JPH01107417A - Flame retardant wire and cable - Google Patents

Abstract

PURPOSE:To prevent generation of any noxious halogen gas or the like at the time of combustion, besides low fumeability, by installing a insulating fireproof layer, consisting of an insulating fireproof layer with a specific minute hollow sphere on an insulating wire core outer circumference, and installing a protective sheath made up of a specific constituent, on this outer circumference. CONSTITUTION:An insulating fireproof layer made up of a constituent containing a minute hollow sphere of less than 0.2kcal/mh deg.C in heat conductivity as much as 50-300wt. part to polyolefine 100wt. part is installed on an insulating wire core outer circumference, and a protective sheath made up of a constituent containing a moisture inorganic compound as much as 50-200wt. part to the polyolefoine 100wt. part is installed on this outer circumference. As for polyolefine forming the insulating fireproof layer, an ethylene-propylene copolymer or the like is usable. If an additive quantity of the hollow sphere is less than 50wt. part, heat insulation is seldom or never effective, but when exceeding a range of 300wt. part, it falls behind from the standpoint of extruding. In the moisture inorganic compound, it fails to give flame resistance at less than the 50wt. part, but when exceeding the 200wt. part, a drop in a mechanical characteristic and environment resistance is remarkable.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to flame-retardant electric wires and cables that do not generate toxic halogen gases when burned, particularly vertical trays of IEEE (Institute of Electrical and Electronics Engineers) 383. Combustion test (VTFT)
This relates to flame-retardant wires and cables that have a high degree of flame retardancy that passes the standards and have low smoke generation.

[Conventional technology]

In recent years, in consideration of fires occurring in buildings, high-rise buildings, power stations, various plants, etc., flame-retardant electric wires and cables that do not emit halogen gases that can affect the human body or cause corrosion of equipment have been developed. is strongly desired.

Moreover, the flame retardance level in this case is required to be extremely strict as shown in the above-mentioned VTFT.

Previously, the only cables that met such strict flame retardant standards were those with an insulator made of vinyl or polyolefin mixed with a halogen flame retardant, and a sheath made of vinyl, chloroprene rubber, etc. .

[Problem that the invention seeks to solve]

However, these cables have a problem in that they generate a large amount of halogen gas when burned, and also generate a large amount of smoke, which hinders aN and firefighting activities.

In addition, when considering the function of the sheath to protect the insulated wire core, mechanical properties and environmental resistance are important, and increasing flame retardance would sacrifice these, so there was a limit.

The present invention has been made based on the above, and has a high degree of flame retardancy that passes VTFT and has a 1/! A: The purpose of the present invention is to provide flame-retardant wires and cables that have excellent mechanical properties and environmental resistance, have low smoke emission, and do not emit toxic halogen gases when burned.

[Means and effects for solving the problems] The gist of the present invention is first to provide a heat insulating fireproof layer between the insulated wire core and the protective sheath, thereby greatly improving the M flammability of the cable. What's more, it is made of 100% polyolefin! 50 to 200 of the water-containing inorganic compound per part of the amount
The inventors have discovered that it is extremely effective to form a protective sheath with a composition containing 100 parts by weight of polyolefin, and have thus arrived at the present invention. Conductivity is 0.2Kcal/+
A heat insulating and fireproof layer made of a composition containing 50 to 300 parts by weight of micro hollow spheres having a temperature of mh °C or less is provided, and on the outer periphery of this layer is polyolefin 1003i! A flame-retardant electric wire characterized in that it is provided with a protective sheath made of a composition containing 50 to 200 parts by weight of a water-containing inorganic compound.
Achieved by cable.

In the present invention, the insulated wire core is constructed by providing an insulator around the outer periphery of the conductor, and may be a single strand or a plurality of strands twisted together.

The insulator of the insulated wire core is made of a halogen-free polymer, such as polyethylene, polypropylene, polybutene, poly 4
Methylpentene-11 crosslinked polyethylene, crosslinked polypropylene, ethylene/propylene copolymer, ethylene/propylene terpolymer, ethylene/ethyl acrylate copolymer, ethylene/butene copolymer, ethylene/vinyl acetate copolymer, natural rubber, Examples include butyl rubber, styrene-butadiene rubber, and silicone rubber.

As a result of intensive study on the coating layer for protecting such an insulated wire core in the event of a fire, the inventor of the present invention discovered that the IEEE383 V
In order to provide a high degree of flame retardancy that passes TFT, we believe that the best material is one that has the effect of heat insulation and fire protection to prevent the insulated wire core from melting and decomposing during combustion.
+8) bl per 100 parts by weight of polyolefin
Thermal conductivity is 0. A heat insulating fireproof layer was formed using a composition containing 50 to 300 parts by weight of micro hollow spheres of 2Kcal/ah''c or less.

In the present invention, the polyolefin forming the heat-insulating fireproof layer includes ethylene propylene copolymer, ethylene propylene dientro polymer, polyethylene, ethylene vinyl acetate copolymer, ethylene ethyl acrylate copolymer,
Examples include ethylene butene copolymer and ethylene butene terpolymer, and these can be used alone or in combination of two or more.

The micro hollow spheres used in the present invention generally include micro squares, micro drunes, and hollow bubbles.

It is called syntufting tsuohm material and usually has a thickness of 5 μm to 3
It is a fine hollow sphere that exists between about 0.11m, and there are inorganic and organic types.0 Typical examples include glass balloons,
Silica balloon, Shirasu balloon, Carbon balloon,
Examples include phenol balloons, alumina balloons, and zirconia balloons.

The hollow sphere contains 50 to 100 parts by weight of polyolefin.
It is necessary to contain an amount of 3001iE. The reason for this is that if the amount of the hollow spheres added is less than 50 parts by weight, there will be no heat insulating effect, and if it exceeds 300 parts by weight, the extrusion processability will be poor. In addition to the above ingredients, antioxidants, lubricants, and softeners as necessary.

A dispersant or the like may be added as appropriate.

The heat insulating and fireproof layer in the present invention is formed by extrusion or by winding a tape-formed material.

The fireproof layer made of the above composition may be formed directly on the outer periphery of one or more insulated wire cores, but if necessary, one or both of a metal tape and a flame retardant tape may be applied to the outer periphery of the insulated wire core. Alternatively, when the insulated wire core is made of a plurality of twisted wires, it is preferable to insert paper such as kraft paper into the gap.

In the present invention, the polyolefin used for the protective sheath may be the same as or different from the polyolefin used for the heat insulating and fireproof layer.

In addition, examples of hydrated inorganic compounds include aluminum hydroxide,
Examples include magnesium hydroxide, basic magnesium carbonate, hydrotalcites, and calcium hydroxide.

The hydrous inorganic compound must be contained in an amount of 50 to 200 parts by weight based on 100 parts by weight of Polio 1747. If it is less than 50 parts by weight, the desired flame retardancy cannot be imparted,
If it exceeds 200 parts by weight, the mechanical properties and environmental resistance will deteriorate significantly.

In addition to the above components, ferrocene, red phosphorus, molybdenum oxide, etc. may be added, and further, carbon blank, antioxidant, lubricant, softener, dispersant, etc. may be added as appropriate.

〔Example〕

Examples of the present invention will be described below.

130 according to the proportions of various ingredients shown in Table 1.
The composition was put into a 12-inch roll kept at 10°C and kneaded with rolls to prepare a composition for a fireproof layer.

Further, various components were added to a 12-inch roll maintained at 130° C. according to the compounding ratios shown in Table 2, and roll kneading was performed to prepare a composition for a protective sheath.

Next, the compositions of each formulation example in Tables 1 and 2 were applied to the outer periphery of the insulated wire core as shown on each side of Table 3 in a 40 m/m extruder (L/D = 25 ) were extrusion coated to a predetermined thickness to produce electrical cables.

The evaluation results on each side are shown in Table 3.

The evaluation was performed as follows.

Flame retardant: Cables 2.4 m long on a vertical tray with a spacing of 1/2 of the outer diameter, conductor cross section of 22 mm, 3 cores, 8 u
For cables with one wire core, 8 cables are arranged vertically, and for cables with conductor cross section of 2 mm and 3 wire cores, 10 cables are arranged vertically. After applying a flame of 78,000 TU/fir from below for 20 minutes, the burner is extinguished. If the flame was self-extinguished, the flame was passed, and if it burned to a height of 1.8 m, it was regarded as a failure.

Tensile Properties 2 After peeling off the protective sheath from the cable and leaving it in a constant temperature room at 20°C for 24 hours, the Schipper type tensile speed 2 was applied.
Measured at 00m/wm.

Possibility of consideration: After heat deterioration of the peeled protective sheath at 100° C. for 2 days, the residual tensile strength was determined.

In Table 1 of the heat-insulating and fire-protective compositions, Formulation Examples 1 to 6 meet the conditions for the heat-insulating and fire-protective layer according to the present invention, but Formulation Example 7 has the weight percent of micro hollow spheres less than 5θ%, In Example 8, the thermal conductivity of the micro hollow sphere is 0.2 Kcal/
sh°C or more, and in Formulation Examples 9 and 10, the weight parts of the micro hollow spheres are 300 or more, which exceeds the conditions.

Also, in Table 2 of the protective sheath composition, Formulation Example E.

In F, the content of the hydrous inorganic compound is 200 parts by weight or more, which is outside the conditions of the present invention.

In Table 3, Examples 1 to 6 have flame retardancy, tensile properties,
Comparative Examples 1 to 3 show excellent performance in both heat aging resistance and extrusion processability of the fireproof layer, but Comparative Examples 1-
8 indicates that the performance is unsatisfactory in any of the flame retardance, tensile properties, aging resistance, and extrusion properties of the fireproof layer.

〔Effect of the invention〕

The present invention provides a heat insulating fire protection layer on the outer periphery of the insulated wire core, which is made of a composition containing 50 to 300 parts by weight of micro hollow spheres with a thermal conductivity of 0.2 Kcal/nh"C or less per 100 parts by weight of polyolefin. , 50 to 2 parts of a water-containing inorganic compound is added to the outer periphery of the polyolefin based on 100 parts of polyolefin.
The flame-retardant wire/cable is characterized by being provided with a protective sheath made of a composition containing 0.00 parts by weight, which has a high degree of M flammability that passes VTFT, and has excellent mechanical properties and environmental resistance. Moreover, it was possible to provide flame-retardant wires and cables that have low smoke emission properties and do not generate toxic halogen gases when burned.

Claims (1)

[Claims] A heat-insulating fireproof layer made of a composition containing 50 to 300 parts by weight of micro hollow spheres with a thermal conductivity of 0.2 Kcal/mh°C or less per 100 parts by weight of polyolefin is provided on the outer periphery of the insulated wire core. A flame-retardant electric wire/cable comprising a protective sheath made of a composition containing 50 to 200 parts by weight of a hydrous inorganic compound per 100 parts by weight.