WO2011062105A1

WO2011062105A1 - Polycarbonate resin composition

Info

Publication number: WO2011062105A1
Application number: PCT/JP2010/070067
Authority: WO
Inventors: 敬直竹内; 誠一前場
Original assignee: 出光興産株式会社
Priority date: 2009-11-20
Filing date: 2010-11-11
Publication date: 2011-05-26
Also published as: TW201124469A; JP5654744B2; KR20120092129A; TWI490269B; JP2011105914A; CN102612542A

Abstract

Provided are: a polycarbonate resin composition which comprises (A) 100 parts by mass of an aromatic polycarbonate resin that contains a polycarbonate-polyorganosiloxane copolymer, (B) 30 to 100 parts by mass of graphite, (C) 1 to 10 parts by mass of polytetrafluoroethylene, and (D) 0.05 to 1 part by mass of an organoalkali metal salt and/or an organoalkaline earth metal salt and which exhibits excellent flame retardance (even in a thin-wall state), thermal conductivity, and impact characteristics, even without using a chlorinated flame retardant, a brominated flame retardant, or a phosphorus-based flame retardant; and molded products of the composition.

Description

Polycarbonate resin composition

The present invention relates to a polycarbonate resin composition and a molded article comprising the resin composition, and flame retardancy (particularly thin-walled flame retardancy) without using a chlorine-based flame retardant, a bromine-based flame retardant, or a phosphorus-based flame retardant. The present invention relates to a polycarbonate resin composition excellent in thermal conductivity and impact properties and a molded product comprising the same.

In product development in the electrical and electronic field, heat dissipation due to high pixel count and high speed processing in digital cameras and digital video cameras, miniaturization of projectors, high speed processing in personal computers and mobile devices, and the use of LEDs for various light sources. Emphasis is placed on countermeasures.
Measures to configure the heat dissipation circuit with metal parts have also been taken, but since the heat dissipation circuit becomes complicated in a downsized device, the resin casing and the heat dissipation circuit can be integrated, and it has excellent thermal conductivity In addition, a resin material having excellent mechanical strength as a housing is required.
Further, in a small electronic device, the casing and the chassis are required to be thin, and accordingly, the flame retardancy of the thin molded body is also required.

Polycarbonate resin is widely used for the casings of the above electronic devices, but halogen flame retardants such as chlorinated flame retardants and brominated flame retardants are added to make molded products made of polycarbonate resin flame retardant. It is known to do. However, recently, from the viewpoint of safety and impact on the environment at the time of disposal / incineration, a flame retardant method using a flame retardant containing no halogen is required from the market. As such a non-halogen flame retardant, an organic phosphorus flame retardant, particularly an organic phosphate ester compound, is blended into the polycarbonate resin composition, and in order to make it flame retardant, a relatively large amount of the phosphate ester compound is blended. There is a need. Since the polycarbonate resin has a high molding temperature and a high melt viscosity, the molding temperature tends to be high. Therefore, although the phosphate ester compound generally contributes to flame retardancy, it may not always be sufficient in terms of molding environment and appearance of the molded product, such as die corrosion during molding and generation of gas.
Therefore, without using halogen-based flame retardants such as chlorine-based flame retardants and bromine-based flame retardants, and phosphorus-based flame retardants, the required flame resistance (particularly thin-walled flame retardant properties) of molded products is achieved and heat is achieved. It is desired to find a polycarbonate resin composition having excellent conductivity.

It is known that graphite is blended as a means for imparting heat dissipation to the thermoplastic resin (see Patent Document 1 and Patent Document 2). Patent Document 1 discloses that a thermoplastic resin composition having low metal corrosivity and excellent thermal conductivity can be obtained by blending specific graphite with a thermoplastic resin. In order to improve the properties, it is described that it is preferable to use an organic halogen flame retardant such as a halogenated carbonate oligomer or a halogenated epoxy compound or a phosphate ester flame retardant. It does not disclose a technique that does not use a flame retardant and a phosphorus-based flame retardant.
Further, Patent Document 2 relates to a heat radiating housing in which a heating element is accommodated, but there is no description regarding flame retardancy required for a housing such as an electronic device, and organic bromine as an additive to be blended as necessary. Although flame retardants such as flame retardants and phosphorous flame retardants are disclosed, technology that does not actively use chlorine flame retardants, bromine flame retardants and phosphorus flame retardants is not disclosed, and its implementation In the example, since there is no addition of a flame retardant or an anti-drip agent, it is considered that the flame retardant is not sufficient.
Furthermore, a polycarbonate resin composition is known in which graphite is blended in order to impart antistatic properties and electrical conductivity to the polycarbonate resin and a flame retardant is blended (see Patent Document 3 and Patent Document 4). Patent Document 3 discloses an aromatic polycarbonate resin composition containing a specific silicone compound in a blend composed of an aromatic polycarbonate resin and graphite, and its antistatic property and flame retardancy are evaluated. There is no description of the technical content that can provide sufficient flame retardancy with a thin wall of about 1.5 mm required for a housing of an electronic device or the like. Further, Patent Document 4 discloses a flame retardant comprising a polycarbonate resin, graphite, and an alkali (earth) metal salt of an organic sulfonate as a technique not actively using a chlorine-based flame retardant, a bromine-based flame retardant, and a phosphorus-based flame retardant. In the flame retardant evaluation, only evaluation with a molded body having a thickness of 2.5 mm has been made, and as in Patent Document 3, about 1.5 mm required for a housing of an electronic device or the like. Insufficient flame retardancy is not obtained with the thin wall.

JP 2007-31611 A JP 2008-31358 A JP 2007-126499 A JP 2006-273931 A

In the present invention, flame retardancy (thickness: 1.2 to 1.0 mm, hereinafter referred to as “thin flame retardant”) without using a chlorine-based flame retardant, bromine-based flame retardant, and phosphorus-based flame retardant. It is an object of the present invention to provide a polycarbonate resin composition and a molded article excellent in impact characteristics having excellent thermal conductivity.

As a result of extensive research, the present inventors have found that an aromatic polycarbonate resin containing a polycarbonate-polyorganosiloxane copolymer, graphite, polytetrafluoroethylene, and an organic alkali metal salt and / or an organic alkaline earth metal salt. By blending at a specific ratio, it was found that a polycarbonate resin composition having excellent thin-wall flame retardancy and further excellent thermal conductivity and impact properties was obtained, and the present invention was completed.

That is, the present invention
(1) (B) 30-100 parts by mass of graphite, (C) 1-10 parts by mass of polytetrafluoroethylene, with respect to 100 parts by mass of (A) an aromatic polycarbonate resin containing a polycarbonate-polyorganosiloxane copolymer, And (D) a polycarbonate resin composition comprising 0.05 to 1 part by mass of an organic alkali metal salt and / or an organic alkaline earth metal salt,
(2) The polycarbonate resin composition according to the above (1), wherein the content of polyorganosiloxane in (A) is 1 to 6% by mass,
(3) The polycarbonate resin composition according to the above (1) or (2), wherein the polyorganosiloxane of the aromatic polycarbonate-polyorganosiloxane copolymer is polydimethylsiloxane,
(4) The polycarbonate resin composition according to any one of the above (1) to (3), wherein the graphite is natural graphite,
(5) The polycarbonate resin composition according to any one of the above (1) to (3), wherein the graphite is artificial graphite,
(6) (D) An organic alkali metal salt and / or an organic alkaline earth metal salt is an organic sulfonic acid alkali metal salt, an organic sulfonic acid alkaline earth metal salt, a polystyrene sulfonic acid alkali metal salt, or a polystyrene sulfonic acid alkaline earth. The polycarbonate resin composition according to any one of the above (1) to (5), which is at least one selected from metal salts;
(7) A molded article comprising the polycarbonate resin composition according to any one of (1) to (6) above,
(8) The molded product according to (7), which is a part for electrical / electronic equipment,
(9) The molded product according to (7), which is a casing for an electric / electronic device,
(10) The molded body according to (7), which is a chassis for electric / electronic devices,
Is to provide.

According to the present invention, it is excellent in thin-wall flame retardancy, impact properties, and thermal conductivity without impairing the original mechanical properties of polycarbonate, and it can suppress the decrease in molecular weight during granulation, thereby increasing the strength of the product. A resin composition that can be kept high can be obtained.

Hereinafter, the present invention will be described in detail.
The polycarbonate resin of the present invention (hereinafter sometimes abbreviated as “PC resin”) is composed of (A) aromatic polycarbonate resin, (B) graphite, (C) polytetrafluoroethylene, and (D) organic. A polycarbonate resin composition containing an alkali metal salt and / or an organic alkaline earth metal salt as an essential component.
The aromatic polycarbonate resin (A) in the present invention includes (A-1) an aromatic polycarbonate containing a polycarbonate-polyorganosiloxane copolymer (hereinafter sometimes abbreviated as “PC-POS copolymer”). Resin is used.
Specifically, the (A-1) PC-POS copolymer alone or a (A-2) aromatic polycarbonate resin (hereinafter referred to as “general”) produced by reaction of a dihydric phenol and a carbonate precursor. Abbreviated as “PC resin”). An aromatic polycarbonate resin having a content of the PC-POS copolymer of 10 to 100% by mass is preferably used.

The production method of the general PC resin which is the component (A-2) in the component (A) is not particularly limited, and those produced by various conventional methods can be used. For example, a dihydric phenol and a carbonate precursor produced by a solution method (interfacial polycondensation method) or a melting method (transesterification method), that is, a dihydric phenol and phosgene are reacted in the presence of a terminal terminator. An interfacial polycondensation method to be produced or a product produced by a reaction by a transesterification method of a dihydric phenol and diphenyl carbonate in the presence of a terminal terminator can be used.
Various dihydric phenols can be mentioned, and in particular, 2,2-bis (4-hydroxyphenyl) propane [bisphenol A], bis (4-hydroxyphenyl) methane, 1,1-bis (4 -Hydroxyphenyl) ethane, 2,2-bis (4-hydroxy-3,5-dimethylphenyl) propane, 4,4'-dihydroxydiphenyl, bis (4-hydroxyphenyl) cycloalkane, bis (4-hydroxyphenyl) Examples thereof include oxide, bis (4-hydroxyphenyl) sulfide, bis (4-hydroxyphenyl) sulfone, bis (4-hydroxyphenyl) sulfoxide, and bis (4-hydroxyphenyl) ketone. In addition, hydroquinone, resorcin, catechol and the like can also be mentioned. These may be used alone or in combination of two or more. Among them, bis (hydroxyphenyl) alkanes are preferable, and bisphenol A is particularly preferable.

On the other hand, the carbonate precursor is carbonyl halide, carbonyl ester, haloformate or the like, specifically, phosgene, dihaloformate of dihydric phenol, diphenyl carbonate, dimethyl carbonate, diethyl carbonate or the like.
The general PC resin may have a branched structure, and 1,1,1-tris (4-hydroxyphenyl) ethane, α, α ′, α ″ -tris (4 -Hydroxyphenyl) -1,3,5-triisopropylbenzene, phloroglysin, trimellitic acid and isatin bis (o-cresol).
In the present invention, the viscosity average molecular weight (Mv) of the general PC resin used as the component (A-2) is usually 10,000 to 50,000, preferably 13,000 to 35,000, more preferably 15, 000 to 20,000.
This viscosity average molecular weight (Mv) is obtained by measuring the viscosity of a methylene chloride solution at 20 ° C. using an Ubbelohde viscometer, obtaining the intrinsic viscosity [η] from this, and calculating the viscosity by the following formula.
[Η] = 1.23 × 10 ⁻⁵ Mv ^0.83

In the aromatic polycarbonate resin of the component (A), the (A-1) PC-POS copolymer is composed of a polycarbonate part and a polyorganosiloxane part. For example, a polycarbonate constituting a polycarbonate part produced in advance. An oligomer (hereinafter abbreviated as PC oligomer) and a polyorganosiloxane moiety (segment) having a reactive group such as an o-allylphenol residue, a p-hydroxystyrene residue, or an eugenol residue at the terminal. Dissolve organosiloxane in a solvent such as methylene chloride, chlorobenzene, or chloroform, add a caustic aqueous solution of dihydric phenol, and use a tertiary amine (such as triethylamine) or a quaternary ammonium salt (trimethylbenzylammonium chloride) as a catalyst. Etc.) Presence of the end terminating agent, can be prepared by interfacial polycondensation reaction.
The PC oligomer used for the production of this PC-POS copolymer is obtained by reacting the aforementioned dihydric phenol with a carbonate precursor such as phosgene in a solvent such as methylene chloride, or with a dihydric phenol. It can be easily produced by reacting a carbonate ester compound, for example, a carbonate precursor such as diphenyl carbonate.
Examples of the carbonate compound include diaryl carbonates such as diphenyl carbonate, and dialkyl carbonates such as dimethyl carbonate and diethyl carbonate.

The PC oligomer used for the production of the PC-POS copolymer may be a homo-oligomer using one kind of the aforementioned dihydric phenol or a co-oligomer using two or more kinds. Furthermore, the thermoplastic random branched oligomer obtained by using a polyfunctional aromatic compound together with the said bihydric phenol may be sufficient.
In that case, 1,1,1-tris (4-hydroxyphenyl) ethane, α, α ′, α ″ -tris (4-hydroxyphenyl) -1,3 is used as a branching agent (polyfunctional aromatic compound). , 5-triisopropylbenzene, 1- [α-methyl-α- (4′-hydroxyphenyl) ethyl] -4- [α ′, α′-bis (4 ″ -hydroxyphenyl) ethyl] benzene, phloroglucin, Trimellitic acid, isatin bis (o-cresol) and the like can be used.
This PC-POS copolymer is disclosed in, for example, JP-A-3-292359, JP-A-4-202465, JP-A-8-81620, JP-A-8-302178, and JP-A-10-7897. Etc. are disclosed.

As the PC-POS copolymer, those having a polymerization degree of the polycarbonate part of about 3 to 100 and a polymerization degree of the polyorganosiloxane part of about 2 to 500 are preferably used.
In addition, the content of the polyorganosiloxane part in the PC-POS copolymer in the total component (A) is such that the flame retardancy imparting effect, impact resistance imparting effect, and economic efficiency of the obtained PC resin composition From the viewpoint of balance and the like, the content is preferably 1 to 6% by mass.
Further, the viscosity average molecular weight (Mv) of the PC-POS copolymer is usually 5,000 to 100,000, preferably 10,000 to 30,000, particularly preferably 12,000 to 30,000. Here, these viscosity average molecular weights (Mv) can be obtained in the same manner as in the general PC resin.
The polyorganosiloxane portion in the PC-POS copolymer is preferably a segment made of polydimethylsiloxane, polydiethylsiloxane, polymethylphenylsiloxane, or the like, and particularly preferably a polydimethylsiloxane segment.

The ratio of the (A-1) PC-POS copolymer in the component (A) to the general PC resin as the component (A-2) depends on the polyorganosiloxane part in the PC-POS copolymer ( The content in the whole component A) is 1 to 6% by mass, and the raw material molecular weight (viscosity average molecular weight) as the whole component (A) is preferably in the range of 17,000 to 30,000, preferably Is preferably adjusted to 18,000 to 26,000.
For example, regarding the content of the polyorganosiloxane part, when using a PC-POS copolymer having a polyorganosiloxane part having a high content exceeding 6% by mass, a large amount of general PC resin can be used. When using a low content PC-POS copolymer, the content in the total component (A) is 1 to 6% by mass by using no general PC resin or a small amount of general PC resin. And can be adjusted.
Usually, the (A-1) PC-POS copolymer in the component (A) is used in the range of 10 to 100% by mass. When the ratio of the PC-POS copolymer is large, it is easier to obtain the impact strength of the molded article, and the molecular weight reduction during granulation is suppressed.

As the molecular weight regulator used as the molecular end group in the aromatic PC resin as the component (A), any molecular weight regulator may be used as long as it is usually used for polymerization of polycarbonate, and various monohydric phenols can be used. Specific examples include phenol, p-cresol, p-tert-butylphenol, p-tert-octylphenol, p-cumylphenol, bromophenol, tribromophenol, nonylphenol and the like.

In the PC resin composition of the present invention, a bifunctional carboxylic acid such as terephthalic acid, or an ester thereof, as long as the object of the present invention is not impaired, in addition to the aromatic PC resin and the PC-POS copolymer. A copolymer resin such as a polyester-polycarbonate resin obtained by polymerizing a polycarbonate in the presence of an ester precursor such as a forming derivative, or other polycarbonate resin can be appropriately contained.

The polycarbonate resin composition of the present invention is blended with (B) graphite mainly for imparting thermal conductivity.
As the graphite used in the present invention, either natural graphite or various artificial graphites can be used. As natural graphite, any of earth-like graphite, scale-like graphite (Vein Graphite also called massive graphite), and scale-like graphite (Flake Graphite) can be used. Of the natural graphites exemplified above, scaly graphite can be suitably used. By applying natural graphite, higher thermal conductivity and higher elastic modulus can be obtained.

Artificial graphite is obtained by heat-treating amorphous carbon and artificially aligning irregularly arranged fine graphite crystals. In addition to artificial graphite used for general carbon materials, Kish graphite, cracked graphite, and Includes pyrolytic graphite. Artificial graphite used for general carbon materials is usually produced by graphitization treatment using petroleum coke or coal-based pitch coke as a main raw material.
Such artificial graphite has a merit that high weld strength can be improved, although elasticity and thermal conductivity are lowered as compared with natural graphite.
The blending amount of component (B) is required to be in the range of 30 to 100 parts by weight, preferably in the range of 30 to 70 parts by weight, with respect to 100 parts by weight of component (A). When the blending amount is less than 30 parts by mass, it is difficult to obtain sufficient thermal conductivity, and when it exceeds 100 parts by mass, there is a problem that the impact strength tends to decrease.

In the present invention, graphite having a 50% cumulative diameter of 30 to 180 μm can be suitably used. The fixed carbon amount of graphite is preferably 80% by weight or more, more preferably 90% by weight or more, and still more preferably 98% by weight or more. The volatile content of graphite is preferably 3% by weight or less, more preferably 1.5% by weight or less, and still more preferably 1% by weight or less.
The surface of the graphite is subjected to surface treatment such as epoxy treatment, urethane treatment, silane coupling treatment, and oxidation treatment in order to increase the affinity with the thermoplastic resin as long as the characteristics of the composition of the present invention are not impaired. May be.

The polycarbonate resin composition of the present invention is blended with (C) polytetrafluoroethylene (PTFE) in order to improve thin flame retardancy. This component (C) gives the resin composition of the present invention a melt dripping preventing effect, and exhibits excellent thin flame retardancy.
The component (C) preferably has a fibril forming ability. Here, “fibril forming ability” means that resins tend to be bonded and become fibrous due to an external action such as shearing force. Examples of the component (C) of the present invention include polytetrafluoroethylene, a tetrafluoroethylene copolymer (for example, a tetrafluoroethylene / hexafluoropropylene copolymer) and the like. Of these, polytetrafluoroethylene is preferred.
PTFE having fibril-forming ability has a very high molecular weight, and the number average molecular weight determined from the standard specific gravity is usually 500,000 or more, preferably 500,000 to 15 million, more preferably 1,000,000 to 10 million. Specifically, tetrafluoroethylene is polymerized in an aqueous solvent in the presence of sodium, potassium or ammonium peroxydisulfide at a pressure of about 7 to 700 kPa and a temperature of about 0 to 200 ° C., preferably 20 to 100 ° C. Can be obtained.

In addition to solid forms, those in the form of an aqueous dispersion can also be used, and those classified as type 3 according to the ASTM standard can be used. Commercially available products classified as Type 3 include, for example, “Teflon 6-J” (trade name, manufactured by Mitsui Dupont Fluoro Chemical Co., Ltd.), “Polyflon D-1” and “Polyflon F-103” [trade name. , Manufactured by Daikin Industries, Ltd.]. Other than Type 3, “Algoflon F5” (trade name, manufactured by Solvay Solexis), “Polyflon MPAFA-100” (trade name, manufactured by Daikin Industries, Ltd.) and the like can be mentioned.
The PTFE may be used alone or in combination of two or more.

The blending amount of (C) polytetrafluoroethylene (PTFE) is in the range of 1 to 10 parts by mass, preferably 1.5 to 9 parts by mass with respect to 100 parts by mass of the above-mentioned (A) aromatic polycarbonate resin. . When the blending amount is less than 1 part by mass, the effect of preventing dripping is lost, and when it exceeds 10 parts by mass, impact characteristics are deteriorated.
When the blending amount is 1 to 1.5 parts by mass, it has an effect as an anti-dripping agent. However, when it exceeds 1.5 parts by mass, not only as an anti-dripping agent, but also an effect of improving impact strength and mold release properties The mold release action during molding is also improved.

In order to further improve the thin flame retardancy of the polycarbonate resin composition of the present invention, (D) an organic alkali metal salt and / or an organic alkaline earth metal salt is blended.
(D) Organic alkali metal salts and / or organic alkaline earth metal salts include various organic acids, organic acids having at least one carbon atom, or alkali metal salts of organic acid esters and organic alkaline earth metals Salt can be used.
Here, the organic acid or the organic acid ester is an organic sulfonic acid, an organic carboxylic acid, or the like. On the other hand, the alkali metal is lithium, sodium, potassium, cesium or the like, and the alkaline earth metal is magnesium, calcium, strontium, barium or the like, and among these, sodium and potassium salts are preferably used. The salt of the organic acid may be substituted with a halogen such as fluorine, chlorine or bromine. Alkali metal salts and organic alkaline earth metal salts can be used singly or in combination of two or more.
Among the above various organic alkali metal salts and organic alkaline earth metal salts, for example, in the case of organic sulfonic acid, the alkali metal salt and alkaline earth metal of perfluoroalkanesulfonic acid represented by the following general formula (1) A salt is preferably used.
(C _e F _{2e + 1} SO ₃ ) _f M (1)
In the formula, e represents an integer of 1 to 10, M represents an alkaline metal such as lithium, sodium, potassium or cesium, or an alkaline earth metal such as magnesium, calcium, strontium or barium, and f represents the valence of M. Show.
As these compounds, for example, those described in Japanese Patent Publication No. 47-40445 correspond to this.

In the general formula (1), examples of perfluoroalkanesulfonic acid include perfluoromethanesulfonic acid, perfluoroethanesulfonic acid, perfluoropropanesulfonic acid, perfluorobutanesulfonic acid, perfluoromethylbutanesulfonic acid, Fluorohexanesulfonic acid, perfluoroheptanesulfonic acid, perfluorooctanesulfonic acid and the like can be mentioned. In particular, these potassium salts are preferably used. In addition, p-toluenesulfonic acid, 2,5-dichlorobenzenesulfonic acid; 2,4,5-trichlorobenzenesulfonic acid; diphenylsulfone-3-sulfonic acid; diphenylsulfone-3,3′-disulfonic acid; naphthalenetrisulfonic acid And alkali metal salts of organic sulfonic acids such as

Examples of the organic carboxylic acid include perfluoroformic acid, perfluoromethanecarboxylic acid, perfluoroethanecarboxylic acid, perfluoropropanecarboxylic acid, perfluorobutanecarboxylic acid, perfluoromethylbutanecarboxylic acid, perfluorohexanecarboxylic acid. Perfluoroheptanecarboxylic acid, perfluorooctanecarboxylic acid and the like, and alkali metal salts of these organic carboxylic acids are used.

Next, as the alkali metal salt and / or alkaline earth metal salt of polystyrene sulfonic acid that can be used as the component (D), a sulfonate group-containing aromatic vinyl resin represented by the following general formula (2) may be used. it can.

In the above formula (2), Z ¹ represents a sulfonate group, Z ² represents a hydrogen atom or a hydrocarbon group having 1 to 10 carbon atoms. g is an integer of 1 to 5. h represents a mole fraction, and 0 <h ≦ 1.
Here, the sulfonate group is an alkali metal salt and / or alkaline earth metal salt of sulfonic acid, and examples of the metal include sodium, potassium, lithium, rubidium, cesium, beryllium, magnesium, calcium, strontium, barium and the like. It is done.
In the formula, Z ² is a hydrogen atom or a hydrocarbon group having 1 to 10 carbon atoms, preferably a hydrogen atom or a methyl group. Further, g is an integer of 1 to 5, and h has a relationship of 0 <h ≦ 1. That is, the sulfonate group (Z ¹ ) may be a fully substituted or partially substituted aromatic ring.
In order to further enhance the flame retardancy effect of the polycarbonate resin composition of the present invention, the substitution ratio of the sulfonate group is determined in consideration of the content of the sulfonate group-containing aromatic vinyl resin, and is generally Is used with 10 to 100% substitution.

In the alkali metal salt and / or alkaline earth metal salt of polystyrene sulfonic acid, the sulfonate group-containing aromatic vinyl resin is not limited to the polystyrene resin of the above general formula (2), but a styrene-based single resin. It may be a copolymer with another monomer copolymerizable with the monomer.
Here, as a method for producing a sulfonate group-containing aromatic vinyl resin, (I) the above aromatic vinyl monomer having a sulfonic acid group or the like, or another monomer copolymerizable therewith (II) Aromatic vinyl polymers, copolymers of aromatic vinyl monomers and other copolymerizable monomers, or mixed polymers of these And neutralizing with an alkali metal compound and / or an alkaline earth metal compound.
For example, as the method (II), a polystyrene sulfone oxide is produced by adding a mixture of concentrated sulfuric acid and acetic anhydride to a 1,2-dichloroethane solution of polystyrene resin, heating the mixture, and reacting for several hours. Then, polystyrene sulfonate potassium salt or sodium salt can be obtained by neutralizing with sulfonic acid group and equimolar amount of potassium hydroxide or sodium hydroxide.
The weight average molecular weight of the sulfonate group-containing aromatic vinyl resin used in the present invention is about 1,000 to 300,000, preferably about 2,000 to 200,000. The weight average molecular weight can be measured by the GPC method.

The above (D) organic alkali metal salt and / or organic alkaline earth metal salt may be used singly or in combination of two or more. The content thereof is 0.05 to 1 part by weight, preferably 0.1 to 0.9 part by weight, based on 100 parts by weight of the (A) aromatic polycarbonate resin. When the content is less than 0.05 parts by mass, it is difficult to achieve the target thin-walled flame retardancy.

In the polycarbonate resin composition of the present invention, for the purpose of moldability, impact resistance, appearance improvement, weather resistance improvement, rigidity improvement, etc., the components comprising the above (A) to (D) are added with phenol, phosphorus, A sulfur-based (E) antioxidant and (F) a release agent can be contained.
(E) The amount of antioxidant added is preferably 0.001 to 0.5 parts by mass for phosphorus antioxidants. If it is 0.001 part by mass or more, thermal stability in the granulation step / molding step can be maintained, and if it is less than 0.5 part by mass, it is difficult to cause a decrease in molecular weight. In addition, in the case of a phenolic antioxidant, it is preferable to add 0.001 to 0.5 parts by mass, and the impact strength is easily improved.
(F) The release agent is not particularly limited as long as it can be mixed with a polycarbonate resin to improve the release property at the time of molding. In particular, organic compounds such as beeswax, glycerin monostearate, glycerin tristearate, pentaerythritol monostearate, pentaerythritol tristearate, pentaerythritol tetrastearate, montanic acid ester wax, carboxylic acid ester have excellent release properties. Shown and used preferably.
These include, for example, “honey wax golden brand” manufactured by Miki Chemical Industry Co., Ltd., “Rikemar S-100A”, “Riquemar SL-900”, and “Riquestar EW-440A” manufactured by Riken Vitamin Co., Ltd., Cognis Japan “Roxyol V P G 8 6 1” manufactured by Clariant Japan, “Rico Wax E” manufactured by Clariant Japan, and “Roxyol EP-32” manufactured by Cognis Japan. The blending amount is preferably 0.001 to 2 parts by mass.
Furthermore, additive components commonly used in other synthetic resins, elastomers, and thermoplastic resins can be included as necessary. The above additives include antistatic agents, polyamide polyether block copolymers (permanent antistatic performance), benzotriazole and benzophenone UV absorbers, hindered amine light stabilizers (weathering agents), plasticizers, antibacterial agents Agents, compatibilizers and colorants (dyes, pigments) and the like.
The amount of the optional component is not particularly limited as long as the characteristics of the polycarbonate resin composition of the present invention are maintained.

Next, the manufacturing method of the polycarbonate resin composition of this invention is demonstrated.
The polycarbonate resin composition of the present invention can be obtained by blending the above components (A) to (D) in the above proportions and various optional components used as necessary in an appropriate proportion and kneading.
The compounding and kneading are premixed with commonly used equipment such as a ribbon blender, drum tumbler, etc., Henschel mixer, Banbury mixer, single screw extruder, twin screw extruder, multi screw extruder and It can be performed by a method using a conida or the like. The heating temperature at the time of kneading is usually appropriately selected within the range of 240 to 320 ° C. As the melt-kneading molding, it is preferable to use an extrusion molding machine, particularly a vent type extrusion molding machine.
In addition, the components other than the polycarbonate resin can be added in advance as a master batch with melt-kneading with the polycarbonate resin or other thermoplastic resin.

The polycarbonate resin composition of the present invention is an injection molding method, an injection compression molding method, an extrusion molding method, a blow molding method, a press molding method, a vacuum molding method, using the above melt kneading molding machine or the obtained pellets as a raw material. Various molded bodies can be produced by a foam molding method or the like. In particular, the obtained pellets can be used suitably for the production of injection molded articles by injection molding and injection compression molding.
The molded body comprising the polycarbonate resin composition of the present invention is, for example,
(1) TV, radio cassette, video camera, video tape recorder, audio player, DVD player, air conditioner, mobile phone, display, computer, register, calculator, copier, printer, facsimile, etc.
(2) The housing for the electric / electronic device according to 1 above,
(3) Chassis for electrical / electronic equipment according to 1 above,
Etc. can be suitably used.

EXAMPLES Hereinafter, although an Example and a comparative example are shown and this invention is demonstrated more concretely, this invention is not restrict | limited at all by these.
The performance evaluation method and raw materials used are shown below.
[Performance evaluation method]
(1) Viscosity average molecular weight Using an Ubbelohde type viscosity tube, the intrinsic viscosity [η] of a methylene chloride solution at 20 ° C. was measured and calculated from the following relational expression (Schnell's formula). [Η] = 1.23 × 10 ⁻⁵ × Mv ^0.83
In addition, the pellet molecular weight measured the molecular weight of the extracted polycarbonate resin by melt | dissolving the pellet sample for evaluation in a methylene chloride, isolate | separating an insoluble matter.

(2) Flame retardancy A vertical combustion test was performed using a test piece (length 127 mm, width 12.7 mm, thickness 1.2 mm) prepared according to UL standard 94. Based on the test results, UL94 V-0, V-1, or V-2 grades were evaluated, and those that did not reach V-2 were designated as V-2out.
The UL standard 94 is a method for evaluating the flame retardancy from the afterflame time after the burner flame is indirectly fired for 10 seconds on a test piece of a predetermined size held vertically.

(3) Thermal conductivity The thermal conductivity was measured by a hot disk method using a thermal conductivity measuring device “TPA-501” [manufactured by Kyoto Electronics Industry Co., Ltd.].
(4) Density The density was measured in accordance with JIS K7112.

(5) Flexural properties Elastic modulus: measured in accordance with ASTM D790.
Bending strength: measured in accordance with ASTM D790.

(6) Impact characteristics Notched Izod impact strength (IZOD)
Using a test piece (length 12.7 mm, width 63 mm, height 3.2 mm) produced by an injection molding machine, impact strength was measured at a measurement temperature of 23 ° C. in accordance with ASTM standard D-256.

[Raw materials]
(A) Aromatic polycarbonate resin A-1 (1); Polycarbonate-polydimethylsiloxane copolymer [Idemitsu Kosan Co., Ltd., “FC1700”; viscosity average molecular weight = 17,800, polydimethylsiloxane (PDMS) part Degree of polymerization = 40, PDMS content = 3.5% by mass]
A-1 (2): Polycarbonate-polydimethylsiloxane copolymer obtained in Production Example 1 below [viscosity average molecular weight = 17,300, degree of polymerization of polydimethylsiloxane (PDMS) part = 90, PDMS content = 6.6% by mass]

Production Example 1
(Polycarbonate oligomer synthesis process)
2,000 ppm of sodium dithionite is added to 5.6% by mass sodium hydroxide aqueous solution to bisphenol A (BPA) which is later dissolved, and BPA is added to this so that the BPA concentration becomes 13.5% by mass. After dissolution, an aqueous sodium hydroxide solution of BPA was prepared.
Phosgene was continuously passed through a tubular reactor having an inner diameter of 6 mm and a tube length of 30 m at a flow rate of 4.0 kg / hr at a flow rate of 40 liter / hr of sodium hydroxide aqueous solution of BPA and 15 liter / hr of methylene chloride. The tubular reactor had a jacket portion, and the temperature of the reaction solution was kept at 40 ° C. or lower by passing cooling water through the jacket.
The reaction liquid exiting the tubular reactor was continuously introduced into a baffled tank reactor having an internal volume of 40 liters equipped with a receding blade, and further 2.8 liters / hr of sodium hydroxide aqueous solution of BPA, 25 The reaction was carried out by adding 0.07 L / hr of a mass% aqueous sodium hydroxide solution, 17 L / hr of water, and 0.64 L / hr of a 1 mass% aqueous triethylamine solution. The reaction liquid overflowing from the tank reactor was continuously extracted and allowed to stand to separate and remove the aqueous phase, and the methylene chloride phase was collected.
The polycarbonate oligomer thus obtained had a concentration of 318 g / l and a chloroformate group concentration of 0.75 mol / l.

(Production Example 1 of Polycarbonate-Polydimethylsiloxane Copolymer)
Allylphenol terminal-modified poly having a polycarbonate oligomer solution 15L, methylene chloride 9.0L, and a dimethylsiloxane unit repeating number 90 in a 50L tank reactor equipped with a baffle plate, a paddle type stirring blade and a cooling jacket 396 g of dimethylsiloxane (PDMS) and 8.8 mL of triethylamine were charged, and 1389 g of a 6.4% by mass aqueous sodium hydroxide solution was added thereto with stirring, and the reaction between the polycarbonate oligomer and allylphenol terminal-modified PDMS was performed for 10 minutes.
In this polymerization solution, a methylene chloride solution of pt-butylphenol (PTBP) (140 g of PTBP dissolved in 2.0 L of methylene chloride), a sodium hydroxide aqueous solution of BPA (577 g of NaOH and 2.0 g of sodium dithionite) in water A solution obtained by dissolving 1012 g of BPA in an aqueous solution dissolved in 8.4 L) was added, and a polymerization reaction was carried out for 50 minutes.
For dilution, 10 L of methylene chloride was added and stirred for 10 minutes. Then, the organic phase was separated into an organic phase containing a polycarbonate-polydimethylsiloxane copolymer and an aqueous phase containing excess BPA and NaOH, and the organic phase was isolated.
The methylene chloride solution of the polycarbonate-polydimethylsiloxane copolymer thus obtained was sequentially washed with 15% by volume of 0.03 mol / L NaOH aqueous solution and 0.2 mol / L hydrochloric acid with respect to the solution. Washing with pure water was repeated until the electrical conductivity in the aqueous phase became 0.01 μS / m or less.
The methylene chloride solution of the polycarbonate-polydimethylsiloxane copolymer obtained by washing was concentrated and pulverized, and the obtained flakes were dried at 120 ° C. under reduced pressure.
The amount of PDMS residue (PDMS copolymerization amount) determined by nuclear magnetic resonance (NMR) of the obtained polycarbonate-polydimethylsiloxane copolymer was 6.6% by mass, measured according to ISO 1628-4 (1999). The viscosity number was 46.7, and the viscosity average molecular weight Mv was 17,300.

A-1 (3): Polycarbonate-polydimethylsiloxane copolymer obtained in Production Example 2 below [viscosity average molecular weight = 17,300, degree of polymerization of polydimethylsiloxane (PDMS) part = 40, PDMS content = 10% by mass]

Production Example 2
(Production Example 2 of Polycarbonate-Polydimethylsiloxane Copolymer)
Repetition of 15 L of polycarbonate oligomer solution, 8.9 L of methylene chloride, and dimethylsilanooxy unit used in the production of A-1 (2) above in a 50 L tank reactor equipped with baffle plates, paddle type stirring blades and cooling jacket 670 g of allylphenol-terminated PDMS having a number of 40 and 8.8 mL of triethylamine were charged, and 1389 g of a 6.4% by mass aqueous sodium hydroxide solution was added thereto under stirring, and the reaction between the polycarbonate oligomer and allylphenol-end-modified PDMS was performed for 10 minutes. Went.
In this polymerization solution, methylene chloride solution of pt-butylphenol (PTBP) (PTBP 137.9 g dissolved in 2.0 L of methylene chloride), BPA aqueous solution of sodium hydroxide (NaOH 581 g and sodium dithionite 2.3 g) 1) of BPA dissolved in 8.5 L of water was added, and the polymerization reaction was carried out for 50 minutes. For dilution, 10 L of methylene chloride was added and stirred for 10 minutes, and then the organic phase was separated into an organic phase containing polycarbonate and an aqueous phase containing excess BPA and NaOH, and the organic phase was isolated.
The methylene chloride solution of the polycarbonate thus obtained was washed successively with 15% by volume of 0.03 mol / L NaOH aqueous solution and 0.2N hydrochloric acid, and the electric conductivity in the aqueous phase after washing was 0. Washing with pure water was repeated until the pressure became 0.01 μS / m or less. The methylene chloride solution of polycarbonate obtained by washing was concentrated and pulverized, and the obtained flakes were dried at 120 ° C. under reduced pressure.
The amount of PDMS residue determined by NMR was 10.0% by mass, the viscosity number measured according to ISO 1628-4 (1999) was 46.6, and the viscosity average molecular weight Mv = 17,300.

A-2 (1): polycarbonate [made by Idemitsu Kosan Co., Ltd., homopolycarbonate “Taflon FN1900A” manufactured from bisphenol A, viscosity average molecular weight = 19,500]
A-2 (2): polycarbonate [made by Idemitsu Kosan Co., Ltd., homopolycarbonate “Taflon FN2200A” manufactured from bisphenol A, viscosity average molecular weight = 21,500]
A-2 (3): Polycarbonate [Homopolycarbonate “Taflon FN2600A” produced from bisphenol A, manufactured by Idemitsu Kosan Co., Ltd., viscosity average molecular weight = 26,000]
In addition, POS content in a table | surface: Polyorganosiloxane content (mass%) in (A) component is shown.

(B) Graphite B-1; natural graphite [“CB-150” manufactured by Nippon Graphite Industries Co., Ltd .; scale-like, particle size distribution 63 μm or less 77 to 87%, 106 μm or more and 5% or less, apparent density 0.2 to 0.3 g / cm ³ , 50% cumulative diameter 31-48 μm, fixed carbon 98 mass% or more, ash content 1 mass% or less, volatile content 1 mass% or less]
B-2; Artificial graphite [“PAG-420” manufactured by Nippon Graphite Industries Co., Ltd .; irregular, 50% cumulative diameter 30-40 μm (50 μm or more and 50% or less), apparent density 0.29 to 0.37 g / cm ³ , fixed Carbon 99.4 mass% or more, ash content 0.3 mass% or less, volatile content 0.3 mass% or less]

(C) Polytetrafluoroethylene (PTFE)
C-1; PTFE [manufactured by Solvay Solexis, “Algoflon F5”; Algoflon F5 is prone to agglomerate and is once masterbatched with PC flakes (mixing ratio (mass) PC: PTFE = 90: 10 to 80 : 20) then blended]

(D) Organic alkali (earth) metal salt D-1; potassium perfluorobutane sulfonate [Mitsubishi Materials Co., Ltd., “F-top KFBS”]
D-2: Sodium paratoluenesulfonate [DAH DIING CHEMICAL INDUSTRY, purity 93% product, sodium sulfate 3% by mass or less, moisture 5% by mass or less as impurities]

(E) Other additives Antioxidant E-1; Phosphorous antioxidant (diphenylisooctyl phosphite) [manufactured by ADEKA, “ADK STAB C”]
E-2: Phenol antioxidant (octadecyl-3- (3,5-di-t-butyl-hydroxyphenyl) propionate) [Ciba Japan Co., Ltd., “Irganox1076”]
(F) Other additives Mold release agent F-1: Stearic acid monoglyceride [“Riquemar S-100A” manufactured by Riken Vitamin Co., Ltd.]
F-2: Pentaerythritol tetrastearate [Rikenstar EW-440A, manufactured by Riken Vitamin Co., Ltd.]

Examples 1 to 13 and Comparative Examples 1 to 7
Each component is mixed in the proportions shown in Tables 1 and 2 and supplied to a vent type twin screw extruder (Toshiba Machine Co., Ltd .: TEM35), barrel temperature 300 to 320 ° C., screw rotation speed 200 to 600 rotations, discharge The mixture was melt-kneaded at an amount of 10 to 30 kg / hr to obtain a pellet sample for evaluation.
Using this pellet sample for evaluation, the viscosity average molecular weight was measured. Moreover, the test piece for performing each test was created with the injection molding machine, and each test was done. The results are shown in Tables 1 and 2.

Tables 1 and 2 revealed the following.
From Table 1, in Examples 1 to 13, which satisfy all the components (A) to (D) of the present invention, thin-walled (thickness 1.2 mm) flame retardancy, thermal conductivity, bending characteristics, and impact strength And a polycarbonate resin composition in which a decrease in the molecular weight of the polycarbonate resin during granulation is suppressed is obtained.
From Table 2, in the comparative example 1 which consists only of homopolycarbonate resin, thin-walled flame retardance falls. In Comparative Example 2 in which the graphite content of the component (B) is low, the thermal conductivity is reduced, and in Comparative Example 3 in which the component (B) is too much, the impact strength is reduced. In Comparative Example 4 in which the PTFE content of the component (C) is low, the thin-wall flame retardancy is reduced, and in Comparative Example 5 in which the component (C) is too much, the impact strength is reduced.
In Comparative Example 6 where the metal salt content of the component (D) is low, the thin-wall flame retardancy is reduced, and in Comparative Example 7 where there is too much component (D), the molecular weight of the polycarbonate resin is greatly reduced during granulation.

Claims

(A) 30 to 100 parts by mass of graphite, (C) 1 to 10 parts by mass of polytetrafluoroethylene, and (D) with respect to 100 parts by mass of an aromatic polycarbonate resin containing a polycarbonate-polyorganosiloxane copolymer. ) A polycarbonate resin composition comprising 0.05 to 1 part by mass of an organic alkali metal salt and / or an organic alkaline earth metal salt.
2. The polycarbonate resin composition according to claim 1, wherein the content of polyorganosiloxane in (A) is 1 to 6% by mass.
The polycarbonate resin composition according to claim 1 or 2, wherein the polyorganosiloxane of the aromatic polycarbonate-polyorganosiloxane copolymer is polydimethylsiloxane.
The polycarbonate resin composition according to any one of claims 1 to 3, wherein the graphite is natural graphite.
The polycarbonate resin composition according to any one of claims 1 to 3, wherein the graphite is artificial graphite.
(D) The organic alkali metal salt and / or the organic alkaline earth metal salt is an organic sulfonic acid alkali metal salt, an organic sulfonic acid alkaline earth metal salt, a polystyrene sulfonic acid alkali metal salt, and a polystyrene sulfonic acid alkaline earth metal salt. The polycarbonate resin composition according to any one of claims 1 to 5, which is at least one selected.
A molded body comprising the polycarbonate resin composition according to any one of claims 1 to 6.
The molded body according to claim 7, which is a part for an electric / electronic device.
The molded body according to claim 7, which is a casing for an electric / electronic device.
The molded article according to claim 7, which is a chassis for electrical and electronic equipment.