JP4685125B2 - Optical drop cable - Google Patents

Description

  The present invention relates to an optical drop cable used for lead-in wiring from a wiring system cable to a subscriber's house such as a building or a general house.

  In recent years, optical drop cables have been required to have flame retardancy as a disaster prevention measure. In particular, flame retardancy by so-called non-halogen materials that do not generate harmful gases such as hydrogen halide gas or a large amount of smoke during combustion is required. It has been.

  As an optical drop cable with such non-halogen flame retardant properties, the cable is made of a flame retardant composition obtained by blending a metal hydrate such as magnesium hydroxide or aluminum hydroxide with a polyolefin containing no flammable halogen. What was used as a jacket material is known.

  However, in order for the optical drop cable to be flame retardant to the extent that it has self-extinguishing properties, it is necessary to add a large amount of metal hydrate. As a result, the cable's external resistance, abrasion resistance, machine The strength of the cable has been reduced, and it has been difficult to lay pipes when the cable is drawn into the subscriber's house and wired.

In order to facilitate insertion into a pipeline, as a method for improving the surface smoothness of a cable, for example, a method using talc having a specific crystal diameter in a cable jacket material has been proposed (for example, (See Patent Documents 1 to 3.) However, although this method improves the surface smoothness, the mechanical strength of the entire coating is hardly improved, and the flexibility is also lowered by the surface modification by talc. Could not improve.
JP 2007-140445 A JP 2007-272199 A JP 2007-270120 A

  The present invention has been made in response to the above-mentioned problems of the prior art, and has excellent low friction properties, wear resistance, mechanical strength and flexibility that are excellent in flame retardancy and can sufficiently cope with pipe laying. An object of the present invention is to provide an optical drop cable having the characteristics.

In order to achieve the above object, an optical drop cable according to an aspect of the present invention includes an optical fiber core, tensile strength members arranged in parallel with an interval from the optical fiber core, and a jacket covering them all together. An optical drop cable having a linear low density polyethylene, a high density polyethylene or a mixture thereof as a base resin and containing 35 to 45 parts by mass of ultrahigh molecular weight polyolefin per 100 parts by weight of the base resin , only red phosphorus as a flame retardant component, the non-halogen composition obtained by blending 20 to 35 parts by weight per 100 parts by weight resin component, it is shall be the wherein said jacket is formed.

  According to the optical drop cable according to one aspect of the present invention, it has good flame retardancy, and is excellent in low friction, wear resistance, mechanical strength and flexibility, and is sufficiently compatible with pipe laying. Is possible.

  Embodiments of the present invention will be described below. Although the description will be made based on the drawings, the drawings are provided for illustration only, and the present invention is not limited to the drawings.

  FIG. 1 is a cross-sectional view showing an embodiment of the optical drop cable of the present invention.

  The optical drop cable 101 of this embodiment is used as an optical drop cable for drawing and wiring from a wiring cable installed between utility poles to a subscriber's house such as a building or a general house. It is comprised from the part 20 and the connection part 30 which connects these.

  The cable unit 10 includes an optical fiber ribbon 11 in which a plurality of optical fiber strands (four in the example in the drawing) are arranged in parallel and the outer periphery thereof is collectively covered, and the width of the optical fiber ribbon 11. First and second strength members 12a made of steel wires, glass fiber reinforced plastics, aramid fiber reinforced plastics, and the like arranged in parallel so as to be centered on the same plane on both sides in the direction, 12b and a jacket 13 for covering them all together. The outer jacket 13 has an oval or rectangular cross section. Further, a pair of tearing notches 14a and 14b are provided on both side surfaces of the portion of the jacket 13 where the optical fiber ribbon 11 is positioned so that the optical fiber ribbon 11 can be easily taken out during cable terminal processing. Is provided.

  On the other hand, the support wire portion 20 is composed of a support wire 21 made of a steel wire and the like, and a sheath 22 which is extrusion-coated integrally with the outer cover 13 of the cable portion 10 and the connecting portion 30 on the outer periphery thereof. The covering 22 has a circular cross section.

  In this embodiment, the sheath 13 of the cable portion 10, the connecting portion 30, and the covering 22 of the support wire portion 20 are non-halogen compositions having a linear low density polyethylene, a high density polyethylene, or a mixture thereof as a base resin. It is formed of a composition comprising 20 to 35 parts by mass, preferably 20 to 35 parts by mass of 100% by mass of the resin component alone as a flame retardant component.

  Linear low-density polyethylene (LLDPE) has a density of 0.910 to 0.000 in which short-chain branches are introduced into a linear polymer using α-olefin (propylene, butene, hexene, octene, 4-methylpentene, etc.) as a comonomer. 925 polyethylene. Specifically, for example, Moretech 0168N, Moretech 0138N (all of which are trade names of Prime Polymer Co., Ltd.) are used.

  The high density polyethylene (HDPE) has a density of 0.942 to 0.960 and a melt flow rate (MFR) (load 2.16 kg) measured in accordance with JIS K 7210 of 0.27 to 0. .45 g / 10 min is suitable, and specifically, for example, Hi-Zex 5600B, Hi-Zex 5100B (all of which are trade names manufactured by Prime Polymer Co., Ltd.) are used.

  Further, as red phosphorus blended alone as a flame retardant component, for example, Novaquel FST100, Nova Red 120UF (both are trade names manufactured by Phosphor Chemical Co., Ltd.) and the like are used.

  The non-halogen composition may contain only these linear low-density polyethylene, high-density polyethylene and red phosphorus as composition components, but as a resin component, other than linear low-density polyethylene and high-density polyethylene resin. Ultra high molecular weight high density polyethylene (UMWHDPE) is blended in an amount of 35 to 45 parts by mass, preferably 38 to 43 parts by mass, per 100 parts by mass of the total amount of linear low density polyethylene and high density polyethylene resin. Can do. As ultra-high molecular weight high density polyethylene, for example, Lübmer L4000 (trade name, manufactured by Mitsui Chemicals, Inc.) is used. By blending ultrahigh molecular weight high-density polyethylene, the mechanical strength and hardness are improved, whereby the wear resistance and the low friction property can be further improved. In addition, when the compounding quantity of this ultra high molecular weight high density polyethylene exceeds the said upper limit, elongation will fall remarkably and mechanical strength will fall conversely. Moreover, the effect by addition will not be acquired if less than the said minimum.

In addition, an adhesive polymer obtained by grafting an acid anhydride such as maleic anhydride to polyolefin with about 1 to 10% by mass, an organic oxide such as dicumyl peroxide, etc. Can be blended to the limit. For example, Adtex L6101M (trade name, manufactured by Nippon Polyolefin Co., Ltd.) is used as the adhesive polymer. By blending the adhesive polymer, the mechanical strength can be further improved by improving the elongation. In addition, when the compounding quantity of this adhesive polymer exceeds the said upper limit, on the contrary, mechanical strength will fall and abrasion resistance will fall remarkably.

  In the non-halogen composition, a non-halogen polymer containing a polyolefin other than the above-described linear low-density polyethylene, high-density polyethylene and ultra-high molecular weight high-density polyethylene can be blended as long as the effects of the present invention are not impaired. Such polyolefins include low density polyethylene (LDPE), medium density polyethylene (MDPE), very low density polyethylene (VLDPE), ethylene / propylene copolymer, ethylene / propylene / diene terpolymer, ethylene / acetic acid. Examples thereof include a vinyl copolymer (EVA), an ethylene / ethyl acrylate copolymer (EEA), and an ethylene / methyl acrylate copolymer (EMA).

  In addition, colorants, antioxidants, ultraviolet absorbers, processing aids, lubricants, stabilizers and other additives that are usually blended in this type of non-halogen composition do not impair the effects of the present invention, if necessary. It can mix | blend in the range.

This non-halogen composition is easily produced by uniformly mixing (dry blending) or kneading the above components using a conventional kneader such as a Banbury mixer, tumbler, pressure kneader, kneading extruder, mixing roller, etc. can do.
The thus obtained non-halogen composition has good non-halogen flame retardancy, and, like a composition using a conventional metal hydrate, has low friction, wear resistance, and mechanical strength of the cable. And the flexibility of the cable is not lowered as in the case of using conventional talc.

  Therefore, the optical drop cable 101 of the present embodiment has good flame retardancy and is excellent in low friction, wear resistance, mechanical strength and flexibility, and has good workability in the pipeline. Can be laid.

  The present invention is not limited to the embodiment described above, and can be implemented in various forms without departing from the gist of the present invention. For example, like the optical drop cable 102 shown in FIG. 2, it may be comprised only by the cable part 10 of the optical drop cable 101 shown in FIG. This optical drop cable 102 is normally used as an underground optical drop cable laid in the basement.

  Further, in the optical drop cable 101 shown in FIG. 1, one optical fiber tape core wire 11 is embedded in the jacket 13, but for example, a plurality of optical fibers are used like the optical drop cable 103 shown in FIG. The fiber tape core wire 11 may be embedded. In this case, the arrangement method of the plurality of optical fiber ribbons 11 is not particularly limited. Further, as in the optical drop cable 104 shown in FIG. 4, one or a plurality of (two in the illustrated example) single-core optical fiber cores 15 may be used instead of the optical fiber tape cores 11. .

  Further, the number of strength members 12a, 12b and the shape of tearing notches 14a, 14b are not particularly limited.

  In each of these optical drop cables 102 to 104, etc., the jacket 13 has a non-halogenous good flame retardancy and is also excellent in low friction, wear resistance, mechanical strength and flexibility. Thus, like the optical drop cable 101, it can be laid in the pipe line with good workability.

  Next, examples of the present invention will be described, but the present invention is not limited to the following examples.

Examples 1-28, Comparative Examples 1-6
Polyolefin and red phosphorus, maleic anhydride-modified polyethylene (MAHPE) (trade name: Adtex L6101M, manufactured by Nippon Polyolefin Co., Ltd.) as an adhesive polymer, hindered phenol antioxidant (ADEKA) as an antioxidant Product name ADK STAB AO-60), carbon black as a colorant (trade name Carbon Seast G116 manufactured by Tokai Carbon Co., Ltd.), fatty acid amide lubricant (product name Alfro P-10 manufactured by Nippon Oil & Fats Co., Ltd.) as a processing aid, Tables 1 to 5 were used as the lubricant by using stearic acid-based lubricant (trade name LE-5 manufactured by Kawaken Fine Chemical Co., Ltd.) and magnesium hydroxide (trade name Mag Seeds N-4 manufactured by Kamishima Chemical Industry Co., Ltd.). Each component was uniformly kneaded with the formulation shown to obtain a resin composition.
LLDPE (a): Made by Prime Polymer Co., Ltd. Product name MORETECH 0168N
LLDPE (b): Made by Prime Polymer Co., Ltd. Product name MORETEC 0138N
HDPE (a): Made by Prime Polymer Co., Ltd. Product name Hi-Zex 5600B
HDPE (b): Made by Prime Polymer Co., Ltd. Product name Hi-Zex 5100B
UMWHDPE: Product name manufactured by Mitsui Chemicals Co., Ltd. Ryubumer L4000
Red phosphorus (a): Phosphor Chemical Co., Ltd. Product name NOVAQUEL FST100
Red phosphorus (b): Product name manufactured by Rin Chemical Industry Co., Ltd. Nova Red 120UF

  Subsequently, the optical drop cable of the structure shown in FIG. 1 was manufactured using the obtained resin composition. First, a four-fiber optical fiber ribbon (width 1.1 mm, thickness 0.3 mm) 11 and two tensile members 12a and 12b made of G-FRP (glass fiber reinforced plastic) having an outer diameter of 0.4 mm; The support wire 21 made of a galvanized single steel wire having an outer diameter of 1.2 mm is introduced into an extruder in a state of being parallel to each other as shown in FIG. An outer cover 13 having tearing notches 14a and 14b was formed on the surface, and an optical drop cable having a width of about 2 mm and a height of about 5.8 mm was manufactured.

  About the optical drop cable obtained by each said Example and each comparative example, various characteristics were evaluated by the method shown below. The mechanical properties (tensile strength, elongation, and hardness (Shore D)) were determined at 180 ° C. × 10 ° C. by using the resin composition obtained in each Example and each Comparative Example separately from the cable production. A test sheet was produced by heating and pressing under conditions of a pressure of 20 MPa for a minute and measured.

[Tensile strength and elongation]
It measured based on JISK6251.
[Hardness (Shore D)]
It was measured with a JIS K 6253 type D durometer.
[Flame retardance]
The 60 degree inclination combustion test prescribed | regulated to JISC3005 was done, the case where it did not spread to the upper end was set as the pass ((circle)), and other cases were determined to be disqualified (x).
[Abrasion resistance]
Using a wear tester stipulated in JIS C 3005, a weight of 1 kg was applied to the support wire portion cut off from the cable portion, and the wear rotation speed until the support wire was exposed was determined. The case where the number of revolutions of wear was 500 times or more was determined to be acceptable (◯), and the case where the number of rotations was less than 500 was determined to be unacceptable (x).
[Dynamic friction coefficient]
About the cable part which cut | disconnected the support wire part, the dynamic friction force was measured by the method (weight 2kg, extraction test piece length 300mm, fixed test piece length 150mm) according to JISK7125, and it computed from following Formula.
μ ₀ = F _D / F _p
(Μ ₀ : dynamic friction coefficient, F _D : dynamic friction force (N), F _p : normal force generated by mass of weight (N))
These results are shown in the lower column of Tables 1 to 5.

  As is apparent from Tables 1 to 5, in the examples, the outer cover has good mechanical properties (breaking strength of 10 MPa or more, elongation of 400% or more), and the optical drop cable has sufficient flexibility. It was confirmed to have (flexibility). Further, the optical drop cable of the example was excellent in flame retardancy and had wear resistance and low friction suitable for pipe laying. On the other hand, the amount of red phosphorus added is too small or too large, and the conventional type optical cable using magnesium hydroxide has a small elongation and insufficient flame retardancy and wear resistance.

It is sectional drawing which shows the optical drop cable which concerns on one Embodiment of this invention. It is sectional drawing which shows other embodiment of this invention. It is sectional drawing which shows other embodiment of this invention. It is sectional drawing which shows other embodiment of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Cable part, 11 ... Optical fiber tape core wire, 12a, 12b ... 1st and 2nd tension body, 13 ... Outer sheath, 15 ... Single-core optical fiber core wire, 20 ... Support wire part, 21 ... Support wire 22 ... covering, 30 ... connecting portion, 101-104 ... optical drop cable.

Claims (3)

An optical drop cable comprising an optical fiber core, tensile strength members arranged in parallel to the optical fiber core at intervals, and a jacket covering them all together,
Linear low density polyethylene, high density polyethylene or a mixture thereof is used as a base resin, and 35 to 45 parts by mass of ultrahigh molecular weight polyolefin per 100 parts by weight of the base resin, and only red phosphorus as a flame retardant component, An optical drop cable in which the jacket is formed of a non-halogen composition formed by blending 20 to 35 parts by mass per 100 parts by mass of a resin component.   2. The optical drop cable according to claim 1, wherein the compounding amount of red phosphorus is 25 to 30 parts by mass per 100 parts by mass of the resin component. The optical fiber to be arranged substantially in parallel, the envelope of the claims 1 or 2, wherein the optical drop cable characterized by comprising a support wire having a formed coated integrally on the outer periphery.

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