JPS62246203A - Acid resistant flame retardant 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 [Industrial Field of Application] The present invention relates to a non-halogen flame-retardant cable that shows significantly less deterioration in flame-retardant properties even when immersed in an acidic aqueous solution.

[Conventional technology]

Conventionally, a polymer containing halogen is used for the outer sheath to make the cable flammable. Polymers containing halogens have the problem of generating toxic and corrosive gases when burned. In order to improve this problem, a non-halogen flame-retardant cable has been developed in which the olefin polymer is filled with a large amount of inorganic hydrates such as magnesium hydroxide and aluminum hydroxide and has a flame-retardant resin-gold jacket. This inorganic filler is usually treated with a fatty acid to improve its dispersibility in the resin, but this treated inorganic filler leaches into an acidic aqueous solution and has extremely low flame retardancy. There was a problem with the decline.

[Problem that the invention seeks to solve]

Using an inorganic photonic agent gold treated with a special coupling agent such as silver or titanium improves acid resistance, but compared to fatty acid treated products, it has inferior dispersibility when blended into resin and is more expensive. There were drawbacks such as.

An object of the present invention is to provide a non-halogen flame-retardant communication, power, and composite cable that solves the problem of inorganic hydrate dissolving in an acidic aqueous solution and reducing flame retardancy.

[Means for solving problems]

To summarize the present invention, the present invention relates to an acid-resistant flame-retardant cable, and the present invention relates to an olefinic polymer completely blind to polar groups or a mixture of this polymer and other polymers.
The entire feature is that the outer cover is made of an acid-resistant flame-retardant resin containing 40 to 150 parts by weight of an inorganic hydrate.

The cable of the present invention uses an olefinic polymer into which polar groups such as carboxyl groups, alkoxysilane groups, and hydroxyl groups are introduced, and firmly bonds the polymer and the inorganic hydrate photonic agent. The main feature of gold is that it has an acid-resistant resin-gold outer coating that completely prevents the elution of the metal into acidic solutions and eliminates any deterioration in flame retardancy. When conventional flame-retardant cables with an outer sheath made of inorganic hydrated flame-retardant resin are immersed in an acidic solution, the inorganic photoresist easily dissolves, resulting in a significant decrease in flame retardancy. The flame-retardant cable of the present invention has the advantage that even when immersed in an acidic solution, there is little elution of inorganic hydrates, and there is little deterioration in flammability compared to the conventional flame-retardant jacket filled with inorganic hydrates. Different from cable.

In the present invention, examples of olefinic polymers completely blinding to polar groups include unsaturated carboxylic acids or their acid anhydrides;
Guy7 or copolymerized olefinic polymer, 7
Examples include run-modified olefin polymers.

Examples of olefinic polymers grafted or copolymerized with unsaturated carboxylic acids or their acid anhydrides in the present invention include polyethylene, polypropylene, ethylene-propylene copolymers, ethylene-butene copolymers, and ethylene-vinyl acetate copolymers. Examples include polymers, acrylic acid graft-modified products such as ethylene-ethyl acrylate copolymer, maleic anhydride graft-modified products, ethylene-acrylic acid copolymer, and ethylene-acrylic acid-ethyl acrylate copolymer.

Examples of the silane-modified olefin polymer in the present invention include polyethylene, polypropylene, ethylene-
Propylene copolymer, ethylene-ethyl acrylate copolymer, ethylene-methacrylic ugly methyl copolymer, etc., are graft polymerized with alkoxysilane compounds that completely blind unsaturated double bonds as t-base polymers.Aroise is an alkoxysilane compound. It is possible to simply add .

As polymers to be mixed with these polymers, u, yH'
) Ethylene, polypropylene, ethylene-propylene copolymer, ethylene-vinyl acetate copolymer, ethylene-ethyl acrylate copolymer, polybutadiene, polyester elastomer, styrene elastomer, silicone elastomer, etc. can be used.

Examples of inorganic hydrates include aluminum hydroxide, magnesium hydroxide, calcium hydroxide, or mixtures thereof, which are contained in an amount of 40 to 150 parts by weight based on 100 parts by weight of the polymer, but 40 parts by weight. If it is less than 150 parts by weight, the flame retardance will be insufficient, and if it exceeds 150 parts by weight, the mechanical properties, especially the elongation, will decrease to 100X or less, causing a practical problem.

In the present invention, when carbon black, phosphorus, phosphorus compounds, molybdenum oxide, etc. are added in addition to the above-mentioned inorganic hydrate,
Furthermore, flame retardancy can be improved.

Further, antioxidants, lubricants, dispersants, etc. may all be added at appropriate times, if necessary.

The acid-resistant flame-retardant cable of the present invention can be molded with an acid-resistant resin jacket using an extruder in the same way as ordinary electric cables, communication cables, and composite cables. Further, it is possible to wrap the tape gold cable made of acid-resistant flame-retardant resin on the outside to form an outer covering.

Examples of cables according to the invention will be explained with reference to the accompanying drawings.

FIG. 1 is a sectional view of a 200-fiber slot type optical fiber cable. In Fig. 1, numeral 1 is an acid-resistant flame retardant resin jacket (2x thick), 2 is an aluminum wrap (0,2vn thick), 3 is a nonwoven fabric, 4 is a polyethylene rod with 12 grooves, and 5 is a 5-core optical fiber. Tape, 6 means center tension member. Reference numeral 1 in FIG. 1 is the outer cover according to the present invention, and the other members may be conventionally used members. For example, an example of the nonwoven fabric in No. 5 is a heat-insulating polyester-based one, and an example of No. 60 is a steel wire.

The cable for the combustion experiment does not include optical fiber. The test was conducted as follows.

(LL) #II Flammability IgKK383 Vertical Tray Burn Test evaluated the flame retardancy of the cable. In the combustion test, a cable of 240 mm was placed on a rack and heated with a burner for 20 minutes at a height of 60 mm.
This is one of the flame retardant evaluation methods for cables, in which all cables are passed if the length of damage is 180 crn or less.

(bJ 50C cable in 1FRP container with acid-resistant end sealed)
', after being placed in a 10% sulfuric acid aqueous solution for 1 day, and then dried in a 50C constant temperature room for 1 day, the flame retardance was evaluated by the 11 [E 583 vertical tray combustion test. At the same time, 1 was produced using a heat press.
The weight change was measured for the No. 111 sheet.

〔Example〕

EXAMPLES Hereinafter, the present invention will be explained in more detail with reference to Examples, but the present invention is not limited to these Examples.

Examples 1 to 111 Comparative Examples 1 to 4 Acid-resistant flame retardant resins having the formulations shown in Table 1 below were used in an extruder to form the jacket of the cable shown in FIG. In Examples 1 to 10 and Comparative Example 1, low density polyethylene (Example 1), ethylene-ethyl acrylate copolymer (Examples 2 to 9, and Comparative Example 1), and ethylene-vinyl acetate copolymer were used as the olefin polymer. In Example 11, a maleic anhydride graft of low density polyethylene was used as the olefin polymer grafted or copolymerized with an unsaturated carboxylic acid or its acid anhydride. This is an example in which a silane-modified ethylene-vinyl acetate copolymer was used as the system polymer. Examples of inorganic hydrates include magnesium hydroxide (Examples 1 to B, 10.11 and Comparative Example 1) and aluminum hydroxide (Example 9). It is shown in Table 1.

1) Ethyl acrylate content 15% by weight, melt index 0.51/10 m1n2) Vinyl acetate content 12% by weight, melt index 0.4.9
/ 10 win3) Ethylene-vinyl acetate copolymer (vinyl acetate content 19% by weight, melt flow rate 15
1/10 oIin) 1 part by weight of r-methacryloxyglobil trimethoxysilane to 100iii parts,
and 0.2 parts by weight of 1,1-bis(t-butylperoxy)3,3.5-)limethylcyclohexane as a radical polymerization initiator, and the entire mixture was kneaded in an extruder to form a silane graft. It was treated as a modified product.

Amount of maleic anhydride grafted: 1% by weight or less, melt index: 1/i/IQ win5) Kisuma 5a (manufactured by Kyowa Kagaku Co., Ltd.) 6) Hisilite H-42M (manufactured by Showa Light Metal Co., Ltd.) Flame retardance of magnesium hydroxide is 50 If the amount is insufficient, it is necessary to use 40 parts by weight or more. When the amount is 40 parts by weight or more, it not only satisfies the initial flame retardant properties, but also shows almost no weight loss after being immersed in the sulfuric acid aqueous solution, and the flame retardance remains the same as the initial properties, showing excellent acid resistance. have

Like Examples 1 to 10, Example 11 not only fully satisfied the initial properties of flame retardancy, but also showed almost no weight loss after immersion in the sulfuric acid aqueous solution, and the flame retardancy was unchanged from the initial properties.
Excellent acid resistance and blindness.

Comparative Examples 2 to 4 are oletuin-based polymers [low-density polyethylene (Comparative Example 2), ethylene-ethyl acrylate copolymer (Comparative Example 3), ethylene-vinyl acetate copolymer (Comparative Example 4)] with inorganic hydration. This is an example in which all magnesium hydroxide was added. Although the initial flame retardant properties are satisfactory, there is a large weight loss after immersion in a sulfuric acid aqueous solution, and the flame retardant properties are lower than [EK38].
3 Vertical tray combustion test was unsatisfactory and acid resistance was poor? show.

For some of the items shown in Table 1 in Figure 2, 1g838
Damage length (tnr, vertical axis) in 3-core straight tray combustion test
The relationship between the amount of magnesium hydroxide added and the amount of added magnesium hydroxide (N1 part, horizontal axis) is shown as a complete graph.

In addition, when an olefin-based polymer is used in a gold jacket, an ethylene-ethyl acrylate copolymer exhibits superior flame retardancy compared to low-density polyethylene and ethylene-vinyl acetate copolymer. This is made of low-density polyethylene, ethylene-vinyl acetate copolymer, and ethylene-vinyl acetate copolymer.
This is because the outer jacket made of olefinic polymer forms a foamed shell without falling off, and acts as a heat insulating layer and a flame barrier inside the cable.

Furthermore, the addition of red phosphorus improves flammability.

The less inorganic hydrates there are, the better the mechanical properties of the flame retardant resin will be. Ethylene as an olefin polymer for flame retardant resin
Ethyl acrylate copolymer By using the gold-containing polymer, the amount of inorganic hydrate added can be reduced, and a flame-retardant cable with excellent acid resistance and mechanical properties can be provided.

〔Effect of the invention〕

As explained above, the cable of the present invention is made of a flame-retardant resin whose jacket is made by blending an inorganic hydrate of a flame retardant with an olefin-based polymer that is completely blind to polar groups. Because a strong bond is formed, flame retardancy does not decrease even when immersed in an acidic aqueous solution, and it has the advantage of having excellent acid resistance.

The acid-resistant flame-retardant cable of the present invention does not generate harmful halogen-based gases when burned, and its flame retardancy does not deteriorate even when exposed to acidic solutions such as acid rain, industrial wastewater, mineral water, and hot springs, and Compared to other types of non-halogen flame-retardant cables, the material and manufacturing costs are different, so the cable price remains the same. For this reason, it is effective to use underground cables in tunnels, conduits, gutters, subways, mine roads, etc. where acidic solutions that require flame retardancy may flow. Of course, it has the advantage that it can be used as a flame-retardant cable indoors or in vehicles such as trains, buses, and ships, where acidic solutions are not a problem.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view of a 200-fiber slot type optical fiber cable, and FIG. 2 is a graph showing the relationship between damage length and amount of magnesium hydroxide added in the IKEIE 383 vertical tray combustion test. 1: Acid-resistant flame retardant resin jacket, 2: Niall lap, 3: Non-woven fabric, 4: Polyethylene rond with 12 grooves, 5: 5 optical fiber tape, 6: Center tension member

Claims (1)

[Claims] 1. An acid-resistant flame-retardant resin containing 40 to 150 parts by weight of an inorganic hydrate per 100 parts by weight of an olefinic polymer having a polar group or a mixture of this polymer and another polymer. An acid-resistant flame-retardant cable characterized by having an outer sheath. 2. The acid-resistant flame-retardant cable according to claim 1, wherein the olefin polymer having a polar group is an olefin polymer obtained by grafting or copolymerizing an unsaturated carboxylic acid or an acid anhydride thereof. 3. The acid-resistant flame-retardant cable according to claim 1, wherein the olefin polymer having a polar group is a silane-modified olefin polymer. 4. The acid-resistant flame-retardant cable according to claim 1, wherein the inorganic hydrate is aluminum hydroxide, magnesium hydroxide, calcium hydroxide, or a mixture thereof.