JPH0268818A - Run-water prevention groove type cable - Google Patents

Abstract

PURPOSE:To prevent the enlargement of water immersion effectively by surrounding a water-absorbing resin composite of core wires and core members of a groove type cable, with a tape. CONSTITUTION:In a groove type cable, at least one piece of core wires 3 is wound by a water-absorbing tape 4, a water-absorbing wire-like body 5 is interposed at least a part of gap in a core material groove to the core wires 3, a core material aggregate is formed by being wound by a water-absorbing tape 6, and the aggregate is wound by a water-absorbing tape 11 together with a water-absorbing wire-like body 12. The water absorbing tape and water- absorbing wire-like body are, respectively, composed of a water-absorbing high molecular composite obtained by polymerizing impregnated or coated water soluble ethylene unsaturable monomer to a support to be processed in the form of tape or wire. Since the water-absorbing high molecular composite swells speedily due to the water absorbing action, the volume of cable increases due to the swelling at the time of generation of water immersion caused by breakage of the outer of cable. It is thus possible to prevent the enlargement of water immersion effectively.

Description

BACKGROUND OF THE INVENTION Technical Field The present invention relates to improvements in cables having optical fiber cores or conductor cores. More specifically, the present invention relates to a water running prevention cable that prevents so-called "water running" in which water that has entered the cable due to damage to the cable jacket permeates in the longitudinal direction of the cable, and particularly to an improvement thereof.

BACKGROUND ART Cables having optical fiber core wires and cables having conductor core wires are well known, and the former is particularly attracting attention for its future potential due to advances in optical communication technology.

A specific example of such a cable is a groove cable, especially a V-groove cable. In this method, one or more core wires are housed in a plurality of grooves (often having a v-shaped cross section) provided in the longitudinal direction of the outer circumference of the core material.
It has a structure in which such a core material is used as it is, or a plurality of core materials are covered with an outer covering.

Although such cables come in a variety of constructions in addition to those described above, they generally have an outer sheath to protect the inner core wire from the outside world. However, damage to the outer cover due to aging or breakage accidents is inevitable. One of the damages when the outer sheath is damaged is the adverse effect on the core wire due to the infiltration of moisture, but once water infiltrates into the cable, it permeates in the longitudinal direction of the cable, causing damage over a wide range of cables. has an inherent problem.

Conventional technology The damage caused by such infiltration water has already been recognized, and the so-called
Several "water running prevention cables" have been proposed. All of these are designed to fill gaps in the cable that allow water to enter. One such method is to apply water-repellent jelly (specifically, a mixture based on petrolatum or polybutene after petroleum refinement, with additions of petroleum wax, low molecular weight polyethylene, antioxidants, etc.) to channel-shaped cables. In this case, a method is known in which the material is press-fitted into the space inside the groove of the core material. However, with this method, it is difficult to uniformly fill the jelly up to the end of the cable, and unfilled areas tend to occur. In addition, in consideration of this point, press-fitting is performed in a heated state to increase the fluidity of the jelly, but after press-fitting, there is a problem that voids are generated due to thermal contraction of the jelly, and water passages are formed. be. On the other hand,
If the press-fitting pressure is increased, there is a risk that the fiber properties will deteriorate if the core wire is an optical fiber.

To solve this problem inherent in the water-repellent jelly injection method, it has been proposed to add a super absorbent resin to the jelly.

This method has the benefit of improving the prevention effect, but since the hydrophilic superabsorbent resin is dispersed in an oily jelly, the oil becomes an obstacle to water absorption, and the superabsorbent resin's ability is insufficient. Since it is not fully utilized, a complete solution has not been reached.

On the other hand, by taping the outside of the core wire or core material with a sheet made by fixing a superabsorbent resin to a base material such as a film or nonwoven fabric with a binder, the superabsorbent resin swells when water enters, thereby preventing the expansion of water intrusion. Methods are known to prevent this. However, this method also has some problems. In other words, since the superabsorbent resin holding power of the base material is weak, the resin often falls off during cable production (Also, thin sheets are required for small diameter core wires, and it is not easy to make such sheets thinner. This is because the processability is difficult.

[Summary of the invention]

Summary The present invention aims to provide a solution to the above-mentioned points, and includes a method of surrounding the core wire and the core material of a grooved cable with a tape of a water-absorbing resin composite (details will be described later) and the void in the core material groove. The aim is to achieve this objective by filling it with linear bodies.

That is, the water running prevention groove type cable according to the present invention accommodates one or more core wires in a plurality of grooves provided in the longitudinal direction of the outer circumference of the core material, and at least one of the core wires is covered with an outer jacket. In the coated grooved cable, at least one of the core wires is wrapped with a water-absorbing tape, and a water-absorbing linear body is provided in at least a part of the gap between the core wire and the core wire in the core groove. The core material itself and/or the core material aggregate must be wrapped with water-absorbing tape, and in the case of a core material aggregate, the core material itself and/or the core material aggregate must absorb water together with the water-absorbing linear body. The water-absorbing tape and the water-absorbing linear body are each wrapped in a tape or a line, or a support that can be processed into a tape or a line. It is characterized in that it is made of a water-absorbing polymer composite obtained by polymerizing a water-soluble ethylenically unsaturated monomer impregnated or coated with.

Effects According to the present invention, a "dry" anti-water running material is used instead of a water-repellent jelly, and the anti-running material is disposed during cable formation, which eliminates the problems inherent in the prior art described above. is unrelated.

Furthermore, since the water-absorbing polymer composite (details will be described later), which is the water running prevention material used in the present invention, quickly swells due to water absorption, when water intrusion occurs due to damage to the cable sheath, it will occur due to volume increase due to swelling. By pressure,
The spread of flooding can be effectively prevented.

[Detailed description of the invention]

1. Basic configuration of cable The cable targeted by the present invention is a grooved cable, and as described above, one or more core wires are grouped together,
It has a structure in which the core material is housed in a plurality of grooves provided in the longitudinal direction of the outer periphery of the core material, and one or more core materials are covered with an outer jacket.

Cables with this basic configuration are well known.

That is, the "core wire" is a metal wire such as copper or aluminum if the cable is an electric wire, and is an optical fiber if the cable is for optical communication. Groove cables are particularly suitable as fiber optic cables. In addition, especially in the case of a tip fiber, the optical fiber is sometimes covered with a buffer layer (for example, a soft ultraviolet cross-linked plastic layer) and further provided with a coating made of plastic such as nylon to protect it. Then, we also refer to wires with this kind of structure as "core wires."
It is called. In addition, the core wire may be composed of a single wire or a plurality of wires, especially twisted wires, and both are defined as the "core wire" of the present invention. In that case, the plurality of core wires may be different in type, thickness, etc.

One or more of these core wires are accommodated in a groove of the core material to form a grooved cable. If one core wire or a plurality of core wires having such a structure are combined and covered with an outer sheath, a grooved cable will be obtained.

Optical fibers are usually weak against tension, so it is reasonable to house them in a groove in the core material to make a cable, but even so, they are usually weak against tension, so it is necessary In order to provide sufficient tensile strength, it is common to arrange a linear tensile strength member made of metal wire or other material. The linear tensile strength member may be a metal wire itself or may have a suitable coating (for example, a cushioning coating). The tensile strength required for the cable can be achieved by placing a linear tensile strength member inside the core material or in the groove, or if there are multiple core members, placing them side by side with the core material when covering the core material with an outer jacket. It can be secured by placing it in the outer covering.

In any configuration, the sheath that covers the outer circumference of the cable to protect the core wire and core material may be made of rubber, plastic, rubber- or plastic-impregnated cloth, or other materials, all of which are well known. be.

A method of manufacturing a grooved cable having such a basic configuration is also well known, and basically consists of a core wire (one or more).
consists of the introduction of the core material into the groove and the application of the outer covering thereto.

■1 Groove-type cable to prevent water running according to the present invention The groove-type cable to prevent water running according to the present invention is one and/or a plurality of core wires of the groove-type cable having the above-mentioned basic structure wrapped together with water-absorbing tape. , a water-absorbent linear body is present in at least a part of the gap between the core wire in the core groove, and one core material and/or multiple core materials are wrapped together with water-absorbent tape. It is characterized by either or a combination of the following: or, in the case of a plurality of core materials, the aggregate is wrapped with a water-absorbing tape together with a water-absorbing linear body.

The water-absorbing linear body that should fill the grooves or linear voids in the cable core material and the water-absorbing linear body that should coexist with the aggregate when wrapping the aggregate with water-absorbing tape in the case of multiple core wires are: In order to arrange this in the cable, the necessary number (one or more) of water-absorbing linear bodies may be used at the time of manufacturing the cable, taking into account the voids formed in the grooves or between the core materials.

The attached drawings are sectional views of specific examples of two types of anti-water run groove type cables according to the present invention, in which FIG. 1 shows a type with a single core material, and FIG. 2 shows a type with multiple core materials. It is of the type consisting of All of these specific examples are examples in which the core wire or its core material is covered with a water-absorbing tape and the voids within the cable are filled to the maximum extent with a water-absorbing linear body, and represent typical aspects of the present invention. (It has been mentioned above that the present invention is not limited to such a structure).

The water running prevention groove type cable according to the present invention is produced by winding the core wire and the core material with a water-absorbing tape (tape winding is a well-known unit process in cable manufacturing) in the well-known manufacturing method of the cable with the above-mentioned basic structure. It can be manufactured by storing the core wire in the core material groove together with the water-absorbing linear body, and when there is a plurality of core materials, winding the core wire together with the water-absorbing linear body with a water-absorbing tape.

■Water-absorbing tape and water-absorbing linear material In the present invention, water-soluble ethylene impregnated or coated on a tape-like, linear, or processable support It consists of a water-absorbing polymer composite obtained by polymerizing sexually unsaturated monomers.

First, water-soluble ethylenically unsaturated monomers include acrylic acid or methacrylic acid (hereinafter, the acrylic or methacrylic moiety is referred to as "(meth)acrylic") or partially or fully neutralized products thereof (for example, alkali metal salts or ammonium salts). ), (meth)acrylamide, N-methylol (meth)acrylamide, ethylene glycol mono(
There are meth)acrylic acid esters, vinyl sulfonic acid, and others. (meth)acrylic acid or its neutralized product (especially
20% or more carboxyl group neutralized products) are particularly preferred.

In order to impart the desired water insolubility to the hydrophilic polymer produced by the polymerization of such monomers, crosslinking monomers can be copolymerized (crosslinking monomers can also include
Purposeful monomers can be copolymerized, and therefore, such embodiments also fall within the scope of the "water-absorbing polymer composite obtained by polymerizing water-soluble monomers" as referred to in the present invention). Such crosslinkable heptamers include N, N'-
Examples include methylene bis(meth)acrylamide, polyethylene glycol di(meth)acrylate, glycerin di- or tri(meth)acrylate, and others.

The support on which such monomers are supported to form a water-absorbing polymer composite may be made of fibrous, spongy or other absorbent materials or non-absorbent materials.
It is tape-shaped or linear, or it has a shape that can be processed into a tape-shaped or linear shape. Specifically, non-woven fabrics, knitted fabrics, sponges (not just sponges in the narrow sense, but broadly elastic porous materials. Open-celled materials are preferable)
, plastic film, and others. Before or after the polymerization process, it is processed into tape-like pieces or linear pieces with the required dimensions.

Polymerization of the monomers mentioned above on such a support can be carried out by any convenient method. A typical method involves impregnating, coating, or spraying a support with an aqueous monomer solution, and generating radicals by decomposing a radical polymerization initiator dissolved in the aqueous monomer solution (for example, by heating, Alternatively, if the dissolved polymerization initiator is a redox-based oxidizing agent component, polymerization may be initiated by addition of a reducing agent component), irradiation with high-energy radiation, or the like. Note that the method of adding the radical polymerization initiator is arbitrary. For example, a radical polymerization initiator solution may be dissolved in a monomer solution, or a radical polymerization initiator solution may be sprayed onto a support coated with a monomer solution, or conversely, a monomer solution may be sprayed onto a support coated with a radical polymerization initiator. good. After polymerization,
A tape or linear body is obtained by drying, shredding, and other treatments. The content of water-absorbing polymer to the support is
1 to 1000% by weight of the support, preferably 10 to 100%
It is usually about % by weight.

The tape and wire need not be of the same material for a given cable. For example, the tape may have a nonwoven fabric as a support, and the linear body may have a subbonde as a support.

(2) Example A 70 mol% neutralized potassium acrylate aqueous solution with a solid content of 63% by weight was prepared. In this solution, 0.4% by weight of N-N' methylenebisacrylamide and 0.3% by weight of potassium persulfate were dissolved relative to the potassium acrylate monomer, and then polyester having a basis weight of 40 g/rrr was dissolved. Fiber nonwoven fabric (Marix 90 manufactured by Unitika Co., Ltd.)
403WSO) was uniformly impregnated with this aqueous solution so that the polymer basis weight was 50 g/d.

On the other hand, a string-like product based on polyester fiber has a thickness of 1
The base material was impregnated with the monomer solution to a polymer basis weight of 0.5 g/g, and wound up around a mesh core made of Teflon.

These monomer-impregnated materials were placed in an oven purged with nitrogen for one hour to polymerize the monomers, and then dried under reduced pressure at 100°C to obtain water-absorbing sheets and linear bodies made of water-absorbing polymer composites. . This water-absorbing sheet is then used for 2 cs.
A water-absorbent tape was obtained by slitting the tape widthwise.

As a model experiment, a low-density polyethylene rod (diameter 8
11II×approximately 7 m) was prepared, the above-mentioned 2c11 width water absorbent tape was wound at a constant pitch, and the tape was cut into 1 m pieces to prepare products equivalent to seven core wires.

This is bundled by sandwiching one water-absorbing linear body in the center and six around it in the same direction in the internal gap, and after fixing, further attaching the water-absorbing linear body to the four outer parts in the same direction. I lined it up and buried it, wrapping it with absorbent tape and fixing it in place. The produced assembly was covered with polyethylene to a thickness of 2 m.

Lay the obtained cable equivalent horizontally and mark 0 and 1 on one end.
A watertight test was conducted at room temperature by applying a water pressure of Kg/rrr, but no water dripped from the other end even after 6 hours.

From the above model experiments, it was confirmed that the water running prevention groove type cable according to the present invention is effective in preventing the expansion of water penetration even if water intrusion occurs due to damage to the outer jacket. In addition, it was not sticky like conventional water-repellent jelly and was easy to manufacture.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing an embodiment of the optical fiber of the water running prevention groove type cable of the present invention. FIG. 2 is a cross-sectional view showing an embodiment of a unit stranded cable in which the portion of the anti-water run cable shown in FIG. 1 excluding the jacket is made into one unit. 1... Tensile strength body, 2... V-shaped grooved core material, 3...
Core wire, 4... Water-absorbing tape, 5... Water-absorbing linear body,
6... Water-absorbing tape, 7... Outer cover, 8... V-shaped groove cable unit, 9... Tensile strength body, 10... Center interposition, 11... Water-absorbing tape, 12... ...Water-absorbing linear body, 13... Water-absorbing linear body, 14... Water-absorbing tape, 15... Outer cover, 16... V-groove unit type cable.

Claims (1)

[Claims] In a grooved cable in which one or more core wires are accommodated in a plurality of grooves provided in the longitudinal direction of the outer circumference of the core material, and at least one of the core wires is covered with an outer sheath, at least one of the core wires is One of the wires is wrapped with a water-absorbing tape, the water-absorbing linear body is present in at least a part of the gap between the core wire and the core wire in the core groove, and the core material itself and ( or) Either the core material aggregate is wrapped with water-absorbing tape, and in the case of a core material aggregate, the core material aggregate is wrapped with water-absorbing tape together with a water-absorbing linear body. or a combination thereof, and the water-absorbing tape and the water-absorbing linear body each contain a water-soluble ethylenically unsaturated monomer impregnated or coated on a tape-like or linear support, or a support that can be processed into a tape-like or linear form. A groove-type cable to prevent running of water, characterized in that it is made of a water-absorbing polymer composite obtained by polymerization.