WO2019176886A1

WO2019176886A1 - Cable and wiring harness

Info

Publication number: WO2019176886A1
Application number: PCT/JP2019/009824
Authority: WO
Inventors: 亮渡部; 成一平; 学佐々木; 中村　詳一郎
Original assignee: 株式会社フジクラ
Priority date: 2018-03-13
Filing date: 2019-03-11
Publication date: 2019-09-19
Also published as: JPWO2019176886A1

Abstract

This cable comprises: a transmission medium which is composed of a conductor or an optical fiber; and an insulating layer which covers the transmission medium. The insulating layer comprises an outermost layer and an inner layer that is provided inside the outermost layer; and the outermost layer contains a base resin and a flame retardant. The flame retardant contains: inorganic particles, which are composed of at least one kind of particles selected from the group consisting of calcium carbonate particles and silicate compound particles; a silicone compound; and a fatty acid-containing compound. The cross-sectional area ratio of the outermost layer in the insulating layer is 0.5% or more but less than 86%.

Description

Cable and wire harness

The present invention relates to a cable and a wire harness.

The cable has a transmission medium made of a conductor or an optical fiber and an insulating layer covering the transmission medium, and a flame retardant resin composition may be used for the insulating layer. For example, in Patent Document 1 below, as an insulating layer, calcium carbonate particles blended at a ratio of 10 parts by mass or more with respect to 100 parts by mass of the base resin, a silicone compound blended at a ratio of more than 1 part by mass, A cable using a flame retardant resin composition containing a fatty acid-containing compound blended at a ratio of more than 3 parts by mass is disclosed. In this cable, the insulating layer has excellent flame retardancy.

JP 2014-94969 A

However, the cable described in Patent Document 1 has the following problems.

That is, since the cable described in Patent Document 1 has an insulating layer having excellent flame retardancy, the cable as a whole has excellent flame retardancy, but wear resistance of the cable when the insulating layer is exposed. There was room for improvement.

This invention is made | formed in view of the said situation, and it aims at providing the cable and wire harness which have the outstanding abrasion resistance, maintaining favorable flame retardance.

In order to solve the above problems, the present inventors first considered dividing the insulating layer into an outermost layer and an inner layer in the cable described in Patent Document 1. And, as a result of intensive studies, the present inventors have found that the outermost layer is a base resin and at least one inorganic particle selected from the group consisting of calcium carbonate particles and silicate compound particles as a flame retardant, a silicone compound In addition, it has been found that it is effective in solving the cable wear resistance that the cross-sectional area ratio of the outermost layer in the insulating layer is within a specific range in the cross section of the cable after adding the fatty acid-containing compound. It was. Thus, the present inventors have completed the present invention.

That is, the present invention includes a transmission medium composed of a conductor or an optical fiber, and an insulating layer that covers the transmission medium, and the insulating layer includes an outermost layer and an inner layer provided inside the outermost layer. And the outermost layer contains a base resin and a flame retardant, and the flame retardant comprises at least one inorganic particle selected from the group consisting of calcium carbonate particles and silicate compound particles, and a silicone compound, And a fatty acid-containing compound, wherein the cross-sectional area ratio of the outermost layer in the insulating layer is 0.5% or more and less than 86%.

The cable of the present invention has excellent wear resistance while maintaining good flame retardancy.

In addition, the present inventors infer the reason why the above effect is obtained as follows.

That is, in the insulating layer, the outermost layer containing inorganic particles, silicone compound and fatty acid-containing compound that can form a barrier layer on the surface of the base resin during combustion has a cross-sectional area ratio of 0.5% or more and less than 86%. If so, the cable can maintain good flame retardancy. On the other hand, since the outermost layer has the above-mentioned cross-sectional area ratio, the cable can maintain good flame retardancy, so in the inner layer, the blending ratio of the flame retardant can be reduced from the blending ratio of the flame retardant in the outermost layer. Further, the wear resistance of the inner layer can be further improved. As a result, it is possible to improve the wear resistance of the entire insulating layer, and the wear resistance of the entire cable can be improved. For this reason, the present inventors speculate that the above-mentioned effect may be obtained.

In the cable, the cross-sectional area ratio of the outermost layer in the insulating layer is preferably 50% or less.

In this case, compared to the case where the cross-sectional area ratio of the outermost layer in the insulating layer exceeds 50%, it is possible to further improve the wear resistance or lead processability.

In the cable, the content of the inorganic particles in the insulating layer is 0.03 to 7.00% by mass, and the content of the silicone compound in the insulating layer is 0.01 to 4.30% by mass. The content of the fatty acid-containing compound in the insulating layer is preferably 0.02 to 7.50% by mass.

In this case, the flame retardancy of the cable can be further improved as compared with the case where the content of the inorganic particles in the insulating layer is less than 0.03% by mass. Moreover, compared with the case where the content rate of the inorganic particle in an insulating layer exceeds 7.00 mass%, the abrasion resistance of a cable can be improved more. Moreover, the flame retardance of a cable can be improved more compared with the case where the content rate of the silicone type compound in an insulating layer is less than 0.01 mass%. In addition, when the content of the silicone compound is within the above range, the abrasion resistance of the cable can be further improved compared to the case where the content of the silicone compound in the insulating layer exceeds 4.30% by mass. it can. Furthermore, in this case, the flame retardancy of the cable can be further improved as compared with the case where the content of the fatty acid-containing compound in the insulating layer is less than 0.02% by mass. Moreover, compared with the case where the content rate of the fatty-acid containing compound in an insulating layer exceeds 7.50 mass%, the abrasion resistance of a cable can be improved more.

In the cable, the outermost layer preferably has a thickness of 0.008 to 0.400 mm.

In this case, the flame retardancy of the cable can be further improved as compared with the case where the thickness of the outermost layer is less than 0.008 mm. Moreover, compared with the case where the thickness of outermost layer exceeds 0.400 mm, a cable can be reduced in weight and diameter, and the abrasion resistance and lead-out workability of the cable can be further improved.

In the cable, the specific gravity of the insulating layer is preferably 0.84 to 1.04.

In this case, the flame retardancy of the cable can be further improved as compared with the case where the specific gravity of the insulating layer is less than 0.84. In addition, the cable can be reduced in weight and the wear resistance of the cable can be further improved as compared with the case where the specific gravity of the insulating layer exceeds 1.04.

In the cable, in the outermost layer, the blending ratio of the inorganic particles with respect to 100 parts by weight of the base resin is 6 to 20 parts by weight, and the blending ratio of the silicone compound with respect to 100 parts by weight of the base resin is 1.5. It is preferable that the blending ratio of the fatty acid-containing compound to 100 parts by mass of the base resin is 3 to 20 parts by mass.

In this case, the flame retardancy of the cable can be further improved as compared with the case where the blending ratio of the inorganic particles to 100 parts by mass of the base resin is less than 6 parts by mass. Moreover, the abrasion resistance of a cable can be improved more compared with the case where the inorganic particle with respect to 100 mass parts of base resins exceeds 20 mass parts. Moreover, the flame retardance of a cable can be improved more compared with the case where the compounding ratio of the silicone compound with respect to 100 parts by mass of the base resin is less than 1.5 parts by mass. Moreover, compared with the case where the compounding ratio of the silicone compound with respect to 100 parts by mass of the base resin exceeds 10 parts by mass, the bloom of the silicone compound is less likely to occur, and the wear resistance of the cable can be further improved. Furthermore, the flame retardance of the cable can be further improved as compared with the case where the blending ratio of the fatty acid-containing compound to 100 parts by mass of the base resin is less than 3 parts by mass. Moreover, the abrasion resistance of a cable can be improved more compared with the case where the mixture ratio of the fatty acid-containing compound with respect to 100 parts by mass of the base resin exceeds 20 parts by mass.

In the cable, the base resin preferably contains a polyolefin resin.

In this case, compared with the case where the base resin does not contain a polyolefin resin, flame retardancy and wear resistance can be further improved.

In the cable, the inner layer is composed of a resin composition containing a base resin, the content of the propylene-based resin in the base resin is greater than 80% by mass, and the resin composition has a temperature of 230 ° C. and 2.16 kg weight. The MFR is preferably 1.0 g / 10 min or more and less than 15.0 g / 10 min.

In this case, the abrasion resistance of the cable is further improved as compared with the case where the content of the propylene resin in the base resin of the inner layer is 80% by mass or less. Further, the appearance of the cable is more excellent as compared with the case where the MFR of the resin composition is less than 1.0 g / 10 minutes. Moreover, the abrasion resistance of a cable improves more compared with the case where MFR of a resin composition is 15.0 g / 10min or more.

In the cable, the conductor is preferably aluminum or an aluminum alloy. In this case, the weight of the cable can be reduced as compared with the case where copper or the like is used as the conductor.

The cable may further include a covering layer that covers the insulating layer described above.

This cable has excellent wear resistance while maintaining good flame resistance while maintaining good flame resistance even if it does not have a coating layer, and has excellent wear resistance while maintaining good flame resistance Is possible.

Also, the present invention is a wire harness having the cable described above.

Since the wire harness of the present invention has a cable having excellent wear resistance while maintaining good flame retardancy, it is possible to have excellent wear resistance while maintaining good flame resistance. Become.

According to the present invention, a cable and a wire harness having excellent wear resistance while maintaining good flame retardancy are provided.

It is a partial side view which shows one Embodiment of the cable of this invention. FIG. 2 is a cross-sectional view taken along line II-II in FIG. It is sectional drawing which shows one Embodiment of the wire harness of this invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to FIGS. 1 and 2.

[cable]
FIG. 1 is a partial side view showing an embodiment of a cable according to the present invention. FIG. 2 is a sectional view taken along line II-II in FIG. As shown in FIGS. 1 and 2, the cable 10 includes an insulated wire 4 and a coating layer 3 that covers the insulated wire 4. And the insulated wire 4 has the conductor 1 as a transmission medium which transmits a signal, and the insulating layer 2 which coat | covers the conductor 1. FIG. The insulating layer 2 includes an outermost layer 2B and an inner layer 2A provided inside the outermost layer 2B.

Here, the outermost layer 2B of the insulating layer 2 includes a base resin and a flame retardant, and the flame retardant includes at least one inorganic particle selected from the group consisting of calcium carbonate particles and silicate compound particles, and silicone. A system compound and a fatty acid-containing compound. The cross-sectional area ratio (R) of the outermost layer 2B in the insulating layer 2 is 0.5% or more and less than 86%.

The insulated wire 4 has excellent wear resistance while maintaining good flame retardancy. For this reason, the cable 10 can also have excellent wear resistance while maintaining good flame retardancy.

Hereinafter, the conductor 1, the insulating layer 2, and the covering layer 3 will be described in detail.

≪Conductor≫
The conductor 1 may be configured by only one strand, or may be configured by bundling a plurality of strands. The material of the conductor 1 is not particularly limited, but is preferably aluminum or an aluminum alloy. In this case, compared with the case where copper etc. are used as the conductor 1, the insulated wire 4 and by extension, the cable 10 can be reduced in weight. As for the cross-sectional area of the conductor 1, is not particularly limited, in view of the small-diameter and weight of the cable 10, preferably less than 5 mm ^2, and more preferably 3 mm ² or less . However, from the viewpoint of the strength and conductivity of the conductor 1, the cross-sectional area of the conductor 1 is preferably 0.13 mm ² or more.

≪Insulating layer≫
As described above, the insulating layer 2 is composed of the outermost layer 2 </ b> B and the inner layer 2 </ b> A provided inside the outermost layer 2. The insulating layer 2 includes a base resin and a flame retardant, and the flame retardant includes at least one inorganic particle selected from the group consisting of calcium carbonate particles and silicate compound particles, a silicone compound, and a fatty acid-containing compound. including.

(Content of flame retardant in the insulation layer)
The content of inorganic particles in the insulating layer 2 is preferably 0.03 to 7.00 mass%. In this case, compared with the case where the content rate of the inorganic particles in the insulating layer 2 is less than 0.03% by mass, the flame retardancy of the insulated wire 4 can be further improved. Moreover, compared with the case where the content rate of the inorganic particle in the insulating layer 2 exceeds 7.00 mass%, the abrasion resistance of the insulated wire 4 can be improved more.

The content of the inorganic particles in the insulating layer 2 is preferably 0.20 to 5.50% by mass, and more preferably 0.40 to 4.00% by mass.

The content of the silicone compound in the insulating layer 2 is preferably 0.01 to 4.30% by mass. In this case, compared with the case where the content rate of the silicone type compound in the insulating layer 2 is less than 0.01 mass%, the flame retardance of the insulated wire 4 can be improved more. Moreover, when the content rate of a silicone type compound exists in the said range, compared with the case where the content rate of the silicone type compound in the insulating layer 2 exceeds 4.30 mass%, the abrasion resistance of the insulated wire 4 and an insulated wire. 4 can be further improved in peel resistance (hereinafter referred to as “internal peel resistance”).

The content of the silicone compound in the insulating layer 2 is preferably 0.04 to 2.80% by mass, and more preferably 0.08 to 2.10% by mass.

The content of the fatty acid-containing compound in the insulating layer 2 is preferably 0.02 to 7.50% by mass. In this case, the flame retardance of the insulated wire 4 can be further improved as compared with the case where the content of the fatty acid-containing compound in the insulating layer 2 is less than 0.02% by mass. Moreover, compared with the case where the content rate of the fatty-acid containing compound in the insulating layer 2 exceeds 7.50 mass%, the abrasion resistance and internal peeling resistance of the insulated wire 4 can be improved more.

The content of the fatty acid-containing compound in the insulating layer 2 is preferably 0.07 to 4.00% by mass, and more preferably 0.16 to 2.10% by mass.

(Calculation method of flame retardant content in insulating layer)
The content of the flame retardant in the insulating layer 2 can be calculated as follows.
Mass percentage of inorganic particles in the insulating layer 2 (mass%)
_{_{= 100 × {ρ A × S}} A × L × A 1/100 + ρ B × S B × L × B 1/100} / (ρ A × S A × L + ρ B × S B × L)
= {Ρ _A × S _A × A ₁ + ρ _B × S _B × B ₁ } / (ρ _A × S _A + ρ _B × S _B )
Similarly, the general formula of the mass percentage of the silicone compound and the fatty acid-containing compound in the outermost layer 2B can be calculated as follows.
Mass percentage (mass%) of silicone compound in insulating layer 2
= {Ρ _A × S _A × A ₂ + ρ _B × S _B × B ₂ } / (ρ _A × S _A + ρ _B × S _B )
Mass percentage (mass%) of fatty acid-containing compound in the insulating layer 2
= {Ρ _A × S _A × A ₃ + ρ _B × S _B × B ₃ } / (ρ _A × S _A + ρ _B × S _B )

In the above formula, L, A ₁ to A ₃ , B ₁ to B ₃ , S _A , S _B , ρ _A and ρ _B are as follows.
L: Length of cable 10 A ₁ : Content of inorganic particles in inner layer 2A (mass%)
A ₂ : Content of silicone compound in inner layer 2A (% by mass)
A ₃ : Content of fatty acid-containing compound in the inner layer 2A (% by mass)
B ₁ : Content (% by mass) of inorganic particles in the outermost layer 2B
B ₂ : Content of silicone compound in outermost layer 2B (% by mass)
B ₃ : Content of fatty acid-containing compound in outermost layer 2B (% by mass)
S _A : sectional area of inner layer 2A (mm ² )
S _B : Cross-sectional area of outermost layer 2B (mm ² )
ρ _A : Specific gravity of the inner layer 2A ρ _B : Specific gravity of the outermost layer 2B

(Specific gravity of insulating layer)
The specific gravity of the insulating layer 2 is not particularly limited, but is preferably 0.84 to 1.04. In this case, compared with the case where the specific gravity of the insulating layer 2 is less than 0.84, the flame retardance of the insulated wire 4 can be improved more. Moreover, compared with the case where the specific gravity of the insulating layer 2 exceeds 1.04, the insulated wire 4 can be reduced in weight and the wear resistance of the insulated wire 4 can be further improved.

The specific gravity of the insulating layer 2 is more preferably 0.99 or less. In this case, since the insulating layer 2 can float in water, the insulating layer 2 peeled off from the insulated wire 4 can be easily floated on the water and collected, and the efficiency of the recycling work can be improved. Furthermore, the specific gravity of the insulating layer 2 is preferably less than 0.97. In this case, since the insulating layer 2 is further reduced in weight, the insulated wire 4 is also reduced in weight. Moreover, when the insulating layer 2 peeled off from the insulated wire 4 is poured into water, the ascending speed becomes very fast, and the efficiency of the recycling work can be further increased. In particular, the specific gravity of the insulating layer 2 is preferably less than 0.95. In this case, the wear resistance of the cable 10 can be further improved as compared with the case where the specific gravity of the insulating layer 2 is 0.95 or more.

(Other)
More preferably, the insulating layer 2 does not have voids inside due to foaming or the like. In this case, the insulated wire 4 can obtain excellent mechanical properties.

(Base resin in insulating layer)
The base resin in the insulating layer 2 should just be comprised with resin, and polyolefin resin, polyamide resin, polyester resin, styrene resin etc. are mentioned as resin. These can be used alone or in admixture of two or more. Here, the resin includes rubber and elastomer. The resin should just be comprised by at least 1 sort (s) selected from polyolefin resin etc., rubber | gum, an elastomer, etc. The base resin may or may not contain a polyolefin resin, but preferably contains a polyolefin resin. In this case, compared with the case where base resin does not contain polyolefin resin, a flame retardance and abrasion resistance can be improved more.

Examples of the polyolefin resin include non-polar group-containing polyolefins such as polyethylene (PE), propylene resin, polybutene, and polymethylpentene, polar group-containing polyolefins, and olefin-based thermoplastic elastomers. These can be used alone or in combination of two or more.

The polyolefin resin is preferably PE or a propylene resin from the viewpoint of cost and specific gravity, and is preferably a propylene resin from the viewpoint of heat resistance and wear resistance.

The propylene-based resin is a resin containing propylene as a structural unit, and examples of the propylene-based resin include homopolypropylene, propylene block copolymer, and propylene random copolymer. These can be used alone or in combination of two or more. Among these, a propylene block copolymer is preferable from the viewpoint of impact resistance and low temperature brittleness.

The polar group-containing polyolefin is a polyolefin containing a polar group.

Examples of the polar group of the polar group-containing polyolefin include a maleic acid group, a methacrylic acid group, a fumaric anhydride group, a maleic anhydride group, a hydroxyl group, and a carboxyl group. Among these, as the polar group, a maleic anhydride group is preferable. In this case, even if the polyolefin content in the base resin is small, the compatibility between the base resin and the flame retardant containing the inorganic particles, the silicone-based compound, and the fatty acid-containing compound is further increased, and the generation of bloom can be more sufficiently suppressed. In addition, the wear resistance of the insulating layer 2 can be further improved. For this reason, the deterioration of the mechanical properties of the insulating layer 2 can be more sufficiently suppressed.

Examples of the polar group-containing polyolefin include ethylene-vinyl acetate copolymer (EVA), ethylene-ethyl acrylate copolymer (EEA), ethylene-butyl acrylate copolymer (EBA), their maleic anhydride-modified polymers, Examples thereof include maleic anhydride-modified polypropylene and ethylene-α-olefin copolymers modified with an unsaturated carboxylic acid such as maleic acid and maleic anhydride.

Here, the content of the polar group-containing polyolefin in the polyolefin resin is not particularly limited, but is preferably 1 to 10% by mass. In this case, compared with the case where the content of the polar group-containing polyolefin in the polyolefin resin is less than 1% by mass, the compatibility between the polyolefin resin and the flame retardant (inorganic particles, silicone compound and fatty acid-containing compound) is further increased. The occurrence of bloom can be more sufficiently suppressed, and the wear resistance of the insulating layer 2 can be further improved. On the other hand, compared with the case where the content of the polar group-containing polyolefin in the polyolefin resin exceeds 10% by mass, an increase in cost can be suppressed more sufficiently. The content of the polar group-containing polyolefin in the polyolefin resin is more preferably 2 to 5% by mass.

The base resin may be cross-linked or not cross-linked, but is preferably cross-linked. When the base resin is cross-linked, the heat resistance and wear resistance of the inner layer 2A or the outermost layer 2B can be further improved. Here, examples of the crosslinking include silane crosslinking, electron beam crosslinking, and peroxide crosslinking. Of these, silane crosslinking is preferred. Silane cross-linking does not require sophisticated equipment as compared with electron beam cross-linking, and can sufficiently cross-link the base resin even if the inner layer 2A or the outermost layer 2B is thick. Silane cross-linking can sufficiently suppress the occurrence of scorch during extrusion compared to peroxide cross-linking.

(Inorganic particles in the insulating layer)
The inorganic particles in the insulating layer 2 are intended to improve the flame retardancy of the insulated wire 4 by forming a barrier layer against the base resin together with the silicone compound and the fatty acid-containing compound when the insulated wire 4 is burned. Inorganic particles include calcium carbonate particles and silicate compound particles. These can be used alone or in admixture of two or more. Use of calcium carbonate particles, silicate compound particles, or a mixture thereof as inorganic particles can effectively improve the flame retardancy in a small amount compared to metal hydroxides such as magnesium hydroxide. It is possible to reduce the weight of the layer 2 and hence the insulated wire 4. The calcium carbonate particles may be either heavy calcium carbonate or light calcium carbonate. Examples of the silicate compound particles include talc particles and clay particles.

The average particle diameter of the inorganic particles is not particularly limited, but is preferably 0.7 μm or more. In this case, more excellent flame retardancy can be obtained as compared with the case where the average particle size of the inorganic particles is less than 0.7 μm. However, the average particle size of the inorganic particles is preferably 1.8 μm or less. In this case, the wear resistance of the insulating layer 2 and the coating layer 3 can be improved as compared with the case where the average particle size of the inorganic particles exceeds 1.8 μm.

(Silicone compound in insulating layer)
The silicone compound in the insulating layer 2 functions as a flame retardant, and examples of the silicone compound include polyorganosiloxane. Here, the polyorganosiloxane has a siloxane bond as a main chain and an organic group in a side chain. Examples of the organic group include alkyl groups such as a methyl group, an ethyl group, and a propyl group; a vinyl group; and an aryl group such as a phenyl group. Specific examples of the polyorganosiloxane include dimethylpolysiloxane, methylethylpolysiloxane, methyloctylpolysiloxane, methylvinylpolysiloxane, methylphenylpolysiloxane, and methyl (3,3,3-trifluoropropyl) polysiloxane. Is mentioned. Examples of the polyorganosiloxane include silicone powder, silicone oil, silicone gum, and silicone resin. Among these, silicone gum is preferable. In this case, compared to the case where the silicone compound is a silicone compound other than silicone gum, blooming is less likely to occur in the insulating layer 2 and the flame retardancy of the insulating layer 2 can be further improved.

The silicone compound may be attached in advance to the surface of the inorganic particles.

As a method for attaching the silicone compound to the surface of the inorganic particles, for example, a silicone compound is added to and mixed with calcium carbonate particles to obtain a mixture, and then the mixture is dried at 40 to 75 ° C. for 10 to 40 minutes. And a method of pulverizing the dried mixture with a Henschel mixer, an atomizer or the like.

(Fatty acid-containing compound in the insulating layer)
The fatty acid-containing compound in the insulating layer 2 functions as a flame retardant. The fatty acid-containing compound refers to a fatty acid or a metal salt thereof. Here, as the fatty acid, for example, a fatty acid having 12 to 28 carbon atoms is used. Examples of such fatty acids include lauric acid, myristic acid, palmitic acid, stearic acid, tuberculostearic acid, oleic acid, linoleic acid, arachidonic acid, behenic acid and montanic acid. Among these, stearic acid is preferable as the fatty acid. In this case, compared with the case where fatty acids other than stearic acid are used, the flame retardance of the insulating layer 2 can be further improved.

Examples of the metal constituting the fatty acid metal salt include magnesium, calcium, zinc and lead. As the fatty acid metal salt, magnesium stearate or zinc stearate is preferable. In this case, compared with the case where fatty acid metal salts other than magnesium stearate or zinc stearate are used, the flame retardance of the insulating layer 2 can be further improved with a smaller addition amount. As the fatty acid metal salt, magnesium stearate is particularly preferred.

<Inner layer>
The inner layer 2A contains a base resin. The inner layer 2A may further contain at least one of inorganic particles consisting of at least one selected from the group consisting of calcium carbonate particles and silicate compound particles, a silicone-based compound, and a fatty acid-containing compound. It does not have to be.

Further, the inner layer 2A may be a single layer or a multilayer body composed of two or more layers.

The blending ratio (F1) of the fatty acid-containing compound in the inner layer 2A with respect to 100 parts by weight of the base resin is preferably smaller than the blending ratio (F2) of the fatty acid-containing compound in the outermost layer 2B with respect to 100 parts by weight of the base resin. In this case, as compared with the case where F1 is F2 or more, not only the separation between the inner layer 2A and the conductor 1 but also the separation between the inner layer 2A and the outermost layer 2B can be more sufficiently suppressed. That is, the internal peel resistance of the insulated wire 4 can be further improved.

F2-F1 is not particularly limited as long as it is larger than 0 parts by mass, but it is preferably 3.0 parts by mass or more. In this case, the internal peel resistance of the insulated wire 4 can be more effectively improved as compared with the case where F2-F1 is less than 3.0 parts by mass. F2-F1 is more preferably 5.0 parts by mass or more. However, F2-F1 is more preferably 20.0 parts by mass or less. In this case, the internal peel resistance of the insulated wire 4 can be further improved as compared with the case where F2-F1 exceeds 20.0 parts by mass. More preferably, F2-F1 is 10 parts by mass or less. In this case, the internal peel resistance can be further improved.

F1 is not particularly limited, but is preferably less than 3.0 parts by mass. In this case, compared with the case where F1 is 3.0 parts by mass or more, the internal peel resistance of the insulated wire 4 can be further improved. However, F1 is more preferably 2.0 parts by mass or less.

The blending ratio (C1) of the inorganic particles in the inner layer 2A with respect to 100 parts by mass of the base resin may be less than the blending ratio (C2) of the inorganic particles in the outermost layer 2B with respect to 100 parts by mass of the base resin or C2 or more. However, C1 is preferably less than C2. In this case, compared with the case where C1 is C2 or more, the abrasion resistance in the insulated wire 4 can be improved more sufficiently.

When C2-C1 is larger than 0 parts by mass, C2-C1 is not particularly limited, but is preferably 6.0 parts by mass or more. In this case, compared with the case where C2-C1 is less than 6.0 mass parts, the flame retardance in the insulated wire 4 can be improved more fully. C2-C1 is more preferably 8.0 parts by mass or more. However, C2-C1 is more preferably 20.0 parts by mass or less. In this case, the wear resistance of the insulated wire 4 can be more sufficiently improved than when C2-C1 exceeds 20.0 parts by mass.

C1 is not particularly limited, but is preferably 8.0 parts by mass or less. In this case, compared with the case where C1 exceeds 8.0 mass parts, the abrasion resistance in the insulated wire 4 can be improved more fully. However, C1 is more preferably 3.0 parts by mass or less.

The blending ratio (S1) of the silicone compound in the inner layer 2A with respect to 100 parts by weight of the base resin is at least S2 or less than the blending ratio (S2) of the silicone compound in the outermost layer 2B with respect to 100 parts by weight of the base resin. However, it is preferable that S1 is less than S2. In this case, compared with the case where S1 is S2 or more, the internal peel resistance of the insulated wire 4 can be more sufficiently improved.

When S2-S1 is larger than 0 parts by mass, S2-S1 is not particularly limited, but is preferably 1.5 parts by mass or more. In this case, compared to the case where S2-S1 is less than 1.5 parts by mass, the internal peel resistance and flame retardancy of the insulated wire 4 can be improved more effectively. S2-S1 is more preferably 3.0 parts by mass or more. However, S2-S1 is more preferably 10.0 parts by mass or less. In this case, the internal peel resistance of the insulated wire 4 can be more sufficiently improved than when S2-S1 exceeds 10.0 parts by mass.

S1 is not particularly limited, but is preferably 2.5 parts by mass or less. In this case, compared to the case where S1 exceeds 2.5 parts by mass, the bloom of the silicone compound is less likely to occur, and the internal peel resistance of the insulated wire 4 can be more sufficiently improved. However, S1 is more preferably 1.5 parts by mass or less.

In the inner layer 2A, the base resin is not particularly limited, but is preferably a base resin in which the content of the propylene-based resin is larger than 80% by mass.

In this case, the wear resistance of the insulated wire 4 can be further improved as compared with the case where the content of the propylene-based resin in the base resin is 80% by mass or less.

When the base resin in the inner layer 2A is a base resin having a propylene resin content greater than 80% by mass, the MFR at 230 ° C. and 2.16 kg weight of the resin composition constituting the inner layer 2A is 1.0 g / 10 It is preferable that it is 15.0 g / 10 min or more. In this case, the appearance of the insulated wire 4 is more excellent as compared with the case where the MFR of the resin composition is less than 1.0 g / 10 minutes. Moreover, abrasion resistance improves more compared with the case where MFR of a resin composition is 15.0 g / 10min or more. However, the MFR of the resin composition is more preferably 3.0 g / 10 min or more and less than 10.0 g / 10 min.

The inner layer 2A may further contain a filler such as an antioxidant, a metal deactivator, an ultraviolet degradation inhibitor, a processing aid, a color pigment, a lubricant, and carbon black as necessary.

<Outermost layer>
The outermost layer 2B includes a base resin and a flame retardant, and the flame retardant includes at least one inorganic particle selected from the group consisting of calcium carbonate particles and silicate compound particles, a silicone compound, and a fatty acid-containing compound. including.

The compounding ratio F2 of the fatty acid-containing compound with respect to 100 parts by mass of the base resin is not particularly limited, but is preferably 3 to 20 parts by mass. In this case, compared with the case where F2 is less than 3 mass parts, the flame retardance of the insulated wire 4 can be improved more. Moreover, compared with the case where F2 exceeds 20 mass parts, the abrasion resistance of the insulated wire 4 can be improved more. F2 is more preferably 4.0 parts by mass or more and less than 14.0 parts by mass, and particularly preferably 5.0 parts by mass or more and less than 8.0 parts by mass.

The mixing ratio (C2) of the inorganic particles with respect to 100 parts by mass of the base resin is not particularly limited, but is preferably 6 to 20 parts by mass. In this case, compared with the case where C2 is less than 6 mass parts, the flame retardance of the insulated wire 4 can be improved more. Moreover, compared with the case where C2 exceeds 20 mass parts, the abrasion resistance of the insulated wire 4 can be improved more. C2 is more preferably 7.0 parts by mass or more and less than 17.0 parts by mass, and particularly preferably 8.0 parts by mass or more and less than 15 parts by mass.

The blending ratio (S2) of the silicone compound with respect to 100 parts by mass of the base resin is not particularly limited, but is preferably 1.5 to 10 parts by mass. In this case, compared with the case where S2 is less than 1.5 mass parts, the flame retardance of the insulated wire 4 can be improved more. Moreover, compared with the case where S2 exceeds 10 mass parts, the bloom of a silicone type compound becomes difficult to occur and the wear resistance of the insulated wire 4 can be further improved. S2 is more preferably 3.0 parts by mass or more and less than 9.0 parts by mass, and particularly preferably 4.0 parts by mass or more and less than 7.0 parts by mass.

The cross-sectional area ratio (R) of the outermost layer 2B in the insulating layer 2 is 0.5% or more and less than 86%. In this case, compared with the case where the cross-sectional area ratio R is less than 0.5%, the flame retardance of the insulated wire 4 can be further improved. Moreover, compared with the case where cross-sectional area ratio R exceeds 86%, while being able to improve the abrasion resistance of the insulated wire 4, the cost of the insulated wire 4 can be reduced more and the insulated wire 4 can be reduced in weight. .

Here, the cross-sectional area ratio R is calculated using the following equation.
R = 100 × (2r + 2t2 + t1) × t1 / (2r + t2 + t1) × (t2 + t1)
(In the above formula, r represents the radius of the conductor 1, t2 represents the thickness of the inner layer 2A, and t1 represents the thickness of the outermost layer 2B.)

The cross-sectional area ratio R is more preferably 50% or less, and even more preferably 30% or less. In this case, compared with the case where the cross-sectional area ratio R exceeds 50%, the wear resistance or lead processability of the cable 10 can be further improved.

The cross-sectional area ratio R is more preferably 1% or more, and even more preferably 2.5% or more. In this case, the cable 10 can have more excellent flame retardancy.

The thickness t1 of the outermost layer 2B is not particularly limited, but is preferably 0.008 to 0.400 mm. In this case, compared with the case where thickness t1 is less than 0.008 mm, the flame retardance of the insulated wire 4 can be improved more. Moreover, compared with the case where thickness t1 exceeds 0.400 mm, while the insulated wire 4 can be reduced in weight and diameter, the abrasion resistance and lead-out workability of the insulated wire 4 can be improved more.

The thickness t1 of the outermost layer 2B is more preferably 0.010 to 0.200 mm, and particularly preferably 0.020 to 0.100 mm. In this case, compared to the case where the thickness t1 of the outermost layer 2B exceeds 0.200 mm, the insulated wire 4 can be further reduced in weight and the wear resistance can be further improved. Moreover, the flame retardance of the insulated wire 4 can be improved more compared with the case where the thickness t1 of the outermost layer 2B is less than 0.010 mm.

The outermost layer 2B may further contain a filler such as an antioxidant, a metal deactivator, an ultraviolet degradation inhibitor, a processing aid, a color pigment, a lubricant, and carbon black as necessary.

≪Coating layer≫
The covering layer 3 protects the insulating layer 2 from physical or chemical damage.

The thickness of the coating layer 3 is not particularly limited, but is preferably less than 2.0 mm. In this case, the weight of the cable 10 can be further reduced as compared with the case where the thickness of the covering layer 3 is 2.0 mm or more. The thickness of the coating layer 3 is more preferably 1.0 mm or less, and further preferably 0.5 mm or less. However, from the viewpoint of wear resistance, the thickness of the coating layer 3 is preferably 0.2 mm or more.

[Cable manufacturing method]
Next, a method for manufacturing the cable 10 described above will be described.

First, conductor 1 is prepared.

Next, the insulated wire 4 is obtained by covering the conductor 1 with the insulating layer 2. At this time, the insulating layer 2 may be formed by simultaneously forming the inner layer 2A and the outermost layer 2B, or by forming the outermost layer 2B on the inner layer 2A after forming the inner layer 2A. Also good.

The inner layer 2A and the outermost layer 2B may be formed by preparing an inner layer resin composition for forming the inner layer 2A and an outermost layer resin composition for forming the outermost layer 2B, respectively, and extruding them. it can.

Examples of the method for forming the insulating layer 2 on the conductor 1 include three methods: a co-extrusion method, a tandem extrusion method, and a separate extrusion method.

In the coextrusion method, the inner layer resin composition discharged from the crosshead is coated on the conductor 1 to form the inner layer 2A, and immediately after obtaining the inner layer coated electric wire, the outermost layer resin composition is continued in the same crosshead. The outermost layer 2B is formed by extruding and coating on the inner-layer coated electric wire.

In the tandem extrusion method, the inner layer resin composition discharged from the cross head is coated on the conductor 1 to form the inner layer 2A, and after obtaining the inner layer covered electric wire, the inner layer resin wire is discharged from another cross head on the same extrusion line. In this method, the outermost layer 2B is formed by coating the outermost layer resin composition on the inner-layer coated electric wire.

In another extrusion method, the inner layer resin composition discharged from the crosshead is coated on the conductor 1 to form the inner layer 2A, the inner layer covered electric wire is obtained, wound once on the bobbin, and then wound up. The outermost layer resin composition discharged from the same crosshead or another crosshead is coated on the inner coated wire to form the outermost layer.

Among the above methods, a co-extrusion method and a tandem extrusion method are preferable because continuous production is possible. The coextrusion method is particularly preferable. In this case, when the inner layer resin composition and the outermost layer resin composition are in contact with each other in a molten state, the adhesion between the inner layer 2A and the outermost layer 2B is increased, and the peeling between the inner layer 2A and the outermost layer 2 is further improved. It can be suppressed sufficiently.

Finally, one insulated wire 4 obtained as described above is prepared, and this insulated wire 4 is covered with the coating layer 3. The coating layer 3 can also be formed by preparing a coating layer resin composition for forming the coating layer 3 and extruding it using an extruder.

The cable 10 is obtained as described above.

The present invention is not limited to the above embodiment. For example, although the cable 10 has one insulated wire 4 in the above embodiment, the cable of the present invention may have two or more insulated wires 4 inside the coating layer 3.

In the above embodiment, the cable 10 has the covering layer 3, but the covering layer 3 may be omitted.

Furthermore, although the cable 10 whose transmission medium is the conductor 1 is used in the above embodiment, the cable of the present invention may be an optical fiber cable in which the transmission medium is replaced from the conductor 1 to the optical fiber in the cable 10. Good. In this optical fiber cable, the covering layer 3 may be omitted.

[Wire harness]
FIG. 3 is a cross-sectional view showing an embodiment of the wire harness of the present invention. As shown in FIG. 3, the wire harness 20 includes a tape 21 that bundles a plurality of (four in FIG. 3) insulated wires 4 as cables. The tape 21 does not need to cover the plurality of insulated wires 4 entirely along the length direction, and partially covers the plurality of insulated wires 4 at a necessary position along the length direction. If you do.

Since this wire harness 20 has the insulated wire 4 having excellent wear resistance while maintaining good flame resistance, it is possible to have excellent wear resistance while maintaining good flame resistance. It becomes.

The wire harness 20 includes a plurality of insulated wires 4 as cables, but may include only one insulated wire 4. In the wire harness 20, the cable 10 can be used instead of the insulated wire 4. The wire harness 20 includes only the insulated wire 4 as a cable inside the tape 21, but may include two types of the insulated wire 4 and the cable 10.

The wire harness 20 includes a tape 21, but the wire harness 20 may use a binding band, a corrugated tube, or the like instead of the tape 21.

Hereinafter, the contents 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 to 113 and Comparative Examples 1 to 23)
<Outermost layer resin composition>
Base resin, silicone masterbatch (silicone MB), fatty acid-containing compound, inorganic particles and magnesium hydroxide were blended in the blending amounts shown in Tables 1 to 15 and a twin-screw extruder (manufactured by Nippon Steel Works, cylinder diameter 32 mm) Kneaded to obtain an outermost resin composition. In Tables 1 to 15, the unit of the blending amount of each blending component is part by mass. In Tables 1 to 15, there are examples or comparative examples in which the compounding amount in the base resin column is not 100 parts by mass. In these examples or comparative examples, the silicone MB also contains a resin. If the blending amount in the column of the base resin and the blending amount of the resin in the silicone MB are summed, the sum is 100 parts by mass.

<Inner layer resin composition>
Base resin, silicone masterbatch (silicone MB), fatty acid-containing compound, inorganic particles and magnesium hydroxide were blended in the blending amounts shown in Tables 1 to 15 and a twin-screw extruder (manufactured by Nippon Steel Works, cylinder diameter 32 mm) Were kneaded to obtain an inner layer resin composition. In Tables 1 to 15, the unit of the blending amount of each blending component is part by mass. In Tables 1 to 15, there are examples or comparative examples in which the compounding amount in the base resin column is not 100 parts by mass. In these examples or comparative examples, the silicone MB also contains a resin. If the blending amount in the column of the base resin and the blending amount of the resin in the silicone MB are summed, the sum is 100 parts by mass. For the inner layer resin composition, MFRs at 230 ° C. and 2.16 kg weight are shown in Tables 1 to 15. In Tables 1 to 15, “−” in the MFR column indicates that the inner layer resin composition did not flow at 230 ° C. and MFR measurement could not be performed.

Specific examples of the base resin, silicone MB, fatty acid-containing compound, inorganic particles, and magnesium hydroxide are as follows.

(1) Base resin (propylene resin)
Propylene block copolymer: MFR (230 ° C., 2.16 kg weight) 9.0 g / 10 min (manufactured by Prime Polymer)
Propylene random copolymer: MFR (230 ° C., 2.16 kg weight) 7.0 g / 10 min (manufactured by Nippon Polypro)
Homopolypropylene: MFR (230 ° C., 2.16 kg weight) 0.5 g / 10 min (manufactured by Sun Allomer)
(polyethylene)
Linear low density polyethylene (LLDPE): MFR (230 ° C., 2.16 kg weight) 7.4 g / 10 min, density 0.937 g / cm ³ (manufactured by Ube Maruzen Polyethylene)
Low density polyethylene (LDPE): MFR (190 ° C., 2.16 kg weight) 10.0 g / 10 min density 0.917 g / cm ³ (manufactured by Ube Maruzen Polyethylene)
(Polybutene)
1-Polybutene (Mitsui Chemicals)
(Polymethylpentene)
Polymethylpentene (Mitsui Chemicals)
(Polyolefin elastomer)
Polypropylene (PP) -ethylene propylene (EP) elastomer (manufactured by ExxonMobil)
Polypropylene elastomer (Mitsui Chemicals)
(Modified polyolefin)
Maleic anhydride-modified polypropylene (propylene, manufactured by Mitsui Chemicals)
Maleic anhydride modified linear low density polyethylene (polyethylene, DuPont)
Maleic anhydride modified ethylene butyl acrylate (ethylene butyl acrylate, DuPont)

(2) Silicone MB
Silicone MB1:
Contains 50% by weight silicone gum and 50% by weight low density polyethylene (LLDPE) (manufactured by Shin-Etsu Chemical Co., Ltd.)
Silicone MB2:
Contains 50% by weight silicone gum and 50% by weight propylene resin (PP) (manufactured by Shin-Etsu Chemical Co., Ltd.)

(3) Fatty acid-containing compound Mg stearate (manufactured by ADEKA)
Zn stearate (Nitto Kasei Kogyo Co., Ltd.)
Stearic acid (manufactured by NOF Corporation)

(4) Inorganic particles Calcium carbonate particles 1: Average particle size 1.7 μm, paraffin surface treatment (manufactured by Nitto Flour Chemical Co., Ltd.)
Calcium carbonate particles 2: Average particle size 1.7 μm, stearic acid surface treatment (manufactured by Nitto Flourishing Co., Ltd.)
Clay particles: average particle size 1.5 μm (manufactured by Takehara Chemical Industries)
Talc particles: average particle size 2.5 μm (made by Nippon Talc Co., Ltd.)

(5) Magnesium hydroxide average particle size 1.1 μm, higher fatty acid surface treatment (manufactured by Kamishima Chemical Co., Ltd.)

<Production of insulated wires>
The insulated electric wire as a cable was produced as follows according to the kind of the following electric wire.

Electric wire 1 ... Thick wall 0.5 sq (mm ² )
Electric wire 2 ... Ultra thin 0.5sq
Electric wire 3 ... Ultra thin 1.5sq
Electric wire 4 ... Thick wall 100sq

In addition, the kind of the said electric wire is based on JASO D611. “0.5”, “100”, and “1.5” indicate the cross-sectional area of the conductor, and “thick” and “ultra-thin” indicate the thickness of the insulating layer. However, the thickness of the insulating layer may differ depending on the conductor cross-sectional area even if the same “thick” notation is used. That is, the electric wires 1 to 4 are as follows.

Electric wire 1 ... conductor cross-sectional area 0.5 mm ² , insulation layer thickness 0.50 mm
Electric wire 2 ... conductor cross-sectional area 0.5 mm ² , insulation layer thickness 0.20 mm
Electric wire 3: conductor cross-sectional area 1.5 mm ² , insulation layer thickness 0.20 mm
Electric wire 4 ... conductor cross-sectional area 100 mm ² , insulation layer thickness 2.00 mm

(Wires 1 to 3)
For the electric wires 1 to 3, the inner layer resin composition prepared as described above was pushed out by a single screw extruder (manufactured by Mars Seiki Co., Ltd., cylinder outer diameter: 25 mm), discharged from the crosshead, and placed on the conductors as shown in Tables 1 to 3. The inner layer was formed by coating so as to have a thickness shown in FIG. 15, and the obtained inner layer covered electric wire was wound around a bobbin, and then the wound inner layer covered electric wire was sent out. On the other hand, the outermost layer resin composition prepared as described above is extruded by a single-screw extruder (made by Mars Seiki Co., Ltd., cylinder outer diameter 25 mm), discharged from the crosshead, and displayed on the fed inner layer covered electric wire. The outermost layer was formed by coating so as to have a thickness shown in 1 to 15. Thus, an insulated wire as a cable was produced.
(Wire 4)
The electric wire 4 produced the insulated electric wire similarly to the above except having used the single screw extruder (made by Mars Seiki Co., Ltd.) whose cylinder outer diameter is 60 mm as a single screw extruder.

The wire design of the insulated wire produced as described above, that is, the outer diameter of the conductor, the outer diameter of the wire, the thickness of the inner layer, the thickness of the outermost layer, and the cross-sectional area ratio of the outermost layer in the insulating layer As shown in 1-15.

(Specific gravity of insulating layer)
The specific gravity of the insulating layer of the insulated wire produced as described above was measured as follows. That is, the insulating layer is peeled off from the insulated wire, the insulating layer is melt-kneaded to produce a uniform sheet having a thickness of 2 mm, and the insulating layer is measured with an electronic hydrometer (manufactured by Alpha Mirage) based on the Archimedes method. The specific gravity of was measured. The results are shown in Tables 1-15.

<Characteristic evaluation>
The insulated wires of Examples 1 to 113 and Comparative Examples 1 to 23 obtained as described above were evaluated for flame retardancy, wear resistance, internal peel resistance and lead processability as follows. .

<Flame retardance>
With respect to the insulated wires of Examples 1 to 113 and Comparative Examples 1 to 23, a horizontal combustion test was performed by the test method described in JASO D618. In the horizontal combustion test, the flame was contacted until the insulating layer burned, and the afterflame time until the fire was extinguished after the flame was removed was measured. And it ranked and evaluated as follows for every following after flame time. The results are shown in Tables 1-15. The acceptance criteria for flame retardancy were as follows.
(Evaluation rank)
◎ ・・・ After flame time is less than 15 seconds ○ ・・・ After flame time is 15 seconds or more and less than 25 seconds Δ ・・・ After flame time is 25 seconds or more and 30 seconds or less × ・・・ After flame time is more than 30 seconds Or the total burn (acceptance criteria) evaluation rank is ◎, ○ or △

<Abrasion resistance>
The abrasion resistance was determined by performing a scrape wear test on the insulated wires of Examples 1 to 113 and Comparative Examples 1 to 23 according to the test method described in JASO D618. As the index. And about the insulated wire, it ranked as follows according to the kind, and evaluated. The results are shown in Tables 1-15. The acceptance criteria for wear resistance were as follows. For Examples 96 to 100 and Comparative Example 9, in order to show that better wear resistance can be obtained when the cross-sectional area ratio of the outermost layer in the insulating layer is 50% or less, the evaluation rank Table 16 shows the corresponding values of the number of scrape wear.
(Wire 2)
(Evaluation rank)
◎ ・・・ Scrape wear frequency is 300 times or more ○ ・・・ Scrape wear frequency is 200 times or more and less than 300 times Δ ・・・ Scrape wear frequency is 150 times or more and less than 200 times × ・・・ Scrape wear frequency is less than 150 times (Acceptance criteria) Evaluation rank is ◎, ○ or △ (JASO standard value: 150 times or more)
(

Wires

1, 3, and 4)
(Evaluation rank)
◎ ・・・ Scrape wear frequency is 2000 times or more ○ ・・・ Scrape wear frequency is 500 times or more and less than 2000 times Δ ・・・ Scrape wear frequency is 150 times or more and less than 500 times × ・・・ Scrape wear frequency is less than 150 times (Acceptance criteria) Evaluation rank is ◎, ○ or △ (JASO standard value: 150 times or more)

The meanings of the above x, Δ, ◯ and ◎ are as follows.
X means that the number of scrape wear is less than the JASO standard value.
Δ means that the number of scrape wear is equal to or greater than the JASO standard value, but there is a margin. In the cable, the conductor is eccentric to some extent due to manufacturing variations. Further, since the discharge amount at the time of extrusion also varies, the thickness of the insulating layer also varies to some extent when viewed as a long length. For this reason, a thick part and a thin part inevitably occur in the insulating layer of the cable. In the experiment, even if the number of scrape wears meets the JASO standard, the number of scrape wears does not meet the JASO standard in the thin part of the insulating layer due to eccentricity or long outer diameter fluctuation in practice. There are things to do. At this time, a cable whose scrape wear frequency does not satisfy the JASO standard in a portion where the insulating layer is thin due to eccentricity has no tolerance, and a cable whose scrape wear frequency satisfies the JASO standard has tolerance. That is, the tolerance is an allowance for manufacturing variations (eccentricity), and the tolerance increases as the number of scrape wears increases.
“O” means that the cable can be used in a normal environment (an environment in which wear is relatively difficult at a normal vibration level) where the number of scrape wear is equal to or higher than the JASO standard value and the tolerance is high.
◎ means that the scrape wear frequency is more than the JASO standard value and has a higher tolerance, and the cable can be used even in harsh environments (for example, in the vicinity of automobile engines where vibrations are high and there is a high risk of wear). . For this reason, if the evaluation rank is ◎, the cable can be used even around the engine, which is difficult to be used with ×, △, and ◯, and is easily rubbed and worn by intense vibration.

<Internal peel resistance>
Internal peel resistance was evaluated by cutting the insulated wires of Examples 1 to 113 and Comparative Examples 1 to 23 into a length of 350 mm, putting them in a thermostatic bath at 150 ° C. for 6 hours, and taking them out. After winding around a mandrel having a diameter of 5 times, an optical microscope is used to observe the presence or absence of delamination between the conductor and the inner layer and between the inner layer and the outermost layer at the end of the insulated wire, and rank as follows: Was done by. The results are shown in Tables 1-15.
(Evaluation rank)
〇・・・ No peeling × ・・・ With peeling

<Outgoing processability>
The 10 insulated wires obtained in Examples 1 to 113 and Comparative Examples 1 to 23 were subjected to terminal strips with the strip length set to 10 mm. Then, the end of the insulated wire after the terminal strip was observed with a microscope, the length of the beard was measured, and the length of the beard was used as an index of the lead processability. And ranking was performed as follows and the lead processability was evaluated. The results are shown in Tables 1-15. In Examples 77 to 84, the beard length corresponding to the evaluation rank is shown in order to show that excellent lead processability is obtained when the cross-sectional area ratio of the outermost layer in the insulating layer is 50% or less. Table 17 shows the values.
(Evaluation rank)
◎ ・・・・ Beard length less than 0.3mm ○ ・・・・ Beard length of 0.3mm or more and less than 0.4mm Δ ・・・・ Beard length of 0.4mm or more and less than 0.5mm × ··· Beard Length 0.5 mm or more and less than 0.6 mm XX ... Beard length 0.6 mm or more The meanings of the above xx, x, Δ, ◯ and ◎ are as follows.
XX means that when connecting the conductor of the cable that has been led out and the connection terminal, the possibility that a beard enters between the conductor and the connection terminal to cause a contact failure is very high.
X means that when connecting the conductor of the cable that has been led out and the connection terminal, the beard is likely to enter between the conductor and the connection terminal to cause contact failure.
△ is suitable for the outer diameter of the insulating layer and the outer diameter of the conductor, although it is unlikely that whisker will enter between the conductor and the connecting terminal when connecting the conductor of the leaded cable and the connecting terminal. This means that it is necessary to perform the lead processing in consideration of the variation (conductor eccentricity) at the time of normal manufacturing while using a dedicated lead processing blade.
○ is suitable for the outer diameter of the insulating layer and the outer diameter of the conductor, although when connecting the conductor of the cable and the connection terminal, the possibility that a whisker will enter between the conductor and the connection terminal and contact failure is low In addition, it means that it is possible to perform the squeezing process without taking into account the variation during manufacture (concentration of the conductor) while using a dedicated squeezing blade.
◎ indicates that when connecting the conductor of the leaded cable and the connection terminal, it is unlikely that whiskers will enter between the conductor and the connection terminal, resulting in poor contact. It can also be used as a cable with a somewhat different outer diameter of the conductor, which means that the lead-out process can be performed without taking into account variations during manufacture (conductor eccentricity). In this case, the frequency of replacing the blade for each cable having a different outer diameter of the insulating layer and the outer diameter of the conductor is reduced, and management of the blade is facilitated.

From the above, it was confirmed that the cable of the present invention has excellent wear resistance while maintaining good flame retardancy.

The cable of the present invention has excellent wear resistance while maintaining good flame retardancy, so that it is an insulated wire for automobiles, industrial wires, automotive cables, industrial cables, communication cables, coaxial cables, and electronic wires. It can be applied to various uses such as. The cable of the present invention can also be applied to an optical fiber cable in which the transmission medium is replaced with an optical fiber from a conductor.

DESCRIPTION OF SYMBOLS 1 ... Conductor 2 ... Insulating layer 2A ... Inner layer 2B ... Outermost layer 3 ... Covering layer 4 ... Insulated electric wire 10 ... Cable 20 ... Wire harness

Claims

A transmission medium composed of a conductor or an optical fiber;
An insulating layer covering the transmission medium;
The insulating layer has an outermost layer and an inner layer provided inside the outermost layer;
The outermost layer includes a base resin and a flame retardant,
The flame retardant comprises inorganic particles consisting of at least one selected from the group consisting of calcium carbonate particles and silicate compound particles, a silicone compound, and a fatty acid-containing compound,
The cable, wherein a cross-sectional area ratio of the outermost layer in the insulating layer is 0.5% or more and less than 86%.
The cable according to claim 1, wherein a cross-sectional area ratio of the outermost layer in the insulating layer is 50% or less.
The content of the inorganic particles in the insulating layer is 0.03 to 7.00 mass%,
The content of the silicone compound in the insulating layer is 0.01 to 4.30% by mass,
The cable according to claim 1 or 2, wherein the content of the fatty acid-containing compound in the insulating layer is 0.02 to 7.50 mass%.
The cable according to any one of claims 1 to 3, wherein a thickness of the outermost layer is 0.008 to 0.400 mm.
The cable according to any one of claims 1 to 4, wherein the specific gravity of the insulating layer is 0.84 to 1.04.
In the outermost layer, the blending ratio of the inorganic particles with respect to 100 parts by mass of the base resin is 6 to 20 parts by mass.
The blending ratio of the silicone compound to 100 parts by mass of the base resin is 1.5 to 10 parts by mass,
The cable according to any one of claims 1 to 5, wherein a blending ratio of the fatty acid-containing compound with respect to 100 parts by mass of the base resin is 3 to 20 parts by mass.
The cable according to any one of claims 1 to 6, wherein the base resin includes a polyolefin resin.
The inner layer is composed of a resin composition containing a base resin, the content of propylene resin in the base resin is greater than 80% by mass, and the MFR at 230 ° C. and 2.16 kg weight of the resin composition is 1 The cable according to any one of claims 1 to 7, which has a value of 0.0 g / 10 min or more and less than 15.0 g / 10 min.
The cable according to any one of claims 1 to 8, wherein the conductor is aluminum or an aluminum alloy.
The cable according to any one of claims 1 to 9, further comprising a covering layer that covers the insulating layer.
A wire harness having the cable according to any one of claims 1 to 10.