JPH10186175A - Optical connector ferrule and resin composition for its molding - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make it possible to produce an optical connector ferule which has high strength and is resistant to chipping by using a biphenyl-base epoxy resin as an essential component and incorporating spherical silica particles of a specific grin size at specific weight % as a packing material into this resin. SOLUTION: The optical connector ferrule is constituted by using the biphenyl-base epoxy resin expressed by the formula as a base resin and using a resin compsn. contg. 75 to 90wt.% spherical silica particles having a grin size of max. 100μm and a grin size distribution of 10 to 20μm in the central gain size as the packing material. Such biphenyl-base epoxy resin which is mixed with a phenol novolak rein as a hardener is incorporated at 10 to 20wt.% into the packing material. Flexibility and elongation may be imparted to the material and even if a large amt. of the packing material is compounded, the embattlement of molded goods does not arise by consisting essentially of biphenyl-base epoxy resin. The strength, etc., of guide pin holes sufficient for practicable use are obtainable by using the silica particles of a specific state as the packing material.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an optical connector ferrule for connecting an optical fiber and a resin composition for molding the same.

[0002]

2. Description of the Related Art In the fields of optical communication, optical measurement, and the like, optical connectors used for connecting optical fibers include single-core and multi-core connectors. The multi-core type is used for connecting a plurality of single-core optical fibers, and the tape type optical fiber is used. It is a target. Thus, the types of optical connectors are many. As an optical connector used in a place where the optical fiber is connected using this optical connector, such as in a manhole or a connection box attached to an overhead wire, once it is connected, it is hardly detachable. A pair of multi-core connectors are connected using a simple gripping tool such as a clip, so-called M
T (Mechanically Transferferab)
le) Connectors are used. In applications where the number of times of attachment and detachment is relatively large indoors, a so-called MPO (Multi-pass Push O) is provided which has a housing having a push-pull mechanism and is connected via a connector adapter.
n) Connectors are often used.

FIG. 1 is an explanatory view of an MT connector that has been put into practical use. FIG. 1 (A) is a perspective view before the connector is connected, and FIG. 1 (B) is a perspective view when the connector is connected. In the figure, 10 is an optical fiber, 11 is an optical connector ferrule,
11a is a guide pin hole, 12 is a tape-shaped optical fiber core wire, 13 is a guide pin, and 14 is a clip.

As shown in FIG. 1A, two guide pin holes 11a for fitting with the guide pins 13 are formed in the joint end faces of the pair of optical connector ferrules 11, and a plurality of optical pins are provided between the guide pin holes 11a. A hole for inserting the fiber 10 is provided. After fixing a plurality of optical fibers 10 of the multi-core optical fiber core 12 in this hole with an epoxy adhesive or the like so that the ends are exposed, the end face of the optical connector ferrule 31 is Is polished together with the end face.

In the coupled state, two guide pins 1
The right and left optical connector ferrules 11 are positioned and abutted by 3 and the right and left optical fibers 10 precisely aligned and fixed in the guide pin holes 11a are connected to each other via a refractive index matching agent, and are connected as shown in FIG. It is fixed with a clip 14 as shown in FIG.

FIG. 2 is an explanatory view of an MPO connector that has been put into practical use. FIG. 2 (A) is a perspective view of a connector plug, FIG. 2 (B) is a perspective view of a connector adapter, FIG.
(C) is an enlarged view of the end face of the optical connector ferrule.
In the figure, the same parts as those in FIG. 21 is an optical connector ferrule, 21a is a guide pin hole, 22 is a connector plug, 23 is a connector housing, and 24 is a connector adapter.

As shown in FIG. 2A, the connector plug 22 is a connector housing 23 in which an optical connector ferrule 21 is accommodated, and the end face of the multi-core optical fiber 10 of the tape-shaped optical fiber core 12. However, as shown in FIG. 2C, it is exposed at the end face of the optical connector ferrule 21. After the optical fiber 10 is fixed to the optical connector ferrule 21 with an epoxy adhesive or the like, the end face of the optical connector ferrule 21 is polished together with the end face of the optical fiber 10. The optical connector ferrule 21 is provided with a guide pin hole 21a for inserting a guide pin.

A pair of connector plugs 22 are connected to each other as shown in FIG.
The connector ferrules 21 are inserted from the left and right sides of a rectangular connector adapter 24 as shown in FIG.
It is called "PC connection". ). Although a detailed description is omitted, a connector locking mechanism is provided inside the connector adapter 24 and the connector housing 23 is provided.
The insertion guide at the tip of the connector is locked in the connector adapter. The gap between the connector housing 23 and the optical connector ferrule 21 is a floating space.

In this MPO connector, the optical connector ferrules are usually connected by a PC coupling method in which the optical connector ferrules are brought into contact with each other without using a refractive index matching agent. To this end, the end face of the optical connector ferrule 21 is polished obliquely, for example, at an angle of 8 degrees.

[0010] As described above, when two optical connector ferrules are butted and connected in the connection of the optical fiber by the optical connector ferrule, the dimensional accuracy greatly affects the coupling loss. In particular, a guide pin hole having a low strength may cause a situation in which the guide pin hole is chipped during the joining operation, and when such a situation occurs,
It is necessary to replace the optical fiber with a new optical connector ferrule, and if the optical connector ferrule cannot be replaced at the work site, there will be a great hindrance to the connection work.

The resin composition for producing a multi-core optical connector ferrule described in Japanese Patent Application Laid-Open No. 2-19808 has a cresol novolak type epoxy resin, a phenol novolak type epoxy resin, and a bisphenol A type epoxy resin as main components. As a filler, 10 spherical silica particles were used.
-100% by weight is described. Also,
The resin composition for producing an optical connector ferrule described in JP-A-6-278157 has a phenol novolak type epoxy resin as a main component, and has a particle size of up to 100 μm and a central particle size of 20 μm or less as a filler. Patent Document 1 discloses a composition containing 75 to 90% by weight of spherical silica particles having a distribution.

[0012] However, the conventional technology containing an epoxy resin as a main component and spherical silica particles as a filler has a problem that the strength of the guide pin hole is not large.

[0013]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and has a high strength.
It is an object of the present invention to provide a molding resin composition capable of manufacturing an optical connector ferrule that is difficult to chip, and also provides an optical connector ferrule using such a resin composition, and further has a guide pin hole. It is an object of the present invention to provide an optical connector ferrule in which the strength of a guide pin hole is large.

[0014]

According to the first aspect of the present invention, there is provided a resin composition for molding an optical connector ferrule for positioning, holding and coupling an optical fiber, comprising a biphenyl epoxy resin. Main ingredient, filler with maximum particle size of 100μm and central particle size of 10-20μ
The composition contains 75 to 90% by weight of spherical silica particles having a particle size distribution of m.

According to a second aspect of the present invention, there is provided a molding resin composition used for molding an optical connector ferrule for positioning, holding and coupling an optical fiber, wherein the resin composition comprises a dicyclopentadiene-based epoxy resin as a main component, The filler is characterized by containing 75 to 90% by weight of spherical silica particles having a particle size distribution of a maximum of 100 μm and a central particle size of 10 to 20 μm as a filler.

According to a third aspect of the present invention, there is provided a molding resin composition used for molding an optical connector ferrule for positioning, holding and coupling an optical fiber, comprising a naphthalene epoxy resin as a main component and a filler. Particle size up to 1
A molding resin composition for an optical connector ferrule, comprising 75 to 90% by weight of spherical silica particles having a particle size distribution of 00 μm and a central particle size of 10 to 20 μm.

According to a fourth aspect of the present invention, there is provided an optical connector ferrule formed by using the molding resin composition according to any one of the first to third aspects.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of an optical connector ferrule according to the present invention is a biphenyl-based epoxy resin, a dicyclopentadiene-based epoxy resin, a naphthalene-based epoxy resin as a base resin, and a filler having a maximum particle size of 10%.
A resin composition containing 75 to 90% by weight of spherical silica particles having a particle size distribution of 0 μm and a central particle size of 10 to 20 μm is used.

The biphenyl-based epoxy resin has the following structural formula.

Embedded image In the first embodiment, a mixture of the biphenyl-based epoxy resin and a phenol novolak resin as a curing agent is added in an amount of 10 to 20% by weight, and the above-mentioned filler is contained. It is a mixture of several percent of a coupling agent, a flame retardant, carbon, a curing accelerator, and the like.

The dicyclopentadiene-based epoxy resin is
It has the following structural formula.

Embedded image In the second embodiment, a mixture of the dicyclopentadiene-based epoxy resin and a phenol novolak resin as a curing agent is added to the mixture in an amount of 10 to 20% by weight, and the filling is performed in the same manner as in the first embodiment. In addition, a mixture of a mold release agent, a silane coupling agent, a flame retardant, carbon, a curing accelerator, and the like is also mixed.

The naphthalene-based epoxy resin has the following structural formula.

Embedded image In the third embodiment, a mixture of the naphthalene-based epoxy resin and a phenol novolak resin as a curing agent is used in an amount of 10 to 20% by weight, and the above-described filler is used as in the first embodiment. It contains several percent of a release agent, a silane coupling agent, a flame retardant, carbon, a curing accelerator, and the like.

Examples will be described together with comparative examples.
FIG. 3 is an explanatory diagram of the result of measuring the strength of the guide pin hole of the prototype optical connector ferrule. A resin composition containing the same filler as the base resin of the biphenyl-based epoxy resin, dicyclopentadiene-based epoxy resin, and naphthalene-based epoxy resin of the present invention, and the conventional cresol novolak-type epoxy resin and phenol novolak-type epoxy resin. A prototype of a multi-fiber optical connector ferrule was manufactured using a product, and the strengths of the guide pin holes were compared. As can be seen from FIG. 3, it is understood that the strengths of the guide pin holes in Examples 2, 6, and 10 are higher than those in Comparative Examples 1 and 2.

The strength of the guide pin hole is determined by inserting a 5.5 mm stainless steel guide pin into the guide pin hole.
It is a value obtained by measuring the breaking strength when a pin portion protruding 5 mm from the end face of the optical connector ferrule is pressed at a pressing speed of 5 mm / min in a direction in which the thickness of the outer side of the optical connector ferrule is thinnest.

In order to examine the reason, JIS
Was molded and the flexural strength and flexural modulus were measured.
FIG. 4 is an explanatory diagram of the results of measuring the bending strength and the bending elastic modulus. According to the measurement results, the test pieces 1, 2, and 3, which are the resin composition of the present invention, were able to increase the bending strength by reducing the flexural modulus relative to the test piece 4 of the comparative example. it is conceivable that. This is because the biphenyl-based epoxy resin, dicyclopentadiene-based epoxy resin, and naphthalene-based epoxy resin of the present invention have a low molecular weight and a low crosslink density after curing as compared with the cresol novolac-type epoxy resin. It is considered that a cured product having a certainty was obtained.

In order to increase the flexibility of the cured product of the resin composition, it can be achieved by reducing the filling amount of the filler. However, if the filling amount of the filling material is reduced, the dimensional accuracy is reduced. There is a limit to the decline. In the present invention, by selecting a specific epoxy resin as the resin, it is possible to obtain an optical connector ferrule having high strength despite the high filling amount of the filler.

In the case of using these specific epoxy resins, the molding shrinkage and the amount of warping are affected by the properties and amount of the filler. Regarding the particle size distribution of the filler, it is desired that the fluidity is good in consideration of molding. Therefore, the shape of the silica particles as the filler was spherical. The spherical shape here is not limited to a perfect spherical shape, but it is sufficient if the shape is substantially spherical, and includes a shape in which the spherical shape is slightly crushed like a spheroid.

Since the biphenyl-based epoxy resin, dicyclopentadiene-based epoxy resin and naphthalene-based epoxy resin have low melt viscosities, the base resin flows overwhelmingly more easily than the silica particles. When the diameter is large, the silica particles are offset due to the location of the silica particles during molding, and the molded product is not uniform. In an optical connector ferrule that requires dimensional accuracy on the order of submicrons, unevenness of a molded product is a problem because dimensional accuracy deteriorates. From this viewpoint, it can be said that the smaller the particle size, the better the fluidity is. However, when the central particle size of the particle size distribution of the silica particles is smaller than 10 μm, there arises a problem that burrs are generated as shown in FIG.

FIG. 5 is an explanatory diagram of the experimental results obtained by measuring the length at which the resin composition penetrates into the gap of 10 μm and forms burrs when the center particle size of the particle size distribution of the silica particles is changed. . It can be seen that, when the central particle size of the particle size distribution of the silica particles is smaller than 10 μm, the outflow length to the gap rapidly increases and burrs occur. Therefore, it can be said that the central particle size of the silica particle size distribution of 10 μm or more is a requirement for preventing generation of large burrs.

FIGS. 6, 7 and 8 show the properties and content of silica in each of the resin compositions based on biphenyl-based epoxy resin, dicyclopentadiene-based epoxy resin, and naphthalene-based epoxy resin. FIG. 9 is an explanatory diagram showing the results of an example and a comparative example in which the strength of the guide pin holes, the molding shrinkage, and the amount of warpage were measured.

The maximum particle size is 100 μm and the central particle size is 20 μm.
Any of the resin compositions of Examples 1 to 12 containing 75 to 90% by weight of spherical silica particles having a particle size distribution of μm or less,
About the strength of the guide pin hole, the molding shrinkage, and the amount of warpage,
It can be said that it is sufficient for practical use. On the other hand, it can be seen that the crushed silica particles of Comparative Examples 1, 5, and 9 each having a non-spherical shape have a large amount of warpage. In Comparative Examples 2, 6, and 10 in which the silica content is 70% by weight, which is less than 75% by weight, it can be seen that the resin component is too large and the molding shrinkage is large. In Comparative Examples 3, 7, and 11 in which the silica content is more than 75% by weight and 95% by weight, the molding shrinkage is smaller than that of the example, but the amount of warpage is large because the resin component is too small. Further, the maximum particle size of silica exceeds 100 μm and the central particle size of the particle size distribution is 2 μm.
Also in Comparative Examples 4, 8, and 12 having a thickness of more than 0 μm and 25 μm, the amount of warpage was large, and it was found that this was not appropriate. Also,
If the content of the silica particles exceeds 90% by weight, there is a problem in terms of uniformity, and there is also a problem that the particles become brittle, which is not suitable.

[0031]

As is apparent from the above description, according to the present invention, a biphenyl-based epoxy resin, a dicyclopentadiene-based epoxy resin, and a naphthalene-based epoxy resin are used as a molding resin composition for molding an optical connector ferrule. By using as a main component, the material can have flexibility and elongation, and there is an effect that a molded article does not become brittle even if a large amount of filler is blended. Further, the shape of the silica particles used as the filler is spherical, the particle size is a maximum of 100 μm, the central particle size is 10 to 20 μm, and the content is 75 to 90% by weight. There is an effect that an optical connector ferrule which is practically sufficient in strength, molding shrinkage, and warpage can be molded.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of an MT connector that has been put into practical use.

FIG. 2 is an explanatory view of an MPO connector that is put into practical use.

FIG. 3 is an explanatory diagram of a result of measuring the strength of a guide pin hole of a prototype optical connector ferrule.

FIG. 4 is an explanatory diagram of a result of measuring a bending strength and a bending elastic modulus.

FIG. 5 is an explanatory diagram of an experimental result for explaining formation of burrs.

FIG. 6 is an explanatory diagram of characteristics of an optical connector ferrule using a resin composition containing a biphenyl-based epoxy resin as a base resin.

FIG. 7 is an explanatory diagram of characteristics of an optical connector ferrule using a resin composition containing a dicyclopentadiene-based epoxy resin as a base resin.

FIG. 8 is an explanatory diagram of characteristics of an optical connector ferrule using a resin composition containing a naphthalene-based epoxy resin as a base resin.

[Explanation of symbols]

10 optical fiber, 11 optical connector ferrule, 11
a: guide pin hole, 12: tape-shaped optical fiber core, 1
3 ... guide pin, 14 ... clip, 21 ... optical connector ferrule, 21a ... guide pin hole, 22 ... connector plug, 23 ... connector housing, 24 ... connector adapter.

Claims (4)

[Claims] 1. A molding resin composition for molding an optical connector ferrule for positioning, holding and coupling an optical fiber, comprising a biphenyl-based epoxy resin as a main component, and a filler having a particle size of up to 100 μm. Central particle size is 1
75 to 9 spherical silica particles having a particle size distribution of 0 to 20 μm.
A resin composition for molding an optical connector ferrule, comprising 0% by weight. 2. A molding resin composition for molding an optical connector ferrule for positioning, holding and coupling an optical fiber, wherein the molding resin composition comprises a dicyclopentadiene-based epoxy resin as a main component and has a maximum particle size as a filler. A molding resin composition for an optical connector ferrule, comprising 75 to 90% by weight of spherical silica particles having a particle size distribution of 100 μm and a central particle size of 10 to 20 μm. 3. A molding resin composition used for molding an optical connector ferrule for positioning, holding and coupling an optical fiber, comprising a naphthalene-based epoxy resin as a main component, and a particle size of up to 100 μm as a filler. Central particle size is 1
75 to 9 spherical silica particles having a particle size distribution of 0 to 20 μm.
A resin composition for molding an optical connector ferrule, comprising 0% by weight. 4. An optical connector ferrule formed by using the resin composition for molding according to claim 1. Description: