JP2007197619A - Non-halogen flame-retardant resin composition and electric wire/cable using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a flame-retardant resin composition which does not contain halogen-containing flame-retardants, exhibits the flame retardancy equivalent with that of a PVC-containing electric wire and can form an enveloping layer excellent in mechanical properties, heat resistance, heat-deforming resistance and the like and to provide an electric wire/cable using this flame-retardant resin composition as its enveloping layer. <P>SOLUTION: This non-halogen flame-retardant resin composition comprises 5-70 pts.wt. of a nitrogen-containing flame-retardant agent based on 100 pts.wt. of a resin component, and is substantially free of a phosphorous-containing flame retardant. In 100 pts.wt. of the resin component, 40-70 pts.wt. of a styrenic ether resin and 30-60 pts.wt. of a styrenic elastomer are contained. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a halogen-free flame retardant resin composition suitably used as a coating layer for electric wires and the like, and an electric wire / cable using the resin composition.

  In the internal wiring of OA equipment and electronic equipment such as copiers and printers, a large amount of wire harnesses that supply power and send signals between printed boards and between electronic parts such as printed boards and sensors, actuators, and motors are used.

  A wire harness is an assembly of terminals such as connectors that can be inserted into and removed from a terminal by bundling a plurality of electric wires and cables. From the viewpoints of flame retardancy, electrical insulation, etc., PVC electric wires using polyvinyl chloride (PVC) as an insulating material are used for electric wires for wire harnesses. Since PVC wires are excellent in flexibility, they are easy to handle in the case of a wire harness and have sufficient strength, so there is no problem that the insulator is broken or worn during wiring of the wire harness. Furthermore, it is excellent in the workability of attaching the pressure contact connector attached to the terminal.

  However, since PVC elements contain halogen elements, there is a problem that toxic gas of hydrogen chloride is generated when incinerating the wire harness after use, or dioxin is generated depending on the incineration conditions. Medium PVC that is required to reduce environmental burden is not a preferable material as an insulating material.

  In recent years, halogen-free electric wires using coating materials that do not contain polyvinyl chloride resin or halogen-based flame retardants have been developed in order to meet the increasing demand for reducing the environmental burden. On the other hand, electric wires such as insulated wires and insulated cables used for in-machine wiring of electronic devices are generally required to have various characteristics conforming to UL (Underwriters Laboratories Inc.) standards. The UL standard stipulates in detail various properties such as flame retardancy, heat deformability, low temperature properties, tensile properties after heat aging of coating materials, and the like to be satisfied by products. Among these, regarding flame retardancy, it is necessary to pass a vertical combustion test called a VW-1 test, which is one of the strictest requirements in the UL standard.

  In general, as a coating material for halogen-free electric wires, a flame retardant resin composition prepared by blending a polyolefin resin such as polypropylene with a metal hydroxide (also referred to as a metal hydrate) such as magnesium hydroxide or aluminum hydroxide. in use. However, in order to pass the vertical combustion test VW-1, it is necessary to mix a large amount of metal hydroxide in the polyolefin resin. As a result, there is a problem that the flexibility and elongation of the coating material are remarkably impaired and the molding processability such as extrusion molding is also lowered.

  For this reason, Japanese Patent Application Laid-Open No. 2002-105255 (Patent Document 1) heats and kneads a metal hydrate to a thermoplastic resin component in which an elastomer such as ethylene propylene rubber or styrene butadiene rubber is blended with a propylene resin. A flame retardant resin composition is disclosed. Filler receptivity can be increased by blending elastomers, and dynamic vulcanization of these elastomers balances mechanical properties such as flexibility and elongation with extrudability and flame retardancy. Is being considered. However, such materials have poor abrasion resistance and edge resistance as compared with PVC, and there is a problem in that, when trying to improve these characteristics, flexibility is lowered and the balance of characteristics is lost.

  On the other hand, a high-strength non-halogen electric wire using a polyphenylene ether resin described in Patent Document 2 or a polyphenylene sulfide resin described in Patent Document 3 as a coating material has also been proposed. Although these resins are excellent in terms of flame retardancy and strength, they have a drawback of poor flexibility and a high extrusion temperature. Therefore, a method has been studied in which a phosphate ester is blended with these resins as a plasticizer to impart flexibility and improve the extrusion processability. Since the phosphate ester also acts as a flame retardant, there is no problem that the flame retardancy decreases due to the improvement in flexibility and extrusion processability.

  However, phosphoric acid esters tend to evaporate during the extrusion process, and there is a problem that the working environment is deteriorated by giving off a bad odor peculiar to phosphoric acid esters. In addition, it has been pointed out that when it is landfilled after use, it is extracted by rainwater or the like and causes eutrophication of the river, which is not preferable from the viewpoint of reducing environmental load. Further, the addition of phosphate ester is not preferable because the heat distortion temperature of the molded product may be lowered.

JP 2002-105255 A Japanese Patent Laid-Open No. 11-189585 Japanese Patent Laid-Open No. 05-012924

  The present invention is a non-halogen flame retardant resin composition which is excellent in flame resistance, flexibility, abrasion resistance, edge resistance, and other mechanical strength equivalent to PVC, and is useful for reducing environmental load, and the flame retardancy. It is an object to provide an electric wire / cable using a resin composition as a coating layer.

  As a result of intensive studies, the present inventor has found that the above problem can be solved by combining a resin composition containing a polyphenylene ether resin and a styrene elastomer and a nitrogen flame retardant, and has completed the present invention.

  That is, the present invention provides a halogen-free flame retardant resin composition containing 5 to 70 parts by weight of a nitrogen-based flame retardant and substantially free of a phosphorus-based flame retardant with respect to 100 parts by weight of a resin component. A non-halogen flame retardant resin composition comprising 40 to 70 parts by weight of a polyphenylene ether resin and 30 to 60 parts by weight of a styrene elastomer in 100 parts by weight of the resin component. ).

  The invention according to claim 2 is the non-halogen flame retardant resin composition according to claim 1, wherein the styrene-based elastomer is a block copolymer elastomer of styrene and a rubber component. When the styrene elastomer is a block copolymer elastomer of styrene and a rubber component, a resin composition having excellent extrudability can be obtained.

  The invention according to claim 3 is the non-halogen flame retardant resin composition according to claim 1 or 2, wherein the polyphenylene ether resin is a polyphenylene ether resin obtained by melt blending polystyrene. The extrusion processability is improved by using a polyphenylene ether resin obtained by melt blending polystyrene.

  The invention according to claim 4 is the non-halogen flame retardant resin composition according to any one of claims 1 to 3, wherein the deflection temperature under load of the polyphenylene ether resin is 130 ° C or higher. When the deflection temperature under load of the polyphenylene ether-based resin is 130 ° C. or higher, a coating layer for an electric wire having high mechanical strength can be obtained.

The invention according to claim 5 is the halogen-free flame retardant resin composition according to any one of claims 1 to 4, wherein the nitrogen-based flame retardant is melamine cyanurate.
By using melamine cyanurate as a nitrogen-based flame retardant, thermal stability during mixing is improved, and flame retardancy is also improved.

  The invention according to claim 6 is the non-halogen flame retardant resin composition according to any one of claims 1 to 5, further comprising a crosslinking aid. By further containing a crosslinking aid, the plasticizing effect of the resin can be obtained, the extrusion processability can be improved, and the crosslinking efficiency can be increased upon irradiation with ionizing radiation.

  The invention according to claim 7 is the non-halogen flame retardant resin composition according to claim 6, wherein the crosslinking aid is trimethylolpropane trimethacrylate. Trimethylolpropane trimethacrylate has good compatibility with the resin and can be easily mixed.

  The invention according to claim 8 is an electric wire / cable characterized by using the non-halogen flame retardant resin composition according to any one of claims 1 to 7 as a coating layer. According to the present invention, a non-halogen insulated wire excellent in flame retardancy, flexibility and mechanical properties equivalent to that of a PVC wire can be obtained.

  A ninth aspect of the present invention is the electric wire / cable according to the eighth aspect, wherein the coating layer has a thickness of 0.3 mm or less. When the thickness of the insulating coating layer is as small as 0.3 mm or less, the mechanical properties such as wear resistance and edge resistance are significantly different from those of the conventional electric wires, and an excellent effect is exhibited.

  The invention according to claim 10 is the electric wire / cable according to claim 8 or 9, wherein the coating layer is crosslinked by irradiation with ionizing radiation. Heat resistance and mechanical strength are improved because the coating layer is cross-linked.

  ADVANTAGE OF THE INVENTION According to this invention, the non-halogen insulated electric wire which is excellent in mechanical strengths, such as a flame retardance equivalent to PVC, a softness | flexibility, abrasion resistance, and edge resistance, and is useful for reduction of an environmental load can be provided.

  Next, the best mode for carrying out the present invention will be described. Polyphenylene ether is an engineering plastic obtained by oxidative polymerization of 2,6-xylenol synthesized using methanol and phenol as raw materials. In order to improve the moldability of polyphenylene ether, various materials are commercially available as modified polyphenylene ether resins in which polystyrene is blended with polyphenylene ether. As the polyphenylene ether resin used in the present invention, any of the above-mentioned polyphenylene ether resin alone and a polyphenylene ether resin obtained by melt blending polystyrene can be used. Moreover, what introduce | transduced carboxylic acid, such as maleic anhydride, can also be blended suitably and used.

  When a polyphenylene ether resin obtained by melt blending polystyrene is used as the polyphenylene ether resin, workability at the time of melt mixing with the styrene elastomer is preferably improved. Since the polyphenylene ether resin obtained by melt blending polystyrene is excellent in compatibility with the styrene elastomer, the resin pressure during the extrusion process is reduced, and the extrusion processability is improved.

  In such a polyphenylene ether resin, the deflection temperature under load changes depending on the blend ratio of polystyrene. However, when a resin with a deflection temperature under load of 130 ° C or higher is used, the mechanical strength of the electric wire coating increases and thermal deformation occurs. It is preferable because of its excellent characteristics. The deflection temperature under load is a value measured at a load of 1.80 MPa by the method of ISO75-1,2.

  A polyphenylene ether resin not blended with polystyrene can also be used as the polyphenylene ether resin. In this case, if a low-viscosity polyphenylene ether resin is used, the resin pressure during extrusion can be reduced while maintaining the mechanical strength. The intrinsic viscosity of the polyphenylene ether resin is preferably 0.1 to 0.6 dl / g, and more preferably 0.3 to 0.5 dl / g.

  Styrene elastomers used in the present invention include styrene / ethylene butene / styrene copolymers, styrene / ethylene propylene / styrene copolymers, styrene / ethylene / ethylene propylene / styrene copolymers, styrene / butylene / styrene copolymers. Examples thereof include hydrogenated polymers and partially hydrogenated polymers. Moreover, what introduce | transduced carboxylic acid, such as maleic anhydride, can also be blended suitably and used.

  Among these, use of a block copolymer elastomer of styrene and a rubber component is preferable from the viewpoints of improving extrudability, improving tensile elongation at break, and improving impact resistance. Block copolymers include hydrogenated styrene / butylene / styrene block copolymers, triblock copolymers such as styrene / isobutylene / styrene copolymers, styrene / ethylene copolymers, styrene / ethylene propylene, etc. It is preferable that the triblock component in the styrene elastomer is contained in an amount of 50% by weight or more because the strength and hardness of the electric wire coating is improved.

Also, those having a styrene content of 20% by weight or more contained in the styrene elastomer can be suitably used from the viewpoint of mechanical properties and flame retardancy. When the styrene content is less than 20% by weight, the hardness and extrusion processability are lowered. On the other hand, if the styrene content exceeds 50% by weight, the tensile elongation at break decreases, which is not preferable.
Further, the melt flow rate (abbreviated as “MFR”; measured at 230 ° C. × 2.16 kgf in accordance with JIS K 7210) serving as an index of molecular weight is preferably in the range of 0.8 to 15 g / 10 min. This is because if the melt flow rate is less than 0.8 g / 10 min, the extrusion processability is lowered, and if it exceeds 15 g / 10 min, the mechanical strength is lowered.

  The polyphenylene ether resin and the styrene elastomer can be melt-mixed at an arbitrary ratio, but from the viewpoint of the flexibility of the electric wire and the handleability as a harness, the polyphenylene ether resin is 40 to 40% of the entire resin composition. The amount of styrene-based elastomer is preferably 30 to 60 parts by weight based on the entire resin composition. When the content of the polyphenylene ether-based resin exceeds 70% by weight, the extrusion processability is lowered, and when it is less than 40% by weight, the mechanical strength and flame retardancy are lowered. More preferably, the polyphenylene ether resin is 50 to 60% by weight and the styrene elastomer is 40 to 50% by weight.

  Furthermore, as a resin component, it is possible to mix various resins, such as a polypropylene and a polyethylene, in the range which does not impair the meaning of this invention. A resin composition in which polyethylene and random polypropylene are mixed can be cross-linked by irradiation with ionizing radiation such as an accelerated electron beam or gamma ray, and is therefore suitable when heat resistance needs to be improved.

  Examples of the nitrogen-based flame retardant used in the present invention include melamine resin and melamine cyanurate. Nitrogen-based flame retardants do not generate toxic gases such as hydrogen halides even when incinerated after use, and can reduce the environmental burden. When melamine cyanurate is used as a nitrogen-based flame retardant, it is preferable in terms of heat stability at the time of mixing and an effect of improving flame retardancy.

  Melamine cyanurate can also be used after surface treatment with a silane coupling agent or a titanate coupling agent. Wear resistance and mechanical strength can be improved by combining surface-treated melamine cyanurate with a polyphenylene ether resin or styrene elastomer into which a carboxylic acid has been introduced.

  The content of the nitrogen-based flame retardant is preferably 5 to 70 parts by weight with respect to 100 parts by weight of the resin composition. If the amount is less than 5 parts by weight, the flame retardancy of the insulated wire is insufficient, and if it exceeds 70 parts by weight, the elongation and the extrusion processability are deteriorated. The content of the nitrogen flame retardant is more preferably 10 to 40 parts by weight.

  Further, the non-halogen flame retardant resin composition of the present invention is characterized by substantially not containing a phosphorus-based flame retardant. The environmental load such as eutrophication of the river can be reduced by substantially not including the phosphorus-based flame retardant. The term “substantially free” means that a flame retardant such as a phosphate ester is not actively added, and a material containing a trace amount of phosphorus component derived from a raw material resin or an additive of the present invention It is not excluded from the scope.

  Furthermore, a crosslinking aid can be added to the non-halogen flame retardant resin composition of the present invention. As the crosslinking aid, a polyfunctional monomer having a plurality of carbon-carbon double bonds in the molecule such as trimethylolpropane trimethacrylate, triallyl cyanurate, triallyl isocyanurate and the like can be preferably used. Moreover, it is preferable that a crosslinking adjuvant is a liquid at normal temperature. This is because when it is a liquid, it can be easily mixed with a polyphenylene ether resin or a styrene elastomer. Furthermore, it is preferable to use trimethylolpropane trimethacrylate as a crosslinking aid because compatibility with the resin is improved.

  In the non-halogen flame retardant resin composition of the present invention, an antioxidant, a processing stabilizer, a colorant, a heavy metal deactivator, a foaming agent, a polyfunctional monomer, and the like can be appropriately mixed as necessary. These materials can be prepared by mixing using a known melt mixer such as a short screw extruder, a pressure kneader, or a Banbury mixer.

  Furthermore, this invention provides the electric wire and cable which used said halogen-free flame-retardant resin composition as a coating layer. The electric wire / cable according to the present invention includes a conductor and a coating layer covering the conductor, and a known extruder can be used to form the coating layer on the conductor.

  The thickness of the coating layer can be appropriately selected according to the conductor diameter, but the thickness of the coating layer is preferably 0.3 mm or less in terms of mechanical strength. In the halogen-free electric wire according to the prior art, when the thickness of the covering layer is 0.3 mm or less, the performance is remarkably reduced in wear resistance and edge resistance. Performance is obtained, and the difference from the conventional electric wire is noticeable. Moreover, in the pressure welding electric wire, an electric wire having a coating layer thickness of 0.3 mm or less is preferably used from the viewpoint of fitting property with the connector.

  Furthermore, it is preferable that the coating layer is cross-linked by irradiation with ionizing radiation in that the mechanical strength is improved. Examples of ionizing radiation sources include accelerating electron beams, gamma rays, X-rays, α rays, ultraviolet rays, and the like. However, accelerated electrons are used from the viewpoint of industrial use, such as ease of use of ion sources, transmission thickness of ionizing radiation, and speed of crosslinking treatment. Lines are most preferably available.

  Next, the best mode for carrying out the invention will be described by way of examples. The examples are not intended to limit the scope of the invention.

[Examples 1 to 16]
(Creation of non-halogen flame retardant resin composition pellets)
Each component was melt-mixed according to the formulation shown in Table 1. Using a twin-screw mixer (45 mmφ, L / D = 42), melt-mixed at a cylinder temperature of 230 ° C. and a screw rotation speed of 100 rpm, melt-extruded into a strand, and then cooled and cut the molten strand to produce pellets .

(Production of insulated wires)
Using a single screw extruder (30 mmφ, L / D = 24), an insulated wire was manufactured by extrusion coating on a conductor. The conductor used was a seven-strand conductor (outer diameter 0.48 mm, twist pitch 5.6 mm) of a tin-plated copper wire with an element diameter of 0.16 mm, and the coating thickness was 0.25 mm. The extrusion conditions were such that the conductor preheating temperature was 120 ° C, the cylinder temperature was 230 ° C, the die temperature was 240 ° C, and the line linear velocity was 300 mm / min. In addition, the insulated electric wire of Example 16 was irradiated with an accelerated electron beam so that the irradiation amount was 6 Mrad.

(Evaluation of coating layer: tensile properties)
A conductor was extracted from the produced electric wire, and a tensile test of the coating layer was performed. The test conditions were tensile rate = 500 mm / min, distance between marked lines = 25 mm, temperature = 23 ° C., tensile strength and tensile elongation at break were measured with three samples, and the average value was obtained. A sample having a tensile strength of 10.3 MPa or more and a tensile elongation at break of 100% or more was judged as “pass”.

(Evaluation of coating layer: 2% modulus)
Using a sample similar to the above tensile test, after performing a tensile test at a tensile rate of 50 mm / min, a distance between marked lines of 25 mm, and a temperature of 23 ° C., the elongation becomes 2% from the stress-elongation curve. The elastic modulus was calculated.

(Evaluation of insulated wires: abrasion resistance test)
As shown in FIG. 1, a metal blade (0.125 mmR) is applied to the insulation coating from the direction orthogonal to the electric wire, and is reciprocated in the direction parallel to the electric wire with a load of 130 g, and the metal blade comes into contact with the internal conductor and becomes conductive. The number of reciprocations until the time was measured. As an index for passing the wear resistance, 30 times or more at which the PVC electric wire ratio is 70% or more is accepted.

(Evaluation of insulated wires: edge resistance test)
As shown in FIG. 2, a metal blade (0.125 mmR) was applied to the insulating coating from the direction orthogonal to the electric wire, and the load until contact with the internal conductor and conduction was measured. As an evaluation index, 100N or more is acceptable.

(Evaluation of insulated wires: Flame resistance test)
Ten samples were provided for the VW-1 vertical flame retardant test described in UL Standard 1581, 1080, and when all 10 points passed, it was determined as “pass”. The criterion is that when each sample is ignited 15 times for 5 seconds, the fire extinguishes within 60 seconds, and the absorbent cotton laid on the bottom is not burnt down by burning fallen objects, and the kraft paper attached to the top of the sample burns. Or that does not burn.

(Evaluation of insulated wires: Heat deformation test)
Based on UL Standard 758, the heat deformation test described in UL Standard 1581, 560 was performed. The electric wire was horizontally arranged, a metal round bar was pressed from the orthogonal direction, a load of 250 g was applied, and held at 136 ° C. for one hour, and the deformation rate of the insulation thickness was measured. The remaining ratio with respect to the initial thickness was determined to be 50% or more.

[Example 17]
A wire was produced in the same manner as in Example 2 except that the thickness of the insulating coating was 0.16 mm, and a series of evaluations were performed.

[Example 18]
A wire was prepared in the same manner as in Example 2 except that a tin-plated copper wire having an outer diameter of 0.81 mm was used as the conductor of the wire, and the thickness of the insulating coating was 0.3 mm, and a series of evaluations were performed. The results are shown in Table 1. Moreover, as a comparison, the evaluation result in a commercially available PVC electric wire is shown simultaneously.

[Comparative Examples 1 to 12]
Except having used the resin composition which has the mixing | blending prescription shown in Table 2, the electric wire was produced similarly to Examples 1-16, and a series of evaluation was performed. The results are shown in Table 2.

(footnote)
(* 1) Modified polyphenylene ether resin with a deflection temperature under load of 170 ° C. (* 2) Modified polyphenylene ether resin with a deflection temperature under load of 145 ° C. (* 3) Modified polyphenylene ether resin with a deflection temperature under load of 130 ° C. (* 4) Intrinsic viscosity 0. 47 dl / g polyphenylene ether resin (* 5) Polyphenylene ether resin with an intrinsic viscosity of 0.38 dl / g (* 6) Hydrogenated SEBS with a styrene content of 30 wt% and MFR = 5.0 g / 10 min
(* 7) Hydrogenated SEBS with a styrene content of 42 wt% and MFR = 0.8 g / 10 min
(* 8) Hydrogenated SEBS with styrene content of 67wt% and MFR = 2.0g / 10min
(* 9) Hydrogenated SEPS with a styrene content of 30 wt% and MFR = 2.4 g / 10 min
(* 10) Hydrogenated SEBS with a styrene content of 35 wt% and MFR = 8.0 g / 10 min
(* 11) MC860 manufactured by Nissan Chemical Industries, Ltd.
(* 12) MC6000 manufactured by Nissan Chemical Industries, Ltd.
(* 13) Aromatic condensed phosphate: PX200 manufactured by Daihachi Chemical Co., Ltd.
(* 14) Aromatic condensed phosphate: FP-500 manufactured by Asahi Denka Kogyo Co., Ltd.
(* 15) Nitrogen-phosphorus flame retardant: FP-2100 manufactured by Asahi Denka Kogyo Co., Ltd.
(* 16) Trimethylolpropane trimethacrylate (* 17) Other ingredients: Irganox 1010 manufactured by Ciba Specialty Chemicals, Adeka Stub CDA-1, manufactured by Asahi Denka Kogyo Co., Ltd., oleic acid amide

  Examples 1 to 16 are resins in which a polyphenylene ether / polystyrene blend polymer (polyphenylene ether resin) having a deflection temperature under load of 130 ° C. to 170 ° C. and a styrene elastomer are mixed at a weight ratio of 40/60 to 70/30. In the evaluation result of the electric wire using the non-halogen flame retardant resin composition in which melamine cyanurate which is a nitrogen-based organic flame retardant is blended in the range of 5 to 70 parts by weight with respect to 100 parts by weight of the composition as an insulating coating layer is there.

  As a result, the tensile strength and elongation at break of the coating layer were all acceptable levels. In addition, it is acceptable in all evaluations of wear resistance, edge resistance, flame resistance, and heat deformation test of electric wires, and electric wires using the non-halogen flame retardant resin composition of the present invention satisfy all required characteristics. I understood.

  Examples 17 and 18 are evaluation results of electric wires produced by changing the insulating film thickness and the conductor diameter. It was found that all required characteristics were satisfied regardless of the conductor diameter and insulating film thickness.

  Comparative Examples 1 to 6 are evaluation results of electric wires using a resin composition using a phosphate ester as a flame retardant without using a nitrogen-based flame retardant as a coating layer. The comparative example 1 which does not contain a flame retardant and the comparative examples 2 and 3 with a small amount of phosphoric acid ester fail the flame retardancy. In addition, when a large amount of phosphate ester is blended, flame retardancy increases, but flexibility as an electric wire is lost, and tensile properties and heat deformability are reduced.

  Comparative Examples 7 to 10 are evaluation results of electric wires in which a nitrogen-based flame retardant was not used and a resin composition in which the type of styrene elastomer was changed was used as a coating layer. In Comparative Examples 11 and 12, the type of the phosphorus-based flame retardant is changed. In any case, the flame retardancy is inferior, and when a phosphate ester is used, the heat deformability is greatly reduced.

  As a utilization example of the present invention, there is a higher harness for internal wiring of electronic devices such as copying machines and printers.

Claims (10)

  A halogen-free flame retardant resin composition containing 5 to 70 parts by weight of a nitrogen-based flame retardant and substantially free of a phosphorus-based flame retardant with respect to 100 parts by weight of a resin component, the resin A non-halogen flame retardant resin composition comprising 40 to 70 parts by weight of a polyphenylene ether resin and 30 to 60 parts by weight of a styrene elastomer in 100 parts by weight of a component.   The non-halogen flame retardant resin composition according to claim 1, wherein the styrene elastomer is a block copolymer elastomer of styrene and a rubber component.   The non-halogen flame retardant resin composition according to claim 1 or 2, wherein the polyphenylene ether resin is a polyphenylene ether resin obtained by melt blending polystyrene.   The non-halogen flame retardant resin composition according to any one of claims 1 to 3, wherein a deflection temperature under load of the polyphenylene ether resin is 130 ° C or higher.   The non-halogen flame retardant resin composition according to any one of claims 1 to 4, wherein the nitrogen-based flame retardant is melamine cyanurate.   The non-halogen flame retardant resin composition according to any one of claims 1 to 5, further comprising a crosslinking aid.   The non-halogen flame-retardant resin composition according to claim 6, wherein the crosslinking aid is trimethylolpropane trimethacrylate.   An electric wire / cable comprising the non-halogen flame retardant resin composition according to claim 1 as a coating layer.   The electric wire / cable according to claim 8, wherein the covering layer has a thickness of 0.3 mm or less.   The electric wire / cable according to claim 8 or 9, wherein the coating layer is crosslinked by irradiation with ionizing radiation.