Polycarbonate resin composition and molded object

Abstract

To provide a polycarbonate resin composition that enables production of a molded body exhibiting minimal color variation in light guiding along a long light-guiding path and superior long-term heat and moisture-heat resistance.SOLUTION: This polycarbonate resin composition comprises a polycarbonate resin, a phosphorus-compound antioxidant, and an alicyclic epoxy compound. The phosphorus-compound antioxidant includes a pentaerythritol diphosphite compound. Based on 100 pts.mass of the polycarbonate resin, the content of the alicyclic epoxy compound is 0.01 pt.mass or more and 0.6 pt.mass or less, the content of the pentaerythritol diphosphite compound is 0.01 pt.mass or more and 0.35 pt.mass or less, and the content of the phosphorus-compound antioxidant is 0.2 pt.mass or more. The ratio of the content of the alicyclic epoxy compound to the content of the pentaerythritol diphosphite compound is 0.5 or higher.SELECTED DRAWING: None

Description

[Technical Field]

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

[0002] Polycarbonate resins such as aromatic polycarbonate resins are excellent in transparency, mechanical properties, thermal properties, and electrical properties, and are used to their advantage in various optical molded products such as light guide lenses such as light guide plates, optical fibers, etc. In recent years, the use of polycarbonate resin compositions in daytime running lights or daytime running lamps (hereinafter, these may be collectively referred to as "DRL") for vehicles, etc., or light guide parts that constitute the light guide portions of various optical components has also been considered.

[0003] Patent Document 1 discloses a polycarbonate resin composition for optical parts, which contains a polycarbonate resin (A), a polyether derivative (B), a phosphite ester compound (C), and an epoxy compound (D). It discloses that the polycarbonate resin composition contains specific amounts of components (A) to (D), and therefore has good hue and brightness even when molded at high temperatures, and also has excellent hydrolysis resistance. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 2017 / 212512 Summary of the Invention [Problem to be solved by the invention]

[0005] In recent years, DRLs have tended to use LEDs as light sources with higher output and longer lengths to improve vehicle visibility. There is a demand for the development of resin compositions that are less susceptible to deterioration due to the light or heat caused by irradiation with high-output LED light and that minimize color change in the guided light over long light guide paths.

[0006] On the other hand, Patent Document 1 does not disclose any change in color tone of guided light in a long light guide path, long-term heat resistance, or long-term moist heat resistance of the molded article molded from the polycarbonate resin composition for optical parts.

[0007] An object of one aspect of the present invention is to provide a polycarbonate resin composition capable of producing a molded article that exhibits little change in color tone of guided light over a long light guide path and has excellent long-term heat resistance and long-term moist heat resistance. [Means for solving the problem]

[0008] As a result of intensive investigations aimed at solving the above-mentioned problems, the present inventors have found that the above-mentioned problems can be solved by a polycarbonate resin composition in which a polycarbonate resin is blended with an alicyclic epoxy compound and a phosphorus-based antioxidant having a specific structure in specific amounts, and have thus completed the present invention.

[0009] A polycarbonate resin composition according to one aspect of the present invention comprises a polycarbonate resin, a phosphorus-based antioxidant, and an alicyclic epoxy compound, The phosphorus-based antioxidant contains a pentaerythritol diphosphite compound represented by the following general formula (1): the content of the alicyclic epoxy compound is 0.01 parts by mass or more and 0.6 parts by mass or less relative to 100 parts by mass of the polycarbonate resin, the content of the pentaerythritol diphosphite compound is 0.01 parts by mass or more and 0.35 parts by mass or less relative to 100 parts by mass of the polycarbonate resin, the content of the phosphorus-based antioxidant is 0.2 parts by mass or more relative to 100 parts by mass of the polycarbonate resin; The polycarbonate resin composition has a ratio of the content of the alicyclic epoxy compound to the content of the pentaerythritol diphosphite compound of 0.5 or more: [ka] In formula (1), R C11 ~R C16 teeth, (i) a hydrogen atom or an aromatic ring-containing group having 6 to 15 carbon atoms, which may be the same or different, or (ii) a hydrogen atom or an alkyl group having 1 to 12 carbon atoms, which may be the same or different; However, R C11 ~R C16 Not all of them will be hydrogen atoms. [Effects of the Invention]

[0010] According to one aspect of the present invention, it is possible to provide a polycarbonate resin composition capable of producing a molded article that exhibits little change in color tone of guided light over a long light guide path and has excellent long-term heat resistance and long-term moist heat resistance. DETAILED DESCRIPTION OF THE INVENTION

[0011] One embodiment of the present invention will be described in detail below. In this specification, unless otherwise specified, the expression "A to B" representing a range of numerical values ​​means "A or more and B or less."

[0012] <1. Polycarbonate resin composition> A polycarbonate resin composition according to one aspect of the present invention (hereinafter sometimes simply referred to as "resin composition") comprises a polycarbonate resin, a phosphorus-based antioxidant, and an alicyclic epoxy compound. The resin composition according to one aspect of the present invention includes a blend obtained by blending raw materials for the resin composition containing the aforementioned components, and a kneaded product obtained by melt-kneading the blend.

[0013] [Polycarbonate resin] The polycarbonate resin is not particularly limited in type as long as it is a resin containing a polymer having a carbonate bond (-O-CO-O-) in the main chain. The polycarbonate resin may be, for example, an aromatic polycarbonate resin or an aliphatic polycarbonate. The aromatic polycarbonate resin is a polycarbonate resin containing an aromatic ring such as a benzene ring between carbonate bonds in the main chain, and the aliphatic polycarbonate resin is a polycarbonate resin not containing an aromatic ring such as a benzene ring between carbonate bonds in the main chain. The polycarbonate resin may also have a branched structure. One type of polycarbonate resin may be used alone, or two or more types may be used in combination in any ratio.

[0014] The polycarbonate resin can be produced by a known method. For example, the polycarbonate resin can be produced by reacting a dihydric phenol with a carbonate precursor by a solution method (interfacial polycondensation method) or a melting method (ester exchange method), that is, the polycarbonate resin can be produced by reacting a dihydric phenol with phosgene in the presence of an end-capping agent by an interfacial polycondensation method, or by reacting a dihydric phenol with diphenyl carbonate or the like in the presence of an end-capping agent by an ester exchange method or the like.

[0015] The dihydric phenol, carbonate precursor, end-capping agent, etc. that can be used in the production of polycarbonate resins can be those commonly used in the art. For example, the dihydric phenol, carbonate precursor, end-capping agent, etc. disclosed in WO 2018 / 181949 can be used in the production of polycarbonate resins.

[0016] In one embodiment of the present invention, the viscosity average molecular weight (Mv) of the polycarbonate resin is not limited, but from the viewpoint of flowability, it is preferably 10,000 or more and 30,000 or less, more preferably 11,000 or more and 26,000 or less. In particular, when the resin composition according to one embodiment of the present invention is used in a light-guiding component (e.g., a DRL), the Mv of the polycarbonate resin is preferably 12,000 or more and 25,000 or less, and more preferably 13,000 or more and 23,000 or less.

[0017] In this specification, the viscosity average molecular weight (Mv) is calculated by the following formula using the intrinsic viscosity [η] obtained by measuring the viscosity of a methylene chloride solution at 20°C using an Ubbelohde viscometer. [η]=1.23×10-5Mv 0.83

[0018] (Preferred type of polycarbonate resin)

[0019] The polycarbonate resin preferably contains an aromatic polycarbonate resin whose main chain has a repeating unit represented by the following general formula (I). [ka] (In the formula (I), R A1 and R A2 is an alkyl or alkoxy group having 1 to 6 carbon atoms, and R A1 and R A2 may be the same as or different from; X represents a single bond, an alkylene group having 1 to 8 carbon atoms, an alkylidene group having 2 to 8 carbon atoms, a cycloalkylene group having 5 to 15 carbon atoms, a cycloalkylidene group having 5 to 15 carbon atoms, -S-, -SO-, -SO2-, -O-, or -CO-; a and b each independently represent an integer of 0 or more and 4 or less; If a is 2 or more, R A1 may be the same or different, and when b is 2 or more, R A2may be the same or different.)

[0020] R A1 and R A2 Examples of alkyl groups represented by R include methyl, ethyl, n-propyl, isopropyl, various butyl groups (the term "various" refers to both linear and branched groups, and the same applies hereinafter), various pentyl groups, and various hexyl groups. A1 and R A2 Examples of the alkoxy group represented by the formula (I) include an alkoxy group in which the alkyl group moiety is one of the alkyl groups exemplified above. A1 and R A2 is preferably an alkyl group having 1 to 4 carbon atoms or an alkoxy group having 1 to 4 carbon atoms.

[0021] Examples of the alkylene group represented by X include a methylene group, an ethylene group, a trimethylene group, a tetramethylene group, and a hexamethylene group, and alkylene groups having 1 to 5 carbon atoms are preferred. Examples of the alkylidene group represented by X include an ethylidene group and an isopropylidene group. Examples of the cycloalkylene group represented by X include a cyclopentanediyl group, a cyclohexanediyl group, and a cyclooctanediyl group, and cycloalkylene groups having 5 to 10 carbon atoms are preferred. Examples of the cycloalkylidene group represented by X include a cyclohexylidene group, a 3,5,5-trimethylcyclohexylidene group, and a 2-adamantylidene group, and cycloalkylidene groups having 5 to 10 carbon atoms are preferred, and cycloalkylidene groups having 5 to 8 carbon atoms are more preferred.

[0022] a and b each independently represent an integer of 0 or more and 4 or less, preferably 0 or more and 2 or less, and more preferably 0 or 1.

[0023] Examples of aromatic polycarbonate resins having a main chain with a repeating unit represented by the following general formula (I) include aromatic polycarbonate resins having a bisphenol A structure (in the general formula (I) above, X is an isopropylidene group).

[0024] Specific examples of aromatic polycarbonate resins having a bisphenol A structure include Toughlon. TM (FORMOSA IDEMITSU PETROCHEMICAL CORP.) and the like.

[0025] In one embodiment of the present invention, the aromatic polycarbonate resin preferably contains an aromatic polycarbonate resin having a bisphenol A structure, from the viewpoints of the transparency, mechanical properties, thermal properties, etc. of the resulting molded article.

[0026] There are no restrictions on the content of the aromatic polycarbonate resin having a bisphenol A structure in the aromatic polycarbonate resin, but since the expected effects of including the aromatic polycarbonate resin having a bisphenol A structure can be fully obtained, the content is preferably 50% by mass or more and 100% by mass or less, more preferably 75% by mass or more and 100% by mass or less, even more preferably 85% by mass or more and 100% by mass or less, and even more preferably 95% by mass or more and 100% by mass or less.

[0027] [Phosphorus-based antioxidants] The phosphorus-based antioxidant includes a pentaerythritol diphosphite compound represented by the following general formula (1). [ka] In formula (1), R C11 ~R C16 teeth, (i) a hydrogen atom or an aromatic ring-containing group having 6 to 15 carbon atoms, which may be the same or different, or (ii) a hydrogen atom or an alkyl group having 1 to 12 carbon atoms, which may be the same or different; However, R C11 ~R C16 Not all of them will be hydrogen atoms.

[0028] R in formula (1) C11 ~R C16 is preferably the above (i). C11 ~R C16 When (i) above is satisfied, examples of the aromatic ring-containing group having 6 to 15 carbon atoms include a phenyl group, a tolyl group, a xylyl group, a naphthyl group, a biphenyl group, a benzyl group, a phenethyl group, a phenylpropyl group, a cumyl group, etc. These groups may further have a substituent such as a hydroxyl group or an amino group.

[0029] Furthermore, R in formula (1) C11 ~R C16 When (ii) above is satisfied, examples of the alkyl group having 1 to 12 carbon atoms include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, various butyl groups, various pentyl groups, various hexyl groups, various octyl groups, various nonyl groups, various decyl groups, various undecyl groups, and various dodecyl groups.

[0030] Specific examples of the compound represented by the formula (1) include bis(2,4-dicumylphenyl)pentaerythritol diphosphite, bis(2,6-di-tert-butyl-4-methylphenyl)pentaerythritol diphosphite, and the like.

[0031] (Preferred examples of compounds represented by formula (1)) R in the formula (1) C11 ~R C16 However, in the case of (i) above, the number of carbon atoms in the aromatic ring-containing group is preferably 6 or more and 13 or less, more preferably 6 or more and 10 or less. Examples of the aromatic ring include a benzene ring, a naphthalene ring, a phenanthrene ring, and an anthracene ring, with a benzene ring being preferred.

[0032] Among these, the aromatic ring-containing group having 6 or more and 15 or less carbon atoms is preferably a group represented by the following general formula (1a). [ka] In formula (1a), R C17 , R C18 are alkyl or alkenyl groups, which may be the same or different. Alternatively, R C17 and R C18 may be bonded to each other to form a ring. C17 , R C18 is preferably an alkyl group having 1 to 5 carbon atoms or an alkenyl group having 2 to 5 carbon atoms, more preferably an alkyl group having 1 to 3 carbon atoms, and even more preferably a methyl group.

[0033] In formula (1a), R C19 is a hydrogen atom or an alkyl group, preferably a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, more preferably a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and even more preferably a hydrogen atom. m is an integer of 0 to 5. When m is 2 or more, multiple R C19 may be the same or different.

[0034] In formula (1a), Z represents a single bond or a carbon atom. When Z represents a single bond, R C17 , R C18 is excluded from general formula (1a).

[0035] When the compound represented by the formula (1) has two or more groups represented by the general formula (1a), the multiple groups may be the same or different from each other.

[0036] The compound represented by the formula (1) is a compound represented by the formula (1), wherein R C11 and R C14 is a hydrogen atom, and R C12 ~R C13 , R C15 ~R C16 is preferably an aromatic ring-containing group having 6 to 15 carbon atoms, and R C11 and R C14 is a hydrogen atom, and R C12 ~R C13 , RC15 ~R C16 is more preferably a group represented by the general formula (1a).

[0037] That is, the compound represented by the formula (1) is preferably a pentaerythritol diphosphite compound represented by the following general formula (1-1). [ka] In the formula, R C17a ~R C17d , R C18a ~R C18d are alkyl or alkenyl groups, which may be the same or different; alternatively, R C17a and R C18a , R C17b and R C18b , R C17c and R C18c , R C17d and R C18d may be bonded to each other to form a ring.

[0038] R C19a ~R C19d are hydrogen atoms or alkyl groups, and may be the same or different.

[0039] m1 to m4 are integers of 0 to 5, and may be the same or different. When m1 to m4 are 2 or more, multiple R C19a , R C19b , R C19c , R C19d may be the same or different.

[0040] Z 1 ~Z 4 represents a single bond or a carbon atom, and may be the same or different. Z 1 ~Z 4 If represents a single bond, R C17a ~R C17d , R C18a ~R C18d is excluded from the general formula (1-1).

[0041] In general formula (1-1), RC17a ~R C17d , R C18a ~R C18d R is preferably an alkyl group having 1 to 5 carbon atoms or an alkenyl group having 2 to 5 carbon atoms, more preferably an alkyl group having 1 to 3 carbon atoms, and even more preferably a methyl group. C17a ~R C17d and R C18a ~R C18d It is even more preferred that all of are methyl groups.

[0042] R C19a ~R C19d is preferably a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, more preferably a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and even more preferably a hydrogen atom; R C19a ~R C19d It is even more preferable that all of are hydrogen atoms.

[0043] m1 to m4 are preferably integers of 0 or more and 3 or less, more preferably integers of 0 or more and 1 or less, and even more preferably 0. Z 1 ~Z 4 is preferably a carbon atom.

[0044] Among the pentaerythritol diphosphite compounds represented by the general formula (1-1), bis(2,4-dicumylphenyl)pentaerythritol diphosphite represented by the following formula (1-2) is particularly suitable. Bis(2,4-dicumylphenyl)pentaerythritol diphosphite is available as a commercially available product, and for example, "Doverphos S-9228PC" manufactured by Dover Chemical Company can be used.

[0045] [ka]

[0046] In addition, R in the formula (1) C11 ~R C16is (ii) above, in formula (1), R C11 ~R C16 Each of R is preferably an alkyl group having 1 to 12 carbon atoms. C11 ~R C16 is more preferably one or more selected from the group consisting of methyl group, ethyl group, n-propyl group, isopropyl group, various butyl groups, various pentyl groups, various hexyl groups, and various octyl groups, and even more preferably one or more selected from the group consisting of methyl group, ethyl group, isopropyl group, and tert-butyl group.

[0047] Among them, the compound represented by the formula (1) is R C11 , R C13 , R C14 and R C16 is a tert-butyl group, and R C12 and R C15 is a methyl group. That is, the compound represented by the formula (1) is preferably bis(2,6-di-tert-butyl-4-methylphenyl)pentaerythritol diphosphite represented by the following formula (1-3). Bis(2,6-di-tert-butyl-4-methylphenyl)pentaerythritol diphosphite is available as a commercially available product, and for example, "ADEKA STAB PEP-36" manufactured by ADEKA Corporation can be used.

[0048] [ka]

[0049] (Pentaerythritol diphosphite compound content) A resin composition according to one embodiment of the present invention contains a pentaerythritol diphosphite compound in an amount of 0.01 to 0.35 parts by mass per 100 parts by mass of polycarbonate resin. When the content of the pentaerythritol diphosphite compound in the resin composition is within the above-mentioned range, a molded article containing the resin composition exhibits little change in the color tone of guided light in a long light guide path, and has improved long-term heat resistance.

[0050] In order to further reduce the change in color tone of guided light over the long light guide path of a molded article containing the resin composition, the content of the pentaerythritol diphosphite compound in the resin composition according to one embodiment of the present invention is preferably 0.05 parts by mass or more, more preferably 0.07 parts by mass or more, and even more preferably 0.1 parts by mass or more, relative to 100 parts by mass of polycarbonate resin. Furthermore, in order to further improve the long-term heat resistance of a molded article containing the resin composition, the content of the pentaerythritol diphosphite compound in the resin composition according to one embodiment of the present invention is preferably 0.3 parts by mass or less, more preferably 0.25 parts by mass or less, relative to 100 parts by mass of polycarbonate resin.

[0051] The phosphorus-based antioxidant may be a single pentaerythritol diphosphite compound represented by the general formula (1), or a combination of two or more pentaerythritol diphosphite compounds. Examples of phosphorus-based antioxidants other than the pentaerythritol diphosphite compound represented by the general formula (1) include aryl phosphite compounds and aryl phosphine compounds.

[0052] (Aryl phosphite compounds) The aryl phosphite compound is not particularly limited, and examples thereof include compounds represented by the following general formula (2).

[0053] [ka] In formula (2), R C21 ~R C25 are hydrogen atoms, alkyl groups having 1 to 12 carbon atoms, or aryl groups having 6 to 14 carbon atoms, and may be the same or different. However, from the viewpoint of the effect as an antioxidant, R C21 ~R C25 cannot all be hydrogen atoms, and R C21 ~R C25 At least two of the groups are alkyl groups having 1 to 12 carbon atoms or aryl groups having 6 to 14 carbon atoms.

[0054] Specific examples of the compound represented by the formula (2) include tris(2,4-di-tert-butylphenyl)phosphite.

[0055] (Preferred examples of compounds represented by formula (2)) In the formula (2), R C21 ~R C25 and R is a compound in which any two of R are alkyl groups having 1 to 12 carbon atoms or aryl groups having 6 to 14 carbon atoms, and the remaining are hydrogen atoms. C21 ~R C25 Among compounds in which any two of the groups are alkyl groups having 1 to 12 carbon atoms or aryl groups having 6 to 14 carbon atoms, and the remaining groups are hydrogen atoms, R C21 or R C25 More preferred are compounds in which at least one of the groups is an alkyl group having 1 to 12 carbon atoms or an aryl group having 6 to 14 carbon atoms.

[0056] Examples of alkyl groups having 1 to 12 carbon atoms include methyl, ethyl, n-propyl, isopropyl, various butyl groups, various pentyl groups, various hexyl groups, various octyl groups, various decyl groups, various dodecyl groups, etc. Among these, one or more selected from the group consisting of methyl, ethyl, n-propyl, isopropyl, various butyl groups, various pentyl groups, various hexyl groups, and various octyl groups is preferred, one or more selected from the group consisting of methyl, ethyl, isopropyl, and tert-butyl groups is more preferred, and tert-butyl groups is even more preferred.

[0057] Examples of the aryl group having 6 to 14 carbon atoms include a phenyl group, a tolyl group, and a xylyl group.

[0058] Among them, R C21 ~R C25is more preferably a hydrogen atom or an alkyl group having 1 to 12 carbon atoms, further preferably a hydrogen atom, a methyl group, an ethyl group, an isopropyl group, or a tert-butyl group, and even more preferably a hydrogen atom or a tert-butyl group. A particularly preferred compound represented by the formula (2) is C21 and R C23 is a tert-butyl group, and R C22 , R C24 and R C25 is a hydrogen atom, for example, tris(2,4-di-tert-butylphenyl)phosphite represented by the following formula (2-1): Tris(2,4-di-tert-butylphenyl)phosphite is commercially available, and for example, "IRGAFOS168" manufactured by BASF can be used.

[0059] [ka]

[0060] (Examples other than the compound represented by formula (2)) Other examples of the aryl phosphite compound include a compound represented by the following general formula (4) and a compound represented by the following general formula (5). [ka]

[0061] The compound represented by formula (4) is 2,2'-methylenebis(4,6-di-tert-butylphenyl)2-ethylhexyl phosphite. 2,2'-methylenebis(4,6-di-tert-butylphenyl)2-ethylhexyl phosphite is commercially available, and for example, "ADEKA Tab HP-10" manufactured by ADEKA Corporation can be used.

[0062] The compound represented by formula (5) is 2-tert-butyl-6-methyl-4-{3-[2,4,8,10-tetra-tert-butyldibenzo[d,f][1,3,2]dioxaphosphepin-6-yl)oxy]propyl}phenol. 2-tert-butyl-6-methyl-4-{3-[2,4,8,10-tetra-tert-butyldibenzo[d,f][1,3,2]dioxaphosphepin-6-yl)oxy]propyl}phenol is commercially available, and for example, "Sumilizer GP" manufactured by Sumitomo Chemical Co., Ltd. can be used.

[0063] (Aryl phosphine compounds) The arylphosphine compound may be any phosphine compound having one or more aryl groups, and examples thereof include compounds represented by the following general formula (3). P-(R D21 )3(3) In the formula (3), R D21 is a hydrocarbon group which may have a substituent, and at least one of them is an aryl group having 6 to 18 carbon atoms. D21 may be the same or different.

[0064] Examples of the compound represented by general formula (3) include triphenylphosphine, diphenylbutylphosphine, diphenyloctadecylphosphine, tris(p-tolyl)phosphine, tris(p-nonylphenyl)phosphine, tris(naphthyl)phosphine, diphenyl(hydroxymethyl)phosphine, diphenyl(acetoxymethyl)phosphine, diphenyl(β-ethylcarboxyethyl)phosphine, tris(p-chlorophenyl)phosphine, tris(p-fluorophenyl)phosphine, diphenylbenzylphosphine, diphenyl-β-cyanoethylphosphine, diphenyl(p-hydroxyphenyl)phosphine, diphenyl-1,4-dihydroxyphenyl-2-phosphine, and phenylnaphthylbenzylphosphine.

[0065] (Preferred examples of compounds represented by formula (3)) Among them, R in the general formula (3) D21 are all aryl groups, and triphenylphosphine is more preferred. Triphenylphosphine is commercially available, for example, "JC-263" manufactured by Johoku Chemical Industry Co., Ltd.

[0066] (Total content of phosphorus-based antioxidants) A resin composition according to one embodiment of the present invention contains a total of 0.2 parts by mass or more of phosphorus-based antioxidants per 100 parts by mass of polycarbonate resin. When the total content of the phosphorus-based antioxidants in the resin composition is within the above-mentioned range, a molded article containing the resin composition exhibits less color change in guided light along a long light guide path and has improved long-term heat resistance and moist heat resistance.

[0067] The total content of the phosphorus-based antioxidants in the resin composition according to one embodiment of the present invention is preferably 0.25 parts by mass or more, and more preferably 0.3 parts by mass or more, per 100 parts by mass of polycarbonate resin, in order to reduce the color change of light guided through a long light guide path and the initial color change after molding in a molded article containing the resin composition. Furthermore, the total content of the phosphorus-based antioxidants in the resin composition according to one embodiment of the present invention is preferably 0.6 parts by mass or less, and more preferably 0.55 parts by mass or less, per 100 parts by mass of polycarbonate resin, in order to improve the long-term heat resistance of a molded article containing the resin composition at 140°C and 120°C in a balanced manner.

[0068] [Alicyclic epoxy compounds] The alicyclic epoxy compound refers to a cyclic aliphatic compound having an alicyclic epoxy group, i.e., an epoxy group in which one oxygen atom is added to an ethylene bond in an aliphatic ring. The type of alicyclic epoxy compound is not particularly limited and can be selected appropriately.

[0069] Examples of alicyclic epoxy compounds include (i) compounds having an alicyclic epoxy group in the molecule, and (ii) compounds in which an epoxy group is directly bonded to an alicyclic ring via a single bond. Here, the "alicyclic epoxy group" refers to an epoxy group composed of two adjacent carbon atoms and an oxygen atom that constitute an alicyclic ring. Examples of the "compound having an alicyclic epoxy group in the molecule" include compounds having a cyclopentene oxide group and compounds having a cyclohexene oxide group.

[0070] As the alicyclic epoxy compound, for example, alicyclic epoxy compounds represented by the following formulas (B-1) to (B-10) are suitably used.

[0071] [ka] (wherein R is H or CH3). [ka] (wherein R is H or CH3). [ka] (wherein a+b=1 or 2.) [ka] (wherein a+b+c+d=1, 2, or 3.) [ka] (wherein a+b+c=n (an integer), and R is a hydrocarbon group.) [ka] (wherein n is an integer.) [ka] (wherein R is a hydrocarbon group). [ka] (wherein n is an integer and R is a hydrocarbon group.)

[0072] The alicyclic epoxy compounds represented by the formulae (B-1) to (B-6) and (B-8) are examples of the "compound having a cyclohexene oxide group." The alicyclic epoxy compounds represented by the formulae (B-7), (B-9) and (B-10) are examples of the "compound in which an epoxy group is directly bonded to an alicyclic ring via a single bond."

[0073] The alicyclic epoxy compounds may be used alone or in combination of two or more kinds in any ratio.

[0074] (Preferred type of alicyclic epoxy compounds) The alicyclic epoxy compound is preferably one or more selected from the group consisting of compounds represented by formula (B-1) and formula (B-10), and more preferably a compound represented by formula (B-1), in terms of excellent compatibility with polycarbonate resins and not impairing transparency.

[0075] For example, the compound represented by formula (B-1) is 3',4'-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate, which is commercially available under the product name "Celloxide 2021P" (manufactured by Daicel Corporation).

[0076] Furthermore, an example of the compound represented by formula (B-10) is 1,2-epoxy-4-(2-oxiranyl)cyclohexane adduct of 2,2-bis(hydroxymethyl)-1-butanol, which is commercially available under the product name "EHPE3150" (manufactured by Daicel Corporation).

[0077] Furthermore, a mixture of Celloxide 2021P and EHPE3150, commercially available from Daicel Corporation under the product name "EHPE3150CE", can also be preferably used.

[0078] Therefore, the alicyclic epoxy compound preferably includes 3',4'-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate.

[0079] In addition to the alicyclic epoxy compounds exemplified above, bi-7-oxabicyclo[4.1.0]heptane can also be preferably used. Bi-7-oxabicyclo[4.1.0]heptane is commercially available under the product name "Celloxide 8010" (manufactured by Daicel Corporation).

[0080] (Alicyclic epoxy compound content) A resin composition according to one embodiment of the present invention contains an alicyclic epoxy compound in an amount of 0.01 to 0.6 parts by mass per 100 parts by mass of polycarbonate resin. When the content of the alicyclic epoxy compound in the resin composition is within the above range, a molded article containing the resin composition exhibits less color change due to a long light guide path and has improved long-term heat resistance and long-term moist heat resistance.

[0081] The content of the alicyclic epoxy compound in the resin composition according to one embodiment of the present invention is preferably 0.05 parts by mass or more, more preferably 0.1 parts by mass or more, even more preferably 0.2 parts by mass or more, even more preferably more than 0.2 parts by mass, and even more preferably 0.25 parts by mass or more, relative to 100 parts by mass of polycarbonate resin, in order to reduce color change in the light guide path of a molded article containing the resin composition and to improve long-term heat resistance and long-term moist heat resistance. Furthermore, the content of the alicyclic epoxy compound in the resin composition according to one embodiment of the present invention is preferably 0.55 parts by mass or less, more preferably 0.5 parts by mass or less, even more preferably 0.45 parts by mass or less, relative to 100 parts by mass of polycarbonate resin.

[0082] (Ratio of alicyclic epoxy compound content to pentaerythritol diphosphite compound content) In a resin composition according to one embodiment of the present invention, the ratio of the alicyclic epoxy compound content to the pentaerythritol diphosphite compound content is 0.5 or more. When the ratio of the alicyclic epoxy compound content to the pentaerythritol diphosphite compound content is within the above-mentioned range, a molded article containing the resin composition exhibits less change in color tone of guided light in a long light guide path, and has improved long-term heat resistance and long-term moist heat resistance.

[0083] In a molded article containing the resin composition, the ratio of the content of the alicyclic epoxy compound to the content of the pentaerythritol diphosphite compound in the resin composition according to one aspect of the present invention is preferably 0.7 or more, more preferably 1.0 or more, even more preferably 1.5 or more, and even more preferably 2.0 or more, in terms of reducing the change in color tone of guided light in a long light guide path and improving the long-term heat resistance and long-term moist heat resistance.

[0084] Furthermore, in the resin composition according to one embodiment of the present invention, the ratio of the content of the alicyclic epoxy compound to the content of the pentaerythritol diphosphite compound is preferably 50 or less, more preferably 10 or less, and even more preferably 5.0 or less.

[0085] [Other ingredients] In addition to the above-described components, the resin composition according to one embodiment of the present invention can contain any additives such as fatty acid esters, polyorganosiloxanes, polyether compounds, etc., within a range that does not impair the effects of the present invention. The additives can be any common additives commonly used in the art.

[0086] The resin composition according to one aspect of the present invention may further contain a fatty acid ester, which is a condensation product of an aliphatic carboxylic acid and an alcohol, from the viewpoint of improving the releasability and long-term heat resistance of the resulting molded article.

[0087] Examples of the 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. These may be used alone or in combination of two or more. Among these, stearic acid esters are preferred as fatty acid esters, and glycerin monostearate is more preferred. Glycerin monostearate is commercially available, and for example, "S-100A" manufactured by Riken Vitamin Co., Ltd. can be used.

[0088] When the resin composition contains a fatty acid ester, the content of the fatty acid ester in the resin composition is preferably 0.01 part by mass or more, more preferably 0.02 part by mass or more, and even more preferably 0.03 part by mass or more per 100 parts by mass of the aromatic polycarbonate resin, in order to improve releasability. Furthermore, the content of the fatty acid ester in the resin composition is preferably 0.2 part by mass or less, more preferably 0.1 part by mass or less per 100 parts by mass of the aromatic polycarbonate resin, in order to further improve long-term heat resistance.

[0089] The polyorganosiloxane is preferably a compound having one or more functional groups such as an alkoxy group, an aryloxy group, a polyoxyalkylene group, a carboxyl group, a silanol group, an amino group, a mercapto group, an epoxy group, and a vinyl group.

[0090] The kinematic viscosity of the polyorganosiloxane is preferably 10 mm at 25°C from the viewpoint of the lubrication effect as a mold release property. 2 / s or more, and from the viewpoint of dispersibility in polycarbonate resin, it is preferably 200 mm 2 From this viewpoint, the viscosity of the polyorganosiloxane is more preferably 20 mm / s or less. 2 / s or more 150mm 2 / s or less, more preferably 40 mm 2 / s or more 120mm 2 / s or less.

[0091] The refractive index of the polyorganosiloxane is preferably as small as possible so as not to reduce the transparency when added to polycarbonate. Since the refractive index of polycarbonate is 1.58, the refractive index of the polyorganosiloxane is preferably 1.45 or more, more preferably 1.50 or more.

[0092] The amount of polyorganosiloxane added is preferably 0.01 to 0.15 parts by mass, more preferably 0.02 to 0.15 parts by mass, and even more preferably 0.05 to 0.1 parts by mass, relative to 100 parts by mass of the aromatic polycarbonate resin (A). Within this range, mold releasability can be improved, and mold deposits can be significantly reduced even under continuous molding conditions.

[0093] Specific examples of the polyether compound include polyoxyethylene glycol-polyoxypropylene glycol, polyoxyethylene glycol-polyoxytetramethylene glycol, polyoxytrimethylene glycol-polyoxytetramethylene glycol, polyoxypropylene glycol-polyoxytetramethylene glycol, polyoxyethylene-polyoxypropylene-bisphenol A ether, and polyethylene glycol-polypropylene glycol-allyl ether. Among these, one or more selected from the group consisting of polyoxyethylene glycol-polyoxypropylene glycol, polyoxyethylene glycol-polyoxytetramethylene glycol, polyoxytrimethylene glycol-polyoxytetramethylene glycol, and polyoxypropylene glycol-polyoxytetramethylene glycol are preferred, one or more selected from the group consisting of polyoxyethylene glycol-polyoxypropylene glycol, polyoxyethylene glycol-polyoxytetramethylene glycol, and polyoxypropylene glycol-polyoxytetramethylene glycol are more preferred, and one or more selected from the group consisting of polyoxyethylene glycol-polyoxytetramethylene glycol and polyoxypropylene glycol-polyoxytetramethylene glycol are even more preferred.

[0094] The molecular weight of the polyether compound is preferably in the range of 200 to 10,000, more preferably 500 to 8,000, even more preferably 800 to 5,000, and still more preferably 1,000 to 4,000, in terms of weight average molecular weight (Mw).

[0095] From the viewpoint of achieving the effects of the present invention, the content of the polyether compound in the resin composition according to one embodiment of the present invention is preferably 0.1 to 2.0 parts by mass, more preferably 0.2 to 2.0 parts by mass, and even more preferably 0.5 to 2.0 parts by mass, relative to 100 parts by mass of the polycarbonate resin. When the content of the polyether compound is 0.1 part by mass or more relative to 100 parts by mass of the polycarbonate resin, an increase in the YI value is suppressed and the color tone is improved. Furthermore, when the content is 2.0 parts by mass or less, the transmittance is improved.

[0096] The resin composition according to one aspect of the present invention preferably does not contain a polyether compound, in terms of the long-term moist heat resistance of a molded article containing the resin composition.

[0097] [Method for producing polycarbonate resin composition] The resin composition according to one embodiment of the present invention may be produced by any known method without any particular limitation. For example, the resin composition may be produced by mixing the above-described components at room temperature (e.g., 20°C to 30°C) and melt-kneading the mixture. The melt-kneading may be carried out by a method commonly used in the art, such as a method using a single-screw extruder, a twin-screw extruder, a co-kneader, or a multi-screw extruder. The heating temperature during melt-kneading is usually selected appropriately from the range of 220°C or higher and 300°C or lower.

[0098] [Characteristics of Polycarbonate Resin Composition] In a resin composition according to one embodiment of the present invention, when a molded article for optical property measurement made of the resin composition is used and colorimetric measurement is performed using a white light-emitting diode as a light source, the molded article for optical property measurement preferably has a y value of 0.41 or less in the CIE 1931 color system at a position 1005 mm from the incident portion of the light guide path. Since the y value is 0.41 or less, a molded article containing the resin composition exhibits little change in color tone of guided light in a long light guide path, making the article suitable for use in light guide parts for vehicles, etc.

[0099] The molded body for measuring optical properties comprises an incident portion where light is incident, an exit portion where the incident light exits, and a light guide portion that guides the incident light from the incident portion to the exit portion, and the light guide portion has an optical path with a curvature that causes total reflection of the incident light.

[0100] The manufacturing conditions for the molded article for measuring optical properties are a cylinder temperature of 300° C., a mold temperature of 80° C., and a cycle time of 40 seconds. Specifically, the molded article for measuring optical properties is obtained by the method described in the examples below.

[0101] The y value is more preferably 0.405 or less, and even more preferably 0.40 or less, in order to reduce the change in color tone of guided light in the long light guide path of a molded article containing the resin composition.

[0102] In a resin composition according to one embodiment of the present invention, a 5 mm-thick molded article is produced using the polycarbonate resin composition by injection molding under manufacturing conditions of a cylinder temperature of 260°C, a mold temperature of 80°C, and a cycle time of 50 seconds, and after storing the molded article at 140°C for 1,000 hours, the YI value (YI1) measured using a spectrophotometer under conditions of Illuminant C and a 2-degree field of view is preferably 2.0 or less. If the YI1 is 2.0 or less, the molded article containing the resin composition has good long-term heat resistance and is suitable for light-guiding components and the like.

[0103] In view of the fact that the long-term heat resistance of a molded article containing the resin composition is better, YI1 is more preferably 1.9 or less, and even more preferably 1.8 or less.

[0104] In terms of good long-term heat resistance of a molded article containing a resin composition according to one embodiment of the present invention, the resin composition according to one embodiment of the present invention is such that a molded article having a thickness of 5 mm is produced using the polycarbonate resin composition by injection molding under manufacturing conditions of a cylinder temperature of 260°C, a mold temperature of 80°C, and a cycle time of 50 seconds, and after storing it at 120°C for 1,000 hours, the YI value (YI2) measured using a spectrophotometer under conditions of Illuminant C and a 2-degree field of view is preferably 2.0 or less, more preferably 1.9 or less, and even more preferably 1.8 or less.

[0105] In order to obtain a molded article containing a resin composition according to one embodiment of the present invention with better long-term heat resistance, it is more preferable that YI1 and YI2 are each 2.0 or less, even more preferably 1.9 or less, and even more preferably 1.8 or less.

[0106] In terms of the good long-term moist heat resistance of a molded article containing a resin composition according to one embodiment of the present invention, when a molded article having a thickness of 5 mm is produced using the resin composition by injection molding under manufacturing conditions of a cylinder temperature of 260°C, a mold temperature of 80°C, and a cycle time of 50 seconds, and stored for 1,000 hours in an environment of 85°C and humidity of 85%, the YI value (YI3) measured using a spectrophotometer under conditions of light source C and a 2-degree field of view is preferably 1.2 or less, and more preferably 1.1 or less.

[0107] In terms of reducing the initial color change after molding of a molded article containing a resin composition according to an embodiment of the present invention, the resin composition according to an embodiment of the present invention is such that a molded article having a thickness of 5 mm is produced using the polycarbonate resin composition by injection molding under manufacturing conditions of a cylinder temperature of 260°C, a mold temperature of 80°C, and a cycle time of 50 seconds, and the YI value (YI0) measured using a spectrophotometer under conditions of a C light source and a 2-degree field of view is preferably 1.2 or less, more preferably 1.1 or less, and even more preferably 1.0 or less.

[0108] YI0 to YI3 can be measured, for example, by the measurement method described in the Examples.

[0109] <2. Molded body> The present invention also includes a molded article containing a resin composition according to an embodiment of the present invention. The resin composition according to an embodiment of the present invention in the molded article according to an embodiment of the present invention has already been described, and therefore will not be repeated here.

[0110] [Method for producing molded body] The molded article according to one embodiment of the present invention can be produced by a production method including a molding step of molding the resin composition according to one embodiment of the present invention. The method for molding the resin composition according to one embodiment of the present invention in the molding step is not particularly limited. For example, the molded article can be produced by a known molding method such as injection molding, injection compression molding, extrusion molding, blow molding, press molding, vacuum molding, or foam molding using a melt-kneaded product of the resin composition according to one embodiment of the present invention or pellets obtained through melt-kneading as a raw material. It is particularly preferable to produce a molded article by injection molding or injection compression molding using the obtained pellets. The molding temperature in the molding step is not particularly limited and can be set appropriately. For example, molding can be performed at a temperature of 240°C or higher and 300°C or lower.

[0111] The molded article according to one embodiment of the present invention exhibits little color change in the light guide path and has excellent long-term heat resistance and long-term moist heat resistance. Because these properties are fully exhibited, the molded article according to one embodiment of the present invention is preferably a light guide component, more preferably a light guide component for a vehicle, and even more preferably a light guide component for a vehicle daytime running light or daytime running lamp, i.e., a vehicle DRL. The light guide path length from the entrance portion to the exit portion of the light guide component may be 100 mm or more, 500 mm or more, 1000 mm or more, or 2000 mm or more. The light guide component may have a plurality of exit portions.

[0112] 〔summary〕 A polycarbonate resin composition according to a first aspect of the present invention comprises a polycarbonate resin, a phosphorus-based antioxidant, and an alicyclic epoxy compound, The phosphorus-based antioxidant contains a pentaerythritol diphosphite compound represented by the following general formula (1): the content of the alicyclic epoxy compound is 0.01 parts by mass or more and 0.6 parts by mass or less relative to 100 parts by mass of the polycarbonate resin, the content of the pentaerythritol diphosphite compound is 0.01 parts by mass or more and 0.35 parts by mass or less relative to 100 parts by mass of the polycarbonate resin, the content of the phosphorus-based antioxidant is 0.2 parts by mass or more relative to 100 parts by mass of the polycarbonate resin; The ratio of the content of the alicyclic epoxy compound to the content of the pentaerythritol diphosphite compound is 0.5 or more: [ka] In formula (1), R C11 ~R C16 teeth, (i) a hydrogen atom or an aromatic ring-containing group having 6 to 15 carbon atoms, which may be the same or different, or (ii) a hydrogen atom or an alkyl group having 1 to 12 carbon atoms, which may be the same or different; However, R C11 ~R C16 Not all of them will be hydrogen atoms.

[0113] In the polycarbonate resin composition according to Aspect 2 of the present invention, in Aspect 1, the content of the pentaerythritol diphosphite compound is preferably 0.05 parts by mass or more and 0.35 parts by mass or less per 100 parts by mass of the polycarbonate resin.

[0114] In the polycarbonate resin composition according to Aspect 3 of the present invention, in Aspect 1 or 2, the ratio of the content of the alicyclic epoxy compound to the content of the pentaerythritol diphosphite compound is preferably 2.0 or more.

[0115] A polycarbonate resin composition according to a fourth aspect of the present invention is preferably any one of the first to third aspects, wherein the polycarbonate resin composition comprises the polycarbonate resin composition and includes an incident portion into which light is incident, an exit portion from which the incident light exits, and a light guide portion that guides the light incident from the incident portion to the exit portion, wherein the light guide portion has an optical path with a curvature that causes total reflection of the incident light. When colorimetry is performed using a molded article for measuring optical properties, the molded article for measuring optical properties has a y value of 0.41 or less in the CIE 1931 color system at a position 1005 mm from the incident portion of the light guide path.

[0116] In the polycarbonate resin composition according to Aspect 5 of the present invention, in any one of Aspects 1 to 4, a molded article having a thickness of 5 mm is produced using the polycarbonate resin composition by injection molding under production conditions of a cylinder temperature of 260°C, a mold temperature of 80°C, and a cycle time of 50 seconds, and after storing the molded article at 140°C for 1,000 hours, the YI value measured using a spectrophotometer under conditions of Illuminant C and a 2-degree field of view is preferably 2.0 or less.

[0117] In the polycarbonate resin composition according to Aspect 6 of the present invention, in any one of Aspects 1 to 5, the polycarbonate resin preferably comprises an aromatic polycarbonate resin whose main chain has a repeating unit represented by the following general formula (I): [ka] In formula (I), R A1 and R A2 is an alkyl or alkoxy group having 1 to 6 carbon atoms, and R A1 and R A2 may be the same as or different from; X represents a single bond, an alkylene group having 1 to 8 carbon atoms, an alkylidene group having 2 to 8 carbon atoms, a cycloalkylene group having 5 to 15 carbon atoms, a cycloalkylidene group having 5 to 15 carbon atoms, -S-, -SO-, -SO2-, -O-, or -CO-; a and b each independently represent an integer of 0 or more and 4 or less; If a is 2 or more, R A1 may be the same or different, and when b is 2 or more, R A2 may be the same or different.

[0118] The polycarbonate resin composition according to a seventh aspect of the present invention is the polycarbonate resin composition according to any one of the first to sixth aspects, wherein in formula (1), R C11 ~R C16 are hydrogen atoms or aromatic ring-containing groups having 6 to 15 carbon atoms, and may be the same or different, provided that R C11 ~R C16 It is preferred that not all of the groups are hydrogen atoms.

[0119] The polycarbonate resin composition according to Aspect 8 of the present invention is preferably the polycarbonate resin composition of any one of Aspects 1 to 7, wherein the pentaerythritol diphosphite compound represented by Formula (1) is bis(2,4-dicumylphenyl)pentaerythritol diphosphite.

[0120] In any one of the above-described aspects 1 to 8, the polycarbonate resin composition according to aspect 9 of the present invention preferably further contains at least one phosphorus-based antioxidant selected from the group consisting of aryl phosphite compounds represented by the following general formula (2) and aryl phosphine compounds represented by the following general formula (3): [ka] In formula (2), R C21 ~R C25 are a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, or an aryl group having 6 to 14 carbon atoms, and may be the same or different, However, R C21 ~R C25 cannot all be hydrogen atoms, and R C21 ~R C25 at least two of the groups are alkyl groups having 1 to 12 carbon atoms or aryl groups having 6 to 14 carbon atoms, P-(RD21 )3(3) In formula (3), R D21 is a hydrocarbon group which may have a substituent, at least one of which is an aryl group having 6 to 18 carbon atoms, and a plurality of R D21 may be the same or different.

[0121] In the polycarbonate resin composition according to Aspect 10 of the present invention, in any one of Aspects 1 to 9, the alicyclic epoxy compound preferably includes at least one selected from the group consisting of 3',4'-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate and bi-7-oxabicyclo[4.1.0]heptane.

[0122] A molded article according to an eleventh aspect of the present invention comprises the polycarbonate resin composition according to any one of the first to tenth aspects.

[0123] The molded article according to the twelfth aspect of the present invention may be a light guide component in the eleventh aspect.

[0124] The molded article according to the thirteenth aspect of the present invention may be a light guide component for a vehicle in the eleventh aspect.

[0125] The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope of the claims. Embodiments obtained by appropriately combining the technical means disclosed in the embodiments are also included in the technical scope of the present invention. [Example]

[0126] EXAMPLES The present invention will be described in more detail below with reference to examples and comparative examples, but the present invention is not limited to these examples.

[0127] <Raw materials for polycarbonate resin compositions> The raw materials for the polycarbonate resin compositions used in the examples and comparative examples are as follows.

[0128] (Polycarbonate resin) Product name: Toughlon TM FN1500” (manufactured by FORMOSA IDEMITSU PETROCHEMICAL CORP., viscosity average molecular weight (Mv)=14,400)

[0129] (phosphorus antioxidant) Product name: Doverphos S-9228PC (bis(2,4-dicumylphenyl)pentaerythritol diphosphite, manufactured by Dover Chemical Co.)

[0130] (phosphorus antioxidant) Product name "IRGAFOS168" (BASF, tris(2,4-di-tert-butylphenyl)phosphite);

[0131] (alicyclic epoxy compounds) Product name: "Celloxide 2021P" (3',4'-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate, manufactured by Daicel Corporation)

[0132] (Other additives: fatty acid esters) Product name: "S-100A" (Glycerin Monostearate, manufactured by Riken Vitamin Co., Ltd.)

[0133] (Other additives: Polyorganosiloxane) Product name: "KR511" (Shin-Etsu Chemical Co., Ltd., polyorganosiloxane compound, kinematic viscosity (25°C): 90 mm 2 / s, refractive index: 1.518)

[0134] (Other additives: Polyether compounds) Product name: Unilube 50DE-25R (NOF Corporation, polyoxyethylene-polyoxypropylene glycol)

[0135] [Examples 1 to 10, Comparative Examples 1 to 7] The components were blended according to the blending ratios shown in Table 1 or Table 2 to obtain polycarbonate resin compositions of Examples 1 to 10 and Comparative Examples 1 to 7. Using a vented twin-screw extruder with a screw diameter of 37 mm ("TEM37SS" manufactured by Shibaura Machine Co., Ltd.), the polycarbonate resin composition was melt-kneaded at a cylinder temperature of 240°C, and pellets were obtained by strand cutting. The obtained pellets were dried at 120°C for 5 hours, and then molded articles were produced and evaluated by the methods described below.

[0136] <Color change of molded body for measuring optical properties> (Preparation of molded body for measuring optical properties) The dried pellets were then injected into an injection molding machine (manufactured by Niigata Machine Techno Co., Ltd., "MD350S7000": screw diameter 35 mm) to obtain an Archimedes spiral molded article for measuring optical properties, measuring 10 mm in width, 3 mm in thickness, and 1100 mm in length.

[0137] In manufacturing the test specimens, a mold was used in which the surface of the mold part corresponding to the light guide part (the part inside the molded body through which light passes) was polished with an abrasive with a grain size of 1000 mesh and given a mirror finish.

[0138] The exit part (1005 mm) of the molded body for measuring optical properties was subjected to mold surface processing to create a fine striped pattern (prism shape) (surface roughness Sa = 4 μm). Each test piece was injection molded for 10 or more shots under conditions of a cylinder temperature of 300°C, a mold temperature of 80°C, and a cycle time of 40 seconds, and then molded under the same conditions after the manufacturing conditions had stabilized.

[0139] The obtained test piece for measuring optical properties had a mirror-finished surface shape for the light guide part, a striped pattern for the light output part, a surface roughness of 4 μm, and a take-out position of 1005 mm.

[0140] <Light guided color tone measurement> The distance between the edge of the test piece at the center of the molded body for measuring optical properties and the LED was set to 2 mm, and an LED light source (manufactured by Nichia Corporation, "NSFW036CT") was used, set to 0.35 A x 3.5 V, 23 lumens (1 m), and irradiation was carried out from the edge of the molded body for measuring optical properties.

[0141] The luminance and chromaticity of the emitted light from the molded article for optical property measurement that was being irradiated were measured using a spectroradiometer (Konica Minolta, Inc., "CS-2000"). The emitted light was extracted from a position 1005 mm away from the incident point and evaluated. The obtained values ​​are shown in Tables 1 and 2 as y values ​​in the CIE 1931 color system. The pass criterion for the y value is 0.41 or less.

[0142] <Initial YI value of molded product> The dried pellets were injection molded into 50 mm x 90 mm x 5 mm thick flat test pieces using an injection molding machine (Nissei Plastic Industrial Co., Ltd., "ES1000"; screw diameter: 26 mm) under the following manufacturing conditions: cylinder temperature 260°C, mold temperature 80°C, and cycle time 50 seconds. The flat test pieces were injection molded after 10 or more injection molding shots were performed under these manufacturing conditions and the manufacturing conditions were stabilized. The YI value (initial YI value: YI0) of the obtained test pieces was measured using a spectrophotometer (Hitachi High-Tech Corporation, "U-4100") under conditions of illuminant C and a 2-degree field of view. The results are shown in Tables 1 and 2. The acceptance criterion for the initial YI value is a YI0 of 1.2 or less.

[0143] <Long-term heat resistance test of molded body> After measuring YI0, the flat test piece was placed in a gear oven (TABAI GPS-222) adjusted to a temperature of 140°C or 120°C for 1,000 hours. The YI value of the test piece after the test was measured in the same manner as above. The YI value measured after storage for 1,000 hours at 140°C was designated YI1, and the YI value measured after storage for 1,000 hours at 120°C was designated YI2. The results are shown in Tables 1 and 2. The pass criterion for the long-term heat resistance test at 140°C is a YI1 of 2.0 or less, and the pass criterion for the long-term heat resistance test at 120°C is a YI1 of 2.0 or less.

[0144] <Long-term humidity and heat resistance test of molded body> After measuring YI0, the flat test piece was placed in a thermo-hygrostat (LH33-12P, manufactured by Nagano Science Co., Ltd.) set at a temperature of 85°C and a relative humidity of 85% for 1,000 hours. After the test, the YI value (YI3) of the test piece was measured in the same manner as above. The pass criterion for the long-term moist heat resistance test is a YI3 of 1.2 or less.

[0145] [Table 1]

[0146] [Table 2]

[0147] It is clear from Tables 1 and 2 that the molded articles containing the resin compositions of Examples 1 to 10 have little change in color tone of guided light in a long light guide path, and are excellent in long-term heat resistance and long-term moist heat resistance.

[0148] The molded articles containing the resin compositions of Comparative Examples 1 to 4, in which the total content of phosphorus-based antioxidants was less than 0.2 phr, had y values ​​exceeding 0.41, and it was found that the color tone of the guided light changed significantly over a long light guide path.

[0149] Furthermore, in Comparative Examples 5 and 6, in which the content of Doverphos S-9228PC was more than 0.35, the YI1 was more than 2.0, and it was found that the long-term heat resistance was poor.

[0150] The molded articles containing the resin compositions of Examples 2 to 10, in which the ratio of the content of Celloxide 2021P to the content of Doverphos S-9228PC (Celloxide 2021P / Doverphos S-9228PC) was 0.7 or higher, had improved long-term moist heat resistance compared to Example 1, in which the ratio was 0.5. Furthermore, a comparison of Examples 1 to 3, which did not contain a polyether compound, with Examples 7 to 10 revealed that the molded articles containing the resin compositions of Examples 7 to 10, in which the ratio was 2.0 or higher, showed little change in the color tone of guided light in the long light guide path, and in addition to having excellent long-term heat resistance, also had further improved long-term moist heat resistance.

[0151] A comparison between Examples 8 and 10 revealed that when the total content of phosphorus-based antioxidants was 0.45 phr or less, the long-term moist heat resistance was further improved, and the long-term heat resistance (YI1 and YI2) at 140°C and 120°C was improved in a balanced manner. Furthermore, it was found that the molded articles containing the resin compositions of Examples 3 to 7, in which the total content of phosphorus-based antioxidants was less than 0.45 phr and the content of Celloxide 2021P was 0.25 phr or more and 0.4 phr or less, had a low y value of 0.40, and showed smaller changes in the color tone of guided light over long light guide paths.

[0152] Comparison between Examples 8 and 9 revealed that the inclusion of a polyorganosiloxane compound did not affect the color change of light guided through a long light path, nor did it affect the long-term heat resistance or long-term moist heat resistance. [Industrial Applicability]

[0153] The resin composition according to one embodiment of the present invention can produce a molded article that exhibits minimal color change in light guide path and excellent long-term heat resistance and long-term moist heat resistance. Therefore, the molded article is suitable for light guide parts such as vehicle light guide parts, and is particularly useful as DRL parts for vehicles.

Claims

1. The composition contains a polycarbonate resin, a phosphorus-based antioxidant, and an alicyclic epoxy compound, The phosphorus-based antioxidant contains a pentaerythritol diphosphite compound represented by the following general formula (1): the content of the alicyclic epoxy compound is 0.01 parts by mass or more and 0.6 parts by mass or less relative to 100 parts by mass of the polycarbonate resin, the content of the pentaerythritol diphosphite compound is 0.01 parts by mass or more and 0.35 parts by mass or less relative to 100 parts by mass of the polycarbonate resin, the content of the phosphorus-based antioxidant is 0.2 parts by mass or more relative to 100 parts by mass of the polycarbonate resin; A polycarbonate resin composition, wherein the ratio of the content of the alicyclic epoxy compound to the content of the pentaerythritol diphosphite compound is 0.5 or more: 【Chemical 1】 In formula (1), R Ｃ１１ ~R Ｃ１６ teeth, (i) a hydrogen atom or an aromatic ring-containing group having 6 to 15 carbon atoms, which may be the same or different, or (ii) a hydrogen atom or an alkyl group having 1 to 12 carbon atoms, which may be the same or different; However, R Ｃ１１ ~R Ｃ１６ Not all of them will be hydrogen atoms.

2. 2. The polycarbonate resin composition according to claim 1, wherein the content of the pentaerythritol diphosphite compound is 0.05 parts by mass or more and 0.35 parts by mass or less per 100 parts by mass of the polycarbonate resin.

3. 2. The polycarbonate resin composition according to claim 1, wherein the ratio of the content of the alicyclic epoxy compound to the content of the pentaerythritol diphosphite compound is 2.0 or more.

4. When a molded article for optical property measurement is used, which is made of the polycarbonate resin composition and includes an incident portion into which light is incident, an exit portion from which the incident light exits, and a light guide portion that guides the light incident from the incident portion to the exit portion, and the light guide portion has an optical path with a curvature that causes total reflection of the incident light, and the molded article is used to measure optical properties using a white light-emitting diode as a light source, 2. The polycarbonate resin composition according to claim 1, wherein the molded article for optical property measurement has a y value of 0.41 or less in the CIE 1931 color system at a position 1005 mm from the incident portion of the light guide path.

5. 2. The polycarbonate resin composition according to claim 1, wherein a molded article having a thickness of 5 mm is produced using the polycarbonate resin composition by injection molding under production conditions of a cylinder temperature of 260°C, a mold temperature of 80°C, and a cycle time of 50 seconds, and after storing the molded article at 140°C for 1,000 hours, the YI value measured using a spectrophotometer under conditions of Illuminant C and a 2-degree field of view is 2.0 or less.

6. 2. The polycarbonate resin composition according to claim 1, wherein the polycarbonate resin comprises an aromatic polycarbonate resin whose main chain has a repeating unit represented by the following general formula (I): 【Chemistry 2】 In formula (I), R Ａ１ and R Ａ２ is an alkyl or alkoxy group having 1 to 6 carbon atoms, and R Ａ１ and R Ａ２ may be the same or different; X is a single bond, an alkylene group having 1 to 8 carbon atoms, an alkylidene group having 2 to 8 carbon atoms, a cycloalkylene group having 5 to 15 carbon atoms, a cycloalkylidene group having 5 to 15 carbon atoms, -S-, -SO-, -SO ２ represents -, -O- or -CO-; a and b each independently represent an integer of 0 or more and 4 or less; When a is 2 or more, R Ａ１ may be the same or different, and when b is 2 or more, R Ａ２ may be the same or different.

7. In formula (1), R Ｃ１１ ~R Ｃ１６ but, are hydrogen atoms or aromatic ring-containing groups having 6 to 15 carbon atoms, and may be the same or different, provided that R Ｃ１１ ~R Ｃ１６ The polycarbonate resin composition according to claim 1 , wherein all of the radicals are not hydrogen atoms.

8. 2. The polycarbonate resin composition according to claim 1, wherein the pentaerythritol diphosphite compound represented by formula (1) is bis(2,4-dicumylphenyl)pentaerythritol diphosphite.

9. The polycarbonate resin composition according to claim 1, further comprising at least one phosphorus-based antioxidant selected from the group consisting of aryl phosphite compounds represented by the following general formula (2) and aryl phosphine compounds represented by the following general formula (3): 【Chemistry 3】 In formula (2), R Ｃ２１ ~R Ｃ２５ are a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, or an aryl group having 6 to 14 carbon atoms, and may be the same or different, However, R Ｃ２１ ~R Ｃ２５ cannot all be hydrogen atoms, and R Ｃ２１ ~R Ｃ２５ at least two of the groups are alkyl groups having 1 to 12 carbon atoms or aryl groups having 6 to 14 carbon atoms, P-(R Ｄ２１ ) ３ (3) In formula (3), R Ｄ２１ is a hydrocarbon group which may have a substituent, at least one of which is an aryl group having 6 to 18 carbon atoms, and a plurality of R Ｄ２１ may be the same or different.

10. 2. The polycarbonate resin composition according to claim 1, wherein the alicyclic epoxy compound comprises at least one selected from the group consisting of 3',4'-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate and bi-7-oxabicyclo[4.1.0]heptane.

11. A molded article comprising the polycarbonate resin composition according to any one of claims 1 to 10.

12. The molded article according to claim 11, which is a light-guiding component.

13. The molded article according to claim 11, which is a light guide part for a vehicle.

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