JP2003003074A - Silica-containing resin composition and its precision molding - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a synthetic resin composition which gives good flow at molding and which can give precision molding parts having low water absorption, short flash length, and little dimensional change after water absorption and also having small surface roughness and circularity, as well as to provide a ferrule or a fiber stub which is fabricated using this synthetic resin composition, is cheap, and has high dimensional precision and besides high dimensional precision against moisture and heat. SOLUTION: The silica-containing resin composition comprises [I] a silica mixture (c) which consists of 75-99.5 wt.% of a globular silica (a) and 0.5-25 wt.% of a fine-powdered silica and which has three or more peaks in the particle size distribution on the particle size distribution curve, and [II] a resin. The silica mixture (c) is contained in an amount of 60-95 wt.% in the whole composition. The resin-made ferrule and fiber stub are provided which are obtained by molding this silica-containing resin composition, which have high dimensional precision and high dimensional precision against moisture and heat, and which allow to largely abbreviate the polishing step compared with ceramic products.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD OF THE INVENTION The present invention relates to a synthetic resin composition containing silica. More specifically, the present invention relates to a silica-containing resin composition having excellent heat resistance, a low shrinkage factor during molding and a low water absorption rate of a molded article, which is suitable for the production of electric / electronic / optical parts. Molded ferrules and fiber stubs.

[0002]

BACKGROUND OF THE INVENTION With the progress of optoelectronic technology in recent years, the development of parts related to optical communication has been actively carried out. Ferrules, which are connectors for optical fibers, and fiber stubs used for connecting optical modules, require extremely strict dimensional accuracy and environmental dimensional stability, so ceramic products are currently the mainstream.

On the other hand, in the full-scale introduction of the optical communication network,
Improvement of production capacity of each part and cost reduction technology development are important issues. Although ceramics can satisfy a high degree of dimensional accuracy by processing, sufficient cutting and precision polishing are required, which has been a cause of increasing the manufacturing cost of ferrules and fiber stubs. In contrast,
The use of synthetic resin for parts is an effective means for cost reduction, and it is expected that ferrules and fiber stubs will also be made of synthetic resin. For example, Japanese Patent Application Laid-Open No. 8-015568 describes a method for producing a single-core ferrule for an optical fiber connector using a liquid crystal polymer. But,
Although this method is low in cost because the ferrule material is a resin, the molecular orientation of the liquid crystal polymer is large, and anisotropy occurs in mechanical strength, molding shrinkage, and thermal expansion. When fibrous substances such as carbon fiber are added to these, the absolute values of mechanical strength, etc. are improved, but the anisotropy becomes larger and the fibrous substances are raised on the surface, so high precision is achieved. It has been difficult to achieve such molding.

Of the synthetic resins, epoxy resins are used in various molded products because of their excellent dimensional accuracy, mechanical strength, chemical resistance, electrical insulation and moldability. It is also a candidate as a material. For example, Japanese Patent Application Laid-Open No. 7-70283 discloses an epoxy resin composition containing spherical silica and crushed silica, which is highly accurate and has excellent dimensional stability. Also,
JP-A-9-318842, JP-A-2000-193
Japanese Patent Publication No. 848 describes a method for producing a ferrule using an epoxy resin composition containing a filler made of silica. However, these also need to be filled with a large amount of silica in order to reduce the molding shrinkage rate and the thermal expansion coefficient of the epoxy resin composition to improve the dimensional accuracy and to bring the thermal expansion coefficients of the optical fiber and the ferrule close to each other. As a result, the resin viscosity rises and the fluidity of the molten resin deteriorates, so the molding pressure must be increased, and burrs become more intense, and the pins that form the optical fiber insertion holes are bent or broken. There was a problem that Regarding this problem, we are trying to improve the fluidity by the maximum particle size and particle shape of the filler and mixing with fine silica, but as a result, burrs become longer and the fluidity is also sufficiently effective. There was still room for improvement.

As described above, the initial dimensional accuracy required for the resin used for the ferrule and the specifications required for the environmental dimensional stability are very strict, and since there is a problem of burr at the time of molding, the balance of these properties is balanced. It has been difficult to use a synthetic resin composition as a material for an optical communication member such as a wire catcher, a ferrule, and a fiber stub.

Therefore, there has been a demand for the appearance of a synthetic resin composition which can satisfy such properties, and a ferrule and a fiber stub made of such a synthetic resin composition.

[0007]

It is an object of the present invention to maintain the excellent physical properties of conventional engineering plastics having high precision and excellent dimensional stability, and to minimize the molding flexibility and very low surface roughness of synthetic resins. By polishing, the specifications of surface accuracy and surface roughness can be satisfied, and by ensuring sufficient fluidity in the molten state, molding can be facilitated and a molded product with ultra-low water absorption can be manufactured. It is an object of the present invention to provide a resin composition and to realize a synthetic resin of ferrules and fiber stubs by using this synthetic resin composition.

[0008]

SUMMARY OF THE INVENTION The inventors of the present invention have conducted intensive studies in order to solve the above problems associated with the prior art. As a result, the spherical silica particles (a) and the finely divided silica particles (b) having a specific particle size distribution are used. By using the silica mixture (c) having three or more particle size distribution peaks in the particle size distribution curve as a filler for the synthetic resin composition, the fluidity of the resin composition at the time of molding can be secured and It was found that it is possible to obtain a silica-containing resin composition having excellent precision and environmental stability,
The present invention has been completed.

That is, the silica-containing resin composition according to the present invention is [I] spherical silica (a) 75-99.5 described below.
% Silica and 0.5 to 25% by mass of finely divided silica (b), and a silica mixture (c) having three or more particle size distribution peaks in a particle size distribution curve and a [II] resin. The silica mixture (c) is added to the total composition in an amount of 60-
It is characterized in that it is contained in an amount of 95% by mass.

The spherical silica (a) has a maximum particle size of 128.
25 μm or less, average particle size 6 to 30 μm, and 25 to 60% by mass for particle size 12 μm or less, 18 to 50% by mass for particle size 6 μm or less, and 10 to 30% by mass for particle size 3 μm or less. Is preferred. The fine powdery silica (b) has a maximum particle size of 40 μm or less and an average particle size of 5
It is preferably μm or less and a specific surface area of 6 m ² / g or more.

Further, in the silica-containing resin composition according to the present invention, the silica mixture (c) has a particle size distribution curve of a particle size of 0.1 to 0.3 μm, a particle size of 3 to 16 μm and a particle size of 20 to 60 μm. It is characterized by having three or more peaks of particle size distribution. In the silica-containing resin composition according to the present invention, the sphericity of the spherical silica (a) is 0.7 to.
It is preferably in the range of 1.0.

The present invention is also a synthetic resin molded article having such a silica-containing resin composition. Further, the present invention is a ferrule comprising such a silica-containing resin composition or a synthetic resin molded product. Furthermore, the present invention is a fiber stub comprising such a silica-containing resin composition or a synthetic resin molded product.

[0013]

DETAILED DESCRIPTION OF THE INVENTION The present invention will be specifically described below. <Silica> [Spherical silica particles (a)] The maximum particle diameter of the spherical silica particles (a) used in the present invention is 128 µm or less, preferably 96 µm or less, and more preferably 24 to 64 µm.

The average particle size of such spherical silica particles (a) is preferably 6 to 30 μm, preferably 6 to 28 μm, and more preferably 10 to 25 μm. Further, the spherical silica particles (a) have a cumulative mass ratio in the particle size distribution of 25 to 60% by mass with a particle size of 12 μm or less,
Preferably 30 to 60% by mass, more preferably 35 to 5
8% by mass, and a particle size of 6 μm or less is 16 to 50% by mass,
Preferably 22 to 50% by mass, more preferably 26 to 5
0% by mass, 10 to 30% by mass when the particle size is 3 μm or less,
Preferably 15 to 30% by mass, more preferably 15 to 2
It is preferably 5% by mass.

Further, such spherical silica particles (a)
Preferably has two or more particle size distribution peaks in the particle size distribution curve. By using the spherical silica particles (a) having such a maximum particle diameter, the surface roughness of the molded body is greatly improved, and the surface of the molded body is not polished or is subjected to the minimum polishing. The surface roughness standard of the molded product can be satisfied. Further, it is possible to minimize the generation of voids due to the dropping of the filler during polishing of the molded product. Further, it is easy to avoid the gate clogging during molding.

Further, by using the spherical silica particles (a) having the above-mentioned particle size distribution, the resin composition does not have a high viscosity even when highly filled, and it becomes possible to secure sufficient moldability. In the present specification, the cumulative mass ratio refers to the cumulative value of the mass ratio of the particle size in the particle size distribution,
The average particle diameter means a particle diameter when the cumulative mass ratio becomes 50 mass%.

Further, the sphericity of the spherical silica particles (a) is
It is desirable to be as high as possible to increase the filling rate,
It is desirable that the range is 0.7 to 1.0, preferably 0.8 to 1.0, and more preferably 0.82 to 1.00. By using a silica having a sphericity in the above range, it is possible to highly fill the silica, a low water absorption rate, a low shrinkage rate, a low expansion rate, the surface roughness of the molded product is further improved silica-containing resin composition You can get things. Also in terms of fluidity, by using silica having a sphericity within the above range, it is possible to obtain a resin composition having a low viscosity even when silica is highly filled.

[Fine powder silica particles (b)] The fine powder silica particles (b) used in the present invention have a maximum particle size of 40 μm.
The following is preferably 0.5 to 20 μm, more preferably 0.5 to 15 μm, and the average particle size is 5 μm or less, preferably 0.1 to 5 μm, more preferably 0.1 to 3 μm, and the specific surface area is 6 m. ² / g or more, preferably 10-3
0 m ² / g, and particularly preferably in the range 12~30m ² / g.

As such finely divided silica particles (b), spherical silica or crushed silica can be used. Here, the crushed silica means a silica that has not been subjected to a melting step for forming a spherical shape in the silica manufacturing step and has been simply selected according to the particle size from the as-crushed state.
By using such finely divided silica particles (b) in addition to the spherical silica particles (a), it is possible to obtain a silica-containing resin composition having a further reduced burr length while maintaining low water absorption. it can.

[Silica mixture (c)] The silica mixture (c) is composed of the spherical silica particles (a) and the finely divided silica particles (b), and the mixing amount thereof is spherical silica particles based on the total amount of silica. It is desirable that (a) is 75 to 99.5% by mass, preferably 80 to 99.5% by mass, more preferably 85 to 99% by mass, and the finely divided silica particles (b) are 0.5 to 9% by mass. 25% by mass, preferably 0.5
It is desirable that the content is -20% by mass, more preferably 1.0-15% by mass.

Such a silica mixture (c) is polydisperse, and in the particle size distribution curve measured by a laser particle size distribution analyzer (CILAS), the mass ratio is% with respect to the particle size.
It is preferable to have three or more particle size distribution peaks when (difference in cumulative mass ratio for each particle size) is plotted. Further, the silica mixture (c) has a particle size distribution curve with a particle size of 0.1 to 0.3 μm and a particle size of 3 to 16 μm.
m and a particle size of 20 to 60 μm, and more preferably a particle size of 0.2 to 0.3 μm, a particle size of 4 to 7 μm, and a particle size of 24 to 48 μm.

Such silica mixture (c) is preferably contained in the total composition in an amount of 60 to 95% by mass, preferably 80 to 95% by mass, more preferably 85 to 93% by mass. . By using the silica mixture (c) having such a wide particle size distribution, the surface roughness of the molded product is further improved and the burr length is shortened with a low water absorption rate, a low shrinkage rate and a low expansion rate. A silica-containing resin composition can be obtained. <Synthetic Resin> As the synthetic resin of the present invention, either a thermosetting resin or a thermoplastic resin can be used. As the thermoplastic resin, polycarbonate resin, liquid crystal polymer (LCP), polyphenylene sulfide (PP)
S), polyether imide (PEI), polyether sulfone (PES) and the like, and examples of the thermosetting resin include phenol resin, epoxy resin, urea resin and melamine resin. Among them, the epoxy resin is most preferably used as the precision molding material from the viewpoints of fluidity, mold transferability, sealing property, low shrinkage property of molded product, low water absorption property, low expansion property and the like.

When an epoxy resin is used, the silica-containing resin composition contains (A) an epoxy resin, (B) a curing agent, (C) a curing accelerator, and (D) in addition to silica as the filler. A release agent can be included. [(A) Epoxy Resin] The epoxy resin used in the present invention can be used without any particular limitation, but it is a polycyclic aromatic system such as a naphthalene skeleton-containing epoxy resin, a biphenyl skeleton-containing epoxy resin, or a fluorene skeleton-containing epoxy resin. Epoxy resins are preferably used, and any one of these may be used alone, or two or more of them may be used in combination at an appropriate ratio. It is also possible to mix and use commonly used cresol novolac-based or bisphenol-based epoxy resins within a range that does not impair the physical properties of the composition. The epoxy equivalent is preferably 300 or less.

In the present invention, the content of the epoxy resin in the total resin composition is usually 5 to 30% by mass, preferably 5 to 20% by mass. [(B) Curing Agent] As the curing agent of the present invention, any curing agent capable of undergoing a curing reaction with the above epoxy resin can be used without particular limitation. Among them, phenol resin is preferable, and examples of the phenol resin include phenol novolac resin and aralkylphenol resin.

The amount of the curing agent blended is 20 to 95 parts by weight, preferably 35 to 95 parts by weight, per 100 parts by weight of the epoxy resin.
It is desirable that the amount is parts by mass, and when expressed by a chemical equivalent ratio, the chemical equivalent ratio to the epoxy resin is 0.5 to 1.5, preferably 0.7, from the viewpoint of moisture resistance and mechanical properties.
It is preferably in the range of 1.3. The amount is preferably 1 to 29 parts by mass with respect to 100 parts by mass of the total composition.

[(C) Curing Accelerator] As the curing accelerator used in the present invention, the following can be preferably used. (A) the general formula: Ar-NH-CO-NR 2 (Ar is a substituted or unsubstituted aryl group, R represents the same or different and an alkyl group) urea derivatives represented by, for example, 3-phenyl-1,1 -Dimethylurea, 3- (p-chlorophenyl) -1,1-dimethylurea, etc., (b) 2-methylimidazole, 2-phenylimidazole, 2-heptadecylimidazole, 2-ethyl-4
-Imidazoles such as methyl imidazole and 2-phenyl-4-methyl imidazole, (c) 1,8-diazabicyclo (5,4,0) undecene-7 and its phenol salts, phenol novolac salts, carbonates, formates Such as amines, especially tertiary amines and their derivatives, (d) ethylphosphine, propylenephosphine, phenylphosphine, triphenylphosphine, trialkylphosphine, etc., generally classified into primary, secondary and tertiary phosphines Examples thereof include organic phosphines.

These curing accelerators are epoxy resin 10
0.5 to 10 parts by mass, preferably 1 to 0 parts by mass
When it is blended in a proportion of 8 parts by mass, the curing reaction proceeds at a sufficient speed. For 100 parts by weight of the total composition,
It is preferably 0.02 to 0.5 parts by mass. [(D) Release Agent] As the release agent used in the present invention,
Higher fatty acids such as montanic acid, stearic acid, behenic acid, oleic acid, esters of higher fatty acids such as carnauba wax (carnauba wax), zinc behenate, zinc oleate, magnesium stearate, barium stearate, aluminum stearate, etc. Examples thereof include metal salts of higher fatty acids and metal soaps such as zinc stearate. These may be used alone or in combination.

The compounding amount of the release agent is 0.
03-1.0% by mass, more preferably 0.05-0.8
It is desirable that the content is% by mass. When the compounding amount of the release agent is within the above range, the resin composition is less attached to the inside of the molding machine cylinder, and stable molding can be performed. In addition to these, for the resin composition, if necessary, a silane coupling agent, a brominated epoxy resin, a flame retardant such as antimony trioxide, a carbon black, a coloring agent such as phthalocyanine, a stress reducing agent, natural Alternatively, a synthetic wax or the like may be blended.

In the present invention, the desired moldable epoxy resin composition can be obtained by heating and kneading all of these materials with a heating kneader or a heating roll, followed by cooling and pulverizing. The composition containing these various components is mixed with a mixer, then heated and kneaded using a heating kneader or a heat roll, cooled and then pulverized into granules, or
It can be a pellet or tablet. Then, a transfer molding machine, an injection molding machine, or a compression molding machine can be used to produce various precision molding members, particularly ferrules and fiber stubs, in a short molding cycle. 10 to 500 kg / cm in transfer molding
It can be molded under the pressure of ² at a temperature of 150 to 200 ° C. under molding conditions of 1 to 5 minutes. In injection molding, the injection pressure is 300 to 600 kg / cm ² , and the temperature is 165 to 185.
It can be manufactured under molding conditions of about 1 minute at 0 ° C.

[0030]

The present invention will be described in more detail based on the following examples, but the invention is not intended to be limited to these examples. The silica-containing resin composition, ferrule and fiber stub were evaluated according to the following methods. The maximum particle size and average particle size of silica particles are CILA.
S, sphericity was measured by a flow-type particle image analysis method, and specific surface area was measured by a BET multipoint method. <Evaluation method><1> Burr length measurement Mold for burr measurement (resin injected into 30Φ part
The epoxy resin composition was transfer-molded by using (made so as to flow out into four clearances of 0, 15, and 20 μm), and the average value of the burr lengths at the four locations was calculated as the burr length. <2> Mold a test piece having a surface roughness of 30 mm x 6 mm x 2 mm,
The center line average roughness Ra of the test piece was measured using Surfcom 570A manufactured by Tokyo Seimitsu Co., Ltd., with a central length of 5 mm as a reference length. Measurement condition is drive speed 0.3
mm / s and a cutoff of 0.8 mm. <3> The roundness center portion of the single-core ferrule and the fiber stub was measured using Roundness 52B manufactured by Tokyo Seimitsu Co., Ltd. <4> Water absorption molded single-core ferrule and fiber stub were put in ion-exchanged water and boiled for 168 hours. Then, the mass change was measured and the water absorption was calculated. <5> A single-core ferrule and fiber stub molded by wet heat dimensional change amount 8
After leaving it in an environment of 0 ° C. for 100 hours, using a three-dimensional measuring instrument ZAIZAX1000D manufactured by Tokyo Seimitsu Co., Ltd.,
The amount of dimensional change in the outer diameter ΦD (outer diameter dimension) of the ferrule and the fiber stub was measured. <6> Single core ferrule and fiber stub with connection loss molding,
The measurement was performed by combining a ceramic split sleeve (a sleeve with a split in the longitudinal direction) and a ceramic single-core ferrule.

[0031]

Example 1 [Production of Silica-Containing Epoxy Resin Composition (1)] After mixing all the raw materials shown in Table 1 with a Henschel mixer, they are heated and kneaded for 4 minutes with a kneader or roll at a temperature of 90 ° C to 110 ° C. Then, it was rapidly cooled to room temperature and then pulverized to obtain a silica-containing epoxy resin composition (1). The spherical silica (a1) used in Example 1 has a maximum particle size of 48 μm, an average particle size of 18 μm, a cumulative mass ratio in the particle size distribution of 12 μm or less is 48% by mass, and a particle size of 6 μm.
The following was 32% by mass, the particle size of 3 μm or less was 21% by mass, and the sphericity was 0.82. Further, the fine powdery silica (b) used in Example 1 had a maximum particle size of 5 μm, an average particle size of 0.3 μm, and a sphericity of 0.8. The silica mixture (c1) consisting of these spherical silica (a1) and finely divided silica (b) has a particle size distribution curve of 0.2 to 0.
3 μm, particle size 1 to 3 μm, particle size 6 to 12 μm, particle size 24
It had a peak at ˜48 μm.

[0032]

[Example 2] [Production of silica-containing epoxy resin composition (2)] In Example 1, spherical silica having a maximum particle size of 64μ was used.
m, average particle size 20 μm, cumulative mass ratio in particle size distribution is such that particle size 12 μm or less is 43% by mass, particle size 6 μm or less is 2
Example 9 was performed in the same manner as in Example 1 except that the synthetic silica (a2) had a content of 9% by mass, a particle size of 3 μm or less was 19% by mass, and a sphericity of 0.82. Finely powdered silica (b) also
Mix as in Example 1 (see Table 1). The silica mixture (c2) consisting of these spherical silica (a2) and finely divided silica (b) has a particle size distribution curve of 0.2-
It had a peak at 0.3 μm, a particle size of 1 to 3 μm, a particle size of 6 to 12 μm, and a particle size of 24 to 48 μm.

As a result, a silica-containing epoxy resin composition (2) was obtained.

[0034]

Example 3 [Production of Silica-Containing Epoxy Resin Composition (3)] In Example 1, spherical silica having a maximum particle size of 64 μm was used.
m, average particle size 24 μm, 40% by mass of particle size 12 μm or less and 3 by particle size 6 μm or less in cumulative mass ratio in particle size distribution.
0% by mass, particle size of 3 μm or less is 17% by mass, and sphericity is 0.
Example 1 except that the synthetic silica (a3) of No. 82 was changed.
I went the same way. Finely powdered silica (b) was also mixed as in Example 1 (see Table 1). These spherical silica (a
Silica mixture (c) consisting of 3) and finely divided silica (b)
3) is a particle size distribution curve with a particle size of 0.2 to 0.3 μ
m, the particle size was 3 to 6 μm, and the particle size was 24 to 48 μm.

As a result, a silica-containing epoxy resin composition (3) was obtained.

[0036]

Comparative Example 1 [Production of Silica-Containing Epoxy Resin Composition (4)] In Example 1, spherical silica having a maximum particle size of 196
μm, average particle size 32 μm, cumulative mass ratio in particle size distribution is such that particle size 12 μm or less is 17% by mass, particle size 6 μm or less is 10% by mass, particle size 3 μm or less is 8% by mass, and sphericity is 0.80. Example 1 was repeated except that the synthetic silica (a4) was changed. Finely powdered silica (b) was also mixed as in Example 1 (see Table 1). The silica mixture (c4) consisting of these spherical silica (a4) and finely divided silica (b) has a particle size distribution curve of 0.2 to 0.
Only two peaks of 3 μm and a particle size of 6 to 12 μm were observed.

As a result, a silica-containing epoxy resin composition (4) was obtained.

[0038]

[Comparative Example 2] [Production of silica-containing epoxy resin composition (5)] In Example 1, spherical silica having a maximum particle size of 48 µm was used.
m, the average particle size is 8 μm, the cumulative mass ratio in the particle size distribution is such that the particle size of 12 μm or less is 69% by mass, and the particle size of 6 μm or less is 52.
% By mass, particle size of 3 μm or less is 46% by mass, sphericity is 0.8
Example 1 was repeated except that the synthetic silica (a5) of No. 1 was changed. Finely powdered silica (b) was also mixed as in Example 1 (see Table 1). These spherical silica (a5)
Silica mixture (c5) consisting of and finely divided silica (b)
In the particle size distribution curve, the particle size is 0.2 to 0.3 μm,
Peaks were observed at particle sizes of 1 to 3 μm and particle sizes of 6 to 12 μm.

As a result, a silica-containing epoxy resin composition (5) was obtained.

[0040]

Comparative Example 3 [Production of Silica-Containing Epoxy Resin Composition (6)] In Example 1, except that the finely powdered silica (b) was not mixed and only the same spherical silica (a1) as in Example 1 was used. The same procedure as in Example 1 was performed (see Table 1). This spherical silica (a1) has a particle size distribution curve of 1 to 3 μm,
It had a peak at a particle size of 6 to 12 μm and a particle size of 24 to 48 μm.

As a result, a silica-containing epoxy resin composition (6) was obtained.

[0042]

[Table 1]

[0043]

Example 4 [of silica-containing epoxy resin composition (1)
Molding Evaluation] Silica-Containing Epoxy Resin Obtained in Example 1
Composition (1) 150 kg / cm ²Under pressure of 18
Transfer molding under 0 ℃ for 3 minutes
After that, after-curing is performed at 180 ℃ for 90 minutes
A fat single-core ferrule and a resin fiber stub
Obtained. The outer diameter of the molded ferrule is 2.499m
m, a single-core ferrule with a fiber hole diameter of 0.125 mm
is there. In addition, the molded fiber stub has an outer diameter
1.249 mm, length 4.1 mm, diameter 0.12
A 5 mm quartz optical fiber was insert-molded. This
Using these molded products, according to the above evaluation method, <1> to
The value of <6> was measured. The results are summarized in Table 2.

A resin composition obtained as shown in Table 2,
The resin ferrule and the resin fiber stub had a low burr length, a low surface roughness, a low circularity, a low water absorption rate, and good fluidity, and could be easily molded. The values of surface roughness, roundness, and splice loss also sufficiently satisfied the standard for single mode.

[0045]

Example 5 [Molding Evaluation of Silica-Containing Epoxy Resin Composition (2)] Using the silica-containing epoxy resin composition (2) obtained in Example 2, a single core was prepared by the same molding method as in Example 4. Mold ferrules and fiber stubs,
The values <1> to <6> were measured according to the above evaluation method. The results are summarized in Table 2. As shown in Table 2, the obtained resin composition, resin ferrule, and resin fiber stub had a low burr length, low surface roughness, low roundness, low water absorption, and good fluidity. Yes, molding could be performed easily. The values of surface roughness, roundness, and splice loss also sufficiently satisfied the standard for single mode.

[0046]

Example 6 [Evaluation of Molding of Silica-Containing Epoxy Resin Composition (3)] Using the silica-containing epoxy resin composition (3) obtained in Example 3, the same molding method as in Example 4 was used to obtain a single core. Mold ferrules and fiber stubs,
The values <1> to <6> were measured according to the above evaluation method. The results are summarized in Table 2. As shown in Table 2, the obtained resin composition, resin ferrule, and resin fiber stub had a low burr length, low surface roughness, low roundness, low water absorption, and good fluidity. Yes, molding could be performed easily. The values of surface roughness, roundness, and splice loss also sufficiently satisfied the standard for single mode.

[0047]

[Table 2]

[0048]

Comparative Example 4 [Molding Evaluation of Silica-Containing Epoxy Resin Composition (4)] Using the silica-containing epoxy resin composition (4) obtained in Comparative Example 1, a single-core ferrule was prepared in the same manner as in Example 4. , Molding the fiber stub,
The values <1> to <6> were measured according to the above evaluation method. The results are summarized in Table 3. As shown in Table 3, in the ferrule and the fiber stub using the resin composition (4), the accuracy was greatly reduced, and the splice loss could not satisfy the standard of the single core ferrule.

[0049]

Comparative Example 5 [Molding Evaluation of Silica-Containing Epoxy Resin Composition (5)] Using the silica-containing epoxy resin composition (5) obtained in Comparative Example 2, the single-core ferrule was prepared in the same manner as in Example 4. , Molding the fiber stub,
The values <1> to <6> were measured according to the above evaluation method. The results are summarized in Table 3. As shown in Table 3, when the resin composition (5) was used, the accuracy was good, but the resin viscosity was high because the particle size distribution was not optimized, molding was difficult, and the yield was low. It was Furthermore, the single core ferrule and the fiber stub after molding had high water absorption and wet heat dimensional change rate, and the standard could not be satisfied in the environment resistance test. As a result, the connection loss also increased.

[0050]

Comparative Example 6 [Molding Evaluation of Silica-Containing Epoxy Resin Composition (6)] Using the silica-containing epoxy resin composition (6) obtained in Comparative Example 3, a single-core ferrule was prepared in the same manner as in Example 4. , Molding the fiber stub,
The values <1> to <6> were measured according to the above evaluation method. The results are summarized in Table 3. As shown in Table 3, since the resin composition (6) did not contain finely divided silica, severe burrs were generated, and the yield was low due to post-processing after molding. In addition, since burrs are generated in the clearance of the mold, the mold clamping accuracy becomes low, and as a result, the connection loss of the single core ferrule and the fiber stub after molding also becomes large.

[0051]

[Table 3]

[0052]

EFFECTS OF THE INVENTION The silica-containing resin composition of the present invention has good fluidity during molding, low water absorption, low burr length, small dimensional change after water absorption, and surface roughness and roundness. Small precision molded parts can be provided. Ferrules and fiber stubs molded by using this silica-containing resin composition or a synthetic resin molded product made of the resin composition have small surface roughness, roundness, dimensional change after water absorption, and splice loss, so that the ferrule is small. Since the fiber stub can be made into resin, it can be provided at a lower cost than conventional ceramic ferrules and ceramic fiber stubs.

[Brief description of drawings]

FIG. 1 is a particle size distribution chart of a silica mixture (c3) of Example 3.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Tsukasa Sakuraba             580-32 Nagaura, Sodegaura-shi, Chiba Mitsui Chemicals, Inc.             Inside the company (72) Inventor Eiji Togashi             580-32 Nagaura, Sodegaura-shi, Chiba Mitsui Chemicals, Inc.             Inside the company F-term (reference) 2H036 QA18 QA20                 4F071 AA02 AA03 AB26 AD02 AF10                       AF36 AF45 AH12                 4J002 CC031 CC181 CD001 CF161                       CG001 CK011 CM041 CN011                       CN031 DJ016 FA086 FD016                       GT00

Claims (6)

[Claims] 1. [I] The following spherical silica (a) 75-9.
Silica mixture (c) and [II] resin, each of which is composed of 9.5 mass% and 0.5 to 25 mass% of finely divided silica (b) and has three or more particle size distribution peaks in a particle size distribution curve. A silica-containing resin composition comprising the above-mentioned silica mixture (c) in an amount of 60 to 95% by mass in the total composition. A: maximum particle size 128 μm or less, average particle size 6 to 30 μm,
Spherical silica (a) having a particle size of 12 μm or less of 25 to 60% by mass, a particle size of 6 μm or less of 18 to 50% by mass, and a particle size of 3 μm or less of 10 to 30% by mass in a cumulative mass ratio in the particle size distribution, B: Finely divided silica (b) having a maximum particle size of 40 μm or less, an average particle size of 5 μm or less, and a specific surface area of 6 m ² / g or more. 2. The silica mixture (c) has three or more particle size distribution peaks at a particle size of 0.1 to 0.3 μm, a particle size of 3 to 16 μm and a particle size of 20 to 60 μm in a particle size distribution curve. It has, The silica containing resin composition of Claim 1 characterized by the above-mentioned. 3. The sphericity of the spherical silica (a) is 0.7 to.
It is in the range of 1.0, or 1 or 2 characterized by the above-mentioned.
The silica-containing resin composition according to item 4. 4. A synthetic resin molded product comprising the silica-containing resin composition according to claim 1. 5. A ferrule comprising the silica-containing resin composition or the synthetic resin molded product according to any one of claims 1 to 4. 6. A fiber stub comprising the silica-containing resin composition or the synthetic resin molded product according to any one of claims 1 to 4.