JP2019106391A - Wire and method for producing the same, and multi-core cable and method for producing the same - Google Patents

Abstract

To provide a wire that has excellent wear resistance and heat resistance and also can be produced at low cost.SOLUTION: A wire according to one embodiment has an insulated wire, and one or a plurality of coating layer(s) put on the outside of the insulated wire, at least one of the one or plurality of coating layer(s) being formed of a resin composition comprising a thermoplastic polyurethane elastomer and an allophanate crosslinking agent.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an electric wire and a method of manufacturing the same, and a multicore cable and a method of manufacturing the same.

  Main applications of electric wires and multicore cables include electronic devices, automobiles, ships, aircrafts, and the like. The electric wire generally comprises a conductor, an insulating layer laminated directly on the conductor, and one or more covering layers further laminated outside the insulating layer as required. In addition, a multi-core cable generally includes a plurality of insulated wires and one or more covering layers laminated on the outside of the plurality of insulated wires. For the purpose of imparting abrasion resistance, chemical resistance, heat resistance, weather resistance and the like to these electric wires and multi-core cables, thermoplastic polyurethane elastomers may be used for the coating layer.

  By the way, there are applications in which heat resistance higher than the melting point or the softening point of the covering material is required for the electric wire and the multi-core cable, and in order to satisfy this request, there is one in which the covering layer is crosslinked. As a method of crosslinking the coating layer of the electric wire and the multicore cable, for example, irradiation of ionizing radiation is known. However, when the coating layer of the electric wire and multicore cable is cross-linked by the irradiation of ionizing radiation, the equipment cost is increased because the irradiation equipment is required, and the cost is increased because the number of processes is also increased compared to a general electric wire. Easy to do. Furthermore, in the case of a multi-core cable with a relatively large number of cores, a larger irradiation facility is required, and the cost is likely to further increase.

  Then, the electric wire which forms a coating layer with the resin composition containing the polyurethane and the monomer which has an isocyanate group as a crosslinking agent is proposed (refer Unexamined-Japanese-Patent No. 2013-129759). This monomer can form a three-dimensional crosslinked structure such as allophanate bond by reacting the isocyanate group with the urea bond of polyurethane.

JP, 2013-129759, A

  However, the resin composition containing the polyurethane and the above-mentioned monomer undergoes a crosslinking reaction in a melt kneader or an extrusion molding machine before extrusion due to heating at the time of kneading and extrusion molding, and as a result, molding at the time of extrusion Not only there is a risk that the properties and yield will be reduced, but also the extruder may be damaged. Therefore, the above-mentioned electric wire met the demand of abrasion resistance and heat resistance, and was difficult to manufacture at low cost.

  The present invention has been made based on the above circumstances, and it is an object of the present invention to provide an electric wire and a multicore cable which are excellent in wear resistance and heat resistance and can be manufactured at low cost.

  An electric wire according to an aspect of the present invention made to solve the above problems is an electric wire comprising an insulated electric wire, and one or more coating layers laminated on the outside of the insulating layer, And at least one layer of the coating layer is formed of a resin composition containing a thermoplastic polyurethane elastomer and an allophanate crosslinking agent.

  A multi-core cable according to another aspect of the present invention made to solve the above problems comprises a plurality of insulated wires, and one or more covering layers laminated on the outside of the plurality of insulated wires. A multicore cable, wherein at least one layer of the one or more coating layers is formed of a resin composition containing a thermoplastic polyurethane elastomer and an allophanate crosslinking agent.

  A method of manufacturing a wire according to still another aspect of the present invention made to solve the above problems is a method of manufacturing a wire comprising: an insulated wire; and one or more covering layers laminated on the outside of the insulated wire. And melting the resin composition containing the thermoplastic polyurethane elastomer and the allophanate crosslinking agent, and coating the melt on the outside of the insulated wire.

  A manufacturing method of a multi-core cable according to still another aspect of the present invention made to solve the above problems comprises: a plurality of insulated wires; and one or a plurality of covering layers laminated on the outside of the plurality of insulated wires. And a step of melting a resin composition containing a thermoplastic polyurethane elastomer and an allophanate crosslinking agent, and a step of covering the melt on the outside of a plurality of insulated wires.

  Here, the term "insulated wire" refers to a wire comprising a conductor and an insulating layer outside the conductor.

  The electric wire and the multi-core cable according to one aspect of the present invention are excellent in wear resistance and heat resistance, and can be manufactured at low cost.

It is a typical sectional view showing the electric wire concerning a 1st embodiment of the present invention. It is a schematic cross section which shows the multicore cable which concerns on 2nd Embodiment of this invention. It is a schematic cross section which shows the multicore cable which concerns on 3rd Embodiment of this invention. It is a schematic cross section which shows the multicore cable which concerns on 4th Embodiment of this invention.

Description of the embodiment of the present invention
A wire according to an aspect of the present invention is a wire comprising an insulated wire and one or more coating layers laminated on the outside of the insulated wire, wherein at least one of the one or more coating layers is It is formed by a resin composition containing a thermoplastic polyurethane elastomer and an allophanate crosslinking agent.

  The said electric wire is excellent in abrasion resistance, since at least one layer of a coating layer is formed of the said resin composition containing a thermoplastic polyurethane elastomer. Moreover, since the said resin composition contains an allophanate crosslinking agent, after extrusion-molding the said coating layer, the thermoplastic polyurethane elastomer contained in the said coating layer will be bridge | crosslinked, and the said electric wire will exhibit the outstanding heat resistance. Furthermore, since the said electric wire can be manufactured by the manufacturing process similar to a general electric wire, and the radiation installation etc. of an ionizing radiation are not required, it can manufacture at low cost.

  The outermost layer of the coating layer may be formed of a resin composition containing a thermoplastic polyurethane elastomer and an allophanate crosslinking agent. Thus, abrasion resistance and heat resistance can be further improved by forming the outermost layer of a coating layer with the said resin composition.

  As content of the allophanate crosslinking agent with respect to 100 mass parts of thermoplastic polyurethane elastomers in the said resin composition, 0.4 mass parts or more and 15 mass parts or less are preferable. As described above, by setting the content of the allophanate crosslinking agent in the above range, the heat resistance can be further improved while maintaining the moldability at the time of extrusion.

  The above resin composition is preferably a mixture of agent A containing a thermoplastic polyurethane elastomer and agent B containing a thermoplastic polyurethane elastomer and a monomer having an isocyanate group as an allophanate crosslinking agent. As described above, by forming the resin composition as a mixture of the agent A and the agent B, melting and extrusion can be started from the state in which the monomer is dispersed to some extent in the thermoplastic polyurethane elastomer, and thus local high concentration It is possible to diffuse the above-mentioned monomer rapidly while suppressing the hardening, and as a result, it is possible to accelerate the crosslinking after the extrusion while suppressing the crosslinking before the extrusion and to improve the uniformity of the crosslinking in the longitudinal direction of the electric wire. That is, the covering layer can be molded easily and reliably by melting and extrusion. Here, the "mixture" refers to one which is physically mixed by dry blending or the like.

  As content of the said monomer in the said B agent, 15 mass% or more and 65 mass% or less are preferable. By setting the content of the above-mentioned monomer in the agent B to the above-mentioned range, the above-mentioned monomer can be more rapidly diffused while suppressing the local high concentration during melting and extrusion, and as a result, the coating layer is melted and It can be molded more easily and reliably by extrusion molding.

  The resin composition may further contain a flame retardant. Thus, in addition to the outstanding heat resistance, the outstanding flame-retardant effect can be provided by the said resin composition further containing a flame retardant.

  As content of the flame retardant with respect to 100 mass parts of thermoplastic polyurethane elastomers in the said resin composition, 3 mass parts or more and 90 mass parts or less are preferable. Thus, by making content of a flame retardant into the said range, a flame retardance effect can be improved more, hold | maintaining abrasion resistance.

  A multicore cable according to another aspect of the present invention is a multicore cable comprising a plurality of insulated wires and one or more covering layers laminated on the outside of the plurality of insulated wires, Alternatively, at least one layer of the plurality of covering layers is formed of a resin composition containing a thermoplastic polyurethane elastomer and an allophanate crosslinking agent.

  The multicore cable is excellent in abrasion resistance because at least one layer of the coating layer is formed of the above-described resin composition containing a thermoplastic polyurethane elastomer. Moreover, since the said resin composition contains an allophanate crosslinking agent, the thermoplastic polyurethane elastomer contained in the said coating layer will be bridge | crosslinked after extrusion, and the said multicore cable will exhibit the outstanding heat resistance. Furthermore, in the case where the multicore cable includes a jacketed core wire, the jacket is formed of the above-described resin composition to melt the core jacket due to heat during extrusion or during coating layer extrusion after assembly of core wires. It exerts an excellent effect of being able to prevent adhesion with other core wires. Furthermore, since the multicore cable can be manufactured by the same manufacturing process as a general multicore cable and does not require equipment such as an electron beam irradiator, it can be manufactured at low cost.

  The coating layer is preferably composed of a plurality of layers, and the outermost layer is preferably formed of a resin composition containing a thermoplastic polyurethane elastomer and an allophanate crosslinking agent. Thus, abrasion resistance and heat resistance can be further improved by forming the outermost layer of a plurality of covering layers with the above-mentioned resin composition containing a thermoplastic polyurethane elastomer and an allophanate crosslinking agent.

  The coating layer may be composed of a plurality of layers, and the inner layer may be formed of a resin composition containing a thermoplastic polyurethane elastomer and an allophanate crosslinking agent. As described above, by forming the inner layer of the coating layer with the above-described resin composition, it is possible to form another layer on the outer side and to improve desired properties such as the flame retardant effect and the mechanical strength.

  A method of manufacturing a wire according to still another aspect of the present invention is a method of manufacturing a wire comprising an insulated wire and one or more coating layers laminated on the outside of the insulated wire, and a thermoplastic polyurethane elastomer And melting the resin composition containing the allophanate crosslinking agent, and coating the melt on the outside of the insulated wire.

  According to the manufacturing method of the electric wire, since the covering layer which has the crosslinked thermoplastic polyurethane elastomer as the main component can be formed, the electric wire excellent in abrasion resistance and heat resistance can be provided easily and surely at low cost.

  A manufacturing method of a multi-core cable according to still another aspect of the present invention is a manufacturing method of a multi-core cable comprising a plurality of insulated wires and one or more covering layers laminated on the outside of the plurality of insulated wires. And melting the resin composition containing the thermoplastic polyurethane elastomer and the allophanate crosslinking agent, and covering the melt on the outside of the plurality of insulated wires.

  According to the manufacturing method of the multi-core cable, it is possible to form a coating layer having a cross-linked thermoplastic polyurethane elastomer as a main component, and a multi-core cable excellent in wear resistance and heat resistance can be provided easily and reliably at low cost. it can.

Details of the Embodiment of the Present Invention
Hereinafter, an electric wire and a method of manufacturing the same according to an embodiment of the present invention, and a multi-core cable and a method of manufacturing the same will be described in detail with reference to the drawings.

First Embodiment
<Wire>
The electric wire 1 of FIG. 1 includes a conductor 2, an insulating layer 3 stacked directly on the conductor 2, and a protective layer 4 stacked on the insulating layer 3. The conductor 2 and the insulating layer 3 constitute an insulated wire 5. That is, the said electric wire 1 is equipped with the insulated wire 5 and the protective layer 4 as a coating layer laminated | stacked on the outer side of this insulated wire 5.

  Although it does not specifically limit as a cross-sectional shape of the said electric wire 1, For example, various shapes, such as circular, a square, a rectangle, are employable. Moreover, when making the cross-sectional shape of the said electric wire 1 circular, it can be 0.3 mm as a minimum of an average outer diameter, for example. On the other hand, the upper limit of the average outer diameter may be, for example, 60 mm.

(conductor)
Although it does not specifically limit as the conductor 2, For example, a copper wire, a copper alloy wire, an aluminum wire, an aluminum alloy wire etc. are mentioned.

  The cross-sectional shape of the conductor 2 is not particularly limited, but various shapes such as a circle, a square, a rectangle and the like can be adopted. The size of the cross section of the conductor 2 is not particularly limited, but when the cross sectional shape of the conductor 2 is circular, the lower limit of the average outer diameter can be, for example, 0.1 mm. On the other hand, as an upper limit of the above-mentioned average outside diameter, it can be 12 mm, for example.

(Insulating layer)
The insulating layer 3 is formed of an insulating resin material, and is laminated on the circumferential surface of the conductor 2 so as to cover the conductor 2. The lower limit of the average thickness of the insulating layer 3 is not particularly limited, and may be, for example, 0.1 mm. On the other hand, the upper limit of the average thickness is not particularly limited, and may be, for example, 10 mm. Here, "average thickness" refers to the average value of the thickness measured at any ten points. In addition, it is defined similarly also in the case of being called "average thickness" with respect to another member etc. below.

  The main component of the insulating resin material is not particularly limited, but a polyolefin resin is preferable. As the polyolefin resin, for example, polypropylene (homopolymer, block polymer, random polymer), polypropylene thermoplastic elastomer, reactor type polypropylene resin Thermoplastic elastomer, Dynamically crosslinked polypropylene thermoplastic elastomer, Polyethylene (high density polyethylene, linear low density polyethylene, low density polyethylene, ultra low density polyethylene), ethylene-vinyl acetate copolymer, ethylene-ethyl acrylate Copolymer, ethylene-methyl methacrylate copolymer, ethylene-methyl acrylate copolymer, ethylene-methyl methacrylate copolymer, ethylene-ethyl acrylate copolymer, ethylene-acrylate Polyethylene resin such as ethylene-propylene rubber, ethylene-acrylic rubber, ethylene-glycidyl methacrylate copolymer, ethylene-methacrylic acid copolymer, ethylene-methacrylic acid copolymer, ethylene-acrylic acid copolymer For example, an ionomer resin in which molecules of the above are intermolecularly bonded with metal ions such as sodium and zinc can be used. Further, those obtained by modifying these resins with maleic anhydride and the like, and those having an epoxy group, an amino group, an imide group, and the like can also be mentioned.

  The insulating resin material may contain a flame retardant, a flame retardant auxiliary agent, an antioxidant, a lubricant, a coloring agent, a reflection imparting agent, a masking agent, a processing stabilizer, a plasticizer and the like. As said flame retardant, the thing similar to what is illustrated with the resin composition mentioned later, for example is mentioned.

(Protective layer)
The protective layer 4 is the outermost layer of the above-mentioned covering layer, and is formed of a resin composition described later. The lower limit of the average thickness of the protective layer 4 is not particularly limited, and may be, for example, 0.05 mm. On the other hand, the upper limit of the average thickness is not particularly limited, and may be, for example, 10 mm.

(Resin composition)
The resin composition contains a thermoplastic polyurethane elastomer and an allophanate crosslinking agent, may contain a flame retardant as a preferred component, and may contain other components as long as the effects of the present invention are not impaired. Moreover, the said resin composition may contain other resin components, such as a thermoplastic polyester elastomer.

[Thermoplastic polyurethane elastomer]
The thermoplastic polyurethane elastomer is a resin having a urethane bond in its molecular structure and exhibiting a property as an elastomer among thermoplastic polyurethanes which exhibit plasticity by heating. However, in the molecular structure of the thermoplastic polyurethane elastomer, other bonds such as urea bond, buret bond, allophanate bond and the like may be present in addition to the urethane bond. The thermoplastic polyurethane elastomer can be used singly or in combination of two or more.

  Thermoplastic polyurethanes are synthesized by the polyaddition reaction of polyols and polyisocyanates. The polyol forms a soft segment (flexible component) exhibiting rubber elasticity, and the polyisocyanate forms a hard segment (molecularly constrained component) which serves as a crosslinking point of a crosslinked rubber which prevents plastic deformation. As the thermoplastic polyurethane, a chain extender may be further added to this polyaddition reaction.

Examples of the polyol include polyether polyols such as polyoxyethylene glycol, polyoxypropylene glycol and polyoxytetramethylene glycol;
Polyester polyols such as polyethylene adipate, polybutylene adipate and polyhexamethylene adipate;
Polylactone polyols such as poly-ε-caprolactone;
Polycarbonate polyols such as polyhexamethylene carbonate and the like can be mentioned. The number of hydroxyl groups in the polyol is preferably 2, 3 and 4, more preferably 2 and 3, and still more preferably 2. A polyol can be used individually by 1 type or in combination of 2 or more types.

As the polyisocyanate, for example, 2,4-toluene diisocyanate (2,4-TDI), 2,6-toluene diisocyanate (2,6-TDI), 4,4'-diphenylmethane diisocyanate (MDI), 1,5-dimethane Isocyanato naphthalene (NDI), 3,3'-bitrylene-4,4'-diisocyanate, xylylene diisocyanate, tetramethyl xylylene diisocyanate, 1,4-phenylene diisocyanate (PPDI), 4,4'-methylene-bis ( Aromatic polyisocyanates such as phenylisocyanate);
Alicyclic polyisocyanates such as 4,4'-dicyclohexylmethane diisocyanate, hydrogenated xylylene diisocyanate, isophorone diisocyanate (IPDI);
And aliphatic polyisocyanates such as hexamethylene diisocyanate (HDI). The number of isocyanate groups in the polyisocyanate is preferably 2, 3 and 4, more preferably 2 and 3, and still more preferably 2. The polyisocyanate can be used singly or in combination of two or more.

As a chain extender, for example, ethylene glycol, 1,3-propylene glycol, 1,2-propylene glycol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 2-methyl-1 And polyols such as 3-propanediol and 1,5-pentanediol;
Polyamines such as ethylene diamine, hexamethylene diamine, xylylene diamine, isophorone diamine, ethylene triamine and the like;
And amino alcohols such as monoethanolamine, diethanolamine, monopropanolamine and the like. The chain extender may be used alone or in combination of two or more.

  From the viewpoint of improving the hydrolysis resistance of the protective layer 4, as a thermoplastic polyurethane elastomer, a polyether thermoplastic polyurethane elastomer using a polyether polyol as a polyol is preferable. Moreover, as a thermoplastic polyurethane elastomer, from the viewpoint of improving the mechanical strength of the protective layer 4, a polyester thermoplastic polyurethane elastomer using a polyester polyol as a polyol is also preferable. Furthermore, as the thermoplastic polyurethane, a water resistant ester-based thermoplastic polyurethane elastomer is also preferable from the viewpoint of improving the hydrolysis resistance and the mechanical strength of the protective layer 4 in a well-balanced manner. The water resistant ester-based thermoplastic polyurethane is a thermoplastic polyurethane elastomer in which a soft segment is formed of a relatively high molecular weight polyester polyol, and is excellent in water resistance because the number of urea bonds relative to the molecular weight is relatively small.

  As a minimum of content of a thermoplastic polyurethane elastomer in the above-mentioned resin composition, 50 mass% is preferred, 55 mass% is more preferred, and 60 mass% is still more preferred. On the other hand, as an upper limit of content of the thermoplastic polyurethane elastomer in the said resin composition, 99.7 mass% is preferable, 98 mass% is more preferable, 95 mass% is more preferable, and 90 mass% is especially preferable. When the content of the thermoplastic polyurethane elastomer is smaller than the above lower limit, the abrasion resistance and the heat resistance of the protective layer 4 of the electric wire 1 may be reduced. Conversely, when the content of the thermoplastic polyurethane elastomer exceeds the above upper limit, the content of the allophanate crosslinking agent and the like in the resin composition is insufficient, and thus the crosslinking and the like of the thermoplastic polyurethane elastomer after extrusion become insufficient. As a result, the heat resistance of the wire 1 may be reduced.

(Allophanate Crosslinker)
The allophanate crosslinker forms a three-dimensional crosslink structure by allophanate bonding by reacting with the urea bond of the thermoplastic polyurethane elastomer. However, the allophanate crosslinking agent may form a three-dimensional crosslinked structure by other bonds such as burette bonds. As an allophanate crosslinking agent, the monomer which has the isocyanate mentioned later, etc. are mentioned, for example.

  The lower limit of the content of the allophanate crosslinking agent in the resin composition is preferably 0.4 parts by mass, more preferably 0.55 parts by mass, and 0.9 parts by mass with respect to 100 parts by mass of the thermoplastic polyurethane elastomer. More preferably, 1.5 parts by mass is particularly preferred. On the other hand, the upper limit of the content of the allophanate crosslinking agent in the resin composition is preferably 15 parts by mass, more preferably 10 parts by mass, and still more preferably 8 parts by mass with respect to 100 parts by mass of the thermoplastic polyurethane elastomer. Parts by weight are particularly preferred. When the content of the allophanate crosslinking agent is smaller than the above lower limit, the crosslinking of the thermoplastic polyurethane elastomer may be insufficient. Conversely, when the content of the allophanate crosslinking agent exceeds the above upper limit, the crosslinking reaction proceeds before extrusion, which may lead to difficulty in extrusion, fluctuation of the average outer diameter of the electric wire 1, or failure of the device.

〔Flame retardants〕
The flame retardant imparts a flame retardant effect to the protective layer 4 formed of the above resin composition. Examples of the flame retardant include halogen flame retardants such as bromine flame retardants and chlorine flame retardants, and non-halogen flame retardants such as metal hydroxides, nitrogen flame retardants and phosphorus flame retardants. A flame retardant can be used individually by 1 type or in combination of 2 or more types.

  Examples of brominated flame retardants include decabromodiphenylethane and the like.

  Examples of chlorinated flame retardants include chlorinated paraffin, chlorinated polyethylene, chlorinated polyphenols, perchloropentacyclodecane and the like.

  As a metal hydroxide, magnesium hydroxide, aluminum hydroxide etc. are mentioned, for example.

  Examples of nitrogen flame retardants include melamine cyanurate, triazine, isocyanurate, urea, guanidine and the like.

  Examples of phosphorus-based flame retardants include metal phosphinates, phosphaphenanthrenes, melamine phosphates, ammonium phosphates, phosphate esters, polyphosphazenes and the like.

  As the flame retardant, non-halogen flame retardants are preferable from the viewpoint of environmental load reduction, metal hydroxide, nitrogen type flame retardant and phosphorus flame retardant are more preferable, and melanin cyanurate, phosphate ester and metal phosphinate are further added preferable.

  When the said resin composition contains a flame retardant, as a minimum of content of the flame retardant in the said resin composition, it is 3 mass parts with respect to 100 mass parts of thermoplastic polyurethane elastomers, for example, and 4 mass parts is preferable. 5.5 mass parts is more preferable, and 10 mass parts is further more preferable. On the other hand, as an upper limit of content of a flame retardant in the above-mentioned resin composition, 90 mass parts is preferred to 100 mass parts of thermoplastic polyurethane elastomer, 30 mass parts is more preferred, 20 mass parts is still more preferred, and 15 mass. Parts are particularly preferred. When the content of the flame retardant is smaller than the above lower limit, there is a possibility that the flame retardant effect can not be sufficiently imparted to the wire 1. On the contrary, when content of a flame retardant exceeds the above-mentioned maximum, there is a possibility that extrusion nature of the electric wire 1 may be impaired, and mechanical characteristics, such as extension and tensile strength, may be impaired.

(Thermoplastic polyester elastomer)
The thermoplastic polyester elastomer is a resin having an ester bond in the main chain and exhibiting a property as an elastomer among thermoplastic polyesters which exhibit plasticity by heating. The durability and chemical resistance of the electric wire 1 can be further improved by the resin composition further containing a thermoplastic polyester elastomer. Examples of thermoplastic polyester elastomers include block copolyesters of hard segments containing crystalline rigid polyesters and soft segments containing amorphous flexible polyesters or polyethers. As said hard segment, aromatic polyester etc. are mentioned, for example. Moreover, as said soft segment, aliphatic polyether, aliphatic polyester, etc. are mentioned, for example.

  When the said resin composition contains a thermoplastic polyester elastomer, as a minimum of content of the thermoplastic polyester elastomer in the said resin composition, 20 mass parts is preferable with respect to 100 mass parts of thermoplastic polyurethane elastomers, and 30 mass. Part is more preferable, and 40 parts by mass is further preferable. On the other hand, the lower limit of the content of the thermoplastic polyester elastomer is preferably 90 parts by mass, more preferably 80 parts by mass, and still more preferably 70 parts by mass with respect to 100 parts by mass of the thermoplastic polyurethane elastomer. When the content of the thermoplastic polyester elastomer is smaller than the above lower limit, the durability and the chemical resistance of the electric wire 1 may not be sufficiently improved. On the contrary, when content of a thermoplastic polyester elastomer exceeds the above-mentioned maximum, there is a possibility that abrasion resistance and heat resistance may fall because content of a thermoplastic polyurethane elastomer of the above-mentioned resin composition falls.

[Other ingredients]
Other components include, for example, flame retardant aids, antioxidants, lubricants, colorants, processing stabilizers, plasticizers and the like.

  The resin composition is preferably a mixture of agent A containing a thermoplastic polyurethane elastomer and agent B containing a thermoplastic polyurethane elastomer and a monomer having an isocyanate group as an allophanate crosslinking agent. The resin composition may be a mixture of agent A, agent B and components other than these.

  As a form of A agent and B agent, pellet form, a sheet form, powder form, flake form etc. are mentioned, for example. As a form of B agent, a pellet form is preferable. Thus, in addition to the fact that the agent B is formed in the form of pellets, it becomes easy to mix with the agent A and dry blending etc before melting and extrusion, and the heat history of the agent A can also be minimized. It is difficult to lose the properties of the material. As a result, the monomer can be diffused more quickly while further suppressing local high concentration during melting and extrusion, and the protective layer 4 of the wire 1 can be molded more easily and reliably by melting and extrusion.

  As a minimum of content of B agent in the above-mentioned resin composition, 2.5 mass parts is preferred to 100 mass parts of A agent, 5 mass parts is more preferred, and 8 mass parts is still more preferred. On the other hand, as an upper limit of content of B agent in the above-mentioned resin composition, 25 mass parts is preferred to 100 mass parts of A agent, 15 mass parts is more preferred, and 12 mass parts is still more preferred. When the content of the agent B is smaller than the above lower limit, crosslinking after extrusion becomes insufficient, and as a result, the heat resistance of the wire 1 may be reduced. In addition, the mixing of the agent B with the agent A tends to be uneven, and there is a possibility that the heat resistance and the like vary in the length direction of the electric wire 1. On the contrary, when the content of the agent B exceeds the above upper limit, the crosslinking reaction proceeds before extrusion molding, and the extrusion molding property of the above resin composition is reduced, the outer diameter of the protective layer 4 is changed, the device failure, etc. There is a fear. In addition, due to the liberation of the agent B, there is a possibility that the generation of residue (die residue) at the die portion of the extrusion molding machine, the appearance deterioration of the protective layer 4 of the electric wire 1, and the like.

(A agent)
The agent A contains a thermoplastic polyurethane elastomer. The agent A may contain the above-described flame retardant and thermoplastic polyester elastomer or other components as long as the effects of the present invention are not impaired. The lower limit of the content of the thermoplastic polyurethane elastomer in the agent A is preferably 40% by mass, more preferably 55% by mass, and still more preferably 60% by mass. When the content of the thermoplastic polyurethane elastomer is smaller than the above lower limit, the content of the thermoplastic polyurethane elastomer in the resin composition is insufficient, and the abrasion resistance and the heat resistance of the protective layer 4 of the wire 1 may be deteriorated. .

(B agent)
The agent B contains a thermoplastic polyurethane elastomer and a monomer having an isocyanate group as an allophanate crosslinking agent. In addition, the agent B may contain the above-described flame retardant and thermoplastic polyester elastomer or other components as long as the effects of the present invention are not impaired. Conversely, the agent B may contain only the thermoplastic polyurethane elastomer and the allophanate crosslinking agent. In this case, the agent A may contain only a thermoplastic polyurethane elastomer, and may further contain an additive such as a flame retardant or another resin such as a thermoplastic polyester elastomer.

  As a thermoplastic polyurethane elastomer which B agent contains, the thing similar to the thermoplastic polyurethane elastomer illustrated by the said resin composition, etc. are mentioned, for example. As a thermoplastic polyurethane elastomer which B agent contains, a polyether type thermoplastic polyurethane elastomer is preferable. The thermoplastic polyurethane elastomer contained in the agent B may be the same as or different from the thermoplastic polyurethane elastomer contained in the agent A.

  The lower limit of the number average molecular weight (Mn) of the thermoplastic polyurethane elastomer contained in the agent B is preferably 500, more preferably 1,000, still more preferably 1,500, and particularly preferably 1,700. On the other hand, the upper limit of the Mn of the thermoplastic polyurethane elastomer contained in the agent B is preferably 4,000, more preferably 3,000, still more preferably 2,500, and particularly preferably 2,000. When Mn of the thermoplastic polyurethane elastomer contained in the agent B is smaller than the above lower limit or exceeds the above upper limit, the dispersibility in the resin composition is reduced, and as a result, the heat resistance of the wire 1 may be reduced. is there.

  The lower limit of the content of the thermoplastic polyurethane elastomer in the agent B is preferably 40% by mass, more preferably 55% by mass, and still more preferably 60% by mass. On the other hand, the upper limit of the content of the thermoplastic polyurethane elastomer in the agent B is preferably 90% by mass, more preferably 82% by mass, and still more preferably 75% by mass. When the content of the thermoplastic polyurethane elastomer is smaller than the above lower limit, mixing by dry blending, molding into a shape such as pellets, etc. may be difficult. On the contrary, when content of a thermoplastic polyurethane elastomer exceeds the above-mentioned maximum, there is a possibility that content of the above-mentioned monomer in B agent may become insufficient.

[Monomer having an isocyanate group]
The monomer having an isocyanate group is a compound having an isocyanate group and functioning as an allophanate crosslinking agent. It is good for the said monomer to be disperse | distributed to the thermoplastic polyurethane elastomer which B agent contains. As a monomer which has an isocyanate group, the polyisocyanate etc. which were mentioned above by the material of the thermoplastic polyurethane elastomer are mentioned, for example. The monomer having an isocyanate group is preferably a monomer having two isocyanate groups, more preferably MDI, IPDI, 2,4-TDI, 2,6-TDI, HDI, PPDI and NDI, and still more preferably MDI.

  As a minimum of content of a monomer which has an isocyanate group in B agent, 15 mass% is preferred, 25 mass% is more preferred, and 30 mass% is more preferred. On the other hand, as an upper limit of content of the monomer which has an isocyanate group in B agent, 60 mass% is preferable, 45 mass% is more preferable, and 40 mass% is more preferable. When the content of the monomer having an isocyanate group is smaller than the above lower limit, the content of the agent B in the resin composition is increased, and as a result, mixing by dry blending may take time and cost may be increased. Conversely, when the content of the monomer having an isocyanate group exceeds the above upper limit, a rapid increase in torque due to the progress of crosslinking reaction before melting and extrusion molding tends to occur, and extrusion moldability may be reduced.

(Flame retardancy of electric wire)
It is preferable that the said electric wire 1 passes the horizontal flame-retardant test of JASO D 618 specification. As a procedure of this horizontal flame retardant test, first, a wire cut into 300 mm is used as a sample, and this sample is fixed in a state of being horizontal. Next, the tip of the reducing flame of a 10 mm bore Bunsen burner is brought into contact with the lower side of the center of the sample, and the flame is gently removed after the coating layer burns. Then, measure the afterflame time until the flames out, pass those of 30 seconds or less, and reject those of more than 30 seconds.

It is further preferable that the said electric wire 1 passes the 45 degree inclination flame-retardant test of ISO6722 specification. As a procedure of this 45-degree inclination flame retardancy test, first, a wire cut out to 600 mm is used as a sample, and this sample is fixed in a state of being inclined at an angle of 45 degrees with respect to the horizontal plane. Next, a flame of a gas burner is applied 500 mm from the upper end of the sample, and the conductor is exposed or exposed for a predetermined time (15 seconds if the average cross-sectional area of the conductor is 2.5 mm ² or less) When the average cross-sectional area exceeds 2.5 mm ² , the flame contact is ended after the lapse of 30 seconds. Then, measure the time from the end of the flame to self-extinguishing of the sample, self-extinguish within 70 seconds, and pass when the insulating layer remains 50 mm or more from the top of the sample, self-extinguishing within 70 seconds If not, or if the insulating layer does not remain 50 mm or more from the top of the sample, it is rejected.

<Method of manufacturing wire>
Next, the manufacturing method of the said electric wire 1 is demonstrated. The manufacturing method of the said electric wire 1 is equipped with the process (melting process) of fuse | melting the said resin composition, and the process (coating process) which coat | covers the said molten material on the outer side of the insulated wire 5. FIG. The manufacturing method of the said electric wire 1 is the process (dry blending process) of carrying out the dry blending of each component used as an extrusion material beforehand, and / or the process of crosslinking the coated said melt before the above-mentioned melting process (crosslinking process) It is good to further

Dry blending process
In this process, for example, each component such as an agent A and an agent B to be extruded materials is dry-blended in advance. As a method of dry blending, for example, a method using a dry blender, a Henschel mixer, etc. may be mentioned. By providing the dry blending step before the melt-kneading, the dispersibility of each component such as the above-described monomer in the protective layer 4 of the wire 1 can be improved, and as a result, the heat resistance of the wire 1 can be further improved. In addition, local cross-linking in the protective layer 4 can be suppressed.

[Melting process]
In the present step, the resin composition is melted. As a method of melting the above-mentioned resin composition, for example, the above-mentioned resin composition (in the case of performing a dry blending step, the obtained dry blend) is put into an extruder and melted by heating in the cylinder of the extruder. And the like.

[Coating process]
In this step, the melt obtained in the melting step is extruded and coated on the peripheral surface of the insulating layer 3, that is, the outer side of the insulated wire 5. The lower limit of the extrusion temperature of the melt is, for example, 160 ° C. On the other hand, the upper limit of the extrusion temperature of the melt is, for example, 250 ° C. When the extrusion temperature is lower than the above lower limit, the resin may not be sufficiently melted, and the productivity of the wire 1 may be deteriorated. On the contrary, when extrusion temperature exceeds the said upper limit, a crosslinking reaction may advance in an extruder, and there exists a possibility that extrusion of the said molten material may become difficult.

[Crosslinking step]
In this step, the coated melt is crosslinked. Examples of the method of crosslinking the melt include a method of heating to promote crosslinking, a method of standing at room temperature during storage, transportation and the like to naturally advance crosslinking. When the storage elastic modulus at 190 ° C. of the protective layer 4 is 1.0 × 10 ⁶ Pa or more, it is judged that the thermoplastic polyurethane elastomer is crosslinked.

<Advantage>
Since the said electric wire 1 is a thermoplastic polyurethane elastomer with which the main component of the protective layer 4 was bridge | crosslinked, it is excellent in abrasion resistance and heat resistance. Moreover, since the said electric wire 1 can be manufactured by the manufacturing process similar to a general electric wire, and since the irradiation installation of ionizing radiation etc. is not required, it can manufacture at low cost. Furthermore, the said electric wire 1 can improve desired characteristics, such as an electrical property, by making an insulation resin material appropriate.

Second Embodiment
<Multi-core cable>
The multicore cable 11 shown in FIG. 2 includes two insulated wires 5 and a protective layer 4 directly laminated on the outside of the two insulated wires 5. That is, the multicore cable 11 includes the plurality of insulated wires 5 and the covering layer 1 stacked on the outside of the plurality of insulated wires 5. The protective layer 4 is the same as that of the first embodiment, so the same reference numeral is given and the description is omitted. The multicore cable 21 may be provided with three or more insulated wires 5.

  The insulated wire 5 includes a conductor 2 and an insulating layer 3 directly laminated on the conductor 2. The conductor 2 and the insulating layer 3 are the same as in the first embodiment, so the same reference numerals are given and the description is omitted.

<Method of manufacturing multi-core cable>
As a method of manufacturing the multicore cable 11, for example, in the covering step of the method of manufacturing the electric wire 1 of the first embodiment, a method of extruding the melt of the resin composition on the peripheral surface of the two insulated wires 5 Can be mentioned.

<Advantage>
Since the multicore cable 11 is a thermoplastic polyurethane elastomer in which the main component of the protective layer 4 is cross-linked, the multicore cable 11 is excellent in wear resistance and heat resistance. In addition, the multicore cable 11 can be cross-linked even if the diameter is increased due to the increase in the number of cores. Therefore, the multicore cable 11 can be suitably used, for example, in applications where high wear resistance and heat resistance are required, such as various sensor cables.

Third Embodiment
<Multi-core cable>
The multicore cable 21 of FIG. 3 includes two insulated wires 5, an intervening layer 6 directly laminated on the outside of the two insulated wires 5, and a protective layer 4 laminated on the outside of the intervening layer 6. And Since the insulated wire 5 is the same as that of 2nd Embodiment, it attaches | subjects the same number and abbreviate | omits description. The multicore cable 21 may be provided with three or more insulated wires 5.

As a formation material of the protective layer 4 and the intervening layer 6, the said resin composition, the said insulation resin material, etc. are mentioned, for example. However, at least one of the protective layer 4 and the intervening layer 6 is formed of the above resin composition. That is, the multicore cable 21 includes the plurality of insulated wires 5 and the plurality of covering layers stacked on the outside of the plurality of insulated wires 5, and the protective layer 4 which is the outermost layer and the intervening layer which is the inner layer. At least one of 6 is formed of the above resin composition. In addition, as for the said multi-core cable 21, both the protective layer 4 and the intervening layer 6 may be formed of the said resin composition.

<Method of manufacturing multi-core cable>
As a method of manufacturing the multicore cable 21, for example, after the intervening layer 6 is laminated on the peripheral surfaces of the two insulated wires 5 in the covering step of the method of manufacturing the electric wire 1 of the first embodiment, The protective layer 4 is laminated on the circumferential surface, and the method of laminating the intervening layer 6 and / or the protective layer 4 by coating the melt of the above resin composition is mentioned. The specific method of extrusion molding of the intervening layer 6 can be made to be the same as the above-mentioned coating process.

<Advantage>
The multicore cable 21 is a thermoplastic polyurethane elastomer in which the main component of at least one of the intervening layer 6 and the protective layer 4 is crosslinked, and thus is excellent in abrasion resistance and heat resistance. Further, the multi-core cable 21 can be cross-linked even if the diameter is increased due to the increase in the number of cores. Furthermore, the said multicore cable 21 can improve a desired characteristic by making the formation material of the intervening layer 6 into an appropriate thing. Therefore, the multicore cable 21 can be suitably used, for example, in applications where high wear resistance and heat resistance are required, such as various sensor cables.

Fourth Embodiment
<Multi-core cable>
The multicore cable 31 shown in FIG. 4 includes a plurality of insulated wires 5, a protective layer 4 stacked directly on the insulated wires 5 of a part of the plurality of insulated wires 5, the protective layer 4 and the remaining layers. It includes an intervening layer 6 stacked directly on the plurality of insulated wires 5 and an outermost layer 7 stacked directly on the intervening layer 6. The protective layer 4 is preferably formed of the resin composition or the insulating resin material, and is preferably formed of the resin composition. Since the insulated wire 5 is the same as that of 1st Embodiment, 2nd Embodiment, and 3rd Embodiment, it attaches | subjects the same number and abbreviate | omits description.

  In addition, 1 or multiple may be sufficient as the insulated wire 5 by which the protective layer 4 is laminated | stacked. Moreover, the insulated wire 5 by which the intervening layer 6 is laminated | stacked immediately above may also be 1 or multiple.

  As a formation material of outermost layer 7 and intervening layer 6, the above-mentioned resin composition, the above-mentioned insulating resin material, etc. are mentioned, for example. However, at least one of the outermost layer 7 and the intervening layer 6 is formed of the above resin composition. That is, the multicore cable 31 includes the plurality of insulated wires 5 and the plurality of covering layers stacked on the outside of the plurality of insulated wires 5, and at least any of the outermost layer 7 and the intervening layer 6 which is the inner layer. The gum is formed by the above resin composition. In addition, as for the said multi-core cable 31, it is preferable that the protective layer 4 which is an inner layer is also formed by the said resin fat composition.

<Method of manufacturing multi-core cable>
As a method of manufacturing the multicore cable 31, for example, in the covering step of the method of manufacturing the electric wire 1 of the first embodiment, the protective layer 4 is laminated on the peripheral surfaces of the plurality of insulated electric wires 5, The intermediate layer 6 is laminated on the peripheral surfaces of the plurality of insulated wires 5, the outermost layer 7 is laminated on the peripheral surface of the intermediate layer 6, and the protective layer 4 is laminated by covering the melt of the resin composition. The method of performing lamination | stacking of the intervening layer 6 and / or the outermost layer 7 by coating | cover of the melt of the said resin composition etc. is mentioned. The specific method of extrusion of the intervening layer 6 and the outermost layer 7 can be similar to the above-mentioned coating step.

<Advantage>
Since the multicore cable 31 is a thermoplastic polyurethane elastomer in which the main component of at least one of the intervening layer 6 and the outermost layer 7 is crosslinked, the multicore cable 31 is excellent in abrasion resistance and heat resistance. Further, the multicore cable 31 is preferably a thermoplastic polyurethane elastomer in which the main component of the protective layer 4 is crosslinked, and in this case, the protective layer 4 is melted by the heat at the time of the extrusion of the intervening layer 6 and the outermost layer 7 As a result, it is possible to suppress such inconveniences as the shape can not be maintained. Further, the multi-core cable 31 can be cross-linked even if the diameter is increased due to the increase in the number of cores. Furthermore, the said multicore cable 31 can improve a desired characteristic by making the formation material of the intervening layer 6 and the outermost layer 7 into an appropriate thing. Therefore, the multicore cable 31 can be suitably used, for example, in applications where high wear resistance and heat resistance are required by combining various sensor cables and the like.

Other Embodiments
It should be understood that the embodiments disclosed herein are illustrative and non-restrictive in every respect. The scope of the present invention is not limited to the configurations of the above embodiments, but is indicated by the claims, and is intended to include all modifications within the meaning and scope equivalent to the claims. Ru.

  The said electric wire may be equipped with two or more layers of an insulating layer and a protective layer, respectively. When the said electric wire is equipped with two or more layers of protective layers, two or more layers of protective layers may be laminated | stacked adjacently, and may be laminated | stacked via the other layer in between.

  The multicore cable may have two or more protective layers and two or more intervening layers. When the multicore cable includes two or more protective layers and intervening layers, the two or more protective layers and intervening layers may be laminated adjacent to each other, and may be laminated via another layer therebetween. It is also good.

  The multicore cable may include a coaxial wire or a wire in which a plurality of conductors are coated at one time. In addition, the multicore cable may include one or more units in which a plurality of insulated wires are bound. Furthermore, the multicore cable does not have an intervening layer, and includes a plurality of insulated wires, a tape such as a resin tape wound with the plurality of insulated wires, and a protective layer covering the outside of the tape. This protective layer may be formed of the above resin composition. Furthermore, the multicore cable may be provided with a collective shield layer inside the protective layer.

  The conductor can also be formed from a plurality of metal wires twisted together. In this case, a plurality of metal wires may be combined. The number of twists is generally seven or more.

  The insulated wire may have a primer layer laminated directly to the conductor. As this primer layer, those obtained by crosslinking a crosslinkable resin such as ethylene containing no metal hydroxide can be suitably used. By providing such a primer layer, it is possible to prevent the deterioration with time of the releasability of the insulating layer and the conductor, and to prevent the efficiency reduction of the wire connection work.

  The wire may further include an outer conductor inside the protective layer. This outer conductor serves as a ground or as a shield to prevent electrical interference from other circuits. Therefore, the said electric wire further provided with an outer conductor can be used as a shielded wire or a shielded cable, for example.

  Hereinafter, the electric wire and the multi-core cable according to one aspect of the present invention will be more specifically described by way of examples, but the present invention is not limited to the following production examples.

[Dry blend product No. 1 to No. Preparation of 12]
Dry blending of dry blend No. 1 was performed using a mixer with agent A containing a thermoplastic polyurethane elastomer, and agent B containing a thermoplastic polyurethane elastomer and MDI as a monomer having an isocyanate group using a mixer. 1 to No. 11 was prepared. Dry blend No. 5-No. The agent A of No. 8 further contains a flame retardant (melamine polyphosphate), and dry blend No. 8 9 to No. The agent A of 12 further contains a thermoplastic polyester elastomer. Moreover, dry blend thing No. 4, no. 8 and No. 12 did not use B agent. The compounding amount of each component was as described in Table 1. In Table 1, "TPU" indicates a thermoplastic polyurethane elastomer, and "TPEE" indicates a thermoplastic polyester elastomer.

Production Example 1
Dry blend No. A resin composition was produced by charging 1 into a melt extrusion molding machine and melt kneading in an extrusion molding machine. An insulated wire comprising a conductor and an insulating layer directly laminated to the conductor is prepared, and a melt of the resin composition is extrusion coated on the outer surface of the insulated wire at 170 ° C. or more and 200 ° C. or less to form a protective layer did. The extrusion was set such that the average outer diameter of the wire was 2.4 mm. The conductor used the soft copper wire of the round wire whose average diameter is 1 mm. The insulating layer was crosslinked polyethylene having an average thickness of 0.5 mm. The thickness of the protective layer was 0.2 mm. The insulated wire which extrusion-coated the said resin composition was left still for 1 week at room temperature, and the wire of manufacture example 1 was obtained.

[Production Example 2 to Production Example 7]
Dry blend No. Instead of 1, dry blend No. 1 is used. 2-No. 4 and No. 4 9 to No. Electric wires of Production Example 2 to Production Example 7 were obtained in the same manner as Production Example 1 except that No. 11 was used.

<Evaluation>
About the electric wire of manufacture example 1-manufacture example 7, abrasion resistance, heat resistance, and the degree of crosslinking were evaluated by the following methods. The evaluation results are shown in Table 2.

[Abrasion resistance]
The electric wire of Production Example 1 to Production Example 7 is cut into a length of 750 mm and used as a test piece, and the blade is at a speed of 50 times per minute at a length of 10 mm or more in the axial direction with respect to the coating layer of the test piece at room temperature. The number of reciprocations was measured until the conductor was touched. The load applied to the blade was 7N. The case where the number of reciprocations to contact the conductor is 200 times or more is A (pass), and the case less than 200 is B (fail).

[Heat-resistant]
The electric wire of Production Example 1 to Production Example 7 was wound around a mandrel of the same diameter six times, heated for 30 minutes in a constant temperature bath at 200 ° C., and then allowed to cool to room temperature. The case where melting or a crack was in the appearance was B (fail), and the case other than that was taken as A (pass).

[Crosslinking degree]
The wire coating (protective layer) of Production Example 1 to Production Example 7 is used as a test piece, and measurement is performed at a temperature rise rate of 5 ° C./min with a frequency of 1 Hz using a DMS (dynamic viscoelasticity) measuring device. Modulus change was investigated. The degree of crosslinking was A (good) when the storage elastic modulus at 190 ° C. was 1.0 × 10 ⁶ Pa or more and B (poor) when the storage elastic modulus was less than 1.0 × 10 ⁶ Pa.

  As shown in Table 2, the electric wires of Production Examples 1 to 3, 5 and 6 gave good results in terms of abrasion resistance, heat resistance and degree of crosslinking. On the other hand, although the electric wire of manufacture example 4 and manufacture example 7 obtained a good result about abrasion resistance, a good result was not obtained about heat resistance and a degree of crosslinking.

[Production Example 8 to Production Example 11]
Dry blend No. Instead of 1, dry blend No. 1 is used. 5-No. Electric wires of Production Examples 8 to 11 were obtained in the same manner as in Production Example 1 except that No. 8 was used.

<Evaluation>
About the electric wire of manufacture example 1 and manufacture example 8-manufacture example 11, abrasion resistance, heat resistance, a degree of crosslinking, and a flame retardance (flame-retardant effect) were evaluated. The methods of measuring the abrasion resistance, heat resistance and crosslinking degree are the same as those described above, and thus the description thereof is omitted. The flame retardancy was evaluated by the following measurement method. The evaluation results are shown in Table 3.

[Flame retardance]
In accordance with JASO-D 618, the horizontal combustion test was performed on the wires of Production Examples 1 and 8 to 11. In this horizontal combustion test, 30 seconds is defined as A (pass) when the flame of a tyryl burner is in contact for 30 seconds at an angle of 20 ° C with the lower side of the central part of the horizontally held electric wire and the flame is extinguished within 30 seconds. The case where it did not extinguish even if exceeded was considered as B (fail).

  As shown in Table 3, the electric wires of Production Example 8 to Production Example 10 obtained good results in terms of abrasion resistance, heat resistance, crosslinking degree and flame retardancy. On the other hand, in the wire of Production Example 1, good results were obtained with respect to wear resistance, heat resistance and crosslinking degree, but good results were not obtained for flame retardancy. Moreover, although the electric wire of manufacture example 11 obtained a favorable result about abrasion resistance and a flame retardance, a favorable result was not acquired about heat resistance and a crosslinking degree.

[Production Example 12 to Production Example 18]
Dry blend No. 1 to No. 4 and No. 4 9 to No. 11 was introduced into a melt extrusion molding machine, and the resin composition was manufactured by melt-kneading in an extrusion molding machine. This resin composition was extrusion molded at 170 ° C. or more and 200 ° C. or less on a strand of two insulated wires. The extrusion was performed so that the average outer diameter of the multicore cable was 4 mm. The multicore cable which extrusion-coated the said resin composition was left still for 1 week at room temperature, and the multicore cable of manufacture example 12-manufacture example 18 was obtained.

<Evaluation>
The wear resistance, heat resistance, crosslinking degree and moldability of the multi-core cables of Production Example 12 to Production Example 18 were evaluated. The methods of measuring the abrasion resistance, heat resistance and crosslinking degree are the same as those described above, and thus the description thereof is omitted. Mold processability was evaluated by the following measurement method. The evaluation results are shown in Table 4.

[Mold processability]
A mold is disposed around the multicore cable of Production Example 12 to Production Example 18, and a PBT resin composition is injection-molded, and a PBT resin layer having a length of 10 mm and an average thickness of 30 mm is adhered closely to the periphery of the multicore cable. It formed. After allowed to cool to room temperature, the mold was removed, and the portion where the PBT resin layer was laminated was cut. The cut surface is observed with an electron microscope, and when there are no air bubbles between the protective layer and the PBT resin layer as A (good), the case where air bubbles exist between the protective layer and the PBT resin layer is B (defect ).

  As shown in Table 4, the multicore cables of Production Examples 12 to 14, 16 and 17 gave good results in terms of abrasion resistance, heat resistance, crosslinking degree and moldability. On the other hand, in the multi-core cables of Production Example 15 and Production Example 18, good results were obtained for wear resistance, but good results were not obtained for heat resistance, crosslinking degree and moldability. .

[Production Example 19 to Production Example 25]
The ethylene-vinyl acetate copolymer was introduced into a melt extrusion molding machine, and extrusion molded onto a twisted strand of two insulated wires at 170 ° C. or more and 200 ° C. or less to form an intervening layer. The extrusion was set so that the average outer diameter of the intervening layer was 4 mm. Dry blend No. 1 to No. 4 and No. 4 9 to No. 11 was introduced into a melt extrusion molding machine, and the resin composition was manufactured by melt-kneading in an extrusion molding machine. The resin composition and the resin composition were extruded on the circumferential surface of the above-mentioned intervening layer at 170 ° C. or more and 200 ° C. or less. The extrusion was performed so that the average outer diameter of the multicore cable was 5 mm. The multicore cable which extrusion-coated the said resin composition was left still for 1 week at room temperature, and the multicore cable of manufacture example 19-manufacture example 25 was obtained.

<Evaluation>
The wear resistance, heat resistance and degree of crosslinking of the multi-core cables of Production Example 19 to Production Example 25 were evaluated. The methods of measuring the abrasion resistance, heat resistance and crosslinking degree are the same as those described above, and thus the description thereof is omitted. The evaluation results are shown in Table 5.

  As shown in Table 5, the multi-core cables of Production Examples 19 to 21, 23 and 24 gave good results in terms of abrasion resistance, heat resistance, crosslinking degree and moldability. On the other hand, in the multi-core cables of Production Example 22 and Production Example 25, good results were obtained for the abrasion resistance, but good results were not obtained for the heat resistance, the degree of crosslinking, and the moldability. .

  The electric wire and the multi-core cable according to one aspect of the present invention are excellent in wear resistance and heat resistance, and can be manufactured at low cost.

DESCRIPTION OF SYMBOLS 1 electric wire 2 conductor 3 insulating layer 4 protective layer 5 insulated wire 6 intervening layer 7 outermost layer 11, 21, 31 multi-core cable

Claims (10)

A wire comprising: an insulated wire; and one or more covering layers laminated on the outside of the insulated wire,
At least one of the one or more coating layers comprises a cross-linked thermoplastic polyurethane elastomer formed by a resin composition comprising a thermoplastic polyurethane elastomer and an allophanate crosslinker,
The above resin composition is
A agent containing a thermoplastic polyurethane elastomer,
A mixture of a thermoplastic polyurethane elastomer and a B agent containing a monomer having an isocyanate group as an allophanate crosslinking agent,
Content of the said B agent with respect to 100 mass parts of said A agents is 2.5 mass parts or more and 25 mass parts or less,
The electric wire whose content of the said allophanate crosslinking agent in the said resin composition is 0.4 mass part or more and 15 mass parts or less with respect to 100 mass parts of said thermoplastic polyurethane elastomers.   The electric wire according to claim 1, wherein the covering layer comprises a plurality of layers, and the outermost layer thereof comprises a crosslinked thermoplastic polyurethane elastomer formed by a resin composition containing a thermoplastic polyurethane elastomer and an allophanate crosslinking agent.   The electric wire according to claim 1 or 2, wherein a content of the monomer in the agent B is 15% by mass or more and 60% by mass or less.   The electric wire according to claim 1, 2 or 3, wherein the resin composition further contains a flame retardant.   The electric wire according to claim 4, wherein the content of the flame retardant relative to 100 parts by mass of the thermoplastic polyurethane elastomer in the resin composition is 3 parts by mass or more and 90 parts by mass or less. A multicore cable comprising: a plurality of insulated wires; and one or a plurality of covering layers laminated on the outside of the plurality of insulated wires,
At least one of the one or more coating layers comprises a cross-linked thermoplastic polyurethane elastomer formed by a resin composition comprising a thermoplastic polyurethane elastomer and an allophanate crosslinker,
The above resin composition is
A agent containing a thermoplastic polyurethane elastomer,
A mixture of a thermoplastic polyurethane elastomer and a B agent containing a monomer having an isocyanate group as an allophanate crosslinking agent,
Content of the said B agent with respect to 100 mass parts of said A agents is 2.5 mass parts or more and 25 mass parts or less,
The multicore cable whose content of the said allophanate crosslinking agent in the said resin composition is 0.4 mass part or more and 15 mass parts or less with respect to 100 mass parts of said thermoplastic polyurethane elastomers.   The multi-core cable according to claim 6, wherein the covering layer comprises a plurality of layers, and the outermost layer thereof comprises a crosslinked thermoplastic polyurethane elastomer formed by a resin composition containing a thermoplastic polyurethane elastomer and an allophanate crosslinking agent. .   8. The crosslinked thermoplastic polyurethane elastomer according to claim 6, wherein the coating layer is composed of a plurality of layers, and the inner layer thereof is formed of a thermoplastic polyurethane elastomer and a resin composition containing an allophanate crosslinking agent. Multicore cable. What is claimed is: 1. A method of manufacturing a wire comprising: an insulated wire; and one or more covering layers laminated on the outside of the insulated wire,
Melting a resin composition comprising a thermoplastic polyurethane elastomer and an allophanate crosslinker;
Coating the molten material on the outside of the insulated wire.
The above resin composition is
A agent containing a thermoplastic polyurethane elastomer,
A mixture of a thermoplastic polyurethane elastomer and a B agent containing a monomer having an isocyanate group as an allophanate crosslinking agent,
Content of the said B agent with respect to 100 mass parts of said A agents is 2.5 mass parts or more and 25 mass parts or less,
The manufacturing method of the electric wire whose content of the said allophanate crosslinking agent in the said resin composition is 0.4 mass part or more and 15 mass parts or less with respect to 100 mass parts of said thermoplastic polyurethane elastomers. A method of manufacturing a multi-core cable comprising: a plurality of insulated wires; and one or a plurality of covering layers laminated on the outside of the plurality of insulated wires,
Melting a resin composition comprising a thermoplastic polyurethane elastomer and an allophanate crosslinker;
Coating the melt on the outside of the plurality of insulated wires;
The above resin composition is
A agent containing a thermoplastic polyurethane elastomer,
A mixture of a thermoplastic polyurethane elastomer and a B agent containing a monomer having an isocyanate group as an allophanate crosslinking agent,
Content of the said B agent with respect to 100 mass parts of said A agents is 2.5 mass parts or more and 25 mass parts or less,
The manufacturing method of the multicore cable whose content of the said allophanate crosslinking agent in the said resin composition is 0.4 mass part or more and 15 mass parts or less with respect to 100 mass parts of said thermoplastic polyurethane elastomers.

Images