JP7658771B2 - Flame-retardant polycarbonate resin composition and molded article thereof - Google Patents

Description

The present invention relates to a flame-retardant polycarbonate resin composition and a molded article thereof. More specifically, the present invention relates to a flame-retardant polycarbonate resin composition in which the impact strength and flame retardancy are improved and the decrease in impact strength and flame retardancy due to moist heat degradation is suppressed by adding an impact modifier, a phosphazene containing 98.5 mol % or more of a phosphazene cyclic trimer, an organic sulfonic acid metal salt, and an anti-drip agent to a polycarbonate resin.

Polycarbonate resin has excellent mechanical properties, dimensional accuracy, electrical properties, and thermal properties, and is widely used as an engineering plastic in various fields such as electrical and electronic equipment, automobiles, and office automation. In recent years, as products have become smaller and lighter, products for office automation equipment and home appliances have become thinner, and materials with excellent impact strength and flame retardancy are required. Furthermore, due to the diversification of usage environments, including indoors and outdoors, and the increased utilization rate of recycled materials through closed recycling, these products require materials that not only have excellent impact strength and flame retardancy, but also have excellent durability with little deterioration even after long-term use. In other words, there is a demand for materials that have excellent impact strength and flame retardancy, and that do not deteriorate much due to moist heat degradation.

In order to solve such problems, Patent Document 1 discloses a flame-retardant polycarbonate resin composition comprising an aromatic polycarbonate resin, an impact modifier, a phosphazene containing 98.5 mol % or more of a phosphazene cyclic trimer, and an anti-drip agent. However, the desired suppression of the decrease in impact strength and flame retardancy due to moist heat deterioration was insufficient and unsatisfactory.

On the other hand, it is known to combine phosphazene and an organic sulfonic acid metal salt to improve impact strength and flame retardancy. Patent Document 2 discloses a flame-retardant polycarbonate resin composition consisting of a polycarbonate resin, a phosphazene, a silicone compound, an organic sulfonic acid metal salt, and an anti-drip agent. Patent Document 3 discloses a flame-retardant polycarbonate resin composition consisting of a polycarbonate resin, a phosphazene, an organic sulfonic acid metal salt, a core-shell type graft copolymer, and a fluorinated polyolefin. However, in both documents, the suppression of the decrease in impact strength and flame retardancy due to moist heat deterioration required was insufficient and unsatisfactory.

WO2020/066535 publication JP 2004-67881 A JP 2016-84414 A

In view of the above, the object of the present invention is to provide a flame-retardant polycarbonate resin composition that is excellent in impact strength and flame retardancy and in which the decrease in impact strength and flame retardancy due to moist heat degradation is suppressed.

As a result of intensive research by the present inventors to solve the above problems, they have found a method for obtaining a flame-retardant polycarbonate resin composition having improved impact strength and flame retardancy and suppressed deterioration in impact strength and flame retardancy due to moist heat degradation, by adding an impact modifier, a phosphazene containing 98.5 mol % or more of a phosphazene cyclic trimer, an organic sulfonic acid metal salt, and an anti-drip agent to a polycarbonate resin, and have thus completed the present invention.

According to the present invention, the above object is achieved by a flame-retardant polycarbonate resin composition, which is characterized by containing, relative to 100 parts by weight of (A) polycarbonate resin (component A), 1 to 8 parts by weight of (B) impact modifier (component B), 1 to 8 parts by weight of (C) phosphazene containing 98.5 mol% or more of phosphazene cyclic trimer (component C), 0.01 to 0.5 parts by weight of (D) organic sulfonic acid metal salt (component D), and 0.05 to 2 parts by weight of (E) drip prevention agent (component E).

The details of the present invention are described below.

(Component A: polycarbonate resin)
The polycarbonate resin used in the present invention is obtained by reacting a dihydric phenol with a carbonate precursor. Examples of the reaction method include an interfacial polymerization method, a melt transesterification method, a solid-phase transesterification method of a carbonate prepolymer, and a ring-opening polymerization method of a cyclic carbonate compound.

Representative examples of the dihydric phenols used herein include hydroquinone, resorcinol, 4,4'-biphenol, 1,1-bis(4-hydroxyphenyl)ethane, 2,2-bis(4-hydroxyphenyl)propane (commonly known as bisphenol A), 2,2-bis(4-hydroxy-3-methylphenyl)propane, 2,2-bis(4-hydroxyphenyl)butane, 1,1-bis(4-hydroxyphenyl)-1-phenylethane, 1,1-bis(4-hydroxyphenyl)cyclohexane, 1,1-bis(4-hydroxyphenyl)-3,3,5-trimethylcyclohexane, 2,2-bis(4-hydroxyphenyl)pentane, 4,4'-(p-phenylene) Examples of the dihydric phenol include 4,4'-(m-phenylenediisopropylidene)diphenol, 1,1-bis(4-hydroxyphenyl)-4-isopropylcyclohexane, bis(4-hydroxyphenyl)oxide, bis(4-hydroxyphenyl)sulfide, bis(4-hydroxyphenyl)sulfoxide, bis(4-hydroxyphenyl)sulfone, bis(4-hydroxyphenyl)ketone, bis(4-hydroxyphenyl)ester, bis(4-hydroxy-3-methylphenyl)sulfide, 9,9-bis(4-hydroxyphenyl)fluorene, and 9,9-bis(4-hydroxy-3-methylphenyl)fluorene. The preferred dihydric phenols are bis(4-hydroxyphenyl)alkanes, and among them, bisphenol A is particularly preferred from the viewpoint of impact resistance and is widely used.

In the present invention, in addition to the general-purpose polycarbonate bisphenol A polycarbonate, it is possible to use special polycarbonates produced using other dihydric phenols as component A.

For example, polycarbonates (homopolymers or copolymers) using 4,4'-(m-phenylenediisopropylidene)diphenol (hereinafter sometimes abbreviated as "BPM"), 1,1-bis(4-hydroxyphenyl)cyclohexane, 1,1-bis(4-hydroxyphenyl)-3,3,5-trimethylcyclohexane (hereinafter sometimes abbreviated as "Bis-TMC"), 9,9-bis(4-hydroxyphenyl)fluorene and 9,9-bis(4-hydroxy-3-methylphenyl)fluorene (hereinafter sometimes abbreviated as "BCF") as part or all of the dihydric phenol components are suitable for applications where dimensional change due to water absorption and dimensional stability are particularly demanding. These dihydric phenols other than BPA are preferably used in an amount of 5 mol % or more, particularly 10 mol % or more, of the total dihydric phenol components constituting the polycarbonate.

In particular, when high rigidity and better hydrolysis resistance are required, it is particularly preferable that the component A constituting the resin composition is a copolymer polycarbonate of the following (1) to (3).
(1) A copolymer polycarbonate in which, relative to 100 mol % of the dihydric phenol component constituting the polycarbonate, BPM is 20 to 80 mol % (more preferably 40 to 75 mol %, and even more preferably 45 to 65 mol %) and BCF is 20 to 80 mol % (more preferably 25 to 60 mol %, and even more preferably 35 to 55 mol %).
(2) A copolymer polycarbonate in which, relative to 100 mol % of the dihydric phenol component constituting the polycarbonate, BPA is 10 to 95 mol % (more preferably 50 to 90 mol %, even more preferably 60 to 85 mol %) and BCF is 5 to 90 mol % (more preferably 10 to 50 mol %, even more preferably 15 to 40 mol %).
(3) A copolymer polycarbonate in which, relative to 100 mol % of the dihydric phenol component constituting the polycarbonate, BPM is 20 to 80 mol % (more preferably 40 to 75 mol %, and even more preferably 45 to 65 mol %) and Bis-TMC is 20 to 80 mol % (more preferably 25 to 60 mol %, and even more preferably 35 to 55 mol %).

These special polycarbonates may be used alone or in a suitable mixture of two or more. They may also be used in a mixture with the commonly used bisphenol A polycarbonate.

The manufacturing methods and properties of these special polycarbonates are described in detail, for example, in JP-A-6-172508, JP-A-8-27370, JP-A-2001-55435, and JP-A-2002-117580.

Among the various polycarbonates mentioned above, those in which the copolymer composition and the like are adjusted to bring the water absorption rate and Tg (glass transition temperature) into the ranges described below have good hydrolysis resistance of the polymer itself and are also remarkably excellent in terms of low warpage after molding, and are therefore particularly suitable in fields where dimensional stability is required.
(i) A polycarbonate having a water absorption of 0.05 to 0.15%, preferably 0.06 to 0.13%, and a Tg of 120 to 180°C, or (ii) a polycarbonate having a Tg of 160 to 250°C, preferably 170 to 230°C, and a water absorption of 0.10 to 0.30%, preferably 0.13 to 0.30%, more preferably 0.14 to 0.27%.

The water absorption rate of polycarbonate is measured by measuring the moisture content after immersing a disk-shaped test piece with a diameter of 45 mm and a thickness of 3.0 mm in water at 23°C for 24 hours in accordance with ISO 62-1980. The glass transition temperature (Tg) is a value determined by differential scanning calorimetry (DSC) in accordance with JIS K7121.

Carbonate precursors include carbonyl halides, carbonic acid diesters, or haloformates, such as phosgene, diphenyl carbonate, or dihaloformates of dihydric phenols.

When the dihydric phenol and carbonate precursor are used to produce the polycarbonate resin by interfacial polymerization, a catalyst, a terminal stopper, an antioxidant to prevent the dihydric phenol from being oxidized, etc. may be used as necessary. The polycarbonate resin of the present invention includes a branched polycarbonate resin copolymerized with a trifunctional or higher polyfunctional aromatic compound, a polyester carbonate resin copolymerized with an aromatic or aliphatic (including alicyclic) bifunctional carboxylic acid, a copolymerized polycarbonate resin copolymerized with a bifunctional alcohol (including alicyclic), and a polyester carbonate resin copolymerized with such a bifunctional carboxylic acid and a bifunctional alcohol. The polycarbonate resin may also be a mixture of two or more of the obtained polycarbonate resins.

The branched polycarbonate resin can impart drip prevention properties and the like to the resin composition of the present invention. Examples of trifunctional or higher polyfunctional aromatic compounds used in such branched polycarbonate resins include phloroglucine, phloroglucide, 4,6-dimethyl-2,4,6-tris(4-hydroxyphenyl)heptene-2,2,4,6-trimethyl-2,4,6-tris(4-hydroxyphenyl)heptane, 1,3,5-tris(4-hydroxyphenyl)benzene, 1,1,1-tris(4-hydroxyphenyl)ethane, 1,1,1-tris(3,5-dimethyl-4-hydroxyphenyl)ethane, 2,6-bis(2-hydroxy-5-methylbenzyl)-4-methylphenol, 4-{4-[1,1-bis(4- Examples include trisphenols such as {4-hydroxyphenyl)ethyl]benzene}-α,α-dimethylbenzylphenol, tetra(4-hydroxyphenyl)methane, bis(2,4-dihydroxyphenyl)ketone, 1,4-bis(4,4-dihydroxytriphenylmethyl)benzene, trimellitic acid, pyromellitic acid, benzophenonetetracarboxylic acid, and acid chlorides thereof, among which 1,1,1-tris(4-hydroxyphenyl)ethane and 1,1,1-tris(3,5-dimethyl-4-hydroxyphenyl)ethane are preferred, with 1,1,1-tris(4-hydroxyphenyl)ethane being particularly preferred.

In the branched polycarbonate, the constituent units derived from the polyfunctional aromatic compound preferably account for 0.01 to 1 mol %, more preferably 0.05 to 0.9 mol %, and even more preferably 0.05 to 0.8 mol %, of the total 100 mol % of the constituent units derived from the dihydric phenol and the constituent units derived from the polyfunctional aromatic compound.

In particular, in the case of the melt transesterification method, branched structural units may be generated as a side reaction, and the amount of such branched structural units is preferably 0.001 to 1 mol %, more preferably 0.005 to 0.9 mol %, and even more preferably 0.01 to 0.8 mol %, based on the total of 100 mol % including the structural units derived from the dihydric phenol. The proportion of such branched structures can be calculated by ¹ H-NMR measurement.

The aliphatic bifunctional carboxylic acid is preferably an α,ω-dicarboxylic acid. Examples of the aliphatic bifunctional carboxylic acid include linear saturated aliphatic dicarboxylic acids such as sebacic acid (decanedioic acid), dodecanedioic acid, tetradecanedioic acid, octadecanedioic acid, and icosane diacid, as well as alicyclic dicarboxylic acids such as cyclohexanedicarboxylic acid. As the bifunctional alcohol, an alicyclic diol is more preferable, and examples thereof include cyclohexanedimethanol, cyclohexanediol, and tricyclodecane dimethanol.

The reaction formats for producing the polycarbonate resin of the present invention, such as the interfacial polymerization method, the melt transesterification method, the carbonate prepolymer solid-phase transesterification method, and the ring-opening polymerization method of a cyclic carbonate compound, are well known in various literature and patent publications.

The viscosity average molecular weight (M) of the polycarbonate resin is not particularly limited, but is preferably 1.8×10 ⁴ to 4.0×10 ⁴ , more preferably 2.0×10 ⁴ to 3.5×10 ⁴ , and even more preferably 2.2×10 ⁴ to 3.0×10 ^4. With a polycarbonate resin having a viscosity average molecular weight of less than 1.8×10 ⁴ , good mechanical properties may not be obtained. On the other hand, a resin composition obtained from a polycarbonate resin having a viscosity average molecular weight of more than 4.0×10 ⁴ is inferior in versatility in that it has poor fluidity during injection molding.

The polycarbonate resin may be obtained by mixing those having a viscosity average molecular weight outside the above range. In particular, polycarbonate resins having a viscosity average molecular weight exceeding the above range (5×10 ⁴ ) have improved entropy elasticity. As a result, they exhibit good moldability in gas-assisted molding and foam molding, which are sometimes used when molding reinforced resin materials into structural members. Such improvement in moldability is even better than that of the branched polycarbonate. In a more preferred embodiment, component A is composed of a polycarbonate resin (component A-1-1-1) having a viscosity average molecular weight of ⁷ ×10 ⁴ to 3×10 ⁵ , and ^a polycarbonate resin (component A-1-1-2) having a viscosity average molecular weight of 1×10 ⁴ to 3×10 4, and a polycarbonate resin (component A-1-1) having a viscosity average molecular weight of 1.6×10 4 to 3.5×10 ⁴ (hereinafter sometimes referred to as a “polycarbonate resin containing a high molecular weight component”) can also be used.

In such a high molecular weight component-containing polycarbonate resin (component A-1-1), the molecular weight of component A-1-1-1 is preferably 7 x 10 ⁴ to 2 x 10 ⁵ , more preferably 8 x 10 ⁴ to 2 x 10 ⁵ , even more preferably 1 x 10 ⁵ to 2 x 10 ⁵ , and particularly preferably 1 x 10 ⁵ to 1.6 x 10 ^5. The molecular weight of component A-1-1-2 is preferably 1 x 10 ⁴ to 2.5 x 10 ⁴ , more preferably 1.1 x 10 ⁴ to 2.4 x 10 ⁴ , even more preferably 1.2 x 10 ⁴ to 2.4 x 10 ⁴ , and particularly preferably 1.2 x 10 ⁴ to 2.3 x 10 ⁴ .

The polycarbonate resin containing high molecular weight components (component A-1-1) can be obtained by mixing the components A-1-1-1 and A-1-1-2 in various ratios and adjusting to satisfy a specified molecular weight range. Preferably, the component A-1-1-1 is 2 to 40% by weight out of 100% by weight of component A-1-1, more preferably 3 to 30% by weight, even more preferably 4 to 20% by weight, and particularly preferably 5 to 20% by weight.

Methods for preparing the A-1-1 component include (1) a method in which the A-1-1-1 and A-1-1-2 components are polymerized independently and then mixed; (2) a method in which a polycarbonate resin that shows multiple polymer peaks in a molecular weight distribution chart obtained by GPC, as typified by the method shown in JP-A-5-306336, is produced in the same system, and the polycarbonate resin is produced so as to satisfy the conditions for the A-1-1 component of the present invention; and (3) a method in which the polycarbonate resin obtained by the above production method (production method (2)) is mixed with the A-1-1-1 and/or A-1-1-2 components that have been produced separately.

The viscosity average molecular weight in the present invention is determined by first determining the specific viscosity (η _SP ) calculated by the following formula using an Ostwald viscometer from a solution in which 0.7 g of polycarbonate resin is dissolved in 100 ml of methylene chloride at 20° C.:
Specific viscosity (η _SP )=(t−t ₀ )/t ₀
[ _t0 is the number of seconds that methylene chloride falls, and t is the number of seconds that the sample solution falls]
The viscosity average molecular weight M is calculated from the specific viscosity (η _SP ) thus determined according to the following formula.
η _SP /c = [η] + 0.45 × [η] ² c (where [η] is the intrinsic viscosity)
[η]=1.23× ^10-4 M ^0.83
c=0.7

The viscosity average molecular weight of the polycarbonate resin in the flame-retardant polycarbonate resin composition of the present invention is calculated as follows. That is, the composition is mixed with methylene chloride in an amount 20 to 30 times its weight, and the soluble components in the composition are dissolved. The soluble components are collected by filtration through Celite. The solvent in the resulting solution is then removed. The solid after the solvent removal is thoroughly dried to obtain a solid of components that dissolve in methylene chloride. 0.7 g of the solid is dissolved in 100 ml of methylene chloride to obtain a solution, and the specific viscosity at 20°C is determined in the same manner as above, and the viscosity average molecular weight M is calculated from the specific viscosity in the same manner as above.

A polycarbonate-polydiorganosiloxane copolymer resin can also be used as the polycarbonate resin (component A) of the present invention. The polycarbonate-polydiorganosiloxane copolymer resin is preferably a copolymer resin prepared by copolymerizing a dihydric phenol represented by the following general formula (1) and a hydroxyaryl-terminated polydiorganosiloxane represented by the following general formula (3).

[In the above general formula (1), R ¹ and R ² each independently represent a group selected from the group consisting of a hydrogen atom, a halogen atom, an alkyl group having 1 to 18 carbon atoms, an alkoxy group having 1 to 18 carbon atoms, a cycloalkyl group having 6 to 20 carbon atoms, a cycloalkoxy group having 6 to 20 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, an aryl group having 6 to 14 carbon atoms, an aryloxy group having 6 to 14 carbon atoms, an aralkyl group having 7 to 20 carbon atoms, an aralkyloxy group having 7 to 20 carbon atoms, a nitro group, an aldehyde group, a cyano group, and a carboxy group, and when there are a plurality of each, they may be the same or different, e and f each represent an integer of 1 to 4, and W represents a single bond or at least one group selected from the group consisting of groups represented by the following general formula (2).]

[In the above general formula (2), R ¹¹ , R ¹² , R ¹³ , R ¹⁴ , R ¹⁵ , R ¹⁶ , R ¹⁷ and R ¹⁸ each independently represent a group selected from the group consisting of a hydrogen atom, an alkyl group having 1 to 18 carbon atoms, an aryl group having 6 to 14 carbon atoms and an aralkyl group having 7 to 20 carbon atoms; R ¹⁹ and R ²⁰ each independently represents a group selected from the group consisting of a hydrogen atom, a halogen atom, an alkyl group having 1 to 18 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, a cycloalkyl group having 6 to 20 carbon atoms, a cycloalkoxy group having 6 to 20 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, an aryl group having 6 to 14 carbon atoms, an aryloxy group having 6 to 10 carbon atoms, an aralkyl group having 7 to 20 carbon atoms, an aralkyloxy group having 7 to 20 carbon atoms, a nitro group, an aldehyde group, a cyano group, and a carboxy group, and when there are a plurality of such groups, they may be the same or different, g is an integer from 1 to 10, and h is an integer from 4 to 7.]

[In the above general formula (3), R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ and R ⁸ are each independently a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 12 carbon atoms; R ⁹ and R ¹⁰ are each independently a hydrogen atom, a halogen atom, an alkyl group having 1 to 10 carbon atoms, or an alkoxy group having 1 to 10 carbon atoms; p is a natural number; q is 0 or a natural number; and p+q is a natural number from 10 to 300. X is a divalent aliphatic group having 2 to 8 carbon atoms.]

Examples of the dihydric phenol (I) represented by the general formula (1) include 4,4'-dihydroxybiphenyl, bis(4-hydroxyphenyl)methane, 1,1-bis(4-hydroxyphenyl)ethane, 1,1-bis(4-hydroxyphenyl)-1-phenylethane, 2,2-bis(4-hydroxyphenyl)propane, 2,2-bis(4-hydroxy-3-methylphenyl)propane, 1,1-bis(4-hydroxyphenyl)-3,3,5-trimethylcyclohexane, 2,2-bis(4-hydroxy-3,3'-biphenyl)propane, 2,2-bis(4-hydroxy-3-isopropylphenyl)propane, 2,2-bis(3-t- butyl-4-hydroxyphenyl)propane, 2,2-bis(4-hydroxyphenyl)butane, 2,2-bis(4-hydroxyphenyl)octane, 2,2-bis(3-bromo-4-hydroxyphenyl)propane, 2,2-bis(3,5-dimethyl-4-hydroxyphenyl)propane, 2,2-bis(3-cyclohexyl-4-hydroxyphenyl)propane, 1,1-bis(3-cyclohexyl-4-hydroxyphenyl)cyclohexane, bis(4-hydroxyphenyl)diphenylmethane, 9,9-bis(4-hydroxyphenyl)fluorene, 9,9-bis(4-hydroxy-3-methylphenyl)fluorene, 1,1-bis (4-hydroxyphenyl)cyclohexane, 1,1-bis(4-hydroxyphenyl)cyclopentane, 4,4'-dihydroxydiphenyl ether, 4,4'-dihydroxy-3,3'-dimethyldiphenyl ether, 4,4'-sulfonyldiphenol, 4,4'-dihydroxydiphenyl sulfoxide, 4,4'-dihydroxydiphenyl sulfide, 2,2'-dimethyl-4,4'-sulfonyldiphenol, 4,4'-dihydroxy-3,3'-dimethyldiphenyl sulfoxide, 4,4'-dihydroxy-3,3'-dimethyldiphenyl sulfide, 2,2'-diphenyl-4,4'-sulfonyldiphenol, 4,4'-di Examples include hydroxy-3,3'-diphenyldiphenyl sulfoxide, 4,4'-dihydroxy-3,3'-diphenyldiphenyl sulfide, 1,3-bis{2-(4-hydroxyphenyl)propyl}benzene, 1,4-bis{2-(4-hydroxyphenyl)propyl}benzene, 1,4-bis(4-hydroxyphenyl)cyclohexane, 1,3-bis(4-hydroxyphenyl)cyclohexane, 4,8-bis(4-hydroxyphenyl)tricyclo[5.2.1.02,6]decane, 4,4'-(1,3-adamantanediyl)diphenol, and 1,3-bis(4-hydroxyphenyl)-5,7-dimethyladamantane.

Among these, 1,1-bis(4-hydroxyphenyl)-1-phenylethane, 2,2-bis(4-hydroxyphenyl)propane, 2,2-bis(4-hydroxy-3-methylphenyl)propane, 1,1-bis(4-hydroxyphenyl)cyclohexane, 1,1-bis(4-hydroxyphenyl)-3,3,5-trimethylcyclohexane, 4,4'-sulfonyldiphenol, 2,2'-dimethyl-4,4'-sulfonyldiphenol, 9,9-bis(4-hydroxy-3-methylphenyl)fluorene, 1,3-bis{2-(4-hydroxyphenyl)propyl}benzene, and 1,4-bis{2-(4-hydroxyphenyl)propyl}benzene are preferred, and 2,2-bis(4-hydroxyphenyl)propane, 1,1-bis(4-hydroxyphenyl)cyclohexane (BPZ), 4,4'-sulfonyldiphenol, and 9,9-bis(4-hydroxy-3-methylphenyl)fluorene are particularly preferred. Among these, 2,2-bis(4-hydroxyphenyl)propane, which has excellent strength and good durability, is the most suitable. These may be used alone or in combination of two or more.

As the hydroxyaryl-terminated polydiorganosiloxane represented by the above general formula (3), for example, the compounds shown below are preferably used.

Hydroxyaryl-terminated polydiorganosiloxane (II) is easily produced by subjecting a phenol having an olefinic unsaturated carbon-carbon bond, preferably vinylphenol, 2-allylphenol, isopropenylphenol, or 2-methoxy-4-allylphenol, to a polysiloxane chain end having a predetermined degree of polymerization through a hydrosilylation reaction. Among these, (2-allylphenol)-terminated polydiorganosiloxane and (2-methoxy-4-allylphenol)-terminated polydiorganosiloxane are preferred, and (2-allylphenol)-terminated polydimethylsiloxane and (2-methoxy-4-allylphenol)-terminated polydimethylsiloxane are particularly preferred. Hydroxyaryl-terminated polydiorganosiloxane (II) preferably has a molecular weight distribution (Mw/Mn) of 3 or less. In order to achieve even better low outgassing properties during high-temperature molding and low-temperature impact properties, the molecular weight distribution (Mw/Mn) is more preferably 2.5 or less, and even more preferably 2 or less. If the upper limit of this preferred range is exceeded, the amount of outgassing during high-temperature molding may be large, and low-temperature impact resistance may be poor.

In order to achieve a high level of impact resistance, the diorganosiloxane polymerization degree (p+q) of the hydroxyaryl-terminated polydiorganosiloxane (II) is preferably 10 to 300. The diorganosiloxane polymerization degree (p+q) is preferably 10 to 200, more preferably 12 to 150, and even more preferably 14 to 100. Below the lower limit of this preferred range, the impact resistance that is a characteristic of the polycarbonate-polydiorganosiloxane copolymer is not effectively expressed, and above the upper limit of this preferred range, poor appearance appears.

The polydiorganosiloxane content of the polycarbonate-polydiorganosiloxane copolymer resin is preferably 0.1 to 50% by weight. The polydiorganosiloxane content is more preferably 0.5 to 30% by weight, and even more preferably 1 to 20% by weight. At or above the lower limit of this preferred range, excellent impact resistance and flame retardancy are obtained, while at or below the upper limit of this preferred range, a stable appearance that is less susceptible to the effects of molding conditions is easily obtained. The polydiorganosiloxane polymerization degree and polydiorganosiloxane content can be calculated by 1H-NMR measurement.

In the present invention, only one type of hydroxyaryl-terminated polydiorganosiloxane (II) may be used, or two or more types may be used.

In addition, other comonomers than the dihydric phenol (I) and the hydroxyaryl-terminated polydiorganosiloxane (II) may be used in an amount of 10% by weight or less based on the total weight of the copolymer, provided that the use of these comonomers does not interfere with the performance of the present invention.

In the present invention, a mixed solution containing an oligomer having a terminal chloroformate group is prepared in advance by reacting a dihydric phenol (I) with a carbonate ester-forming compound in a mixed solution of a water-insoluble organic solvent and an aqueous alkaline solution.

When producing an oligomer of dihydric phenol (I), the entire amount of dihydric phenol (I) used in the method of the present invention may be converted into an oligomer at once, or a part of it may be added as a post-added monomer as a reaction raw material to the interfacial polycondensation reaction in the latter stage. A post-added monomer is added to speed up the polycondensation reaction in the latter stage, and there is no need to add it if it is not necessary.

The method for this oligomer formation reaction is not particularly limited, but it is usually preferable to carry out the reaction in a solvent in the presence of an acid binder.

The proportion of the carbonate ester-forming compound used may be adjusted appropriately, taking into consideration the stoichiometric ratio (equivalents) of the reaction. When using a gaseous carbonate ester-forming compound such as phosgene, it is preferable to blow this into the reaction system.

As the acid binder, for example, an alkali metal hydroxide such as sodium hydroxide or potassium hydroxide, an alkali metal carbonate such as sodium carbonate or potassium carbonate, an organic base such as pyridine, or a mixture of these may be used. Similarly to the above, the proportion of the acid binder used may be appropriately determined taking into account the stoichiometric ratio (equivalents) of the reaction. Specifically, it is preferable to use 2 equivalents or a slightly excess amount of the acid binder relative to the number of moles of the dihydric phenol (I) used to form the oligomer (usually 1 mole corresponds to 2 equivalents).

As the solvent, a solvent inert to various reactions, such as those used in the production of known polycarbonates, may be used alone or as a mixture of solvents. Representative examples include hydrocarbon solvents such as xylene, and halogenated hydrocarbon solvents such as methylene chloride and chlorobenzene. In particular, halogenated hydrocarbon solvents such as methylene chloride are preferably used.

There are no particular restrictions on the reaction pressure for oligomer formation, and it may be normal pressure, elevated pressure, or reduced pressure, but it is usually advantageous to carry out the reaction under normal pressure. The reaction temperature is selected from the range of -20 to 50°C, and since heat is generated during polymerization in many cases, it is desirable to cool the reaction with water or ice. The reaction time depends on other conditions and cannot be specified in general, but is usually carried out for 0.2 to 10 hours. The pH range for the oligomer formation reaction is the same as known interfacial reaction conditions, and the pH is always adjusted to 10 or higher.

In this way, the present invention obtains a mixed solution containing an oligomer of dihydric phenol (I) having terminal chloroformate groups, and then adds hydroxyaryl-terminated polydiorganosiloxane (II) represented by general formula (4) that has been highly refined to a molecular weight distribution (Mw/Mn) of 3 or less to the dihydric phenol (I) while stirring the mixed solution, and obtains a polycarbonate-polydiorganosiloxane copolymer by interfacially polycondensing the hydroxyaryl-terminated polydiorganosiloxane (II) and the oligomer.

(In the above general formula (4), R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ and R ⁸ are each independently a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 12 carbon atoms; R ⁹ and R ¹⁰ are each independently a hydrogen atom, a halogen atom, an alkyl group having 1 to 10 carbon atoms, or an alkoxy group having 1 to 10 carbon atoms; p is a natural number; q is 0 or a natural number; and p+q is a natural number from 10 to 300; and X is a divalent aliphatic group having 2 to 8 carbon atoms.)

In carrying out the interfacial polycondensation reaction, an acid binder may be appropriately added in consideration of the stoichiometric ratio (equivalents) of the reaction. Examples of acid binders include alkali metal hydroxides such as sodium hydroxide and potassium hydroxide, alkali metal carbonates such as sodium carbonate and potassium carbonate, organic bases such as pyridine, and mixtures thereof. Specifically, when the hydroxyaryl-terminated polydiorganosiloxane (II) used or a portion of the dihydric phenol (I) as described above is added to this reaction stage as a post-added monomer, it is preferable to use 2 equivalents or an excess amount of alkali relative to the total moles of the post-added dihydric phenol (I) and hydroxyaryl-terminated polydiorganosiloxane (II) (usually 1 mole corresponds to 2 equivalents).

The polycondensation by interfacial polycondensation reaction between the oligomer of dihydric phenol (I) and the hydroxyaryl-terminated polydiorganosiloxane (II) is carried out by vigorously stirring the above mixture.

In such polymerization reactions, a terminal terminator or a molecular weight regulator is usually used. Examples of terminal terminators include compounds having a monovalent phenolic hydroxyl group, such as ordinary phenol, p-tert-butylphenol, p-cumylphenol, tribromophenol, and the like, as well as long-chain alkylphenols, aliphatic carboxylic acid chlorides, aliphatic carboxylic acids, hydroxybenzoic acid alkyl esters, hydroxyphenyl alkyl acid esters, and alkyl ether phenols. The amount of the agent used is in the range of 100 to 0.5 moles, preferably 50 to 2 moles, per 100 moles of all dihydric phenol compounds used, and it is of course possible to use two or more compounds in combination.

To accelerate the polycondensation reaction, a catalyst such as a tertiary amine like triethylamine or a quaternary ammonium salt may be added.

The reaction time for such a polymerization reaction is preferably 30 minutes or more, more preferably 50 minutes or more. If desired, a small amount of an antioxidant such as sodium sulfite or hydrosulfide may be added.

A branching agent can be used in combination with the above dihydric phenol compound to produce a branched polycarbonate-polydiorganosiloxane. Examples of trifunctional or higher polyfunctional aromatic compounds used in such branched polycarbonate-polydiorganosiloxane copolymer resins include phloroglucine, phloroglucide, 4,6-dimethyl-2,4,6-tris(4-hydroxyphenyl)heptene-2,2,4,6-trimethyl-2,4,6-tris(4-hydroxyphenyl)heptane, 1,3,5-tris(4-hydroxyphenyl)benzene, 1,1,1-tris(4-hydroxyphenyl)ethane, 1,1,1-tris(3,5-dimethyl-4-hydroxyphenyl)ethane, 2,6-bis(2-hydroxy-5-methylbenzyl)-4-methylphenol, 4-{4-[1 [0113] Examples of the hydroxyphenyl group include trisphenols such as {1,1,1-bis(4-hydroxyphenyl)ethyl]benzene}-α,α-dimethylbenzylphenol, tetra(4-hydroxyphenyl)methane, bis(2,4-dihydroxyphenyl)ketone, 1,4-bis(4,4-dihydroxytriphenylmethyl)benzene, trimellitic acid, pyromellitic acid, benzophenonetetracarboxylic acid, and acid chlorides thereof. Among these, 1,1,1-tris(4-hydroxyphenyl)ethane and 1,1,1-tris(3,5-dimethyl-4-hydroxyphenyl)ethane are preferred, and 1,1,1-tris(4-hydroxyphenyl)ethane is particularly preferred. The proportion of the polyfunctional compound in the branched polycarbonate-polydiorganosiloxane copolymer resin is preferably 0.001 to 1 mol %, more preferably 0.005 to 0.9 mol %, still more preferably 0.01 to 0.8 mol %, and particularly preferably 0.05 to 0.4 mol %, based on the total amount of the polycarbonate-polydiorganosiloxane copolymer resin. The amount of branched structures can be calculated by ¹ H-NMR measurement.

The reaction pressure can be reduced, normal, or increased, but is usually suitable for carrying out the reaction at normal pressure or at the reaction system's own pressure. The reaction temperature is selected from the range of -20 to 50°C, and since the polymerization often generates heat, it is desirable to cool the reaction with water or ice. The reaction time varies depending on other conditions such as the reaction temperature and cannot be specified in general, but is usually carried out for 0.5 to 10 hours.

In some cases, the obtained polycarbonate-polydiorganosiloxane copolymer resin can be appropriately subjected to a physical treatment (mixing, fractionation, etc.) and/or a chemical treatment (polymer reaction, crosslinking treatment, partial decomposition treatment, etc.) to obtain a polycarbonate-polydiorganosiloxane copolymer resin having a desired reduced viscosity [η _SP /c].

The resulting reaction product (crude product) can be subjected to various post-treatments, such as known separation and purification methods, to recover a polycarbonate-polydiorganosiloxane copolymer resin of the desired purity (degree of purification).

The average size of the polydiorganosiloxane domains in the polycarbonate-polydiorganosiloxane copolymer resin molded product is preferably in the range of 1 to 60 nm. Such an average size is more preferably 3 to 55 nm, and even more preferably 5 to 50 nm. Below the lower limit of this preferred range, impact resistance and flame retardancy may not be fully exhibited, and above the upper limit of this preferred range, impact resistance may not be stably exhibited.

(Component B: Impact modifier)
The flame-retardant polycarbonate resin composition of the present invention contains an impact modifier as component B. The impact modifier is preferably a graft polymer obtained by graft polymerizing at least one compound including a (meth)acrylic acid ester compound to one rubber selected from the group consisting of butadiene rubber, acrylic rubber, and silicone-acrylic composite rubber, and is more preferably a graft polymer having a core-shell structure. The core-shell type graft polymer is a graft copolymer obtained by copolymerizing a rubber component having a glass transition temperature of 10°C or less as a core with one or more monomers selected from (meth)acrylic acid ester compounds, aromatic alkenyl compounds, and vinyl compounds copolymerizable therewith as a shell.

Examples of rubber components of component B include butadiene rubber, butadiene-acrylic composite rubber, acrylic rubber, silicone-acrylic composite rubber, isobutylene-silicone composite rubber, isoprene rubber, styrene-butadiene rubber, chloroprene rubber, ethylene-propylene rubber, nitrile rubber, ethylene-acrylic rubber, silicone rubber, epichlorohydrin rubber, fluororubber, and those with hydrogen added to the unsaturated bonds of these rubber components. However, rubber components that do not contain halogen atoms are preferable in terms of environmental impact, in terms of concerns about the generation of harmful substances during combustion. In addition, the glass transition temperature of the rubber component is preferably -10°C or lower, more preferably -30°C or lower, and from these points of view, butadiene rubber and acrylic silicone-acrylic composite rubber are particularly preferable as rubber components. Composite rubber refers to rubber in which two types of rubber components are copolymerized, or rubber polymerized to form an IPN structure in which the components are intertwined with each other so that they cannot be separated. In the core-shell graft polymer, the particle diameter of the core is preferably 240 to 300 nm, more preferably 250 to 290 nm, and even more preferably 260 to 280 nm, in terms of weight average particle diameter. In some cases, better impact resistance can be achieved within the range of 240 to 300 nm. In addition, a bidisperse type having two peaks in the particle size distribution is preferable, and a bidisperse type having two peaks near 100 nm and 300 nm is particularly preferable, and better impact resistance can be achieved than with a monodisperse type having a single peak.

Examples of aromatic vinyls in the vinyl compounds copolymerized as the shell of the core-shell graft polymer with the rubber component include styrene, α-methylstyrene, p-methylstyrene, alkoxystyrene, and halogenated styrene. Examples of acrylic acid esters include methyl acrylate, ethyl acrylate, butyl acrylate, cyclohexyl acrylate, and octyl acrylate. Examples of methacrylic acid esters include methyl methacrylate, ethyl methacrylate, butyl methacrylate, cyclohexyl methacrylate, and octyl methacrylate, with methyl methacrylate being particularly preferred. Among these, it is particularly preferred to contain methacrylic acid esters such as methyl methacrylate as an essential component, and from the viewpoint of mechanical properties and flame retardancy, it is even more preferred not to contain an aromatic vinyl component. This is because the core-shell graft polymer has excellent affinity with the polycarbonate resin, so that more rubber components are present in the resin, and the good impact resistance of the polycarbonate resin is more effectively exerted, resulting in good impact resistance of the resin composition. More specifically, the methacrylic acid ester is preferably contained in 100% by weight of the graft component (100% by weight of the shell in the case of a core-shell type polymer), preferably 10% by weight or more, more preferably 15% by weight or more. The elastic polymer containing a rubber component having a glass transition temperature of 10° C. or less may be produced by any of the polymerization methods of bulk polymerization, solution polymerization, suspension polymerization, and emulsion polymerization, and the copolymerization method may be either one-stage grafting or multi-stage grafting. It may also be a mixture with a copolymer of only the graft component that is a by-product during production. In addition to the general emulsion polymerization method, examples of the polymerization method include a soap-free polymerization method using an initiator such as potassium persulfate, a seed polymerization method, and a two-stage swelling polymerization method. In addition, in the suspension polymerization method, the aqueous phase and the monomer phase are held separately and both are accurately supplied to a continuous disperser, and the particle size is controlled by the rotation speed of the disperser, and in the continuous production method, a method in which the monomer phase is supplied to an aqueous liquid having dispersibility by passing it through a fine orifice or a porous filter having a diameter of several to several tens of μm to control the particle size may be performed. In the case of a core-shell type graft polymer, the reaction may be one-stage or multi-stage for both the core and the shell.

Such polymers are commercially available and easily available. For example, the rubber component is mainly made of butadiene rubber, and examples of such include Mitsubishi Chemical's Metablen E series (e.g., E-875A, whose shell component is mainly made of methyl methacrylate, and E-870A, whose shell component is mainly made of methyl methacrylate and styrene). The rubber component is mainly made of acrylic rubber, and examples of such include Mitsubishi Chemical's W series (e.g., W-600A, whose shell component is mainly made of methyl methacrylate). The rubber component is mainly made of silicone-acrylic composite rubber, and examples of such include Mitsubishi Chemical's Metablen S series (e.g., S-2001, S-2030, whose shell component is mainly made of methyl methacrylate).

The content of component B is 1 to 8 parts by weight, preferably 1.5 to 7 parts by weight, and more preferably 2 to 6 parts by weight, per 100 parts by weight of component A. If the content of component B is less than 1 part by weight, sufficient impact strength cannot be obtained, and if it exceeds 8 parts by weight, flame retardancy decreases.

(Component C: phosphazene)
The flame-retardant polycarbonate resin composition of the present invention contains a phosphazene containing 98.5 mol % or more of a phosphazene cyclic trimer as a C component. Such a phosphazene can impart an effect of suppressing the decrease in impact strength and flame retardancy to the flame-retardant polycarbonate resin composition by containing a phosphorus atom and a nitrogen atom in the molecule. When a compound other than phosphazene, such as a phosphorus ester or a condensed phosphorus ester, is used as a phosphorus-based flame retardant, the addition of the compound to the polycarbonate resin causes a decrease in impact strength and flame retardancy, and further causes a decrease in impact strength and flame retardancy due to moist heat deterioration. The phosphazene is not particularly limited as long as it does not contain a halogen atom and has a phosphazene structure in the molecule. The phosphazene structure here represents a structure represented by the formula: -P(R2)=N- [wherein R2 is an organic group]. The phosphazene is represented by the general formulas (5) and (6).

(In the formula, X ₁ , X ₂ , X ₃ , and X ₄ each represent a hydrogen atom, a hydroxyl group, an amino group, or an organic group not containing a halogen atom, and n represents an integer of 3 to 10.)

In the above formulas (5) and (6), examples of the organic groups not containing a halogen atom represented by X ₁ , X ₂ , X ₃ and X ₄ include an alkoxy group, a phenyl group, an amino group and an allyl group.

The phosphazene component C must contain 98.5 mol% or more of phosphazene cyclic trimer. The content is preferably in the range of 99 mol% to 100 mol%, more preferably 99.5 mol% to 100 mol%. If the phosphazene cyclic trimer content is less than 98.5 mol%, the decrease in impact strength and flame retardancy due to moist heat degradation cannot be suppressed.

A typical method for producing phosphazenes is described in European Patent Application Publication No. 728811 and International Patent Publication No. WO 97/40092, etc.

During the manufacturing process, phosphazene produces cyclic trimers and higher oligomers as by-products in addition to the cyclic trimers. However, the content of phosphazene cyclic trimers can be increased by purifying the product using column chromatography or other methods.

The content of the phosphazene cyclic trimer in the phosphazene can be determined by ³¹ PNMR (chemical shifts: δ trimer 6.5 to 10.0 ppm, δ tetramer -10 to -13.5 ppm, oligomers higher than δ -16.5 to -25.0 ppm).

The content of component C is 1 to 8 parts by weight, preferably 1.5 to 7 parts by weight, and more preferably 2 to 6 parts by weight, per 100 parts by weight of component A. If the content of component C is less than 1 part by weight, the flame retardant effect is not obtained, and if it exceeds 8 parts by weight, the impact strength decreases.

(Component D: organic sulfonic acid metal salt)
The flame-retardant polycarbonate resin composition of the present invention contains an organic sulfonate metal salt as component D. When component D is a flame retardant other than an organic sulfonate metal salt, not only is a sufficient flame retardant effect not obtained, but the decrease in flame retardancy and impact strength due to moist heat deterioration is not suppressed. The organic sulfonate metal salt is preferably an organic sulfonate alkali (earth) metal salt having 1 to 50, preferably 1 to 40, carbon atoms. The organic sulfonate alkali (earth) metal salt includes a metal salt of a fluorine-substituted alkylsulfonic acid such as a metal salt of a perfluoroalkylsulfonic acid having 1 to 10, preferably 2 to 8, carbon atoms and an alkali metal or alkaline earth metal, and a metal salt of an aromatic sulfonic acid having 7 to 50, preferably 7 to 40, carbon atoms and an alkali metal or alkaline earth metal. Examples of the alkali metal constituting the metal salt include lithium, sodium, potassium, rubidium, and cesium, and examples of the alkaline earth metal include beryllium, magnesium, calcium, strontium, and barium. An alkali metal is more preferable. Among these alkali metals, rubidium and cesium, which have a larger ionic radius, are suitable when transparency is required, but they are not widely used and are difficult to purify, which may result in a disadvantage in terms of cost. On the other hand, metals with a smaller ionic radius, such as lithium and sodium, may be disadvantageous in terms of flame retardancy. Taking these factors into consideration, the alkali metals in the alkali metal sulfonates can be used differently, but potassium sulfonates, which have an excellent balance of properties, are most suitable in all respects. Such potassium salts can also be used in combination with alkali metal sulfonates made of other alkali metals.

Specific examples of the alkali metal salt of perfluoroalkyl sulfonate include potassium trifluoromethanesulfonate, potassium perfluorobutanesulfonate, potassium perfluorohexanesulfonate, potassium perfluorooctane sulfonate, sodium pentafluoroethanesulfonate, sodium perfluorobutanesulfonate, sodium perfluorooctane sulfonate, lithium trifluoromethanesulfonate, lithium perfluorobutanesulfonate, lithium perfluoroheptanesulfonate, cesium trifluoromethanesulfonate, cesium perfluorobutanesulfonate, cesium perfluorooctane sulfonate, cesium perfluorohexanesulfonate, rubidium perfluorobutanesulfonate, and rubidium perfluorohexanesulfonate, and these can be used alone or in combination of two or more. Here, the carbon number of the perfluoroalkyl group is preferably in the range of 1 to 18, more preferably in the range of 1 to 10, and even more preferably in the range of 1 to 8. Among these, potassium perfluorobutanesulfonate is particularly preferred. In the alkali (earth) metal salt of perfluoroalkylsulfonic acid made of an alkali metal, fluoride ions (F-) are usually mixed in no small amount. The presence of such fluoride ions can be a factor in reducing flame retardancy, so it is preferable to reduce them as much as possible. The proportion of such fluoride ions can be measured by ion chromatography. The content of fluoride ions is preferably 100 ppm or less, more preferably 40 ppm or less, and particularly preferably 10 ppm or less. It is also preferable that the content is 0.2 ppm or more for production efficiency. The alkali (earth) metal salt of perfluoroalkylsulfonic acid having a reduced amount of fluoride ions can be produced by using a known production method, and by a method of reducing the amount of fluoride ions contained in the raw material when producing a fluorine-containing organic metal salt, a method of removing hydrogen fluoride obtained by the reaction by gas generated during the reaction or by heating, and a method of reducing the amount of fluoride ions by using a purification method such as recrystallization and reprecipitation when producing a fluorine-containing organic metal salt. In particular, since organic sulfonate metal salts are relatively soluble in water, it is preferable to produce them by using ion-exchanged water, particularly water having an electric resistance value of 18 MΩ cm or more, i.e., an electric conductivity of approximately 0.55 μS/cm or less, and dissolving and washing the salt at a temperature higher than room temperature, followed by cooling and recrystallization. Specific examples of the aromatic sulfonic acid alkali (earth) metal salt include disodium diphenyl sulfide-4,4'-disulfonate, dipotassium diphenyl sulfide-4,4'-disulfonate, potassium 5-sulfoisophthalate, sodium 5-sulfoisophthalate, polysodium polyethylene terephthalate polysulfonate, calcium 1-methoxynaphthalene-4-sulfonate, disodium 4-dodecylphenyl ether disulfonate, polysodium poly(2,6-dimethylphenylene oxide) polysulfonate, polysodium poly(1,3-phenylene oxide) polysulfonate, polysodium poly(1,4-phenylene oxide) polysulfonate, polypotassium poly(2,6-diphenylphenylene oxide) polysulfonate, lithium poly(2-fluoro-6-butylphenylene oxide) polysulfonate, potassium sulfonate of benzenesulfonate, sodium benzenesulfonate, and benzenesulfonic acid. Examples of the sulfonate include strontium, magnesium benzenesulfonate, dipotassium p-benzenedisulfonate, dipotassium naphthalene-2,6-disulfonate, calcium biphenyl-3,3'-disulfonate, sodium diphenylsulfone-3-sulfonate, potassium diphenylsulfone-3-sulfonate, dipotassium diphenylsulfone-3,3'-disulfonate, dipotassium diphenylsulfone-3,4'-disulfonate, sodium α,α,α-trifluoroacetophenone-4-sulfonate, dipotassium benzophenone-3,3'-disulfonate, disodium thiophene-2,5-disulfonate, dipotassium thiophene-2,5-disulfonate, calcium thiophene-2,5-disulfonate, sodium benzothiophenesulfonate, potassium diphenylsulfoxide-4-sulfonate, a formalin condensate of sodium naphthalenesulfonate, and a formalin condensate of sodium anthracenesulfonate. Of these alkali (earth) metal salts of aromatic sulfonates, potassium salts are particularly preferred. Among these alkali (earth) metal salts of aromatic sulfonates, potassium diphenylsulfone-3-sulfonate and dipotassium diphenylsulfone-3,3'-disulfonate are particularly preferred, and mixtures thereof (wherein the weight ratio of the former to the latter is 15/85 to 30/70) are particularly preferred.

The content of component D is 0.01 to 0.5 parts by weight, preferably 0.03 to 0.4 parts by weight, and more preferably 0.05 to 0.3 parts by weight, relative to 100 parts by weight of component A. If the content of component D is less than 0.01 part by weight, the decrease in flame retardancy due to moist heat deterioration is not suppressed, and if it exceeds 0.5 part by weight, the impact strength decreases.

(Component E: Anti-drip agent)
The flame-retardant polycarbonate resin composition of the present invention contains an anti-drip agent as component E. By containing this anti-drip agent, good flame retardancy can be achieved without impairing the physical properties of the molded article.

The drip prevention agent of component E can be a fluorine-containing polymer having fibril-forming ability, and examples of such polymers include polytetrafluoroethylene, tetrafluoroethylene-based copolymers (e.g., tetrafluoroethylene/hexafluoropropylene copolymers, etc.), partially fluorinated polymers such as those shown in U.S. Pat. No. 4,379,910, and polycarbonate resins produced from fluorinated diphenols. Of these, polytetrafluoroethylene (hereinafter sometimes referred to as PTFE) is preferred.

PTFE with fibril-forming ability has an extremely high molecular weight, and shows a tendency to bond PTFE together and become fibrous due to external action such as shear force. Its molecular weight is 1 million to 10 million, preferably 2 million to 9 million, in number average molecular weight calculated from standard specific gravity. Such PTFE can be used in solid form or in aqueous dispersion form. Furthermore, such PTFE with fibril-forming ability can be used in a mixed form with other resins to improve dispersibility in resins and obtain even better flame retardancy and mechanical properties.

Commercially available PTFE products having such fibril-forming ability include, for example, Teflon (registered trademark) 6J from Mitsui DuPont Fluorochemicals Co., Ltd. and Polyflon MPA from Daikin Industries, Ltd.
Representative examples of commercially available aqueous dispersions of PTFE include Fluon AD-1 and AD-936 manufactured by Asahi ICI Fluoropolymers Co., Ltd., Fluon D-1 and D-2 manufactured by Daikin Industries, Ltd., and Teflon (registered trademark) 30J manufactured by DuPont-Mitsui Fluorochemicals Co., Ltd.

PTFE in a mixed form can be prepared by (1) mixing an aqueous dispersion of PTFE with an aqueous dispersion or solution of an organic polymer and co-precipitating to obtain a coagulated mixture (methods described in JP-A-60-258263 and JP-A-63-154744, etc.), (2) mixing an aqueous dispersion of PTFE with dried organic polymer particles (method described in JP-A-4-272957), or (3) homogeneously mixing an aqueous dispersion of PTFE with a solution of organic polymer particles and extracting each medium from the mixture at the same time. (4) a method of polymerizing a monomer that forms an organic polymer in an aqueous dispersion of PTFE (method described in JP-A-06-220210, JP-A-08-188653, etc.), and (5) a method of homogeneously mixing an aqueous dispersion of PTFE and an organic polymer dispersion, and then polymerizing a vinyl monomer in the mixed dispersion to obtain a mixture (method described in JP-A-11-29679, etc.). Commercially available products of these mixed forms of PTFE include "Metabrene A3800" (trade name) manufactured by Mitsubishi Chemical Corporation, and "BLENDEX B449" (trade name) manufactured by GE Specialty Chemicals.

The proportion of PTFE in the mixed form is preferably 1 to 60% by weight, more preferably 5 to 55% by weight, in 100% by weight of the PTFE mixture. When the proportion of PTFE is within this range, good dispersibility of PTFE may be achieved. The proportion of the F component indicates the net amount of the drip prevention agent, and in the case of mixed PTFE, indicates the net amount of PTFE.

The content of component E is 0.05 to 2 parts by weight, preferably 0.1 to 1.5 parts by weight, and more preferably 0.2 to 1 part by weight, per 100 parts by weight of component A. If the content of component E is less than 0.05 parts by weight, sufficient flame retardancy cannot be obtained, and if it exceeds 2 parts by weight, the impact strength decreases.

The styrene monomer used in the organic polymer used in the polytetrafluoroethylene mixture of the present invention may be styrene that may be substituted with one or more groups selected from the group consisting of an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, and a halogen, such as ortho-methylstyrene, meta-methylstyrene, para-methylstyrene, dimethylstyrene, ethyl-styrene, para-tert-butylstyrene, methoxystyrene, fluorostyrene, monobromostyrene, dibromostyrene, and tribromostyrene, vinylxylene, and vinylnaphthalene, but is not limited thereto. The styrene monomer may be used alone or in a mixture of two or more types.

The acrylic monomer used in the organic polymer used in the polytetrafluoroethylene mixture of the present invention includes a (meth)acrylate derivative which may be substituted. Specifically, the acrylic monomer may be a (meth)acrylate derivative which may be substituted with one or more groups selected from the group consisting of an alkyl group having 1 to 20 carbon atoms, a cycloalkyl group having 3 to 8 carbon atoms, an aryl group, and a glycidyl group, such as (meth)acrylonitrile, methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, butyl (meth)acrylate, amyl (meth)acrylate, hexyl (meth)acrylate, 2-ethyl ... Examples of the acrylic monomer include, but are not limited to, (meth)acrylate, cyclohexyl (meth)acrylate, octyl (meth)acrylate, dodecyl (meth)acrylate, phenyl (meth)acrylate, benzyl (meth)acrylate, and glycidyl (meth)acrylate, maleimides that may be substituted with an alkyl group having 1 to 6 carbon atoms or an aryl group, such as maleimide, N-methyl-maleimide, and N-phenyl-maleimide, maleic acid, phthalic acid, and itaconic acid. The acrylic monomers may be used alone or in combination of two or more kinds. Among these, (meth)acrylonitrile is preferred.

The amount of acrylic monomer-derived units contained in the organic polymer used in the coating layer is preferably 8 to 11 parts by weight, more preferably 8 to 10 parts by weight, and even more preferably 8 to 9 parts by weight, per 100 parts by weight of styrene monomer-derived units. If the amount of acrylic monomer-derived units is less than 8 parts by weight, the coating strength may decrease, and if it is more than 11 parts by weight, the surface appearance of the molded product may deteriorate.

The polytetrafluoroethylene mixture of the present invention preferably has a residual moisture content of 0.5% by weight or less, more preferably 0.2 to 0.4% by weight, and even more preferably 0.1 to 0.3% by weight. If the residual moisture content is more than 0.5% by weight, it may have a negative effect on flame retardancy.

The process for producing the polytetrafluoroethylene blend of the present invention includes a step of forming a coating layer containing one or more monomers selected from the group consisting of styrene-based monomers and acrylic monomers on the outside of the branched polytetrafluoroethylene in the presence of an initiator. It is preferable to further include a step of drying the mixture after the step of forming the coating layer so that the residual moisture content is 0.5 wt% or less, preferably 0.2 to 0.4 wt%, and more preferably 0.1 to 0.3 wt%. The drying step can be performed using a method known in the art, such as hot air drying or vacuum drying.

The initiator used in the polytetrafluoroethylene mixture of the present invention may be any initiator used in the polymerization reaction of styrene-based and/or acrylic monomers, without limitation. Examples of the initiator include, but are not limited to, cumyl hydroperoxide, di-tert-butyl peroxide, benzoyl peroxide, hydrogen peroxide, and potassium peroxide. In the polytetrafluoroethylene mixture of the present invention, one or more of the initiators may be used depending on the reaction conditions. The amount of the initiator may be freely selected within a range that is used in consideration of the amount of polytetrafluoroethylene and the type/amount of monomer, and it is preferable to use 0.15 to 0.25 parts by weight based on the amount of the total composition.

The polytetrafluoroethylene mixture of the present invention was produced by the suspension polymerization method according to the following procedure.

First, water and a branched polytetrafluoroethylene dispersion (solid concentration: 60%, polytetrafluoroethylene particle size: 0.15-0.3 μm) were placed in a reactor, and then acrylic monomer, styrene monomer, and cumene hydroperoxide as a water-soluble initiator were added while stirring, and the reaction was carried out at 80-90°C for 9 hours. After the reaction was completed, the water was removed by centrifuging in a centrifuge for 30 minutes to obtain a paste-like product. The product paste was then dried in a hot air dryer at 80-100°C for 8 hours. The dried product was then pulverized to obtain the polytetrafluoroethylene mixture of the present invention.

Such a suspension polymerization method does not require a polymerization step by emulsion dispersion in the emulsion polymerization method exemplified in Patent No. 3469391, and does not require an emulsifier or electrolyte salts for coagulating and precipitating the latex after polymerization. In addition, in a polytetrafluoroethylene mixture produced by an emulsion polymerization method, the emulsifier and electrolyte salts in the mixture tend to be mixed and are difficult to remove, making it difficult to reduce the sodium metal ions and potassium metal ions derived from such emulsifiers and electrolyte salts. The polytetrafluoroethylene mixture used in the present invention is produced by a suspension polymerization method, and does not use such emulsifiers or electrolyte salts, so that the sodium metal ions and potassium metal ions in the mixture can be reduced, and thermal stability and hydrolysis resistance can be improved.

In addition, in the present invention, coated branched PTFE can be used as an anti-drip agent. The coated branched PTFE is a polytetrafluoroethylene mixture consisting of branched polytetrafluoroethylene particles and an organic polymer, and has a coating layer made of an organic polymer, preferably a polymer containing a unit derived from a styrene monomer and/or a unit derived from an acrylic monomer, on the outside of the branched polytetrafluoroethylene. The coating layer is formed on the surface of the branched polytetrafluoroethylene. In addition, the coating layer preferably contains a copolymer of a styrene monomer and an acrylic monomer.

The polytetrafluoroethylene contained in the coated branched PTFE is branched polytetrafluoroethylene. If the polytetrafluoroethylene contained is not branched polytetrafluoroethylene, the drip prevention effect will be insufficient when the amount of polytetrafluoroethylene added is small. The branched polytetrafluoroethylene is particulate and has a particle size of preferably 0.1 to 0.6 μm, more preferably 0.3 to 0.5 μm, and even more preferably 0.3 to 0.4 μm. If the particle size is smaller than 0.1 μm, the surface appearance of the molded product is excellent, but it is difficult to commercially obtain polytetrafluoroethylene having a particle size smaller than 0.1 μm. Also, if the particle size is larger than 0.6 μm, the surface appearance of the molded product may be deteriorated. The number average molecular weight of the polytetrafluoroethylene used in the present invention is preferably 1×10 ⁴ to 1×10 ⁷ , more preferably 2×10 ⁶ to 9×10 ⁶ , and generally, polytetrafluoroethylene with a high molecular weight is more preferable in terms of stability. Either powder or dispersion form may be used. The content of the branched polytetrafluoroethylene in the coated branched PTFE is preferably 20 to 60 parts by weight, more preferably 40 to 55 parts by weight, even more preferably 47 to 53 parts by weight, particularly preferably 48 to 52 parts by weight, and most preferably 49 to 51 parts by weight, relative to 100 parts by weight of the total weight of the coated branched PTFE. When the proportion of the branched polytetrafluoroethylene is within this range, good dispersibility of the branched polytetrafluoroethylene may be achieved.

(Other additives)
(i) Phosphorus-Based Stabilizers Examples of phosphorus-based stabilizers include phosphorous acid, phosphoric acid, phosphonous acid, phosphonic acid, and esters thereof, as well as tertiary phosphines.

Specific examples of phosphite compounds include triphenyl phosphite, tris(nonylphenyl)phosphite, tridecyl phosphite, trioctyl phosphite, trioctadecyl phosphite, didecyl monophenyl phosphite, dioctyl monophenyl phosphite, diisopropyl monophenyl phosphite, monobutyl diphenyl phosphite, monodecyl diphenyl phosphite, monooctyl diphenyl phosphite, tris(diethylphenyl)phosphite, tris(di-iso-propylphenyl)phosphite, tris(di-n-butylphenyl)phosphite, tris(2,4-di-tert-butylphenyl)phosphite, tris(2,6-di-tert- butylphenyl) phosphite, distearyl 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{2,4-bis(1-methyl-1-phenylethyl)phenyl} pentaerythritol diphosphite, phenyl bisphenol A pentaerythritol diphosphite, bis(nonylphenyl) pentaerythritol diphosphite, and dicyclohexyl pentaerythritol diphosphite.

Furthermore, other phosphite compounds that react with dihydric phenols to form a cyclic structure can also be used. Examples include 2,2'-methylenebis(4,6-di-tert-butylphenyl)(2,4-di-tert-butylphenyl)phosphite, 2,2'-methylenebis(4,6-di-tert-butylphenyl)(2-tert-butyl-4-methylphenyl)phosphite, and 2,2-methylenebis(4,6-di-tert-butylphenyl)octylphosphite.

Examples of phosphate compounds include tributyl phosphate, trimethyl phosphate, tricresyl phosphate, triphenyl phosphate, trichlorophenyl phosphate, triethyl phosphate, diphenyl cresyl phosphate, diphenyl monoorthoxenyl phosphate, tributoxyethyl phosphate, dibutyl phosphate, dioctyl phosphate, diisopropyl phosphate, etc., and preferably triphenyl phosphate and trimethyl phosphate.

Examples of the phosphonite compound include tetrakis(2,4-di-tert-butylphenyl)-4,4'-biphenylene diphosphonite, tetrakis(2,4-di-tert-butylphenyl)-4,3'-biphenylene diphosphonite, tetrakis(2,4-di-tert-butylphenyl)-3,3'-biphenylene diphosphonite, tetrakis(2,6-di-tert-butylphenyl)-4,4'-biphenylene diphosphonite, tetrakis(2,6-di-tert-butylphenyl)-4,3'-biphenylene diphosphonite, tetrakis(2,6-di-tert-butylphenyl)-3,3'-biphenylene diphosphonite, bis(2,4-di-tert-butylphenyl)-4-phenyl-phenylphosphonite, bis Examples of the phosphonite include (2,4-di-tert-butylphenyl)-3-phenyl-phenyl phosphonite, bis(2,6-di-n-butylphenyl)-3-phenyl-phenyl phosphonite, bis(2,6-di-tert-butylphenyl)-4-phenyl-phenyl phosphonite, and bis(2,6-di-tert-butylphenyl)-3-phenyl-phenyl phosphonite. Tetrakis(di-tert-butylphenyl)-biphenylene diphosphonite and bis(di-tert-butylphenyl)-phenyl-phenyl phosphonite are preferred, and tetrakis(2,4-di-tert-butylphenyl)-biphenylene diphosphonite and bis(2,4-di-tert-butylphenyl)-phenyl-phenyl phosphonite are more preferred. Such phosphonite compounds can be used in combination with the phosphite compounds having an aryl group substituted with two or more alkyl groups, and are therefore preferred.

Examples of phosphonate compounds include dimethyl benzenephosphonate, diethyl benzenephosphonate, and dipropyl benzenephosphonate.

Examples of tertiary phosphines include triethylphosphine, tripropylphosphine, tributylphosphine, trioctylphosphine, triamylphosphine, dimethylphenylphosphine, dibutylphenylphosphine, diphenylmethylphosphine, diphenyloctylphosphine, triphenylphosphine, tri-p-tolylphosphine, trinaphthylphosphine, and diphenylbenzylphosphine. A particularly preferred tertiary phosphine is triphenylphosphine.

The above phosphorus-based stabilizers can be used alone or in combination of two or more. Among the above phosphorus-based stabilizers, phosphonite compounds or phosphite compounds represented by the following general formula (7) are preferred.

(In formula (7), R and R' represent an alkyl group having 6 to 30 carbon atoms or an aryl group having 6 to 30 carbon atoms, and may be the same or different.)

As mentioned above, the phosphonite compound is preferably tetrakis(2,4-di-tert-butylphenyl)-biphenylene diphosphonite, and stabilizers containing this phosphonite as the main component are commercially available as Sandostab P-EPQ (trademark, manufactured by Clariant) and Irgafos P-EPQ (trademark, manufactured by CIBA SPECIALTY CHEMICALS), either of which can be used.

Among the above formula (7), more suitable phosphite compounds are distearyl pentaerythritol diphosphite, bis(2,4-di-tert-butylphenyl)pentaerythritol diphosphite, bis(2,6-di-tert-butyl-4-methylphenyl)pentaerythritol diphosphite, and bis{2,4-bis(1-methyl-1-phenylethyl)phenyl}pentaerythritol diphosphite.

Distearyl pentaerythritol diphosphite is commercially available as ADK STAB PEP-8 (trademark, manufactured by Asahi Denka Kogyo Co., Ltd.) and JPP681S (trademark, manufactured by Johoku Chemical Industry Co., Ltd.), and either can be used. Bis(2,4-di-tert-butylphenyl)pentaerythritol diphosphite is commercially available as ADK STAB PEP-24G (trademark, manufactured by Asahi Denka Kogyo Co., Ltd.), Alkanox P-24 (trademark, manufactured by Great Lakes Corporation), Ultranox P626 (trademark, manufactured by GE Specialty Chemicals), Doverphos S-9432 (trademark, manufactured by Dover Chemical Company), and Irgaofos 126 and 126FF (trademarks, manufactured by CIBA SPECIALTY CHEMICALS), and any of these may be used. Bis(2,6-di-tert-butyl-4-methylphenyl)pentaerythritol diphosphite is commercially available as Adekastab PEP-36 (trademark, manufactured by Asahi Denka Kogyo Co., Ltd.) and can be easily used. Bis{2,4-bis(1-methyl-1-phenylethyl)phenyl}pentaerythritol diphosphite is commercially available as Adekastab PEP-45 (trademark, manufactured by Asahi Denka Kogyo Co., Ltd.) and Doverphos S-9228 (trademark, manufactured by Dover Chemical Co., Ltd.), and either can be used.

The phosphorus-based stabilizers can be used alone or in combination of two or more kinds. The content of the phosphorus-based stabilizer is preferably 0.01 to 1.0 parts by weight, more preferably 0.03 to 0.8 parts by weight, and even more preferably 0.05 to 0.5 parts by weight, per 100 parts by weight of component A. If the content is less than 0.01 part by weight, the effect of suppressing thermal decomposition during processing will not be manifested, and there may be no deterioration in mechanical properties, whereas if the content exceeds 1.0 part by weight, there may be a deterioration in mechanical properties.

(ii) Phenol-Based Stabilizer The resin composition of the present invention may contain a phenol-based stabilizer. Examples of phenol-based stabilizers include hindered phenols, semi-hindered phenols, and less hindered phenol compounds. From the viewpoint of providing a heat-stabilizing formulation to a polypropylene-based resin, a hindered phenol compound is more preferably used. Examples of such hindered phenol compounds include α-tocopherol, butyl hydroxytoluene, sinapyl alcohol, vitamin E, octadecyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, 2-tert-butyl-6-(3'-tert-butyl-5'-methyl-2'-hydroxybenzyl)-4-methylphenyl acrylate, 2,6-di-tert-butyl-4-(N,N-dimethylaminomethyl)phenol, 3,5-di-tert-butyl-4-hydroxybenzylphosphone, and the like. diethyl ester, 2,2'-methylenebis(4-methyl-6-tert-butylphenol), 2,2'-methylenebis(4-ethyl-6-tert-butylphenol), 4,4'-methylenebis(2,6-di-tert-butylphenol), 2,2'-methylenebis(4-methyl-6-cyclohexylphenol), 2,2'-dimethylene-bis(6-α-methyl-benzyl-p-cresol), 2,2'-ethylidene-bis(4,6-di-tert-butylphenol), 2,2'-butylidene-bis(4-methyl-6- tert-butylphenol), 4,4'-butylidenebis(3-methyl-6-tert-butylphenol), triethylene glycol-N-bis-3-(3-tert-butyl-4-hydroxy-5-methylphenyl)propionate, 1,6-hexanediol bis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], bis[2-tert-butyl-4-methyl 6-(3-tert-butyl-5-methyl-2-hydroxybenzyl)phenyl]terephthalate, 3,9-bis{2-[3-(3- tert-butyl-4-hydroxy-5-methylphenyl)propionyloxy]-1,1,-dimethylethyl}-2,4,8,10-tetraoxaspiro[5,5]undecane, 4,4'-thiobis(6-tert-butyl-m-cresol), 4,4'-thiobis(3-methyl-6-tert-butylphenol), 2,2'-thiobis(4-methyl-6-tert-butylphenol), bis(3,5-di-tert-butyl-4-hydroxybenzyl)sulfide, 4,4'-di-thiobis(2,6-di-tert-butylphenyl) nol), 4,4'-tri-thiobis(2,6-di-tert-butylphenol), 2,2-thiodiethylene bis-[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], 2,4-bis(n-octylthio)-6-(4-hydroxy-3,5-di-tert-butylanilino)-1,3,5-triazine, N,N'-hexamethylene bis-(3,5-di-tert-butyl-4-hydroxyhydrocinnamide), N,N'-bis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] pionyl]hydrazine, 1,1,3-tris(2-methyl-4-hydroxy-5-tert-butylphenyl)butane, 1,3,5-trimethyl-2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl)benzene, tris(3,5-di-tert-butyl-4-hydroxyphenyl)isocyanurate, tris(3,5-di-tert-butyl-4-hydroxybenzyl)isocyanurate, 1,3,5-tris(4-tert-butyl-3-hydroxy-2,6-dimethylbenzyl)isocyanurate, 1, 3,5-tris-2[3(3,5-di-tert-butyl-4-hydroxyphenyl)propionyloxy]ethyl isocyanurate, tetrakis[methylene-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate]methane, triethylene glycol-N-bis-3-(3-tert-butyl-4-hydroxy-5-methylphenyl)propionate, triethylene glycol-N-bis-3-(3-tert-butyl-4-hydroxy-5-methylphenyl)acetate, 3,9-bis[2-{3-(3-t Examples of the tetrakis[methylene-3-(3-tert-butyl-4-hydroxy-5-methylphenyl)acetyloxy]-2,4,8,10-tetraoxaspiro[5,5]undecane, tetrakis[methylene-3-(3-tert-butyl-4-hydroxy-5-methylphenyl)propionate]methane, 1,3,5-trimethyl-2,4,6-tris(3-tert-butyl-4-hydroxy-5-methylbenzyl)benzene, and tris(3-tert-butyl-4-hydroxy-5-methylbenzyl)isocyanurate are mentioned. Among the above compounds, tetrakis[methylene-3-(3-tert-butyl-4-hydroxy-5-methylphenyl)propionate]methane and octadecyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate are preferably used, and further, as compounds excellent in suppressing deterioration of mechanical properties due to thermal decomposition during processing, (3,3',3'',5,5',5''-hexa-tert-butyl-a,a',a''-(mesitylene-2,4,6-triyl)tri-p-cresol represented by the following formula (8) and 1,3,5-tris-(3,5-di-tert-butyl-4-hydroxybenzyl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione represented by the following formula (9) are more preferably used.

The above phenolic stabilizers can be used alone or in combination of two or more kinds. The content of the phenolic stabilizer is preferably 0.05 to 1.0 parts by weight, more preferably 0.07 to 0.8 parts by weight, and even more preferably 0.1 to 0.5 parts by weight, per 100 parts by weight of component A. If the content is less than 0.05 parts by weight, the effect of suppressing thermal decomposition during processing will not be achieved, and mechanical properties may decrease, while if the content exceeds 1.0 part by weight, mechanical properties may decrease.

It is preferable to use either a phosphorus-based stabilizer or a phenol-based stabilizer, and it is even more preferable to use them in combination. When using them in combination, it is preferable to use 0.01 to 0.5 parts by weight of a phosphorus-based stabilizer and 0.01 to 0.5 parts by weight of a phenol-based stabilizer per 100 parts by weight of component A.

(iii) Ultraviolet Absorber The flame-retardant polycarbonate resin composition of the present invention may contain an ultraviolet absorber. Examples of the ultraviolet absorber include benzophenone-based ultraviolet absorbers such as 2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-octoxybenzophenone, 2-hydroxy-4-benzyloxybenzophenone, 2-hydroxy-4-methoxy-5-sulfoxybenzophenone, 2-hydroxy-4-methoxy-5-sulfoxytrihydridorate benzophenone, 2,2'-dihydroxy-4-methoxybenzophenone, 2,2',4,4'-tetrahydroxybenzophenone, 2,2'-dihydroxy-4,4'-dimethoxybenzophenone, 2,2'-dihydroxy-4,4'-dimethoxy-5-sodium sulfoxybenzophenone, bis(5-benzoyl-4-hydroxy-2-methoxyphenyl)methane, 2-hydroxy-4-n-dodecyloxybenzophenone, and 2-hydroxy-4-methoxy-2'-carboxybenzophenone.

In the benzotriazole series, for example, 2-(2-hydroxy-5-methylphenyl)benzotriazole, 2-(2-hydroxy-5-tert-octylphenyl)benzotriazole, 2-(2-hydroxy-3,5-dicumylphenyl)phenylbenzotriazole, 2-(2-hydroxy-3-tert-butyl-5-methylphenyl)-5-chlorobenzotriazole, 2,2'-methylenebis[4-(1,1,3,3-tetramethylbutyl)-6-(2H-benzotriazol-2-yl)phenol], 2-(2-hydroxy-3,5-di-tert-butylphenyl)benzotriazole, 2-(2-hydroxy-3,5-di-tert-butylphenyl)-5-chlorobenzotriazole, 2-(2-hydroxy-3,5-di-tert-amylphenyl)benzotriazole, 2-(2-hydroxy-5-tert-octylphenyl)benzotriazole, Examples include polymers having a 2-hydroxyphenyl-2H-benzotriazole skeleton, such as azole, 2-(2-hydroxy-5-tert-butylphenyl)benzotriazole, 2-(2-hydroxy-4-octoxyphenyl)benzotriazole, 2,2'-methylenebis(4-cumyl-6-benzotriazolephenyl), 2,2'-p-phenylenebis(1,3-benzoxazin-4-one), and 2-[2-hydroxy-3-(3,4,5,6-tetrahydrophthalimidomethyl)-5-methylphenyl]benzotriazole, as well as copolymers of 2-(2'-hydroxy-5-methacryloxyethylphenyl)-2H-benzotriazole and vinyl monomers copolymerizable with the monomer, and copolymers of 2-(2'-hydroxy-5-acryloxyethylphenyl)-2H-benzotriazole and vinyl monomers copolymerizable with the monomer.

Examples of hydroxyphenyltriazines include 2-(4,6-diphenyl-1,3,5-triazin-2-yl)-5-hexyloxyphenol, 2-(4,6-diphenyl-1,3,5-triazin-2-yl)-5-methyloxyphenol, 2-(4,6-diphenyl-1,3,5-triazin-2-yl)-5-ethyloxyphenol, 2-(4,6-diphenyl-1,3,5-triazin-2-yl)-5-propyloxyphenol, and 2-(4,6-diphenyl-1,3,5-triazin-2-yl)-5-butyloxyphenol. Further examples include compounds in which the phenyl group of the above-mentioned compounds is replaced with a 2,4-dimethylphenyl group, such as 2-(4,6-bis(2,4-dimethylphenyl)-1,3,5-triazin-2-yl)-5-hexyloxyphenol.

Examples of cyclic imino esters include 2,2'-p-phenylenebis(3,1-benzoxazine-4-one), 2,2'-m-phenylenebis(3,1-benzoxazine-4-one), and 2,2'-p,p'-diphenylenebis(3,1-benzoxazine-4-one).

Examples of cyanoacrylates include 1,3-bis-[(2'-cyano-3',3'-diphenylacryloyl)oxy]-2,2-bis[(2-cyano-3,3-diphenylacryloyl)oxy]methyl)propane and 1,3-bis-[(2-cyano-3,3-diphenylacryloyl)oxy]benzene.

Furthermore, the above-mentioned ultraviolet absorber may be a polymer-type ultraviolet absorber in which such an ultraviolet absorbing monomer and/or a light stable monomer is copolymerized with a monomer such as an alkyl (meth)acrylate by adopting a structure of a monomer compound capable of radical polymerization. Suitable examples of the ultraviolet absorbing monomer include compounds containing a benzotriazole skeleton, a benzophenone skeleton, a triazine skeleton, a cyclic imino ester skeleton, and a cyanoacrylate skeleton in the ester substituent of the (meth)acrylic acid ester.

Among the above compounds, in the present invention, compounds represented by any one of the following formulas (10), (11), and (12) are more preferably used.

The above ultraviolet absorbents can be used alone or in combination of two or more kinds.
The content of the ultraviolet absorber is preferably 0.1 to 3 parts by weight, more preferably 0.12 to 2 parts by weight, and even more preferably 0.15 to 1 part by weight, relative to 100 parts by weight of component A. If the content of the ultraviolet absorber is less than 0.1 part by weight, sufficient light resistance may not be exhibited, while if it is more than 3 parts by weight, it is not preferable in terms of poor appearance and deterioration of physical properties due to gas generation.

(iv) Hindered amine light stabilizer The flame-retardant polycarbonate resin composition of the present invention may contain a hindered amine light stabilizer. Hindered amine light stabilizers are generally called HALS (Hindered Amine Light Stabilizers) and are compounds having a 2,2,6,6-tetramethylpiperidine skeleton in their structure, such as 4-acetoxy-2,2,6,6-tetramethylpiperidine, 4-stearoyloxy-2,2,6,6-tetramethylpiperidine, 4-acryloyloxy-2,2,6,6-tetramethylpiperidine, 4-(phenylacetoxy)-2,2,6,6-tetramethylpiperidine, 4-benzoyloxy-2,2,6,6-tetramethylpiperidine, 4-methoxy ... ethylpiperidine, 4-stearyloxy-2,2,6,6-tetramethylpiperidine, 4-cyclohexyloxy-2,2,6,6-tetramethylpiperidine, 4-benzyloxy-2,2,6,6-tetramethylpiperidine, 4-phenoxy-2,2,6,6-tetramethylpiperidine, 4-(ethylcarbamoyloxy)-2,2,6,6-tetramethylpiperidine, 4-(cyclohexylcarbamoyloxy)-2,2,6,6-tetramethylpiperidine, 4-(phenylcarbamoyloxy)-2,2,6,6 -tetramethylpiperidine, bis(2,2,6,6-tetramethyl-4-piperidyl)carbonate, bis(2,2,6,6-tetramethyl-4-piperidyl)oxalate, bis(2,2,6,6-tetramethyl-4-piperidyl)malonate, bis(2,2,6,6-tetramethyl-4-piperidyl)sebacate, bis(2,2,6,6-tetramethyl-4-piperidyl)adipate, bis(2,2,6,6-tetramethyl-4-piperidyl)terephthalate, bis(1,2,2,6,6-pentamethyl-4-piperidyl) bis(1,2,2,6,6-pentamethyl-4-piperidyl) carbonate, bis(1,2,2,6,6-pentamethyl-4-piperidyl) oxalate, bis(1,2,2,6,6-pentamethyl-4-piperidyl) malonate, bis(1,2,2,6,6-pentamethyl-4-piperidyl) sebacate, bis(1,2,2,6,6-pentamethyl-4-piperidyl) adipate, bis(1,2,2,6,6-pentamethyl-4-piperidyl) terephthalate, N,N'-bis-2,2,6,6-tetramethyl-4-piperidinyl-1,3-benzenedicarboxamide , 1,2-bis(2,2,6,6-tetramethyl-4-piperidyloxy)ethane, α,α'-bis(2,2,6,6-tetramethyl-4-piperidyloxy)-p-xylene, bis(2,2,6,6-tetramethyl-4-piperidyltolylene-2,4-dicarbamate, bis(2,2,6,6-tetramethyl-4-piperidyl)-hexamethylene-1,6-dicarbamate, tris(2,2,6,6-tetramethyl-4-piperidyl)-benzene-1,3,5-tricarboxylate, N,N',N'',N'''-Tetrakis-(4,6-bis-(butyl-(N-methyl-2,2,6,6-tetramethylpiperidin-4-yl)amino)-triazin-2-yl)-4,7-diazadecane-1,10-diamine, polycondensate of dibutylamine, 1,3,5-triazine, N,N'-bis(2,2,6,6-tetramethyl-4-piperidyl)-1,6-hexamethylenediamine and N-(2,2,6,6-tetramethyl-4-piperidyl)butylamine, poly[{6-(1,1,3,3-tetramethylbutyl)amino-1,3,5-triazine] riazine-2,4-diyl}{(2,2,6,6-tetramethyl-4-piperidyl)imino}hexamethylene{(2,2,6,6-tetramethyl-4-piperidyl)imino}], tetrakis(2,2,6,6-tetramethyl-4-piperidyl)-1,2,3,4-butanetetracarboxylate, tetrakis(1,2,2,6,6-pentamethyl-4-piperidyl)-1,2,3,4-butanetetracarboxylate, tris(2,2,6,6-tetramethyl-4-piperidyl)-benzene-1,3,4-tricarboxylate silyl, 1-[2-{3-(3,5-di-t-butyl-4-hydroxyphenyl)propionyloxy}butyl]-4-[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionyloxy]2,2,6,6-tetramethylpiperidine, and a condensation product of 1,2,3,4-butanetetracarboxylic acid, 1,2,2,6,6-pentamethyl-4-piperidinol, and β,β,β',β'-tetramethyl-3,9-[2,4,8,10-tetraoxaspiro(5,5)undecane]diethanol.

Hindered amine light stabilizers are broadly divided into three types based on the bond partner of the nitrogen atom in the piperidine skeleton: N-H type (hydrogen bonded to the nitrogen atom), N-R type (alkyl group (R) bonded to the nitrogen atom), and N-OR type (alkoxy group (OR) bonded to the nitrogen atom). When applying to polycarbonate resin, it is more preferable to use the N-R type or N-OR type, which have low basicity, from the viewpoint of the basicity of the hindered amine light stabilizer.

Among the above compounds, the compounds represented by the following formulas (13) and (14) are more preferably used in the present invention.

The hindered amine light stabilizer may be used alone or in combination of two or more kinds. The content of the hindered amine light stabilizer is preferably 0 to 1 part by weight, more preferably 0.05 to 1 part by weight, even more preferably 0.08 to 0.7 parts by weight, and particularly preferably 0.1 to 0.5 parts by weight, per 100 parts by weight of component A. If the content of the hindered amine light stabilizer is more than 1 part by weight, gas generation may cause a poor appearance, or the physical properties may decrease due to decomposition of the polycarbonate resin. If the content is less than 0.05 parts by weight, sufficient light resistance may not be achieved.

(v) Mold release agent It is preferable to further blend a mold release agent in the flame-retardant polycarbonate resin composition of the present invention for the purpose of improving the productivity during molding and reducing distortion of the molded product. As such a mold release agent, a known one can be used. For example, saturated fatty acid esters, unsaturated fatty acid esters, polyolefin waxes (polyethylene wax, 1-alkene polymers, etc., those modified with functional group-containing compounds such as acid modification can also be used), silicone compounds, fluorine compounds (fluorine oils represented by polyfluoroalkyl ethers, etc.), paraffin wax, beeswax, etc. can be mentioned. Among them, fatty acid esters can be mentioned as a preferred mold release agent. Such fatty acid esters are esters of aliphatic alcohols and aliphatic carboxylic acids. Such aliphatic alcohols may be monohydric alcohols or polyhydric alcohols having dihydric or higher valences. The carbon number of the alcohol is in the range of 3 to 32, more preferably in the range of 5 to 30. Examples of such monohydric alcohols include dodecanol, tetradecanol, hexadecanol, octadecanol, eicosanol, tetracosanol, ceryl alcohol, and triacontanol. Such polyhydric alcohols include pentaerythritol, dipentaerythritol, tripentaerythritol, polyglycerol (triglycerol to hexaglycerol), ditrimethylolpropane, xylitol, sorbitol, mannitol, etc. Polyhydric alcohols are more preferred in the fatty acid ester of the present invention.

On the other hand, the aliphatic carboxylic acid preferably has 3 to 32 carbon atoms, and particularly preferably has 10 to 22 carbon atoms. Examples of the aliphatic carboxylic acid include saturated aliphatic carboxylic acids such as decanoic acid, undecanoic acid, dodecanoic acid, tridecanoic acid, tetradecanoic acid, pentadecanoic acid, hexadecanoic acid (palmitic acid), heptadecanoic acid, octadecanoic acid (stearic acid), nonadecanoic acid, behenic acid, icosanoic acid, and docosanoic acid, and unsaturated aliphatic carboxylic acids such as palmitoleic acid, oleic acid, linoleic acid, linolenic acid, eicosenoic acid, eicosapentaenoic acid, and cetoleic acid. Among the above, the aliphatic carboxylic acid is preferably one having 14 to 20 carbon atoms. Among them, saturated aliphatic carboxylic acids are preferred. Stearic acid and palmitic acid are particularly preferred.

The above-mentioned aliphatic carboxylic acids such as stearic acid and palmitic acid are usually produced from natural oils and fats such as animal oils and fats such as beef tallow and lard, and vegetable oils and fats such as palm oil and sunflower oil, and therefore these aliphatic carboxylic acids are usually mixtures containing other carboxylic acid components with different numbers of carbon atoms. Therefore, in the production of the fatty acid ester of the present invention, aliphatic carboxylic acids produced from such natural oils and fats and in the form of a mixture containing other carboxylic acid components, particularly stearic acid and palmitic acid, are preferably used.

The fatty acid ester of the present invention may be either a partial ester or a full ester (full ester). However, partial esters usually have a high hydroxyl value and are prone to inducing decomposition of the resin at high temperatures, so full esters are more preferable. The acid value of the fatty acid ester of the present invention is preferably 20 or less, more preferably in the range of 4 to 20, and even more preferably in the range of 4 to 12, from the viewpoint of thermal stability. The acid value can be substantially 0. The hydroxyl value of the fatty acid ester is more preferably in the range of 0.1 to 30. The iodine value is preferably 10 or less. The iodine value can be substantially 0. These properties can be determined by the method specified in JIS K 0070.

The content of the release agent is preferably 0.005 to 2 parts by weight, more preferably 0.01 to 1 part by weight, and even more preferably 0.05 to 0.5 parts by weight, per 100 parts by weight of component A. In this range, the flame-retardant polycarbonate resin composition may have good mold and roll releasability. In particular, such an amount of fatty acid ester may provide a flame-retardant polycarbonate resin composition that has good mold and roll releasability without impairing the good hue.

(vi) Dyes and Pigments The flame-retardant polycarbonate resin composition of the present invention further contains various dyes and pigments, and can provide molded articles that exhibit a variety of designs. By blending a fluorescent brightening agent or other fluorescent dyes that emit light, it is possible to impart even better design effects that make use of the emitted color. It is also possible to provide a flame-retardant polycarbonate resin composition that is colored with a very small amount of dyes and pigments and has vivid color development.

Fluorescent dyes (including fluorescent whitening agents) used in the present invention include, for example, coumarin-based fluorescent dyes, benzopyran-based fluorescent dyes, perylene-based fluorescent dyes, anthraquinone-based fluorescent dyes, thioindigo-based fluorescent dyes, xanthene-based fluorescent dyes, xanthone-based fluorescent dyes, thioxanthene-based fluorescent dyes, thioxanthone-based fluorescent dyes, thiazine-based fluorescent dyes, and diaminostilbene-based fluorescent dyes. Among these, coumarin-based fluorescent dyes, benzopyran-based fluorescent dyes, and perylene-based fluorescent dyes are preferred because they have good heat resistance and are less susceptible to deterioration during molding of polycarbonate resin.

Dyes other than the above bluing agents and fluorescent dyes include perylene dyes, coumarin dyes, thioindigo dyes, anthraquinone dyes, thioxanthone dyes, ferrocyanides such as Prussian blue, perinone dyes, quinoline dyes, quinacridone dyes, dioxazine dyes, isoindolinone dyes, and phthalocyanine dyes. Furthermore, the resin composition of the present invention can be blended with a metallic pigment to obtain better metallic colors. As metallic pigments, those having a metal coating or a metal oxide coating on various plate-like fillers are suitable.

The content of the above dyes and pigments is preferably 0.00001 to 1 part by weight, and more preferably 0.00005 to 0.5 parts by weight, per 100 parts by weight of component A.

(vii) Other Heat Stabilizers The flame-retardant polycarbonate resin composition of the present invention may also contain heat stabilizers other than the phosphorus-based stabilizer and the phenol-based stabilizer. Such other heat stabilizers are preferably used in combination with either one of these stabilizers and the antioxidant, and particularly preferably used in combination with both. Suitable examples of such other heat stabilizers include lactone-based stabilizers such as the reaction product of 3-hydroxy-5,7-di-tert-butyl-furan-2-one and o-xylene (details of such stabilizers are described in JP-A-7-233160). Such a compound is commercially available as Irganox HP-136 (trademark, manufactured by CIBA SPECIALTY CHEMICALS), and this compound can be used. Furthermore, stabilizers in which this compound is mixed with various phosphite compounds and hindered phenol compounds are commercially available. Suitable examples include Irganox HP-2921 manufactured by the above company. In the present invention, such premixed stabilizers can also be used. The amount of the lactone stabilizer to be added is preferably 0.0005 to 0.05 parts by weight, more preferably 0.001 to 0.03 parts by weight, per 100 parts by weight of component A.

Other examples of stabilizers include sulfur-containing stabilizers such as pentaerythritol tetrakis (3-mercaptopropionate), pentaerythritol tetrakis (3-laurylthiopropionate), and glycerol-3-stearylthiopropionate. Such stabilizers are particularly effective when the resin composition is applied to rotational molding. The amount of such sulfur-containing stabilizers is preferably 0.001 to 0.1 parts by weight, more preferably 0.01 to 0.08 parts by weight, per 100 parts by weight of component A.

(viii) Filler Various fillers can be blended as reinforcing fillers in the flame-retardant polycarbonate resin composition of the present invention within the range in which the effects of the present invention are exhibited. For example, silicate minerals, calcium carbonate, glass fibers, glass beads, glass balloons, milled glass fibers, glass flakes, carbon fibers, carbon flakes, carbon beads, milled carbon fibers, graphite, vapor-grown ultrafine carbon fibers (fiber diameter less than 0.1 μm), carbon nanotubes (fiber diameter less than 0.1 μm, hollow), fullerenes, metal flakes, metal fibers, metal-coated glass fibers, metal-coated carbon fibers, metal-coated glass flakes, silica, metal oxide particles, metal oxide fibers, metal oxide balloons, and various whiskers (potassium titanate whiskers, aluminum borate whiskers, basic magnesium sulfate, etc.). These reinforcing fillers may be used alone or in combination of two or more.

The content of these fillers is preferably 0.1 to 60 parts by weight, more preferably 0.5 to 50 parts by weight, per 100 parts by weight of component A.

(ix) Other Resins and Elastomers The resin composition of the present invention may contain other resins or elastomers in small proportions within the range in which the effects of the present invention are exhibited.

Examples of such other resins include polyester resins such as polyethylene terephthalate and polybutylene terephthalate, polyamide resins, polyimide resins, polyetherimide resins, polyurethane resins, silicone resins, polyphenylene ether resins, polyphenylene sulfide resins, polysulfone resins, polymethacrylate resins, phenolic resins, and epoxy resins.

Examples of elastomers include isobutylene/isoprene rubber, ethylene/propylene rubber, acrylic elastomers, polyester elastomers, polyamide elastomers, etc.

(x) Other Additives In order to impart various functions to the molded article or to improve the characteristics, the flame-retardant polycarbonate resin composition of the present invention may contain small amounts of additives known per se. These additives may be added in normal amounts as long as they do not impair the object of the present invention.

Such additives include sliding agents (e.g., PTFE particles), colorants (e.g., pigments such as carbon black and titanium oxide, dyes), light diffusing agents (e.g., acrylic crosslinked particles, silicone crosslinked particles, ultrathin glass flakes, calcium carbonate particles), fluorescent dyes, inorganic phosphors (e.g., phosphors with aluminate as the host crystal), antistatic agents, crystal nucleating agents, inorganic and organic antibacterial agents, photocatalytic antifouling agents (e.g., fine particle titanium oxide, fine particle zinc oxide), radical generators, infrared absorbing agents (heat ray absorbing agents), and photochromic agents.

<Method of producing resin composition>
Any method can be used to produce the flame-retardant polycarbonate resin composition of the present invention. For example, the components and optionally other components are premixed, then melt-kneaded, and pelletized. Premixing means include a Nauta mixer, a V-type blender, a Henschel mixer, a mechanochemical device, and an extrusion mixer. In premixing, granulation can be performed using an extrusion granulator or a briquetting machine. After premixing, the mixture is melt-kneaded using a melt mixer such as a vented twin-screw extruder, and pelletized using a pelletizer or other device. Other examples of the melt mixer include a Banbury mixer, a kneading roll, and a thermostatic stirring vessel, but a vented twin-screw extruder is preferred. Alternatively, each component and optionally other components can be independently supplied to a melt mixer such as a twin-screw extruder without premixing.

<Regarding Molded Products>
The flame-retardant polycarbonate resin composition of the present invention obtained as described above can be injection molded from pellets produced as described above to produce various products. Furthermore, it is also possible to directly produce sheets, films, irregular extrusion molded products, and injection molded products from the resin melt-kneaded in an extruder without passing through pellets. In such injection molding, molded products can be obtained using injection molding methods such as injection compression molding, injection press molding, gas-assisted injection molding, foam molding (including injection of supercritical fluid), insert molding, in-mold coating molding, heat-insulating mold molding, rapid heating and cooling mold molding, two-color molding, sandwich molding, and ultra-high speed injection molding, in addition to ordinary molding methods, depending on the purpose. The advantages of these various molding methods are already widely known. In addition, molding can be performed using either the cold runner method or the hot runner method. In addition, the resin composition of the present invention can be extrusion molded into various irregular extrusion molded products and sheets.

The flame-retardant polycarbonate resin composition of the present invention is a resin composition that has excellent impact strength and flame retardancy, and in which the decrease in impact strength and flame retardancy due to moisture resistance deterioration is suppressed, and is therefore widely useful in the fields of office automation equipment, electronic and electrical equipment, and various other fields. Therefore, the industrial effects of the present invention are extremely significant.

The embodiments for carrying out the present invention are a summary of the preferred ranges of each of the above-mentioned requirements, and representative examples are described in the following examples. Of course, the present invention is not limited to these embodiments.

The present invention will be further explained below with reference to examples. In the examples, parts are parts by weight and percentages are percentages by weight unless otherwise specified. Evaluations were performed using the following methods.

(Evaluation of Flame Retardant Polycarbonate Resin Composition)
(i) Charpy Impact Strength Using ISO bending test pieces obtained by the following method, the notched Charpy impact strength was measured according to ISO 179.
(ii) Flame retardancy Using the UL test specimens obtained by the following method, a V test was carried out according to UL 94. The cases where the judgment did not satisfy any of the criteria of V-0, V-1, and V-2 were indicated as "not V".
(iii) Wet Heat Resistance The Charpy notched impact strength and flame retardancy after wet heat treatment under the following conditions were measured in the same manner as in (i) and (ii) above.
(Wet heat treatment conditions)
Equipment used: PR-3KP (manufactured by Espec)
Temperature: 75°C
Humidity: 90% RH
Test time: 1,000 hours

[Examples 1 to 11, Comparative Examples 1 to 11]
The mixture was fed from the first feed port of the extruder with the composition shown in Table 1. The mixture was obtained by mixing the following pre-mixture (i) with other components in a V-type blender. That is, (i) is a mixture of the drip prevention agent of component E and the polycarbonate resin of component A, which was homogeneously mixed in a polyethylene bag by shaking the entire bag so that component E was 2.5% by weight. The amount of the mixture fed was precisely measured with a weighing machine [CWF manufactured by Kubota Corporation]. The extrusion was performed using a vented twin-screw extruder (TEX30α-38.5BW-3V manufactured by Japan Steel Works, Ltd.) with a diameter of 30 mmφ, and melt-kneaded at a screw rotation speed of 230 rpm, a discharge rate of 25 kg/h, and a vent vacuum of 3 kPa to obtain pellets. The extrusion temperature was 280°C from the first feed port to the die portion. A portion of the obtained pellets was dried in a hot air circulation dryer at 90 to 100°C for 6 hours, and then molded into ISO bending test pieces (ISO179) and UL test pieces using an injection molding machine at a cylinder temperature of 280°C and a mold temperature of 70°C.

The symbols used in Table 1 denote the following components:
(Component A)
A-1: Aromatic polycarbonate resin (polycarbonate resin powder having a viscosity average molecular weight of 22,400, produced by a conventional method from bisphenol A and phosgene, manufactured by Teijin Limited, Panlite L-1225WP (product name))
(Component B)
B-1: Butadiene-based core-shell type graft polymer (a graft copolymer having a core-shell structure in which the core is mainly composed of butadiene rubber and the shell is mainly composed of methyl methacrylate and styrene, manufactured by Mitsubishi Chemical Corporation, Metablen E-870A (product name))
(Component C)
C-1: Cyclic phenoxyphosphazene having a content of k=1 trimer of formula (15) of 100 mol%; C-2: Cyclic phenoxyphosphazene having a content of k=1 trimer of formula (15) of 98.5 mol%, a content of k=2 tetramer of 1 mol%, and a content of k=3 or more multimer of 0.5 mol; C-3: Cyclic phenoxyphosphazene having a content of k=1 trimer of formula (15) of 98 mol%, a content of k=2 tetramer of 1.5 mol%, and a content of k=3 or more multimer of 0.5 mol; C-4: Cyclic phenoxyphosphazene having a content of k=1 trimer of formula (15) of 70 mol%, a content of k=2 tetramer of 20 mol%, and a content of k=3 or more multimer of 10 mol%

(Component D)
D-1: Potassium perfluorobutanesulfonate (product name: Megafac F-114P, manufactured by Dai Nippon Ink Co., Ltd.)
D-2: Potassium diphenylsulfone sulfonate (KSS (product name) manufactured by Arichem)
D-3: Condensed phosphate ester (manufactured by Daihachi Chemical Industry Co., Ltd., product name CR-741)
(Component E)
E-1: PTFE (Polyflon MPA FA500H (product name) manufactured by Daikin Industries, Ltd.)
(Other ingredients)
STB: Phenol-based heat stabilizer (octadecyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, molecular weight 531, Irganox 1076 (product name) manufactured by BASF Japan Ltd.)
Wax: Fatty acid ester release agent (Rikemal SL900 (product name) manufactured by Riken Vitamin Co., Ltd.)

Claims (4)

A flame-retardant polycarbonate resin composition comprising 100 parts by weight of (A) polycarbonate resin (component A), 1 to 8 parts by weight of (B) impact modifier (component B), 1 to 8 parts by weight of (C) phosphazene containing 98.5 mol% or more of phosphazene cyclic trimer (component C), 0.01 to 0.5 parts by weight of (D) organic sulfonic acid metal salt (component D), and 0.05 to 2 parts by weight of (E) drip prevention agent (component E). The flame-retardant polycarbonate resin composition according to claim 1, characterized in that component B is a graft copolymer obtained by graft polymerizing at least one compound including a (meth)acrylic acid ester compound onto a butadiene rubber. The flame-retardant polycarbonate resin composition according to claim 1 or 2, characterized in that component D is an alkali metal salt of perfluoroalkylsulfonic acid or an alkali metal salt of aromatic sulfonic acid. A molded article obtained by molding the resin composition according to any one of claims 1 to 3.