JPS6041706A - 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] FIELD OF THE INVENTION The present invention relates to fireproof cables.

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 and Disaster Management Agency's fire resistance test (840°C, 30 minutes).

The present invention relates to a fireproof cable that has passed the Fire and Disaster Management Agency's severe fireproofing test and can be used for low-voltage and high-voltage heavy-duty circuits.

The basic structure of this type of fireproof cable is to sequentially provide a fireproof layer, an intermediate insulating layer made of polyethylene or the like, and a protective layer made of polyvinyl chloride or the like on a conductor. As a tape, a laminated mica glass tape impregnated with silicone varnish or a tape made of a woven glass fiber tape impregnated with a heat-resistant resin having a heat resistance class H class or higher are used.

A fire-resistant cable constructed in this manner has the disadvantage that carbon residue tends to remain in a roasted state with little oxygen, which tends to cause insulation failure.

In order to eliminate this drawback, the amount of adhesive used can be reduced to a very small amount, but in the case of glass-mica tape, the adhesiveness between mica and glass is lacking, so there are problems when taping it onto the conductor. The reliability of the dielectric breakdown voltage of the resulting fireproof cable is also low, and even in the case of glass cables, the threads are likely to become frayed during taping.

They had the disadvantage of being susceptible to breakdown due to electrical stress and poor insulation.

The present invention improves these drawbacks, and
In 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, the number of carbons in the ring structure interwoven with the repeating unit of the basic structure/aliphatic carbon is used as an adhesive for the fire-resistant layer. Ratio of numbers, N is 0
．． The present invention relates to a fireproof cable made of a polymer having a molecular weight of less than 5.

In the present invention, the ratio of the number of carbon atoms in the ring structure to the number of aliphatic carbon atoms, N is the ratio of the number of carbon atoms in the ring structure to the number of aliphatic carbon atoms included in the repeating unit of the basic structure of the polymer. This ratio may be set to 0. For example, in the case of polyethylene, the repeating unit of the basic structure is -CH2CH2-, so it does not have an aromatic ring, so the number of carbons in the R structure is zero, and the ratio of the number of carbons in the fR groove structure to the number of aliphatic carbons is O/ 2=O is stopped. Or the basic structure.

This is because aromatic polyamide has two aromatic rings.

Since the number of carbon atoms in the ring structure is 12 and the number of aliphatic carbons is 2, the ratio is 12/2=6.

The ratio of methylphenyl silicone resin is 12/2=
It becomes 6.

Therefore, in the present invention, the adhesive used for the fireproof layer should either have no ring structure carbon such as aromatic carbon in the basic structure of the polymer, or even if it does have it, the ratio of the number of aliphatic carbons to is very small.

Table 1 shows the ratio, N, of the number of carbon atoms/the number of aliphatic carbons in the ring structure of the repeating units of the basic structure of typical polymers used in adhesives.

The following is Table 1 of Kanayama Table 1 continued Table 1 continued The adhesive of the present invention has the above ratio, N is 0.5
Since it is less than 1.2, 7, 9゜10.11,
It was around 12.13 mag. If the above ratio (N) is 0.5 or more, the insulation resistance of the high-temperature insulation will be extremely reduced, so that it cannot be used in the present invention.

In addition to the above-mentioned polymers, the adhesive used in the present invention includes:
Contains solvent, curing catalyst, etc. as necessary.

Toluene, methanol, acetone, etc. are used as the solvent. As the curing catalyst, peroxides such as benzoyl peroxide and dicumyl peroxide, amines such as triethanolamine, metal salts such as dibutyltin octoate, etc. are used.

In the present invention, the insulating layer provided on the conductor is composed 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.

The fireproof layer provided on the conductor is made by laminating mica lamination using the above-mentioned adhesive onto a base material such as glass cloth, glass yarn, or aliphatic plastic film such as polyethylene film. The above base material may be impregnated with the above adhesive without bonding the mica aggregate. For example, a polyethylene tube is used as the intermediate insulating layer. For example, a polyvinyl chloride tube is used as the protective layer.

For example, the fireproof cable is manufactured as follows.

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

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

The present invention will be described in detail.

Example 1 Soft laminated mica sheet (manufactured by Hitachi Chemical Co., Ltd., thickness 0.08 mm) and glass cloth (manufactured by Nittobo Co., Ltd.,
WE-03), 100 parts by weight of polybutadiene resin (Nippon Soda Co., Ltd., PB-B12O3) and 1.0 parts by weight of benzoyl peroxide as an adhesive. A mixture of parts of OM and 3 parts by weight of toluene was impregnated so that the amount of adhesive was 15% by weight.

By heating and drying at 140° C. for 10 minutes, an insulating tape having a thickness of 0.14 mm and serving as a fireproof layer was obtained.

Example 2 Acrylic acid and butyl acrylate copolymer (
A compound prepared by kneading mica powder (manufactured by Hitachi Chemical Co., Ltd.) with tolylene diiso7anate (manufactured by Hitachi Chemical Co., Ltd., AD103P) as a curing agent was dissolved in ethyl acetate to obtain a 10 weight percent solution. Add glass tape (Nittobo Co., Ltd., TB13) into this solution.
25) was impregnated with adhesive to a concentration of 13% by weight.

It was dried at 110° C. for 20 minutes to obtain an insulating tape having a thickness of 0.16 mm and serving as a fireproof layer.

Comparative Example Epoxy resin EP834 was used as an adhesive on a soft laminated mica sheet (manufactured by Hitachi Chemical Co., Ltd., thickness 0.08 mm) and glass cloth (manufactured by Nittobo B Co., Ltd., WE-03).
(Manufactured by Shell Chemical Co., Ltd.) 101tt part.

B Fs monoethyl amine/complex (mixed with 1 part of IL-5) was impregnated with adhesive in an amount of 8% by weight, heated and dried at 140°C for 15 minutes, and a thickness of 0.13
Insulating tape was obtained to serve as a fireproof layer for the anus.

The above tape was used as a fireproof layer on a copper wire having a diameter of 2 m, and was taped in a half-lap manner. Next, this wire was extruded and coated with polyethylene, two of the resulting polyethylene-coated wires were lined up, and polyvinyl chloride was extruded and coated to obtain a fire-resistant cable.

The insulation resistance of the fireproof cable obtained above was measured in a fireproof test, and the results are shown in Table 2.

Table 2 The above test method involves cutting the fireproof cable 5 obtained above into lengths of 1.3 m and fixing them with fixing parts 6 with an interval of 200 holes, as shown in Figure 2. A load 7 corresponding to .6 m was applied, and the insulation resistance (MΩ) f after 30 minutes of combustion was measured according to the fire temperature curve shown in Fig. 3.

It is shown that the fireproof cable according to the present invention has excellent insulation resistance after 30 minutes at 840°C.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view of a fire-resistant cable according to an embodiment of the present invention, FIG. 2 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 weight...Fireproof cable 6...Fixing part 7...Load

Claims (1)

[Claims] 1. In a fire-resistant cable in which an absolute R layer consisting of a fire-resistant layer, an insulating layer between '+1' and a protective layer is sequentially provided on a conductor,
A fire-resistant cable made of a polymer having a ratio of the number of carbon atoms in a ring structure/the number of aliphatic carbons, N, which is composed of repeating units of the basic structure, as an adhesive used in the fire-resistant layer, is less than 0.5.