JP2007272199A - Optical fiber cable - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical fiber cable which is an extrusion molding body of olefin resin excellent in high slippage, abrasion resistance and fire resistance. <P>SOLUTION: By adding talc 11 with a crystal diameter of 3 to 10 μm to olefin resin and forming an olefin resin mixture to which the talc 11 is added by extrusion molding, the talc 11 is induced to the surface side of the olefin resin which is base resin during the extrusion molding and arrayed like scales on the surface of a cable jacket 1, so that surface hardness is increased and high slippage (low friction) and abrasion resistance can be improved by the talc 11 covering the surface like scales. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an extruded product cable formed by extrusion using an olefin-based resin as a base resin, and is particularly excellent in flame retardancy, high slipperiness and wear resistance, and to a conduit for drawing overhead wires into a home. The present invention relates to an optical fiber cable that can be easily inserted.

  In recent years, flame resistance has been strongly demanded for cables and electric wires including optical fiber cables so that they do not generate toxic gas or smoke by burning in the event of a fire. A combination of a metal hydroxide such as magnesium hydroxide or phosphorus is generally used as a component (flame retardant) that imparts flame retardancy to a resin molded body used as such a cable jacket. In addition, appropriately selected fillers and additives are added to the resin molded body that places importance on flame retardancy in order to improve the combustion suppression effect and mechanical characteristics. As an example of a conventional resin molded body having such flame retardancy, a method relating to a method for manufacturing a heat insulating tube is disclosed in Japanese Patent Application Laid-Open No. 7-330941.

  In the conventional method for manufacturing a heat insulating tube, a polystyrene or styrene copolymer resin containing 0.1 to 20% red phosphorus and 0.5 to 10% liquefied hydrocarbon gas is formed on the outer periphery of a metal tube with an expansion ratio of 3 to 20. Double-extrusion coating.

In this conventional heat insulating tube manufacturing method, nucleating agents such as calcium stearylate, zinc stearate, calcium silicate, reinforcing agents such as talc, alumina, kaolin, silica, calcium carbonate, calcium sulfate, mica, celite, By adding additives such as asbestos, zeolite, and diatomaceous earth, the expanded polystyrene or styrene copolymer resin can have a dense and rigid structure. The addition amount of these is suitably about 0.01 to 1.0% by weight, preferably about 0.05 to 0.2% by weight for the nucleating agent relative to polystyrene or styrene copolymer resin. The reinforcing agent is about 0.5 to 5% by weight, preferably about 1.5 to 3% by weight. By adding these additives, the bubble diameter can be made finer and the mechanical strength is improved.
In addition, as another example of the conventional flame retardant resin molded article, a polyolefin resin molded article is disclosed in Japanese Patent Application Laid-Open No. 11-21392.

In the conventional resin molding, an inorganic filler such as an alkaline earth metal oxide, metal hydroxide, metal carbonate, talc, zeolite, titanium oxide and the like is added to a base resin polypropylene together with a phosphorus-based flame retardant. Configured. Talc, an inorganic substance of hydrated magnesium silicate powder, can reduce the amount of polypropylene to increase the ignition temperature, heat transfer coefficient and specific gravity, and reduce the burning rate, especially compared to other inorganic substances. It is preferable because it has good chemical resistance, high whiteness of about 95, softness of about 1 and no deterioration of the workability of the molded product. The amount of talc added is preferably 10 to 100 parts by weight with respect to 100 parts by weight of polypropylene. More preferably, it is 20-60 weight part.
JP-A-7-330941 Japanese Patent Laid-Open No. 11-21392

  According to the method for manufacturing a heat insulating tube described in Patent Document 1, although the mechanical strength of polystyrene or styrene copolymer resin can be improved by adding talc or calcium stearate, the wear resistance of the surface of the obtained resin molded body is obtained. Therefore, there is a problem that the frictional resistance is increased due to wear due to contact with other objects, and it is not suitable for use in a cable jacket that requires high slipperiness and wear resistance.

  Moreover, although the resin molding of the said patent document 2 is comprised as mentioned above and can reduce a burning rate by addition of talc and can improve a flame retardance, the surface of the resin molding obtained as mentioned above Has a relatively low wear resistance, and the frictional resistance increases due to wear due to contact with other objects, which makes it difficult to apply to a cable jacket that requires high slipperiness and wear resistance.

  The present invention has been made in order to solve the above-mentioned problems, and provides an optical fiber cable having a hard surface excellent in not only flame retardancy but also high slipperiness and wear resistance, and excellent usability such as tearability. The purpose is to provide.

  An optical fiber cable according to the present invention includes one or a plurality of optical fiber core wires, one or a plurality of reinforcing wires arranged in parallel with the optical fiber core wires, and a jacket covering the outer periphery of the optical fiber core wires and the reinforcing wires. In an optical fiber cable provided with an outer sheath to be formed, talc having a crystal diameter of 3 to 10 μm is added to an olefin resin, and the olefin resin mixture to which the talc is added is formed by extrusion molding. is there.

  As described above, according to the present invention, talc having a crystal diameter of 3 to 10 μm is added to an olefin resin, and an outer sheath of an optical fiber cable is obtained through extrusion molding of the olefin resin mixture to which the talc is added. During molding, talc is attracted to the surface side of the olefin resin that is the base resin and is arranged in a scaly manner on the surface of the cable jacket, and the surface hardness is increased by the talc that covers the surface in a scaly manner as a cable High lubricity (low friction) and wear resistance can be improved.

  In addition, the optical fiber cable according to the present invention has a support line in which a messenger wire is covered with a jacket with respect to the optical fiber main line formed by coating the optical fiber core wire and the reinforcing wire with the jacket as necessary. The optical fiber main wire is integrated with the optical fiber core wire and the reinforcing wire in a direction parallel to the optical fiber core wire and the reinforcing wire.

As described above, according to the present invention, the optical fiber main line and the support line are integrated in parallel, so that the optical fiber core line can be suspended overhead without giving a load.
Moreover, the optical fiber cable according to the present invention is provided with one or a plurality of cutout groove portions at predetermined positions on the surface of the jacket near the optical fiber core wire as necessary.

As described above, according to the present invention, the structure in which the notch groove portion is provided on the outer surface of the outer cover allows the incision operation to be easily and reliably performed by hand without using a special tool when the optical fiber core wire is pulled out from the outer cover. be able to.
Moreover, the optical fiber cable which concerns on this invention is arrange | positioned as needed by the said notch groove part on the jacket surface by the arrangement | positioning which becomes opposing relationship centering | focusing on the said optical fiber core wire position.

As described above, according to the present invention, the notch groove portion on the outer surface of the jacket is arranged so as to face the center of the core wire, so that the tearability of the jacket and the removal of the optical fiber core wire can be facilitated.
Further, in the optical fiber cable according to the present invention, if necessary, the reinforcing wires are arranged in two symmetrical positions with respect to the optical fiber core wire, and the notch groove portion has a wedge-shaped cross-sectional shape. The groove center line extending from the groove entrance side to the groove depth is arranged so as to be a line that does not pass through the optical fiber core line by being inclined by a predetermined angle with respect to the straight line connecting the reinforcing wires.

  Thus, according to the present invention, by arranging the notch groove portion of the outer jacket surface as a wedge-shaped cross-sectional shape so that the direction does not face the optical fiber core wire, in addition to improving the tearability of the outer jacket, It is possible to prevent damage to the optical fiber core wire.

(First embodiment of the present invention)
Hereinafter, an optical fiber cable according to a first embodiment of the present invention will be described with reference to FIGS. 1 and 2 by taking an aerial optical drop cable as an example. FIG. 1 is a cross-sectional view of an optical fiber cable according to the present embodiment, and FIG. 2 is a cross-sectional view of the optical fiber cable shown in FIG.

  In each of the drawings, an optical fiber cable 50 according to the present embodiment is formed by joining an optical fiber main line 20 covered with a jacket 1 made of a polyethylene resin mixture having a predetermined mixing ratio and a support line 21 at a neck portion 22. The

  The optical fiber main line 20 includes a two-core optical fiber core wire 2 covered with a jacket 1 and two FRP reinforcing wires 3 disposed on both sides of the optical fiber core line 2. . In addition, a notch groove 10a is formed at a side facing position on the surface of the jacket 1 of the optical fiber main line 20, and this notch groove 10a reduces the contact area to the inner wall of the pipe line as much as possible when entering the pipe line to reduce the friction coefficient. While making it small, the appropriate flexibility of the optical fiber main line 20 itself is acquired. In particular, the notch groove portion 10a can perform the incision work easily and reliably when the optical fiber core wire 2 is pulled out from the jacket 1. The support wire 21 is formed by coating a steel messenger wire 4 with the same jacket 1 as the optical fiber main wire 20.

  The jacket 1 used for the optical fiber main line 20 and the support line 21 uses an olefin resin such as high-density polyethylene as a base resin, and talc is in a ratio of 10 to 20 parts by weight with respect to 100 parts by weight of the olefin resin. And a resin mixture is formed by adding a flame retardant which is a metal hydroxide such as magnesium hydroxide, an antioxidant, a lubricant, a pigment, and the like.

  The talc preferably has a crystal diameter of 3 to 10 μm. If the crystal diameter is 3 μm or less, it cannot be arranged in a scaly manner on the surface of the molded body, and if the crystal diameter is 10 μm or more, the shape of the cable jacket to be extruded is deteriorated.

  Specific examples of blending including talc are: 70 parts by weight of high density polyethylene, 10 parts by weight of compatibilizer, 20 parts by weight of low density polyethylene, 70 parts by weight of magnesium hydroxide, 15 parts by weight of talc, flame retardant 4 parts by weight of the auxiliary agent, 0.6 part by weight of the antioxidant, 1 part by weight of the lubricant, and 4 parts by weight of the pigment are used to form a polyethylene resin mixture. This blending content (DE-4) is shown in Table 1.

  Next, a process for manufacturing the outer sheath of the optical fiber cable according to this embodiment will be described. First, a polyethylene resin mixture that becomes the jacket 1 with the above blending ratio is kneaded and formed, and this polyethylene resin mixture is extruded at an extrusion speed of 10 m / min to 500 m / min to form the optical fiber cable 50. The extrusion speed can also be controlled so as to decrease from 500 m / min to 10 m / min as the talc crystal diameter increases between 3 μm and 10 μm.

  Talc kneaded in a polyethylene resin mixture based on high-density polyethylene is selected to have a crystal diameter of 3 μm to 10 μm, and the extrusion speed of the polyethylene resin mixture is controlled between 10 μm / min and 500 μm / min. Thus, the talc 11 is attracted to the surface of the outer cover 1 formed by extruding the polyethylene resin mixture, and the talc 11 is arranged on the surface of the outer cover 1 as a scaly talc 11a as shown in FIG. It will be. Thus, by arranging the scale-like talc 11a on the surface of the outer jacket 1, it is possible to obtain an optical fiber cable in which the surface hardness of the outer jacket 1 is increased and the high lubricity (low friction) and wear resistance are improved. it can.

  Thus, in the optical fiber cable according to the present embodiment, in addition to the flame retardancy due to magnesium hydroxide in the polyethylene resin mixture forming the jacket 1, the blended talc is applied to the surface of the jacket 1 in the process of extrusion molding. High slidability (low friction) and wear resistance can be obtained by arranging in a scale shape, and the workability is excellent, such as the cable tension can be suppressed during work such as laying a passage through a pipe.

(Second embodiment of the present invention)
An optical fiber cable according to a second embodiment of the present invention will be described with reference to FIG. 3, taking an aerial optical drop cable as an example, as in the above embodiment. FIG. 3 is a cross-sectional view taken along line AA of the optical fiber cable shown in FIG.

  The optical fiber cable 50 according to the present embodiment is formed by joining the optical fiber main line 20 and the support line 21 at the neck portion 22 as in the first embodiment, while the polyethylene resin mixture forming the jacket 1 is formed. Some blends are different. The cable structure is the same as that of the cable according to the first embodiment shown in FIG.

  The jacket 1 in the present embodiment uses an olefin resin such as high-density polyethylene as a base resin, and kneads talc at a ratio of 10 to 20 parts by weight with respect to 100 parts by weight of the olefin resin. Instead of magnesium hydroxide and the flame retardant aid used in the embodiment, red phosphorus is added, and other additives are added to form a resin mixture.

  The red phosphorus is optimally 5 wt% to 9 wt% with respect to the amount of high density polyethylene base resin. Addition of 5 wt% or less reduces flame retardancy, while addition of 9 wt% or more does not improve flame retardancy. Moreover, since magnesium hydroxide and a flame retardant aid are not added to the resin mixture, but red phosphorus is added, the filler in the resin can be reduced, and the outer shell 1 after molding has low friction. To improve wear resistance.

  Examples of specific blends including red phosphorus include 70 parts by weight of high density polyethylene, 10 parts by weight of compatibilizer, 20 parts by weight of low density polyethylene, 11.7 parts by weight of red phosphorus, 15 parts by weight of talc, It becomes 0.6 parts by weight of the antioxidant, 1 part by weight of the lubricant, and 4 parts by weight of the pigment, thereby producing a polyethylene resin mixture. The blended content (DE-21) is shown in Table 1 above.

  Next, the flame retardancy of the optical fiber cable according to the present embodiment will be described. In the production of the cable, as in the first embodiment, a polyethylene resin mixture that becomes the outer jacket 1 is kneaded and produced at the blending ratio, and the polyethylene resin mixture is extruded at an extrusion speed of 10 m / min to 500 m / min. Thus, the optical fiber cable 50 is formed. The extrusion speed can also be controlled so as to decrease from 500 m / min to 10 m / min as the talc crystal diameter increases between 3 μm and 10 μm.

  Since talc and red phosphorus are kneaded in a polyethylene resin mixture based on this high-density polyethylene resin, as in the first embodiment, the surface of the jacket 1 is as shown in FIG. In addition to the arrangement of the scale-like talc 11a, the red phosphorus 12 is distributed in a slightly scattered manner in the outer jacket 1, even if the optical fiber cable 50 is exposed to a high temperature such as a flame. The carbonized film 12a can be formed on the surface, and high flame retardancy can be obtained.

  In this optical fiber cable 50, if the polyethylene resin mixture is melted into a liquid state and becomes a fluid state due to high heat generated during combustion, the carbonized coating 12a is collapsed, including the scale-like talc 11a arranged on the surface. Since the temperature to release talc crystal water is as high as 800 ° C., it is difficult for crystal water to be released by the heat during combustion, and the melting and fluidization of the polyethylene resin mixture can be suppressed, and the carbonized coating 12a can be reliably destroyed. Can be prevented. In addition, inorganic fillers such as metal hydroxides (for example, magnesium hydroxide, aluminum hydroxide, etc.) other than talc 11 and plate crystal fillers (for example, kaolinite) are crystal water at 200 ° C. to 400 ° C. , And the carbonized film 12a is easily collapsed by heat during combustion as compared with talc.

  As described above, the optical fiber cable according to the present embodiment uses red phosphorus as a flame retardant blended in the polyethylene resin mixture forming the jacket 1 and reduces filler, so that the surface of the jacket 1 is scale-like. Along with the action of the arranged talc, the wear resistance is greatly improved, and an excellent high slip property (low friction property) is obtained, and the characteristics preferable as a cable are exhibited as compared with the case of the first embodiment. It is possible to further improve the workability such as laying a line through the pipe.

(Third embodiment of the present invention)
An optical fiber cable according to a third embodiment of the present invention will be described with reference to FIG. 4, taking an aerial optical drop cable as an example, as in the above embodiments. FIG. 4 is a cross-sectional view of the overhead optical drop cable according to the present embodiment.

  In FIG. 4, the optical fiber cable 51 according to the present embodiment is formed by joining the optical fiber main line 70 and the support line 71 at the neck portion 72 as in the first embodiment. The notch groove portion 60a on the surface of the target 6 has a wedge-shaped cross-sectional shape, and the groove center line 60b from the groove entrance side toward the groove depth is inclined by a predetermined angle with respect to the straight line connecting the reinforcing wires 8 to each other. It has the structure arrange | positioned so that it may become the line of the diagonal direction which does not pass.

  The optical fiber main line 70 includes a four-core optical fiber core wire 7 covered with a jacket 6 and two FRP reinforcing wires 8 disposed on both sides of the optical fiber core wire 7. . In addition, a wedge-shaped notch groove portion 60a is formed obliquely at a rotationally symmetric position around the optical fiber main line 70 on the surface of the outer cover 6 of the optical fiber main line 70, and when the optical fiber core wire 7 is pulled out from the outer cover 6, In addition to the original function of making the tearing of the cover 6 easy, the thin protruding piece of the cover 6 on the outside of the notch groove portion 60a is bent when the pipe enters, so that the inner wall of the pipe In addition, it is possible to reduce the friction coefficient by minimizing the contact area with the existing cable. Furthermore, since the groove depth direction of the notch groove portion 60a is deviated from the optical fiber core wire 7, damage to the core wire caused by insects such as cicada having the property of inserting a laying tube into such a narrow gap portion can be avoided. It becomes.

  The notch groove portion 60a is disposed such that the groove center line 60b is inclined by 15 ° to 45 ° with respect to the straight line connecting the reinforcement lines 8 and the reinforcement line 8 is positioned on the extension of the groove center line 60b. Is preferred. The opening angle of the wedge-shaped cross section of the notch groove portion 60a is preferably 30 ° or less. Furthermore, when the cross-sectional shape of the optical fiber main line 70 is a rectangular shape as shown in FIG. 4, the notch groove portion 60 b is arranged so that the groove opening is located at the corner of the optical fiber main line 70. Desirable in terms of layout and cable handling.

As in the first embodiment, the support wire 71 is configured by covering a steel messenger wire 9 with the same jacket 6 as the optical fiber main wire 70.
The jacket 6 used for the optical fiber main line 70 and the support line 71 is formed by producing a polyethylene resin mixture with the same composition as in the first embodiment or the second embodiment. Detailed description will be omitted.

  As for the surface state of the optical fiber cable according to this embodiment, talc 11 is attracted to the surface of the jacket 1 in the process of extrusion molding of the polyethylene resin mixture, as in the first and second embodiments, and the surface of the jacket 1 2 and 3 are arranged in the form of scaly talc 11a, the surface hardness of the jacket 1 is increased to provide high slip (low friction) and wear resistance. Can be improved.

  As described above, the optical fiber cable according to the present embodiment, as in the first and second embodiments, greatly improves the high slip (low friction) and wear resistance while ensuring flame retardancy. In addition to being able to reduce the risk of damage to the optical fiber core wire 7 by appropriately arranging the notch groove portion 60a in the main portion of the optical fiber 70, durability in an overhead wiring state and reliability as a cable can be reduced. Enhanced.

  In addition, in the optical fiber cable according to each of the above embodiments, the optical fiber core wires 2 and 7 are arranged in the optical fiber main lines 20 and 70 in two or four vertically arranged, but not limited thereto, As shown in FIG. 5 and FIG. 6, the number of optical fiber core wires and how to arrange them can be set as appropriate as long as they are properly accommodated in the optical fiber main line. Further, the optical fiber core wire is not limited to a configuration in which one or a plurality of single-core optical fiber core wires are arranged, but one or a plurality of bundle-like or tape-like core wires in which a plurality of core wires are integrated with a common coating. It can also be set as the structure to arrange.

  Further, in the optical fiber cables according to the above-described embodiments, the cutout groove portions 10a and 60a on the surfaces of the jackets 1 and 6 are provided at two locations that are rotationally symmetric about the optical fiber core wires 2 and 7, respectively. However, the present invention is not limited to this, and the arrangement position may be any position around the optical fiber core wire as long as the outer shell can be easily cut and the core wire can be taken out. The number of notched groove portions is not limited to two, but may be one or three or more. If the number of notched groove portions is increased, the flexibility of the optical fiber main line can be increased. Furthermore, as shown in FIG. 5, when the tool for taking out the core wire can be used at all times, or when it is desired to reduce the risk of strength reduction and increased risk of damage to the core wire due to the presence of the notch groove, as in each of the above embodiments. Further, the optical fiber cable 52 can be configured to have a structure including the optical fiber main line 74 and the support line 75 in which the optical fiber core wire 73 and the reinforcing wire 81 are covered with the outer sheath 61, but not having the notch groove portion at all.

  Further, in the optical fiber cable according to each of the above embodiments, the support wires 21 and 71 in which the messenger wires 4 and 9 are covered with the jackets 1 and 6 are integrated with the optical fiber main lines 20 and 70 to form the optical fiber cable 50, However, it is possible to handle only the main fiber optic line by inserting a pipeline or the like by separating and removing the support line as necessary, such as when retracting into the house. Further, as shown in FIG. 6, an optical fiber cable is used only by the main part of the optical fiber in which the supporting fiber is not used from the beginning, the optical fiber core wire 76 and the reinforcing wire 82 are covered with the jacket 62, and the notch groove 63 is provided on the surface. 53, and when the strength in the aerial state is not so great, the cost can be reduced by adopting a simple structure. It can be done easily and quickly without the need for separation and the like, and since there is no remainder of the neck after separation, the frictional resistance is reduced and the work can be performed smoothly.

  Furthermore, in the optical fiber cable according to each of the above-described embodiments, the reinforcing wires are arranged to be arranged in a straight line with the optical fiber core wire and the messenger wire. You may change suitably the arrangement position and the number of arrangement | positioning of the reinforcement line with respect to a core wire according to an environment.

  A test for confirming the performance of the optical fiber cable of the present invention was carried out using the test system described in FIGS. FIG. 7 is a configuration diagram of a low-friction test apparatus for testing the low-friction property of the optical fiber cable according to each embodiment of the present invention, and FIG. 8 is a pipe line test of the optical fiber cable according to each embodiment of the present invention. It is a system configuration diagram. In all the cables to be tested, the height L1 of the optical fiber main line 20 is 3.7 mm, the height L2 of the entire cable is 6.0 mm, and the width L3 of the entire cable is 2.0 mm.

Example 1
7 together with the optical fiber cables (DE-4, DE-21) according to the first and second embodiments by using the low friction test apparatus shown in FIG. NUC-9739 was used as a comparative example, and a low-friction test was performed only on the optical fiber main line from which the support line of each optical fiber cable was cut.

  In this low friction test, as shown in FIG. 7, an optical fiber cable as a pull-out test piece is sandwiched from above and below by a fixed test piece, and the sandwiched optical fiber cable is sandwiched by a sample fixing plate with a weight of 3 kg applied load. Pressurize. With the applied load of 3 kg, the pull-out test piece was pulled at a rate of 100 mm / min in the direction of the tensile axis with a load cell, and the frictional force was measured to obtain a friction coefficient. The results of this low friction test are shown in Table 2.

(Example 2)
The wear resistance test using the wear ring was performed in the same manner as in Example 1 together with the optical fiber cables (DE-4, DE-21) according to the first and second embodiments, and the conventional optical fiber cables (Japan Using NUC-9739 manufactured by Unicar Co., Ltd.) as a comparative example, the test was performed on the support line of each optical fiber cable. The results of this abrasion resistance test are shown in Table 3. In the table, the optical fiber cable according to the first embodiment has a result of having 6 times the wear resistance of the conventional cable as a comparative example. In addition, in the same table, the optical fiber cable according to the second embodiment similarly has the result of having 24 times the wear resistance of the comparative example.

(Example 3)
A conventional optical fiber cable (Nippon Unicar is used as the jacket material) together with the optical fiber cables (DE-4, DE-21) according to the first and second embodiments using the pipe line test system shown in FIG. Using a NUC-9739 manufactured by Co., Ltd.) as a comparative example, a pipeline passage test was conducted. In this pipeline passage test, a nominal line (about 31 m, 6 mmφ pair twisted structure) is inserted into the pipeline shown in FIG. 8, and the test line is exposed to the nominal line exposed from the delivery end of this pipeline. A fiber cable is connected, and the nominal line to which the optical fiber cable is connected is pulled from the cable pulling end. The cable was pulled manually by a distance of 10 m (at the start of pulling, the pull-in length was 0) four times at a speed of 10 m / min, and the tension at a pull-in total length of 40 m was measured. The test results are shown in Table 4. In the same table, when the total pull-in length is 40 m, the optical fiber cable according to the first and second embodiments has a tension of 1/5 of the conventional cable as a comparative example, and was obtained in a low friction test. It can be seen that the same tendency as the coefficient of dynamic friction is shown.

Example 4
About the talc in the polyethylene resin mixture in the optical fiber cable according to the second embodiment of the present invention, the cables of Experiments 1, 2, and 3 were obtained by changing the particle diameter and the addition amount, and the second embodiment was used. Comparison with the cable (DE-21) was performed. Table 5 shows the composition of each cable jacket and the comparison results. As shown in the table, the cable jacket of each experiment was configured such that the crystal diameter of talc 11 was 2 μm and 17 μm, and the addition amount was changed to 15 parts by weight and 30 parts by weight. As a result, it can be seen that when the crystal diameter of talc 11 is 17 μm (experiment 2), the appearance of the extruded crystals is poor, and when the crystal diameter is 2 μm (experiment 1), the wear resistance is slightly deteriorated. Moreover, when the addition amount of talc 11 becomes 30 weight part (experiment 3), it turns out that heat aging property worsens.

(Example 5)
About the red phosphorus in the polyethylene resin mixture in the optical fiber cable according to the second embodiment of the present invention, the amount of addition was varied to obtain the cables of Experiments 4 to 8, and the cable according to the second embodiment (DE- Comparison with 21) was performed. Table 6 shows the composition of each cable jacket and the comparison results. As shown in the table, the cable jacket of each experiment was prepared by adding 1.5 parts by weight of red phosphorus 12 (Experiment 4), 4.4 parts by weight (Experiment 5), 7.5 parts by weight (Experiment 6). ), 11.7 parts by weight (DE-21), 14.3 parts by weight (Experiment 7), and 19.8 parts by weight (Experiment 8). As a result, it can be seen that the flame retardance is poor when the phosphorus concentration of red phosphorus 12 is 3 wt% or less, and that the extruded appearance of the cable is deteriorated when the phosphorus concentration of red phosphorus 12 is 12 wt% or more. That is, the phosphorus concentration of red phosphorus is desirably in the range of 5 wt% to 9 wt%.

1 is a cross-sectional view of an optical fiber cable according to a first embodiment of the present invention. It is the sectional view on the AA line of the optical fiber cable of FIG. It is the sectional view on the AA line in the carbonized film generation state of the optical fiber cable of FIG. It is a cross-sectional view of the optical fiber cable which concerns on the 3rd Embodiment of this invention. It is a cross-sectional view of the optical fiber cable which concerns on other embodiment of this invention. It is a cross-sectional view of the optical fiber cable which concerns on other embodiment of this invention. It is a block diagram of the low friction property testing apparatus which tests the low friction property of the optical fiber cable which concerns on each embodiment of this invention. 1 is a configuration diagram of an optical fiber cable pipe line test system according to each embodiment of the present invention.

Explanation of symbols

1, 6, 61, 62 Outer sheath 10a, 60a, 63 Notched groove 11 Talc 11a Scale-like talc 12 Red phosphorus 12a Carbonized coating 2, 7, 73, 76 Optical fiber core wire 20, 70, 74 Main optical fiber wire 21, 71, 75 Support line 22, 72 Neck part 3, 8, 81, 82 Reinforcement line 4, 9 Messenger wire 50, 51, 52, 53 Optical fiber cable 60b Groove center line

Claims (5)

An optical fiber comprising one or a plurality of optical fiber core wires, one or a plurality of reinforcing wires arranged in parallel with the optical fiber core wires, and a jacket that is collectively covered on the outer periphery of the optical fiber core wires and the reinforcing wires. In the cable
An optical fiber cable, wherein talc having a crystal diameter of 3 to 10 μm is added to an olefin-based resin, and the olefin-based resin mixture to which the talc is added is formed by extrusion molding. The optical fiber cable according to claim 1,
In contrast to the optical fiber main line in which the optical fiber core wire and the reinforcing wire are covered with the outer sheath, the support wire formed by covering the messenger wire with the outer sheath is in the direction parallel to the optical fiber core wire and the reinforcing wire. An optical fiber cable that is integrated with the main fiber. In the optical fiber cable according to claim 1 or 2,
One or a plurality of notch grooves are provided at a predetermined position on the surface of the jacket near the optical fiber core wire. In the optical fiber cable according to claim 3,
An optical fiber cable characterized in that two notch grooves are arranged on the outer surface of the jacket so as to be opposed to each other centering on the position of the optical fiber core wire. The optical fiber cable according to claim 4, wherein
Two of the reinforcing wires are arranged in a symmetrical positional relationship around the optical fiber core wire,
The notch groove portion has a wedge-shaped cross-sectional shape, and the groove center line from the groove entrance side to the groove depth is inclined by a predetermined angle with respect to the straight line connecting the reinforcing wires so as not to pass through the optical fiber core wire. An optical fiber cable characterized by being arranged in a cable.

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