Polycarbonate resin composition and molded article containing same

Abstract

To provide a polycarbonate resin composition combining high light resistance and excellent initial appearance with good balance, without deteriorating impact strength of the polycarbonate resin composition, and a molding containing the same.SOLUTION: A polycarbonate-based resin composition characterized by containing 0.5 to 10 pts.mass of an acrylic triblock copolymer (C) containing a polymer block (a) containing an acrylic acid ester monomer unit and a polymer block (b) containing a methacrylic acid ester monomer unit and 0.01 to 1.0 pts.mass of a hindered amine-based photostabilizer (D) to 100 pts.mass of a resin component made of 50 to 99 mass% of a polycarbonate-based resin composition (A) and 1 to 50 mass% of an acrylonitrile-butadiene- styrene resin (B).SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a polycarbonate resin composition and a molded article containing the same. [Background technology]

[0002] Polycarbonate resin is a general-purpose engineering plastic that is a thermoplastic resin with excellent transparency, impact resistance, heat resistance, and dimensional stability. Due to its excellent properties, it is widely used in fields such as electrical and electronic equipment, IT, machinery, and automobiles.

[0003] However, polycarbonate resin has the problem of high melt viscosity and poor moldability, and as molded products become thinner and larger, there is a strong demand for improving moldability (fluidity).

[0004] As a means for solving the above problems, many compositions have been proposed in which a rubber-modified styrene resin is blended with a polycarbonate resin. In order to improve the molding processability of polycarbonate resin, a composition in which an acrylonitrile-butadiene-styrene resin (ABS resin) is blended with a polycarbonate resin has been used as a polymer alloy in many molding fields due to its heat resistance and molding processability.

[0005] One problem with polymer alloys that combine polycarbonate resin with ABS resin is that when the ABS resin content is increased to improve moldability (fluidity), the ABS resin discolors when exposed to sunlight, including ultraviolet rays, which impairs the overall appearance of the molded product.

[0006] The use of hindered amine light stabilizers is a widely known method for improving the light resistance of polymer alloys made of polycarbonate resin and ABS resin. However, these basic hindered amine light stabilizers are known to decompose the polymer chains of polycarbonate resin, resulting in a problem of reduced impact strength of the product.

[0007] Furthermore, the addition of a hindered amine light stabilizer or an ultraviolet absorber to a polycarbonate resin causes yellowing of the resin composition after molding, resulting in a problem of significantly impairing the appearance of the molded product.

[0008] Patent Document 1 proposes a method of adding a polyether polymer to a hindered amine light stabilizer having a specific structure as a method for improving the effect of the hindered amine light stabilizer on a polycarbonate resin, but does not mention the impact strength of the polycarbonate resin.

[0009] Patent Document 2 proposes a method of adding a hindered amine light stabilizer to a resin composition containing a polyester resin and a polycarbonate resin, but does not mention the initial yellowness. Furthermore, the hindered amine light stabilizer, which has basic properties, promotes the decomposition of the polycarbonate resin, making it difficult to maintain impact strength. [Prior art documents] [Patent documents]

[0010] [Patent Document 1] Patent No. 4637980 [Patent Document 2] Patent No. 4880174 Summary of the Invention [Problem to be solved by the invention]

[0011] An object of the present invention is to provide a polycarbonate resin composition that maintains the high impact resistance inherent to polycarbonate resins and also has a good balance of high light resistance and excellent initial appearance, and to provide a molded article containing the same. [Means for solving the problem]

[0012] The present inventors have conducted extensive research in light of the above-mentioned problems and have found that by blending an acrylic block copolymer constituted by a polymer block containing an acrylic acid ester monomer unit and a polymer block containing a methacrylic acid ester monomer unit, and a hindered amine light stabilizer with a resin component consisting of a polycarbonate resin and an acrylonitrile-butadiene-styrene resin, it is possible to maintain high impact strength and achieve a good balance between high light resistance and excellent initial appearance, thereby completing the present invention.

[0013] That is, the present invention provides a polycarbonate resin (A) of 50 to 100% by weight. 80 Mass %, and acrylonitrile-butadiene-styrene resin (B) 20 0.5 to 10 parts by mass of an acrylic triblock copolymer (C) containing a polymer block (a) containing an acrylic acid ester monomer unit and a polymer block (b) containing a methacrylic acid ester monomer unit, and 0.01 to 1.0 parts by mass of a hindered amine light stabilizer (D) relative to 100 parts by mass of a resin component consisting of 50% by mass or less. , 0.1 to 1.0 parts by mass of ultraviolet absorber (E) and a molded article containing the same. [Effects of the Invention]

[0014] According to the present invention, it is possible to provide a polycarbonate resin composition that maintains high impact strength and has a good balance of high light resistance and excellent initial appearance, and a molded article containing the same. DETAILED DESCRIPTION OF THE INVENTION

[0015] The polycarbonate composition and molded article of the present invention have high impact strength, high light resistance, and excellent initial appearance. The polycarbonate composition and molded article of the present invention are suitable for electrical equipment, electronic equipment, and IT equipment, and are particularly suitable for meter panel housings and vehicle equipment housings that are intended for use in environments exposed to sunlight and where the appearance of the molded article is important.

[0016] The polycarbonate resin composition according to the present invention contains a polycarbonate resin (A), an ABS resin (B), an acrylic triblock copolymer (C), and a hindered amine light stabilizer (D).

[0017] The polycarbonate resin (A) used in the present invention is a polymer obtained by the phosgene method in which various dihydroxydiaryl compounds are reacted with phosgene, or by the transesterification method in which a dihydroxydiaryl compound is reacted with a carbonate ester such as diphenyl carbonate, and a representative example is a polycarbonate resin produced from 2,2-bis(4-hydroxyphenyl)propane (commonly known as bisphenol A).

[0018] Examples of the dihydroxydiaryl compounds include, in addition to bisphenol A, bis(hydroxyaryl)alkanes such as bis(4-hydroxyphenyl)methane, 1,1-bis(4-hydroxyphenyl)ethane, 2,2-bis(4-hydroxyphenyl)butane, 2,2-bis(4-hydroxyphenyl)octane, bis(4-hydroxyphenyl)phenylmethane, 2,2-bis(4-hydroxyphenyl-3-methylphenyl)propane, 1,1-bis(4-hydroxy-3-tert-butylphenyl)propane, 2,2-bis(4-hydroxy-3-bromophenyl)propane, 2,2-bis(4-hydroxy-3,5-dibromophenyl)propane, and 2,2-bis(4-hydroxy-3,5-dichlorophenyl)propane; dihydroxydiaryl ethers such as 4,4'-dihydroxydiphenyl ether and 4,4'-dihydroxy-3,3'-dimethyldiphenyl ether; dihydroxydiaryl sulfides such as 4,4'-dihydroxydiphenyl sulfoxide and 4,4'-dihydroxy-3,3'-dimethyldiphenyl sulfoxide; dihydroxydiaryl sulfones such as 4,4'-dihydroxydiphenyl sulfone and 4,4'-dihydroxy-3,3'-dimethyldiphenyl sulfone; and the like.

[0019] These may be used alone or in combination of two or more. In addition to these, piperazine, dipiperidylhydroquinone, resorcinol, 4,4'-dihydroxydiphenyl, etc. may also be used in combination.

[0020] Furthermore, the above dihydroxyaryl compounds may be used in combination with the following trivalent or higher phenolic compounds: Trivalent or higher phenolic compounds include phloroglucin, 4,6-dimethyl-2,4,6-tri-(4-hydroxyphenyl)-heptene, 2,4,6-dimethyl-2,4,6-tri-(4-hydroxyphenyl)-heptane, 1,3,5-tri-(4-hydroxyphenyl)-benzene, 1,1,1-tri-(4-hydroxyphenyl)-ethane, and 2,2-bis-[4,4-(4,4'-dihydroxydiphenyl)-cyclohexyl]-propane.

[0021] The viscosity average molecular weight of the polycarbonate resin (A) is preferably 17,000 to 30,000 in terms of strength. By using a polycarbonate resin with such a viscosity average molecular weight, a polycarbonate resin composition with high impact strength can be obtained. In terms of molding processability and strength, the viscosity average molecular weight of the polycarbonate resin (A) is more preferably 19,000 to 28,000. If the viscosity average molecular weight exceeds 30,000, processability may be impaired. Furthermore, when producing such a polycarbonate resin, a molecular weight modifier, a catalyst, etc. may be used as needed.

[0022] The polymerization method for the acrylonitrile-butadiene-styrene resin (hereinafter also referred to as ABS resin) used in the present invention includes polymerization methods such as emulsion polymerization, suspension polymerization, and bulk polymerization, but ABS resin produced by bulk polymerization (continuous bulk polymerization) is particularly preferred.

[0023] The blending amount of ABS resin (B) is preferably 1 to 50 parts by mass relative to 50 to 99 parts by mass of polycarbonate resin (A). If the blending amount of ABS resin (B) is less than 1 part by mass, moldability may be insufficient, and if the blending amount of ABS resin (B) is more than 50 parts by mass, heat resistance may be reduced, which is not preferable.

[0024] The acrylic triblock copolymer (C) used in the present invention is composed of a polymer block (a) containing acrylic ester monomer units and a polymer block (b) containing methacrylic ester monomer units.

[0025] The content of the acrylic acid ester monomer units contained in polymer block (a) is preferably 60% by mass or more and 100% by mass or less (i.e., the main component) relative to 100% by mass of polymer block (a), and more preferably 70% by mass or more and 100% by mass or less. Examples of the acrylic acid ester monomer units in polymer block (a) include structural units derived from monomers such as methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, isobutyl acrylate, n-octyl acrylate, dodecyl acrylate, 2-ethylhexyl acrylate, stearyl acrylate, phenyl acrylate, and dimethylaminoethyl acrylate, and one or more of these may be used.

[0026] This polymer block (a) is obtained by a polymerization reaction of the above-mentioned monomers, and the weight-average molecular weight of the polymer block (a) is preferably from 6,000 to 1,000,000, more preferably from 10,000 to 800,000, and particularly preferably from 15,000 to 500,000. When the weight-average molecular weight of the polymer block (a) is within the above range, it is desirable from the viewpoint of obtaining an acrylic triblock copolymer (C) having excellent impact resistance and fluidity.

[0027] In addition to the acrylate-derived structural units, the polymer block (a) may contain other structural units, such as glycidyl acrylate, allyl acrylate, acrylonitrile, methacrylonitrile, and olefin monomers, as long as the desired effects are not impaired.

[0028] The content of the methacrylic acid ester monomer units contained in polymer block (b) is preferably 60% by mass or more and 100% by mass or less (i.e., the main component) relative to 100% by mass of polymer block (b), and more preferably 70% by mass or more and 100% by mass or less. Examples of the methacrylic acid ester monomer units in polymer block (b) include structural units derived from monomers such as methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, butyl (meth)acrylate, isobutyl (meth)acrylate, n-octyl (meth)acrylate, dodecyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, stearyl (meth)acrylate, phenyl (meth)acrylate, and dimethylaminoethyl (meth)acrylate, and one or more of these may be used.

[0029] This polymer block (b) is obtained by a polymerization reaction of the above-mentioned monomers, and the weight-average molecular weight of the polymer block (b) is preferably from 1,000 to 1,000,000, more preferably from 2,000 to 750,000, and particularly preferably from 3,000 to 500,000. When the weight-average molecular weight of the polymer block (b) is within the above range, it is desirable from the viewpoint of obtaining an acrylic triblock copolymer (C) that has excellent dispersibility in a matrix resin.

[0030] In addition to the methacrylic acid ester-derived structural unit, the polymer block (b) may contain other structural units as long as the desired effect is not impaired. Examples of the other structural units include other monomers such as acrylic acid ester, methacrylic acid, acrylic acid, aromatic vinyl compounds, acrylonitrile, methacrylonitrile, and olefin.

[0031] The acrylic triblock copolymer used in the present invention preferably has a (b)-(a)-(b) triblock structure in which one end of polymer block (b) is bonded to each of both ends of polymer block (a). By using the (b)-(a)-(b) triblock structure, the polycarbonate resin composition can maintain high impact strength while improving moldability.

[0032] Examples of methods for producing an acrylic triblock copolymer include the following. Specifically, a method of living polymerization of the monomers constituting each block can be mentioned. Examples of such living polymerization techniques include anionic polymerization using an organic alkali metal compound as a polymerization initiator in the presence of a mineral acid salt such as an alkali metal or alkaline earth metal salt, anionic polymerization using an organic alkali metal compound as a polymerization initiator in the presence of an organoaluminum compound, polymerization using an organic rare earth metal complex as a polymerization initiator, and radical polymerization using an α-halogenated ester compound as an initiator in the presence of a copper compound. Other examples include a method in which the monomers constituting each block are polymerized using a polyvalent radical polymerization initiator or a polyvalent radical chain transfer agent to produce a mixture containing the acrylic triblock copolymer of the present invention. Among these methods, anionic polymerization using an organic alkali metal compound as a polymerization initiator in the presence of an organoaluminum compound is preferred because it produces a block copolymer with high purity and a narrow molecular weight distribution, i.e., it does not contain oligomers that can reduce the impact strength and heat resistance of the polycarbonate resin composition of the present invention, or high molecular weight components that can reduce the flowability.

[0033] The weight average molecular weight of the acrylic triblock copolymer (C) in the present invention is preferably 1,000 or more and 1,000,000 or less, more preferably 2,000 or more and 500,000 or less, from the viewpoint of improving impact resistance, flowability, and dispersibility.

[0034] Specifically, the acrylic triblock copolymer (C) used in the present invention is preferably a triblock copolymer containing a polymer block having polybutyl acrylate as a monomer unit and a polymer block having polymethyl methacrylate as a monomer unit.

[0035] The acrylic triblock copolymer (C) may be used singly or in combination of two or more. When two or more types are used in combination, block copolymers having different molecular weights or block copolymers having different contents of polymer block (a) containing an acrylic acid ester monomer and polymer block containing monomer units (b) derived from a methacrylic acid ester may be used in combination.

[0036] As the acrylic triblock copolymer (C), commercially available products may be used, and examples of such commercially available products include "LA2149e (trade name)" manufactured by Kuraray Co., Ltd., "LA2250 (trade name)" manufactured by Kuraray Co., Ltd., "LA4285 (trade name)" manufactured by Kuraray Co., Ltd., "LA1114 (trade name)" manufactured by Kuraray Co., Ltd., and "LA2140 (trade name)" manufactured by Kuraray Co., Ltd.

[0037] The blending amount of the acrylic triblock copolymer (C) is preferably 0.5 to 10 parts by mass per 100 parts by mass of the total of the polycarbonate resin (A) and the ABS resin (B). If the blending amount of the acrylic triblock copolymer (C) is outside this range, it is not preferable because the impact strength may decrease.

[0038] The hindered amine light stabilizer (D) used in the present invention may be one represented by the following general formula (1). General formula (1): [ka] (In general formula (1), R1 and R2 bonded to the nitrogen atom of the piperidine skeleton are hydrocarbon substituents which may contain a hydrogen atom or a heteroatom.)

[0039] Examples of the hindered amine light stabilizer represented by general formula (1) include N-CH3-type hindered amine light stabilizers, NH-type hindered amine light stabilizers, and NR-type hindered amine light stabilizers. Here, the N-CH3-type hindered amine light stabilizer is one in which the hydrogen atom bonded to the nitrogen atom of the piperidine skeleton is substituted with a methyl group, and the NH-type hindered amine light stabilizer is one in which the hydrogen atom bonded to the nitrogen atom of the piperidine skeleton is not substituted with an alkyl group (it remains a hydrogen atom), and the NR-type hindered amine light stabilizer is one other than the NH-type hindered amine light stabilizers and the N-CH3-type hindered amine light stabilizers. Among these, the N-CH3-type hindered amine light stabilizer is preferred.

[0040] N-CH3 type hindered amine light stabilizers are available, for example, as Adeka STAB LA-52, Adeka STAB LA-63P, and Adeka STAB LA-72 manufactured by Adeka Corporation, and as TINUVIN PA144 and TINUVIN 765 manufactured by BASF.

[0041] NR-type hindered amine light stabilizers are available as Adekastab LA-81 manufactured by Adeka Corporation, Sanol LS2626 manufactured by Sankyo Kasei, and TINUVIN622 manufactured by BASF.

[0042] Specific examples of suitable hindered amine light stabilizers include bis(1,2,2,6,6-pentamethyl-4-piperidyl)[[3,5-bis(1,1-dimethylethyl)-4-hydroxyphenyl]methyl]butylmalonate, bis(1,2,2,6,6-pentamethyl-4-piperidyl)sebacate, methyl 1,2,2,6,6-pentamethyl-4-piperidylsebacate, bis(2,2,6,6-tetramethyl-4-piperidyl)sebacate, N,N'-bis(2,2,6,6-tetramethyl-4-piperidyl)-N,N'-diformylhexamethylenediamine, dibutylamine·1,3,5-triazine·N,N'-bis(2,2,6,6-tetramethyl-4-piperidyl)sebacate, Examples of suitable copolymers include polycondensates of N-(2,2,6,6-tetramethyl-4-piperidyl)-1,6-hexamethylenediamine and N-(2,2,6,6-tetramethyl-4-piperidyl)butylamine, poly[{6-(1,1,3,3-tetramethylbutyl)amino-1,3,5-triazine-2,4-diyl}{(2,2,6,6-tetramethyl-4-piperidyl)imino}hexamethylene{(2,2,6,6-tetramethyl-4-piperidyl)imino}], polymers of dimethyl succinate and 4-hydroxy-2,2,6,6-tetramethyl-1-piperidineethanol, and copolymers of olefins (C20-24), maleic anhydride, and 4-amino-2,2,6,6-tetramethylpiperidine.

[0043] In addition to those described above, commercially available products such as ADK STAB LA-77, ADK STAB LA-57, ADK STAB LA-62, ADK STAB LA-67, ADK STAB LA-68, ADK STAB LA-94, ADK STAB LA-82, ADK STAB LA-87, and ADK STAB LA-502XP (all manufactured by ADEKA Corporation) may also be used.

[0044] The amount of the hindered amine light stabilizer (D) is preferably 0.01 to 1.0 part by mass per 100 parts by mass of the total of the polycarbonate resin (A) and the ABS resin (B). If the amount of the hindered amine light stabilizer (D) is less than 0.01 part by mass, the light resistance will be insufficient, which is not preferred. If the amount of the hindered amine light stabilizer (D) is more than 1.0 part by mass, the initial appearance may be deteriorated (coloration may occur) and the impact strength may be reduced, which is not preferred.

[0045] As the ultraviolet absorber (E) used in the present invention, benzotriazole-based ultraviolet absorbers, triazine-based ultraviolet absorbers, etc. can be used, with benzotriazole-based ultraviolet absorbers being particularly preferred.

[0046] The benzotriazole-based ultraviolet absorber (E) used in the present invention includes 2-(2-hydroxy-5-methylphenyl)benzotriazole, 2-(2-hydroxy-5-tert-octylphenyl)benzotriazole, 2-(2-hydroxy-3,5-dicumylphenyl)phenylbenzotriazole, 2-(2-hydroxy-3-tert-butyl-5-methylphenyl)-5-chlorobenzotriazole, 2,2'-methylenebis[4-(1,1,3,3-tetramethylbutyl)-6-(2H-benzotriazol-2-yl)phenol], 2-(2-hydroxy-3,5-di-tert-butylphenyl)benzotriazole ... )benzotriazole, 2-(2-hydroxy-3,5-di-tert-butylphenyl)-5-chlorobenzotriazole, 2-(2-hydroxy-3,5-di-tert-amylphenyl)benzotriazole, 2-(2-hydroxy-5-tert-octylphenyl)benzotriazole, 2-(2-hydroxy-5-tert-butylphenyl)benzotriazole, 2-(2-hydroxy-4-octoxyphenyl)benzotriazole, 2,2'-methylenebis(4-cumyl-6-benzotriazolephenyl), 2,2'-p-phenylenebis(1,3-benzoxazin-4-one), and the like are examples.

[0047] Among these, 2-(2-hydroxy-5-t-octylphenyl)benzotriazole is particularly suitable, and commercially available examples include TINUVIN 329 (TINUVIN is a registered trademark) manufactured by BASF, Seesorb 709 manufactured by Shipro Kasei Co., Ltd., and Chemisorb 79 manufactured by Chemipro Kasei Co., Ltd.

[0048] The blending amount of the ultraviolet absorber (E) is preferably 0.1 to 1.0 parts by mass per 100 parts by mass of the resin component. A blending amount less than 0.1 part by mass results in poor weather resistance, while a blending amount exceeding 1.0 part by mass is undesirable because initial coloring occurs. The blending amount of the ultraviolet absorber (E) is more preferably in the range of 0.1 to 0.6 parts by mass, and even more preferably 0.1 to 0.4 parts by mass.

[0049] Furthermore, the polycarbonate resin composition according to the embodiment may contain, as appropriate, various additives such as an antioxidant (e.g., 2,4,8,10-tetra-t-butyl-6-[3-(3-methyl-4-hydroxy-5-t-butylphenyl)propoxy]dibenzo[d,f][1,3,2]dioxaphosphepine, Sumilizer GP manufactured by Sumitomo Chemical Co., Ltd. ("Sumilizer" is a registered trademark)), a release agent (e.g., fatty acid ester: glycerin monostearate, Rikemal S-100A manufactured by Riken Vitamin Co., Ltd.), a heat stabilizer, a colorant, a softener, an antistatic agent, an impact modifier, and the like, as well as polymers other than the aromatic polycarbonate resin (A), the ABS resin (B), and the acrylic triblock copolymer (C), within a range that does not impair the effects of the present invention.

[0050] The polycarbonate resin composition according to the present invention can be produced, for example, by mixing a polycarbonate resin (A), an ABS resin (B), an acrylic triblock copolymer (C), and a hindered amine light stabilizer (D), and, if necessary, mixing various additives and / or other polymers. The production method is not particularly limited as long as the polycarbonate resin composition of the present invention can be obtained, and the type and amount of each component can be adjusted appropriately. The method for mixing the components is also not particularly limited, and examples include a method of mixing using a known mixer such as a tumbler or ribbon blender, and a method of melt-kneading using an extruder. Pellets of the polycarbonate resin composition can be easily obtained by these methods.

[0051] The molded article according to the present invention can be obtained by molding the above-mentioned polycarbonate resin composition.

[0052] The method for producing the molded article is not particularly limited as long as it can produce the molded article intended by the present invention. For example, known methods such as injection molding and compression molding can be used to mold a polycarbonate resin composition.

[0053] The molded article according to the present invention is suitable for housings of electrical and electronic devices, IT devices, and vehicle meter panels, and is particularly suitable for peripheral parts and housings for vehicles that require heat resistance.

[0054] Although the embodiments have been described above as examples of the present invention, the technology of the present invention is not limited to these and can be applied to embodiments in which appropriate changes, substitutions, additions, omissions, etc. are made. [Example]

[0055] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples. Unless otherwise specified, "parts" and "%" are based on mass.

[0056] The following raw materials were used: 1. Polycarbonate resin (A) Polycarbonate resin synthesized from bisphenol A and carbonyl chloride 1-1, SD Polyca 200-3 (trade name) manufactured by Sumika Polycarbonate Co., Ltd. (viscosity average molecular weight: 28500): "SD Polyca" is a registered trademark of Sumika Polycarbonate Co., Ltd., hereinafter abbreviated as "PC-1" 1-2. SD Polyca 200-13 (trade name) manufactured by Sumika Polycarbonate Co., Ltd. (viscosity average molecular weight: 21500): "SD Polyca" is a registered trademark of Sumika Polycarbonate Co., Ltd., hereinafter abbreviated as "PC-2" 1-3. SD Polyca 200-30 (trade name) manufactured by Sumika Polycarbonate Co., Ltd. (viscosity average molecular weight: 17600): "SD Polyca" is a registered trademark of Sumika Polycarbonate Co., Ltd., hereinafter abbreviated as "PC-3"

[0057] 2.ABS resin (B) 2-1. Trinseo MAGNUM A-156 (product name) (Bulk polymerization ABS resin): "MAGNUM" is a registered trademark of Trinseo Co., Ltd., hereinafter abbreviated as "ABS-1" 2-2. Santac AT05 (product name) manufactured by Nippon A&L Co., Ltd. (Bulk polymerization ABS resin): "Santac" is a registered trademark of Nippon A&L Co., Ltd., hereinafter abbreviated as "ABS-2" 2-3. Clarustic SXH330 (product name) manufactured by Nippon A&L Co., Ltd. (Emulsion polymerized ABS resin): "Clarastic" is a registered trademark of Nippon A&L Co., Ltd., hereinafter abbreviated as "ABS-3"

[0058] 3. Acrylic triblock copolymer (C) composed of a polymer block (a) containing an acrylic acid ester monomer unit and a polymer block containing a methacrylic acid ester monomer unit 3-1. Kuraray Clarity LA2140 (product name) (Low molecular weight acrylic triblock copolymer): "CLARITY" is a registered trademark of Kuraray Co., Ltd., hereinafter abbreviated as "MAM-1" 3-2. Kuraray Clarity LA2330 (product name) (Medium molecular weight acrylic triblock copolymer): "CLARITY" is a registered trademark of Kuraray Co., Ltd., hereinafter abbreviated as "MAM-2" 3-3. Kuraray Clarity LA3320 (product name) (High molecular weight acrylic triblock copolymer): "CLARITY" is a registered trademark of Kuraray Co., Ltd., hereinafter abbreviated as "MAM-3"

[0059] 4. Hindered amine light stabilizers (D) 4-1. Adeka Stab LA-52 (product name) manufactured by Adeka Corporation (Low molecular weight hindered amine): "ADK STAB" is a registered trademark of ADEKA CORPORATION, hereinafter abbreviated as "HALS-1" 4-2. Adeka Stab LA-63P (product name) manufactured by Adeka Corporation (High molecular weight hindered amine): "ADK STAB" is a registered trademark of ADEKA CORPORATION, hereinafter abbreviated as "HALS-2" 4-3. Adeka Stab LA-81 (product name) manufactured by Adeka Corporation (Low molecular weight hindered amine): "ADK STAB" is a registered trademark of ADEKA CORPORATION, hereinafter abbreviated as "HALS-3" 4-4. Sanol LS-2626 (product name) manufactured by Sankyo Kasei Co., Ltd. (High molecular weight hindered amine): "Sanol" is a registered trademark of Sankyo Kasei Co., Ltd., hereinafter abbreviated as "HALS-4"

[0060] 5. UV absorber (E) 5-1. Chemisorb 79 (trade name) manufactured by Chemipro (Low molecular weight benzotriazole type ultraviolet absorber): "Chemisorb" is a registered trademark of Chemipro Kasei Co., Ltd., hereinafter abbreviated as "UVA-1" 5-2. Adeka Stab LA-31RG (product name) manufactured by Adeka Corporation (High molecular weight benzotriazole-type ultraviolet absorber): "ADEKA STAB" is a registered trademark of ADEKA CORPORATION, hereinafter abbreviated as "UVA-2" 5-3. Adeka Stab LA-36 (product name) manufactured by Adeka Corporation (Low molecular weight benzotriazole-type ultraviolet absorber): "ADEKA STAB" is a registered trademark of ADEKA CORPORATION, hereinafter abbreviated as "UVA-3" 5-4.BASF Tinuvin T-1577ED (product name) (Triazine-type UV absorber): "Tinuvin" is a registered trademark of BASF Ltd., hereinafter abbreviated as "UVA-4"

[0061] (Examples 1 to 24 and Comparative Examples 1 to 5) The various ingredients described above were all charged into a tumbler in the blending ratios shown in Tables 1 to 5, dry-mixed for 10 minutes, and then kneaded at a melt temperature of 240°C using a twin-screw extruder (TEX30α manufactured by The Japan Steel Works, Ltd.) to obtain pellets of a resin composition. The resin composition contains 0.2 parts by mass of Sumilizer GP as a phosphorus-based antioxidant and 0.1 parts by mass of S-100A as a mold release agent, per 100 parts by mass of the resin component.

[0062] (Evaluation of Charpy notched impact strength) The pellets of each resin composition obtained above were dried at 100°C for 4 hours, and then test specimens were prepared in accordance with the ISO test method using an injection molding machine (FANUC ROBOSHOT S2000i100B) at a set temperature of 250°C. The notched Charpy impact strength of the obtained test specimens was measured in accordance with ISO179-1 and ISO75-2. 2 Above: ◎ 80KJ / m 2 More than 90KJ / m 2 Less than 80KJ / m 2 Less than this was marked as ×.

[0063] (Evaluation of initial coloration due to additives) The pellets of each resin composition obtained above were each dried at 100°C for 4 hours, and then flat test pieces measuring 80mm x 50mm x 2mm were prepared using an injection molding machine (ROBOSHOT S2000i100B manufactured by FANUC) at a set temperature of 260°C.The yellowness index (YI(1)) was then measured using a spectrophotometer (CMS-35SP manufactured by Murakami Color Research Institute) using a D65 light source, a viewing angle of 10°, and a reflection method.

[0064] Furthermore, flat test pieces were similarly prepared for polycarbonate resin compositions containing neither the hindered amine light stabilizer (D) nor the ultraviolet absorber (E), and the yellowness index (YI(2)) was measured in the same manner.

[0065] The difference between the measured yellowness index (YI(1)) and the yellowness index (YI(2)) was calculated and defined as the initial YI. An initial YI of less than 3.0 was rated as ◎, 3.0 or more but less than 9.0 as ○, and 9.0 or more as ×.

[0066] (Evaluation of light resistance) The pellets of each resin composition obtained above were each dried at 100°C for 4 hours, and then an injection molding machine (ROBOSHOT S2000i100B manufactured by FANUC) was used to prepare flat test pieces measuring 80 mm x 50 mm x 2 mm at a set temperature of 250°C. Next, a highly accelerated weathering tester (Super Xenon Weather Meter SX75 manufactured by Suga Test Instruments Co., Ltd.) was used to test the pellets at a radiation intensity of 180 W / m 2 The samples were irradiated for 300 hours under the conditions of a BPT temperature of 63°C and a humidity of 50%RH in the chamber. After the irradiation, the yellowness index (YI(3)) was measured using a spectrophotometer (Murakami Color Research Institute CMS-35SP) under a D65 light source with a viewing angle of 10° using the reflection method.

[0067] The difference between the measured yellowness index (YI(3)) and the yellowness index (YI(1)) was calculated and defined as ΔYI. ΔYI of less than 40 was rated as ◎, 40 or more but less than 50 as ○, and 50 or more as ×.

[0068] [Table 1]

[0069] [Table 2]

[0070] [Table 3]

[0071] [Table 4]

[0072] [Table 5]

[0073] As shown in Tables 1 to 4, when the polycarbonate resin compositions satisfied all of the constituent requirements of the present invention (Examples 1 to 24), good results were obtained in all evaluation items.

[0074] On the other hand, as shown in Table 5, when the polycarbonate resin compositions did not satisfy the constituent requirements of the present invention (Comparative Examples 1 to 5), all of them had some kind of defect.

[0075] In Comparative Examples 1 and 2, a significant decrease in impact strength was observed due to the absence of an acrylic triblock copolymer and the addition of a hindered amine light stabilizer.

[0076] In Comparative Example 3, the blending amounts of the hindered amine light stabilizer and the ultraviolet absorber were less than the specified amounts, and significant yellowing was observed after the accelerated weather resistance test.

[0077] In Comparative Example 4, the amount of the hindered amine light stabilizer blended was greater than the specified amount, and yellowing of the initial appearance was observed.

[0078] In Comparative Example 5, the amount of the hindered amine light stabilizer blended was greater than the specified amount, and a significant decrease in impact strength was observed despite the incorporation of an acrylic triblock copolymer. [Industrial Applicability]

[0079] The polycarbonate composition of the present invention has a good balance of high impact resistance, high light resistance, and excellent initial appearance, and is therefore suitable for housings of electrical equipment, electronic equipment, IT equipment, and vehicle equipment, and is particularly suitable for meter panel housings and vehicle equipment housings that are expected to be used in environments exposed to sunlight and for which design is also important.

Claims

1. A polycarbonate resin composition comprising 100 parts by mass of a resin component consisting of 50 to 80% by mass of a polycarbonate resin (A) and 20 to 50% by mass of an acrylonitrile-butadiene-styrene resin (B), 0.5 to 10 parts by mass of an acrylic triblock copolymer (C) including a polymer block (a) containing an acrylic acid ester monomer unit and a polymer block (b) containing a methacrylic acid ester monomer unit, 0.01 to 1.0 part by mass of a hindered amine light stabilizer (D), and 0.1 to 1.0 part by mass of an ultraviolet absorber (E).

2. 2. The polycarbonate resin composition according to claim 1, wherein the viscosity average molecular weight of the polycarbonate resin (A) is 17,000 to 30,000.

3. 2. The polycarbonate-based resin composition according to claim 1, wherein the acrylic triblock copolymer (C) is a triblock copolymer in which one end of the polymer block (b) is bonded to each of both ends of the polymer block (a).

4. 2. The polycarbonate resin composition according to claim 1, wherein the hindered amine light stabilizer (D) has a structure represented by the following general formula (1): General formula (1): 【Chemical 1】 (In general formula (1), R1 and R2 bonded to the nitrogen atom of the piperidine skeleton are each a hydrogen atom or a hydrocarbon substituent which may contain a heteroatom.)

5. 2. The polycarbonate resin composition according to claim 1, wherein the ultraviolet absorber (E) has a benzotriazole structure.

6. A molded article comprising the polycarbonate resin composition according to any one of claims 1 to 5.

7. The molded article according to claim 6, wherein the molded article comprises a housing for an electronic device or a housing for a vehicle part.

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