JP7547752B2 - Polycarbonate resin composition and molded article thereof - Google Patents

Description

The present invention relates to a polycarbonate resin composition. More specifically, the present invention relates to a polycarbonate resin composition that is excellent in rigidity, flame retardancy, fluidity, dimensional accuracy, impact resistance, and chemical resistance, and is particularly suitable for use as a chassis and frame material for office automation equipment and optical housings, and to a molded article obtained by molding this polycarbonate resin composition.

Polycarbonate resins are excellent in heat resistance, mechanical properties and electrical characteristics, and are widely used, for example, in automobile materials, electrical and electronic equipment materials, housing materials, and materials for manufacturing parts in other industrial fields.
In particular, flame-retardant polycarbonate resin compositions are suitably used as components for information and mobile devices such as computers, notebook personal computers, tablet terminals, smartphones, and mobile phones, and office equipment such as printers and copiers.
Polycarbonate resin compositions containing reinforcing materials such as glass fiber, carbon fiber, glass flake, talc, and mica to increase rigidity are also widely used.

Resin materials used in the chassis and frames of office equipment such as laser beam printers, copiers, and projectors are required to be both flame retardant and rigid. In addition, they are also required to have fluidity, dimensional accuracy (low anisotropy), strength (impact resistance), and chemical resistance, and many proposals have already been made.

Patent Document 1 discloses a thermoplastic resin composition containing a thermoplastic resin, an organic phosphorus compound, a plate-like filler (mica, talc), and a fibrous filler. However, although the resin composition shown there has high rigidity due to the high filler content, there is no data on impact resistance, and it is considered to be insufficient. In addition, because it contains a large amount of fibrous filler, it is considered to have high anisotropy and insufficient dimensional precision.

Patent Document 2 discloses a thermoplastic resin composition containing an aromatic polycarbonate, at least one thermoplastic polymer selected from a styrene-based rigid polymer and a polyphenylene ether, a flame retardant consisting of an organic phosphorus compound, talc, and at least one filler selected from mica and wollastonite. However, although the resin composition disclosed therein has excellent rigidity, flame retardancy and dimensional accuracy, it cannot be said that its impact resistance is sufficient. Furthermore, no consideration has been given to chemical resistance.

Patent Document 3 discloses a thermoplastic resin composition containing an aromatic polycarbonate, at least one thermoplastic polymer selected from a styrene-based rigid polymer and a polyphenylene ether, a flame retardant consisting of an organic phosphorus compound, mica, and at least one filler selected from talc and wollastonite. However, although the resin composition shown therein is excellent in rigidity, flame retardancy and dimensional accuracy, there is no data on impact resistance, and it is considered to be insufficient. Furthermore, no consideration has been given to chemical resistance.

Patent Document 4 discloses an aromatic polycarbonate resin composition that is composed of aromatic polycarbonate, acrylonitrile-styrene copolymer, inorganic filler, organic phosphorus compound-based flame retardant, and fluorine-containing drip prevention agent, and uses mica and at least one selected from talc and wollastonite as the inorganic filler. However, although the resin composition shown therein is excellent in rigidity, flame retardancy, and dimensional accuracy, its impact resistance is insufficient. In addition, although data is available on chemical resistance, the results are similar in all examples and comparative examples of the polycarbonate resin composition, and are not sufficient for comparing chemical resistance.

Patent Document 5 discloses a polycarbonate resin composition consisting of polycarbonate, a phosphate ester compound, white mica, glass flakes, and a fibrous filler. However, although the resin composition disclosed therein has excellent rigidity, flame retardancy, and dimensional accuracy, it cannot be said that its impact resistance is sufficient.

JP 2003-41131 A JP 2004-323565 A JP 2004-315645 A JP 2004-2737 A JP 2005-146219 A

The present invention was devised in consideration of the above problems, and aims to provide a polycarbonate resin composition that is excellent in rigidity, flame retardancy, fluidity, dimensional accuracy, impact resistance, and chemical resistance, and is particularly suitable for use as chassis and frame materials for office automation equipment and optical housings, and a molded article made from this polycarbonate resin composition.

As a result of extensive research aimed at solving the above problems, the inventors have discovered that a polycarbonate resin composition made by blending a specific molecular weight polycarbonate resin with a flow modifier, a condensed phosphate ester-based flame retardant, an inorganic filler mainly made of talc, and a fluoropolymer in specific ratios has excellent rigidity, flame retardancy, flowability, dimensional accuracy, impact resistance, and chemical resistance.

The present invention was achieved based on these findings and is summarized as follows:

[1] A polycarbonate resin composition containing 100 parts by mass of polycarbonate resin (A) having a viscosity average molecular weight of 18,500 or more, 5 to 30 parts by mass of a flowability modifier (B), 3 to 20 parts by mass of a phosphorus-based flame retardant (C), 0.05 to 2 parts by mass of a fluoropolymer (D), and 20 to 45 parts by mass of an inorganic filler including talc (E), in which the proportion of fillers (F) other than talc (E) in the inorganic filler is 20 mass% or less.

[2] The polycarbonate resin composition according to [1], in which the flowability modifier (B) is at least one selected from an acrylonitrile-styrene copolymer, an acrylonitrile-butadiene-styrene copolymer, a polycarbonate oligomer, and a polycaprolactone.

[3] The polycarbonate resin composition according to [1] or [2], in which the average particle size of the talc (E) is 8.5 μm or less.

[4] A polycarbonate resin composition according to any one of [1] to [3], in which the ratio of the phosphorus-based flame retardant (C) to the flowability modifier (B) is 20 mass% or more.

[5] The polycarbonate resin composition according to any one of [1] to [4], wherein the phosphorus-based flame retardant (C) is a condensed phosphate ester-based flame retardant (C-1) and/or a phosphazene compound (C-2).

[6] The polycarbonate resin composition according to any one of [1] to [5], further comprising 0.05 to 1 part by mass of a phosphorus compound (G) other than the phosphorus-based flame retardant (C) per 100 parts by mass of the polycarbonate resin (A).

[7] The polycarbonate resin composition according to [6], wherein the phosphorus compound (G) is at least one selected from a phosphite ester, a phosphate ester, and a metal salt of a phosphate ester.

[8] The polycarbonate resin composition according to [7], in which the phosphite ester is represented by the following formula (1), the phosphate ester is represented by the following formula (2), and the phosphate metal salt is represented by the following formula (5) or formula (6).

(In formula (1), R ¹ is an alkyl group or an aryl group, and the two R ^1s may be the same or different.)

(In formula (2), ^R2 is an alkyl group or an aryl group, and (3-n) ^R2s may be the same or different. n is an integer of 0 to 2.)

(In formulas (5) and (6), ^R3 is an alkyl group or an aryl group, and M is a metal.)

[9] The polycarbonate resin composition according to [8], wherein R ¹ in the formula (1) is an alkyl group having 1 to 30 carbon atoms or an aryl group having 6 to 30 carbon atoms, R ² in the formula (2) is an alkyl group having 1 to 30 carbon atoms or an aryl group having 6 to 30 carbon atoms, and R ³ in the formulas (5) and (6) is an alkyl group having 1 to 30 carbon atoms or an aryl group having 6 to 30 carbon atoms.

[10] The polycarbonate resin composition according to [9], wherein R ¹ in the formula (1) is a stearyl group, a nonyl group, or a phenyl group having a substituent; the alkyl group of R ² in the formula (2) has 13, 18, or 24 carbon atoms; and the alkyl group of R ³ in the formulas (5) and (6) has 13, 18, or 24 carbon atoms.

[11] The polycarbonate resin composition according to [10], wherein the phosphite is distearyl pentaerythritol diphosphite, the phosphate is represented by the following formula (2A) and is a mixture of distearyl acid phosphate in which n = 1 and monostearyl acid phosphate in which n = 2 in formula (2A), and the phosphate metal salt is a mixture of a zinc salt of distearyl acid phosphate represented by the following formula (5A) and a zinc salt of monostearyl acid phosphate represented by the following formula (6A).
O=P(OH) _n (OC ₁₈ H ₃₇ ) _3-n ...(2A)

[12] A polycarbonate resin composition according to any one of [6] to [11], in which the ratio of the phosphorus compound (G) to the talc (E) is 0.2 to 2.0 mass%.

[13] The polycarbonate resin composition according to any one of [1] to [12], which has a retention of tensile breaking strength of 70% or more as measured by the following method (I):
Method (I): The polycarbonate resin composition was injection molded using an injection molding machine with a clamping force of 75 tons under conditions of a cylinder temperature of 280°C, a mold temperature of 60°C, and a molding cycle of 48 seconds to obtain an ISO multipurpose test piece with a thickness of 3 mm. The test piece was fixed to a jig and bent so that the distortion was 1%, and the rust inhibitor "Barrier Guard (registered trademark) Part II" was applied to the bent part. The test piece was then placed in a hot air oven set at 55°C and held for 72 hours. The test piece was then removed from the jig and the tensile breaking strength was measured in accordance with ISO 527. The tensile breaking strength was measured by dividing the measured value by the tensile breaking strength of an uncoated test piece to obtain the tensile breaking strength retention rate.

[14] A polycarbonate resin composition according to any one of [1] to [13], which has a flame retardancy of 5VB at a thickness of 2 mm in a UL94 test.

[15] The polycarbonate resin composition according to any one of [1] to [14], having an unnotched Charpy impact strength at a thickness of 4 mm according to ISO 179 of 35 kJ/ ^m2 or more.

[16] A polycarbonate resin composition according to any one of [1] to [15], having a flexural modulus of 5,000 MPa or more according to ISO 178.

[17] A molded article obtained by molding a polycarbonate resin composition according to any one of [1] to [16].

[18] The molded product according to [17], which is a chassis or an optical housing.

The polycarbonate resin composition of the present invention has excellent rigidity, flame retardancy, fluidity, dimensional accuracy, impact resistance, and chemical resistance, and can be used for a variety of applications, particularly as chassis and frame materials for office automation equipment.

The present invention will be described in detail below with reference to the embodiments and examples, but the present invention is not limited to the embodiments and examples shown below, and can be modified as desired without departing from the spirit of the present invention.

[Polycarbonate resin composition]
The polycarbonate resin composition of the present invention contains at least a polycarbonate resin (A), a flowability modifier (B), a phosphorus-based flame retardant (C), a fluoropolymer (D), and an inorganic filler mainly composed of talc (E) in specific ratios. The polycarbonate resin composition of the present invention may further contain other components as necessary.

<Mechanism>
The polycarbonate resin composition of the present invention can obtain excellent flame retardancy by containing the phosphorus-based flame retardant (C) and the fluoropolymer (D) in a predetermined ratio, and furthermore, the composition has excellent flowability and moldability. In the polycarbonate resin composition containing such a phosphorus-based flame retardant (C) and a fluoropolymer (D), the composition contains an inorganic filler mainly composed of talc (E) in a predetermined ratio, and thus the composition has excellent flame retardancy in addition to rigidity, dimensional accuracy, and impact resistance. In addition, the composition contains a flowability modifier (B) in a predetermined ratio, and thus the composition has excellent flowability and moldability without impairing flame retardancy. In addition, the composition has excellent chemical resistance by using a polycarbonate resin (A) having a viscosity average molecular weight of a predetermined value or more, and appropriately selecting the flowability modifier (B), the phosphorus-based flame retardant (C), and the inorganic filler.

<Polycarbonate resin (A)>
The polycarbonate resin (A) contained in the polycarbonate resin composition of the present invention may be any conventionally known polycarbonate resin. Examples of the polycarbonate resin (A) include aromatic polycarbonate resins, aliphatic polycarbonate resins, and aromatic-aliphatic polycarbonate resins, with aromatic polycarbonate resins being preferred.

Aromatic polycarbonate resin is a linear or branched aromatic polycarbonate polymer obtained by reacting an aromatic hydroxy compound with phosgene or a diester of carbonic acid. The method for producing the aromatic polycarbonate resin is not particularly limited, and it can be produced by a conventional method such as the phosgene method (interfacial polymerization method) or the melting method (ester exchange method). It may also be a polycarbonate resin produced by the melting method with the amount of OH groups in the terminal groups adjusted.

Representative examples of aromatic dihydroxy compounds, which are one of the raw materials for the aromatic polycarbonate resin used in the present invention, include bis(4-hydroxyphenyl)methane, 2,2-bis(4-hydroxyphenyl)propane, 2,2-bis(4-hydroxy-3-methylphenyl)propane, 2,2-bis(4-hydroxy-3-t-butylphenyl)propane, 2,2-bis(4-hydroxy-3,5-dimethylphenyl)propane, 2,2-bis(4-hydroxy-3,5-dibromophenyl)propane, 4,4-bis(4-hydroxyphenyl)heptane, 1,1-bis(4-hydroxyphenyl)cyclohexane, 4,4'-dihydroxybiphenyl, 3,3',5,5'-tetramethyl-4,4'-dihydroxybiphenyl, bis(4-hydroxyphenyl)sulfone, bis(4-hydroxyphenyl)sulfide, bis(4-hydroxyphenyl)ether, and bis(4-hydroxyphenyl)ketone.
Furthermore, a small amount of a polyhydric phenol having three or more hydroxy groups in the molecule, such as 1,1,1-tris(4-hydroxyphenyl)ethane or 1,3,5-tris(4-hydroxyphenyl)benzene, can be used in combination as a branching agent.
Among these aromatic dihydroxy compounds, 2,2-bis(4-hydroxyphenyl)propane (bisphenol A) is preferred. These aromatic dihydroxy compounds can be used alone or in combination of two or more.

To obtain a branched aromatic polycarbonate resin, polyhydroxy compounds such as phloroglucine, 4,6-dimethyl-2,4,6-tris(4-hydroxyphenyl)heptene-2, 4,6-dimethyl-2,4,6-tris(4-hydroxyphenyl)heptane, 2,6-dimethyl-2,4,6-tris(4-hydroxyphenyl)heptene-3, 1,3,5-tris(4-hydroxyphenyl)benzene, and 1,1,1-tris(4-hydroxyphenyl)ethane, or 3,3-bis(4-hydroxyaryl)oxindole (=isatin bisphenol), 5-chloruisatin, 5,7-dichloruisatin, and 5-bromoisatin may be used as part of the aromatic dihydroxy compounds, and the amount used is 0.01 to 10 mol %, preferably 0.1 to 2 mol %, based on the hydroxy compound.

In the polymerization by the transesterification method, a carbonic acid diester is used as a monomer instead of phosgene. Representative examples of the carbonic acid diester include diphenyl carbonate, substituted diaryl carbonates such as ditolyl carbonate, and dialkyl carbonates such as dimethyl carbonate, diethyl carbonate, and di-tert-butyl carbonate. These carbonic acid diesters can be used alone or in combination of two or more. Among these, diphenyl carbonate and substituted diphenyl carbonates are preferred.

The above carbonic acid diester may be substituted with a dicarboxylic acid or a dicarboxylic acid ester, preferably in an amount of 50 mol % or less, more preferably 30 mol % or less. Representative dicarboxylic acids or dicarboxylic acid esters include terephthalic acid, isophthalic acid, diphenyl terephthalate, diphenyl isophthalate, etc. When substituted with such a dicarboxylic acid or dicarboxylic acid ester, a polyester carbonate is obtained.

When producing aromatic polycarbonate resins by the transesterification method, a catalyst is usually used. There are no limitations on the type of catalyst, but generally basic compounds such as alkali metal compounds, alkaline earth metal compounds, basic boron compounds, basic phosphorus compounds, basic ammonium compounds, and amine compounds are used, with alkali metal compounds and/or alkaline earth metal compounds being particularly preferred. These may be used alone or in combination of two or more types. In the transesterification method, the polymerization catalyst is generally deactivated with p-toluenesulfonic acid ester or the like.

Preferred examples of the polycarbonate resin (A) include aromatic polycarbonate resins derived from 2,2-bis(4-hydroxyphenyl)propane, or aromatic polycarbonate copolymers derived from 2,2-bis(4-hydroxyphenyl)propane and other aromatic dihydroxy compounds. In addition, for the purpose of imparting flame retardancy, etc., a polymer or oligomer having a siloxane structure can be copolymerized. The polycarbonate resin (A) may be a mixture of two or more polymers and/or copolymers made from different raw materials, and may have a branched structure of up to 0.5 mol%.

The terminal hydroxyl group content of polycarbonate resin (A) such as aromatic polycarbonate resin has a significant effect on thermal stability, hydrolysis stability, color tone, etc. In order to provide practical physical properties, the terminal hydroxyl group content of polycarbonate resin (A) is usually 30 to 2000 ppm, preferably 100 to 1500 ppm, and more preferably 200 to 1000 ppm, and p-tert-butylphenol, phenol, cumylphenol, p-long-chain alkyl-substituted phenol, etc. can be used as a blocking agent to adjust the terminal hydroxyl group content.

The amount of residual monomers in polycarbonate resin (A), such as aromatic polycarbonate resin, is 150 ppm or less of aromatic dihydroxy compounds, preferably 100 ppm or less, and more preferably 50 ppm or less. When synthesized by the ester exchange method, the amount of residual carbonate diester is 300 ppm or less, preferably 200 ppm or less, and more preferably 150 ppm or less.

The molecular weight of the polycarbonate resin (A) used in the present invention is 18,500 or more in terms of viscosity average molecular weight calculated from the solution viscosity measured at 20°C using methylene chloride as a solvent. If the viscosity average molecular weight of the polycarbonate resin (A) is less than 18,500, the chemical resistance may be insufficient, and mechanical properties such as impact resistance may be insufficient. However, if the viscosity average molecular weight is too large, the flowability and moldability of the polycarbonate resin composition may be impaired, so the viscosity average molecular weight of the polycarbonate resin (A) used in the present invention is preferably 18,500 to 25,000, particularly 20,000 to 25,000, and particularly 20,500 to 22,500.
As the polycarbonate resin (A), a mixture of two or more polycarbonate resins having different viscosity average molecular weights may be used, or a polycarbonate resin having a viscosity average molecular weight outside the above preferred range may be mixed to bring the viscosity average molecular weight within the above molecular weight range.

Furthermore, the polycarbonate resin (A) used in the present invention may be not only a polycarbonate resin as a virgin raw material, but also a polycarbonate resin regenerated from used products, that is, a polycarbonate resin that has been so-called material recycled. Preferred examples of used products include optical recording media such as optical disks, light guide plates, automobile window glass, automobile headlamp lenses, transparent vehicle components such as windshields, containers such as water bottles, eyeglass lenses, soundproof walls, glass windows, and building components such as corrugated sheets. There are also no particular limitations on the form of the recycled polycarbonate resin, and any of the following can be used: non-conforming products, crushed products such as sprues or runners, and pellets obtained by melting them.

<Flowability improver (B)>
The polycarbonate resin composition of the present invention contains a flowability modifier (B) in order to improve the flowability, moldability, and surface appearance of the molded article obtained. The flowability modifier (B) is a component that improves the flowability of the polycarbonate resin (A), and various low molecular weight compounds or polymeric compounds can be used. Particularly preferred as the flowability modifier (B) used in the present invention are one or a combination of two or more selected from vinyl cyanide-aromatic vinyl copolymers, vinyl cyanide-diene-aromatic vinyl copolymers, polycarbonate oligomers, and polycaprolactones, among which vinyl cyanide-aromatic vinyl copolymers, vinyl cyanide-diene-aromatic vinyl copolymers, and polycarbonate oligomers are preferred, and it is particularly preferred to use vinyl cyanide-aromatic vinyl copolymers.

The vinyl cyanide-aromatic vinyl copolymer is a thermoplastic copolymer obtained by copolymerizing a vinyl cyanide compound and an aromatic vinyl compound. Examples of the vinyl cyanide compound include vinyl cyanide compounds such as acrylonitrile and methacrylonitrile, with acrylonitrile being particularly preferred. Examples of the aromatic vinyl compound include styrene and styrene derivatives such as styrene, α-methylstyrene, p-methylstyrene, vinylxylene, dimethylstyrene, p-t-butylstyrene, bromostyrene, and dibromostyrene, with styrene being preferred. These may be used alone or in combination of two or more.

In the vinyl cyanide-aromatic vinyl copolymer, the preferred proportions of the structural units derived from the vinyl cyanide compound and the aromatic vinyl compound, when the total is taken as 100% by mass, are 10 to 40% by mass, more preferably 15 to 30% by mass, and 90 to 60% by mass, more preferably 85 to 70% by mass, of the structural units derived from the vinyl cyanide compound and 90 to 60% by mass, more preferably 85 to 70% by mass, of the structural units derived from the aromatic vinyl compound. Furthermore, during copolymerization, these vinyl compounds can be mixed with other copolymerizable vinyl compounds, and the mixing ratio of these is preferably such that the structural units derived from the other vinyl compounds in the vinyl cyanide-aromatic vinyl copolymer are 15% by mass or less.

Vinyl cyanide-aromatic vinyl copolymers are produced by emulsion polymerization, solution polymerization, bulk polymerization, suspension polymerization, or bulk/suspension polymerization, but any method may be used. In addition, known initiators, chain transfer agents, etc., may be used in the copolymerization reaction as necessary.

As the vinyl cyanide-aromatic vinyl copolymer, an acrylonitrile-styrene copolymer is particularly preferred. The melt volume rate (MVR) reflecting the molecular weight of the acrylonitrile-styrene copolymer is preferably 20 to 200 cm ³ /10 min at 220° C. and a load of 10 kg, and more preferably 70 to 150 cm ³ /10 min. As the acrylonitrile-styrene copolymer, those commercially available as AS resin or SAN resin can be widely used.

Vinyl cyanide-diene-aromatic vinyl copolymer is a thermoplastic copolymer obtained by copolymerizing a vinyl cyanide compound, a diene, and an aromatic vinyl compound. Examples of dienes include butadiene and isoprene, and preferably prepolymerized diene rubbers, such as polybutadiene rubber, acrylonitrile-butadiene copolymer rubber, styrene-butadiene copolymer rubber, and polyisoprene rubber, with polybutadiene rubber being particularly preferred. These may be used alone or in a mixture of two or more.

Examples of vinyl cyanide compounds include vinyl cyanide compounds such as acrylonitrile and methacrylonitrile, with acrylonitrile being particularly preferred. Examples of aromatic vinyl compounds include styrene and styrene derivatives such as styrene, α-methylstyrene, p-methylstyrene, vinylxylene, dimethylstyrene, p-t-butylstyrene, bromostyrene, and dibromostyrene, with styrene being preferred among these. These compounds may be used alone or in combination of two or more.

As a preferred copolymerization composition ratio of the vinyl cyanide-diene-aromatic vinyl copolymer, when the entire copolymer is taken as 100% by mass, the structural units derived from the diene rubber are preferably 10 to 50% by mass, more preferably 10 to 40% by mass, from the viewpoint of improving moldability. In addition, the structural units derived from the vinyl cyanide compound are 5 to 30% by mass, more preferably 10 to 25% by mass, and the structural units derived from the aromatic vinyl compound are 20 to 80% by mass, more preferably 40 to 70% by mass. Furthermore, during copolymerization, other copolymerizable vinyl compounds can be mixed and used, and the mixing ratio of these is preferably such that the structural units derived from the other vinyl compounds in the vinyl cyanide-diene-aromatic vinyl copolymer are 15% by mass or less.

The vinyl cyanide-diene-aromatic vinyl copolymer is produced by a method such as emulsion polymerization, solution polymerization, bulk polymerization, suspension polymerization, or bulk/suspension polymerization, but any method may be used. In addition, known initiators, chain transfer agents, etc., may be used in the copolymerization reaction as necessary.

As the vinyl cyanide-diene-aromatic vinyl copolymer, an acrylonitrile-butadiene-styrene copolymer is particularly preferred. Acrylonitrile-butadiene-styrene copolymers that are commercially available as ABS resins can be widely used.

The polycarbonate oligomer is preferably obtained by a reaction between an aromatic dihydric phenol compound, typically exemplified by 2,2-bis(4-hydroxyphenyl)propane, 2,2-bis(4-hydroxy-3,5-dimethylphenyl)propane, or 2,2-bis(4-hydroxy-3,5-dibromophenyl)propane, and a carbonate precursor, typically phosgene, or by a transesterification reaction between an aromatic dihydric phenol and diphenyl carbonate, etc., and the aromatic dihydric phenol compound may be used alone or in combination.

The polycarbonate oligomer preferably has an average degree of polymerization of 2 to 15. If the average degree of polymerization of the polycarbonate oligomer is less than 2, it becomes difficult to prevent the polycarbonate oligomer from bleeding out from the molded article during molding, and if the average degree of polymerization exceeds 15, there is a risk that the appearance of the resulting molded article will deteriorate. In the interfacial polymerization method using phosgene, the degree of polymerization of the polycarbonate oligomer can be adjusted by adding phenol and/or alkyl-substituted phenol to the polymerization system to block the ends.

Polycaprolactone is a polymer of caprolactone, particularly ε-caprolactone, that is, one having a repeating unit of [-CH ₂ -CH ₂ -CH ₂ -CH ₂ -CH ₂ -CO-O-], and is a polymer or copolymer containing at least 70% by mass, preferably 75% by mass or more, and more preferably 80% by mass or more of such a constitutional unit in the polymer. When polycaprolactone is a copolymer of ε-caprolactone and another monomer, examples of the monomer copolymerized with ε-caprolactone include lactone monomers such as β-propiolactone, pivalolactone, and butyrolactone, alkylene oxides such as ethylene oxide, 1,2-propionoxide, 1,3-propylene oxide, and tetrahydrofuran, unsaturated monomers such as styrene, methyl methacrylate, and butadiene, and coupling agents such as dimethyl terephthalate and diphenyl carbonate. These may be used alone or in combination of two or more. A portion of the hydrogen atoms in the methylene chain of the polycaprolactone may be substituted with halogen atoms or hydrocarbon groups, and the terminals of the polycaprolactone may be treated by esterification, etherification, or the like.

The number average molecular weight of polycaprolactone is preferably 4,000 to 50,000, more preferably 5,000 to 40,000, and even more preferably 8,000 to 30,000, in terms of polystyrene equivalent determined by gel permeation chromatography (GPC).
The method for producing polycaprolactone is not particularly limited, but may be a method of ring-opening polymerization of ε-caprolactone using a suitable initiator such as alcohol, glycol, water, etc., and a catalyst such as titanium tetrabutoxide, tin chloride, etc.

The content of the flowability modifier (B) in the polycarbonate resin composition of the present invention is 5 to 30 parts by mass, preferably 7 to 20 parts by mass, and more preferably 10 to 15 parts by mass, per 100 parts by mass of the polycarbonate resin (A). If the content of the flowability modifier (B) is less than the above lower limit, the effect of improving moldability and the effect of improving surface appearance due to the improvement in flowability achieved by blending the flowability modifier (B) cannot be fully obtained, and if the content is more than the above upper limit, the flame retardancy, heat resistance, and impact resistance tend to decrease, and poor appearance is likely to occur.

<Phosphorus-based flame retardant (C)>
The phosphorus-based flame retardant (C) used in the present invention is not particularly limited as long as it is a flame retardancy-imparting component containing phosphorus in the molecule, but preferred phosphorus-based flame retardants (C) include condensed phosphate ester flame retardants (C-1) and phosphazene compounds (C-2).

The phosphorus-based flame retardant (C) may be used alone or in combination of two or more.

(Condensed phosphate ester flame retardant (C-1))
The condensed phosphate ester flame retardant (C-1) may be a condensed phosphate ester compound represented by the following formula (3):

The condensed phosphate ester compound represented by the above formula (3) may be a mixture of compounds having different k numbers, and in the case of a mixture of condensed phosphate esters having different k numbers, k is the average value of the mixture. k is usually an integer from 0 to 5, and in the case of a mixture of compounds having different k numbers, the average k number is preferably in the range of 0.5 to 2, more preferably 0.6 to 1.5, even more preferably 0.8 to 1.2, and particularly preferably 0.95 to 1.15.

X ¹ represents a divalent arylene group, for example, a divalent group derived from a dihydroxy compound such as resorcinol, hydroquinone, bisphenol A, 2,2'-dihydroxybiphenyl, 2,3'-dihydroxybiphenyl, 2,4'-dihydroxybiphenyl, 3,3'-dihydroxybiphenyl, 3,4'-dihydroxybiphenyl, 4,4'-dihydroxybiphenyl, 1,2-dihydroxynaphthalene, 1,3-dihydroxynaphthalene, 1,4-dihydroxynaphthalene, 1,5-dihydroxynaphthalene, 1,6-dihydroxynaphthalene, 1,7-dihydroxynaphthalene, 1,8-dihydroxynaphthalene, 2,3-dihydroxynaphthalene, 2,6-dihydroxynaphthalene, 2,7-dihydroxynaphthalene, etc. Among these, divalent groups derived from resorcinol, bisphenol A, and 3,3'-dihydroxybiphenyl are particularly preferred.

In formula (3), p, q, r, and s each represent 0 or 1, and preferably 1.

In formula (3), R ¹¹ , R ¹² , R ¹³ and R ¹⁴ each represent an alkyl group having 1 to 6 carbon atoms or an aryl group which may be substituted with an alkyl group and has 6 to 20 carbon atoms. Examples of such an aryl group include a phenyl group, a cresyl group, a xylyl group, an isopropylphenyl group, a butylphenyl group, a tert-butylphenyl group, a di-tert-butylphenyl group and a p-cumylphenyl group, with the phenyl group, the cresyl group and the xylyl group being more preferred.

Specific examples of the condensed phosphate ester compound represented by formula (3) include aromatic phosphate esters such as triphenyl phosphate (TPP), tricresyl phosphate (TCP), trixylenyl phosphate (TXP), cresyl diphenyl phosphate (CDP), 2-ethylhexyl diphenyl phosphate (EHDP), tert-butylphenyl diphenyl phosphate, bis-(tert-butylphenyl)phenyl phosphate, tris-(tert-butylphenyl)phosphate, isopropylphenyl diphenyl phosphate, bis-(isopropylphenyl)diphenyl phosphate, and tris-(isopropylphenyl)phosphate; and condensed phosphate esters such as resorcinol bis-diphenyl phosphate (RDP), resorcinol bis-dixylenyl phosphate (RDX), bisphenol A bis-diphenyl phosphate (BDP), and biphenyl bis-diphenyl phosphate.

The acid value of the condensed phosphate ester compound represented by formula (3) is preferably 0.2 mgKOH/g or less, more preferably 0.15 mgKOH/g or less, even more preferably 0.1 mgKOH or less, and particularly preferably 0.05 mgKOH/g or less. The lower limit of the acid value can be set to substantially 0. The content of the half ester of the condensed phosphate ester compound represented by formula (3) is preferably 1 mass% or less, more preferably 0.5 mass% or less. If the acid value exceeds 0.2 mgKOH/g or the half ester content exceeds 1 mass%, the thermal stability and hydrolysis resistance of the polycarbonate resin composition of the present invention will be reduced.

In addition to the above, the phosphate ester compounds also include polyester resins, polycarbonate resins, and epoxy resins that contain phosphate ester moieties.

These condensed phosphate ester flame retardants (C-1) may be used alone or in combination of two or more.

(Phosphazene compound (C-2))
The phosphazene compound (C-2) of the present invention is an organic compound having a -P=N- bond in the molecule, and examples of the phosphazene compound (C-2) include a cyclic phosphazene compound represented by the following formula (4A), a chain phosphazene compound represented by the following formula (4B), and a crosslinked phosphazene compound obtained by crosslinking at least one phosphazene compound selected from the group consisting of the following formulas (4A) and (4B) via a crosslinking group. As the crosslinked phosphazene compound, one crosslinked by a crosslinking group represented by the following formula (4C) is preferred from the viewpoint of flame retardancy.

In formula (4A), a is an integer of 3 to 25, and ^R5 may be the same or different and represents an aryl group or an alkylaryl group.

（式（４Ｂ）中、ｂは３～１０，０００の整数であり、Ｚは、－Ｎ＝Ｐ（ＯＲ^５）_３基又は－Ｎ＝Ｐ（Ｏ）ＯＲ^５基を示し、Ｙは、－Ｐ（ＯＲ^５）_４基又は－Ｐ（Ｏ）（ＯＲ^５）_２基を示す。Ｒ^５は、同一又は異なっていてもよく、アリール基又はアルキルアリール基を示す。）

(In formula (4B), b is an integer of 3 to 10,000, Z is a -N=P(OR ⁵ ) ₃ group or a -N=P(O)OR ⁵ group, and Y is a -P(OR ⁵ ) ₄ group or a -P(O)(OR ⁵ ) ₂ group. R ⁵ may be the same or different and is an aryl group or an alkylaryl group.)

(In formula (4C), A is —C(CH ₃ ) ₂ —, —SO ₂ —, —S—, or —O—, and l is 0 or 1.)

Examples of the cyclic and/or linear phenoxyphosphazene compounds represented by formulae (4A) and (4B) include cyclic and/or linear C 1-6 alkyl C phosphazenes such as phenoxyphosphazene, (poly)tolyloxyphosphazene (e.g., o-tolyloxyphosphazene, m-tolyloxyphosphazene, p-tolyloxyphosphazene, o,m-tolyloxyphosphazene, o,p-tolyloxyphosphazene, m,p-tolyloxyphosphazene, o,m,p-tolyloxyphosphazene, etc.), and (poly) _{xylyloxyphosphazene} . Examples of cyclic and/or linear C 6-20 aryl, C 1-10 alkyl, C _6-20 aryloxyphosphazenes include (poly)phenoxytolyloxyphosphazene (for example, phenoxy o-tolyloxyphosphazene, phenoxy m-tolyloxyphosphazene, phenoxy p-tolyloxyphosphazene, phenoxy o,m-tolyloxyphosphazene, phenoxy o,p-tolyloxyphosphazene, phenoxy m,p-tolyloxyphosphazene, phenoxy o,m,p-tolyloxyphosphazene, etc.), (poly)phenoxyxylyloxyphosphazene, (poly)phenoxytolyloxyxylyloxyphosphazene _{, etc., and preferably cyclic and/or linear phenoxyphosphazene, cyclic and/or linear C 1-3 alkyl C 6-20 aryloxyphosphazene} , C _6-20 aryloxy C _1-3 alkyl C and _6-20 aryloxyphosphazenes (for example, cyclic and/or chain tolyloxyphosphazene, cyclic and/or chain phenoxytolylphenoxyphosphazene, etc.). Here, the description "C _1-6 " means "having 1 to 6 carbon atoms", and the same applies to "C _6-20 ", "C _1-10 ", etc. Furthermore, the description "(poly)phenoxy..." refers to either or both of "phenoxy..." and "polyphenoxy...".

As the cyclic phosphazene compound represented by formula (4A), a cyclic phenoxyphosphazene in which R ⁵ is a phenyl group is particularly preferred. Examples of such a cyclic phenoxyphosphazene compound include compounds such as phenoxycyclotriphosphazene, octaphenoxycyclotetraphosphazene, and decafenoxycyclopentaphosphazene, which are obtained by extracting cyclic chlorophosphazenes such as hexachlorocyclotriphosphazene, octachlorocyclotetraphosphazene, and decachlorocyclopentaphosphazene from a cyclic and linear chlorophosphazene mixture obtained by reacting ammonium chloride with phosphorus pentachloride at a temperature of 120 to 130° C., and then substituting them with a phenoxy group. In addition, the cyclic phenoxyphosphazene compound is preferably a compound in which a in formula (4A) is an integer of 3 to 8, and may be a mixture of compounds with different a's. Among these, a mixture of compounds in which a=3 is 50% by mass or more, a=4 is 10 to 40% by mass, and a=5 or more is 30% by mass or less in total is preferred.

As the linear phosphazene compound represented by formula (4B), linear phenoxyphosphazene in which R ⁵ is a phenyl group is particularly preferred. Examples of such linear phenoxyphosphazene compounds include compounds obtained by ring-opening polymerization of hexachlorocyclotriphosphazene obtained by the above method at a temperature of 220 to 250° C., and substituting the obtained linear dichlorophosphazene having a polymerization degree of 3 to 10,000 with a phenoxy group. In the linear phenoxyphosphazene compound represented by formula (4B), b is preferably 3 to 1,000, more preferably 3 to 100, and even more preferably 3 to 25.

Examples of bridged phenoxyphosphazene compounds include compounds having a bridged structure of 4,4'-diphenylene groups, such as compounds having a bridged structure of 4,4'-sulfonyldiphenylene (bisphenol S residue), compounds having a bridged structure of 2,2-(4,4'-diphenylene)isopropylidene groups, compounds having a bridged structure of 4,4'-oxydiphenylene groups, and compounds having a bridged structure of 4,4'-thiodiphenylene groups.

As the bridged phosphazene compound, a bridged phenoxyphosphazene compound obtained by crosslinking a cyclic phenoxyphosphazene compound in which R ⁵ in the above formula (4A) is a phenyl group with a crosslinking group represented by the above formula (4C) or a bridged phenoxyphosphazene compound obtained by crosslinking a chain phenoxyphosphazene compound in which R ⁵ in the above formula (4B) is a phenyl group with a crosslinking group represented by the above formula (4C) is preferred from the viewpoint of flame retardancy, and a bridged phenoxyphosphazene compound obtained by crosslinking a cyclic phenoxyphosphazene compound with a crosslinking group represented by the above formula (4C) is more preferred.

The content of phenylene groups in the bridged phenoxyphosphazene compound is usually 50 to 99.9%, preferably 70 to 90%, based on the total number of phenyl groups and phenylene groups in the cyclic phosphazene compound represented by formula (4A) and/or the chain phenoxyphosphazene compound represented by formula (4B). The bridged phenoxyphosphazene compound is particularly preferably a compound that does not have a free hydroxyl group in its molecule.

In the present invention, the phosphazene compound (C-2) is preferably at least one selected from the group consisting of a cyclic phenoxyphosphazene compound represented by the above formula (4A) and a crosslinked phenoxyphosphazene compound obtained by crosslinking the cyclic phenoxyphosphazene compound represented by the above formula (4A) with a crosslinking group, from the viewpoints of flame retardancy and mechanical properties.
Commercially available products of such phosphazene compounds (C-2) include, for example, "Ravitol FP-110T" manufactured by Fushimi Pharmaceutical Co., Ltd., which is a phenoxyphosphazene, and "SPS100" manufactured by Otsuka Chemical Co., Ltd.

These phosphazene compounds (C-2) may be used alone or in combination of two or more.

The content of the phosphorus-based flame retardant (C) in the polycarbonate resin composition of the present invention is 3 to 20 parts by mass, preferably 3 to 15 parts by mass, and more preferably 3 to 10 parts by mass, per 100 parts by mass of the polycarbonate resin (A). If the content of the phosphorus-based flame retardant (C) is less than 3 parts by mass, the flame retardancy becomes insufficient, and if it exceeds 20 parts by mass, it causes a decrease in heat resistance and a decrease in mechanical properties.

The phosphorus-based flame retardant (C) is preferably contained such that the weight ratio of the content of the phosphorus-based flame retardant (C) to the content of the flowability modifier (B) described above (hereinafter sometimes referred to as the "(C)/(B) ratio") is 20 mass% or more, particularly 35 mass% or more, especially 50 mass% or more, and of these, 60 mass% or more. When the (C)/(B) ratio is 20 mass% or more, the effect of improving flame retardancy by the phosphorus-based flame retardant (C) can be obtained more effectively. However, if the (C)/(B) ratio is excessively large, it may not be possible to satisfy the respective suitable contents of the flowability modifier (B) and the phosphorus-based flame retardant (C), so the (C)/(B) ratio is preferably 100 mass% or less, especially 80 mass% or less.

<Fluoropolymer (D)>
The fluoropolymer (D) is usually a polymer or copolymer containing a polyfluoroethylene structure. Specific examples include difluoroethylene polymer, tetrafluoroethylene polymer, tetrafluoroethylene/hexafluoropropylene copolymer, etc., and among these, tetrafluoroethylene polymer is preferred.
In addition, the fluoropolymer (D) is preferably one having fibril-forming ability, specifically, a fluoropolymer resin having fibril-forming ability can be mentioned. In this way, by having fibril-forming ability, drip prevention during combustion tends to be significantly improved.

In addition, organic polymer-coated fluoroolefin resins can also be suitably used as the fluoropolymer (D). By using an organic polymer-coated fluoroolefin resin, dispersibility is improved, the surface appearance of the molded product is improved, and surface foreign matter can be suppressed. The organic polymer-coated fluoroolefin resin can be produced by various known methods, such as (1) a method of mixing an aqueous dispersion of polyfluoroethylene particles and an aqueous dispersion of organic polymer particles, and powdering the mixture by coagulation or spray drying, (2) a method of polymerizing a monomer constituting an organic polymer in the presence of an aqueous dispersion of polyfluoroethylene particles, and then powdering the mixture by coagulation or spray drying, and (3) a method of emulsion-polymerizing a monomer having an ethylenically unsaturated bond in a dispersion obtained by mixing an aqueous dispersion of polyfluoroethylene particles and an aqueous dispersion of organic polymer particles, and then powdering the mixture by coagulation or spray drying.

As a monomer for producing an organic polymer that coats the fluoropolymer, from the viewpoint of dispersibility when blended with the polycarbonate resin (A), one that has high affinity with the polycarbonate resin (A) is preferred, and aromatic vinyl monomers, (meth)acrylic acid ester monomers, and vinyl cyanide monomers are more preferred.

The apparent density of the fluoropolymer (D) is preferably 0.4 g/ml or more. By making the apparent density of the fluoropolymer (D) 0.4 g/ml or more, the drip prevention property during combustion is further improved. The apparent density of the fluoropolymer is more preferably 0.45 g/ml or more, and from the viewpoint of handling, is preferably 2.0 g/ml or less, more preferably 1.5 g/ml or less, and even more preferably 1.0 g/ml or less.
The apparent density of the fluoropolymer is measured using an apparent density measuring device based on JIS K6820.

These fluoropolymers (D) may be used alone or in combination of two or more.

The content of fluoropolymer (D) in the polycarbonate resin composition of the present invention is 0.05 to 2 parts by mass per 100 parts by mass of polycarbonate resin (A). If the content of fluoropolymer (D) is less than 0.05 parts by mass, the effect of improving flame retardancy is likely to be insufficient, and if it exceeds 2 parts by mass, the molded product molded from the resin composition is likely to have poor appearance and reduced mechanical strength. The content of fluoropolymer (D) is preferably 0.1 parts by mass or more, more preferably 0.2 parts by mass or more, and is preferably 1.5 parts by mass or less, and particularly preferably 1.2 parts by mass or less.

<Inorganic filler>
The inorganic filler used in the present invention is mainly composed of talc (E), and contains 80% by mass or more in the inorganic filler. If the proportion of talc (E) in the inorganic filler blended in the polycarbonate resin composition is less than 80% by mass, the high impact resistance targeted in the present invention cannot be obtained. From the viewpoint of impact resistance, the content of talc (E) in the inorganic filler is more preferably 85% by mass or more, even more preferably 90% by mass or more, and it is particularly preferable that 100% by mass of the inorganic filler is talc (E).

The talc (E) used in the present invention preferably has an average particle size of 8.5 μm or less. When the average particle size of the talc (E) is 8.5 μm or less, the mechanical strength such as bending properties is more excellent. From this viewpoint, the average particle size of the talc (E) is more preferably 8 μm or less.
On the other hand, in order to effectively obtain the effect of improving rigidity, dimensional accuracy, and the like by blending talc (E), the average particle size of talc (E) is preferably 2 μm or more, and more preferably 4 μm or more.
In addition, the particle diameter of talc (E) is the length of the widest part of the gap between two parallel plates when talc (E) is sandwiched between them, and corresponds to the long diameter of the plate surface of the plate-like talc (E). The average particle diameter of talc (E) can be obtained by observing the cross section of the obtained molded product with a SEM (scanning electron microscope) and calculating the number average value of 50 arbitrarily selected measured values, or by measuring by a microtrack laser diffraction method. For example, if talc (E) is supplied as a product, the average particle diameter as a product standard can be adopted.

In the present invention, inorganic fillers other than talc (E) (hereinafter, sometimes referred to as "other inorganic fillers (F)") may be used in combination with talc (E) as the inorganic filler, provided that the ratio of the other inorganic fillers (F) in the inorganic filler (hereinafter, sometimes referred to as "the ratio of (F) in the inorganic filler") is 20% by mass or less, preferably 15% by mass or less, and more preferably 10% by mass or less.

The other inorganic filler (F) is not particularly limited, but examples thereof include glass-based fillers such as glass fiber (chopped strands), milled glass fiber (short glass fiber), glass flakes, and glass beads; carbon-based fillers such as carbon fiber, short carbon fiber, carbon nanotubes, and graphite; whiskers such as potassium titanate and aluminum borate; silicate compounds such as wollastonite, mica, kaolinite, xonotlite, sepiolite, attapulgite, montmorillonite, bentonite, and smectite; silica, alumina, and calcium carbonate. Of these, glass fiber, glass flakes, and mica are preferred, and among these, glass flakes and mica are preferred from the viewpoint of dimensional accuracy. These other inorganic fillers (F) may be used alone or in combination of two or more.

Inorganic fillers such as talc may be surface-treated with various surface treatment agents such as silane treatment agents in order to enhance adhesion with polycarbonate resin (A). Surface treatment agents are not particularly limited and can be used with conventionally known agents, but hydrogen siloxane compounds such as methyl hydrogen siloxane, epoxy group-containing silane coupling agents such as epoxy silane, and amino group-containing silane coupling agents such as amino silane are preferred because they do not reduce the physical properties of polycarbonate resin (A). Other agents such as polyoxyethylene silane can also be used.
The method for treating the inorganic filler with the surface treatment agent is not particularly limited, and may be carried out by a conventional method, for example, by adding the surface treatment agent to talc and stirring or mixing in a solution or while heating.

The content of the inorganic filler in the polycarbonate resin composition of the present invention is 20 to 45 parts by mass per 100 parts by mass of polycarbonate resin (A). If the content of the inorganic filler is less than 20 parts by mass, the effect of improving rigidity and dimensional stability will be insufficient, and if it exceeds 45 parts by mass, problems such as embrittlement (reduced impact strength) and deterioration of appearance may occur. From these viewpoints, the content of the inorganic filler per 100 parts by mass of polycarbonate resin (A) is preferably 25 to 40 parts by mass, particularly 25 to 35 parts by mass.

<Phosphorus Compound (G)>
In order to enhance thermal stability and chemical resistance, the polycarbonate resin composition of the present invention preferably contains a phosphorus compound (G) other than the above-mentioned phosphorus-based flame retardant (C). Preferred examples of the phosphorus compound (G) include a phosphite ester represented by the following formula (1), a phosphate ester represented by the following formula (2), and a phosphate metal salt represented by the following formula (5) or (6).

These phosphorus compounds are described below.

(In formula (1), R ¹ is an alkyl group or an aryl group, and the two R ^1s may be the same or different.)

(In formula (2), ^R2 is an alkyl group or an aryl group, and (3-n) ^R2s may be the same or different. n is an integer of 0 to 2.)

(In formulas (5) and (6), ^R3 is an alkyl group or an aryl group, and M is a metal.)

(Phosphite ester)
In the formula (1), when ^R1 is an alkyl group, it is preferably an alkyl group having 1 to 30 carbon atoms, particularly preferably a stearyl group or a nonyl group. When ^R1 is an aryl group, it is preferably an aryl group having 6 to 30 carbon atoms, particularly preferably a phenyl group having an alkyl group as a substituent.

Specific examples of phosphorous esters include distearyl pentaerythritol diphosphite, dinonyl pentaerythritol diphosphite, bisnonylphenyl pentaerythritol diphosphite, bis(2,4-di-tert-butylphenyl) pentaerythritol diphosphite, bis(2,6-di-tert-butyl-4-methylphenyl) pentaerythritol diphosphite, bis(2,6-di-tert-butyl-4-ethylphenyl) pentaerythritol diphosphite, bis(2,6-di-tert-butyl-4-isopropylphenyl) pentaerythritol diphosphite, and bis(2,4-dicumylphenyl) pentaerythritol diphosphite.

Among the above, preferred phosphite esters are distearyl pentaerythritol diphosphite, bis(2,4-di-tert-butylphenyl)pentaerythritol diphosphite, and bis(2,6-di-tert-butyl-4-methylphenyl)pentaerythritol diphosphite, with distearyl pentaerythritol diphosphite being particularly preferred.

(Phosphate ester)
In the formula (2), R ² is preferably an alkyl group having 1 to 30 carbon atoms or an aryl group having 6 to 30 carbon atoms, more preferably an alkyl group having 2 to 25 carbon atoms, a phenyl group, a nonylphenyl group, a stearylphenyl group, a 2,4-di-tert-butylphenyl group, a 2,4-di-tert-butyl-methylphenyl group, or a tolyl group, and particularly preferably an alkyl group having 2 to 25 carbon atoms. Examples of the alkyl group include an octyl group, a 2-ethylhexyl group, an isooctyl group, a nonyl group, an isononyl group, a decyl group, an isodecyl group, a dodecyl group, a tridecyl group, an isotridecyl group, a tetradecyl group, a hexadecyl group, and an octadecyl group.
It is preferred that n is 1 or 2.

(Phosphate metal salt)
In the formulas (5) and (6), R ³ is preferably an alkyl group having 1 to 30 carbon atoms or an aryl group having 6 to 30 carbon atoms, more preferably an alkyl group having 2 to 25 carbon atoms, a phenyl group, a nonylphenyl group, a stearylphenyl group, a 2,4-di-tert-butylphenyl group, a 2,4-di-tert-butyl-methylphenyl group, or a tolyl group, and particularly preferably an alkyl group having 2 to 25 carbon atoms. Examples of the alkyl group include an octyl group, a 2-ethylhexyl group, an isooctyl group, a nonyl group, an isononyl group, a decyl group, an isodecyl group, a dodecyl group, a tridecyl group, an isotridecyl group, a tetradecyl group, a hexadecyl group, and an octadecyl group.

M can be an alkali metal, alkaline earth metal, zinc, aluminum, or other metal.

In particular, from the viewpoint of chemical resistance, the phosphorus compound (G) is preferably the above-mentioned phosphites, phosphates, and metal phosphate salts having an alkyl group with 10 or more carbon atoms, and more preferably the phosphites, phosphates, and metal phosphate salts having a stearyl group as the alkyl group.

Therefore, the phosphorous ester is preferably distearyl pentaerythritol diphosphite. The phosphorous ester is more preferably one in which the alkyl group of ^R2 has 13, 18 or 24 carbon atoms, and is particularly preferably one represented by the following formula (2A), which is a mixture of distearyl acid phosphate in which n=1 and monostearyl acid phosphate in which n=2 in formula (2A). The phosphorous ester metal salt is preferably one in which the alkyl group of ^R3 has 13, 18 or 24 carbon atoms and M is zinc, and is particularly preferably one represented by the following formulas (5A) and (6A), which is a mixture of the zinc salt of distearyl acid phosphate represented by formula (5A) and the zinc salt of monostearyl acid phosphate represented by formula (6A).
O=P(OH) _n (OC ₁₈ H ₃₇ ) _3-n ...(2A)

These phosphorus compounds (G) may be used alone or in combination of two or more.

When the polycarbonate resin composition of the present invention contains a phosphorus compound (G), the content of the phosphorus compound (G) in the polycarbonate resin composition is preferably 0.05 to 1 part by mass, more preferably 0.1 to 0.7 parts by mass, and even more preferably 0.2 to 0.5 parts by mass, per 100 parts by mass of the polycarbonate resin (A). If the content of the phosphorus compound (G) is equal to or higher than the above lower limit, the effects of containing the phosphorus compound (G), such as thermal stability and chemical resistance, can be sufficiently obtained. If the content of the phosphorus compound (G) is too high, the corresponding effect may not be obtained, and problems such as a decrease in hydrolysis resistance and mold deposits may occur, so the content of the phosphorus compound (G) is preferably equal to or lower than the above upper limit.

When the polycarbonate resin composition of the present invention contains a phosphorus compound (G), the content of the phosphorus compound (G) in the polycarbonate resin composition is preferably 0.2 to 2.0% by mass relative to the talc (E), more preferably 0.5 to 1.8% by mass, and even more preferably 0.8 to 1.5% by mass. If the content ratio of the phosphorus compound (G) relative to the talc (E) (hereinafter sometimes referred to as the "(G)/(E) ratio") is equal to or higher than the above lower limit, the effects of containing the phosphorus compound (G), such as thermal stability and chemical resistance, can be sufficiently obtained. If the (G)/(E) ratio is too high, the corresponding effect may not be obtained, and problems such as a decrease in hydrolysis resistance and mold deposits may occur, so the (G)/(E) ratio is preferably equal to or lower than the above upper limit.

<Other thermoplastic resins>
The polycarbonate resin composition of the present invention may contain a thermoplastic resin other than the polycarbonate resin (A) within a range that does not impair the effects of the present invention. In this case, the type and amount of the thermoplastic resin may be appropriately selected for the purpose of improving performance such as moldability and chemical resistance. Examples of thermoplastic resins other than the polycarbonate resin (A) include thermoplastic polyester resins such as polyethylene terephthalate, polybutylene terephthalate, and copolymer polyester, polyolefin resins such as polyethylene and polypropylene, styrene-based resins such as polystyrene and high impact polystyrene (HIPS), acrylic resins such as polyacrylate and polymethacrylate, polyamide resins, polyimide resins, polyamideimide resins, polyetherimide resins, polyphenylene ether resins, polysulfone resins, polyethersulfone resins, and polyphenylene sulfide resins. These thermoplastic resins other than the polycarbonate resin (A) may be contained alone or in any combination and ratio of two or more.

When the polycarbonate resin composition of the present invention contains a thermoplastic resin other than polycarbonate resin (A), the amount of the thermoplastic resin is preferably less than 50 mass% of the total amount of polycarbonate resin (A) and the thermoplastic resin other than polycarbonate resin (A), more preferably 30 mass% or less, and most preferably 20 mass% or less.

<Additives>
In order to obtain desired physical properties, various additives, for example, impact resistance modifiers, ultraviolet absorbers, antioxidants, stabilizers such as heat stabilizers other than the above-mentioned phosphorus compounds (G), pigments, dyes, lubricants, flame retardants other than the phosphorus-based flame retardant (C), release agents, and agents for improving sliding properties, may be blended into the polycarbonate resin composition of the present invention as necessary.

(Impact resistance modifier)
Examples of the impact resistance modifier include core/shell type graft copolymers, and preferred are core/shell type graft copolymers having a core layer made of a rubber component and a shell layer formed around the core layer by copolymerizing at least one monomer component selected from the group consisting of (meth)acrylic acid ester compounds, (meth)acrylic acid compounds, aromatic vinyl compounds, and unsaturated nitrile compounds.

Specific examples of rubber components include polybutadiene rubber, polyisoprene rubber, polyalkyl acrylate rubbers such as polybutyl acrylate, poly(2-ethylhexyl acrylate), and butyl acrylate-2-ethylhexyl acrylate copolymers, silicone-based rubbers such as polyorganosiloxane rubber, butadiene-acrylic composite rubber, silicone-acrylate composite rubber, styrene-butadiene rubber, ethylene-α-olefin-based rubbers such as ethylene-propylene rubber, ethylene-butene rubber, and ethylene-octene rubber, ethylene-acrylic rubber, and fluororubber. These may be used alone or in combination of two or more.

In the present invention, the preferred core/shell type graft copolymer is a graft copolymer having a silicone-acrylate composite rubber as the core, and in particular a core/shell type graft copolymer having an acrylic polymer or copolymer component as the shell layer around the silicone-acrylate composite rubber core.

The silicone-acrylate composite rubber constituting the core layer is preferably one that is composed of a polyorganosiloxane, for example a polymer containing dimethylsiloxane units as a constituent unit, and an acrylic component such as a (meth)acrylic acid ester compound or an unsaturated nitrile compound such as acrylonitrile.

The shell of the acrylic component can be obtained by polymerizing a (meth)acrylic acid ester compound, a (meth)acrylic acid compound, or the like.
Examples of the (meth)acrylic acid ester compound include (meth)acrylic acid alkyl esters such as methyl methacrylate, ethyl methacrylate, n-butyl methacrylate, and hexyl methacrylate; aryl (meth)acrylates such as phenyl methacrylate and naphthyl methacrylate; and glycidyl group-containing (meth)acrylates such as glycidyl acrylate and glycidyl methacrylate. Among these, methacrylic acid alkyl esters are preferred, and methyl methacrylate is more preferred.
The (meth)acrylic acid ester compounds may be used alone or in combination.

In addition to the (meth)acrylic acid ester compound, other vinyl monomers may be contained. Examples of other vinyl monomers include aromatic vinyls such as styrene and α-methylstyrene; unsaturated nitriles such as acrylonitrile and methacrylonitrile; vinyl ethers such as methyl vinyl ether and butyl vinyl ether; maleimide compounds such as maleimide, N-methylmaleimide, and N-phenylmaleimide; α,β-unsaturated carboxylic acid compounds such as maleic acid, phthalic acid, and itaconic acid, and anhydrides thereof (e.g., maleic anhydride, etc.); and the like.

In addition, crosslinkable monomers such as aromatic polyfunctional vinyl compounds such as divinylbenzene and divinyltoluene; unsaturated carboxylic acid esters of polyhydric alcohols such as ethylene glycol dimethacrylate, 1,3-butanediol diacrylate, trimethylolethane triacrylate, trimethylolpropane trimethacrylate, and pentaerythritol tetramethacrylate; unsaturated carboxylic acid allyl esters such as allyl acrylate and allyl methacrylate; and di- and triallyl compounds such as diallyl phthalate, diallyl sebacate, and triallyl triazine can also be used in combination.

When an impact modifier is contained in the polycarbonate resin composition of the present invention, the content is 1 to 10 parts by mass, preferably 3 to 8 parts by mass, per 100 parts by mass of the polycarbonate resin (A). If the content of the impact modifier is less than 1 part by mass, the impact resistance cannot be sufficiently improved, and if it exceeds 10 parts by mass, the heat resistance and flame retardancy are reduced.

(Antioxidants)
The antioxidant may be a hindered phenol-based antioxidant. 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, thiodiethylene bis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], N,N'-hexane-1,6-diylbis[3-(3,5-di-tert-butyl-4-hydroxyphenylpropionamide], 2,4-dimethyl-6-(1-methylpentadecyl)phenol, diethyl[[3,5-bis(1,1-dimethylethyl)-4-hydroxyphenyl]methyl]phosphonate, 3,3',3",5,5',5"-hexa-tert-butyl ethyl-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], 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-triazin-2-ylamino)phenol, and the like. These may be used in combination of two or more kinds.

Of the above, pentaerythritol tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] and octadecyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate are preferred. These two phenolic antioxidants are commercially available from Ciba Specialty Chemicals under the names "Irganox 1010" and "Irganox 1076."

When an antioxidant is contained in the polycarbonate resin composition of the present invention, the amount of the antioxidant is usually 0.001 to 1 part by mass, and preferably 0.01 to 0.5 parts by mass, per 100 parts by mass of the polycarbonate resin (A) in the polycarbonate resin composition of the present invention. If the amount of the antioxidant is less than 0.001 part by mass, the antioxidant effect is insufficient, and if it exceeds 1 part by mass, the effect will plateau and problems such as mold deposits may occur.

(Release Agent)
The releasing agent may be at least one compound selected from the group consisting 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, and polysiloxane-based silicone oils.

Examples of aliphatic carboxylic acids include saturated or unsaturated aliphatic mono-, di- or tri-carboxylic acids. Here, 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, and more preferred are saturated aliphatic mono-carboxylic acids having 6 to 36 carbon atoms. 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.

The aliphatic carboxylic acid in the ester of an aliphatic carboxylic acid and an alcohol can be the same as the aliphatic carboxylic acid described above. On the other hand, the alcohol can be 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 or polyhydric alcohol having 30 or less carbon atoms is more preferred. Here, the term "aliphatic" also includes alicyclic compounds. 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, dipentaerythritol, etc.

The above ester compounds may contain aliphatic carboxylic acids and/or alcohols as impurities, and may be mixtures of multiple compounds.

Specific examples of esters of aliphatic carboxylic acids and alcohols include beeswax (a mixture mainly composed of myricyl palmitate), stearyl stearate, behenyl behenate, stearyl behenate, glycerin monopalmitate, glycerin monostearate, glycerin distearate, glycerin tristearate, pentaerythritol monopalmitate, pentaerythritol monostearate, pentaerythritol distearate, pentaerythritol tristearate, pentaerythritol tetrastearate, etc.

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

Examples of polysiloxane-based silicone oils include dimethyl silicone oil, phenylmethyl silicone oil, diphenyl silicone oil, and fluorinated alkyl silicone.

When a release agent is contained in the polycarbonate resin composition of the present invention, the amount of the release agent is usually 0.001 to 2 parts by mass, and preferably 0.01 to 1 part by mass, per 100 parts by mass of the polycarbonate resin (A) in the polycarbonate resin composition of the present invention. If the amount of the release agent is less than 0.001 parts by mass, the release effect may be insufficient, and if it exceeds 2 parts by mass, problems such as reduced hydrolysis resistance and mold deposits may occur.

(Ultraviolet absorber)
Specific examples of the ultraviolet absorber include inorganic ultraviolet absorbers such as cerium oxide and zinc oxide, as well as organic ultraviolet absorbers such as benzotriazole compounds, benzophenone compounds, and triazine compounds. Of these, organic ultraviolet absorbers are preferred. In particular, at least one selected from the group consisting of benzotriazole compounds, 2-(4,6-diphenyl-1,3,5-triazin-2-yl)-5-[(hexyl)oxy]-phenol, 2-[4,6-bis(2,4-dimethylphenyl)-1,3,5-triazin-2-yl]-5-(octyloxy)phenol, 2,2'-(1,4-phenylene)bis[4H-3,1-benzoxazin-4-one], and [(4-methoxyphenyl)-methylene]-propane dioic acid-dimethyl ester is preferred.

Specific examples of benzotriazole compounds include methyl-3-[3-tert-butyl-5-(2H-benzotriazol-2-yl)-4-hydroxyphenyl]propionate-polyethylene glycol condensates. Specific examples of other benzotriazole compounds include 2-bis(5-methyl-2-hydroxyphenyl)benzotriazole, 2-(3,5-di-tert-butyl-2-hydroxyphenyl)benzotriazole, 2-(3',5'-di-tert-butyl-2'-hydroxyphenyl)-5-chlorobenzotriazole, 2-(3-tert-butyl-5-methyl-2-hydroxyphenyl)-5-chlorobenzotriazole, and 2-(2'-hydroxy-5'-tert-octylphenyl)benzotriazole. , 2-(3,5-di-tert-amyl-2-hydroxyphenyl)benzotriazole, 2-[2-hydroxy-3,5-bis(α,α-dimethylbenzyl)phenyl]-2H-benzotriazole, 2,2'-methylene-bis[4-(1,1,3,3-tetramethylbutyl)-6-(2N-benzotriazol-2-yl)phenol][methyl-3-[3-tert-butyl-5-(2H-benzotriazol-2-yl)-4-hydroxyphenyl]propionate-polyethylene glycol] condensate, etc. These may be used in combination of two or more kinds.

Among the above, 2-(2'-hydroxy-5'-tert-octylphenyl)benzotriazole, 2-[2-hydroxy-3,5-bis(α,α-dimethylbenzyl)phenyl]-2H-benzotriazole, 2-(4,6-diphenyl-1,3,5-triazin-2-yl)-5-[(hexyl)oxy]-phenol, 2-[4,6-bis(2,4-dimethylphenyl)-1,3,5-triazin-2-yl]-5-(octyloxy)phenol, and 2,2'-methylene-bis[4-(1,1,3,3-tetramethylbutyl)-6-(2N-benzotriazol-2-yl)phenol] are preferred.

When an ultraviolet absorber is contained in the polycarbonate resin composition of the present invention, the amount of the ultraviolet absorber is usually 0.01 to 3 parts by mass, and preferably 0.1 to 1 part by mass, per 100 parts by mass of the polycarbonate resin (A) in the polycarbonate resin composition of the present invention. If the amount of the ultraviolet absorber is less than 0.01 parts by mass, the effect of improving weather resistance may be insufficient, and if it exceeds 3 parts by mass, problems such as mold deposits may occur.

(dyes and pigments)
Examples of the dyes and pigments include inorganic pigments, organic pigments, and organic dyes. Examples of the inorganic pigments include sulfide pigments such as carbon black, cadmium red, and cadmium yellow; silicate pigments such as ultramarine; oxide pigments such as zinc white, red iron oxide, chromium oxide, titanium oxide, iron black, titanium yellow, zinc-iron brown, titanium cobalt green, cobalt green, cobalt blue, copper-chromium black, and copper-iron black; chromate pigments such as yellow lead and molybdate orange; and ferrocyanide pigments such as Prussian blue. Examples of the organic pigments and organic dyes include phthalocyanine dyes and pigments such as copper phthalocyanine blue and copper phthalocyanine green; azo dyes and pigments such as nickel azo yellow; condensed polycyclic dyes and pigments such as thioindigo, perinone, perylene, quinacridone, dioxazine, isoindolinone, and quinophthalone; anthraquinone, heterocyclic, and methyl dyes and pigments. These may be used in combination of two or more kinds. Among these, carbon black, titanium oxide, cyanine-based, quinoline-based, anthraquinone-based and phthalocyanine-based compounds are preferred from the viewpoint of thermal stability.

When a dye or pigment is contained in the polycarbonate resin composition of the present invention, the amount of the dye or pigment is usually 20 parts by mass or less, preferably 15 parts by mass or less, and more preferably 12 parts by mass or less, per 100 parts by mass of the polycarbonate resin (A) in the polycarbonate resin composition of the present invention. If the amount of the dye or pigment exceeds 20 parts by mass, the impact resistance may be impaired.

<Method for producing polycarbonate resin composition>
The polycarbonate resin composition of the present invention can be produced by mixing each component by a conventionally known method and melt-kneading.Specific mixing methods include weighing out a predetermined amount of thermoplastic resin (A), flowability modifier (B), phosphorus-based flame retardant (C), fluoropolymer (D), inorganic filler including talc (E), and phosphorus compound (G) and other additive components that are mixed as necessary, mixing them using various mixers such as a tumbler or Henschel mixer, and then melt-kneading them using a Banbury mixer, roll, plastic blender, single-screw kneading extruder, twin-screw kneading extruder, kneader, etc.

<Preferable physical properties of polycarbonate resin composition>
The polycarbonate resin composition of the present invention has excellent flame retardancy, preferably satisfying 5VB in flame retardancy at a thickness of 2 mm in the UL94 test described later in the Examples section.
In addition, the polycarbonate resin composition of the present invention has high impact resistance, such as an unnotched Charpy impact strength at a thickness of 4 mm according to ISO 179, which will be described in the Examples section below, of 35 kJ/ ^m2 or more, particularly 40 kJ/ ^m2 or more.
Furthermore, the polycarbonate resin composition of the present invention has high rigidity, such as a flexural modulus of 5,000 MPa or more in accordance with SO178, which will be described in the Examples section below.
Furthermore, the polycarbonate resin composition of the present invention has excellent chemical resistance, such as a retention rate of tensile breaking strength of 70% or more, particularly 80% or more, and especially 90% or more, in the evaluation of chemical resistance described in the Examples section below.

[Molded products]
The molded article of the present invention is obtained by molding the polycarbonate resin composition of the present invention as described above.

When producing the molded article of the present invention by molding the polycarbonate resin composition of the present invention, any conventionally known method for molding a molded article from a thermoplastic resin material can be used without any restrictions. Specific examples include general injection molding, ultra-high speed injection molding, injection compression molding, two-color molding, gas-assisted and other hollow molding methods, molding using an insulated mold, molding using a rapidly heated mold, foam molding (including supercritical fluids), insert molding, in-mold coating (IMC) molding, extrusion molding, sheet molding, thermoforming, rotational molding, lamination molding, and press molding.

[Application]
The molded article of the present invention obtained by molding the polycarbonate resin composition of the present invention has excellent rigidity, flame retardancy, flowability, dimensional accuracy, impact resistance, and chemical resistance, and can be suitably used for various applications. In particular, the molded article of the present invention can be suitably used for chassis and frame materials of office automation equipment, optical housings, etc.

The present invention will be explained in more detail below with reference to examples. However, the present invention is not limited to the following examples, and can be modified as desired without departing from the gist of the present invention.

[Ingredients used]
The raw materials used in the following Examples and Comparative Examples are as shown in Tables 1 and 2 below.

[Evaluation method]
The methods for evaluating various characteristics and physical properties in the following Examples and Comparative Examples are as follows.

<Liquidity>
The pellets obtained in the examples and comparative examples were dried at 100°C for 6 hours, and then injection molded into barflow molded articles with a width of 20 mm and a thickness of 2 mm using a Nissei Plastic Industrial Co., Ltd. NEX80III (clamping force 80 tons) under conditions of a cylinder temperature of 280°C, a mold temperature of 60°C, an injection pressure of 100 MPa, and a molding cycle of 40 seconds, and the flow length (unit: mm) of the molded articles was evaluated.
This value is preferably about 200 to 350 mm.

<Mold shrinkage anisotropy>
The pellets obtained in the examples and comparative examples were dried at 100°C for 6 hours, and then test pieces 80 mm long, 40 mm wide, and 3.2 mm thick were injection molded using a NEX80III (clamping force 80 tons) manufactured by Nissei Plastic Industrial Co., Ltd. under the conditions of a cylinder temperature of 280°C, a mold temperature of 80°C, an injection pressure of 90 MPa, and a molding cycle of 45 seconds. The dimensions of the obtained test pieces in the resin flow direction (MD) and the direction perpendicular to the flow (TD) were measured, the shrinkage rate was calculated from the mold dimensions, and the anisotropy of the molding shrinkage rate was evaluated from the value obtained by dividing the MD value by the TD value.
The closer the value calculated by this method is to 1, the smaller the anisotropy of the shrinkage rate is, and the more excellent the dimensional accuracy and the less warpage are.

<Bending properties>
Using the ISO multipurpose test pieces having a thickness of 4 mm obtained in the examples and comparative examples, the flexural modulus and flexural strength were measured and evaluated in accordance with ISO 178. The flexural modulus is preferably 5000 MPa or more, and the flexural strength is preferably 110 MPa or more.

<Impact resistance>
Using the ISO multipurpose test pieces having a thickness of 4 mm obtained in the examples and comparative examples, the unnotched Charpy impact strength was measured and evaluated in accordance with ISO 179. This value is 35 kJ/ ^m2 or more, and the higher the value, the more preferable.

<Heat resistance>
Using the ISO multipurpose test pieces having a thickness of 4 mm obtained in the examples and comparative examples, the deflection temperature under load of 1.8 MPa was measured and evaluated in accordance with ISO 75. The higher the deflection temperature under load, the more excellent the heat resistance.

<Flame retardancy evaluation>
The UL test specimens obtained in the examples and comparative examples were conditioned for 48 hours in a thermostatic chamber at a temperature of 23°C and a humidity of 50%, and a 5V bar sample combustion test was performed in accordance with the UL94 test (combustion test of plastic materials for equipment parts) specified by Underwriters Laboratories (UL) in the United States. The 5V bar sample combustion test is a method of evaluating flame retardancy from the residual flame time and drip property after a test specimen of a predetermined size held vertically is in contact with a flame at a predetermined position on the test specimen for 5 seconds with a predetermined flame size and burner angle, and then removed and held for 5 seconds, which is repeated four times, and then in contact with a flame for another 5 seconds (fifth time). A total of five test specimens were tested, and in order to have 5VB, it is necessary for all five test specimens to meet the criteria shown in Table 3 below.

Here, the afterflame time is the total time that the test specimen continues to burn with flame and continues to emit light (with fire source) after the ignition source is moved away. Cotton ignition by dripping is determined by whether or not the cotton marker located about 300 mm below the bottom end of the test specimen is ignited by dripping from the test specimen.
In Tables 4 to 14 below, "NR" indicates that 5VB is not satisfied.

In addition to the 5VB judgment, the average afterflame time of the five test pieces in the 5V bar sample combustion was calculated. The smaller this value, the higher the self-extinguishing property and the higher the flame retardancy.

<Chemical resistance>
The 3 mm thick ISO multipurpose test pieces obtained in the Examples and Comparative Examples were fixed to a jig and bent to a distortion of 1%, and the rust inhibitor "Barrier Guard (registered trademark) Part II" (colorless, manufactured by Yamaichi Chemical Industry Co., Ltd.) was applied to the part, and the part was placed in a hot air oven set at 55°C and held for 72 hours. Thereafter, the test piece was removed from the jig, and the tensile breaking strength was measured in accordance with ISO527. The value was divided by the tensile breaking strength value of an uncoated test piece to evaluate the retention of tensile breaking strength. This value is 70% or more, preferably 80% or more, and more preferably 90% or more, and the higher the value, the better.

[Examples 1 to 37, Comparative Examples 1 to 20]
<Production of resin pellets>
The raw materials shown in Tables 4 to 14 were used, and the ingredients other than the phosphorus-based flame retardant (C) were blended in the ratios shown in Tables 4 to 14. The mixture was mixed in a tumbler for 20 minutes, and then fed from an upstream feeder to a twin-screw extruder "TEX30α" manufactured by Japan Steel Works, Ltd. equipped with one vent. While feeding the phosphorus-based flame retardant (C) from the middle of the barrel using a liquid injection pump, the mixture was kneaded under conditions of a rotation speed of 200 rpm, a discharge rate of 30 kg/h, and a barrel temperature of 270° C. The molten resin extruded in the form of strands was cooled in a water tank and pelletized using a pelletizer to obtain pellets of a polycarbonate resin composition.

<Preparation of test specimen>
The obtained pellets were dried at 100°C for 6 hours, and then injection molded using a Toyo Machinery & Metals injection molding machine "Si-80-6" (clamping force 80 tons) under conditions of a cylinder temperature of 280°C, a mold temperature of 60°C, and a molding cycle of 50 seconds to mold ISO multipurpose test pieces having a thickness of 4 mm.
Similarly, the obtained pellets were dried at 100°C for 6 hours, and then injection molded using a Toshiba Machine Co., Ltd. injection molding machine "EC75SX" (clamping force 75 tons) under conditions of a cylinder temperature of 280°C, a mold temperature of 60°C, and a molding cycle of 48 seconds to mold ISO multipurpose test pieces with a thickness of 3 mm.
Similarly, the obtained pellets were dried at 100°C for 6 hours, and then injection molded using an injection molding machine "SE100D" (clamping force 100 tons) manufactured by Sumitomo Heavy Industries, Ltd. under conditions of a cylinder temperature of 280°C, a mold temperature of 60°C, and a molding cycle of 30 seconds to mold a UL test specimen having a length of 125 mm, a width of 13 mm, and a thickness of 2 mm.

The above-mentioned evaluations were carried out using the obtained pellets and test pieces, and the results are shown in Tables 4 to 14.

It is clear from Tables 4 to 14 that the polycarbonate resin composition of the present invention is excellent in all of rigidity, flame retardancy, flowability, dimensional accuracy, impact resistance and chemical resistance.
In contrast, Comparative Examples 1 to 20, which do not satisfy the requirements of the present invention, are inferior in any one of rigidity, flame retardancy, fluidity, dimensional accuracy, impact resistance, and chemical resistance.

Claims (14)

A polycarbonate resin composition comprising 100 parts by mass of a polycarbonate resin (A) having a viscosity average molecular weight of 18,500 or more, 5 to 30 parts by mass of a flowability modifier (B), 3 to 20 parts by mass of a phosphorus-based flame retardant (C), 0.05 to 2 parts by mass of a fluoropolymer (D), and 20 to 45 parts by mass of an inorganic filler including talc (E), wherein the proportion of a filler (F) other than talc (E) in the inorganic filler is 20 mass% or less,
the phosphorus-based flame retardant (C) is a condensed phosphate ester-based flame retardant (C-1) and/or a phosphazene compound (C-2);
Further, the composition contains a phosphorus compound (G) other than the phosphorus-based flame retardant (C) in an amount of 0.2 to 0.5 parts by mass per 100 parts by mass of the polycarbonate resin (A),
the phosphorus compound (G) is a phosphite and/or a phosphate having an alkyl group having 10 or more carbon atoms,
A polycarbonate resin composition in which the ratio of the phosphorus compound (G) to the talc (E) is 0.8 to 1.5 mass %. The polycarbonate resin composition according to claim 1, wherein the flowability modifier (B) is at least one selected from an acrylonitrile-styrene copolymer, an acrylonitrile-butadiene-styrene copolymer, a polycarbonate oligomer, and a polycaprolactone. The polycarbonate resin composition according to claim 1 or 2, wherein the average particle size of the talc (E) is 8.5 μm or less. The polycarbonate resin composition according to any one of claims 1 to 3, wherein the ratio of the phosphorus-based flame retardant (C) to the flowability modifier (B) is 20 mass% or more. 5. The polycarbonate resin composition according to claim 1, wherein the phosphite ester is represented by the following formula (1) and the phosphate ester is represented by the following formula (2):

(In formula (1), R ¹ is an alkyl group , and two R ^1s may be the same or different.)

(In formula (2), R ² is an alkyl group , and (3-n) R ^2s may be the same or different. n represents an integer of 0 to 2.) 6. The polycarbonate resin composition according to claim 5, wherein R ¹ in the formula (1) is an alkyl group having 10 to 30 carbon atoms, and R ² in the formula (2) is an alkyl group having 10 to 30 carbon atoms. 7. The polycarbonate resin composition according to claim 6, wherein R ¹ in the formula (1) is a stearyl group , and the alkyl group of R ² in the formula (2) has 13, 18 or 24 carbon atoms. 8. The polycarbonate resin composition according to claim 7, wherein the phosphorous ester is distearyl pentaerythritol diphosphite, and the phosphoric ester is represented by the following formula (2A), which is a mixture of distearyl acid phosphate in which n=1 and monostearyl acid phosphate in which n=2 in formula (2A).
O=P(OH) _n (OC ₁₈ H ₃₇ ) _3-n ...(2A) 9. The polycarbonate resin composition according to claim 1, which has a retention of 70% or more of tensile breaking strength measured by the following method (I).
Method (I): The polycarbonate resin composition was injection molded using an injection molding machine with a clamping force of 75 tons under conditions of a cylinder temperature of 280°C, a mold temperature of 60°C, and a molding cycle of 48 seconds, to obtain an ISO multipurpose test piece having a thickness of 3 mm. The test piece was fixed to a jig and bent so that the distortion was 1%, and the rust inhibitor "Barrier Guard (registered trademark) Part II" was applied to the bent part. The test piece was then placed in a hot air oven set at 55°C and held for 72 hours. The test piece was then removed from the jig and the tensile breaking strength was measured in accordance with ISO 527. The tensile breaking strength was measured by dividing the measured value by the tensile breaking strength of an uncoated test piece to obtain the tensile breaking strength retention rate. The polycarbonate resin composition according to any one of claims 1 to 9, which has a flame retardancy of 5VB at a thickness of 2 mm in the UL94 test. The polycarbonate resin composition according to any one of claims 1 to 10, which has an unnotched Charpy impact strength at a thickness of 4 mm according to ISO 179 of 35 kJ/ ^m2 or more. The polycarbonate resin composition according to any one of claims 1 to 11, having a flexural modulus of 5,000 MPa or more according to ISO 178. A molded article obtained by molding the polycarbonate resin composition according to any one of claims 1 to 12. The molded article according to claim 13, which is a chassis or an optical housing.