JP2008222852A - Electroconductive aromatic polycarbonate resin composition and molding - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an aromatic polycarbonate resin composition and moldings, stably manifesting surface resistivity within a range of 10<SP>2</SP>-10<SP>12</SP>Ω, excellent in mechanical strengths and melt stability, little in electronic component pollution owing to little carbon black disengagement and excellent in dimensional stability and appearance. <P>SOLUTION: The resin composition comprises 100 pts.wt. aromatic polycarbonate (A), 3-30 pts.wt. carbon black (B), 0.1-40 pts.wt. silicate compound (C), and 0.001-10 pts.wt. organic acid and/or organic acid derivative (D), and has surface resistivity within a range of 10<SP>2</SP>-10<SP>12</SP>Ω. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

The present invention relates to a conductive aromatic polycarbonate resin composition containing carbon black and a molded article.
Specifically, the surface resistivity value is stably expressed in the range of 10 ² to 10 ¹² Ω, excellent in mechanical strength and melt stability, less carbon black desorption, and less contamination of electronic components. The present invention relates to an aromatic polycarbonate resin composition and a molded article excellent in stability and appearance.

Resin composition consisting of aromatic polycarbonate and carbon black is excellent in strength and heat resistance, and can express the surface resistivity necessary to prevent the destruction of electronic parts due to static electricity. Its use is expanding as a material for packaging containers for parts.
These packaging containers include various forms such as injection molding trays, vacuum molding trays, magazines, carrier tapes, etc., but polycarbonate resins are excellent in strength (required strength can be obtained even for thin molded products), It has features such as impact resistance, moldability, and heat resistance that can be baked, and has recently attracted particular attention as a packaging container material that can cope with the complexity, precision, and miniaturization of electronic components. .

The packaging container for electronic parts is required to be provided with conductivity necessary for preventing destruction of the IC due to static electricity. For this purpose, it is required to satisfy both an insulating property that prevents the IC from being destroyed by energizing the IC from the outside and an electrical conductivity that removes static electricity generated in the packaging container itself. As the conductivity index, the surface resistivity of the packaging container itself is preferably a semiconductive region in the range of 10 ² to 10 ¹² Ω, and in the conductive region of less than 10 ² Ω or the insulating region exceeding 10 ¹² Ω, the electronic component The requirements for packaging containers cannot be met.

In general, carbon black is blended with polycarbonate to obtain a conductive resin by melt kneading using an extruder or the like to uniformly disperse carbon black in the polycarbonate.
However, in the prior art, in order to obtain a desired surface resistivity, usually 5% by weight or more, preferably 10% by weight or more, and if necessary, 20% by weight or more of carbon black based on the polycarbonate conductive resin. It is necessary to mix.

For example, in Patent Documents 1, 2, and 3, the amount of carbon black necessary for developing conductivity is preferably 5 to 50 parts by weight based on the conductive resin.
On the other hand, by adding a large amount of carbon black in this way, carbon black agglomerates are likely to occur, and the mechanical strength of the resin composition is reduced, and cracks and fractures are particularly likely to occur in thin portions. There is a problem of becoming.

  Regarding the production of the resin composition, it is often technically difficult to uniformly disperse a large amount of carbon black in the resin composition, especially when a thin sheet or the like is produced, the carbon dispersion is poor. There arises a problem that appearance defects such as aggregates and silver are likely to occur. The carbon black agglomerates are easily detached when used as a packaging container for electronic parts, and become a contaminant for electronic parts.

  In addition, as a problem in the production of a resin composition containing a large amount of carbon black, the problem is that carbon black is likely to be scattered and color contamination to surrounding equipment is likely to occur, and melting at the extruder outlet for melt kneading. The problem is that continuous production is not possible because the resin strands are easy to cut, resulting in a decrease in productivity, and a large amount of carbon black is not easily transported quantitatively when it is put into the extruder. Various problems are likely to occur in industrially stable production, such as the problem of carbon black being easily blocked by the mouth.

Therefore, mechanical strength, surface appearance, reduction of pollutants, and production for the purpose of obtaining a conductive resin that has a surface resistivity of 10 ² to 10 ¹² Ω in a stable range by blending carbon black with polycarbonate. In order to improve the properties, it is desirable that the amount of carbon black to be blended is as small as possible. However, in the prior art, in order to stably obtain the required surface resistivity, a suitable amount of carbon black is necessary. Met.

On the other hand, dimensional stability is desired for packaging containers for electronic components.
Patent Document 4 discloses a conductive resin composition having a small dimensional change in which an inorganic polycarbonate and a conductive powder are blended with an aromatic polycarbonate.
Patent Document 5 discloses a resin composition excellent in dimensional accuracy, slidability, and heat resistance obtained by blending an aromatic polycarbonate with a conductive filler and talc.
As shown in Patent Documents 4 and 5, techniques for improving the dimensional stability of a resin composition by blending an inorganic compound with an aromatic polycarbonate are known.

  However, in general, aromatic polycarbonate is compounded with an inorganic compound, so that decomposition of the resin is promoted in melt-kneading, material deterioration proceeds significantly, strength decreases, decomposition gas is generated during molding, silver streak, etc. There is a problem that the appearance defect is likely to occur. That is, since the melt stability and the appearance of the molded product are greatly impaired, there is a problem that it is difficult to add an inorganic compound for improving the dimensional stability to the aromatic polycarbonate.

  As described above, in an aromatic polycarbonate resin composition containing carbon black, a stable surface specific resistance value, mechanical strength, melt stability, low resistance to electronic components, which are required as a packaging container material for electronic components. Although aromatic polycarbonate resin compositions that simultaneously satisfy various requirements such as contamination, dimensional stability, and appearance of molded products are desired, these have not led to improved resin compositions at the same time. Currently.

JP 2002-326318 A JP 2002-67258 A International Publication No. 01/30569 Japanese Patent Laid-Open No. 2-51237 JP-A-10-152618

In the present invention, the surface resistivity value is stably expressed in the range of 10 ² to 10 ¹² Ω, excellent in mechanical strength and melt stability, and less desorption of carbon black results in less contamination of electronic components. It is an object of the present invention to provide an aromatic polycarbonate resin composition and a molded product excellent in dimensional stability and appearance.

As a result of intensive studies to solve the above-mentioned problems, the present inventors have found that a resin composition in which carbon black, a silicate compound, and an organic acid and / or an organic acid derivative are blended in a specific quantitative ratio with respect to an aromatic polycarbonate. Thus, the inventors have found that the above-described problems can be achieved, and have reached the present invention.
That is, the present invention includes the following [1] to [6].

[1] 100 parts by weight of aromatic polycarbonate (A), 3 to 30 parts by weight of carbon black (B), 0.1 to 40 parts by weight of silicate compound (C), organic acid and / or organic acid derivative (D) 0 A resin composition characterized by containing 0.001 to 10 parts by weight and having a surface resistivity of 10 ² to 10 ¹² Ω.
[2] The resin composition according to [1], wherein the specific surface area of the component (B) is in the range of 30 to 1500 m ² / g.
[3] When the pH value of the mixture of the component (D), the component (B), the component (C), and the component (D) is measured based on JIS-K5101, the mixture (D) The resin composition as described in [1] or [2] above, wherein the pH value is 4 to 9 parts by weight.
[4] A molded article comprising the resin composition according to [1] to [3].
[5] The molded product according to [4], wherein the molded product is an extrusion molded product.
[6] The molded product according to [5], wherein the extruded product is a conductive sheet.

The following 1) -5) can be mentioned as the characteristic of the resin composition of this invention.
1) Carbon black, silicate compound, and organic acid and / or organic acid derivative are used in combination with a specific quantity ratio with respect to aromatic polycarbonate, thereby reducing carbon black compared to the prior art composition. The surface specific resistance value in the range of 10 ² to 10 ¹² Ω can be stably expressed with the blending amount of.
2) Since a stable surface resistivity value can be obtained with a small amount of carbon black, desorption of carbon black from the resin composition is reduced, and contamination of electronic components is reduced.
3) Although the dimensional stability of the resin composition can be increased by blending the silicate compound, the resin composition of the present invention has excellent melt stability and little deterioration in physical properties, so that good mechanical strength is maintained. Is done.
4) Since the resin composition of this invention is excellent in melt stability, it is excellent in the external appearance of a molded article.
5) Since the amount of carbon black used can be reduced, contamination of the working environment can be reduced in the production of the resin composition, and the frequency of production troubles due to strand breakage, feed failure, etc. can be reduced. The level can be suppressed, and the continuous stability of the composition is excellent.

That is, the aromatic polycarbonate resin composition and the molded product of the present invention are stably expressed in the range of surface resistivity of 10 ² to 10 ¹² Ω, excellent in mechanical strength and melt stability, and desorbing carbon black. The aromatic polycarbonate resin composition and the molded product, which are less contaminated with electronic components due to the small amount, and further excellent in dimensional stability and appearance of the molded product, have extremely high industrial utility value.

The present invention will be specifically described below.
Component (A) of the present invention is an aromatic polycarbonate.
The aromatic polycarbonate preferably used as the component (A) of the present invention is an aromatic polycarbonate derived from an aromatic dihydroxy compound. Examples of the aromatic dihydroxy compound include 1,1-bis (4-hydroxy-t -Butylphenyl) propane, bis (hydroxyaryl) alkanes such as 2,2-bis (4-hydroxyphenyl) propane, 1,1-bis (4-hydroxyphenyl) cyclopentane, 1,1-bis (4- Bis (hydroxyaryl) cycloalkanes such as hydroxyphenyl) cyclohexane, dihydroxyaryl ethers such as 4,4′-dihydroxydiphenyl ether, 4,4′-dihydroxy-3,3′-dimethylphenyl ether, 4,4′- Dihydroxydiphenyl sulfide, 4,4 -Dihydroxyaryl sulfides such as dihydroxy-3,3'-dimethylphenyl sulfide, dihydroxyaryl sulfoxides such as 4,4'-dihydroxydiphenyl sulfoxide, 4,4'-dihydroxy-3,3'-dimethylphenyl sulfoxide, 4 , 4'-dihydroxydiphenylsulfone, dihydroxyarylsulfones such as 4,4'-dihydroxy-3,3'-dimethylphenylsulfone, and the like.
Among these, 2,2-bis (4-hydroxyphenyl) propane (common name, bisphenol A) is particularly preferable. These aromatic dihydroxy compounds can be used alone or in combination of two or more.

  As the aromatic polycarbonate preferably used as the component (A), those produced by a known method can be used. Specifically, a known method of reacting an aromatic dihydroxy compound and a carbonate precursor, for example, reacting an aromatic dihydroxy compound and a carbonate precursor (for example, phosgene) in the presence of an aqueous sodium hydroxide solution and a methylene chloride solvent. Crystallized carbonate prepolymer obtained by interfacial polymerization method (eg phosgene method), transesterification method (melting method) in which aromatic dihydroxy compound and carbonic acid diester (eg diphenyl carbonate) are reacted, phosgene method or melting method Polymerization method (Japanese Patent Laid-Open No. 1-158033 (corresponding to US Pat. No. 4,948,871)), Japanese Patent Laid-Open No. 1-271426, Japanese Patent Laid-Open No. 3-68627 (US Pat. No. 5,204,377) Can be used.

  The weight average molecular weight (Mw) of the aromatic polycarbonate is usually 5,000 to 500,000, preferably 10,000 to 100,000, more preferably 13,000 to 50,000, and particularly preferably. Is 15,000 to 30,000, particularly preferably 17,000 to 27,000.

In the present invention, the weight average molecular weight (Mw) of the aromatic polycarbonate can be measured using gel permeation chromatography (GPC), and the measurement conditions are as follows. That is, it is obtained by using a converted molecular weight calibration curve according to the following formula from the composition curve of standard monodisperse polystyrene using polystyrene gel with tetrahydrofuran as a solvent.
M _PC = 0.3591 M _PS ^1.0388
( _MPC is the molecular weight of aromatic polycarbonate, _MPS is the molecular weight of polystyrene)
Moreover, the aromatic polycarbonate used as said component (A) can also be used combining 2 or more types of aromatic polycarbonates from which molecular weight differs.

In the present invention, the component (A) includes polystyrene, high impact polystyrene (HIPS), acrylonitrile-styrene resin (AS resin), acrylonitrile-butadiene-styrene resin (ABS resin), methyl methacrylate-butadiene-styrene resin (MBS resin), Thermoplastic resins other than component (A) such as butyl acrylate-acrylonitrile-styrene resin (AAS resin), polyester resins such as polyethylene terephthalate and polybutylene terephthalate, polyamide resin, polymethyl methacrylate, polyarylate, etc. can also be blended. .
When a thermoplastic resin other than the component (A) is used, the amount is preferably 100 parts by weight or less, more preferably 50 parts by weight or less, and still more preferably 30 parts by weight with respect to 100 parts by weight of the aromatic polycarbonate. Part or less, particularly preferably 20 parts by weight or less.

Component (B) in the present invention is carbon black, preferably having a large specific surface area, and a high conductivity can be obtained with a small amount added to the resin.
The specific surface area of the component (B) is preferably in the range of 30 to 1,500 m ² / g, more preferably 100 to 1,450 m ² / g, particularly preferably 200 to 1,430 m ² / g, most preferably. Is 500 to 1,400 m ² / g. These specific surface areas of carbon black are measured by the liquid nitrogen adsorption method (hereinafter also referred to as BET adsorption isotherm method) in the present invention.

The carbon black of component (B), dibutyl phthalate absorption (hereinafter, also referred to as DBP oil absorption) is preferably in the range of 100~500cm ³ / 100g, more preferably 150~500cm ³ / 100g, particularly preferably in the range of 200~500cm ³ / 100g, most preferred 300~500cm ³ / 100g.

Moreover, the pH value of the component (B) is preferably in the range of 4 to 10, more preferably in the range of 5 to 10, and still more preferably in the range of 6 to 9.5.
Aromatic polycarbonate has the property of being easily deteriorated in an acidic or basic atmosphere. Therefore, when acidic carbon having a pH of 4 or less or basic carbon having a pH of 10 or more is blended, the melt-kneading is performed. The decomposition of the aromatic polycarbonate proceeds, the mechanical strength is lowered, and the appearance of the molded product may be impaired.

Examples of preferable carbon black used as the component (B) of the present invention are furnace black, channel black, acetylene black, ketjen black and the like, and particularly preferable is ketjen black.
In this invention, the compounding quantity of a component (B) is 3-30 weight part with respect to 100 weight part of component (A), Preferably it is 3.5-20 weight part, More preferably, 4-15 weight part More preferably, it is 4.5 to 10 parts by weight, particularly preferably 5 to 8 parts by weight. If the amount is less than 3 parts by weight, it is difficult to obtain a surface specific resistance value sufficient to prevent destruction of the electronic component due to static electricity. On the other hand, if it exceeds 30 parts by weight, the strength of the resin composition, the contamination to the electronic component, and the molded product As the surface appearance is lowered, the production stability of the resin composition is also lowered.

Component (C) in the present invention is a silicate compound.
In the present invention, by using the component (C), the effect of stably expressing the surface resistivity of the composition even in the case of blending a small amount of the component (B) and the dimensional stability of the composition are achieved. Demonstrate the effect of increasing.
The silicate compound is a silicate compound composed of a metal oxide component and a SiO ₂ component, and any of natural products and artificial compounds can be used.
The silicate compound preferably used as the component (C) has a composition substantially represented by the following formula (1).
xMO.ySiO ₂ .zH ₂ O (1)
(Here, x and y represent natural numbers, z represents an integer of 0 or more, MO represents a metal oxide component, and may be a plurality of metal oxide components.)

Examples of the metal M in the metal oxide MO include potassium, sodium, lithium, barium, calcium, zinc, manganese, iron, cobalt, magnesium, zirconium, aluminum, and titanium.
In the metal oxide MO, preferred is one that substantially contains either CaO or MgO. Further preferred is the case where the metal oxide MO consists essentially of at least one component selected from CaO and MgO, and particularly preferred is the case consisting essentially of MgO.

Specific examples of the silicate compound preferably used as component (C) include talc, mica, wollastonite, zonotlite, kaolin clay, montmorillonite, bentonite, sepiolite, imogolite, sericite, lawsonite, smectite, and the like. It can be used alone or in combination of two or more.
The “silicate compound” can be of any shape (plate, needle, granular, fiber, etc.), but is preferably plate or needle, and in particular, plate Is most preferred.

Here, the plate-like form means that when the average particle diameter is (a) and the thickness is (c), the a / c ratio is 5 to 500, preferably 10 to 300, more preferably 20 to 200. It is of shape.
The needle-like form means that the a / c ratio is 5 to 500, preferably 10 to 10 when the average particle diameter in the major axis direction is (a) and the average particle diameter in the uniaxial direction is (c). 300, more preferably 20-200.

Among the “silicate compounds”, talc and mica are particularly preferable as the component (C).
The talc is a hydrous magnesium silicate having a layered structure, and is represented by a chemical formula 4SiO ₂ .3MgO.H ₂ O. Usually, SiO _{2 is} about 63% by weight, MgO is about 32%, H ₂ O is about 5% by weight, In addition, Fe ₂ O ₃ , CaO, Al ₂ O _{3 and the} like are contained, and the specific gravity is about 2.7.
As the talc, calcined talc, talc washed with an acid such as hydrochloric acid or sulfuric acid to remove impurities, and the like can be preferably used. Furthermore, talc that has been subjected to surface hydrophobic treatment with a silane coupling agent, a titanate coupling agent, or the like can also be used.

On the other hand, the mica is a pulverized product of silicate mineral containing aluminum, potassium, magnesium, sodium, iron and the like. Mica includes muscovite (mascobite, chemical formula: K (AlSi ₃ O ₁₀ ) (OH) ₂ Al ₄ (OH) ₂ (AlSi ₃ O ₁₀ ) K), phlogopite (phlogopite, chemical formula: K (AlSi ₃ O ₁₀₎ ) (OH) ₂ Mg ₆ (OH) ₂ (AlSi ₃ O ₁₀ ) K), biotite (biotite, chemical formula: K (AlSi ₃ O ₁₀ ) (OH) ₂ (Mg, Fe) ₆ (OH) ₂ ( AlSi ₃ O ₁₀ ) K), artificial mica (fluorine phlogopite, chemical formula: K (AlSi ₃ O ₁₀ ) (OH) ₂ F ₂ Mg ₆ F ₂ (AlSi ₃ O ₁₀ ) K), etc. Although it can be used, muscovite is preferred.
Such mica may be subjected to surface hydrophobic treatment with a silane coupling agent, a titanate coupling agent, or the like.

The average particle size of the component (C) according to the present invention is preferably 0.1 to 500 μm, more preferably 0.5 to 100 μm, further preferably 1 to 50 μm, particularly preferably 2 to 30 μm, most preferably 3 to 20 μm. preferable.
The average particle diameter in the present invention is determined by a laser diffraction method (for example, using SALD-2000 manufactured by Shimadzu Corporation).

  In this invention, the usage-amount of a component (C) is 0.1-40 weight part with respect to 100 weight part of components (A), 1-30 weight part is preferable, 2-20 weight part is more preferable, 3 to 12 parts by weight is more preferable, and 4 to 10 parts by weight is particularly preferable.

Component (D) according to the present invention is an organic acid and / or an organic acid derivative.
In the present invention, component (D) exhibits the effect of improving the melt stability of the composition and the effect of stabilizing the surface resistivity of the composition within a preferred range.
Specific examples of the component (D) include organic acids and / or organic acid derivatives selected from organic acid esters and organic acid anhydrides. These are not only low molecular compounds but also oligomeric or A polymer-like thing can be used and 2 or more types can also be used together.

The “organic acid” is an organic compound containing at least one group selected from the group consisting of —SO ₃ H group, —COOH group, and —POH group in the molecular structure, ie, organic sulfonic acid, organic carboxylic acid, Of these, organic sulfonic acids and organic carboxylic acids are preferable, and organic sulfonic acids are particularly preferable.

  In the present invention, when the organic sulfonic acid or organic sulfonic acid ester is used as the component (D), the melt stability of the resin composition is particularly excellent, and the generation of volatile components can be suppressed to a low level. The molding process can be performed over a wide temperature range, the volatile component of the roll is less contaminated, the productivity is excellent, and the appearance of the sheet or film is also excellent.

  As the organic sulfonic acid that can be preferably used as the component (D), benzenesulfonic acid, p-toluenesulfonic acid, xylenesulfonic acid, naphthalenesulfonic acid, diisopropylnaphthalenesulfonic acid, diisobutylnaphthalenesulfonic acid, dodecylbenzenesulfonic acid, And aromatic sulfonic acids such as C8-C18 aliphatic sulfonic acids, sulfonated polystyrene, methyl acrylate / sulfonated styrene copolymers, and oligomeric organic sulfonic acids.

  Further, as the organic sulfonate ester that can be preferably used as the component (D), methyl benzenesulfonate, ethyl benzenesulfonate, propyl benzenesulfonate, butyl benzenesulfonate, octyl benzenesulfonate, phenyl benzenesulfonate, methyl p-toluenesulfonate, ethyl p-toluenesulfonate, propyl p-toluenesulfonate, butyl p-toluenesulfonate, octyl p-toluenesulfonate, phenyl p-toluenesulfonate, methyl naphthalenesulfonate, naphthalenesulfonic acid Examples include ethyl, propyl naphthalenesulfonate, butyl naphthalenesulfonate, 2-phenyl-2-propyl dodecylbenzenesulfonate, and 2-phenyl-2-butyl dodecylbenzenesulfonate. Door can be.

In this invention, the compounding quantity of a component (D) is 0.001-10 weight part with respect to 100 weight part of components (A), 0.01-5 weight part is preferable, 0.05-3 weight part Is more preferable, and 0.1 to 1 part by weight is particularly preferable.
In particular, in the present invention, the blending amount (parts by weight) of the component (D) was determined by measuring the pH value of a mixture comprising the component (B), the component (C) and the component (D) based on JIS-K5101. In such a case, the pH value of the mixture is preferably 4 parts by weight, more preferably 4.5 to 9, and even more preferably 5 to 8.5.
That is, the most preferable blending amount of the component (D) varies depending on factors such as the respective pH values of the component (B) and the component (C), the number of blended parts, the size, and the shape.
Here, in the measurement of the pH value of JIS-K5105, there are a boiling method and a room temperature method as an operation method, but the boiling method is used in the present invention.

  In the resin composition of the present invention, a flame retardant, an anti-dripping agent, a dye / pigment, a heat stabilizer, an ultraviolet absorber, a fluorescent whitening agent, a lubricant, a processing aid, a dispersant, a release agent, an increase agent, if necessary. It is also possible to add a sticky agent, an antioxidant, an antistatic agent and the like.

The surface resistivity of the resin composition of the present invention is in the range of 10 ² to 10 ¹² Ω, preferably 10 ³ to 10 ¹¹ Ω, and more preferably 10 ⁴ to 10 ¹⁰ Ω.
When the surface resistivity exceeds 10 ¹² Ω, sufficient antistatic effect cannot be obtained. On the other hand, when the surface resistivity is less than 10 ² Ω, the conductivity is too good and the static electricity generated outside the molded product can easily be energized. A container or the like is not preferable because static electricity charged on the container itself may destroy an IC or the like that is a content.

The resin composition of the present invention can be obtained by melt-kneading using a melt-kneader such as an extruder.
The component (B), the component (C), and the component (D) may be premixed together with the component (A) and then charged into the extruder. However, the component (B), the component (C), and the component ( The mixture obtained by mixing D) is fed into an extruder by a feeder different from component (A), whereby the supply stability of component (B), component (C) and component (D), component (B) This is preferable because it can prevent scattering of the resin, prevent aggregation of the component (B), and improve the melt stability of the resin composition.
Also, the mixture of component (B), component (C) and component (D) may be supplied to the same supply position as component (A) and melt-kneaded, or may be separately supplied from the middle of the extruder. Good.

  Compounding of each component and melt kneading are generally used equipment such as premixing equipment such as tumbler, ribbon blender, super mixer, gravimetric feeder, single-screw extruder, twin-screw extruder, and kneader. A melt kneading apparatus can be used. Further, when melt kneading, it is desirable to perform open devolatilization and, if necessary, vacuum devolatilization.

Moreover, in order to shape | mold the said resin composition into a sheet | seat and a film, the T-die method, the inflation method, the calendar method, the casting method, the press method, etc. can be used.
When forming a sheet or film, the raw resin composition pellets are sufficiently pre-dried, and the water content in the pellets is preferably 500 ppm or less, more preferably 300 ppm or less, and even more preferably 100 ppm or less. preferable. The cylinder set temperature of the sheet or film extruder is preferably set to 300 ° C. or less, more preferably 290 ° C. or less, still more preferably 280 ° C. or less, and particularly preferably 270 ° C. or less. It is preferable that the residence time of the molten resin in the sheet and film extruder is as short as possible, and an opening is provided in the extruder to perform open devolatilization and, if necessary, vacuum devolatilization.

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples.
In Examples or Comparative Examples, the following components were used to produce resin compositions.
1. Component (A): Aromatic polycarbonate (A-1) Aromatic polycarbonate produced by melt transesterification “Wonderlite PC-110 (registered trademark)” manufactured by Asami Kasei (Tom) Co., Ltd., Taiwan
(This is a bisphenol A polycarbonate produced from bisphenol A and diphenyl carbonate by the melt transesterification method.)
(A-2) Polycarbonate produced by the phosgene method “Iupilon S-2000 (registered trademark)” manufactured by Mitsubishi Engineering Plastics Co., Ltd.

2. Component (B): Carbon Black (B-1) “Ketjen Black EC600JD (registered trademark)” manufactured by Lion Corporation
(B-2) “Ketjen Black EC300J (registered trademark)” manufactured by Lion Corporation
(B-3) “VULCAN XC72 (registered trademark)” manufactured by Cabot Specialty Chemicals Co., Ltd.
(B-4) “Mitsubishi Carbon Black 3400B” manufactured by Mitsubishi Chemical Corporation

3. Component (C): Silicate compound (C-1) “Microace P-3 (registered trademark)” manufactured by Nippon Talc Co., Ltd.
4). Component (D): Organic acid and / or organic acid derivative (D-1) p-toluenesulfonic acid (manufactured by Wako Pure Chemical Industries, Ltd.)

[Examples 1-7 and Comparative Examples 1-5]
Each component was melt kneaded in the amounts shown in Tables 1 and 2 (units are parts by weight) using a twin screw extruder to obtain a resin composition.
Component (B), component (C), and component (D) were premixed for 3 minutes in advance using a super mixer to obtain a mixture.
In Examples 1 to 7 and Comparative Examples 1 to 5, pH values of mixtures of component (B), component (C) and component (D) were measured based on JIS-K5101. The result was shown in.

Ingredients (A) to (D) use a twin screw extruder (ZSK-25, L / D = 37, manufactured by Werner & Pfleiderer). The mixture was melt kneaded. As for the supply of the raw materials, the mixture of the component (B), the component (C) and the component (D) was fed into the extruder from the forefront of the extruder by a weight type feeder different from the component (A).
The melt-kneaded resin composition was extruded into a strand shape and pelletized. The obtained pellets were dried for 5 hours with a hot air circulation dryer set at 120 ° C.

A plate having a length of 120 mm, a width of 60 mm, and a thickness of 2 mm was produced from the dried pellets by an injection molding machine (50D manufactured by FANUC). The plate was prepared by using a mold filled with molten resin through a gate portion having a shape of 2 mm in thickness, 3 mm in width, and 3 mm in length.
In addition, the cylinder set temperature was set to 260 ° C. by a 50 mm single-axis sheet extruder (PG 50-32V, manufactured by Pla Giken) equipped with a T-die, and an opening was provided in the latter part of the extruder and connected to a vacuum pump. Various sheets with thicknesses shown in Table 1 were created at a roll temperature of 130 ° C. (metal surface) and a sheet width of 400 mm while performing vacuum devolatilization at 10 ⁴ [Pa].

The following evaluation was implemented about the used raw material, the obtained injection molding plate, and a sheet | seat.
(1) Specific surface area of carbon black (component (B)) The specific surface area of the used component (B) was measured by the BET method.
(2) pH value of the mixture comprising the components (B), (C) and (D) A mixture comprising the component (B), the component (C) and the component (D) in the ratio shown in Table 1 is based on JIS-K5101. The pH value was measured.

(3) Molded product surface appearance
The surface appearance of the obtained molded product was visually evaluated according to the following evaluation criteria.
[Evaluation criteria for surface appearance of sheet molded products]
As a result of visually observing 5 sheets cut out to a size of 10 cm × 10 cm and observing all 5 sheets,
A: Aggregates having a maximum length of 0.2 mm or more are not observed.
Δ: 1 to 4 aggregates having a maximum length of 0.2 mm or more are observed.
X: Five or more aggregates having a maximum length of 0.2 mm or more are observed.
[Evaluation criteria for surface appearance of injection molded products]
For a plate having a length of 120 mm, a width of 60 mm, and a thickness of 2 mm,
○: There is no silver streak on the surface of the molded product, or it occurs slightly.
X: The silver streak on the surface of the molded product is intense.

(4) Surface resistivity value After the obtained injection-molded plate or sheet was held in an environment of a temperature of 23 ° C. and a humidity of 50% for 2 days, a super insulation meter manufactured by Toa Denpa Kogyo Co., Ltd. (model: SM-8220) The surface resistance value (unit: Ω) was measured under the conditions of an applied voltage of 5 V, an application time of 50 seconds, and a measurement time of 10 seconds using a flat plate electrode (model: SME-8411) manufactured by Toa Denpa Kogyo Co., Ltd.
Measurement samples were arbitrarily selected and measured for each of 5 samples, and the surface resistivity and its stability were evaluated.

(5) Melt stability A molded product having a length of 150 mm, a width of 20 mm, and a thickness of 2 mm was prepared by an injection molding machine (FANUC 50D), and after pulverizing the molded product, the MI value was measured and compared with the initial MI value. The MI increase rate was evaluated according to the following evaluation criteria. The MI value was measured under the conditions of a temperature of 280 ° C. and a load of 2.16 kg. The lower the MI increase rate, the better the melt stability.
[Evaluation criteria]
○: MI increase rate is less than 10%.
Δ: MI increase rate is in the range of 10-30%.
X: MI increase rate exceeds 30%.

(6) Carbon detachability The prepared sheet is fixed to a shaking table, a 20 mm × 20 mm frame is placed on it, an IC is placed therein, and the horizontal direction is 700,000 times at an amplitude of 30 mm and a speed of 450 reciprocations per minute. The amount of carbon adhering to the IC was visually observed.
○: There is almost no carbon adhesion.
Δ: Slight adhesion of carbon is observed.
X: There is much adhesion of carbon.

Examples 1 to 7 are excellent in the appearance of the molded product, obtain a stable surface resistance value, and are excellent in melt stability and carbon detachability.
In Example 3, the blending amount of carbon black based on the total amount of the resin composition is 4% by weight, which is extremely small compared with the blending amount of carbon black required in the conventional polycarbonate-based conductive resin of 5 to 50% by weight. Nevertheless, the surface specific resistance value of 10 ⁵ to 10 ⁷ Ω level is stably expressed.

Comparative Examples 1 to 3 are cases where either component (C) or component (D) or both are not blended. This is an example in which the balance of surface appearance, antistatic properties (surface resistivity), and melt stability is lacking.
Comparative Example 4 is an example in which the blending amount of component (B) is outside the blending amount range defined in the present invention.
Comparative Example 5 is an example of only component (A) and component (B). It can be seen that the balance of surface appearance, surface resistivity, and melt stability is lacking. Furthermore, in Comparative Example 5, when melt-kneading, the feed stability of the component (B) when introduced into the extruder was poor, and the strands were easily cut, so the production stability of the composition was poor.

The resin composition of the present invention exhibits a stable surface resistivity of 10 ² to 10 ¹² Ω, is excellent in mechanical strength and melt stability, and is less contaminated with electronic parts due to less carbon black desorption. An aromatic polycarbonate resin composition and a molded product having a small amount and excellent in dimensional stability and appearance, and extremely useful as a resin composition for electronic component packaging containers.

Claims (6)

Aromatic polycarbonate (A) 100 parts by weight, carbon black (B) 3-30 parts by weight, silicate compound (C) 0.1-40 parts by weight, organic acid and / or organic acid derivative (D) 0.001-0.001 A resin composition comprising 10 parts by weight and having a surface resistivity of 10 ² to 10 ¹² Ω. The specific surface area of a component (B) is the range of 30-1,500 m < ² > / g, The resin composition of Claim 1 characterized by the above-mentioned.   When the pH value of the mixture of component (B), component (C), and component (D) is measured based on JIS-K5101, the weight value of component (D) is the pH value of the mixture. The resin composition according to claim 1, wherein the resin composition is 4 to 9 parts by weight.   The molded article which consists of a resin composition in any one of Claims 1-3.   The molded article according to claim 4, wherein the molded article is an extrusion molded article.   The molded product according to claim 5, wherein the extruded product is a conductive sheet.