JPS59221903A - Wire and 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 The present invention relates to heat-resistant wires and cables, and particularly to wires and cables that can suppress the generation of toxic gases during combustion to an extremely small amount.

Tetraflu A loethylene-brobylene copolymer is known as a crosslinkable fluorine-containing elastomer copolymer that has high heat resistance, chemical resistance, and flame retardancy, and can be used as a conductor or electric wire. By coating the outer periphery of the core, it is possible to obtain electric wires and cables having the above features.

However, when these electric wires and cables burn during a fire, there is a problem in that they generate a large amount of toxic hydrogen fluoride due to heat splitting.To prevent this, conventional methods such as magnesium oxide, lead oxide, calcium oxide, and calcium hydroxide Hydrogen fluoride scavengers, such as The problem of damage has come to be newly recognized.

The present invention is based on the above, and aims to provide electric wires and cables that can suppress the generation of toxic gases during combustion without impairing the heat resistance, which is an inherent feature of tetrafluoroethylene-propylene copolymers. This is the purpose.

That is, the electric wire/cable of the present invention is constructed by providing a crosslinked coating layer of a composition containing 25 to 200 parts by weight of calcium carbonate per 100 parts by weight of a tetrafluoroethylene-propylene copolymer. It is.

In the present invention, the tetrafluoroethylene-propylene copolymer includes, in addition to the main components tetrafluoroethylene and propylene, components copolymerizable with these, such as ethylene, butene-1, isobutene, acrylic acid, and its alkyl ester, methacrylic acid and its alkyl ester, vinyl fluoride, vinylidene fluoride, hexaflu A lopropene, chloroethyl vinyl ether,
It may contain glycidyl vinyl ether, chlorotrifluoroethylene, perfluoroalkyl vinyl ether, etc. as appropriate.

In such a copolymer, the molar ratio of tetrafluoroethylene/propylene is 9515 to 30/70,
In particular, it is preferable to select from the range of 90/10 to 45155 from the viewpoint of heat resistance, moldability, etc., and the content of components other than the main component, which may be added as appropriate, is usually 50 mol% or less, particularly 30 mol%. It is preferable to select from the following ranges.

Calcium carbonate used in the present invention is as follows:
It may be either precipitated calcium carbonate or ground calcium carbonate, and is not particularly limited. Alternatively, the surface of these calcium carbonates may be treated with a fatty acid, a silane coupling agent, a titanate coupling agent, or the like.

The content of calcium carbonate is 25 to 200 parts by weight per 100 parts by weight of the tetrafluoroethylene-propylene copolymer.
If it is less than 25 parts by weight, the effect of suppressing the generation of hydrogen fluoride during combustion is small;
If the suspension exceeds 0, the heat resistance of the composition will be impaired and the viscosity will increase, making extrusion difficult.

The composition containing the tetrafluoroethylene-propylene copolymer and calcium carbonate as essential components is coated on the outer periphery of the conductor or wire core and then crosslinked.

As the crosslinking method, chemical crosslinking using organic peroxides, amines, etc., or irradiation crosslinking using ionizing radiation such as γ rays or electron beams is employed, and there is no particular limitation.

Specific examples of organic peroxides include di-t-butyl peroxide, [-butylcumyl peroxide, dicumyl peroxide, 2,5-dimethyl-2,5-di(-
butylperoxy)-hexyne-3,1,3-dosu(
Examples include t-butylperoxy-isobrobyl)benzene.

Specific examples of amines include hexamethylene diamine,
Examples include so-called alkyl polyamines such as tetraethylenepentamine and triethylenetetramine, their salts such as carbamic acid and cinnamylidenic acid, and aromatic polyamines such as piperazine, piperidine, pyridine, aniline, and phenanthroline, and their salts.

It is also possible to employ crosslinking aids such as allyl compounds, sulfur, organic amines, maleimide, methacrylates, and divinyl compounds, and preferably diallyl phthalate, triallyl phosphoric acid, triallyl isocyanurate, triallyl cyanurate, etc. Allyl compounds can be employed.

In the present invention, in addition to the above components, fluororesins such as polyvinylidene fluoride, ethylenetetrafluoroethylene, and polytetrafluoroethylene, and fluororubbers such as vinylidene fluoride-hexafluoropropylene copolymers may be appropriately mixed. good.

In addition, various additives such as carbon black such as MT carbon and 1N carbon, fillers such as talc, clay, and silicic anhydride, reinforcing agents, pigments, lubricants, extrusion aids, antioxidants, and stabilizers are added. agents may be mixed.

Examples of the present invention will be described below in comparison with comparative examples.

Predetermined amounts of various components shown in Table 1 were blended and kneaded using 8-inch rolls heated to 60°C. Next, set this to head=1
00℃, cylinder 1: 100℃, cylinder 2280
Using a 407 FL/m extruder (L/D = 22> ) for 3 minutes at 120°C to prepare an electric wire.

The electric wire produced as described above was burned in a burner, and the amount of hydrogen fluoride generated per unit U was determined by gas chromatography. In addition, after heating the wire at 250°C, it was allowed to cool to room temperature, and the heat resistance life was evaluated by the time until it broke when the wire was wound to its own diameter (= J digits).These results are listed in the lower column of Table 1.

As is clear from Table 1, in Examples 1 to 7, which fall within the scope of the present invention, there is almost no IF or raw hydrogen fluoride, and the heat resistance R life is sufficiently long.

On the other hand, in Comparative Example 1, in which the content of calcium carbonate was small, a large amount of hydrogen fluoride was generated, and in Comparative Example 2, in which the content was too high, the viscosity of the composition became high and extrusion was impossible. In addition, magnesium oxide, which is conventionally used as a hydrogen fluoride scavenger,
Calcium oxide is inferior to calcium carbonate in terms of heat resistance life.

As explained above, according to the present invention, it is possible to suppress the generation of hydrogen fluoride during combustion without impairing the heat resistance of the Te1-rafluoroethylene-propylene copolymer,
Its industrial value is extremely large.

Claims (1)

[Scope of Claims] 1. A coating layer of a composition containing 25 to 200 parts by weight of calcium carbonate based on 100 parts by weight of a fluoroethylene-propylene copolymer, and the coating layer is crosslinked. Electric wires and cables characterized by: 2 The molar ratio of tetrafluoroethylene/propylene in the tetrafluoroethylene-propylene copolymer is 9
515 to 30/70, the electric wire/couple according to claim 1.