JP2024124629A - Polycarbonate resin composition and molded article made thereof - Google Patents

Abstract

To provide a polycarbonate resin composition having excellent tensile strength, dimensional accuracy and flame retardancy and having little strength degradation even under severe processing conditions and having excellent recyclability and to provide a molded article comprising the same.SOLUTION: There is provided a polycarbonate resin composition which comprises (C) 3 to 40 pts.wt. of a halogenated polycarbonate compound (C component), (D) 0.1 to 3 pts.wt. of a drip prevention agent (D component), (E) 25 to 150 pts.wt. of a glass fiber and/or a carbon fiber (E component), (F) 0.1 to 8 pts.wt. of a phenoxy resin and/or an epoxy resin (F component) and (G) 0.01 to 3 pts.wt. of a phosphonic acid ester (G component) having an acid value of 0.01 to 0.30 mg KOH/g, based on 100 pts.wt. of a component comprising (A) an aromatic polycarbonate-based resin (A component) and (B) a liquid-crystalline polyester resin (B component), wherein the weight ratio [(A)/(B)] of the Component A to the component B is 95/5 to 60/40.SELECTED DRAWING: None

Description

The present invention relates to a resin composition comprising a component consisting of a specific ratio of aromatic polycarbonate resin and liquid crystal polyester resin, a halogenated carbonate compound, an anti-drip agent, glass fiber and/or carbon fiber, a phenoxy resin and/or an epoxy resin, and a specific phosphonic acid ester, and to a molded article comprising the same. More specifically, the present invention relates to a polycarbonate resin composition that is excellent in tensile strength, dimensional accuracy, and flame retardancy, and further has little loss of strength even under severe processing conditions and is highly recyclable.

Polycarbonate resin is a resin with excellent heat resistance, impact resistance, and dimensional stability, and is widely used in fields such as electrical and electronic parts, mechanical parts, automotive parts, and office equipment parts. In recent years, as products have become more sophisticated and lighter, thinner, shorter, and smaller, there is a strong demand for resin materials that have high strength even when thin-walled products are designed, as well as thin-wall flame retardancy that can maintain product safety. Furthermore, in the industrial field, where thin-wall rigidity and thin-wall flame retardancy are required to achieve a sustainable society, there is a growing demand for high recyclability of the resin compositions used.

Conventionally, methods of adding fibrous fillers (see Patent Document 1) have been used to improve the mechanical properties of polycarbonate resins, such as the tensile strength, and methods of adding fibrous fillers and adhesion improvers to further improve strength (see Patent Documents 2 and 3) have been used, but when the molded product is thin, sufficient properties cannot be obtained.

Many methods have been proposed for simultaneously improving rigidity and fluidity by blending a polymer that exhibits liquid crystallinity with a thermoplastic resin and fiberizing the liquid crystal polymer within the composition. Many attempts have also been made to blend liquid crystal polymers with aromatic polycarbonate resins, and examples have been reported in which fibrous inorganic reinforcing materials have been blended to further increase rigidity (see Patent Documents 4 and 5).

Patent Document 6 and Patent Document 7 describe resin compositions consisting of polycarbonate resin, liquid crystal polymer, flame retardant (including phosphorus-based flame retardant), and polytetrafluoroethylene-containing mixed powder consisting of polytetrafluoroethylene and organic polymer particles, but do not achieve both strength and flame retardancy.

On the other hand, it is known that in compositions consisting of polycarbonate resin and liquid crystal polymer, phosphorus-based compounds are used as heat stabilizers to effectively realize the effect of improving mechanical properties by fiberizing the liquid crystal polymer (see Patent Documents 5 and 7). However, in applications requiring thin and lightweight materials, molding conditions tend to be high temperatures, and the thermal stability during molding processing is still insufficient with existing methods, and recyclability has not yet been verified.

Patent No. 2683662 JP 2009-292953 A JP 2013-221072 A Japanese Patent Application Publication No. 07-258531 JP 2012-188578 A JP 2003-113314 A JP 2008-163315 A

In view of the above, the object of the present invention is to provide a polycarbonate resin composition and a molded article made therefrom that have excellent tensile strength, dimensional accuracy, and flame retardancy, and further exhibit little loss in strength even under harsh processing conditions, and that also have excellent recyclability.

As a result of intensive research conducted by the present inventors to solve the above problems, they discovered that by blending a halogenated carbonate compound, an anti-drip agent, glass fiber and/or carbon fiber, an epoxy resin and/or a phenoxy resin, and a phosphonic acid ester having a specific acid value with a component consisting of an aromatic polycarbonate resin and a liquid crystal polyester resin in a specific ratio, it is possible to provide a thermoplastic resin composition and a molded article made of the same that are excellent in tensile strength, dimensional accuracy, and flame retardancy, and further exhibit little loss in strength even under severe processing conditions, and that are also excellent in recyclability, and thus arrived at the present invention.

That is, the present invention is as follows.
1. A polycarbonate resin composition comprising 100 parts by weight of a component consisting of (A) an aromatic polycarbonate resin (component A) and (B) a liquid crystal polyester resin (component B), 3 to 40 parts by weight of (C) a halogenated carbonate compound (component C), 0.1 to 3 parts by weight of (D) an anti-drip agent (component D), 25 to 150 parts by weight of (E) glass fiber and/or carbon fiber (component E), 0.1 to 8 parts by weight of (F) a phenoxy resin and/or epoxy resin (component F), and 0.01 to 3 parts by weight of (G) a phosphonic acid ester (component G) having an acid value of 0.01 to 0.30 mgKOH/g, and wherein the weight ratio of component A to component B [(A)/(B)] is 95/5 to 60/40.
2. The polycarbonate resin composition according to the above paragraph 1, wherein the viscosity average molecular weight of component A is 1.7×10 ⁴ to 2.1×10 ⁴ .
3. The polycarbonate resin composition according to item 1 or 2 above, wherein component B is a liquid crystal polyester resin containing a repeating unit derived from p-hydroxybenzoic acid and a repeating unit derived from 6-hydroxy-2-naphthoic acid.
4. The polycarbonate resin composition according to any one of items 1 to 3 above, wherein component E is a flat cross-section glass fiber having an average major axis of fiber cross section of 10 to 50 μm and an average major axis to minor axis ratio (major axis/minor axis) of 1.5 to 8.
5. The polycarbonate resin composition according to any one of items 1 to 4 above, wherein Component F is a bisphenol A type phenoxy resin and/or a bisphenol A type epoxy resin.
6. The polycarbonate resin composition according to any one of items 1 to 5 above, wherein the G component is triethylphosphonoacetate.
7. A molded article obtained by molding the polycarbonate resin composition according to any one of items 1 to 6 above.

The details of the present invention are described below.

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

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

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

For example, polycarbonates (homopolymers or copolymers) using 4,4'-(m-phenylenediisopropylidene)diphenol (hereinafter sometimes abbreviated as "BPM"), 1,1-bis(4-hydroxyphenyl)cyclohexane, 1,1-bis(4-hydroxyphenyl)-3,3,5-trimethylcyclohexane (hereinafter sometimes abbreviated as "Bis-TMC"), 9,9-bis(4-hydroxyphenyl)fluorene and 9,9-bis(4-hydroxy-3-methylphenyl)fluorene (hereinafter sometimes abbreviated as "BCF") as part or all of the dihydric phenol components are suitable for applications where dimensional 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.

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

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

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

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

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

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

When producing an aromatic polycarbonate resin by the interfacial polymerization method of the dihydric phenol and the carbonate precursor, a catalyst, a terminal terminator, an antioxidant for preventing oxidation of the dihydric phenol, etc. may be used as necessary. The aromatic polycarbonate resin of the present invention also includes a branched polycarbonate resin copolymerized with a polyfunctional aromatic compound having three or more functionalities, 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. It may also be a mixture of two or more of the obtained aromatic polycarbonate resins.

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

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

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

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

The reaction formats for producing aromatic polycarbonate resins, such as interfacial polymerization, melt transesterification, carbonate prepolymer solid-phase transesterification, and ring-opening polymerization of cyclic carbonate compounds, are well known in various literature and patent publications.

In producing the polycarbonate resin composition of the present invention, the viscosity average molecular weight (M) of the aromatic polycarbonate resin is not particularly limited, but is preferably 1×10 ⁴ to 5×10 ⁴ , more preferably 1.4×10 ⁴ to 3×10 ⁴ , even more preferably 1.4×10 ⁴ to 2.4×10 ⁴ , and particularly preferably 1.7×10 ⁴ to 2.1×10 ^4. With an aromatic polycarbonate resin having a viscosity average molecular weight of less than 1×10 ⁴ , good mechanical properties, particularly high tensile strength, may not be obtained. On the other hand, a resin composition obtained from an aromatic polycarbonate resin having a viscosity average molecular weight of more than 5×10 ⁴ may be inferior in versatility in terms of poor fluidity during injection molding.

The aromatic polycarbonate resin may be obtained by mixing those having a viscosity average molecular weight outside the above range. In particular, polycarbonate resins having a viscosity average molecular weight exceeding the above range (5×10 ⁴ ) have improved entropy elasticity. As a result, they exhibit good processability in gas-assisted molding and foam molding, which are sometimes used when molding reinforced resin materials into structural members. Such improvement in processability is even better than that of the branched polycarbonate. In a more preferred embodiment, component A is composed of an aromatic 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 an aromatic 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-1-2 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 high molecular weight component-containing polycarbonate resin (A-1 component) can be obtained by mixing the A-1-1 and A-1-2 components 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 the A-1 component, more preferably 3 to 30% by weight, even more preferably 4 to 20% by weight, and particularly preferably 5 to 20% by weight of the A-1-1 component.

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 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 aromatic polycarbonate resins is calculated as follows. That is, the composition is mixed with 20 to 30 times its weight of methylene chloride to dissolve the soluble components in the composition. 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 to obtain a solution, and the specific viscosity at 20°C is calculated 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 aromatic polycarbonate resin, a polycarbonate-polydiorganosiloxane copolymer resin can also be used. The polycarbonate-polydiorganosiloxane copolymer resin is preferably a copolymer resin prepared by copolymerizing a dihydric phenol represented by the following general formula (1) and a hydroxyaryl-terminated polydiorganosiloxane represented by the following general formula (3).

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

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

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

Examples of the dihydric phenol (I) represented by the general formula (1) include 4,4'-dihydroxybiphenyl, bis(4-hydroxyphenyl)methane, 1,1-bis(4-hydroxyphenyl)ethane, 1,1-bis(4-hydroxyphenyl)-1-phenylethane, 2,2-bis(4-hydroxyphenyl)propane, 2,2-bis(4-hydroxy-3-methylphenyl)propane, 1,1-bis(4-hydroxyphenyl)-3,3,5-trimethylcyclohexane, 2,2-bis(4-hydroxy-3,3'-biphenyl)propane, 2,2-bis(4-hydroxy-3-isopropylphenyl)propane, 2,2-bis(3-t- butyl-4-hydroxyphenyl)propane, 2,2-bis(4-hydroxyphenyl)butane, 2,2-bis(4-hydroxyphenyl)octane, 2,2-bis(3-bromo-4-hydroxyphenyl)propane, 2,2-bis(3,5-dimethyl-4-hydroxyphenyl)propane, 2,2-bis(3-cyclohexyl-4-hydroxyphenyl)propane, 1,1-bis(3-cyclohexyl-4-hydroxyphenyl)cyclohexane, bis(4-hydroxyphenyl)diphenylmethane, 9,9-bis(4-hydroxyphenyl)fluorene, 9,9-bis(4-hydroxy-3-methylphenyl)fluorene, 1,1-bis (4-hydroxyphenyl)cyclohexane, 1,1-bis(4-hydroxyphenyl)cyclopentane, 4,4'-dihydroxydiphenyl ether, 4,4'-dihydroxy-3,3'-dimethyldiphenyl ether, 4,4'-sulfonyldiphenol, 4,4'-dihydroxydiphenyl sulfoxide, 4,4'-dihydroxydiphenyl sulfide, 2,2'-dimethyl-4,4'-sulfonyldiphenol, 4,4'-dihydroxy-3,3'-dimethyldiphenyl sulfoxide, 4,4'-dihydroxy-3,3'-dimethyldiphenyl sulfide, 2,2'-diphenyl-4,4'-sulfonyldiphenol, 4,4'-di Hydroxy-3,3'-diphenyldiphenyl sulfoxide, 4,4'-dihydroxy-3,3'-diphenyldiphenyl sulfide, 1,3-bis{2-(4-hydroxyphenyl)propyl}benzene, 1,4-bis{2-(4-hydroxyphenyl)propyl}benzene, 1,4-bis(4-hydroxyphenyl)cyclohexane, 1,3-bis(4-hydroxyphenyl)cyclohexane, 4,8-bis(4-hydroxyphenyl)tricyclo[5.2.1.02,6]decane, 4,4'-(1,3-adamantanediyl)diphenol, 1,3-bis(4-hydroxyphenyl)-5,7-dimethyladamantane, and the like. Among these, 1,1-bis(4-hydroxyphenyl)-1-phenylethane, 2,2-bis(4-hydroxyphenyl)propane, 2,2-bis(4-hydroxy-3-methylphenyl)propane, 1,1-bis(4-hydroxyphenyl)cyclohexane, 1,1-bis(4-hydroxyphenyl)-3,3,5-trimethylcyclohexane, 4,4'-sulfonyldiphenol, 2,2'-dimethyl-4,4'-sulfonyldiphenol, 9,9-bis(4-hydroxy-3-methylphenyl)fluorene, 1,3-bis{2-(4-hydroxyphenyl)propyl}benzene, and 1,4-bis{2-(4-hydroxyphenyl)propyl}benzene are preferred, and 2,2-bis(4-hydroxyphenyl)propane, 1,1-bis(4-hydroxyphenyl)cyclohexane (BPZ), 4,4'-sulfonyldiphenol, and 9,9-bis(4-hydroxy-3-methylphenyl)fluorene are particularly preferred. Among these, 2,2-bis(4-hydroxyphenyl)propane, which has excellent strength and good durability, is the most suitable. These may be used alone or in combination of two or more.

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

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

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

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

In the present invention, the hydroxyaryl-terminated polydiorganosiloxane (II) may be used alone or in combination of two or more kinds.
In addition, comonomers other than the dihydric phenol (I) and the hydroxyaryl-terminated polydiorganosiloxane (II) may be used in an amount of up to 10% by weight based on the total weight of the copolymer, provided that the use does not impede the present invention.

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

In producing an oligomer of the dihydric phenol (I), the entire amount of the dihydric phenol (I) used in the method of the present invention may be converted into an oligomer at once, or a part of it may be added as a post-added monomer as a reaction raw material to the interfacial polycondensation reaction in the latter stage. The post-added monomer is added to quickly advance the polycondensation reaction in the latter stage, and there is no need to add it if it is not necessary.
The method for this oligomer formation reaction is not particularly limited, but it is usually preferable to carry out the reaction in a solvent in the presence of an acid binder.

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

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

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

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

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

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

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

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

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

To accelerate the polycondensation reaction, a catalyst such as a tertiary amine, such as triethylamine, or a quaternary ammonium salt may be added.
The reaction time of such a polymerization reaction is preferably 30 minutes or more, more preferably 50 minutes or more. If desired, a small amount of an antioxidant such as sodium sulfite or hydrosulfide may be added.

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

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

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

The resulting reaction product (crude product) can be subjected to various post-treatments such as known separation and purification methods to recover a polycarbonate-polydiorganosiloxane copolymer resin of the desired purity (degree of purification). The average size of the polydiorganosiloxane domains in the polycarbonate-polydiorganosiloxane copolymer resin molded product is preferably in the range of 1 to 40 nm. Such an average size is more preferably 1 to 30 nm, and even more preferably 5 to 25 nm. Below the lower limit of this preferred range, impact resistance and flame retardancy may not be fully exhibited, and above the upper limit of this preferred range, impact resistance may not be stably exhibited.

The average domain size and normalized dispersion of the polydiorganosiloxane domains of the polycarbonate-polydiorganosiloxane copolymer resin molded product in this invention were evaluated by small angle X-ray scattering (SAXS). Small angle X-ray scattering is a method for measuring diffuse scattering and diffraction that occurs in the small angle region of scattering angle (2θ) < 10°. In this small angle X-ray scattering method, if there are regions in a substance with different electron densities of about 1 to 100 nm in size, the diffuse scattering of X-rays is measured based on the difference in electron density. The particle size of the object to be measured is calculated based on the scattering angle and scattering intensity. In the case of a polycarbonate-polydiorganosiloxane copolymer resin having an aggregate structure in which polydiorganosiloxane domains are dispersed in a polycarbonate polymer matrix, the electron density difference between the polycarbonate matrix and the polydiorganosiloxane domains causes diffuse scattering of X-rays. The scattering intensity I at each scattering angle (2θ) in the range of scattering angles (2θ) less than 10° is measured to measure a small-angle X-ray scattering profile, and assuming that the polydiorganosiloxane domains are spherical domains and that there is variation in particle size distribution, a simulation is performed using commercially available analysis software from a tentative particle size and a tentative particle size distribution model to determine the average size and particle size distribution (normalized variance) of the polydiorganosiloxane domains. The small-angle X-ray scattering method allows the average size and particle size distribution of the polydiorganosiloxane domains dispersed in a polycarbonate polymer matrix to be measured accurately, easily, and with good reproducibility, which cannot be accurately measured by observation using a transmission electron microscope. The average domain size means the number average of the individual domain sizes. The normalized variance means a parameter that normalizes the spread of the particle size distribution by the average size. Specifically, it is a value that normalizes the variance of the polydiorganosiloxane domain size by the average domain size, and is expressed by the following formula (1).

In the above formula (1), δ is the standard deviation of the polydiorganosiloxane domain size, and Dav is the average domain size.

The terms "average domain size" and "normalized dispersion" used in connection with the present invention refer to the measured values obtained by measuring a 1.0 mm thick section of a three-tiered plate prepared by the method described in the Examples using the small angle X-ray scattering method. In addition, the analysis was performed using an isolated particle model that does not take into account interparticle interactions (interparticle interference).

(Component B: Liquid crystal polyester resin)
The liquid crystal polyester resin used as component B in the present invention is a thermotropic liquid crystal polyester resin, and has the property that polymer molecular chains are aligned in a certain direction in a molten state. The form of such an alignment state may be any of nematic type, smectic type, cholesteric type, and discotic type, and may also have two or more forms. Furthermore, the structure of the liquid crystal polyester resin may be any of main chain type, side chain type, and rigid main chain bent side chain type, but the main chain type liquid crystal polyester resin is preferred.

The morphology of the above-mentioned alignment state, i.e., the nature of the anisotropic molten phase, can be confirmed by a conventional polarized light inspection method using crossed polarizers. More specifically, the anisotropic molten phase can be confirmed by observing a molten sample placed on a Leitz hot stage at a magnification of 40 times under a nitrogen atmosphere using a Leitz polarizing microscope. When the polymer of the present invention is inspected between crossed polarizers, polarized light passes through it even when it is in a molten, stationary state, and it exhibits optical anisotropy.

The heat resistance of the liquid crystal polyester resin may be in any range, but it is appropriate that it melts and forms a liquid crystal phase at a temperature close to the processing temperature of the polycarbonate resin. Liquid crystal polyesters with a deflection temperature under load (ISO75-1/2 load 1.8 MPa conditions) of 150 to 280°C, preferably 150 to 250°C, are more suitable. Such liquid crystal polyesters belong to the so-called Type II heat resistance category. When they have such heat resistance, they have excellent moldability compared to Type I, which has higher heat resistance, and achieve good flame retardancy compared to Type III, which has lower heat resistance.

The liquid crystal polyester resin used in the present invention preferably contains polyester units and polyester amide units, and is preferably an aromatic polyester resin or an aromatic polyester amide resin. A preferred example is a liquid crystal polyester resin that partially contains aromatic polyester units and aromatic polyester amide units in the same molecular chain.

Particularly preferred are fully aromatic polyester resins and fully aromatic polyesteramide resins having as unit components derived from one or more compounds selected from the group consisting of aromatic hydroxycarboxylic acids, aromatic hydroxyamines, and aromatic diamines. More specifically, 1) liquid crystal polyester resins synthesized mainly from one or more compounds selected from the group consisting of aromatic hydroxycarboxylic acids and their derivatives, 2) liquid crystal polyester resins synthesized mainly from a) one or more compounds selected from the group consisting of aromatic hydroxycarboxylic acids and their derivatives, b) one or more compounds selected from the group consisting of aromatic dicarboxylic acids, alicyclic dicarboxylic acids and their derivatives, and c) one or more compounds selected from the group consisting of aromatic diols, alicyclic diols, aliphatic diols and their derivatives, 3) mainly from a) one or more compounds selected from the group consisting of aromatic hydroxycarboxylic acids and their derivatives, b) one or more compounds selected from the group consisting of aromatic hydroxyamines, aromatic diamines and their derivatives, and c) aromatic dicarboxylic acids, and 4) liquid crystal polyesteramide resins synthesized mainly from a) one or more compounds selected from the group consisting of aromatic hydroxycarboxylic acids and their derivatives, b) one or more compounds selected from the group consisting of aromatic hydroxyamines, aromatic diamines and their derivatives, c) one or more compounds selected from the group consisting of aromatic dicarboxylic acids, alicyclic dicarboxylic acids and their derivatives, and d) one or more compounds selected from the group consisting of aromatic diols, alicyclic diols, aliphatic diols and their derivatives. However, 1) liquid crystal polyester resins synthesized mainly from one or more compounds selected from the group consisting of aromatic hydroxycarboxylic acids and their derivatives are preferred.
Furthermore, a molecular weight regulator may be used in combination with the above-mentioned components, if necessary.

Preferred examples of specific compounds used in the synthesis of the liquid crystal polyester resin used in the polycarbonate resin composition of the present invention are naphthalene compounds such as 2,6-naphthalenedicarboxylic acid, 2,6-dihydroxynaphthalene, 1,4-dihydroxynaphthalene, and 6-hydroxy-2-naphthoic acid, biphenyl compounds such as 4,4'-diphenyldicarboxylic acid, 4,4'-dihydroxybiphenyl, para-substituted benzene compounds such as p-hydroxybenzoic acid, terephthalic acid, hydroquinone, p-aminophenol, and p-phenylenediamine, and their nuclear-substituted benzene compounds (substituents selected from chlorine, bromine, methyl, phenyl, and 1-phenylethyl), meta-substituted benzene compounds such as isophthalic acid and resorcin, and compounds represented by the following general formula (4), (5), or (6). Among these, p-hydroxybenzoic acid and 6-hydroxy-2-naphthoic acid are particularly preferred, and a liquid crystal polyester resin obtained by mixing the two is preferred. The ratio of the two is preferably in the range of 90 to 50 mol% for the former, more preferably in the range of 80 to 65 mol%, and preferably in the range of 10 to 50 mol% for the latter, more preferably in the range of 20 to 35 mol%.

(X is a group selected from the group consisting of alkylene and alkylidene groups having 1 to 4 carbon atoms, -O-, -SO-, -SO ₂ -, -S-, and -CO-, and Y is a group selected from the group consisting of -(CH ₂ )n- (n = 1 to 4) and -O(CH ₂ )nO- (n = 1 to 4).)

In addition to the above-mentioned components, the liquid crystal polyester resin used in the present invention may also contain polyalkylene terephthalate-derived units that do not partially exhibit an anisotropic molten phase in the same molecular chain. In this case, the alkylene group has 2 to 4 carbon atoms.

The basic manufacturing method of the liquid crystal polyester resin used in the present invention is not particularly limited, and it can be manufactured in accordance with the known polycondensation method of liquid crystal polyester resin. The above liquid crystal polyester resin also generally exhibits an inherent viscosity (IV value) of at least about 2.0 dl/g, for example about 2.0 to 10.0 dl/g, when dissolved in pentafluorophenol at 60°C at a concentration of 0.1% by weight.

Due to the above characteristics, liquid crystal polyester resin becomes finely fibril-like during injection molding, and the shape is maintained during the cooling and solidifying process, providing a reinforcing effect to the matrix. This makes it possible to impart tensile strength to the liquid crystal polyester resin. The liquid crystal polyester resin also reduces the viscosity of the resin composition, which has the effect of reducing the injection speed and resin pressure.

The weight ratio [(A)/(B)] of the aromatic polycarbonate resin (A) to the liquid crystal polyester resin (B) used in the present invention is in the range of 95/5 to 60/40, preferably 90/10 to 80/20, and more preferably 90/10 to 85/15. If the proportion of the liquid crystal polyester resin is greater than this range, the tensile strength and flame retardancy will decrease. If the proportion is less than this range, the tensile strength improvement effect of blending the liquid crystal polyester resin will not be obtained.

(Component C: halogenated carbonate compound)
As the halogenated carbonate compound used as component C in the present invention, a halogenated carbonate compound in which the structural unit represented by the following general formula (7) accounts for at least 60 mol % of all structural units and which has a specific viscosity of 0.015 to 0.1 is suitably used.

[In general formula (7), 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 -SO ₂ -.]

In the formula (7), 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 polycarbonate resin composition is improved, and molding at higher temperatures is possible, resulting in a resin composition with superior molding processability.

Furthermore, 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 polycarbonate 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.

Such halogenated carbonate compounds are commercially available, for example, tetrabromobisphenol A carbonate oligomers (product names FG-7000, FG-8500) manufactured by Teijin Limited, and these can be used in the present invention.

The content of component C is 3 to 40 parts by weight, preferably 5 to 30 parts by weight, and more preferably 10 to 30 parts by weight, per 100 parts by weight of the total of components A and B. If the content of component C is less than 3 parts by weight, sufficient flame retardancy is not obtained, and if it exceeds 40 parts by weight, there is a large decrease in tensile strength.

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

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

Commercially available PTFE products with such fibril-forming ability include, for example, Teflon (registered trademark) 6-J from Mitsui-Chemours Fluoroproducts, Inc., and Polyflon MPA FA500H and F-201 from Daikin Industries, Ltd. Representative examples of commercially available aqueous dispersions of PTFE include the Fluon D series from Daikin Industries, Ltd., and Teflon (registered trademark) 31-JR from Mitsui-Chemours Fluoroproducts, Inc.

PTFE in a mixed form can be prepared by (1) mixing an aqueous dispersion of PTFE with an aqueous dispersion or solution of an organic polymer and co-precipitating to obtain a coagulated mixture (methods described in JP-A-60-258263, JP-A-63-154744, etc.), (2) mixing an aqueous dispersion of PTFE with dried organic polymer particles (method described in JP-A-4-272957), or (3) homogeneously mixing an aqueous dispersion of PTFE with a solution of organic polymer particles and simultaneously extracting each medium from the mixture. (4) a method of polymerizing a monomer that forms an organic polymer in an aqueous dispersion of PTFE (method described in JP-A-06-220210, JP-A-08-188653, etc.), and (5) a method of homogeneously mixing an aqueous dispersion of PTFE and an organic polymer dispersion, and then polymerizing a vinyl monomer in the mixed dispersion to obtain a mixture (method described in JP-A-11-29679, etc.). Commercially available products of these mixed forms of PTFE include "Metabrene A3800" (trade name) and "Metabrene A3750" from Mitsubishi Chemical Corporation.

The proportion of PTFE in the mixed form is preferably 1 to 60% by weight, more preferably 5 to 55% by weight, of 100% by weight of the PTFE mixture. When the proportion of PTFE is within this range, good dispersibility of PTFE can be achieved.

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

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

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

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

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

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

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

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

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

The polytetrafluoroethylene contained in the coated branched PTFE is branched polytetrafluoroethylene. If the polytetrafluoroethylene contained is not branched polytetrafluoroethylene, the drip prevention effect will be insufficient when the amount of polytetrafluoroethylene added is small. The branched polytetrafluoroethylene is particulate and has a particle size of preferably 0.1 to 0.6 μm, more preferably 0.3 to 0.5 μm, and even more preferably 0.3 to 0.4 μm. If the particle size is smaller than 0.1 μm, the surface appearance of the molded product is excellent, but it is difficult to commercially obtain polytetrafluoroethylene having a particle size smaller than 0.1 μm. Also, if the particle size is larger than 0.6 μm, the surface appearance of the molded product may be deteriorated. The number average molecular weight of the polytetrafluoroethylene used in the present invention is preferably 1×10 ⁴ to 1×10 ⁷ , more preferably 2×10 ⁶ to 9×10 ⁶ , and generally, polytetrafluoroethylene with a high molecular weight is more preferable in terms of stability. Either powder or dispersion form may be used.

The content of branched polytetrafluoroethylene in the coated branched PTFE is preferably 20 to 60 parts by weight, more preferably 40 to 55 parts by weight, even more preferably 47 to 53 parts by weight, particularly preferably 48 to 52 parts by weight, and most preferably 49 to 51 parts by weight, per 100 parts by weight of the total weight of the coated branched PTFE. When the proportion of branched polytetrafluoroethylene is within this range, good dispersibility of the branched polytetrafluoroethylene can be achieved.

The content of component D is 0.1 to 3 parts by weight, preferably 0.15 to 2 parts by weight, and more preferably 0.5 to 1.5 parts by weight, per 100 parts by weight of the total of components A and B. If it is greater than this range, costs will increase and extrusion processability will be insufficient. On the other hand, if it is less than this range, flame retardancy will be insufficient. Note that the proportion of component D above indicates the net amount of drip prevention agent, and in the case of mixed PTFE, indicates the net amount of PTFE.

(Component E: Glass fiber and/or carbon fiber)
Suitable examples of the glass fibers used as component E in the present invention include glass fibers having a round cross section, flat cross section glass fibers having an average major axis value of 10 to 50 μm and an average major axis to minor axis ratio (major axis/minor axis) of 1.5 to 8, and glass milled fibers. In particular, flat cross section glass fibers having an average major axis value of 10 to 50 μm and an average major axis to minor axis ratio (major axis/minor axis) of 1.5 to 8 are more preferred in terms of tensile strength and dimensional accuracy.

The glass composition of the above glass fiber is not particularly limited, and various glass compositions such as A glass, C glass, and E glass are applied. Such glass fiber may contain components such as TiO ₂ , SO ₃ , and P ₂ O ₅ as necessary. Among these, E glass (alkali-free glass) is more preferable. Such glass fiber is preferably surface-treated with a known surface treatment agent, such as a silane coupling agent, a titanate coupling agent, or an aluminate coupling agent, from the viewpoint of improving mechanical strength. In addition, it is preferable to use olefin resin, styrene resin, acrylic resin, polyester resin, epoxy resin, and urethane resin for bundling, and epoxy resin and urethane resin are particularly preferable from the viewpoint of mechanical strength. The amount of bundling agent attached to the bundling-treated glass fiber is preferably 0.1 to 3% by weight, more preferably 0.2 to 1% by weight, based on 100% by weight of the glass fiber.

The carbon fibers used as component E in the present invention include, for example, metal-coated carbon fibers, carbon milled fibers, vapor-grown carbon fibers, and other carbon fibers, as well as carbon nanotubes. The carbon nanotubes may have a fiber diameter of 0.003 to 0.1 μm and may be single-walled, double-walled, or multi-walled, with multi-walled (so-called MWCNT) being preferred. Of these, carbon fibers are preferred because of their excellent mechanical strength.

As carbon fibers, any of cellulose-based, polyacrylonitrile-based, and pitch-based types can be used. Also usable are those obtained by a method of spinning without going through an infusible step, such as a method in which a raw material composition consisting of a polymer formed by methylene bonds of aromatic sulfonic acids or their salts and a solvent is spun or molded, and then carbonized. Furthermore, any of general-purpose types, medium elastic modulus types, and high elastic modulus types can be used. Of these, polyacrylonitrile-based high elastic modulus types are particularly preferred.

In addition, the surface of the carbon fiber is preferably oxidized to increase adhesion to the matrix resin and improve mechanical strength. The oxidation method is not particularly limited, but suitable examples include (1) a method of treating the carbon fiber with an acid or alkali or a salt thereof, or an oxidizing gas, (2) a method of baking the fiber or carbon fiber that can be converted into carbon fiber at a temperature of 700°C or higher in the presence of an inert gas containing an oxygen-containing compound, and (3) a method of oxidizing the carbon fiber and then heat treating it in the presence of an inert gas.

Metal-coated carbon fiber is a carbon fiber with a metal layer coated on its surface. Examples of metals include silver, copper, nickel, and aluminum, with nickel being preferred in terms of the corrosion resistance of the metal layer. Methods for metal coating include known methods such as plating and vapor deposition, with plating being the most preferred. In the case of such metal-coated carbon fiber, the carbon fibers listed above can be used as the base carbon fiber. The thickness of the metal coating layer is preferably 0.1 to 1 μm, more preferably 0.15 to 0.5 μm, and even more preferably 0.2 to 0.35 μm.

These carbon fibers and metal-coated carbon fibers are preferably bundled and treated with olefin resins, styrene resins, acrylic resins, polyester resins, epoxy resins, urethane resins, etc. Carbon fibers treated with urethane resins and epoxy resins are particularly suitable for the present invention because of their excellent mechanical strength.

The content of component E is 25 to 150 parts by weight, preferably 30 to 140 parts by weight, and more preferably 40 to 120 parts by weight, per 100 parts by weight of the total of components A and B. If the content of component E is less than 25 parts by weight, the improvement in tensile strength will be insufficient. On the other hand, if it exceeds 150 parts by weight, the strength and flame retardancy will decrease.

(Component F: Phenoxy resin and/or epoxy resin)
The phenoxy resin used as the component F in the present invention includes, for example, a phenoxy resin represented by the following general formula (8).

(In the formula, X is at least one group selected from the group consisting of groups represented by the following general formula (9), Y is a residue of a compound that reacts with a hydrogen atom or a hydroxyl group, and n is an integer of 0 or more.)

(In the formula, Ph represents a phenyl group.)

In the above general formula (9), examples of compounds that react with hydroxyl groups include esters, carbonates, compounds having epoxy groups, carboxylic anhydrides, acid halides, compounds having isocyanate groups, etc., and as esters, intramolecular esters are particularly preferred, such as caprolactone. In the phenoxy resin represented by the above general formula (8), a compound in which Y is a hydrogen atom can be easily produced from divalent phenols and epichlorohydrin. In addition, a compound in which Y is a residue of a compound that reacts with hydroxyl groups can be easily produced by mixing a phenoxy resin produced from divalent phenols and epichlorohydrin with the above compound that reacts with hydroxyl groups under heating.

The epoxy resin used as component F in the present invention may, for example, be an epoxy resin represented by the following general formula (10):

(In the formula, X is the same as in general formula (9), and n is an integer of 0 or more.)

The epoxy resin represented by the above formula (10) can be easily produced from a dihydric phenol and epichlorohydrin. As the dihydric phenol, 2,2-bis(4-hydroxyphenyl)propane [bisphenol A], 1,1-bis(4-hydroxyphenyl)ethane, 4,4'-dihydroxybiphenyl, etc. can be used.

Among these phenoxy resins and epoxy resins, particularly preferred embodiments include bisphenol A type phenoxy resins and/or bisphenol A type epoxy resins. Commercially available products can also be used as the phenoxy resins and epoxy resins. Commercially available products of phenoxy resins (bisphenol A type) include PKHB (manufactured by Gabriel Phenoxies, Mw = 32,000), PKHH (manufactured by Gabriel Phenoxies, Mw = 52,000), and PKFE (manufactured by Gabriel Phenoxies, Mw = 60,000). Commercially available products of epoxy resins (bisphenol A type) include jER1256 (manufactured by Mitsubishi Chemical Corporation, Mw = 50,000).

The weight average molecular weight of the phenoxy resin and epoxy resin is not particularly limited, but is preferably 5,000 to 100,000, more preferably 8,000 to 80,000, and even more preferably 10,000 to 50,000. If the weight average molecular weight is in the range of 5,000 to 100,000, the mechanical properties may be particularly good.

The content of component F is 0.1 to 8 parts by weight, preferably 1 to 7 parts by weight, and more preferably 3 to 6 parts by weight, per 100 parts by weight of the total of components A and B. If the content is too low beyond the above range, the tensile strength will be low. On the other hand, if the content exceeds the above range, the flame retardancy will be poor and the tensile strength will be reduced.

(G component: phosphonic acid ester)
The phosphonate ester used in the present invention may be a phosphonate monoester, a phosphonate diester, or a phosphonate triester, but a phosphonate triester is preferred. Various combinations of esters with carbon numbers from 1 to 22 may be used, but triethyl phosphonoacetate is most preferred. The acid value of the phosphonate ester is 0.01 to 0.30 mgKOH/g, preferably 0.01 to 0.20 mgKOH/g, and more preferably 0.05 to 0.15 mgKOH/g. An acid value of less than 0.01 mgKOH/g is not practical in terms of production, and an acid value of more than 0.30 mgKOH/g results in poor thermal stability, a reduced tensile strength during retention, and a reduced recyclability. The acid value was measured using a potentiometric titrator, and an alcohol solution of the phosphonate ester was titrated with an alcohol solution of KOH.

The content of component G is 0.01 to 3 parts by weight, preferably 0.1 to 2 parts by weight, and more preferably 0.2 to 1 part by weight, per 100 parts by weight of the total of components A and B. If the content of component G is less than 0.01 parts by weight, the thermal stability is deteriorated, and not only does the tensile strength specific to this composition not appear, but recyclability is also reduced. If the content exceeds 3 parts by weight, a large amount of volatile gas is generated during extrusion processing, resulting in insufficient extrusion processability.

(Other additives)
Furthermore, the resin composition of the present invention may further contain other thermoplastic resins (e.g., polyarylate resins, fluororesins, polyester resins, polyphenylene sulfide resins, etc.), phosphorus-based stabilizers other than phosphonic acid esters (e.g., phosphite-based compounds, etc.), antioxidants (e.g., hindered phenol-based compounds, etc.), impact improvers, ultraviolet absorbers, light stabilizers, release agents, lubricants, colorants, inorganic fillers (talc, mica, wollastonite, kaolin, etc.), and the like, provided such addition does not impair the object of the present invention.

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

The polycarbonate resin composition of the present invention obtained as described above can be used to produce various products by injection molding the pellets produced as described above. Furthermore, it is also possible to directly make sheets, films, profile extrusion products, and injection molded products from the resin melt-kneaded in an extruder without going through the pellet process.

In such injection molding, molded products can be obtained using not only ordinary molding methods, but also injection molding methods such as injection compression molding, injection press molding, gas-assisted injection molding, foam molding (including injection of supercritical fluids), 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, 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. In addition, the polycarbonate resin composition of the present invention can also be molded into various profile extrusion molded products and sheets by extrusion molding.

Molded articles in which the resin composition of the present invention can be used include, for example, electrical and electronic parts such as connectors, sockets, relay parts, coil bobbins, optical pickups, oscillators, printed wiring boards, and computer-related parts; semiconductor manufacturing process-related parts such as IC trays and wafer carriers; home electrical product parts and housing materials such as computers, VTRs, televisions, irons, air conditioners, stereos, vacuum cleaners, refrigerators, rice cookers, and lighting fixtures; lighting fixture parts such as lamp reflectors and lamp holders; audio product parts such as compact discs, laser discs (registered trademark), and speakers; communication device parts such as ferrules for optical cables, telephone parts, facsimile parts, and modems; These include photocopier-related parts such as release claws and heater holders; machine parts such as impellers, fans, cogwheels, bearings, motor parts and cases; automotive parts such as automotive mechanism parts, engine parts, engine room parts, electrical parts and interior parts; cooking utensils such as microwave cooking pots and heat-resistant tableware; heat insulation and soundproofing materials such as flooring and wall materials, supporting materials such as beams and pillars, building materials such as roofing materials or civil engineering and construction materials; aircraft parts, spacecraft parts, radiation facility parts such as nuclear reactors, marine facility parts, cleaning tools, optical equipment parts, valves, pipes, nozzles, filters, membranes, medical equipment parts and materials, sensor parts, sanitary equipment, sporting goods, leisure goods, etc.

The polycarbonate resin composition of the present invention has excellent tensile strength, dimensional accuracy, and flame retardancy, and furthermore, exhibits little loss of strength even under harsh processing conditions, and is also highly recyclable. These properties are not available in conventional technologies, and therefore the industrial effects of the present invention are extremely significant.

The form of the invention that the inventors currently consider to be the best is a combination of the preferred ranges of each of the above requirements, and representative examples are described in the examples below. Of course, the present invention is not limited to these forms.

The present invention will be further explained below with reference to examples. The evaluation was carried out according to the following methods.

(Evaluation of polycarbonate resin composition)
(i) Tensile strength: The tensile strength was measured using a tensile test piece (dumbbell-shaped No. 3 according to JIS K6251, thickness 2 mm) obtained by the following method (tensile speed: 5 mm/min, test temperature: 23° C.).
(ii) Molding shrinkage: A square plate of 50 mm width × 100 mm length × 2 mm thickness obtained by the following method was left for 24 hours in an atmosphere of 23°C and 50% relative humidity, and the dimensions of the square plate were measured with a three-dimensional measuring machine (manufactured by Mitutoyo Corporation) to calculate the molding shrinkage. The molded product was molded using a mold cavity having a film gate at one end in the length direction. Therefore, the length direction is the flow direction, and the width direction is the direction perpendicular to the flow direction.
(iii) Flame retardancy: Using UL test pieces obtained by the following method, a V (vertical flame test) test at a thickness of 0.8 mm was carried out in accordance with UL94.
(iv) Strength retention during retention: Tensile test pieces (dumbbell-shaped No. 3 type as defined in JIS K6251: thickness 2 mm) were successively molded by the following method, and then the operation of the molding machine was interrupted to allow the resin to retain in the cylinder. After 15 minutes, a test piece was molded again to obtain test pieces before and after retention. The tensile properties of the test piece before and after retention were measured, and the strength retention before and after retention was calculated by the following formula.
Strength retention rate (%) = [tensile strength after dwelling/tensile strength before dwelling] x 100
(v) Recyclability: The test pieces used in "(i) Tensile strength" before storage were left horizontally outdoors in Midori-ku, Chiba City for one year, and then crushed and remolded into test pieces. The tensile properties of the test pieces before storage and the remolded test pieces were measured in the same manner as in "(iv) Strength retention during storage", and the strength retention before and after storage was measured using the following formula.
Strength retention rate (%) = [tensile strength of regenerated test piece/tensile strength of test piece before standing] x 100
(vi) Extrusion processability: The stability during extrusion was evaluated according to the following criteria.
The strands during extrusion are stable: ◯ The strands during extrusion are somewhat unstable, but pelletization is possible: △
The strands are quite unstable during extrusion. It is difficult to pelletize, or there is a lot of volatile gas. ：×

[Examples 1 to 18, Comparative Examples 1 to 13]
A mixture consisting of the components excluding component B, with the composition shown in Tables 1 and 2, was fed from the first feed port of the extruder. This mixture was obtained by mixing in a V-type blender. Component B was fed from the second feed port using a side feeder. Extrusion was performed using a vented twin-screw extruder (TEX30α-38.5BW-3V, Japan Steel Works, Ltd.) with a diameter of 30 mmφ, and melt-kneaded at a screw rotation speed of 200 rpm, a discharge rate of 25 kg/h, and a vent vacuum of 3 kPa to obtain pellets. The extrusion temperature was 300°C from the first feed port to the die portion. A part of the obtained pellets was dried in a hot air circulation type dryer at 120°C for 6 hours, and then molded into a tensile test piece (JIS K6251 dumbbell type No. 3) having a thickness of 2 mm, a test piece for measuring mold shrinkage rate, and a UL test piece using an injection molding machine (NEX50-5E manufactured by Nissei Plastic Co., Ltd.) at a cylinder temperature of 300°C and a mold temperature of 80°C.
The components represented by symbols in Tables 1 and 2 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))
A-2: Aromatic polycarbonate resin (polycarbonate resin powder having a viscosity average molecular weight of 19,700, produced by a conventional method from bisphenol A and phosgene, manufactured by Teijin Limited, Panlite L-1225WX (product name))
A-3: Aromatic polycarbonate resin (polycarbonate resin powder having a viscosity average molecular weight of 16,000, produced by a conventional method from bisphenol A and phosgene, manufactured by Teijin Limited, Panlite CM-1000 (product name))
A-4: Aromatic polycarbonate resin (polycarbonate resin powder having a viscosity average molecular weight of 25,100, produced by a conventional method from bisphenol A and phosgene, manufactured by Teijin Limited, Panlite L-1250WQ (product name))

(Component B)
B-1: Liquid crystal polyester resin (liquid crystal polyester resin pellets containing repeating units derived from p-hydroxybenzoic acid and repeating units derived from 6-hydroxy-2-naphthoic acid, manufactured by Polyplastics Co., Ltd., LAPEROS A-950RX (product name), melting point = 275 to 285°C)

(Component C)
C-1: Halogenated carbonate compound (brominated carbonate oligomer having a bisphenol A skeleton, Fire Guard FG-7000 (product name) manufactured by Teijin Limited)

(Component D)
D-1: Anti-drip agent (polytetrafluoroethylene (Polyflon MPA FA-500H (product name) manufactured by Daikin Industries, Ltd.)

(Component E)
E-1: Glass fiber: flat cross-section chopped glass fiber (manufactured by Nitto Boseki Co., Ltd.: CSG 3PA-830 (product name), major axis 28 μm, minor axis 7 μm, cut length 3 mm, epoxy-based sizing agent)
E-2: Carbon fiber: PAN-based carbon fiber (Teijin Limited, HTC422 (product name), fiber diameter 7 μm, cut length 6 mm, urethane-based bundling agent)

(F component)
F-1: Bisphenol A phenoxy resin (manufactured by Gabriel Phenoxies, PKHH (trade name), weight average molecular weight 52,000)
F-2: Bisphenol A type epoxy resin (jER1256 (trade name), manufactured by Mitsubishi Chemical Corporation, epoxy equivalent: 7,5000 to 8,000 g/eq, weight average molecular weight: 50,000)

(G component)
G-1: Triethyl phosphonoacetate (JC-224 (trade name), manufactured by Johoku Chemical Industry Co., Ltd., acid value 0.08 mg KOH/g)
G-2 (Comparative Example): Triethylphosphonoacetate (Solvay, acid value 0.39 mg KOH/g)
G-3: Triethyl phosphonoacetate (mixture of B-1 and B-2 (weight ratio 1:1), acid value 0.23 mg KOH/g)

(Other ingredients)
Phosphite compound: bis(2,4-di-t-butylphenyl)pentaerythritol diphosphite (SONGNOX6260PW (product name) manufactured by Songwon International Japan Co., Ltd.)
Release agent-1: Licowax E powder (manufactured by Clariant Japan Co., Ltd.)
Release material-2: Hiwax 405MP (manufactured by Mitsui Chemicals, Inc.)
Colorant: Carbon black master pellets produced by melt-mixing a total of 100 parts by weight of four components using a twin-screw extruder: 40 parts by weight of carbon black (Carbon Black MA-100 (trade name) manufactured by Mitsubishi Chemical Corporation), 3 parts by weight of white mineral oil (Primol N382 (trade name) manufactured by Exxon Mobil Corporation), 0.2 parts by weight of Montan acid ester wax (Licowax E powder (trade name) manufactured by Clariant Japan K.K.), and 56.8 parts by weight of bisphenol A type polycarbonate resin (CM-1000 (trade name) manufactured by Teijin Limited, viscosity average molecular weight 16,000).

It is clear from Tables 1 and 2 above that the blending of the present invention provides polycarbonate resin compositions which have high tensile strength, little anisotropy in molding shrinkage, high dimensional accuracy, excellent flame retardancy, little decrease in strength even under severe processing conditions, and excellent recyclability.

Claims (7)

A polycarbonate resin composition comprising 100 parts by weight of (A) an aromatic polycarbonate resin (component A) and (B) a liquid crystal polyester resin (component B), 3 to 40 parts by weight of (C) a halogenated carbonate compound (component C), 0.1 to 3 parts by weight of (D) an anti-drip agent (component D), 25 to 150 parts by weight of (E) glass fiber and/or carbon fiber (component E), 0.1 to 8 parts by weight of (F) a phenoxy resin and/or epoxy resin (component F), and 0.01 to 3 parts by weight of (G) a phosphonic acid ester (component G) having an acid value of 0.01 to 0.30 mg KOH/g, and the weight ratio of component A to component B [(A)/(B)] is 95/5 to 60/40. 2. The polycarbonate resin composition according to claim 1, wherein the viscosity average molecular weight of component A is 1.7×10 ⁴ to 2.1×10 ⁴ . The polycarbonate resin composition according to claim 1 or 2, wherein component B is a liquid crystal polyester resin containing repeating units derived from p-hydroxybenzoic acid and repeating units derived from 6-hydroxy-2-naphthoic acid. The polycarbonate resin composition according to claim 1 or 2, wherein component E is a flat cross-section glass fiber having an average major axis of 10 to 50 μm and an average major axis/minor axis ratio (major axis/minor axis) of 1.5 to 8. The polycarbonate resin composition according to claim 1 or 2, wherein component F is a bisphenol A type phenoxy resin and/or a bisphenol A type epoxy resin. The polycarbonate resin composition according to claim 1 or 2, in which component G is triethylphosphonoacetate. A molded article obtained by molding the polycarbonate resin composition according to claim 1 or 2.