JP2014017139A - cable - Google Patents

Abstract

An object of the present invention is to provide a cable capable of suppressing exposure of an inner core even when a coating layer is damaged by wear.
In a cable according to the present invention, an ultrahigh molecular weight polyethylene film is welded in the longitudinal direction inside at least one layer of a covering layer. Even if 4 (outermost layer 41) is damaged due to wear, the progress of further wear can be suppressed at the stage where wear has reached the ultrahigh molecular weight polyethylene film 3 which is a low wear material. It is possible to prevent the polyethylene film 3 from reaching the inner core 2 and to prevent the core 2 from being exposed to the outside.
[Selection] Figure 1

Description

  The present invention relates to a cable. More specifically, the present invention relates to a core that is a transmission medium and a cable in which a coating layer is formed around the core including at least the outermost layer.

  A cable such as a communication cable is often required to be installed over a long distance in an aerial installation or underground. On the other hand, in the case of such long laying, there has been a problem that the coating layer is damaged by abrasion, the core serving as a transmission medium existing inside is exposed, and thus the conductor or the like is disconnected.

  In order to solve such a problem, a cable using a low-abrasion material (low-abrasion material) for the outermost layer is provided (see, for example, Patent Document 1). In addition, a heating wire is provided that includes a coated wire having a low friction layer made of ultrahigh molecular weight polyethylene as the outermost layer (see, for example, Patent Document 2).

JP 2002-237223 A JP 2009-117037 A

  Each of the cables shown in Patent Document 1 and Patent Document 2 is one in which a low-abrasion material is arranged on the outermost layer, but when the ultrahigh molecular weight polyethylene or the like, which is a low-abrasion material, is used as the outermost layer, While it can be expected that the coating layer is prevented from being damaged due to abrasion, the friction coefficient of the ultrahigh molecular weight polyethylene is too small to cause slipping, which may cause the following problems. For example, a cable is generally wound in a drum at a length of 1000 m or more. However, if a low-abrasion material such as ultra-high molecular weight polyethylene is present in the outermost layer, the friction coefficient is too small and the cables slip and cause the winding to occur. It was difficult to do.

  Also, when a drum-wound cable is transported on a truck or the like, the cables slip due to vibration during transportation, and the drum-wound cable is loosened, and the cable is pulled out when laying. It was difficult. In addition, it is difficult to extrude ultra-high molecular weight polyethylene as compared with ordinary materials, and the high cost of the materials increases the cost. As described above, there is a problem in using the outermost layer of the cable as a low wear material such as ultra high molecular weight polyethylene.

  An object of the present invention is to provide a cable that can suppress the exposure of an internal core even when a coating layer is damaged due to wear.

  In order to solve the above-described problem, a cable according to the present invention is a cable in which a core serving as a transmission medium and a coating layer including at least an outermost layer are formed around the core, and at least of the coating layer. An ultra high molecular weight polyethylene film is welded in the longitudinal direction inside one layer.

  The cable according to the present invention is characterized in that, in the above-described present invention, the ultra-high molecular weight polyethylene film is welded in the longitudinal direction on the inner side of the coating layer which is the outermost layer.

  The cable according to the present invention is characterized in that, in the above-described present invention, the ultra high molecular weight polyethylene film has a weight average molecular weight of 500,000 to 6,000,000.

  In the cable according to the present invention, in the above-described present invention, when the ultrahigh molecular weight polyethylene film is heat-treated at 180 ° C. for 5 minutes, the shrinkage dimensional change rate (according to JIS C2151, 21, 1, and b) is ± 5%. It is in the range of.

  The cable according to the present invention is characterized in that in the above-described present invention, the ultrahigh molecular weight polyethylene film is subjected to weathering resistance treatment.

  In the cable according to the present invention, since the ultrahigh molecular weight polyethylene film is welded in the longitudinal direction inside at least one layer of the covering layer, even if the jacket is damaged due to wear during cable laying, the cable is low. As the wear of the ultra high molecular weight polyethylene film, which is a wearable material, can be prevented from further progressing, it prevents the wear from reaching the inner core and prevents the core from being exposed to the outside. Can be suppressed.

It is sectional drawing which showed the one aspect | mode of the structure of the cable which concerns on this invention. It is sectional drawing which showed the other aspect of the structure of the cable which concerns on this invention. It is sectional drawing which showed the other aspect of the structure of the cable which concerns on this invention. It is sectional drawing which showed another aspect of the structure of the cable which concerns on this invention.

  Hereinafter, the structure of the cable 1 which concerns on this invention is demonstrated based on drawing.

(I) Configuration of cable 1:
FIG. 1 is a cross-sectional view showing an embodiment of the structure of a cable 1 according to the present invention. In the cable 1 according to the present invention, a core 2 serving as a transmission medium, and a coating layer 4 including at least an outermost layer 41 are formed around the core 2, and an ultra-high height is formed inside at least one layer of the coating layer 4. The molecular weight polyethylene film 3 is welded (fused) over the longitudinal direction.

  The cable 1 of the present embodiment has a coating layer 4 of an outermost layer 41 and an inner layer 42 around a core 2 serving as a transmission medium, and an ultrahigh molecular weight polyethylene film 3 extends in the longitudinal direction inside the outermost layer 41. The structure which is welded is shown. The core 2 serving as a transmission medium for transmitting a desired signal is not particularly limited. For example, a metal cable that is an aggregate of insulated wires serving as a transmission medium for a general communication cable, a slot rod or a slot equipped with an optical fiber. The core 2 that is used as a transmission medium such as an optical fiber cable (for example, an optical fiber drop cable, a slotless optical fiber cable, etc.) without a rod, and a communication cable in general such as a coaxial cable can be widely used.

  As shown in FIG. 1, the ultrahigh molecular weight polyethylene film 3 is welded in the longitudinal direction inside the outermost layer 41. As in the configuration of the present invention, the ultrahigh molecular weight polyethylene film 3 (hereinafter sometimes simply referred to as “film 3”), which is a low-abrasion material, does not appear outside, and the cable is formed inside the coating layer 4. 1, even if the covering layer 4 (the outermost layer 41 in the case of the configuration of FIG. 1) is damaged due to wear when the cable 1 is laid long, Since the high molecular weight polyethylene film 3 is not easily worn, it is possible to prevent wear reaching the inside from the ultra high molecular weight polyethylene film 3 and to prevent the core 2 from being exposed. In the configuration of FIG. 1, since the ultra-high molecular weight polyethylene film 3 is welded in the longitudinal direction inside the outermost layer 41, the exposure of the core 2 when the outermost layer 41 that is relatively easily damaged is damaged is suppressed. can do.

  Hereinafter, the results of measuring the wear amount by the taper wear test in accordance with JIS K7204 for ultra high molecular weight polyethylene film 3 (UHMW-PE) and, as a comparison, high density polyethylene (HDPE) film and low density polyethylene (LDPE) film, Place in Table 1. The measurement was performed under the following measurement conditions.

(Measurement condition)
Test equipment: Rotary ablation tester (manufactured by Toyo Seiki Seisakusho)
Abrasion wheel: CS-17 (Dressing every test)
Rotation speed: 72rpm
Number of rotations: 1000 times

(Measurement result)

  As shown in Table 1, the ultrahigh molecular weight polyethylene film 3 has a lower wear amount than the high density polyethylene film and the low density polyethylene film, indicating that it is a low wear material. Further, as shown in Table 1, the wear amount of the ultrahigh molecular weight polyethylene film 3 is generally smaller as the weight average molecular weight is larger.

  In addition, since the ultra-high molecular weight polyethylene film 3 is integrated by welding inside the outermost layer 41, even if the outermost layer 41 is pulled (pulled) or bent when the cable 1 is laid or the like, Since the outer layer 41 and the ultra high molecular weight polyethylene film 3 are uniformly strained, the outermost layer 41 and the ultra high molecular weight polyethylene film 3 do not move independently even when the traction tension or bending is released. It is possible to prevent buckling and the like from occurring. Therefore, it is possible to prevent an increase in loss due to a lateral pressure on the transmission medium due to buckling of the outermost layer 41, and it is possible to prevent deterioration such as cracks due to stress concentration on the outermost layer 41 due to buckling.

  The thickness of the ultrahigh molecular weight polyethylene film 3 to be welded to the inner side of the outermost layer 41 is not particularly limited, but is preferably in the range of 10 to 500 μm, and preferably in the range of 25 to 100 μm. Particularly preferred.

  The weight average molecular weight of the ultrahigh molecular weight polyethylene film 3 is preferably 500000 to 6000000. By setting the weight average molecular weight within such a range, it is possible to suppress the wear of the jacket, and thus it is possible to design a thin coating layer 4 (outermost layer 41) on which the ultrahigh molecular weight polyethylene film 3 is welded. The cable 1 can be made thinner and lighter. In addition, such thinning enables multiple laying of the cable 1 in a limited space, and enables effective use of existing pipes and the like. Further, the cable 1 can be made lighter, so that it is possible to lay a longer length, improve workability when the cable 1 is laid, and reduce the laying cost. On the other hand, if the weight average molecular weight of the ultrahigh molecular weight polyethylene film 3 is less than 500,000, the effect of suppressing wear may be reduced. If it is greater than 6000000, the extrusion load when extruding the film 3 becomes too large, Manufacturability may decrease, and manufacturing costs may increase.

  Moreover, it is preferable that the ultra high molecular weight polyethylene film 3 has a shrinkage dimensional change rate (according to JIS C2151, 21, 1 and b) within a range of ± 5% when heat-treated at 180 ° C. for 5 minutes. By using the ultrahigh molecular weight polyethylene film 3 in such a range that the dimensional change rate is applied, the ultrahigh molecular weight polyethylene film 3 and the coating layer 4 are formed at the time of extrusion molding of the coating layer 4 of the cable 1 (the outermost layer 41 in the configuration of FIG. 1). When welding, the distortion held by the film 3 is reduced by the heat of the coating layer 4 in the molten state, resulting in poor appearance such as wrinkles and unevenness of the coating layer 4 due to dimensional changes (expansion and shrinkage). Can be suppressed. On the other hand, when the dimensional change rate is out of the range of ± 5%, wrinkles, irregularities, etc. appear on the outer appearance of the coating layer 4 welded to the inside, which may cause the outer appearance of the coating layer 4 to be poor. The shrinkage dimensional change rate (according to JIS C2151, 21, 1, and b) is particularly preferably within a range of ± 2.5%.

  In addition, Table 2 is an example of the measurement result of the shrinkage | contraction dimensional change rate based on JIS C2151, 21, 1, and b in the ultra high molecular weight polyethylene film 3.

Specifically, an ultrahigh molecular weight polyethylene film 3 having a weight average molecular weight of 4000000 and a thickness of 50 μm was cut into a width of 20 mm and a length of 150 mm, and a standard line of 100 ± 2 mm was attached to a substantially central portion in the longitudinal direction. Prepare two test pieces (n ₁ , n ₂ ), suspend the prepared test pieces in a hot-air circulating thermostatic chamber under no load, and change the shrinkage dimension at the temperature and time shown in Table 2. It is the result of measuring the rate. Of the values shown in Table 2, those marked with “-” indicate that the gap between the marked lines is larger (expanded) than before the test (before heating). The temperature around 180 ° C. is the temperature at which the coating layer 4 is extruded (the melting temperature of the synthetic resin constituting the coating layer 4).

(Dimensional change rate)

  Furthermore, the ultrahigh molecular weight polyethylene film 3 is preferably subjected to a weather resistance treatment. By subjecting the ultrahigh molecular weight polyethylene film 3 to a weather resistance treatment, it is possible to prevent the film 3 from being deteriorated by ultraviolet rays or the like even when the outer casing is worn and the film 3 is exposed when a cable is laid.

  There is no restriction | limiting in particular as a method of giving a weather resistance process to the ultrahigh molecular weight polyethylene film 3, When improving a weather resistance by adding an additive, for example, an ultraviolet-ray inhibitor, a light absorber, oxidation What is necessary is just to mix | blend additives, such as an inhibitor, anti-aging agent, carbon black, and a color pigment, in the range which does not impair the objective of this invention.

  The ultrahigh molecular weight polyethylene film 3 may be formed by, for example, drawing a melt kneaded product obtained by extruding ultrahigh molecular weight polyethylene by an extruder having a film forming die attached to the tip with a cooling roll. In addition, ultra high molecular weight polyethylene may be molded by a hot press molding machine, or may be molded by quenching by sandwiching a molten kneaded material between cooled metal plates, and further cutting ultra high molecular weight polyethylene lump. It may be processed into a film.

  The synthetic resin that can be used as the resin composition constituting the coating layer 4 is not particularly limited. For example, high-density polyethylene (HDPE), low-density polyethylene (LDPE), and linear low-density polyethylene (LLDPE). ), Polyolefin resins such as ethylene / α-olefin copolymer, ethylene / vinyl acetate copolymer (EVA), ethylene / ethyl acrylate copolymer (EEA), and thermoplastic resins such as polyvinyl chloride. It is done. One of these synthetic resins may be used alone, or two or more of these synthetic resins may be used in combination as a resin composition.

  The resin or resin composition constituting the coating layer in the cable 1 of the present invention may contain various resin components and various additives other than those described above as long as the object and effect of the present invention are not hindered. Can be added as appropriate. As the additive, conventionally known ones can be used. For example, flame retardants, lubricants, modifiers, antioxidants, light stabilizers composed of metal hydrates such as magnesium hydroxide and aluminum hydroxide. , Process oil, silicone oil, UV absorber, carbon black, dispersant, pigment, dye, anti-blocking agent, crosslinking agent, crosslinking aid, etc. In addition, flame retardant aids such as polyphosphate compounds, zinc hydroxystannate, zinc stannate, zinc borate, calcium carbonate, hydrotalcite, and antimony oxide may be added. In consideration of welding with the ultrahigh molecular weight polyethylene film 3 at the time of extrusion molding, generally, low density polyethylene (LDPE), linear low density polyethylene (LLDPE), ethylene / vinyl acetate copolymer (EVA), ethylene It is preferable to use a flame retardant polyolefin resin containing a flame retardant based on a synthetic resin such as ethyl acrylate copolymer (EEA).

  The thickness of the covering layer 4 is not particularly limited and may be appropriately determined depending on the required characteristics of the cable 1 and the environment in which the cable 1 is laid, etc. The thickness of the outermost layer 41 is, for example, 1.0-2. It is preferable to be within the range of 0 mm. Moreover, as shown in FIG. 1, when providing the inner layer 42, it is preferable that the thickness of the inner layer 42 shall be in the range of 0.5-1.0 mm, for example.

  Further, in the cable 1 of the present invention, in addition to the covering layer 4 such as the outermost layer 41 and the inner layer 42 and the ultrahigh molecular weight polyethylene film 3 shown in FIG. Depending on the situation, a material such as a film used in a normal cable may be appropriately interposed around the core 2.

  In order to weld the ultrahigh molecular weight polyethylene film 3 to the inner side of the coating layer 4 (the outermost layer 41 in FIG. 1), for example, the ultrahigh molecular weight polyethylene film 3 is attached to the core 2 or the core 2 in which the inner layer 42 is sheathed. Is formed in the periphery of the core 2 by extruding the coating layer 4 to be welded around the ultrahigh molecular weight polyethylene film 3 in a molten state at around 180 ° C. What is necessary is just to make it weld to the inner side of the coating layer 4 because the ultra-high molecular weight polyethylene film 3 softened.

(II) Effects of the present invention:
In the cable 1 according to the present invention described above, the ultrahigh molecular weight polyethylene film 3 is welded in the longitudinal direction on the inner side of the outermost layer 41 which is the covering layer 4. Even if 4 (outermost layer 41) is damaged due to wear, the progress of further wear can be suppressed at the stage where wear has reached the ultrahigh molecular weight polyethylene film 3 which is a low wear material. It is possible to prevent the polyethylene film 3 from reaching the inner core 2 and to prevent the core 2 from being exposed to the outside.

  In addition, since the ultra-high molecular weight polyethylene film 3 is welded inside at least one layer of the coating layer, the problem of slipping of the cable 1 does not occur. For example, aligned winding on a drum can be performed without any problem. In addition, the cables do not slip due to vibrations during transportation, the coiled cable 1 does not loosen, and the cable 1 can be easily pulled out during laying.

  And even if the coating layer 4 is damaged by abrasion, it can be protected by the ultrahigh molecular weight polyethylene film 3 and the internal core 2 can be prevented from being exposed, so that it is possible to maintain long-term characteristics as the cable 1. Since long cable laying of the cable 1 can be carried out without problems, the laying workability is improved and the laying cost is reduced.

(III) Variation of the embodiment:
The aspect described above shows one aspect of the present invention, and the present invention is not limited to the above-described embodiment, and has the configuration of the present invention and can achieve the objects and effects. It goes without saying that modifications and improvements within the scope are included in the content of the present invention. Further, the specific structure, shape, and the like in carrying out the present invention are not problematic as other structures, shapes, and the like as long as the objects and effects of the present invention can be achieved. The present invention is not limited to the above-described embodiments, and modifications and improvements within the scope that can achieve the object of the present invention are included in the present invention.

In the embodiment described above, as shown in FIG. 1, the coating layer 4 such as the outermost layer 41 and the inner layer 42 is provided around the core 2 serving as a transmission medium, and the ultrahigh molecular weight polyethylene film 3 is disposed inside the outermost layer 41. The configuration welded over the longitudinal direction has been described as an example. On the other hand, the cable 1 according to the present invention is not limited to such a configuration, and for example, the configuration shown in FIGS. 2 and 3 may be used.
In the following description, the same structure and the same members as those in FIG. 1 described above are denoted by the same reference numerals, and detailed description thereof is omitted or simplified.

  2 and 3 are cross-sectional views showing other aspects of the structure of the cable 1 according to the present invention, and FIG. 2 shows that the ultra-high molecular weight polyethylene film 3 is elongated inside the inner layer 42 instead of the outermost layer 41. The structure welded over the direction is shown. FIG. 3 shows a configuration in which the ultrahigh molecular weight polyethylene film 3 is welded in the longitudinal direction inside both the outermost layer 41 and the inner layer 42. Thus, in the present invention, the ultrahigh molecular weight polyethylene film 3 only needs to be welded in the longitudinal direction inside at least one layer of the coating layer 4 formed around the core 2. .

In the above-described embodiment, the two coating layers 4 of the outermost layer 41 and the inner layer 42 are formed around the core 2 that is a transmission medium. However, the inner layer 42 is not necessarily required. FIG. 4 is a cross-sectional view showing another aspect of the structure of the cable according to the present invention. As shown in FIG. 4, the coating layer 4 is only the outermost layer 41, and the inner layer of the outermost layer 41 is extremely high. The molecular weight polyethylene film 3 may be integrated by welding in the longitudinal direction.
In addition, the specific structure, shape, and the like in the implementation of the present invention may be other structures as long as the object of the present invention can be achieved.

  The present invention can be used as a cable that can suppress the exposure of the inner core even if the covering layer is damaged due to wear when the laying is long, and the industrial applicability is very high. high.

DESCRIPTION OF SYMBOLS 1 ... Cable 2 ... Core 3 ... Ultra high molecular weight polyethylene film 4 ... Covering layer 41 ... Outermost layer 42 ... Inner layer

Claims (5)

A core serving as a transmission medium, and a cable including a coating layer including at least an outermost layer around the core,
A cable characterized in that an ultrahigh molecular weight polyethylene film is welded in the longitudinal direction inside at least one of the covering layers.   The cable according to claim 1, wherein the ultrahigh molecular weight polyethylene film is welded in the longitudinal direction inside a coating layer that is an outermost layer.   The cable according to claim 1 or 2, wherein the ultrahigh molecular weight polyethylene film has a weight average molecular weight of 500,000 to 6,000,000.   The shrinkage dimensional change rate (according to JIS C2151, 21, 1, and b) when the ultrahigh molecular weight polyethylene film is heat-treated at 180 ° C for 5 minutes is within a range of ± 5%. The cable according to claim 3.   The cable according to any one of claims 1 to 4, wherein the ultrahigh molecular weight polyethylene film is subjected to weathering resistance treatment.

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