JP6121742B2 - Conductive thermoplastic resin composition and cable - Google Patents

Description

  The present invention relates to a conductive thermoplastic resin composition and a cable.

  In a cable such as a power cable or a lead cable for a quick charger, a conductive layer such as a semiconductive layer may be provided between the conductive wire and the insulating layer surrounding the conductive wire and outside the insulating layer.

As a material for such a conductive layer, for example, the following cited document 1 discloses a resin composition for a semiconductive layer of a power cable obtained by blending carbon black having a specific surface area of 1000 m ² / g or more into an ethylene copolymer. Things are disclosed.

Japanese Patent Laid-Open No. 9-298012

  By the way, in addition to having favorable electroconductivity, the conductive layer of the cable is required to have sufficient heat deformation resistance. This is due to the following reason. That is, if the resistance to heat deformation of the cable is insufficient, the conductive layer included in the cable is crushed when subjected to a load, which may adversely affect the cable characteristics. In particular, when the cable is laid in a high temperature area or a lead cable connected to a quick charger of an electric vehicle, it is desirable that the conductive layer of the cable has a sufficient heat deformation resistance.

  However, the resin composition for a semiconductive layer described in Patent Document 1 cannot be said to have sufficient heat deformation resistance, and has room for further improvement.

  The present invention has been made in view of the above circumstances, and a conductive thermoplastic resin composition capable of ensuring excellent heat distortion resistance while ensuring excellent conductivity, and the same are used. The purpose is to provide a cable.

  In order to solve the above-mentioned problems, the present inventor has intensively studied focusing on the characteristics of the carbon material to be blended with the thermoplastic resin. As a result, the inventor includes a carbon material having a specific surface area in a specific range in the resin composition, and the parameter obtained by multiplying the specific surface area of the carbon material by the content ratio of the carbon material is defined as the specific range. As a result, it has been found that the above problems can be solved, and the present invention has been completed.

That is, the present invention is a conductive thermoplastic resin composition comprising a thermoplastic resin and a carbon material, wherein the thermoplastic resin consists only of a polyvinyl chloride resin and an ethylene vinyl acetate copolymer, and the carbon the specific surface area of the material is 600~2240m ² / g, and a conductive thermoplastic resin composition having a specific surface area of 195 ~561m ² / g per the electrically conductive thermoplastic resin composition unit mass.

According to the conductive thermoplastic resin composition of the present invention, it is possible to ensure excellent heat deformation resistance while ensuring excellent conductivity. Moreover, since the said thermoplastic resin contains a polyvinyl chloride resin, the said conductive thermoplastic resin composition has the outstanding softness | flexibility. Furthermore, since the said thermoplastic resin contains the ethylene vinyl acetic acid copolymer as a polyethylene-type resin, the said conductive thermoplastic resin composition has a more excellent heat deformation characteristic.

  About the reason why the conductive thermoplastic resin composition of the present invention can ensure excellent conductivity, the present inventor presumes as follows.

  That is, when the specific surface area of the carbon material contained in the conductive thermoplastic resin composition is sufficiently large and the specific surface area per unit mass of the conductive thermoplastic resin composition is sufficiently large, between the adjacent carbon material particles. Part of the intervening thermoplastic resin is adsorbed on the surface of the carbon material particles. As a result, the distance between adjacent carbon material particles is reduced. The inventor infers that the conductive thermoplastic resin composition can ensure excellent conductivity by this action.

  In addition, the present inventors speculate as follows about the reason why excellent heat distortion resistance characteristics can be obtained in the conductive thermoplastic resin composition of the present invention.

  That is, carbon material particles such as carbon black are aggregated to form an aggregated structure (structure), and the carbon material with the developed structure has a large specific surface area. When the structure of the carbon material contained in the conductive thermoplastic resin composition is developed, the specific surface area is sufficiently large, and the specific surface area per unit mass of the conductive thermoplastic resin composition is sufficiently large, the above carbon The material becomes pseudo-crosslinked by a large structure. The inventor presumes that the conductive thermoplastic resin composition has excellent heat deformation resistance due to this action.

  The present invention is a cable comprising at least one conductive wire and a conductive layer surrounding the conductive wire, wherein the conductive layer is made of the above conductive thermoplastic resin composition.

  According to the cable of the present invention, since the conductive layer is made of the above conductive thermoplastic resin composition, it is possible to ensure excellent heat deformation resistance.

  In the present invention, the specific surface area of the carbon material is measured by the BET method.

In the present invention, the specific surface area per unit mass of the conductive thermoplastic resin composition is defined by the following formula.
[Specific surface area per unit mass of conductive thermoplastic resin composition (m ² / g)]
= [Specific surface area of carbon material (m ² / g)] × [Content of carbon material in conductive thermoplastic resin composition (mass%)] × (1/100)

  ADVANTAGE OF THE INVENTION According to this invention, the conductive thermoplastic resin composition which can ensure the outstanding heat-deformation characteristic, ensuring the outstanding electroconductivity, and a cable using the same are provided.

It is sectional drawing which shows 1st Embodiment of the cable of this invention. It is sectional drawing which shows 2nd Embodiment of the cable of this invention.

  Hereinafter, an embodiment of the present invention will be described in detail with reference to FIGS.

[First Embodiment]
First, a first embodiment of the cable of the present invention will be described with reference to FIG. FIG. 1 is a cross-sectional view of a power cable as a first embodiment of the cable of the present invention.

  As shown in FIG. 1, the cable 100 includes a conductive wire 1, an internal semiconductive layer 2 surrounding the conductive wire 1, an insulating layer 3 surrounding the internal semiconductive layer 2, and an external semiconductive layer surrounding the insulating layer 3. 4 and a sheath 5 surrounding the outer semiconductive layer 4.

Here, the inner semiconductive layer 2 and the outer semiconductive layer 4 are made of a conductive thermoplastic resin composition, and the conductive thermoplastic resin composition includes a thermoplastic resin and a carbon material. Here, the specific surface area of the carbon material is 600 to 2240 m ² / g, and the specific surface area per unit mass of the conductive thermoplastic resin composition is 130 to 561 m ² / g.

  The inner semiconductive layer 2 and the outer semiconductive layer 4 made of the conductive thermoplastic resin composition can ensure excellent heat distortion resistance while ensuring excellent conductivity. For this reason, when the cable 100 receives a load, the internal semiconductive layer 2 and the external semiconductive layer 4 are not easily crushed, and it is possible to sufficiently suppress an adverse effect on the characteristics of the cable 100.

<Cable manufacturing method>
Next, a method for manufacturing the cable 100 described above will be described.

(Conductor)
First, the lead wire 1 is prepared. The conducting wire 1 may be composed of only one strand, or may be configured by bundling a plurality of strands. Moreover, the conducting wire 1 is not specifically limited about a conductor diameter, the material of a conductor, etc., It can determine suitably according to a use.

(Internal semiconductive layer and external semiconductive layer)
Next, a conductive thermoplastic resin composition for forming the inner semiconductive layer 2 and the outer semiconductive layer 4 is prepared. The conductive thermoplastic resin composition includes a thermoplastic resin and a carbon material, the specific surface area of the carbon material is 600 to 2240 m ² / g, and the conductive thermoplastic resin composition per unit mass. The specific surface area is 130 to 561 m ² / g.

(Thermoplastic resin)
Although the thermoplastic resin contained in the said conductive thermoplastic resin composition is not specifically limited, It is preferable that the said thermoplastic resin contains a polyvinyl chloride resin.

  In this case, the conductive thermoplastic resin composition has more excellent flexibility.

  The average degree of polymerization of the polyvinyl chloride resin is not particularly limited, but is preferably 1000 to 5000. The average degree of polymerization of the polyvinyl chloride resin is more preferably 1000 or more and less than 2000. In this case, as a cable application material, the advantage that it is excellent in a physical property, workability, and handleability is acquired. The “average degree of polymerization” refers to the average degree of polymerization obtained by estimating and converting the specific viscosity of the polyvinyl chloride resin measured according to JIS K6720-2 according to JIS K6720-1.

  The polyvinyl chloride resin is usually contained in the thermoplastic resin in an amount of 15 to 100% by mass, but preferably 15 to 80% by mass. In this case, the conductive thermoplastic resin composition has further excellent flexibility. The content of the polyvinyl chloride resin in the thermoplastic resin is more preferably 15 to 75% by mass. Here, when the content rate of the polyvinyl chloride resin in the thermoplastic resin is less than 100% by mass, the thermoplastic resin includes a resin other than the polyvinyl chloride resin. Here, the resin other than the polyvinyl chloride resin is not particularly limited, but examples of such a resin include ethylene vinyl acetate copolymer (EVA), ethylene ethyl acrylate copolymer (EEA), and chlorine. And polyethylene glycol, ethylene-methyl acrylate (EMA), ethylene butyl acrylate (EBA), and modified polyolefin. These can be used alone or in combination of two or more.

  Further, the thermoplastic resin may include at least one resin selected from the group consisting of a polyethylene resin and a polypropylene resin instead of the polyvinyl chloride resin. Here, the polyethylene-based resin refers to a resin including a structural unit derived from ethylene, and the polypropylene-based resin refers to a resin including a structural unit derived from propylene.

  In this case, the conductive thermoplastic resin composition can have better heat deformation resistance.

  Examples of the polyethylene resin include ethylene, α-olefin copolymers such as polyethylene, ethylene-propylene copolymer, ethylene-1-butylene copolymer, ethylene-methyl acrylate copolymer (EMA), ethylene- Ethylene acrylate copolymers (EEA), ethylene-alkyl acrylate copolymers such as ethylene-butyl acrylate copolymer (EBA), maleic anhydride modified polyethylene, maleic anhydride modified ethylene-propylene copolymer, anhydrous Acid-modified ethylene-α-olefin copolymers such as maleic acid-modified ethylene-1-butene copolymer, ethylene-vinyl acetate copolymer (EVA), chlorinated polyethylene, ethylene-propylene-diene rubber (EPDM), and nitrile rubber (NBR) and the like. These can be used alone or in combination of two or more.

  Examples of the polypropylene resin include propylene-α-olefin copolymers such as polypropylene and propylene-1-butene copolymer, maleic anhydride-modified polypropylene, maleic anhydride-modified propylene-1-butene copolymer, and the like. Acid-modified propylene-α-olefin copolymer, chlorinated polypropylene, and the like. These can be used alone or in combination of two or more.

  60-100 mass% of at least 1 sort (s) of resin chosen from the group which consists of said polyethylene-type resin and polypropylene-type resin may be contained in a thermoplastic resin. In this case, the conductive thermoplastic resin composition can further have excellent heat deformation resistance.

  The thermoplastic resin may contain a resin other than the polyethylene resin and the polypropylene resin instead of the polyvinyl chloride resin. Examples of such a resin include thermoplastic polyurethane resin (TPU), thermoplastic elastomer resin (TPE), methacrylbutadiene styrene resin (MBS), and acrylonitrile butadiene styrene resin (ABS). These can be used alone or in combination of two or more.

  In the conductive thermoplastic resin composition, the content of the thermoplastic resin in the component other than the carbon material is not particularly limited, but the content of the thermoplastic resin in the component other than the carbon material is Preferably it is 32-100 mass%, More preferably, it is 40-70 mass%.

(Carbon material)
The carbon material contained in the conductive thermoplastic resin composition is not particularly limited as long as it imparts sufficient conductivity and sufficient heat deformation resistance to the conductive thermoplastic resin composition. . Examples of the carbon material include carbon black, graphite, glassy carbon, carbon fiber, and carbon nanotube. These can be used alone or in combination of two or more. Among these, carbon black is particularly preferable.

As described above, the specific surface area of the carbon material is 600 to 2240 m ² / g. When the specific surface area of the carbon material is less than 600 m ² / g, sufficient heat deformation resistance cannot be imparted to the conductive thermoplastic resin composition. Moreover, when the specific surface area of a carbon material exceeds 2240 m < ² > / g, since a carbon material adsorb | sucks a thermoplastic resin too much, workability will fall.

Preferably the specific surface area of the carbon material is 600~1800m ² / g, more preferably from 600~1500m ² / g.

The specific surface area per unit mass of the conductive thermoplastic resin composition is 130 to 561 m ² / g. When the specific surface area per unit mass of the conductive thermoplastic resin composition is less than 130 m ² / g, the conductive thermoplastic resin composition cannot ensure sufficient heat deformation resistance. Moreover, when the specific surface area per unit mass of the said conductive thermoplastic resin composition exceeds 561 m < ² > / g, workability will fall.

Preferably the specific surface area per mass conductive thermoplastic resin composition units are 130~400m ² / g, more preferably from 130~350m ² / g.

  The conductive thermoplastic resin composition includes a plasticizer, a stabilizer, a flame retardant, a filler, a surface treatment agent, a drip inhibitor, a processing aid, an activator, an anti-aging agent, a crosslinking agent, a crosslinking aid, and a scorch prevention. You may further contain an agent etc. as needed. In particular, when the thermoplastic resin includes a polyvinyl chloride resin, it is preferable to include a plasticizer. In this case, more excellent heat deformation resistance can be ensured. Examples of the plasticizer include phthalic acid esters such as diisononyl phthalate and di (2-ethylhexyl) phthalate, adipic acid esters, trimellitic acid esters, low molecular weight polyesters, phosphoric acid esters, citric acid esters, epoxy plasticizers, Examples thereof include sebacic acid ester, azelaic acid ester, maleic acid ester, and benzoic acid ester. The content of the plasticizer in the conductive thermoplastic resin composition is preferably 1 to 50% by mass, more preferably 10 to 40% by mass.

  The conductive thermoplastic resin composition can be obtained by kneading a thermoplastic resin, a carbon material, and various additives as required. The kneading can be performed with a kneading machine such as a Banbury mixer, a tumbler, a pressure kneader, a kneading extruder, a twin screw extruder, a mixing roll, and the like.

(Insulating layer and sheath)
Next, an insulating material for forming the insulating layer 3 and the sheath 5 is prepared. Any insulating material may be used as long as it exhibits insulating properties. Examples of such insulating materials include polyethylene, polypropylene, ethylene butadiene diene rubber (EPDM), polyvinyl chloride resin (PVC), chlorinated polyethylene resin (CPE), ethylene vinyl acetate copolymer (EVA), and ethylene ethyl acrylate. (EEA), chloroprene rubber (CR), polyester resin, thermoplastic polyurethane resin (TPU), natural rubber (NR), and the like can be used. These can be used alone or in combination of two or more.

  Then, the conductive wire 1 forms a conductive thermoplastic resin composition for forming the internal semiconductive layer 2, an insulating material for forming the insulating layer 3, and the external semiconductive layer 4 by, for example, a coextrusion molding method. The conductive thermoplastic resin composition for forming the sheath 5 and the insulating material for forming the sheath 5 are sequentially coated.

  The cable 100 is obtained as described above.

[Second Embodiment]
Next, 2nd Embodiment of the cable of this invention is described using FIG. FIG. 2 is a cross-sectional view of a cable connected to a quick charger of an electric vehicle as a second embodiment of the cable of the present invention.

  As shown in FIG. 2, the cable 200 includes a collective cable 210, a conductive layer 220 provided so as to surround the collective cable 210, and a sheath 230 provided so as to surround the conductive layer 220. The collective cable 210 includes two power lines 240 and two sets of signal lines 250 and 260. The power line 240 is composed of the conductive wire 1 and the insulating layer 241 surrounding the conductive wire 1, and the signal line 250 is composed of the two insulated wires 252 composed of the conductive wire 1 and the insulating layer 251 surrounding the conductive wire 1, 2 And an intermediate member 253 surrounding the insulated wire 252 of the book. The signal line 260 includes seven insulated wires 252 and a medium 263 that surrounds the seven insulated wires 252. The two power lines 240 and the two sets of signal lines 250 and 260 are twisted and wound with a mesh tape (not shown) or the like. Here, the material of the insulating layer 241 and the insulating layer 251 is composed of the same material as that of the insulating layer 3, for example. Further, the interposition materials 253 and 263 are made of, for example, jute.

  The material of the conductive layer 220 is made of the conductive thermoplastic resin composition. The material of the sheath 230 is made of the same material as that of the sheath 5, for example.

  In the cable 200, since the conductive layer 40 is made of the conductive thermoplastic resin composition, the conductive layer 40 can secure excellent heat distortion resistance in addition to ensuring excellent conductivity. Can do. For this reason, according to the cable 200, even if the electroconductive layer 40 receives a load, it becomes difficult to be crushed and it can fully suppress the fall of an electrical property.

  The present invention is not limited to the above embodiment. For example, in the first embodiment, the inner semiconductive layer 2 and the outer semiconductive layer 4 of the cable 100 are made of the conductive thermoplastic resin composition of the present invention. One of the layers 4 may be composed of a general semiconductive resin composition that does not satisfy the requirements of the present invention, and only the other may be composed of the conductive thermoplastic resin composition of the present invention.

  Hereinafter, the content of the present invention will be described more specifically with reference to examples. However, the present invention is not limited to the following examples.

<Preparation of conductive thermoplastic resin composition and cable>
The following were used as raw materials for the conductive thermoplastic resin composition.
(1) Thermoplastic resin (A) Polyvinyl chloride resin (PVC)
PVC-1: Average polymerization degree 1000 (manufactured by Taiyo PVC Co., Ltd., trade name “TH-1000”)
PVC-2: Average polymerization degree 1350 (manufactured by Taiyo PVC Co., Ltd., trade name “TH-1400”)
PVC-3: Average polymerization degree 2000 (manufactured by Taiyo PVC Co., Ltd., trade name “TH-2000”)
PVC-4: Average polymerization degree 2800 (manufactured by Taiyo PVC Co., Ltd., trade name “TH-2800”)
PVC-5: Average polymerization degree 4500 (manufactured by Taiyo PVC Co., Ltd., trade name “TU-400”)

(B) Polyethylene resin (B-1) Ethylene-vinyl acetate copolymer (EVA)
EVA-1: vinyl acetate content 19% by mass (Mitsui / DuPont Polychemical Co., Ltd., trade name “Evaflex EV460R”)
EVA-2: vinyl acetate content 33% by mass (Mitsui / DuPont Polychemical Co., Ltd., trade name “Evaflex EV180”)
EVA-3: vinyl acetate content 33% by mass (Mitsui / DuPont Polychemical Co., Ltd., trade name “Evaflex EV150”)
(B-2) Ethylene-ethyl acrylate copolymer (EEA)
EEA-1: ethyl acrylate content 23% by mass (manufactured by Nihon Unicar Co., Ltd., trade name “NUC6510”)
EEA-2: ethyl acrylate content 15% by mass (manufactured by Nippon Polyethylene Co., Ltd., trade name “RESQUE PEARL A1150”)
EEA-3: Ethyl acrylate content 16% by mass (Mitsui / DuPont Polychemical Co., Ltd., trade name “Elvalloy 2116”)
(B-3) Chlorinated polyethylene (chlorinated PE): Chlorine content 40% by mass (manufactured by Showa Denko KK, trade name “Elaslene 404B”)
(B-4) Ethylene-methyl acrylate copolymer (EMA): Methyl acrylate content 25% by mass (trade name “Elvalloy 1125” manufactured by Mitsui DuPont Polychemical Co., Ltd.)
(B-5) Ethylene-butyl acrylate copolymer (EBA): butyl acrylate content 17% by mass (Mitsui / DuPont Polychemical Co., Ltd., trade name “Elvalloy 3117”)
(B-6) Modified polyethylene (modified PE): Maleic anhydride modified ethylene-1-butene copolymer (Mitsui Chemicals, trade name “Toughmer MA8510”)

(C) Polypropylene-based resin-modified polypropylene (modified PP): propylene-1-butene copolymer (Mitsui Chemicals, trade name “Toughmer XM5070”)

(2) Carbon material Carbon material-1: Ketjen black, specific surface area 1300 m ² / g, oil absorption (DBP oil absorption) 495 mL / 100 g (product name “EC600JD”, manufactured by Lion Corporation)
Carbon material-2: Ketjen black, specific surface area 800 m ² / g, oil absorption (DBP oil absorption) 360 mL / 100 g (manufactured by Lion, trade name “EC300J”)
Carbon material-3: Carbon black, specific surface area 254 m ² / g, oil absorption (DBP oil absorption) 174 mL / 100 g (trade name “Vulcan XC-72” manufactured by Cabot Corporation)
Carbon material-4: Acetylene black, specific surface area 68 m ² / g, oil absorption (DBP oil absorption) 125 mL / 100 g (manufactured by Denki Kagaku Kogyo Co., Ltd., trade name “DENKA BLACK”)

(3) Filler calcium carbonate: specific surface area 1.4 m ² / g, average particle diameter 1.7 μm, oil absorption (DBP oil absorption) 30 ml / 100 g (manufactured by Nitto Powder Chemical Co., Ltd., trade name “NCC-P”)

(4) Plasticizer Plasticizer-1: Diisononyl phthalate (product name “DINP” manufactured by J. Plus)
Plasticizer-2: Di (2-ethylhexyl) phthalate (trade name “DOP” manufactured by J. Plus)

(5) Stabilizer Ca / Zn-based stabilizer (made by Mizusawa Chemical Industry Co., Ltd., trade name “STABINEX NL221-5”, calcium stearate, zinc stearate, hydrotalcite, etc.)

(Examples 1-85 and Comparative Examples 1-47)
Examples 1 to 85 and Examples 1 to 85 and the above thermoplastic resins, carbon materials, fillers, plasticizers, and stabilizers were blended in the ratios shown in Tables 1 to 21 and kneaded at 180 ° C. for 15 minutes using a Banbury mixer. The conductive thermoplastic resin compositions of Comparative Examples 1 to 47 were obtained. In Tables 1-21, the unit of the compounding quantity of a thermoplastic resin, a carbon material, a filler, a plasticizer, and a stabilizer is a mass part.

  On the other hand, an assembly cable was prepared by twisting two power wires and two communication wires and winding them with mesh tape. Here, two power lines each having an outer diameter of 8.89 mm and an insulation thickness of 1.71 mm are used, and two sets of communication lines are wires having an outer diameter of 1.1 mm and an insulation thickness of 0.57 mm. A pair of communication wires formed by twisting two wires and enclosing them in jute, and by twisting 1,6 wires out of seven wires having an outer diameter of 1.1 mm and an insulation thickness of 0.57 mm. One set of communication lines was used.

Then, the obtained conductive thermoplastic resin composition was put into a single screw extruder (L / D = 20, screw shape: full flight screw, manufactured by Mars Seiki Co., Ltd.), and a tubular extrudate was removed from the extruder. Extruded and a conductive layer was formed on the aggregated cable to a thickness of 1.09 mm. Thereafter, the sheath was coated using the single screw extruder so as to have a thickness of 2.95 mm. Thus, a lead cable for a quick charger was obtained.

<Characteristic evaluation>
(Heat deformation resistance)
A conductive layer was cut out from the lead cables obtained in Examples 1 to 85 and Comparative Examples 1 to 47 to prepare a test piece of 35 mm × 35 mm × 2 mm, and the 6.5 heat deformation test described in JIS K 6723 ( 120 ° C., 9.8 N load, 60 minutes). And the heat deformation rate (%) was calculated by the following formula from the thickness of the test piece before the test (thickness before the test) and the thickness of the test piece after the test (thickness after the test).

Heat deformation rate (%)
= [(Thickness before test)-(Thickness after test)] / (Thickness before test) x 100 (%)

The results are shown in Tables 1-21. Regarding the heat deformation resistance, the case where the heat deformation rate was 1% or less was accepted, and the case where the heat deformation rate exceeded 1% was rejected.

(Conductivity)
A conductive layer was cut out from the lead cables obtained in Examples 1 to 85 and Comparative Examples 1 to 47 to prepare test pieces of 100 mm × 100 mm × 1 mm. And about these test pieces, volume resistivity (rho) (ohm * cm) was measured. The volume resistivity is measured by a Wheatstone bridge when the volume resistivity is 10 ⁹ Ω · cm or less, and when the volume resistivity is greater than 10 ⁹ Ω · cm, a superinsulator (R-503) is used. , Manufactured by Kawaguchi Electric Manufacturing Co., Ltd., 500 V, 1 min value). The volume resistivity was measured at 30 ° C. The results are shown in Tables 1-21. In Tables 1 to 21, the volume resistivity is expressed in the common logarithm log ρ of ρ. Here, when log ρ is 5 or less, that is, when the volume resistivity is 1 × 10 ⁵ Ω · cm or less, it is accepted, and when log ρ exceeds 5, that is, the volume resistivity exceeds 1 × 10 ⁵ Ω · cm. The case was rejected.

(Hardness)
A conductive layer was cut out from the lead cables obtained in Examples 1 to 85 and Comparative Examples 1 to 47 to prepare test pieces of 50 mm × 20 mm × 2 mm. About this test piece, the hardness test based on JISK6253 was done, and durometer hardness D (5-second value) was measured. The results are shown in Tables 1-21. The durometer hardness is a measure of hardness (or flexibility), and the durometer hardness value increases as the test piece becomes harder.

  As shown in Tables 1 to 21, the conductive thermoplastic resin compositions of Examples 1 to 85 reached the acceptance criteria in terms of heat distortion resistance and conductivity. On the other hand, the conductive thermoplastic resin compositions of Comparative Examples 1 to 47 did not reach the acceptance criteria at least in terms of heat deformation resistance.

  From the above, it was confirmed that according to the conductive thermoplastic resin composition of the present invention, excellent heat distortion resistance can be ensured while ensuring excellent conductivity.

DESCRIPTION OF SYMBOLS 1 ... Conductor 2 ... Internal semiconductive layer (conductive layer)
4. External semiconductive layer (conductive layer)
100, 200 ... cable 220 ... conductive layer

Claims (2)

A conductive thermoplastic resin composition comprising a thermoplastic resin and a carbon material,
The thermoplastic resin consists only of a polyvinyl chloride resin and an ethylene vinyl acetate copolymer,
The carbon material has a specific surface area of 600 to 2240 m ² / g,
And, wherein the conductive heat specific surface area per the thermoplastic resin composition unit mass 195 ~561m 2 / ^g conductive thermoplastic resin composition is. At least one conductor;
A conductive layer surrounding the conductor;
With
The cable which the said conductive layer consists of a conductive thermoplastic resin composition of Claim 1 .

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