JP2025003084A - Polycarbonate resin composition and molded article - Google Patents

Abstract

To provide a polycarbonate resin composition having high flame retardancy and excellent impact resistance.SOLUTION: The polycarbonate resin composition contains 5-30 pts.mass of a phosphorus-based flame retardant (C), 1-12 pts.mass of a diene-based elastomer (D), and 0.1-1 pt.mass of a fluoropolymer (E) based on 100 pts.mass of the total of (A) and (B) consisting of 70-90 mass% of a polycarbonate resin (A) and 10-30 mass% of a graft copolymer (B) containing an aromatic vinyl monomer component (b1), a vinyl cyanide monomer component (b2), and a diene-based rubbery polymer component (b3). The total amount of phosphorus of the diene-based elastomer (D) in fluorescent X-ray analysis is 1,000 ppm or more.SELECTED DRAWING: None

Description

The present invention relates to a polycarbonate resin composition and a molded article, and more specifically to a polycarbonate resin composition having high flame retardancy and excellent impact resistance, and a molded article obtained by molding the same.

Polycarbonate resin has excellent heat resistance, mechanical properties, and electrical characteristics, and is widely used, for example, as a material for automobiles, electrical and electronic equipment, housing, and materials for manufacturing parts in other industrial fields. In particular, flame-retardant polycarbonate resin compositions are suitable for use as parts for various electrical and electronic equipment, information terminal devices, etc.

Polycarbonate resin has excellent heat resistance, mechanical properties, and electrical characteristics, and is 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/ABS resin alloys are ideally used as components for computers, notebook PCs, various mobile terminals, printers, copiers, and other electrical and electronic equipment, as well as office and information equipment.

Among these, polycarbonate/ABS resin alloys that have been flame-retarded with phosphorus-based flame retardants have excellent moldability due to the plasticizing effect of the phosphorus-based flame retardants, making them an ideal composition for obtaining thin-walled, large molded products (see, for example, Patent Documents 1 to 3).

In recent years, high flame retardancy has been required for parts of electric and electronic devices, information terminal devices, etc., and in particular, there has been a demand in recent years for these materials to meet the UL-94 V-0 standard and also to have excellent impact resistance.
In order to improve flame retardancy and impact resistance, a flame retardant is blended with an elastomer, but it is not easy to achieve a good balance between flame retardancy and impact resistance.

Patent No. 3638806 Patent No. 4080851 Patent No. 4157271

The present invention was devised in consideration of the above problems, and aims to provide a polycarbonate/ABS resin composition that has high flame retardancy and excellent impact resistance.

Means for Solving the Problems The present inventors have conducted extensive research in order to solve the above problems, and as a result have found that in a resin alloy with a graft copolymer such as ABS resin, a polycarbonate resin composition having high flame retardancy and excellent impact resistance can be obtained by using a diene-based elastomer having a total phosphorus content of 1000 ppm or more as the phosphorus-based flame retardant and the elastomer to be combined therewith, and further combining a fluoropolymer in a specific amount, and have thus completed the present invention.
The present invention provides the following polycarbonate resin composition and molded article.

1. A polycarbonate resin composition comprising 100 parts by mass of a total of 70 to 90% by mass of polycarbonate resin (A) and 10 to 30% by mass of graft copolymer (B) containing an aromatic vinyl monomer component (b1), a vinyl cyanide monomer component (b2) and a diene rubber polymer component (b3), and containing 5 to 30 parts by mass of a phosphorus-based flame retardant (C), 1 to 12 parts by mass of a diene elastomer (D), and 0.1 to 1 part by mass of a fluoropolymer (E), wherein the total amount of phosphorus of the diene elastomer (D) is 1000 ppm or more as determined by fluorescent X-ray analysis.
2. The polycarbonate resin composition according to the above 1, wherein the content of the diene elastomer (D) is 2 to 10 parts by mass per 100 parts by mass of the total of (A) and (B).
3. The polycarbonate resin composition according to the above 1, wherein the diene elastomer (D) has a total phosphorus content of 1,500 ppm or more and 2,200 ppm or less as determined by fluorescent X-ray analysis.
4. Pellets of the polycarbonate resin composition according to any one of 1 to 3 above.
5. A molded article obtained by molding the polycarbonate resin composition according to any one of 1 to 3 above.
6. A molded article obtained by molding the polycarbonate resin pellets described in 4 above.

The polycarbonate resin composition of the present invention is excellent in both high flame retardancy and impact resistance. By having a total phosphorus content of 1,000 ppm or more in fluorescent X-ray analysis of the diene-based elastomer (D), char formation of the diene-based rubber graft copolymer during combustion is promoted, improving flame retardancy, and a polycarbonate/ABS resin can be obtained that exhibits a higher level of flame retardancy and is well balanced with impact strength.

The present invention will be described in detail below with reference to embodiments and examples, but the present invention should not be construed as being limited to the embodiments and examples shown below.

The polycarbonate resin composition of the present invention is characterized in that it contains 5 to 30 parts by mass of a phosphorus-based flame retardant (C), 1 to 12 parts by mass of a diene-based elastomer (D), and 0.1 to 1 part by mass of a fluoropolymer (E) relative to a total of 100 parts by mass of (A) and (B) consisting of 70 to 90% by mass of a polycarbonate resin (A) and 10 to 30% by mass of a graft copolymer (B) containing an aromatic vinyl monomer component (b1), a vinyl cyanide monomer component (b2), and a diene-based rubber polymer component (b3), and that the total phosphorus content of the diene-based elastomer (D) is 1000 ppm or more in a fluorescent X-ray analysis.

[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 them, aromatic polycarbonate resins are preferred as the polycarbonate resin (A) from the viewpoints of heat resistance, mechanical properties, electrical properties, etc.

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;

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;

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;

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,
1,1-bis(4-hydroxyphenyl)-1-naphthylethan,
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:

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:

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

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.

Among these, bis(hydroxyaryl)alkanes are preferred, and among these, bis(4-hydroxyphenyl)alkanes are preferred. In particular, from the standpoint of impact resistance and heat resistance, 2,2-bis(4-hydroxyphenyl)propane (i.e., bisphenol A) and 2,2-bis(3-methyl-4-hydroxyphenyl)propane (i.e., bisphenol C) are more preferred, and 2,2-bis(4-hydroxyphenyl)propane (i.e., bisphenol A) is particularly preferred.
The aromatic dihydroxy compound may be used alone or in any combination of two or more kinds in any ratio.

Among the monomers that are the raw materials for polycarbonate resin, examples of carbonate precursors include carbonyl halides and carbonate esters. Note that one type of carbonate precursor may be used, or two or more types may be used in any combination and ratio.

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

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.

The method for producing the polycarbonate resin (A) is not particularly limited, and any method can be used. Examples include interfacial polymerization, melt transesterification, the 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 are more effective in improving resistance to moist heat, and the interfacial polymerization method is particularly preferred.

The polycarbonate resin (A) used in the present invention may be a polycarbonate resin having a terminal structure represented by the following formula (1) as a part or all of it.

In formula (1), n is an integer of 0 or 1, and ^R1 is an alkyl group having a carbon number of 5 to 14. When the polycarbonate resin has the terminal structure of formula (1), high fluidity is possible while maintaining strength, and high fluidity can be achieved even when a desired molecular weight is adopted without lowering the molecular weight of the polycarbonate resin, thereby enabling high impact resistance and high impact resistance at low temperatures.

The number of carbon atoms in the alkyl group of ^R1 is preferably 6 or more, more preferably 7 or more, and is preferably 12 or less, more preferably 10 or less. The alkyl group of ^R1 may be linear or branched.
Among them, R ¹ is preferably one or more selected from the group consisting of an n-octyl group, an iso-octyl group, and a t-octyl group, more preferably a t-octyl group, and particularly preferably the terminal structure in general formula (1) is a t-octylphenyl group (i.e., a 1,1,3,3-tetramethylbutylphenyl group).

In the above formula (1), the position of the -(O) _n R ¹ group bonded to the phenyl group may be the ortho position, meta position or para position, but the para position shown in the following formula (1') is preferable.

Specific examples of the R ¹ group represented by the above formula (1) or (1') preferably include alkylphenyl groups such as p-pentylphenyl group, p-hexylphenyl group, p-heptylphenyl group, p-n-octylphenyl group, p-iso-octylphenyl group, p-t-octylphenyl group, p-dodecylphenyl group and p-tetradecylphenyl group, p-nonylphenol, p-dodecylphenol, amylphenol, hexylphenol, heptylphenol, octylphenol, nonylphenol, decylphenol, dodecylphenol, and myristylphenol, and alkoxyphenyl groups such as p-hexyloxyphenyl group, p-n-octyloxyphenyl group, p-iso-octyloxyphenyl group, p-t-octyloxyphenyl group, and p-dodecyloxyphenyl group.
Among these, the R ¹ group represented by formula (1) or (1') is preferably an n-octyl group, an iso-octyl group, or a t-octyl group, more preferably a p-n-octyl group, a p-iso-octyl group, or a pt-octyl group, and particularly preferably a pt-octyl group, since it can achieve a high degree of fluidity and therefore enables high impact resistance and low-temperature impact resistance.

When the polycarbonate resin having the terminal structure of the above formula (1) is contained, the proportion is preferably 40% by mass or more, and also preferably 100% by mass, of the total 100% by mass of the polycarbonate resin (A).

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 11,000 to 40,000, even more preferably 12,000 to 35,000, and particularly preferably 13,000 to 30,000. By setting the viscosity average molecular weight to the lower limit of the above range or more, the mechanical strength of the polycarbonate resin composition of the present invention can be further improved, and by setting the viscosity average molecular weight to the upper limit of the above range or less, the decrease in flowability of the polycarbonate resin composition of the present invention can be suppressed and improved, and molding processability can be improved to facilitate molding process.
Two or more kinds of polycarbonate resins having different viscosity average molecular weights may be mixed and used. In this case, polycarbonate resins having a viscosity average molecular weight outside the above-mentioned preferable range may be mixed.

The viscosity average molecular weight [Mv] refers to a value calculated from the Schnell viscosity formula, i.e., η = 1.23 × 10 ^-4 Mv 0.83, by determining the intrinsic viscosity [η] (unit: dl/g) at 25°C using methylene chloride as a solvent and an Ubbelohde viscometer. The intrinsic viscosity [η] is a value calculated from the specific viscosity [η _sp ] at each solution concentration [C] (g/dl) using the following formula:

In order to improve the appearance and flowability of the molded product, the polycarbonate resin (A) may contain a polycarbonate oligomer. The viscosity average molecular weight [Mv] of this polycarbonate oligomer is usually 1500 or more, preferably 2000 or more, and usually 9500 or less, preferably 9000 or less. Furthermore, the amount of the polycarbonate oligomer contained is preferably 30% by mass or less in 100% by mass of the polycarbonate resin (A) (including the polycarbonate oligomer).

Furthermore, polycarbonate resin (A) may be not only virgin raw materials but also polycarbonate resin regenerated from used products (so-called material recycled polycarbonate resin), and it is also preferable that it contains both virgin raw materials and recycled resin, or it may be made of recycled polycarbonate resin. The proportion of recycled polycarbonate resin in polycarbonate resin (A) is preferably 40% by mass or more, 50% by mass or more, 60% by mass or more, or 80% by mass or more, and it is also preferable that the recycled polycarbonate resin is 100% by mass.

[Graft copolymer (B)]
The graft copolymer (B) contained in the polycarbonate resin composition of the present invention is a graft copolymer (B) containing an aromatic vinyl monomer component (b1), a cyanide vinyl monomer component (b2), and a diene rubber polymer component (b3). The graft copolymer (B) preferably comprises 40 to 80 mass% of the aromatic vinyl monomer component (b1), 10 to 30 mass% of the cyanide vinyl monomer component (b2), and 10 to 50 mass% of the diene rubber polymer component (b3), and may further contain 0 to 30 mass% of other monomer components (b4).

Examples of the aromatic vinyl monomer component (b1) in the graft copolymer (B) include styrene, α-methylstyrene, o-methylstyrene, p-methylstyrene, vinylxylene, ethylstyrene, dimethylstyrene, p-t-butylstyrene, vinylnaphthalene, methoxystyrene, monobromostyrene, dibromostyrene, fluorostyrene, and tribromostyrene, with styrene being particularly preferred.
The proportion of the aromatic vinyl monomer component (b1) in the graft copolymer (B) is preferably in the range of 40 to 80 mass%, more preferably 45 mass% or more, even more preferably 50 mass% or more, particularly preferably 55 mass% or more, and more preferably 75 mass% or less, even more preferably 70 mass% or less, particularly preferably 65 mass% or less, based on 100 mass% of the graft copolymer (B).

Examples of the vinyl cyanide monomer component (b2) in the graft copolymer (B) include acrylonitrile and methacrylonitrile, with acrylonitrile being particularly preferred.
The proportion of the vinyl cyanide monomer component (b2) in the graft copolymer (B) is preferably in the range of 10 to 30% by mass, more preferably 12% by mass or more, even more preferably 14% by mass or more, particularly preferably 15% by mass or more, and more preferably 28% by mass or less, even more preferably 26% by mass or less, particularly preferably 25% by mass or less, based on 100% by mass of the graft copolymer (B).

As the diene rubber polymer component (b3) of the graft copolymer (B), for example, a rubber component such as polybutadiene, polyisoprene, or styrene-butadiene copolymer is used, and the proportion of the diene rubber polymer component (b3) in the graft copolymer (B) is preferably in the range of 10 to 50 mass% of 100 mass% of the graft copolymer (B), more preferably 13 mass% or more, even more preferably 14 mass% or more, particularly preferably 15 mass% or more, and more preferably 45 mass% or less.

Furthermore, it may be a copolymer of other monomer components (b4) copolymerizable with these. In this case, examples of the other copolymerizable vinyl monomers include maleimide-based monomers such as maleimide, N-methylmaleimide, N-cyclohexylmaleimide, and N-phenylmaleimide, acrylamide-based monomers such as acrylamide and N-methylacrylamide, unsaturated acid anhydrides such as maleic anhydride and itaconic anhydride, unsaturated acids such as acrylic acid and methacrylic acid, glycidyl acrylate, glycidyl methacrylate, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, and methoxypolyethylene glycol methacrylate.
The proportion of the other monomer component (b4) in the graft copolymer (B) is preferably in the range of 0 to 30% by mass, more preferably 20% by mass or less, even more preferably 10% by mass or less, even more preferably 5% by mass or less, particularly preferably 3% by mass or less, and even more preferably 2% by mass or less, based on 100% by mass of the graft copolymer (B).

Specific examples of the graft copolymer (B) include acrylonitrile-butadiene-styrene graft copolymer, acrylonitrile-butadiene-styrene-α-methylstyrene graft copolymer, and acrylonitrile-ethylene-propylene-diene-styrene copolymer, among which acrylonitrile-butadiene-styrene graft copolymer (ABS resin) is particularly preferred.

The graft copolymer (B) is usually produced by a method such as bulk polymerization, solution polymerization, suspension polymerization, or emulsion polymerization, and any method can be used.

The content of the graft copolymer (B) is 5 to 45% by mass, based on 100% by mass of the total of the polycarbonate resin (A) and the graft copolymer (B), and is preferably 10% by mass or more, more preferably 15% by mass or more, preferably 42% by mass or less, and more preferably 30% by mass or less. By having the content in such a range, the resin composition can be made excellent in heat resistance and fluidity. If the amount of the graft copolymer (B) exceeds 45% by mass, the heat resistance decreases, and if it is less than 5% by mass, the fluidity decreases.

[Phosphorus-based flame retardant (C)]
The polycarbonate resin composition of the present invention contains a phosphorus-based flame retardant (C).
The phosphorus-based flame retardant is a compound containing phosphorus in the molecule, and may be a low molecular weight compound, an oligomer, or a polymer. From the viewpoint of thermal stability, for example, a phosphate ester compound represented by the following general formula (1) or a phosphazene compound represented by the following general formula (2) or (3) is preferred.

<Phosphate Ester Compound>
The phosphate compound represented by the above general formula (1) 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 of 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 addition, p, q, r, and s in general formula (1) each represent 0 or 1, and preferably 1.

Furthermore, R ¹ , R ² , R ³ and R ⁴ each represent an alkyl group having 1 to 6 carbon atoms or an aryl group having 6 to 20 carbon atoms which may be substituted with an alkyl group. 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 phosphate ester compound represented by the general formula (1) include aromatic phosphate esters such as triphenyl phosphate, tricresyl phosphate, trixylenyl phosphate, cresyl diphenyl phosphate, 2-ethylhexyl diphenyl phosphate, 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, resorcinol bis-dixylenyl phosphate, bisphenol A bis-diphenyl phosphate, and biphenyl bis-diphenyl phosphate.

The acid value of the phosphate ester compound represented by general formula (1) 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. On the other hand, the content of the half ester is more preferably 1.1 parts by mass or less, and even more preferably 0.9 parts by mass or less. If the acid value exceeds 0.2 mgKOH/g or the content of the half ester exceeds 1.1 parts by mass, the thermal stability and hydrolysis resistance of the polycarbonate resin composition of the present invention tend to be reduced.

In addition to the above, the phosphate ester compounds used in the present invention naturally also include 10-(2,5-dihydroxyphenyl)-10H-9-oxa-10-phosphaphenanthrene-10-oxide, 10-(2,3-dihydroxyphenyl)-10H-9-oxa-10-phosphaphenanthrene-10-oxide, 10-(2,4-dihydroxyphenyl)-10H-9-oxa-10-phosphaphenanthrene-10-oxide, and polyester resins, polycarbonate resins, or epoxy resins that contain a phosphate ester moiety.

<Phosphazene Compound>
Examples of the phosphazene compound represented by the above general formula (2) or (3) include cyclic and/or chain 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 include cyclic and/or linear _{C 6-20} aryl, C 1-10 alkyl, C 6-20 aryloxyphosphazenes such as C 6-20 aryloxyphosphazene, (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, and (poly _{) phenoxytolyloxyxylyloxyphosphazene} .
Of these, preferred are 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 _6-20 aryloxyphosphazene (for example, cyclic and/or linear tolyloxyphosphazene, cyclic and/or linear phenoxytolylphenoxyphosphazene, etc.).

In the cyclic phosphazene compound represented by the general formula (2), ^R5 and ^R6 may be the same or different and represent an aryl group or an alkylaryl group. Examples of such an aryl group or an alkylaryl group include a phenyl group, a naphthyl group, a methylphenyl group, a benzyl group, etc., and among them, a cyclic phenoxyphosphazene in which ^R5 and ^R6 are phenyl groups is particularly preferred.
Examples of such cyclic phenoxyphosphazene compounds 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 the cyclic chlorophosphazenes with phenoxy groups.

In addition, in general formula (2), t represents an integer of 3 to 25, and among these, compounds in which t is an integer of 3 to 8 are preferred, and a mixture of compounds with different t's may also be used. Among these, a mixture of compounds in which t=3 is 50% by mass or more, t=4 is 10 to 40% by mass, and t=5 or more is 30% by mass or less in total is preferred.

In the general formula (3), ^R7 and ^R8 may be the same or different and represent an aryl group or an alkylaryl group. Examples of such an aryl group or an alkylaryl group include a phenyl group, a naphthyl group, a methylphenyl group, a benzyl group, etc., and a chain phenoxyphosphazene in which ^R7 and ^R8 are phenyl groups 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 resulting linear dichlorophosphazene having a polymerization degree of 3 to 10,000 with a phenoxy group.

Furthermore, R ⁹ represents at least one selected from -N=P(OR ⁷ ) ₃ groups, -N=P(OR ⁸ ) ₃ groups, -N=P(O)OR ⁷ groups, and -N=P(O)OR ⁸ groups, and R ¹⁰ represents at least one selected from -P(OR ⁷ ) ₄ groups, -P(OR ⁸ ) ₄ groups, -P(O)(OR ⁷ ) ₂ groups, and -P(O)(OR ⁸ ) ₂ groups.

In addition, in general formula (3), u represents an integer of 3 to 10,000, preferably 3 to 1,000, more preferably 3 to 100, and even more preferably 3 to 25.

The phosphazene compound may be a crosslinked phosphazene compound in which a portion of the phosphazene compound is crosslinked. The presence of such a crosslinked structure tends to improve heat resistance.
Examples of such crosslinked phosphazene compounds include those having a crosslinked structure represented by the following general formula (4), for example, compounds having a crosslinked structure of a 4,4'-diphenylene group, such as a compound having a crosslinked structure of 4,4'-sulfonyldiphenylene (bisphenol S residue), a compound having a crosslinked structure of a 2,2-(4,4'-diphenylene)isopropylidene group, a compound having a crosslinked structure of a 4,4'-oxydiphenylene group, and a compound having a crosslinked structure of a 4,4'-thiodiphenylene group.

［式（４）中、Ｘ^２は－Ｃ（ＣＨ_３）_２－、－ＳＯ_２－、－Ｓ－、又は－Ｏ－であり、ｖは０又は１である。］

[In formula (4), X ² is —C(CH ₃ ) ₂ —, —SO ₂ —, —S—, or —O—, and v is 0 or 1.]

As the bridged phosphazene compound, a bridged phenoxyphosphazene compound obtained by crosslinking a cyclic phenoxyphosphazene compound in which ^R5 and ^R6 are phenyl groups in the general formula (2) with a crosslinking group represented by the above general formula (4), or a bridged phenoxyphosphazene compound obtained by crosslinking a chain phenoxyphosphazene compound in which ^R7 and ^R8 are phenyl groups in the general formula (3) with a crosslinking group represented by the above general formula (4) 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 general formula (4) is more preferred.

The content of phenylene groups in the crosslinked 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 general formula (2) and/or the chain phenoxyphosphazene compound represented by general formula (3). The crosslinked 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 is preferably at least one selected from the group consisting of a cyclic phenoxyphosphazene compound represented by the above general formula (2) and a crosslinked phenoxyphosphazene compound in which a chain phenoxyphosphazene compound represented by the above general formula (3) is crosslinked by a crosslinking group, from the viewpoints of flame retardancy and mechanical properties.

The content of the phosphorus-based flame retardant (C) is 5 to 30 parts by mass per 100 parts by mass of the polycarbonate resin (A) and the graft copolymer (B). If the content of the phosphorus-based flame retardant (C) is less than 5 parts by mass, the flame retardancy is insufficient, and if it exceeds 30 parts by mass, it causes a significant decrease in heat resistance and a decrease in mechanical properties. When the phosphorus-based flame retardant (C) is a phosphate ester compound, the preferred content is 5 to 20 parts by mass per 100 parts by mass of the polycarbonate resin (A) and the graft copolymer (B), and when the phosphorus-based flame retardant (C) is a phosphazene compound, the preferred content is 5 to 15 parts by mass per 100 parts by mass of the polycarbonate resin (A) and the graft copolymer (B).

[Diene-based elastomer (D)]
The polycarbonate resin composition of the present invention contains a diene-based elastomer (D) having a total phosphorus content of 1000 ppm or more as determined by fluorescent X-ray analysis. The diene-based elastomer (D) is preferably a graft copolymer obtained by graft-polymerizing a diene-based rubber component with a monomer component copolymerizable therewith.

Specific examples of diene rubber components include polybutadiene rubber, butadiene-acrylic composite rubber, styrene-butadiene rubber, and ethylene-propylene-butadiene rubber. These may be used alone or in combination of two or more.

Specific examples of monomer components graft copolymerizable with the diene rubber component include aromatic vinyl compounds, cyanide vinyl compounds, (meth)acrylic acid ester compounds, (meth)acrylic acid compounds, epoxy group-containing (meth)acrylic acid ester compounds such as glycidyl (meth)acrylate, 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 (for example, maleic anhydride, etc.), etc. These monomer components may be used alone or in combination of two or more kinds.
Among these, from the viewpoint of mechanical properties and surface appearance, aromatic vinyl compounds, vinyl cyanide compounds, (meth)acrylic acid ester compounds, and (meth)acrylic acid compounds are preferred, and styrene and (meth)acrylic acid ester compounds are more preferred. Specific examples of (meth)acrylic acid ester compounds include methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, cyclohexyl (meth)acrylate, and octyl (meth)acrylate.
Here, "(meth)acrylic" refers to either or both of "acrylic" and "methacrylic". The same applies to "(meth)acrylate".

The diene-based elastomer (D) is particularly preferably a core-shell type graft copolymer consisting of a core layer made of a polybutadiene-containing rubber component and a shell layer formed by copolymerizing a (meth)acrylic acid ester around the core layer. The above-mentioned core-shell type graft copolymer preferably contains 40% by mass or more of the butadiene-based rubber component, and more preferably contains 60% by mass or more. In addition, it is preferable that the (meth)acrylic acid component contains 10% by mass or more.

Preferred specific examples of these core-shell type graft copolymers include methyl methacrylate-butadiene-styrene copolymer (MBS), methyl methacrylate-acrylonitrile-butadiene-styrene copolymer (MABS), methyl methacrylate-butadiene copolymer (MB), methyl methacrylate-acrylic-butadiene rubber copolymer, methyl methacrylate-acrylic-butadiene rubber-styrene copolymer, etc. Such rubbery polymers may be used alone or in combination of two or more kinds.

Methods suitable for producing the diene-based elastomer (D) are well known, and examples of the polymerization method may include any of the following production methods: bulk polymerization, solution polymerization, suspension polymerization, and emulsion polymerization. Combinations of bulk polymerization-solution polymerization, bulk polymerization-suspension polymerization, and the like are also preferred. The copolymerization method may be either single-stage grafting or multi-stage grafting.

The diene elastomer (D) used has a phosphorus content of 1000 ppm or more as determined by fluorescent X-ray analysis. By having a phosphorus content of 1000 ppm or more, it is possible to obtain an alloy of the polycarbonate resin (A) and the graft copolymer (B) that exhibits a higher level of flame retardancy and is well balanced with impact strength.
The total phosphorus content of the diene based elastomer (D) is preferably greater than 1200 ppm, more preferably 1500 ppm or more, and preferably 2500 ppm or less, more preferably 2200 ppm or less.

The total amount of phosphorus atoms in the diene elastomer (D) is measured using an X-ray fluorescence analyzer. It means the mass ppm of the phosphorus component contained in the diene elastomer (D) converted into phosphorus element. The specific details of the measurement method are as described in the Examples.

The phosphorus in the diene elastomer (D) is thought to originate from the polymerization initiator, dispersant, and other components used and compounded in the manufacturing process, but diene elastomer (D) that satisfies the above-mentioned specified amount of phosphorus can also be selected and used from commercially available products.

The content of the diene elastomer (D) is in the range of 1 to 12 parts by mass per 100 parts by mass of the total of the polycarbonate resin (A) and the graft copolymer (B). If the content is less than 1 part by mass, the impact resistance improvement effect aimed at by the present invention cannot be obtained, and if the content exceeds 12 parts by mass, the heat resistance decreases and the flame retardancy of the polycarbonate resin composition deteriorates.

When the phosphorus-based flame retardant (C) is a condensed phosphate ester-based flame retardant, the content of the diene-based elastomer (D) is preferably in the range of 1 to 8 parts by mass per 100 parts by mass of the total of the polycarbonate resin (A) and the graft copolymer (B).
When the phosphorus-based flame retardant (C) is a phosphazene-based flame retardant, the content of the diene-based elastomer (D) is preferably in the range of 1 to 10 parts by mass per 100 parts by mass of the total of the polycarbonate resin (A) and the graft copolymer (B).

[Fluoropolymer (E)]
The polycarbonate resin composition of the present invention contains the fluoropolymer (E) in an amount of 0.1 to 1 part by mass per 100 parts by mass of the total of the polycarbonate resin (A) and the graft copolymer (B).
The fluoropolymer may be used alone or in any combination of two or more in any ratio. By containing the fluoropolymer in this way, the melting property of the resin composition can be improved, and the drip prevention property during combustion can be improved, and by combining with the phosphorus-based flame retardant (C), the flame retardancy can be further improved.
If the content of the fluoropolymer (E) is less than 0.1 parts by mass, the effect of improving flame retardancy becomes insufficient, and if it exceeds 1 part by mass, the molded product molded from the resin composition will have poor appearance and reduced mechanical strength. The content of the fluoropolymer (E) is preferably 0.15 parts by mass or more, particularly preferably 0.2 parts by mass or more, and is preferably 0.8 parts by mass or less, more preferably 0.6 parts by mass or less, and particularly preferably 0.5 parts by mass or less, based on 100 parts by mass of the total of the polycarbonate resin (A) and the graft copolymer (B).

The fluoropolymer (E) is preferably a fluoroolefin resin. The fluoroolefin resin is usually a polymer or copolymer containing a fluoroethylene structure, and specific examples thereof include a difluoroethylene resin, a tetrafluoroethylene resin, and a tetrafluoroethylene/hexafluoropropylene copolymer resin, with the tetrafluoroethylene resin being preferred.
In addition, the fluoropolymer is preferably one having fibril-forming ability, specifically, a fluoroolefin resin having fibril-forming ability can be mentioned. By having fibril-forming ability, the drip prevention property during combustion tends to be significantly improved.

As the fluoroolefin resin having fibril-forming ability, a fluoroethylene resin having fibril-forming ability is preferable, and examples thereof include "Teflon (registered trademark) 6J" manufactured by Mitsui-Chemours Fluoroproducts, Inc., and "Polyflon F201L", "Polyflon F103", and "Polyflon FA500C" manufactured by Daikin Industries, Ltd. Furthermore, examples of commercially available aqueous dispersions of fluoroethylene resins include "Teflon (registered trademark) 30J" and "Teflon (registered trademark) 31-JR" manufactured by Mitsui-Chemours Fluoroproducts, Inc., and "Fluon D-1" manufactured by Daikin Industries, Ltd.
Furthermore, a fluoroethylene polymer having a multilayer structure obtained by polymerizing a vinyl monomer can also be used. Examples of such a fluoroethylene polymer include a polystyrene-fluoroethylene composite, a polystyrene-acrylonitrile-fluoroethylene composite, a polymethyl methacrylate-fluoroethylene composite, and a polybutyl methacrylate-fluoroethylene composite, such as "Metablen A-3800" manufactured by Mitsubishi Chemical Corporation and "Brendex 449" manufactured by GE Specialty Chemicals.

The fluoropolymer (E) may be one type, or two or more types may be contained in any combination and ratio.

[Phosphorus-based stabilizer]
The polycarbonate resin composition of the present invention preferably contains a phosphorus-based stabilizer (heat stabilizer, antioxidant). Any known phosphorus-based stabilizer can be used. Specific examples include phosphorus oxoacids such as phosphoric acid, phosphonic acid, phosphorous acid, phosphinic acid, and polyphosphoric acid; acid pyrophosphate metal salts 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; organic phosphate compounds, organic phosphite compounds, and organic phosphonite compounds, with organic phosphite compounds being particularly preferred.

Examples of the organic phosphite compound include triphenyl phosphite, tris(mononylphenyl)phosphite, tris(mononyl/dinonyl phenyl)phosphite, tris(2,4-di-tert-butylphenyl)phosphite, monooctyldiphenyl phosphite, dioctyl monophenyl phosphite, monodecyldiphenyl phosphite, didecyl monophenyl phosphite, tridecyl phosphite, trilauryl phosphite, tristearyl phosphite, and 2,2-methylenebis(4,6-di-tert-butylphenyl)octyl phosphite. Specific examples of such organic phosphite compounds include "ADK STAB 1178", "ADK STAB 2112", and "ADK STAB HP-10" manufactured by ADEKA CORPORATION, "JP-351", "JP-360", and "JP-3CP" manufactured by Johoku Chemical Industry Co., Ltd., and "IRGAFOS 168" manufactured by BASF SE.
The phosphorus-based stabilizer may be contained alone or in any combination and ratio of two or more kinds.

The content of the phosphorus-based stabilizer is usually 0.001 parts by mass or more, preferably 0.01 parts by mass or more, more preferably 0.03 parts by mass or more, and usually 1 part by mass or less, preferably 0.7 parts by mass or less, more preferably 0.5 parts by mass or less, per 100 parts by mass of the total of the polycarbonate resin (A) and the graft copolymer (B). If the content of the phosphorus-based stabilizer is less than the lower limit of the above range, the thermal stabilization effect may be insufficient, and if the content of the phosphorus-based stabilizer is more than the upper limit of the above range, the effect may plateau and become uneconomical.

[Phenol-based stabilizer]
The polycarbonate resin composition of the present invention preferably contains a phenol-based stabilizer (heat stabilizer, antioxidant). Examples of the phenol-based stabilizer include hindered phenol-based antioxidants. 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]phosphate, 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], 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, 2-[1-(2-hydroxy-3,5-di-tert-pentylphenyl)ethyl]-4,6-di-tert-pentylphenyl acrylate, and the like.

Among these, pentaerythritol tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] and octadecyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate are preferred. Specific examples of such phenol-based antioxidants include "Irganox 1010" and "Irganox 1076" manufactured by BASF Corporation, and "Adeka STAB AO-50" and "Adeka STAB AO-60" manufactured by ADEKA Corporation.
The phenol-based stabilizer may be contained alone or in any combination and ratio of two or more kinds.

The content of the phenolic stabilizer is usually 0.001 parts by mass or more, preferably 0.01 parts by mass or more, and usually 1 part by mass or less, preferably 0.5 parts by mass or less, per 100 parts by mass of the total of the polycarbonate resin (A) and the graft copolymer (B). If the content of the phenolic stabilizer is less than the lower limit of the above range, the effect of the phenolic stabilizer may be insufficient, and if the content of the phenolic stabilizer exceeds the upper limit of the above range, the effect may plateau and it may become uneconomical.

[Ultraviolet absorber]
The polycarbonate resin composition of the present invention preferably contains an ultraviolet absorber. By containing an ultraviolet absorber, weather discoloration resistance can be further improved.

Examples of ultraviolet absorbers include inorganic ultraviolet absorbers such as cerium oxide and zinc oxide; and organic ultraviolet absorbers such as benzotriazole compounds, benzophenone compounds, salicylate compounds, cyanoacrylate compounds, triazine compounds, oxanilide compounds, malonic acid ester compounds, and hindered amine compounds. Of these, organic ultraviolet absorbers are preferred, with benzotriazole compounds, cyanoacrylate compounds, and triazine compounds being more preferred.

Specific examples of benzotriazole compounds include, for example, 2-(2'-hydroxy-5'-methylphenyl)benzotriazole, 2-[2'-hydroxy-3',5'-bis(α,α-dimethylbenzyl)phenyl]-benzotriazole, 2-(2'-hydroxy-3',5'-di-tert-butyl-phenyl)-benzotriazole, 2-(2'-hydroxy-3',5'-di-tert-butyl-phenyl)-5-chlorobenzotriazole, 2-(2'-hydroxy-3',5'-di-tert-butyl-phenyl)-5-chlorobenzotriazole, 2-(2'-hydroxy-3',5'-di-tert -amyl)-benzotriazole, 2-(2'-hydroxy-5'-tert-octylphenyl)benzotriazole, 2,2'-methylenebis[4-(1,1,3,3-tetramethylbutyl)-6-(2H-benzotriazol-2-yl)phenol], etc. are included, among which 2-(2'-hydroxy-5'-tert-octylphenyl)benzotriazole and 2,2'-methylenebis[4-(1,1,3,3-tetramethylbutyl)-6-(2H-benzotriazol-2-yl)phenol] are preferred, and 2-(2'-hydroxy-5'-tert-octylphenyl)benzotriazole is particularly preferred.

Specific preferred examples of benzophenone compounds include 2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-methoxybenzophenone-5-sulfonic acid, 2-hydroxy-4-n-octoxybenzophenone, 2-hydroxy-n-dodecyloxybenzophenone, bis(5-benzoyl-4-hydroxy-2-methoxyphenyl)methane, 2,2'-dihydroxy-4-methoxybenzophenone, and 2,2'-dihydroxy-4,4'-dimethoxybenzophenone.

Specific preferred examples of the cyanoacrylate compound include 1,3-bis[(2-cyano-3,3-diphenylacryloyl)oxy]-2,2-bis[[(2-cyano-3,3-diphenylacryloyl)oxy]methyl]propane, ethyl-2-cyano-3,3-diphenylacrylate, and 2-ethylhexyl-2-cyano-3,3-diphenylacrylate.
Preferable specific examples of the triazine compound include 2-(4,6-diphenyl-1,3,5-triazin-2-yl)-5-(hexyl)oxyphenol, 2-(4,6-bis-2,4-dimethylphenyl-1,3,5-triazin-2-yl)-5-(hexyl)oxyphenol, and 2-(4,6-diviphenyl-1,3,5-triazin-2-yl)-5-[(2-ethylhexyl)oxy]phenol.
Preferred specific examples of the salicylate compound include phenyl salicylate, 4-tert-butylphenyl salicylate, and the like.
A specific example of a preferred oxanilide compound is 2-ethoxy-2'-ethyloxalinic acid bis-arylamide.
As the malonic acid ester compound, 2-(alkylidene)malonic acid esters are preferred, and 2-(1-arylalkylidene)malonic acid esters are more preferred.

The content of the ultraviolet absorber, when contained, is usually 0.05 parts by mass or more, preferably 0.1 parts by mass or more, and usually 1 part by mass or less, preferably 0.5 parts by mass or less, based on 100 parts by mass in total of the polycarbonate resin (A) and the graft copolymer (B). If the content of the ultraviolet absorber is less than the lower limit of the above range, the effect of improving weather resistance may be insufficient, and if the content of the ultraviolet absorber is more than the upper limit of the above range, mold deposits and the like may occur, causing mold contamination.
The ultraviolet absorbing agent may be contained alone or in any combination and ratio of two or more kinds.

[Release agent]
The polycarbonate resin composition of the present invention also preferably contains a 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.

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.

As the aliphatic carboxylic acid in the ester of an aliphatic carboxylic acid and an alcohol, for example, the same aliphatic carboxylic acid as described above can be used. On the other hand, as the alcohol, for example, a saturated or unsaturated monohydric or polyhydric alcohol can be used. 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. Note that the term aliphatic is used here as a term that 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 esters may contain aliphatic carboxylic acids and/or alcohols as impurities. The above esters may be pure substances or mixtures of multiple compounds. Furthermore, the aliphatic carboxylic acids and alcohols that combine to form an ester may each be used alone or in any combination and ratio of two or more kinds.

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. 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 having various constituent components and molecular weights can also be used as long as the main component is within the above range.

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

The above-mentioned release agents may be contained in one type or in any combination and ratio of two or more types.

The content of the release agent is usually 0.001 parts by mass or more, preferably 0.01 parts by mass or more, and usually 2 parts by mass or less, preferably 1 part by mass or less, per 100 parts by mass of the total of the polycarbonate resin (A) and the graft copolymer (B). If the content of the release agent is less than the lower limit of the above range, the release effect may be insufficient, and if the content of the release agent is more than the upper limit of the above range, there is a possibility that the hydrolysis resistance may decrease and the mold may be contaminated during injection molding.

[Other ingredients]
The polycarbonate resin composition of the present invention may contain other components in addition to those described above, as necessary, as long as the desired physical properties are not significantly impaired. Examples of other components include resins other than the polycarbonate resin (A) and the graft copolymer (B), various resin additives, etc. Note that the other components may be contained alone or in any combination and ratio of two or more.

Other Resins Examples of other resins include thermoplastic polyester resins such as polyethylene terephthalate resin, polytrimethylene terephthalate resin, and polybutylene terephthalate resin;
Examples of the resin include 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.
The other resins may be contained either alone or in any combination and ratio of two or more kinds.
When a resin other than the polycarbonate resin (A) and the graft copolymer (B) is contained, the content thereof is preferably 20 parts by mass or less, more preferably 10 parts by mass or less, still more preferably 5 parts by mass or less, and particularly preferably 3 parts by mass or less, per 100 parts by mass of the total of the polycarbonate resin (A) and the graft copolymer (B).

Resin additives Examples of resin additives include dyes and pigments (including carbon black), antistatic agents, antifogging agents, antiblocking agents, flow improvers, plasticizers, dispersants, antibacterial agents, etc. The resin additives may be contained alone or in any combination and ratio of two or more kinds.

[Method for producing polycarbonate resin composition]
There is no limitation on the method for producing the polycarbonate resin composition of the present invention, and a wide variety of known methods for producing polycarbonate resin compositions can be used.
Specific examples include a method in which the above-mentioned essential components and other components to be blended as necessary are premixed using various mixers 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, or a kneader.

Also, for example, the polycarbonate resin composition of the present invention can be produced by not mixing the components in advance, or by mixing only some of the components in advance, feeding the mixture to an extruder using a feeder, and melt-kneading the mixture.
In addition, for example, some of the components are mixed in advance, fed to an extruder, and melt-kneaded to obtain a resin composition to be used as a masterbatch, and this masterbatch is then mixed again with the remaining components and melt-kneaded to produce the polycarbonate resin composition of the present invention.
In addition, for example, when mixing a component that is difficult to disperse, the dispersibility can be improved by dissolving or dispersing the component in advance in a solvent such as water or an organic solvent, and kneading the component with the solution or dispersion.

The manufacturing method of the molded product can be any molding method generally used for polycarbonate resin compositions. Examples include 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, IMC (in-mold coating molding) molding, extrusion molding, sheet molding, thermoforming, rotational molding, lamination molding, press molding, blow molding, and the like. Also, molding methods using a hot runner system can be used. Among these, injection molding methods such as injection molding, ultra-high speed injection molding, and injection compression molding are preferred.

[Molded products]
Examples of molded articles include parts for electric/electronic devices, office automation equipment, information terminal equipment, machine parts, home appliances, vehicle parts, building materials, various containers, leisure goods/miscellaneous goods, lighting equipment, etc. Among these, it is particularly suitable for use in the housings of electric/electronic devices and office automation equipment, and is particularly suitable for the housings of printers, copiers, projectors, modems, routers, etc.

The present invention will be explained in more detail below with reference to examples. However, the present invention should not be construed as being limited to the following examples.

The components used in the examples and comparative examples are as shown in Table 1 below.

The amount of phosphorus in the diene rubber graft copolymer was measured in vacuum using a Rigaku Corporation tabletop X-ray fluorescence analyzer "ZSX mini II" with a measurement area diameter of Φ30 mm and sample rotation of 30 rpm (ppm by mass).

(Examples 1 to 4, Comparative Examples 1 to 6)
<Resin pellet production>
The components listed in Table 1 above, except for the phosphorus-based flame retardant, were blended in the ratios (parts by mass) listed in the table below, and mixed in a tumbler for 20 minutes. The mixture was then fed from an upstream feeder into a twin-screw extruder "TEX30α" manufactured by Japan Steel Works, Ltd., equipped with one vent. While further feeding the phosphorus-based flame retardant from the middle of the barrel, the mixture was kneaded under conditions of a screw rotation speed of 450 rpm, a discharge rate of 35 kg/hr, and a barrel temperature of 260°C. The molten resin extruded in the form of strands was quenched in a water tank and pelletized using a pelletizer to obtain pellets of a polycarbonate resin composition.

<Preparation of test specimen>
The pellets obtained by the above-mentioned manufacturing method were dried at 80°C for 4 hours, and then injection molded into ISO multipurpose test pieces (3 mm) using a NEX80III injection molding machine manufactured by Nissei Plastic Industrial Co., Ltd. under conditions of a cylinder temperature of 240°C and a mold temperature of 40°C.
In addition, the pellets obtained by the above-mentioned production method were dried at 80°C for 4 hours, and then injection molded using an SE100DU injection molding machine manufactured by Sumitomo Heavy Industries, Ltd. under conditions of a cylinder temperature of 240°C, a mold temperature of 40°C, and a molding cycle of 30 seconds, to injection mold test pieces for UL combustion tests having a length of 125 mm, a width of 13 mm, and thicknesses of 1.0 mm and 1.5 mm.

<Impact resistance evaluation>
Using the ISO multipurpose test piece (3 mm) obtained by the above-mentioned method, a V-notch of R=0.25 was made in accordance with ISO179, and the notched Charpy impact strength (unit: kJ/m ² ) was measured at 23° C.

<Flame retardancy evaluation>
The flame retardancy of each polycarbonate resin composition was evaluated by conditioning the UL combustion test specimen obtained by the above-mentioned method in a temperature- and humidity-controlled room at a temperature of 23° C. and a humidity of 50% for 48 hours, in accordance with the UL94 test (combustion test for plastic materials for equipment parts) specified by the U.S. UL.
・UL94-V
The UL94-V test is a method for evaluating flame retardancy based on the afterflame time and dripping properties after a burner flame is applied for 10 seconds to the bottom end of a test specimen of a specified size held vertically. In order to have flame retardancy of V-0, V-1, or V-2, it is necessary to satisfy the standards shown in Table 2 below.

The afterflame time here refers to the length of time that the test specimen continues to burn with a flame after the ignition source is removed. Cotton ignition due to dripping is determined by whether or not the cotton used for marking, located approximately 300 mm below the bottom end of the test specimen, is ignited by dripping material from the test specimen. Furthermore, if even one of five tests for one material does not meet the above criteria, it is evaluated as not satisfying V-2 and is given an NR (not rated) rating.

・UL94-5V
In the UL94-5V test, flame retardancy is evaluated based on the afterflame time and dripping properties after a burner flame, tilted 20° from the vertical, is applied to the corner of a bar test piece of a specified size held vertically for 5 seconds and then removed for 5 seconds, repeated five times. In order to have 5VB flame retardancy, it is necessary to satisfy the standards shown in Table 3 below.

The afterflame time here is the length of time the test specimen continues to burn with a flame after the fifth contact with the flame. Cotton ignition by dripping is determined by whether or not the cotton used for marking, located approximately 300 mm below the bottom end of the test specimen, is ignited by dripping material from the test specimen. Furthermore, if any of the five tests for one material did not meet the above criteria even once, it was rated as NR (not rated).

The results are shown in Tables 4 and 5 below.

The polycarbonate resin composition of the present invention has excellent flame retardancy and impact resistance, and can therefore be widely and suitably used for components of electrical and electronic equipment, office automation equipment, information terminal equipment, machine parts, home appliances, vehicle parts, building materials, various containers, leisure goods and sundries, lighting equipment, etc.

Claims (6)

A polycarbonate resin composition comprising 70-90 mass% polycarbonate resin (A) and 10-30 mass% graft copolymer (B) containing aromatic vinyl monomer component (b1), vinyl cyanide monomer component (b2) and diene rubber polymer component (b3) for a total of 100 mass% of (A) and (B), comprising 5-30 mass parts of phosphorus-based flame retardant (C), 1-12 mass parts of diene elastomer (D), and 0.1-1 mass part of fluoropolymer (E), characterized in that the total phosphorus content of diene elastomer (D) is 1000 ppm or more in fluorescent X-ray analysis. The polycarbonate resin composition according to claim 1, wherein the content of the diene-based elastomer (D) is 2 to 10 parts by mass per 100 parts by mass of the total of (A) and (B). The polycarbonate resin composition according to claim 1, wherein the total phosphorus content of the diene elastomer (D) is 1500 ppm or more and 2200 ppm or less in fluorescent X-ray analysis. Pellets of the polycarbonate resin composition according to any one of claims 1 to 3. A molded article obtained by molding the polycarbonate resin composition according to any one of claims 1 to 3. A molded article obtained by molding the polycarbonate resin pellets according to claim 4.