WO2014136848A1

WO2014136848A1 - Optical connector

Info

Publication number: WO2014136848A1
Application number: PCT/JP2014/055673
Authority: WO
Inventors: 登志久佐藤; 服部　知之; 大村　真樹; 蔀　龍彦
Original assignee: 住友電気工業株式会社
Priority date: 2013-03-07
Filing date: 2014-03-05
Publication date: 2014-09-12
Also published as: JP2014197188A; CN105026967A

Abstract

An optical connector (1) is provided with a fibre connection member (8) for mechanically connecting optical fibres together. The fibre connection member (8) is provided with: a base part (5) provided with a fibre groove for accommodating an optical fibre (3); and a lid part (6) which presses the optical fibre (3) accommodated in the fibre groove, against the base part (5). The base part (5) and/or the lid part (6) are/is formed from a polymer alloy of: a first thermoplastic resin comprising basic units having an aromatic ring and an ether bond; and a second thermoplastic resin different to the first thermoplastic resin. The glass transition temperature of the polymer alloy is at least 140˚C.

Description

Optical connector

The present invention relates to an optical connector for connecting optical fibers.

For example, an optical connector described in Patent Document 1 is known as a conventional optical connector. The optical connector described in Patent Document 1 includes a ferrule that holds a built-in optical fiber, and a connection mechanism (mechanical splice) that extends to the opposite side of the connection end surface of the ferrule. The connection mechanism includes a base in which a positioning groove for positioning the optical fiber connected to the built-in optical fiber is formed, a lid portion facing the base, and a C-shaped leaf spring that elastically clamps the base and the lid portion. It is comprised by.

JP 2010-186058 A

When connecting two optical fibers using the optical connector described in Patent Document 1, first, the two optical fibers are inserted into the gap between the base portion and the lid portion along the positioning groove of the base portion. And match each other. Thereafter, the gap is closed by the pressing force of the C-type spring, and the two optical fibers in a state of being butted against each other are fixed by pressing them with the base portion and the lid portion. At this time, the position of the optical fiber may shift due to the progress of creep of the material forming the base portion and the lid portion over time. As a result, the axes of the connected optical fibers are misaligned, resulting in an increase in connection loss, and as a result, communication quality may be impaired.

An object of the present invention is to provide an optical connector that can suppress connection loss of optical fibers when optical fibers are mechanically connected to each other.

The optical connector according to the present invention is an optical connector provided with a fiber connecting member for mechanically connecting optical fibers. In this optical connector, the fiber connection member has a base portion having a fiber groove that accommodates the optical fiber, and a lid portion that presses the optical fiber accommodated in the fiber groove against the base portion. At least one of the base portion and the lid portion is formed from a polymer alloy of a first thermoplastic resin composed of a basic unit having an aromatic ring and an ether bond and a second thermoplastic resin different from the first thermoplastic resin. Has been. The glass transition temperature of the polymer alloy is 140 ° C. or higher.

According to the present invention, connection loss of optical fibers can be suppressed when optical fibers are mechanically connected. As a result, it is possible to improve the reliability of the optical fiber while ensuring the necessary characteristics when mechanically connecting the optical fibers.

FIG. 1 is a schematic cross-sectional view showing an embodiment of an optical connector. FIG. 2 is a cross-sectional view showing an open / close state of the mechanical splice with a ferrule shown in FIG. FIG. 3 is a graph showing the relationship between the glass transition temperature of the polymer alloy and the initial loss.

[Description of Embodiment of Present Invention]
First, embodiments of the present invention will be listed and described. The optical connector which concerns on 1 side of this invention is an optical connector provided with the fiber connection member for connecting optical fibers mechanically. In this optical connector, the fiber connection member has a base portion having a fiber groove that accommodates the optical fiber, and a lid portion that presses the optical fiber accommodated in the fiber groove against the base portion. At least one of the base portion and the lid portion is formed from a polymer alloy of a first thermoplastic resin composed of a basic unit having an aromatic ring and an ether bond and a second thermoplastic resin different from the first thermoplastic resin. Has been. The glass transition temperature of the polymer alloy is 140 ° C. or higher.

In such an optical connector, since the glass transition temperature of the polymer alloy is as high as 140 ° C. or higher, the deflection temperature under load of the polymer alloy becomes high. For this reason, a polymer alloy will be in the state which the creep phenomenon with respect to the load load of a high temperature or a long time does not advance easily. Accordingly, the creep characteristics of the fiber connecting member formed from such a polymer alloy are improved. That is, the progress of the creep phenomenon in the base portion and the lid portion is suppressed, and the creep strain per unit time in the base portion and the lid portion is reduced. Therefore, since the optical fiber misalignment caused by the passage of time can be suppressed, the connection loss of the optical fiber can be suppressed.

In the optical connector according to one aspect, the first thermoplastic resin may be a polyphenylene ether resin. Polyphenylene ether resins are relatively high in heat resistance among common polymers and have a high deflection temperature under load. For this reason, the polyphenylene ether resin can be used as a polymer alloy for forming a fiber connecting member.

In the optical connector according to one aspect, the second thermoplastic resin may be a polystyrene-based resin or a polyphenylene sulfide-based resin. A polymer alloy obtained by adding a polystyrene-based resin is excellent in ease of coloring, a good balance of mechanical properties, ease of flame retardancy improvement, and the like. In addition, the polystyrene resin has good compatibility with the polyphenylene ether resin. Therefore, for example, when a polystyrene-based resin is mixed with a polyphenylene ether-based resin, a polymer alloy in which physical properties such as heat resistance and mechanical properties are complemented without impairing excellent moldability can be obtained. In addition, a polymer alloy obtained by adding a polyphenylene sulfide resin is excellent in heat resistance. Thereby, a polymer alloy in which the creep phenomenon is more difficult to proceed can be obtained. Therefore, the fiber connecting member can be formed from a polymer alloy having desired physical properties.

In the optical connector according to one aspect, the ratio of the first thermoplastic resin to the total of the first thermoplastic resin and the second thermoplastic resin may be 25 wt% or more and 75 wt% or less. In this case, a polymer alloy excellent in molding processability and supplemented with physical properties such as heat resistance and mechanical properties can be obtained. Therefore, the fiber connecting member can be formed from a polymer alloy having desired physical properties.

In the optical connector according to one embodiment, a filler may be added to the polymer alloy by 10% by weight or more. The filler may be, for example, a fibrous filler made of glass fiber. In this case, since the glass alloy is mixed with the polymer alloy, the physical properties such as the bending elastic modulus or the drawing property of the polymer alloy are controlled to an appropriate value, so that the rigidity of the fiber connecting member is ensured.

In the optical connector according to one aspect, a ferrule that holds a built-in optical fiber constituting one of the optical fibers may be fixed to the base portion. In this case, the optical connector can be used as an on-site optical connector.

[Details of the embodiment of the present invention]
DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of an optical connector according to the present invention will be described in detail with reference to the drawings.

FIG. 1 is a schematic sectional view showing an embodiment of an optical connector according to the present invention. In the figure, the optical connector 1 of this embodiment is a mechanical splice type optical connector.

The optical connector 1 includes a mechanical splice 2 with a ferrule that mechanically connects and fixes optical fibers, and a housing (not shown) that covers the mechanical splice 2 with a ferrule.

As shown in FIGS. 1 and 2A, the mechanical splice 2 with a ferrule is accommodated in the fiber groove 4 and a base portion 5 having a fiber groove 4 having a V-shaped cross section for positioning and accommodating the optical fiber 3. The optical fiber 3 has a lid portion 6 that presses against the base portion 5. Further, the mechanical splice 2 has a clamp spring 7 having a U-shaped cross section that sandwiches the base portion 5 and the lid portion 6. The base portion 5 and the lid portion 6 constitute a resin fiber connection member 8. The end portion of the optical fiber 3 is removed from the coating to expose the bare fiber 3a. The bare fiber 3a is made of, for example, quartz glass.

A ferrule 9 is fixed to the front end portion of the base portion 5. The ferrule 9 holds a short built-in fiber 10. The built-in fiber 10 has the same configuration as that of the bare fiber 3 a and extends from the front end surface (connection end surface) of the ferrule 9 to the fiber groove 4 of the fiber connection member 8.

A plurality of wedge insertion recesses 12 into which the wedge members 11 are inserted are provided at the boundary portion between the base portion 5 and the lid portion 6 in the fiber connection member 8. The fiber connection member 8 is sandwiched between the clamp springs 7 from the opposite side of the wedge insertion recess 12.

In such an optical connector 1, when the optical fiber 3 is connected to the built-in fiber 10 held by the ferrule 9, the wedge member 11 is connected to the wedge of the fiber connection member 8 as shown in FIG. Insert into the insertion recess 12. As a result, the base portion 5 and the lid portion 6 are opened against the urging force of the clamp spring 7.

Then, as shown in FIG. 1, the optical fiber 3 is introduced into the fiber connecting member 8 from the rear side of the mechanical splice 2 with a ferrule, and the tip surface of the optical fiber 3 is abutted against the built-in fiber 10. The fiber connection member 8 is filled with a refractive index matching agent S for eliminating optical discontinuity between the optical fiber 3 and the built-in fiber 10.

In this state, the wedge member 11 is removed from the wedge insertion recess 12 as shown in FIG. Then, the base portion 5 and the lid portion 6 are closed by the urging force of the clamp spring 7, and the optical fiber 3 and the built-in fiber 10 are optically connected via the refractive index matching agent S, and both are in the base portion. 5 and the lid 6 are pressed and fixed.

The base portion 5 and the lid portion 6 are formed from a polymer alloy of a first thermoplastic resin composed of a basic unit having an aromatic ring and an ether bond and a second thermoplastic resin different from the first thermoplastic resin. ing. The glass transition temperature of this polymer alloy is 140 ° C. or higher. The upper limit of the glass transition temperature is not particularly limited, but is usually about 200 ° C. The glass transition temperature of this polymer alloy is preferably 140 ° C. or higher and 190 ° C. or lower, for example.

As the first thermoplastic resin, it is preferable to use a polyphenylene ether (PPE) resin. As the second thermoplastic resin, it is preferable to use a polystyrene (PS) resin or a polyphenylene sulfide (PPS) resin. Furthermore, it is preferable that the ratio of the 1st thermoplastic resin with respect to a 1st thermoplastic resin and a 2nd thermoplastic resin is 25 to 75 weight%. It is preferable that 10% by weight or more of filler is added to the polymer alloy.

Here, the fiber connecting member 8 was formed by a polymer alloy mainly composed of polyphenylene ether and polystyrene, and various properties were actually evaluated. The evaluation results are described below.

First, the relationship between the glass transition temperature of the polymer alloy, the deflection temperature under load, the connection loss of the optical fiber, and the creep strain was evaluated. Specifically, a plurality of polymer alloys having different ratios of polyphenylene ether to polyphenylene ether and polystyrene were molded. A fiber connecting member 8 was formed from the plurality of polymer alloys.

Then, by setting the optical fiber 3 in the fiber groove 4 of the fiber connection member 8, the optical fiber 3 was assembled against the base portion 5 by the lid portion 6. Thereafter, only the optical fiber 3 was removed once, and after 3 days, the optical fiber 3 was set again, and the connection loss value was measured at a wavelength of 1.31 μm. In addition, the creep strain of the fiber connection member 8 which was kept under the same environmental conditions and passed for 3 days was measured. The results obtained by this measurement are shown in FIG.

Table 1 shows the results obtained for the glass transition temperature (° C.) of the polymer alloy, the deflection temperature under load of the polymer alloy (° C.), the connection loss of the polymer alloy, and the creep strain.

As shown in Table 1, the following could be confirmed in a plurality of polymer alloys having different ratios of polyphenylene ether to polyphenylene ether and polystyrene. It was confirmed that the deflection temperature under load of the polymer alloy increases as the glass transition temperature of the polymer alloy increases. It was confirmed that the creep strain value decreased as the glass transition temperature of the polymer alloy increased. In particular, when the glass transition temperature of the polymer alloy was 140 ° C. or higher, it was confirmed that the creep strain value was smaller than 3.0. Moreover, when the glass transition temperature of the polymer alloy was 140 ° C. or higher, it was confirmed that the creep strain value was smaller than 3.0.

Further, among the results shown in Table 1, the relationship between the glass transition temperature (° C.) of the polymer alloy and the connection loss of the optical connector 1 using the fiber connection member 8 formed from the polymer alloy is shown in FIG. Shown in

As shown in FIG. 3, when the glass transition temperature exceeded 140 ° C., it was confirmed that the connection loss was less than 0.25 dB. Furthermore, it was confirmed that the connection loss was less than 0.17 dB when the glass transition temperature was about 160 ° C. That is, it was found that the connection loss is suppressed when the glass transition temperature is approximately 140 ° C. or higher and 160 ° C. or lower.

Next, the characteristics of a plurality of polymer alloys having different ratios of polyphenylene ether to polyphenylene ether and polystyrene were evaluated using a plurality of types of samples. Specifically, seven polymer alloy samples having different ratios of polyphenylene ether and polyphenylene ether to polystyrene were prepared, and in each sample, moldability was evaluated and an environmental test was performed. The obtained results are shown in Table 2. In Table 2, A is all good, B is all bad, and C is a state where good and bad are mixed. Here, the criteria for determining whether the moldability is good are as follows. A dimensional error of a finished product when molding is performed under a predetermined condition, that is, a deviation from a design value is not more than a predetermined value is determined as good. The criteria for determining whether or not the environmental test result is good are as follows. The case where the maximum value of the change amount of the connection loss during the test is 0.4 dB or less with respect to the connection loss before the start of the test is considered good. From the connection loss evaluation results shown in Table 1, polymers having a polyphenylene ether / polystyrene ratio of 40% to 70%, 30% to 60%, and 30% to 70% by weight based on polyphenylene ether and polystyrene are shown. The alloy was found to have a glass transition temperature of 140 ° C. or higher.

As shown in Table 2, it was confirmed that the moldability was good when the ratio of polyphenylene ether to the total of polyphenylene ether and polystyrene was 25% by weight or more and less than 75% by weight. Further, when the glass transition temperature of the polymer alloy is 140 ° C. or higher, the ratio of the polyphenylene ether to the polyphenylene ether and polystyrene is 25% by weight to 75% by weight, preferably 30% by weight to 70% by weight. Good evaluation results were obtained in an environmental test while maintaining good moldability.

In addition, the above-described environmental test was performed continuously by the following Test 1 to Test 3. Test 1 (high temperature test) was held in an environment of 85 ° C. for 50 hours. Test 2 (wet heat test) was held for 50 hours in an environment of 60 ° C. and 93% humidity. In test 3 (heat cycle test), holding in an environment of −40 ° C. for 1 hour and holding in an environment of 75 ° C. for 1 hour were alternately performed 6 times. The maximum value of change in connection loss was evaluated after the end of Test 3 and before the start of Test 1.

And the characteristic of the polymer alloy which added the fibrous filler was evaluated. Specifically, fibrous fillers made of glass fibers were added to a plurality of polymer alloys having different ratios of polyphenylene ether and polystyrene relative to polystyrene. The bending elastic modulus and pulling force were measured when a glassy filler was added and when a fibrous filler was not added. The obtained results are shown in Table 3.

As shown in Table 3, it was confirmed that the polymer alloy to which the fibrous filler was added had a large flexural modulus value and a large pulling force value. Therefore, it was confirmed that the rigidity of the polymer alloy was ensured by adding a fibrous filler to the polymer alloy.

As the fibrous filler, in addition to potassium titanate whiskers (KTW) and KTW, needle fillers such as wollastonite, aluminum borate, basic magnesium sulfate (MOS), zonolite, and zinc oxide may be used. In order to impart other characteristics, a plate-like or spherical filler having a small Mohs hardness may be added. The Mohs hardness is an index representing the hardness of a substance, and a substance having a lower hardness is obtained when the minerals are rubbed against each other and scratched.

Further, as the fibrous filler, those having a Mohs hardness smaller than that of quartz glass forming the optical fiber 3 or those having a Mohs hardness smaller than 5 may be used. In this case, the fibrous filler can be employed because it is sufficiently softer than the optical fiber.

As described above, according to this embodiment, a polymer alloy having a high glass transition temperature is formed, and a polymer alloy in which physical properties such as heat resistance and mechanical properties are complemented while maintaining excellent molding processability is obtained. The fiber connection member 8 formed of such a polymer alloy has improved creep characteristics. Therefore, even if time elapses, the optical fiber 3 is less likely to be misaligned with respect to the internal fiber 10. Thereby, the connection loss of the optical fiber 3 can be suppressed.

Note that the present invention is not limited to the above embodiment. For example, in the said embodiment, both the base part 5 and the cover part 6 which comprise the fiber connection member 8 are the 1st thermoplastic resin and 1st thermoplastic resin which consist of a basic unit which has an aromatic ring and an ether bond. However, the present invention is not limited to this, and at least one of the base portion 5 and the lid portion 6 may be formed of such a material.

The optical connector 1 of the above embodiment is a mechanical splice type optical connector that connects the optical fiber 3 to the built-in fiber 10. However, the present invention introduces two optical fibers into the mechanical splice from both sides. It can also be applied to a type that is connected and fixed.

Further, the present invention can be applied to an optical connector such as an MT connector ferrule or an optical positioning member in addition to a mechanical splice that mechanically connects and fixes optical fibers.

The present invention can be used for an optical connector for connecting optical fibers.

DESCRIPTION OF SYMBOLS 1 ... Optical connector, 2 ... Mechanical splice, 3 ... Optical fiber, 4 ... Fiber groove, 5 ... Base part, 6 ... Cover part, 8 ... Fiber connection member, 9 ... Ferrule, 10 ... Built-in fiber.

Claims

In an optical connector provided with a fiber connection member for mechanically connecting optical fibers,
The fiber connection member includes a base portion having a fiber groove that accommodates the optical fiber, and a lid portion that presses the optical fiber accommodated in the fiber groove against the base portion,
At least one of the base part and the lid part is a polymer of a first thermoplastic resin comprising a basic unit having an aromatic ring and an ether bond and a second thermoplastic resin different from the first thermoplastic resin. Formed from alloys,
The glass transition temperature of the said polymer alloy is an optical connector which is 140 degreeC or more.
The optical connector according to claim 1, wherein the first thermoplastic resin is a polyphenylene ether resin.
The optical connector according to claim 1 or 2, wherein the second thermoplastic resin is a polystyrene resin or a polyphenylene sulfide resin.
The optical connection according to claim 2 or 3, wherein a ratio of the first thermoplastic resin to a total of the first thermoplastic resin and the second thermoplastic resin is 25% by weight or more and 75% by weight or less. vessel.
The optical connector according to any one of claims 1 to 4, wherein a filler is added to the polymer alloy in an amount of 10% by weight or more.
6. The optical connector according to claim 1, wherein a ferrule that holds a built-in optical fiber that constitutes one of the optical fibers is fixed to the base portion.