JPH0753767A - Production of thermoplastic resin composition containing conductive carbon black - Google Patents

Abstract

PURPOSE:To produce a thermosetting resin compsn. with little variation in conductivity at a high productivity without scattering a carbon black. CONSTITUTION:This resin compsn. comprises 73-97 pts.wt. thermoplastic resin and 27-3 pts.wt. conductive carbon black having a specific surface area of 700-1,500m<2>/g and is produced by feeding the resin to a continuous corotating twin-screw extruder, changing the resin into a gel, feeding the carbon black forcibly into the barrel of the extruder through a side feeder, degassing under normal pressure through a venthole installed on the extruder before the carbon black is completely dispersed in the resin, continuing kneading, and extruding the resulting mixture of the resin and the carbon black through the die.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a thermoplastic resin composition comprising a thermoplastic resin and a specific carbon black and having a small variation in conductivity with high productivity without scattering of carbon black. .

[0002]

2. Description of the Related Art A conductive thermoplastic resin, which is made conductive by blending carbon black with a thermoplastic resin, is
In recent years, there has been a marked increase in demand for electronic parts, computers, home appliances, and other applications such as antistatic and electromagnetic wave shielding applications. As a method for producing such a conductive thermoplastic resin, a method using a continuous twin-screw extruder has been conventionally performed. As a feeding method to the extruder in the manufacturing method using a continuous twin-screw extruder, carbon black and resin are blended in advance with a Henschel mixer or a tumbler mixer, and then fed by various feeders, using a quantitative feeder. A method of quantitatively supplying the resin and the carbon black is generally used. However, since the resin and the carbon black have different true specific gravities, bulk densities, shapes, and the like regardless of which supply method is used, the carbon black in the composition is classified as a result of the classification at the blending stage or after being supplied to the extruder. In some cases, a resin having a stable conductivity with a small difference in conductivity cannot be obtained, which makes it practically unusable.

Further, since the bulk density of carbon black used for giving conductivity to a resin is very low, it contains a large amount of air, and when the carbon black is dispersed in the resin in a twin-screw extruder. Since a large amount of air escapes and the air rises from the carbon black supply port, the carbon black scatters as the air rises. As a result, there are various problems such as a difference in concentration of carbon black in the composition, deterioration of work environment due to scattering of carbon black, and floating carbon black fine particles adhering to the inside of precision machinery and destroying electronic parts inside. Points are also pointed out. Since the blowing up of carbon black has a correlation with the supply amount of carbon black, when the carbon black scatters, the supply amount must be reduced, and therefore the productivity is reduced. As a manufacturing method that can be applied when the raw material is a fine powder, an opening is provided downstream of the material supply port, and the screw configuration between the material supply part and the opening is performed only for melting or kneading without compression of the material. Although a production method based on the constitution has been proposed (Japanese Patent Laid-Open No. 58-29644), in the case of carbon black used in the present invention, it could not be improved even by using this method.

[0004]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a method for producing a thermoplastic resin composition having less variation in conductivity with high productivity without scattering of carbon black.

[0005]

The present invention has been made based on the finding that the above object can be achieved by a specific manufacturing method using a specific carbon black and a continuous type co-rotating twin-screw extruder. It is a thing. That is, the present invention is a method for producing a conductive carbon black-containing thermoplastic composition containing 73 parts by weight to 97 parts by weight of a thermoplastic resin and 27 to 3 parts by weight of conductive carbon black, the method comprising: Specific surface area of carbon black 700 ~
1500 m ² / g of carbon black is used, and a continuous type co-rotating twin screw extruder is forcibly fed from a side feeder after the thermoplastic resin is supplied to the continuous type co-rotating twin screw extruder to cause gelation. The conductive carbon black was fed into the barrel of the, and before the conductive carbon black was completely dispersed in the thermoplastic resin, it was degassed under atmospheric pressure from the degassing holes provided in the continuous type co-rotating twin-screw extruder. Then, the kneading is continued to obtain a kneaded product of the thermoplastic resin and the conductive carbon black from a die, which provides a method for producing a conductive carbon black-containing thermoplastic composition.

The thermoplastic resin used in the present invention has strength, heat resistance, and heat resistance depending on the use of the conductive thermoplastic resin composition.
A thermoplastic resin having moldability is used. For example,
Polyethylene resins such as high-, medium-, low-density polyethylene and linear low-density polyethylene; polypropylene resins; poly-1,2-butadiene resins, ethylene-vinyl acetate copolymers, acrylates of ethylene and methyl, ethyl, propyl, and butyl, or Copolymers with methacrylate, or chlorinated products of these, or mixtures of two or more thereof; polystyrene resins,
Styrene resins such as ABS resin and AS resin; 6-, 6,
Polyamide resin such as 6-, 6,10-, 12-, MXD-nylon resin; polycarbonate resin; polyester resin such as polyethylene terephthalate resin and polybutylene terephthalate resin; polyvinyl chloride resin; thermoplastic urethane resin, thermoplastic polyester Thermoplastic elastomers such as resins; polyacetal resins; modified polyphenylene ether resins; polysulfone resins, modified polysulfone resins, polyallyl sulfone resins, polyketone resins, polyetherimide resins, polyarylate resins, polyphenylene sulfide resins, liquid crystal polymers, polyether monkeys Examples include super engineering resins such as phon resin, polyetheretherketone resin, polyimide resin, polyamideimide resin, and fluororesin.
Among these, high-density polyethylene resin, low-density polyethylene resin, polypropylene resin, polystyrene resin, polycarbonate resin, polyamide resin, polyethylene terephthalate resin, polybutylene terephthalate resin, thermoplastic urethane resin, thermoplastic polyester Resins, polyacetal resins, modified polyphenylene ether resins, polyetherimide resins and polyphenylene sulfide resins are preferred.

The carbon black used in the present invention has a bulk specific gravity of 160 g / l or less and a specific surface area of 700 to 1500 m ² / g.
It preferably has a bulk specific gravity of 150 g / l or less and a specific surface area of 750 to 1300 m ² / g. Bulk specific gravity is more than 160g / l or specific surface area is 700m
^When carbon black having a value smaller than ² / g is used, it becomes difficult to impart conductivity to the obtained resin composition, which is not preferable. The amount of carbon black used in the present invention is 3 to 27 parts by weight, preferably 5 to 22 parts by weight, based on 100 parts by weight of the total amount of carbon black and thermoplastic resin. When the amount is less than 3 parts by weight, it becomes difficult to impart conductivity to the obtained resin composition, and when the amount is more than 27 parts by weight, the strength of the obtained electrically conductive resin composition is significantly reduced. However, it is not preferable because it is not put to practical use. In addition to the above-mentioned essential components, the composition of the present invention may contain known fillers and additives within a range that does not impair the object of the present invention. For example, glass fiber, asbestos fiber, carbon fiber, talc, reinforcing agents such as mica, graphite, inorganic fillers, foaming materials, lubricants, antioxidants, anti-UV agents, coupling agents, flame retardants, heat stabilizers. And so on. These are preferably added to the barrel after the conductive carbon black is dispersed in the thermoplastic resin.

In the manufacturing method of the present invention, when the total barrel length of the co-rotating twin-screw extruder is 100, the thermoplastic resin charging port is located at 0 to 10%, preferably 0 to 7% from the motor side. Should be installed. The resin may be introduced into the barrel by a natural drop from the popper, or may be forcibly supplied into the barrel, but preferably by a natural drop. In the present invention, the thermoplastic resin thus supplied into the barrel is gelated by the kneading action of the screw installed in the barrel and the heating from the outside, and then the conductive resin is forcibly conductive from at least one side feeder. Carbon black is supplied into the barrel to disperse the conductive carbon black in the gelled resin. Here, any side feeder can be used as long as the conductive carbon black can be forcibly supplied into the barrel, but it is preferable to use the method of forcibly supplying with a screw. Specific examples include TWIN FEEDER 251 manufactured by Nakatani Machine. In addition, this side feeder is installed in the barrel at the position where the resin is gelled, and normally 29% from the motor side when the total barrel length of the extruder is 100.
It is suitable to install at a position of -50%, preferably 33% -50%. If the side feeder is installed at a position where the resin does not gel, the carbon black thrown from the side feeder scatters from the resin feeding port or degassing hole to reduce productivity, and the conductive heat has stable conductivity. It is not preferable because a plastic resin cannot be obtained.
Similarly, instead of the feeder, a charging port is provided at the same position, a quantitative feeder is used, and when carbon black is charged by spontaneous falling from the upper part of the charging port, carbon black scatters from this charging port and the productivity decreases, Further, it is not preferable because a conductive thermoplastic resin having stable conductivity cannot be obtained.

In the present invention, before the conductive carbon black is completely dispersed in the thermoplastic resin, for example, 17% upstream to 23% downstream from the installation position of the side feeder.
%, Preferably 13% on the upstream side to 17% on the downstream side, one or more deaeration holes are provided in the barrel, and deaeration is performed from here through atmospheric pressure. When the degassing holes are provided at the same positions as the side feeders, it is preferable that they be spaced at least 45 degrees in the circumferential direction. In particular, it is preferable to provide the deaeration hole at the top (upper side) of the barrel. The size of the deaeration holes varies depending on the size of the extruder, but is suitably typically 1cm ² ~80cm ^2, preferably 1 to 10 cm ^2. When carbon black is introduced without providing deaeration holes, the air contained in the carbon black escapes from the side feeder, and as a result, the carbon black cannot be introduced, resulting in a decrease in productivity, which is not preferable. Known screws are used as the screw of the co-rotating twin-screw extruder used in the present invention, and the diameter is generally 20 mm to 150 mm and the length is generally 20 to 50 times the diameter. As the motor, a known motor is used according to the size of the screw. Known screw parts are also used as extruder screw parts, specifically, as described in Journal of Plastic Molding Processing, "Molding," Volume 3, No. 6 (1991), pages 431 to 403. There are elements, right type (R-KD), left type (L-KD), and neutral type kneading disk (N-KD), and these are in an appropriate order depending on the properties of the resin used and the amount of carbon black compounded. You can also use it at. In particular, if a neutral kneading disc that does not have the ability to convey or backfeed and only performs kneading and / or a light type kneading disc that performs conveying and kneading is placed at the position where the side feeder is installed, the production of carbon black does not occur. It is preferable because the amount is improved.

The thermoplastic resin of the present invention is charged using a known feeder from the resin charging port provided at the above-mentioned position, but for the purpose of obtaining a conductive thermoplastic resin composition having stable conductivity. It is preferable to use a gravimetric quantitative feeder having a quantitative accuracy within ± 1%. Further, the carbon black of the present invention is forcibly supplied by the side feeder after gelling the resin. For the purpose of obtaining a conductive thermoplastic resin composition having stable conductivity, the screw of the side feeder is rotated in advance so that it can be charged at a higher speed than the charging speed of carbon, and the carbon black has a quantitative accuracy within ± 1%. It is preferable to drop onto the screw of the side feeder using a gravimetric quantitative feeder, and then forcefully feed into the extruder by the side feeder. The gravimetric quantitative feeder used to feed the resin and carbon black uses the interlocking type feeder in which the feed amount of the other feeder also changes according to the change of the feed amount of the one feeder. It is particularly preferable because the conductivity is more stable.

The temperature of the barrel of the co-direction twin-screw extruder used in the present invention is determined by the gelling temperature of the thermoplastic resin used, and is set at a temperature 30 ° C to 150 ° C higher than the gelling temperature of the resin and stable. In order to obtain the conductive resin composition, the temperature from the upstream side of the barrel where the side feeder is installed to the position where the degassing holes are installed is 10% higher than the temperature of the barrel of the resin. The temperature of the barrel downstream from the position where the degassing holes are installed is set to 60 ° C to 150 ° C, preferably 70 ° C to 150 ° C, preferably 30 ° C to 70 ° C, preferably 30 ° C to 60 ° C.
It is desirable to set the temperature higher by ℃. The rotation speed of the screw may be, for example, about 100 to 300 rpm. In the present invention, after degassing under normal pressure, the kneading is continued, and the kneaded product of the thermoplastic resin and the conductive carbon black is discharged from the die in any form, for example, in the form of a sheet, a pellet, a line, or the like. Obtainable.

[0012]

EFFECTS OF THE INVENTION According to the present invention, a conductive thermoplastic resin composition having stable conductivity can be obtained in a good production amount without scattering of carbon black. Therefore, the conductive resin composition obtained by the present invention can be used in various applications such as electromagnetic shielding materials, coating materials for high voltage cables, ignition cords, planar heating elements, planar switches, and other conductive materials such as electrodes. It can be used in many fields such as application to packaging materials such as electronic devices and ICs and holding materials for testing. Further, since the production method of the present invention is suitable for obtaining a composition in which powder is filled in a resin, when filling an inorganic filler or metal having a low bulk specific gravity or when obtaining a plastic magnet or a high specific gravity plastic It can also be applied as a manufacturing method in the case of highly filling a resin with powder such as. Next, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples.

[0013]

【Example】

Example 1 Four kinds of continuous type co-rotating twin-screw extruders (screw diameter: 57 mm, L / L) shown schematically in (A) to (D) of FIG.
D: 36, using a NR-II 57 mm co-rotating twin-screw vent type extruder manufactured by Nakatani Machinery, 90 parts by weight of a polycarbonate resin (Taflon A-220 manufactured by Idemitsu Petrochemical Co., Ltd.)
0) and bulk specific gravity of 140 g / l, specific surface area of 810 m2 / g
10 parts by weight of carbon black of Example 1 was added by the method shown in Table 1 to obtain a conductive resin composition at a screw rotation speed of 220 rpm. In FIG. 1, 1 to 12: barrel zone, 13:
Dice, 14: resin charging port, 15: closed side feeder, 16: carbon black charging port, 17: degassing hole (4 cm x 4 cm square), 18: degassing hole (4 cm x 4 cm square), 19: motor is there. In addition, barrel zone 1
The length of each zone of ~ 12 is 1/12 of the length when the total length of the barrel is 100. The screw configuration is such that the materials are not compressed in the barrel zones 1 to 5 and melting, kneading, and carrying are performed, the barrel zones 6 and 8 are kneading, compressing, and carrying, and the others are compressing and carrying. .

The method of adding the resin and carbon black is as follows. Charge method A : As shown in FIG. 1 (A), a mixture of resin and carbon black is allowed to fall naturally from a charge port installed in 14 using a quantitative feeder (Kuma Engineering's Arcureate 602 type). Thus, it was charged into a twin-screw extruder. The deaeration hole is provided at the 17th position. Feeding method B : As shown in FIG. 1 (B), a twin-screw extruder is prepared by allowing the resin to spontaneously drop from a feeding port installed at 14 using a quantitative feeder (Arcrate 602 model, Kuma Engineering). In addition, in the figure, the screw of the side feeder (TWIN FEEDER 251 made by Nakatani Machinery) installed at 15 in the figure was rotated so that it could be fed at a higher speed than the feeding speed of carbon black, and the fixed amount feeder (made by Kuma Engineering Co., Ltd. Carbon black was naturally dropped on the screw using an arcuate 602 type), and was forcibly supplied into the twin-screw extruder by a side feeder. The deaeration hole is provided at the 17th position.

Feeding method C : As shown in FIG. 1 (C), the resin is naturally dropped from a feeding port provided at 14 by using a quantitative feeder (Kuma Engineering Arcureate 602 type). It is charged into the axial extruder, and the screw of the side feeder (TWIN FEEDER 251 made by Nakatani Machinery) installed at 15 in the figure is rotated so that it can be charged at a higher speed than the charging speed of carbon black, and the quantitative feeder ( Carbon black was naturally dropped on the screw using Kuma Engineering Arcureate 602 type, and was forcibly supplied into the twin-screw extruder by a side feeder. The deaeration holes are provided at the 18th position. Feeding method D : As shown in FIG. 1 (D), a twin-screw extruder is prepared by allowing the resin to spontaneously drop from a feeding port installed at 14 using a quantitative feeder (Kurma Engineering's Arcurate 602 type). Carbon black was fed into the twin-screw extruder by allowing the carbon black to drop naturally from a feeding port installed at 16 in the figure using a quantitative feeder (Arcrate 602 model, manufactured by Kuma Engineering). The deaeration hole is provided at the 17th position.

The temperature conditions of the twin screw extruder are as follows. Temperature condition 1: Barrel zone 1; Cooling barrel zone 2
~ 6; 320 ° C barrel zone 7 to 12; 280 ° C, die; 280 ° C Temperature condition 2: barrel zone 1; cooling barrel zone 2
~ 6; 320 ° C barrel zone 7 to 12; 320 ° C, die; 280 ° C temperature condition 3: barrel zone 1; cooling barrel zone 2
~ 6; 240 ° C barrel zone 7 ~ 12; 280 ° C, die; 280 ° C The screw parts of the barrel zone 5 in which the side feeder is installed are as follows. 4N: 4K type kneading disc made by Nakatani Machinery 41: 41 type screw element made by Nakatani Machinery 3N: 3N type kneading disc made by Nakatani Machinery 31: 3R type kneading disc made by Nakatani Machinery

Table 1 shows how to add the thermoplastic resin and carbon black, the type of screw parts at the same position as the side feeder is installed, the temperature setting conditions for each barrel, and the resin gel at position 5 in FIG. Status,
Maximum discharge amount when carbon black is not scattered at all,
The scattering state of carbon black and the volume resistivity value of the obtained conductive resin composition when the discharge rate is 80 kg / hr are shown. The gelation state of the resin is represented by ◯ when the resin is gelled at position 5 in FIG. 1 and by x when it is not gelled. The scattering state of carbon black was evaluated as ◯ when the carbon black did not scatter, and as × when the carbon black scatters violently. Further, the volume resistivity value was obtained by press-molding the obtained thermoplastic resin composition to prepare 5 points of 10 cm × 10 cm × 0.2 cm samples, and the volume resistivity values of these samples were measured by SRIS-2301. It measured according to the measuring method, and the maximum value and the minimum value are shown in Table-1.

[0018]

[Table 1] Table-1 No. 1 2 3 4 5 6 * 7 * 8 * 9 * How to add resin and carbon black B B B B B D D AC B Screw parts (position 5) 4N 41 4N 3R 3N 41 41 41 41 Temperature conditions of each barrel 1 1 2 2 2 1 1 1 1 3 Gelation of resin Condition ○ ○ ○ ○ ○ ○ ○ ○ × (Position 15) Maximum discharge rate (kg / hr) 120 110 110 120 120 55 30 30 35 ○ ○ ○ ○ ○ × × × × scattering volume resistivity maximum of carbon black Value (Ω ・ cm) 52 64 63 53 54 250 1500 3300 2300 Minimum value (Ωcm) 42 44 45 43 42 54 50 57 58 In the table, 6 * to 9 * are comparative examples. The maximum discharge rate (kg / hr) is
The maximum discharge amount of carbon black without scattering
Moreover, the dispersion of carbon black is set at a discharge rate of 80 kg / hr.
The scattering state of carbon black is shown below.

From the results shown in Table 1, according to the method of the present invention,
There is no scattering of carbon black, and the discharge amount is 110-12
It can be seen that the productivity is 0 kg / hr and the productivity is good, and that the conductive thermoplastic resin composition obtained by this method shows stable conductivity without variation in the volume resistivity value. On the other hand, as a comparative example, No. 6 (a method in which carbon black is charged by natural dropping from the charging port at the same barrel position instead of the side feeder), No. 7 (carbon black by natural falling from the charging port for charging resin) No. 8) (method in which there is no deaeration hole at position 17), No. 9 (method when the resin at the position where carbon black is charged by the side feeder has not gelled), the discharge amount is 80 kg. In the case of / hr, the carbon black scatters violently, and in order to prevent the scattering, the discharge amount must be reduced to 1/2 to 1/3 of that of the manufacturing method of the present invention, and therefore the productivity may decrease. Recognize. Further, even in a conductive thermoplastic resin composition produced with reduced productivity, the variation in conductivity is 4 to 55 times (volume specific resistance maximum value / volume specific resistance value minimum), which is not practically used.

Example 2 A continuous type co-rotating twin-screw extruder (screw diameter: 57 mm, L / D: 36, manufactured by Nakatani Machinery) equipped with a resin charging port, a degassing hole, and a forced side feeder shown in FIG. NR-
II 57 mm co-rotating twin screw vent type extruder)
A predetermined amount of the thermoplastic resin was charged from 33 charging ports by the same method as in Example 1, and a predetermined amount of carbon black was forcibly supplied by the side feeder of 34, and the conductive resin composition was rotated at a screw rotation speed of 220 rpm. I got a thing.
In the figure, 36 glass fiber inlets were sealed when the composition did not contain glass fibers. The screw configuration is shown in Figure 2.
In the barrel zones 20 to 24 of the material melt without compression of the material,
The composition was such that kneading and transportation were performed, the barrel zones 25 and 27 were configured to perform kneading, compression and transportation, and the other zones were configured to perform compression and transportation. The length of each of the barrel zones 20 to 31 is 1 when the total length of the barrel is 100.
It is half the length. In Table-2, composition, type of screw parts at the same position where the side feeder is installed, temperature setting conditions of each barrel zone, Fig. 2, 34
The gelled state of the resin at the position, the maximum discharge amount when carbon black does not scatter, and the volume specific resistance value of the obtained conductive resin composition are shown. The gelation state and volume resistivity of the resin were evaluated by the same method as that described in Example 1.

The types of thermoplastic resin, carbon black and glass fiber used in Example 2 and the set temperature of the barrel of the twin-screw extruder are shown below. Thermoplastic resin used Polypropylene resin (PP): Idemitsu Polypro J-750
H (manufactured by Idemitsu Petrochemical) Polybutylene terephthalate resin (PBT): Toray PB
T1401X04 (Toray) Modified polyphenylene ether resin (M-PPE): Noryl 115 (Nippon GE Plastics) Polyetherimide resin (PEI): Ultem 1010
(Manufactured by Nippon GE Plastics) Polyethylene terephthalate resin (PET): Vyroppet EMC307 × 04 (Toyobo)

Glass fiber: CS03MA416 (made by Asahi Fiber Glass) Carbon black A: Bulk specific gravity: 140 g / l, specific surface area: 810 m2 / g carbon black B: Bulk specific gravity: 125 g / l, specific surface area: 1240 m2 / g Carbon black C: Bulk specific gravity: 250 g / l, specific surface area: carbon black having a specific surface area of 70 m2 / g Temperature condition 4: Barrel zone 20; Cooling barrel zone 21-26; 280 ° C, barrel zone 27-31; 24
0 ° C., die; 240 ° C. Temperature condition 5: Barrel zone 20; Cooling Barrel zone 21-26; 320 ° C., barrel zone 27-31; 28
0 ° C, die; 280 ° C Temperature condition 6: Barrel zone 1; Cooling Barrel zone 2
~ 6; 380 ° C, barrel zones 7-12; 370 ° C, dies; 370 ° C

[0023]

[Table 2] Table-2 No. 10 11 12 13 14 15 16 * 17 * 18 * Composition (parts by weight) PP 95 0 0 0 0 75 0 0 0 PBT 0 90 0 0 0 0 98 0 0 M-PPE 0 0 0 85 0 0 0 70 75 PEI 0 0 0 0 93 0 0 0 0 PET 0 0 88 0 0 0 0 0 0 Glass fiber 0 0 0 30 10 0 0 0 0 Carbon black A 0 10 0 15 7 25 2 0 0 Carbon black B 5 0 12 0 0 0 0 30 0 Carbon black C 0 0 0 0 0 0 0 0 25 Screw parts * 1 4N 4N 4N 4N 4N 4N 4N 4N 4N Resin gelation condition ○ ○ ○ ○ ○ ○ ○ ○ ○ (Position 24) Installation temperature of each zone 4 5 5 5 6 6 4 5 5 5 5 Conditions Maximum discharge rate (kg / hr) 120 130 110 110 130 110 160 −^* 90 Volume resistivity maximum value (Ωcm) 54 78 3.2 84 82 1.2 ** −^*5.4 × 10^Ten Minimum value (Ωcm) 39 59 2.8 69 71 1.1 ** −^*3.2 × 10 ⁸  In the table, 16 * to 18 * are comparative examples. Maximum discharge rate (kg / hr)
Is the maximum discharge amount without carbon black scattering
is there. * 1 Screw parts installed in barrel zone 24^*: No carbon black scattering, but Torqua
However, the conductive resin composition could not be obtained. **: All 10¹⁶that's all

[0024]

[Brief description of drawings]

FIG. 1 shows an outline of a continuous type co-rotating twin-screw extruder for carrying out the present invention.

FIG. 2 shows an outline of another continuous type co-rotating twin-screw extruder for carrying out the present invention. In the figure, 1 to 12 and 20 to 31 are barrel zones, 13 and 32 are dies, 14 and 33 are resin inlets, 15 and 34 are side feeders, 16 is a carbon black inlet, 17, 18 and 35 are deaeration holes. , 19 and 37 are motors.

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Hideo Komatsu 1-3-7 Main Office, Sumida-ku, Tokyo Lion Corporation

Claims (3)

[Claims] 1. A method for producing a conductive carbon black-containing thermoplastic composition comprising 73 parts by weight to 97 parts by weight of a thermoplastic resin and 27 to 3 parts by weight of conductive carbon black. Carbon black with a specific surface area of 700-1500 m ² / g is used as black.
In addition, after feeding the thermoplastic resin to the continuous type co-rotating twin-screw extruder to cause gelation, conductive carbon black is forcibly fed into the barrel of the continuous type co-rotating twin-screw extruder from the side feeder. , Before the conductive carbon black is completely dispersed in the thermoplastic resin, after degassing at atmospheric pressure from the degassing holes provided in the continuous type co-rotating twin-screw extruder, the kneading is continued, and the thermoplastic resin is discharged from the die. A method for producing a conductive carbon black-containing thermoplastic composition, which comprises obtaining a kneaded product of a resin and a conductive carbon black. 2. When the total barrel length of the continuous type co-rotating twin-screw extruder is set to 100, 17% upstream to 23% downstream from the position where the side feeder is connected to the barrel.
The manufacturing method according to claim 1, wherein deaeration is performed through a deaeration hole provided at a position of%. 3. A neutral type kneading disk and / or a conveying and kneading machine provided with a conductive carbon black forcibly supplied from a side feeder into the barrel and having only kneading without conveying or reverse feeding ability. The manufacturing method according to claim 1, wherein the manufacturing method is supplied to a light type kneading disk for kneading.