JPH10312713A - Electric wire/cable - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reuse coating materials of a wire and a cable for an insulator and a sheath of an electric wire or cable without classifying them by each layer. SOLUTION: An insulator, a sheath, stuffing and a covering pressure tape are constituted of the same kind of resin. For the insulator and the sheath, a copolymer satisfying the following requirement (A) is used as their base; for the covering pressure tape, a tape containing a copolymer as its base satisfying the following requirement (B) or (C) is used; the stuffing is formed by drawing this tape uniaxially. (A) A copolymer that is formed by copolymerizing ethylene and α-olefin having a carbon number of 2 to 10 using a single site catalyst under the following conditions; (1) Mw/Mn <=2 (2) a concentration of 0.91 g/cm<3> or less (3) MI<=3 g/10 min (B) The same copolymer as (A) excluding the following conditions: (1) a concentration of 0.93 to 0.94 g/cm<3> (2) MI<=10 g/10 min (C) A copolymer that is formed by copolymerizing ethylene and α-olefin having a carbon number of 2 to 10 under the following conditions: (1) 2 <=Mw/Mn <=10 (2) a concentration of 0.93 to 0.94 g/cm<3> (3) MI<=10 g/10 min.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric wire or cable, and more particularly to an electric wire or cable which can be integrally reused as an electric wire covering member without separating all coating materials other than conductors when disassembling and reusing. It is about cables.

[0002]

2. Description of the Related Art As for the reuse of electric wires and cables, the reuse of conductors is first mentioned. The reuse of conductors such as copper and aluminum has been done since the birth of the electric wire business, and the remaining conductors were reused by incinerating the wires and cables, or the wires were crushed and separated from the covering material by methods such as specific gravity selection. The conductor has been reused, and the cladding has been disposed of in landfills or incinerated.

[0003] In recent years, as the shortage of landfill sites and the environmental problems caused by exhaust gas from incineration have been highlighted, the collection and reuse of not only conductors but also coating materials has been advanced. This reuse is generally performed in two ways.

[0004] One is to use a material obtained by crushing the entire coating material for uses other than electric wires and cables.

[0005] Another method is a method generally called "peeling", in which a covering material is peeled by a portion such as a sheath or an insulator, and a material obtained by sorting is processed into a pellet or the like, and then the wire is cut. It is reused as a coating material. In this case, the inclusions and the holding tape are often incinerated or landfilled as industrial waste.

The former method is easy in disassembly and separation by an unmanned dismantling equipment line, and is desirable in terms of cost. However, apart from the disassembly of an electric wire composed only of the same coating material, a material obtained by mixing different materials without separating them has non-uniform performance and poor characteristics, and is not suitable for electric wires and cables.

That is, most of electric wires and cables have insulators, inclusions, holding tapes, and sheaths on conductors. The inclusions are polypropylene, paper, jute, etc., and holding tapes are polyester, polyethylene terephthalate, and cotton. It is composed of On the other hand, the insulator and the sheath are made of vinyl, polyethylene, cross-linked polyethylene, or the like, and are made of a material different from that of the inclusion or the holding tape. When these different materials are mixed into the insulator and the sheath, the physical properties of the materials, particularly the tensile strength and elongation, are extremely reduced, so that they cannot be reused as a covering material for electric wires. It is.

[0008] In the latter case, the material characteristics can be made uniform because the separated material is reused. However, usually, various shapes and
It is disadvantageous in terms of labor and other costs because it is necessary to manually supply the wires and cables wound around the sized bundle or drum to the dismantling machine.

On the other hand, electric wires and cables using vinyl as an insulator and a sheath are inexpensive and have good flame retardancy, and thus occupy the mainstream of electric cable materials. However, dismantled and recovered coating materials are harmful if incinerated. To generate halogen gas,
At present it is landfilled. As a technique related to a flame-retardant resin composition suitable for a covering material for electric wires and cables, the inventions described in JP-A-1-108235 and JP-A-5-247281 are known.

In the former, a metal inorganic hydroxide is used as a flame retardant.
500500 parts by weight, and the latter uses a mixture of an ethylene ethyl acrylate copolymer and an ethylene vinyl acetate copolymer as a base resin.

However, in the former technique, a large amount of an inorganic flame retardant is added, resulting in a decrease in mechanical strength and flexibility. Further, when magnesium hydroxide is used as the flame retardant, CO _{2 in} the atmosphere and magnesium hydroxide react via moisture in the atmosphere to become magnesium carbonate, and the material surface becomes white. This problem does not occur with aluminum hydroxide,
Since the decomposition temperature of aluminum hydroxide is lower than that of magnesium hydroxide, raising the processing temperature causes the material to foam.

[0012] The copolymers of the latter technology have higher flame retardancy than materials based on polyethylene alone, but have lower mechanical strength.

[0013]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide an electric wire / cable which can be reused as an insulator / sheath of the electric wire / cable without separating the coating material recovered by crushing and dismantling. It is in.

More specifically, an object of the present invention is to provide the following electric wires and cables. The coating material that has been repeatedly reused deteriorates and will eventually be incinerated. However, it should not generate halogen gas that is harmful to the human body and corrosive during incineration.

When the coating material collected without being separated is reused as an insulating material or a sheath of an electric wire / cable, the electric wire / cable must have a required flame retardancy (inclined flame retardancy of JIS C 3005).

The coating material collected without separation has a predetermined tensile strength and elongation. That is, ensure that the tensile strength is 10MPa or more and the elongation is 350% or more, which are specified as materials for electric wires and cables by JIS standards.

The inclusions have a heat shrinkage equivalent to that of the most common uniaxially oriented polypropylene inclusions. That is, the heat shrinkage when heated in an air environment at 120 ° C. for 30 minutes (heat shrinkage = 100 × length after heating / length before heating) should be 20% or less. Inclusions that do not satisfy this condition violently shrink due to the heat during sheath extrusion, making it impossible to produce electric wires and cables having good shapes.

Since the holding tape is a pre-stage product of the inclusions, it should be the same resin base as the inclusions.

[0019]

Means for Solving the Problems The present inventor has made various studies in view of the above circumstances, and as a result, has found that insulators, sheaths, inclusions,
The inventors have found that the above object can be achieved by using a specific copolymer for each of the holding tapes, and have completed the present invention.

That is, the present invention provides an electric wire / cable having an insulator and a sheath and having at least one of an inclusion and a holding tape on the inner periphery of the sheath, wherein the following three conditions are satisfied. . -The insulator and the sheath are composed of a resin based on a copolymer satisfying the following requirement (A). The inclusions are formed by uniaxially stretching a tape made of a resin based on a copolymer satisfying the following requirements (B) or (C). The holding tape is a tape made of a resin based on a copolymer satisfying the following requirements (B) or (C). (A) A copolymer obtained by copolymerizing ethylene and an α-olefin having 2 to 10 carbon atoms using a single-site catalyst and satisfying the following conditions: Mw / Mn ≦ 2 Density 0.91 g / cm ³ or less
MI ≦ 3 g / 10 min (B) Copolymer of ethylene and α-olefin having 2 to 10 carbon atoms using a single-site catalyst, satisfying the following conditions: Mw / Mn ≦ 2 Density 0.93 to 0.94 g / cm ³
MI ≦ 10 g / 10 min (C) Copolymer of ethylene and α-olefin having 2 to 10 carbon atoms, satisfying the following conditions: 2 ≦ Mw / Mn ≦ 10 Density 0.93 to 0.94 g / cm ³
MI ≦ 10 g / 10 min In each of the copolymers (A), (B), and (C), a more preferred α-olefin has 6 to 8 carbon atoms.

Here, a specific configuration of the electric wire / cable is a cable in which a three-core cable core is collectively covered with a sheath. Each core is formed by extrusion-coating a central conductor with an insulator. Match these cores from 3 cores,
An intervening body is arranged between the cores to make the whole outer shape circular, and the outer periphery thereof is wound with a holding tape. Then, a sheath is extrusion-coated on the outer periphery of the holding tape to form a cable.

Further, the electric wire / cable according to the present invention is characterized in that an insulator or a sheath is constituted by any one of the following compositions (1) to (5).

(1) With respect to 100 parts by weight of the copolymer (A) 80 to 99 parts by weight and the following (D) 20 to 1 part by weight,
(E) A composition comprising 50 to 200 parts by weight. (D) Polyolefin obtained by graft-polymerizing an acid anhydride to a polyolefin-based resin at 0.1 to 3% by weight (E) Magnesium hydroxide satisfying the following conditions: amorphous flat particles having an average particle size of 2 to 6 μm Fatty acid or phosphorus as a surface treatment material Use acid ester

(2) A composition further comprising 50 to 200 parts by weight of a total of the inorganic filler (F) and (E) in the composition of the above (1).

(3) 30 parts to 99 parts by weight of the copolymer (A) and 70 parts to 1 part by weight of the following (G):
A composition comprising (H) 1 to 20 parts by weight and (I) 120 to 200 parts by weight. (G) Polyolefin copolymer obtained by copolymerizing at least 10% by weight of unsaturated carboxylic acid, unsaturated carboxylic acid ester or acid anhydride with ethylene (H) Grafting 0.1 to 3% by weight of acid anhydride to polyolefin resin Polymerized polyolefin (I) Magnesium hydroxide hexagonal plate particles satisfying the following conditions: Maximum particle size is 5 μm or less, and average particle size is 0.5 to 2.0 μm. Fatty acid or phosphate ester is used as a surface treatment material.

(4) 50 to 100 parts by weight of (K) and (L) with respect to 100 to 100 parts by weight of 30 to 70 parts by weight of the copolymer (A) and 70 to 30 parts by weight of the following (J). 2 to 15 parts by weight. (J) Polyolefin copolymer obtained by copolymerizing at least 10% by weight of unsaturated carboxylic acid, unsaturated carboxylic acid ester or acid anhydride with ethylene (K) Magnesium hydroxide satisfying the following conditions: Amorphous flat particles Average Particle size 2-6μm Use fatty acid or phosphate ester as surface treatment material (L) Red phosphorus

(5) 1 to 20 parts by weight of (N) and (O) with respect to 100 to 100 parts by weight of the copolymer (A) (30 to 70 parts by weight) and the following (M) 70 to 30 parts by weight. ) 50-100 parts by weight,
(P) 2 to 15 parts by weight. (M) Polyolefin copolymer obtained by copolymerizing an unsaturated carboxylic acid, unsaturated carboxylic acid ester or acid anhydride in an amount of 10% by weight or more with respect to ethylene. (N) 0.1 to 3% by weight of an acid anhydride grafted to a polyolefin resin. Polymerized polyolefin (O) Magnesium hydroxide hexagonal plate-shaped particles satisfying the following conditions: Maximum particle size is 5 μm or less, and average particle size is 0.5 to 2.0 μm. Fatty acid or phosphate ester is used as a surface treatment material. (P) Red Rin

The details of the main raw materials and the reasons for limiting the conditions in each of the above-mentioned inventions are as follows. First, the base resin
A polyolefin-based material was used from the viewpoint of not generating halogen gas even when incinerated and finally being economical, and economical efficiency.
By using the same type of polyolefin-based material for all of the insulator, the sheath, the inclusion, and the holding tape, the covering material can be collectively reused without separation.

In this case, examples of the resin include high-density polyethylene, polypropylene, ethylene-vinyl acetate copolymer (EVA), ethylene-ethyl acrylate copolymer (EEA), and a copolymer of ethylene and α-olefin. Low-density polyethylene (so-called L-LDPE). Here, high-density polyethylene or polypropylene has poor extrusion processability, and the finished cable is too hard to obtain sufficient flexibility. EVA and EEA are expensive. Therefore, low-density polyethylene, which is a copolymer of ethylene and α-olefin, was selected as the base resin. However, when importance is placed on flame retardancy, EVA, EE
A may be used together.

Regarding the requirement of the polyolefin (A), when the ratio Mw / Mn of the weight average molecular weight to the number average molecular weight exceeds 2, the strength becomes low. On the other hand, when the density exceeds 0.91 g / cm ³ , it is not possible to add necessary amounts of various flame retardants and additives. In addition, melt index (temperature 190 ℃, load 2160g)
If it exceeds 3 g / 10 min, the material becomes too soft during extrusion and cannot be processed.

Regarding the requirement of the polyolefin (B), if the ratio Mw / Mn of the weight average molecular weight to the number average molecular weight exceeds 2, the strength will be low. On the other hand, if the density is less than 0.93 g / cm ³ , the resin shrinks due to heat during extrusion molding. Conversely, if the density exceeds 0.94 g / cm ³ , various flame retardants and additives cannot be added in required amounts. In addition, melt index (temperature 190 ℃, load
If 2160g) exceeds 10g / 10min, the material becomes too soft during extrusion and cannot be processed.

Concerning the requirements of the polyolefin (C), those having a weight average molecular weight to number average molecular weight ratio Mw / Mn of less than 2 are difficult to produce, and exceeding 10 reduce the strength. On the other hand, if the density is less than 0.93 g / cm ^3, it shrinks due to heat during extrusion molding, and if it exceeds 0.94 g / cm ³ , it is not possible to add various flame retardants and additives in necessary amounts. Furthermore, the melt index (temperature 190 ℃, load 2160g) is 1
If it exceeds 0 g / 10min, the material becomes too soft during extrusion and cannot be processed.

When the amount of the polyolefin (A) and the amount of the polyolefin (D) are limited, the effect of improving the processability is insufficient if the amount is less than 1 part by weight, and if the amount exceeds 20 parts by weight, the affinity becomes too strong. This is because workability deteriorates. Also,
The reason for limiting the amount of each of the polyolefin (A) and the polyolefin copolymers (G), (J), and (M) is as follows.
If the lower limit of polyolefin (A) is less than the lower limit, the required mechanical strength (10 MPa) when processed into an electric wire shape cannot be obtained. Is reduced.

Various known single-site catalysts can be used for the synthesis of the polyolefins (A) and (B). For example, a catalyst composition containing a lanthanoid-based metal belonging to Groups 3 to 10 of the periodic table, a metal coordination complex, and an activating cocatalyst (Japanese Patent Application Laid-Open No. 6-306121) can be mentioned.

Polyolefin copolymers (G), (J),
In (M), if the copolymerization amount of the unsaturated carboxylic acid, unsaturated carboxylic acid ester or acid anhydride is less than 10%, sufficient flame retardancy cannot be obtained. Specific substances to be copolymerized include acrylate and vinyl acetate.

Polyolefins (D), (H) and (N) obtained by graft-polymerizing an acid anhydride such as maleic anhydride cannot obtain a sufficient affinity if the amount of the acid anhydride grafted is less than 0.1% by weight. On the other hand, if it exceeds 3% by weight, the affinity is too strong, and the processed surface is hindered. In addition, polyolefin (H),
If the amount of (N) is less than 1 part by weight, the surface whitening due to the reaction with CO ₂ cannot be suppressed. Conversely, if it exceeds 20 parts by weight, the affinity becomes too strong, and the processability deteriorates.

Regarding magnesium hydroxide, amorphous ones (E) and (K) can be obtained by pulverizing brucite ore, and hexagonal plate-like ones (I) and (O) can be manufactured by known means. Can be obtained by synthetic synthesis.

In the case of the amorphous (E) and (K), when the average particle diameter is less than 2 μm, the particles are aggregated to cause poor dispersion.
Even if the value exceeds, dispersion becomes poor. The amorphous magnesium hydroxides (E) and (K) are made of SiO ₂ CaO, CaCO ₃
From 1 to 2% by weight in terms of CaO, and 0.1% of Fe ₂ O ₃ .
It is preferably contained in an amount of 1.0 to 1.0% by weight. As a result, the acid resistance can be improved. These (E),
If (K) has a fixed shape, the acid resistance is poor.

The hexagonal plates (I) and (O) are:
If the maximum particle size is more than 5 μm, it becomes a fracture starting point, which tends to lower the strength. If the average particle size is less than 0.5 μm, the particles will aggregate and cause poor dispersion, and conversely, if the average particle size exceeds 2 μm, poor dispersion will occur. In addition, if these (I) and (O) are indefinite, the dispersibility is inferior.

These magnesium hydroxides (E),
(I), (K) and (O) need to be surface-treated. Examples of the surface treatment material include fatty acids such as lauric acid, stearic acid, oleic acid, and balmitic acid, and phosphate esters such as triphenyl phosphate and tricresyl phosphate. These surface treatment materials are particularly desirable in terms of dispersibility of magnesium hydroxide.

The above magnesium hydroxide (E),
The reason why the amounts of (I), (K) and (O) are limited is that if the composition is less than the lower limit of the specified value, the composition does not pass the vertical tray combustion test when the composition is used as a coating layer of an electric wire. This is because, if it exceeds 2,000, the mechanical strength (10 MPa) required for covering the electric wire cannot be obtained.

Examples of the inorganic filler (F) include calcium carbonate, clay, calcium silicate, talc, alumina, metal powder (fiber), glass powder (fiber), and carbon fiber. The amount of the inorganic filler (F) to be added may be any amount necessary for maintaining the shape. The effect varies depending on the processing size and also depends on the amount of magnesium hydroxide (E) added, but there is no problem if it is approximately 150 parts by weight or less. When the inorganic filler (F) is added, the total amount is 50 to 200 parts by weight with the magnesium hydroxide (E).

The red phosphorus (L) and (P) are preferably coated with at least one of an organic compound and an inorganic compound in order to prevent generation of toxic phosphine gas. For example, a red phosphorus particle surface coated with an epoxy resin, a phenol resin, or the like, a red phosphorus particle surface coated with aluminum hydroxide, zinc, or the like, and further coated with a thermosetting resin may be used. When the amount of red phosphorus (L) and (P) is limited, if the amount is less than 2 parts by weight, a sufficient flame retardant aid effect cannot be obtained and the flame retardancy becomes insufficient. This is because the effect as an auxiliary agent reaches a plateau.

Further, an antioxidant, a stabilizer, an ultraviolet ray inhibitor, a copper damage inhibitor,
An appropriate amount of a lubricant, a pigment, and the like may be blended.

[0046]

Embodiments of the present invention will be described below. First, a test example regarding a material for an insulator and a sheath will be described. After kneading and processing each compounding agent shown in Tables 1 to 4 with an open roll to obtain a composition, "CO ₂ whitening test"
Evaluations were made on "vertical tray combustion test", "workability", and "tensile strength" (Test Examples 1 to 4). The test results are also shown in each table. The method and evaluation criteria for each test are as follows.

CO ₂ bleaching test After the composition was processed into a sheet having a thickness of 1 mm, the sheet was suspended in a desiccator with water on the bottom surface, and the sheet was exposed to CO ₂ gas.
Exposure at 48 ° C for 48 hours to measure weight change. Weight gain
When the content was 0.5% by weight or more, white precipitates were remarkable.

Vertical Tray Burning Test An insulating layer having a thickness of 1.2 mm was formed of polyethylene on a conductor having a cross-sectional area of 22 mm ² , and the composition was formed as a sheath on the insulating layer.
Make a 1.5mm thick extrusion coated cable. The vertical tray test specified in IEEE383 was performed on this cable. Based on the criteria of the test, those that burned to the upper end were rejected, and those that did not burn were passed.

Processability The composition was extrusion-coated on a conductor having a cross-sectional area of 2 mm ^{2 at} a thickness of 0.8 mm, and a product having a good appearance was determined to be good even if the extrusion linear speed was 50 m / min or more, which was a measure of productivity. In addition, those having poor appearance such as melt fracture were evaluated as defective.

Tensile Strength The composition is processed into a sheet having a thickness of 1 mm, and the tensile strength is measured. Those with an electric wire standard of 10 MPa or more were accepted as acceptable, and those with less than 10 MPa were rejected.

[0051]

[Table 1]

[0052]

[Table 2]

[0053]

[Table 3]

[0054]

[Table 4]

(Test Example 1) As shown in Table 1, Example 1
1 and 12 passed both tests. In contrast,
Comparative Example 11 containing no maleic anhydride-modified polymer and Comparative Example 12 containing less than 80 parts by weight of polyolefin (A) were insufficient in workability. Comparative Example 13 using a polyolefin synthesized with a multi-site catalyst and Comparative Example 16 containing a large amount of magnesium hydroxide failed in terms of tensile strength. Comparative Example 14 having a small average particle size of magnesium hydroxide failed the CO ₂ whitening test, and Comparative Example 15 having a small amount of magnesium hydroxide failed the vertical tray combustion test.

Since the polyolefin (A) has better mechanical strength than conventional polyolefins, it is possible to add more flame retardants and to obtain high flame retardancy without using red phosphorus as a flame retardant aid. Sex can be obtained. In addition, by using the polyolefin (D), a composition having excellent processability can increase the affinity between the polyolefin (A) and the magnesium hydroxide (E1), (E2) or the inorganic filler (F). Can be obtained. Magnesium hydroxides (E1) and (E2) can suppress surface whitening due to CO ₂ even if they are added in large amounts by specifying their shapes and particle sizes. Further, the use of the non-combustible inorganic filler (F) contributes to maintaining the shape of the composition at the time of combustion, and can pass the combustion test.

(Test Example 2) As shown in Table 2, Example 2
1,22 passed both tests. On the other hand, Comparative Example 11, which did not contain the maleic anhydride-modified polymer (H),
₂ Regarding the whitening test, Comparative Example 22 containing a large amount of the same modified polymer was workable, and Comparative Example 24 containing less magnesium hydroxide (H1) was insufficient for the vertical tray combustion test. Comparative Example 23 in which the blending amount of the polyolefin (A) was small,
Comparative Example 25 containing a large amount of magnesium hydroxide (I1) and Comparative Example 26 using amorphous magnesium hydroxide (I ′) both had insufficient strength.

The use of polyolefin (A) compensates for the lack of strength of polyolefins (G1) and (G2), and polyolefins (G1) and (G2) cover the low flame retardancy of polyolefin (A). Further, by using the modified polymer (H), the affinity between the polyolefins (A), (G1), (G2) and the magnesium hydroxides (I1), (I2) is increased, and the magnesium hydroxides (I1), (I2) ) Can react with CO ₂ in the atmosphere via moisture and suppress the phenomenon of surface whitening. Furthermore, by using magnesium hydroxides (I1) and (I2) having a hexagonal plate shape and a uniform shape, a composition having sufficient mechanical strength can be obtained.

(Test Example 3) As shown in Table 3, Example 3
1 and 32 passed both tests. On the other hand, Comparative Example 31 containing less polyolefin (A), magnesium hydroxide
Comparative Example 35 having a large amount of (K1) had insufficient strength, and Comparative Example 36 having a small average particle size of magnesium hydroxide (K ′) failed the CO ₂ whitening test. Comparative Example 32 containing a large amount of polyolefin (A), Comparative Example 33 containing a small amount of red phosphorus, and Comparative Example 34 containing a small amount of magnesium hydroxide (K1) failed the vertical tray combustion test.

The use of polyolefin (A) compensates for the lack of strength of polyolefins (J1) and (J2), and polyolefins (J1) and (J2) cover the low flame retardancy of polyolefin (A). In addition, magnesium hydroxide (K1), (K
2) can suppress the surface whitening due to CO ₂ even if it is added in a large amount by specifying its shape and particle size.
Further, by using red phosphorus (L), sufficient flame retardancy can be obtained without using a large amount of magnesium hydroxide (K1) and (K2). Therefore, magnesium hydroxide (K
1) There is no decrease in mechanical strength caused by using a large amount of (K2).

(Test Example 4) As shown in Table 4, Example 4
1,42 passed both tests. On the other hand, Comparative Example 41 containing no modified polymer (N) failed the CO ₂ whitening test, and Comparative Example 42 containing a large amount of the modified polymer (N) was insufficient in processability. Further, Comparative Example 43 containing less polyolefin (A), Comparative Example 47 containing more magnesium hydroxide (O1), and Comparative Example 48 containing amorphous magnesium hydroxide (O ′) particles were all insufficient in strength. Furthermore, Comparative Example 44 containing a large amount of polyolefin (A), Comparative Example 45 containing a small amount of red phosphorus (P), and Comparative Example 46 containing a small amount of magnesium hydroxide (O1) all failed the vertical tray combustion test.

Next, a description will be given of a test example regarding materials for inclusions and holding tapes. After kneading each compounding agent shown in Tables 5 to 8 to obtain a composition, "tape processability",
"Young's modulus" and "heat shrinkage" were evaluated (Test Examples 5 to 8). Here, 1-butene, 1-hexene, and 1-octene were selected as α-olefins copolymerized with ethylene. The tape processability was evaluated based on whether the tape could be processed and the Young's modulus was 1.0 GPa or more. The heat shrinkage was obtained by uniaxially stretching each composition processed into a tape, and then heating the film in an air environment at 120 ° C. for 30 minutes (heat shrinkage = 100 × length after heating / (The length before heating) was 20% or less. Tables 5 to 8 also show the results.

[0063]

[Table 5]

[0064]

[Table 6]

[0065]

[Table 7]

[0066]

[Table 8]

(Test Examples 5 and 6) As shown in Tables 5 and 6, Examples 51 to 56 and 61 to 66 had good tape workability, had an appropriate Young's modulus, and had a heat shrinkage rate. It can be seen that the content is also 20% or less and suitable as inclusions.

(Test Examples 7 and 8) On the other hand, Comparative Examples 51, 53, 61 and 63 having a density of 0.925 g / cm ³ had a heat shrinkage of 90%.
Comparative Example 65 using the copolymer of ethylene and 1-butene as a base resin was large before and after, and could not be processed into a tape.
Further, Comparative Examples 52, 54, 62 and 64 having a density of 0.945 g / cm ³ and Comparative Example 66 using polypropylene as a base resin have obtained good results in this test. However, these are described in Test Examples 9 to 14 (suitability test when “a material obtained by integrally collecting an insulator / sheath and an inclusion / holding tape”) is reused as an insulator / sheath of a wire / cable). The wire was insufficient in flexibility and physical properties.

Further, the above-mentioned material for the insulator and the sheath and the above-mentioned material for the inclusion and the holding tape are collectively collected, and the collected material is reused as an insulator or a sheath of electric wires and cables. (Test Examples 9 to 14). The test items are "extrudability", "tensile strength", "elongation", "flame retardancy", and "flexibility of electric wire". The extrusion processability was determined based on whether or not the extrusion process could be performed favorably as an insulator or a sheath of the electric wire based on the evaluation criteria. As the evaluation of extrusion processability, the composition on a conductor cross-sectional area 2 mm ²
Extrusion coating with 0.8 mm thickness, extrusion linear speed is a measure of productivity
Even if it was 50 m / min or more, those having good appearance were evaluated as good (O), and those having poor appearance such as melt fracture were evaluated as poor. The tensile strength is 10MPa or more, and the elongation is 350MPa.
% Or more, and the flame retardancy was evaluated based on passing the inclined flame retardant test of JIS C 3005. Further, the flexibility of the electric wire was evaluated based on whether or not the electric wire had the required flexibility. Tables 9 to 16 show combinations of the materials for the insulator and the sheath, the materials for the inclusions and the holding tape, and the test results. In addition, "remarks" in the table describes the evaluation in consideration of the results of Test Examples 5 to 8.

[0070]

[Table 9]

[0071]

[Table 10]

[0072]

[Table 11]

[0073]

[Table 12]

[0074]

[Table 13]

[0075]

[Table 14]

[0076]

[Table 15]

[0077]

[Table 16]

(Test Example 9, Test Example 11, Test Example 13, Test Example 15) As shown in Table 9, Table 11, Table 13, and Table 15, all of the sheaths, insulators, inclusions, and holding tapes were used. An electric wire in which the composition material used in the example is reused satisfies each evaluation criterion. Therefore, it is understood that the base resin is a copolymer of ethylene and an α-olefin, and that the density thereof is suitably 0.93 to 0.94 g / cm ³ .

(Test Example 10, Test Example 12, Test Example 14,
Test Example 16) On the other hand, as shown in Table 10, Table 12, Table 14 and Table 16, the sheath and the insulator were made the composition materials of the examples, and the inclusions and the holding tape were made the composition materials of the comparative example. The used electric wire could not satisfy any of the evaluation criteria, which proved that the electric wire was not suitable for reuse.

[0080]

As described above, the electric wire / cable of the present invention has the following effects. By configuring each covering material (insulator, sheath, inclusion, holding tape) of electric wires and cables with the same resin composition, it is possible to separate electric wires and cables without separating them for each component of the covering material.
It can be reused as a cable covering material.

The coating material deteriorates due to repeated reuse and cannot be reused, and no harmful halogen gas is generated even when incinerated.

The covering material used for the electric wire / cable of the present invention has excellent extrusion workability even when reused. Therefore, it is effective in improving the manufacturability.

The covering material used for the electric wire / cable of the present invention has excellent mechanical strength. Since it has a tensile strength of 10 MPa or more, which is an electric wire standard, it is suitable for reuse as an insulator or sheath for electric wires and cables.

The covering material used for the electric wire / cable of the present invention has sufficient flame retardancy. It has flame retardancy that can pass the vertical tray combustion test and can be used in various fields where flame retardancy is required.

The coating material used for the electric wire / cable of the present invention can suppress whitening due to CO ₂ . By specifying the shape and particle size of magnesium hydroxide and increasing the affinity between magnesium hydroxide and the base resin, magnesium hydroxide and C
To suppress the reaction of O ₂ suppress the whitened.

[0086] Among the covering materials used for the electric wires and cables of the present invention, those which do not use red phosphorus may cause impact ignition during processing,
The risk of toxic phosphine gas generation can be eliminated. Also, high flame retardancy can be obtained without using red phosphorus.

Continued on the front page (51) Int.Cl. ⁶ Identification symbol FI H01B 7/18 H01B 7/18 HE // (C08K 13/06 3:02 9:04)

Claims (6)

[Claims] 1. An electric wire or cable comprising an insulator and a sheath, wherein at least one of an inclusion and a pressing tape is provided on the inner periphery of the sheath, wherein the insulator and the sheath satisfy the following requirement (A). The inclusions are formed by uniaxially stretching a tape made of a copolymer-based resin satisfying the following requirement (B) or (C). The holding tape is a tape made of a resin based on a copolymer satisfying the following requirements (B) or (C). (A) A copolymer obtained by copolymerizing ethylene and an α-olefin having 2 to 10 carbon atoms using a single-site catalyst and satisfying the following conditions: Mw / Mn ≦ 2 Density 0.91 g / cm ³ or less
MI ≦ 3 g / 10 min (B) Copolymer of ethylene and α-olefin having 2 to 10 carbon atoms using a single-site catalyst, satisfying the following conditions: Mw / Mn ≦ 2 Density 0.93 to 0.94 g / cm ³
MI ≦ 10 g / 10 min (C) Copolymer of ethylene and α-olefin having 2 to 10 carbon atoms, satisfying the following conditions: 2 ≦ Mw / Mn ≦ 10 Density 0.93 to 0.94 g / cm ³
MI ≦ 10g / 10min 2. An insulator and a sheath, wherein (A) 80-99
2. The electric wire according to claim 1, comprising a resin composition containing (E) 50 to 200 parts by weight with respect to a total of 100 parts by weight of the following (D) 20 to 1 part by weight. ·cable. (D) Polyolefin obtained by graft-polymerizing an acid anhydride to a polyolefin-based resin at 0.1 to 3% by weight (E) Magnesium hydroxide satisfying the following conditions: amorphous flat particles having an average particle size of 2 to 6 μm Fatty acid or phosphorus as a surface treatment material Use acid ester 3. The total amount of the inorganic filler (F) and (E) is 50.
The electric wire / cable according to claim 2, wherein the electric wire / cable contains up to 200 parts by weight. 4. An insulator and a sheath comprising (A) 30 to 99 parts by weight and (G) 70 to 1 part by weight, a total of 100 parts by weight, (H) 1 to 20 parts by weight and (I) The electric wire / cable according to claim 1, comprising 120 to 200 parts by weight. (G) Polyolefin copolymer obtained by copolymerizing at least 10% by weight of unsaturated carboxylic acid, unsaturated carboxylic acid ester or acid anhydride with ethylene (H) Grafting 0.1 to 3% by weight of acid anhydride to polyolefin resin Polymerized polyolefin (I) Magnesium hydroxide hexagonal plate particles satisfying the following conditions: Maximum particle size is 5 μm or less, and average particle size is 0.5 to 2.0 μm. Fatty acid or phosphate ester is used as a surface treatment material. 5. The insulator and the sheath are (A) 30 to 70 parts by weight and the following (J) 70 to 30 parts by weight, a total of 100 parts by weight, (K) 50 to 100 parts by weight and (L) The electric wire / cable according to claim 1, comprising 2 to 15 parts by weight. (J) Polyolefin copolymer obtained by copolymerizing at least 10% by weight of unsaturated carboxylic acid, unsaturated carboxylic acid ester or acid anhydride with ethylene (K) Magnesium hydroxide satisfying the following conditions: Amorphous flat particles Average Particle size 2-6μm Use fatty acid or phosphate ester as surface treatment material (L) Red phosphorus 6. The insulator and the sheath are (A) 30 to 70 parts by weight and the following (M) 70 to 30 parts by weight, a total of 100 parts by weight, (N) 1 to 20 parts by weight, (O) A wire or cable comprising 50 to 100 parts by weight and (P) 2 to 15 parts by weight. (M) Polyolefin copolymer obtained by copolymerizing at least 10% by weight of unsaturated carboxylic acid, unsaturated carboxylic acid ester or acid anhydride with ethylene. (N) Grafting of 0.1 to 3% by weight of acid anhydride to polyolefin resin. Polymerized polyolefin (O) Magnesium hydroxide hexagonal plate-shaped particles satisfying the following conditions Maximum particle size is 5 μm or less and average particle size is 0.5 to 2.0 μm Use fatty acid or phosphate ester as surface treatment material (P) Red Rin