JP2009275191A - Flame retardant resin composition, insulated wire and wire harness - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a flame retardant resin composition capable of obtaining an insulated wire having not only flame retardance, abrasion resistance and scratch resistance, but also heat resistance, and to provide the insulated wire and a wire harness. <P>SOLUTION: This flame retardant resin composition is provided by containing an ethylene-propylene-diene rubber containing a ≥70 mass% structural unit originated from ethylene, an ethylene-vinyl acetate copolymer containing a ≥20 mass% structural unit originated from the vinyl acetate and flame retardant particles containing metal hydroxide particles, having the 50 to 200 pts.mass ratio of the flame retardant particles based on the 100 pts.mass mixed resin of the ethylene-propylene-diene rubber with vinyl acetate copolymer and attaching a silane-coupling agent on the surface of the flame retardant particles. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a flame retardant resin composition, an insulated wire, and a wire harness.

  In automobiles and electronic devices, insulated wires are used for electrical connection between components. Such an insulated wire includes a conductor and an insulating layer covering the conductor, and the insulating material constituting the insulating layer has excellent properties such as flame resistance, oil resistance, water resistance, and insulation. Polyvinyl chloride resin is most commonly used because of having it. In recent years, lead-free polyvinyl chloride resins that do not use lead as a stabilizer have become the mainstream because of concerns about the impact on the environment and the human body.

  However, the insulating material contains a chlorine atom which is a halogen in the molecular structure, and generates toxic and harmful chlorine gas at the time of incineration. Therefore, a vinyl chloride electric wire substitute using a so-called eco-material with higher safety is being studied.

Examples of such eco-materials include ethylene materials such as polyethylene (PE), ethylene vinyl acetate copolymer (EVA), and ethylene ethyl acrylate copolymer (EEA), polypropylene (PP), and ethylene propylene rubber ( EP rubber), and those obtained by adding a large amount of metal hydroxides such as magnesium hydroxide and aluminum hydroxide based on a composite resin blended with polyolefin such as styrene elastomer (see, for example, Patent Document 1). .
Japanese Patent No. 3358228

  By the way, it is desirable that the insulated wire is excellent in flame retardancy, wear resistance, trauma resistance and heat resistance.

  However, the insulating material described in Patent Document 1 contains a large amount of metal hydroxide that is a flame retardant. For this reason, an insulated wire obtained using the insulating material can achieve high flame retardancy, but a sufficient wear resistance cannot be obtained because a decrease in mechanical strength is induced. In addition, external factors may cause damage on the surface of the wire covering material.

  Here, in order to realize an insulated wire having sufficient wear resistance, it is necessary to increase the hardness of the insulating material of the insulated wire, that is, to increase the crystallinity, but to increase the hardness of the insulating material. And heat resistance decreases. That is, wear resistance and heat resistance are in a trade-off relationship. Therefore, it has been difficult to realize an insulated wire that is excellent not only in flame retardancy, wear resistance and trauma resistance but also in heat resistance. In this specification, “heat resistance” means “heat deformation” and means that the insulated wire has voltage resistance in a state where it is recessed by external pressure.

  The present invention has been made in view of the above circumstances, and a flame-retardant resin composition and an insulated wire that can realize an insulated wire excellent not only in flame resistance, wear resistance, and external resistance but also in heat resistance. And it aims at providing a wire harness.

  As a result of intensive studies to solve the above problems, the present inventors have intervened a specific substance at the interface between the flame retardant particles containing metal hydroxide particles and a specific resin, and the total of the flame retardant particles. It has been found that by including the amount in a specific ratio with respect to the specific resin, not only flame retardancy, wear resistance and trauma resistance, but also heat resistance can be effectively improved. The present invention has been completed.

  That is, the present invention includes 20 structural units derived from ethylene propylene diene rubber (hereinafter referred to as “EPDM”) containing 70 mass% or more of structural units derived from ethylene and vinyl acetate (hereinafter referred to as “VA”). An ethylene vinyl acetate copolymer (hereinafter referred to as “EVA”) containing at least mass%, and flame retardant particles containing metal hydroxide particles, and the ethylene propylene diene rubber and the vinyl acetate copolymer The flame retardant particles are contained in a ratio of 50 to 200 parts by mass with respect to 100 parts by mass of the mixed resin, and the silane coupling agent is attached to the surface of the flame retardant particles. It is a flammable resin composition.

  According to this flame retardant resin composition, the silane coupling agent adheres to the surface of the flame retardant particles. That is, the silane coupling agent is interposed at the interface between the flame retardant particles and the mixed resin of EPDM and EVA. In addition, in the flame-retardant resin composition of the present invention, as the resin, ethylene propylene diene rubber containing 70 mass% or more of structural units derived from ethylene and ethylene containing 20 mass% or more of structural units derived from vinyl acetate. Vinyl acetate copolymers are used. By producing an insulated wire using the flame retardant resin composition having such a configuration, it is possible to realize an insulated wire that is excellent not only in flame resistance, wear resistance, and scratch resistance but also in heat resistance. It becomes possible.

  The reason why the above effect is obtained is not yet clear. However, the present inventors have (i) a mixture of EPDM and EVA and a silane coupling agent and a flame retardant particle and a silane cup by a silane coupling agent. The ionic intermolecular interaction with the ring agent is strengthened, the bond between the mixed resin of EPDM and EVA and the flame retardant particles is reinforced, and (ii) EPDM and EVA are blended in a well-balanced manner. Including the rubber component in an appropriate ratio in the conductive resin composition is a cause that can improve not only the flame retardancy, wear resistance and trauma resistance of the insulated wire, but also the heat resistance. I'm guessing.

  In addition, when the flame retardant particles are contained in a proportion of less than 50 parts by mass with respect to 100 parts by mass of the EPDM and EVA mixed resin, the flame retardant resin composition is coated on the conductor to produce an insulated wire. In this case, the flame retardancy of the insulated wire is significantly reduced. In addition, when the flame retardant particles are contained in a proportion exceeding 200 parts by mass with respect to 100 parts by mass of the EPDM and EVA mixed resin, the flame retardant resin composition is coated on the conductor to produce an insulated wire. In this case, the tensile strength at break of the obtained insulated wire is lowered, the damage resistance is remarkably lowered, and the wear resistance is also remarkably lowered.

  In addition, when the EVA content in 100% by mass of EPDM and EVA mixed resin exceeds 70% by mass, the content of EPDM becomes less than 30% by mass. descend. In addition, when the content of EPDM in 100% by mass of EPDM and EVA mixed resin exceeds 70% by mass, the content of EVA becomes less than 30% by mass, and in that case, heat resistance and tensile strength are significantly reduced. To do. Furthermore, when the content of structural units derived from VA in EVA is less than 20% by mass, compared to the case where the content of structural units derived from VA in EVA is 20% by mass or more, wear resistance, Trauma and tensile strength are significantly reduced. Furthermore, when the content of structural units derived from ethylene in EPDM is less than 70% by mass, the wear resistance is lower than when the content of structural units derived from ethylene in EPDM is 70% by mass or more. Remarkably reduced.

  Moreover, this invention is equipped with the conductor and the insulating layer which coat | covers the said conductor, The said insulating layer is comprised with the flame-retardant resin composition mentioned above, It is an insulated wire characterized by the above-mentioned. The present invention further comprises a conductor and an insulating layer covering the conductor, and the insulating layer is obtained by crosslinking the flame retardant resin composition described above by electron beam irradiation. It may be an electric wire.

  These insulated wires have excellent heat resistance as well as flame resistance, wear resistance, and damage resistance.

  Furthermore, this invention is a wire harness characterized by having at least one insulated wire as described above.

  When a wire harness is routed in an internal space of an automobile or an electronic device, the internal space of the automobile or electronic device is narrow, and thus the wire harness is likely to come into contact with the inner wall of the automobile or electronic device. Even in such a case, the wire harness includes at least one of the above-described insulated wires, and the above-described insulated wires are excellent in flame retardancy, wear resistance, trauma resistance, and heat resistance. For this reason, according to the wire harness of the present invention, the wiring harness can be operated without worrying about the wire harness coming into contact with the inner wall of the automobile or electronic device during the routing operation in the automobile or electronic device. The harness can be routed efficiently. Moreover, when an automobile or an electronic device is placed at a high temperature, a short circuit between insulated wires can be prevented.

  Further, in the flame retardant resin composition, the flame retardant particles include a fatty acid, and in the flame retardant particles, the fatty acid is attached to a surface of the metal hydroxide particles, and the flame retardant particles in the flame retardant particles The fatty acid content is preferably 2% by mass or less.

  In this case, compared with the case where the content of the fatty acid in the flame retardant particles exceeds 2% by mass, the wear resistance is further improved while maintaining good heat resistance, trauma resistance, tensile strength and tensile elongation. Can do.

  ADVANTAGE OF THE INVENTION According to this invention, the flame-retardant resin composition, the insulated wire, and wire harness which can implement | achieve the insulated wire excellent not only in a flame retardance, abrasion resistance, and external resistance but also in heat resistance are provided.

  Hereinafter, an embodiment of the present invention will be described in detail with reference to FIG.

(Insulated wire)
FIG. 1 is a cross-sectional view showing an embodiment of an insulated wire according to the present invention. As shown in FIG. 1, the insulated wire 10 of this embodiment includes a conductor 1 and an insulating layer 2 that covers the conductor 1. The insulating layer 2 is obtained by crosslinking a flame retardant resin composition by electron beam irradiation. The flame retardant resin composition contains EVA, EPDM, and flame retardant particles including metal hydroxide particles.

  Moreover, when the said mixed resin is 100 mass parts, EVA is contained in the ratio of 30-70 mass parts, and EPDM is contained in the ratio of 30-70 mass parts. For example, when EVA is contained in a proportion of 40 parts by mass, EPDM is contained in a proportion of 60 parts by mass.

  EVA contains 20 mass% or more of structural units derived from VA, and EPDM contains 70 mass% or more of structural units derived from ethylene. And a flame retardant particle | grain is contained in the ratio of 50-200 mass parts with respect to 100 mass parts of said mixed resins.

  Furthermore, in the flame retardant resin composition, a silane coupling agent is attached to the surface of the flame retardant particles. That is, a silane coupling agent is present at the interface between the flame retardant particles and the mixed resin of EVA and EPDM. The insulated wire 10 is obtained by crosslinking the flame retardant resin composition by electron beam irradiation. As a result, the insulated wire 10 has excellent heat resistance as well as flame resistance, wear resistance, and damage resistance.

  In addition, in the insulated wire 10, the insulating layer 2 is provided with the crosslinked body of the mixed resin and metal hydroxide particles.

  The insulated wire 10 described above is manufactured as follows.

(conductor)
First, the conductor 1 is prepared. The conductor 1 may be configured by only one strand, or may be configured by bundling a plurality of strands. Moreover, the conductor 1 is not specifically limited about a conductor diameter, the material of a conductor, etc., It can determine suitably according to a use.

(Flame retardant resin composition)
On the other hand, the flame retardant resin composition is prepared. As described above, the flame retardant resin composition contains EVA, EPDM, flame retardant particles including metal hydroxide particles, and a silane coupling agent attached to the surface of the flame retardant particles. .

(EVA)
As described above, EVA contains 20% by mass or more of structural units derived from VA. When the content of structural units derived from VA in EVA is less than 20% by mass, the wear resistance and trauma resistance are higher than when the content of structural units derived from VA in EVA is 20% by mass or more. Properties and tensile strength are significantly reduced. The reason for this is that as the proportion of VA in EVA decreases, the proportion of oxygen atoms in EVA decreases, so that the ionic intermolecular interaction between the metal hydroxide particles and the above mixed resin occurs. The present inventors speculate that it may be weakened.

  The content of the structural unit derived from VA in EVA is preferably 20% by mass to 33% by mass, and more preferably 28% by mass to 33% by mass.

(EPDM)
As described above, EPDM contains 70% by mass or more of structural units derived from ethylene. When the content of structural units derived from ethylene in EPDM is less than 70% by mass, the wear resistance is significantly higher than when the content of structural units derived from ethylene in EPDM is 70% by mass or more. descend. The present inventors presume that the reason is that the crystallinity of EPDM decreases as the ethylene ratio decreases.

  The content of the structural unit derived from ethylene in EPDM is preferably 75% by mass or more, and more preferably 77% by mass to 80% by mass. When the content of the structural unit derived from ethylene in EPDM is 75% by mass or more, the blocking property of EPDM is greatly improved as compared with the case where the content is less than 75% by mass.

  In addition to EPDM and EVA, the flame retardant resin composition includes polyethylene such as high density polyethylene (HDPE), linear low density polyethylene (LLDPE), and low density polyethylene (LDPE), and ethylene-α olefin co-polymer. Polyolefins such as polymers, isotactic polypropylene, and atactic polypropylene may be included within a range that does not affect the properties.

  Although the content rate of EVA and EPDM mixed resin in the said flame-retardant resin composition is not specifically limited, For example, it is preferable that it is 70-100 mass%.

(Flame retardant particles)
The flame retardant particles include metal hydroxide particles, and the metal hydroxide particles are composed of metal hydroxide. Examples of the metal hydroxide include magnesium hydroxide, calcium hydroxide, and aluminum hydroxide. Among these, magnesium hydroxide is preferable. This is because the extrudability and flame retardancy when coating the conductor can be improved.

  The flame retardant particles are contained at a ratio of 50 to 200 parts by mass with respect to 100 parts by mass of the mixed resin of EVA and EPDM. When the flame retardant particles are contained at a ratio of less than 50 parts by mass with respect to 100 parts by mass of the mixed resin of EVA and EPDM, the flame retardancy of the insulated wire 10 is significantly reduced. Further, when the flame retardant particles are contained in a proportion exceeding 200 parts by mass with respect to 100 parts by mass of the EVA and EPDM mixed resin, the wear resistance, the trauma resistance, the tensile breaking strength, and the tensile breaking elongation are significantly reduced. .

  It is preferable that the flame retardant particles are contained in a ratio of 70 to 100 parts by mass with respect to 100 parts by mass of the mixed resin of EVA and EPDM because the abrasion resistance and the damage resistance are further improved.

(Silane coupling agent)
A silane coupling agent adheres to the surface of the flame retardant particles. The silane coupling agent is not particularly limited, but those having a methacryloxy group, an acryloxy group, a vinyl group, an amino group, or two or more functional groups thereof are preferably used. Among these, those having a vinyl group are preferable because they can exhibit excellent heat resistance.

  Examples of the silane coupling agent having a methacryloxy group include methacryloxysilane such as γ-methacryloxypropyltrimethoxysilane and γ-methacryloxypropylmethyldiethoxysilane.

  Examples of the silane coupling agent having an acryloxy group include 3-acryloxypropyltrimethoxysilane.

  Examples of the silane coupling agent having a vinyl group include vinyl silanes such as vinyl tris (β methoxyethoxy) silane, vinyl triethoxy silane, and vinyl trimethoxy silane.

  Examples of the silane coupling agent having an amino group include aminosilanes such as γ-aminopropyltriethoxysilane and γ-aminopropyltrimethoxysilane.

  Examples of the method of attaching the silane coupling agent to the surface of the flame retardant particles include a method of surface-treating the flame retardant particles with the silane coupling agent. Specifically, the silane coupling agent adhered to the surface of the flame retardant particles is added to and mixed with the flame retardant particles to obtain a mixture, and then the mixture is heated to 40 to 75 ° C. For 10 to 40 minutes, and the dried mixture is pulverized with a Henschel mixer, an atomizer or the like.

  Here, the silane coupling agent is preferably contained in an amount of 10 parts by mass or less, more preferably 5 parts by mass or less, with respect to 100 parts by mass of the EVA and EPDM mixed resin. When the silane coupling agent is contained at a ratio exceeding 10 parts by mass with respect to 100 parts by mass of the mixed resin of EVA and EPDM, the effect corresponding to the content ratio cannot be obtained.

  However, the silane coupling agent is contained in a proportion of 0.5 parts by mass or more with respect to 100 parts by mass of the mixed resin of EVA and EPDM, particularly improving the wear resistance and the damage resistance of the insulated wire. It is preferable from the point of making it.

  The flame retardant particles only need to contain metal hydroxide particles. Therefore, the flame retardant particles may be composed only of metal hydroxide particles, or may be composed of metal hydroxide particles and other substances attached to the surface of the metal hydroxide particles. Examples of the other substance include acrylic acid and fatty acid.

  Of these, fatty acids are preferred. When the fatty acid adheres to the surface of the metal hydroxide particles, the wear resistance and tensile elongation of the insulated wire 10 can be further improved.

  Here, the fatty acid is preferably contained in the flame retardant particles in a proportion of greater than 0% by mass and 2% by mass or less. In this case, the tensile elongation of the insulated wire 10 can be further increased.

  Examples of the fatty acid include stearic acid, margaric acid, palmitic acid, pentadecylic acid, myristic acid and lauric acid.

  When stearic acid is used as the fatty acid, vinyl silane is preferably used as the silane coupling agent. In this case, the abrasion resistance and the damage resistance of the insulated wire can be further improved.

  Examples of the method for attaching the fatty acid to the surface of the metal hydroxide particles include a method for treating the surface of the metal hydroxide particles with a fatty acid. Specifically, the fatty acid adhered to the surface of the metal hydroxide particles was added and mixed with the metal hydroxide particles to obtain a mixture, and then the mixture was dried and dried. The mixture can be obtained by grinding with a Henschel mixer, an atomizer or the like. Further, metal hydroxide particles that have been surface-treated with a fatty acid in advance are commercially available and can be easily obtained.

  The flame retardant resin composition is filled with a flame retardant aid, an antioxidant, an ultraviolet absorber, an ultraviolet degradation inhibitor, an antistatic agent, a processing aid, a colorant, a lubricant, a crosslinking aid, an inorganic filler, and the like. An agent may be included.

  The flame retardant resin composition can be obtained by kneading the EVA, EPDM, or a material in which a silane coupling agent is previously attached to the surface of the flame retardant particles, if necessary. The silane coupling agent may be added at the time of kneading without adhering to the surface of the flame retardant particles in advance. The kneading can be performed with a kneading machine such as a Banbury mixer, a tumbler, a pressure kneader, a kneading extruder, a twin screw extruder, or a roll.

  Next, the conductor 1 is covered with the flame retardant resin composition. The coating of the flame retardant resin composition may be performed by, for example, extruding the flame retardant resin composition into a tube shape by extrusion molding so as to adhere to the surface of the conductor 1, or by placing the conductor 1 in a die containing the flame retardant resin composition It can be done by passing through.

  Next, the flame retardant resin composition is crosslinked by electron beam irradiation. By this crosslinking treatment, the mixed resin of EVA and EPDM becomes a crosslinked body, and the insulating layer 2 covering the conductor 1 is obtained. Thus, the insulated wire 10 is obtained. The amount of electron beam irradiation at the time of the crosslinking treatment is not particularly limited as long as the mixed resin of EVA and EPDM is crosslinked, but for example, when it is 50 to 150 kGy, the hardness of the insulating layer 2 is further increased and the damage resistance is increased. In addition, the wear resistance can be further improved.

  As described above, the insulated wire 10 according to the present embodiment is excellent not only in flame retardancy, wear resistance, and trauma resistance, but also in heat resistance. For this reason, the insulated wire 10 is particularly useful for at least one insulated wire constituting the wire harness.

  That is, when the wire harness is routed in the internal space of an automobile or an electronic device, the internal space of the automobile or the electronic device is narrow, and thus the wire harness is likely to come into contact with the inner wall of the automobile or the electronic device. In that respect, since the insulated wire 10 is excellent not only in flame retardancy but also in abrasion resistance and damage resistance, the wire harness having the insulated wire 10 is used for automobiles and electronic devices in the routing work in automobiles and electronic devices. Work can be performed without worrying about contacting the inner wall of the device, and the wire harness can be routed efficiently. Moreover, when an automobile or an electronic device is placed at a high temperature, a short circuit between insulated wires can be prevented.

  The present invention is not limited to the above embodiment. For example, in the above embodiment, the insulating layer 2 is obtained by crosslinking a flame retardant resin composition by electron beam irradiation. However, the crosslinking treatment by electron beam irradiation is performed on the flame retardant resin composition. If the flame retardancy, wear resistance, and trauma resistance are sufficiently high in a state where the conductor 1 is coated with the flame retardant resin composition, an electron beam is used for the flame retardant resin composition. The crosslinking treatment by irradiation may not be performed.

  Hereinafter, the content of the present invention will be described more specifically with reference to examples and comparative examples, but the present invention is not limited to the following examples.

(Examples 1-12 and Comparative Examples 1-7)
Table 1 shows magnesium hydroxide surface-treated with EVA, EPDM, and stearic acid (hereinafter, “magnesium hydroxide” is referred to as “Mg hydroxide”) particles or Mg hydroxide particles that are not surface-treated and silane coupling agents. And it mix | blended with the compounding ratio shown in Table 2, and knead | mixed for 15 minutes at 150 degreeC with the Banbury mixer, and obtained the flame-retardant resin composition.

The following were used as EVA, EPDM, Mg hydroxide particles and silane coupling agent.
EVA (VA content = 33% by mass): EVAFLEX EV-130 (trade name, manufactured by Mitsui DuPont Polychemical Co., Ltd.)
EVA (VA content = 45% by mass): EVAFLEX EV-45LX (trade name, manufactured by Mitsui DuPont Polychemical Co., Ltd.)
EVA (VA content = 19% by mass): EVAFLEX EV-460 (trade name, manufactured by Mitsui DuPont Polychemical Co., Ltd.)
EPDM (ethylene content = 78% by mass): Mitsui EPT X-75 (trade name, manufactured by Mitsui Chemicals)
EPDM (ethylene content = 72% by mass): Mitsui EPT X-3012P (trade name, manufactured by Mitsui Chemicals)
EPDM (ethylene content = 66 mass%): Mitsui EPT X-3095 (trade name, manufactured by Mitsui Chemicals)
Mg hydroxide particles (surface untreated): Kisuma 5 (trade name, manufactured by Kyowa Chemical Co., Ltd.)
Mg hydroxide particles (stearic acid (fatty acid) 1.6 mass% surface treatment): Kisuma 5AL (trade name, manufactured by Kyowa Chemical Co., Ltd.)
Mg hydroxide particles (stearic acid (fatty acid) 3.0 mass% surface treatment): Kisuma 5A (trade name, manufactured by Kyowa Chemical Co., Ltd.)
Silane coupling agent (vinyl silane): KBM-1003 (trade name, manufactured by Shin-Etsu Chemical Co., Ltd.)
Silane coupling agent (methacryloxysilane): KBM-503 (trade name, manufactured by Shin-Etsu Chemical Co., Ltd.)
Silane coupling agent (aminosilane): KBM-903 (trade name, manufactured by Shin-Etsu Chemical Co., Ltd.)

  In addition, Mg hydroxide particles (stearic acid (fatty acid) 1.6% by mass surface treatment) are obtained by surface-treating Mg hydroxide particles with stearic acid, and the total of Mg hydroxide particles and stearic acid is 100% by mass. The content of stearic acid is 1.6% by mass. The Mg hydroxide particles (stearic acid (fatty acid) 3.0% by mass surface treatment) are obtained by surface-treating Mg hydroxide particles with stearic acid, and the total amount of Mg hydroxide particles and stearic acid is 100% by mass. The content of stearic acid is 3.0% by mass.

Next, this flame retardant resin composition was kneaded at 150 ° C. for 15 minutes by a Banbury mixer. Thereafter, the flame retardant resin composition is extruded into a tube shape with an extruder, and the flame retardant resin composition is formed on the conductor (58 strands / 0.26 mm strand diameter) to a thickness of 0.7 mm. The object was coated. And the crosslinking process by electron beam irradiation was performed with respect to the flame-retardant resin composition. The electron beam dose at this time was 100 kGy. Thus, an insulated wire having an outer diameter of 3.7 mm was obtained.

  About the insulated wires of Examples 1 to 12 and Comparative Examples 1 to 7 obtained as described above, the evaluation of wear resistance, trauma resistance, flame retardancy and heat resistance, and the tensile breaking strength and tensile breaking elongation. The measurement was performed as follows.

(Abrasion resistance)
The wear resistance was evaluated according to the following procedure based on a scrape test (ISO 6722). That is, while a needle having a diameter of 0.45 mm was pressed against the surface of the insulated wire with a load of 7 N, the surface of the insulated wire was subjected to reciprocating wear. At that time, the number of reciprocations until the needle contacted the conductor in the insulated wire was measured. Then, after the insulated wire was moved with respect to the needle, it was rotated 90 ° with the longitudinal direction as the central axis, and the number of reciprocations was measured in the same manner as described above at the location facing the needle. This operation was repeated 12 times, and the average value was obtained. And the insulated wire whose average value of the measured number of reciprocations was 3000 times or more was passed, and the insulated wire which was less than 3000 times was rejected. The measurement was terminated when the number of reciprocations exceeded 5000.

(Trauma resistance)
The condition of the surface of the insulated wire when the insulated wire is pulled out with the edge of the metal terminal for harness pressed against the surface of the insulated wire with a load of 500g against the insulated wire placed on a flat surface. By observing, the damage resistance of the insulated wire was evaluated. At this time, the insulated wire in which shavings were generated was rejected, and the insulated wire in which shavings were not generated was accepted.

(Tensile strength at break)
The tensile breaking strength of the insulated wire was measured under the test conditions of a tensile speed of 200 mm / min and a distance between marked lines of 20 mm. And the insulated wire whose tensile breaking strength is 10 Mpa or more was made into the pass, and the insulated wire which was less than 10 Mpa was made into the failure.

(Tensile breaking elongation)
The tensile breaking elongation of the insulated wire was measured under the test conditions of a tensile speed of 200 mm / min and a distance between marked lines of 20 mm. And the insulated wire whose tensile breaking elongation is 250% or more was set as the pass, and the insulated wire which is less than 250% was set as the failure.

(Flame retardance)
Based on the ISO 6722 45 degree inclination combustion test, the flame retardance evaluation of the insulated wire was performed as follows. That is, the fire was extinguished within 70 seconds, and the insulated wire in which the upper 50 mm in 500 mm remained was accepted, and the insulated wire that was not so was rejected.

(Heat-resistant)
Based on ISO6722, the heat resistance of the insulated wire was evaluated as follows. That is, an insulated wire was installed in an oven at 125 ° C., and an edge of a metal blade having a thickness of 0.7 mm was pressed with a load of 4.7 N for 4 hours. And the withstand voltage test was done to the part which pressed the edge. At this time, the insulated wire in which dielectric breakdown did not occur was accepted, and the insulated wire in which dielectric breakdown occurred was rejected.

  In Tables 1 and 2, the evaluation results for trauma resistance, flame retardancy and heat resistance are indicated by “◯” if they are acceptable, and “x” if they are not acceptable. did.

  From the results shown in Tables 1 and 2, the insulated wires of Examples 1 to 12 are not only flame retardant, abrasion resistant and trauma resistant, but also heat resistant compared to the insulated wires of Comparative Examples 1 to 7. It turns out that it is also excellent.

  From this, it was confirmed that according to the flame-retardant resin composition of the present invention, it is possible to realize an insulated wire excellent not only in flame retardancy, wear resistance and external resistance but also in heat resistance.

It is sectional drawing which shows one Embodiment of the insulated wire of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Conductor, 2 ... Insulating layer, 10 ... Insulated electric wire.

Claims (5)

Ethylene propylene diene rubber containing 70 mass% or more of structural units derived from ethylene;
An ethylene vinyl acetate copolymer containing 20% by mass or more of a structural unit derived from vinyl acetate;
Flame retardant particles comprising metal hydroxide particles;
Containing
The flame retardant particles are contained in a proportion of 50 to 200 parts by mass with respect to 100 parts by mass of the mixed resin of the ethylene propylene diene rubber and the vinyl acetate copolymer,
A silane coupling agent is attached to the surface of the flame retardant particles;
A flame retardant resin composition. The flame retardant particles include fatty acids;
In the flame retardant particles, the fatty acid is attached to the surface of the metal hydroxide particles,
The content of the fatty acid in the flame retardant particles is 2% by mass or less,
The flame-retardant resin composition according to claim 1. Conductors,
An insulating layer covering the conductor;
With
The insulating layer is composed of the flame retardant resin composition according to claim 1 or 2,
Insulated wire characterized by Conductors,
An insulating layer covering the conductor;
With
The insulating layer is obtained by crosslinking the flame retardant resin composition according to claim 1 or 2 by electron beam irradiation,
Insulated wire characterized by Having at least one insulated wire according to claim 3 or 4,
Wire harness characterized by

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