JPS60189115A - Refractory cable - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] (Technical field to which the invention pertains) FIELD OF THE INVENTION The present invention relates to fireproof cables.

(Technical background of the invention and its problems) Recently, fire-related equipment such as fire extinguishing equipment, fire alarm equipment, and evacuation guidance equipment in the event of a fire is required to be equipped with an emergency power source. The wires used in this emergency power circuit are
It is necessary to pass the fire resistance test (840°C for 30 minutes) by the Tachibanbo Agency.

The basic structure of this type of fireproof cable is to provide a fireproof layer on the conductor, an intermediate insulating layer made of polyethylene or the like, and a protective layer made of polyvinyl chloride or the like. As the fireproof layer, resin-impregnated laminated mica glass tape or resin-impregnated laminated mica film tape is used.

Fireproof cables constructed in this way tend to leave carbon residue in a roasted state with little oxygen.

It has the disadvantage of easily causing insulation failure. In order to eliminate this drawback, a method is adopted in which the amount of adhesive is extremely reduced, but the laminated mica and the base material are lacking.
Kusunoki, 44 up. Mica tends to fall off or crack during carpise.

Moreover, in the fire resistance test of the obtained fire resistant cable, it has the disadvantage that it is easily broken due to electrical stress and causes insulation failure. Furthermore, these resin-impregnated laminated mica tapes are
The disadvantage is that the manufacturing process of making mica paper and bonding it to the base material is very expensive.

(Purpose of the invention) This invention has passed the Fire and Disaster Management Agency's severe fire resistance test.

The object of the present invention is to provide a fireproof cable that can be used for low-voltage and high-voltage heavy-duty circuits.

(Summary of the Invention) The present invention provides a fire-resistant cable in which an insulating layer consisting of a fire-resistant layer, an intermediate insulating layer, and a protective layer is sequentially provided on a conductor. , relates to a fire-resistant cable using a composition containing at least one of silicone rubber and silicone resin as a main component.

The black bean-based plastics used in the present invention are preferably aliphatic plastics in the form of pellets, such as polyethylene pellets and polypropylene pellets having a melting point in the range of 60 to 120°C.

The mica powder can be freely selected from fine powder to one with a relatively high asbestos ratio (diameter of micaline piece/thickness of micaline piece).

At least one of silicone oil, silicone rubber, and silicone resin may contain or not contain a curing catalyst or vulcanizing agent. The silicone oil is preferably a dimethyl type silicone oil, which is a siloxane obtained by condensation from organochlorosilane.

Examples include TSF400 (manufactured by Toshiba Silicone) and KF96 (Shin-Etsu Chemical #). As the silicone rubber, dimethyl silicone and rubber are preferred, and liquid type ones are more preferred. For example, there is TSE3221 (manufactured by Toshiba Silicone). The silicone resin is preferably methylpolysiloxane, and may be in liquid or solid form. In particular, as the silicone resin, a silicone with excellent flexibility in which silicone raw rubber and a silicone resin of a low polymerization degree polymer are bonded is preferable. For example, KR
'1O1 (Shin-Etsu Chemical System), etc.

Furthermore, the organic groups contained in these silicone compounds preferably have a small proportion of phenyl groups. As the curing catalyst, peroxides such as benzoyl peroxide and dicumyl peroxide, organic acid salts such as diptyltin dilaurate, tin dioctenate, and iron stearate are used.

In addition to these, inorganic fillers and glass fibers may also be used. Examples of inorganic fillers include water-containing alumina, aluminum hydroxide, and aluminum oxide.

Magnesium carbonate, calcium carbonate, silica, and the like are preferred. The glass fiber preferably has a diameter of 0.1 mm or less and a length of about 1 to 3 mm.

Based on electrical properties such as insulation resistance and dielectric breakdown voltage at high temperatures for fireproof cables, black bean-based plastics are
Preferably, the amount of mica powder is about 50 to 80% by weight, and the amount of at least one of silicone oil, silicone rubber, and silicone resin is about 5 to 30% by weight.

In the present invention, the insulating layer provided on the conductor is:

It consists of a fireproof layer, an intermediate insulating layer, and a protective layer.

In the present invention, a copper wire or the like is used as the conductor, and a polyethylene tube or the like is used as the intermediate insulating layer. A polyvinyl chloride tube or the like is used as the protective layer.

The composition containing the above-mentioned black soybean plastics, etc. is thoroughly mixed and placed in a cylinder of an extruder, preferably at a
The mixture is stirred and kneaded at 120° C., melted and extruded through an extruder, and formed into a tape, which is taped with half wrap or the like or directly extruded and coated onto a conductor to form a fireproof layer.

A fireproof cable is manufactured, for example, as follows.

The above-mentioned fireproof layer is formed on the conductor, then an intermediate insulating layer is formed by extrusion coating or the like, these are arranged, and a protective layer is formed thereon by extrusion coating or the like to obtain a fireproof cable.

An embodiment of the fireproof cable according to the present invention will be described with reference to FIG. 1. In FIG. 1, 1 is a conductor, 2 is a fireproof layer, 3 is an intermediate insulating layer, and 4 is a protective layer.

(Example of the invention) An example of the present invention is shown.

Example 1 68% by weight of powder of soft laminated mica (product name Pulp Mica manufactured by Hitachi Chemical Co., Ltd.), 18% by weight of Tetrocene 203 (manufactured by Toyo Soda Co., Ltd.) as thermoplastic plastic pellets, silicone oil KF96 (manufactured by Shin-Etsu Chemical Co., Ltd.) company) 12% by weight and Irrigation Alumina 2% by weight
Mix thoroughly and use as raw materials. This mixture was supplied from the hopper of an extruder (extrusion laminator manufactured by Nippon Steel Corporation) and stirred and kneaded at 95±5° C. in the cylinder of the extruder. This is melted and extruded with this extruder to a thickness of 0.15 to 0.201 nn+
This was cut into a sheet with a width of 25 mm to obtain a tape. This tape was half-wrapped in two layers as a fireproof layer on a copper wire having a diameter of 3.5 mm. Next, this wire was extruded and coated with polyethylene, and two of the obtained polyethylene coated wires were placed side by side and polyvinyl chloride was extruded and coated to obtain a fireproof cable.

Example 2 77% by weight of powder of soft laminated mica (trade name Pulp Mica, manufactured by Hitachi Chemical Co., Ltd.), 12% by weight of Tetrocene 203 (manufactured by Toyo Soda Co., Ltd.) as a thermoplastic plastic svelette, and 101-10 (manufactured by Toyo Soda Co., Ltd.) as a silicone resin. (manufactured by Shin-Etsu Chemical Co., Ltd.) 4% by weight, silicone resin KR2
20 (manufactured by Shin-Etsu Chemical Co., Ltd.) and 5% by weight of hydrated alumina were thoroughly mixed to prepare a raw material.

This mixture was fed into an extruder (a plastic type extruder made by Tabata Kikai) through a potper, and stirred and kneaded at 110±5° C. in the cylinder of the extruder. When a copper wire with a diameter of 3.5 m+n is passed through a die by this extruder, it is coated with the above composition, and at the same time polyethylene is melt-extruded as an intermediate insulating layer to form a tube.

Two well-obtained polyethylene coated wires were lined up and coated with polyvinyl chloride by extrusion to obtain one pull of fireproof goo.

Comparative example polyethylene film (HB-2 manufactured by Tamabori Co., Ltd.)
Silicone resin (Shin-Etsu Chemical KR101) was used as an adhesive.
-10) A mixture of 100 parts by weight of benzoyl peroxide, 3 parts by weight of benzoyl peroxide, and 200 parts by weight of toluene is applied to the obtained sheet so that the impregnated amount is 10% by weight, and the soft laminated mica A sheet (product name: Pulp Mica, manufactured by Hitachi Chemical Co., Ltd., thickness: 0.08 mm) was pasted together, dried at 150°C for 5 minutes, and then cut to a width of 25 wn.
A mica tape with a thickness of 0.15 mm was obtained. ``Two layers of the above mica tape were taped onto a copper wire with a diameter of 3.5 mm using a no-flap as a fireproof layer.

Next, this material is extruded and coated with polyethylene.

Further, two of the obtained polyethylene coated wires were placed side by side and coated with polyvinyl chloride by extrusion to obtain a fireproof cable.

A fire resistance test was conducted on the fire resistant cable obtained above, and the results are shown in Table 1.

Table 1 Fireproof test method: As shown in Figure 2, the fireproof cable 5 obtained above was cut into lengths of 1.3 m and fixed to the fixing parts 6 with 9 intervals of 200 mm. 2.6
A load 7 corresponding to m was applied and the fire was burned according to the fire temperature curve shown in FIG. 3, and the insulation resistance (MΩ) and dielectric breakdown voltage (KV) were measured after 30 minutes.

(Effects of the Invention) The fire-resistant cable according to the present invention has a fire-resistant layer formed without mica falling off or cracking, and has a heat resistance of 840°C.

The drop in insulation resistance was small in a 30 minute fire test.

It has been shown to have excellent fire resistance properties.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a fire-resistant cable according to an embodiment of the present invention, FIG. 7 is a schematic diagram showing a fire-resistance test method for the fire-resistant cable, and FIG. 3 is a fire temperature curve diagram during the test. Explanation of symbols 1...Conductor -2...Fireproof layer 3...Intermediate insulating layer 4...Protective layer 5...Fireproof cable 6...Fixing part 7...Load at rtI in Figure 3 (Furnace

Claims (1)

[Claims] 1. A fire-resistant cable in which an insulating layer consisting of a fire-resistant layer, an intermediate insulating layer, and a protective layer is sequentially provided on a conductor and removed, wherein the fire-resistant layer is made of thermofusible plastic, mica powder, or silicone. A fire-resistant cable made of a composition containing at least one of oil, silicone rubber, and silicone resin as a main component. 2. The fireproof cable according to claim 1, wherein the thermofusible plastic is polyethylene. 3. The fireproof cape according to claim 1, wherein the thermoplastic plastic is polypropylene.