strain at the center reached 0.34 mm.

[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 a cylinder temperature of 260°C and a mold temperature of 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 piece were chamfered with #100 grit sandpaper, and then small burrs were removed with a cutter knife to obtain small test pieces for creaking noise evaluation.

[0107] The large and small test specimens for evaluation were left in a thermostatic chamber at 85°C for 400 hours (heat treatment) and then cooled to 25°C for 24 hours to obtain heat-treated test specimens. The large test specimen was placed on the movable stage of a Ziegler SSP-04 stick-slip tester, and the small test specimen was placed on the fixed stage. The large test specimen was rubbed against the small test specimen three times with an amplitude of 20 mm, according to the German Association of the Automotive Industry standard VDA230-206, at a temperature of 23°C, humidity of 50%, and the load (N) and speed (mm / sec) shown in Tables 2 to 4. The dynamic and static friction coefficients were measured, as well as the abnormal noise risk index (RPN) (also known as abnormal noise generation risk). The abnormal noise risk index (RPN) is displayed on a scale of 1 to 10. A lower abnormal noise risk index indicates a lower likelihood of squeaking noise, while a higher index indicates a higher likelihood of squeaking noise. According to the German Association of the Automotive Industry standard VDA230-206, if the noise risk index is between 1 and 3, the risk of creaking noises occurring is low and the product is considered to be at an acceptable level for practical use.

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

[0109] The evaluation results are shown in Tables 2 to 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 generate little creaking noise (unusual noise), and therefore can be suitably used as parts that come into contact with each other or with other molded articles, such as parts in the automotive, office automation equipment, home appliance, electrical and electronic fields, and are particularly suitable for use as automotive interior parts, making them highly valuable industrially.< / mvr>

Claims

1. The polycarbonate resin (A) contains 55 to 90 parts by mass of an aromatic vinyl monomer component (b1), a vinyl cyanide monomer component (b2), and a diene rubber polymer component (b3) containing 10 to 45 parts by mass of a graft copolymer (B). The density of the polycarbonate resin (A) is 0.905 g / cm 3 or more and 0.940 g / cm 3 or less per 100 parts by mass of the total of (A) and (B). ３ Hereinafter, there will be provided a polycarbonate resin composition characterized by containing 3.2 to 15 parts by mass of an ethylene-α-olefin copolymer (C) having an MFR (measured at 190°C and 21.18 N) of 0.9 g / 10 min or more, and 1 to 15 parts by mass of a methyl methacrylate-butadiene copolymer (MB resin) which is a core / shell type elastomer.

2. 2. The polycarbonate resin composition according to claim 1, which has an abnormal noise risk index of 1 to 3 based on VDA 203-206 of the German Association of the Automotive Industry.

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

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

5. 5. The molded article according to claim 4, which is an interior part of an automobile.

6. A molded product according to claim 4, which is a part that comes into contact with other molded products or with other molded products.

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