Cable

Abstract

A cable provided with an electric wire and a metal layer covering the electric wire, the electric wire comprising a conductor and an insulating material provided on the outer peripheral surface of the conductor, the insulating material containing a polyolefin resin, a phenolic antioxidant, and a copper aging inhibitor, the polyolefin resin content of the insulating material is 98% by mass or more, and the insulating material contains 0.01-0.5 parts by mass of the phenolic antioxidant and 0.01-0.5 parts by mass of the copper aging inhibitor per 100 parts by mass of the polyolefin resin. The dielectric loss tangent of the insulating material at 10 GHz is 3.0 * 10 <-4 > or less, the metal layer includes a longitudinally wrapped metal layer formed by longitudinally wrapping metal strips, the metal strips partially overlap each other in the width direction of the metal strips to form an overlapping portion, and the width of the overlapping portion is 1 / 20 to 1 / 3 of the width of the metal strips.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to a cable. This application claims priority based on Japanese Patent Application, i.e., Japanese Patent Application No. 2023-106957 filed on June 29, 2023. The entire disclosure of the Japanese Patent Application is incorporated herein by reference. BACKGROUND

[0002] With the demand for automated driving technology and driving assistance functions of automobiles, further increases in the capacity and speed of information transmission in vehicle information electric wires are required. A vehicle information electric wire is a wire in which a conductor composed of a metal such as copper is covered with an insulating material composed of a polyolefin-based resin. Transmission loss has a positive correlation with the frequency of a signal and the dielectric loss tangent of the insulating material, and thus, in order to increase the speed of signal transmission, it is necessary to reduce the dielectric loss tangent of the insulating material, further reduce the transmission loss, and thereby stably transmit a signal.

[0003] Generally, in order to improve mechanical protection and flame retardancy, oil resistance, and the like, a vehicle information electric wire is used as a vehicle information transmission cable in which an outer skin material is covered on one or a plurality of vehicle information electric wires. A vehicle information transmission cable is sometimes bundled with a wire, a cable, and a harness in which a polyvinyl chloride (hereinafter, also referred to as “PVC”) is used as an insulating material. In this case, an antioxidant contained in the insulating material of the vehicle information transmission cable sometimes migrates to the PVC of the surrounding wire or the like, and thus, the insulating material of the vehicle information transmission cable is oxidatively deteriorated, or the insulating material of the vehicle information transmission cable is deteriorated due to the generation of hydrochloric acid gas from the PVC of the surrounding wire or the like.

[0004] In Patent Literature 1, a technology is disclosed in which, in a case where a vehicle information transmission cable is bundled with a harness having an insulating material composed of PVC, the deterioration of the insulating material of the vehicle information transmission cable is suppressed. Specifically, in order to suppress the deterioration of the insulating material, a large amount of an antioxidant is added to the insulating material.

[0005] PRIOR ART DOCUMENTS

[0006] PATENT LITERATURE

[0007] Patent Literature 1: Japanese Patent Application Publication No. 2022-60751 SUMMARY

[0008] The cable disclosed herein is a cable having wires and a metal layer covering the wires, wherein the wires include a conductor and an insulating material disposed on the outer peripheral surface of the conductor, the insulating material comprising a polyolefin resin, a phenolic antioxidant, and a copper aging inhibitor, wherein the polyolefin resin content of the insulating material is 98% by mass or more, and relative to 100 parts by mass of the polyolefin resin, the insulating material contains 0.01 to 0.5 parts by mass of the phenolic antioxidant and 0.01 to 0.5 parts by mass of the copper aging inhibitor, and the dielectric loss tangent of the insulating material at 10 GHz is 3.0 × 10⁻⁶. －4 Hereinafter, the metal layer includes a longitudinally wrapped metal layer composed of longitudinally wrapped metal strips, wherein the metal strips partially overlap each other in the width direction to form an overlapping portion, and the width of the overlapping portion is more than 1 / 20 and less than 1 / 3 of the width of the metal strips. Attached Figure Description

[0009] Figure 1 These are schematic cross-sectional views of the cables in Embodiments 1 and 2.

[0010] Figure 2 This is a schematic cross-sectional view of the cable according to embodiment 3.

[0011] Figure 3 This is a diagram used to illustrate the longitudinal wrapping of metal strips.

[0012] Figure 4 This is a diagram used to illustrate the wrapping of metal strips.

[0013] Figure 5A This is a schematic cross-sectional view of an example of the cable in Embodiment 4.

[0014] Figure 5B This is a schematic cross-sectional view of another example of the cable in Embodiment 4.

[0015] Figure 6A This is a schematic cross-sectional view of an example of the cable in Embodiment 5.

[0016] Figure 6B This is a schematic cross-sectional view of another example of the cable in Embodiment 5.

[0017] Figure 7 This is a schematic cross-sectional view of the cable according to embodiment 6.

[0018] Figure 8 This is a schematic cross-sectional view of another example of the cable in Embodiment 6.

[0019] Figure 9 This is a schematic cross-sectional view of the cable according to embodiment 7.

[0020] Figure 10 This is a schematic cross-sectional view of another example of the cable in Embodiment 7.

[0021] Figure 11A This is a cross-sectional view of an example of a test structure used for evaluating the inhibition of insulation degradation.

[0022] Figure 11B This is a cross-sectional view of another example of a test structure used for evaluating the inhibition of insulation degradation. Detailed Implementation

[0023] [The problem this disclosure aims to solve]

[0024] Adding large amounts of antioxidants can increase the dielectric loss tangent of the insulating material, thus hindering high-speed signal transmission, and is therefore not preferred.

[0025] Therefore, the object of this disclosure is to provide a cable in which the dielectric loss tangent of the insulation material does not increase, even when used bundled with wire harnesses having insulation material made of PVC, and the degradation of the insulation material is suppressed. Degradation of the insulation material referred to herein includes both heat aging and degradation caused by harmful gases emitted by PVC.

[0026] [Effects of this disclosure]

[0027] According to this disclosure, a cable can be provided in which the dielectric loss tangent of the cable's insulation material does not increase even when used bundled with a wire harness having insulation material made of PVC, and the degradation of the cable's insulation material is suppressed.

[0028] [Description of embodiments of this disclosure]

[0029] First, the implementation plan disclosed herein will be listed for illustration.

[0030] (1) The cable disclosed herein is a cable having wires and a metal layer covering the wires, wherein the wires include a conductor and an insulating material disposed on the outer peripheral surface of the conductor, the insulating material comprising a polyolefin resin, a phenolic antioxidant, and a copper inhibitor, wherein the polyolefin resin content of the insulating material is 98% by mass or more, and relative to 100 parts by mass of the polyolefin resin, the insulating material contains 0.01 to 0.5 parts by mass of the phenolic antioxidant and 0.01 to 0.5 parts by mass of the copper inhibitor, and the dielectric loss tangent of the insulating material at 10 GHz is 3.0 × 10⁻⁶. －4Hereinafter, the metal layer includes a longitudinally wrapped metal layer composed of longitudinally wrapped metal strips, wherein the metal strips partially overlap each other in the width direction to form an overlapping portion, and the width of the overlapping portion is more than 1 / 20 and less than 1 / 3 of the width of the metal strips.

[0031] (2) The cable disclosed herein is a cable having wires and a metal layer covering the wires, wherein the wires include a conductor and an insulating material disposed on the outer peripheral surface of the conductor, the insulating material comprising a polyolefin resin, a phenolic antioxidant, and a copper aging inhibitor, the polyolefin resin content of the insulating material being 98% by mass or more, and relative to 100 parts by mass of the polyolefin resin, the insulating material comprising 0.01 parts by mass and 0.5 parts by mass of the phenolic antioxidant and 0.01 parts by mass and 0.5 parts by mass of the copper aging inhibitor, and the dielectric loss tangent of the insulating material at 10 GHz being 3.0 × 10⁻⁶. －4 Hereinafter, the metal layer includes a wrapped metal layer formed by wrapping metal strips, wherein the metal strips partially overlap each other in the width direction of the metal strips to form an overlapping portion, the width of the overlapping portion is more than 1 / 5 and less than 1 / 2 of the width of the metal strips, and the rotation angle of the metal strips is greater than 0° and less than 80°.

[0032] Based on (1) and (2) above, it is possible to provide a cable in which the dielectric loss tangent of the cable insulation does not increase even when used bundled with wire harnesses having insulation material made of PVC, and the degradation of the cable insulation material is suppressed. The reason for this is speculated as follows.

[0033] The insulation material of the cable disclosed herein comprises a polyolefin resin and a phenolic antioxidant. In this insulation material, the amount of the phenolic antioxidant is between 0.01 and 0.5 parts by mass relative to 100 parts by mass of the polyolefin resin, indicating a low content of the phenolic antioxidant. Therefore, the dielectric loss tangent of the insulation material does not increase, and oxidative degradation of the insulation material is suppressed.

[0034] The metal layer of the cable disclosed herein also has a shielding effect against the intrusion of hydrochloric acid gas generated by the PVC of the surrounding wire harness into the cable interior. Therefore, hydrochloric acid gas will not reach the cable insulation material, thus inhibiting its degradation.

[0035] The metal layer of the cable disclosed herein also has a noise-blocking effect. Therefore, the cable of this disclosure can reliably transmit signals.

[0036] The cable disclosed herein has a small dielectric loss tangent, making it particularly suitable for high-speed transmission.

[0037] (3) In (1) or (2) above, the cable may also include a plurality of the wires, and the metal layer covers each of the wires.

[0038] This results in a higher noise shielding effect.

[0039] (4) In (1) or (2) above, the cable may also have a first wire group consisting of two or more wires, and the metal layer covers the first wire group together.

[0040] Therefore, a high noise shielding effect can be achieved while controlling costs.

[0041] (5) In any of (1) to (4) above, the cable may also include a metal braid on the opposite side of the side of the wire that is covered by the metal layer.

[0042] This results in a higher noise shielding effect and makes it easy to bend, thus facilitating wiring.

[0043] (6) In any of (1) to (5) above, the metal strip may also include a metal thin layer with a thickness of 0.1 μm or more and 20 μm or less.

[0044] This will inhibit the breakage of the metal strip, and the metal strip also has good flexibility.

[0045] (7) In any of (1) to (6) above, the polyolefin resin may be a polypropylene resin.

[0046] This suppresses the increase in dielectric loss tangent and dielectric constant of the insulation material, enabling the cable to have excellent transmission characteristics.

[0047] (8) In any of (1) to (7) above, the cable may also include an outer sheath material covering the metal layer, the outer sheath material comprising a polyolefin resin and a metal hydroxide, the metal hydroxide being at least one selected from the group consisting of magnesium hydroxide and aluminum hydroxide, and the outer sheath material comprising 50 parts by mass and 200 parts by mass of the metal hydroxide relative to 100 parts by mass of the polyolefin resin.

[0048] Therefore, a cable can be provided that can mechanically protect the wires and metal layers, and impart functions such as flame retardancy and oil resistance. Moreover, even when used bundled with wire harnesses having insulation material made of PVC, it can suppress the deterioration of the insulation material.

[0049] (9) In any of (1) to (8) above, the metal strip may also be a laminated structure consisting of a substrate film, an adhesive layer and a metal thin layer stacked in the order described above, wherein the substrate film is composed of polyethylene terephthalate and the metal thin layer comprises aluminum or copper.

[0050] This will inhibit the breakage of the metal strip, and the metal strip also has good flexibility.

[0051] (10) In any of (1) to (8) above, the metal strip may be aluminum foil or copper foil.

[0052] This will suppress metal strip breakage, maintain good flexibility of the metal strip, and control costs.

[0053] (11) In (1) or (2) above, the cable may also include two wires that are twisted together.

[0054] (12) In (1) or (2) above, the cable may also include two wires wrapped with resin tape.

[0055] [Details of the embodiments disclosed herein]

[0056] The following description, with reference to the accompanying drawings, illustrates specific examples of cables according to this disclosure. In the drawings of this disclosure, the same reference numerals denote the same or equivalent parts. Furthermore, dimensional relationships such as length, width, thickness, and depth have been appropriately modified for clarity and simplification of the drawings and do not necessarily represent actual dimensional relationships.

[0057] In this specification, the expression "A~B" refers to the upper and lower limits of the range (i.e., above A and below B). If no unit is recorded in A but only in B, the unit of A is the same as the unit of B.

[0058] In this disclosure, when more than one value is recorded as the lower limit and the upper limit of the numerical range, it is assumed that any combination of any value recorded as the lower limit and any value recorded as the upper limit is also disclosed. For example, when a1 or higher, b1 or higher, and c1 or higher are recorded as the lower limit and a2 or lower, b2 or lower, and c2 or lower are recorded as the upper limit, it is assumed that the following combinations are disclosed: a1 or higher and a2 or lower, a1 or higher and b2 or lower, a1 or higher and c2 or lower, b1 or higher and a2 or lower, b1 or higher and b2 or lower, b1 or higher and c2 or lower, c1 or higher and a2 or lower, c1 or higher and b2 or lower, and c1 or higher and c2 or lower.

[0059] [Implementation Method 1]

[0060] <Cable>

[0061] use Figure 1 The cable of one embodiment of this disclosure (hereinafter also referred to as "Embodiment 1") will be described. Figure 1 This is a schematic cross-sectional view of cable 10 according to embodiment 1. (As shown) Figure 1 As shown, the cable 10 of Embodiment 1 includes an electric wire 1, a metal layer 4 covering the electric wire 1, and an outer sheath material 5. The electric wire 1 includes a conductor 2 and an insulating material 3 disposed on the outer peripheral surface of the conductor 2. The metal layer 4 includes a longitudinally wrapped metal layer 4a. The metal strips partially overlap each other in the width direction of the metal strips to form an overlapping portion, the width of which is more than 1 / 20 and less than 1 / 3 of the width of the metal strips.

[0062] <Electric wire>

[0063] like Figure 1 As shown, in the cable 10 of Embodiment 1, the wire 1 includes a conductor 2 and an insulating material 3 disposed on the outer peripheral surface of the conductor 2.

[0064] <Conductor>

[0065] The conductor 2 is preferably made of a metallic material with high conductivity and high mechanical strength. Examples of such metallic materials include copper, copper alloys, aluminum, aluminum alloys, nickel, silver, soft iron, steel, and stainless steel. The conductor 2 can be a wire formed by shaping a single metallic material into a linear form. Furthermore, the conductor 2 can also be a multilayer conductor, formed by further coating the wire with other metals using techniques such as plating. Examples of multilayer conductor 2 include tin-plated copper wire, nickel-plated copper wire, silver-plated copper wire, copper-plated aluminum wire, and copper-plated steel wire.

[0066] The shape of conductor 2 is not particularly limited and can use shapes that are known in the past. For example, the shape of conductor 2 can be described as a circular wire with a circular cross-section, a square wire with a square cross-section, a flat wire with a rectangular cross-section, or a stranded wire made by twisting multiple wires together.

[0067] The average cross-sectional area of ​​conductor 2 is not particularly limited and can be appropriately selected according to the application. The average cross-sectional area of ​​conductor 2 can be 0.01 mm². 2 Above and 10mm 2 The following can also be 0.1mm 2 Above and 10mm 2 The following is a method for determining the average cross-sectional area of ​​conductor 2 in this disclosure. A conductor 2 is stretched into a straight line and cut along a plane with the first direction connecting one end of conductor 2 to the other as the normal, exposing the cross-section and measuring the cross-sectional area. For a single conductor 2, the conductor 2 is cut at any five points along a plane with the first direction as the normal and the cross-sectional area is measured; the average value is calculated. This average value corresponds to the average cross-sectional area of ​​conductor 2.

[0068] <Insulating Materials>

[0069] In the cable 10 of embodiment 1, the insulating material 3 is provided on the outer peripheral surface of the conductor 2.

[0070] Insulating material 3 may contain polyolefin resin, phenolic antioxidant, and copper aging inhibitor.

[0071] Polyolefin resins

[0072] Examples of polyolefin resins include, for example, polypropylene, polypropylene-based thermoplastic elastomers, reactor-type polypropylene-based thermoplastic elastomers, dynamically cross-linked polypropylene-based thermoplastic elastomers, polyethylene (high-density polyethylene (HDPE), linear low-density polyethylene (LLDPE), low-density polyethylene (LDPE), ultra-low-density polyethylene (VLDPE)), ethylene-propylene copolymers, polymethylpentene, ethylene-vinyl acetate copolymers, ethylene-ethyl acrylate copolymers, ethylene-methyl methacrylate copolymers, ethylene-ethyl methacrylate copolymers, ethylene-butyl acrylate copolymers, ethylene-propylene rubber, ethylene acrylate rubber, ethylene-glycidyl methacrylate copolymers, ethylene-methacrylic acid copolymers, etc., as well as ionomer resins formed by intermolecular bonding of ethylene-methacrylic acid copolymers and ethylene-acrylic acid copolymers with metal ions such as sodium and zinc. Resins modified with maleic anhydride or the like, and resins having epoxy, amino, or imide groups on these resins can also be used as polyolefin resins.

[0073] "High-density polyethylene (HDPE)" refers to polyethylene with a density of 0.942 g / cm³. 3 The above refers to polyethylene. "Linear low-density polyethylene (LLDPE)" refers to polyethylene with a density of 0.910 g / cm³. 3 Above and below 0.930 g / cm 3 Low-density polyethylene (LDPE) is polyethylene obtained by copolymerizing ethylene with α-olefins. LDPE refers to polyethylene with a density of 0.910 g / cm³. 3 Above and below 0.930 g / cm 3 Ultra-low density polyethylene (VLDPE) is polyethylene obtained by polymerizing ethylene under high pressure. VLDPE refers to polyethylene with a density of 0.870 g / cm³. 3 Above and below 0.910 g / cm³ 3Polyethylene. Examples of "polymethylpentene" include, for example, homopolymers of 4-methyl-1-pentene, copolymers of 4-methyl-1-pentene with 3-methyl-1-pentene, or other α-olefins. Examples of α-olefins include, for example, propylene, butene, pentene, hexene, heptene, octene, vinyl acetate, methyl acrylate, ethyl acrylate, methyl methacrylate, and ethyl methacrylate.

[0074] Polyolefin resins can be used in one or more ways.

[0075] Polyolefin resins can be polypropylene. Examples of polypropylene include homopolymer polypropylene, atactic polypropylene, and block polypropylene. Homopolymer polypropylene is a homopolymer of propylene. Atactic polypropylene includes, for example, copolymers of propylene with ethylene or α-olefins having 4 to 20 carbon atoms. Block polypropylene is a resin composed of an atactic copolymer elastomer (a homopolymer of which is a major component) and an ethylene polymer (an arbitrary component). When block polypropylene or homopolymer polypropylene is used, the mechanical strength is better. By using polypropylene as an olefin resin, the reduction effect of the dielectric loss tangent and the heat resistance of the insulating material 3 can be further improved. In this disclosure, "major component" refers to the component with the highest content.

[0076] The lower limit of the polyolefin resin content in insulating material 3 is 98% by mass or more, and it can also be 99% by mass or more. When the polyolefin resin content is 98% by mass or more, the dielectric loss tangent of insulating material 3 can be effectively reduced. The upper limit of the polyolefin resin content can be 99.98% by mass or less, and it can also be 99.99% by mass or less. When the polyolefin resin content is 99.98% by mass or less, the content of antioxidants, etc., in insulating material 3 can be ensured, and the resistance to oxidation degradation and heat resistance of insulating material 3 becomes better. The polyolefin resin content in insulating material 3 can be 98% by mass or more and 99.99% by mass or less, and it can also be 99% by mass or more and 99.98% by mass or less. When two or more polyolefin resins are used, the above-mentioned polyolefin resin content refers to the total content of the two or more polyolefin resins.

[0077] The insulating material 3 may also contain resins other than polyolefin resins. For example, the insulating material 3 may also contain polytetrafluoroethylene, acrylic resin, fluororubber, etc. as a processability modifier in a range of more than 0.01% by mass and less than 2.0% by mass.

[0078] Phenolic antioxidants

[0079] Phenolic antioxidants have the function of preventing the oxidation of easily oxidized polyolefin resins. By containing phenolic antioxidants, insulating material 3 can inhibit the oxidative degradation of polyolefin resins.

[0080] Phenolic antioxidants are not particularly limited, and known phenolic antioxidants can be used. Examples of phenolic antioxidants include 3,9-bis[2-{3-(3-tert-butyl-4-hydroxy-5-methylphenyl)propionyloxy}-1,1-dimethylethyl]-2,4,8,10-tetraoxaspiro[5,5]undecane (e.g., Sumitomo Chemical's "Sumilizer GA-80" (trademark), ADEKA's "ADK STAB AO-80" (trademark)), ethylene bis(oxoethylene)bis[3-(5-tert-butyl-hydroxy-m-tolyl)propionate] (BASF Japan's "Irganox 245" (trademark)), and triethylene glycol bis[3-(3-tert-butyl-4-hydroxy-5-methylphenyl)propionate] (e.g., ADEKA's "ADK STAB"). AO-70 (trademark)), 1,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione (e.g., ADK STAB AO-60 (trademark) manufactured by ADEKA), 4,4'-thiobis(6-tert-butyl-m-cresol) (e.g., Sumitomo Chemical Co., Ltd., "Sumilizer WX-R" (trademark)), 4,4'-butylenebis(3-methyl-6-tert-butylphenol) (e.g., NOCRAC NS-30 (trademark) manufactured by Ouchi Shinsei Chemical Co., Ltd., and ADK STABAO-40 (trademark) manufactured by ADEKA), 4,4'-thiobis(3-methyl-6-tert-butyl)phenol ... "NOCRAC NS-30" (trademark) manufactured by Ouchi Shinsei Chemical Co., Ltd., "NOCRAC NS-30" (trademark) manufactured by Ouchi Shinsei Chemical Co., Ltd., "NOCRAC NS-30" (trademark) manufactured by Ouchi Shinsei Chemical Co., Ltd., "NOCRAC NS-30" (trademark) manufactured by Ouchi Shinsei Chemical Co., Ltd., "NOCRAC NS-30" (trademark) manufactured by Ouchi Shinsei Chemical Co., Ltd., "NOCRAC NS 300 (trademark)), 1,1,3-tris(2-methyl-4-hydroxy-5-tert-butylphenyl)butane (e.g., ADK STAB AO-30 (trademark) manufactured by ADEKA), and bis[3,3-bis(3-tert-butyl-4-hydroxyphenyl)butyrate] glycol ester (e.g., HOSTANOX O3 (trademark) manufactured by Clariant Chemicals).

[0081] Phenolic antioxidants can be used in one or more ways.

[0082] In the insulating material 3, the amount of phenolic antioxidant relative to 100 parts by mass of the polyolefin resin is 0.01 parts by mass or more and 0.5 parts by mass or less. When the amount of phenolic antioxidant is 0.01 parts by mass or more, the antioxidant effect of the polyolefin resin is further improved. When the amount of phenolic antioxidant is 0.5 parts by mass or less, the increase in the dielectric loss tangent of the insulating material 3 caused by the antioxidant can be suppressed, and the transmission characteristics of the cable 10 can be further improved. The lower limit of the amount of phenolic antioxidant relative to 100 parts by mass of the polyolefin resin is 0.01 parts by mass or more, and it can also be 0.010 parts by mass or more, and it can also be 0.05 parts by mass or more. The upper limit of the amount of phenolic antioxidant relative to 100 parts by mass of the polyolefin resin is 0.5 parts by mass or less, and it can also be 0.3 parts by mass or less. The amount of phenolic antioxidant relative to 100 parts by weight of polyolefin resin can be 0.05 parts by weight or more and 0.3 parts by weight or less. When two or more phenolic antioxidants are used, the above-mentioned amount of phenolic antioxidant refers to the total content of the two or more phenolic antioxidants.

[0083] Insulating material 3 may also contain antioxidants other than phenolic antioxidants. For example, insulating material 3 may also contain sulfur-based antioxidants other than sulfur-containing phenolic antioxidants.

[0084] Anti-copper aging agent

[0085] The anti-copper aging agent stabilizes copper ions by forming chelates, inhibiting the degradation of the resin contained in the insulating material 3 caused by copper ions, i.e., so-called copper damage. The insulating material 3 also contains an anti-copper aging agent, which can inhibit copper damage and suppress the oxidative degradation of the polyolefin resin.

[0086] The copper aging inhibitor is not particularly limited, and known copper aging inhibitors can be used. Examples of copper aging inhibitors include, for example, salicylic acid derivatives, phthalic acid derivatives, triazole compound complexes, and aromatic secondary amine compounds. Examples of salicylic acid derivatives include, for example, N,N'-bis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl]hydrazine (BASF Japan, "Irganox MD1024" (trademark) etc.), 3-(N-salicylic acid)amino-1,2,4-triazole (ADEKA, "ADK STAB CDA-1"), and decamethyldicarboxylic acid disalicylic acid hydrazine (ADEKA, "ADK STABCDA-6"). Examples of triazole compound complexes include, for example, complexes with 2-hydroxy-N-1H-1,2,4-triazole-3-ylbenzamide as the main component (ADEKA, "ADK STAB CDA-1M" (trademark)). Examples of aromatic secondary amine compounds include, for instance, N,N'-di-2-naphthyl-p-phenylenediamine (NOCRAC White, manufactured by Ouchi Shinshin Chemical Industry Co., Ltd., a trademark).

[0087] One or more copper anti-aging agents can be used.

[0088] In insulating material 3, the amount of anti-copper aging agent relative to 100 parts by weight of polyolefin resin is 0.01 parts by weight or more and 0.5 parts by weight or less. When the amount of anti-copper aging agent is 0.01 parts by weight or more, the copper damage inhibition effect is further improved. When the amount of anti-copper aging agent is 0.5 parts by weight or less, it is easy to inhibit the occurrence of so-called frosting, which is caused by the crystallization of copper-damaging additives on the surface of insulating material 3, thus ensuring the quality of insulating material 3. The lower limit of the amount of anti-copper aging agent relative to 100 parts by weight of polyolefin resin can be 0.010 parts by weight or more, or 0.05 parts by weight or more. The upper limit of the amount of anti-copper aging agent relative to 100 parts by weight of polyolefin resin can also be 0.3 parts by weight or less. The amount of anti-copper aging agent relative to 100 parts by weight of polyolefin resin can also be 0.05 parts by weight or more and 0.3 parts by weight or less. When two or more anti-copper aging agents are used, the above-mentioned amount of anti-copper aging agents refers to the total content of the two or more anti-copper aging agents.

[0089] Insulating material 3 may also contain anti-metal aging agents other than anti-copper aging agents.

[0090] Other Ingredients

[0091] In addition to polyolefin resins, phenolic antioxidants, and copper aging inhibitors, the insulating material 3 may also contain, for example, processing modifiers, lubricants, pigments, etc., in a range of more than 0.01% by mass and less than 2.0% by mass.

[0092] Processing modifiers improve the extrusion processability of insulating material 3. Examples of processing modifiers include polytetrafluoroethylene, acrylic resin, and fluororubber.

[0093] Lubricants improve the release properties of insulating materials from mixers and extruders. Examples of lubricants include paraffin wax, stearic acid, zinc stearate, and fatty amides.

[0094] The pigment colors the insulating material 3. Various known pigments can be used as pigments; for example, titanium oxide can be listed.

[0095] The dielectric loss tangent of insulating material 3 under a high-frequency electric field of 10 GHz is 3.0 × 10⁻⁶. －4 The following. Therefore, the reduction in transmission loss can be significantly improved.

[0096] The upper limit of the relative permittivity of insulating material 3 can be below 2.5 or below 2.3. By setting the relative permittivity of insulating material 3 to below 2.5, the reduction effect of transmission loss can be significantly improved.

[0097] The above-mentioned "dielectric loss tangent" and "relative permittivity" are values ​​measured according to the method of JIS-R1641 (2007).

[0098] The lower limit of the average thickness of the insulating material 3 can be 50 μm or more, or 100 μm or more. When the average thickness of the insulating material 3 is 50 μm or more, it tends to ensure sufficient insulation. The upper limit of the average thickness of the insulating material 3 can be 1500 μm or less, or 1000 μm or less. When the average thickness of the insulating material 3 is 1500 μm or less, the volumetric efficiency of the cable 10 and the like formed using this wire becomes good. The average thickness of the insulating material 3 can be 50 μm or more and 1500 μm or less, or 100 μm or more and 1000 μm or less.

[0099] In this disclosure, the method for determining the average thickness of the insulating material 3 is as follows: A conductor 2 is stretched into a straight line and cut along a plane with the first direction connecting one end of the conductor 2 as the normal, exposing the cross-section. The thickness of the insulating material 3 is measured at any three points in this cross-section, and their average is calculated to obtain a first average value. For a single conductor 2, the conductor 2 is cut at any five points along a plane with the first direction as the normal, and the first average value is measured. Their average is calculated to obtain a second average value. The second average value corresponds to the average thickness of the insulating material 3.

[0100] <Metal layer>

[0101] <Longitudinal cladding metal layer>

[0102] The cable 10 of Embodiment 1 includes a metal layer 4 covering the wires 1. In the cable 10 of Embodiment 1, the metal layer 4 is composed of a longitudinally wrapped metal layer 4a made of longitudinally wrapped metal strips. Figure 3 As shown, the metal strips partially overlap each other in the width direction to form an overlapping portion 16. The width W2 of the overlapping portion 16 is more than 1 / 20 and less than 1 / 3 of the width W1 of the metal strip.

[0103] In this disclosure, such as Figure 3 As shown, longitudinal wrapping refers to winding the metal strip in a manner that wraps around the extension direction X of the wire 1. In this disclosure, the width direction of the metal strip refers to the direction perpendicular to the extension direction of the metal strip.

[0104] The width W1 of the metal strip can be appropriately selected based on the outer perimeter length of the wire 1 to be covered and the width W2 of the overlapping portion of the metal strip. The lower limit of the width W1 of the metal strip can be 2 mm or more, or 3 mm or more. The upper limit of the width W1 of the metal strip can be 30 mm or less, 25 mm or less, or 20 mm or less. The width W1 of the metal strip can be 2 mm or more and 30 mm or less, 3 mm or more and 25 mm or less, or 2 mm or more and 20 mm or less. In this disclosure, the width W1 of the metal strip refers to the shortest distance between a set of first and second side edges extending in the extension direction of the metal strip.

[0105] The metal strips partially overlap each other in the width direction to form an overlap portion. The width W2 of the overlap portion is not particularly limited as long as it is more than 1 / 20 and less than 1 / 3 of the width W1 of the metal strip. For example, the width W2 of the overlap portion can be more than 0.01 mm and less than 10 mm, or more than 0.015 mm and less than 8 mm. When the width W2 of the overlap portion is more than 0.01 mm, the effect of suppressing the degradation of the insulation material 3 is improved. When the width W2 of the overlap portion is less than 10 mm, the cable is easier to bend, and the cost is also reduced.

[0106] The metal strip may comprise a laminated structure consisting of a substrate film, an adhesive layer, and a thin metal layer stacked in the order described. The metal strip may also be composed of a laminated structure formed by stacking the adhesive layer and the thin metal layer on one main surface of a strip-shaped substrate film in the order described.

[0107] A metal strip, with an adhesive applied to the side of a substrate film opposite to the metal thin layer, is secured to the wire by the adhesive after being wound around it. In this case, it is preferable that the metal strip will not peel off from the wire.

[0108] The substrate film can be made of polyethylene terephthalate. The thickness of the substrate film can be greater than 1 μm and less than 20 μm.

[0109] The material of the adhesive layer is not particularly limited as long as it can bond the substrate film to the metal foil; conventionally known materials can be used. Examples of adhesive layer materials include, for instance, acrylic resin, epoxy resin, urethane resin, polyolefin resin, cyanoacrylate resin, silicone resin, styrene-butadiene rubber, phenolic resin, nitrile rubber, polyamide resin, polyvinyl acetate resin, and polyvinyl alcohol resin.

[0110] The metal thin layer can be made of aluminum or copper. The metal thin layer can be made of aluminum foil or copper foil. The thickness of the metal thin layer made of aluminum foil or copper foil can be greater than 5 μm and less than 20 μm.

[0111] The metal strip can also be a metal strip on which a metal vapor-deposited layer has been formed on the substrate film. In this case, the metal thin layer is composed of the metal vapor-deposited layer. The thickness of the metal thin layer composed of the metal vapor-deposited layer can be more than 0.5 μm and less than 2 μm.

[0112] When the metal strip is composed of a laminated structure including a substrate film and a metal thin layer, when the metal strip is wound around the wire 1, the surface of the metal strip opposite to the wire 1 can be either the exposed surface on the substrate film side or the exposed surface on the metal thin layer side.

[0113] The metal strip can also be a single-layer structure made of aluminum foil or copper foil. In this case, the thickness of the aluminum foil or copper foil can be greater than 0.1 μm and less than 20 μm.

[0114] <Outer Skin Material>

[0115] like Figure 1 As shown, the cable 10 of Embodiment 1 may further include an outer sheath material 5 covered with a metal layer 4. The outer sheath material 5 protects the wire 1 and the metal layer 4, and imparts functions such as flame retardancy and oil resistance. Moreover, even when used bundled with a wire harness having insulation material made of PVC, it can further suppress the deterioration of the insulation material.

[0116] <Polyolefin Resins>

[0117] The outer sheath material 5 may comprise a polyolefin resin and a metal hydroxide. The polyolefin resin of the outer sheath material 5 may be any polyolefin resin of the type described above, used as the polyolefin resin in the insulating material 3. One or more polyolefin resins may be used. The polyolefin resin of the outer sheath material 5 may be the same as or different from the polyolefin resin of the insulating material 3.

[0118] The lower limit of the polyolefin resin content in the outer sheath material 5 can be 33% by mass or more, or 35% by mass or more. When the polyolefin resin content is 33% by mass or more, the mechanical properties and oil resistance of the outer sheath material 5 can be well maintained. The upper limit of the polyolefin resin content can be 67% by mass or less, or 60% by mass or less. When the polyolefin resin content is 67% by mass or less, the flame retardancy is good. Moreover, when the cable of Embodiment 1 is bundled with a wire harness having insulation material made of PVC, the deterioration of the cable insulation material is further suppressed. When two or more polyolefin resins are used, the above-mentioned polyolefin resin content refers to the total content of the two or more polyolefin resins.

[0119] The outer skin material 5 may also contain resins other than polyolefin resins. For example, the outer skin material 5 may contain polytetrafluoroethylene, acrylic resin, fluororubber, etc. as a processability modifier in a range of more than 0.1% by mass and less than 5.0% by mass.

[0120] <Metal hydroxides>

[0121] Metal hydroxides undergo an endothermic dehydration reaction at temperatures above 200°C, inhibiting the combustion of materials containing metal hydroxides. Furthermore, when the outer sheath material contains metal hydroxides, the degradation of the cable insulation is further suppressed when the cable of Embodiment 1 is bundled with a wire harness having PVC insulation. At least one metal hydroxide selected from the group consisting of magnesium hydroxide and aluminum hydroxide can be used.

[0122] In the outer skin material 5, the amount of metal hydroxide relative to 100 parts by mass of the polyolefin resin can be 50 parts by mass or more and 200 parts by mass or 80 parts by mass or more and 180 parts by mass. When two or more metal hydroxides are used, the above-mentioned amount of metal hydroxide refers to the total content of the two or more metal hydroxides.

[0123] Other Ingredients

[0124] In addition to polyolefin resins and metal hydroxides, the outer skin material 5 may also contain, for example, halogenated flame retardants, phosphorus-based flame retardants (red phosphorus, phosphate esters, sodium hypophosphite, etc.), intumescent flame retardants, flame retardant additives (antimony trioxide, melamine cyanurate, zinc borate, zinc oxide, zinc hydroxystannate, etc.), inorganic fillers (calcium carbonate, talc, silica, clay, etc.), pigments, lubricants, antioxidants, copper aging inhibitors, ultraviolet absorbers, light stabilizers, etc.

[0125] [Implementation Method 2]

[0126] use Figure 1 and Figure 4 Another embodiment of the cable (hereinafter also referred to as "Embodiment 2") of this disclosure will be described. Figure 1 This is a schematic cross-sectional view of cable 10 according to embodiment 2. (As shown) Figure 1 As shown, the cable 10 of Embodiment 2 includes a wire 1 and a metal layer 4 covering the wire 1. The wire 1 includes a conductor 2 and an insulating material 3 disposed on the outer peripheral surface of the conductor 2. The metal layer 4 includes a wrapped metal layer 4b formed by wrapping metal strips. The metal strips partially overlap each other in the width direction to form an overlap portion, the width W2 of the overlap portion being more than 1 / 5 and less than 1 / 2 of the width W1 of the metal strips, and the rotation angle of the metal strips being greater than 0° and less than 80°. The cable 10 of Embodiment 2 suppresses the deterioration of the insulation material 3 even when bundled with a wire harness having insulation material made of PVC. The cable 10 of Embodiment 2 can adopt the same structure as Embodiment 1, except that it includes a wrapped metal layer 4b instead of the longitudinal wrapped metal layer 4a of Embodiment 1. The wrapped metal layer 4b will be described below.

[0127] <Wrapped metal layer>

[0128] In embodiment 2, the metal layer 4 is composed of a wrapped metal layer 4b formed by wrapping a metal strip. For example... Figure 3 As shown, the metal strips partially overlap each other in the width direction to form an overlapping portion 16. The width W2 of the overlapping portion 16 is more than 1 / 5 and less than 1 / 2 of the width W1 of the metal strip, and the rotation angle A of the metal strip is greater than 0° and less than 80°.

[0129] In this disclosure, such as Figure 4 As shown, wrapping refers to spirally winding a metal strip around the outer periphery of the wire 1. The metal strip can be a metal strip with the same structure as in Embodiment 1.

[0130] The metal strips partially overlap each other in the width direction to form an overlap portion. The width W2 of the overlap portion is not particularly limited as long as it is more than 1 / 5 and less than 1 / 2 of the width W1 of the metal strip. For example, the width W2 of the overlap portion can be more than 0.4 mm and less than 15 mm, or more than 0.6 mm and less than 13 mm. When the width W2 of the overlap portion is more than 0.4 mm, the effect of suppressing the degradation of the insulation material 3 is improved. When the width W2 of the overlap portion is less than 15 mm, the cable is easier to bend, and the cost is also reduced.

[0131] The rotation angle of the metal strip is greater than 0° and less than 80°, or it can be greater than 7° and less than 80°. In this disclosure, as... Figure 4 As shown, the rotation angle of the metal strip refers to the angle A formed by the acute angle between the extension direction X1 of the wire 1 and the side edge of the metal strip when the metal strip is wrapped around the wire 1 in a top view.

[0132] [Implementation Method 3]

[0133] use Figure 2 Another embodiment of the cable (hereinafter also referred to as "Embodiment 3") of this disclosure will be described. Figure 2 This is a schematic cross-sectional view of the cable 10 according to Embodiment 3. The cable 10 of Embodiment 3, except that it includes a metal braid 6 covering the longitudinally wrapped metal layer 4a or wrapping around the metal layer 4b opposite to the face of the wire 1, can adopt the same configuration as Embodiment 1 or Embodiment 2. The metal braid 6 is disposed between the metal layer 4 and the outer sheath material 5. The cable 10 of Embodiment 3 further suppresses the deterioration of the insulation material 3. The metal braid 6 will be described below.

[0134] The metal braid 6 is preferably made of a metal material with high electrical conductivity and high mechanical strength. Examples of such metal materials include copper and copper alloys. The metal braid can be made into a tubular braid by weaving a metal material into a wire. Alternatively, a multi-layered braid can be used, where the wire is further coated with other metals. Examples of multi-layered wires include tin-plated copper wire, nickel-plated copper wire, silver-plated copper wire, copper-plated aluminum wire, and copper-clad steel wire.

[0135] [Implementation Method 4]

[0136] use Figure 5A and Figure 5B Another embodiment of the cable of this disclosure (hereinafter also referred to as "Embodiment 4") will be described. Figure 5A This is a schematic cross-sectional view of an example of cable 10 in embodiment 4. Figure 5A This illustrates a configuration where two wires are twisted together, a configuration known as a twisted pair.Figure 5A In the diagram, the dashed line represents the outer edge 4c of the metal layer 4 covering the wire that is not exposed in the cross section. Figure 5B This is a schematic cross-sectional view of another example of the cable in Embodiment 4. Figure 5B This illustrates a configuration where two wires are arranged in parallel, a so-called dual-core parallel configuration.

[0137] The cable 10 of embodiment 4 includes two wires 1 and a metal layer 4 covering the two wires 1. Each wire 1 includes a conductor 2 and an insulating material 3 disposed on the outer periphery of the conductor 2. The metal layer 4 is composed of a longitudinally wrapped metal layer 4a or a wrap-around metal layer 4b. For the two wires 1 covered by the metal layer 4, a resin tape 7 (e.g., PET tape) is wrapped around the outside of the metal layer 4 to fix the relative position of the two wires. An outer sheath material 5 is provided outside the resin tape 7. Figure 5A As shown, when the two wires are twisted, when resin tape 7 is wrapped around the outside of the metal layer 4 of the twisted wire 1, the relative positions will not change due to the loosening of the twist, even when the cable is bent. Figure 5B As shown, when the two wires are arranged in parallel, resin tape 7 is wrapped around them to fix their positions.

[0138] exist Figure 5A and Figure 5B The diagram shows two wires 1, but the number of wires 1 is not particularly limited and can be set to any number of more than two depending on the purpose.

[0139] [Implementation Method 5]

[0140] use Figure 6A and Figure 6B Another embodiment of the cable (hereinafter also referred to as "Embodiment 5") of this disclosure will be described. Figure 6A This is a cross-sectional view of an example of cable 10 in embodiment 5. Figure 6A This shows the form of two wires twisted together, known as a twisted pair. Figure 6B This is a schematic cross-sectional view of another example of the cable in Embodiment 5. Figure 6B This illustrates a configuration where two wires are arranged in parallel, a so-called dual-core parallel configuration.

[0141] The cable 10 in Embodiment 5, except that it includes a metal braid 6 covering the outer periphery of the longitudinally wrapped metal layer 4a or wrapping the outer periphery of the metal layer 4b, can have the same configuration as in Embodiment 4. Details of the metal braid 6 are as described in Embodiment 3.

[0142] [Implementation Method 6]

[0143] use Figure 7 and Figure 8Another embodiment of the cable (hereinafter also referred to as "Embodiment 6") of this disclosure will be described. Figure 7 and Figure 8 This is a schematic cross-sectional view of the cable 10 according to Embodiment 6. The cable 10 of Embodiment 7, except that it has a first wire group consisting of two or more wires 1, and the metal layer 4 covers the first wire group, can adopt the same configuration as Embodiment 1 or Embodiment 2. Hereinafter, the structure in which the first wire group consisting of two or more wires 1 is covered by the metal layer 4 will also be referred to as the first structure. Figure 7 In such cases, it is preferable to wind the resin tape 7 over the metal layer 4. Especially when the metal layer 4 is longitudinally wrapped, it is preferable to press the resin tape 7 so that the longitudinally wrapped tape does not unravel.

[0144] exist Figure 7 and Figure 8 The diagram shows a wire group consisting of two wires 1 in the first structure, but the number of wires 1 included in a wire group is not particularly limited, and may include more than two wires depending on the application. Figure 7 In this cable 10, one first structure is included, but the number of first structures included in one cable 10 is not particularly limited, and more than two first structures may be included depending on the application. For example, as Figure 8 As shown, two first structures can also be included in one cable 10.

[0145] [Implementation Method 7]

[0146] use Figure 9 and Figure 10 Another embodiment of the cable of this disclosure (hereinafter also referred to as "Embodiment 7") will be described. Figure 9 and Figure 10 This is a schematic cross-sectional view of the cable 10 according to Embodiment 7. The cable 10 of Embodiment 7, except that it includes a metal braid 6 covering the longitudinally wrapped metal layer 4a or the side opposite to the wire 1, can have the same configuration as in Embodiment 6. Details of the metal braid 6 are as described in Embodiment 3.

[0147] [Example]

[0148] This embodiment is illustrated in more detail through examples. However, this embodiment is not limited to these examples.

[0149] [Deterioration Inhibition Evaluation Test for Insulation Materials]

[0150] <Preparation of Test Samples>

[0151] To evaluate the degradation suppression effect of the insulating material achieved by the metal layer, test specimens were prepared according to the following steps.

[0152] Seven stranded wires (AWG26) of 0.16 mm diameter single-wire conductors made of tin-plated soft copper were prepared as conductors. An insulation material with a thickness of 0.36 mm was formed on the outer circumference of the conductors by extrusion molding to obtain the wire. The composition of the insulation material is shown in the "Insulation Material" column of Tables 1 and 2. The "Polyolefin Resin" listed in the "Insulation Material" column of Tables 1 and 5 is block polypropylene, the "Antioxidant" is a hindered phenolic antioxidant, and the "Copper Anti-aging Agent" is a copper anti-aging agent with an acylhydrazine structure. In all samples, the insulation material used polyolefin resin, antioxidant, and copper anti-aging agent as raw materials; other components were not used as raw materials. One or two wires were prepared for each sample. In the case of two wires, the two wires were twisted together to form a twisted pair.

[0153] A metal strip with aluminum foil (equivalent to a thin metal layer) is wound around the outer periphery of the wire, forming a longitudinally wrapped metal layer or a wrapped metal layer. The width W1 of the metal strip and the thickness of the aluminum foil (equivalent to a thin metal layer) are shown in the "Width W1 of Metal Strip" and "Thickness of Metal Layer" columns of Tables 2 and 6. The coating method of the metal strip for each sample is described in the "Coating Method" column of Tables 2 and 6. "Longitudinal wrapping" means that the metal strip is wound longitudinally around the outer periphery of the wire. "Wrapping" means that the metal strip is wrapped around the outer periphery of the wire. "Single" means that each wire is coated with metal strip. "Together" means that two wires are coated together with metal strip. The width W2 of the overlapping portion of the metal strip in longitudinal wrapping or wrapping and the ratio W2 / W1 of the width W2 of the overlapping portion to the width W1 of the metal strip are shown in the "Width W2 of Overlapping Portion" and "W2 / W1" columns of Tables 2 and 6.

[0154] In the samples marked "Yes" in the "Metal Braid" column of Tables 2 and 6, a longitudinal or wrapping metal layer was applied to the samples using a metal braid. The metal braid consisted of tin-plated soft copper wire with a diameter of 0.1 mm and a thickness of 0.4 mm. In the case of a single wire, two wires covered with metal strips were twisted together, and the twisted wires were then surrounded by the metal braid.

[0155] Further, a 0.6 mm thick outer sheath material was extruded onto the outside of the metal layer or metal braid to obtain the test specimens. The composition of the outer sheath material is shown in the "Outer Sheath Material" column of Tables 3 and 7. The "polyolefin resin" listed in the "Outer Sheath Material" column of Tables 3 and 7 is block polypropylene. In all specimens, no components other than polyolefin resin and Mg(OH)2 and Al(OH)3 were used as raw materials for the outer sheath material. In the case of a single wire, two wires covered with metal strips were twisted together, and the outer sheath was then applied around the two twisted wires.

[0156]

[0157]

[0158]

[0159]

[0160]

[0161]

[0162]

[0163]

[0164] [Deterioration Inhibition Evaluation Test]

[0165] The test specimen is brought into contact with PVC at 100°C, and the time until the appearance of the insulation material becomes abnormal is measured. The longer the time until the appearance of the insulation material becomes abnormal, the more the degradation of the insulation material is suppressed. The specific test method is as follows.

[0166] Figure 11A and Figure 11B This is a cross-sectional view of the test structure 11 used for evaluating the degradation inhibition of insulating materials.

[0167] Figure 11A This is a cross-sectional view of the test structure 11 when a single electrical wire is used as the test specimen 12. Figure 11A As shown, the test structure 11 is a structure formed by binding the test specimen 12 and six PVC-coated wires 14 arranged to cover the periphery of the test specimen 12 with PVC tape 15.

[0168] Figure 11B This is a cross-sectional view of the test structure when a test specimen uses two electrical wires. For example... Figure 11BAs shown, the test structure 11 is a structure formed by binding the test specimen 12 and six PVC-coated wires 14, which are sealed around the test specimen 12, with PVC tape 15.

[0169] The PVC-coated wire 14 consists of conductor 2 (65 stranded single conductors of 0.32 mm diameter made of tinned soft copper, with a diameter of 3.0 mm) and PVC insulation material 13 (4.6 mm diameter) of cross-linked polyvinyl chloride with a thickness of 0.8 mm around the outer periphery of conductor 2.

[0170] The PVC tape used for the test structure 11 was a VTA tape (0.135 mm thick, 19 mm wide) manufactured by Yazaki Sogyo Co., Ltd. Furthermore, the test structure 11 was formed by bundling the test specimen 12 and the PVC-coated wire 14 together with the VTA tape through a semi-overlapping winding.

[0171] In the degradation inhibition evaluation test, multiple test structures 11 were placed in an oven at 100°C and removed after 1000 hours, 2000 hours, and 3000 hours. Next, the test structure 11 was disassembled and the wire was removed. The wire was then wound around a mandrel of the same diameter as the wire, approximately half a turn in circumference. The mandrel, here referring to a mandrel with the same diameter as the wire, is wound around the mandrel. The length of the outer circumference of the wire wound around the mandrel is 1.5 times longer than the length of the wire's center section.

[0172] In the degradation suppression evaluation test, for the insulation material of the wire wound around the self-diameter core rod, visual inspection is performed to check for appearance abnormalities such as cracks, fissures, and exposed conductors. The time when the appearance abnormality is observed is defined as the appearance abnormality occurrence time. The results are shown in the "Time" column of the "Degradation Suppression Evaluation Test" under the "Evaluation" section of Tables 4 and 8. In Tables 4 and 8, ">3000" indicates that no appearance abnormality occurred at the time point of 3000 hours. In Tables 4 and 8, "<1000" indicates that an appearance abnormality occurred at the time point of 1000 hours. The longer the appearance abnormality occurs, the higher the degradation suppression effect of the insulation material. Samples marked with "-" in this column did not undergo the degradation suppression evaluation test.

[0173] [Heat resistance aging test]

[0174] Seven stranded wires (AWG26) with a diameter of 0.16 mm and made of tin-plated soft copper were prepared as conductors. An insulation material with a thickness of 0.36 mm was formed on the outer circumference of the conductors by extrusion molding to obtain the wire. The length of the wire was set to 350 mm. For each sample of wire, a heat resistance aging test was conducted based on ISO 6722 standard (Class B). Long-term aging tests and short-term aging tests were performed as part of the heat resistance aging test. The test conditions for each test are as follows.

[0175] <Long-term aging test>

[0176] The wire was taken out after being heated in a thermostatic bath at 100 °C for 3000 hours, and after being kept at room temperature for 16 hours, it was wound around a mandrel with a diameter 5 times that of the wire at room temperature for three turns. If the insulating material has no cracks and no insulation breakdown occurs in the withstand voltage test (1 kV × 1 minute) after being immersed in brine, it is considered qualified.

[0177] <Short-term aging test>

[0178] It was taken out after being heated in a thermostatic bath at 125 °C for 240 hours, and after being kept at room temperature for 16 hours, it was wound around a mandrel with a diameter 5 times that of the wire and the cable at -25 °C for three turns. If the insulating material has no cracks and no insulation breakdown occurs in the withstand voltage test (1 kV × 1 minute) after being immersed in brine, it is considered qualified.

[0179] The results are shown in the "Heat resistance aging" column of "Evaluation" in Table 1 and Table 2. In Table 1 and Table 2, "A" indicates that both the long-term aging test and the short-term aging test are qualified, and "B" indicates that at least one of the long-term aging test and the short-term aging test is unqualified. Among the specimens recorded as "-" in this column, the heat resistance aging test was not conducted.

[0180] [Flexibility test]

[0181] In each specimen, a flexible test specimen was prepared by covering the test specimen 12 with the resin tape 7 Figure 11A and Figure 11B The compression test fixture was attached to the tensile testing machine, the flexible test specimen was fixed to the fixture, and the reaction force when bending with a bending radius of 25 mm was measured and evaluated. Regarding the evaluation criteria for bending performance, specimens with a bending reaction force of 1 N or less were considered qualified, and specimens with a bending reaction force greater than 1 N were considered unqualified.

[0182] The results are shown in the "Flexibility" column of "Evaluation" in Table 4 and Table 8. In Table 4 and Table 8, "A" indicates qualified, and "B" indicates unqualified. Among the specimens recorded as "-" in this column, the flexibility test was not conducted.

[0183] [Abrasion resistance test]

[0184] In each specimen, a test specimen 12 was prepared Figure 11A and Figure 11B Based on the ISO6722 standard, the strength of the outer skin material was measured by a scratch abrasion test. It was carried out with a needle diameter of 0.45 mm, a load of 7 N, and an action speed of 55 cycles / minute. If the number of times until the metal braid or metal tape is exposed is 200 times or more, it is considered qualified.

[0185] The results are shown in the "Abrasion Resistance" column of the "Evaluation" section in Tables 4 and 8. In Tables 4 and 8, "A" indicates pass, and "B" indicates fail.

[0186] [Evaluation of Insulation Materials]

[0187] <Fabrication of Experimental Insulating Sheets>

[0188] In order to determine the dielectric loss tangent and relative permittivity of the insulating material used in the above-mentioned test specimen 12, as well as the heat aging test, the test insulating sheet was prepared according to the following steps.

[0189] A resin composition for insulating materials was obtained by mixing polyolefin resin, antioxidant, and copper aging inhibitor according to the formulations listed in the "Insulating Materials" column of Tables 1 and 2. The resin composition for insulating materials was then pressure-molded to produce experimental insulating sheets. The pressure molding conditions were: preheating at 180°C for 5 minutes, followed by further pressurization at that temperature and holding for 5 minutes.

[0190] <Determination of Dielectric Loss Tangent and Relative Permittivity>

[0191] For the test insulating sheet, the dielectric loss tangent and relative permittivity were determined under a high-frequency electric field of 10 GHz applied, according to JIS-R1641 (2007). The measurements were performed three times, and the average value was calculated. The results are shown in Tables 1 and 2 under “Dielectric Loss Tangent” and “Relative Permittivity”.

[0192] [Inspection]

[0193] Samples 1 to 12 and samples 101 to 112 are equivalent to the examples. It was confirmed that the dielectric loss tangent of the insulating material of samples 1 to 12 and samples 101 to 112 did not increase, and the degradation suppression effect of the insulating material was high.

[0194] Samples 1-1 to 1-9 and samples 2-1 to 2-8 are equivalent to comparative examples. Samples 1-1, 1-3, 2-1, and 2-3 received a "B" rating in the heat aging test, indicating failure; therefore, no further tests were conducted. Samples 1-2, 1-4, 2-2, and 2-4 showed poor degradation inhibition; therefore, no further tests were conducted. Samples 1-5, 1-6, 1-7, 2-5, and 2-6 had a dielectric loss tangent greater than 3.0 × 10⁻⁶. －4 Therefore, no other tests were conducted. The flexibility test evaluation of samples 1-8, 1-9, 2-7, and 2-8 was "B", which is unqualified. Therefore, no tests were conducted on degradation inhibition and heat aging resistance.

[0195] The embodiments and examples of this disclosure have been described as above, but it is also intended from the outset that the above embodiments and examples may be appropriately combined or modified in various ways.

[0196] The embodiments and examples disclosed herein should be considered exemplary rather than limiting in all respects. The scope of the invention is set forth not by the foregoing embodiments and examples, but by the claims, and is intended to include all modifications within the meaning and scope equivalent to the claims.

[0197] Explanation of reference numerals in the attached figures:

[0198] 1: Wire; 2: Conductor; 3: Insulation material; 4: Metal layer; 4a: Longitudinal metal layer; 4b: Wrapped metal layer; 4c: Outer edge of metal layer; 5: Outer sheath material; 6: Metal braid; 7: Resin tape; 10: Cable; 11: Test structure; 12: Test specimen; 13: PVC insulation material; 14: PVC-coated wire; 15: PVC tape; 16: Overlapping section.

Claims

1. A cable having wires and a metal layer covering the wires, wherein, The wire includes a conductor and an insulating material disposed on the outer peripheral surface of the conductor. The insulating material comprises polyolefin resin, phenolic antioxidant, and copper aging inhibitor. The polyolefin resin content of the insulating material is 98% or more by mass. Relative to 100 parts by weight of the polyolefin resin, the insulating material contains 0.01 to 0.5 parts by weight of the phenolic antioxidant and 0.01 to 0.5 parts by weight of the anti-copper aging agent, and the dielectric loss tangent of the insulating material at 10 GHz is 3.0 × 10⁻⁶. －4 the following, The metal layer includes a longitudinally wrapped metal layer composed of longitudinally wrapped metal strips. The metal strips partially overlap each other in the width direction to form an overlapping portion. The width of the overlapping portion is more than 1 / 20 and less than 1 / 3 of the width of the metal strip.

2. A cable having wires and a metal layer covering the wires, wherein, The wire includes a conductor and an insulating material disposed on the outer peripheral surface of the conductor. The insulating material comprises polyolefin resin, phenolic antioxidant, and copper aging inhibitor. The polyolefin resin content of the insulating material is 98% or more by mass. Relative to 100 parts by weight of the polyolefin resin, the insulating material contains 0.01 to 0.5 parts by weight of the phenolic antioxidant and 0.01 to 0.5 parts by weight of the anti-copper aging agent, and the dielectric loss tangent of the insulating material at 10 GHz is 3.0 × 10⁻⁶. －4 the following, The metal layer includes a wrapped metal layer formed by wrapping a metal strip. The metal strips partially overlap each other in the width direction to form an overlapping portion. The width of the overlapping portion is more than 1 / 5 and less than 1 / 2 of the width of the metal strip. The rotation angle of the metal strip is greater than 0° and less than 80°.

3. The cable according to claim 1 or 2, wherein, The cable includes a plurality of the wires. The metal layer covers each of the wires.

4. The cable according to claim 1 or 2, wherein, The cable has a first wire group consisting of two or more of the aforementioned wires. The metal layer also covers the first wire assembly.

5. The cable according to any one of claims 1 to 4, wherein, The cable also includes a metal braid on the opposite side of the side of the wire that is covered by the metal layer.

6. The cable according to any one of claims 1 to 5, wherein, The metal strip comprises a thin metal layer. The thickness of the metal thin layer is greater than 0.1 μm and less than 20 μm.

7. The cable according to any one of claims 1 to 6, wherein, The polyolefin resin is polypropylene resin.

8. The cable according to any one of claims 1 to 7, wherein, The cable also has an outer sheath material covering the metal layer. The outer skin material comprises a polyolefin resin and a metal hydroxide. The metal hydroxide is at least one selected from the group consisting of magnesium hydroxide and aluminum hydroxide. Relative to 100 parts by weight of the polyolefin resin, the outer skin material contains 50 parts by weight and 200 parts by weight of the metal hydroxide.

9. The cable according to any one of claims 1 to 8, wherein, The metal strip comprises a laminated structure consisting of a substrate film, an adhesive layer, and a thin metal layer stacked in the order described above. The substrate film is made of polyethylene terephthalate. The thin metal layer contains aluminum or copper.

10. The cable according to any one of claims 1 to 8, wherein, The metal strip is aluminum foil or copper foil.

11. The cable according to claim 1 or 2, wherein, The cable comprises two of the aforementioned wires. The two wires are twisted together.

12. The cable according to claim 1 or 2, wherein, The cable comprises two of the aforementioned wires. The two wires are wrapped with resin tape.

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