JPH06331862A - Plastic optical fiber cable - Google Patents

Abstract

PURPOSE:To obtain a better outfit characteristic with the same structure as heretofore by coating a plastic optical fiber with a vinyl sheath having a heat resistant plasticizer consisting of a trimellitic acid deriv. CONSTITUTION:The plastic optical fiber 1 is coated with the vinyl sheath having the heat resistant plasticizer consisting of the trimellitic acid deriv. Tri-(2-ethyl hexyl)trimellitate, etc., are used as the trimellitic acid cleriv. The vinyl sheath 3 is required to have >=90 Shore A hardness. Polymethyl methacrylate is generally used as the core material of the plastic optical fiber 1 and a fluorine polymer is used as the clad material thereof. The clad material is coated with polyethylene, etc., as a jacket material. As a result, the single-fiber plastic optical fiber cable which is strong to bending and compressing, is low in loss and has the excellent outfit characteristic is obtd.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a single-core type plastic optical fiber cable.

[0002]

2. Description of the Related Art Plastic optical fibers have a transmission loss larger than that of silica optical fibers, but they are excellent in flexibility and workability, and because they have a large diameter, they are easy to handle and are low cost. It has been used as a lead wire for scanners of bar code readers.

[0003]

Taking advantage of the flexibility and toughness of this plastic optical fiber, when it is used as a cable for fixed laying of a single-core cord type, it is handled as if it were a normal metal cable. There is a problem that sometimes the loss increases due to over-bending or over-tightening with a cable band.

The object of the present invention is to maintain the same structure as the conventional one,
An object of the present invention is to provide a single-fiber plastic optical fiber cable having a better outfitting property.

[0005]

To achieve the above object, the present invention provides a plastic optical fiber coated with a vinyl sheath having a heat-resistant plasticizer made of a trimellitic acid derivative.

Trimellitic acid derivatives include tri-
(2-Ethylhexyl) trimellitate or the like is used, and the vinyl sheath has a Shore A hardness of 90 or more.

[0007]

In a plastic optical fiber, polymethylmethacrylate (PMMA) is generally used as a core material, a fluoropolymer is used as a clad material, and polyethylene or the like is coated thereon as a jacket material.

PMMA as the core material is compatible with the plasticizer of the PVC (polyvinyl chloride) sheath material, and the results when left in the plasticizer at 60 ° C. are as shown in Table 1. Compared with the case of using DOP (n-di (2-ethylhexyl)), the effect of using TOTM (tri- (2-ethylhexyl) trimellitate) of the present invention was significantly improved.

[0009]

[Table 1]

Further, considering the tightening of the cable band and the like when the equipment is being rigged, the loss of the transmission can be reduced by setting the hardness of the PVC sheath to a Shore A hardness of 90 or more.

[0011]

An embodiment of the present invention will be described in detail below with reference to the accompanying drawings.

FIG. 1 shows a plastic optical fiber cable of the present invention. In the figure, 1 is a plastic optical fiber (core wire) consisting of a core and a clad, 2 is a tensile strength member made of aromatic polyamide fiber, and 3 is a tensile strength member. PVC using a heat resistant plasticizer composed of a trimellitic acid derivative such as TOTM (tri- (2-ethylhexyl) trimellitate)
It is a vinyl sheath made of.

Next, FIGS. 2 and 3 show the results of testing the transmission loss characteristics of the plastic fiber optical cables of the examples using TOTM as the plasticizer and the conventional DOP.

2 and 3, the vinyl sheath of the present invention was prepared with three types of cables having Shore A hardnesses of 90, 92, and 96 in consideration of tightening of a cable band or the like when fitting. In the conventional product, the Shore A hardness is 85.

FIG. 2 shows the loss characteristic against a compressive load. It can be seen that the loss characteristic is improved as compared with the conventional product by setting the Shore A hardness to 90 or more as in the present invention.

FIG. 3 shows the loss characteristics during tie wrap compression due to tie wrap compression used for actual cable tightening. From FIG. 3, when the hardness is 90 or more, a remarkable improvement is recognized as compared with the conventional product.

From the above, in the structure called a cord type, which is usually found in this cable, it is necessary to avoid using it like a general power cord, but even if it is the same structure as the cord type. By selecting the sheath material, it is possible to provide a cable that can be used for fixed wiring, and it can be used for a wide range of wiring from homes to factories as a small diameter single core optical fiber cable that can be used in any range.

[0018]

In summary, according to the present invention, a single-fiber plastic optical fiber cable that is strong against bending and compression, has a small loss, and is excellent in mounting property can be obtained.

[Brief description of drawings]

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

FIG. 2 is a diagram showing loss characteristics with respect to a compressive load of the present invention and a conventional example.

FIG. 3 is a diagram showing loss characteristics during tie wrap compression of the present invention and a conventional example.

[Explanation of symbols]

 1 Plastic optical fiber 3 Vinyl sheath

Claims (3)

[Claims] 1. A plastic optical fiber cable comprising a plastic optical fiber coated with a vinyl sheath having a heat-resistant plasticizer made of a trimellitic acid derivative. 2. The trimellitic acid derivative is tri- (2-
The plastic optical fiber cable according to claim 1, which is ethylhexyl) trimellitate. 3. The plastic optical fiber cable according to claim 2, wherein the vinyl sheath has a Shore A hardness of 90 or more.