Polycarbonate resin composition and molded article

Abstract

Provided is a polycarbonate resin composition that allows the production of a molded article that exhibits little change in the color tone of guided light over a long light guide path and is excellent in long-term heat resistance and long-term moist heat resistance. [Solution] The polycarbonate resin composition disclosed herein contains a polycarbonate resin, a phosphorus-based antioxidant, and an alicyclic epoxy compound. The phosphorus-based antioxidant contains a pentaerythritol diphosphite compound. Relative to 100 parts by mass of the polycarbonate resin, the content of the alicyclic epoxy compound is 0.01 parts by mass or more and 0.6 parts by mass or less, the content of the pentaerythritol diphosphite compound is 0.01 parts by mass or more and 0.35 parts by mass or less, and the content of the phosphorus-based antioxidant is 0.2 parts by 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 more.

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 full potential in various optical molded products such as light guide lenses, optical fibers, and other light guide members such as light guide plates. 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, or light guide parts constituting the light guide parts 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 compound (C), and an epoxy compound (D). It discloses that the polycarbonate resin composition contains specific amounts of the components (A) to (D), and thus has good hue and brightness even when molded at high temperatures, and is also excellent in 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, there has been a trend for DRLs 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 light or heat caused by irradiation with high-output LED light and that cause little change in the color tone of the guided light in a long light guide path.

[0006] On the other hand, Patent Document 1 does not disclose any change in color tone of light guided through a long light guide path, long-term heat resistance, or long-term resistance to moist heat for the molded article formed 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 color change in guided light along a long light guide path and is excellent in long-term heat resistance and long-term resistance to moist heat. [Means for solving the problem]

[0008] Means for Solving the Problems The present inventors have conducted intensive studies to solve the above-mentioned problems, and as a result have found that the above-mentioned problems can be solved by a polycarbonate resin composition in which an alicyclic epoxy compound and a phosphorus-based antioxidant having a specific structure are blended with a polycarbonate resin in specific amounts, thereby completing the present invention.

[0009] A polycarbonate resin composition according to one embodiment 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, A polycarbonate resin composition, wherein a ratio of a content of the alicyclic epoxy compound to a 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. Effect 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 which exhibits little change in color tone of guided light in a long light guide path and has excellent long-term heat resistance and long-term moist heat resistance. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] One embodiment of the present invention will be described in detail below. In this specification, unless otherwise specified, "A to B" indicating a numerical range 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, may be simply referred to as "resin composition") contains 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 above-mentioned components, and a kneaded product obtained by melt-kneading the blend.

[0013] [Polycarbonate resin] The type of polycarbonate resin is not particularly limited 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 the carbonate bonds of the main chain, and the aliphatic polycarbonate resin is a polycarbonate resin not containing an aromatic ring such as a benzene ring between the carbonate bonds of the main chain. The polycarbonate resin may also have a branched structure. The polycarbonate resin may be used alone or in combination of two or more kinds 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 a terminal terminator by an interfacial polycondensation method, or by reacting a dihydric phenol with diphenyl carbonate or the like in the presence of a terminal terminator by an ester exchange method or the like.

[0015] The dihydric phenol, carbonate precursor, end terminator, 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 terminator, etc. disclosed in International Publication No. 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 fluidity, 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 for a light guide component (e.g., DRL, etc.), 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 measuring the viscosity of a methylene chloride solution at 20° C. using an Ubbelohde viscometer, determining the intrinsic viscosity [η] from the viscosity, and then using the following formula: [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 or different; 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 to 4; 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 the alkyl group represented by R include methyl, ethyl, n-propyl, isopropyl, various butyl groups (the term "various" refers to both linear and branched butyl groups, and the same applies below), 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 an alkyl group as exemplified above. A1 and R A2 is preferably an alkyl group having 1 or more and 4 or less carbon atoms or an alkoxy group having 1 or more and 4 or less 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 an alkylene group having 1 to 5 carbon atoms is preferable. 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 an alkylene group having 5 to 10 carbon atoms is preferable. Examples of the cycloalkylidene group represented by X include a cyclohexylidene group, a 3,5,5-trimethylcyclohexylidene group, and a 2-adamantylidene group, and an alkylidene group having 5 to 10 carbon atoms is preferable, and an alkylidene group having 5 to 8 carbon atoms is more preferable.

[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.)

[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, and the like of the resulting molded article.

[0026] The content of the aromatic polycarbonate resin having a bisphenol A structure in the aromatic polycarbonate resin is not limited, but since the expected effects due to the inclusion of 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 In the case where (i) is the above, 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] In addition, 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 above formula (1) C11 ~R C16 In the case of (i), 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, and a benzene ring is 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; or 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 further 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 is 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.

[0036] The compound represented by the formula (1) is 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; or 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 preferable 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 further preferably a hydrogen atom; R C19a ~R C19d It is even more preferable that all of are hydrogen atoms.

[0043] Each of m1 to m4 is preferably an integer of 0 or more and 3 or less, more preferably an integer of 0 or more and 1 or less, and further preferably 0. 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 commercial product, and for example, "Doverphos S-9228PC" manufactured by Dover Chemical Co. can be used.

[0045] [ka]

[0046] In addition, R in the formula (1) C11 ~R C16When it is the above (ii), 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 a methyl group, an ethyl group, an n-propyl group, an isopropyl group, various butyl groups, various pentyl groups, various hexyl groups, and various octyl groups, and is even more preferably one or more selected from the group consisting of a methyl group, an ethyl group, an isopropyl group, and a 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 more preferably 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 commercial product, and for example, "ADEKA STAB PEP-36" manufactured by ADEKA CORPORATION can be used.

[0048] [ka]

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

[0050] In order to reduce the color change of light guided in 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. 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, and 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 one kind of pentaerythritol diphosphite compound represented by the general formula (1) or two or more kinds of them. 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 any two of R are an alkyl group having 1 to 12 carbon atoms or an aryl group having 6 to 14 carbon atoms, and the remaining is a hydrogen atom. C21 ~R C25 Among compounds in which any two of the above are alkyl groups having 1 to 12 carbon atoms or aryl groups having 6 to 14 carbon atoms, and the remaining are hydrogen atoms, R C21 or R C25 More preferred is a compound 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 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 decyl groups, various dodecyl groups, etc. Among them, one or more selected from the group consisting of a methyl group, an ethyl group, an n-propyl group, an isopropyl group, various butyl groups, various pentyl groups, various hexyl groups, and various octyl groups is preferred, one or more selected from the group consisting of a methyl group, an ethyl group, an isopropyl group, and a tert-butyl group is more preferred, and a tert-butyl group 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. 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 available as a commercial product, and for example, "IRGAFOS168" manufactured by BASF can be used.

[0059] [ka]

[0060] (Examples of compounds other than those 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 the 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 available as a commercially available product, and for example, "ADEKA Tab HP-10" manufactured by ADEKA Corporation can be used.

[0062] The compound represented by the 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 available as a commercial product, 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 the 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 the compound represented by formula (3)) Among them, R in the general formula (3) D21 is preferably an aryl group, and more preferably triphenylphosphine. Triphenylphosphine is commercially available, for example, "JC-263" manufactured by Johoku Chemical Industry Co., Ltd.

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

[0067] The total content of the phosphorus-based antioxidant 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, relative to 100 parts by mass of polycarbonate resin, in order to reduce the color change of light guided in a long light guide path and the initial color change after molding for a molded article containing the resin composition. Also, the total content of the phosphorus-based antioxidant 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, relative to 100 parts by mass of polycarbonate resin, in order to improve the long-term heat resistance at 140°C and 120°C of a molded article containing the resin composition in a well-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 the alicyclic epoxy compound is not particularly limited and can be appropriately selected.

[0069] Examples of the alicyclic epoxy compound include (i) a compound having an alicyclic epoxy group in the molecule, and (ii) a compound in which an epoxy is directly bonded to an alicyclic ring by 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 a compound having a cyclopentene oxide group, a compound having a cyclohexene oxide group, and the like.

[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] (In the formula, a+b=1 or 2.) [ka] (wherein a+b+c+d=1, 2 or 3.) [ka] (In the formula, a+b+c=n (an integer), and R is a hydrocarbon group.) [ka] (In the formula, n is an integer.) [ka] (In the formula, R is a hydrocarbon group.) [ka] (In the formula, 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 types of alicyclic epoxy compounds) In terms of excellent compatibility with polycarbonate resins and not impairing transparency, 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).

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

[0078] Therefore, the alicyclic epoxy compound preferably comprises 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) The 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 in the above-mentioned range, a molded article containing the resin composition exhibits less color change due to the 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 the color change of the light guided in the long light guide path of the molded article containing the resin composition and to improve the long-term heat resistance and long-term moist heat resistance. 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, and 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 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 0.5 or more. When the ratio of the content of the alicyclic epoxy compound to the content of the pentaerythritol diphosphite compound is in the above-mentioned range, the color change of the light guided in the long light guide path is small, and the long-term heat resistance and long-term moist heat resistance are improved in the molded article containing the resin composition.

[0083] In terms of reducing the color change of light guided through a long light guide path and improving the long-term heat resistance and long-term moist heat resistance of 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 embodiment 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.

[0084] In addition, 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-mentioned components, the resin composition according to one embodiment of the present invention can contain any additive such as a fatty acid ester, a polyorganosiloxane, or a polyether compound, as long as the additive does not impair the effects of the present invention. The additive can be any general additive commonly used in the art.

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

[0087] Examples of the fatty acid ester 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 can 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 parts by mass or more, more preferably 0.02 parts by mass or more, and even more preferably 0.03 parts by mass or more, relative to 100 parts by mass of the aromatic polycarbonate resin, in terms of improving releasability. Also, in terms of further improving long-term heat resistance, the content of the fatty acid ester in the resin composition is preferably 0.2 parts by mass or less, more preferably 0.1 parts by mass or less, relative to 100 parts by mass of the aromatic polycarbonate resin.

[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 kinetic viscosity of the polyorganosiloxane is preferably 10 mm at 25° C. from the viewpoint of the lubricating effect as a mold releasability. 2 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 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 the 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, based on 100 parts by mass of aromatic polycarbonate resin (A). Within the above range, the mold releasability can be improved, and even under continuous molding conditions, the mold deposits can be significantly reduced.

[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] 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, from the viewpoint of obtaining the effects of the present invention. When the content of the polyether compound is 0.1 parts by mass or more relative to 100 parts by mass of the polycarbonate resin, the increase in the YI value is suppressed and the color tone becomes good. When the content is 2.0 parts by mass or less, the transmittance is good.

[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 method for producing the resin composition according to one embodiment of the present invention is not particularly limited, and the resin composition can be produced by a known method. For example, the resin composition can be produced by mixing the above-mentioned components at room temperature (for example, 20°C to 30°C) and melt-kneading the mixture. The melt-kneading can be carried out by a method commonly used in the art, for example, a method using a single screw extruder, a twin screw extruder, a co-kneader, a multi-screw extruder, or the like. The heating temperature during melt-kneading is usually appropriately selected from the range of 220°C or higher and 300°C or lower.

[0098] [Characteristics of polycarbonate resin composition] In the resin composition according to one embodiment of the present invention, when a molded article for measuring optical properties 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 measuring optical properties preferably has a y value of 0.41 or less in the CIE 1931 color system at a position 1005 mm from the incident part of the light guide path. Since the y value is 0.41 or less, the molded article containing the resin composition exhibits small change in color tone of the light guided in a long light guide path, making it suitable for 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 guiding portion that guides the light incident from the incident portion to the exit portion, and the light guiding portion has an optical path with a curvature such that the incident light is totally reflected.

[0100] The manufacturing conditions for the molded article for optical property measurement 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 optical property measurement is obtained by the method described in the Examples below.

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

[0102] In a resin composition according to one embodiment of the present invention, a molded article having a thickness of 5 mm is produced by injection molding using the polycarbonate resin composition 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 a C light source and a 2-degree field of view is preferably 2.0 or less. If YI1 is 2.0 or less, the molded article containing the resin composition has good long-term heat resistance and is suitable for light guide parts 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 further 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 the molded article at 120°C for 1,000 hours, the YI value (YI2) measured using a spectrophotometer under conditions of a C light source 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 having better long-term heat resistance, it is more preferable that YI1 and YI2 are each 2.0 or less, even more preferable that they are 1.9 or less, and even more preferable that they are 1.8 or less.

[0106] In terms of 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 then 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 a C light source 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 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 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 the resin composition according to one aspect of the present invention. The resin composition according to one aspect of the present invention in the molded article according to one aspect of the present invention has already been described, and 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. In the molding step, the method of molding the resin composition according to one embodiment of the present invention is not particularly limited. For example, the molded article can be produced by a known molding method such as an injection molding method, an injection compression molding method, an extrusion molding method, a blow molding method, a press molding method, a vacuum molding method, and a foam molding method using a melt-kneaded product of the resin composition according to one embodiment of the present invention or a pellet obtained through melt-kneading as a raw material. In particular, it is preferable to produce a molded article by an injection molding method or an injection compression molding method using the obtained pellets. There is no particular limit to the molding temperature in the molding step and it can be set appropriately, for example, it can be molded at a temperature of 240 ° C. or more and 300 ° C. or less.

[0111] The molded article according to one embodiment of the present invention has a small color change in the light guided path, and is excellent in long-term heat resistance and long-term wet heat resistance. In terms of fully exhibiting these characteristics, the molded article according to one embodiment of the present invention is preferably a light guide part, more preferably a light guide part for a vehicle, and even more preferably a light guide part for a vehicle daytime running light or daytime running lamp, which is a vehicle DRL. The light guide path length from the entrance part to the exit part of the light guide part may be 100 mm or more, 500 mm or more, 1000 mm or more, or 2000 mm or more. The light guide part may have a plurality of exit parts.

[0112] 〔summary〕 The polycarbonate resin composition according to the 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] The polycarbonate resin composition according to aspect 4 of the present invention, in any one of aspects 1 to 3, is preferably made of the polycarbonate resin composition and comprises an incident portion where light is incident, an exit portion where the incident light exits, and a light guiding portion that guides the light incident from the incident portion to the exit portion, wherein the light guiding portion is used as a molded article for measuring optical properties having an optical path of a curvature such that the incident light is totally reflected, and when color measurement is performed using a white light emitting diode as a light source, the y value of the molded article for measuring optical properties in the CIE 1931 color system at a position 1005 mm from the incident portion of the light guiding path is preferably 0.41 or less.

[0116] The polycarbonate resin composition according to a fifth aspect of the present invention, in any one of the first to fourth aspects, is preferably such that 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 a C light source and a 2-degree field of view is 2.0 or less.

[0117] In the polycarbonate resin composition according to a sixth aspect of the present invention, in any one of the first to fifth aspects, 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 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 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 to 4; 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 are hydrogen atoms.

[0119] The polycarbonate resin composition according to aspect 8 of the present invention is preferably such that in any one of aspects 1 to 7, the pentaerythritol diphosphite compound represented by formula (1) is bis(2,4-dicumylphenyl)pentaerythritol diphosphite.

[0120] The polycarbonate resin composition according to a ninth aspect of the present invention, in any one of the above-mentioned aspects 1 to 8, 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, 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 a twelfth aspect of the present invention may be a light-guiding component in the eleventh aspect described above.

[0124] The molded article according to a thirteenth aspect of the present invention may be a light guiding part 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 respective embodiments are also included in the technical scope of the present invention. EXAMPLES

[0126] 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 composition> The raw materials of 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-based antioxidant) Product name: Doverphos S-9228PC (Dover Chemical, bis(2,4-dicumylphenyl)pentaerythritol diphosphite)

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

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

[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" (manufactured by Shin-Etsu Chemical Co., Ltd., polyorganosiloxane compound, dynamic 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 products were produced and various evaluations were performed 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-shaped molded product 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 part of the mold that corresponds to the surface of the light guide (the part inside the molded body through which light passes) had its surface polished with an abrasive with a grain size of 1000 mesh to give a mirror finish.

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

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

[0140] <Light guided color tone measurement> The distance between the end of the test piece at the center of the molded body for measuring optical properties and the LED was 2 mm, and an LED light source (manufactured by Nichia Corporation, "NSFW036CT") was used, set to 0.35A x 3.5V, 23 lumens (1m), and irradiation was performed from the end face 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 ("CS-2000" manufactured by Konica Minolta, Inc.). The emitted light was taken out from a position 1005 mm away from the incident part and evaluated. The obtained values ​​are shown in Tables 1 and 2 as y values ​​in the CIE1931 color system. The pass standard for the y value is 0.41 or less.

[0142] <Initial YI value of molded product> The dried pellets were molded into flat test pieces of 50 mm x 90 mm x 5 mm thickness by injection molding using an injection molding machine (Nissei Plastic Industrial Co., Ltd. "ES1000": screw diameter 26 mm) under manufacturing conditions of cylinder temperature 260 ° C, mold temperature 80 ° C, and cycle time 50 seconds. The flat test pieces were injection molded after 10 shots or more of injection molding were performed under the 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 C light source and 2-degree visual field. The results are shown in Tables 1 and 2. The acceptance standard for the initial YI value is 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's 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 is YI1, and the YI value measured after storage for 1,000 hours at 120°C is YI2. The results are shown in Tables 1 and 2. The pass standard for the long-term heat resistance test at 140°C is YI1 of 2.0 or less, and the pass standard for the long-term heat resistance test at 120°C is 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 thermohygrostat (LH33-12P, Nagano Science Co., Ltd.) set at a temperature of 85°C and a relative humidity of 85% for 1,000 hours. The YI value (YI3) of the test piece after the test was measured in the same manner as above. The pass standard for the long-term wet heat resistance test is 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 the guided light in a long light guide path, and are excellent in long-term heat resistance and long-term resistance to moist heat.

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

[0149] Moreover, 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 bodies 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) is 0.7 or more, have improved long-term moist heat resistance compared to Example 1, in which Celloxide 2021P / Doverphos S-9228PC is 0.5. In addition, from a comparison between Examples 1 to 3 and Examples 7 to 10, which do not contain a polyether compound, it was found that the molded bodies containing the resin compositions of Examples 7 to 10, in which Celloxide 2021P / Doverphos S-9228PC is 2.0 or more, have little change in the color tone of the guided light in the long light guide path, have excellent long-term heat resistance, and further improved long-term moist heat resistance.

[0151] Comparing Examples 8 and 10, it was found 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 well-balanced manner. In addition, 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 or less, had a low y value of 0.40, and the color change of the guided light in the long light guide path was smaller.

[0152] Comparison between Examples 8 and 9 reveals that the inclusion of a polyorganosiloxane compound does not affect the color change of light guided along a long light guide path, the long-term heat resistance, and the long-term moist heat resistance. [Industrial Applicability]

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

Claims

1. The composition 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 based on 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 0.7 or more: 【Chemistry 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 based on 100 parts by mass of the polycarbonate resin.

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

4. When a molded article for optical characteristic measurement is used that is made of the polycarbonate resin composition and that is provided with 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 color is measured 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 a C light source and a 2-degree visual field is 2.0 or less.

6. 2. The polycarbonate resin composition according to claim 1, wherein the polycarbonate resin comprises an aromatic polycarbonate resin having a main chain having 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; 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 an aryl phosphite compound represented by the following general formula (2) and an aryl phosphine compound 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 All of R cannot be hydrogen atoms. 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, Ｄ２１ may be the same or different.

10. 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. A molded article containing a polycarbonate resin composition, which is a light-guiding part, The polycarbonate resin 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 based on 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: 【Chemistry 4】 In formula (1), R C11 to R C16 are (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 to R C16 cannot all be hydrogen atoms.

13. A molded article containing a polycarbonate resin composition, which is a light-guiding part for a vehicle, The polycarbonate resin 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 based on 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: 【Chemistry 5】 In formula (1), R C11 to R C16 are (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 to R C16 cannot all be hydrogen atoms.

Images