JP2001110251A - Insulated wire/cable - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide environment adaptive insulated wire/cable having high flame retardancy without using resin composition containing polyvinyl chloride and halogen based flame retardant agent as coating material, and being superior in extruding workability, mechanical property, damage resistance and weather resistance without producing harmful substances including dioxine, heavy metal compound and corrosive gas during waste disposal such as reclamation and incineration. SOLUTION: An insulated wire/cable with good extruding workability and high flame retardancy comprises a outermost layer coating material for at its outer layer side accounting for 10-50% of the cross section of non-halogen flame retardant composition containing inorganic hydrate such as magnesium hydroxide, aluminum hydroxide and calcium hydroxide and at its inner layer of polyolefin based polymer such as polyethylene, polyethylene copolymer and polypropylene.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an insulated wire / cable which does not generate harmful halogen-based gas and does not elute heavy metal compounds during incineration and disposal.

[0002]

2. Description of the Related Art In recent years, due to problems such as the generation of dioxin during incineration, coating materials for insulated wires and cables have been developed.
Environmentally friendly insulated wires and cables using non-halogen flame-retardant materials instead of the conventionally used resin compositions containing polyvinyl chloride and halogen-based flame retardants containing bromine and chlorine in the molecule are used. Has begun. In these insulated wires / cables, as a covering material, in order to impart the same flame retardancy as a resin composition containing polyvinyl chloride or a halogen-based flame retardant, a polyolefin-based polymer such as metal hydrate A composition to which an inorganic filler is added is used.

By the way, in order to impart the same flame retardancy as a flame-retardant resin composition in which the above-mentioned polyolefin-based polymer contains polyvinyl chloride or a halogen-based flame retardant, a large amount of metal hydrate or the like is required. It is necessary to add an inorganic filler.
However, when a large amount of an inorganic filler such as a metal hydrate is added to a polyolefin-based polymer, flame retardancy is obtained, but there is a problem that extrudability, mechanical properties, and weather resistance are poor.

[0004] In order to improve the extrusion processability and mechanical properties, as a polymer, a relatively soft filler such as EEA (ethylene / ethyl acrylate copolymer) or EVA (ethylene / vinyl acetate copolymer) is used. Although the use of such a soft material for the coating of the outermost layer of the cable is also used, the cable can be used when the cable is passed through a pipeline when it is extended or laid in various environments. However, there is a defect that the outer surface of the cable is easily scratched and the scratch resistance is poor. In order to improve trauma resistance, non-halogen flame-retardant materials based on strong polyolefin polymers have been studied, but this type of strong polymer uses inorganic fillers such as metal hydrates. When filled in a large amount, there is a problem that the mechanical properties, particularly the elongation properties at low temperatures, are extremely reduced.

[0005]

In order to solve these problems, a method has been considered in which the coating layer of the insulated wire / cable has a two-layer structure. The coating layer of the insulated wire has a two-layer structure and the inner layer has an olefin structure. -Based resin composition, a method of forming the outer layer with a high-performance polymer composition, a flame-retardant composition in which the inner layer is blended with an inorganic hydrate and red phosphorus in a polyolefin-based resin, and the outer layer is an inorganic hydrate in a polyolefin-based resin. A method of forming a flame-retardant composition containing no red phosphorus,
Further, a method of forming the inner layer with a composition in which a metal hydrate and red phosphorus are blended with a polyolefin resin, and a method of forming the outer layer with a flame retardant composition in which an ammonium polyphosphate flame retardant is blended with a polyolefin resin, and the like are also performed. However, at present, none of these methods has been able to provide good flame retardancy, extrudability, mechanical properties, trauma resistance and weather resistance.

SUMMARY OF THE INVENTION The present invention has been made to solve such a problem, and does not use a resin composition containing polyvinyl chloride or a halogen-based flame retardant as a coating material.
Has a high degree of flame retardancy and excellent extrudability, mechanical properties, trauma resistance and weather resistance, and harmful substances such as dioxins, heavy metal compounds, corrosive gases, etc. during disposal treatment such as landfill and incineration. It is an object of the present invention to provide an environmentally friendly insulated wire / cable that does not generate any noise.

[0007]

In order to solve the above-mentioned problems, the present invention relates to an insulated wire / cable having an outer layer side having a total cross-sectional area of a coating layer made of rubber or plastic as an insulator and / or a sheath. % To 50% is made of a halogen-free flame retardant composition, and the inner layer side of the coating layer is made of a polyolefin-based polymer. The polyolefin-based polymer is made of polyethylene, polyethylene copolymer or polypropylene having a density of 0.925 or more. It is characterized by comprising at least one kind. Also,
The non-halogen flame-retardant composition is magnesium hydroxide,
One or more of aluminum hydroxide and calcium hydroxide are at least 25% by weight of the total amount of the non-halogen flame-retardant composition, and at least 1% by weight of at least one of organopolysiloxane and red phosphorus having a viscosity of 10,000 cp or more. % Or more. The base polymer of the non-halogen flame-retardant composition is polyethylene having a weight average molecular weight of 300,000 or more, and the non-halogen flame-retardant composition of the outermost coating layer contains a weather resistance imparting agent. It is characterized by the following.

In the present invention, the coating layer made of the non-halogen flame-retardant composition is provided on 10% to 50% of the outer layer side of the cross-sectional area of the coating layer, so that the inner layer side is a flammable polyolefin polymer. Are also self-extinguishing as insulated wires and cables. In addition, by adopting such a configuration, compared with the case where the halogen-free flame-retardant composition is conventionally used for all layers of the coating layer, the inner layer side can use a normal polyolefin-based polymer, so that the processability is very good. In addition, workability is improved by reducing the amount of extrusion on the outer layer side.

The use of one of polyethylene, polyethylene copolymer, and polypropylene having a density of 0.925 or more as the polyolefin-based polymer on the inner layer side results in good trauma resistance. In the non-halogen flame-retardant composition of 10% to 50% on the outer layer side in the cross-sectional area ratio of the coating layer, magnesium hydroxide, aluminum hydroxide,
Any one or more of calcium hydroxide is used in a total amount of 25% by weight or more in the non-halogen flame-retardant composition, and one or both of an organopolysiloxane and a red phosphorus having a viscosity of 10,000 cp or more. High flame retardancy can be obtained by adding 1% by weight or more. By using a base polymer of the non-halogen flame-retardant composition on the outermost layer side having a weight average molecular weight of 300,000 or more, the scratch resistance is improved, and a weather resistance imparting agent is contained in the non-halogen flame-retardant composition. The inclusion improves the weather resistance.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail.

FIG. 1 shows a cross section of an insulated wire / cable according to the present invention. The present invention comprises an outer layer 2 made of a non-halogen flame-retardant composition and an inner layer 3 made of a polyolefin-based polymer occupying 10% to 50% of the cross-sectional area ratio of the covering material provided around the insulated wire / cable 1. .

Although the configuration of the present invention can be used regardless of the outer diameter of the insulated wire / cable, in a high-voltage power cable having a large outer diameter, the effect of using this configuration becomes more remarkable. . In the case of a high-voltage power cable having a large outer diameter, the outer surface of the cable is easily damaged at the time of wire drawing, and therefore it is preferable to use a strong material to make the coating layer flame-retardant. Attempting to achieve flame retardancy with a non-halogen flame-retardant composition using a high-strength base polymer has the problem that extrudability deteriorates because a large amount of inorganic hydrate filler is used. However, in the case where the outer layer side is 10% to 50% in the cross-sectional area ratio of the coating material of the present invention made of a non-halogen flame-retardant composition and the remaining inner layer side is made of a polyolefin-based polymer, the outer layer side is made of the inorganic material. By reducing the extrusion amount of the non-halogen flame retardant composition containing the hydrate filler, and by improving the extrusion processability by using a normal polyolefin-based polymer on the inner layer side, the outer layer side has high strength. It is possible to use strong base polymers. Further, by using a high-density polyethylene, polyethylene copolymer, or polypropylene having a density of 0.925 or more among the polyolefin-based polymers on the inner layer side, the scratch resistance is improved. The preferred density range of the polyolefin polymer is 0.925 to 0.960.
It is. If the density is less than 0.925, good strength cannot be obtained, and if it exceeds 0.960, the extrudability becomes poor. When the cross-sectional area ratio of the coating layer is in the range of 10% to 50% with the halogen-free flame retardant material composition, sufficient flame retardancy can be obtained. If the cross-sectional area ratio is less than 10%, sufficient flame retardancy cannot be obtained, and if it is 50% or more, the flame retardancy is sufficient, but the extrudability is impaired.

As the non-halogen flame retardant, magnesium borate, aluminum hydroxide, calcium hydroxide, zinc borate and the like can be used. These additives may be used alone or in combination. The additive amount is preferably 25% by weight to 70% by weight, and 50% by weight to 55% by weight.
Is most preferred. The amounts of these additives are adjusted according to the intended flame-retardant level of the insulated wire / cable. Generally, it is about 50% by weight in the flame retardancy test of JIS 60 ° inclination, and in the UL VW-1 class, it may be added in an amount of 200 parts by weight or more. When the amount of any of the additives is small, the flame retardancy is insufficient, and when the amount is too large, the mechanical properties and the extrudability are deteriorated. The non-halogen flame-retardant composition to which the above-mentioned magnesium hydroxide, aluminum hydroxide, calcium hydroxide or the like is added in the above-mentioned amount has a viscosity of 10,000 c.
A high level of flame retardancy can be obtained by adding at least 1% by weight of either or both of the organopolysiloxane and the red phosphorus of p or more. The preferred addition amount of the organopolysiloxane and red phosphorus is 1% by weight to 10% by weight.
It is. If the addition amount is less than 1% by weight, the effect is small and 10%
If the content is more than the weight percentage, workability is impaired. On the other hand, if the viscosity of the organopolysiloxane is too low, it does not lead to an improvement in flame retardancy, and generally up to about 2,000,000 cp is used.

In order to improve the scratch resistance, the preferable range of the weight average molecular weight of the base polymer of the non-halogen flame-retardant composition on the outer layer side is 300,000 to 1,450,000.
If it is 300,000 or less, the trauma resistance is not improved, and if it is 14.5 million or more, the extrudability becomes poor. Further, by adding a weather resistance imparting agent such as an ultraviolet absorber or a light stabilizer to the non-halogen flame-retardant composition on the outer layer side, the entire conventional coating layer is formed of a non-halogen flame-retardant material. Compared with the case where a weathering agent is added to the coating layer of the cable, it is not necessary to consider workability and the like, so that the weatherability can be more easily improved.

[0015]

Next, examples of the present invention will be described. The power cable in the present invention is prepared by compounding the compounding agents described in Table 1 on a 66 kV 325 mm ² core in advance.
With the extruder of φ175mm, the inner layer side of coating material is
The outer layer side was simultaneously extruded by an extruder. Extrusion conditions were the same as those of the conventional compound, and the resin temperature was 180 ° C. The molding could be performed without any problem.

Example 1 The outer layer made of the non-halogen flame-retardant composition had a cross-sectional area ratio of 30% on the outer layer side of the coating material made of the non-halogen flame-retardant composition.
520) 30 parts by weight, PE 500,000 (weight average molecular weight 50
70 parts by weight of Mitsui Chemicals product name Lubmar L4000) and magnesium hydroxide (Kyowa Chemicals product name Kisuma 5)
A) 120 parts by weight, 0.5 parts by weight of Irganox1010, 0.1 part by weight of an ultraviolet absorber (trade name: Tinuvin 234, manufactured by Ciba Specialty Chemicals), and a light stabilizer (trade name: Tinuvin 622LD, manufactured by Ciba Specialty Chemicals)
3 parts by weight and 0.2 parts by weight of carbon black were added.
The inner layer side is MDPE (density 0.930, manufactured by Mitsui Chemicals, Inc.)
It was extruded using Neozex 3510F) by the method described above.

Example 2 The polymer on the outer layer side composed of a non-halogen flame-retardant composition was composed of PE 1.54 million (weight average molecular weight 1.45 million, manufactured by Mitsui Chemicals, Inc.).
Extrusion molding was carried out in the same manner as in Example 1 except that 70 parts by weight of Hizex Million 145 (trade name) and HDPE (trade name: Hizex 5502 manufactured by Mitsui Chemicals, Inc.) on the inner layer side were used.

Example 3 The cross-sectional area ratio of the outer layer made of a halogen-free flame-retardant composition was set to 40%, and the polymer of the outer layer was made to be 1.54 million PE.
Same as Example 1 except that 60 parts by weight, 40 parts by weight of EEA, 200 parts by weight of magnesium hydroxide, no UV absorber and light stabilizer were used, and HDPE was used on the inner layer side. And extruded.

Example 4 The cross-sectional area ratio of the outer layer side made of a halogen-free flame-retardant composition was set to 40%, and magnesium hydroxide was added to the outer layer side.
0 parts by weight, organopolysiloxane (100
Extrusion molding was carried out in the same manner as in Example 1 except that 3 parts by weight of dimethyl type (10,000 cp) and 1 part by weight of red phosphorus were added and the polymer on the inner layer side was changed to HDPE.

Comparative Example 1 The outermost layer coating material was not divided into two layers, an outer layer and an inner layer, but was made into one layer.
All layers were made of HDPE (density 0.940, Hi-Zex 5502 manufactured by Mitsui Chemicals), and magnesium hydroxide was added to the HDPE.
20 parts by weight of Iruganox 1010 0.5 was added, and the mixture was extruded by a conventional method without adding organopolysiloxane, red phosphorus, an ultraviolet absorber, and a light stabilizer.

COMPARATIVE EXAMPLE 2 As in Comparative Example 1, the outermost coating material was not divided into two layers, an outer layer and an inner layer. One layer was used, and all layers were made of semi-hard polyvinyl chloride. Magnesium hydroxide, Iruganox1010, organopolysiloxane, Red phosphorus and carbon black were extruded by an ordinary method without blending.

Comparative Example 3 The cross-sectional area ratio of the outer layer made of a halogen-free flame-retardant composition was 30%, and the outer layer was 70 parts by weight of LDPE (density 0.915, product name: UBEC130, manufactured by Ube Industries) and 30 parts by weight of EEA. Extrusion was performed in the same manner as in Example 1 except that the side was also made of LDPE.

Comparative Example 4 The cross-sectional area ratio of the outer layer made of a halogen-free flame-retardant composition was 30%, and the polymer of the outer layer was PE 500,000.
30 parts by weight, EEA 70 parts by weight, HDP on the inner layer side
Extrusion was performed in the same manner as in Example 1 except that E was used.
Regarding the cables obtained in each of the above Examples and Comparative Examples, JISC3005 was used for the flame retardancy of 60 ° inclination, and IE for the vertical tray combustion.
It was evaluated by EEstd383. The trauma resistance was evaluated by the sheath breaking load. The corrosive gas generation test was evaluated according to JIS K0107. The weather resistance was evaluated by using a sunshine carbon arc lamp-type accelerated weather resistance tester manufactured by Suga Test Instruments, and irradiating for 2000 hours with a black panel temperature of 63 ° C. and a rainfall time of 18 minutes / 120 minutes. The presence or absence of hair cracks was observed on a test piece wound around its own diameter (a test piece wound with an insulated wire / cable around itself and subjected to stress). The results of these evaluations are shown in the lower column of Table 1.

[0024]

[Table 1]

As is clear from Table 1, the cable according to the present invention has the same flame retardancy as a cable using polyvinyl chloride as a coating material, and does not generate corrosive gas by combustion. In addition, extrudability is good even when about 200 parts by weight of an inorganic hydrate such as magnesium hydroxide is blended. Further, both the scratch resistance and the weather resistance are good.

[0026]

As is clear from the above embodiments, according to the present invention, the cross-sectional area ratio of the outermost coating material is 10% to 50%.
% By a non-halogen flame-retardant composition containing an inorganic hydrate such as magnesium hydroxide, and the inner layer side by a polyolefin-based polymer such as polyethylene.
Without impairing the extrudability, it has the same flame retardancy as a cable using polyvinyl chloride as a coating material, and since the extrudability is good, the inner layer has HDP.
High-density polyethylene such as E or MDPE and polyethylene having a weight-average molecular weight of 300,000 or more can be used for the outer layer.
You can get the cable. The addition of an ultraviolet absorber or a light stabilizer to the composition of the outermost layer also improves the weather resistance.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of the present invention.

[Explanation of symbols]

 1 ... insulated wire / cable 2 ... outer layer 3 ... inner layer 4 ... conductor

Continuation of the front page (72) Inventor Kisunori Kurihara 2-1-1 Oda Sakae, Kawasaki-ku, Kawasaki-shi, Kanagawa Prefecture F-term in Showa Electric Wire & Cable Co., Ltd.

Claims (4)

[Claims] 1. An insulated electric wire comprising a rubber / plastic coating layer as an insulator and / or a sheath.
In the cable, the outer layer side 1 of the total cross-sectional area of the covering layer
An insulated wire or cable comprising 0% to 50% of a non-halogen flame-retardant composition, and a remaining inner layer portion made of one of polyethylene, polyethylene copolymer and polypropylene having a density of 0.925 or more. . 2. The insulated wire or cable according to claim 1, wherein the non-halogen flame-retardant composition contains at least one of magnesium hydroxide, aluminum hydroxide and calcium hydroxide in the non-halogen flame-retardant composition. 25% by weight
An insulated wire or cable comprising at least 1% by weight of an organopolysiloxane having a viscosity of 10,000 cp or more and / or red phosphorus. 3. The insulated wire / cable according to claim 1, wherein the base polymer of the halogen-free flame-retardant composition is polyethylene having a weight average molecular weight of 300,000 or more. Electric wires and cables. 4. The insulated wire / cable according to claim 1, wherein the non-halogen flame-retardant composition contains a weather resistance imparting agent. .