JP5133578B2 - Insulated wire and wire harness - Google Patents

Description

  The present invention relates to an insulated wire and a wire harness, and more particularly to an insulated wire and a wire harness that are suitably used for vehicle parts, electrical / electronic device parts, and the like.

  Conventionally, as an insulated wire used for wiring of vehicle parts such as automobile parts and electrical / electronic equipment parts, generally, the outer periphery of a conductor is widely coated with a vinyl chloride resin composition to which a halogen-based flame retardant is added. Has been used.

  However, since this type of vinyl chloride resin composition contains a halogen element, it releases harmful halogen-based gases to the atmosphere during combustion such as in the event of a vehicle fire or incineration and disposal of electrical and electronic equipment. There was a problem of causing environmental pollution.

  Therefore, from the viewpoint of reducing the burden on the global environment, in recent years, so-called non-halogen flame retardant, in which a metal hydroxide such as magnesium hydroxide is added as a non-halogen flame retardant to an olefin resin such as polyethylene. Alternatives to resin compositions are underway.

  However, olefinic resins are basically flammable, and non-halogen flame retardants are inferior in flame retardancy compared to halogen flame retardants. Therefore, in the halogen-free flame retardant resin composition, it is necessary to add a large amount of metal hydroxide in order to ensure sufficient flame retardancy, resulting in remarkable mechanical properties such as scratch resistance. There was a problem of lowering.

  Therefore, in order to improve such a problem, for example, in Patent Document 1, a metal hydroxide and a crosslinking aid are added to a resin component containing polyethylene or α-olefin copolymer and ethylene copolymer or rubber. Furthermore, a flame retardant resin composition containing a specific functional group is disclosed.

Japanese Patent No. 3280105

  However, an insulated wire in which the outer periphery of a conductor is coated with a conventionally known flame retardant resin composition is not yet satisfactory in mechanical properties such as scratch resistance and wear resistance, and there is room for further improvement.

  The problem to be solved by the present invention is to provide an insulated wire that has sufficient flame retardancy and is more excellent in damage resistance and wear resistance than in the past. Moreover, it is providing the wire harness containing this insulated wire.

In order to solve the above-mentioned problems, the insulated wire according to the present invention is such that at least one insulating layer is coated on the outer periphery of the conductor, and at least one of the insulating layers is (A) olefin resin 60 to 99 parts by weight, (B) 100 parts by weight of a polymer component containing 40 to 1% by weight of a styrenic thermoplastic elastomer, (C) 50 to 200 parts by weight of a metal hydroxide, and (D) an aspect ratio of 30 or more. Ri Na from the resin composition containing a fibrous material 0.1 to 20 parts by weight, the fibrous material are those summarized in that a fibrous material of the carbon-based.

  In this case, it is preferable that 60% or more of the fibrous substance is arranged substantially parallel to the axial direction of the electric wire.

Moreover, the volume specific resistance value of the resin composition is preferably 10 ⁹ (Ω · mm) or more.

Moreover, the resin composition preferably further contains a spherical substance (excluding (C) a metal hydroxide) .

  And the said insulated wire is coat | covered with the insulating layer of 2 or more layers on the outer periphery of a conductor, Among the said insulating layers, at least 1 layer located in an inner layer consists of the said resin composition, Of the said insulating layers The outermost layer preferably does not contain a fibrous material.

  At this time, the water contact angle on the surface of the electric wire is preferably 60 ° or more.

  Furthermore, the thickness of the outermost layer is preferably in the range of 5 to 300 μm.

  On the other hand, the wire harness which concerns on this invention makes it a summary to contain the said insulated wire.

  In the insulated wire according to the present invention, at least one of the insulating layers coated on the outer periphery of the conductor includes a specific amount of metal hydroxide and a specific amount of fibrous substance having an aspect ratio within a specific range. It consists of a resin composition. Therefore, it has sufficient flame retardancy and is excellent in external resistance and abrasion resistance as compared with conventional insulated wires. This is presumably because the strength against scratches and abrasion is improved by blending the fibrous substance together with the metal hydroxide.

  In this case, when 60% or more of the fibrous substance is arranged substantially parallel to the axial direction of the electric wire, the above effect is further improved.

Further, if the volume specific resistance value of the resin composition is 10 ⁹ (Ω · mm) or more, it is more excellent in insulation.

  In addition, when the fibrous material is a carbon-based fibrous material, the wound resistance and wear resistance are further improved.

  Further, when the resin composition further contains a spherical substance, the resin composition is further excellent in the damage resistance and wear resistance. This is presumed to be because the friction coefficient on the surface of the insulating layer containing the spherical material is reduced by blending the spherical material.

  If the insulated wire has a multilayer structure, at least one layer located in the inner layer of the insulating layer is made of the resin composition, and the outermost layer of the insulating layer does not contain a fibrous material. It has excellent flammability, damage resistance, and wear resistance, and improves the smoothness of the wire surface. Thereby, even if a foreign substance contacts the insulating layer, the slipping is improved, so that the insulating layer is hardly damaged and the reliability of the insulated wire is increased. Moreover, while being excellent also in an external appearance, productivity at the time of processing the said insulated wire into a wire harness improves.

  At this time, when the water contact angle on the surface of the electric wire is 60 ° or more, the smoothness of the surface of the electric wire is further improved, and thus the above effect is further improved.

  Furthermore, when the thickness of the outermost layer is in the range of 5 to 300 μm, the balance between the effects of excellent flame retardancy, damage resistance, and wear resistance and the effect of improving the smoothness of the wire surface is excellent. .

  On the other hand, since the wire harness which concerns on this invention contains the said insulated wire, it has sufficient flame retardance and is excellent in external resistance and abrasion resistance. Therefore, when processing into a wire harness, there exists an advantage that an electric wire is hard to be damaged. Further, since the insulated wire is less likely to be worn when the wire harness is used, high reliability can be ensured over a long period of time.

  Next, an embodiment of the present invention will be described in detail.

  The insulated wire according to the present invention (hereinafter sometimes referred to as the present wire) has at least one insulating layer coated on the outer periphery of the conductor, and at least one of the insulating layers has a specific resin composition. It consists of things.

  Examples of the conductor include a single metal wire, a twisted wire in which a plurality of metal strands are twisted together, and a material in which a twisted wire is compressed. The conductor diameter, material, and the like are not particularly limited, and can be appropriately selected depending on the application.

  Here, the resin composition includes a polymer component containing (A) an olefin resin, (B) a styrene thermoplastic elastomer, (C) a metal hydroxide, and (D) a fiber having an aspect ratio of 30 or more. Containing substances.

  In the resin composition, the polymer component contains (A) an olefin resin in a range of 60 to 99% by weight and (B) a styrene thermoplastic elastomer in a range of 40 to 1% by weight. Preferably, (A) the olefin resin is 75 to 95% by weight, (B) the styrene thermoplastic elastomer is within the range of 25 to 5% by weight, and more preferably (A) the olefin resin is 80 to 90% by weight. (B) Styrenic thermoplastic elastomer exists in the range of 20 to 10 weight%.

  When the content of (A) olefin resin is less than 60% by weight and (B) styrene-based thermoplastic elastomer exceeds 40% by weight, there is a tendency that the damage resistance, wear resistance, etc. tend to decrease. In addition, when (A) the content of the olefin resin exceeds 99% by weight and (B) the styrene thermoplastic elastomer is less than 1% by weight, flexibility, workability, and the like tend to decrease.

  In the polymer component, examples of the (A) olefin resin include polypropylene, low density polyethylene, linear low density polyethylene, high density polyethylene, and ethylene-α olefin copolymer. These may be used alone or in combination of two or more. Of these, polypropylene and linear low density polyethylene are preferable.

  Examples of the ethylene-α-olefin copolymer include ethylene and an α-olefin having 3 to 20 carbon atoms, such as propylene, 1-butene, 4-methyl-1-pentene, 1-hexene, 1-heptene, 1-octene, 1 -Nonene, 1-decene, 1-undecene, 1-dodecene, 1-tridecene, 1-tetradecene, 1-pentadecene, 1-hexadecene, 1-heptadecene, 1-nonadecene, 1-eicosene, 9-methyl-1-decene And copolymers with 11-methyl-1-dodecene, 12-ethyl-1-tetradecene, and the like.

  (A) The olefin resin preferably has a melt flow rate (MFR) in the range of 0.3 to 15 g / 10 min. More preferably, it is in the range of 0.5 to 10 g / 10 min. This is because if the MFR is less than 0.3 g / 10 min, the fluidity of the resin composition tends to decrease, and if it exceeds 15 g / 10 min, the mechanical properties and the like tend to decrease. The melt flow rate (MFR) is measured according to JIS K 6758 (temperature 230 ° C., load 2.16 Kg).

  In the polymer component, (B) the styrene thermoplastic elastomer is obtained by copolymerizing styrene and a monomer such as butadiene or isoprene. At this time, monomers such as butadiene and isoprene may be used singly or in combination.

  (B) Specific examples of the styrenic thermoplastic elastomer include a styrene-butadiene block copolymer and a hydrogenated or partially hydrogenated styrene-ethylene-styrene copolymer (SES) or styrene-ethylene- Examples include butylene-styrene copolymer (SEBS) and modified butadiene rubber having a core-shell structure. Further, styrene-isoprene block copolymers and hydrogenated or partially hydrogenated derivatives thereof such as styrene-ethylene-propylene copolymers (SEP), styrene-ethylene-propylene-styrene copolymers (SEPS), styrene-ethylene- Examples thereof include an ethylene-propylene-styrene copolymer (SEEPS) and a modified isoprene rubber having a core-shell structure. These may be used alone or in combination.

  At this time, styrene is a hard segment, and a polymer sandwiched between styrene is a soft segment, and the ratio of the hard segment to the soft segment is within the range of 10/90 to 40/60 by weight ratio of the hard segment / soft segment. It is preferable. This is because the damage resistance, wear resistance, flexibility and the like can be improved in a balanced manner.

  (B) The styrenic thermoplastic elastomer may be acid-modified. Examples of acids used for acid modification include maleic anhydride and its derivatives maleic anhydride, maleic acid monoester, maleic acid diester, fumaric acid and its derivatives fumaric anhydride, fumaric acid monoester, and fumaric acid. A diester etc. can be illustrated. These may be used alone or in combination of two or more.

  (B) Examples of the method for introducing an acid into the styrene-based thermoplastic elastomer include a graft method and a direct (copolymerization) method. Moreover, as an acid modification amount, it is 0.1 to 10 weight% with respect to (B) styrene-type thermoplastic elastomer, Preferably, it is 0.2 to 5 weight%. This is because if the amount of acid modification is less than 0.1% by weight, the wear resistance tends to decrease, and if it exceeds 10% by weight, the moldability tends to deteriorate.

  In addition to (A) the olefin resin and (B) the styrene thermoplastic elastomer, the polymer component may further contain rubber or a thermoplastic elastomer. Examples of the rubber include ethylene-propylene rubber, butadiene rubber, isoprene rubber, natural rubber, nitrile rubber, and isobutylene rubber. Examples of the thermoplastic elastomer include 1,2-polybutadiene. Can do. These rubbers and thermoplastic elastomers may be acid-modified.

  The ethylene-propylene rubber is mainly composed of a random copolymer mainly composed of ethylene and propylene, and further, one or more diene monomers such as dicyclopentadiene and ethylidene norbornene added as a third component. Examples thereof include a random copolymer as a component.

  In the resin composition, (C) the metal hydroxide has a function of imparting flame retardancy to the insulating layer. (C) The metal hydroxide is contained in an amount of 50 to 200 parts by weight with respect to 100 parts by weight of the polymer component. Preferably, the amount is 50 to 150 parts by weight with respect to 100 parts by weight of the polymer component. This is because if the amount is less than 50 parts by weight, the flame retardancy tends to decrease, and if it exceeds 200 parts by weight, sufficient mechanical properties are difficult to obtain.

  (C) As a metal hydroxide, magnesium hydroxide, aluminum hydroxide, calcium hydroxide, etc. can be illustrated. Of these, magnesium hydroxide is preferred because of its high decomposition temperature (about 360 ° C.). Magnesium hydroxide may be a natural product made from a natural mineral or a so-called synthetic product. Natural products are preferable in that the production cost is reduced.

  (C) It is preferable that the average particle diameter of a metal hydroxide exists in the range of 0.5-10 micrometers. More preferably, it exists in the range of 0.5-5 micrometers, More preferably, it exists in the range of 0.5-3 micrometers. This is because when the particle diameter is less than 0.5 μm, secondary aggregation of the particles is likely to occur, and the mechanical properties of the electric wire are likely to deteriorate. On the other hand, if the particle diameter exceeds 10 μm, the mechanical properties of the electric wire are likely to deteriorate.

  (C) The metal hydroxide may be surface-treated with a surface treatment agent. Examples of the surface treatment agent include fatty acids (such as stearic acid and oleic acid), fatty acid metal salts, silane coupling agents (such as vinyl silane and acrylic silane), and titanate coupling agents. These may be used alone or in combination of two or more. (C) When the surface of the metal hydroxide is surface-treated, productivity is easily improved in addition to adhesion with the polymer component.

  The surface treatment agent is preferably in the range of 0.1 to 10 parts by weight with respect to 100 parts by weight of (C) metal hydroxide. More preferably, it is in the range of 0.5 to 3 parts by weight. If the amount is less than 0.1 part by weight, the effect of improving the electric wire characteristics is likely to be reduced, and if the amount exceeds 10 parts by weight, excessively added impurities are likely to remain as impurities, and the physical properties of the wire are likely to be deteriorated.

  At this time, (C) the metal hydroxide may be surface-treated with a surface treatment agent in advance, or is blended in the resin composition together with the surface treatment agent and kneaded with the resin composition. May be.

  In the above resin composition, (D) a fibrous material having an aspect ratio of 30 or more (hereinafter, sometimes referred to as (D) a fibrous material) has mechanical properties such as trauma resistance and abrasion resistance on the insulating layer. It has the function to give. The aspect ratio is represented by (D) the ratio of the major axis to the minor axis of the fibrous substance (major axis / minor axis). The upper limit of the aspect ratio is preferably 100 or less from the viewpoint that the (D) fibrous substance can be stably present in the resin composition.

  (D) The fibrous substance is contained in an amount of 0.1 to 20 parts by weight with respect to 100 parts by weight of the polymer component. Preferably, the amount is 1 to 15 parts by weight, more preferably 1 to 10 parts by weight with respect to 100 parts by weight of the polymer component.

  If the amount is less than 0.1 parts by weight, the effect of improving the mechanical properties such as damage resistance and wear resistance tends to be reduced. On the other hand, if the amount exceeds 20 parts by weight, the resin composition is kneaded or the present electric wire is produced. Sometimes the load on the screw of the kneader becomes large, which is likely to cause mixing failure and extrusion failure, and (D) increase in the content of the fibrous material, It is easy to cause.

  (D) It is preferable that 60% or more of the fibrous substances are arranged substantially parallel to the axial direction of the electric wire. This is because the impact resistance is improved in addition to the damage resistance and wear resistance. More preferably, it is 70% or more, More preferably, it is 80% or more.

  (D) In order to arrange the fibrous substances substantially parallel to the axial direction of the electric wire, the aspect ratio is preferably 30 or more. In addition, (D) the resin composition containing a fibrous substance may be extrusion coated on the outer periphery of the conductor. At this time, if the extrusion is performed at a relatively high linear velocity, the arrangement becomes easier. If extrusion is performed too slowly, the arrangement of (D) fibrous substances tends to be sparse and difficult to arrange. The presence state of the (D) fibrous substance in the insulating layer can be confirmed, for example, by observing a cross section of the insulating layer with an SEM.

  Examples of (D) fibrous materials include synthetic (organic) fibers, inorganic fibers, and natural fibers. These may be used alone or in combination of two or more. Synthetic (organic) fibers include polyamide fibers (such as nylon), polyester fibers, acrylic fibers, polyolefin fibers, and polyurethane fibers. Examples of inorganic fibers include ceramic fibers, glass fibers, carbon-based fibers (such as activated carbon fibers, carbon black, and carbon nanotubes), metal fibers, and mineral fibers. Natural fibers include pulp, silk, wool and the like. It is not specifically limited to these, What is necessary is just a fibrous substance with an aspect ratio of 30 or more. Among the synthetic (organic) fibers, those having low hydrolyzability are preferable.

When (D) the fibrous material is blended in the resin composition forming the insulating layer, it is preferable to pay attention to the value of the volume resistivity value of the entire resin composition. That is, in order to ensure the required insulating properties of the insulating layer, the volume specific resistance value of the resin composition is preferably 10 ⁹ (Ω · mm) or more. Therefore, it is preferable to appropriately select the type and blending amount of (D) fibrous substance in consideration of the insulating properties and the effect of improving mechanical properties such as trauma resistance and wear resistance.

  (D) Of the fibrous materials, inorganic fibers such as metal fibers have a relatively low volume resistance value, so it is difficult to increase the amount of the compound, and in particular, the insulating properties of the insulating layer should be noted.

  (D) The fibrous substance is more preferably a carbon-based fiber such as activated carbon fiber, carbon black, or carbon nanotube. Because the volume resistivity is relatively high, the insulation of the insulating layer can be secured even if the amount is increased, and the mechanical properties such as damage resistance and wear resistance can be further improved. is there.

  Examples of carbon nanotubes include single-walled carbon nanotubes composed of a single graphene sheet, multi-walled carbon nanotubes composed of many graphene sheets, cup-stacked carbon nanotubes, and carbon nanowhiskers. These may be used alone or in combination of two or more. The ends of the carbon nanotubes may be closed (closed carbon nanotubes) or open (open carbon nanotubes).

  The diameter of the carbon nanotube is preferably 0.4 nm or more in consideration of production cost. The aspect ratio is preferably 30 or more as described above. Carbon nanotubes have chirality due to the difference in how the graphene sheet is wound, but the chirality is not particularly limited.

  The method for producing the carbon nanotube is not particularly limited, and a general method can be used. Specific examples include a laser ablation method, an arc discharge method, a catalytic CVD (chemical vapor deposition) method, and the like. When the metal catalyst remains on the carbon nanotube, it is preferable to remove it. As a removing method, after making the carbon nanotube defective using heated hydrogen peroxide or the like, it may be removed using sulfuric acid, or may be removed using other known methods.

  When single-walled carbon nanotubes are used, it is preferable to disperse them in advance because carbon nanotubes may form bundles intricately entangled with each other. As a bundle dispersion method, ultrasonic waves may be used, or other known methods may be used.

  (D) A spherical substance may be blended together with the fibrous substance. This is because when the spherical substance is blended, the friction coefficient on the surface of the electric wire is likely to decrease due to the rotation of the spherical substance, so that the damage resistance and the wear resistance are further improved. Examples of the spherical substance include spherical fullerenes (C60 and the like). The particle size of the spherical substance is preferably in the range of 1 nm to 1 μm. This is because dispersibility is improved and physical properties of the electric wire are improved.

  In the said resin composition, the other additive may be mix | blended in the range which does not impair the physical property of the said composition as needed. For example, general fillers used for wire covering materials, pigments, antioxidants, antioxidants, copper damage inhibitors, and the like may be blended, and are not particularly limited.

  As the configuration of the electric wire, as described above, one or more insulating layers are coated on the outer periphery of the conductor. The thickness of the entire insulating layer is preferably 0.3 mm or less. More preferably, it is 0.25 mm or less. This is because if it exceeds 0.3 mm, the lightness of the electric wire is inferior. The outer diameter of the electric wire is not particularly limited, but is 3 mm or less, more preferably 2 mm or less.

  When one insulating layer is coated on the outer periphery of the conductor, this one layer is made of the resin composition.

  On the other hand, when two or more insulating layers are coated on the outer periphery of the conductor, it is sufficient that at least one layer is made of the resin composition. At this time, the layer made of the resin composition may be located in the outermost layer of the insulating layer, or may be located in the inner layer of the outermost layer. In the case of being located in the innermost outer layer, it may be located in any inner layer.

  More preferably, the layer made of the resin composition is located in the innermost outermost layer. At this time, it is preferable that the outermost layer is formed of a material that does not contain a fibrous substance. This is because if the fibrous material is not contained in the outermost layer, the smoothness of the electric wire surface is improved and the insulating layer is hardly damaged. Moreover, it is excellent also in an external appearance and the productivity at the time of processing the said insulated wire into the wire harness mentioned later improves. At this time, since at least one of the innermost outer layers is made of the resin composition, the insulating layer as a whole is excellent in mechanical characteristics such as external resistance and abrasion resistance.

  The fibrous substance here includes (D) a fibrous substance having an aspect ratio of 30 or more, and other fibrous substances having an aspect ratio of less than 30, for example. It contains a fibrous material that tends to deteriorate the smoothness of the wire surface.

  The outermost layer is not particularly limited with respect to the material except that it does not contain a fibrous substance. For example, only the polymer component which comprises the said resin composition, only the other polymer component, Furthermore, what was formed with what contains the said polymer component and other polymer components, etc. can be mentioned. These materials may further contain various fillers other than the fibrous substance.

  The outermost layer material is more preferably a material excellent in water repellency. This is because the outermost layer forms the surface of the electric wire, so that the coefficient of friction on the surface of the electric wire is lowered and the surface of the electric wire is hardly damaged. The material excellent in water repellency is preferably a material that makes the water contact angle on the surface of the outermost layer the electric wire 60 ° or more. More preferably, it is a material which makes a water contact angle 70 degrees or more. This is because the surface of the electric wire is further hardly damaged.

  Specific examples of the material for forming the outermost layer include olefin resins such as polypropylene and polyethylene, waxes, silicone-acrylic copolymers, acrylic coating agents, glass coating agents, oil-type water-repellent silicone agents, Examples thereof include emulsion-type water-repellent silicone agents, acrylic lacquer paints, alkyd resin paints, acrylic emulsions, and water-repellent compositions using inorganic / organic fine particles.

  More preferably, a silicon-acrylic copolymer, an acrylic coating agent, a glass coating agent, an oil-type water-repellent silicone agent, an emulsion-type water-repellent silicone agent, an acrylic lacquer paint, an alkyd resin paint, an acrylic emulsion, and inorganic / organic fine particles For example, a water-repellent composition.

  The outermost layer is preferably a thin film, that is, a film layer. The thickness of the outermost layer is preferably in the range of 5 to 300 μm. More preferably, it exists in the range of 5-100 micrometers. If the thickness is less than 5 μm, the effect of smoothing the surface of the electric wire tends to be difficult to obtain, and if it exceeds 300 μm, it tends to be difficult to reduce the diameter of the electric wire.

  The outermost layer may be directly coated on the outer periphery of the inner layer, or another intermediate member, for example, a shield conductor such as a braid or metal foil, is interposed between the inner layer and the outermost layer. The outer periphery may be covered.

  Next, the manufacturing method of this electric wire is demonstrated. As a manufacturing method of this electric wire, a generally known method can be used and is not particularly limited.

  In the case where the insulating layer of the electric wire is composed of one layer, for example, first, (A) an olefin resin, (B) a styrene thermoplastic elastomer, (C) a metal hydroxide, (D) a fibrous substance, and If necessary, other ingredients and additives can be arbitrarily blended, and these can be dry blended with a normal tumbler or the like, or a Banbury mixer, pressure kneader, kneading extruder, twin screw extruder, roll The resin composition is prepared by, for example, melt-kneading with a normal kneader such as the above and uniformly dispersing. Next, for example, if the prepared resin composition is coated with an arbitrary thickness on the outer periphery of the conductor using an extruder, the electric wire can be obtained.

  When the insulating layer of the electric wire is composed of two or more layers, in the same manner as the method of coating the outer periphery of the conductor with the resin composition, the inner layer or the outer layer of the layer made of the resin composition is made of the resin composition. If this layer or a layer made of a material other than this is extrusion-coated at an arbitrary thickness, the present electric wire can be obtained.

  At this time, in order to smooth the surface of the electric wire, the outermost layer may be formed of a material that does not contain a fibrous substance. At this time, the material that does not contain the fibrous substance is extrusion coated at an arbitrary thickness on the outermost periphery of the inner layer of the insulating layer in the same manner as the method of coating the resin composition, or is applied at an arbitrary thickness. Work (apply or spray). The formation method is not particularly limited.

  Next, the wire harness according to the present invention will be described.

  In the wire harness according to the present invention, a plurality of the electric wires alone, or an electric wire bundle composed of the electric wires and other electric wires is covered with a wire harness protective material. As another electric wire, an electric wire containing a halogen element (such as a vinyl chloride electric wire) may be used, or an electric wire not containing a halogen element may be used. The number of electric wires can be determined arbitrarily and is not particularly limited.

  A wire harness protective material has a role which covers the outer periphery of the electric wire bundle in which the multiple insulated electric wire was bundled, and protects an internal electric wire bundle from the external environment. Although it does not specifically limit as a base material which comprises a wire harness protective material, Polyolefin-type resin compositions, such as polyethylene and a polypropylene, are preferable. A flame retardant such as a metal hydroxide may be appropriately added to the resin composition.

  As the form of the wire harness protective material, such as those in which an adhesive is applied to at least one surface of the base material formed in a tape shape, those having a base material formed in a tube shape, a sheet shape, etc. It can be appropriately selected and used depending on the application.

  EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited thereto.

(Test material and manufacturer)
The test materials used in this example are shown together with the manufacturer, product name, physical property values, and the like.

(A) Olefin resin / polypropylene [manufactured by Nippon Polypro Co., Ltd., trade name “NOVATEC PP EC7”, MFR = 1.5 g / 10 min]
(B) Styrenic thermoplastic elastomer / styrene-ethylene-propylene-styrene block copolymer (SEPS) [Kuraray Co., Ltd., trade name “Septon 2002”]
(C) Metal hydroxide / magnesium hydroxide [manufactured by Martinsberg, trade name “Magnifine H10”, average particle size = 1.0 μm]
(D) Fibrous material / activated carbon fiber [reagent, short diameter (diameter) 10 μm]
・ Carbon nanotube [reagent, short diameter (diameter) 1μm]
(E) Coating layer material, dimethyl silicone oil [Shin-Etsu Silicone Co., Ltd., trade name “KF-995”]

(Preparation of insulated wire consisting of one insulating layer)
Each component shown in Table 1 and Table 2 described below was mixed using a Henschel mixer, and kneaded at 200 ° C. to 230 ° C. by a twin screw extruder. Each composition obtained was stranded conductor cross-sectional area 0.5 mm ² extruded at 0.3mm thickness on the outer circumference of the (stranded conductor of soft copper wire seven) (extrusion coating). For the extrusion molding, a die having a diameter of 1.25 mm and a nipple having a diameter of 0.87 mm were used, the extrusion temperature was 230 to 250 ° C. and the cylinder was 230 to 250 ° C., and extrusion was performed at a linear speed of 500 m / min. Thereby, the insulated wire which concerns on Examples 1-7 and Comparative Examples 1-7 in which an insulating layer consists of 1 layer was produced.

(Production of insulated wire consisting of two insulating layers)
In Examples 1 to 7, dimethyl silicone oil was applied to the outer periphery of the insulating layer composed of the above-mentioned one layer using a brush having a width of 1 cm to form a coating layer (thickness 5 to 20 μm).

(Test method and measurement method)
For each insulated wire produced as described above, measurement of the fibrous material aspect ratio, confirmation of the orientation of the fibrous material, flame retardancy test, wire workability test, insulation test, water contact angle of the wire surface Measurement, trauma resistance test, and abrasion resistance test were conducted. Each test method, evaluation method, and measurement method will be described below.

(Aspect ratio measurement)
A fibrous material having a short diameter (diameter) of 10 μm or more is measured by using a scanning electron microscope, and a fibrous material having a short diameter (diameter) of less than 10 μm is measured by using a transmission electron microscope. Was measured respectively. The aspect ratio of each fibrous material was calculated from the average value of the major axis and the minor axis of 100 fibers.

(Method for confirming the orientation of fibrous materials)
The orientation of the fibrous material was confirmed using a transmission electron microscope. That is, the wire coating is sliced into a thin film, dyed with ruthenium, and the fibrous material in the wire coating is mapped by a two-dimensional plot. The number of long-diameter ends extending in the direction of the electric wire axis per 1000 fibrous substances mapped was calculated and converted to a 2-digit percentage.

(Flame retardancy test)
This was performed according to ISO6722. That is, first, the insulated wire according to the example and the comparative example was cut out to a length of 600 mm to obtain a test piece. Next, each test piece is tilted at 45 °, and a flame is applied to a portion of 500 ± 5 mm from the upper end of the test piece for 15 seconds. All flames on the test piece insulator disappear within 70 seconds, and the insulator on the upper part of the test piece. Was left unburned for 50 mm or more, and it was regarded as acceptable “◯”, and when it was not, it was regarded as unacceptable “x”.

(Electric wire workability test)
When peeling the resin-coated part of the terminal part of each coated electric wire, it is confirmed whether or not a beard is formed. × ”.

(Insulation test)
Measurement was performed in accordance with ISO 6722, and the volume resistivity value of the insulating layer was 10 ⁹ Ω · mm or more as a pass “◯”, and when it was not, it was determined as a fail “x”.

(Measurement of water contact angle)
Distilled water was sprayed on the surface of each coated electric wire by spraying, and the contact angle between the water droplets on the surface and the electric wire was measured using a microscope. The value of the water contact angle in the table is an average value of three times of the test.

(Trauma resistance test)
As shown in FIG. 1A (plan view) and FIG. 1B (side view), an electric wire 1 cut to a length of 30 cm is placed on plastic plates 2a and 2b. The interval between the plastic plate 2a and the plastic plate 2b is 5 mm. The left end of the electric wire 1 is fixed to the plastic plate 2b, and a tension of 30N is applied to the right end of the electric wire 1 to straighten the electric wire 1. Next, in the electric wire 1, the thickness is 0.5 mm at a position 1 cm away from the lower part of the portion disposed between the plastic plate 2 a and the plastic plate 2 b and about 0.8 mm away from the radial center of the electric wire 1 to the outer peripheral side. A metal piece 3 is arranged.

  Next, as shown in FIGS. 2A to 2C, the load applied to the metal piece 3 of the electric wire 1 by moving the metal piece 3 upward while contacting the insulating layer 4 at a speed of 50 mm / min. Measure. At this time, when the conductor 5 of the electric wire 1 is not exposed, the metal piece 3 is brought closer to the center of the electric wire 1 in units of 0.01 mm, and the measurement is continued until the conductor 5 is exposed. The upper limit load at which the conductor is not exposed is defined as the ability of the wire to be damaged, and when the conductor is not exposed even at a load of 20N or more, the damage resistance is set to “O”, and the conductor is not exposed even at a load of 30N or more. In addition, “◎”, which is more excellent in resistance to trauma. On the other hand, when the conductor was exposed with a load of 20 N or less, the damage resistance was determined to be “X”.

(Abrasion resistance test)
This was performed by a blade reciprocating method in accordance with ISO6722. The load applied to the blade was 7N, the minimum value of the number of tests 4 times was 300 or more, and the pass “◯”, and 500 or more was “◎”, which is superior in wear resistance. On the other hand, if the minimum value of the number of tests of 4 times is less than 300 times, the failure was judged as “x”.

  Tables 1 and 2 below show the component composition and evaluation results of the resin composition forming the insulating layer of each insulated wire according to the present example and the comparative example. In addition, the quantity of each component of a resin composition represents each component of a polymer component by weight%, and represents the metal hydroxide and the fibrous material in the weight part with respect to 100 weight part of polymer components.

  According to Table 2, it can be seen that the insulated wire according to the comparative example has difficulty in any of the evaluation items of flame retardancy, external resistance, abrasion resistance, workability, and insulation.

  Specifically, since Comparative Example 1 does not contain a fibrous material, it is inferior in trauma resistance and wear resistance. In Comparative Examples 2 to 5, since the aspect ratio of the fibrous material is less than 30, the wound resistance and wear resistance are poor. Moreover, in Comparative Examples 2-3, the orientation of the fibrous material is low. In Comparative Examples 6 to 7, the content of the metal hydroxide is small and not within a specific range, so that the flame retardancy is inferior. In Comparative Example 7, the content of the fibrous substance is large and not within a specific range, so that the scratch resistance, workability, and insulation are poor. In addition, the orientation of the fibrous material is low.

  On the other hand, according to Table 1, the insulated wire according to the example having an insulating layer containing a specific amount of metal hydroxide and a specific amount of fibrous substance having an aspect ratio within a specific range is flame retardant. It has been confirmed that it is excellent in all of the property, trauma resistance, wear resistance, workability, and insulation. In particular, when a coating layer was provided (when there were two insulating layers), it was confirmed that the water contact angle was also high, and the trauma resistance and wear resistance were further improved. When a coating layer is provided, the appearance is further excellent.

  Although the embodiments of the present invention have been described in detail above, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the gist of the present invention.

It is a figure showing the method of carrying out the test evaluation of the damage resistance of an insulated wire. It is a figure showing the method of carrying out the test evaluation of the damage resistance of an insulated wire.

Claims (8)

The outer periphery of the conductor is coated with at least one insulating layer,
At least one of the insulating layers is
(A) 60 to 99% by weight of an olefin resin,
(B) Styrenic thermoplastic elastomer 40 to 1% by weight,
100 parts by weight of a polymer component containing
(C) 50 to 200 parts by weight of a metal hydroxide,
(D) Ri aspect ratio name of a resin composition comprising a 30 or more fibrous materials from 0.1 to 20 parts by weight,
The insulated wire , wherein the fibrous material is a carbon-based fibrous material .   2. The insulated wire according to claim 1, wherein 60% or more of the fibrous substance is arranged substantially parallel to the axial direction of the wire. The insulated wire according to claim 1 or 2, wherein the resin composition has a volume resistivity of 10 ⁹ (Ω · mm) or more. The insulated wire according to any one of claims 1 to 3 , wherein the resin composition further contains a spherical substance (excluding (C) a metal hydroxide) . The outer periphery of the conductor is covered with two or more insulating layers,
Among the insulating layers, at least one layer located in the inner layer is made of the resin composition,
The insulated wire according to any one of claims 1 to 4 , wherein the outermost layer of the insulating layers does not contain a fibrous material. The insulated wire according to claim 5 , wherein a water contact angle on the surface of the wire is 60 ° or more. The insulated wire according to claim 5 or 6 , wherein the outermost layer has a thickness in a range of 5 to 300 µm. A wire harness comprising the insulated wire according to claim 1 .

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