JP2005140809A - Cleaning device for optical connector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a tape for cleaning an optical connector superior in cleaning the end face of an optical fiber, and especially superior in reducing reflection loss, and to provide a cleaning device which uses the tape. <P>SOLUTION: In the cleaning device of the optical connector provided with the tape for cleaning the optical fiber end face of the optical connector, the cleaning tape is constituted of cloth, consisting of extra fine fibers of which the single fiber fineness is 1 dtex or smaller and containing an end face processing agent of 1 wt% of smaller for the optical connector in the tape. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an optical connector cleaning device for cleaning a fiber end face in an optical connector connection operation.

  In recent years, communication devices using optical fibers have been popularized and optical fiber communication networks have been constructed, and various optical connectors have been used to connect optical fibers. In general, the optical connector employs a method in which optical fiber end faces are directly brought into contact with each other. If the end faces are contaminated with dust, oil, metal powder, or the like, there is a possibility that the optical signal transmission characteristics may deteriorate. Further, it is known that the transmission characteristic of an optical signal deteriorates due to a phenomenon in which input light is reflected at a connection end face, that is, “reflection loss” caused by so-called Fresnel reflection.

  Conventionally, in order to reduce this reflection loss, connection using a refractive index matching agent (matching grease) made of silicone grease, paraffin or the like has been performed as described in JP-A-2001-290053. However, in order to obtain the effect of the refractive index matching agent, it is necessary to uniformly apply a certain amount to the connection surface, requiring skill in the work, problems due to mixing of bubbles and impurities, deterioration due to aging, and problems of heat generation. For these reasons, in recent years, reflection loss has been reduced by precisely polishing the connector terminal in a planar shape, a spherical shape, or an oblique shape without using a refractive index matching agent.

  On the other hand, since it is desirable to clean the end face at the time of connecting the optical connector, for example, as disclosed in JP-A-6-242347, a window portion having an opening / closing mechanism is provided in the exterior case, and the cleaning tape is sequentially provided from the reel. There has been proposed an optical connector cleaning device which is supplied. Generally used cleaning tapes are made of ultrafine synthetic fibers that have high wiping properties and are less likely to generate dust.

However, the cleaning tape made of ultrafine synthetic fibers has excellent dirt removal performance, but when measuring the reflection loss at the optical connector interface after wiping, use ethanol, which is the wiping method with the smallest reflection loss. The reflection loss was a big problem compared with cleaning with a paper wiper. As described above, there has been no tape that has been improved by paying attention to this point even though a low loss of the connection portion is required. In addition, although cleaning work using alcohol has low reflection loss, it is a cumbersome work using a flammable solvent, and it has hardly been performed in practice, and a simple and low wiping method with low reflection loss has been desired. .
JP 2001-290053 A JP-A-6-242347

  In view of the background of the prior art, the present invention is intended to provide an extremely excellent optical connector cleaning device that does not generate as much reflection loss as possible at the connection portion when the optical connector is cleaned.

  The present invention employs the following means in order to solve such problems. That is, the optical connector cleaning device of the present invention is an optical connector cleaning device comprising a tape for cleaning the fiber end face of the optical connector, wherein the cleaning tape is made of ultrafine fibers having a single fiber fineness of 1 dtex or less. And the tape contains 1% by weight or less of the end face treating agent of the optical connector with respect to the weight of the tape.

  ADVANTAGE OF THE INVENTION According to this invention, in the end surface cleaning of an optical connector, the cleaning apparatus of the outstanding optical connector which does not generate | occur | produce the reflection loss of a connection part can be provided.

  The present invention has been intensively studied on the above-mentioned problem, that is, an optical connector cleaning device excellent in reducing reflection loss, and the cleaning tape is made of a specific fiber material and used with a specific chemical applied. Surprisingly, however, they have sought to solve this problem.

  That is, when a tape made of a fabric made of ultrafine fibers having a single fiber fineness of 1 dtex or less and containing a trace amount of an end surface treating agent of 1% by weight or less based on the weight of the tape is used, the end face of the optical connector is obtained. It has been shown that the effect of matching the refractive index of the optical fiber portion, which is an optical transmission path, is improved, and that it has an extremely excellent effect in reducing the reflection loss. Conventionally, cleaning tape for optical connectors has not been made to contain chemicals so as not to cause contamination of the end face. However, when a small amount of chemicals is contained in the tape, surprisingly dirt is generated. It has been found that the reflection loss is reduced and the conventional problems are solved.

  The optical connector cleaning device of the present invention is characterized by the cleaning tape used. That is, it is characterized by a synergistic effect between the fabric made of ultrafine fibers having a single fiber fineness of 1 dtex or less and the application of a drug for improving the consistency of the optical connector end face.

  In the present invention, it is necessary to match the refractive index at the interface in order to suppress the light reflection at the end face of the optical fiber at the center of the two optical connectors that are attached together. That is, a foreign material having a different refractive index present at the interface so that the refractive index n of the interface is close to the refractive index of silica glass (n = 1.659, light source wavelength 5893 angstrom, 25 ° C.) as a raw material of the optical fiber. In particular, it is important to exclude low refractive index air (n = 1.000). For this reason, it is desirable to apply some treatment agent to the end face of the optical connector. However, when the end surface treatment agent to be applied forms a thick film at the interface, transparency is impaired, light loss occurs, and reflection loss may be deteriorated due to contained bubbles and impurities. . From this, the end face treating agent of the optical connector used in the present invention has a refractive index of about n = 1.3 to 1.6 which is close to the refractive index (n = 1.594) of quartz glass which is a raw material of optical fiber. In addition, it is a chemically stable agent that can be applied to the end face of an optical connector thinly and uniformly, and does not undergo photooxidation or alteration even during long-term use. Evaluation is “Pass” when the return loss is measured by the method described below. Say what will be. For example, silicone oil, paraffin, polyethylene glycol and the like can be raised, but are not limited thereto. Furthermore, the process of applying the treatment agent to the fabric is generally an aqueous process, and from this point of view, the water-dispersible treatment agent is better than the hydrophobic one, and has a chemical structure similar to that of polyethylene glycol. Desirable polyoxyalkylene alkyl ethers, so-called nonionic surfactants, and water-soluble silicone agents in which some functional groups are modified with water-soluble functional groups are preferred, but are not limited thereto.

  The refractive index of the end-face treatment agent is generally measured using an Abbe refractometer at room temperature and 1 atm, and sodium D-line (wavelength 5893 angstrom) is generally used as the light source.

  The measurement of the content rate of this end surface treating agent is measured according to the moisture content and the moisture content test method described in the test item (1) of JIS L1013. That is, since the fiber material used in the cleaning tape of the present invention is preferably a material having an official moisture content of not 0%, such as polyester or nylon, as will be described later, the weight of the sample is a specified temperature (105 ± 2 The mass in a state of being kept constant by being allowed to stand for 6 hours or more in a hot air dryer at (° C.) is adopted. When weighing, in order not to absorb moisture in the air when it is taken out from the hot air dryer, it is immediately put into a weighing bottle with a glass lid, which has been weighed in advance, in an environment of 20 ° C. and 50% RH. For 10 minutes to cool to room temperature and quickly measure the weight. The content ratio of the end face treating agent of the optical connector is equal to or more than 100 times the weight of the fabric if the optical connector treating agent is uniformly contained in the sample fabric or tape and weighed and then weighed. If the treatment agent is removed using a sufficient excess of water and the lipophilic treatment agent is used, the treatment agent is removed using an organic solvent such as hexane, ethanol, dimethyl ether, or acetone according to the polarity. The content rate is calculated from the weight difference before and after being measured by the gravimetric method. The content of the end surface treating agent of the optical connector measured in this way is preferably 0.1% by weight or more, and a reduction in reflection loss is sufficiently observed at about 0.2% by weight, but the content is high. In some cases, the dirt cleaning property of the tape is lowered, and in some cases, the connector terminal is soiled. Therefore, the content is preferably 1% by weight or less.

  As a method of uniformly containing a trace amount of the optical connector end surface treating agent in the fabric, after impregnating the agent in a bath diluted with water or an organic solvent and then uniformly squeezing with a roller mangle, the content rate is made constant. There are a method of drying, a method of spraying a solution containing the optical connector end face treating agent on the fabric by spraying, and the like.

  In the cleaning tape of the present invention, it is essential to use a fabric made of ultrafine fibers having a single fiber fineness of 1 dtex or less. Preferably, an ultrafine filament yarn having a single fiber fineness of 0.0001 to 1 dtex is used. Such a fabric composed of extra fine filament yarn has an excellent cleaning effect on the end face of the optical connector. More preferably, the upper limit of the single fiber fineness is 0.5 dtex or less, particularly preferably 0.1 dtex or less, in view of the above effects. Such ultrafine filament yarns may be untwisted or twisted. The weaving structure is preferably a plain weave.

  The polymer constituting the ultrafine filament yarn is not particularly limited as long as it is fiber-forming. For example, polyester or nylon can be preferably used. From the standpoint of cleanliness against dirt, a fabric made of super fine filament yarn made of polyester is preferably used.

  As the form of the filament, those having a normal round cross section are used, but those having an irregular cross section and those having crimps are preferable, and a more excellent cleaning effect can be obtained.

  Fabrication of filaments made of filament yarns of ultrafine fibers as described above is made into a fabric such as knitted fabric or woven fabric using multi-component fibers called sea-island type composite fibers, and a solvent or a decomposing agent is used in subsequent fabric processing steps. The ultrafine fibers may be formed by removing sea components using, or the ultrafine fibers may be formed by peeling-type division.

The shape of the optical connector varies, but in the case of a typical single mode SC ferrule terminal, the end surface of the wiping portion is a circular shape with a diameter of 2.5 mm. From this viewpoint, a plain fabric is preferable as the fabric in the present invention. Furthermore, in order to cut the fabric into a tape, wind it on a reel, and mount it on a compact cassette, a fabric with a fabric weight of 50 to 100 g / m ² is desirable.

  Furthermore, in order to satisfy the cleansing effect against dirt, it is preferable to perform entanglement treatment on the fabric to increase the density of the fabric or improve the openability of the ultrafine fibers. More specifically, even a high-density woven fabric that has been subjected to a water jet punching treatment that can provide sufficient entanglement and opening effect is desirable.

  The cleaning tape of the present invention is desirably cut by a melt cutting method so as not to generate dust, and the fabric after such entanglement treatment is preferably slit, for example, to a tape width of about 20 mm. The tape width is not particularly limited and is appropriately selected according to the size of the optical connector cleaning device.

  As an optical connector cleaning device of the present invention, for example, a so-called reel type cleaner, which is provided with a window portion having an opening / closing mechanism in a box-type outer case that can be grasped with one hand, is sequentially supplied from a cleaning tape supply reel. And a known apparatus that is wound on another reel through an opening / closing window. This reel rotates only in a certain direction (winding direction) and has a ratchet mechanism so as not to cause the tape to loosen. For example, Japanese Patent Laid-Open No. 2002-214476 or Japanese Patent Laid-Open No. 6-242347 A cleaning device of the structure as described is mentioned. In these known cleaning apparatuses, the cleaning apparatus of the present invention can be obtained by using the cleaning tape of the present invention.

  In addition, as a cleaning method of the optical connector, for example, using these reel type cleaners, the lever is rotated to open the window shutter, the wiping tape is exposed, the optical connector is applied to the cleaning surface at a right angle, It is known as a standard work to rotate twice to the left and right and then wipe it twice while sliding on the tape with a cleaning load of 600 to 700 g.

  Hereinafter, although an Example demonstrates in detail, this invention is not limited to these. In addition, the performance evaluation shown to an Example and a comparative example was implemented with the following method.

<Measurement of drug content on tape>
The test is performed in accordance with the test method for moisture content and adhesion moisture content described in the test item (1) of JIS L1013. After the evaluation fabric cut into about 20 g is immersed in the treatment solution for 1 minute, the rotating test mangle Squeezed under conditions where the pickup amount was about 75%. Immediately after this, dry heat setting was performed at 140 ° C. for 60 seconds, and this treated cloth was left in a hot air dryer at a specified temperature (105 ± 2 ° C.) for 6 hours or more, and then the glass property was weighed in advance. The sample was immediately placed in a weighing bottle with a lid and left to stand in an environment of 20 ° C. and 50% RH for 10 minutes, thereby cooling to room temperature and quickly measuring the weight.

  Subsequently, the mixture was stirred for 10 minutes using distilled water 100 times the weight of the fabric, and immediately after that, it was allowed to stand for 6 hours or longer in a hot air dryer at a specified temperature (105 ± 2 ° C.) and weighed in advance. Quickly placed in a weighing bottle with a lid with a glass lid, left to stand in an environment of 20 ° C. and 50% RH for 10 minutes, cooled to room temperature, quickly measured for weight, and the weight of the fabric containing the treatment agent. The content rate was calculated from the comparison.

<Evaluation of return loss>
The SC ferrule terminal on which the cleaning operation was performed was measured using a return loss measuring device (model 2050 manufactured by JDS). The optical fiber was subjected to bending roster termination by making three loops of about 6 mm for reflection measurement. The return loss is calculated from the ratio of the incident light quantity and the reflected light quantity to be measured and is shown in decibels. A smaller numerical value indicates a smaller amount of reflected light and a smaller loss.
The measured wavelength of light was the wavelength generally used in optical fiber communication, that is, 1310 nm, because the transmission loss of the glass optical fiber was minimized. In order to eliminate individual differences in the SC ferrules used, measurements should be made using the same one, and be sure to include the level of the sample for comparison (paper wiper wiping with ethanol and no drug applied). Relative evaluation by. The number of n was 10, and the average value of 10 times showed a return loss value superior to the level of paper wiper wiping using ethanol.

<Evaluation of optical connector end surface contamination>
The evaluation tape was attached to a cleaning cassette, and the SC ferrule terminal was wiped once. After cleaning with tape, the presence or absence of dirt on the end face was determined using a 200 × optical microscope. The number of n was 10, and the number of remaining foreign matters out of 10 passed 0 to 1 and rejected 2 or more. In addition, the foreign material here refers to dust, oily substances, wiping lines, fiber debris, and the like that can be visually determined.

[Comparative Example 1]
The optical connector was wiped with a commercially available paper wiper (trade name Kimwipe) using several milliliters of ethanol.

[Examples 1 to 4, Comparative Examples 2 to 7]
Polyethylene terephthalate as island component, polyethylene terephthalate copolymerized with 5 mol% sodium sulfoisophthalic acid as sea component, component weight ratio 80/20, number of islands 70, composite fiber fineness 7.3 dtex <island component A sea-island composite fiber (manufactured by Toray Industries, Inc., 66 dtex, 9 filaments) having a fiber fineness (single fiber fineness) of 0.07 dtex> is woven by a water jet loom, 120 cm wide, 145 warps / inch, weft density 105 / inch. A fabric (plain woven fabric) having a basis weight of 75 g / m ² was obtained. By subjecting this to an alkali weight loss treatment under the conditions of caustic soda 10 g / L, 80 ° C., 60 minutes, bath ratio 1:10, the easy alkali weight loss component which is a sea component in the sea-island structure is eluted, and both warp and weft are 53 dtex, A plain polyester woven fabric having ultrafine fibers of 630 filaments was obtained.

Subsequently, this plain fabric was dyed at 130 ° C. for 15 minutes so that 0.15% by weight with respect to the weight of the fabric was applied using a disperse dye (Sumicaron Yellow E-RPD®). Then, it was dried at a dry heat temperature of 130 ° C., and then water jet punching with an amplitude of 5 mm, a water pressure of 9.8 mPa, and a treatment speed of 3 m / min was performed. This dough was cut into a width of 30 cm and a length of 50 cm, dipped in a chemical aqueous solution, and then squeezed under a condition of a pickup amount of about 75% using a rotary test mangle. Immediately after this, dry heat setting was performed at 140 ° C. for 60 seconds. As a result, a dyed processed product comprising ultrafine fibers containing a drug having a warp density of 150 yarns / inch, a weft density of 110 yarns / inch, and a basis weight of 85 g / m ² was obtained. After confirming the amount of the drug adhered, this fabric was melt cut using a heat cutter (SURE-RC35, manufactured by Ishizaki Electric Manufacturing Co., Ltd.) and processed into a tape shape having a width of 18 mm to obtain a cleaning tape. This tape is wound around a reel, mounted on a reel-type wiping cassette (trade name “Cletop S”) sold by NTME, and the optical connector is wiped off. Wiping was performed in two reciprocations with a clean load of 0.6 to 0.7 kg.

  Table 1 summarizes the results of studies on the content of the optical connector end face treating agent with respect to the tape. In Examples 1 to 3 and Comparative Example 3, a drug aqueous solution was prepared using a nonionic surfactant (trade name: Daisurf MOL315, main component polyoxyalkylene alkyl ether, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) as a drug.

表１から明らかなように、光コネクタをエタノールを用いて市販の紙ワイパー（商品名：キムワイプ（登録商標））で拭取った場合（比較例１）では、反射減衰量は良好であるが、紙ワイパーから発塵した塵埃が観察され、光コネクタ端面の汚れに関しては問題があった。また、極細繊維からなるテープを用いた場合（比較例２）、汚れについては良好であったが、反射減衰量が低下すること傾向にあった。

As is apparent from Table 1, when the optical connector was wiped with ethanol using a commercially available paper wiper (trade name: Kimwipe (registered trademark)) (Comparative Example 1), the return loss was good. Dust generated from the paper wiper was observed, and there was a problem regarding the contamination of the end face of the optical connector. Further, when a tape made of ultrafine fibers was used (Comparative Example 2), the stain was good, but the reflection attenuation amount tended to decrease.

  On the other hand, when a nonionic surfactant (made by Daiichi Kogyo Seiyaku Co., Ltd., trade name Daisurf MOL315, main component polyoxyalkylene alkyl ether) is applied to a tape made of ultrafine fibers (Examples 1 to 3). Shows improved return loss and excellent wiping performance. Since the effect of improving the return loss becomes smaller as the content increases, it can be said that the content is sufficient. When the adhesion rate was as high as 1% or more (Comparative Example 3), not only the effect of improving the return loss was small, but also the end face treating agent adhered to the end face of the optical connector after wiping, which was inappropriate.

  Table 2 summarizes the results of studying the types of end surface treating agents applied to the tape.

表２から明らかなように、付与する端面処理剤については慎重な選択が必要であり、異なる種類の非イオン・アニオン界面活性剤（三洋化成工業社製、イオネットＲＡＰ−２５０、比較例４）、界面活性剤（明成化学工業社製、デトロールＵＳ６０Ｆ、比較例５）、界面活性剤（日華化学社製、サンモールＦＬ、比較例６）やフッ素系薬剤（旭硝子社製、アサヒガードＡＧ７０００、比較例７）では、１％以下の付着条件においても反射減衰量が急激に悪化した。

As is clear from Table 2, careful selection is required for the end surface treatment agent to be applied, and different types of nonionic and anionic surfactants (Sanyo Chemical Industries, Ionette RAP-250, Comparative Example 4), Surfactant (manufactured by Meisei Chemical Industry Co., Ltd., Detrol US60F, Comparative Example 5), surfactant (manufactured by Nikka Chemical Co., Ltd., Sunmall FL, Comparative Example 6) and fluorine-based chemicals (manufactured by Asahi Glass Co., Ltd., Asahi Guard AG7000) In Example 7), the return loss was abruptly deteriorated even under the adhesion condition of 1% or less.

On the other hand, when the water-soluble silicone agent (trade name SF8421 manufactured by Toray Dow Corning Silicone Co., Ltd.) was applied (Example 4), the return loss was improved and excellent soil cleanliness was exhibited.

Claims (6)

In an optical connector cleaning device comprising a tape for cleaning an optical connector end face, the cleaning tape is made of a fabric made of ultrafine fibers having a single fiber fineness of 1 dtex or less, and the tape weight An optical connector cleaning device comprising 1% by weight or less of an optical connector end face treating agent. 2. The optical connector cleaning device according to claim 1, wherein the end surface treating agent of the optical connector is a nonionic surfactant or water-soluble silicon. The optical connector cleaning device according to claim 1, wherein the fabric is a plain fabric. It said fabric, cleaning apparatus for an optical connector according to claim 1, characterized in that a fabric in the range of basis weight 50 to 100 g / m ^2. A fabric for cleaning an end face of an optical connector, comprising a cloth made of ultrafine fibers having a single fiber fineness of 1 dtex or less, and an end face treating agent for an optical connector of 1 wt% or less with respect to the fabric weight. A fabric for cleaning an optical connector, comprising: An optical connector cleaning tape comprising the optical connector cleaning fabric according to claim 5.