JP2003344670A - Optical fiber sheet - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical fiber sheet that is free from causing a micro bent loss, and also enables thermal fusion closely in a temperature range of causing no thermal degradation of optical fibers. <P>SOLUTION: The optical fiber sheet is made by fusion bonding through coil type optical fibers where two pieces of resin films are wound in a coil-like bundle. The optical fiber sheet is formed by fire resistant materials, in which either one of resin films has flexibility, and which are thermally fusible in the temperature range of 80 to 170°C. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical fiber sheet in which two resin films are bonded together via a coil type optical fiber wound in a coil shape.

[0002]

2. Description of the Related Art Generally, in a device such as an optical fiber amplifier or a dispersion compensating fiber module, a long optical fiber is used as its element. When incorporating such a long optical fiber into an apparatus, it is necessary to collectively store the optical fibers in the device. Therefore, in the past, a long optical fiber wound around a bobbin was used, but when such winding is performed, a small bending, a so-called micro, is locally generated at a portion where the optical fibers overlap each other. There has been a problem that the loss of the optical fiber increases due to the bending. In addition, when using a bobbin, the handling is poor and the cost is high.

In order to solve these problems, instead of using the bobbin, an optical fiber sheet has been developed in which optical fibers are arranged in a row on a resin film and wired in a predetermined area. However, since such an optical fiber sheet becomes relatively large due to its structure, it becomes difficult to store the optical fiber sheet in such a device as the device becomes compact in recent years. There is.

Therefore, as a part of such space saving, cost reduction, and micro vent loss reduction, an optical fiber having a structure in which two resin films are bonded together via a coil type optical fiber wound in a coil shape. The seat was developed. FIG. 3 is a simplified cross-sectional view of a conventional typical optical fiber sheet 11. In the optical fiber sheet 11 shown in FIG. 3, of the two resin films, one base film 12 is made of flame-retardant polyethylene terephthalate (PET) and the other cover film 13 is polytetrafluoroethylene ( An example formed of a fluororesin such as PTFE) is shown. An adhesive layer 15 for fixing the coiled optical fiber 14 is provided on the surface of the base film 12 on which the coiled optical fiber 14 is placed. The optical fiber sheet 11 is formed by heat-sealing the base film 12 and the cover film 13 with the coil-type optical fiber 14 interposed therebetween.

However, the optical fiber sheet 11 using the fluororesin cover film 13 is inferior in flexibility because of the high rigidity of the cover film 13, and when the optical fiber sheet 11 is formed, the cover film 13 and the base are formed. A gap 16 is formed between the film 12 and the air expands during the heat resistance test (80 ° C.), and the films peel off from each other. Further, the coil-type optical fiber 14 is sandwiched between the cover film 13 and the base film 12 in a crushed form, and a problem occurs that the transmission loss is increased due to the lateral pressure applied to the optical fiber (micro vent loss). To do. Furthermore, in such an optical fiber sheet 11, the cover film 13 has a high melting point (300
C. to about 340.degree. C.) Since it is formed of fluororesin, when the coil film optical fiber 14 is heat-sealed to the base film 12 through the coil film optical fiber 14 as described above, the coil film optical fiber 14 is heated. It deteriorates (the optical fiber usually deteriorates at a temperature of 170 ° C. or higher).

FIG. 4 is a schematic cross-sectional view showing another typical conventional optical fiber sheet 21. The optical fiber sheet 21 shown in FIG. 4 is the same as the optical fiber sheet 11 shown in FIG. 3 except that the cover film 22 is made of flame-retardant silicone rubber. The same reference numeral as 2 is attached.).
Since the cover film 22 of the optical fiber sheet 21 is made of flame-retardant silicone rubber, the cover film 22 has sufficient flexibility unlike the optical fiber sheet 11 shown in FIG. The optical fiber sheet 21 with the coil type optical fiber 14 sandwiched between the base film 12 and the base film 12.
In the state in which the above is formed, the above gap does not occur between the cover film 22 and the base film 12. However, in such an optical fiber sheet 21, since the silicone rubber is crosslinked, it has the property of returning to its original shape when fixed in the stretched state, so that the cover film 22 crushes the coiled optical fiber 14. There is a problem that the optical fiber is microsealed due to the microseal in which it is sealed.

An optical fiber sheet having a cover film made of polyethylene has also been proposed. In such an optical fiber sheet, since the cover film is made of polyethylene, the cover film has sufficient flexibility, and the optical fiber sheet is formed by sandwiching the coil type optical fiber with the base film. The cover film and the base film can be heat-sealed at a temperature (about 120 ° C.) that does not cause a gap between the cover film and the base film and does not adversely affect the optical fiber. Further, since polyethylene is used, the heat fusion does not occur in such a manner that the coil type optical fiber is crushed.

[0008] However, since the optical fiber sheet is to be installed in the equipment, it usually needs to have the flame retardancy defined in UL94 V-0, but the cover film is made of polyethylene. The fiber sheet does not satisfy such flame retardancy. Therefore, it is conceivable to add an appropriate flame retardant such as a brominated flame retardant, a metal hydrate flame retardant, or a phosphoric acid compound flame retardant to polyethylene so as to satisfy the flame retardancy, but for example, a thickness of 0.1 mm U in film
In order to satisfy L94 V-0, it is necessary to add a large amount of flame retardant, which causes a problem that the flexibility of the film itself is impaired or the film becomes brittle.

[0009]

SUMMARY OF THE INVENTION The present invention has been made in order to solve the above-mentioned problems, and its object is to obtain a temperature at which micro vent loss does not occur and the optical fiber is not thermally deteriorated. An object of the present invention is to provide an optical fiber sheet that can be heat-sealed without a gap in the range.

[0010]

The present inventors have completed the present invention as a result of intensive research to solve the above problems. That is, the present invention is as follows. (1) An optical fiber sheet in which two resin films are fused via a coil type optical fiber wound in a coil shape, and one of the resin films has flexibility. , 80 ° C
An optical fiber sheet formed of a flame-retardant material that can be heat-sealed in a temperature range of 170 ° C. (2) The optical fiber sheet according to (1), wherein the resin film of any one of the above is formed of soft polyvinyl chloride containing a flame retardant. (3) The optical fiber sheet according to (2), wherein the flame retardant is a brominated flame retardant or a metal hydrate flame retardant. (4) A primer treatment, a corona treatment, a plasma treatment, a roughening treatment, on the surface of one of the above resin films,
The optical fiber according to any one of the above (1) to (3), which is subjected to at least one surface treatment selected from an adhesive coating treatment, a hot melt resin attachment, and a sandblasting treatment. Sheet.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below.
FIG. 1A is a simplified sectional view showing an optical fiber sheet 1 of a preferred example of the present invention, and FIG. 1B is a top view thereof. FIG. 1A is a sectional line I of FIG.
It is sectional drawing seen from B-IB. The optical fiber sheet 1 of the present invention has a basic structure in which two resin films (a base film 2 and a cover film 3) are fusion-bonded via a coil type optical fiber 4 wound in a coil.
According to the present invention, in the optical fiber sheet 1 having such a basic structure, the cover film 3, which is one of the two resin films, has flexibility and has a temperature of 80 ° C.
The main feature is that it is formed of a flame-retardant material that can be heat-sealed in a temperature range of 170 to 170 ° C. The optical fiber sheet 1 of the present invention has a temperature of 80 ° C to 170 ° C.
The base film 2 and the cover film 3 can be heat-sealed (heat-sealed) in the temperature range of 1, and no gap is formed between the base film 2 and the cover film 3 after heat-sealing. Therefore, the optical fiber is not thermally deteriorated by heat fusion, and it is possible to eliminate the peeling between the films that has occurred during the heat resistance test that has conventionally occurred due to the formation of the gap. In addition, since heat fusion can be performed without applying lateral pressure to the optical fiber, micro vent loss does not occur in the obtained optical fiber sheet 1. Here, “fusion” means that, of the two resin sheets in the obtained optical fiber sheet, one resin sheet formed of a flame-retardant material that can be heat-fused in the above temperature range is melted and solidified. It means that they are fixed to each other. In addition, “having flexibility” means JIS K 692.
The flexural modulus measured according to the regulations of 2-2 is 10
It is in the range of MPa to 500 MPa. The term "flame retardant" means that the flame retardancy test standard defined in UL94 V-0 is satisfied.

In the present invention, it is used for forming the cover film 3 and has the above-mentioned flexibility and 80 ° C. to 170 ° C.
Examples of flame-retardant materials that can be heat-sealed in the temperature range are soft polyvinyl chloride, polyvinylidene chloride, low density polyethylene, ethylene-vinyl acetate copolymer (EVA), ethylene-ethyl acrylate copolymer (EEA), etc. The flame retardant is added to the base polymer. Among them, since the base polymer itself is flame retardant, it is not necessary to add a large amount of flame retardant to obtain the desired flame retardancy, and even if a flame retardant is added. From the reason that flexibility is maintained and brittleness does not occur, soft polyvinyl chloride containing a flame retardant is preferable.

The soft polyvinyl chloride is a mixture of polyvinyl chloride and a plasticizer. Polyvinyl chloride is
It contains a unit represented by the following formula.

[0014]

[Chemical 1]

Polyvinyl chloride is commercially available, for example, H-1300 (manufactured by Nissan Chemical Co., Ltd.), Denka Vinyl SS-130 (manufactured by Denki Kagaku Co., Ltd.), SG-130.
0 (manufactured by Mitsubishi Chemical Corporation), Nipolit SM (manufactured by Asahi Glass Co., Ltd.), TH-1400 (manufactured by Taiyo PVC Co., Ltd.),
TK1300 (Shin-Etsu Chemical Co., Ltd.), Vinica KR80
0 (manufactured by Mitsubishi Chemical Corporation) may be used.

The soft polyvinyl chloride used in the present invention is prepared by blending the above-mentioned polyvinyl chloride with a plasticizer. The plasticizer is not particularly limited, and examples thereof include dibutyl phthalate (DBP) and di (2
-Ethylhexyl) phthalate (DOP), diisobutyl phthalate (DIBP), diheptyl phthalate (D
HP), diisodecyl phthalate (DIDP), tri (2-ethylhexyl) trimellitate (TOTM), and the like. Among them, TOTM is preferable from the viewpoint of heat resistance. The blending amount of the plasticizer varies depending on the plasticizer to be used, but from the viewpoint of achieving the above-mentioned flexibility, 10 parts by weight of the plasticizer is added to 100 parts by weight of polyvinyl chloride.
It is preferable to add 100 parts by weight, preferably 30 parts by weight to 8 parts by weight.
It is more preferable to add 0 part by weight.

The flame retardant is not particularly limited, and is a brominated flame retardant (described later), a metal hydrate flame retardant (described later), an antimony flame retardant (such as antimony trioxide), a phosphoric acid compound flame retardant ( Examples include various conventionally known flame retardants such as tris (chloroethyl) phosphate) and chlorine-based flame retardants (chlorinated polyolefin). Among them, bromine can be effectively imparted with superior flame retardancy. A flame retardant or a metal hydrate flame retardant is preferable.

Specific examples of the brominated flame retardant include tetrabromobutane, hexabromobenzene, hexabromobiphenyl, hexabromoethylbenzene, decabromodiphenyl oxide, pentabromochlorocyclohexane, tetrabromobisphenol A derivative, tetrabromobisphenol. Examples of S, tris (2,3-dibromopropyl-1) -isocyanurate and the like, among them,
Decabromodiphenyl oxide is particularly preferable because it can effectively impart more excellent flame retardancy. When a brominated flame retardant is used, in order to realize the above-described flame-retardant cover film 3, soft polyvinyl chloride 100
The amount is preferably 1 part by weight to 50 parts by weight, more preferably 2 parts by weight to 10 parts by weight with respect to parts by weight.

Specific examples of the metal hydrate-based flame retardant include aluminum hydroxide and magnesium hydroxide. Above all, since more excellent flame retardancy can be imparted,
Aluminum hydroxide is particularly preferred. When a metal hydrate-based flame retardant is used, in order to realize the above-described flame-retardant cover film 3, soft polyvinyl chloride 100
The amount is preferably 10 to 100 parts by weight, more preferably 30 to 80 parts by weight, based on parts by weight.

The thickness D1 of the cover film 3 is not particularly limited, but is 50 μm to 2 because it is subjected to heat fusion for a short time with a vacuum press machine as described later.
The thickness is preferably 00 μm, more preferably 70 μm to 150 μm. When the thickness D1 of the cover film 3 is less than 50 μm, the flame retardancy (UL94 V-
0) tends to not be satisfied, and when the thickness D1 of the cover film 3 exceeds 200 μm, heat fusion for a short time using a vacuum press cannot be performed, and the fiber coating material deteriorates due to heat. This is because there is a risk that it will end.

The material for forming the base film 2 in the present invention is not particularly limited, and polyethylene terephthalate (PET), polyimide, fluororesin, polyether ether ketone (PEEK), polyether sulfone (PES), polycarbonate (PC ) And the like, and there is no particular limitation, but PET is preferable from the viewpoint of cost. When forming the base film 2 with PET or PC, a flame retardant is usually added. The flame retardant is not particularly limited, and examples thereof include brominated flame retardants, metal hydrate flame retardants, antimony flame retardants, phosphoric acid compound flame retardants, chlorine flame retardants, and more excellent flame retardants. Brominated flame retardants are preferred because they can effectively impart flammability. The blending amount of the flame retardant is PET10 in the case of PET so as to satisfy the standard of the flame retardancy test specified in UL94 V-0.
It is preferably from 1 to 50 parts by weight, more preferably from 5 to 20 parts by weight, relative to 0 parts by weight.

The thickness of the base film 2 is not particularly limited, but it is preferably 50 μm to 1000 μm, and more preferably 350 μm to 450 μm from the viewpoints of flame retardancy, economy, size of the entire product, and the like. preferable.
If the thickness of the base film 2 is less than 50 μm, the rigidity becomes small, so that warpage occurs during vacuum pressing, and when flame-retardant PET is used, it tends to have no flame-retardant property. This is because if the thickness of the base film 2 exceeds 1000 μm, the cost of the film becomes high and the economical efficiency tends to deteriorate.

An adhesive layer 5 for fixing the coil type optical fiber 4 is provided on one surface of the base film 2.
The pressure-sensitive adhesive that forms the pressure-sensitive adhesive layer 5 is not particularly limited, and various conventionally known pressure-sensitive adhesives such as silicone-based pressure-sensitive adhesives and acrylic pressure-sensitive adhesives can be used. Agents are preferred.

As the coil type optical fiber 4 used in the present invention, a conventionally known appropriate optical fiber bundled in a coil shape can be used without particular limitation. Especially, erbium-doped fiber (EDF) for optical amplifier, dispersion compensating fiber (DCF), single mode fiber (SM
F), zero-dispersion fiber (DSF), non-zero-dispersion fiber (NZ-DSF), and the like. The optical fiber sheet of the present invention using the coil type optical fiber formed by such an optical fiber is an optical fiber amplifier, high output. Broadband (A
SE) It can be suitably used for a device such as a light source.
Further, an optical fiber having a normal optical fiber length of about 1 km such as a dispersion compensating fiber (DCF), a single mode fiber (SMF), a zero dispersion fiber (DSF) and a non-zero dispersion fiber (NZ-DSF) is also a coil type in the present invention. It can be suitably applied to an optical fiber.

The method for producing the optical fiber sheet 1 of the present invention is not particularly limited, but it can be produced, for example, as follows. First, an optical fiber is wound in a coil shape to form a coil-type optical fiber 4, which is fixed to a base film 2 having an adhesive layer 5 formed on one surface thereof. To this, cover film 3
Heat fusion (heat sealing) is performed at a temperature of 0 ° C to 170 ° C.
Such heat fusion is performed by applying heat in the above temperature range for 30 seconds to 10 minutes, for example, using an appropriate vacuum press device. After heat-sealing, the optical fiber sheet 1 of the present invention can be manufactured by cutting into a predetermined size and shape so as to include the coiled optical fiber 4 according to the purpose.

In the present invention, the surface of any one of the above resin films is selected from primer treatment, corona treatment, plasma treatment, surface roughening treatment, adhesive coating treatment, hot melt resin sticking, and sandblast treatment. At least one kind of surface treatment may be applied. As a result, the adhesiveness between the resin films in the heat-sealed state as shown in FIG. 1 is improved. The cover film 3 is preferable as the resin film subjected to the surface treatment. For example, in the case of performing the primer treatment, a known appropriate primer can be used without particular limitation, but it is preferable to use the urethane primer because the adhesive strength between the cover film and the pressure-sensitive adhesive is high. A primer obtained by dissolving such a primer in an appropriate solvent may be applied to the surface of the cover film 3 that is to be heat-sealed to the base film 2. Also, the adhesive may be applied to the surface of the cover film 3 on which the base film 2 is to be heat-melt-bonded, either after the primer treatment or alone. The adhesive is not particularly limited, but since the adhesive strength between the cover film and the pressure-sensitive adhesive is high, an ethylene ethyl acrylate (EEA) adhesive, an ethylene vinyl acetate copolymer (EVA) adhesive is used. Can be preferably used. Further, plasma irradiation treatment, corona treatment, roughening treatment (using sandpaper or the like), and sandblasting treatment are known methods for roughening the surface (increasing the surface area), and can be performed without particular limitation. Above all, plasma processing is preferable because of good workability. The plasma treatment may be performed under appropriate conditions that have been widely used in the art.

[0027]

EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to the following examples. Example 1 Flame-retardant soft polyvinyl chloride (polyvinyl chloride (PVC) 100 parts by weight, aluminum hydroxide (flame retardant) 60 parts by weight, tri (2-ethylhexyl)) in a cover film.
Flame-retardant polyethylene terephthalate film (50 mm × 5) in which a film (thickness: 100 μm) of trimellitate (plasticizer) is used (thickness: 100 μm) and a silicone adhesive is applied to the surface of the base film at a thickness of 30 μm.
0 mm, thickness: 380 μm), and an erbium-doped fiber coil (inner circumference: 30 mm, outer circumference: 40 mm, fiber length: 20 m) was placed on the adhesive-attached base film. A cover film was covered from above, and heat fusion was carried out at 140 ° C. for 1 minute using a vacuum press machine to produce an optical fiber sheet.

Example 2 Polyvinyl chloride 100 as a material for forming a cover film
Examples except that a flame-retardant soft polyvinyl chloride obtained by blending 7 parts by weight of decabromodiphenyl oxide (flame retardant) and 60 parts by weight of tri (2-ethylhexyl) trimellitate (plasticizer) was used. An optical fiber sheet was produced in the same manner as in 1.

Comparative Example 1 An optical fiber sheet was produced in the same manner as in Example 1 except that a polytetrafluoroethylene (PTFE) film (thickness: 80 μm) was used as the material for forming the cover film.

Comparative Example 2 An optical fiber sheet was produced in the same manner as in Example 1 except that a flame-retardant silicone film (thickness: 100 μm) was used as the cover film forming material.

Comparative Example 3 An optical fiber sheet was produced in the same manner as in Example 1 except that a low density polyethylene (low density PE) film (thickness: 80 μm) was used as the material for forming the cover film.

The optical fiber sheets obtained in Examples 1 and 2 and Comparative Examples 1 to 3 were evaluated for the presence or absence of micro vent loss, flame retardancy and flexibility as follows.

(1) Light having a wavelength of 1550 nm is incident from one end of the coil fiber before heat-sealing the micro vent loss cover film, and the amount of light emitted from the other end is measured at room temperature (25 ℃)
After heat-sealing the cover film, the amount of light at 1550 nm was measured at room temperature using an optical power meter,
The difference in light amount was defined as micro vent loss. The light intensity difference is 0.
Less than 5 dB was evaluated as ◯, and 0.5 dB or more was evaluated as x.

(2) Flame retardancy (UL94 vertical test) A cover film alone was cut into a size of 127 mm x 12.7 mm to prepare 5 samples, which were used for the test. FIG. 2 is a diagram schematically showing a flame retardancy evaluation test. As shown in FIG. 2, the sample was attached to a predetermined clamp, and a diameter of 9.
5 mm Bunsen burner (methane gas: 37 MJ / m
³ , blue flame: 19 mm), ignited for 10 seconds, and the time until the flame disappeared and the presence or absence of fire spread to the clamp part were confirmed. The glowing time after extinction (time to turn red without flame) was also measured. When the sample melts and drops down, the Bunsen burner is moved so as to follow the bottom of the remaining sample. The surgical cotton (51 mm) placed 305 mm below the sample for both the first and second
mm × 51 mm, thickness: 6.4 mm), and the presence or absence of ignition was confirmed. The pass criteria for the test are as follows. Those that passed the UL94 V-0 standard were evaluated as ◯, and those that failed were evaluated as x.

[0035]

[Table 1]

(3) Flexibility The flexural modulus was measured in accordance with JIS K 6922-2 in the flexibility evaluation test.・ Sample thickness: 4 mm ・ Width: 10 mm ・ Length: 80 mm ・ Test speed: 1 mm / min ・ Distance between fulcrums: 40 mm ・ Number of tests: n = 5 ・ Pass criteria: The average value of n = 5 is 10 MPa to 500 MP
The case of a was evaluated as ◯, and the case of greater than 500 MPa was evaluated as x.

The results are shown below.

[0038]

[Table 2]

[0039]

As is apparent from the above description, according to the present invention, an optical fiber sheet can be heat-sealed without gaps in a temperature range in which micro vent loss does not occur and the optical fiber is not thermally deteriorated. Can be provided.

[Brief description of drawings]

FIG. 1 (a) is a schematic sectional view showing an optical fiber sheet 1 of a preferred example of the present invention.
(B) is the top view. FIG. 1A is the same as FIG.
It is sectional drawing seen from the cutting plane line IB-IB of FIG.

FIG. 2 is a diagram schematically showing a flame retardancy evaluation test.

FIG. 3 is a simplified cross-sectional view showing a conventional typical optical fiber sheet 11.

FIG. 4 is a diagram showing another conventional typical optical fiber sheet 21.
It is sectional drawing which simplifies and shows.

[Explanation of symbols]

1 Optical fiber sheet 2 base film 3 cover film 4 Coil type optical fiber

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Katsuaki Kondo             2 3 Kiyohara Industrial Park, Utsunomiya City, Tochigi Prefecture             Ryoden Kogyo Co., Ltd.Utsunomiya Factory F-term (reference) 2H038 CA52

Claims (4)

[Claims] 1. An optical fiber sheet comprising two resin films fused together via a coil type optical fiber wound in a coil shape, wherein one of the resin films has flexibility. Have, 80 ℃
An optical fiber sheet formed of a flame-retardant material that can be heat-sealed in a temperature range of 170 ° C. 2. The optical fiber sheet according to claim 1, wherein one of the resin films is made of soft polyvinyl chloride containing a flame retardant. 3. The optical fiber sheet according to claim 2, wherein the flame retardant is a bromine flame retardant or a metal hydrate flame retardant. 4. At least one selected from a primer treatment, a corona treatment, a plasma treatment, a surface roughening treatment, an adhesive coating treatment, a hot melt resin sticking, and a sandblast treatment on the surface of any one of the above resin films. 4. A surface treatment of seeds is applied.
The optical fiber sheet according to any one of 1.