Polycarbonate resin composition

Abstract

To provide a polycarbonate resin composition having superior surface hardness and transparency, and further having superior residence heat stability and long-term heat stability.SOLUTION: A polycarbonate resin composition contains, relative to 100 pts.mass of polycarbonate resin (A), 5 to 100 pts.mass of a (meth)acrylic copolymer (B) comprising 5 to 85 mass% of a (meth)acrylate unit represented by a specific structural formula and 15 to 95 mass% of a methyl (meth)acrylate unit, and 0.001 to 1 pt.mass of a malonate-based or oxanilide-based ultraviolet absorber (C).SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a polycarbonate resin composition, and more particularly to a polycarbonate resin composition having excellent surface hardness and transparency, as well as excellent residence heat stability and long-term heat stability, and a molded article thereof. [Background technology]

[0002] Polycarbonate resins are widely used in various fields because they have excellent impact resistance, heat resistance, electrical insulation, dimensional stability, and other properties, with a good balance of these properties. In particular, polycarbonate resins made from bisphenol compounds have the advantages of being transparent, impact-resistant, and heat-resistant, as well as being light and shatter-resistant, and are therefore used as a glass substitute for automotive parts, building materials, and optical components such as lenses. In recent years, they have also been widely used as front components for panel components of display devices used in various mobile terminals such as smartphones, tablet computers, car navigation systems, car audio systems, portable game consoles, digital cameras, and the like.

[0003] However, molded products of polycarbonate resin have a drawback in that they have lower surface hardness than products made of metal or glass, and therefore have poor scratch resistance and are easily scratched on the surface, and improvement in this area is particularly required in the fields mentioned above.

[0004] In the past, it has been proposed to blend a (meth)acrylic copolymer in order to improve the surface hardness of an aromatic polycarbonate resin. Patent Documents 1 and 2 also propose blending a (meth)acrylic copolymer consisting of a (meth)acrylate unit having two or more benzene rings in the ester moiety and a methyl (meth)acrylate unit. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent No. 5975194 [Patent Document 2] Patent No. 6794799 Summary of the Invention [Problem to be solved by the invention]

[0006] The (meth)acrylic copolymers described in Patent Documents 1 and 2 are excellent in improving the surface hardness of polycarbonate resin compositions, but it has been found that their retention heat stability and long-term heat stability are insufficient. The present invention has been made in view of the above circumstances, and an object (object) of the present invention is to provide a polycarbonate resin composition which is excellent in surface hardness and transparency, and which is also excellent in retention heat stability and long-term heat stability. [Means for solving the problem]

[0007] The present inventors have conducted extensive research to achieve the above object, and have found that the above object can be achieved by incorporating a specific amount of a malonic acid ester-based or oxalic acid anilide-based ultraviolet absorber. Although there are various types of ultraviolet absorbers, such as benzotriazole-based, triazine-based, and benzoxazine-based, the inventors have found that malonic acid ester-based or oxalic acid anilide-based ultraviolet absorbers significantly improve retention heat stability and long-term heat stability, and have completed the present invention. The present invention relates to the following polycarbonate resin composition and molded article.

[0008] 1. A polycarbonate resin composition characterized by containing, relative to 100 parts by mass of a polycarbonate resin (A), 5 to 100 parts by mass of a (meth)acrylic copolymer (B) containing 5 to 85% by mass of (meth)acrylate units represented by the following general formula (1) and 15 to 95% by mass of methyl (meth)acrylate units, and 0.001 to 1 part by mass of a malonic acid ester-based or oxalic acid anilide-based ultraviolet absorber (C): [ka] [(In formula (1), R 1is a hydrogen atom or a methyl group, m1 is an integer of 0 to 10, and Ar is a substituted or unsubstituted aryl group. 2. The polycarbonate resin composition according to the above item 1, further comprising 0.001 to 1 part by mass of a phenolic stabilizer (D) per 100 parts by mass of the polycarbonate resin (A). 3. The polycarbonate resin composition according to the above 1 or 2, further comprising a phosphorus-based stabilizer (E) in an amount of 0.001 to 0.5 parts by mass per 100 parts by mass of the polycarbonate resin (A). 4. The polycarbonate resin composition according to 3 above, wherein the value of [number of moles of the phenolic stabilizer (D) contained in the resin composition × number of phenol groups in one molecule of the phenolic stabilizer (D)] / [number of moles of the phosphorus-based stabilizer (E) contained in the resin composition × number of P in one molecule of the phosphorus-based stabilizer (E)] is in the range of 2 to 7. 5. The polycarbonate resin composition according to any one of the above 1 to 4, wherein the ultraviolet absorber (C) is a malonic acid ester-based ultraviolet absorber. 6. The polycarbonate resin composition according to any one of the above 1 to 5, wherein the polycarbonate resin (A) contains a recycled polycarbonate resin. 7. Pellets of the polycarbonate resin composition according to any one of 1 to 6 above. 8. A molded article made of the polycarbonate resin composition according to any one of 1 to 6 above. 9. A molded article made from pellets of the polycarbonate resin composition described in 7 above. [Effects of the Invention]

[0009] The polycarbonate resin composition of the present invention is excellent in surface hardness and transparency, and is also excellent in residence heat stability and long-term heat stability. DETAILED DESCRIPTION OF THE INVENTION

[0010] The present invention will now be described in detail. In this specification, unless otherwise specified, the symbol "to" is used to mean that the numerical values ​​before and after it are included as the lower limit and upper limit.

[0011] The polycarbonate resin composition of the present invention is characterized by containing, per 100 parts by mass of polycarbonate resin (A), 5 to 100 parts by mass of (meth)acrylic copolymer (B) containing 5 to 85% by mass of (meth)acrylate units represented by general formula (1) above and 15 to 95% by mass of methyl (meth)acrylate units, and 0.001 to 1 part by mass of a malonic acid ester-based or oxalic acid anilide-based ultraviolet absorber compound (C).

[0012] [Polycarbonate resin (A)] The polycarbonate resin (A) used in the present invention is not particularly limited, and various types can be used. Polycarbonate resins can be classified into aromatic polycarbonate resins in which the carbons directly bonded to the carbonate bonds are aromatic carbons, and aliphatic polycarbonate resins in which the carbons directly bonded to the carbonate bonds are aliphatic carbons, and either type can be used. Among these, aromatic polycarbonate resins are preferred as the polycarbonate resin (A) from the viewpoints of heat resistance, mechanical properties, electrical properties, etc.

[0013] Among the monomers that are raw materials for aromatic polycarbonate resins, examples of aromatic dihydroxy compounds include: dihydroxybenzenes such as 1,2-dihydroxybenzene, 1,3-dihydroxybenzene (i.e., resorcinol), and 1,4-dihydroxybenzene; dihydroxybiphenyls such as 2,5-dihydroxybiphenyl, 2,2'-dihydroxybiphenyl, and 4,4'-dihydroxybiphenyl;

[0014] dihydroxynaphthalenes such as 2,2'-dihydroxy-1,1'-binaphthyl, 1,2-dihydroxynaphthalene, 1,3-dihydroxynaphthalene, 2,3-dihydroxynaphthalene, 1,6-dihydroxynaphthalene, 2,6-dihydroxynaphthalene, 1,7-dihydroxynaphthalene, and 2,7-dihydroxynaphthalene;

[0015] dihydroxydiaryl ethers such as 2,2'-dihydroxydiphenyl ether, 3,3'-dihydroxydiphenyl ether, 4,4'-dihydroxydiphenyl ether, 4,4'-dihydroxy-3,3'-dimethyldiphenyl ether, 1,4-bis(3-hydroxyphenoxy)benzene, and 1,3-bis(4-hydroxyphenoxy)benzene;

[0016] 2,2-bis(4-hydroxyphenyl)propane (i.e., bisphenol A), 1,1-bis(4-hydroxyphenyl)propane, 2,2-bis(3-methyl-4-hydroxyphenyl)propane (i.e., bisphenol C), 2,2-bis(3-methoxy-4-hydroxyphenyl)propane, 2-(4-hydroxyphenyl)-2-(3-methoxy-4-hydroxyphenyl)propane, 1,1-bis(3-tert-butyl-4-hydroxyphenyl)propane, 2,2-bis(3,5-dimethyl-4-hydroxyphenyl)propane, 2,2-bis(3-cyclohexyl-4-hydroxyphenyl)propane, 2-(4-hydroxyphenyl)-2-(3-cyclohexyl-4-hydroxyphenyl)propane, α,α'-bis(4-hydroxyphenyl)-1,4-diisopropylbenzene, 1,3-bis[2-(4-hydroxyphenyl)-2-propyl]benzene, bis(4-hydroxyphenyl)methane, bis(4-hydroxyphenyl)cyclohexylmethane, bis(4-hydroxyphenyl)phenylmethane, bis(4-hydroxyphenyl)(4-propenylphenyl)methane, bis(4-hydroxyphenyl)diphenylmethane, bis(4-hydroxyphenyl)naphthylmethane, 1,1-bis(4-hydroxyphenyl)ethane, 1,1-bis(4-hydroxyphenyl)-1-phenylethane (i.e., bisphenol AP), 1,1-bis(4-hydroxyphenyl)-1-naphthylethane, 1,1-bis(4-hydroxyphenyl)butane, 2,2-bis(4-hydroxyphenyl)butane, 2,2-bis(4-hydroxyphenyl)pentane, 1,1-bis(4-hydroxyphenyl)hexane, 2,2-bis(4-hydroxyphenyl)hexane, 1,1-bis(4-hydroxyphenyl)octane, 2,2-bis(4-hydroxyphenyl)octane, 4,4-bis(4-hydroxyphenyl)heptane, 2,2-bis(4-hydroxyphenyl)nonane, 1,1-bis(4-hydroxyphenyl)decane, 1,1-bis(4-hydroxyphenyl)dodecane, Bis(hydroxyaryl)alkanes such as;

[0017] 1,1-bis(4-hydroxyphenyl)cyclopentane, 1,1-bis(4-hydroxyphenyl)cyclohexane, 1,1-bis(4-hydroxyphenyl)-3,3-dimethylcyclohexane, 1,1-bis(4-hydroxyphenyl)-3,4-dimethylcyclohexane, 1,1-bis(4-hydroxyphenyl)-3,5-dimethylcyclohexane, 1,1-bis(4-hydroxyphenyl)-3,3,5-trimethylcyclohexane, 1,1-bis(4-hydroxy-3,5-dimethylphenyl)-3,3,5-trimethylcyclohexane, 1,1-bis(4-hydroxyphenyl)-3-propyl-5-methylcyclohexane, 1,1-bis(4-hydroxyphenyl)-3-tert-butyl-cyclohexane, 1,1-bis(4-hydroxyphenyl)-4-tert-butyl-cyclohexane, 1,1-bis(4-hydroxyphenyl)-3-phenylcyclohexane, 1,1-bis(4-hydroxyphenyl)-4-phenylcyclohexane, Bis(hydroxyaryl)cycloalkanes such as;

[0018] 9,9-bis(4-hydroxyphenyl)fluorene, Cardo structure-containing bisphenols such as 9,9-bis(4-hydroxy-3-methylphenyl)fluorene;

[0019] 4,4'-dihydroxydiphenyl sulfide, Dihydroxydiaryl sulfides such as 4,4'-dihydroxy-3,3'-dimethyldiphenyl sulfide; dihydroxydiaryl sulfoxides such as 4,4'-dihydroxydiphenyl sulfoxide and 4,4'-dihydroxy-3,3'-dimethyldiphenyl sulfoxide; 4,4'-dihydroxydiphenyl sulfone, dihydroxydiarylsulfones such as 4,4'-dihydroxy-3,3'-dimethyldiphenylsulfone; etc.

[0020] Of these, bis(hydroxyaryl)alkanes are preferred, and bis(4-hydroxyphenyl)alkanes are particularly preferred. In particular, from the standpoints of impact resistance and heat resistance, 2,2-bis(4-hydroxyphenyl)propane (i.e., bisphenol A), 2,2-bis(3-methyl-4-hydroxyphenyl)propane (i.e., bisphenol C), and 1,1-bis(4-hydroxyphenyl)-1-phenylethane (i.e., bisphenol AP) are preferred. The aromatic dihydroxy compounds may be used alone or in any combination of two or more in any ratio.

[0021] Among the monomers that serve as raw materials for polycarbonate resins, examples of carbonate precursors include carbonyl halides, carbonate esters, etc. The carbonate precursors may be used alone or in any combination and ratio of two or more.

[0022] Specific examples of carbonyl halides include phosgene; haloformates such as bischloroformates of dihydroxy compounds and monochloroformates of dihydroxy compounds; and the like.

[0023] Specific examples of carbonate esters include diaryl carbonates such as diphenyl carbonate and ditolyl carbonate; dialkyl carbonates such as dimethyl carbonate and diethyl carbonate; biscarbonates of dihydroxy compounds, monocarbonates of dihydroxy compounds, and carbonates of dihydroxy compounds such as cyclic carbonates.

[0024] The method for producing the polycarbonate resin (A) is not particularly limited, and any method can be used. Examples include interfacial polymerization, melt transesterification, pyridine method, ring-opening polymerization of cyclic carbonate compounds, and solid-phase transesterification of prepolymers. Among these, the interfacial polymerization and melt transesterification methods are preferred because they have a greater effect of improving moist heat resistance, and the interfacial polymerization method is particularly preferred.

[0025] The molecular weight of the polycarbonate resin (A), expressed as a viscosity-average molecular weight (Mv) calculated from the solution viscosity measured at 25° C. using methylene chloride as a solvent, is preferably 10,000 to 50,000, more preferably 10,000 to 40,000, and even more preferably 10,000 to 30,000, and even more preferably 10,500 or more, 11,000 or more, particularly 11,500 or more, most preferably 12,000 or more, and even more preferably 29,000 or less, and particularly preferably 28,500 or less. By setting the viscosity-average molecular weight at or above the lower limit of the above range, the mechanical strength of the polycarbonate resin composition of the present invention can be further improved, while by setting the viscosity-average molecular weight at or below the upper limit of the above range, the decrease in flowability of the polycarbonate resin composition of the present invention can be suppressed and improved, and molding processability can be improved, allowing for easier molding processability. Two or more polycarbonate resins having different viscosity average molecular weights may be mixed together, and in this case, polycarbonate resins having viscosity average molecular weights outside the above-mentioned preferred range may be mixed.

[0026] The viscosity average molecular weight [Mv] is calculated by using methylene chloride as a solvent and an Ubbelohde viscometer to determine the intrinsic viscosity [η] (unit: dl / g) at a temperature of 25°C, and then calculating it using the Schnell viscosity formula, i.e., η = 1.23 × 10 -4 Mv 0.83 The intrinsic viscosity [η] is the specific viscosity [η] at each solution concentration [C] (g / dl). sp ] was measured and the value was calculated according to the following formula.

number

[0027] Furthermore, in order to improve the appearance and flowability of the molded article, the polycarbonate resin (A) may contain a polycarbonate oligomer. The viscosity average molecular weight [Mv] of this polycarbonate oligomer is usually 1,500 or more, preferably 2,000 or more, and usually 9,500 or less, preferably 9,000 or less. Furthermore, the polycarbonate oligomer contained is preferably 30% by mass or less of the polycarbonate resin (including the polycarbonate oligomer).

[0028] Furthermore, the polycarbonate resin (A) may be not only made from virgin raw materials but also from polycarbonate resin recycled from used products (so-called material-recycled polycarbonate resin or chemically recycled polycarbonate resin, collectively referred to as recycled polycarbonate resin), and it is also preferable to contain both virgin raw materials and recycled polycarbonate resin, or it may consist of recycled polycarbonate resin. When recycled polycarbonate resin is contained, the proportion of recycled polycarbonate resin in polycarbonate resin (A) is preferably 10% by mass or more, particularly 20% by mass or more, 30% by mass or more, 40% by mass or more, 50% by mass or more, 60% by mass or more, 70% by mass or more, 80% by mass or more, 90% by mass or more, and even 100% is preferred. The proportion of the polycarbonate resin (A) in the polycarbonate resin composition is usually 50% by mass or more, and preferably 60% by mass or more.

[0029] [(Meth)acrylic copolymer (B)] The polycarbonate resin composition of the present invention contains a (meth)acrylic copolymer (B) containing 5 to 85 mass % of (meth)acrylate units (b1) represented by the general formula (1) and 15 to 95 mass % of methyl (meth)acrylate units (b1). By containing the (meth)acrylic copolymer (B), the surface hardness of the resulting molded article can be further increased.

[0030] By including the aromatic (meth)acrylate unit of general formula (1), the (meth)acrylic copolymer (B) has improved compatibility with the polycarbonate resin (A), and the transparency of the resulting molded article can be further improved.

[0031] [ka] [In formula (1), R 1 is a hydrogen atom or a methyl group, m1 is an integer of 0 to 10, and Ar is a substituted or unsubstituted aryl group.

[0032] R 1 is preferably a methyl group. m1 is preferably an integer of 5 or less, more preferably an integer of 3 or less, even more preferably 0 or 1, and particularly preferably 1. Ar is a substituted or unsubstituted phenyl group. When Ar has a substituent, the substituent is preferably a halogen atom, a cyano group, a nitro group, a hydroxy group, an alkyl group, an alkoxy group, an aryl group, an aryloxy group, a heterocyclic group, a heterocyclic oxy group, an alkenyl group, an alkylsulfanyl group, an arylsulfanyl group, an acyl group, or an amino group, more preferably a halogen atom, an alkyl group, an alkoxy group, an aryl group, an aryloxy group, an alkenyl group, or an acyl group, even more preferably an alkyl group, an aryl group, an aryloxy group, or an alkenyl group, and even more preferably an aryl group. The formula weight of these substituents is preferably 15 or more and preferably 200 or less. For example, the formula weight is 15 for a methyl group (-CH3). These substituents may further have a substituent.

[0033] The (meth)acrylate unit (b1) represented by general formula (1) more preferably contains a unit represented by the following general formula (2): By containing the unit represented by general formula (2), the transparency of the obtained molded article tends to be further improved.

[0034] [ka]

[0035] In formula (2), X represents a single bond, -C(R 2 )(R 3 )-, -C(=O)-, -O-, -OC(=O)-, -OC(=O)O-, -S-, -SO-, -SO2-, and a combination of two or more thereof; R 1 is a hydrogen atom or a methyl group, and R 2 and R 3 are each independently a hydrogen atom, a linear alkyl group having 1 to 10 carbon atoms, a branched alkyl group having 3 to 10 carbon atoms, a cyclic alkyl group having 3 to 10 carbon atoms, a linear alkoxy group having 1 to 10 carbon atoms, a branched alkoxy group having 3 to 10 carbon atoms, a cyclic alkoxy group having 3 to 10 carbon atoms, a phenyl group, or a phenylphenyl group; R 2 and R 3 may be linked to each other to form a ring having 3 to 10 carbon atoms together with the carbon atom to which they are attached, and R 4 and R 5 are each independently a linear alkyl group having 1 to 10 carbon atoms, a branched alkyl group having 3 to 10 carbon atoms, a cyclic alkyl group having 3 to 10 carbon atoms, a linear alkoxy group having 1 to 10 carbon atoms, a branched alkoxy group having 3 to 10 carbon atoms, a cyclic alkoxy group having 3 to 10 carbon atoms, a halogen atom, a phenyl group, or a phenylphenyl group; m2 is an integer of 1 to 10, p is an integer of 0 to 4, and q is an integer of 0 to 5.

[0036] X is a single bond, -C(R 2 )(R 3 )-, -C(=O)-, -O-, -SO-, or -SO2- is preferred, -CH2- or a single bond is more preferred, and a single bond is even more preferred. R 2 and R 3 are each independently selected from a hydrogen atom, a methyl group, a methoxy group, a phenyl group, and a phenylphenyl group, and are more preferably a hydrogen atom. 2 and R 3may be linked to each other to form a ring having 3 to 10 carbon atoms together with the carbon atom to which they are bonded, or may further be linked to the carbon atom to form a cyclic alkyl group having 3 to 10 carbon atoms. R 2 and R 3 are linked to each other to form a ring having 3 to 10 carbon atoms together with the carbon atoms to which they are attached, R 2 and R 3 are each independently a linear alkyl group having 1 to 10 carbon atoms, a branched alkyl group having 3 to 10 carbon atoms, a cyclic alkyl group having 3 to 10 carbon atoms, a linear alkoxy group having 1 to 10 carbon atoms, a branched alkoxy group having 3 to 10 carbon atoms, or a cyclic alkoxy group having 3 to 10 carbon atoms. R 2 and R 3 are preferably not linked to each other to form a ring.

[0037] R 4 and R 5 are each independently preferably a methyl group, a methoxy group, a chloro group, a bromo group or a phenyl group, and more preferably a phenyl group. m2 is preferably an integer of 1 to 3, and more preferably 1. p is preferably an integer of 0 to 1, and more preferably 0. q is preferably an integer of 0 to 2, and more preferably 0.

[0038] Examples of the (meth)acrylate monomer constituting the (meth)acrylate unit (b1) include phenyl(meth)acrylate, 4-phenylbenzyl(meth)acrylate, 3-phenylbenzyl(meth)acrylate, 2-phenylbenzyl(meth)acrylate, 4-biphenylbenzyl(meth)acrylate, 3-biphenylbenzyl(meth)acrylate, 2-biphenylbenzyl(meth)acrylate, 4-benzylbenzyl(meth)acrylate, 3-benzylbenzyl(meth)acrylate, 2-benzylbenzyl(meth)acrylate, 4-benzylbenzyl(meth)acrylate, 3-benzylbenzyl(meth)acrylate, 2-benzylbenzyl(meth)acrylate. Acrylate, 4-phenethylbenzyl (meth)acrylate, 3-phenethylbenzyl (meth)acrylate, 2-phenethylbenzyl (meth)acrylate, 4-phenethylphenethyl (meth)acrylate, 3-phenethylphenethyl (meth)acrylate, 2-phenethylphenethyl (meth)acrylate, 4-(4-methylphenyl)benzyl (meth)acrylate, 3-(4-methylphenyl)benzyl (meth)acrylate, 2-(4-methylphenyl)benzyl (meth)acrylate, 4-(4-methoxyphenyl)benzyl (meth)acrylate Acrylate, 3-(4-methoxyphenyl)benzyl (meth)acrylate, 2-(4-methoxyphenyl)benzyl (meth)acrylate, 4-(4-bromophenyl)benzyl (meth)acrylate, 3-(4-bromophenyl)benzyl (meth)acrylate, 2-(4-bromophenyl)benzyl (meth)acrylate, 4-benzoylbenzyl (meth)acrylate, 3-benzoylbenzyl (meth)acrylate, 2-benzoylbenzyl (meth)acrylate, 4-(phenylsulfinyl)benzyl (meth)acrylate, 3 -(Phenylsulfinyl)benzyl (meth)acrylate, 2-(phenylsulfinyl)benzyl (meth)acrylate, 4-(phenylsulfonyl)benzyl (meth)acrylate, 3-(phenylsulfonyl)benzyl (meth)acrylate, 2-(phenylsulfonyl)benzyl (meth)acrylate, 4-((phenoxycarbonyl)oxy)benzyl (meth)acrylate, 3-((phenoxycarbonyl)oxy)benzyl (meth)acrylate, 2-((phenoxycarbonyl)oxy)benzyl (meth)acrylate,4-(((meth)acryloxy)methyl)phenyl benzoate, 3-(((meth)acryloxy)methyl)phenyl benzoate, 2-(((meth)acryloxy)methyl)phenyl benzoate, phenyl 4-(((meth)acryloxy)methyl)benzoate, phenyl 3-(((meth)acryloxy)methyl)benzoate, phenyl 2-(((meth)acryloxy)methyl)benzoate, 4-(1-phenylcyclohexyl)benzyl (meth)acrylate, 3-(1-phenylcyclohexyl)benzyl Examples of the methylbenzyl (meth)acrylate include benzyl (meth)acrylate, 2-(1-phenylcyclohexyl)benzyl (meth)acrylate, 4-phenoxybenzyl (meth)acrylate, 3-phenoxybenzyl (meth)acrylate, 2-phenoxybenzyl (meth)acrylate, 4-(phenylthio)benzyl (meth)acrylate, 3-(phenylthio)benzyl (meth)acrylate, 2-(phenylthio)benzyl (meth)acrylate, and 3-methyl-4-(2-methylphenyl)benzyl methacrylate. Of these, phenyl(meth)acrylate and 4-phenylbenzyl(meth)acrylate are preferred, with 4-phenylbenzyl(meth)acrylate being more preferred.

[0039] The methyl (meth)acrylate monomer constituting the methyl (meth)acrylate unit (b2) is preferably methyl methacrylate, and by including the methyl methacrylate unit, the surface hardness of the resulting molded article can be further increased.

[0040] The mass ratio of the (meth)acrylate units (b1) and the methyl (meth)acrylate units (b2) in the (meth)acrylic copolymer (B) is 5 to 85 mass% of the (meth)acrylate units (b1) and 15 to 95 mass% of the methyl (meth)acrylate units (b2) relative to 100 mass% in total of the (meth)acrylate units (b1) and the methyl (meth)acrylate units (b2). The upper limit of the (meth)acrylate units (b1) is preferably 70% by mass or less, particularly 60% by mass or less, 50% by mass or less, 40% by mass or less, and particularly 35% by mass or less, while the lower limit of the (meth)acrylate units (b1) is preferably 10% by mass or more, more preferably 12% by mass or more. The lower limit of the methyl (meth)acrylate units (b2) is preferably 30% by mass or more, particularly 40% by mass or more, 50% by mass or more, 60% by mass or more, and particularly 65% ​​by mass or more, while the upper limit of the (meth)acrylate units (b2) is preferably 90% by mass or less, more preferably 88% by mass or less.

[0041] The (meth)acrylic copolymer (B) may or may not contain other monomer units other than the (meth)acrylate units (b1) and the methyl (meth)acrylate units (b2). Examples of other monomer units include aliphatic methacrylates other than methyl methacrylate, such as ethyl methacrylate, butyl methacrylate, propyl methacrylate, and 2-ethylhexyl methacrylate; aliphatic acrylates other than methyl acrylate, such as ethyl acrylate, butyl acrylate, propyl acrylate, 2-ethylhexyl acrylate, and glycidyl acrylate; vinyl cyanide monomers such as acrylonitrile and methacrylonitrile; diene monomers such as butadiene, isoprene, and dimethylbutadiene; vinyl methyl ether, vinyl ethyl ether, and the like. vinyl ether monomers; carboxylic acid vinyl monomers such as vinyl acetate and vinyl butyrate; olefin monomers such as ethylene, propylene, and isobutylene; ethylenically unsaturated carboxylic acid monomers such as acrylic acid, methacrylic acid, maleic acid, and itaconic acid; halogenated vinyl monomers such as vinyl chloride and vinylidene chloride; maleimide monomers such as maleimide, N-phenylmaleimide, N-cyclohexylmaleimide, and N-methylmaleimide; allyl (meth)acrylate, divinylbenzene, and 1,3-butylene dimethacrylate.

[0042] In the (meth)acrylic copolymer (B), the total of the (meth)acrylate units (b1) and the methyl (meth)acrylate units (b2) preferably accounts for 90% by mass or more, more preferably 95% by mass or more, and even more preferably 98% by mass or more, of 100% by mass of all monomer units.

[0043] The (meth)acrylic copolymer (B) may be a recycled product (including recovered products, material recycled products, chemical recycled products, etc.) of the (meth)acrylic copolymer (B), a rejected product, or scrap material generated when a molded product is produced from the resin composition.

[0044] The number average molecular weight (Mn) of the (meth)acrylic copolymer (B) is preferably 3,000 or more, more preferably 4,000 or more, and even more preferably 5,000 or more, and is preferably 25,000 or less, more preferably 20,000 or less, even more preferably 15,000 or less, and even more preferably 10,000 or less. By setting it to be equal to or greater than the lower limit, gas generation during molding tends to be further reduced. By setting it to be equal to or less than the upper limit, compatibility with polycarbonate resins tends to be further improved. The weight average molecular weight (Mw) of the (meth)acrylic copolymer (B) is preferably 5,000 or more, more preferably 7,000 or more, and even more preferably 9,000 or more, and is preferably 20,000 or less, more preferably 18,000 or less, even more preferably 15,000 or less, and even more preferably 12,000 or less. By setting it to be equal to or greater than the lower limit, gas generation during molding tends to be further reduced. By setting it to be equal to or less than the upper limit, compatibility with polycarbonate resins tends to be further improved. When the polycarbonate resin composition of the present invention contains two or more kinds of (meth)acrylic copolymers (B), the average molecular weight is calculated as the mass of the mixture.

[0045] The number average molecular weight (Mn) and weight average molecular weight (Mw) of the (meth)acrylic copolymer (B) are determined from the polystyrene equivalent values ​​detected by RI by GPC (gel permeation chromatography) using a Tosoh HLC-8420, tetrahydrofuran as a solvent, and three TOSOH TSKgel SuperHM-M columns at a column temperature of 40°C and a flow rate of 0.6 mL / min.

[0046] The content of (meth)acrylic copolymer (B) is 5 to 100 parts by mass per 100 parts by mass of polycarbonate resin (A). By combining this amount with polycarbonate resin (A) and further combining it with a predetermined amount of malonic acid ester or oxalic acid anilide UV absorber compound (C), a polycarbonate resin composition can be obtained that has excellent surface hardness and transparency, and an excellent balance between residence thermal stability, long-term thermal stability, and heat resistance. The content of (meth)acrylic copolymer (B) is preferably 8 parts by mass or more, more preferably 10 parts by mass or more. When surface hardness is more important, it may be 15 parts by mass or more, 20 parts by mass or more, 25 parts by mass or more, or 30 parts by mass or more. The upper limit of the content is preferably 90 parts by mass or less, particularly 80 parts by mass or less, 70 parts by mass or less, or 60 parts by mass or less, and more preferably 55 parts by mass or less, relative to 100 parts by mass of the polycarbonate resin (A). When transparency and a low YI value are more important, the upper limit is even more preferably 50 parts by mass or less, and particularly preferably 45 parts by mass or less. The (meth)acrylic copolymer (B) may contain one kind or two or more kinds. When two or more kinds are contained, the total amount is preferably within the above range.

[0047] [Malonate ester or oxalic acid anilide ultraviolet absorber (C)] The polycarbonate resin composition of the present invention contains a malonic acid ester-based or oxalic acid anilide-based ultraviolet absorber (C).

[0048] The malonic acid ester-based ultraviolet absorber is preferably a 2-(alkylidene)malonic acid ester, more preferably a 2-(1-arylalkylidene)malonic acid ester, and preferably includes a 2-(1-arylalkylidene)malonic acid ester, tetraethyl 2,2'-(1,4-phenylenedimethanylilidene)dimalonate, etc. Specific examples of such malonic acid ester compounds include "PR-25" manufactured by Clariant and "B-CAP" manufactured by Clariant.

[0049] Examples of oxalic acid anilide-based ultraviolet absorbers include oxanilide compounds having a hydrocarbon group having 1 to 12 carbon atoms, such as 2-ethoxy-2'-ethyl oxalic acid bis-anilide. Specific examples of such oxanilide compounds include "HOSTAVIN VSU P" and "HOSTAVIN 3206 LIQ" manufactured by Clariant.

[0050] The content of the malonic acid ester-based or oxalic acid anilide-based ultraviolet absorber (C) is 0.001 to 1 part by mass per 100 parts by mass of the polycarbonate resin (A). By incorporating such an amount, a polycarbonate resin composition can be obtained that exhibits excellent surface hardness and transparency, as well as excellent residence thermal stability and long-term thermal stability. A content of less than 0.001 part by mass fails to fully achieve the above effects, while a content of more than 1 part by mass is undesirable because it can cause problems such as gas generation during processing due to bleed-out and a decrease in total light transmittance and mechanical strength. The content is preferably 0.01 part by mass or more, particularly 0.1 part by mass or more, 0.2 part by mass or more, 0.3 part by mass or more, or even 0.4 part by mass or more, and is preferably 0.9 part by mass or less, and more preferably 0.8 part by mass or less. When both a malonic acid ester-based ultraviolet absorber and an oxalic acid anilide-based ultraviolet absorber are contained, the content is the total amount of both.

[0051] As the malonate ester-based or oxalic acid anilide-based ultraviolet absorber (C), a malonate ester-based ultraviolet absorber is particularly preferred because it can further improve the residence heat stability and long-term heat stability of the polycarbonate resin composition of the present invention, and can also improve the long-term moist heat resistance and weather resistance.

[0052] [Phenol-based stabilizer (D)] The polycarbonate resin composition of the present invention preferably contains a phenolic stabilizer (D), which can suppress decomposition and color deterioration of the polycarbonate resin during long-term tests such as moist heat tests.

[0053] Examples of the phenolic stabilizer (D) include hindered phenolic stabilizers. Specific examples thereof include pentaerythritol tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], octadecyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, tris(3,5-di-tert-butyl-4-hydroxybenzyl)isocyanurate, thiodiethylenebis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], N,N'-hexane-1,6-diylbis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionamide], 2,4-dimethyl-6-(1-methylpentyl)propionamide, and the like. hexadecyl)phenol, 3,3',3'',5,5',5''-hexa-tert-butyl-a,a',a''-(mesitylene-2,4,6-triyl)tri-p-cresol, 4,6-bis(octylthiomethyl)-o-cresol, ethylene bis(oxyethylene) bis[3-(5-tert-butyl-4-hydroxy-m-tolyl)propionate], hexamethylene bis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], 2,6-di-tert-butyl-4-(4,6-bis(octylthio)-1,3,5-triazin-2-ylamino)phenol, and the like.

[0054] Among these, pentaerythritol tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], octadecyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, and tris(3,5-di-tert-butyl-4-hydroxybenzyl)isocyanurate are preferred. Examples of commercially available phenolic stabilizers include "Irganox 1010" and "Irganox 1076" manufactured by BASF, and "Adekastab AO-60," "Adekastab AO-50," and "Adekastab AO-20" manufactured by ADEKA. Among these, tris(3,5-di-tert-butyl-4-hydroxybenzyl)isocyanurate and pentaerythritol tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] are particularly preferred, and pentaerythritol tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] is preferred when used in combination with a malonic acid ester or oxalic acid anilide ultraviolet absorber (C), as this can further improve the retention heat stability and long-term heat stability.

[0055] The phenolic stabilizer (D) may be used alone or in combination of two or more kinds.

[0056] When a phenolic stabilizer (D) is contained, its content is preferably 0.001 part by mass or more, more preferably 0.01 part by mass or more, even more preferably 0.05 part by mass or more, and is preferably 1 part by mass or less, more preferably 0.8 part by mass or less, even more preferably 0.5 part by mass or less, particularly preferably 0.4 part by mass or less, 0.3 part by mass or less, and particularly preferably 0.2 part by mass or less, per 100 parts by mass of the polycarbonate resin (A). When it is contained in combination with a malonic acid ester-based or oxalic acid anilide-based ultraviolet absorber (C) in such a range, retention heat stability and long-term heat stability can be further improved, and therefore it is preferred.

[0057] [Phosphorus-based stabilizer (E)] The polycarbonate resin composition of the present invention also preferably contains a phosphorus-based stabilizer (E). By containing the phosphorus-based stabilizer (E), the residence heat stability and long-term heat stability of the polycarbonate resin composition of the present invention are further improved. Any known phosphorus stabilizer (E) can be used. Specific examples include phosphorus oxoacids such as phosphoric acid, phosphonic acid, phosphorous acid, phosphinic acid, and polyphosphoric acid; metal acid pyrophosphates such as sodium acid pyrophosphate, potassium acid pyrophosphate, and calcium acid pyrophosphate; phosphates of Group 1 or Group 2B metals such as potassium phosphate, sodium phosphate, cesium phosphate, and zinc phosphate; phosphate compounds, phosphite compounds, and phosphonite compounds, with compounds having a phosphite structure being particularly preferred. Selecting a phosphite compound can result in a polycarbonate resin composition with higher retention heat stability and long-term heat stability.

[0058] Here, the phosphite compound is a trivalent phosphorus compound represented by the general formula: P(OR)3, where R represents a monovalent or divalent organic group. Examples of such phosphite compounds include triphenyl phosphite, tris(mononylphenyl)phosphite, tris(mononyl / dinonylphenyl)phosphite, tris(2,4-di-tert-butylphenyl)phosphite, monooctyldiphenyl phosphite, dioctylmonophenyl phosphite, monodecyldiphenyl phosphite, didecylmonophenyl phosphite, tridecyl phosphite, trilauryl phosphite, tristearyl phosphite, distearyl pentaerythritol diphosphite, bis(2,4- di-tert-butyl-4-methylphenyl)pentaerythritol phosphite, bis(2,6-di-tert-butylphenyl)octyl phosphite, 2,2-methylenebis(4,6-di-tert-butylphenyl)octyl phosphite, tetrakis(2,4-di-tert-butylphenyl)-4,4'-biphenylene-diphosphite, 6-[3-(3-tert-butyl-hydroxy-5-methylphenyl)propoxy]-2,4,8,10-tetra-tert-butyldibenzo[d,f][1,3,2]-dioxaphosphepine, and the like.

[0059] Among these phosphite compounds, aromatic phosphite compounds represented by the following formula (3) or (4) are more preferred because they effectively enhance the heat discoloration resistance of the polycarbonate resin composition of the present invention.

[0060] [ka] [In formula (3), R 1 , R 2 and R 3 may be the same or different and represent an aryl group having 6 to 30 carbon atoms.

[0061] [ka] [In formula (4), R 4 and R 5may be the same or different and represent an aryl group having 6 to 30 carbon atoms.

[0062] Of the phosphite compounds represented by the above formula (3), triphenyl phosphite, tris(mononylphenyl) phosphite, tris(2,4-di-tert-butylphenyl) phosphite, etc. are preferred, and of these, tris(2,4-di-tert-butylphenyl) phosphite is more preferred. As the phosphite compound represented by the above formula (4), those having a pentaerythritol diphosphite structure, such as bis(2,4-di-tert-butyl-4-methylphenyl)pentaerythritol diphosphite, bis(2,6-di-tert-butyl-4-methylphenyl)pentaerythritol diphosphite, and bis(2,4-dicumylphenyl)pentaerythritol diphosphite, are particularly preferred.

[0063] The amount of the phosphorus-based stabilizer (E) added is preferably 0.001 to 0.5 parts by mass, more preferably 0.005 parts by mass or more, even more preferably 0.01 parts by mass or more, still more preferably 0.02 parts by mass or more, particularly preferably 0.03 parts by mass or more, and more preferably 0.4 parts by mass or less, even more preferably 0.3 parts by mass or less, and particularly preferably 0.2 parts by mass or less, relative to 100 parts by mass of the polycarbonate resin.

[0064] The polycarbonate resin composition of the present invention preferably contains both a phosphorus-based stabilizer (E) and a phenol-based stabilizer (D). In this case, the contents of the phosphorus-based stabilizer (E) and the phenol-based stabilizer (D) preferably satisfy the following formula (I): [Number of moles of the phenolic stabilizer (D) contained in the resin composition × number of phenolic groups in one molecule of the phenolic stabilizer (D)] / [Number of moles of the phosphorus-based stabilizer (E) contained in the resin composition × number of Ps in one molecule of the phosphorus-based stabilizer (E)]=2 to 7 ... (I) The molecular part of the formula (I) is calculated by dividing the content of the phenolic stabilizer (D) in the resin composition per 100 parts by mass of the polycarbonate resin (A) by the molecular weight of the phenolic stabilizer (D), multiplied by the number of phenolic groups per molecule of the phenolic stabilizer (D). For example, in Example 1, 0.10 parts by mass of pentaerythritol tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate (molecular weight: 1178, number of phenolic groups: 4) was contained, so the molecular weight is calculated as 0.10 ÷ 1178 × 4 = 0.00034. If the resin composition contains two or more phenolic stabilizers (D), the molecular weight is calculated for each phenolic stabilizer (D) based on the above formula, and the sum of these values ​​is used as the molecular weight. The denominator in the above formula (I) is the number of moles obtained by dividing the content of the phosphorus-based stabilizer (E) in the resin composition per 100 parts by mass of the polycarbonate resin (A) by the molecular weight of the phosphorus-based stabilizer (E), and multiplying this number by the number of Ps in one molecule of the phosphorus-based stabilizer (E). For example, in Example 1, 0.043 parts by mass of bis(2,4-dicumylphenyl)pentaerythritol diphosphite (molecular weight: 853, number of Ps: 2) was contained, so 0.043 ÷ 853 × 2 = 0.00010, and the value of the above formula (I) is 0.00034 ÷ 0.00010 = 3.4. In addition, when the resin composition contains two or more phosphorus-based stabilizers (E), the denominator is determined based on the above for each phosphorus-based stabilizer (E) by calculating [the number of moles of the phosphorus-based stabilizer (E) contained in the resin composition × the number of P in one molecule of the phosphorus-based stabilizer (E)], and the sum of these values ​​is used as the value of the denominator. A good balance between residence heat stability, long-term heat stability, moist heat resistance, and weather resistance is achieved by setting the value of the above formula (I) in the range of 2 to 7. The value of the formula (I) is more preferably 2.5 or more, even more preferably 3 or more, and more preferably 5.5 or less.

[0065] The total amount of the phosphorus-based stabilizer (E) and the phenol-based stabilizer (D) is preferably 0.006 to 1.5 parts by mass, more preferably 0.05 part by mass or more, even more preferably 0.08 part by mass or more, particularly preferably 0.10 part by mass or more, and more preferably 1.0 part by mass or less, even more preferably 0.7 part by mass or less, of which 0.5 part by mass or less, particularly preferably 0.3 part by mass or less, per 100 parts by mass of the polycarbonate resin (A).

[0066] [Release agent] The resin composition of the present invention also preferably contains a mold release agent. Examples of the release agent include aliphatic carboxylic acids, esters of aliphatic carboxylic acids and alcohols, aliphatic hydrocarbon compounds having a number average molecular weight of 200 to 15,000, and polysiloxane-based silicone oils.

[0067] Examples of aliphatic carboxylic acids include saturated or unsaturated aliphatic mono-, di-, or tri-carboxylic acids. Aliphatic carboxylic acids also include alicyclic carboxylic acids. Among these, preferred aliphatic carboxylic acids are mono- or di-carboxylic acids having 6 to 36 carbon atoms, with saturated aliphatic mono-carboxylic acids having 6 to 36 carbon atoms being more preferred. Specific examples of such aliphatic carboxylic acids include palmitic acid, stearic acid, caproic acid, capric acid, lauric acid, arachic acid, behenic acid, lignoceric acid, cerotic acid, melissic acid, tetralinic acid, montanic acid, adipic acid, and azelaic acid.

[0068] The aliphatic carboxylic acid in the ester of an aliphatic carboxylic acid and an alcohol can be, for example, the same as the aliphatic carboxylic acid described above. On the other hand, the alcohol can be, for example, a saturated or unsaturated monohydric or polyhydric alcohol. These alcohols may have a substituent such as a fluorine atom or an aryl group. Among these, a monohydric or polyhydric saturated alcohol having 30 or less carbon atoms is preferred, and an aliphatic saturated monohydric alcohol or an aliphatic saturated polyhydric alcohol having 30 or less carbon atoms is more preferred. Here, the term "aliphatic" is used to include alicyclic compounds.

[0069] Specific examples of such alcohols include octanol, decanol, dodecanol, stearyl alcohol, behenyl alcohol, ethylene glycol, diethylene glycol, glycerin, pentaerythritol, 2,2-dihydroxyperfluoropropanol, neopentylene glycol, ditrimethylolpropane, and dipentaerythritol.

[0070] The ester may contain an aliphatic carboxylic acid and / or an alcohol as an impurity. The ester may be a pure substance or a mixture of multiple compounds. The aliphatic carboxylic acid and the alcohol that combine to form an ester may each be used alone or in any combination and ratio of two or more.

[0071] Specific examples of esters of aliphatic carboxylic acids and alcohols include beeswax (a mixture containing myricyl palmitate as a main component), stearyl stearate, behenyl behenate, stearyl behenate, glycerin monopalmitate, glycerin monostearate, glycerin distearate, glycerin tristearate, pentaerythritol monopalmitate, pentaerythritol monostearate, pentaerythritol distearate, pentaerythritol tristearate, and pentaerythritol tetrastearate.

[0072] Examples of aliphatic hydrocarbons having a number average molecular weight of 200 to 15,000 include liquid paraffin, paraffin wax, microcrystalline wax, polyethylene wax, Fischer-Tropsch wax, and α-olefin oligomers having 3 to 12 carbon atoms. Aliphatic hydrocarbons also include alicyclic hydrocarbons. These hydrocarbons may also be partially oxidized. Among these, paraffin wax, polyethylene wax, or a partial oxide of polyethylene wax is preferred, and paraffin wax and polyethylene wax are more preferred. The number average molecular weight of the aliphatic hydrocarbon is preferably 5,000 or less. The aliphatic hydrocarbon may be a single substance, but a mixture of substances with various constituent components and molecular weights can also be used as long as the main component is within the above range.

[0073] Examples of polysiloxane-based silicone oils include dimethyl silicone oil, methylphenyl silicone oil, diphenyl silicone oil, and fluorinated alkyl silicone.

[0074] The above-mentioned release agents may be contained either alone or in any combination and ratio of two or more.

[0075] The content of the release agent is usually 0.001 part by mass or more, preferably 0.01 part by mass or more, and usually 2 parts by mass or less, preferably 1 part by mass or less, more preferably 0.8 parts by mass or less, especially preferably 0.7 parts by mass or less, and particularly preferably 0.6 parts by mass or less, relative to 100 parts by mass of the polycarbonate resin (A). If the content of the release agent is less than the lower limit of the above range, the release effect may be insufficient, whereas if the content of the release agent is more than the upper limit of the above range, the hydrolysis resistance may decrease and mold contamination during injection molding may occur.

[0076] [Additives, etc.] The polycarbonate resin composition of the present invention may contain additives other than those described above, such as fluorescent whitening agents, pigments, dyes, flame retardants, impact modifiers, plasticizers, compatibilizers, etc. These additives may be contained alone or in combination of two or more. Furthermore, resins other than the polycarbonate resin (A) and the (meth)acrylic copolymer (B) may be contained. Examples of other resins include thermoplastic polyester resins such as polyethylene terephthalate, polytrimethylene terephthalate, and polybutylene terephthalate; styrene-based resins such as polystyrene resin, high-impact polystyrene resin (HIPS), and acrylonitrile-styrene copolymer (AS resin); polyolefin resins such as polyethylene resin and polypropylene resin; polyamide resin; polyimide resin; polyetherimide resin; polyurethane resin; polyphenylene ether resin; polyphenylene sulfide resin; polysulfone resin; and polymethacrylate resin. ABS resin and polybutylene terephthalate resin are particularly preferred as other resins. The other resins may be contained either alone or in any combination and ratio of two or more. However, when other resins are contained, the content thereof is preferably 20 parts by mass or less, more preferably 10 parts by mass or less, even more preferably 5 parts by mass or less, and particularly preferably 3 parts by mass or less, per 100 parts by mass of the polycarbonate resin (A).

[0077] [Method of producing resin composition] To produce the polycarbonate resin composition of the present invention, the polycarbonate resin (A), the (meth)acrylic copolymer (B), the malonic acid ester-based or oxalic acid anilide-based UV absorber (C), and other components added as needed may be premixed using a mixer such as a tumbler or a Henschel mixer, and then melt-kneaded using a mixer such as a Banbury mixer, a roll, a Brabender, a single-screw kneading extruder, a twin-screw kneading extruder, a kneader, etc. The melt-kneading temperature is not particularly limited, but is usually in the range of 240 to 320°C.

[0078] [Molded products] The polycarbonate resin composition (e.g., pellets) obtained above can be molded into a molded article by various molding methods. The shape of the molded article is not particularly limited and can be appropriately selected depending on the use and purpose of the molded article, and examples thereof include film-like, rod-like, cylindrical, ring-like, circular, elliptical, polygonal, irregular-shaped, hollow, frame-like, box-like, panel-like, and button-like shapes.

[0079] The method for forming the molded article is not particularly limited, and conventionally known molding methods can be used, such as injection molding, injection compression molding, extrusion molding, profile extrusion, transfer molding, blow molding, gas-assisted blow molding, blow molding, extrusion blow molding, IMC (in-mold coating) molding, rotational molding, multilayer molding, two-color molding, insert molding, sandwich molding, foam molding, and pressure molding. The resin composition of this embodiment is particularly suitable for molded articles obtained by injection molding, injection compression molding, and extrusion molding. However, it goes without saying that the resin composition of this embodiment is not limited to molded articles obtained by these methods.

[0080] The molded article of this embodiment is suitable for use in parts for electrical and electronic devices, office automation equipment, personal digital assistants, machine parts, home appliances, vehicle parts, various containers, lighting equipment, displays, and the like. In particular, it is preferably used for applications such as display panels, which require high heat resistance, high hardness and high transparency. [Example]

[0081] The present invention will be explained in more detail below by showing examples, but the present invention should not be construed as being limited to the following examples. The ingredients used are as shown in Table 1 below.

[0082] [Table 1]

[0083] (Examples 1 to 9, Comparative Examples 1 to 7) The above-mentioned components were blended in the proportions (parts by mass) shown in Tables 2 to 4 below and mixed in a tumbler for 20 minutes, and then the mixture was fed to an extruder (TEM26SX) manufactured by Shibaura Machine Co., Ltd., and kneaded under conditions of a screw rotation speed of 200 rpm, a discharge rate of 20 kg / hour, and a barrel temperature of 240°C, and extruded into a strand shape. This was cooled with water and pelletized using a pelletizer.

[0084] The obtained pellets were dried at 120°C for 5 hours and then injection molded using an injection molding machine (Japan Steel Works, Ltd., "J55AD-6H"; screw diameter 25 mm, stroke 100 mm) using a steel mold under conditions of a cylinder temperature of 260°C, a mold temperature of 80°C, an injection speed of 50 mm / sec, and a cycle time of 30 seconds, to obtain three-stage plate test pieces having thicknesses of 1.0 mm, 2.0 mm, and 3.0 mm, respectively.

[0085] <Hue (YI) measurement> The YI in the thickness direction ("initial YI after 260°C molding") was measured for a 3.0 mm thick portion of the three-stage plate test piece (260°C molded product) obtained above. Measurements were made in accordance with JIS K7105 using a color difference meter "SE-6000" manufactured by Nippon Denshoku Industries Co., Ltd., with the light source set to C and the field of view set to 2°. The YI measurements below were also made in the same manner.

[0086] <Evaluation of retention heat stability> A three-stage plate was obtained in the same manner as above, except that the cylinder temperature was 280°C and the cycle time was 3 minutes, and the YI ("280°C residence YI") at the 3.0 mm thick section was measured.

[0087] <Evaluation of long-term thermal stability> The above-mentioned 260°C molded product was subjected to a heat aging treatment in a 95°C dryer for 1000 hours, and the YI ("YI after 1000 hours at 95°C") of a 3.0 mm thick section was measured.

[0088] The evaluation results are shown in Tables 2 to 4 below.

[0089] [Table 2] *The amount of C3 listed in Table 2 is the amount of the compound with the structural formula listed in Table 1.

[0090] [Table 3]

[0091] [Table 4] [Industrial Applicability]

[0092] The polycarbonate resin composition of the present invention is excellent in surface hardness and transparency, and also in residence heat stability and long-term heat stability, and therefore can be suitably used for various molded articles.

Claims

1. A polycarbonate resin composition characterized by containing, relative to 100 parts by mass of a polycarbonate resin (A), 5 to 100 parts by mass of a (meth)acrylic copolymer (B) represented by the following general formula (1) which contains 5 to 85% by mass of (meth)acrylate units and 15 to 95% by mass of methyl (meth)acrylate units, and 0.001 to 1 part by mass of a malonic acid ester-based or oxalic acid anilide-based ultraviolet absorber (C): 【Chemical 1】 [(In formula (1), R １ represents a hydrogen atom or a methyl group, m1 represents an integer of 0 to 10, and Ar represents a substituted or unsubstituted aryl group.

2. 2. The polycarbonate resin composition according to claim 1, further comprising a phenolic stabilizer (D) in an amount of 0.001 to 1 part by mass per 100 parts by mass of the polycarbonate resin (A).

3. 3. The polycarbonate resin composition according to claim 1, further comprising a phosphorus-based stabilizer (E) in an amount of 0.001 to 0.5 parts by mass per 100 parts by mass of the polycarbonate resin (A).

4. The polycarbonate resin composition according to claim 3, wherein the value of [number of moles of the phenolic stabilizer (D) contained in the resin composition × number of phenol groups in one molecule of the phenolic stabilizer (D)] / [number of moles of the phosphorus-based stabilizer (E) contained in the resin composition × number of P groups in one molecule of the phosphorus-based stabilizer (E)] is in the range of 2 to 7.

5. 3. The polycarbonate resin composition according to claim 1, wherein the ultraviolet absorber (C) is a malonic acid ester-based ultraviolet absorber.

6. 3. The polycarbonate resin composition according to claim 1, wherein the polycarbonate resin (A) contains a recycled polycarbonate resin.

7. Pellets of the polycarbonate resin composition according to any one of claims 1 to 6.

8. A molded article made from the polycarbonate resin composition according to any one of claims 1 to 6.

9. A molded article comprising pellets of the polycarbonate resin composition according to claim 7.

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