JP2013129759A - Crosslinked resin composition, and electric wire and cable using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To achieve crosslinking at room temperature under normal pressure, while providing glycol resistance.SOLUTION: Thermoplastic polyurethane and thermoplastic polyamide or thermoplastic polyamide elastomer are mixed in a ratio of 90:10-50:50 in terms of weight ratio. A monomer of 1-20 pts.wt. having a plurality of isocyanate groups in the molecule is contained in 100 pts.wt. of this mixed resin.

Description

  The present invention relates to a crosslinked resin composition containing a mixed resin of thermoplastic polyurethane and thermoplastic polyamide or thermoplastic polyamide elastomer, and an electric wire and a cable using the same.

  Thermoplastic polyurethane has excellent wear resistance, mechanical properties (tensile strength, elongation at break), flexibility, chemical resistance, and general oil resistance against gasoline and kerosene, so it is used in a wide range of product fields. Yes. It is also widely used in the field of electric wires and cables, and is used in a wide range of applications regardless of the presence or absence of flame retardancy. In addition to flexibility and mechanical properties, a method for obtaining heat resistance by applying a crosslinking treatment to thermoplastic polyurethane by electron beam irradiation is known for product fields that require heat resistance. (For example, see Patent Documents 1 to 3).

JP 7-238220 A JP 2007-95439 A International Publication No. 2005/013291 Pamphlet

  However, in this method, it is necessary to separately provide a crosslinking step by electron beam irradiation after resin molding. For example, in the field of multilayer coated cables, it may be necessary to go through several crosslinking steps, so the number of steps increases accordingly. Manufacturing costs will increase. For this reason, a crosslinked resin composition capable of achieving crosslinking under normal temperature and normal pressure is desired.

  On the other hand, although thermoplastic polyurethane is excellent in general oil resistance against gasoline, kerosene, etc., it is insufficient in resistance to oil such as glycol and glycol ether, and swells and changes in dimensions and physical properties. There was a drawback. Specifically, the oil such as glycol and glycol ether is, for example, paint, photographic copying liquid, hydraulic oil, brake liquid, antifreeze liquid, electrolytic solution, and the like. For this reason, products such as tubes, hoses, films, sheets, rollers, containers, bags, packings, tapes, belts, etc., or cables, electric wires, cords, optical fibers, optical cords, in the environment where oil such as glycol or glycol ether is used It was difficult to apply to a coating such as a coating filter.

  Accordingly, an object of the present invention is to provide a crosslinked resin composition having flexibility, capable of achieving crosslinking under normal temperature and normal pressure, and excellent resistance to oils such as glycol and glycol ether (hereinafter referred to as glycol resistance). It is to provide an object, an electric wire using the object, and a cable. Another object of the present invention is to provide a crosslinked resin composition having mechanical properties and flame retardancy in addition to the above properties, and an electric wire and a cable using the same.

According to one aspect of the present invention, thermoplastic polyurethane and thermoplastic polyamide or thermoplastic polyamide elastomer are mixed in a weight ratio of 90:10 to 50:50, and the mixed resin mixture There is provided a crosslinked resin composition containing 1 to 20 parts by weight of a monomer having a plurality of isocyanate groups in the molecule with respect to 100 parts by weight.
Preferably, 30 to 200 parts by weight of a flame retardant is contained. Preferably, the flame retardant is melamine cyanurate.

  Moreover, according to the other aspect of this invention, in the electric wire which has a coating layer on the outer side of a conductor, the electric wire whose main component of the said coating layer is the crosslinked resin composition mentioned above is provided.

  According to another aspect of the present invention, there is provided a cable having a sheath on the outside of an insulated wire whose conductor is covered with an insulator, the main component of the sheath being the above-described crosslinked resin composition. .

  According to the present invention, it is possible to obtain a crosslinked resin composition having flexibility and glycol resistance and capable of crosslinking even at ordinary temperature and pressure, and an electric wire and a cable using the same.

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

Embodiments of the present invention will be described below with reference to embodiments.
[First Embodiment]
(Crosslinked resin composition)
In the first embodiment of the present invention, the weight ratio of thermoplastic polyurethane (hereinafter referred to as TPU) and thermoplastic polyamide (hereinafter referred to as PA) or thermoplastic polyamide elastomer (hereinafter referred to as PA elastomer) is TPU: PA or PA elastomer is a mixed resin of 90:10 to 50:50, and consists of a crosslinked resin composition containing 1 to 20 parts by weight of a monomer having a plurality of isocyanate groups in the molecule with respect to 100 parts by weight of the mixed resin.

  If the TPU ratio (TPU / 100) is higher than the upper limit specified value (90/100), sufficient glycol resistance cannot be obtained. If the TPU ratio is lower than the lower limit specified value (50/100), it is possible. Insufficient flexibility. Therefore, by setting the TPU ratio within the above range, sufficient flexibility and glycol resistance can be provided.

  Further, if the amount of monomer having an isocyanate group blended in a mixed resin of TPU and PA or PA elastomer is less than 1 part by weight, a sufficient degree of crosslinking cannot be obtained, and if it exceeds 20 parts by weight, scorch is generated. Therefore, by setting the amount of the monomer having an isocyanate group within the above range, the generation of scorch can be eliminated and the crosslinking can be sufficiently performed at normal temperature and pressure.

  Therefore, according to the above-mentioned crosslinked resin composition, it has excellent heat resistance, scorch, flexibility, elongation at break, and glycol resistance regardless of the presence or absence of flame retardancy, and can be crosslinked even at normal temperature and pressure. .

Examples of the TPU used in the first embodiment of the present invention include polyester urethane (adipate, caprolactone, polycarbonate) and polyether urethane, and polyether urethane is preferred from the viewpoint of heat and humidity resistance. Examples of PA include ring-opening polycondensates of ε-caprolactam, ring-opening polycondensates of undecane lactam, ring-opening polycondensates of lauryl lactam, and alternating copolymers composed of diamine and dicarboxylic acid. Examples of the diamine include hexamethylenediamine, heptamethylenediamine, p-diaminomethylcyclohexane, bis (p-aminocyclohexyl) methane, m-xylenediamine, piperazine, and isophoronediamine. Examples of the dicarboxylic acid include adipic acid, sebacic acid, azelanic acid, undecanoic acid, dodecanoic acid, isophthalic acid, terephthalic acid, acyclic dimer acid, and monocyclic dimer acid.

  When oil resistance is important, PA is sufficient, but PA elastomer is effective for applications that require high flexibility. PA elastomer is a multi-block copolymer using PA as a hard segment and polyether, polyester or polyether ester as a soft segment. Examples of the soft segment include polyether diol or polyester diol, and polyether ester diol long-chain polyol. Examples of the polyether diol include diol poly (oxytetramethylene) glycol and poly (oxypropylene) glycol. Polyester diols include poly (ethylene adipate) glycol and poly (butylene-1,4 adipate) glycol. Examples of the polyether ester include a copolymer of the above polyether and polyester.

  Examples of the monomer having an isocyanate group include methane diphenyl diisocyanate (MDI), isophorone diisocyanate (IPDI), triresin diisocyanate (TDI), hexamethylene diisocyanate (HDI), phenylene diisocyanate (PPDI), naphthalene diisocyanate (NDI), and the like. It is done. The isocyanate group is a highly reactive functional group and reacts with a urethane bond of TPU to form a three-dimensional structure by an allophanate bond. The isocyanate group reacts with the amide group of PA to react with a urea bond and further with a carboxylic acid of a thermoplastic polyamide to develop an amide bond, and the crosslinking reaction proceeds at normal temperature and pressure. A sufficient degree of crosslinking can be obtained in 4 to 7 days.

  Moreover, in the case of a use which needs a flame retardance, a flame retardant can be added to the said crosslinked resin composition. In this case, it is preferable to contain 30 to 200 parts by weight of the flame retardant with respect to 100 parts by weight of the mixed resin. If the flame retardant is less than 30 weights, sufficient flame retardancy cannot be imparted, and if it exceeds 200 parts by weight, mechanical properties, particularly tensile strength, are lowered. Therefore, by adding a flame retardant within the above range defined in the crosslinked resin composition, heat resistance, scorch, flexibility, mechanical properties (tensile strength, elongation at break), flame resistance, glycol resistance And can be sufficiently crosslinked even at normal temperature and pressure.

  The type of flame retardant is not particularly limited as long as the effects of the present invention are exhibited. However, some flame retardants include halogen-based flame retardants containing chlorine and bromine, and generate harmful gases during combustion. Non-halogen flame retardants are more preferable. The flame retardant that can be applied is not particularly limited, and examples thereof include metal hydrates, phosphorus compounds, and triazine compounds. Examples of the phosphorus compound include red phosphorus, phosphate ester, aromatic condensed phosphate ester, phosphazene compound, and ammonium polyphosphate. Examples of metal hydrates include magnesium hydroxide, aluminum hydroxide, calcium hydroxide, and hydrotalcite. Examples of the triazine flame retardant include melamine, melamine cyanurate, melamine phosphate, melamine sulfate, and melem. Among these, melamine cyanurate is preferable because it has a decomposition temperature of 300 to 400 ° C. and a high initial extinguishing effect of polymer combustion.

  As described above, in the first embodiment of the present invention, the monomer having an isocyanate group is 1 with respect to 100 parts by weight of the mixed resin having a weight ratio of TPU and PA or PA elastomer of 90:10 to 50:50. ~ 20 parts by weight are required. Moreover, in the case of a use which requires a flame retardance, it is preferable to add 30-200 weight part of flame retardants, such as a melamine cyanurate.

  In addition to the flame retardant, the crosslinked resin composition, if necessary, a flame retardant aid, an antioxidant, an ultraviolet absorber, a light stabilizer, a softener, a lubricant, a colorant, a reinforcing agent, and a surfactant. Inorganic fillers, coupling agents, plasticizers, metal chelating agents, foaming agents, compatibilizers, processing aids, stabilizers, and the like can be added.

[Second Embodiment]
(Electric wire, cable)
Next, a second embodiment in which the above-described crosslinked resin composition of the first embodiment is applied to the outermost layer of the electric wires and cables will be described.

  1 and 2 show an insulated wire, and FIGS. 3 and 4 show schematic sectional views of the cable, respectively. FIG. 1 shows an insulated wire 11 composed of a conductor 11a and a single-layer coating layer (insulator) 11b that is coated on the outer periphery of the conductor 11a and mainly contains the crosslinked resin composition of the present embodiment. FIG. 2 also shows the insulated wire 11, but the insulator has a multi-layer structure composed of an inner layer insulator 11b 'and an outer layer insulator 11c. FIG. 3 shows an insulated wire 11 in which a conductor 11a is covered with an insulator 11b, a multi-core stranded wire 13 formed by twisting a plurality of insulated wires 11, and an outer periphery of the insulated wire 11 covered with this embodiment. The cable 10 comprised from the single layer sheath 12 which has the crosslinked resin composition of a form as a main component is shown. FIG. 4 also shows the cable 10, but the sheath 12 has a multilayer structure composed of an outer layer sheath 12 a and an inner layer sheath 12 b. Thus, the insulating layer and sheath of the electric wire and cable may be a single layer or a multilayer structure. In the case of a multilayer structure, all the layers can be composed of the crosslinked resin product, but the outermost insulating layer or sheath may be composed of the crosslinked resin composition.

  Furthermore, a separator, a braid, etc. may be given to the insulating layer and the sheath of the electric wire and cable as necessary. It is also possible to make the insulating layer or the sheath into a multi-layer structure, and to extrusion coat the polyolefin resin on the outermost layer and the crosslinked resin composition on the outermost layer. Polyolefin resins include low density polyethylene, ethylene vinyl acetate copolymer (EVA), ethylene-ethyl acrylate copolymer, ethylene-methyl acrylate copolymer, ethylene-glycidyl methacrylate copolymer, maleic anhydride polyolefin, ethylene-based α -An olefin copolymer etc. are mentioned, These may be used independently and may mix and use 2 or more types. Flame retardants, flame retardant aids, crosslinking agents, crosslinking aids, UV absorbers, light stabilizers, softeners, lubricants, colorants, reinforcing agents, surfactants, antioxidants, inorganic fillers as necessary Coupling agents, plasticizers, metal chelating agents, foaming agents, compatibilizers, processing aids, stabilizers, and the like can be added. The cross-linking treatment includes chemical cross-linking with an organic peroxide or a sulfur compound, irradiation cross-linking with an electron beam or radiation, and cross-linking using other chemical reaction, and any cross-linking method can be applied.

  Thus, if the crosslinked resin composition of the first embodiment is applied to an electric wire or cable, heat resistance, scorch, flexibility, elongation at break, glycol, glycol ether, etc. Electric wires and cables with excellent resistance to oil (hereinafter referred to as glycol resistance) can be obtained. Moreover, since it can fully be bridge | crosslinked also under normal temperature normal pressure, an electric wire shape and a cable shape can be hold | maintained at high temperature. In particular, when applied to a heat-resistant cable for automobiles, its performance can be improved. Further, since irradiation crosslinking is not required and crosslinking can be performed even at room temperature and normal pressure, it can be applied to, for example, a urethane sheath crosslinking method for an automobile ABS sensor cable. Moreover, it is not necessary to separately provide a cross-linking step by electron beam irradiation after the mixed resin is formed, and the number of steps can be reduced and the manufacturing cost of electric wires and cables can be reduced.

  For applications that require flame retardancy, sufficient flame retardancy can be obtained by adding a specified amount of a flame retardant, such as melamine cyanurate, that fills the outer layer material. Electric wires and cables that can be secured are obtained.

[Modification]
In addition, in 2nd Embodiment, although the case where the crosslinked resin composition of this invention was applied to an electric wire and a cable was demonstrated, this invention is not limited to this, For example, a tube, a hose, a film, It can be applied to sheets, rollers, containers, bags, packings, cords, optical fibers, optical cords, coatings, filters, tapes, belts, and the like.

The present invention was applied to a sheath or outer sheath of a cable. As a single-layer sheath cable configuration, a conductor of 48 copper wires / 0.08 mm and low density polyethylene (density d: 920 kg / m ³ ) Mirason 3530 (made by Prime Polymer) as an insulator so that the outer diameter is 1.4 mm. And extrusion coating using a 40 mm screw extruder (L / D = 24). The obtained insulated wire was irradiated with an electron beam at an irradiation amount of 100 kGy, and a multi-core stranded wire was prepared by twisting two insulated wires. The outer layer sheath shown in Table 1 as a sheath was extrusion-coated on the multi-core stranded wire so as to have an outer diameter of 4.0 mm. The obtained cable was allowed to stand at room temperature and normal pressure for 7 days to crosslink the sheath, and a cable 10 having a sheath 12 as a single layer as shown in FIG. 3 was produced.

  Further, as the cable configuration of the two-layer sheath, the inner layer sheath shown in Table 1 is coated on the above multi-core stranded wire so that the outer diameter is 3.4 mm, and the composition shown in Table 1 is used as the outer layer sheath. Extrusion coating was performed so that the diameter was 4.0 mm. The obtained cable was allowed to stand at normal temperature and pressure for 7 days to crosslink the sheath, and a cable 10 having two layers of sheath 12 as shown in FIG. 4 was produced.

  The evaluation of the degree of cross-linking was based on JASO D 608-92 AVX (A: low-voltage electric wire for automobiles, V: vinyl, X: cross-linking), and tetrahydrofuran was used as the extract, and the gel fraction was evaluated. This gel fraction is reflected in the heat resistance described later.

<< Test (I) group >>
(1) The heat resistance evaluation is based on JASO D 608 as a heat resistance test, wound six times around a mandrel with the same cable diameter (4 mmφ), heated in a thermostatic bath at 200 ° C. for 30 minutes, and then released to room temperature. When the cable was cooled, the cable had no melting or cracking as a pass.
(2) As scorch evaluation, what did not generate | occur | produce a burn at the time of cable extrusion was set as the pass. (3) Glycol resistance is evaluated by taking a cable with a length of about 600 mm and immersing it in glycol ether oil (brake oil) stipulated in JIS 2233 at 100 ° C. for 20 hours leaving 40 mm at both ends. Was passed.
(4) For flexibility evaluation, one end of the cable was fixed to the pedestal, the other end protruded into the space from the pedestal by 200 mm, a 10 g weight was suspended from the other end, and the amount of cable deflection was measured. When the amount of deflection was less than 50 mm, x was rejected, and when 50 mm or more and less than 100 mm, ○, 100 mm or more was rated ◎, and ◎ and ○ were accepted.

<< Test (II) group >>
(5) Evaluation of tensile strength was based on AVX of JASO D 608-92 as a tensile test, and the tensile strength passed 15 MPa or more.
(6) The elongation at break was evaluated in accordance with the AVX of JASO D 608-92, and the elongation at break was determined to be 200% or more.
(7) For the flame retardancy evaluation, the cable was kept horizontal and applied with a flame for 10 seconds, and digested within 30 seconds after removing the flame was regarded as acceptable.

[Example 1]
In Example 1, in the sheath, 90 parts by weight of ET890 (made by BASF Japan) as TPU, 10 parts by weight of SP-500 (made by Toray) as PA, and 1 part by weight of MDI (made by Mitsubishi Chemical Fine) as a monomer having an isocyanate group A compound (mixed resin) was produced by kneading using a twin screw extruder (Laboplast Mill, Toyo Seiki, L / D = 30) at a die temperature of 200 ° C., a screw rotation speed of 150 rpm, and a discharge rate of 3 kg / h. Extrusion coating was performed with an extruder (L / D = 24) having a screw diameter of 40 mm so that the outer diameter of the sheath was 4.0 mm, and a cable as shown in FIG. 3 was produced. The obtained cable was allowed to stand at normal temperature and pressure for 7 days for crosslinking treatment.

[Example 2]
In Example 2, 20 parts by weight of MDI was kneaded as a monomer having an isocyanate group. Other components and production methods are the same as those in Example 1.

[Example 3]
In Example 3, in the sheath, 90 parts by weight of ET890 (manufactured by BASF Japan) as TPU, 10 parts by weight of UBESTEXPA (manufactured by Ube Industries) as PA elastomer, and 1 part by weight of MDI (manufactured by Mitsubishi Chemical Fine) as a monomer having an isocyanate group A compound was prepared by kneading using a twin screw extruder (Laboplast Mill, Toyo Seiki, L / D = 30) at a die temperature of 200 ° C., a screw rotation speed of 150 rpm, and a discharge rate of 3 kg / h. Extrusion coating was performed with an extruder (L / D = 24) having a screw diameter of 40 mm so that the outer diameter of the sheath was 4.0 mm, and a cable as shown in FIG. 3 was produced. The obtained cable was allowed to stand at normal temperature and pressure for 7 days for crosslinking treatment.

[Example 4]
In Example 4, 20 parts by weight of MDI was kneaded as a monomer having an isocyanate group. Other components and production methods are the same as in Example 3.

[Example 5]
In Example 5, in the sheath, 50 parts by weight of ET890 (manufactured by BASF Japan) as TPU, 50 parts by weight of SP-500 (manufactured by Toray) as PA, and 1 part by weight of MDI (manufactured by Mitsubishi Chemical Fine) as a monomer having an isocyanate group A compound was prepared by kneading using a twin screw extruder (Laboplast Mill, Toyo Seiki, L / D = 30) at a die temperature of 200 ° C., a screw rotation speed of 150 rpm, and a discharge rate of 3 kg / h. Extrusion coating was performed with an extruder (L / D = 24) having a screw diameter of 40 mm so that the outer diameter of the sheath was 4.0 mm, and a cable as shown in FIG. 3 was produced. The obtained cable was allowed to stand at normal temperature and pressure for 7 days for crosslinking treatment.

[Example 6]
In Example 6, 20 parts by weight of MDI was kneaded as a monomer having an isocyanate group. Other components and production methods are the same as in Example 5.

[Example 7]
In the sheath, 70 parts by weight of ET890 (BASF Japan) as TPU, 30 parts by weight of UBESTEXPA (manufactured by Ube Industries) as PA elastomer, and 1 part by weight of MDI (manufactured by Mitsubishi Chemical Fine) as a monomer having an isocyanate group are twin screw extruders (Toyo Seiki Laboplast Mill, L / D = 30) kneaded to prepare a compound at a die temperature of 200 ° C., a screw rotation speed of 150 rpm, and a discharge rate of 3 kg / h. Extrusion coating was performed with an extruder (L / D = 24) having a screw diameter of 40 mm so that the outer diameter of the sheath was 4.0 mm, and a cable as shown in FIG. 3 was produced. The obtained cable was allowed to stand at normal temperature and pressure for 7 days for crosslinking treatment.

[Example 8]
In Example 8, 5 parts by weight of MDI was kneaded as a monomer having an isocyanate group. Other components and production methods are the same as in Example 7.

[Example 9]
In Example 9, in the sheath, 70 parts by weight of ET890 (manufactured by BASF Japan) as TPU, 30 parts by weight of SP-500 (manufactured by Toray) as PA, 1 part by weight of MDI (manufactured by Mitsubishi Chemical Fine) as a monomer having an isocyanate group, 30 parts by weight of melamine cyanurate MC-2010N (manufactured by Sakai Chemical Industry Co., Ltd.) as a flame retardant is kneaded using a twin screw extruder (Laboplast Mill, L / D = 30 manufactured by Toyo Seiki Co., Ltd.), die temperature 200 ° C., screw A compound was produced at a rotational speed of 150 rpm and a discharge rate of 3 kg / h. Extrusion coating was performed with an extruder (L / D = 24) having a screw diameter of 40 mm so that the outer diameter of the sheath was 4.0 mm, and a cable as shown in FIG. 3 was produced. The obtained cable was allowed to stand at normal temperature and pressure for 7 days for crosslinking treatment.

[Example 10]
In Example 10, 200 parts by weight of melamine cyanurate MC-2010N (manufactured by Sakai Chemical Industry Co., Ltd.) as a flame retardant was used, and other components and production methods are the same as in Example 9.

[Example 11]
In Example 11, in the sheath, 70 parts by weight of ET890 (manufactured by BASF Japan) as TPU, 30 parts by weight of SP-500 (manufactured by Toray) as PA, 1 part by weight of MDI (manufactured by Mitsubishi Chemical Fine) as a monomer having an isocyanate group, 20 parts by weight of MC-2010N (manufactured by Sakai Chemical Industry Co., Ltd.) as a flame retardant is kneaded using a twin-screw extruder (Toyo Seiki Laboplast Mill, L / D = 30), a die temperature of 200 ° C., and a screw speed of 150 rpm. A compound was produced at a discharge rate of 3 kg / h. Extrusion coating was performed with an extruder (L / D = 24) having a screw diameter of 40 mm so that the outer diameter of the sheath was 4.0 mm, and a cable as shown in FIG. 3 was produced. The obtained cable was allowed to stand at normal temperature and pressure for 7 days for crosslinking treatment.

[Example 12]
In Example 12, in the sheath, 70 parts by weight of ET890 (manufactured by BASF Japan) as TPU, 30 parts by weight of SP-500 (manufactured by Toray) as PA, 1 part by weight of MDI (manufactured by Mitsubishi Chemical Fine) as a monomer having an isocyanate group, As a flame retardant, 210 parts by weight of MC-2010N (manufactured by Sakai Chemical Industry Co., Ltd.) is kneaded using a twin screw extruder (Toyo Seiki Laboplast Mill, L / D = 30), a die temperature of 200 ° C., and a screw rotation speed of 150 rpm. A compound was produced at a discharge rate of 3 kg / h. Extrusion coating was performed with an extruder (L / D = 24) having a screw diameter of 40 mm so that the outer diameter of the sheath was 4.0 mm, and a cable as shown in FIG. 3 was produced. The obtained cable was allowed to stand at normal temperature and pressure for 7 days for crosslinking treatment.

[Example 13]
In Example 13, in the sheath, 70 parts by weight of ET890 (manufactured by BASF Japan) as TPU, 30 parts by weight of UBESTEXPA (manufactured by Ube Industries) as a PA elastomer, 5 parts by weight of MDI (manufactured by Mitsubishi Chemical Fine) as a monomer having an isocyanate group, As a flame retardant, 60 parts by weight of MC-2010N (manufactured by Sakai Chemical Industry Co., Ltd.) is kneaded using a twin screw extruder (Toyo Seiki Laboplast Mill, L / D = 30), a die temperature of 200 ° C., and a screw rotation speed of 150 rpm. A compound was produced at a discharge rate of 3 kg / h. Extrusion coating was performed with an extruder (L / D = 24) having a screw diameter of 40 mm so that the outer diameter of the sheath was 4.0 mm, and a cable as shown in FIG. 3 was produced. The obtained cable was allowed to stand at normal temperature and pressure for 7 days for crosslinking treatment.

[Example 14]
In Example 14, 100 parts by weight of melamine cyanurate MC-2010N (manufactured by Sakai Chemical Industry Co., Ltd.) as a flame retardant was used, and other components and production methods are the same as in Example 13.

[Example 15]
In Example 15, EVA EV170 (manufactured by Mitsui DuPont Chemical) was used as the inner layer sheath. In the outer sheath, 70 parts by weight of ET890 (BASF Japan) as TPU, 30 parts by weight of UBESTEXPA (manufactured by Ube Industries) as PA elastomer, 5 parts by weight of MDI (manufactured by Mitsubishi Chemical Fine) as a monomer having an isocyanate group, MC as a flame retardant -60 parts by weight of 2010N (manufactured by Sakai Chemical Industry Co., Ltd.) was kneaded using a twin screw extruder (Toyo Seiki Laboplast Mill, L / D = 30), die temperature 200 ° C., screw rotation speed 150 rpm, discharge rate 3 kg A compound was prepared at / h. Extrusion coating was performed with a 40 mm extruder (L / D = 24) so that the outer diameter of the sheath was 4.0 mm, and a cable as shown in FIG. 4 was produced. The obtained cable was allowed to stand at normal temperature and pressure for 7 days for crosslinking treatment.

[Example 16]
In Example 16, an ethylene-based α-olefin copolymer TAFMER DF605 (manufactured by Mitsui Chemicals) was used as an inner layer sheath. In the outer sheath, 70 parts by weight of ET890 (BASF Japan) as TPU, 30 parts by weight of UBESTEXPA (manufactured by Ube Industries) as PA elastomer, 5 parts by weight of MDI (manufactured by Mitsubishi Chemical Fine) as a monomer having an isocyanate group, MC as a flame retardant -60 parts by weight of 2010N (manufactured by Sakai Chemical Industry Co., Ltd.) was kneaded using a twin screw extruder (Toyo Seiki Laboplast Mill, L / D = 30), die temperature 200 ° C., screw rotation speed 150 rpm, discharge rate 3 kg A compound was prepared at / h. A cable as shown in FIG. 4 was produced by extrusion coating with an extruder (L / D = 24) having a screw diameter of 40 mm so that the sheath outer diameter was 4.0 mm. The obtained cable was allowed to stand at normal temperature and pressure for 7 days for crosslinking treatment.

[Results of Examples]
As is apparent from Table 1 showing the results of Examples 1 to 16, Examples 1 to 16 were made of thermoplastic polyurethane (TPU) and thermoplastic polyamide (PA) or thermoplastic polyamide elastomer (PA elastomer). The range specified by the present invention (TPU: PA or PA elastomer = 90: 10-50: 50), and the range specified by the present invention is a monomer having a plurality of isocyanate groups in the molecule (1-20 parts by weight) It is contained. Therefore, regardless of the presence or absence of flame retardancy, the outer layer sheaths of Examples 1 to 16 showed good results in all the characteristics of heat resistance, presence or absence of scorch, glycol resistance, and flexibility.

  Among Examples 9 to 16 in which a flame retardant was added assuming an application requiring further flame retardancy among Examples 1 to 16, Examples 9, 10, and 13 to 16 had all the characteristics described above. In addition, good results are also shown in flame retardancy and tensile strength. Compared with Example 11 having a problem with flame retardancy and Example 12 having a problem with tensile strength, the amount of flame retardant added It was found that 30 to 200 parts by weight is preferable.

[Comparative Example 1]
Comparative Example 1 is a single-layer sheathed cable to which no flame retardant is added, as in Examples 1 to 8, but is different in that it does not contain PA and PA elastomer. That is, in Comparative Example 1, a cable as shown in FIG. 3 was prepared using a compound in which 100 parts by weight of TPU and 1 part by weight of MDI were kneaded using a twin screw extruder as the sheath. This was allowed to stand for 7 days at room temperature and normal pressure, as in the examples, and subjected to crosslinking treatment. It differs from the conditions defined in this example in that it does not contain thermoplastic polyamide.

[Comparative Example 2]
Comparative Example 2 is a single-layer sheathed cable to which no flame retardant is added, as in Examples 1 to 8, but the TPU ratio (TPU / 100) is higher than the specified values of Examples 1 to 8. Is different. That is, in Comparative Example 2, a cable in which 95 parts by weight of TPU, 5 parts by weight of PA, and 1 part by weight of MDI were kneaded using a twin-screw extruder was used as a sheath to produce a cable as shown in FIG. This was allowed to stand for 7 days at room temperature and normal pressure, as in the examples, and subjected to crosslinking treatment. The conditions defined in this example differ from the conditions in which the ratio of the thermoplastic polyurethane is higher than the specified value.

[Comparative Example 3]
Comparative Example 3 is a single-layer sheathed cable to which no flame retardant is added, as in Examples 1-8, but the TPU ratio (TPU / 100) is lower than the specified values of Examples 1-8. Is different. That is, in Comparative Example 3, a cable as shown in FIG. 3 was prepared using a compound in which 45 parts by weight of TPU, 55 parts by weight of PA, and 1 part by weight of MDI were kneaded using a twin screw extruder as the sheath. This was allowed to stand for 7 days at room temperature and normal pressure, as in the examples, and subjected to crosslinking treatment. The conditions defined in this example differ from the conditions in which the ratio of the thermoplastic polyurethane is lower than the specified value.

[Comparative Example 4]
Comparative Example 4 is a single-layer sheathed cable to which no flame retardant is added, as in Examples 1 to 8, but differs in that it does not contain a monomer having an isocyanate group. That is, in Comparative Example 4, a cable as shown in FIG. 3 was prepared using a compound in which 90 parts by weight of TPU and 10 parts by weight of PA were kneaded using a twin screw extruder as the sheath. This was allowed to stand for 7 days at room temperature and normal pressure, as in the examples, and subjected to crosslinking treatment. This is different from the conditions defined in this example in that no monomer having an isocyanate group is contained.

[Comparative Example 5]
Comparative Example 5 is a single-layer sheathed cable to which no flame retardant is added, as in Examples 1 to 8, but the content of the monomer having an isocyanate group is less than those of Examples 1 to 8. It is different in point. That is, in Comparative Example 5, a cable as shown in FIG. 3 was prepared using a compound in which 90 parts by weight of TPU, 10 parts by weight of PA, and 0.5 parts by weight of MDI were kneaded using a twin screw extruder. This was allowed to stand for 7 days at room temperature and normal pressure, as in the examples, and subjected to crosslinking treatment. This is different from the conditions defined in this example in that the content of the monomer having an isocyanate group is reduced.

[Comparative Example 6]
Comparative Example 6 is a single-layer sheathed cable to which no flame retardant is added, as in Examples 1 to 8, but the content of the monomer having an isocyanate group is higher than those of Examples 1 to 8. It is different in point. That is, in Comparative Example 6, a cable as shown in FIG. 3 was prepared using a compound in which 90 parts by weight of TPU, 10 parts by weight of PA, and 21 parts by weight of MDI were kneaded using a twin screw extruder as the sheath. This was allowed to stand for 7 days at room temperature and normal pressure, as in the examples, and subjected to crosslinking treatment. This is different from the conditions defined in this example in that the content of the monomer having an isocyanate group is increased.

[Results of comparative example]
As shown in Table 2, in Comparative Example 1, the change in the cable outer diameter was 16.4%, and there was a problem in glycol resistance. In Comparative Example 2, although the glycol resistance was improved as compared with Comparative Example 1, the change in the cable outer diameter was 15.9%, which was still unacceptable. In Comparative Example 3, the amount of deflection was 45 mm, and there was a problem in flexibility. In Comparative Example 4, the gel fraction was 0%, and in the heat resistance test, there was melting and it was rejected. In Comparative Example 5, the gel fraction was 40%, and there was melting in the heat resistance test, which was unacceptable. In Comparative Example 6, burns occurred during cable extrusion, and there was a scorch, which was unacceptable.

10 Cable 11 Insulated wire 11a Conductor 11b Insulator (covering layer)
11b 'inner layer insulator 11c outer layer insulator (coating layer)
12 sheath 12a outer sheath 12b inner sheath 13 multi-core stranded wire

Claims (4)

Thermoplastic polyurethane and thermoplastic polyamide or thermoplastic polyamide elastomer in weight ratio,
Mixed in a ratio of 90:10 to 50:50,
A crosslinked resin composition comprising 1 to 20 parts by weight of a monomer having a plurality of isocyanate groups in a molecule with respect to 100 parts by weight of the mixed resin.   The cross-linked resin composition according to claim 1, wherein the flame retardant is contained in an amount of 30 to 200 parts by weight.   The electric wire which has a coating layer on the outer side of a conductor, The electric wire characterized by the main component of the said coating layer being the crosslinked resin composition of Claim 1 or 2.   A cable having a sheath on the outside of an insulated wire in which a conductor is covered with an insulator, wherein the main component of the sheath is the crosslinked resin composition according to claim 1 or 2.

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