JP3084035B2 - Heat resistant wires and cables - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a heat-resistant electric wire / cable, and more particularly, to a method for connecting an insulator covering layer and a separator at an end of an electric wire / cable at the time of connection or the like. The present invention relates to a heat-resistant wire / cable that can be easily removed in a single operation.

[Conventional technology]

In a heat-resistant electric wire whose outer periphery is covered with a fluorine-containing elastomer, between the stranded conductor and the coating layer, fusion and self-adhesion at 150 ° C or higher are performed to prevent adhesion between the stranded conductor and the coating layer. It is known that a separator, such as a fluororesin tape, which does not break, is interposed between the stranded conductor and the coating layer. (Japanese Patent Publication No. 1-381414).

[Problems to be solved by the invention]

However, in such a conventional electric wire, when a covering layer at an end of the electric wire is removed (hereinafter, referred to as a cut strip) in a work such as connection, only the covering layer is removed, and a separator remains, This separator must be removed again, which complicates the operation and increases the time loss.

[Means for solving the problem]

The present inventor has conducted various studies in order to solve the problems of the related art, and as a result, if the adhesive force between the fluoroelastomer coating layer and the separator is increased, the coating layer and the separator can be formed in a single operation. Can be simultaneously cut and stripped, and the present invention has been completed.

That is, the present invention relates to a heat-resistant wire or cable having an outer periphery coated with a fluoroelastomer composition and a separator provided on the inner surface of the coating layer, wherein an adhesive force A (Kg / mm) between the separator and the coating layer is provided. ) Satisfies the following expression.

A ≧ SWT / L (where S is the tensile strength of the separator (Kg / mm ² ), W is the width of the separator (mm), T is the thickness of the separator (mm), L is the cut strip length of the insulator (mm) In the present invention, as the fluorine-containing composition used for coating the outer periphery of the electric wire / cable, a tetrafluoroethylene-vinylidene fluoride hexafluoropropylene-based copolymer or a vinylidene fluoride-hexafluoropropylene-based copolymer is used. Copolymer, tetrafluoroethylene-vinylidene fluoride pentafluoropropylene-based copolymer, tetrafluoroethylene-propylene-based copolymer, tetrafluoroethylene-vinylidene fluoride-propylene-based copolymer, vinylidene fluoride-chlorotrifluoro Ethylene copolymer, vinylidene fluoride-pentafluoropropylene copolymer, polyflu Aroalkyl group-containing acrylate-based elastomer, tetrafluoroethylene-ethylene-isobutylene-based copolymer, ethylene-hexafluoroethylene-butene-1-based copolymer, tetrafluoroethylene-ethylvinylether-based copolymer, fluorine-containing phosphonitrile-based Elastomers, tetrafluoroethylene-fluorovinyl ether-based copolymers and the like can be mentioned. These copolymers may be used alone or as a mixture. In addition, 150 ℃ like silicone rubber
It can also be used by mixing with the rubber composition having the above heat resistance.

Further, the fluorine-containing elastomer composition of the present invention optionally contains additives such as a crosslinking agent, a crosslinking accelerator, a reinforcing agent, a filler, a pigment, a processing aid, a lubricant, an antioxidant, and a stabilizer. be able to.

Furthermore, in the present invention, a separator is provided on the inner surface of the coating layer made of the fluorine-containing elastomer composition, that is, between the coating layer and the stranded wire conductor or the shield layer. A resin tape or a thermoplastic resin tape having a melting point of 200 ° C. or more is used, and its thickness is suitably 0.2 mm or less. Examples of the fluororesin used for the separator include, for example, polyvinylidene fluoride, ethylene-tetrafluoroethylene copolymer, ethylene tetrafluoride-propylene hexafluoride copolymer, ethylene-chlorotrifluoroethylene copolymer, and polyfluoroethylene copolymer. Vinyl chloride,
Polyfluorinated ethylene propylene ether, polyfluorinated alkoxyethylene, polychlorotrifluoroethylene,
Examples include thermoplastic resins having a melting point of 200 ° C. or higher, such as 4,6-nylon, polyetheretherketone, polyetherketone, polyetherimide, and thermoplastic polyimide. .
In order to increase the adhesive strength between the separator and the coating layer, any processing method can be used. For example, a complex compound etching method of immersing in metal sodium, naphthalene, or tetrahydrofuran complex compound for 10 seconds to 1 minute, 10 ^-1
In an argon gas atmosphere of ~ 10 ^-2 Pa, the distance between the electrodes is 5 to 12
The power supply frequency is 10 to 20 MHz (typically 1
Glow discharge at 3.56 MHz) and expose it for 10 seconds to several minutes. Sputtering method, corona discharge method, plasma discharge method, graft polymerization method for graft polymerization of various monomers by γ-ray irradiation, 10% aqueous solution of osmic acid Osmic acid treatment method immersed for more than 10 minutes, under vacuum of about 10 ^-6 Torr
A metal vapor deposition method for vapor-depositing a metal such as Ni, Fe, or Ti can be used. Further, a method of immersing into a liquid ammonia solution of metallic sodium as a processing method according to another chemical etching agent, a method of contacting an alkali metal mercury _{amalgam, (C 4 H 9) N} + BF 4 - was immersed in a dimethylformamide solution , -2 V or less.

In order to achieve the object of the present invention, a sputtering method is most preferable, followed by a complex compound etching method and a corona discharge method. When using the metal deposition method,
Since the metal surface is easily charged with electric charges, it is not suitable for use in high-voltage cables.

An appropriate adhesive primer may be applied to the surface of the separator that has been treated.

The separator in the present invention is usually used in the form of a tape, and the adhesive force A (Kg / mm) between the separator and the fluoroelastomer coating layer needs to satisfy the following expression.

A ≧ SWT / L (where, S is the tensile strength of the separator (Kg / mm ² ), W is the width of the separator (mm), T is the thickness of the separator (mm), L
Represents a cut strip length (mm) of the stranded conductor or the insulator attached to the shield layer. Here, at the time of cut stripping, in order to prevent the stranded wire conductor or the shield layer from being damaged, it is best to cut and pull out only the fluorine-containing elastomer without damaging the separator layer.

The adhesion A (Kg / mm) between the separator and the fluoroelastomer coating layer was measured by the following method.

Place the fluoroelastomer on the separator and treat it with a press molding machine at 150 Kg / cm ³ at 170 ° C for 15 minutes to a thickness of 5 mm.
Vulcanized and adhered to the fluoroelastomer layer. Next, a test piece of 5 mm in width and 2 cm in length was cut out from this,
The separator and the fluoroelastomer layer are peeled off at a speed of 50 mm / min by an autograph, and the peel strength (Kg / 5m
m), and the adhesive force A per 1 mm (Kg / mm) is calculated.

If the adhesive force A (Kg / mm) does not satisfy the above equation, only the fluoroelastomer coating layer is removed and the separator remains at the time of cutting and stripping the wire / cable end, and the coating layer and the separator are separated. At the same time, the object of the present invention of removing by a single operation cannot be achieved.

[Action]

In the heat-resistant wire / cable of the present invention, since the adhesive force between the separator and the fluoroelastomer coating layer is greater than the tensile strength of the separator, the separator and the fluoroelastomer coating layer are peeled off at the time of cutting and stripping the end of the wire / cable. Instead, the separator breaks and is removed together with the fluoroelastomer coating layer. Therefore, the separator and the fluoroelastomer coating layer can be simultaneously removed by one cut strip operation.

〔Example〕

 Hereinafter, the present invention will be described in more detail with reference to examples.

 In addition, the evaluation of the cut strip property
Of the fluoroelastomer coating layer 5 cm from the tip of the
Make a notch with a knife, and use a tis stripper (T
.Stripper) [USA Idea Ruindas
Tory Incorporated (USA Ideal Industrie
s Inc.)]
Check whether the separator remains on the core wire when
The determination was made by visual inspection. Separators remained
× when the separator tape did not remain and 〇 when the separator tape did not remain
did.

Reference Example 1 (Preparation of Fluorine-Containing Elastomer) To 100 parts by weight of a tetrafluoroethylene-propylene copolymer (manufactured by Asahi Glass Co., Ltd.) having a number average molecular weight of 50,000 and a molar ratio of tetrafluoroethylene / propylene = 55/45, 3-bis- (tert.-butylperoxy-isopropyl) benzene 1 part by weight, triallyl isocyanurate 5 parts by weight,
40 parts by weight of thermal carbon, sodium stearate 1
Add the parts by weight, knead with a rubber roll of 300 mm diameter set at a temperature of 50 to 60 ° C, and mix the Mooney viscosity (JISK6300 compliant) ML
A composition having a _{1 + 4} (100 ° C.) of 40 was obtained. This composition is referred to as a fluorine-containing elastomer.

Reference Example 2 (Preparation of Fluorine-Containing Elastomer) Daiel G-902 (tetrafluoroethylene-fluoride)
Vinylidene hexafluoropropylene copolymer, die
2,5-dimethyl-2,5-di (tert.
-Butyl peroxy) hexane 1.5 parts by weight, MT-carbo
Black [Thermax ), RT
-Vanderbilt Company Incorporated (R.
T.Vanderbilt Co.Inc.)] 20 parts by weight, triallyliso
30 parts by adding 4 parts by weight of cyanurate and setting the temperature to 50-60 ° C
Kneaded with a rubber roll of 0mm diameter, Mooney viscosity ML_{1 + 4}(Ten
0 ° C.) of 50. This composition contains fluoroelastomer
Stompers.

Examples 1 to 14, Comparative Examples 1 to 4 Twisted wire conductor (outer diameter 3.8 m
m), various surface-treated separator tapes (width (W) 20 mm) shown in Table 1 were wound, and a 75 mm extruder (L / D = 16, head: 80 ° C, cylinder 1: 80 ℃, cylinder
2: 80 ° C) to 0.6 m of the above-mentioned various fluorine-containing elastomers.
m and extruded to a thickness of 13 m and crosslinked by holding in steam at 13 atm for 3 minutes. The adhesive strength A of each separator tape and the cut-strip property of each obtained electric wire were as shown in Table 2.

 However, the cut strip length (L) was 10 mm.

(Examples 15 to 28, Comparative Examples 11 to 20) An ethylene tetrafluoride-propylene hexafluoride copolymer was extruded on a stranded conductor having an outer diameter of 1.1 mm made of a tin-plated annealed copper wire to have a thickness of 0.3 mm. Was formed, a glass paper was added while twisting the three coated wires, and a shield layer (tin-plated annealed copper wire) was further applied thereon to prepare a twisted coated cable. This cable was wound with a separator tape and covered with a fluorine-containing elastomer in the same manner as in Examples 1 to 14 and Comparative Examples 1 to 10, respectively. However,
The cut strip length was 12 mm, and the thickness of the fluorine-containing elastomer coating layer was 0.8 mm.

The cut strip properties of each cable were the same as in Examples 1 to 14 and Comparative Examples 1 to 10, respectively.

(Examples 29 to 42, Comparative Examples 21 to 34) Materials, thickness, tensile strength, tape width, and surface treatment
An electric wire was prepared in the same manner as in Example 1 using the separator modified as shown in the table. The outer diameter of the stranded conductor is 3.
8 mm (however, Examples 33, 34, 41, 42, Comparative Examples 25, 26, 3
The outer diameters of the stranded conductors 3 and 34 were 11.5 mm).

The adhesive strength A of each separator tape and the cut strip properties of each obtained electric wire were as shown in Table 4. However, the cut strip length was changed as shown in Table 3.

From the above results, the examples satisfying the condition of A ≧ SWT / L showed good cut strip properties, but A <SWT / L.
In each comparative example of SWT / L, the cut strip property was poor.

[Effects of the Invention] According to the heat-resistant wire / cable of the present invention, the separator and the fluorine-containing coating layer can be simultaneously removed by a single operation at the time of cut-strip, greatly improving the efficiency of work such as connection. Can be enhanced.

Continuation of the front page (56) References JP-A-58-1921 (JP, A) JP-A-58-1922 (JP, A) Japanese Utility Model Application No. 57-50125 (JP, U) Japanese Utility Model Application No. 61-6113 (JP) , U) Japanese Utility Model Showa 62-55822 (JP, U) Japanese Utility Model Showa 57-179214 (JP, U)

Claims (2)

(57) [Claims] 1. A heat-resistant wire or cable having an outer periphery coated with a fluoroelastomer composition and a separator provided on the inner surface of the coating layer, wherein an adhesive force A (Kg / mm) between the separator and the coating layer is provided. Satisfies the following formula: A ≧ SWT / L (where S is the tensile strength of the separator (Kg / mm ² ), W is the width of the separator (mm), T is the thickness of the separator (mm), L is the cut strip length of the insulator (mm) Represents.) 2. The heat-resistant wire / cable according to claim 1, wherein the separator is a fluororesin.