JP7613856B2 - Thermoplastic resin composition - Google Patents

Description

The present invention relates to a thermoplastic resin composition. More specifically, the present invention relates to a thermoplastic resin composition in which yellowing during molding dwell, resin deterioration in high-temperature and high-humidity environments, and flame retardancy are improved by blending an appropriate amount of an orthophosphate compound, a phenolic compound, and a flame retardant with a resin component consisting of a polycarbonate resin and a polyarylate resin.

Compositions consisting of polycarbonate resin, polyarylate resin and flame retardant have excellent properties such as heat resistance, mechanical strength, dimensional stability and flame retardancy, and molded products thereof are widely used in fields such as electrical and electronic equipment parts, automobile parts and machine parts (see Patent Documents 1 and 2). However, there is no disclosure of the possibility of obtaining a composition that can suppress resin deterioration in high-temperature and high-humidity environments.

JP 2009-256429 A JP 2009-275062 A

The object of the present invention is to provide a thermoplastic resin composition that has excellent heat resistance and flame retardancy, does not discolor during molding, and inhibits resin deterioration in high-temperature and high-humidity environments.

As a result of extensive research to achieve the above object, the inventors have discovered that by blending an appropriate amount of an orthophosphate compound, a phenolic compound, and a flame retardant into a resin composition consisting of a polycarbonate resin and a polyarylate resin, a thermoplastic resin composition can be obtained that is excellent in heat resistance and flame retardancy, and that is improved in yellowing during molding retention and in resin degradation under high temperature and high humidity environments. After further extensive research, the inventors have completed the present invention.

The present invention will be described in detail 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 bisphenol A-based polycarbonate resins, which are general-purpose polycarbonate resins, it is possible to use special polycarbonate resins produced using other dihydric phenols as component A.

For example, polycarbonate resins (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 changes 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 resin.

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 copolymeric polycarbonate resin of the following (1) to (3).
(1) A copolymerized polycarbonate resin in which, relative to 100 mol % of a dihydric phenol component constituting the polycarbonate resin, 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 copolymerized polycarbonate resin in which, relative to 100 mol % of the dihydric phenol component constituting the polycarbonate resin, BPA is 10 to 95 mol % (more preferably 50 to 90 mol %, and even more preferably 60 to 85 mol %) and BCF is 5 to 90 mol % (more preferably 10 to 50 mol %, and even more preferably 15 to 40 mol %).
(3) A copolymerized polycarbonate resin in which, relative to 100 mol % of the dihydric phenol component constituting the polycarbonate resin, 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 polycarbonate resins may be used alone or in a suitable mixture of two or more kinds. They may also be used in a mixture with the commonly used bisphenol A type polycarbonate resin. The manufacturing methods and properties of these special polycarbonate resins 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 polycarbonate resins mentioned above, those having water absorption and glass transition temperature (Tg) within the following ranges by adjusting the copolymer composition, etc., have good hydrolysis resistance of the polymer itself and are remarkably excellent in low warpage after molding, and are therefore particularly suitable in fields where dimensional stability is required.
(i) A polycarbonate resin 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 resin 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 resin is measured by using a disk-shaped test piece with a diameter of 45 mm and a thickness of 3.0 mm, and measuring the moisture content after immersing it in water at 23°C for 24 hours in accordance with ISO 62-1980. In addition, Tg (glass transition temperature) is a value determined by differential scanning calorimetry (DSC) measurement 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 the interfacial polymerization method, a catalyst, a terminal terminator, an antioxidant to prevent the dihydric phenol from being oxidized, etc. may be used as necessary. The polycarbonate resin of the present invention also 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.

The structural unit derived from the polyfunctional aromatic compound in the branched polycarbonate resin is preferably 0.01 to 1 mol%, more preferably 0.05 to 0.9 mol%, and even more preferably 0.05 to 0.8 mol% out of the total 100 mol% of the structural unit derived from the dihydric phenol and the structural unit derived from the polyfunctional aromatic compound. In addition, particularly in the case of the melt transesterification method, a branched structural unit may be generated as a side reaction, and the amount of such branched structural unit is also preferably 0.001 to 1 mol%, more preferably 0.005 to 0.9 mol%, and even more preferably 0.01 to 0.8 mol% out of the total 100 mol% of the structural unit 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.

In producing the thermoplastic resin composition of the present invention, 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 terms of poor fluidity during injection molding.

The polycarbonate resin may be a mixture of polycarbonate resins 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 resin. In a more preferred embodiment, component A is composed of a polycarbonate resin (component A-1-1) having a viscosity average molecular weight of 7×10 ⁴ to 3×10 ⁵ , and an aromatic polycarbonate resin (component A-1-2) having a viscosity average molecular weight of 1×10 ⁴ to 3×10 ⁴ , and a polycarbonate resin (component A-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), the molecular weight of component A-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) can be obtained by mixing the components A-1-1 and A-1-2 in various ratios and adjusting to satisfy a specified molecular weight range. Preferably, the A-1-1 component is 2 to 40% by weight out of 100% by weight of component A-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 component A-1 include (1) a method of independently polymerizing components A-1-1 and A-1-2 and mixing them together, (2) a method of producing an aromatic polycarbonate resin that exhibits multiple polymer peaks in a molecular weight distribution chart obtained by GPC in the same system, as typified by the method shown in JP-A-5-306336, and producing such an aromatic polycarbonate resin so as to satisfy the conditions for component A-1 of the present invention, and (3) a method of mixing the aromatic polycarbonate resin obtained by such a production method (production method (2)) with components A-1-1 and/or A-1-2 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 thermoplastic 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 celite filtration. 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, 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.

As the polycarbonate resin of the present invention, a polycarbonate-polydiorganosiloxane copolymer resin can also be used. The polycarbonate-polydiorganosiloxane copolymer resin is preferably a copolymer resin containing a dihydric phenol unit represented by the following general formula (1) and a hydroxyaryl-terminated polydiorganosiloxane unit 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 carboxyl group, and when there are a plurality of each, they may be the same or different, a and b 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 carboxyl group, and when there are a plurality of groups, they may be the same or different, c is an integer from 1 to 10, and d 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; e and f are each an integer of 1 to 4; p is a natural number; q is 0 or a natural number; and p+q is a natural number of 4 or more and 150 or less. X is a divalent aliphatic group having 2 to 8 carbon atoms.]

Examples of dihydric phenols (I) that derive the carbonate structural unit represented by 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 '-Dihydroxy-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, 1,3-bis(4-hydroxyphenyl)-5,7-dimethyladamantane, etc.

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.

In the carbonate structural unit represented by the above general formula (3), R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ and R ⁸ are each independently preferably a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 12 carbon atoms, with a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or a phenyl group being particularly preferred. ^{R 9} and R ¹⁰ are each independently preferably a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, with a hydrogen atom or an alkyl group having 1 to 4 carbon atoms being particularly preferred. As the dihydroxyaryl-terminated polydiorganosiloxane (II) from which the carbonate structural unit represented by the above general formula (3) is derived, for example, a compound as shown in the following general formula (I) is suitably used.

p+q is preferably 4 to 120, more preferably 30 to 120, even more preferably 30 to 100, and most preferably 30 to 60.

Next, a method for producing the above-mentioned preferred polycarbonate-polydiorganosiloxane copolymer resin will be described below. In advance, in a mixture of a water-insoluble organic solvent and an aqueous alkali solution, a dihydric phenol (I) is reacted with a chloroformate-forming compound such as phosgene or a chloroformate of dihydric phenol (I) to prepare a mixed solution of chloroformate compounds containing the chloroformate of dihydric phenol (I) and/or a carbonate oligomer of dihydric phenol (I) having a terminal chloroformate group. Phosgene is preferred as the chloroformate-forming compound.

In producing a chloroformate compound from a dihydric phenol (I), the entire amount of the dihydric phenol (I) from which the carbonate structural unit represented by the above general formula (1) is derived may be converted into a chloroformate compound at once, or a part of it may be added as a post-added monomer as a reaction raw material to the subsequent interfacial polycondensation reaction. The post-added monomer is added to rapidly advance the subsequent polycondensation reaction, and it is not necessary to add it if it is not necessary. The method of this chloroformate compound production 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. Furthermore, if desired, a small amount of an antioxidant such as sodium sulfite or hydrosulfide may be added, and it is preferable to add it. The proportion of the chloroformate-forming compound used may be appropriately adjusted taking into account the stoichiometric ratio (equivalent) of the reaction. In addition, when phosgene, which is a suitable chloroformate-forming compound, is used, a method of blowing gasified phosgene into the reaction system can be preferably adopted.

As the acid binder, for example, 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, or mixtures thereof can be used. Similarly to the above, the proportion of the acid binder used can be appropriately determined taking into account the stoichiometric ratio (equivalents) of the reaction. Specifically, it is preferable to use 2 equivalents or a slight excess of the acid binder per mole of dihydric phenol (I) used to form the chloroformate compound of dihydric phenol (I) (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 pressure in the reaction to produce chloroformate compounds, 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 the reaction often generates heat, 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 in the reaction to produce chloroformate compounds can use known interfacial reaction conditions, and the pH is usually adjusted to 10 or higher.

In the production of the polycarbonate-polydiorganosiloxane copolymer resin of the present invention, a mixed solution of chloroformate compounds containing a chloroformate of dihydric phenol (I) and a carbonate oligomer of dihydric phenol (I) having a terminal chloroformate group is thus prepared, and then, while stirring the mixed solution, dihydroxyaryl-terminated polydiorganosiloxane (II) which derives carbonate structural units represented by general formula (3) is added at a rate of 0.01 mol/min or less per 1 mol of dihydric phenol (I) charged in preparing the mixed solution, and the dihydroxyaryl-terminated polydiorganosiloxane (II) and the chloroformate compound are subjected to interfacial polycondensation to obtain a polycarbonate-polydiorganosiloxane copolymer resin.

Polycarbonate-polydiorganosiloxane copolymer resins can be made into branched polycarbonate-polydiorganosiloxane copolymer resins by using a branching agent in combination with a dihydric phenol compound. Examples of trifunctional or higher polyfunctional aromatic compounds used in such branched polycarbonate resins include phloroglucin, 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.

The method for producing such a branched polycarbonate-polydiorganosiloxane copolymer resin may be a method in which a branching agent is included in the mixed solution during the production reaction of the chloroformate compound, or a method in which a branching agent is added during the interfacial polycondensation reaction after the completion of the production reaction. The proportion of carbonate constituent units derived from the branching agent is preferably 0.005 to 1.5 mol%, more preferably 0.01 to 1.2 mol%, and particularly preferably 0.05 to 1.0 mol% of the total amount of carbonate constituent units constituting the copolymer resin. The amount of branched structures can be calculated by ¹ H-NMR measurement.

The pressure in the system during the polycondensation reaction may be reduced, normal, or increased, but is usually preferably normal pressure or the natural pressure of the reaction system. The reaction temperature is selected from the range of -20 to 50°C, and in many cases, since heat is generated during polymerization, it is desirable to cool the reaction with water or ice. The reaction time cannot be generally specified because it varies depending on other conditions such as the reaction temperature, but is usually performed for 0.5 to 10 hours. In some cases, the obtained polycarbonate-polydiorganosiloxane copolymer resin can be appropriately subjected to physical treatment (mixing, fractionation, etc.) and/or chemical treatment (polymer reaction, crosslinking treatment, partial decomposition treatment, etc.) to obtain a polycarbonate-polydiorganosiloxane copolymer resin with a desired reduced viscosity [η _SP /c]. The obtained reaction product (crude product) can be subjected to various post-treatments such as known separation and purification methods, and recovered as a polycarbonate-polydiorganosiloxane copolymer resin with a desired purity (purity).

The content of the polydiorganosiloxane block represented by the following general formula (4) contained in the above general formula (3) is preferably 1.0 to 10.0% by weight, more preferably 1.0 to 8.0% by weight, even more preferably 1.0 to 5.0% by weight, and most preferably 1.0 to 3.0% by weight, based on the total weight of the polycarbonate resin composition.

(In the above general formula (4), R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ and R ⁸ each independently represent 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; p is a natural number; q is 0 or a natural number; and p+q is a natural number of 4 or more and 150 or less.)

<Component B: Polyarylate Resin>
The polyarylate resin used as component B of the present invention may be obtained by a conventional method from a dihydric phenol or its derivative and an aromatic dicarboxylic acid or its derivative. Examples of the dihydric phenol used here include 2,2-bis(4-hydroxyphenyl)propane, 1,1-bis(4-hydroxyphenyl)-3,3,5-trimethylcyclohexane, 4,4-dihydroxy-biphenyl, bis(4-hydroxyphenyl)methane, 2,2-bis(4-hydroxy-3,5-dimethylphenyl)propane, 2,2-bis(4-hydroxy-3,5-dibromophenyl)propane, 2,2-(4-hydroxy-3-methylphenyl)propane, 4,4'-dihydroxydiphenylsulfone, 4,4'-dihydroxydiphenylether, and 4,4'-dihydroxydiphenylsulfide. Two or more of them may be used in combination.

Any aromatic dicarboxylic acid may be used as long as it reacts with a dihydric phenol to give a satisfactory polymer, and may be used alone or in combination of two or more. Preferred aromatic dicarboxylic acids include terephthalic acid and isophthalic acid, and mixtures of these are particularly preferred in terms of melt processability and overall performance. There is no need to limit the mixing ratio of these mixtures, but a terephthalic acid/isophthalic acid ratio of 9/1 to 1/9 (molar ratio) is preferred, and a molar ratio of 7/3 to 3/7 is particularly preferred in terms of the balance between melt processability and performance.

The polyarylate resin used as component B of the present invention is preferably a copolymer containing polymerization units represented by any one of the following general formulas (5) to (7). If a polyarylate resin that does not contain this structure is used, the impact resistance may decrease.

[In the above general formula (5), l, m, and n are positive integers that satisfy l+m+n=100, l:n=50:50 to 70:30, and (l+n):m=75:25 to 40:60.]

[In the above general formula (6), m and n are positive integers, and m/n = 8/2 to 2/8.]

[In the above general formula (7), n is a positive integer.]

The content of the polyarylate resin used as component B of the present invention is 1 to 99 parts by weight, preferably 10 to 50 parts by weight, and more preferably 20 to 40 parts by weight, per 100 parts by weight of the resin component consisting of components A and B. If the content of component B exceeds 99 parts by weight, yellowing during molding retention increases, and if it is less than 1 part by weight, excellent heat resistance cannot be obtained, and further deterioration of the resin in a high-temperature, high-humidity environment increases.

Commercially available polyarylate resins include "U-100" (product name), "M-2040" (product name), and "M-2040H" (product name) manufactured by Unitika Ltd.

<Component C: Orthophosphate Ester Compound>
The content of the orthophosphate compound used as component C of the present invention is 0.001 to 2 parts by weight, preferably 0.005 to 0.5 parts by weight, and more preferably 0.01 to 0.1 parts by weight, relative to 100 parts by weight of the resin component consisting of components A and B. If the content of component C is less than 0.001 part by weight, yellowing during molding retention increases, and if it exceeds 2 parts by weight, resin deterioration in a high-temperature, high-humidity environment increases. Note that if a phosphoric acid ester compound other than an orthophosphate compound is used as component C, resin deterioration in a high-temperature, high-humidity environment increases.

The type of orthophosphate ester compound is not particularly limited, but an orthophosphate ester compound having a number average molecular weight of 50 to 600 is preferred. The number average molecular weight is more preferably 100 to 550, and even more preferably 140 to 500. The melting point of the orthophosphate ester compound is preferably 30 to 80°C. An orthophosphate ester compound that satisfies these requirements may be particularly effective in suppressing yellowing during molding retention and suppressing resin deterioration in high temperature and high humidity environments.

Specific examples of orthophosphate ester 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, and diisopropyl phosphate, with triphenyl phosphate and trimethyl phosphate being preferred.

<Component D: Phenolic Compound>
The content of the phenolic compound used as component D in the present invention is 0.001 to 2 parts by weight, preferably 0.01 to 0.5 parts by weight, and more preferably 0.03 to 0.08 parts by weight, based on 100 parts by weight of the resin component consisting of components A and B. If the content of component D is less than 0.001 part by weight, deterioration of the resin in a high-temperature and high-humidity environment increases, while if it exceeds 2 parts by weight, yellowing during retention in molding increases.

The type of phenolic compound used as component D of the present invention is not particularly limited, but when a hindered phenolic antioxidant or a phenolic compound with a melting point of 30 to 70°C is used, the effect of suppressing yellowing during molding retention and suppressing resin deterioration in a high-temperature, high-humidity environment may be particularly exhibited. Examples of phenolic antioxidants include α-tocopherol, butyl hydroxytoluene, sinapyl alcohol, vitamin E, n-octadecyl-β-(4'-hydroxy-3',5'-di-tert-butylphenyl)propionate, 2-tert-butyl-6-(3'-tert-butyl-5'-methyl-2'-hydroxybenzyl)-4-methylphenyl acrylate, 2,6-di-tert-butyl-4-(N,N-dimethyl (aminomethyl)phenol, 3,5-di-tert-butyl-4-hydroxybenzylphosphonate 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-tetrahydrofuran xaspiro[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-butylphenol), 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)propionyl]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-hydroxyphenyl)propionyl]hydrazine Examples include 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, and tetrakis[methylene-3-(3',5'-di-tert-butyl-4-hydroxyphenyl)propionate]methane. All of these are readily available.

<Component E: Flame retardant>
The thermoplastic resin composition of the present invention contains a flame retardant as component E. The incorporation of such a compound not only improves flame retardancy, but also improves antistatic properties, fluidity, rigidity, and thermal stability, etc., based on the properties of each compound. Examples of such flame retardants include (i) halogen-based compounds, (ii) condensed phosphate ester compounds, (iii) phosphazene compounds, (iv) organic metal salts, and (v) inorganic compounds. These may be used alone or in combination.

(i) Halogen-Based Compounds Examples of the brominated flame retardants used in the present invention include brominated bisphenol A polycarbonate flame retardants having a bromine content of 20% by weight or more, brominated bisphenol A epoxy resins and modified products thereof in which the terminal glycidyl groups are partially or completely blocked, brominated diphenyl ether flame retardants, brominated imide flame retardants, brominated polystyrene flame retardants, and the like.

Specific examples include decabromodiphenyl oxide, octabromodiphenyl oxide, tetrabromodiphenyl oxide, tetrabromophthalic anhydride, hexabromocyclododecane, bis(2,4,6-tribromophenoxy)ethane, ethylenebistetrabromophthalimide, hexabromobenzene, 1,1-sulfonyl[3,5-dibromo-4-(2,3-dibromopropoxy)]benzene, polydibromophenylene oxide, tetrabromobisphenol S, tris(2,3-dibromopropyl-1)isocyanurate, tribromophenol, tribromophenyl allyl ether, tribromoneopentyl alcohol, brominated polystyrene, brominated polyethylene, tetrabromobisphenol A, tetrabromobisphenol A derivatives, tetrabromobisphenol A-epoxy ether ... oligomers or polymers, tetrabromobisphenol A-carbonate oligomers or polymers, brominated epoxy resins such as brominated phenol novolac epoxy, tetrabromobisphenol A-bis(2-hydroxydiethyl ether), tetrabromobisphenol A-bis(2,3-dibromopropyl ether), tetrabromobisphenol A-bis(allyl ether), tetrabromocyclooctane, ethylene bispentabromodiphenyl, tris(tribromoneopentyl)phosphate, poly(pentabromobenzyl polyacrylate), octabromotrimethylphenylindane, dibromoneopentyl glycol, pentabromobenzyl polyacrylate, dibromocresyl glycidyl ether, N,N'-ethylene-bis-tetrabromophthalimide, etc. Among them, tetrabromobisphenol A-epoxy oligomers, tetrabromobisphenol A-carbonate oligomers, brominated epoxy resins, etc. are included.

As the brominated flame retardant of the present invention, brominated polycarbonate (including oligomers) is particularly suitable. Brominated polycarbonate has excellent heat resistance and can significantly improve flame retardancy. The brominated polycarbonate used in the present invention is a brominated polycarbonate compound in which the structural unit represented by the following general formula (8) accounts for at least 60 mol %, preferably at least 80 mol %, of all structural units, and is particularly preferably substantially composed of the structural unit represented by the following general formula (8).

(In the above general formula (8), X is a bromine atom, and R is an alkylene group having 1 to 4 carbon atoms, an alkylidene group having 1 to 4 carbon atoms, or _-SO2- .)
In the formula (8), R preferably represents a methylene group, an ethylene group, an isopropylidene group, or --SO ₂ --, and particularly preferably an isopropylidene group.

The brominated polycarbonate preferably has a small amount of residual chloroformate terminals, with the amount of terminal chlorine being 0.3 ppm or less, more preferably 0.2 ppm or less. The amount of terminal chlorine can be determined by dissolving a sample in methylene chloride, adding 4-(p-nitrobenzyl)pyridine to react with the terminal chlorine (terminal chloroformate), and measuring the result with an ultraviolet-visible spectrophotometer (U-3200, manufactured by Hitachi, Ltd.). If the amount of terminal chlorine is 0.3 ppm or less, the thermal stability of the resin composition is improved, enabling molding at even higher temperatures, resulting in a resin composition with superior moldability.

The brominated polycarbonate preferably has few residual terminal hydroxyl groups. More specifically, the amount of terminal hydroxyl groups is preferably 0.0005 mol or less, more preferably 0.0003 mol or less, per mol of the constituent units of the brominated polycarbonate. The amount of terminal hydroxyl groups can be determined by dissolving a sample in deuterated chloroform and measuring by ¹ H-NMR. Such an amount of terminal hydroxyl groups is preferable because it further improves the thermal stability of the resin composition.

The specific viscosity of the brominated polycarbonate is preferably in the range of 0.015 to 0.1, more preferably in the range of 0.015 to 0.08. The specific viscosity of the brominated polycarbonate is calculated according to the above-mentioned formula for calculating the specific viscosity used when calculating the viscosity average molecular weight of the polycarbonate resin, which is the component A of the present invention.

The content of the halogen-based compound is 0.005 to 20 parts by weight, preferably 1 to 10 parts by weight, and more preferably 5 to 10 parts by weight, per 100 parts by weight of the resin component consisting of components A and B. If the content is less than 0.005 parts by weight, it is difficult to obtain the flame retardant effect, and if it exceeds 20 parts by weight, yellowing during molding retention and resin deterioration in high temperature and high humidity environments will increase.

(ii) Condensed phosphate ester compound As the condensed phosphate ester compound, an aryl phosphate compound is preferably used. Since the condensed phosphate ester compound has a plasticizing effect, it is advantageous in that it can improve molding processability. As the aryl phosphate compound, various phosphate compounds known as flame retardants can be used, but more preferably, one or more phosphate compounds represented by the following general formula (9) can be used.

(In the above general formula (9), M represents a divalent organic group derived from a dihydric phenol, and Ar ¹ , Ar ² , Ar ³ , and Ar ⁴ each represent a monovalent organic group derived from a monohydric phenol. a, b, c, and d each independently represent 0 or 1, and m represents an integer from 0 to 5. In the case of a mixture of condensed phosphate esters having different degrees of polymerization m, m represents the average value thereof and is a value from 0 to 5.)

The phosphate compound of the formula above may be a mixture of compounds having different m numbers, and in such a mixture, the average m number is preferably in the range of 0.5 to 1.5, more preferably 0.8 to 1.2, even more preferably 0.95 to 1.15, and particularly preferably 1 to 1.14.

Specific examples of suitable dihydric phenols from which M is derived include hydroquinone, resorcinol, bis(4-hydroxydiphenyl)methane, bisphenol A, dihydroxydiphenyl, dihydroxynaphthalene, bis(4-hydroxyphenyl)sulfone, bis(4-hydroxyphenyl)ketone, and bis(4-hydroxyphenyl)sulfide, of which resorcinol, bisphenol A, and dihydroxydiphenyl are preferred.

Preferred specific examples of the monohydric phenol from which Ar ¹ , Ar ² , Ar ³ and Ar ⁴ are derived include phenol, cresol, xylenol, isopropylphenol, butylphenol and p-cumylphenol, and among these, phenol and 2,6-dimethylphenol are preferred.

The monohydric phenol may be substituted with a halogen atom, and specific examples of phosphate compounds having a group derived from the monohydric phenol include tris(2,4,6-tribromophenyl)phosphate, tris(2,4-dibromophenyl)phosphate, and tris(4-bromophenyl)phosphate.

On the other hand, specific examples of phosphate compounds not substituted with halogen atoms include monophosphate compounds such as tri(2,6-xylyl)phosphate, as well as phosphate oligomers mainly composed of resorcinol bis(di(2,6-xylyl)phosphate), phosphate oligomers mainly composed of 4,4-dihydroxydiphenyl bis(diphenyl phosphate), and phosphoric ester oligomers mainly composed of bisphenol A bis(diphenyl phosphate). (Here, "mainly composed" means that it may contain small amounts of other components with different degrees of polymerization, and more preferably means that the component of m=1 in the above formula (9) is contained in an amount of 80% by weight or more, more preferably 85% by weight or more, and even more preferably 90% by weight or more.)
The content of the condensed phosphate ester compound is 0.005 to 20 parts by weight, preferably 5 to 15 parts by weight, and more preferably 8 to 10 parts by weight, based on 100 parts by weight of the resin component consisting of components A and B. If the content is less than 0.005 parts by weight, it is difficult to obtain a flame retardant effect, and if it exceeds 20 parts by weight, there is a decrease in heat resistance, yellowing during retention in molding, and significant deterioration of the resin in a high-temperature, high-humidity environment.

(iii) Phosphazene Compounds Phosphazene compounds have a plasticizing effect, and therefore are advantageous in that they can improve molding processability. As the phosphazene compound, various phosphazene compounds conventionally known as flame retardants can be used, but phosphazene compounds represented by the following general formulas (10) and (11) are preferred.

(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 r represents an integer of 3 to 10.)

In the above formulas (10) and (11), examples of the organic group not containing a halogen atom represented by ^X1 , ^X2 , ^X3 , and ^X4 include an alkoxy group, a phenyl group, an amino group, an allyl group, etc. Among them, the cyclic phosphazene compound represented by the above formula (10) is preferred, and further, a cyclic phenoxyphosphazene in which ^X1 and ^X2 in the above formula (10) are phenoxy groups is particularly preferred.

The content of the phosphazene compound is 0.005 to 20 parts by weight, preferably 2 to 10 parts by weight, and more preferably 3 to 7 parts by weight, per 100 parts by weight of the resin component consisting of components A and B. If the content of the phosphazene compound is less than 0.005 parts by weight, it is difficult to obtain a flame retardant effect, and if it exceeds 20 parts by weight, there will be a decrease in heat resistance, yellowing during molding retention, and significant resin deterioration in high temperature and humidity environments.

(iv) Organic Metal Salt The organic metal salt is preferably an alkali (earth) metal salt of an organic acid having 1 to 50, preferably 1 to 40 carbon atoms, preferably an alkali (earth) metal salt of an organic sulfonate. The alkali (earth) metal salt of an organic sulfonate 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 an 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 an 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. More preferred are alkali metals. Among these alkali metals, rubidium and cesium, which have a larger ionic radius, are preferred when a higher transparency is required, but these are not versatile and are difficult to purify, which may result in a disadvantage in terms of cost. On the other hand, metals with smaller ionic radii such as lithium and sodium may be disadvantageous in terms of flame retardancy. Taking these into consideration, the alkali metals in the alkali metal sulfonates can be selected appropriately, but in all respects, potassium sulfonates, which have an excellent balance of properties, are most suitable. Such potassium salts can also be used in combination with alkali metal sulfonates made of other alkali metals.

Specific examples of alkali metal salts of perfluoroalkylsulfonates 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 number of carbon atoms in 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. Perfluoroalkylsulfonic acid alkali (earth) metal salts made of alkali metals usually contain a certain amount of fluoride ions (F-). 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 fluoride ion content is preferably 100 ppm or less, more preferably 40 ppm or less, and particularly preferably 10 ppm or less. For production efficiency, it is also preferable for the content to be 0.2 ppm or more. Such perfluoroalkylsulfonic acid alkali (earth) metal salts with reduced amounts of fluoride ions can be produced by known production methods, and can be produced by a method of reducing the amount of fluoride ions contained in the raw materials when producing a fluorine-containing organometallic salt, a method of removing hydrogen fluoride and the like obtained by the reaction by heating or using gas generated during the reaction, 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 organometallic salt. In particular, since organometallic salts are relatively soluble in water, it is preferable to produce them using ion-exchanged water, particularly water with an electrical resistance of 18 MΩ·cm or more, i.e., an electrical conductivity of about 0.55 μS/cm or less, and dissolving and washing at a temperature higher than room temperature, followed by cooling and recrystallization.

Specific examples of aromatic sulfonic acid alkali (earth) metal salts include, for example, 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, benzenesulfonic acid 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 of these (with a weight ratio of the former to the latter of 15/85 to 30/70) are particularly preferred.

Suitable examples of organic metal salts other than alkali (earth) metal sulfonates include alkali (earth) metal salts of sulfates and alkali (earth) metal salts of aromatic sulfonamides. Examples of alkali (earth) metal salts of sulfates include alkali (earth) metal salts of sulfates of monohydric and/or polyhydric alcohols, and examples of sulfates of monohydric and/or polyhydric alcohols include methyl sulfate, ethyl sulfate, lauryl sulfate, hexadecyl sulfate, sulfate of polyoxyethylene alkylphenyl ether, mono-, di-, tri-, and tetrasulfate of pentaerythritol, sulfate of lauric acid monoglyceride, sulfate of palmitic acid monoglyceride, and sulfate of stearic acid monoglyceride. Examples of the alkali (earth) metal salts of these sulfates include alkali (earth) metal salts of lauryl sulfate. Examples of alkali (earth) metal salts of aromatic sulfonamides include saccharin, N-(p-tolylsulfonyl)-p-toluenesulfonimide, N-(N'-benzylaminocarbonyl)sulfanilimide, and alkali (earth) metal salts of N-(phenylcarboxyl)sulfanilimide. The content of the organic metal salt is 0.005 to 20 parts by weight, preferably 0.005 to 1 part by weight, and more preferably 0.01 to 0.1 parts by weight, per 100 parts by weight of the total of components A and B. If the content is less than 0.005 parts by weight, it is difficult to obtain a flame retardant effect, and if it exceeds 20 parts by weight, yellowing during molding retention and resin deterioration in a high temperature and high humidity environment will increase.

(v) Inorganic Compounds Examples of inorganic compounds include silicone compounds, fibril-forming fluorine-containing polymers and antimony compounds.

Silicone compounds improve flame retardancy through a chemical reaction during combustion. As such compounds, various compounds that have been proposed as flame retardants for aromatic polycarbonate resins can be used. Silicone compounds are thought to impart a high flame retardant effect, particularly when used with polycarbonate resins, by forming a structure by bonding with themselves or with components derived from the resin during combustion, or by a reduction reaction during the formation of the structure.

Therefore, it is preferable that the silicone compound contains a group that is highly active in such a reaction, and more specifically, it is preferable that the silicone compound contains a predetermined amount of at least one group selected from alkoxy groups and hydrogen (i.e., Si-H groups). The content ratio of such groups (alkoxy groups, Si-H groups) is preferably in the range of 0.1 to 1.2 mol/100g, more preferably in the range of 0.12 to 1 mol/100g, and even more preferably in the range of 0.15 to 0.6 mol/100g. This ratio can be determined by measuring the amount of hydrogen or alcohol generated per unit weight of the silicone compound using an alkaline decomposition method. The alkoxy group is preferably an alkoxy group with 1 to 4 carbon atoms, and in particular, a methoxy group is preferable.

Generally, the structure of a silicone compound is formed by arbitrarily combining the following four types of siloxane units. That is, M units are monofunctional siloxane units _such as ( _CH3 ) _{3SiO1 /2} , H( _CH3 ) _2SiO1 / ₂ , _H2 ( _CH3 ) _SiO1 /2, (CH3) ₂ ( _CH2 =CH)SiO1 _/2 , ( _CH3 ) ₂ ( _C6H5 )SiO1 _{/ 2} , ( _CH3 )( _{C6H5 )} ( _CH2 =CH)SiO1 _/2 , D units are bifunctional siloxane units such as ( _CH3 ) _2SiO , H( _CH3 )SiO, _H2SiO , H(C6H5)SiO, (CH3)(CH2=CH)SiO, ( _C6H5 )2SiO, T units are monofunctional siloxane units such as ( _CH3 )2SiO, H( _CH3 )SiO, H2SiO, H( _C6H5 )SiO, (CH3)( _CH2 =CH)SiO _, ( _C6H5 ) _2SiO , etc. )SiO _3/2 , (C ₃ H ₇ )SiO _3/2 , HSiO _3/2 , (CH ₂ ═CH)SiO _3/2 , (C ₆ H ₅ )SiO _3/2 and other trifunctional siloxane units, and Q unit: a tetrafunctional siloxane unit represented by SiO ₂ .

Specific examples of the structures of silicone compounds used in silicone flame retardants include the rational formulas Dn, Tp, MmDn, MmTp, MmQq, MmDnTp, MmDnQq, MmTpQq, MmDnTpQq, DnTp, DnQq, and DnTpQq. Among these, preferred silicone compound structures are MmDn, MmTp, MmDnTp, and MmDnQq, and more preferred structures are MmDn and MmDnTp.

Here, the coefficients m, n, p, and q in the rational formula are integers of 1 or more that represent the degree of polymerization of each siloxane unit, and the sum of the coefficients in each rational formula is the average degree of polymerization of the silicone compound. This average degree of polymerization is preferably in the range of 3 to 150, more preferably in the range of 3 to 80, even more preferably in the range of 3 to 60, and particularly preferably in the range of 4 to 40. The more preferable the range, the better the flame retardancy. Furthermore, as described later, silicone-based compounds containing a predetermined amount of aromatic groups are also excellent in transparency and hue. As a result, good reflected light is obtained. In addition, when any of m, n, p, and q is a value of 2 or more, the siloxane unit with that coefficient can be two or more types of siloxane units with different hydrogen atoms or organic residues bonded to them.

The silicone compound may be linear or branched. The organic residue bonded to the silicone atom is preferably an organic residue having 1 to 30 carbon atoms, more preferably 1 to 20 carbon atoms. Specific examples of such organic residues include alkyl groups such as methyl, ethyl, propyl, butyl, hexyl, and decyl, cycloalkyl groups such as cyclohexyl, aryl groups such as phenyl, and aralkyl groups such as tolyl. More preferred are alkyl groups, alkenyl groups, or aryl groups having 1 to 8 carbon atoms. As the alkyl group, alkyl groups having 1 to 4 carbon atoms, such as methyl, ethyl, and propyl, are particularly preferred. Furthermore, the silicone compound used as the silicone flame retardant preferably contains an aryl group. On the other hand, the silane and siloxane compounds used as the organic surface treatment agents for titanium dioxide pigments are clearly distinguished from silicone flame retardants in their preferred aspects in that they are more effective when they do not contain an aryl group. Silicone compounds used as silicone flame retardants may contain reactive groups other than the Si-H group and alkoxy group. Examples of such reactive groups include amino groups, carboxyl groups, epoxy groups, vinyl groups, mercapto groups, and methacryloxy groups.

The content of the silicon-based compound is 0.005 to 20 parts by weight, preferably 0.5 to 10 parts by weight, and more preferably 1 to 5 parts by weight, per 100 parts by weight of the resin component consisting of components A and B. If the content is less than 0.005 parts by weight, it is difficult to obtain the flame retardant effect, and if it exceeds 20 parts by weight, yellowing during molding retention and resin deterioration in high temperature and high humidity environments will increase.

An example of the fibril-forming fluoropolymer is polytetrafluoroethylene (fibrillated PTFE). The fibrillated PTFE may be fibrillated PTFE alone or a mixture of fibrillated PTFE particles, i.e., a polytetrafluoroethylene mixture consisting of fibrillated PTFE particles and an organic polymer. The fibrillated PTFE has an extremely high molecular weight and tends to bond PTFE particles together to form a fiber by external action such as shear force. The number average molecular weight is in the range of 1.5 million to tens of millions. The lower limit is more preferably 3 million. The number average molecular weight is calculated based on the melt viscosity of polytetrafluoroethylene at 380°C, as disclosed in, for example, JP-A-6-145520. That is, the fibrillated PTFE has a melt viscosity at 380°C measured by the method described in the publication in the range of ¹⁰⁷ to ¹⁰¹³ poise, preferably ¹⁰⁸ to ¹⁰¹² poise. Such fibrillated PTFE can be used in the form of a solid or an aqueous dispersion. In addition, such fibrillated PTFE can be used in the form of a PTFE mixture mixed with other resins to improve dispersibility in resins and obtain better flame retardancy and mechanical properties.

As disclosed in JP-A-6-145520, a structure in which the fibrillated PTFE is the core and low molecular weight polytetrafluoroethylene is the shell is also preferably used.

Examples of commercially available products of such fibrillated PTFE include Teflon (registered trademark) 6J from Mitsui DuPont Fluorochemicals Co., Ltd., and Polyflon MPA FA500 and F-201L from Daikin Chemical Industries, Ltd.

As for the mixed form of fibrillated PTFE, (1) a method of mixing an aqueous dispersion of fibrillated 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, JP-A-63-154744, etc.), (2) a method of mixing an aqueous dispersion of fibrillated PTFE with dried organic polymer particles (method described in JP-A-4-272957), (3) a method of uniformly mixing an aqueous dispersion of fibrillated PTFE with an organic polymer particle solution and extracting the coagulated mixture from the mixture (methods described in JP-A-4-272957), and (4) a method of uniformly mixing an aqueous dispersion of fibrillated PTFE with an organic polymer particle solution and extracting the coagulated mixture from the mixture (methods described in JP-A-4-272957). (4) a method of simultaneously removing both media (methods described in JP-A-06-220210, JP-A-08-188653, etc.), (5) a method of polymerizing a monomer that forms an organic polymer in an aqueous dispersion of fibrillated PTFE (method described in JP-A-09-95583), and (6) 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, and then obtaining a mixture (methods described in JP-A-11-29679, etc.) can be used.

Commercially available products of these mixed forms of fibrillated PTFE include the Metablen A series, represented by "Metablen A3000" (product name), "Metablen A3700" (product name), and "Metablen A3800" (product name) from Mitsubishi Rayon Co., Ltd., SN3300B7 (product name) from Shine Polymer, and "BLENDEX B449" (product name) from GE Specialty Chemicals.

The ratio of fibrillated PTFE in the mixed form is preferably 1% to 95% by weight, more preferably 10% to 90% by weight, and most preferably 20% to 80% by weight, per 100% by weight of the mixture.

When the ratio of fibrillated PTFE in the mixed form is within this range, good dispersibility of the fibrillated PTFE can be achieved. The content of fibrillated PTFE is 0.005 to 20 parts by weight, preferably 0.01 to 0.5 parts by weight, and more preferably 0.1 to 0.5 parts by weight, per 100 parts by weight of the resin component consisting of components A and B. If the content is less than 0.005 parts by weight, it is difficult to obtain the flame retardant effect, and if it exceeds 20 parts by weight, yellowing during molding retention becomes significant.

It is preferable that the antimony compound is previously heat-treated at a temperature of 100°C or higher, preferably 300°C or higher. If the antimony compound is not heated or if the antimony compound is heated at a temperature below 100°C, the molecular weight of the resulting resin composition may decrease significantly, and a good molded product may not be obtained. This is thought to be because the crystal water or attached water of the antimony compound is released during the melt-kneading process, causing hydrolysis of the polycarbonate resin.

The content of the antimony compound is 0.005 to 20 parts by weight, preferably 0.5 to 10 parts by weight, and more preferably 1 to 5 parts by weight, per 100 parts by weight of the resin component consisting of components A and B. If the content is less than 0.005 parts by weight, it is difficult to obtain the flame retardant effect, and if it exceeds 20 parts by weight, yellowing occurs during molding and resin deterioration increases in high temperature and humidity environments.

(Other additives)
In the thermoplastic resin composition of the present invention, additives used for improving the thermal stability and designability can be advantageously used. These additives will be specifically described below.
(I) Heat Stabilizer (i) Other Heat Stabilizers The thermoplastic resin composition of the present invention may also contain heat stabilizers other than the orthophosphate compounds and phenol compounds. Suitable examples of such other heat stabilizers include lactone 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 orthophosphate compounds and hindered phenol compounds are commercially available. Suitable examples include Irganox HP-2921 manufactured by the same company. The content of the lactone-based stabilizer is preferably 0.0005 to 0.05 parts by weight, more preferably 0.001 to 0.03 parts by weight, based on 100 parts by weight of the resin component consisting of the A component and the B component. Examples of other stabilizers include sulfur-containing stabilizers such as pentaerythritol tetrakis (3-mercaptopropionate), pentaerythritol tetrakis (3-laurylthiopropionate), and glycerol-3-stearylthiopropionate. The content 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, based on 100 parts by weight of the resin component consisting of the A component and the B component. An epoxy compound can be blended into the thermoplastic resin composition of the present invention as necessary. Such an epoxy compound is blended for the purpose of suppressing mold corrosion, and basically all compounds having an epoxy functional group can be applied. Specific examples of preferred epoxy compounds include 3,4-epoxycyclohexylmethyl-3',4'-epoxycyclohexylcarboxylate, 1,2-epoxy-4-(2-oxiranyl)cyclohexane adduct of 2,2-bis(hydroxymethyl)-1-butanol, a copolymer of methyl methacrylate and glycidyl methacrylate, a copolymer of styrene and glycidyl methacrylate, etc. The content of such epoxy compounds is preferably 0.003 to 0.2 parts by weight, more preferably 0.004 to 0.15 parts by weight, and even more preferably 0.005 to 0.1 parts by weight, relative to 100 parts by weight of the resin component consisting of components A and B.

(II) Dyes and Pigments The thermoplastic resin composition of the present invention further contains various dyes and pigments, and can provide molded products that exhibit a variety of designs. Examples of dyes and pigments used in the present invention 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 thermoplastic resin composition of the present invention can be blended with a metallic pigment to obtain a better metallic color. Aluminum powder is suitable as the metallic pigment. In addition, by blending a fluorescent brightener or other fluorescent dye that emits light, a better design effect that makes use of the luminous color can be imparted.

(III) Fluorescent Brightening Agent In the thermoplastic resin composition of the present invention, the fluorescent brightening agent is not particularly limited as long as it is used to improve the color tone of the resin or the like to white or bluish white, and examples thereof include stilbene-based, benzimidazole-based, benzoxazole-based, naphthalimide-based, rhodamine-based, coumarin-based, and oxazine-based compounds. Specific examples include CI Fluorescent Brightener 219:1, Eastman Chemical Company's EASTOBRITE OB-1, and Showa Chemical Company's "HAKKOL PSR." Here, the fluorescent brightening agent has the effect of absorbing the ultraviolet energy of light and radiating this energy in the visible region. The content of the fluorescent brightening agent is preferably 0.001 to 0.1 parts by weight, more preferably 0.001 to 0.05 parts by weight, based on 100 parts by weight of the resin component consisting of the A component and the B component. If the amount exceeds 0.1 part by weight, the effect of improving the color tone of the composition is small.

(IV) Compounds with Heat Absorption Ability The thermoplastic resin composition of the present invention may contain a compound with heat absorption ability. Suitable examples of such compounds include phthalocyanine-based near infrared absorbers, metal oxide-based near infrared absorbers such as ATO, ITO, iridium oxide, ruthenium oxide, immonium oxide, and titanium oxide, various metal compounds with excellent near infrared absorption ability such as metal boride-based and tungsten oxide-based near infrared absorbers such as lanthanum boride, cerium boride, and tungsten boride, and carbon fillers. As such phthalocyanine-based near infrared absorbers, for example, MIR-362 manufactured by Mitsui Chemicals, Inc. is commercially available and easily available. Examples of carbon fillers include carbon black, graphite (both natural and artificial), and fullerene, and preferably carbon black and graphite. These can be used alone or in combination of two or more. The content of the phthalocyanine-based near infrared absorbent is preferably 0.0005 to 0.2 parts by weight, more preferably 0.0008 to 0.1 parts by weight, and even more preferably 0.001 to 0.07 parts by weight, relative to 100 parts by weight of the resin component consisting of components A and B. The contents of the metal oxide-based near infrared absorbent, metal boride-based near infrared absorbent, and carbon filler in the thermoplastic resin composition of the present invention are preferably in the range of 0.1 to 200 ppm (weight ratio), and more preferably in the range of 0.5 to 100 ppm.

(V) Light Diffuser The thermoplastic resin composition of the present invention can be blended with a light diffuser to impart a light diffusion effect. Examples of such light diffusers include polymer fine particles, inorganic fine particles with a low refractive index such as calcium carbonate, and composites thereof. Such polymer fine particles are fine particles already known as light diffusers for polycarbonate resins. More preferred examples include acrylic crosslinked particles with a particle size of several μm and silicone crosslinked particles represented by polyorganosilsesquioxane. Examples of the shape of the light diffuser include spherical, discoid, columnar, and indefinite shapes. Such a sphere does not need to be a perfect sphere and includes deformed ones, and such a columnar shape includes a cube. A preferred light diffuser is spherical, and the more uniform the particle size, the more preferred it is. The content of the light diffuser is preferably 0.005 to 20 parts by weight, more preferably 0.01 to 10 parts by weight, and even more preferably 0.01 to 3 parts by weight, based on 100 parts by weight of the resin component consisting of the A component and the B component. Two or more types of light diffusers can be used in combination.

(VI) Highly light-reflecting white pigment A highly light-reflecting white pigment can be blended into the thermoplastic resin composition of the present invention to impart a light-reflecting effect. Titanium dioxide (particularly titanium dioxide treated with an organic surface treatment agent such as silicone) pigment is particularly preferred as such a white pigment. The content of such highly light-reflecting white pigment is preferably 3 to 30 parts by weight, more preferably 8 to 25 parts by weight, per 100 parts by weight of the resin component consisting of components A and B. Two or more types of highly light-reflecting white pigments can be used in combination.

(VII) UV absorber Weather resistance can be imparted to the thermoplastic resin composition of the present invention by blending an UV absorber. Specific examples of such UV absorbers include benzophenone-based ones such as 2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-octoxybenzophenone, 2-hydroxy-4-benzyloxybenzophenone, 2-hydroxy-4-methoxy-5-sulfoxybenzophenone, 2,2'-dihydroxy-4-methoxybenzophenone, 2,2',4,4'-tetrahydroxybenzophenone, 2,2'-dihydroxy-4,4'-dimethoxybenzophenone, 2,2'-dihydroxy-4,4'-dimethoxy-5-sodiumsulfoxybenzophenone, bis(5-benzoyl-4-hydroxy-2-methoxyphenyl)methane, 2-hydroxy-4-n-dodecyloxybenzophenone, and 2-hydroxy-4-methoxy-2'-carboxybenzophenone. Specific examples of the ultraviolet absorbent include benzotriazole-based ultraviolet absorbents such as 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) Examples of the copolymer include 2-hydroxyphenyl-2H-benzotriazole skeleton-containing polymers such as 2-(2-hydroxy-5-acryloxyethylphenyl)-2H-benzotriazole, 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. Specific examples of the ultraviolet absorber include hydroxyphenyltriazine-based compounds such as 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. Specific examples of the ultraviolet absorber include cyclic iminoesters such as 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). Specific examples of the ultraviolet absorber include cyanoacrylates such as 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 ultraviolet absorber may be a polymer type ultraviolet absorber obtained by copolymerizing such an ultraviolet absorbing monomer and/or a light stable monomer 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 a (meth)acrylic acid ester. Among the above, benzotriazole and hydroxyphenyl triazine are preferred in terms of ultraviolet absorbing ability, and cyclic imino ester and cyanoacrylate are preferred in terms of heat resistance and color. Specific examples include "Chemisorb 79" from Chemipro Chemical Co., Ltd. and "Tinuvin 234" from BASF Japan Co., Ltd. The ultraviolet absorber may be used alone or in a mixture of two or more kinds.

The content of the ultraviolet absorber is preferably 0.01 to 3 parts by weight, more preferably 0.01 to 1 part by weight, even more preferably 0.05 to 1 part by weight, and particularly preferably 0.05 to 0.5 parts by weight, per 100 parts by weight of the resin component consisting of components A and B.

(VIII) Antistatic Agent The thermoplastic resin composition of the present invention may require antistatic performance, and in such a case, it is preferable to include an antistatic agent. Examples of such antistatic agents include (1) organic sulfonate phosphonium salts such as arylsulfonate phosphonium salts, such as dodecylbenzenesulfonate phosphonium salts, and alkylsulfonate phosphonium salts, as well as borate phosphonium salts such as tetrafluoroborate phosphonium salts. The content of the phosphonium salt is appropriately 5 parts by weight or less, preferably 0.05 to 5 parts by weight, more preferably 1 to 3.5 parts by weight, and even more preferably 1.5 to 3 parts by weight, relative to 100 parts by weight of the components consisting of the A component and the B component. Examples of the antistatic agent include (2) organic sulfonate alkali (earth) metal salts, such as lithium organic sulfonate, sodium organic sulfonate, potassium organic sulfonate, cesium organic sulfonate, rubidium organic sulfonate, calcium organic sulfonate, magnesium organic sulfonate, and barium organic sulfonate. As mentioned above, such metal salts are also used as flame retardants. More specifically, examples of such metal salts include metal salts of dodecylbenzenesulfonic acid and metal salts of perfluoroalkanesulfonic acid. The content of the alkali (earth) metal salt of organic sulfonate is suitably 0.5 parts by weight or less, preferably 0.001 to 0.3 parts by weight, and more preferably 0.005 to 0.2 parts by weight, per 100 parts by weight of the resin component consisting of components A and B. In particular, alkali metal salts such as potassium, cesium, and rubidium are suitable.

Examples of antistatic agents include (3) organic ammonium sulfonate salts such as ammonium alkylsulfonate salts and ammonium arylsulfonate salts. The amount of the ammonium salts is preferably 0.05 parts by weight or less per 100 parts by weight of the component consisting of components A and B. Examples of antistatic agents include (4) polymers containing a poly(oxyalkylene) glycol component as a constituent component, such as polyether ester amide. The amount of the polymer is preferably 5 parts by weight or less per 100 parts by weight of the resin component consisting of components A and B.

(IX) Filler The thermoplastic resin composition of the present invention can be blended with various fillers known as reinforcing fillers other than fibrous fillers. As such fillers, various plate-like fillers and granular fillers can be used. Here, the plate-like filler is a filler whose shape is plate-like (including those with uneven surfaces and those with curved plates). The granular filler is a filler whose shape is other than these, including those with irregular shapes.

Preferred examples of plate-like fillers include glass flakes, talc, mica, kaolin, metal flakes, carbon flakes, and graphite, as well as plate-like fillers in which the surface of these fillers is coated with a different material such as a metal or metal oxide. The particle size is preferably in the range of 0.1 to 300 μm. In the range up to about 10 μm, the particle size refers to the value based on the median diameter (D50) of the particle size distribution measured by the X-ray transmission method, which is one of the liquid phase precipitation methods, in the range of 10 to 50 μm, the value based on the median diameter (D50) of the particle size distribution measured by the laser diffraction/scattering method, and in the range of 50 to 300 μm, the value based on the vibration sieving method. The particle size is the particle size in the resin composition. The plate-like filler may be surface-treated with various coupling agents such as silane-based, titanate-based, aluminate-based, and zirconate-based, or may be bundled or compressed with various resins such as olefin-based resins, styrene-based resins, acrylic resins, polyester-based resins, epoxy-based resins, and urethane-based resins, or higher fatty acid esters.

(X) Other resins and elastomers In the thermoplastic resin composition of the present invention, other resins and elastomers can be used in small proportions in place of a part of the resin components, as long as the effects of the present invention are not impaired. The amount of the other resins and elastomers is preferably 20 parts by weight or less, more preferably 10 parts by weight or less, even more preferably 5 parts by weight or less, and most preferably 3 parts by weight or less, based on 100 parts by weight of the resin components consisting of the A component and the B component. 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, styrene/butadiene rubber, ethylene/propylene rubber, acrylic elastomers, polyester elastomers, polyamide elastomers, and core-shell elastomers such as MBS (methyl methacrylate/styrene/butadiene) rubber, MB (methyl methacrylate/butadiene) rubber, and MAS (methyl methacrylate/acrylonitrile/styrene) rubber.

(XI) Other Additives The thermoplastic resin composition of the present invention may contain other flow modifiers, antibacterial agents, dispersants such as liquid paraffin, photocatalytic antifouling agents, photochromic agents, and the like.

<Production of Resin Composition>
The thermoplastic resin composition of the present invention can be pelletized by melt kneading using an extruder such as a single screw extruder or a twin screw extruder. When preparing such pellets, the above-mentioned various reinforcing fillers and additives can also be blended.

<Regarding the manufacturing of molded products>
The thermoplastic resin composition of the present invention can be used to produce various products by injection molding the pellets produced as described above. Furthermore, it is also possible to directly produce sheets, films, irregular extrusion molded products, direct blow 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 the usual molding methods, depending on the purpose. The advantages of these various molding methods are already widely known. In addition, either the cold runner method or the hot runner method can be selected for molding. The resin composition of the present invention can also be used in the form of various irregular extrusion molded products, sheets, and films by extrusion molding. Inflation method, calendar method, casting method, etc. can also be used for molding sheets and films. Furthermore, it is also possible to mold the resin composition into a heat-shrinkable tube by subjecting it to a specific stretching operation. The resin composition of the present invention can also be formed into molded articles by rotational molding, blow molding, or the like.

The thermoplastic resin composition of the present invention has excellent heat resistance and flame retardancy, does not discolor during molding, and inhibits resin deterioration in high-temperature and high-humidity environments. Therefore, it is useful for a variety of applications, such as electrical and electronic parts, household appliances, automobile-related parts, infrastructure-related parts, housing-related parts, and medical instruments and devices, and the industrial effects it provides are exceptional.

The embodiments for carrying out the present invention are those that summarize 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 Thermoplastic Resin Composition)
(i) Deflection Temperature Under Load Using ISO bending test pieces obtained by the following method, the deflection temperature under load (load 0.45 MPa) was measured according to ISO 75-1 and ISO 75-2. The resin composition of the present invention needs to have a deflection temperature under load of 145° C. or more.

(ii) Flame retardancy Tests were conducted using test pieces having thicknesses of 0.5 mm, 1.0 mm, and 1.5 mm prepared by the following method according to the UL94 standard. Based on the test results, the test pieces were rated as UL-94 V-0, V-1, V-2, or Not-V (not within the standard). The flame retardancy of the resin composition of the present invention must be V-0 for test pieces having thicknesses of 0.5 mm, 1.0 mm, or 1.5 mm.

(iii) ΔMw (change in viscosity average molecular weight)
The viscosity average molecular weight (Mw) was determined by first determining the specific viscosity (η _SP ) calculated by the following formula using an Ostwald viscometer from a solution prepared by dissolving 0.7 g of a sample plate obtained by the method described below 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]
From the determined specific viscosity (η _SP ), was calculated 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 Mw ^0.83
c=0.7
Next, ΔMw was calculated from the Mw obtained by the above measurement method according to the following formula.
ΔMw=Mw ₁ - Mw _2
Mw1 : Viscosity average molecular weight of a sample plate obtained by the method below before testing. _Mw2 : Viscosity average molecular weight of a sample plate obtained by the method below after 20 hours of testing in a 130°C/100% environment using a highly accelerated life tester (ESPEC EHS-412MD).

(iv) ΔYI
A sample plate with a side length of 50 mm and a thickness of 3 mm was molded continuously from the 1st shot to the 15th shot by the following method, and after 10 minutes of molding was stopped, the 16th and 17th shots were molded continuously. ΔYI was calculated by the following formula. The YI value was measured using a color tone measuring device (Nippon Denshoku SE-2000 colorimeter) based on JIS K7103.
ΔYI=YI ₂ - _{YI 1
YI1} : YI value of the molded product after the eighth shot
_YI2 : YI value of the molded product after the 17th shot

(Component B)
[Production of polyarylate resin (B-1)]
In a reaction vessel equipped with a stirring vessel, 8.2 kg (36 moles) of 2,2-bis(4-hydroxyphenyl)propane, 11.1 kg (36 moles) of 1,1-bis(4-hydroxyphenyl)-3,3,5-trimethylcyclohexane, and 3.4 kg (18 moles) of 4,4-dihydroxy-biphenyl were added as dihydric phenol residues, and 67 kg of p-tert-butylphenol (hereinafter sometimes abbreviated as PTBP) (PTBP manufactured by DIC Corporation) was added as a molecular weight regulator. Into the reaction vessel were poured 8.0 g (4.4 mol), 8.6 kg (213 mol) of sodium hydroxide (manufactured by Tosoh Corporation) as an alkali, 373 g of benzyl-tri-n-butylammonium chloride (hereinafter sometimes abbreviated as BTBAC) (BTBAC-50 manufactured by Lion Akzo) as a polymerization catalyst, and 107 g of sodium hydrosulfite (hereinafter sometimes abbreviated as SHS) (manufactured by BASF Corporation), and 400 L of water was further poured into the reaction vessel to dissolve the catalyst, thereby forming an aqueous phase.

Further, in another reaction vessel, 18.6 kg (91 moles) of mixed phthalic acid chloride (MPC manufactured by Ihara Nikkei Chemical Industry Co., Ltd.; terephthalic acid/isophthalic acid=50/50 (mass%)) was dissolved in 240 L of dichloromethylene (methylene chloride manufactured by Tokuyama Corporation) to obtain an organic phase. This organic phase was added to the aqueous phase already being stirred under strong stirring, and the temperature was kept at 15° C. for 2 hours to carry out a polymerization reaction. After this, stirring was stopped, and the aqueous phase and the organic phase were separated by decantation. 400 L of pure water and 100 mL of acetic acid were added to the organic phase from which the aqueous phase had been removed to stop the reaction, and the mixture was further stirred at 15° C. for 30 minutes. This organic phase was washed five times with pure water, and the organic phase was added to 400 L of hexane to precipitate a polymer. The precipitated polymer was separated from the organic phase and then dried to obtain a polyarylate resin (B-1). The composition of the obtained polyarylate resin (B-1) was analyzed using ¹ H-NMR (ECA500 NMR manufactured by JEOL Ltd.), and it was confirmed that the polymerization ratio of the dihydric phenol residues to the phthalic acid residues was 1:1, which was the same as the mixing ratio of the dihydric phenol residues to the phthalic acid residues. The viscosity average molecular weight of the obtained polyarylate resin was 19,300. The results are shown in Table 1.

[Production of polyarylate resins (B-2, B-3)]
[Polyarylate resin (B-2)] and [Polyarylate resin (B-3)] were obtained in the same manner as in [Production of polyarylate resin (B-1)], except that the blending amounts of dihydric phenol and aromatic dicarboxylic acid were as shown in Table 1. The viscosity average molecular weights of the obtained polyarylate resins were 21,800 and 60,000, respectively. The results are shown in Table 1.

The symbols used in Table 1 represent the following components:
(Aromatic dicarboxylic acid)
TP: terephthalic acid IP: isophthalic acid (dihydric phenol)
BPA: Bisphenol A [2,2-bis(4-hydroxyphenyl)propane]
BPTMC: Bisphenol TMC [bisphenol 3,3,5-trimethylcyclohexane]
BP: Biphenol [4,4-dihydroxy-biphenyl]

(Examples 1 to 14, Comparative Examples 1 to 10)
A mixture of the compositions shown in Tables 2 and 3 was fed from the first feed port of the extruder. Such a mixture was obtained by mixing with a V-type blender. The twin-screw extruder used was a "TEX30αIII" intermeshing type co-rotating twin-screw extruder manufactured by Japan Steel Works, Ltd., with a diameter of 30 mmφ and a total of 10 barrels (referred to as C1 to C10 cylinders from the upstream) having a feed port at the most upstream part C1 and a feed port at the downstream part C5, and one vent. The extrusion conditions were temperature C1: 300°C, C2 to 10: 310°C, screw rotation speed 200 rpm, discharge rate 25 kg/h, and vent vacuum degree 3 kPa, and pellets were obtained by melt kneading.

A part of the obtained pellets was dried in a hot air circulation dryer at 120° C. for 6 hours, and then molded using an injection molding machine at a cylinder temperature of 320° C. and a mold temperature of 90° C. into a sample plate with a side length of 50 mm and a thickness of 3 mm for evaluation, an ISO bending test piece (compliant with ISO 75-1 and 75-2), and a UL94 test piece, and each evaluation was performed. The evaluation results are shown in Tables 2 and 3.
The components represented by symbols in Tables 2 and 3 are as follows:

(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: Resin synthesized in [Production of polyarylate resin (B-1)] B-2: Resin synthesized in [Production of polyarylate resin (B-2)] B-3: Resin synthesized in [Production of polyarylate resin (B-3)] (Component C)
C-1: Trimethyl phosphate (TMP, manufactured by Daihachi Chemical Industry Co., Ltd., number average molecular weight 140)
C-2: 3,9-bis(2,6-di-tert-butyl-4-methylphenoxy)-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5,5]undecane (ADEKA PEP36, number average molecular weight 633)
C-3: Tris(2,4-di-tert-butylphenyl)phosphite (Adeka 2112, number average molecular weight 647)
(Component D)
D-1: Octadecyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate (AO-50 manufactured by ADEKA)
D-2: 3,9-bis{2-[3-(3-tert-butyl-4-hydroxy-5-methylphenyl)propionyloxy]-1,1,-dimethylethyl}-2,4,8,10-tetraoxaspiro[5,5]undecane (AO-80 manufactured by ADEKA)
(Component E)
E-1: Halogen-based compound (Teijin Limited, FG-7000)
E-2: Condensed phosphate ester compound (PX-200, manufactured by Daihachi Chemical Industry Co., Ltd.)
E-3: Phosphazene (FP-100 manufactured by Fushimi Seisakusho Co., Ltd.)
E-4: Potassium perfluoroalkanesulfonate (F-114P, manufactured by Dainippon Ink and Chemicals, Inc.)
E-5: Antimony trioxide (PATOX-K, manufactured by Nihon Seiko Co., Ltd.)
E-6: Organic siloxane compound (X-40-2600J, manufactured by Shin-Etsu Chemical Co., Ltd.)
E-7: Polytetrafluoroethylene (Polyflon MPAFA-500, manufactured by Daikin Chemical Industries, Ltd.)

Claims (9)

A thermoplastic resin composition comprising 100 parts by weight of a resin component consisting of 1 to 99 parts by weight of (A) a polycarbonate resin (component A) and 99 to 1 part by weight of (B) a polyarylate resin (component B), and containing 0.001 to 0.02 parts by weight of (C) an orthophosphate compound (component C), 0.001 to 0.05 parts by weight of (D) a phenolic compound (component D), and 0.005 to 20 parts by weight of (E) a flame retardant (component E). The thermoplastic resin composition according to claim 1, characterized in that component E contains at least one compound selected from the group consisting of halogen-based compounds, condensed phosphate ester compounds, phosphazene compounds, organic metal salts , inorganic compounds and fibril-forming fluorine-containing polymers. The thermoplastic resin composition according to claim 2, characterized in that the organometallic salt is a metal salt of perfluoroalkanesulfonic acid. 3. The thermoplastic resin composition according to claim 2, wherein the inorganic compound is at least one compound selected from the group consisting of silicon compounds and antimony compounds. The thermoplastic resin composition according to any one of claims 1 to 4, characterized in that component D is a hindered phenol-based antioxidant. The thermoplastic resin composition according to any one of claims 1 to 5, wherein the component B is a polyarylate resin containing a polymerization unit represented by any one of the following general formulas (1) to (3):
(In the above general formula (1), l, m, and n are positive integers that satisfy l+m+n=100, l:n=50:50 to 70:30, and (l+n):m=75:25 to 40:60.)
(In the above general formula (2), m and n are positive integers, and m/n=8/2 to 2/8.)
(In the above general formula (3), n is a positive integer.) The thermoplastic resin composition according to any one of claims 1 to 6, characterized in that component D has a melting point of 30 to 70°C. The thermoplastic resin composition according to any one of claims 1 to 7, characterized in that the number average molecular weight of component C is 50 to 600. A molded article obtained by molding a thermoplastic resin composition according to any one of claims 1 to 8.