JPH0128587Y2 - - Google Patents

Description

[Detailed explanation of the idea]

The present invention relates to a watertight insulated electric wire using a watertight conductor in which a watertight compound such as rubber or plastic is filled between the strands of a stranded conductor. In recent years, insulated wires using watertight conductors have
Due to its superior workability, so-called dry type watertight insulated wires using rubber or plastic watertight compounds are increasing. The material used for this dry type watertight compound must have good adhesion to both conductors and insulators in order to ensure its watertightness. For example, ethylene vinyl acetate copolymer (EVA), ethylene ethyl acrylate copolymer (EEA), ethylene propylene rubber, styrene butadiene rubber, butyl rubber, natural rubber,
Chlorinated polyethylene, chlorosulfonated polyethylene, etc. or blends thereof are used. Methods for filling the voids between the stranded wire conductors with a watertight compound made of such a material include, for example, filling the stranded wires with the watertight compound in the form of a tape by vertically applying it or wrapping it with tape, or by using an extruder. , a method is used in which a compound is press-fitted between the finished strands at high pressure. However, even with the conventional method described above, if the compound filling conditions are not appropriate, the adhesion between the metal part of the conductor and the watertight compound is often insufficient, and as a result, the watertightness of the electric wire deteriorates. There were times when it decreased. In addition, to improve heat resistance, insulators and/or watertight compounds are sometimes crosslinked, but as the degree of crosslinking of the compound increases, the adhesion with conductors may decrease and watertightness may deteriorate. Ta. The present invention has been made to improve the deterioration in watertightness caused by poor adhesion between the watertight compound and the conductor. In other words, the feature of the present invention is that the stranded wire conductor is pre-coupled with a silane-based or titanium-based coupling material that has good adhesion to both the conductor made of copper, aluminum, or an alloy thereof, and the watertight compound. It has been treated to improve adhesion with watertight compounds. The silane coupling agent used here is usually represented by R-Si- _X3 , where R is a functional group that reacts with organic substances such as rubber and plastic, such as a vinyl group, an amino group, a chloro group, or an epoxy group. A carbon chain containing a group, a mercapto group, etc.
is a chloro group, a methoxy group, an ethoxy group, a methoxyethoxy group, etc., which are groups that bond to inorganic substances such as metals. Specific examples include vinyltri(β-methoxyethoxy)silane,
γ-aminopropyltriethoxysilane, N-β
Examples include -(aminoethyl)-γ-aminopropyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane, and γ-chloropropyltrimethoxysilane. In addition, titanium-based cutupulin agents include isopropyl triisostearoyl titanate, isopropyl tridodecylbenzenesulfonyl titanate, isopropyl tris (dioctyl pyrophosphate) titanate, tetraisopropyl bis (dioctyl phosphate) titanate, and tetraoctyl bis (ditridecyl phosphate). ) titanate, tetra(2,2-diallyloxymethyl-1-butyl)bis(di-tridecyl)phosphate titanate, bis(dioctylpyrophosphate)oxyacetate titanate, bis(dioctylpyrophosphate)ethylene titanate, etc. In this case, as in the case of the above-mentioned silane coupling agent, it has a functional group that reacts with an organic substance and a group that bonds with an inorganic substance. The treatment of stranded conductors with the above coupling agent is as follows:
Although not particularly limited, it may be used after being diluted with an appropriate organic solvent that dissolves the coupling agent, or when anticorrosion treatment is applied to stranded wire conductors.
It is also possible to treat it at the same time by mixing it into the anti-corrosion solution. At this time, the amount of the coupling agent added is preferably 0.1 to 5% by weight, more preferably 0.2 to 2% by weight. That is, if it is less than 0.1% by weight, the metal surface of the conductor will not have sufficient adhesion to the watertight compound, and conversely, if it exceeds 5% by weight, the adhesion improvement effect will reach the saturation point. This is because although further improvement cannot be expected, the material cost of the coupling agent will increase significantly. The watertight compound used in the present invention may be the same as the conventional ones mentioned above, but in particular, ethylene vinyl acetate copolymer (EVA), ethylene ethyl acrylate copolymer (EEA), ethylene propylene rubber, styrene butadiene Examples include rubber and butyl rubber. Next, a specific example of the present invention will be explained in detail with reference to the drawings, as shown in FIG. 1. In the figure, 1 is a stranded wire conductor, and in this example, 6
The strands 1b of the second layer of the book..., the 12 strands of the strands 1 of the third layer
c... are twisted sequentially, and each strand 1a, 1b..., 1
c... A watertight compound 2 is filled in between.
An insulator layer 3 is provided on this watertight conductor 1. Although it depends on the type of electric wire, if necessary, the inner semiconducting layer (the outermost layer of the watertight compound 2 can also be used as a semiconductor), the outer semiconducting layer coated on the insulator, and the sheath. It is also possible to provide the following as appropriate. Since each of the strands 1a, 1b..., 1c... has been treated with a coupling agent as described above, it adheres well to the watertight compound 2 filled therein and can obtain sufficient watertightness. In addition to watertightness, the required characteristics of the watertight insulated wire thus obtained include:
From the perspective of workability, the peelability of the insulator layer 3 is sometimes emphasized, but the watertight compound 2
If the adhesion between the conductor 1 and the conductor 1 is too strong, the watertight compound 2, which is the outermost layer of the conductor, will remain attached to the conductor when the insulator is stripped, which may cause problems in the extraction work. be. In such a case, in the stranded conductor 1 shown in the above figure, the center strand 1
Either treat only a and the six strands 1b of the second layer with a coupling agent, or treat the 12 strands 1 of the outermost layer with a coupling agent.
It is preferable to adopt a method such as making the degree of treatment of c... lighter than that of each strand 1a, 1b... on the inner layer side, thereby making it possible to carry out smooth extraction work. Examples of the present invention will be described below. As shown in FIG. 1 above, a stranded conductor having a conductor cross-sectional area of 125 mm ² was manufactured using a silane coupling agent treatment in the stranding process of a 19-strand conductor. On this occasion,
As a coupling agent, H ₂ N−CH ₂ CH ₂ CH ₂ −
Si-(OC ₂ H ₅ ) ₃ was used and treated by immersing the stranded conductor in a solution diluted with trichloroethane. The concentration of the coupling agent in the diluent was 1.5% by weight for each strand on the inner layer of the conductor, and 0.5% by weight for each strand on the outermost layer of the conductor. next,
EVA (VA
% = 30%) watertight compound (containing 0.2-0.5 phr anti-aging agent and carbon black),
It was press-fitted using an extruder at a temperature of 120°C to obtain a watertight conductor. Thereafter, polyethylene (PE) containing a crosslinking agent (DCS) was extruded and coated on the watertight conductor at a temperature of 120° C. to give an insulation thickness of 3 mm, and then crosslinking was performed in pressurized steam. The crosslinking was carried out under two conditions: 180°C for 5 minutes and 200°C for 5 minutes. For comparison, a watertight insulated wire similar to the above was manufactured using a conductor that was not treated with a coupling agent. The following tests were conducted on each of these wires to confirm their watertightness and peelability.
The results were as shown in Table 1. Watertightness test: Cut 2m of each wire, 0.5
After holding the conductor at a water pressure of Kg/cm ² for 24 hours, the distance that water penetrated into the conductor was measured. Peelability test: At the end of each wire, the insulator layer is vertically split in the length direction and the insulator is stripped off.
Thereafter, the presence or absence of watertight compound adhesion on the conductor was examined.

[Table] From Table 1, it can be seen that the electric wire of the present invention has significantly improved watertightness compared to the conventional wire (comparative example), and that the watertight compound remains attached to the conductor side when the wire is stripped. It is clear that this is not the case. As is clear from the above explanation, according to the present invention, since the conductor is treated in advance with a silane-based or titanium-based coupling agent, the adhesion between the watertight compound and the conductor is extremely good, and this adhesion is improved. Excellent watertightness can be obtained without deterioration, not only in the case of terminal crosslinking of the compound, but also in the case of crosslinking the compound with a high degree of crosslinking in order to improve heat resistance in the subsequent process. When treated with a coupling agent, by leaving the outermost layer on the conductor side untreated or making it lighter than the inner layer, it is easy to handle and does not affect the peelability of the insulator. Watertight insulated wires can be provided.

[Brief explanation of the drawing]

FIG. 1 is a vertical cross-sectional end view showing an example of a watertight insulated electric wire according to the present invention. 1...Twisted wire conductor, 1a, 1b, 1c...Each strand, 2
…Watertight compound.

Claims (1)

[Scope of utility model registration request] Between stranded conductors in which each strand on the inner layer side other than the outermost layer has been treated with a silane-based or titanium-based coupling agent, or between the strands on the outermost layer side than each strand on the other inner layer side. A watertight insulated electric wire characterized by using a watertight conductor in which a rubber or plastic watertight compound is filled between stranded wire conductors that have been lightly treated in advance.