JP2006241182A - Insulating resin composition and insulated electric wire - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an insulating resin composition that possesses excellent mechanical properties required of an insulated wire, has high abrasion resistance, exhibits high heat resistance even when used simultaneously with a PVC electric wire and causes no problems such as elution of heavy metal compounds or phosphorous compounds when wastes thereof are subjected to reclamation disposal or generation of a large volume of smoke or corrosive gases when wastes thereof are incinerated, and an insulated electric wire using the composition. <P>SOLUTION: The insulating resin composition is constituted of at least a resin component, mainly composed of an ethylene copolymer and a polyolefin resin modified with an unsaturated carboxylic acid, and a flame retardant comprised of aluminum hydroxide, mainly composed of aluminum hydroxide untreated and/or treated with a silane coupling agent bearing a vinyl group and/or a methacryloxy group on its end, or comprised of a silane coupling agent bearing a vinyl group and/or a methacryloxy group and untreated and/or discretionarily treated aluminum hydroxide. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

The present invention relates to an insulating resin composition that does not cause elution of heavy metal compounds, generation of a large amount of smoke or corrosive gas at the time of disposal such as landfill and incineration, and an insulated wire used for internal and external wiring of electric / electronic devices. About.

Insulated wires used for internal and external wiring of electrical / electronic devices are required to have various properties such as flame retardancy, tensile properties, and heat resistance. For this reason, as a covering material for these insulated wires, a resin composition mainly composed of an ethylene-based copolymer containing a polyvinyl chloride (PVC) compound or a halogen-based flame retardant containing a bromine atom or a chlorine atom in the molecule. It is well known to use things.

In recent years, various problems have been raised when an insulated wire using such a coating material is discarded without appropriate treatment. For example, when discarded by landfill, elution of plasticizers and heavy metal stabilizers blended in the coating material, and when incinerated, problems such as generation of a large amount of corrosive gas and generation of dioxins occur.
For this reason, studies are being actively conducted on techniques for coating electric wires with non-halogen flame retardant materials that do not generate harmful heavy metals or halogen-based gases.

Conventional non-halogen flame retardant materials are those in which flame retardancy is expressed by blending a flame retardant containing no halogen with a resin. Examples of flame retardants for such coating materials include magnesium hydroxide, water Metal hydrates such as aluminum oxide, and as resins, polyethylene, ethylene-1-butene copolymer, ethylene-propylene copolymer, ethylene-vinyl acetate copolymer, ethylene-ethyl acrylate copolymer An ethylene-propylene-diene terpolymer is used.

JP 2004-204072 A

By the way, a wire harness used as an automobile or the like is required to have high strength, wear resistance, and oil resistance from the viewpoint of safety.
Moreover, since it is used by being bundled together with the PVC electric wire in the transition period, the non-halogen electric wire is also deteriorated due to the deterioration of the PVC, and the heat resistance is remarkably lowered.

The present invention solves these problems, has excellent mechanical properties required for insulated wires, has high wear resistance, and can obtain high heat resistance even when used simultaneously with PVC wires, and An object of the present invention is to provide an insulating resin composition free from problems such as elution of heavy metal compounds and phosphorus compounds by landfill at the time of disposal, generation of a large amount of smoke and corrosive gas by incineration, and an insulated wire using this composition. And

In order to solve the above-mentioned problems, the present inventors have investigated the improvement of the trauma resistance and acid resistance. As a result, the base material is an ethylene copolymer, a polyolefin modified with an unsaturated carboxylic acid, and, if necessary, polypropylene. By using a resin as the main component and adding a specific amount of aluminum hydroxide, insulation that retains excellent mechanical strength, has high wear resistance, and can maintain high heat resistance even when used in combination with PVC The inventors succeeded in finding a resin composition and an insulated wire. The present invention has been completed based on this finding.
That is, the present invention
(1) Ethylene copolymer 95 to 40% by mass, polyolefin resin 2 to 45% by mass modified with unsaturated carboxylic acid, and resin component (A) 100% by mass of polypropylene resin 0 to 25% by mass Insulating resin composition characterized by containing 60 to 150 parts by mass of aluminum hydroxide with respect to parts,
(2) The aluminum hydroxide is an aluminum hydroxide mainly composed of aluminum hydroxide treated with a silane coupling agent having no treatment and / or vinyl group and / or methacryloxy group as a terminal. The insulating resin composition according to (1),
(3) Ethylene copolymer 95 to 40% by mass, polyolefin resin modified with unsaturated carboxylic acid 2 to 45% by mass, and polypropylene resin 0 to 25% by mass of resin component (A) 100% by mass Insulating resin composition comprising 0.1 to 4 parts by mass of a silane coupling agent having a vinyl group and / or a methacryloxy group and 60 to 150 parts by mass of aluminum hydroxide,
(4) The ethylene-based polymer is an ethylene / α-olefin copolymer synthesized with 35 to 85% by mass of an ethylene-vinyl acetate copolymer and / or an ethylene- (meth) alkyl acrylate copolymer using a metallocene catalyst. The insulating resin composition according to any one of (1) to (3), which contains 0 to 50% by mass of a polymer,
(5) The resin component (A) contains 0.5 to 8 parts by mass of a hindered phenol antioxidant and 0.3 to 6 parts by mass of a heavy metal deactivator with respect to 100 parts by mass. The insulating resin composition according to any one of (1) to (4),
(6) 0.5 to 8 parts by mass of hindered phenol antioxidant, 0.3 to 6 parts by mass of heavy metal deactivator, and benzimidazole antioxidant for 100 parts by mass of the resin component (A) Insulating resin composition according to any one of (1) to (4), comprising 0.2 to 8 parts by mass of an agent,
(7) An insulated wire, wherein the insulating resin composition according to any one of (1) to (6) is coated around a conductor,
(8) The insulating resin composition according to any one of (1) to (6) is coated around a conductor to form a covering, and the covering is crosslinked. Insulated wires,
Is to provide.

  The insulating resin composition of the present invention and the insulated wire using this composition have excellent mechanical properties and high wear resistance, and even when used simultaneously with a PVC wire, high heat resistance is obtained, and There are no problems such as elution of heavy metal compounds and phosphorus compounds by landfill at the time of disposal, generation of large amounts of smoke and corrosive gas by incineration.

  The insulating resin composition of the present invention includes at least an ethylene copolymer, a resin component mainly composed of a polyolefin resin modified with an unsaturated carboxylic acid, and an untreated and / or vinyl group and / or methacryloxy group as a terminal. Aluminum hydroxide mainly composed of aluminum hydroxide treated with a silane coupling agent, or a silane coupling agent having a vinyl group and / or a methacryloxy group and non-treated and / or optionally treated Consists of a flame retardant made of aluminum.

  The insulating resin composition of the present invention combines a surface of aluminum hydroxide or a silane coupling agent on the surface of aluminum hydroxide with a polyolefin resin modified with an ethylene copolymer and an unsaturated carboxylic acid, resulting in high mechanical strength and High wear resistance can be obtained. Further, by adding a specific anti-aging agent and copper damage inhibitor, the heat resistance can be maintained without deteriorating the heat resistance even when brought into contact with the PVC resin or the electric wire. Although the mechanism is not clear, heat resistance cannot be maintained when silane coupling agent-treated magnesium hydroxide is used as a flame retardant even when the same anti-aging agent and copper damage inhibitor are used. Further, in the case of magnesium hydroxide surface-treated with a different surface treatment agent such as fatty acid, the heat resistance is lowered when it is brought into contact with the PVC resin.

Hereinafter, the components contained in the insulating resin composition of the present invention will be described.
(A) Ethylene-based copolymer Examples of the ethylene-based copolymer that can be used in the present invention include an ethylene-vinyl acetate copolymer, an ethylene-acrylic acid copolymer, and an ethylene- (meth) acrylate alkyl copolymer. Polymer, ethylene- (meth) acrylic acid alkyl copolymer rubber, ethylene- (meth) acrylic acid ester- (meth) acrylic acid copolymer rubber (acrylic rubber), ethylene / α-olefin copolymer, ethylene- Examples include propylene rubber.

Of the ethylene-based copolymers that can be used in the present invention, the ethylene / α-olefin copolymer is preferably a copolymer of ethylene and an α-olefin having 4 to 12 carbon atoms, Specific examples thereof include 1-butene, 1-hexene, 4-methyl-1-pentene, 1-octene, 1-decene, 1-dodecene and the like.
Ethylene / α-olefin copolymers include LLDPE (linear low density polyethylene), LDPE (low density polyethylene), VLDPE (very low density polyethylene), EBR (ethylene / butadiene rubber), and single site catalyst. And an ethylene / α-olefin copolymer synthesized in the above. Among these, an ethylene / α-olefin copolymer synthesized in the presence of a single site catalyst is preferable.

  As the ethylene / α-olefin copolymer synthesized in the presence of the single site catalyst used in the present invention, those having improved molding processability are preferable, and as such, from Dow Chemical, “ “AFFINITY” “ENGAGE” (product name) is marketed by Nippon Polychem Co., Ltd. “Kernel” (product name).

  Although not particularly limited, the ethylene / α-olefin copolymer synthesized in the presence of a single site catalyst is 0 to 50% by mass, preferably 5 to 45% by mass, more preferably 100% by mass of the resin component (A). Is preferably 10 to 45% by mass, ethylene- (meth) acrylic acid alkyl copolymer, ethylene- (meth) acrylic acid alkyl copolymer rubber, ethylene- (meth) acrylic acid ester- (meth). The resin component selected from acrylic acid copolymer rubber (acrylic rubber) is 35 to 85% by mass, preferably 40 to 85% by mass, and more preferably 45 to 80% by mass.

If there is too much ethylene / α-olefin copolymer synthesized in the presence of a single-site catalyst, the heat resistance will decrease greatly due to adhesion to PVC, and if it is too small, the wear resistance and mechanical strength will be significantly reduced. It is to do.

The density of the ethylene / α-olefin copolymer is preferably 0.880 g / cm ³ or more, more preferably 0.900 g / cm ³ or more, and particularly preferably 0.910 g / cm ³ or more. This is because when this density is low, wear resistance and mechanical strength are low. The upper limit of the density is not particularly limited, but usually the upper limit is about 0.945 g / cm ³ .
Further, the ethylene / α-olefin copolymer preferably has a melt flow index (ASTM D-1238) of 0.5 to 30 g / 10 min.

Of the ethylene copolymers that can be used in the present invention, ethylene-propylene copolymer rubber (EPM) is a rubber-like copolymer of ethylene and propylene. Here, the ethylene / propylene copolymer rubber means one having an ethylene component content of usually about 40 to 75% by weight. Also included is an ethylene-propylene terpolymer (EPDM) in which a repeating unit having an unsaturated group is added to the polymer as a third component other than ethylene and propylene.

  The ethylene copolymer should be 95 to 40% by mass in 100% by mass of the resin component. When it is more than 95% by mass, the mechanical strength may be lowered or the wear resistance may be significantly lowered.

(B) Polyolefin resin modified with an unsaturated carboxylic acid or derivative thereof As a polyolefin resin modified with an unsaturated carboxylic acid or derivative thereof (hereinafter collectively referred to as unsaturated carboxylic acid or the like) that can be used in the present invention Examples thereof include polyolefin resins such as linear polyethylene, ultra-low density polyethylene, and high density polyethylene, ethylene-vinyl acetate copolymers, ethylene- (meth) acrylate copolymers, and styrene elastomers.

Examples of the unsaturated carboxylic acid used for modification include maleic acid, itaconic acid, fumaric acid and the like, and examples of the unsaturated carboxylic acid derivative include maleic acid monoester, maleic acid diester, maleic anhydride, itaconic acid. Examples include monoesters, itaconic acid diesters, itaconic anhydride, fumaric acid monoesters, fumaric acid diesters, and fumaric anhydride.

The modification of the polyolefin can be performed, for example, by heating and kneading the polyolefin and an unsaturated carboxylic acid in the presence of an organic peroxide. The amount of modification with maleic acid is usually about 0.1 to 7% by weight.
Further, an ethylene- (meth) acrylic acid copolymer may be used for a part or all of the polyolefin resin modified with the unsaturated carboxylic acid or derivative thereof.

  By adding a polyolefin resin modified with this unsaturated carboxylic acid or derivative thereof, the wear resistance and mechanical strength of the resulting resin composition are improved. Moreover, it becomes possible to maintain high heat resistance even if it is bonded to a PVC resin by bonding with aluminum hydroxide treated with a silane coupling agent.

(C) Polypropylene resin In this invention, you may add a polypropylene resin as needed. Examples of the polypropylene resin that can be used in the present invention include homopolypropylene, random polypropylene, block polypropylene, propylene and other small amounts of α-olefin (for example, 1-butene, 1-hexene, 4-methyl-1-pentene, etc.). And a copolymer.
Here, random polypropylene refers to an ethylene / propylene random copolymer having an ethylene component content of about 1 to 4% by weight, and block polypropylene refers to an ethylene / propylene block copolymer having an ethylene component content of about 5 to 20% by weight.
The amount of this polypropylene is limited to 0 to 25% by mass in 100% by mass of the resin component (A). This is because if this amount is more than 25% by mass, the heat resistance when bonded to PVC is significantly reduced.

(D) Aluminum hydroxide Aluminum hydroxide must be used as a flame retardant in the present invention. Aluminum hydroxide used is untreated and / or treated with a silane coupling agent having a vinyl group and / or a methacryloxy group, or mixed with a silane coupling agent having a vinyl group and / or a methacryloxy group. It is necessary to add at the time of kneading or molding. The aluminum hydroxide is preferably untreated and / or treated with a silane coupling agent having a vinyl group and / or a methacryloxy group.

  The amount of the silane coupling agent added is 0.1 to 4 parts by mass, preferably 0.2 to 3 parts by mass, and more preferably 0.4 to 2.5 parts by mass with respect to 100 parts by mass of the resin component (A). It is.

Examples of the silane coupling agent used for the surface treatment include vinyltrimethoxysilane, vinyltriethoxysilane, methacryloxypropyltrimethoxysilane, methacryloxypropyltriethoxysilane, methacryloxypropylmethyldimethoxysilane, and the like. These may be used alone or in combination of two or more.
Preferably, 0.1 to 4 parts by mass of a silane coupling agent having a vinyl group or a methacloxy group and an untreated aluminum hydroxide are used in combination, or the surface-treated water is treated with a silane coupling agent having a vinyl group or a metacloxy group. It is better to use aluminum oxide.

Although this mechanism has not been clearly elucidated, the aluminum hydroxide and the resin are bonded directly or via a silane coupling agent, so that not only the strength and wear resistance are improved, but also a special adhesive bonded to PVC. It also works to improve heat resistance.

  When aluminum hydroxide is treated with a silane coupling agent, the silane coupling agent can be blended with the metal hydrate in advance or can be added simultaneously during kneading.

The compounding quantity of aluminum hydroxide is 60-150 mass parts with respect to 100 mass parts of thermoplastic resin components (A) in the resin composition of this invention.
When the amount is less than 60 parts by mass, the flame retardancy is remarkably lowered. When the amount is more than 150 parts by mass, not only the mechanical strength and wear resistance are remarkably lowered but also the heat resistance when bonded to PVC is remarkably lowered.

(E) Hindered phenol antioxidants As the hindered phenol antioxidant used in the present invention, pentaerythritol tetrakis (3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate), octadecyl -3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate), 3, 3'3 ", 5, 5 ', 5" -hexa-tert-butyl-a, a', a " -(Mesitylene-2,4,6triyl) tri-p-cresol, 1,3,5-tris (3,5-di-tert-butyl-4-hydroxybenzyl) -1,3,5-triazine-2 , 4, 6 (1H, 3H, 5H) -trione and the like.

The amount of the hindered phenol is 0.5 to 8 parts by mass, preferably 1 to 7 parts by mass, and more preferably 1.5 to 6 parts by mass with respect to 100 parts by mass of the resin component (A).
When the amount is small, the heat resistance when bonded to PVC is lowered, and when the amount is large, the wear resistance tends to be lowered.

(F) Heavy metal deactivator The heavy metal deactivator used in the present invention includes N, N′-bis (3- (3,5-di-t-butyl-4-hydroxyphenyl) propionyl) hydrazine, 3 -(N-salicyloyl) amino-1,2,4-triazole, 2,2'-oxamidobis- (ethyl 3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate) and the like.

It is 0.3-6 mass parts with respect to 100 mass parts of these heavy metal resin components, Preferably it is 0.5-6 mass parts, More preferably, it is 0.8-5 mass parts.
When this amount is small, the heat resistance when bonded to PVC is lowered, and when it is too large, not only the mechanical strength and wear resistance are lowered, but also the heat resistance when bonded to PVC tends to be lowered.

(G) Benzimidazole-based antioxidant In the present invention, a benzimidazole-based antioxidant can be blended as needed to help reduce heat resistance due to adhesion with PVC. Although it is not well understood about the mechanism by which the heat resistance decrease can be suppressed by adding this antioxidant, it is possible to suppress the transition of antioxidants used in combination and particularly copper damage inhibitors to PVC, or to promote these effects. It is thought that there is work.

  Examples of the benzimidazole antioxidant include 2-mercaptobenzimidazole, 2-mercaptomethylbenzimidazole, 4-mercaptomethylbenzimidazole, 5-mercaptomethylbenzimidazole, and zinc salts thereof. As for the effect, it is particularly effective to use a zinc salt.

  The amount of the benzimidazole antioxidant is preferably 0.2 to 8 parts by mass with respect to 100 parts by mass of the resin component. When the amount is 0.2 parts by mass or less, there is substantially no effect, and when the amount exceeds 8 parts by mass, the PVC to be bonded is deteriorated, and this deterioration causes the resin composition to deteriorate.

  The insulating resin composition of the present invention can be blended with at least one selected from zinc stannate, zinc hydroxystannate and zinc borate as necessary, and can further improve flame retardancy. By using these compounds, the speed of shell formation during combustion is increased and the shell formation becomes stronger. Accordingly, the flame retardancy can be dramatically improved together with the melamine cyanurate compound that generates gas from the inside during combustion.

The insulating resin composition of the present invention includes various additives commonly used in electric wires and cables, such as antioxidants, light stabilizers, ultraviolet absorbers, and flame retardant (auxiliary) agents. In addition, fillers, lubricants and the like can be appropriately blended within a range that does not impair the object of the present invention.
Examples of the lubricant include hydrocarbons, fatty acids, fatty acid amides, esters, alcohols, and metal soaps.

  The insulating resin composition of the present invention can be obtained by melt-kneading each of the above components with a commonly used kneading apparatus such as a twin-screw kneading extruder, a Banbury mixer, a kneader, or a roll.

Next, the insulated wire of the present invention will be described.
The insulated wire of the present invention is one in which a conductor is coated with a crosslinked product of the above-described insulating resin composition of the present invention. The insulated resin composition of the present invention is a conductor using an ordinary extruder for producing electric wires. It can be produced by extrusion coating around the periphery and then crosslinking the coating layer. By making the coating layer a crosslinked body, not only the heat resistance is improved, but also the flame retardancy is improved. The method for crosslinking is not particularly limited, and can be performed by an electron beam crosslinking method or a chemical crosslinking method.

  When the electron beam crosslinking method is used, the electron beam dose is suitably 1 to 30 Mrad, and in order to perform crosslinking efficiently, a methacrylate compound such as trimethylolpropane triacrylate, an allyl compound such as triallyl cyanurate, You may mix | blend polyfunctional compounds, such as a maleimide type compound and a divinyl type compound, as a crosslinking adjuvant.

  In the case of the chemical crosslinking method, an organic peroxide such as hydroperoxide, dialkyl peroxide, diacyl peroxide, peroxy ester, ketone peroxy ester, and ketone peroxide is blended as a crosslinking agent in the resin composition, and crosslinked by heat treatment after extrusion coating. To do.

  The conductor diameter of the insulated wire of the present invention, the material of the conductor, and the like are not particularly limited, and are appropriately determined depending on the application. The thickness of the coating layer of the insulating resin composition formed around the conductor is not particularly limited, but is preferably 0.10 to 1 mm. In addition, the insulating layer may have a multilayer structure, and may have an intermediate layer in addition to the coating layer formed of the insulating resin composition of the present invention.

EXAMPLES Hereinafter, although this invention is demonstrated further in detail based on an Example, this invention is not limited to this.
Examples 1-8 and Comparative Examples 1-3
First, each component shown in Tables 1 and 2 was dry blended at room temperature, and melt-kneaded using a Banbury mixer to produce each insulating resin composition.
Some materials were kneaded by raising the temperature to 220 ° C.
A 1 mm-thick sheet was prepared using the obtained compound. The sheet was cross-linked at 10 Mrad for the accelerated test.
Next, using an extrusion coating apparatus for producing electric wires, an insulating resin composition previously melt-kneaded is extruded onto a conductor (conducted tin-plated annealed copper stranded wire with a conductor diameter of 0.9 mmφ: 19 / 0.19 mmφ). Insulated wires were manufactured respectively. The outer diameter was 1.5 mm (thickness of the coating layer: 0.25 mm), and some of the electric wires were covered with an electron beam at 10 Mrad and crosslinked.

The components shown in Tables 1 and 2 were as follows.
(01) Ethylene-vinyl acetate copolymer VA content = 17% by mass
(02) Ethylene-ethyl acrylate copolymer EA content = 18% by mass
(03) Polyethylene synthesized in the presence of a single site catalyst, density = 925 kg / m ³
(04) Maleic anhydride modified polyethylene (05) Maleic anhydride modified SEBS
(06) Block polypropylene, MI = 0.5
(07) Silane coupling agent TSL8311 (trade name, manufactured by Toshiba Silicone Co., Ltd.) having a vinyl group at the terminal, vinyl triethoxysilane (08) Silane coupling agent TSL8370 (trade name, manufactured by Toshiba Silicone Co., Ltd.) ), Γ-methacryloxypropyltrimethoxysilane (09) aluminum hydroxide (10) silane coupling agent treated aluminum hydroxide (11) magnesium hydroxide (12) silane coupling agent treated magnesium hydroxide (13) lubricant AC polyethylene No. 6, Hoechst Synthesis Co., Ltd. (14) Hindered phenol antioxidant Irgnox 1010 (trade name, manufactured by Ciba Specialty Chemicals Co., Ltd.)
(15) Benzimidazole antioxidant NOCRACK MBZ (trade name, manufactured by Ouchi Shinko Chemical Co., Ltd.)
(16) Heavy metal deactivator CDA-1 (trade name, manufactured by Asahi Denka Kogyo Co., Ltd.)

The following tests were performed on each of the obtained insulated wires. The results are shown in Tables 3-4.
Elongation and Tensile Strength The elongation (%) of the resin composition and the tensile strength (MPa) of the coating layer were evaluated based on JIS K 6723.
The elongation (%) of each insulated wire and the tensile strength (MPa) of the coating layer were measured under conditions of 25 mm between marked lines and a tensile speed of 500 mm / min.
The required properties of elongation and tensile strength are each 100% or more and 10 MPa or more.
Flame Retardancy For each insulated wire, a horizontal combustion test of UL1581 was performed and the number of passes was shown (passed number / N number).
Contact property with PVC A 1 mm-thick sheet of PVC material shown in Table 5 was prepared, and the wire and a cross-linked resin composition sheet (tensile test dumbbell piece) were sandwiched between them and left at 150 ° C. for 70 hours and for 100 hours.
After removal, the PVC sheet was removed, the wire was self-diametered, the sheet was bent 180 degrees, and the presence of cracks was confirmed.
The thing which the crack did not arise at 150 degreeC70Hr is a pass.

Claims (8)

With respect to 100 parts by mass of the resin component (A) containing 95 to 40% by mass of an ethylene copolymer, 2 to 45% by mass of a polyolefin resin modified with an unsaturated carboxylic acid, and 0 to 25% by mass of a polypropylene resin. An insulating resin composition comprising 60 to 150 parts by mass of aluminum hydroxide. The aluminum hydroxide is mainly composed of aluminum hydroxide treated with a silane coupling agent having no treatment and / or vinyl group and / or methacryloxy group as a terminal. 2. The insulating resin composition according to 1. With respect to 100 parts by mass of the resin component (A) containing 95 to 40% by mass of an ethylene copolymer, 2 to 45% by mass of a polyolefin resin modified with an unsaturated carboxylic acid, and 0 to 25% by mass of a polypropylene resin. An insulating resin composition characterized by containing 0.1 to 4 parts by mass of a silane coupling agent having a vinyl group and / or a methacryloxy group and 60 to 150 parts by mass of aluminum hydroxide. The ethylene-based polymer is an ethylene / α-olefin copolymer synthesized with 35 to 85% by mass of an ethylene-vinyl acetate copolymer and / or an ethylene- (meth) acrylate alkyl copolymer and a metallocene catalyst. It contains 0-50 mass%, The insulating resin composition of any one of Claims 1 thru | or 3 characterized by the above-mentioned. The resin component (A) contains 0.5 to 8 parts by mass of a hindered phenol antioxidant and 0.3 to 6 parts by mass of a heavy metal deactivator with respect to 100 parts by mass of the resin component (A). The insulating resin composition according to any one of claims 1 to 4. 0.5 to 8 parts by mass of hindered phenol aging inhibitor, 0.3 to 6 parts by mass of heavy metal deactivator, and 0 to benzimidazole antioxidant with respect to 100 parts by mass of resin component (A). The insulating resin composition according to any one of claims 1 to 4, wherein the resin composition is contained in an amount of 2 to 8 parts by mass. An insulated wire, wherein the insulating resin composition according to any one of claims 1 to 6 is coated around a conductor. An insulated wire, wherein the insulating resin composition according to any one of claims 1 to 6 is coated around a conductor to form a covering, and the covering is crosslinked.