JP6359281B2 - Flame-retardant resin composition and cable using the same - Google Patents

Description

  The present invention relates to a flame retardant resin composition and a cable using the same.

  So-called eco-materials are widely used for cable coverings, cable sheaths, tubes, tapes, packaging materials, building materials, and the like.

  As such an ecomaterial, for example, an ethylene-vinyl acetate copolymer, an ethylene-hexene-1 copolymer, a maleic anhydride-modified ethylene-octene-1 copolymer, and a flame retardant are blended. A flammable resin composition is known (see Patent Document 1 below).

JP 2001-335665 A

  However, the composition described in Patent Document 1 has room for further improvement in terms of heat deformation resistance. For this reason, there has been a demand for a flame retardant resin composition that can ensure excellent heat distortion resistance while ensuring excellent flame retardancy and excellent mechanical properties.

  The present invention has been made in view of the above circumstances, and a flame retardant resin composition capable of ensuring excellent heat distortion resistance while ensuring excellent flame resistance and excellent mechanical properties. And it aims at providing the cable using this.

  In order to solve the above-mentioned problems, the present inventors have conducted intensive research on the types and blending ratios of the base resins used in the flame-retardant resin composition. As a result, the present inventors have made a base resin containing a specific acid-modified thermoplastic resin and a specific polyethylene resin in a specific ratio in a specific ethylene polymer to contain a flame retardant in a specific ratio. It has been found that the above-described problems can be solved by the flame retardant resin composition, and the present invention has been completed.

That is, the present invention includes an ethylene polymer (A), an acid-modified thermoplastic resin (B), polyethylene (C), and a flame retardant (D), and the ethylene polymer (A) is ethylene -The α-olefin polymer and the ethylene-unsaturated carboxylic acid ester copolymer alone, wherein the acid-modified thermoplastic resin (B) is from the group consisting of maleic anhydride-modified thermoplastic resin and maleic acid-modified thermoplastic resin. At least one thermoplastic resin selected, wherein the polyethylene (C) has a density of 0.950 g / cm ³ or more, and the ethylene polymer (A) and the acid-modified thermoplastic resin (B). The content of the ethylene polymer (A) in 100% by mass of the polyethylene and the polyethylene (C) is 40% by mass to 85% by mass, and the content of the acid-modified thermoplastic resin (B) is 10% by mass. The content of the polyethylene (C) is 5% by mass or more and 30% by mass or less, and the ethylene polymer (A), the acid-modified thermoplastic resin (B), and the polyethylene (C). is blended in an amount of the flame retardant (D) is 96 parts by mass 80 parts by mass or more per 100 parts by weight of the polyethylene (C) is Ri do because only polyethylene non-acid-modified, wherein the acid The modified thermoplastic resin (B) is a flame retardant resin composition comprising a maleic anhydride modified ethylene-propylene copolymer .

  According to the present invention, it is possible to ensure excellent heat distortion resistance while ensuring excellent flame retardancy and excellent mechanical properties.

  In addition, the present inventors speculate as follows about the reason why the heat resistant deformation resistance is excellent in the flame retardant resin composition of the present invention.

  That is, since the flame retardant resin of the present invention is blended with a predetermined ratio of polyethylene (C) having a certain density or more in the ethylene copolymer (A) and the acid-modified thermoplastic resin (B). The present inventors think that the heat deformation resistance is improved. In addition, since polyethylene (C) has high crystallinity, the dispersibility of a flame retardant (D) may be inhibited and mechanical characteristics may be affected. Therefore, the present inventors consider that the mechanical properties can be maintained by minimizing the blending amount of polyethylene (C).

  In the flame retardant resin composition, the α-olefin unit contained in the ethylene-α-olefin polymer is preferably a hexene unit.

  In this case, the flame retardant resin composition. It has excellent hardness and excellent scratch resistance.

  In the flame retardant resin composition, the acid-modified thermoplastic resin (B) is preferably a maleic anhydride-modified thermoplastic resin.

  In this case, the flame retardant thermoplastic resin has further excellent heat distortion resistance.

  In the said flame-retardant resin composition, it is preferable that the said flame retardant (D) contains the flame retardant containing a metal hydroxide and a phosphorus flame retardant.

  In this case, the flame retardant resin composition has particularly excellent flame retardancy.

  Moreover, this invention is a cable which has a conductor, the insulating layer which coat | covers the said conductor, and the sheath which covers the said insulating layer, and the said sheath is comprised with the flame-retardant resin composition mentioned above.

  According to the present invention, since the sheath is composed of the above-mentioned flame retardant resin composition, it is possible to ensure excellent heat distortion resistance while ensuring excellent flame retardancy and excellent mechanical properties. Can do.

  ADVANTAGE OF THE INVENTION According to this invention, the flame retardant resin composition which can ensure the outstanding heat-deformation characteristic, and a cable using the same, while ensuring the outstanding flame retardance and mechanical characteristic are provided.

It is a partial side view which shows one Embodiment of the cable of this invention. It is sectional drawing along the II-II line of FIG.

  Hereinafter, embodiments of the present invention will be described in detail with reference to FIGS. 1 and 2.

[cable]
FIG. 1 is a partial side view showing an embodiment of a cable according to the present invention, and shows a round cable. FIG. 2 is a cross-sectional view taken along the line II-II in FIG. As shown in FIGS. 1 and 2, the round cable 10 includes an insulated wire 4 and a sheath 3 that covers the insulated wire 4. The insulated wire 4 includes an inner conductor 1 and an insulating layer 2 that covers the inner conductor 1.

Here, the insulating layer 2 and the sheath 3 are composed of a flame retardant resin composition, and the flame retardant resin composition includes an ethylene polymer (A), an acid-modified thermoplastic resin (B), Polyethylene (C) and flame retardant (D) are included, and the ethylene polymer (A) is composed of only an ethylene-α-olefin polymer and an ethylene-unsaturated carboxylic acid ester copolymer, and the acid-modified The thermoplastic resin (B) is at least one thermoplastic resin selected from the group consisting of a maleic anhydride-modified thermoplastic resin and a maleic acid-modified thermoplastic resin, and the polyethylene (C) is 0.950 g / cm. ^The ethylene polymer (A) is contained in 100% by mass in total of the ethylene polymer (A), the acid-modified thermoplastic resin (B), and the polyethylene (C) having a density of ³ or more. 40 quality % To 85% by mass, the content of the acid-modified thermoplastic resin (B) is 10% to 30% by mass, the content of the polyethylene (C) is 5% to 30% by mass, The flame retardant (D) is 80 parts by mass or more and 96 parts by mass or less with respect to a total of 100 parts by mass of the ethylene polymer (A), the acid-modified thermoplastic resin (B), and the polyethylene (C), the polyethylene (C) is Ri do because only polyethylene non-acid-modified, wherein the acid-modified thermoplastic resin (B) is maleic anhydride-modified ethylene - of propylene copolymer.

  The sheath 3 composed of the flame retardant resin composition can ensure excellent heat distortion resistance while ensuring excellent flame resistance and excellent mechanical properties.

[Cable manufacturing method]
Next, the manufacturing method of the round cable 10 mentioned above is demonstrated.

(Inner conductor)
First, the inner conductor 1 is prepared. The inner conductor 1 may be composed of only one strand, or may be configured by bundling a plurality of strands. Further, the inner conductor 1 is not particularly limited with respect to the conductor diameter, the material of the conductor, and the like, and can be appropriately determined according to the application.

(Flame retardant resin composition)
On the other hand, a flame retardant resin composition is prepared. As described above, the flame retardant resin includes the ethylene polymer (A), the acid-modified thermoplastic resin (B), polyethylene (C) having a density of 0.950 g / cm ³ or more, a flame retardant ( D).

(Ethylene polymer)
The ethylene polymer used in the flame retardant resin composition of the present invention includes an ethylene-α-olefin polymer and an ethylene-unsaturated carboxylic acid ester copolymer.

  Examples of the ethylene-α-olefin polymer include polymers of ethylene and α-olefins having 2 to 19 carbon atoms. Examples of the α-olefin include ethylene, propylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene, 1-decene, 1-undecene, 1-dodecene, 1- Examples include tridecene, 1-tetradecene, 1-pentadecene, 1-hexadecene, 1-heptadecene, 1-octadecene and 1-nonadecene.

  Among these, the α-olefin is preferably at least one of 1-butene and 1-hexene. Only one type of α-olefin may be contained, or two or more types may be contained.

  In the ethylene-α-olefin polymer, the α-olefin unit is preferably a hexene unit. In this case, the flame retardant resin composition has excellent hardness and excellent scratch resistance. Examples of the ethylene-α-olefin polymer containing an ethylene unit and a hexene unit include an ethylene-1-hexene copolymer and an ethylene-1-hexene-1-octene copolymer.

  The ethylene-α-olefin polymer is preferably produced using a single site catalyst. As a single site catalyst, a metallocene catalyst etc. are mentioned, for example. The polymer produced by a method other than the method using a single site catalyst has a higher polydispersity Mw / Mn than the polymer produced by a method using a single site catalyst. For this reason, when the said polymer manufactured by methods other than the method using a single site catalyst is used as an ethylene-alpha-olefin polymer, sufficient mechanical characteristics can be provided to a flame-retardant resin composition. Can not. Here, Mw represents a weight average molecular weight, and Mn represents a number average molecular weight.

  Examples of the ethylene-unsaturated carboxylic acid ester copolymer include a copolymer of ethylene and an α, β-unsaturated carboxylic acid ester. Examples of the α, β-unsaturated carboxylic acid ester include methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate and the like, and ethyl acrylate is particularly preferable.

  The ethylene-based polymer is preferably composed only of an ethylene-α-olefin polymer and an ethylene-unsaturated carboxylic acid ester copolymer, and the ethylene-α-olefin polymer and the ethylene-unsaturated carboxylic acid ester copolymer In a total of 100 parts by mass, the ethylene-α-olefin polymer content is 85% by mass to 95% by mass, that is, the ethylene-unsaturated carboxylic acid ester copolymer content is 5% by mass to 15% by mass. Preferably there is.

(Acid-modified thermoplastic resin)
The acid-modified thermoplastic resin used in the flame-retardant resin composition of the present invention is at least one thermoplastic resin selected from the group consisting of a maleic anhydride-modified thermoplastic resin and a maleic acid-modified thermoplastic resin.

  Examples of maleic anhydride-modified thermoplastic resins include maleic anhydride-modified polyethylene, maleic anhydride-modified polypropylene, maleic anhydride-modified ethylene-propylene copolymer, maleic anhydride-modified ethylene-1-butene copolymer, and maleic anhydride. Modified ethylene-1-pentene copolymer, maleic anhydride modified ethylene-1-hexene copolymer, maleic anhydride modified ethylene-1-heptene copolymer, maleic anhydride modified ethylene-1-octene copolymer, etc. Can be mentioned. These may be used alone or in combination of two or more.

  Examples of maleic acid-modified thermoplastic resins include maleic acid-modified polyethylene, maleic acid-modified polypropylene, maleic acid-modified ethylene-propylene copolymer, maleic anhydride-modified ethylene-1-butene copolymer, maleic acid-modified maleic acid-modified ethylene. Examples include a -1-pentene copolymer, a maleic acid-modified ethylene-1-hexene copolymer, a maleic acid-modified ethylene-1-heptene copolymer, and a maleic acid-modified ethylene-1-octene copolymer. These may be used alone or in combination of two or more.

  The acid-modified thermoplastic resin used in the flame retardant resin composition of the present invention is preferably a maleic anhydride-modified thermoplastic resin.

  In this case, the flame retardant resin composition has particularly excellent heat deformation resistance.

(polyethylene)
The polyethylene used in the flame retardant resin composition of the present invention is preferably a polyethylene having a density of 0.950 g / cm ³ or more. If the density of the polyethylene is less than 0.950 g / cm ^3, it is impossible to sufficiently improve the resistance to thermal deformation characteristics as compared with the case is 0.950 g / cm ³ or more.

  In the flame-retardant resin composition of the present invention, the ethylene polymer content in a total of 100% by mass of the ethylene polymer, the acid-modified thermoplastic resin and the polyethylene resin is 40% by mass to 85% by mass, The content of the acid-modified thermoplastic resin is 10% by mass to 30% by mass, and the content of polyethylene is 5% by mass to 30% by mass. When the content of the ethylene-based polymer is less than 40% by mass, the flame-retardant resin composition has sufficient mechanical properties as compared with the case where the content of the ethylene-based polymer is 40% by mass or more. I can't. On the other hand, when the content of the ethylene polymer exceeds 85% by mass, the flame retardant resin composition has sufficient heat deformation resistance as compared with the case where the content of the ethylene polymer is 85% by mass or less. I can't. Further, if the content of the acid-modified thermoplastic resin is less than 10% by mass, the flame-retardant resin composition has sufficient heat deformation resistance as compared with the case where the content of the acid-modified thermoplastic resin exceeds 10% by mass. Cannot have. On the other hand, if the content of the acid-modified thermoplastic resin exceeds 30% by mass, the hardness becomes lower than that in the case where the content of the acid-modified thermoplastic resin is 30% by mass or less, the wear resistance is deteriorated and the wound is not damaged. Sex worsens. Further, when the polyethylene content is less than 5% by mass, the flame-retardant resin composition cannot have sufficient heat deformation resistance as compared with the case where the polyethylene content is 5% by mass or more. On the other hand, when the polyethylene content exceeds 30% by mass, sufficient mechanical properties cannot be obtained as compared with the case where the polyethylene content is 30% by mass or less.

(Flame retardants)
Examples of the flame retardant used in the flame retardant resin composition of the present invention include a flame retardant containing a metal hydroxide, a phosphorus-based flame retardant, and an intimescent flame retardant. These may be used alone or in combination of two or more.

  Examples of the metal hydroxide include magnesium hydroxide and aluminum hydroxide. These may be used alone or in combination of two or more. Of these, magnesium hydroxide is particularly preferred. The flame retardant is preferably obtained by surface-treating the metal hydroxide with a surface treatment agent such as a fatty acid-containing compound, a phosphate ester, or a silane coupling agent. In this case, the dispersibility of the flame retardant in the resin is excellent.

The flame retardant containing the metal hydroxide is preferably in the form of particles and has an average particle size of 0.5 μm or more and less than 2 μm. When the average particle size is 0.5 μm or more, workability during processing is improved as compared with the case where the average particle size is less than 0.5 μm. Further, when the average particle size is less than 2.0 μm, there is an advantage that the mechanical strength is improved as compared with the case where the average particle size is 2 μm or more. In the present invention, the “average particle size” of the particles refers to the area S of a two-dimensional image when a plurality of particles are observed with a scanning electron microscope (SEM). Are each equal to the area of the circle, and from these areas the following formula:
R = 2 × (S / π) ^1/2
The average value of R calculated based on

  Examples of the phosphorus flame retardant include a red phosphorus flame retardant.

  The flame retardant preferably contains a flame retardant containing a metal hydroxide and a phosphorus flame retardant. In this case, the flame retardant resin composition is particularly excellent in flame retardancy.

  When the flame retardant contains a flame retardant containing a metal hydroxide and a phosphorus flame retardant, the mass ratio of the phosphorus flame retardant to the flame retardant containing a metal hydroxide is 0.014 to 0.017. preferable. In this case, the flame retardant resin composition has further excellent flame retardancy as compared with the case where the mass ratio of the flame retardant is out of the above range.

  The flame retardant in the flame retardant resin composition of the present invention is blended at a ratio of 80 parts by mass to 96 parts by mass with respect to 100 parts by mass in total of the ethylene polymer, the acid-modified thermoplastic resin, and the polyethylene resin. . When the blending ratio of the flame retardant is less than 80 parts by mass, the flame retardant resin composition cannot ensure sufficient flame retardancy. Moreover, when the blending ratio of the flame retardant exceeds 96 parts by mass, the flame retardant resin composition cannot ensure sufficient mechanical properties. The blending ratio of the flame retardant is preferably 80 parts by mass or more and 90 parts by mass or less.

  The flame retardant resin composition may further contain additives such as an antioxidant, an ultraviolet degradation inhibitor, a processing aid, a color pigment, a lubricant, and carbon black as necessary.

  The flame retardant resin composition can be obtained by kneading an ethylene polymer, an acid-modified thermoplastic resin, high density polyethylene, a metal hydroxide, a phosphorus compound, and the like. 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.

  Next, the inner conductor 1 is covered with the flame retardant resin composition. Specifically, the flame retardant resin composition is melt kneaded using an extruder to form a tubular extrudate. Then, the tubular extrudate is continuously coated on the inner conductor 1. Thus, the insulated wire 4 is obtained.

(sheath)
Finally, the insulated wires 4 obtained as described above are prepared, and these insulated wires 4 are covered with the sheath 3 produced using the above-mentioned flame-retardant resin composition. The sheath 3 protects the insulating layer 2 from physical or chemical damage.

  The round cable 10 is obtained as described above.

  The present invention is not limited to the above embodiment. For example, although the round cable 10 has one insulated wire 4 in the above embodiment, the cable of the present invention is not limited to the round cable, and two insulated wires 4 are provided inside the sheath 3. You may have more. A resin portion made of polypropylene or the like may be provided between the sheath 3 and the insulated wire 4. Furthermore, the cable of the present invention may further include an outer conductor between the sheath 3 and the insulated wire 4 like a coaxial cable.

  Moreover, in the said embodiment, although the insulating layer 2 and the sheath 3 of the insulated wire 4 are comprised with said flame-retardant resin composition, the insulating layer 2 is comprised with normal insulating resin, and only the sheath 3 is the said. The flame retardant resin composition may be used.

  Furthermore, in the above embodiment, the flame retardant resin composition of the present invention is used as a material constituting the insulating layer and the sheath of the cable. However, the flame retardant resin composition of the present invention is a tube, tape, or packaging. It can also be used for materials and building materials.

  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.

(Examples 1-5 and Comparative Examples 1-6)
Tables 1 and 2 show the ethylene copolymer (A), acid-modified thermoplastic resin (B), polyethylene (C), flame retardant (D), carbon black (E) and antioxidant (F). The flame-retardant resin compositions of Examples 1 to 5 and Comparative Examples 1 to 6 were obtained. In Tables 1 and 2, the unit of the blending amount of each blending component is part by mass.

  Specific examples of the ethylene polymer (A), acid-modified thermoplastic resin (B), polyethylene (C), flame retardant (D), carbon black (E) and antioxidant (F) are as follows. Was used.

(A) Ethylene-based polymer (A-1) Ethylene-1-hexene copolymer, manufactured using a metallocene catalyst, density 0.92 g / cm ³ (trade name “Excellen GMH CB5001 manufactured by Sumitomo Chemical Co., Ltd. ")
(A-2) Ethylene-ethyl acrylate copolymer (manufactured by Nippon Polyethylene Co., Ltd., trade name “Lex Pearl A1150”)

(B) Acid-modified thermoplastic resin Maleic anhydride-modified ethylene-propylene copolymer (Mitsui Chemicals, trade name “Toughmer MA8510”)

(C) Polyethylene polyethylene, density: 0.951 g / cm ³ (manufactured by Prime Polymer Co., Ltd., trade name “Hi-Zex 5305E”)

(D) Flame retardant (D-1) Stearic acid surface-treated magnesium hydroxide particles, average particle size 0.8 μm (Kyowa Chemical Industry, trade name “Kisuma 5A”)
5) Red phosphorus flame retardant, red phosphorus content 78% or more, average particle size 10 μm (manufactured by Rin Chemical Industry Co., Ltd., trade name “NOVA Pellet RF-15”)

(E) Carbon (E-1) Carbon black, average particle size 78 nm (Asahi Carbon Co., Ltd., trade name “Carbon Asahi # 35”)
(E-2) Carbon black, average particle size 31 μm (Mitsubishi Chemical Corporation, trade name “Dia Black H”)

F) Antioxidant (F-1) Hindered phenol antioxidant (trade name “Irganox 1010” manufactured by BASF AG)
(F-2) A hindered amine antioxidant (manufactured by BASF, trade name “Tinubin 622LD”)

Subsequently, the flame-retardant resin compositions of Examples 1 to 5 and Comparative Examples 1 to 6 were kneaded at 160 ° C. for 15 minutes using a Banbury mixer. Then, this flame-retardant 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 extruded from the extruder. A conductor (number of strands / cross-sectional area of 2 mm ² ) was coated to a thickness of 0.7 mm. Thus, an insulated wire was obtained.

<Characteristic evaluation>
(Mechanical properties)
(1) Tensile test About the insulating sheets of Examples 1 to 5 and Comparative Examples 1 to 6, a molded plate was prepared with an extruder in accordance with JIS-K6251, and this molded plate was punched with a punching blade, and a dumbbell-shaped test was performed. A piece was made. The size of the dumbbell-shaped test piece was 20 mm between the gauge points, the minimum width was 5 mm, the maximum width was 25 mm, and the total length was 100 mm. And about this dumbbell-shaped test piece, the tensile test was done by JISC3005 and the breaking strength and tensile elongation were measured. In the tensile test, the tensile speed was 200 mm / min 20 mm. The results are shown in Tables 1 and 2. In Tables 1 and 2, the unit of breaking strength is MPa, and the unit of tensile elongation is%. The acceptance criteria for the tensile test were as follows.

Breaking strength of 10 MPa or more and tensile elongation of 300% or more: acceptable breaking strength of less than 10 MPa or tensile elongation of less than 300%: failure

(2) Shore D hardness About a 35 mm × 35 mm × 2 mm thick square test piece formed by molding the flame retardant resin compositions of Examples 1 to 5 and Comparative Examples 1 to 6, a durometer according to JIS K7215 The Shore D hardness indicating the surface hardness was measured with a hardness meter. Tables 1 and 2 show the measurement results at an instantaneous value with a load holding time of 0 seconds. If the Shore D hardness was 55 or higher, the test was accepted.

(Heat deformation resistance)
About the square test piece of 35mmx35mmx thickness 2mm formed by shape | molding the flame-retardant resin composition of Examples 1-5 and Comparative Examples 1-6, the heat deformation test was done and the heat deformation resistance property was evaluated. . In the heat deformation test, the test temperature was 120 ° C., the load was 19.6 N, and the preheating time was 1 hour. The heat deformation resistance is evaluated by measuring the thickness of the specimen before the heat deformation test (thickness before the test) and the thickness of the newly deformed suspicion (thickness after the test), and calculating the following formula. The heating deformation rate (%) was performed.

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

The results are shown in Tables 1 and 2. Regarding the heat deformation resistance, the case where the heat deformation rate was less than 50% was accepted, and the case where the heat deformation rate was 50% or more was rejected.

(Flame retardance)
About the said insulated wire which coat | covered the conductor with the flame-retardant resin composition of Examples 1-5 and Comparative Examples 1-6, the vertical and the example combustion test based on IEEE383-1974 were done. That is, an insulated wire was cut out by 2400 mm and placed on a vertical ladder tray. A burner was installed at a position 600 mm from the bottom of the tray, and combustion was started at a flame length of about 380 mm and a flame center temperature of 815 ° C. or higher. Combustion was carried out for 20 minutes, after which the burner ratio was turned off and held until combustion of the insulated wire was completed. After the completion of combustion, check the combustion position (position where the cable surface is carbonized), and for those that did not burn to the top, enter “○” in the vertical tray combustion test column in Tables 1 and 2 and burn to the top. For those that did, "x" was entered. The acceptance criteria for flame retardancy were as follows.

Vertical tray combustion test result is “O”: Pass Vertical tray combustion test result is “X”: Fail

  As shown in Tables 1 and 2, the flame retardant resin compositions of Examples 1 to 5 reached the acceptance criteria for mechanical properties, heat deformation resistance and flame retardancy. On the other hand, the flame retardant resin compositions of Comparative Examples 1 to 6 did not reach the acceptance criteria for any of mechanical properties, heat deformation resistance, and flame retardancy.

  From this, it was confirmed that according to the flame retardant resin composition of the present invention, excellent heat distortion resistance can be ensured while ensuring excellent flame retardancy and excellent mechanical properties. .

DESCRIPTION OF SYMBOLS 1 ... Internal conductor 2 ... Insulating layer 3 ... Sheath 4 ... Insulated electric wire 10 ... Cable

Claims (4)

An ethylene polymer (A);
An acid-modified thermoplastic resin (B);
Polyethylene (C),
Flame retardant (D),
The ethylene polymer (A) consists only of an ethylene-α-olefin polymer and an ethylene-unsaturated carboxylic acid ester copolymer,
The acid-modified thermoplastic resin (B) is at least one thermoplastic resin selected from the group consisting of a maleic anhydride-modified thermoplastic resin and a maleic acid-modified thermoplastic resin,
The polyethylene (C) has a density of 0.950 g / cm ³ or more,
Content of the ethylene polymer (A) in a total of 100% by mass of the ethylene polymer (A), the acid-modified thermoplastic resin (B), and the polyethylene (C) is 40% by mass or more and 85% by mass. % Or less, the content of the acid-modified thermoplastic resin (B) is 10% by mass or more and 30% by mass or less,
The polyethylene (C) content is 5% by mass or more and 30% by mass or less,
A ratio of 80 to 96 parts by mass of the flame retardant (D) with respect to 100 parts by mass in total of the ethylene polymer (A), the acid-modified thermoplastic resin (B) and the polyethylene (C). Formulated with
The polyethylene (C) is Ri Do because only polyethylene non-acid-modified,
The acid-modified thermoplastic resin (B) is a flame retardant resin composition comprising a maleic anhydride-modified ethylene-propylene copolymer .   The flame retardant resin composition according to claim 1, wherein the α-olefin unit contained in the ethylene-α-olefin polymer is a hexene unit. The flame retardant resin composition according to claim 1 or 2 , wherein the flame retardant (D) contains a flame retardant containing a metal hydroxide and a phosphorus flame retardant. Conductors,
An insulating layer covering the conductor;
A sheath covering the insulating layer;
A cable in which the sheath is composed of the flame retardant resin composition according to any one of claims 1 to 3 .

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