JP2012149187A - Flame retardant resin composition, and optical fiber cable and wire using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a flame retardant resin composition having excellent flame retardancy while containing no red phosphorus, and suppressing the addition amount of metal hydrates to as little as possible, and nevertheless meeting characteristics required for optical fiber cable jacket such as hardness and cold resistance.SOLUTION: The flame retardant resin composition is prepared by blending: 100 pts.wt of a base resin containing at least 40 to 80 pts.wt of a high-density polyethylene or a polypropylenic block copolymer and 60 to 20 pts.wt of a linear low-density polyethylene; 2 to 10 pts.mass of an aromatic phosphate ester as a flame retardant; and 30 to 70 pts.wt of magnesium hydroxide treated concurrently with oleic acid when being treated with vinylsilane, methacryloxysilane, or these silanes.

Description

  The present invention relates to a flame retardant resin composition, and an optical fiber cable and an electric wire using the same. The present invention also relates to a cable and a harness formed by collecting a plurality of the electric wires.

  Since the drop optical cable used for drawing the optical cable into the house is required to be flame retardant, a material having flame resistance is used for the outer jacket. Conventionally, metal hydrate and red phosphorus have been used together as flame retardant components in the jacket of such an optical fiber cable, and the metal hydrate as a flame retardant is also used in the resin composition disclosed in Patent Document 1. Along with red phosphorus. Also, in recent years, with this type of optical fiber cable, there have been many problems that a spear pierces the egg-laying tube into the jacket of the cable, damages the inner optical fiber core, or lays an egg in the jacket. . On the other hand, in patent document 1, the Shore D hardness of a jacket (sheath) is made into a hard material with 55 or more, so that the laying tube of a bear shark is not pierced. This prevents excessive external pressure from being applied to the internal optical fiber core and prevents damage to the optical fiber core.

International Publication No. 08/090880 Pamphlet

However, red phosphorus alone has the risk of spontaneous ignition, and it is difficult to handle in manufacturing because it causes odors in the cable manufacturing process or the vaporized product ignites. It was. Further, since red phosphorus is a deep red color, when red phosphorus is used, the outer cover material is colored red, so that it is not possible to form a white or light-colored outer cover. Therefore, there has been a demand for a jacket material that exhibits excellent flame retardancy without containing red phosphorus.
Conventionally, in order to obtain flame retardancy, a considerable amount of metal hydrate has been added to the resin composition. However, the mechanical strength is reduced, the extrusion torque is increased during molding, and the jacket is brittle in a low temperature environment. It is also desired to reduce the amount of metal hydrate added as much as possible.

  By the way, as described in Patent Document 1, an optical fiber cable such as a drop optical cable is desired to have high hardness in order to prevent damage to the optical fiber core wire caused by piercing by a spawning tube of a spider. Moreover, since the optical fiber cable may be used in a cold region, it is necessary to suppress the embrittlement of the jacket at a low temperature.

  The present invention has been made in view of the above problems, and has excellent flame retardancy while not containing red phosphorus and suppressing the addition amount of metal hydrate as much as possible, as well as hardness and cold resistance. An object of the present invention is to provide a flame retardant resin composition that also satisfies characteristics required for the jacket of an optical fiber cable.

  The flame retardant resin composition of the present invention comprises 100 parts by weight of a base resin comprising at least 40 to 80 parts by weight of high density polyethylene or polypropylene block copolymer and 60 to 20 parts by weight of linear low density polyethylene. As a flame retardant, 2 to 10 parts by mass of an aromatic phosphate, and 30 to 70 parts by weight of magnesium hydroxide treated with vinyl silane treatment, methacryloxy silane treatment, or oleic acid at the time of these treatments It is what was mix | blended (Claim 1).

  In a preferred embodiment of the flame retardant resin composition of the present invention, the linear low density polyethylene is polymerized using a Ziegler-Natta catalyst or a metallocene catalyst. .

  Another preferred embodiment of the flame retardant resin composition of the present invention is that the magnesium hydroxide is any of a treatment using a combination of vinyl silane and oleic acid, a methacryloxy silane treatment, or a treatment using a combination of methacryloxy silane and oleic acid. The surface is treated by any of the above methods (claim 3).

  In another preferred embodiment of the flame retardant resin composition of the present invention, the base resin contains maleic anhydride-modified SEBS (styrene-ethylene-butadiene-styrene block copolymer) in an amount of 10 parts by weight or less. (Claim 4).

  In the optical fiber cable of the present invention, the main body portion and the support wire portion are connected via a neck portion that can be easily cut, and the main body portion is formed in a rectangular shape with a jacket with tension members arranged on both sides of the optical fiber core wire. An optical fiber cable that is covered in a lump and is provided with notches for jacket tearing on both sides, and the support wire portion is disposed on an extension line that connects the tension member and the center of the optical fiber core wire. The outer jacket is made of the flame retardant resin composition (claim 5).

  The electric wire of the present invention is an electric wire in which a conductor is covered with an insulating resin, and at least an outermost layer is made of the flame retardant resin composition (claim 6).

The flame-retardant resin composition of the present invention does not contain red phosphorus, and exhibits excellent flame retardancy while suppressing the addition amount of metal hydrate as much as possible. In addition, the flame-retardant resin composition of the present invention has an excellent extrudability when it is extrusion-coated as a jacket of a cable or the like because the amount of metal hydrate added is suppressed as much as possible. Shows cold resistance that prevents the cover from cracking. This cold resistance is also exhibited by blends other than metal hydrates. Furthermore, an optical fiber cable provided with a jacket made of such a flame retardant resin composition is excellent in hardness and mechanical strength such as tensile strength and tensile elongation.
In addition to the optical fiber cable (preferably drop optical cable), the flame-retardant resin composition of the present invention is used as an insulator or sheath material (sheath covering resin) such as a halogen-free insulated wire or shielded wire (coaxial wire). Can also be used. Further, a plurality of electric wires can be collected and used as a cable or a harness. In any case, by using an electric wire using the flame retardant resin composition of the present invention, it has flame retardancy as an electric wire, cable or harness.

It is the schematic which shows an example of embodiment of the insulated wire or shielded wire of this invention. It is the schematic which shows an example of embodiment of the optical fiber cable of this invention.

The composition of the flame retardant resin composition of the present invention will be described.
The flame retardant resin composition of the present invention comprises 100 parts by weight of a base resin comprising at least 40 to 80 parts by weight of high density polyethylene or polypropylene block copolymer and 60 to 20 parts by weight of linear low density polyethylene. As a flame retardant, 2 to 10 parts by mass of an aromatic phosphate, and 30 to 70 parts by weight of magnesium hydroxide treated with vinyl silane treatment, methacryloxy silane treatment, or oleic acid at the time of these treatments It is a blended one.

The high-density polyethylene that can be used in the present invention is not particularly limited, but preferably has a density of 0.945 g / cm ³ or more.
The polypropylene block copolymer is not particularly limited. For example, an ethylene / propylene block copolymer, or propylene and a small amount of other α-olefin (for example, 1-butene 1-hexene, 4-methyl-1 pentene). And a copolymer of propylene and ethylene propylene (TPO). A polypropylene block copolymer is preferable because it is inexpensive and has an appropriate hardness, and by blending an appropriate amount, it is excellent in workability such as tensile elongation.

As the linear low density polyethylene (LLDPE) that can be used in the present invention, those having a density of 0.91 to 0.94 g / cm ³ are preferable. Linear low-density polyethylene is generally a copolymer of ethylene and an α-olefin (propylene, butene, hexene, octene, 4-methylpentene, etc.) having more carbon atoms than ethylene. In this structure, a short chain branch of α-olefin is introduced. Further, among the linear low density polyethylene, those polymerized by a Ziegler-Natta catalyst or a metallocene catalyst are more preferred, and those polymerized by a metallocene catalyst are particularly preferred. This is because linear low-density polyethylene polymerized with a Ziegler-Natta catalyst or a metallocene catalyst has a narrow molecular weight distribution and composition distribution and is excellent in mechanical strength such as tensile strength.

In this invention, it mix | blends so that 40-80 weight part of high density polyethylene or a polypropylene-type block copolymer and 60-20 weight part of linear low density polyethylene may be contained in 100 weight part of base resins. By setting the blending ratio within this range, it is possible to achieve a balance between hardness, tensile strength, tensile elongation and cold resistance.
The flame-retardant resin composition of the present invention preferably contains maleic anhydride-modified SEBS (styrene-ethylene-butadiene-styrene block copolymer) in an amount of 10 parts by weight or less in the base resin. By introducing maleic anhydride-modified SEBS, cold resistance can be further improved.
As maleic anhydride-modified SEBS that can be used in the present invention, each monomer is copolymerized in a block shape and maleic anhydride is grafted. The styrene content in the maleic anhydride-modified SEBS is preferably 60% by weight or less from the viewpoint of mechanical properties. If it exceeds 60% by weight, it becomes hard and brittle and is not suitable for use in an optical cable sheath. The amount of modification with maleic anhydride is preferably 0.1% by weight to 20% by weight. If the amount is less than 0.1% by weight, the effect is not exhibited.

Furthermore, the flame retardant resin composition of the present invention does not contain red phosphorus as a flame retardant, but includes an aromatic phosphate and magnesium hydroxide.
Examples of the aromatic phosphate ester that can be used in the present invention include (C ₆ H ₅ O) ₂ P (O) OC ₆ H ₄ OP (O) (OC ₆ H ₅ ) ₂ , (C ₆ H ₅ O) ₂ P (O) C ₆ H ₄ C (CH ₃ ) ₂ C ₆ H ₄ OP (O) (OC ₆ H ₅ ) ₂ [(OC ₆ H ₃ (CH ₃ ) ₂ ) P (O) OC ₆ H ₄ OP (O) [OC ₆ H ₃ (CH ₃ ) ₂ ] ₂ or the like can be used. The aromatic phosphate ester is blended in an amount of 2 to 10 parts by weight with respect to 100 parts by weight of the base resin of the jacket. If the blending ratio is less than 2 parts by weight, the flame retardant effect is hardly exhibited, while if it exceeds 10 parts by weight, the cold resistance is deteriorated.

The magnesium hydroxide that can be used in the present invention is a synthetic magnesium hydroxide whose surface is treated with vinyl silane treatment, methacryloxy silane treatment, or in combination with oleic acid during these treatments. By using the synthetic magnesium hydroxide surface-treated by any of the above treatment methods, it is possible to improve the tensile strength and hardness of the jacket, and further the cold resistance. From the viewpoint of obtaining the above effect, synthetic magnesium hydroxide is surface-treated by any of the following methods: treatment with a combination of vinyl silane and oleic acid, treatment with methacryloxy silane, or treatment with a combination of methacryloxy silane and oleic acid. It is desirable.
Synthetic magnesium hydroxide is contained in an amount of 30 to 70 parts by weight with respect to 100 parts by weight of the base resin of the jacket. If it is less than 30 parts by weight, the desired flame retardancy cannot be obtained, and if it exceeds 70 parts by weight, the cold resistance is deteriorated.

  Said aromatic phosphate ester and synthetic magnesium hydroxide are mix | blended as a flame retardant as mentioned above. Further, if the synthetic magnesium hydroxide is within the above addition range, it contributes to the improvement of the tearability of the notch 18 when the optical fiber core wire is taken out when used in the optical fiber cable shown in FIG.

  In addition to the flame retardant, silicone, fatty acid amide, stearic acid, metal stearate, paraffin and the like may be added to the flame retardant resin composition of the present invention as a processing aid. In particular, the fatty acid amide (lubricant) improves the removability of the insulator and sheath when the flame retardant resin composition of the present invention is used as the insulator of the insulated wire and the sheath of the shielded wire shown in FIG. It is blended in. It is also useful in an optical fiber cable that needs to remove the jacket when laying. Similarly, components generally used as a resin compounding agent such as an antioxidant and an antifungal agent may be added.

  The flame-retardant resin composition of the present invention can be obtained by melt-kneading the above components with a kneading apparatus usually used such as a twin-screw kneading extruder, a Banbury mixer, a kneader, or a roll.

The flame-retardant resin composition of the present invention described above can be used as an insulator or sheath material (sheath covering resin) for insulated wires or shielded wires (coaxial wires).
Hereinafter, an insulated wire using the flame retardant resin composition of the present invention will be described in detail with reference to the drawings. 1A and 1B are schematic views illustrating an example of an embodiment of an insulated wire according to the present invention.
An insulated wire 1 shown in FIG. 1A is composed of a central conductor 2 and an insulator 3 that is disposed around the central conductor 2 and covers the central conductor 2. On the other hand, a shielded electric wire 4 shown in FIG. 1 (B) includes an insulated wire 1 shown in FIG. 1 (A) and an outer conductor 5 (for example, a braided conductor) disposed around the central conductor 2 of the insulated wire 1 in a coaxial structure. And a layer in which a plurality of metal wires are spirally wound) and a sheath 6 disposed around the outer conductor 5. The flame-retardant resin composition of the present invention can be used for both the insulator 3 and the sheath 6 of the electric wire shown in FIGS. 1A and 1B, but is desirably used for the outermost layer.

Moreover, the flame-retardant resin composition of the present invention can also be used as a jacket resin for optical fiber cables. In particular, since the flame-retardant resin composition of the present invention is excellent in properties such as tensile strength and tensile elongation in addition to flame retardancy, cold resistance, and hardness, it is particularly useful as an outer sheath of a drop optical cable having a structure described later. It can be used suitably. The drop optical cable is used for drawing the optical cable into the house.
Hereinafter, an optical fiber cable using the flame retardant resin composition of the present invention for the outer cover will be described in detail. FIG. 2 is a schematic view showing an example of an embodiment of a drop optical cable using the flame retardant resin composition of the present invention as a jacket.
FIG. 2A shows an embodiment using one single-core optical fiber core of the optical fiber cable of the present invention, and FIG. 2B shows a four-fiber optical fiber ribbon. Another embodiment using two sheets is shown. The number of cores of the optical fiber core wire is not limited to these, and can be any number of cores such as two cores and four cores.

  In the figure, 11 and 11 'are optical fiber cables, 12 is a main body part, 13 is a support line part, 14 is a neck part, 15 is an optical fiber core wire, 15' is an optical fiber tape core wire, 16 is a tension member, and 17 is a tension member. A jacket, 17a is a side surface of the main body, 18 is a notch, and 19 is a steel wire.

  An optical fiber cable 11 shown in FIG. 2A has a self-supporting structure in which a main body portion 12 having a rectangular cross section and a support line portion 13 having a circular cross section are connected by a narrow neck portion 14 that can be easily cut. It is formed. The main body 12 includes a single optical fiber core 15 disposed at the center, tension members (also referred to as strength members) 16 disposed on both sides thereof, and a body 17 that is integrally covered. Further, notches 18 are provided on both side surfaces 17 a of the main body 12 so that the V-shaped bottom portion approaches the optical fiber core wire 15.

  The support wire portion 13 is a steel wire 19 (outer diameter of about 1.2 mm) made of a single core wire or a stranded wire, and is on or near an extension line of the line Y connecting the center of the optical fiber core wire 15 and the tension member 16. Is provided. The steel wire 19 of the support wire portion 13 is connected to the main body portion 12 via the neck portion 14 that can be easily cut, and is covered by extrusion molding with the same resin material at the time of forming the outer cover 17 of the main body portion 12.

The optical fiber core 15 is, for example, a glass fiber having a standard outer diameter of 125 μm and is coated with one or two layers with a coating outer diameter of around 250 μm. Including those colored. One to several optical fiber cores 15 are directly covered with an outer cover 17 and stored.
As the tension member 16 arranged in parallel with the optical fiber core wire 15, a steel wire having an outer diameter of about 0.4 mm, glass fiber reinforced plastic (FRP), aramid fiber reinforced plastic (KFRP), or the like can be used. The jacket 17 constituting the coating of the main body portion 12 and the support wire portion 13 of the optical fiber cable is formed of the flame retardant resin composition of the present invention. Since the flame-retardant resin composition of the present invention is highly rigid and excellent in tensile strength and tensile elongation, it can be suitably used as a jacket resin excellent in drop resistance of a drop cable for the reasons described later.

  In the optical fiber cable 11 configured as described above, for example, when the number of the optical fiber core wire 15 is one, the longitudinal width L on the long side of the main body 12 is 3.1 mm, and the lateral width W on the short side is 2.0 mm. The diameter D of the support wire portion 13 can be formed with a standard outer dimension of 2.0 mm, and the length K of the neck portion 14 can be 0.2 mm. The notch 18 is formed with a depth of about 0.2 mm and a width of about 0.3 mm. The separation distance S between the bottom end of the notch 18 and the optical fiber core wire 15 is designed in consideration of the jacket material and tearability described later.

  An optical fiber cable 11 ′ shown in FIG. 2 (B) is a configuration in which two optical fiber tape cores 15 ′ are stacked in place of the optical fiber core 15 in FIG. 2 (A). Is the same as that of FIG. However, since the number of optical fiber cores is 8, the longitudinal width L on the long side is 4.1 mm. The other side width W of 2.0 mm, the diameter D of the support wire portion 13 of 2.0 mm, and the length K of the neck portion 14 of 0.2 mm are the same as those in FIG. can do.

  The “optical fiber core wire” in the present invention includes an optical fiber tape core wire such as the optical fiber tape core wire 15 ′. In an optical fiber cable including an optical fiber ribbon or an optical fiber cable including a plurality of optical fiber cores, there are a plurality of lines connecting each optical fiber core and the center of the tension member. Therefore, the support line portion is in the vicinity of the extension line of the line connecting any one of the optical fiber core wires and the tension member.

  When an optical connector or the like is attached to the optical fiber cable 11 or 11 'described above to form a terminal, the notch 18 at the end of the cable is removed with a nipper or the like in order to take out the optical fiber core wires 15 and 15' in the jacket 17 Make a cut of about 10 mm. Next, starting from this notch, the portion of the notch 18 is torn about 100 mm by hand to divide the jacket 17 into two. In order to tear the outer cover 17 by hand, the distance S between the tip of the notch 18 and the optical fiber cores 15 and 15 'is greatly related. However, if the distance reaches the optical fiber core and the separation distance S is increased to avoid this, tearing becomes difficult.

  Further, assuming that the above-mentioned separation distance S is set to a predetermined value, the outer shell 17 can be easily torn when the outer shell 17 has a low tensile strength, but the amount of piercing by the spawning tube of the cocoon increases and the separation is increased. It is necessary to increase the distance S. On the other hand, if the outer shell 17 has a high hardness and a high tensile strength, the amount of puncture by the spawning tube of the spider can be suppressed, but if the tensile strength is too high, tearing becomes difficult.

  In addition to the above structural features, the optical fiber cable of the present invention has an outer sheath formed of the flame retardant resin composition of the present invention that has both weather resistance and flame retardancy and is excellent in cold resistance and tensile elongation. Have. As described above, weather resistance can be obtained by satisfying both hardness and tensile strength suitable for weather resistance. Cold resistance is an important characteristic for preventing damage when a cable is bent in a cold region. Further, the tensile elongation is an important characteristic for the ease of taking out the optical fiber core by tearing the optical fiber cable at the notch portion.

  Hereinafter, the results of evaluation tests using examples and comparative examples according to the present invention will be shown, and the present invention will be described in more detail. The present invention is not limited to these examples.

Using the jacket materials (Examples 1 to 9, Comparative Examples 1 to 10) having the compositions shown in Table 1, various characteristics were evaluated in the following manner. In order to improve the long-term stability of the jacket, 1 part by weight of an antioxidant (hindered phenol type) was added in common to all of the examples and comparative examples.
A sample to be used for the evaluation test was obtained by first heating and mixing each of the blending components shown in Table 1 with an oil heating type open roll heated to 200 ° C., and molding this. For the hardness, tensile strength, tensile elongation, and low temperature embrittlement test, the product obtained by mixing the rolls was molded into a sheet with a press. On the other hand, for the sample used for the JIS 60 degree inclined combustion test, the one obtained by the above roll mixing is cut into pellets with a pelletizer, and this pellet is coated around the optical fiber core using a 65 mmφ extruder. The drop cable shape (1 core and 8 cores) shown in FIG. 2 (A) or (B) was obtained. The obtained cable sample had a lateral width W of 2.0 mm, a longitudinal width L of 3.1 mm, and a diameter of the support wire portion 13 of 2.0 mm.
The evaluation results of each example are also shown in Table 1. The unit of each numerical value in the material composition in the table is “part by weight”.

<Evaluation test method>
[hardness]
The hardness of the jacket was measured using a durometer (type D) defined by JIS K7215 (plastic durometer hardness test method) of Japanese Industrial Standard (hereinafter referred to as Shore D hardness). The criterion for the hardness of the jacket is that the Shore D hardness is 57 or more is a necessary condition for weather resistance.

[Tensile strength]
The tensile strength of the jacket was measured using a No. 2 test piece in accordance with JIS K7113 of Japanese Industrial Standard. The criterion for determining the tensile strength is that when the spawning tube of a spider is pierced into the outer cover, the outer cover is not deformed, and it is possible to prevent the securing of a space for laying the eggs, so that the sputum resistance is not less than 15.2 MPa. It was a necessary condition.

[Tensile elongation]
The tensile elongation of the jacket was performed using a No. 2 test piece in accordance with JIS K7113 of the Japanese Industrial Standard. The criterion for determining the tensile elongation of the jacket is that it is 320% or more, since it can be bent and used when laying the cable.

[Cold resistance (low temperature embrittlement test)]
The low-temperature embrittlement test (cracking temperature) is for verifying impact resistance at low temperatures, and was performed in accordance with Japanese Industrial Standard JIS C3005. The criterion was that a sheet-like test piece having a thickness of 2 mm was hit with a hitting tester at a low temperature of less than −30 ° C., and the sheet surface was not cracked.

[Flame retardance (60 degree inclined combustion test)]
A 1-core cable and an 8-core cable were used for the test. This was performed in accordance with Japanese Industrial Standard JIS C3005. A sample of about 300 mm in length collected from the finished product is supported at an inclination of about 60 degrees with respect to the horizontal, and the tip of the reducing flame is applied to a position about 20 mm from the lower end of the sample until it burns within 30 seconds. , Take out the flame quietly. And the case where it extinguishes naturally is considered as a pass.

  As shown in the above results, the jackets of Examples 1 to 9 made of a jacket material of a predetermined blending amount have excellent performance in flame retardancy, tensile strength, Shore D hardness, cold resistance, and tensile elongation. It was confirmed.

  In Comparative Example 1, since a propylene homopolymer was used as the base resin, tensile elongation was insufficient and cracks occurred at low temperatures.

  Since Comparative Example 2 uses low-density PE (obtained by radical polymerization) as the base resin, the tensile strength and Shore D hardness were small, and cracks occurred at low temperatures.

  Since Comparative Example 3 used magnesium hydroxide treated with oleic acid as a flame retardant, the tensile strength and Shore D hardness were small, and cracks occurred at low temperatures.

  In Comparative Example 4, since the blending amount of the polypropylene block copolymer was small, the Shore D hardness did not increase.

  In Comparative Example 5, since the amount of the polypropylene block copolymer was too large, the tensile elongation was insufficient and cracks occurred at low temperatures.

  In Comparative Example 6, the amount of magnesium hydroxide treated with vinylsilane was too small, resulting in poor flame retardancy.

  In Comparative Example 7, cracking at low temperature occurred because the amount of magnesium hydroxide treated with vinylsilane was too large.

  Since the comparative example 8 reduced the compounding quantity of the aromatic phosphate ester which is a flame retardant with 1 weight part, it resulted in inferior flame retardance.

  In Comparative Example 9, since the blending amount of the aromatic phosphate ester, which is a flame retardant, was increased to 12 parts by weight, cracks occurred at low temperatures.

In Comparative Example 10, no flame retardant such as red phosphorus or aromatic phosphate was added, and therefore the flame retardancy was NG.
When using a resin material exhibiting high hardness as in this example, if a large amount of metal hydroxide is added for the purpose of improving flame retardancy, the impact resistance at low temperatures will deteriorate and the tensile strength will decrease. . Therefore, if a metal hydrate is added to such an extent that a desired strength is achieved, a flame-retardant cable cannot be obtained by itself.

  The optical fiber cable shown in FIG. 2 can ensure flame retardancy, hardness suitable for weathering, and tensile strength by using the flame retardant resin composition of the above-described embodiment as the jacket 17. it can. Moreover, according to the said jacket material, the performance which was excellent also about cold resistance can be ensured. Further, it was found that the outer casing 17 formed of the flame retardant resin composition of the present example has an excellent tensile elongation, and therefore the tearability of the notch 18 is also excellent.

  In addition, in the composition of the jacket material in Example 4, when magnesium hydroxide treated with vinylsilane and oleic acid was used instead of magnesium hydroxide treated with vinylsilane, and hydroxide treated with methacryloxysilane In any case where magnesium was used, it was confirmed that an effect equivalent to that of Example 4 was obtained.

  Although the case of the optical fiber cable has been described in the above embodiment, the flame retardant resin composition of the present invention is used as an insulator or sheath material (sheath covering resin) for halogen-free insulated wires and shielded wires (coaxial wires). it can. These electric wires can be used for in-apparatus wiring applications and in-vehicle applications. Further, a plurality of electric wires can be collected and used as a cable or a harness. In any case, by using an electric wire using the flame retardant resin composition of the present invention, it has flame retardancy as an electric wire, cable or harness. And since the addition amount of a metal hydrate is smaller than before, it is excellent in the extrudability of coating resin when manufacturing. Furthermore, it has excellent impact resistance at low temperatures and does not hinder the development of the mechanical strength of the resin material.

DESCRIPTION OF SYMBOLS 1 Insulated electric wire 2 Center conductor 3 Insulator 4 Shielded electric wire 5 Outer conductor 6 Sheath 11, 11 'Optical fiber cable 12 Main body part 13 Support line part 14 Neck part 15 Optical fiber core wire 15' Optical fiber tape core wire 16 Tension member 17 Outside Cover 17a Side surface 18 Notch 19 Steel wire

Claims (6)

  To 100 parts by weight of base resin comprising at least 40 to 80 parts by weight of high density polyethylene or polypropylene block copolymer and 60 to 20 parts by weight of linear low density polyethylene, aromatic phosphate 2 as a flame retardant 10 parts by mass and vinyl silane treatment, methacryloxy silane treatment, or 30 to 70 parts by weight of magnesium hydroxide treated with oleic acid during these treatments, A flame retardant resin composition.   The flame retardant resin composition according to claim 1, wherein the linear low density polyethylene is polymerized using a Ziegler-Natta catalyst or a metallocene catalyst.   2. The surface treatment of the magnesium hydroxide is performed by any one of a treatment using a combination of vinyl silane and oleic acid, a methacryloxy silane treatment, or a treatment using a combination of methacryloxy silane and oleic acid. Or the flame-retardant resin composition of 2.   The flame retardant according to any one of claims 1 to 3, wherein the base resin contains 10 parts by weight or less of maleic anhydride-modified SEBS (styrene-ethylene-butadiene-styrene block copolymer). Resin composition.   The main body part and the support line part are connected via an easily cut neck part. The main body part is provided with tension members on both sides of the optical fiber core wire and is covered in a rectangular shape with a jacket, and is externally attached to both side surfaces. A notch for tearing is provided, and the support line portion is an optical fiber cable arranged on an extension line connecting the center of the tension member and the optical fiber core wire, and the jacket is claimed. Item 5. An optical fiber cable comprising the flame retardant resin composition according to any one of Items 1 to 4.   It is an electric wire which coat | covered the conductor with insulating resin, Comprising: At least outermost layer consists of a flame-retardant resin composition as described in any one of Claims 1-4, The electric wire characterized by the above-mentioned.

Images