JPH0268817A - Slot ribbon cable of run water prevention type - Google Patents

Abstract

PURPOSE:To prevent enlargement of immersion water effectively by surrounding the core wire ribbon stacked body of slot ribbon cable, with a tape of water- absorbing resin composite body. CONSTITUTION:In a slot ribbon cable, at least one piece of stacked body 3 is wound by a water absorbing tape 4, a water-absorbing wire-like body 5 is interposed at least at a part of gap in a core member groove to the body 3 and the core members are wound by a water-absorbing tape 6. The water absorbing tape and water-absorbing wire-like are composed respectively of water-absorbing high molecular composite body formed by polymerizing soluble ethylene unsaturable monomer impregnated in or applied to a support body to be processed in the form of tape or wire. Since the water-absorbing high molecular composite body swell speedily when it absorbs water, the volume of cable tends to increase at the time of generation of water immersion upon breakage of outer part 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 improvements 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.

One specific example of such a cable is a slotted ribbon cable. This is a stacked body made by stacking multiple core wire ribbons, each of which is made by arranging multiple core wires in parallel and covering the entire core wire in a flat shape with plastic. (slot) and is entirely covered with an outer cover.

Although such cables have various 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 use a water-repellent jelly (specifically, a mixture made from refined petrolatum or polybutene as a base material, with petroleum wax, low molecular weight polyethylene, antioxidants, etc.) in a slotted ribbon shape. In the case of cables, a method is known in which the cable is press-fitted into the space inside the groove of the core material excluding the stacked body.

However, with this method, it is difficult to uniformly fill the jelly 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 is beneficial in terms 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 not fully utilized. Therefore, a complete solution has not been reached.

On the other hand, by taping the outside of the ribbon stack of core wires 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, resulting in water leakage. Methods are known to prevent expansion. However, this method also has some problems. In other words, the superabsorbent resin holding power of the base material is weak, so the resin often falls off during cable production, and 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 solve the above-mentioned problems by surrounding the core ribbon stack of a slotted ribbon cable with a tape of a water-absorbing resin composite (details will be described later), and by surrounding the core ribbon stack of the slot ribbon cable with a tape in the core material groove for storing the stack. This objective is achieved by filling the void with a linear body of the composite and by surrounding the core with a tape of the composite.

That is, the water running prevention slot ribbon type cable according to the present invention has a plurality of core ribbons arranged in parallel and covered entirely with plastic to form a stacked body, and the plurality of core ribbons are stacked around the outer periphery of the core material. A slotted ribbon cable that is housed in a plurality of grooves provided in the longitudinal direction of the cable and covered with an outer sheath, at least one of the stacked bodies being wrapped with water-absorbing tape; Either a water-absorbing linear body is interposed in at least a part of the gap between the core material groove and the stacked body, and the core material is wrapped with water-absorbing tape; or and the water-absorbing tape and the water-absorbing linear body are polymerized with a water-soluble ethylenically unsaturated monomer impregnated or coated on a tape-shaped or linear support, or a tape-shaped or linear support, respectively. It is characterized in that it is made of a water-absorbing polymer composite obtained by

Effects According to the present invention, a "dry" water running prevention material is used instead of the water-repellent jelly, and the water running prevention material is disposed during cable formation, thereby eliminating the disadvantages inherent in the prior art described above. It has nothing to do with it.

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]

I. Basic Structure of Cable The cable targeted by the present invention is a slot ribbon type cable, which, as mentioned above, is a core ribbon made by arranging a plurality of core wires in parallel and covering the entire core wire in a flat shape with plastic. The stacked body is housed in a groove (slot) provided in the longitudinal direction on the outer periphery of the core material, and the slot is covered with an outer cover.

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 a fiber end if the cable is for optical communication. Slotted ribbon cables are particularly suitable as fiber optic cables. In addition, especially in the case of optical fibers, the optical fibers are covered with a buffer layer (
For example, the wire may be covered with a soft ultraviolet crosslinked plastic layer) and further provided with a coating made of plastic such as nylon, and in the present invention, wires with such a structure are also referred to as "core wires."

Further, the core wire may be not only a single wire but also 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.

Such core wires are made by arranging multiple core wires in parallel, covering the entire core wire in a flat shape with plastic to make a core wire ribbon (or core wire tape), stacking multiple core wires on top of each other to make a stack, and then inserting it into the groove of the core material. That is, it is housed in a slot to form a slot ribbon type cable.

Optical fibers, whether in the form of ribbons or stacks, are generally weak against tension, so it is reasonable to accommodate them in the grooves of the core material and make them into cables. However, it is usually still weak against tension.

In order to provide the cable with the necessary tensile strength, a linear tensile strength body made of metal wire or the like is usually placed within the core material. The linear tensile strength member may be a metal wire itself or may have a suitable covering (for example, a cushioning covering 81).

Note that the tensile strength required for the cable can also be ensured by placing linear tensile strength members in the grooves of the core material or in the outer sheath.

Regardless of the configuration, the sheath that covers the outer circumference of the cable to protect the core ribbon is rubber, plastic,
It may be made of rubber or plastic impregnated cloth or other materials, all of which are well known.

A method for producing slotted ribbon cables having this basic configuration is also well known and basically consists of forming a stack of core ribbons, introducing them into the core grooves and applying an outer sheath to them. .

■0 Water running prevention slotted ribbon cable according to the present invention The water running preventing slotted ribbon cable according to the present invention is such that at least one of the core ribbon stacks of the slotted ribbon cable having the above-mentioned basic configuration is wrapped with water-absorbing tape. A water-absorbing linear body is interposed in at least a part of the gap between the core material groove and the stacked body, and the core material is wrapped with water-absorbing tape. , or a combination thereof.

The number of water-absorbing linear bodies that should fill the grooves, that is, the linear voids in the cable core material, is required (one or more) in order to arrange them in the grooves, taking into consideration the voids formed within the grooves. The water-absorbing linear body may be used when manufacturing the cable.

The attached drawings are cross-sectional views of a specific example of the water running prevention slot ribbon type cable according to the present invention, in which FIG. 1 shows a stack of core ribbons, and FIG. 2 shows a stack of ribbons accommodated in a core groove. The present invention is a slotted ribbon type cable to prevent water running. The specific example shown in FIG. 2 is a typical example of the present invention, in which the core ribbon stack is covered with a water-absorbing tape and the voids in the cable are filled to the maximum with a water-absorbing linear body. (It has been mentioned above that the present invention is not limited to such a structure).

The water running prevention slot ribbon type cable according to the present invention is produced by winding a core ribbon stack and a core material with a water-absorbing tape (tape winding is well known as a unit process in cable manufacturing) in the well-known manufacturing method of the cable with the above-mentioned basic structure. ) and a stack of core ribbons is accommodated in the core groove together with the water-absorbing linear body.

■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 such embodiments are also included in the term "water-absorbing polymer composite obtained by polymerizing water-soluble monomers" in the present invention. Such crosslinking monomers 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 these monomers are supported to form a water-absorbing polymer composite may be a tape-like or linear support made of fibrous, sponge-like or other absorbent material or non-absorbent material. It is a tape-like or linear-shaped object. Specifically, non-woven fabrics, knitted fabrics, sponges (not just sponges in the narrow sense, but broadly elastic porous materials. Open-celled materials are preferable),
There are plastic films and others. Before or after the polymerization process, it is processed into tape-like pieces or linear pieces of 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 an aqueous monomer solution onto a support, and generating radicals using an appropriate polymerization initiator, such as decomposition of a radical polymerization initiator dissolved in an aqueous solution of monomer (e.g., by heating). (or by adding a reducing agent component when the dissolved polymerization initiator is a redox-based oxidizing agent component), irradiation with high-energy radiation, or other means. Note that the method of adding the radical polymerization initiator is arbitrary. For example, the radical polymerization initiator solution may be dissolved in a monomer solution, or the radical polymerization initiator solution may be sprayed onto a support coated with a monomer solution, or conversely, the 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 use a nonwoven fabric as a support, and the linear body may use a sponder as a support.

(2) Example A 70 mol% neutralized potassium acrylate aqueous solution with a solid content of 63% by weight was prepared. To this solution, 0.4 ffl amount % of N-N' was added to the potassium acrylate monomer.
Methylenebisacrylamide and 0.3% by weight of potassium persulfate were dissolved, and then the basis weight was 40g/rrIl'
This aqueous solution was applied onto a polyester fiber nonwoven fabric (Marix 90403WSO manufactured by Unitika Co., Ltd.) with a polymer basis weight of 50 g/rr? It was impregnated uniformly so that

On the other hand, a string-like product based on polyester fiber has a thickness of 1
11M x 100m was impregnated with the monomer solution so that the polymer basis weight was 0.5 g/g base material, and wound around a Teflon mesh core.

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 2cm long.
A water-absorbent tape was obtained by slitting the tape widthwise.

As a model experiment, a low-density polyethylene rod (diameter 8
IIIIn×approximately 7 m) was prepared, the 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, the water-absorbing linear body is placed in the external recess 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 coated with polyethylene to a thickness of 21 Ill.

The obtained cable equivalent product is laid horizontally and 0.1K is applied to one end.
A watertight test was conducted at room temperature by applying a water pressure of g/rrf, 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 slot ribbon 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 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 a stacked optical fiber ribbon of the anti-water run slotted ribbon cable of the present invention. FIG. 2 is a sectional view showing an embodiment of the anti-water running slotted ribbon cable according to the present invention. DESCRIPTION OF SYMBOLS 1... Core wire, 2... Core wire ribbon, 3... Ribbon stack, 4... Water-absorbing tape, 5... Water-absorbing linear body,
6... Water-absorbing tape, 7... Tensile strength material, 8... Grooved core material, 9... Outer cover, 10... Water running prevention slot ribbon type cable.

Claims (1)

[Claims] A plurality of core wire ribbons made by arranging a plurality of core wires in parallel and covering the whole with plastic are stacked to form a stacked body, and the plurality of core wires are housed in a plurality of grooves provided in the longitudinal direction of the outer periphery of the core material. , in a slotted ribbon type cable formed by covering it with an outer sheath, at least one of the stacked bodies is wrapped with water-absorbing tape, and a gap between the stacked bodies and the stacked body in the core groove. A water-absorbing linear body is interposed in at least a part of the core material, and the core material is wrapped with a water-absorbing tape, or a combination thereof;
and a water-absorbing material obtained by polymerizing a water-soluble ethylenically unsaturated monomer impregnated or coated on a tape-shaped or linear support, or a support that can be processed into a tape-shaped or linear shape, for the water-absorbing tape and water-absorbing linear body, respectively. 1. A slotted ribbon type cable to prevent running water, characterized in that the cable is made of a synthetic polymer composite.