Polycarbonate resin composition

Abstract

To provide a polycarbonate resin composition which has antibacterial property and improves heat stability while holding color development property, impact resistance, heat resistance and heat stability inherent to a polycarbonate resin.SOLUTION: A polycarbonate resin composition contains 0.1-5.0 pts.wt. of an antibacterial agent (B) containing a glass eluting silver ions as an essential component, and 0.2-1.5 pts.wt. of a polyether derivative (C) represented by the following general formula, with respect to 100 pts.wt. of an aromatic polycarbonate resin (A). General formula: RO-(X-O)m(Y-O)n-R'. In the formula, R and R' each independently represents a hydrogen atom or an alkyl group having 1 to 30 carbon atoms, X represents an alkylene group having 2 to 4 carbon atoms, Y represents a branched alkylene group having 3 to 5 carbon atoms, m and n each independently represents an integer of 3 to 60, and m+n represents an integer of 8-90.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a polycarbonate resin composition having antibacterial properties and thermal stability. [Background technology]

[0002] Polycarbonate resin is a thermoplastic resin with excellent color development, impact resistance, heat resistance, and thermal stability. Taking advantage of these characteristics, it is widely used in fields such as electrical, electronic, ITE, machinery, and automotive. Recently, in addition to these characteristics, performance related to comfort, cleanliness, and safety has also been required. To satisfy these performance requirements, organic or inorganic antibacterial agents are generally used in polycarbonate resin.

[0003] Inorganic antibacterial agents have traditionally been used to impart antibacterial properties to polycarbonate resins because of their excellent safety and thermal stability. Examples include antibacterial agents made of zeolite carrying metal ions such as silver and zinc, which exhibit strong antibacterial activity against bacteria (Patent Document 1), and soluble glass containing such metal ions (Patent Documents 2 and 3). Antibacterial synthetic resin moldings and superabsorbent resin bodies have also been disclosed, which contain water-soluble glass that releases silver ions in moisture-impermeable synthetic resins or superabsorbent resins (Patent Documents 4 and 5).

[0004] However, in actual injection molding of molded products, depending on the shape and size of the molded product, the resin may remain in the cylinder of the injection molding machine for a long period of time, which can cause the antibacterial agent to react with the resin, resulting in discoloration due to a decrease in thermal stability.

[0005] On the other hand, a resin composition has been proposed in which a hindered phenol-based antioxidant is blended with a polycarbonate resin in order to improve the thermal stability of the polycarbonate resin (Patent Document 6). However, although the addition of the antioxidant has been shown to have a certain effect of improving the thermal stability, it is not sufficient, and further improvement has been desired. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Patent No. 3293639 [Patent Document 2] Patent No. 2135769 [Patent Document 3] Japanese Patent Application Publication No. 7-25635 [Patent Document 4] Japanese Patent Application Publication No. 1-313531 [Patent Document 5] Japanese Patent Application Publication No. 1-153748 [Patent Document 6] Japanese Patent Application Laid-Open No. 2009-299004 Summary of the Invention [Problem to be solved by the invention]

[0007] An object of the present invention is to provide a polycarbonate resin composition that has antibacterial properties and improved thermal stability while retaining the color development, impact resistance, heat resistance, thermal stability, and other properties inherent to polycarbonate resins. [Means for solving the problem]

[0008] As a result of intensive research to solve the above problems, the present inventors have found that by blending a specific antibacterial agent and a polyether derivative with a polycarbonate resin, a polycarbonate resin composition can be obtained that retains antibacterial performance while significantly improving thermal stability and the like, and have thus completed the present invention.

[0009] That is, the present invention is The antibacterial agent (B) contains an aromatic polycarbonate resin (A), an antibacterial agent containing glass that elutes silver ions as an essential component, a polyether derivative (C) represented by the following general formula, and a phosphorus-based antioxidant (D), Aromatic polycarbonate resin (A) 100 parts by weight against , an antibacterial agent (B) whose essential component is glass that releases silver ions The content of 0.1 to 5.0 parts by weight of a polyether derivative (C) represented by the following general formula: The content of 0.2 to 1.5 parts by weight of phosphorus-based antioxidant (D) The content of 0.5 part by weight or less Yes The present invention provides a polycarbonate resin composition for exterior packaging (excluding those containing a hindered phenol-based antioxidant). General formula: RO-(XO)m(YO)n-R' (In the formula, R and R′ each independently represent a hydrogen atom or an alkyl group having 1 to 30 carbon atoms, X represents an alkylene group having 2 to 4 carbon atoms, Y represents a branched alkylene group having 3 to 5 carbon atoms, m and n each independently represent an integer of 3 to 60, and m+n represents an integer of 8 to 90.) [Effects of the Invention]

[0010] The polycarbonate resin composition of the present invention, which has excellent antibacterial properties and thermal stability, has significantly improved antibacterial properties and thermal stability while maintaining the excellent impact resistance and heat resistance inherent to polycarbonate resins, and discoloration due to retention in molded articles obtained from such resin compositions is suppressed. In addition, because of its antibacterial properties, it is suitable for use in components for home appliances, stationery, and other products that require comfort, cleanliness, safety, and other features, and its practical utility is extremely high. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, embodiments will be described in detail. However, more detailed explanations than necessary may be omitted. For example, detailed explanations of well-known matters or redundant explanations of substantially identical configurations may be omitted. This is to avoid unnecessary redundancy in the following explanation and to facilitate understanding by those skilled in the art. Note that the inventors provide the following explanation to enable those skilled in the art to fully understand the present invention, and it is not intended to limit the subject matter described in the claims.

[0012] The polycarbonate resin composition according to an embodiment of the present invention contains an aromatic polycarbonate resin (A), an antibacterial agent (B) containing, as an essential component, glass that elutes silver ions, and a polyether derivative (C), and may optionally contain one or more of an antioxidant (D), a mold release agent (E), an ultraviolet absorber (F), and other components.

[0013] In an embodiment of the present invention, the "polycarbonate resin (A)" is a polycarbonate resin based on an aromatic compound, and is not particularly limited as long as it can produce the polycarbonate resin composition of the present invention. Examples of such polycarbonate resins include polymers obtained by the phosgene method, in which various dihydroxydiaryl compounds are reacted with phosgene, or the transesterification method, in which a dihydroxydiaryl compound is reacted with a carbonate ester such as diphenyl carbonate. A representative example includes a polycarbonate resin produced from 2,2-bis(4-hydroxyphenyl)propane (bisphenol A).

[0014] Examples of the dihydroxydiaryl compound 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; Examples of suitable hydroxyaryl compounds include bis(hydroxyaryl)cycloalkanes such as bis(4-hydroxyphenyl)cyclopentane and 1,1-bis(4-hydroxyphenyl)cyclohexane; dihydroxydiaryl ethers such as 4,4'-dihydroxydiphenyl ether and 4,4'-dihydroxy-3,3'-dimethyldiphenyl ether; dihydroxydiaryl sulfides such as 4,4'-dihydroxydiphenyl sulfide; dihydroxydiaryl sulfoxides such as 4,4'-dihydroxydiphenyl sulfoxide and 4,4'-dihydroxy-3,3'-dimethyldiphenyl sulfoxide; and dihydroxydiaryl sulfones such as 4,4'-dihydroxydiphenyl sulfone and 4,4'-dihydroxy-3,3'-dimethyldiphenyl sulfone. These compounds may be used alone or in combination. Other compounds that may be used in combination include piperazine, dipiperidyl hydroquinone, resorcinol, and 4,4'-dihydroxydiphenyl.

[0015] Furthermore, the dihydroxydiaryl compound may be used in combination with, for example, the following trivalent or higher aromatic compounds.

[0016] Examples of the 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.

[0017] The viscosity average molecular weight of the polycarbonate resin (A) is preferably 10,000 to 100,000, and more preferably 12,000 to 30,000. When producing such a polycarbonate resin (A), a molecular weight modifier, a catalyst, etc. may be used as needed.

[0018] The antibacterial agent (B) used in the present invention, which contains glass capable of eluting silver ions as an essential component, is composed of a glass composition capable of eluting silver ions. It is particularly preferable that the composition contains silver oxide, phosphorus oxide, and zinc oxide and that the shape is polyhedral. When the shape is polyhedral, the glass is easily oriented in a certain direction in the resin, allowing it to be uniformly and easily mixed and dispersed in the resin, and light scattering is suppressed, making it suitable for excellent color development.

[0019] The glass composition of the antibacterial agent (B) preferably contains 0.1 to 5 wt% Ag2O, 30 to 80 wt% P2O5, and 1 to 55 wt% ZnO. It may also contain 0.1 to 15 wt% B2O3 and / or 0.1 to 15 wt% CaO. In the former case, silver ions can be stably released and the color development of the glass can be improved. In the latter case, glass with excellent color development and mechanical strength can be obtained. When CaO is contained, it is more preferable that the weight ratio of CaO to ZnO (ZnO / CaO) is within the range of 1.1 to 15.

[0020] In order to maintain the color development of the resin, it is preferable that the average particle size of the glass composition be within the range of 0.1 to 300 μm. Such antibacterial glass is readily available as a commercial product, such as KM10D manufactured by Sinanen Zeomic Co., Ltd.

[0021] The blending amount of the antibacterial agent (B) is 0.1 to 5.0 parts by weight per 100 parts by weight of the polycarbonate resin (A). A blending amount of less than 0.1 part by weight is not preferred because it is difficult to obtain a sufficient antibacterial effect. On the other hand, a blending amount of more than 5.0 parts by weight is not preferred because it impairs color development. A more preferred range is 0.2 to 3.0 parts by weight.

[0022] In an embodiment of the present invention, the polyether derivative (C) is a derivative of a polyether compound and is not particularly limited as long as it can provide the polycarbonate resin composition of the present invention. As the polyether derivative (C), a polyether derivative represented by the following formula (1) can be used.

[0023] Formula (1): RO-(XO)m(YO)n-R' (In the formula, R and R' each independently represent a hydrogen atom or an alkyl group having 1 to 30 carbon atoms, X represents a linear or branched alkylene group having 2 to 4 carbon atoms, Y represents a linear or branched alkylene group having 2 to 5 carbon atoms, X and Y may be the same or different, m and n each independently represent a number from 3 to 60, and m+n represents a number from 6 to 120.)

[0024] The weight average molecular weight of the polyether derivative represented by formula (1) is preferably 500 to 8000, more preferably 1000 to 4000. As the polyether derivative represented by formula (1), commercially available products can be used.

[0025] The polyether derivative represented by formula (1) may be any of those represented by the following formulas (1-1) to (1-3).

[0026] Formula (1-1): RO-(XO)m(YO)n-R' (In the formula, R and R' each independently represent a hydrogen atom or an alkyl group having 1 to 30 carbon atoms, X represents a linear alkylene group having 2 to 4 carbon atoms, Y represents a branched alkylene group having 2 to 5 carbon atoms, m and n each independently represent a number from 3 to 60, and m+n represents a number from 8 to 90.)

[0027] The weight average molecular weight of the polyether derivative represented by formula (1-1) is preferably 500 to 8000, more preferably 1000 to 4000. As the polyether derivative represented by formula (1-1), commercially available products can be used.

[0028] Formula (1-2): RO-(XO)m(YO)n-R' (In the formula, R and R' each independently represent a hydrogen atom or an alkyl group having 1 to 30 carbon atoms, X represents a linear alkylene group having 2 to 4 carbon atoms, Y represents a linear alkylene group having 2 to 5 carbon atoms, X and Y may be the same or different, m and n each independently represent a number from 3 to 60, and m+n represents a number from 6 to 100.)

[0029] The weight average molecular weight of the polyether derivative represented by formula (1-2) is preferably 500 to 8000, more preferably 1000 to 4000. As the polyether derivative represented by formula (1-2), commercially available products can be used.

[0030] Formula (1-3): RO-(XO)m(YO)n-R' (In the formula, R and R' each independently represent a hydrogen atom or an alkyl group having 1 to 30 carbon atoms, X represents a branched alkylene group having 2 to 4 carbon atoms, Y represents a branched alkylene group having 2 to 5 carbon atoms, X and Y may be the same or different, m and n each independently represent a number from 3 to 60, and m+n represents a number from 6 to 120.)

[0031] The weight average molecular weight of the polyether derivative represented by formula (1-3) is preferably 500 to 8000, more preferably 1000 to 4000. As the polyether derivative represented by formula (1-3), commercially available products can be used.

[0032] The polyether derivative represented by formula (1) preferably includes at least one selected from the group consisting of polyether derivatives represented by the following formula (2), polyether derivatives represented by formula (3), polyether derivatives represented by formula (4), polyether derivatives represented by formula (5), polyether derivatives represented by formula (6), polyether derivatives represented by formula (7), polyether derivatives represented by formula (8), polyether derivatives represented by formula (9), and polyether derivatives represented by formula (10).

[0033] The polyether derivative represented by formula (1-1) preferably includes at least one selected from the group consisting of polyether derivatives represented by the following formula (2), polyether derivatives represented by formula (3), polyether derivatives represented by formula (4), polyether derivatives represented by formula (5), and polyether derivatives represented by formula (6).

[0034] The polyether derivative represented by formula (1-2) preferably includes at least one selected from the group consisting of polyether derivatives represented by formula (7) and polyether derivatives represented by formula (8).

[0035] The polyether derivative represented by formula (1-3) preferably includes at least one selected from the group consisting of polyether derivatives represented by formula (9) and polyether derivatives represented by formula (10).

[0036] Formula (2): HO-(CH2CH2CH2CH2O)m(CH(CH3)CH2O)nH (In the formula, m and n each independently represent 3 to 60, and m+n represents 8 to 90.)

[0037] The polyether derivative represented by formula (2) is preferably a modified glycol containing a tetramethylene glycol unit and a propylene glycol unit. Commercially available polyether derivatives can be used, such as NOF Corp.'s Polyserine DCB-1000 (weight average molecular weight 1000), Polyserine DCB-2000 (weight average molecular weight 2000), and Polyserine DCB-4000 (weight average molecular weight 4000). The weight average molecular weight of the polyether derivative represented by formula (2) is preferably 500 to 8000, more preferably 1000 to 4000.

[0038] Formula (3): HO-(CH2CH2CH2CH2O)m(CH2CH2CH(CH3)CH2O)nH (In the formula, m and n each independently represent 3 to 60, and m+n represents 8 to 90.)

[0039] The polyether derivative represented by formula (3) is preferably a modified glycol containing a tetramethylene glycol unit and a 2-methyltetramethylene glycol unit. Commercially available polyether derivatives can be used, such as PTG-L1000 (weight average molecular weight 1000), PTG-L2000 (weight average molecular weight 2000), or PTG-L3000 (weight average molecular weight 3000) manufactured by Hodogaya Chemical Co., Ltd. The weight average molecular weight of the polyether derivative represented by formula (3) is preferably 500 to 8000, more preferably 1000 to 4000.

[0040] Formula (4): HO-(CH2CH2O)m(CH(CH3)CH2O)nH (In the formula, m and n each independently represent 3 to 60, and m+n represents 8 to 90.)

[0041] The polyether derivative represented by formula (4) is preferably a modified glycol containing an ethylene glycol unit and a propylene glycol unit. Commercially available products such as Unilube 50DE-25 (weight average molecular weight 1750) and Unilube 75DE-25 (weight average molecular weight 1400), manufactured by NOF Corporation, can be used. The weight average molecular weight of the polyether derivative represented by formula (4) is preferably 500 to 8000, more preferably 1000 to 4000.

[0042] Formula (5): RO-(CH2CH2CH2CH2O)m(CH(CH3)CH2O)nH (In the formula, R represents an alkyl group having 1 to 30 carbon atoms, m and n each independently represent 3 to 60, and m+n represents 8 to 90.)

[0043] The polyether derivative represented by formula (5) is preferably a modified glycol containing a tetramethylene glycol unit and a propylene glycol unit and having a butyl group or a stearyl group at one end. Commercially available polyether derivatives are available, such as NOF Corp.'s Polyserine BC-1000 (butyl group at one end, weight-average molecular weight 1000) and Polyserine SC-1000 (stearyl group at one end, weight-average molecular weight 1000). The weight-average molecular weight of the polyether derivative represented by formula (5) is preferably 500 to 8000, more preferably 1000 to 4000.

[0044] Formula (6): RO-(CH2CH2O)m(CH(CH3)CH2O)nH (In the formula, R represents an alkyl group having 1 to 30 carbon atoms, m and n each independently represent 3 to 60, and m+n represents 8 to 90.)

[0045] The polyether derivative represented by formula (6) is preferably a modified glycol containing an ethylene glycol unit and a propylene glycol unit and having a butyl group or a stearyl group at one end. Commercially available products of this type of polyether derivative can be used, such as Unilube 50MB-11 (butyl group at one end, weight-average molecular weight 1000), Unilube 50MB-26 (butyl group at one end, weight-average molecular weight 2000), Unilube 50MB-72 (butyl group at one end, weight-average molecular weight 3000), and Unilube 10MS-250KB (stearyl group at one end, weight-average molecular weight 2000), all manufactured by NOF Corporation. The weight average molecular weight of the polyether derivative represented by formula (6) is preferably 500 to 8,000, and more preferably 1,000 to 4,000.

[0046] Formula (7): HO-(CH2CH2CH2CH2O)m(CH2CH2O)nH (In the formula, m and n each independently represent 3 to 60, and m+n represents 8 to 90.)

[0047] The polyether derivative represented by formula (7) is preferably a modified glycol containing a tetramethylene glycol unit and an ethylene glycol unit. Commercially available polyether derivatives can be used, such as NOF Corp.'s Polyserine DC3000E (weight average molecular weight 3000) and Polyserine DC1800E (weight average molecular weight 1800). The weight average molecular weight of the polyether derivative represented by formula (7) is preferably 500 to 8000, more preferably 1000 to 4000.

[0048] Formula (8): HO-(CH2CH2CH2CH2O)pH (In the formula, p represents 6 to 100.)

[0049] The polyether derivative represented by formula (8) is preferably polytetramethylene glycol. Commercially available polyether derivatives are available, such as PTG-650SN (weight average molecular weight 650), PTG-850SN (weight average molecular weight 850), PTG-1000SN (weight average molecular weight 1000), PTG-1400SN (weight average molecular weight 1400), PTG-2000SN (weight average molecular weight 2000), and PTG-2900 (weight average molecular weight 2900), all manufactured by Hodogaya Chemical Co., Ltd. The weight average molecular weight of the polyether derivative (polytetramethylene glycol) represented by formula (8) is preferably 500 to 8000, more preferably 1000 to 4000.

[0050] Formula (9): Formula: HO-(CH(CH3)CH2O)qH (In the formula, q represents 7 to 120.)

[0051] The polyether derivative represented by formula (9) is preferably polypropylene glycol. Commercially available polyether derivatives can be used, such as Polyglycol P2000P (weight average molecular weight 2000) manufactured by Dow Chemical, Uniol D-1000 (weight average molecular weight 1000), Uniol D-2000 (weight average molecular weight 2000), and Uniol D-4000 (weight average molecular weight 4000) manufactured by NOF Corporation. The weight average molecular weight of the polyether derivative (polypropylene glycol) represented by formula (9) is preferably 500 to 8,000, and more preferably 1,000 to 4,000.

[0052] Equation (10): HO-(CH(C2H5)CH2O)rH (In the formula, r represents 6 to 100.)

[0053] Polybutylene glycol is preferred as the polyether derivative represented by formula (10). Commercially available products such as Uniol PB-500 (weight average molecular weight 500), Uniol PB-1000 (weight average molecular weight 1000), and Uniol PB-2000 (weight average molecular weight 2000), all manufactured by NOF Corporation, can be used. The weight average molecular weight of the polyether derivative (polybutylene glycol) represented by formula (10) is preferably 500 to 8,000, and more preferably 1,000 to 4,000.

[0054] By blending the polyether derivative represented by the general formula (1), it is possible to suppress discoloration that occurs when a polycarbonate resin composition blended with the antibacterial agent (B) is molded, which has been a conventional problem.

[0055] Each of the polyether derivatives represented by the formulas (1) to (10) may contain repeating units other than those described in each formula, as long as the polycarbonate resin composition and molded article targeted by the present invention can be obtained. Examples of such repeating units include repeating units based on impurities that may be contained in the starting materials for the polyether derivative, and repeating units based on the initiator (polymerization initiator) used during polymerization.

[0056] When a polymerization initiator is used, examples of the polymerization initiator include the following compounds: hydrogenated bisphenol A, bisphenol A, isosorbide, glycerin, pentaerythritol, sorbitol, glucose, etc.

[0057] An example of a polyether derivative containing a repeating unit based on such a polymerization initiator is Polyserine 60DB-2000H (manufactured by NOF Corporation) which can correspond to the above formula (2) (see formula 2-2). Formula (2-2): [ka] (In the formula, m1+m2 corresponds to m in formula (2), and n1+n2 corresponds to n in formula (2).)

[0058] The weight average molecular weight of the polyether derivative represented by formula (2-2) is preferably 500 to 8,000, and more preferably 1,000 to 4,000.

[0059] Furthermore, the polyether derivative (C) used in the present invention has a moderate lipophilicity and therefore has excellent compatibility with the polycarbonate resin (A), so that the transparency of a molded article obtained from a polycarbonate resin composition containing the polyether derivative (B) can be maintained without being reduced. The weight-average molecular weight of such a polyether derivative (C) is preferably 500 to 8,000, more preferably 1,000 to 4,000.

[0060] Furthermore, the CPR (unit: dimensionless) (Controlled Polymerization Rate: an index showing the amount of basic substances in a polyether derivative; measured in accordance with JIS K1557-4) of the polyether derivative (C) used in the present invention is preferably 2.0 or less, more preferably 1.0 or less. When the CPR is 2.0 or less, the polyether derivative (C) has excellent compatibility with polycarbonate resins, is inhibited from decomposition and deterioration, has excellent storage stability, and is less likely to adversely affect the hue of the resulting polycarbonate resin composition. For example, the CPR of polyserine DCB-2000, which corresponds to the polyether derivative (C) represented by the above formula (2), is less than 1.0; the CPR of polyserine 60DB-2000H (manufactured by NOF Corporation), which corresponds to the polyether derivative (C) represented by the above formula (2), is less than 1.0; and the CPR of PTG-1000SN (manufactured by Hodogaya Chemical Co., Ltd.), which corresponds to the polyether derivative (B) represented by the above formula (8), is less than 1.0.

[0061] Furthermore, the pH (measured in accordance with JIS K1557-5) of the polyether derivative (C) used in the present invention is preferably 5.0 or more and less than 7.5, more preferably 6.0 or more and less than 7.0. When the pH of the polyether derivative (C) is 5.0 or more and less than 7.5, decomposition and deterioration are suppressed, resulting in excellent storage stability and less adverse effects on the color of the resulting polycarbonate resin composition. For example, the pH of Polyserine DCB-2000, which corresponds to the polyether derivative (C) represented by the above formula (2), is 6.7; the pH of Polyserine 60DB-2000H (manufactured by NOF Corporation), which corresponds to the polyether derivative (B) represented by the above formula (2), is 6.8; and the pH of PTG-1000SN (manufactured by Hodogaya Chemical Co., Ltd.), which corresponds to the polyether derivative (C) represented by the above formula (8), is 6.7.

[0062] Furthermore, the temperature at which the polyether derivative (C) used in the present invention reduces to 90% of its weight (or the temperature at which the weight loss rate is 10%) (measured by thermogravimetry in accordance with JIS K7120) is preferably 300°C or higher, more preferably 330°C or higher. When the temperature at which the polyether derivative (C) reduces to 90% of its weight is 300°C or higher, decomposition and deterioration are suppressed, resulting in excellent storage stability and less adverse effects on the color of the resulting polycarbonate resin composition. For example, the temperature at which Polyserine DCB-2000, which corresponds to the polyether derivative (B) represented by the above formula (2), reduces to 90% of its weight is 330°C, and the temperature at which Polyserine 60DB-2000H (manufactured by NOF Corporation), which corresponds to the polyether derivative (B) represented by the above formula (2), reduces to 90% of its weight is 400°C.

[0063] The amount of the polyether derivative is 0.2 to 1.5 parts by weight, preferably 0.4 to 1.2 parts by weight, based on 100 parts by weight of the polycarbonate resin (A). If the amount of the polyether derivative is less than 0.2 parts by weight, the discoloration suppression effect may be insufficient. Conversely, if the amount of the polyether derivative is more than 1.5 parts by weight, the mechanical strength may be reduced.

[0064] The polycarbonate resin composition according to an embodiment of the present invention may contain, together with the polyether derivative (C), an aromatic compound of the following formula: By using the polyether derivative (C) in combination with the aromatic compound in this manner, it is possible to prevent deterioration of the long-term reliability of a molded article made from the resulting polycarbonate resin composition due to deterioration caused by the usage conditions and aging. formula: [ka]

[0065] The amount of aromatic compound used in the present invention is 0.0001 to less than 0.05 parts by weight, preferably 0.0005 to 0.003 parts by weight, per 100 parts by weight of polycarbonate resin (A). If the amount of aromatic compound is less than 0.0001 part by weight, the inhibitory effect on long-term reliability is insufficient. Conversely, if the amount of aromatic compound is 0.05 part by weight or more, it is undesirable because a good hue may not be achieved.

[0066] The polycarbonate resin composition of the present invention preferably contains one or more antioxidants (D) selected from phosphorus-based antioxidants and phenol-based antioxidants.

[0067] The phosphorus-based antioxidant is not particularly limited as long as it can produce the polycarbonate resin composition of the present invention, but it preferably contains a phosphite ester compound having the following phosphite ester structure. [ka]

[0068] In the polycarbonate resin composition according to an embodiment of the present invention, the phosphorus-based antioxidant (D) preferably contains at least one compound selected from the group consisting of a phosphite ester compound represented by the following formula (11), a phosphite ester compound represented by the following formula (12), a phosphite ester compound represented by the following formula (13), and a phosphite ester compound represented by the following formula (14):

[0069] Equation (11): [ka] (In the formula, R 1 represents an alkyl group having 1 to 20 carbon atoms, and a represents an integer of 0 to 3.

[0070] In the formula (11), R 1 is an alkyl group having 1 to 20 carbon atoms, and more preferably an alkyl group having 1 to 10 carbon atoms.

[0071] Examples of the compound represented by formula (11) include triphenyl phosphite, tricresyl phosphite, tris(2,4-di-t-butylphenyl) phosphite, trisnonylphenyl phosphite, etc. Among these, tris(2,4-di-t-butylphenyl) phosphite is particularly suitable, and is commercially available, for example, as Irgafos 168 manufactured by BASF ("Irgafos" is a registered trademark of BASF Societas Europea).

[0072] Formula (12): [ka] (In the formula, R 2 , R 3 , R 5 and R 6 R each independently represents a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, a cycloalkyl group having 5 to 8 carbon atoms, an alkylcycloalkyl group having 6 to 12 carbon atoms, an aralkyl group having 7 to 12 carbon atoms, or a phenyl group. 4 represents a hydrogen atom or an alkyl group having 1 to 8 carbon atoms; X represents a single bond, a sulfur atom, or a group of the formula: -CHR 7 -(where R 7 represents a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, or a cycloalkyl group having 5 to 8 carbon atoms. A represents an alkylene group having 1 to 8 carbon atoms or a group represented by the formula: *-COR 8 -(where R 8represents a single bond or an alkylene group having 1 to 8 carbon atoms, and * represents a bond on the oxygen side. Either Y or Z represents a hydroxyl group, an alkoxy group having 1 to 8 carbon atoms, or an aralkyloxy group having 7 to 12 carbon atoms, and the other represents a hydrogen atom or an alkyl group having 1 to 8 carbon atoms.

[0073] In equation (12), R 2 , R 3 , R 5 and R 6 are each independently a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, a cycloalkyl group having 5 to 8 carbon atoms, an alkylcycloalkyl group having 6 to 12 carbon atoms, an aralkyl group having 7 to 12 carbon atoms, or a phenyl group.

[0074] Examples of alkyl groups having 1 to 8 carbon atoms include methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, sec-butyl, t-butyl, t-pentyl, i-octyl, t-octyl, and 2-ethylhexyl groups. Examples of cycloalkyl groups having 5 to 8 carbon atoms include cyclopentyl, cyclohexyl, cycloheptyl, and cyclooctyl groups. Examples of alkylcycloalkyl groups having 6 to 12 carbon atoms include 1-methylcyclopentyl, 1-methylcyclohexyl, and 1-methyl-4-i-propylcyclohexyl groups. Examples of aralkyl groups having 7 to 12 carbon atoms include benzyl, α-methylbenzyl, and α,α-dimethylbenzyl groups.

[0075] R 2 , R 3 and R 5 are preferably each independently an alkyl group having 1 to 8 carbon atoms, a cycloalkyl group having 5 to 8 carbon atoms, or an alkylcycloalkyl group having 6 to 12 carbon atoms. 2 and R 5 are each preferably independently a t-alkyl group such as a t-butyl group, a t-pentyl group, or a t-octyl group, a cyclohexyl group, or a 1-methylcyclohexyl group. 3is preferably an alkyl group having 1 to 5 carbon atoms such as a methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group, an i-butyl group, a sec-butyl group, a t-butyl group, or a t-pentyl group, and more preferably a methyl group, a t-butyl group, or a t-pentyl group.

[0076] R 6 is preferably a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, or a cycloalkyl group having 5 to 8 carbon atoms, and more preferably a hydrogen atom, or an alkyl group having 1 to 5 carbon atoms such as a methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, i-butyl group, sec-butyl group, t-butyl group, or t-pentyl group.

[0077] In equation (12), R 4 represents a hydrogen atom or an alkyl group having 1 to 8 carbon atoms. Examples of the alkyl group having 1 to 8 carbon atoms include the above-mentioned R 2 , R 3 , R 5 and R 6 In particular, the alkyl groups exemplified in the explanation of R 4 is preferably a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, and more preferably a hydrogen atom or a methyl group.

[0078] In formula (12), X represents a single bond, a sulfur atom, or a group represented by the formula: -CHR 7 -, where the formula is -CHR 7 -R in 7 represents a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, or a cycloalkyl group having 5 to 8 carbon atoms. Examples of the alkyl group having 1 to 8 carbon atoms and the cycloalkyl group having 5 to 8 carbon atoms include the above-mentioned R 2 , R 3 , R 5 and R 6 Examples of the alkyl and cycloalkyl groups include those exemplified in the description of 1. In particular, X is preferably a single bond, a methylene group, or a methylene group substituted with a methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group, an i-butyl group, a t-butyl group, or the like, and more preferably a single bond.

[0079] In formula (12), A is an alkylene group having 1 to 8 carbon atoms or a group represented by the formula: *-COR 8 - represents a group represented by the formula: *-COR. Examples of the alkylene group having 1 to 8 carbon atoms include a methylene group, an ethylene group, a propylene group, a butylene group, a pentamethylene group, a hexamethylene group, an octamethylene group, and a 2,2-dimethyl-1,3-propylene group, and the like, with a propylene group being preferred. 8 -R in 8 represents a single bond or an alkylene group having 1 to 8 carbon atoms. 8 Examples of the alkylene group having 1 to 8 carbon atoms represented by R include the alkylene groups exemplified in the description of A. 8 is preferably a single bond or an ethylene group. 8 The * in - is the bond on the oxygen side, indicating that the carbonyl group is bonded to the oxygen atom of the phosphite group.

[0080] In formula (12), one of Y and Z represents a hydroxyl group, an alkoxy group having 1 to 8 carbon atoms, or an aralkyloxy group having 7 to 12 carbon atoms, and the other represents a hydrogen atom or an alkyl group having 1 to 8 carbon atoms. Examples of the alkoxy group having 1 to 8 carbon atoms include a methoxy group, an ethoxy group, a propoxy group, a t-butoxy group, and a pentyloxy group. Examples of the aralkyloxy group having 7 to 12 carbon atoms include a benzyloxy group, an α-methylbenzyloxy group, and an α,α-dimethylbenzyloxy group. Examples of the alkyl group having 1 to 8 carbon atoms include the above-mentioned R 2 , R 3 , R 5 and R 6 Examples of the alkyl groups include those exemplified in the explanation of 1.

[0081] Examples of the compound represented by formula (12) include 2,4,8,10-tetra-t-butyl-6-[3-(3-methyl-4-hydroxy-5-t-butylphenyl)propoxy]dibenzo[d,f][1,3,2]dioxaphosphepine, 6-[3-(3,5-di-t-butyl-4-hydroxyphenyl)propoxy]-2,4,8,10-tetra-t-butyldibenzo[d,f][1,3,2]dioxaphosphepine, Examples include 6-[3-(3,5-di-t-butyl-4-hydroxyphenyl)propoxy]-4,8-di-t-butyl-2,10-dimethyl-12H-dibenzo[d,g][1,3,2]dioxaphosphocin, 6-[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionyloxy]-4,8-di-t-butyl-2,10-dimethyl-12H-dibenzo[d,g][1,3,2]dioxaphosphocin, and the like. Among these, when the resulting polycarbonate resin composition is to be used in a field where optical properties are particularly required, 2,4,8,10-tetra-t-butyl-6-[3-(3-methyl-4-hydroxy-5-t-butylphenyl)propoxy]dibenzo[d,f][1,3,2]dioxaphosphepine is suitable, and is commercially available, for example, as Sumilizer GP ("Sumilizer" is a registered trademark) manufactured by Sumitomo Chemical Co., Ltd.

[0082] Equation (13): [ka] (In the formula, R 9 and R 10 each independently represents an alkyl group having 1 to 20 carbon atoms or an aryl group which may be substituted with an alkyl group, and b and c each independently represent an integer of 0 to 3.

[0083] Examples of the compound represented by formula (13) include bis(2,4-di-tert-butylphenyl)pentaerythritol diphosphite and phenylbisphenol A pentaerythritol diphosphite. Bis(2,4-di-tert-butylphenyl)pentaerythritol diphosphite is commercially available under the trade name "ADK STAB PEP-24G" manufactured by ADEKA Corporation. ADK STAB PEP-36 ("ADK STAB" is a registered trademark) manufactured by ADEKA Corporation is also commercially available.

[0084] Equation (14): [ka]

[0085] (In the formula, R 11 ~R 18 R each independently represents an alkyl group or alkenyl group having 1 to 3 carbon atoms. 11 and R 12 , R 13 and R 14 , R 15 and R 16 , R 17 and R 18 may be bonded to each other to form a ring. 19 ~R 22 each independently represents a hydrogen atom or an alkyl group having 1 to 20 carbon atoms. d to g each independently represents an integer of 0 to 5. X 1 ~X 4 X each independently represents a single bond or a carbon atom. 1 ~X 4 is a single bond, R 11 ~R 22 Among these, the functional group connected to the single bond is excluded from general formula (14).

[0086] A specific example of the compound represented by formula (14) is bis(2,4-dicumylphenyl)pentaerythritol diphosphite, which is commercially available from Dover Chemical under the trade name "Doverphos (registered trademark) S-9228" and from ADEKA under the trade name "ADEKA STAB PEP-45" (bis(2,4-dicumylphenyl)pentaerythritol diphosphite).

[0087] In addition to the above, other examples include tetrakis(2,4-di-tert-butylphenyl)-4,4'-biphenylene-di-phosphonite, etc. Specific examples of such organic phosphonite compounds include Sandstab PEPQ manufactured by Clariant Japan.

[0088] The phenol-based antioxidant includes a compound represented by the following formula (15).

[0089] Formula (15) [ka] (Wherein, R 23 represents an alkyl group having 1 to 20 carbon atoms or an aryl group which may be substituted with an alkyl group.

[0090] A commercially available compound of formula (5) is Adekastab AO-50 (n-octadecyl-3(3',5'-di-t-butyl-4-hydroxyphenyl)propionate) manufactured by ADEKA Corporation.

[0091] The amount of antioxidant (D) added can be 0 to 0.5 parts by weight per 100 parts by weight of polycarbonate resin (A). An amount exceeding 0.5 parts by weight is not preferred because it can lead to a deterioration in physical properties, insufficient thermal stability during retention during molding, and discoloration.

[0092] The polycarbonate resin composition of the present invention preferably contains a mold release agent (E) for the purpose of improving the mold releasability when removing a resin molded article that has been injected and filled into a mold.

[0093] The release agent (E) is not particularly limited as long as it can produce the polycarbonate resin composition intended by the present invention, but natural beeswax, fatty acid esters, glycerin fatty acid esters, polyol fatty acid esters, etc. can be added alone or in combination of two or more.

[0094] As the fatty acid ester, a condensation compound of a normal aliphatic carboxylic acid and an alcohol can be used.

[0095] The aliphatic carboxylic acid includes saturated or unsaturated monocarboxylic acids, dicarboxylic acids, tricarboxylic acids, etc. The aliphatic carboxylic acids also include alicyclic carboxylic acids. Among these, monocarboxylic acids and dicarboxylic acids having 6 to 36 carbon atoms are preferred, and saturated monocarboxylic acids having 6 to 36 carbon atoms are more preferred.

[0096] Specific examples of the aliphatic carboxylic acid include palmitic acid, stearic acid, valeric acid, caproic acid, capric acid, lauric acid, arachidic acid, behenic acid, lignoceric acid, cerotic acid, melissic acid, tetratriacontanoic acid, montanic acid, glutaric acid, adipic acid, and azelaic acid.

[0097] The alcohols include saturated or unsaturated monohydric alcohols and polyhydric alcohols, and these alcohols may have a substituent such as a fluorine atom, a chlorine atom, a bromine atom, or an aryl group. Among these, saturated alcohols having 30 or less carbon atoms are preferred, and saturated aliphatic monohydric alcohols and saturated aliphatic polyhydric alcohols having 30 or less carbon atoms are more preferred. Note that aliphatic alcohols also include alicyclic alcohols.

[0098] Specific examples of the alcohol include octanol, decanol, dodecanol, tetradecanol, stearyl alcohol, behenyl alcohol, ethylene glycol, diethylene glycol, glycerin, pentaerythritol, 2,2-dihydroxyperfluoropropanol, neopentylene glycol, ditrimethylolpropane, and dipentaerythritol.

[0099] Specific examples of fatty acid esters include behenyl behenate, octyldodecyl behenate, stearyl stearate, glycerin monopalmitate, glycerin monostearate, glycerin monooleate, glycerin distearate, glycerin tristearate, pentaerythritol monopalmitate, pentaerythritol monostearate, pentaerythritol distearate, pentaerythritol tristearate, and pentaerythritol tetrastearate, which can be used alone or in combination of two or more. Among these, pentaerythritol stearate is preferred, and for example, Roxiol VPG861 from Emery Oleo is commercially available.

[0100] The amount of the release agent (E) added can be 0 to 1.0 part by weight per 100 parts by weight of the polycarbonate resin (A). If the amount exceeds 1.0 part by weight, the physical properties will deteriorate, and the thermal stability during retention during molding processing will become insufficient, causing discoloration, which is not preferable.

[0101] For example, an ultraviolet absorber, which is a component that further improves the weather resistance of the resulting polycarbonate resin composition, can be appropriately used in the polycarbonate resin composition according to the embodiment, depending on the application of the molded product obtained by molding the polycarbonate resin composition.

[0102] As the ultraviolet absorber, for example, ultraviolet absorbers that are usually incorporated into polycarbonate resins, such as benzotriazole-based compounds, triazine-based compounds, benzophenone-based compounds, and oxalic acid anilide-based compounds, can be used alone or in combination of two or more.

[0103] Examples of benzotriazole compounds include 2-(2-hydroxy-5-t-octylphenyl)benzotriazole, 2-(3-tert-butyl-2-hydroxy-5-methylphenyl)-5-chloro-2H-benzotriazole, 2-(3,5-di-tert-pentyl-2-hydroxyphenyl)-2H-benzotriazole, and 2-(2H-benzotriazole-2-yl)-4-methyl-6-(3,4,5,6-tetrahydrophthalimid 2,2'-Methylenbis[6-(2H-benzotriazol-2-yl)4-(1,1,3,3-tetramethylbutyl)phenol], 2-(2-hydroxy-4-octyloxyphenyl)-2H-benzotriazole, 2-(2-hydroxy-5-tert-octylphenyl)-2H-benzotriazole, 2-[2'-hydroxy-3,5-di(1,1-dimethylbenzyl)phenyl]-2H-benzotriazole, 2,2'-Methylenbis[6-(2H-benzotriazol-2-yl)4-(1,1,3,3-tetramethylbutyl)phenol], etc. Among these, 2-(2-hydroxy-5-t-octylphenyl)benzotriazole is particularly suitable, and commercially available products include, for example, TINUVIN 329 (TINUVIN is a registered trademark) manufactured by BASF, Seesorb 709 manufactured by Shipro Chemical Co., Ltd., and Chemisorb 79 manufactured by Chemipro Chemical Co., Ltd.

[0104] Examples of triazine compounds include 2,4-diphenyl-6-(2-hydroxyphenyl-4-hexyloxyphenyl)1,3,5-triazine, 2-[4,6-bis(2,4-dimethylphenyl)-1,3,5-triazin-2-yl]-5-(octyloxy)phenol, and 2-(4,6-diphenyl-1,3,5-triazin-2-yl)-5-[(hexyl)oxy]phenol, and commercially available compounds include, for example, TINUVIN 1577 manufactured by BASF.

[0105] As the oxalic acid anilide compound, for example, Sanduvor VSU manufactured by Clariant Japan K.K. is commercially available.

[0106] Examples of benzophenone compounds include 2,4-dihydroxybenzophenone and 2-hydroxy-4-n-octoxybenzophenone.

[0107] The amount of the ultraviolet absorber to be added may be 0 to 1.0 part by weight per 100 parts by weight of the polycarbonate resin (A), depending on the processing method, such as injection molding, extrusion molding, etc. If the amount of the ultraviolet absorber exceeds 1.0 part by weight, the thermal stability of the resulting polycarbonate resin composition may be reduced.

[0108] The polycarbonate resin composition of the present embodiment may contain an epoxy compound.

[0109] The epoxy compound is not particularly limited as long as it has at least one epoxy group in the molecule and can produce the polycarbonate resin composition of the present invention. Examples of the epoxy compound include 3',4'-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate, epoxidized soybean oil, ε-caprolactone-modified 3',4'-epoxycyclohexylmethyl 3,4-epoxycyclohexanecarboxylate, epoxy group-containing acrylic-styrene polymers, and 2,2-bis(4-hydroxycyclohexyl)propane diglycidyl ether.

[0110] The method for producing the polycarbonate resin composition according to the present invention is not particularly limited, and the aromatic polycarbonate resin (A), the antibacterial agent (B), the polyether derivative (C), and any other components that are optionally blended can be mixed in any mixer, such as a tumbler, ribbon blender, high-speed mixer, etc., and then melt-kneaded in a conventional single-screw or twin-screw extruder, etc. There are also no particular limitations on the order in which these components are blended, and whether they may be mixed all at once or in portions.

[0111] In addition to the above components, other known colorants (titanium oxide, carbon black, dyes, etc.), fillers (glass fiber, glass flakes, carbon fiber, wollastonite, whiskers, talc, mica, etc.), pigments added to achieve design or a special appearance (metallic pigments, pearl pigments, etc.), heat stabilizers, softeners, antistatic agents, impact modifiers, flame retardants, fluorescent whitening agents, spreading agents (liquid paraffin, etc.), and other resins may also be blended during mixing, as needed. [Example]

[0112] Examples of the present invention will be described below, but the present invention is not limited to these examples. Unless otherwise specified, "%" and "parts" in the examples are based on weight.

[0113] The following raw materials were used: 1. Polycarbonate resin (A): Polycarbonate resin synthesized from bisphenol A and carbonyl chloride Viscosity average molecular weight: 21,500, SD Polyca 200-13 manufactured by Sumika Polycarbonate Co., Ltd., "SD Polyca" is a registered trademark of Sumika Polycarbonate Co., Ltd., hereinafter abbreviated as (A1).

[0114] 2. Antibacterial agents (B): 2-1. Bactekiller BM-102SD manufactured by Fuji Chemical Co., Ltd., hereafter abbreviated as (B1). 2-2. KM10D manufactured by Shinanoen Zeomic Co., Ltd., hereinafter abbreviated as (B2). 2-3. Ion Pure IPI manufactured by Ishizuka Glass Co., Ltd., hereinafter abbreviated as (B3). 2-4. Million Guard PG711 manufactured by Koa Glass Co., Ltd., hereafter abbreviated as (B4).

[0115] 3. Polyether derivatives (C): 3-1. Modified glycol (random copolymer) consisting of tetramethylene glycol units and propylene glycol units Weight average molecular weight: 2000, pH: 6.7 (JIS K1557-5), Polycerin DCB-2000 (trade name) manufactured by NOF Corporation, hereinafter abbreviated as (C1).

[0116] 3-2. Modified glycols consisting of ethylene glycol units and propylene glycol units (random copolymer) Weight average molecular weight: 1750, Unilube 50DE-25 (trade name) manufactured by NOF Corporation, hereinafter abbreviated as (C2).

[0117] 3-3. Polytetramethylene glycol Weight average molecular weight: 1000, PTG-1000SN (trade name) manufactured by Hodogaya Chemical Co., Ltd., hereinafter abbreviated as (C3).

[0118] 3-4. Polyether derivatives represented by the following formula: Weight average molecular weight: 2000, Polycerin 60DB-2000H (trade name) manufactured by NOF Corporation, hereinafter abbreviated as (C4). [ka]

[0119] 4. Antioxidants (D): 4-1. Tris(2,4-di-t-butylphenyl)phosphite, represented by the following formula: [ka] Irgafos 168 (trade name) manufactured by BASF, hereinafter abbreviated as (D1).

[0120] 4-2. 2,4,8,10-tetra-t-butyl-6-[3-(3-methyl-4-hydroxy-5-t-butylphenyl)propoxy]dibenzo[d,f][1,3,2]dioxaphosphepine represented by the following formula: [ka] Sumilizer GP (product name) manufactured by Sumitomo Chemical Co., Ltd., hereinafter abbreviated as (D2).

[0121] 4-3. Bis(2,4-dicumylphenyl)pentaerythritol diphosphite (IUPAC name: 3,9-bis[2,4-bis(α,α-dimethylbenzyl)phenoxy]-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane) represented by the following formula: [ka] Doverphos S-9228 (trade name) manufactured by Dover Chemical Co., hereinafter abbreviated as (D3).

[0122] 4-4. Bis(2,6-di-tert-butyl-4-methylphenyl)pentaerythritol diphosphite (IUPAC name: 3,9-bis(2,6-di-tert-butyl-4-methylphenoxy)-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5,5]undecane) represented by the following formula: [ka] ADEKA STAB PEP-36 (product name), hereafter abbreviated as (D4).

[0123] 4-5. (n-Octadecyl-3(3',5'-di-t-butyl-4-hydroxyphenyl)propionate) represented by the following formula [ka] Adeka Stab AO-50 (product name) manufactured by ADEKA Corporation, hereafter abbreviated as (D5).

[0124] 5. Release agent (E): 5-1. Glycerin Monostearate Rikemal S-100A (trade name) manufactured by Riken Vitamin Co., Ltd., hereafter abbreviated as (E1). 5-2. Pentaerythritol stearate Roxiol VPG861 (trade name) manufactured by Emery Oleo, hereafter abbreviated as (E2). 5-3. Bee's wax (hereinafter abbreviated as (E3)).

[0125] 6. UV absorber: 6-1,2-(2-hydroxy-5-t-octylphenyl)benzotriazole Chemisorb 79 (trade name) manufactured by Chemipro Chemicals, hereafter abbreviated as (H1). 6-2,2-Ethyl,2'-ethoxy-oxyanilide Sanduvor VSU (product name) manufactured by Clariant Japan, hereafter abbreviated as (H2). 6-3,2-(4,6-diphenyl-1,3,5-triazin-2-yl)-5-[(hexyl)oxy]phenol TINUVIN 1577 (trade name) manufactured by BASF, hereafter abbreviated as (H3).

[0126] 7. Epoxy compounds 3',4'-epoxycyclohexylmethyl-3,4-epoxycyclohexylcarboxylate Celloxide 2021P (product name) manufactured by Daicel Chemical Industries, Ltd., hereinafter abbreviated as (F1).

[0127] 8. Aromatic compounds: 3,5-di-t-butyl-4-hydroxytoluene Manufactured by Wako Pure Chemical Industries, Ltd., hereafter abbreviated as (G1).

[0128] The various raw materials described above were charged into a tumbler in the compounding ratios shown in Tables 1 and 2, respectively, and dry-mixed for 10 minutes. After that, the mixture was kneaded at a melting temperature of 250°C using a twin-screw extruder (TEX30α manufactured by The Japan Steel Works, Ltd., shaft diameter = 30 mmφ, L / D = 41) to obtain pellets for evaluation.

[0129] The obtained pellets were each dried in advance at 120°C for 4 hours, and then flat plate test pieces measuring 50 mm in length, 50 mm in width, and 2 mm in thickness were made using an injection molding machine (J100E2P manufactured by Japan Steel Works) with cylinder set temperatures of 270°C and 310°C.

[0130] Various evaluation items and measurement methods in the present invention will be described below.

[0131] 1. Discoloration Using flat test pieces obtained at cylinder set temperatures of 270°C and 310°C, the change in YI (ΔYI) was measured in accordance with ASTM D-1925 using a spectrophotometer (CMS-35SP manufactured by Murakami Color Research Laboratory). YI represents the degree of yellowness; the smaller the YI, the less yellowness and coloration. ΔYI was defined as the difference between the YI value of the flat test piece obtained at 310°C and the YI value of the flat test piece obtained at 270°C. As an evaluation standard, a ΔYI value of less than 5.0 was considered good (◯), and a value of 5.0 or more was considered poor (×).

[0132] 2. Antibacterial The antibacterial test was carried out based on JIS Z 2801 (film adhesion method). Specifically, 10 Escherichia coli bacteria were inoculated onto the surface of a flat test piece obtained under the same conditions as in the evaluation of initial coloring (cylinder temperature setting 270°C). 5 A bacterial solution containing bacteria was dropped onto the plate, and a PE film was then placed on top of it. After leaving the plate at 35°C for 24 hours, the bacteria adhering to the PE film and the plate test piece were washed out with SCDLP medium, transferred to a petri dish, and cultured at 35°C for 45 hours, after which the viable count of E. coli (y) was counted. The evaluation criteria were as follows: log 10 A value of (x / y) (hereinafter abbreviated as antibacterial activity value) of 2.0 or more was rated as good (◯), and a value of less than 2.0 was rated as poor (×).

[0133] Furthermore, an antibacterial test was conducted under the same procedures and conditions as above, except that Escherichia coli was replaced with Staphylococcus aureus, and the antibacterial activity value was determined and evaluated using the same criteria.

[0134] 3. Overall Judgment In the evaluation of discoloration and antibacterial properties, those that were all good were rated as good (◯), and those that were not were rated as bad (×).

[0135] Tables 1 to 4 show the compositions of the polycarbonate resin compositions of the examples and comparative examples, and the evaluation results.

[0136] [Table 1]

[0137] [Table 2]

[0138] [Table 3]

[0139] [Table 4]

[0140] Examples 1 to 23 (However, Examples 2, 9 to 11 are reference examples.) The polycarbonate resin composition according to the present invention contains an antibacterial agent containing glass that elutes silver ions as an essential component and a polyether derivative within the above-mentioned blending amounts, and both compositions exhibit good initial colorability, thermal stability, color development, antibacterial properties, and chemical resistance. [Industrial Applicability]

[0141] The present invention can be used as a polycarbonate resin composition for constituting various exterior materials and the like.

Claims

1. A polycarbonate resin composition for exterior materials, comprising an aromatic polycarbonate resin (A), an antibacterial agent (B) having as an essential component glass that elutes silver ions, a polyether derivative (C) shown in the general formula below, and a phosphorus-based antioxidant (D), wherein, per 100 parts by weight of the aromatic polycarbonate resin (A), the content of the antibacterial agent (B) having as an essential component glass that elutes silver ions is 0.1 to 5.0 parts by weight, the content of the polyether derivative (C) shown in the general formula below is 0.2 to 1.5 parts by weight, and the content of the phosphorus-based antioxidant (D) is 0.5 parts by weight or less (excluding cases where a hindered phenol-based antioxidant is contained): General formula: RO-(X-O)m(Y-O)n-R' (In the formula, R and R' each independently represent a hydrogen atom or an alkyl group having 1 to 30 carbon atoms, X represents an alkylene group having 2 to 4 carbon atoms, Y represents a branched alkylene group having 3 to 5 carbon atoms, m and n each independently represent an integer of 3 to 60, and m+n represents an integer of 8 to 90.)

2. 2. The polycarbonate resin composition according to claim 1, further comprising a mold release agent (E) in an amount of 1.0 part by weight or less per 100 parts by weight of the aromatic polycarbonate resin (A).

3. 3. The polycarbonate resin composition according to claim 1, further comprising an ultraviolet absorber in an amount of 1.0 part by weight or less per 100 parts by weight of the aromatic polycarbonate resin (A).

4. 4. The polycarbonate resin composition according to claim 1, further comprising at least one selected from the group consisting of a heat stabilizer, a colorant, a softener, an antistatic agent, and an impact modifier.

5. The polycarbonate resin composition according to any one of claims 1 to 4, further comprising an aromatic compound represented by the following formula: 【Chemical 1】

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