JPH09320359A - Flame retardant wire/cable - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a non-halogen flame retardant wire/cable which has sufficient flame resistance, and is excellent in mechanical property and water resistance by adding a lead compound together with non-halogen phosphorus flame retardant into an electric insulation composition. SOLUTION: In a cable 1, the outer periphery of a tensile strength body 2 is coated by a spacer 3, and spiral spacer slit portions 3a are formed along the outer periphery of the spacer 3. Multi-core SM fiber tapes 4 are superimposed in multiple layers and contained in the slit portions 3a, and the outer periphery of the spacer 3 are successively coated by a hygroscopic swelling tape 5 and a sheath 6. Metal hydroxide of 30 to 250 parts by weight, phosphorus-based flame retardant of 0.1 to 50 parts by weight, and lead compound of 0.1 to 50 pts.wt. are mixed and added to polyolefine of 100 parts by weight so as to provide a composition. The composition is used for coating as the insulator of a conductor, a sheath 6, or both so as to provide a flame retardant wire/cable.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flame-retardant electric wire / cable, and more particularly to a halogen-free flame-retardant electric wire / cable.

[0002]

2. Description of the Related Art At present, as the height of buildings rises and effective use of underground areas such as underground malls and subways is promoted, from the viewpoint of ensuring safety, electric wires and cables used must have high flame retardancy. Is starting to appear.

As a standard for judging the flame retardancy, the IEEE
There is VTFT (Vertical Tray Combustion Test) of E (American Electrical Safety and Technology Association) standard 383. This is a combustion test of multi-strand laying that simulates the actual laying condition of electric wires and cables.
It has become common to adopt passing this test as a condition of high flame retardancy.

The flame retardancy level defined by VTFT is quite severe, and conventionally, as a flame retardant electrical insulating composition capable of satisfying such severe conditions, a material containing a halogen compound is proposed and used. It has been.

[0005]

Such a halogen-based flame-retardant electrically insulating composition generates a large amount of non-combustible halogen-based gas in the event of a fire. This nonflammable halogen-based gas not only blocks oxygen around the wires and cables but also prevents combustion.

However, although the halogen-based flame-retardant electrical insulating composition exhibits sufficient flame-retardant properties, the halogen-based gas generated during combustion also contains harmful substances such as hydrogen chloride. Be done.

That is, since the halogen-based flame-retardant electrically insulating composition generates a large amount of smoke containing harmful components, it deteriorates the visibility and visibility during evacuation behavior during a fire and also hinders fire-extinguishing activities. In addition, there is a risk of secondary disaster such as harmful components in the halogen-based gas having a bad effect on the human body. Furthermore, the halogen-based gas may react with moisture in the air to form hydrohalic acid, which may corrode the switchboard.

Therefore, a flame-retardant electrical insulating composition in which an inorganic hydroxide is mixed in place of the halogen-based compound and the safety in the case of fire is emphasized has been proposed and attracted attention.
The flame-retardant electrical insulating composition mixed with an inorganic hydroxide utilizes the endothermic action when the inorganic hydroxide releases crystal water during a fire as a flame-retardant effect. The sex is extremely low.

However, these inorganic hydroxides are inferior in flame retardant effect to the halogen-based compounds, and therefore it is necessary to mix them in a large amount. As a result, the mechanical properties are deteriorated and the practical use range is limited.

For these reasons, the number of cases in which an inorganic flame retardant and a phosphorus flame retardant, which is highly effective as a flame retardant aid, are used in combination is increasing recently. This makes it possible to suppress the amount of the inorganic flame retardant to be mixed and achieve both flame retardancy and mechanical properties, but the phosphorus flame retardant, as represented by red phosphorus, does not have very good water resistance. That is, the flame-retardant electrical insulating composition containing the phosphorus-based flame retardant causes a problem of water absorption when used in a high-humidity environment or in a state of being immersed in water, resulting in deterioration of electrical characteristics.

SUMMARY OF THE INVENTION It is, therefore, an object of the present invention to solve the above problems and provide a non-halogen flame-retardant electric wire / cable having sufficient flame retardancy and good mechanical properties and water resistance.

[0012]

In order to solve the above-mentioned problems, the invention of claim 1 is 30 to 250 parts by weight of metal hydroxide, 0.1 to 100 parts by weight of polyolefin.
A composition obtained by mixing and adding 50 parts by weight of a phosphorus-based flame retardant and 0.1 to 50 parts by weight of a lead compound is used as an insulator of a conductor or a sheath of an electric wire / cable, or the insulator and the sheath. Both are to be coated.

According to a second aspect of the present invention, the phosphorus-based flame retardant is
Red phosphorus or triphenyl phosphate.
The flame-retardant electric wire / cable described.

The invention of claim 3 is the flame-retardant wire / cable according to claim 1, wherein the lead compound is tribasic sulfate or tribasic maleic acid sulfate.

According to a fourth aspect of the present invention, the metal hydroxide is
The flame-retardant wire / cable according to claim 1, which has been surface-treated with a fatty acid metal salt having an average particle size of 3 μm or less, a silane coupling agent, or a titanate coupling agent.

The reason for limiting the above numerical range will be described below.

With respect to 100 parts by weight of polyolefin,
The reason why the mixing of 30 to 250 parts by weight of the metal hydroxide is limited is that the target flame retardancy cannot be obtained when the mixing amount of the metal hydroxide is less than 30 parts by weight, and the metal hydroxide of the metal hydroxide cannot be obtained. This is because if the amount of admixture is more than 250 parts by weight, the mechanical properties will be significantly reduced.

With respect to 100 parts by weight of polyolefin,
The reason for limiting the addition of 0.1 to 50 parts by weight of the phosphorus-based flame retardant is that when the amount of the phosphorus-based flame retardant mixed is less than 0.1 parts by weight, the effect as the flame retardant cannot be obtained, and This is because if the amount of the flame retardant mixed is more than 50 parts by weight, not only the mechanical properties but also the flame retardancy will be deteriorated, and further the water resistance will be significantly decreased.

With respect to 100 parts by weight of polyolefin,
The reason why the addition of 0.1 to 50 parts by weight of the lead compound is limited is that if the addition amount of the lead compound is less than 0.1 parts by weight, the water resistance improving effect cannot be obtained, and the addition amount of the lead compound is 50 This is because if the amount is more than the amount by weight, the mechanical properties are significantly reduced and the effect on water resistance is saturated.

According to the above constitution, 30 to 250 parts by weight of metal hydroxide, 0.1 to 50 parts by weight of phosphorus-based flame retardant, and 0.1 to 100 parts by weight of polyolefin are contained.
~ 50 parts by weight of a lead compound is mixed and added, and this composition is coated as an insulator of a conductor, a sheath of an electric wire / cable, or both an insulator and a sheath. It is possible to obtain a non-halogen flame-retardant electric wire / cable having good mechanical properties and water resistance.

[0021]

Embodiments of the present invention will be described below.

As a result of earnest studies, the inventors of the present invention have found that the flame retardancy is good by mixing a metal hydroxide and a phosphorus-based flame retardant in a polyolefin and adding a lead compound.
It has been found that it is possible to obtain a flame-retardant electrical insulating composition having excellent mechanical properties and water resistance.

FIG. 1 shows one form of a cross section of the flame-retardant electric wire / cable of the present invention.

As shown in FIG. 1, the flame-retardant electric wire of the present invention
The cable 1 covers the outer circumference of a tensile strength member (tension member) 2 with a spacer 3, and each spacer groove portion (six in the figure) 3 formed in a spiral shape along the outer circumference of the spacer 3.
The multi-core SM fiber tape 4 is multilayered on a (5 layers in the figure)
In addition to accommodating the same, the outer periphery of the spacer 3 is sequentially covered with the water-swelling swelling tape 5 and the sheath 6.

An enlarged view of the double-core SM fiber tape in FIG. 1 is shown in FIG.

As shown in FIG. 2, the multi-core SM fiber tape 4 has a plurality of optical fiber cores 13 (4 in the figure) formed by covering the outer circumference of the optical fiber 11 with a buffer layer 12 on the same plane. ) It is arranged and arranged together with the secondary coating layer 14.

With respect to 100 parts by weight of polyolefin,
A flame-retardant electrical insulating composition obtained by mixing and adding 30 to 250 parts by weight of a metal hydroxide, 0.1 to 50 parts by weight of a phosphorus flame retardant, and 0.1 to 50 parts by weight of a lead compound. , The sheath 6 of the flame-retardant electric wire / cable 1, or the secondary coating layer 14 of the optical fiber core wire (conductor) 13 (or the optical fiber 11).
Buffer layer 12), or sheath 6 and secondary coating layer 1
4 as both.

Examples of the polyolefin constituting the flame-retardant electrical insulating composition used in the flame-retardant electric wire / cable of the present invention include polyethylene, ethylene butene polymer,
Ethylene butene terpolymers, ethylene vinyl acetate copolymers, ethylene ethyl acrylate copolymers, ethylene methyl acrylate copolymers, ethylene methyl methacrylate copolymers, etc.
Used in combination with more than one species.

Examples of the metal hydroxide constituting the flame-retardant electric insulating composition used in the flame-retardant electric wire / cable of the present invention include, for example, aluminum hydroxide, magnesium hydroxide, calcium hydroxide, hydrotalcites. And so on. From the viewpoint of cohesiveness, toughness, water resistance, etc., it is more preferable to use a metal hydroxide surface-treated with a fatty acid metal salt having an average particle size of 3 μm or less, a silane coupling agent, a titanate coupling agent, or the like. .

Examples of the phosphorus-based flame retardant which constitutes the flame-retardant electrical insulating composition used in the flame-retardant electric wire / cable of the present invention include red phosphorus, triphenyl phosphate, and aromatic condensed phosphoric acid ester. However, red phosphorus and triphenyl phosphate are particularly preferable.

The lead compound that constitutes the flame-retardant electrical insulating composition used in the flame-retardant electric wire / cable of the present invention is
For example, lead oxide (litharge, lead sulphate), lead sulfate, tribasic lead sulfate, dibasic lead stearate sulfate, tribasic lead maleate sulfate, etc. can be mentioned, but especially tribasic lead maleate sulfate. , Tribasic lead sulfate is preferred.

The insulating layer or sheath made of the flame-retardant electrical insulating composition in the flame-retardant electric wire / cable of the present invention may be non-crosslinked, but it may be exposed to organic peroxide or electron beam irradiation. It may be crosslinked.

In the flame-retardant electric insulation composition used in the flame-retardant electric wire / cable of the present invention, a flame-retardant auxiliary agent such as carbon black, an antioxidant such as hindered phenol, and a lubricant are added. It goes without saying that it is okay.

Next, the operation of the present invention will be described.

With respect to 100 parts by weight of polyolefin,
A flame-retardant electrical insulating composition obtained by mixing and adding 30 to 250 parts by weight of a metal hydroxide, 0.1 to 50 parts by weight of a phosphorus flame retardant, and 0.1 to 50 parts by weight of a lead compound. The flame-retardant electric wire / cable 1 is covered with the sheath 6, the secondary coating layer 14 of the optical fiber core wire 13, or both the sheath 6 and the secondary coating layer 14, so that the flame-retardant property is good and the water resistance is high. It is possible to obtain a flame-retardant electrical insulating composition having excellent properties.

Although the details of the reason why the water resistance is remarkably improved are not clear, it is presumed as follows.

The phosphorus-based flame retardant is easily ionized, as it reacts with water to be converted into phosphoric acid. That is, the phosphorus-based flame retardant in the flame-retardant electrical insulating composition reacts with moisture in the air to generate ionic species in the flame-retardant electrical insulating composition. It is considered that this reduces the osmotic pressure of the flame-retardant electrical insulating composition, so that water penetrates into the flame-retardant electrical insulating composition, leading to a reduction in water resistance of the flame-retardant electrical insulating composition.

It has been confirmed that the combined use of the phosphorus-based flame retardant and the lead compound remarkably reduces the weight increase rate of the flame-retardant electrical insulating composition due to water absorption. Stabilizes the ionized phosphoric acid,
It is estimated to prevent water absorption.

[0039]

EXAMPLE A four-core SM fiber tape is produced by arranging four optical fiber core wires, each of which has an outer periphery of an optical fiber covered with a buffer layer, on the same plane and collectively covered with a secondary coating layer.

The four-core SM fiber tape is housed in five layers in six spacer grooves spirally formed along the outer circumference of the spacer covering the outer circumference of the strength member. Furthermore, the outer circumference of the spacer is covered with a water-swelling tape,
Then, the outer circumference of the water-swelling tape is covered with a sheath to prepare a flame-retardant electric wire / cable.

Example 1 As a constituent material of the sheath of a flame-retardant electric wire / cable, the melt index at 190 ° C. is 0.6 and the ethyl acrylate content is 1
90 parts by weight of 1.5% by weight of ethylene ethyl acrylate and linear low density polyethylene as a base, maleic anhydride content of 0.5% by weight and density of 0.92 g / cm 3.
70 parts by weight of magnesium hydroxide having an average particle size of 0.8 μm and surface-treated with stearic acid is added to 10 parts by weight of modified polyethylene of ² and red phosphorus (Nova Red 120 VFA; manufactured by Rin Kagaku Kogyo) 10 parts by weight, and tribasic lead maleate sulfate (Stabin
ex TcV; manufactured by Mizusawa Chemical Industry Co., Ltd.), mixed in an amount of 5 parts by weight, and further added with stearic acid and Irganox 1
Flame-retardant electrical insulation composition obtained by adding 0.5 part by weight of 010, 1 part by weight of silicone gum (dimethyl silicone, average molecular weight: 9,000), and 10 parts by weight of carbon black. Produces electrical wires and cables.

(Embodiment 2) Ethylene ethyl acrylate is used as a constituent material of the sheath of a flame-retardant electric wire / cable.
And the melt index at 190 ° C. is 1.
0 and a polyolefin composed of 20 parts by weight of ethylene vinyl acetate copolymer having a vinyl acetate content of 40% by weight and 10 parts by weight of modified polyethylene, 100 parts by weight of magnesium hydroxide and 8 parts by weight of red phosphorus. , And 4 parts by weight of tribasic lead maleate sulfate were mixed and added, and further 0.5 parts by weight of stearic acid and Irganox 1010, 1 part by weight of silicone gum, and 10 parts by weight of carbon black were added. A flame-retardant electric wire / cable is produced using the flame-retardant electrical insulating composition.

Example 3 Ethylene ethyl acrylate was used as a constituent material of the sheath of a flame-retardant electric wire / cable.
5 parts magnesium hydroxide to 0 parts by weight polyolefin
0 parts by weight, 30 parts by weight of triphenyl phosphate (manufactured by Daihachi Chemical Co., Ltd.), and 10 parts by weight of tribasic lead maleate sulfate were mixed and added, and further 0.5 parts by weight of stearic acid and Irganox 1010 were added, A flame-retardant electric wire / cable is produced using a flame-retardant electrical insulating composition obtained by adding 1 part by weight of silicone gum and 10 parts by weight of carbon black.

(Embodiment 4) As a constituent material of the sheath of a flame-retardant electric wire / cable, 80% of ethylene ethyl acrylate is used.
80 parts by weight of magnesium hydroxide, 10 parts by weight of red phosphorus, and tribasic lead sulfate (Stabin) in a polyolefin composed of 20 parts by weight of modified polyethylene and 20 parts by weight of modified polyethylene.
ex Tc; manufactured by Mizusawa Chemical Industry Co., Ltd.), and mixed with 5 parts by weight of stearic acid and Irganox 10
A flame-retardant electric wire / cable is produced using the flame-retardant electrical insulating composition obtained by adding 0.5 parts by weight of 10 and 1 part by weight of silicone gum and 10 parts by weight of carbon black.

(Comparative Example 1) As a constituent material of a sheath of an electric wire / cable, a polyolefin composed of 90 parts by weight of ethylene ethyl acrylate and 10 parts by weight of modified polyethylene was added to 80 parts by weight of magnesium hydroxide and red phosphorus. 1
A flame-retardant electrical insulating composition obtained by mixing 0 part by weight, and further adding 0.5 part by weight of stearic acid and Irganox 1010, 1 part by weight of silicone gum, and 10 parts by weight of carbon black, Create electric wires and cables.

(Comparative Example 2) As a constituent material of a sheath of an electric wire / cable, 80 parts by weight of magnesium hydroxide and 3 parts by weight of tribasic lead sulfate were mixed and added to a polyolefin of 100 parts by weight of ethylene ethyl acrylate. ,further,
Stearic acid, 0.5 parts by weight of Irganox 1010, 1 part by weight of silicone gum, 1 part of carbon black
An electric wire / cable is produced using the flame-retardant electrical insulating composition added by 0 part by weight.

(Comparative Example 3) As a constituent material of a sheath of an electric wire / cable, a polyolefin comprising 80 parts by weight of ethylene ethyl acrylate and 20 parts by weight of ethylene vinyl acetate copolymer, 10 parts by weight of magnesium hydroxide,
4 parts by weight of red phosphorus and 2 parts by weight of tribasic lead maleate sulfate were mixed and added, and further 0.5 parts by weight of stearic acid and Irganox 1010 and 1 part of silicone gum were added.
An electric wire / cable is produced using a flame-retardant electrical insulating composition obtained by adding 10 parts by weight of carbon black and 10 parts by weight of carbon black, respectively.

(Comparative Example 4) As a constituent material of a sheath of an electric wire / cable, a polyolefin composed of 90 parts by weight of ethylene ethyl acrylate and 10 parts by weight of modified polyethylene was added to 300 parts by weight of magnesium hydroxide and red phosphorus. 7 parts by weight and 5 parts by weight of tribasic lead sulfate were mixed and added, and further 0.5 parts by weight of stearic acid and Irganox 1010, 1 part by weight of silicone gum, and 10 parts by weight of carbon black were added. An electric wire / cable is produced using the flame-retardant electrical insulating composition.

(Comparative Example 5) As a constituent material of a sheath of an electric wire / cable, a polyolefin composed of 80 parts by weight of ethylene ethyl acrylate and 20 parts by weight of modified polyethylene was added to 90 parts by weight of magnesium hydroxide and red phosphorus. 7
0 parts by weight, and 10 parts by weight of tribasic lead maleate sulfate were mixed and added, and further 0.5 parts by weight of stearic acid and Irganox 1010, 1 part by weight of silicone gum, and 10 parts by weight of carbon black. An electric wire / cable is produced using the flame-retardant electrical insulating composition added.

Table 1 shows the specifications of the flame-retardant electrical insulating composition or composition which is the constituent material of the flame-retardant electric wire / cable or the sheath of the electric wire / cable in Examples 1 to 4 and Comparative Examples 1 to 5. .

[0051]

[Table 1]

Next, regarding the flame-retardant electric wires / cables or electric wires / cables of Examples 1 to 4 and Comparative Examples 1 to 5,
The tensile properties (tensile strength, elongation), water resistance, and flame retardancy were evaluated. The evaluation of each characteristic was performed by the following methods.

Tensile Properties Tensile properties are measured according to JIS after each flame-retardant wire / cable or wire / cable is press-molded at 180 ° C. to a thickness of 1 mm.
A dumbbell No. 3 test piece was prepared, and a tensile test was performed with a Shopper type tensile tester at a speed of 200 mm / min.

Water resistance Water resistance is measured by press-molding each flame-retardant electric wire / cable or electric wire / cable at 180 ° C. to a thickness of 1 mm, and then water temperature 75
It was immersed in water at 0 ° C. for 50 days, then taken out from the water, and the volume resistivity was measured at room temperature.

Flame retardance Flame retardance complies with IEEE 383 and cable length 2.4.
m flame-retardant electric wires / cables or electric wires / cables are vertically arranged in a specified number, and each flame-retardant electric wire / cable or electric wire / cable below 0.6m to 70,000 BTU
Apply / hr flame for 20 minutes. After that, when the flame is removed, if the cable self-extinguishes at less than 1.8 m, it passes.
If the fire was spread over 1.8 m or more, it was rejected.

As shown in Table 1, all of the flame-retardant electric wires / cables of Examples 1 to 4 have excellent tensile properties, and are PE standards (TS (tensile strength): 9.8 MPa) of the Electrical Appliance and Material Control Law.
As described above, TE (elongation): 300% or more) was satisfied. Moreover, it was also excellent in water resistance, and the volume resistivity after flooding was kept in the order of 10 ¹⁴ orders. In addition, it has good flame retardancy, and all flame-retardant wires and cables have passed the standards of the vertical tray combustion test.

On the other hand, the electric wire / cable of Comparative Example 1 has tensile properties (tensile strength: 11.4 MPa, elongation: 50).
0%), the flame retardancy is excellent, but since the lead compound is not mixed in the composition which is the constituent material of the sheath,
The water resistance (volume resistivity: less than 1.6 × 10 ⁹ Ω · cm ³ ) was poor.

The electric wire / cable of Comparative Example 2 has excellent tensile properties (tensile strength: 12.0 MPa, elongation: 550%) and water resistance (5.0 × 10 ¹⁴ Ω · cm ³ ), but has a sheath structure. Since the phosphorus-based flame retardant was not mixed in the composition as the material, the flame retardancy was poor.

The electric wire / cable of Comparative Example 3 has excellent tensile properties (tensile strength: 15.0 MPa, elongation: 600%) and water resistance (3.8 × 10 ¹⁴ Ω · cm ³ ), but has a sheath structure. Since the admixture amount (10 parts by weight) of the metal hydroxide (magnesium hydroxide) in the composition as the material was outside the specified range (30 to 250 parts by weight), the flame retardancy was poor.

The wires and cables of Comparative Example 4 were water resistant (1.
0 × 10 ¹⁴ Ω · cm ³ ), although the flame retardancy is excellent, the admixture amount (300 parts by weight) of the metal hydroxide (magnesium hydroxide) in the composition that is the constituent material of the sheath is within the specified range ( 30 to 250 parts by weight), the tensile properties (tensile strength: 6.0 MPa, elongation: less than 50%) were inferior.

In the electric wire / cable of Comparative Example 5, the admixture amount (70 parts by weight) of the phosphorus-based flame retardant (red phosphorus) in the composition which is the constituent material of the sheath is within the specified range (0.1 to 50 parts by weight). Since it is outside, tensile properties (tensile strength: 5.5MP
a, elongation: less than 50%), water resistance (volume resistivity: 1.0 x 1)
⁰⁹ Ω · cm ³ ) and inferior flame retardancy.

[0062]

In summary, according to the present invention, the following excellent effects are exhibited.

(1) It is possible to obtain a non-halogen flame-retardant electric wire / cable having sufficient flame retardancy and good mechanical properties.

(2) Since the lead compound is added to the flame-retardant electric insulating composition together with the phosphorus-based flame retardant, there is no fear of deterioration in water resistance.

(3) Since a non-halogen flame retardant is used as the flame retardant, no harmful gas is generated during a fire.

[Brief description of drawings]

FIG. 1 is a view showing one form of a cross section of a flame-retardant electric wire / cable of the present invention.

FIG. 2 is an enlarged view of a main part in FIG.

[Explanation of symbols]

 1 Flame-retardant electric wire / cable 6 Sheath 11 Optical fiber (conductor) 12 Buffer layer (insulator) 14 Secondary coating layer (insulator)

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical indication H01B 3/00 H01B 3/00 A 3/44 3/44 P

Claims (4)

[Claims] 1. 100 to 100 parts by weight of polyolefin, 30 to 250 parts by weight of metal hydroxide, 0.1 to 50 parts by weight.
A phosphorus insulator flame retardant and 0.1 to 50 parts by weight of a lead compound are mixed and added to a conductor insulator;
A flame-retardant electric wire / cable which is covered with a sheath of the electric wire / cable, or both the insulator and the sheath. 2. The flame-retardant wire / cable according to claim 1, wherein the phosphorus-based flame retardant is red phosphorus or triphenyl phosphate. 3. The flame-retardant electric wire / cable according to claim 1, wherein the lead compound is tribasic sulfate or tribasic maleic acid sulfate. 4. The metal hydroxide has an average particle size of 3 μm.
The flame-retardant electric wire / cable according to claim 1, which has been surface-treated with the following fatty acid metal salt, silane coupling agent, or titanate coupling agent.