Electric wire or cable

Abstract

To provide an electric wire or cable exhibiting superior flame retardancy and strength.SOLUTION: An electric wire or cable that has an outermost sheath covering a core wire composed of one or more conductors, wherein the sheath contains a carbonate-based thermoplastic polyurethane and has a JIS hardness of A50 or more and A95 or less as measured in accordance with JIS K 7311.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an electric wire or cable, and more particularly to an electric wire or cable having excellent flame retardancy and strength. [Background technology]

[0002] There are various types of electric wires or cables, from fixed cables to movable cables, and they are used for various industrial applications, and various characteristics are required. In particular, movable cables must be able to withstand continuous moving motion, and therefore, higher performance is required than fixed cables, which do not require consideration of mobility.

[0003] For example, electric wires or cables used in robot cables must be wear-resistant to prevent wear and bendable to prevent breakage due to the repeated bending motions that accompany the robot's movements. Furthermore, in the unlikely event of a fire, it is necessary to prevent the spread of flames along the electric wires or cables. There is a high demand for such electric wires or cables with excellent flame retardancy.

[0004] Various methods have been studied for imparting flame retardancy to electric wires or cables, including, for example, the use of highly flame-retardant thermoplastic polyurethane for the sheath of the electric wire or cable.

[0005] For example, a conventional electric wire or cable includes a cable having a conductor, an insulating layer covering the conductor, and an outer jacket layer covering the insulating layer, the outer jacket layer being formed from a flame-retardant resin composition including a base polymer (A), a plasticizer (B), a stabilizer (C), and a flame retardant (D), the base polymer (A) including chlorinated polyethylene (a1) and at least one urethane thermoplastic elastomer (a2) of an adipate type, a lactone type, or a carbonate type, the stabilizer (C) including hydrotalcite (c1) and a metal soap (c2), and the flame retardant (D) including at least one of a metal hydroxide (d1), a bromine-based flame retardant (d2), amorphous silica (d3), and antimony trioxide (d4) (see Patent Document 1).

[0006] Furthermore, for example, a conventional electric wire or cable includes a cable having an outer jacket layer covering the periphery of an insulated electric wire, the outer jacket layer being formed from a resin composition including a base polymer (A), a plasticizer (B), a stabilizer (C), a flame retardant (D), and other additives (E), wherein the base polymer (A) includes a polyvinyl chloride resin (a1) and at least one urethane thermoplastic elastomer (a2) of an adipate type, a lactone type, or a carbonate type, the stabilizer (C) includes hydrotalcite (c1) and a metal soap (c2), the flame retardant (D) includes at least one of a metal hydroxide (d1), a bromine-based flame retardant (d2), amorphous silica (d3), and antimony trioxide (d4), and the other additives (E) include 35 parts by mass or more of calcined clay per 100 parts by mass of the polyvinyl chloride resin (a1) (see Patent Document 2).

[0007] According to the disclosures of Patent Documents 1 and 2, among urethane thermoplastic elastomers, adipate-based elastomers in particular are not only effective in adjusting hardness, but also have superior affinity with polyvinyl chloride resin compared to lactone-based or carbonate-based elastomers, making it easier to form a phase structure in the resin composition that constitutes the outer skin layer, thereby achieving various properties at a more stable and high level.

[0008] Furthermore, for example, a conventional electric wire or cable characterized by a phosphorus-containing flame retardant is a composition for producing a cable sheath, which contains at least one thermoplastic polyurethane, a first phosphorus-containing flame retardant (F1) selected from the group consisting of melamine polyphosphates, and a further phosphorus-containing flame retardant (F2) selected from the group consisting of phosphinic acid derivatives, and does not contain melamine cyanurate (see Patent Document 3).

[0009] Furthermore, the above-mentioned Patent Document 3 also discloses a composition in which the thermoplastic polyurethane is selected from the group consisting of thermoplastic polyurethanes based on at least one aromatic diisocyanate and at least one polycarbonate diol, and thermoplastic polyurethanes based on at least one aromatic diisocyanate and polytetrahydrofuran polyol. [Prior art documents] [Patent documents]

[0010] [Patent Document 1] Japanese Patent Publication No. 2021-086752 [Patent Document 2] Japanese Patent Application Laid-Open No. 2022-044096 [Patent Document 3] Special Publication No. 2021-529854 DISCLOSURE OF THE INVENTION [Problem to be solved by the invention]

[0011] However, while some conventional electric wires or cables use an adipate-based urethane thermoplastic elastomer as the cable sheath, as in Patent Documents 1 and 2, the raw material, polyadipate glycol, has fundamentally low durability in various aspects, and therefore does not provide sufficient flame retardancy for practical use.

[0012] To solve this durability problem, it is common to change the molecular structure of the polyol that makes up the adipate-based urethane thermoplastic elastomer from an ester type to an ether type, but this does not provide sufficient flame retardancy for practical use (see the examples below).

[0013] In addition, for example, Patent Document 3 describes a cable sheath that is characterized by a phosphorus-containing flame retardant, and the VW-1 test described in Patent Document 3 shows an evaluation of flame retardancy performed using a cable with a diameter of 2 mm covered with an insulated wire or sheath. However, this flame retardancy evaluation is based on a cable with a diameter of 2 mm, which is quite thin compared to the diameter of ordinary robot cables, which are 5 mm or more, and therefore cannot be applied to ordinary robot cables that require wear resistance and flexibility under severe practical conditions.

[0014] The present invention has been made to solve the above problems, and an object of the present invention is to provide an electric wire or cable that is excellent in flame retardancy and strength. [Means for solving the problem]

[0015] The present inventors have conducted extensive research into sheath materials for electric wires or cables, and have discovered that by using raw materials that meet specific conditions for the sheath, it is possible to achieve high flame retardancy while maintaining the strength of the electric wire or cable, without using adipate-based urethane thermoplastic elastomers as in Patent Documents 1 and 2 above, or phosphorus-containing flame retardants as in Patent Document 3 above, as raw materials, they have arrived at the present invention.

[0016] Thus, the electric wire or cable according to the present application is an electric wire or cable having an outermost sheath covering a core wire made of one or more conductors, the sheath containing a carbonate-based thermoplastic polyurethane and having a JIS hardness of A50 or more and A95 or less as measured according to JIS K 7311. In this electric wire or cable having an outermost sheath covering a core wire made of one or more conductors, the sheath containing a carbonate-based thermoplastic polyurethane and having a JIS hardness of A50 or more and A95 or less as measured according to JIS K 7311, the carbonate-based thermoplastic polyurethane having the optimal JIS hardness allows the electric wire or cable to exhibit high levels of strength and flame retardancy, and high flame retardancy can be achieved while maintaining the strength of the electric wire or cable.

[0017] Furthermore, the electric wire or cable according to the present application has a JIS hardness of A80 or more and A90 or less, as necessary. Since the JIS hardness is A80 or more and A90 or less, the carbonate-based thermoplastic polyurethane having the optimum JIS hardness exhibits high levels of strength and flame retardancy, and the electric wire or cable can achieve high flame retardancy while maintaining its strength.

[0018] Furthermore, in the electric wire or cable according to the present application, the sheath optionally contains at least one selected from the group consisting of chlorinated polyethylene, antimony trioxide, and a brominated flame retardant. Since the sheath contains at least one selected from the group consisting of chlorinated polyethylene, antimony trioxide, and a brominated flame retardant, the combined effect of the at least one selected from the group consisting of antimony trioxide and a brominated flame retardant coexisting with a carbonate-based thermoplastic polyurethane having an optimal JIS hardness further enhances strength and flame retardancy, thereby achieving high flame retardancy while maintaining the strength of the electric wire or cable.

[0019] Furthermore, in the electric wire or cable according to the present application, the sheath optionally contains at least one selected from the group consisting of a silicone-acrylic composite rubber and a lubricant. Since the sheath contains at least one selected from the group consisting of a silicone-acrylic composite rubber and a lubricant, the combined effect of the silicone-acrylic composite rubber and the lubricant and the carbonate-based thermoplastic polyurethane having an optimal JIS hardness further enhances strength and flame retardancy, thereby achieving high flame retardancy while maintaining the strength of the electric wire or cable.

[0020] In addition, in the electric wire or cable according to the present application, the lubricant is an ester wax, if necessary. Since the lubricant is an ester wax, the combined effect of the ester wax and carbonate-based thermoplastic polyurethane having an optimum JIS hardness is enhanced, resulting in a high level of strength and flame retardancy, allowing the electric wire or cable to achieve high flame retardancy while maintaining its strength.

[0021] Furthermore, in the electric wire or cable according to the present application, the blending ratio of thermoplastic polyurethane to the entire sheath is 60% by mass or more and 70% by mass or less, as necessary. Since the blending ratio of thermoplastic polyurethane to the entire sheath is 60% by mass or more and 70% by mass or less, the carbonate-based thermoplastic polyurethane having an optimum JIS hardness further exhibits high levels of strength and flame retardancy, thereby achieving high flame retardancy while maintaining the strength of the electric wire or cable. [Brief explanation of the drawings]

[0022] [Figure 1] 1 shows an example of a cross-sectional view perpendicular to the length direction of an electric wire or cable according to a first embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0023] (First embodiment) As shown in FIG. 1, the electric wire or cable according to the first embodiment is an electric wire or cable having an outermost sheath that covers a core wire made of one or more conductors, and the sheath contains a carbonate-based thermoplastic polyurethane and has a JIS hardness of A50 or more and A95 or less, measured according to JIS K 7311.

[0024] The electric wire or cable according to the first embodiment may be an electric wire or cable in which an insulator covering the periphery of a conductor is covered with a sheath.

[0025] The core wire constituting this electric wire or cable may be made of one conductor or may be made of multiple conductors. That is, the core wire may be a solid wire made of only one conductor, or a twisted wire made by twisting multiple conductors together.

[0026] In the cable of the first embodiment, for example, when the core wire is a twisted wire made up of multiple conductors, the twisted wire conductor 11 can be covered with an insulator 12, and the cable can have a configuration having multiple internal insulating cores 10 made up of this conductor 11 and insulator 12, as shown in Figure 1.

[0027] There are no particular limitations on the conductor 11, and various metal wires, such as copper wire, copper alloy wire, and aluminum wire, can be used. The metal wire may also be plated with tin or nickel.

[0028] The insulator 12 is not particularly limited, and may be made of, for example, fluororesin such as ETFE (ethylene-tetrafluoroethylene copolymer), PTFE (polytetrafluoroethylene), etc. Alternatively, for example, PBT (polybutylene terephthalate) may be used.

[0029] The sheath 20 covers the periphery of the inner insulating core (insulating core) 10 consisting of the conductor 11 and the insulator 12 with the outermost layer, thereby protecting the electric wire or cable.

[0030] The sheath 20 contains a carbonate-based thermoplastic polyurethane (TPU). Thermoplastic polyurethane is a general term for a thermoplastic polymer that has urethane bonds in its molecule. Carbonate-based refers to a thermoplastic polyurethane that includes a polycarbonate structure. The polycarbonate structure that constitutes this thermoplastic polyurethane is formed by generating a soft segment in the molecule using a carbonate-based polyol, such as polycarbonate diol, as a raw material.

[0031] Such carbonate-based thermoplastic polyurethanes can be obtained, for example, by polymerization using diisocyanate, polycarbonate (long-chain glycol), and diol (short-chain glycol) as raw materials. In the molecule, the diisocyanate and diol (short-chain glycol) bond to form hard segments, while the polycarbonate (long-chain glycol) plays the role of soft segments. The raw material ratio is not particularly limited, but for example, a ratio of diisocyanate:diol (short-chain glycol):polycarbonate (long-chain glycol) of 30:10:60 can be used.

[0032] Examples of the diol (short-chain glycol) that can be used as the raw material include ethylene glycol, 1,4-butanediol, and 1,6-hexanediol. Other examples that can be used include diethylene glycol, triethylene glycol, propylene glycol, 1,3-propanediol, 1,3-butanediol, 1,8-octanediol, 1,9-nonanediol, neopentyl glycol, 2-butyl-2-ethyl-1,3-propanediol, 3-methyl-1,5-pentanediol, 2-methyl-1,3-propanediol, 3,3,5-trimethylpentanediol, 2,4-diethyl-1,5-pentanediol, 1,12-octadecanediol, 1,2-alkanediol, 1,3-alkanediol, 1-monoglyceride, 2-monoglyceride, 1-monoglycerin ether, and 2-monoglycerin ether.

[0033] Examples of the diisocyanate that can be used as the raw material include 4,4'-diphenylmethane diisocyanate, o-tolidine diisocyanate, and hexamethylene diisocyanate.Other examples include butane-1,4-diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, 2,4,4-trimethylhexamethylene diisocyanate, xylylene diisocyanate, and m-tetramethylxylylene diisocyanate.

[0034] The hardness of the sheath 20 is A50 or more and A95 or less as measured in accordance with JIS K 7311, and more preferably A80 or more and A90 or less, for example, it can have a JIS hardness of A80 or A90.

[0035] This JIS hardness is measured in accordance with JIS K 7311, which is an industrial standard for testing polyurethane thermoplastic elastomers. For example, it is measured in accordance with the hardness test of JIS K 7311-1955.

[0036] It is also possible to fill the space around the inner insulating core 10 with an inclusion 30 and further provide a pressure tape 40 inside the sheath 20 that presses and wraps around the space around the inclusion 30 .

[0037] The filler 30 may be filled with polypropylene (PP), jute, paper, or the like, or may be a so-called interposing sheath that surrounds and covers the outer surfaces of the conductor 11 and the insulator 12. The material that constitutes the interposing sheath of the filler 30 is not particularly limited as long as it is made of resin, but examples that can be used include thermoplastic polyurethane, polyvinyl chloride (PVC), polyethylene, tetrafluoroethylene, and urethane, and urethane is preferable from the viewpoint of high strength and high elasticity, and furthermore, it is possible to obtain more than twice the durability.

[0038] The pressing tape 40 is not particularly limited as long as it is a resin tape, and for example, a PET tape can be used, and the conductor 11 and the insulator 12 are twisted together with the inclusion 30 and then pressed and wound together for use. The sheath 20 can be formed on the outer surface of the pressing tape 40 by covering it.

[0039] By including the pressing tape 40 inside in this manner, the strength and elastic modulus inside the cable 1 are further reinforced, and the durability can be further improved.

[0040] In addition, in this electric wire or cable, the insulator preferably contains at least one selected from the group consisting of chlorinated polyethylene (CPE), antimony trioxide (Sb2O3), and brominated flame retardants.

[0041] The chlorine content of the chlorinated polyethylene is not particularly limited, but multiple chlorinated polyethylenes with different chlorine content ratios can be mixed and used. The inclusion of chlorinated polyethylene acts in combination with the polyurethane-based thermoplastic elastomer having the above-mentioned JIS hardness, further enhancing the flame retardancy and drip suppression of the electric wire or cable. This makes it possible to further reduce the size of the flames that occur in the event of a fire.

[0042] Furthermore, when antimony trioxide is contained, the antimony trioxide acts synergistically with the brominated flame retardant, which is a halogenated flame retardant among organic flame retardants, and also acts in combination with the polyurethane-based thermoplastic elastomer having the above-mentioned JIS hardness, thereby further enhancing flame retardancy as a flame retardant aid.

[0043] Examples of brominated flame retardants that can be used include polybrominated diphenyl ethers (PBDEs) such as decabromodiphenyl ether and octabromodiphenyl ether.Other examples include tetrabromobisphenol A, 1,2-bis(2,4,6-tribromophenoxy)ethane, 2,4,6-tris(2,4,6-tribromophenoxy)-1,3,5-triazine, 2,4-dibromophenol, 2,6-dibromophenol, ethylenebistetrabromophthalimide, hexabromocyclododecane, hexabromobenzene, pentabromobenzyl acrylate, and brominated polystyrene.

[0044] As described above, since the insulator contains at least one selected from the group consisting of chlorinated polyethylene, antimony trioxide, and brominated flame retardants, the combined effect of the at least one selected from the group consisting of antimony trioxide and brominated flame retardants coexisting with the carbonate-based thermoplastic polyurethane having the optimum JIS hardness further enhances the strength and flame retardancy, thereby achieving high flame retardancy while maintaining the strength of the electric wire or cable.

[0045] More preferably, the sheath contains at least one selected from the group consisting of silicone-acrylic composite rubber and a lubricant.

[0046] The silicone-acrylic composite rubber may be a composite rubber obtained by polymerization of a polyorganosiloxane rubber component and an acrylic rubber component, and the mass ratio of the polyorganosiloxane rubber component to the acrylic rubber component is not particularly limited. Examples of such silicone-acrylic composite rubber include those obtained by polymerization of polydimethylsiloxane and poly(n-butyl acrylate), and a commercially available product is Metablen S Type (registered trademark) (manufactured by Mitsubishi Rayon Co., Ltd.).

[0047] It has been confirmed that silicone-acrylic composite rubber, when incorporated into carbonate-based thermoplastic polyurethane, improves the flame retardancy of electric wires or cables (see the examples below). It has also been confirmed to have a greater effect on flame retardancy than when incorporated into conventional ether-based thermoplastic polyurethanes (see the examples below). While the detailed mechanism has not yet been clarified, it is presumed that incorporation into carbonate-based thermoplastic polyurethane synergistically enhances the melt viscosity unique to silicone-acrylic composite rubber, preventing it from melting and dripping even at high temperatures during combustion.

[0048] The lubricant is not particularly limited, but ester wax or an acrylic polymer external lubricant can be used. It is more preferable to use ester wax, which improves both wear resistance and flame retardancy.

[0049] In this way, when the lubricant is an ester wax, the combined effect of the ester wax and the carbonate-based thermoplastic polyurethane having the optimum JIS hardness is achieved, resulting in a high level of strength and flame retardancy, and the wire or cable can be made to have high flame retardancy while maintaining its strength.

[0050] As such, since the insulator contains at least one selected from the group consisting of silicone-acrylic composite rubber and lubricants, the combined effect of the silicone-acrylic composite rubber and at least one selected from the group consisting of lubricants and carbonate-based thermoplastic polyurethane with the optimal JIS hardness results in even higher levels of strength and flame retardancy, allowing the wire or cable to achieve high flame retardancy while maintaining its strength.

[0051] The blending ratio of the thermoplastic polyurethane to the entire sheath is not particularly limited, but is preferably 60% by mass or more and 70% by mass or less.

[0052] In this way, since the thermoplastic polyurethane content of the entire sheath is 60% by mass or more and 70% by mass or less, the carbonate-based thermoplastic polyurethane, which has the optimal JIS hardness, exhibits high levels of strength and flame retardancy, thereby achieving high flame retardancy while maintaining the strength of the electric wire or cable.

[0053] The electric wire or cable according to this embodiment has a wide range of applications and is not particularly limited, but can be used as a cable for an FA robot, for example.

[0054] In order to further clarify the features of the present invention, examples are given below, but the present invention is not limited to these examples.

[0055] (Example) The electric wires or cables of Examples 1 to 4 have three internal insulating cores made of conductors and insulators, which are twisted together and then molded into a sheath. Copper wire is used as the conductor and PBT (polybutylene terephthalate) is used as the insulator.

[0056] The sheaths of the electric wires or cables according to Examples 1 to 4 were made of two materials: a carbonate-based thermoplastic polyurethane with a JIS hardness of 80, and a carbonate-based thermoplastic polyurethane with a JIS hardness of 90.

[0057] The electric wires or cables according to Examples 1 to 4 contain, as constituent materials other than the sheath, the following components as necessary: ​​amorphous chlorinated polyethylene (CPE); antimony trioxide as a flame retardant aid; a bromine-based flame retardant as an organic flame retardant; silicone-acrylic composite rubber, acrylic-modified PTFE, a phenol-based stabilizer, and a sulfur-based stabilizer as anti-drip agents; and ester wax and an acrylic polymer external lubricant as lubricants.

[0058] In addition, the electric wires or cables used in the sheaths of the electric wires or cables were used as comparative examples. That is, the electric wires or cables of Comparative Examples 1 and 2 used the sheaths of ether-based thermoplastic polyurethane with a JIS hardness of 90, and apart from the sheaths, had the same configuration as the electric wires or cables of Examples 1 to 4.

[0059] The following table shows a list of raw material components in terms of blend weight (kg) for the electric wires or cables according to Examples 1 to 4 and the electric wires or cables according to Comparative Examples 1 and 2.

[0060] [Table 1]

[0061] The electric wires or cables according to Examples 1 to 4 and the electric wires or cables according to Comparative Examples 1 and 2 were subjected to a room temperature tensile test, a tensile test after heat aging, a combustion simulation test according to the UL1581 Cable Flame Test, and a combustion time test.

[0062] The room temperature tensile test yielded results for 30% mod (MPa), 100% mod (MPa), maximum point tensile strength (MPa), and maximum point tensile elongation (%). The tensile test after heat aging was carried out at 113°C for 168 hours with a substitution rate of 150, yielding results for 30% mod (MPa), 100% mod (MPa), tensile strength retention (%), and tensile elongation retention (%). The results are shown in the table below.

[0063] [Table 2]

[0064] The results of the room temperature tensile test showed that the electric wires or cables according to Examples 1 to 4 exhibited maximum tensile strengths that were approximately 1.5 times higher than those of the electric wires or cables according to Comparative Examples 1 and 2.

[0065] Furthermore, the results of the tensile test after heat aging showed that the wires or cables according to Examples 1 to 4 had significantly higher tensile strength retention and tensile elongation retention than the wires or cables according to Comparative Examples 1 and 2.

[0066] Furthermore, from the results of the combustion simulation test of the UL1581 Cable Flame Test, the wires or cables according to Examples 1 to 4 met the pass criteria for the combustion simulation test (marked with a circle), whereas the wires or cables according to Comparative Examples 1 and 2 did not meet the pass criteria for the combustion simulation test (marked with an x).

[0067] Further, the test results for the burning time shown in the table above are shown below in more detail.

[0068] First, the detailed results of the burning time test for the electric wire or cable according to Example 2 (using a carbonate-based thermoplastic polyurethane with a JIS hardness of A80) are shown in the table below. The average total burning time was a short burning time of 17.8 minutes.

[0069] [Table 3]

[0070] The detailed results of the burning time test for the electric wire or cable according to Example 3 (using a carbonate-based thermoplastic polyurethane with a JIS hardness of A90) are shown in the table below. The average total burning time was a short burning time of 15.2 minutes.

[0071] [Table 4]

[0072] The detailed results of the burning time test for the electric wire or cable according to Example 4 (using a carbonate-based thermoplastic polyurethane with a JIS hardness of A90) are shown in the table below. The average total burning time was 10 minutes, the shortest possible burning time.

[0073] [Table 5]

[0074] The detailed results of the burning time test for the electric wire or cable according to Comparative Example 1 (using an ether-based thermoplastic polyurethane with a JIS hardness of A90) are shown in the table below. The average total burning time was 27.5 minutes, which was a long burning time.

[0075] [Table 6]

[0076] The detailed results of the burning time test for the electric wire or cable according to Comparative Example 2 (using an ether-based thermoplastic polyurethane with a JIS hardness of A90) are shown in the table below. The average total burning time was 27.6 minutes, the longest.

[0077] [Table 7]

[0078] The results of the burn time tests showed that Comparative Examples 1 and 2 (using ether-based thermoplastic polyurethane with a JIS hardness of A90) had a long burn time of approximately 27.6 minutes. In contrast, Examples 2 and 3 (using carbonate-based thermoplastic polyurethane with a JIS hardness of A80 to A90) had shorter burn times of 15.2 to 17.8 minutes. Furthermore, Example 4 (using carbonate-based thermoplastic polyurethane with a JIS hardness of A90) had a burn time of 10 minutes, the shortest burn time. One factor contributing to the difference between Examples 3 and 4 is the presence or absence of silicone-acrylic composite rubber. Therefore, it was considered more preferable to use a sheath with a JIS hardness close to A90 together with the silicone-acrylic composite rubber.

[0079] From the above results, it was confirmed that the electric wires or cables according to Examples 1 to 4 exhibited higher tensile strength and flame retardancy than the electric wires or cables according to Comparative Examples 1 and 2. That is, the electric wires or cables according to the present examples have sheaths containing carbonate-based thermoplastic polyurethane and having a JIS hardness of A50 or more and A95 or less as measured in accordance with JIS K 7311, and it was confirmed that this configuration exhibits an excellent effect of exhibiting significantly higher tensile strength and flame retardancy than Comparative Examples 1 and 2, which use ether-based thermoplastic polyurethanes having similar JIS hardness as the conventional art as the constituent material of the sheath. [Explanation of symbols]

[0080] 1 cable 10 Inner insulating core 11 Conductor 12 Insulators 20 Sheath 30 Inclusions 40 Holding tape

Claims

1. An electric wire or cable having an outermost sheath covering a core wire made of one or more conductors, The sheath contains a carbonate-based thermoplastic polyurethane and has a JIS hardness of A50 or more and A95 or less as measured in accordance with JIS K 7311.

1. An electric wire or cable characterized in that:

2. The wire or cable according to claim 1, The JIS hardness is A80 or more and A90 or less.

1. An electric wire or cable characterized in that:

3. The wire or cable according to claim 1, The sheath contains at least one selected from the group consisting of chlorinated polyethylene, antimony trioxide, and a brominated flame retardant.

1. An electric wire or cable characterized in that:

4. The wire or cable according to claim 1, The sheath contains at least one selected from the group consisting of silicone-acrylic composite rubber and lubricant.

1. An electric wire or cable characterized in that:

5. The wire or cable according to claim 4, The lubricant is an ester wax.

1. An electric wire or cable characterized in that:

6. The wire or cable according to claim 1, The blending ratio of the thermoplastic polyurethane to the entire sheath is 60% by mass or more and 70% by mass or less.

1. An electric wire or cable characterized in that:

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