Resin composition, molded article, and method for producing resin composition

Abstract

The invention provides a resin composition, a molded article, and a method for producing the resin composition. The resin composition comprises a polycarbonate resin (A) (a polycarbonate resin containing a structural unit represented by formula (1) and represented by a bisphenol A polycarbonate resin, and being a regenerated product) and a polycarbonate resin (B) (a polycarbonate resin containing a structural unit represented by formula (2) and represented by a bisphenol C polycarbonate resin), the increase in color difference after heat treatment is suppressed. A resin composition containing a polycarbonate resin (A) containing a structural unit represented by formula (1) and a polycarbonate resin (B) containing a structural unit represented by formula (2), the polycarbonate resin (A) being a regenerated product, and the polycarbonate resin (A) having a Br element content of 10 ppm by mass or less per 100 parts by mass of the polycarbonate resin (A).

Description

Technical Field

[0001] The present invention relates to a resin composition, a molded product, and a method for producing the resin composition, and particularly to a resin composition containing a polycarbonate resin as a main component. Background Art

[0002] Polycarbonate resins are excellent in mechanical strength, electrical properties, transparency, etc., and are widely used as engineering plastics in various fields such as the electric and electronic equipment field and the automobile field.

[0003] On the other hand, in recent years, recycling of resources has been advocated, and research has been conducted on recycling of polycarbonate resins (Patent Document 1, Patent Document 2, etc.).

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Publication No. 2001-226576

[0007] Patent Document 2: International Publication No. 2000 / 029461 Summary of the invention

[0008] Problems to be solved by the invention

[0009] Here, from the viewpoint of improving the hardness of bisphenol A type polycarbonate resin which is a general-purpose polycarbonate resin, bisphenol C type polycarbonate resin or the like may be blended.

[0010] It is found that in such a blend of bisphenol A polycarbonate resin and bisphenol C polycarbonate resin, when a recycled product is used as the bisphenol A polycarbonate resin, the color difference after heat treatment increases significantly.

[0011] The present invention aims to solve the above problems and provides a resin composition, a molded article, and a method for producing the resin composition. The resin composition comprises a polycarbonate resin (A) and a polycarbonate resin (B), wherein the polycarbonate resin (A) is a polycarbonate resin represented by a bisphenol A type polycarbonate resin and comprises a structural unit represented by the formula (1) described below, and is a polycarbonate resin comprising a recycled product, and the polycarbonate resin (B) is a polycarbonate resin represented by a bisphenol C type polycarbonate resin and comprises a structural unit represented by the formula (2) described below, wherein the increase in color difference after heat treatment of the resin composition is suppressed.

[0012] Means for solving problems

[0013] Based on the above problems, the inventors have found that the above problems can be solved by using a polycarbonate resin having a low content of Br element as the polycarbonate resin including the structural unit represented by formula (1).

[0014] Specifically, the above-mentioned problems were solved by the following means.

[0015] <1> A resin composition comprising:

[0016] A polycarbonate resin (A) comprising a structural unit represented by formula (1), and

[0017] A polycarbonate resin (B) comprising a structural unit represented by formula (2),

[0018] The polycarbonate resin (A) is a recycled product.

[0019] The content of the Br element in the polycarbonate resin (A) is 10 ppm by mass or less relative to 100 parts by mass of the polycarbonate resin (A).

[0020] Formula (1)

[0021] [Chemistry 1]

[0022]

[0023] (In formula (1), X 1 represents any of the following,

[0024] [Chemistry 2]

[0025]

[0026] R 3 and R 4 Each independently represents a hydrogen atom or a methyl group, and Z represents a group that is bonded to C to form an alicyclic hydrocarbon group having 6 to 12 carbon atoms and may have a substituent.

[0027] Formula (2)

[0028] [Chemistry 3]

[0029]

[0030] (In formula (2), R 1 Represents methyl, R 2 represents a hydrogen atom or a methyl group, X 2 represents any of the following,

[0031] [Chemistry 4]

[0032]

[0033] R3 and R 4 Each independently represents a hydrogen atom or a methyl group, and Z represents a group that is bonded to C to form an alicyclic hydrocarbon group having 6 to 12 carbon atoms and may have a substituent.

[0034] <2> like <1> The resin composition, wherein the polycarbonate resin (A) contains P element.

[0035] <3> like <2> The resin composition, wherein the mass ratio of Br element / P element in the polycarbonate resin (A) is 0 to 1.0.

[0036] <4> like <1> ~ <3> The resin composition described above, wherein the polycarbonate resin (A) contains an Fe element.

[0037] <5> like <1> ~ <4> The resin composition described above, wherein the polycarbonate resin (A) contains Si element.

[0038] <6> like <1> ~ <5> The resin composition described in any one of the preceding claims, wherein

[0039] In the above formula (2), R 2 is a hydrogen atom, X 2 for

[0040] [Chemistry 5]

[0041]

[0042] R 3 and R 4 It is methyl.

[0043] <7> A pellet, which is <1> ~ <6> Pellets of the resin composition described above.

[0044] <8> A molded product, comprising <1> ~ <6> The resin composition described in any one of the above is formed.

[0045] <9> A method for producing a resin composition, comprising: melt-kneading a polycarbonate resin (A) containing a structural unit represented by formula (1) and a polycarbonate resin (B) containing a structural unit represented by formula (2);

[0046] The polycarbonate resin (A) is a recycled product.

[0047] The content of the Br element in the polycarbonate resin (A) is 10 ppm by mass or less relative to 100 parts by mass of the polycarbonate resin (A).

[0048] Formula (1)

[0049] [Chemistry 6]

[0050]

[0051] (In formula (1), X 1 represents any of the following,

[0052] [Chemistry 7]

[0053]

[0054] R 3 and R 4 Each independently represents a hydrogen atom or a methyl group, and Z represents a group that is bonded to C to form an alicyclic hydrocarbon group having 6 to 12 carbon atoms and may have a substituent.

[0055] Formula (2)

[0056] [Chemistry 8]

[0057]

[0058] (In formula (2), R 1 Represents methyl, R 2 represents a hydrogen atom or a methyl group, X 2 represents any of the following,

[0059] [Chemistry 9]

[0060]

[0061] R 3 and R 4 Each independently represents a hydrogen atom or a methyl group, and Z represents a group that is bonded to C to form an alicyclic hydrocarbon group having 6 to 12 carbon atoms and may have a substituent.

[0062] <10> <1> ~ <6> A method for producing a resin composition according to any one of the preceding claims, comprising: melt-kneading a polycarbonate resin (A) containing a structural unit represented by formula (1) and a polycarbonate resin (B) containing a structural unit represented by formula (2);

[0063] The polycarbonate resin (A) is a recycled product.

[0064] The content of the Br element in the polycarbonate resin (A) is 10 ppm by mass or less relative to 100 parts by mass of the polycarbonate resin (A).

[0065] Effects of the Invention

[0066] According to the present invention, a resin composition, a molded article, and a method for producing a resin composition can be provided. The resin composition is a resin composition comprising a polycarbonate resin (A) and a polycarbonate resin (B), wherein the polycarbonate resin (A) is a polycarbonate resin represented by a bisphenol A type polycarbonate resin and comprises a structural unit represented by formula (1), and is a recycled product, and the polycarbonate resin (B) is a polycarbonate resin represented by a bisphenol C type polycarbonate resin and comprises a structural unit represented by formula (2), and the increase in color difference after heat treatment of the resin composition is suppressed. DETAILED DESCRIPTION

[0067] A specific embodiment of the present invention (hereinafter referred to as "this embodiment") will be described in detail below. It should be noted that the following this embodiment is an example for explaining the present invention, and the present invention is not limited to this embodiment.

[0068] In addition, in this specification, "to" is used to mean that the numerical values ​​described before and after it are included as a lower limit and an upper limit.

[0069] In this specification, various physical property values ​​and characteristic values ​​are values ​​at 23° C. unless otherwise specified.

[0070] In this specification, ppm means mass ppm.

[0071] When the measurement methods and the like described in the standards shown in this specification differ by year, unless otherwise specified, they are based on the standards as of January 1, 2022.

[0072] The resin composition of the present embodiment is characterized in that it contains: a polycarbonate resin (A) comprising a structural unit represented by formula (1) and a polycarbonate resin (B) comprising a structural unit represented by formula (2), the polycarbonate resin (A) is a recycled product, and the content of Br element in the polycarbonate resin (A) is less than 10 mass ppm relative to 100 mass parts of the polycarbonate resin (A).

[0073] Formula (1)

[0074] [Chemistry 10]

[0075]

[0076] (In formula (1), X 1 represents any of the following,

[0077] [Chemistry 11]

[0078]

[0079] R 3 and R4 Each independently represents a hydrogen atom or a methyl group, and Z represents a group that is bonded to C to form an alicyclic hydrocarbon group having 6 to 12 carbon atoms and may have a substituent.

[0080] Formula (2)

[0081] [Chemistry 12]

[0082]

[0083] (In formula (2), R 1 Represents methyl, R 2 represents a hydrogen atom or a methyl group, X 2 represents any of the following,

[0084] [Chemistry 13]

[0085]

[0086] R 3 and R 4 Each independently represents a hydrogen atom or a methyl group, and Z represents a group that is bonded to C to form an alicyclic hydrocarbon group having 6 to 12 carbon atoms and may have a substituent.

[0087] By adopting such a structure, a resin composition can be provided, which comprises: a polycarbonate resin (A) as a recycled product containing a structural unit represented by formula (1) (hereinafter sometimes referred to as "polycarbonate resin (A)"); and a polycarbonate resin (B) containing a structural unit represented by formula (2) (hereinafter sometimes referred to as "polycarbonate resin (B)"), wherein the increase in color difference after heat treatment of the resin composition is suppressed.

[0088] The inventors have conducted research and found that a molded product formed by blending a polycarbonate resin as a recycled product with a polycarbonate resin (B) may be prone to yellowing when subjected to a heat treatment. The inventors found that the problem is that the polycarbonate resin (B) contains a large proportion of the Br element in the recycled polycarbonate resin. That is, the recycled polycarbonate resin may contain components derived from a brominated flame retardant. It is known that brominated flame retardants are activated by using them in combination with metal oxides represented by antimony trioxide, thereby further exerting their effects.

[0089] On the other hand, compared with the polycarbonate resin (A) containing the structural unit represented by the formula (1) such as the bisphenol A polycarbonate resin, the polycarbonate resin (B) containing the structural unit represented by the formula (2) such as the bisphenol C polycarbonate resin tends to be easily discolored. One of the reasons for this is presumably that in the structural unit represented by the formula (2), the benzene ring part derived from the bisphenol structure is substituted with a methyl group, and the methyl group is easily converted into a free radical.

[0090] It is also speculated that, if the polycarbonate resin (B) that is easily radicalized contains a bromine compound derived from a brominated flame retardant, for example, the molded article is likely to yellow. In particular, it is speculated that yellowing is likely to occur when heated. It is further speculated that yellowing is more likely to occur when a metal oxide is contained, and the bromine compound and the metal oxide interact with each other.

[0091] In the present embodiment, it is presumed that the above-mentioned problems can be solved by using a polycarbonate resin having a small content of the Br element as the polycarbonate resin (A).

[0092] <Polycarbonate resin (A)> (A)

[0093] The polycarbonate resin used in the present embodiment is a polycarbonate resin containing a structural unit represented by formula (1), is a recycled product, and has a Br element content of 10 ppm by mass or less relative to 100 parts by mass of the polycarbonate resin (A).

[0094] Among all the structural units of the polycarbonate resin (A), the structural unit represented by the formula (1) is preferably contained in a ratio of more than 50% by mass, more preferably in a ratio of 55% by mass or more, further preferably in a ratio of 60% by mass or more, still more preferably in a ratio of 70% by mass or more, still more preferably in a ratio of 80% by mass or more, still more preferably in a ratio of 90% by mass or more, particularly preferably in a ratio of 95% by mass or more, and preferably in a ratio of 100% by mass or less.

[0095] By using the polycarbonate resin (A), yellowing after heat treatment can be effectively suppressed.

[0096] Formula (1)

[0097] [Chemistry 14]

[0098]

[0099] (In formula (1), X 1 represents any of the following,

[0100] [Chemistry 15]

[0101]

[0102] R 3 and R 4Each independently represents a hydrogen atom or a methyl group, and Z represents a group that is bonded to C to form an alicyclic hydrocarbon group having 6 to 12 carbon atoms and may have a substituent.

[0103] As the alicyclic hydrocarbon formed by bonding Z to C, cycloalkylidene groups such as cyclohexylidene, cycloheptylidene, cyclododecylidene, adamantylidene, and cyclododecylidene can be cited. As the alicyclic hydrocarbon having a substituent formed by bonding Z to C, methyl substituted bodies and ethyl substituted bodies of the above alicyclic hydrocarbon groups can be cited. Among these, cyclohexylidene, methyl substituted bodies of cyclohexylidene (preferably 3,3,5-trimethyl substituted bodies), and cyclododecylidene are preferred.

[0104] In formula (1), X 1 for

[0105] [Chemistry 16]

[0106]

[0107] In the case of R 3 and R 4 Preferably at least one of the groups is a methyl group, and more preferably both of the groups are methyl groups.

[0108] In addition, X 1 for

[0109] [Chemistry 17]

[0110] In the case of Z, carbon C (the carbon C is bonded to the two phenyl groups in the above formula (1)) is bonded to form a divalent alicyclic hydrocarbon group having 6 to 12 carbon atoms. Examples of the divalent alicyclic hydrocarbon group include cyclohexylidene, cycloheptylidene, cyclododecylidene, adamantylidene, cyclododecylidene and other cycloalkylidene groups. As the substituted group, groups having methyl substituents and ethyl substituents thereof are included. Among these, cyclohexylidene, methyl substituted cyclohexylidene (preferably 3,3,5-trimethyl substituted cyclohexylidene) and cyclododecylidene are preferred.

[0111] In formula (1), X 1 The following structure is preferred.

[0112] [Chemistry 18]

[0113]

[0114] A preferred specific example of the structural unit represented by the above formula (1) is a structural unit composed of 2,2-bis(4-hydroxyphenyl)propane, that is, bisphenol A (carbonate structural unit).

[0115] In the polycarbonate resin (A) of the present embodiment, the structural unit represented by the formula (1) may contain only one kind or two or more kinds.

[0116] In the present embodiment, the polycarbonate resin (A) may contain other structural units in addition to the structural unit represented by formula (1). As other structural units, the structural unit represented by formula (2) described later and the structural unit derived from the dihydroxy compound shown below can be exemplified. However, the structural unit with the largest content in the polycarbonate resin (A) is the structural unit represented by formula (1).

[0117] bis(4-hydroxyphenyl)methane, 2,2-bis(4-hydroxyphenyl)butane, 2,2-bis(4-hydroxyphenyl)pentane, 2,2-bis(4-hydroxyphenyl)-4-methylpentane, 2,2-bis(4-hydroxy-3-methylphenyl)propane, 2,2-bis(4-hydroxy-3,5-dimethylphenyl)propane, 2,2-bis(4-hydroxy-3-(1-methylethyl)phenyl)propane, 2,2-bis(4-hydroxy-3-tert-butylphenyl)propane, 2,2-bis(4-hydroxy-3-(1-methylpropyl)phenyl)propane, 2,2-bis(4-hydroxy-3-cyclohexylphenyl)propane, 2,2-bis(4-hydroxy 1,1-bis(4-hydroxyphenyl) cyclohexane, 1,1-bis(4-hydroxyphenyl)-1-phenylethane, 1,1-bis(4-hydroxyphenyl) phenylmethane, 1,1-bis(4-hydroxy-3-methylphenyl) cyclohexane, 1,1-bis(4-hydroxy-3,5-dimethylphenyl) cyclohexane, 1,1-bis(4-hydroxy-3-(1-methylethyl) phenyl) cyclohexane, 1,1-bis(4-hydroxy-3-tert-butylphenyl) cyclohexane, 1,1-bis(4-hydroxy-3-(1-methylpropyl) phenyl) cyclohexane, 1,1-bis(4-hydroxy -3-cyclohexylphenyl)cyclohexane, 1,1-bis(4-hydroxy-3-phenylphenyl)cyclohexane, 1,1-bis(4-hydroxy-3-methylphenyl)-1-phenylethane, 1,1-bis(4-hydroxy-3,5-dimethylphenyl)-1-phenylethane, 1,1-bis(4-hydroxy-3-(1-methylethyl)phenyl)-1-phenylethane, 1,1-bis(4-hydroxy-3-tert-butylphenyl)-1-phenylethane, 1,1-bis(4-hydroxy-3-(1-methylpropyl)phenyl)-1-phenylethane, 1,1-bis(4-hydroxy-3-cyclohexylphenyl)-1-phenylethane, 1,1-bis(4-hydroxy-3-cyclohexylphenyl)-1-phenylethane, 1,1-bis(4-hydroxy-3-(1-methylpropyl)phenyl)-1-phenylethane -3-phenylphenyl)-1-phenylethane, 1,1-bis(4-hydroxyphenyl)cyclopentane, 1,1-bis(4-hydroxyphenyl)cyclooctane, 4,4'-(1,3-phenylene diisopropylidene)bisphenol, 4,4'-(1,4-phenylene diisopropylidene)bisphenol, 9,9-bis(4-hydroxyphenyl)fluorene, 9,9-bis(4-hydroxy-3-methylphenyl)fluorene, 4,4'-dihydroxybenzophenone, 4,4'-dihydroxyphenyl ether, 4,4'-dihydroxybiphenyl, 1,1-bis(4-hydroxyphenyl)-3,3,5-trimethylcyclohexane, 1,1-bis(4-hydroxy-6-methyl-3-tert-butylphenyl)butane.

[0118] In addition, as an embodiment of other structural units, reference can be made to the description in paragraph 0008 of International Publication No. 2017 / 099226, the description in paragraphs 0043 to 0052 of International Publication No. 2017 / 099226, and the description in Japanese Patent Application Publication No. 2011-046769, and these contents are incorporated into this specification.

[0119] The polycarbonate resin (A) used in the present embodiment is a recycled product.

[0120] Recycled products are polycarbonate resins derived from molded products formed from polycarbonate resins. They are products that have been processed by some kind of molding on virgin polycarbonate resins, and are intended to include polycarbonate resin molded products, defective polycarbonate resin molded products, and scraps from the production of polycarbonate resin molded products. Processed molded products include injection molded products, extrusion molded products, and molded products molded by other manufacturing methods.

[0121] Examples of recycled polycarbonate resins include those obtained by material recycling (recovered used polycarbonate resin molded products are crushed, washed with alkali, and reused in fibers, etc.), those obtained by chemical recycling (chemical decomposition method), and those obtained by mechanical recycling.

[0122] Chemical regeneration is a method of chemically decomposing the recycled used polycarbonate resin molded products to restore them to the raw material level and synthesize polycarbonate resin again. On the other hand, mechanical regeneration is a method that can remove dirt from polycarbonate resin molded products more reliably than material regeneration by more strictly performing the alkali cleaning in the above-mentioned material regeneration or vacuum drying at high temperature.

[0123] For example, foreign matter is removed from a used polycarbonate resin molded article, the article is pulverized and cleaned, and then pelletized using an extruder to obtain a recycled polycarbonate resin.

[0124] Examples of used polycarbonate resin molded products include trays, sheets (including films), instrument covers, headlight lenses, and water bottles.

[0125] In the polycarbonate resin (A) used in the present embodiment, the content of Br element is 10 mass ppm or less relative to 100 mass parts of the polycarbonate resin (A). By reducing the content of Br element, when blended with the polycarbonate resin (B), the free radical activation of the polycarbonate resin (B) can be effectively suppressed, and the ΔE before and after the heat treatment can be reduced.

[0126] The content of Br element in the polycarbonate resin (A) is preferably 7 ppm by mass or less relative to 100 parts by mass of the polycarbonate resin (A). The lower limit is ideally 0 ppm by mass, but the actual lower limit may be the detection limit.

[0127] The content of the Br element was measured according to the description in the examples described later.

[0128] One embodiment of the polycarbonate resin (A) in the present embodiment contains the P element. By containing the P element, there is a tendency that ΔE is further reduced. The P element comes from, for example, a stabilizer. When the polycarbonate resin (A) contains the P element, its content is preferably 1 mass ppm or more, more preferably 5 mass ppm or more, more preferably 10 mass parts or more, more preferably 20 mass ppm or more, and more preferably 25 mass ppm or more, relative to 100 mass parts of the polycarbonate resin (A). By being above the above lower limit, there is a tendency that ΔE is further reduced. In addition, relative to 100 mass parts of the polycarbonate resin (A), the upper limit value of the content of the above P element is preferably 100 mass ppm or less, more preferably 90 mass ppm or less, more preferably 80 mass ppm or less, more preferably 70 mass ppm or less, more preferably 60 mass ppm or less, and more preferably 50 mass ppm or less.

[0129] In the above embodiment, the mass ratio of Br element / P element in the polycarbonate resin (A) is preferably 0 or more, and preferably 1.0 or less, more preferably 0.9 or less, further preferably 0.8 or less, further preferably 0.7 or less, and further preferably 0.6 or less.

[0130] Another embodiment of the polycarbonate resin (A) in the present embodiment contains the Fe element. The Fe element is obtained, for example, from a mixer or a manufacturing device. When the polycarbonate resin (A) contains the Fe element, the content thereof is preferably 1 mass ppm or more, more preferably 5 mass ppm or more, further preferably 10 mass parts or more, and further preferably 13 mass ppm or more, relative to 100 mass parts of the polycarbonate resin (A). In addition, the upper limit of the content of the above-mentioned Fe element is preferably 100 mass ppm or less, more preferably 80 mass ppm or less, further preferably 60 mass ppm or less, further preferably 50 mass ppm or less, further preferably 40 mass ppm or less, and further preferably 30 mass ppm or less, relative to 100 mass parts of the polycarbonate resin (A).

[0131] In the above embodiment, the mass ratio of Br element / Fe element in the polycarbonate resin (A) is preferably 0 or more, and is preferably 1.0 or less, more preferably 0.9 or less, and further preferably 0.8 or less.

[0132] Another embodiment of the polycarbonate resin (A) in the present embodiment contains Si element. The Si element is obtained, for example, from a mixer or a manufacturing device. When the polycarbonate resin (A) contains Si element, its content is preferably 5 mass ppm or more, more preferably 10 mass ppm or more, further preferably 15 mass parts or more, and more preferably 20 mass ppm or more relative to 100 mass parts of the polycarbonate resin (A). In addition, the upper limit of the content of the above-mentioned Si element is preferably 100 mass ppm or less, more preferably 90 mass ppm or less, further preferably 80 mass ppm or less, further preferably 70 mass ppm or less, and even more preferably 60 mass ppm or less relative to 100 mass parts of the polycarbonate resin (A).

[0133] In the above embodiment, the mass ratio of the Br element / Si element in the polycarbonate resin (A) is preferably 0 or more, and is preferably 1.0 or less, more preferably 0.5 or less, and further preferably 0.4 or less.

[0134] In another embodiment of the polycarbonate resin (A) in the present embodiment, the Cl element is not contained.

[0135] In another embodiment of the polycarbonate resin (A) in the present embodiment, the Cl element is contained in a ratio of more than 0 mass ppm and 100 mass ppm or less based on 100 mass parts of the polycarbonate resin (A).

[0136] In another embodiment of the polycarbonate resin (A) in the present embodiment, the Al element is not contained.

[0137] In another embodiment of the polycarbonate resin (A) in the present embodiment, the Al element is contained in a ratio of more than 0 mass ppm and 10 mass ppm or less based on 100 parts by mass of the polycarbonate resin (A).

[0138] In another embodiment of the polycarbonate resin (A) in the present embodiment, the S element is not contained.

[0139] In another embodiment of the polycarbonate resin (A) in the present embodiment, the S element is contained in a ratio of more than 0 mass ppm and 20 mass ppm or less based on 100 parts by mass of the polycarbonate resin (A).

[0140] In another embodiment of the polycarbonate resin (A) in the present embodiment, no Ca element is contained.

[0141] In another embodiment of the polycarbonate resin (A) in the present embodiment, the Ca element is contained in a ratio of more than 0 mass ppm and 30 mass ppm or less based on 100 parts by mass of the polycarbonate resin (A).

[0142] An example of the polycarbonate resin (A) used in the present embodiment includes all of the above-mentioned P element, Fe element, and Si element in the above-mentioned ratio.

[0143] The polycarbonate resin (A) used in the present embodiment is preferably a recycled product containing no brominated flame retardant.

[0144] The lower limit of the viscosity average molecular weight (Mv) of the polycarbonate resin (A) used in the present embodiment is preferably 5,000 or more, more preferably 8,000 or more, further preferably 10,000 or more, and further preferably 12,000 or more. The upper limit of Mv is preferably 32,000 or less, more preferably 30,000 or less, further preferably 29,000 or less, and further preferably 27,000 or less.

[0145] In the above polycarbonate resin (A), the pencil hardness measured according to ISO 15184 can be exemplified as 3B to H, preferably 3B to F, and more preferably 2B to H. The pencil hardness is measured according to the method described in the examples described below (the same applies to the following pencil hardness). When two or more polycarbonate resins (A) are included, the pencil hardness of the mixture is preferably within the above range.

[0146] <Polycarbonate resin (B)>

[0147] The polycarbonate resin (B) used in the present embodiment is a polycarbonate resin containing a structural unit represented by formula (2). The proportion of the structural unit represented by formula (2) in the polycarbonate resin (B) is preferably 5% by mass or more, 15% by mass or more, 30% by mass or more, greater than 50% by mass, 55% by mass or more, 60% by mass or more, 70% by mass or more, 80% by mass or more, 90% by mass or more, 95% by mass or more in all structural units, and preferably 100% by mass or less.

[0148] By using the polycarbonate resin (B), a molded article having high hardness can be obtained.

[0149] Formula (2)

[0150] [Chemistry 19]

[0151]

[0152] (In formula (2), R 1 Represents methyl, R 2 represents a hydrogen atom or a methyl group, X 2 represents any of the following,

[0153] [Chemistry 20]

[0154]

[0155] R 3 and R 4 Each independently represents a hydrogen atom or a methyl group, and Z represents a group that is bonded to C to form an alicyclic hydrocarbon group having 6 to 12 carbon atoms and may have a substituent.

[0156] The two R in formula (2) 2 They may be the same or different, but are preferably the same. 2 Preferred is a hydrogen atom.

[0157] In formula (2), X 2 for

[0158] [Chemistry 21]

[0159]

[0160] In the case of R 3 and R 4 Preferably at least one of the groups is a methyl group, and more preferably both of the groups are methyl groups.

[0161] In addition, X 2 for

[0162] [Chemistry 22]

[0163] In the case of, Z is bonded to carbon C (the carbon C is bonded to the two phenyl groups in the above formula (2)) to form a divalent alicyclic hydrocarbon group having 6 to 12 carbon atoms, and examples of the divalent alicyclic hydrocarbon group include cyclohexylidene, cycloheptylidene, cyclododecylidene, adamantylidene, cyclododecylidene and other cycloalkylidene groups. As the substituted group, there can be mentioned groups having methyl substituents, ethyl substituents, etc. Among these, cyclohexylidene, methyl substituted cyclohexylidene (preferably 3,3,5-trimethyl substituted), and cyclododecylidene are preferred.

[0164] In formula (2), X 2 The following structure is preferred.

[0165] [Chemistry 23]

[0166]

[0167] In this embodiment, it is particularly preferred to use the compound containing R in formula (2) 2 is a hydrogen atom, X 2 for

[0168] [Chemistry 24]

[0169] R 3and R 4 A polycarbonate resin having a methyl structural unit.

[0170] In the polycarbonate resin (B) of the present embodiment, the structural unit represented by the formula (2) may contain only one kind or two or more kinds.

[0171] In the polycarbonate resin (B) of the present embodiment, as described above, the structural unit represented by formula (2) may account for 100% by mass, but other structural units may also be contained. However, the structural unit with the largest content in the polycarbonate resin (B) is the structural unit represented by formula (2).

[0172] Examples of the other structural units include the structural unit represented by formula (1) and the other structural units described in the section of the polycarbonate resin (A).

[0173] The lower limit of the viscosity average molecular weight (Mv) of the polycarbonate resin (B) used in the present embodiment is preferably 5,000 or more, more preferably 8,000 or more, further preferably 10,000 or more, and further preferably 12,000 or more. The upper limit of Mv is preferably 32,000 or less, more preferably 30,000 or less, further preferably 29,000 or less, and further preferably 28,000 or less.

[0174] The viscosity average molecular weight (Mv) of the polycarbonate resin was calculated from the following Schnell viscosity formula by determining the intrinsic viscosity (η) (unit: dL / g) at 20° C. using an Ubbelohde viscometer using methylene chloride as a solvent.

[0175] η=1.23×10 -4 Mv 0.83

[0176] In the above polycarbonate resin (B), the pencil hardness measured according to ISO 15184 can be HB to 3H, preferably H to 2H, and more preferably 2H. The pencil hardness is measured according to the method described in the examples described below (the same applies to the following pencil hardness). When two or more polycarbonate resins (B) are included, the pencil hardness of the mixture is preferably in the above range.

[0177] The polycarbonate resin (B) used in the present embodiment may be a virgin product or a recycled product, but a virgin product is preferred.

[0178] Virgin products are polycarbonate resins that are not recycled products.

[0179] <Polycarbonate resin contained in the resin composition>

[0180] In the resin composition of the present embodiment, when the total of polycarbonate resin (A) and polycarbonate resin (B) is set to 100 parts by mass, the ratio of polycarbonate resin (A) is preferably 5 parts by mass or more, more preferably 10 parts by mass or more, further preferably 20 parts by mass or more, more preferably 35 parts by mass or more, more preferably 40 parts by mass or more, further preferably 50 parts by mass or more, and particularly preferably 60 parts by mass or more. By being above the above lower limit, there is a tendency to further reduce ΔE. In addition, when the total of the above-mentioned polycarbonate resin (A) and polycarbonate resin (B) is set to 100 parts by mass, the upper limit of the ratio of polycarbonate resin (A) is preferably 95 parts by mass or less, more preferably 90 parts by mass or less, further preferably 80 parts by mass or less, more preferably 75 parts by mass or less, and more preferably 70 parts by mass or less. By being below the above upper limit, there is a tendency that the hardness of the obtained molded product is further improved.

[0181] In the resin composition of the present embodiment, the polycarbonate resin (A) and the polycarbonate resin (B) may each contain only one kind or two or more kinds. When the polycarbonate resin (A) and / or the polycarbonate resin (B) contain two or more kinds, the total amount of each is preferably within the above range.

[0182] The resin composition of the present embodiment may contain other polycarbonate resins (hereinafter sometimes referred to as “polycarbonate resin (C)”) other than the polycarbonate resin (A) and the polycarbonate resin (B).

[0183] As the polycarbonate resin (C), a native polycarbonate resin other than the polycarbonate resin (B) can be exemplified, preferably a polycarbonate resin as a native product, which is a polycarbonate resin containing the structural unit represented by the above formula (1) in a proportion generally greater than 50% by mass (preferably 55% by mass or more, more preferably 60% by mass or more, further preferably 70% by mass or more, further preferably 80% by mass or more, further preferably 90% by mass or more, further more preferably 95% by mass or more, and preferably 100% by mass or less) in all structural units.

[0184] When the resin composition of the present embodiment contains a polycarbonate resin (C), the content of the polycarbonate resin (C) in the resin composition is preferably less than 50% by mass, more preferably 45% by mass or less, further preferably 40% by mass or less, and may be 25% by mass or less, 15% by mass or less, 5% by mass or less, 3% by mass or less, or 1% by mass or less.

[0185] In the resin composition of the present embodiment, the polycarbonate resin (C) may contain only one type or two or more types.

[0186] In the resin composition of the present embodiment, the total content of the polycarbonate resin (A), the polycarbonate resin (B) and the polycarbonate resin (C) is preferably 85% by mass or more of the resin composition, more preferably 90% by mass or more, further preferably 95% by mass or more, still more preferably 97% by mass or more, and still more preferably 98% by mass or more, and may be 100% by mass or less.

[0187] <Other ingredients>

[0188] The resin composition of the present embodiment may contain other components other than the above as required, as long as the desired properties are not significantly impaired. Examples of other components include thermoplastic resins (such as acrylic resins, etc.) other than the polycarbonate resin (A), various resin additives, etc.

[0189] As resin additives, for example, mold release agents, stabilizers (heat stabilizers, antioxidants, etc.), ultraviolet absorbers, antistatic agents, flame retardants, flame retardant aids, dyes, pigments, antifogging agents, antiblocking agents, fluidity improvers, plasticizers, dispersants, antibacterial agents, etc. can be cited. It should be noted that the resin additive may contain one kind, or may contain two or more kinds in any combination and ratio.

[0190] As the antistatic agent, the description in paragraphs 0063 to 0067 of JP-A-2016-216534 may be referred to, and the contents are incorporated into the present specification.

[0191] As the flame retardant, the description in paragraphs 0068 to 0075 of JP-A-2016-216534 may be referred to, and the contents are incorporated into the present specification.

[0192] <<Release Agent>>

[0193] The resin composition of the present embodiment may contain a release agent.

[0194] Examples of the release agent include aliphatic carboxylic acids, salts of aliphatic carboxylic acids, esters of aliphatic carboxylic acids and alcohols, aliphatic hydrocarbon compounds having a number average molecular weight of 200 to 15,000, polysiloxane silicone oils, ketone waxes, and light aminos. Aliphatic carboxylic acids, salts of aliphatic carboxylic acids, and esters of aliphatic carboxylic acids and alcohols are preferred.

[0195] For details of the release agent, reference can be made to paragraphs 0055 to 0061 of JP-A-2018-095706, and these contents are incorporated into this specification.

[0196] When the resin composition of the present embodiment contains a release agent, the content of the release agent is preferably 0.05 to 3% by mass, more preferably 0.1 to 0.8% by mass, and even more preferably 0.1 to 0.6% by mass in the resin composition.

[0197] In the resin composition of the present embodiment, the mold release agent may contain only one type or two or more types. When two or more types are contained, the total amount is preferably within the above range.

[0198] <<Stabilizer>>

[0199] The resin composition of the present embodiment may contain a stabilizer.

[0200] Examples of the stabilizer include heat stabilizers and antioxidants.

[0201] Examples of the stabilizer include phenol stabilizers, amine stabilizers, phosphorus stabilizers, thioether stabilizers, etc. Among them, phosphorus stabilizers and phenol stabilizers are preferred in the present embodiment.

[0202] As the phosphorus stabilizer, any known phosphorus stabilizer can be used. Specific examples include phosphorus oxygen acids such as phosphoric acid, phosphonic acid, phosphorous acid, phosphinic acid, and polyphosphoric acid; acidic pyrophosphate metal salts such as acidic sodium pyrophosphate, acidic potassium pyrophosphate, and acidic calcium pyrophosphate; phosphates of Group 1 or Group 2 metals such as potassium phosphate, sodium phosphate, cesium phosphate, and zinc phosphate; organic phosphate compounds, organic phosphite compounds, and organic phosphite diester compounds, and organic phosphite compounds are particularly preferred.

[0203] Examples of the organic phosphite compound include triphenyl phosphite, tris(mononylphenyl) phosphite, tris(mononyl / dinonylphenyl) phosphite, tris(2,4-di-tert-butylphenyl) phosphite, monooctyl diphenyl phosphite, dioctyl monophenyl phosphite, monodecyl diphenyl phosphite, didecyl monophenyl phosphite, tridecyl phosphite, trilauryl phosphite, tristearyl phosphite, and 2,2-methylenebis(4,6-di-tert-butylphenyl)octyl phosphite.

[0204] Specific examples of such organic phosphite compounds include "ADKSTAB (registered trademark, hereinafter the same) 1178", "ADKSTAB 2112", and "ADKSTAB HP-10" manufactured by ADEKA, "JP-351", "JP-360", and "JP-3CP" manufactured by Johoku Chemical Industry Co., Ltd., and "Irgafos (registered trademark, hereinafter the same) 168" manufactured by BASF.

[0205] As the phenolic stabilizer, a hindered phenolic stabilizer is preferably used. Specific examples of the hindered phenolic stabilizer include pentaerythritol tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], octadecyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, diethylene sulfide bis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], N,N'-(hexane-1,6-diyl)bis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionamide], 2,4-dimethyl-6-(1-methylpentadecyl)phenol, diethyl[[3,5-bis(1,1-dimethylethyl)-4-hydroxyphenyl]methyl]phosphate, 3,3',3",5,5',5"-hexa-tert-butyl-a,a',a"-( trimethylol-2,4,6-triyl) tri-p-cresol, 4,6-bis(octylthiomethyl)-o-cresol, ethylenebis(oxyethylene)bis[3-(5-tert-butyl-4-hydroxy-m-tolyl)propionate], hexamethylenebis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], 1,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione, 2,6-di-tert-butyl-4-(4,6-bis(octylthio)-1,3,5-triazine-2-ylamino)phenol, 2-[1-(2-hydroxy-3,5-di-tert-pentylphenyl)ethyl]-4,6-di-tert-pentylphenyl acrylate, etc.

[0206] Among them, pentaerythritol tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] and octadecyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate are preferred. Specific examples of such hindered phenol stabilizers include "Irganox (registered trademark, hereinafter the same) 1010" and "Irganox 1076" manufactured by BASF, and "ADKSTAB AO-50" and "ADKSTAB AO-60" manufactured by ADEKA.

[0207] The content of the stabilizer in the resin composition of the present embodiment is generally 0.001 mass parts or more, preferably 0.005 mass parts or more, more preferably 0.01 mass parts or more, and generally 1 mass part or less, preferably 0.5 mass part or less, more preferably 0.3 mass part or less, relative to 100 mass parts in total of polycarbonate resin (A), polycarbonate resin (B) and polycarbonate resin (C). By making the content of the stabilizer within the above range, the addition effect of the stabilizer can be more effectively exerted.

[0208] In the resin composition of the present embodiment, the stabilizer may be contained in one type or in two or more types. When two or more types are contained, the total amount is preferably in the above range.

[0209] <<Ultraviolet light absorber>>

[0210] The resin composition of the present embodiment may contain an ultraviolet absorber.

[0211] Preferred examples of the ultraviolet absorber include benzotriazole ultraviolet absorbers, benzoxazine ultraviolet absorbers, triazine ultraviolet absorbers, and malonate ultraviolet absorbers, and benzotriazole ultraviolet absorbers are preferred.

[0212] Examples of the benzotriazole ultraviolet absorber include 2-(2-hydroxy-5-methylphenyl)-2H-benzotriazole, 2-(2-hydroxy-3,5-di-tert-butylphenyl)-2H-benzotriazole, 2-(2-hydroxy-3-tert-butyl-5-methylphenyl)-2H-benzotriazole, 2-(2-hydroxy-5-tert-octylphenyl)-2H-benzotriazole, 2-(3,5-di-tert-octyl-2-hydroxyphenyl)-2H-benzotriazole, 2-(3,5-di-tert-amyl-2-hydroxyphenyl)-2H-benzotriazole, and 2-(3 -lauryl-5-methyl-2-hydroxyphenyl)-2H-benzotriazole, 2-(3,5-di-tert-butyl-2-hydroxyphenyl)-5-chloro-2H-benzotriazole, 2-(3-tert-butyl-5-methyl-2-hydroxyphenyl)-5-chloro-2H-benzotriazole, 2-(3,5-bis(1-methyl-1-phenylethyl)-2-hydroxyphenyl)-2H-benzotriazole, bis(3-(2H-benzotriazol-2-yl)-2-hydroxy-5-methylphenyl)methane, bis(3-(2H-benzotriazol-2-yl)-2-hydroxy-5 -(1,1,3,3-tetramethylbutyl)phenyl)methane, bis(3-(2H-benzotriazol-2-yl)-2-hydroxy-5-cumylphenyl)methane, bis(3-(2H-benzotriazol-2-yl)-2-hydroxy-5-octylphenyl)methane, 1,1-bis(3-(2H-benzotriazol-2-yl)-2-hydroxy-5-methylphenyl)octane, 1,1-bis(3-(2H-5-chlorobenzotriazol-2-yl)-2-hydroxy-5-methylphenyl)octane, 1,2-ethanediylbis(3-(2H-benzotriazol-2 -yl)-2-hydroxybenzoate), 1,12-dodecanediylbis(3-(2H-benzotriazol-2-yl)-4-hydroxybenzoate), 1,3-cyclohexanediylbis(3-(5-chloro-2H-benzotriazol-2-yl)-2-hydroxybenzoate), 1,4-butanediylbis(3-(2H-benzotriazol-2-yl)-4-hydroxy-5-methylphenyl acetate), 3,6-dioxa-1,8-octanediylbis(3-(5-methoxy-2H-benzotriazol-2-yl)-4-hydroxyphenyl acetate), 1,6-hexanediyl bis(3-(3-(2H-benzotriazol-2-yl)-4-hydroxy-5-tert-butylphenyl) propionate), p-xylenediyl bis(3-(3-(2H-benzotriazol-2-yl)-4-hydroxyphenyl) propionate), bis(3-(2H-benzotriazol-2-yl)-4-hydroxytolyl) malonate, bis(2-(3-(2H-benzotriazol-2-yl)-4-hydroxy-5-octylphenyl)ethyl) terephthalate, bis(3-(2H-benzotriazol-2-yl)-4-hydroxy-5-propyltolyl) suberate, 2-(2 2-(2H-benzotriazole-2-yl)-6-phthalimidemethyl-4-methylphenol, 2-(2H-benzotriazole-2-yl)-6-phthalimideethyl-4-methylphenol, 2-(2H-benzotriazole-2-yl)-6-phthalimideoctyl-4-methylphenol, 2-(2H-benzotriazole-2-yl)-6-phthalimidemethyl-4-tert-butylphenol, 2-(2H-benzotriazole-2-yl)-6-phthalimidemethyl-4-cumylphenol, 2-(2H-benzotriazole-2-yl)-4,6-bis(phthalimidemethyl)phenol, etc. Among these, 2-(2-hydroxy-5-tert-octylphenyl)-2H-benzotriazole is preferred.

[0213] As the ultraviolet absorber, reference may be made to the description in paragraphs 0059 to 0062 of Japanese Patent Application Laid-Open No. 2016-216534 and the description in paragraphs 0069 to 0082 of Japanese Patent Application Laid-Open No. 2018-178019, the contents of which are incorporated into the present specification.

[0214] When the resin composition of the present embodiment contains a UV absorber, the content of the UV absorber is preferably 0.01 to 1 part by mass relative to 100 parts by mass of the total of the polycarbonate resin (A), the polycarbonate resin (B), and the polycarbonate resin (C). The content of the UV absorber is more preferably 0.03 to 0.7 parts by mass, and further preferably 0.05 to 0.5 parts by mass relative to the total of the polycarbonate resin (A), the polycarbonate resin (B), and the polycarbonate resin (C).

[0215] The resin composition of the present embodiment may contain only one type of ultraviolet absorber, or may contain two or more types. When containing two or more types, it is preferable that the total amount is within the above range.

[0216] The resin composition of the present embodiment is adjusted so that the total of the polycarbonate resin (A), the polycarbonate resin (B), the polycarbonate resin (C), and other components blended as needed is 100% by mass.

[0217] <Physical Properties of Resin Composition>

[0218] The resin composition of the present embodiment preferably has high hardness. Specifically, the pencil hardness measured according to ISO 15184 is preferably HB or more, more preferably F or more. In addition, the upper limit is not particularly limited, but is actually 3H or less. Such a high pencil hardness is achieved by using a polycarbonate resin (B).

[0219] In the resin composition of the present embodiment, the color difference (ΔE) after the molded product is heat-treated is preferably low. Specifically, the resin composition of the present embodiment is molded into a test piece with a thickness of 2 mm and the color difference (ΔE) before and after treatment at 100°C for 330 hours is preferably 1.0 or less, more preferably 0.9 or less, and further preferably 0.7 or less. The lower limit of the above ΔE is ideally 0, but even if it is 0.01 or more, it fully satisfies the required performance. Such a low ΔE is achieved by reducing the content of the Br element in the polycarbonate resin (A). In addition, by using a polycarbonate resin (A) containing the P element, a lower ΔE can be achieved. In particular, it can be achieved by precisely adjusting the ratio of the Br element / P element in the polycarbonate resin (A).

[0220] The above ΔE is measured according to the description in the Examples described below.

[0221] <Method for producing resin composition>

[0222] The method for producing the resin composition of the present embodiment comprises melt-kneading a polycarbonate resin (A) containing a structural unit represented by formula (1) and a polycarbonate resin (B) containing a structural unit represented by formula (2). The resin composition produced by the method for producing the resin composition of the present embodiment is preferably the resin composition of the present embodiment.

[0223] More specifically, the method for producing the resin composition of the present embodiment can include the following method: pre-mixing the polycarbonate resin (A) and the polycarbonate resin (B), and other components mixed as needed using various mixers such as a tumble mixer and a Henschel mixer, and then melt-kneading using a mixer such as a Banbury mixer, a roll, a Brabender, a single-screw kneading extruder, a twin-screw kneading extruder, and a kneader. It should be noted that the temperature of the melt kneading is not particularly limited, and is generally in the range of 240 to 320°C.

[0224] <Molding>

[0225] The above-mentioned resin combination (for example pellet) utilizes various molding methods to be molded and is made into molded products. That is, the molded products of the present embodiment are formed by the resin combination of the present embodiment. There is no particular restriction on the shape of the molded products, and it can be appropriately selected according to the use and purpose of the molded products, for example, film-like, rod-like, cylindrical, annular, circular, elliptical, polygonal, special-shaped products, hollow products, frame-like, box-like, panel-like, button-like, etc. can be cited.

[0226] There is no particular restriction on the method for molding the molded product, and existing known molding methods can be adopted, for example, injection molding, injection extrusion molding, extrusion molding, profile extrusion, transfer molding, hollow molding, gas-assisted hollow molding, blow molding, extrusion blow molding, IMC (in-mold coating molding) molding, rotational molding, multilayer molding, two-color molding, insert molding, sandwich molding, foam molding, compression molding, etc. The resin composition of the present embodiment is particularly suitable for the molded product obtained by injection molding, injection extrusion molding, and extrusion molding. However, the resin composition of the present embodiment is certainly not limited to the molded product obtained by these methods.

[0227] The molded article of this embodiment is suitable for use in parts such as electrical and electronic equipment, OA equipment, portable information terminals, machine parts, home appliances, vehicle parts, various containers, lighting equipment, and display screens.

[0228] Example

[0229] The present invention is described in more detail below by enumerating examples. As long as it does not depart from the gist of the present invention, the materials, dosage, ratio, processing content, processing procedures, etc. shown in the following examples can be appropriately changed. Therefore, the scope of the present invention is not limited to the specific examples shown below.

[0230] When the measuring equipment used in the examples is difficult to obtain due to discontinuation of production or the like, other equipment having equivalent performance may be used for measurement.

[0231] 1. Raw materials

[0232] The following raw materials shown in Table 1 and Table 3 were used.

[0233] [Table 1]

[0234]

[0235] PCR-PC is a recycled product of bisphenol A polycarbonate resin.

[0236] The content of each metal element in the above-mentioned polycarbonate resin is as follows.

[0237] [Table 2]

[0238]

[0239] <Method for Determination of Metal Elements in Polycarbonate Resin>

[0240] The quantitative determination (mass ppm) of metal elements in the polycarbonate resin was performed by fluorescent X-ray analysis (XRF). A fluorescent X-ray analyzer (manufactured by Rigaku Co., Ltd., trade name: ZSX Primus) was used, and a Rh bulb (4 kW) was used as the bulb. A 1 mm thick portion of a three-segment test piece obtained by the method described below was used and the sample was analyzed in a vacuum atmosphere. Perform EZ scan on the irradiated area.

[0241] [Table 3]

[0242]

[0243] <Production Example 1: Production of Polycarbonate Resin B1>

[0244] 26.14 mol (6.75 kg) of bisphenol C (BPC) and 26.79 mol (5.74 kg) of diphenyl carbonate were placed in an aluminum (SUS) reactor (internal volume 10 liters) equipped with a stirrer and a distillation condenser. After the interior of the reactor was replaced with nitrogen, the temperature was raised to 220° C. in a nitrogen atmosphere over 30 minutes.

[0245] Next, the reaction solution in the reactor was stirred, and the concentration of BPC in the molten reaction solution was 1.5×10 -6 Cesium carbonate (Cs2CO3) was added as a catalyst for the transesterification reaction in a molar manner, and the reaction solution was stirred and brewed at 220°C for 30 minutes under a nitrogen atmosphere. Then, the pressure in the reactor was reduced to 100 Torr over 40 minutes at the same temperature, and the reaction was further reacted for 100 minutes to distill off phenol.

[0246] Next, the temperature in the reactor was raised to 284°C over 60 minutes, and the pressure was reduced to 3 Torr, so that the phenol equivalent to the theoretical amount of distillation was distilled out. Next, the pressure in the reactor was kept at less than 1 Torr at this temperature, and the reaction was continued for another 60 minutes to terminate the polycondensation reaction. At this time, the stirring speed of the stirrer was 38 rpm, the temperature of the reaction solution just before the end of the reaction was 289°C, and the stirring power was 1.00 kW.

[0247] Next, the reaction solution in a molten state is fed into a twin-screw extruder, and butyl p-toluenesulfonate in an amount 4 times the molar amount of cesium carbonate is fed from the first supply port of the twin-screw extruder and kneaded with the reaction solution. Thereafter, the reaction solution is extruded in the form of strands through the die of the twin-screw extruder and cut with a cutter to obtain pellets of polycarbonate resin B1.

[0248] <Production Example 2: Production of Polycarbonate Resin B2>

[0249] 26.14 mol (6.75 kg) of bisphenol C (BPC) and 26.79 mol (5.74 kg) of diphenyl carbonate were placed in an aluminum (SUS) reactor (internal volume 10 liters) equipped with a stirrer and a distillation condenser. After the interior of the reactor was replaced with nitrogen, the temperature was raised to 220° C. in a nitrogen atmosphere over 30 minutes.

[0250] Next, the reaction solution in the reactor was stirred, and the concentration of BPC in the molten reaction solution was 1.5×10 -6 Cesium carbonate (Cs2CO3) was added as a catalyst for the transesterification reaction in a molar manner, and the reaction solution was stirred and brewed at 220°C for 30 minutes under a nitrogen atmosphere. Then, the pressure in the reactor was reduced to 100 Torr over 40 minutes at the same temperature, and the reaction was further reacted for 100 minutes to distill off phenol.

[0251] Next, the temperature in the reactor was raised to 284°C over 60 minutes, and the pressure was reduced to 3 Torr, so that the phenol equivalent to the theoretical amount of distillation was distilled out. Next, the pressure in the reactor was kept at less than 1 Torr at this temperature, and the reaction was continued for another 60 minutes to terminate the polycondensation reaction. At this time, the stirring speed of the stirrer was 38 rpm, the temperature of the reaction solution just before the end of the reaction was 289°C, and the stirring power was 0.60 kW.

[0252] Next, the reaction solution in a molten state is fed into a twin-screw extruder, and butyl p-toluenesulfonate in a molar amount of 4 times that of cesium carbonate is fed from the first supply port of the twin-screw extruder and kneaded with the reaction solution. Thereafter, the reaction solution is extruded in the form of strands through the die of the twin-screw extruder and cut with a cutter to obtain pellets of polycarbonate resin B2.

[0253] 2. Examples 1 to 11, Comparative Examples 1 to 3, Reference Examples 1 to 7

[0254] The components described in Table 1 above were mixed in the proportions described in Tables 4 to 6 below (the components in Tables 4 to 6 are parts by mass), mixed for 20 minutes using a tumble mixer, and then melt-kneaded using a twin-screw extruder ("TEM-26SX" manufactured by Shibaura Machine Co., Ltd.) at a barrel temperature of 260°C and a discharge rate of 25 kg / h, and a resin composition (pellet) was obtained by strand cutting.

[0255] <Determination of pencil hardness>

[0256] After drying the pellets obtained above at 100° C. for 5 hours, a flat test piece (150 mm×100 mm×2 mm thick) was prepared using an injection molding machine (“α-2000i-150B” manufactured by Fanuc Co., Ltd.) under the conditions of a barrel setting temperature of 260° C., a mold temperature of 70° C., a screw speed of 100 rpm, and an injection speed of 30 mm / sec. The pencil hardness of the flat test piece was determined using a pencil hardness tester under a load of 750 g in accordance with ISO15184.

[0257] The pencil hardness tester used was a device manufactured by Toyo Seiki Seisaku-sho, Ltd.

[0258] <ΔE>

[0259] The pellets obtained above were dried at 100°C for 5 hours using a hot air circulation dryer, and then an injection molding machine ("J55AD-60H" manufactured by Nippon Steel Works, Ltd.) was used to obtain three-segment test pieces (60mm×30mm×1mm thick+60mm×30mm×2mm thick+60mm×30mm×3mm thick) at a barrel temperature of 280°C and a mold temperature of 80°C.

[0260] The obtained test piece was heated at 100° C. for 330 hours, and the color tones before and after the heating were measured using a spectroscopic haze meter in accordance with JIS Z8722, and the color difference ΔE was calculated.

[0261] As the spectrohaze meter, “SH7000” manufactured by Nippon Denshoku Industries Co., Ltd. was used.

[0262] [Table 4]

[0263]

[0264] [Table 5]

[0265]

[0266] [Table 6]

[0267]

[0268] From the above results, it is understood that the resin composition of the present embodiment can provide molded articles having a low ΔE after heat treatment while maintaining high hardness (Examples 1 to 11).

[0269] On the other hand, when the content of the Br element is high (Comparative Examples 1 to 3), ΔE becomes high.

[0270] Example 12, Comparative Example 4

[0271] In Example 1, the polycarbonate resins (A) to (C) were changed as described, and the other procedures were carried out in the same manner.

[0272] [Table 7]

[0273]

[0274] In the above Table 7, the Br amount represents the amount of Br atoms in the polycarbonate resin (A).

[0275] The method for measuring the amount of Br atoms is the method described in the above-mentioned <Method for measuring metal elements in polycarbonate resin>.

[0276] From the above results, it is understood that even when the type of polycarbonate resin (B) containing the structural unit represented by formula (2) is changed, the same tendency as in Examples 1 to 11 and Comparative Examples 1 to 3 is confirmed (Example 12, Comparative Example 4).

Claims

1. A resin composition comprising: A polycarbonate resin (A) comprising a structural unit represented by formula (1), and A polycarbonate resin (B) comprising a structural unit represented by formula (2), The polycarbonate resin (A) is a recycled product, The content of Br element in the polycarbonate resin (A) is 10 ppm by mass or less relative to 100 parts by mass of the polycarbonate resin (A), Formula (1) [Chemistry 1] In formula (1), X 1 represents any of the following, [Chemistry 2] R 3 and R 4 Each independently represents a hydrogen atom or a methyl group, and Z represents a group that bonds to C to form an alicyclic hydrocarbon group having 6 to 12 carbon atoms and may have a substituent; Formula (2) [Chemistry 3] In formula (2), R 1 Represents methyl, R 2 represents a hydrogen atom or a methyl group, X 2 represents any of the following, [Chemistry 4] R 3 and R 4 Each independently represents a hydrogen atom or a methyl group, and Z represents a group which bonds to C to form an alicyclic hydrocarbon which may have a substituent and has 6 to 12 carbon atoms.

2. The resin composition according to claim 1, wherein The polycarbonate resin (A) contains a P element.

3. The resin composition according to claim 2, wherein The mass ratio of Br element / P element in the polycarbonate resin (A) is 0 to 1.

0.

4. The resin composition according to claim 1 or 2, wherein The polycarbonate resin (A) contains Fe element.

5. The resin composition according to claim 1 or 2, wherein The polycarbonate resin (A) contains Si element.

6. The resin composition according to claim 1 or 2, wherein In the formula (2), R 2 is a hydrogen atom, X 2 for [Chemistry 5] R 3 and R 4 It is methyl.

7. Pellets of the resin composition according to claim 1 or 2.

8. A molded article formed from the resin composition according to claim 1 or 2.

9. A method for producing a resin composition, comprising: A polycarbonate resin (A) containing a structural unit represented by formula (1) and a polycarbonate resin (B) containing a structural unit represented by formula (2) are melt-kneaded, The polycarbonate resin (A) is a recycled product, The content of Br element in the polycarbonate resin (A) is 10 ppm by mass or less relative to 100 parts by mass of the polycarbonate resin (A), Formula (1) [Chemistry 6] In formula (1), X 1 represents any of the following, [Chemistry 7] R 3 and R 4 Each independently represents a hydrogen atom or a methyl group, and Z represents a group that bonds to C to form an alicyclic hydrocarbon group having 6 to 12 carbon atoms and may have a substituent; Formula (2) [Chemistry 8] In formula (2), R 1 Represents methyl, R 2 represents a hydrogen atom or a methyl group, X 2 represents any of the following, [Chemistry 9] R 3 and R 4 Each independently represents a hydrogen atom or a methyl group, and Z represents a group which bonds to C to form an alicyclic hydrocarbon which may have a substituent and has 6 to 12 carbon atoms.

10. The method for producing the resin composition according to claim 1 or 2, comprising: A polycarbonate resin (A) containing a structural unit represented by formula (1) and a polycarbonate resin (B) containing a structural unit represented by formula (2) are melt-kneaded, The polycarbonate resin (A) is a recycled product, The content of the Br element in the polycarbonate resin (A) is 10 ppm by mass or less relative to 100 parts by mass of the polycarbonate resin (A).

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