JP2008138320A - Fiber cord tension member - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a fiber cord tension member for optical fiber cables, easily producible at a low cost, excellent in mechanical strength and firmness and also excellent in adhesion to a thermoplastic matrix resin covering the outer periphery of the member. <P>SOLUTION: The fiber cord tension member is obtained by the following process: A water-dispersible or an organic solvent-dispersible resin being 400 MPa or higher in flexural modulus when cured is applied around composite yarns obtained by partially or wholly covering the outer periphery of a core yarn composed of reinforcing synthetic fiber filaments with a sheath yarn composed of synthetic fiber filaments followed by curing the resin. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  TECHNICAL FIELD The present invention relates to a fiber cord tension member for an optical fiber cable used together with an overhead power transmission line, and more specifically, a fiber for an optical fiber cable having excellent strength and tightness and excellent adhesion to a thermoplastic matrix resin covering the outer periphery. Regarding cord tension members.

  Since the strength of the optical fiber cable alone is weak, in general, as shown in the cross-sectional view of FIG. 1, one or a plurality of tension members run along the longitudinal direction in parallel to the optical fiber line, and the outer periphery of both is a thermoplastic matrix resin. It is constituted by covering with.

  Since conventional tension members are made of metal wire, they are easily affected by wind when installed in an overhead power transmission line, and can easily cause vibrations when installed indoors. It was the cause of product failure.

  In addition, there is a proposal that the tension member is composed of FRP. However, because the diameter and weight are not sufficient, it is likely to cause vibration due to the influence of the wind. Since the adhesiveness with the thermoplastic matrix resin covering the outer periphery is insufficient, a terminal peeling treatment at the time of fixing has been required.

  Furthermore, in recent years, damage to optical fiber cables due to crows and the like has become a social problem, and there is a demand for a tension member for optical fiber cables that is not only lightweight and excellent in strength, but also excellent in tension.

  In response to these requirements, a reinforcing fiber bundle and a coating layer made of a thermoplastic resin layer having a strong flexural modulus are provided, and after impregnating the reinforcing fiber bundle with an uncured thermosetting resin, the outer periphery is coated. A rod-shaped product made of fiber-reinforced synthetic resin in which a thermosetting resin is cured after forming a layer and cooling and solidifying has been proposed (see Patent Document 1).

Although the rod-shaped material of Patent Document 1 can surely produce an optical fiber cable excellent in terms of strength and tension, there is a problem in work because the adhesion between the rod-shaped material and the thermoplastic matrix resin is still insufficient. In addition, there is a problem that the manufacturing cost is high because the manufacturing process is complicated.
JP 2001-328189 A

  The present invention was devised in view of the current state of the prior art, and its purpose is excellent in strength and tension, and excellent in adhesion to a thermoplastic matrix resin covering the outer periphery, and manufactured easily and inexpensively. An object of the present invention is to provide a fiber cord tension member for an optical fiber cable.

  As a result of diligent studies to achieve the above object, the present inventor has obtained a water-dispersible or organic solvent-dispersed composite yarn in which a reinforced synthetic fiber filament is used as a core yarn and a synthetic fiber filament is coated on the outer periphery as a sheath yarn. By applying and curing the resin, the core yarn gives strength, the water-dispersible or organic solvent-dispersible resin gives tension, and the surrounding unevenness of the composite yarn by the sheath yarn makes the matrix resin It has been found that adhesion (anchor effect) can be provided, and the present invention has been completed.

  That is, in the present invention, the outer periphery of the core yarn composed of the reinforced synthetic fiber filament is partially or completely covered with the sheath yarn composed of the synthetic fiber filament around the composite yarn. A fiber cord tension member obtained by curing after applying a water dispersible or organic solvent dispersible resin having a flexural modulus of 400 MPa or more.

  In a preferred embodiment of the fiber cord tension member of the present invention, the reinforcing synthetic fiber filament has a total fineness of 330 dtex or more, a tensile strength of 5.3 cN / dtex or more, and a breaking elongation of 9% or less, and the core yarn is A thermoplastic synthetic fiber filament is further included, and the synthetic fiber filament has a total fineness of 277 dtex or more. Further, in a preferred embodiment of the fiber cord tension member of the present invention, the coating is performed by at least one method selected from the group consisting of covering, twisting, air entanglement, and electric fiber opening, and the application of the resin is dip. The method is carried out by at least one method selected from the group consisting of a method, a roller oiling method, and a spray method, and the dry weight of the resin is 50% or less of the weight of the composite yarn.

  In addition, the present invention provides an optical fiber cable obtained by aligning one or more of the above fiber cord tension members along the longitudinal direction in parallel with the optical fiber, and coating the outer periphery of both with a thermoplastic matrix resin. It is.

  The fiber cord tension member of the present invention is a water-dispersible or organic-solvent-dispersible resin excellent in bending elastic modulus that covers a strong core yarn with sheath yarn so that irregularities are formed on the outer periphery. Since it is cured by imparting, it has the effect of not only being excellent in strength and tension, but also being extremely excellent in adhesion to the thermoplastic matrix resin covering the outer periphery. Moreover, since the fiber cord tension member of the present invention can be easily manufactured by using a machine conventionally used in the textile industry, it has an effect of being excellent in manufacturing cost.

  The fiber cord tension member of the present invention is used for an optical fiber cable used together with an overhead power transmission line, and a synthetic yarn that partially or completely covers a core yarn composed of a reinforced synthetic fiber filament and its outer periphery. It is obtained by using a composite yarn consisting of a sheath yarn composed of fiber filaments, and curing it after applying a water-dispersible or organic solvent-dispersible resin having a high bending elastic modulus at the time of curing. is there.

  The core yarn used in the fiber cord tension member of the present invention is for giving high strength and low elongation to the entire tension member, and a reinforced synthetic fiber filament having such properties is used. As the reinforcing synthetic fiber filament, organic fibers such as aromatic polyamide fiber (aramid fiber), polyparaphenylene benzobisoxazole (PBO) fiber, polyester fiber, and vinylon fiber are used, and PBO fiber having particularly excellent heat resistance is used. It is preferable to use it. As the constituent filament of the core yarn, in addition to the reinforcing synthetic fiber filament, other filaments, for example, a thermoplastic synthetic fiber such as a heat-sealing synthetic fiber having binder characteristics may be used in an amount of 30% by weight or less. The core yarn can be formed of drawn or twisted multifilaments, or untwisted or twisted monofilaments.

  The reinforcing synthetic fiber filament constituting the core yarn is required to have high strength and low elongation in terms of the diameter reduction and dimensional stability of the tension member. Therefore, the total fineness of 330 dtex or more, 5.3 cN / dtex or more. It is preferable to have a tensile strength of 10% or less and a breaking elongation of 9% or less, in particular, a total fineness of 450 to 1700 dtex, a tensile strength of 17 to 40 cN / dtex, and a breaking elongation of 2 to 5%. If the total fineness is lower than the above range, it may not be possible to give the entire tension member high strength and low elongation. If the total fineness is higher than the above range, the tension member insertion hole can be passed during the production of the optical fiber cable. There is a risk of disappearing. The reinforced synthetic fiber filament may be a monofilament or a multifilament.

  The sheath yarn used for the fiber cord tension member of the present invention is intended to give remarkable unevenness to the outer periphery of the tension member, and any synthetic fiber filament can be used as long as such an object can be achieved. As the synthetic fiber filament, for example, polyester fiber, polyamide fiber, polyethylene fiber and the like are used, and it is particularly preferable to use polyester fiber. Synthetic fiber filaments are not limited to those composed of a single component, and composite yarns composed of two or more components can also be used. Particularly, composite yarns including a component having a high melting point and a component having a low melting point should be used. Is preferred. Examples of the composite yarn include a heat-sealable yarn having a core-sheath structure having a core portion made of a polyester component having a melting point of 200 ° C to 300 ° C and a sheath portion made of a polyester component having a melting point of 100 ° C to 190 ° C. When the sheath yarn is coated around the core yarn, unevenness is generated, and these unevenness contributes to adhesion with the thermoplastic matrix resin covering the outer periphery.

  The synthetic fiber filament constituting the sheath yarn needs to be able to form remarkable irregularities on the outer periphery of the tension member, and therefore preferably has a total fineness of 277 dtex or more, and particularly preferably has a total fineness of 560 to 1100 dtex. . If the total fineness is lower than the above range, it may be difficult to coat the core yarn of the sheath yarn, and if the total fineness is higher than the above range, the unevenness formed around the core yarn becomes too large. The anchor effect may be reduced. The synthetic fiber filament may be a monofilament or a multifilament.

  The water dispersible or organic solvent dispersible resin used for the fiber cord tension member of the present invention is for giving a strong tension to the entire tension member, and a resin having such characteristics is used. As the water-dispersible or organic solvent-dispersible resin, any resin can be used as long as it can be dispersed in water or an organic solvent and has a specific flexural modulus at the time of curing. Thermosetting resins such as polyester resins, polypropylene resins and polyamide resins, thermosetting resins such as melamine resins and urethane-modified alkyd resins, alkyd resins and the like are used. Since the water-dispersible or organic solvent-dispersible resin can be applied to the core yarn in a liquid state, the manufacturing process is easy. In view of handling and environmental protection, it is preferable to use a water-dispersible resin.

  The water-dispersible or organic solvent-dispersible resin needs to be able to give a strong tension to the composite yarn by being in close contact with the composite yarn and cured, and therefore has a bending elastic modulus of 400 MPa or more when cured. Is required. In particular, the flexural modulus during curing is preferably 500 MPa or more, more preferably 600 MPa or more, or 800 MPa or more.

  As a method of covering the outer periphery of the core yarn with the sheath yarn, various methods conventionally known to those skilled in the art can be adopted. For example, the core yarn is selected from the group consisting of covering, twisting, air entanglement, and electric opening. It is preferably carried out by at least one method. Covering the sheath yarn may be performed partially on the outer periphery of the core yarn, for example, with a certain interval on the outer periphery of the core yarn, or may be performed completely on the entire outer periphery of the core yarn. However, in order to give remarkable unevenness to the outer periphery of the tension member, it is preferable to cover the sheath yarn partially on the outer periphery of the core yarn, and in particular, about 1 mm or more so that the core yarn is exposed at a constant interval. The covering is preferably performed at a pitch of about 2 mm or more (the number of windings of the sheath yarn per 1 m of the core yarn is about 1000 times or less, preferably about 500 times or less).

  As a method for imparting water-dispersible or organic solvent-dispersible resin to the formed composite yarn, various methods conventionally known to those skilled in the art can be employed. For example, dipping, roller oiling, and spraying It is preferably carried out by at least one method selected from the group consisting of The applied resin penetrates from the periphery of the composite yarn into the composite yarn. The amount of the resin applied is preferably 50% or less of the weight of the composite yarn calculated by dry weight, and particularly preferably 20% to 45%. If the resin application amount is lower than the above range, the tension may not be sufficient, and if the resin application amount is higher than the above range, the tension member may be too heavy.

  The applied resin may be cured by appropriately adopting an appropriate method according to the type of the resin. For example, in the case of a thermoplastic resin, it is cured by evaporating the solvent by natural drying or forced drying and solidifying by cooling. In the case of a thermosetting resin, it can be similarly cured by evaporating the solvent and heating it to the curing temperature or higher.

  The fiber cord tension member manufactured as described above creates a ring with a bending resistance of 10 mm or more and a bending resistance of 350 mm or more, further 400 mm or more, and further 500 mm or more in a cantilever test while maintaining the high strength of the core yarn. It has elasticity that it does not bend when it is (10R test), and it can have irregularities with excellent anchoring effect with the thermoplastic matrix resin on the outer periphery. As shown in FIG. 2, one or more fiber cord tension members are arranged in the longitudinal direction in parallel with the optical fiber line, and the outer periphery of both the fiber cord tension member and the optical fiber line is covered with a thermoplastic matrix resin. It is possible to provide an optical fiber cable which is excellent in strength and tension, and has excellent adhesion with a thermoplastic matrix resin covering the outer periphery.

  The excellent effects of the fiber cord tension member of the present invention are shown below, but the present invention is not limited thereto.

The physical properties of the fiber cord tension member were measured according to the following method.
(1) Tensile strength Measured according to the JIS L1013 chemical fiber filament yarn test method.
(2) Elongation at break Measured according to the JIS L1013 chemical fiber filament yarn test method.
(3) Tension waist (i) Cantilever method It measured according to the 45 degree cantilever method which is a test method of the softness of a textile.
(Ii) 10R method It was evaluated whether or not a 10 mm diameter ring was produced using a sample and it was not bent. The evaluation results were evaluated in three stages: ○: not bent; Δ: slightly bent; x: completely bent.
(4) Adhesiveness with thermoplastic matrix resin After coating the sample with polyethylene thermoplastic matrix resin, grip one end, peel off the matrix resin at the other end, and pull the peeled end. Thus, the adhesion to the thermoplastic matrix resin was evaluated. Evaluation results are as follows: ◎: Pulling with both hands does not pull out; ○: Pulling with one hand does not pull out; △: Pulling with light force but pulling with one hand pulls out; Evaluation was made on the 4th floor.

Examples 1-4
Core yarns are prepared according to Table 1, and Examples 1, 3 and 4 are double covering machines (spindle speed: 2000 rpm above, 2500 rpm below, rotating direction up and down, same direction, hoisting speed 9.6 m / min) In Example 2, the sheath yarn was covered onto the core yarn by a single covering machine (spindle speed: 2000 rpm, winding speed: 9.6 m / min). In any of the examples, the number of covering turns was adjusted to be about 1000 turns per 1 m of the core yarn. A resin dispersion prepared by mixing 100 parts by weight of Vironal MD-1200 (manufactured by Toyobo Co., Ltd.) and 85 parts by weight of Sumirez Resin 8% AC (manufactured by Sumitomo Chemtex) to this sample was applied by the dip method, and pulled up. After natural drying, the sample was heated in a dry heat oven at 170 ° C. for 10 minutes to obtain samples of Examples 1 to 4. In addition, the bending elastic modulus at the time of hardening of the resin dispersion liquid used in Examples 1-4 was 850 MPa. Moreover, the resin adhesion amount of each sample was as shown in Table 1.

The physical properties of the samples obtained in Examples 1 to 4 were measured. The results are shown in Table 2.

  The fiber cord tension member of the present invention is excellent in strength and tension, and is excellent in adhesion to the surrounding thermoplastic matrix resin, and therefore can be suitably used for an optical fiber cable.

Sectional drawing of an example of the conventional tension member is shown. Sectional drawing of an example of the tension member of this invention is shown.

Claims (8)

  Bending elastic modulus at the time of curing is 400 MPa or more around the composite yarn formed by partially or completely covering the outer periphery of the core yarn composed of the reinforced synthetic fiber filament with the sheath yarn composed of the synthetic fiber filament. A fiber cord tension member obtained by curing after applying a water dispersible or organic solvent dispersible resin.   The fiber cord tension member according to claim 1, wherein the reinforcing synthetic fiber filament has a total fineness of 330 dtex or more, a tensile strength of 5.3 cN / dtex or more, and a breaking elongation of 9% or less.   The fiber cord tension member according to claim 1 or 2, wherein the core yarn further includes a thermoplastic synthetic fiber filament.   The fiber cord tension member according to any one of claims 1 to 3, wherein the synthetic fiber filament has a total fineness of 277 dtex or more.   The fiber cord tension member according to any one of claims 1 to 4, wherein the covering is performed by at least one method selected from the group consisting of covering, twisting, air entanglement, and electric fiber opening.   The fiber cord tension member according to any one of claims 1 to 5, wherein the application of the resin is performed by at least one method selected from the group consisting of a dip method, a roller oiling method, and a spray method.   The fiber cord tension member according to any one of claims 1 to 6, wherein a dry weight of the resin is 50% or less of a weight of the composite yarn.   The fiber cord tension member according to any one of claims 1 to 7, wherein one or a plurality of the fiber cord tension members are parallel to the optical fiber line along the longitudinal direction, and the outer periphery of both is coated with a thermoplastic matrix resin. A featured optical fiber cable.

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