JP2003098364A - Pressure-sensitive adhesive sheet for wiring optical fiber - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pressure-sensitive adhesive sheet for wiring optical fibers wherein optical fibers are hardly released from the pressure-sensitive adhesive sheet in the manufacturing process. SOLUTION: The pressure-sensitive adhesive sheet S1 for wiring optical fibers having a pressure-sensitive adhesive layer 2 on a base sheet has the following property. When an optical fiber 3 with 125 μm diameter made of glass and having an acrylic resin coating layer is pressed and stuck to the pressure-sensitive adhesive layer 2 with 1/4 of the peripheral surface of the fiber in a contact state and then the pressure-sensitive adhesive sheet S1 is bent around a cylindrical body R together with the fiber 3 in such a manner that the end part 3a of the optical fiber 3 is at the starting point of bending and that the cylindrical body R is in contact with the sheet and its axis is perpendicular to the optical fiber 3, the minimum radius of curvature when the end part 3a of the optical fiber 3 does not peel from the pressure-sensitive adhesive layer 2 is specified to <=20 mm.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an adhesive sheet for optical fiber wiring used for fixing an optical fiber on an adhesive surface.

[0002]

2. Description of the Related Art With the development of optical technology in recent years, wiring by optical fibers has come to be used in communication facilities and computers in place of electric wiring in order to improve transmission speed. Optical amplifiers and optical switches are also used to recover the transmission loss of light. For these devices, the wiring work man-hours are reduced, incorrect wiring is prevented, space is reduced, and wiring accuracy is improved. In order to ensure reliability, optical fiber wiring sheets have been developed for practical use.

As such an optical fiber wiring sheet, an optical fiber is wired and fixed on an adhesive surface of an adhesive sheet,
It is known that a cover material is attached to an adhesive surface to protect it (for example, Japanese Patent Laid-Open No. 2000-3567).
No. 18). By sealing and holding the optical fiber with such a thin sheet material, it is possible to handle multiple optical fibers as a unit without separating or entanglement, a small storage space is required, and downsizing can be achieved. , Can be easily placed in the device. Moreover, since the optical fiber is protected by the adhesive sheet and the cover material, external damage can be prevented.

[0004]

However, in the optical fiber wiring sheet as described above, during the process of fixing the optical fiber to the adhesive sheet and then attaching the optical fiber to the cover material, the adhesive sheet is deformed or vibrated. The optical fiber may be peeled off from the pressure-sensitive adhesive sheet and lifted up due to an external force, a residual stress at the time of wiring the optical fiber, or the like, or the optical fiber may be entangled with each other.

The problem of peeling of the optical fiber is not only the general adhesive strength of the adhesive sheet, but also the material of the optical fiber, the diameter of the wire, the thickness of the adhesive layer, and the pressing force when fixing the optical fiber. It is caused by various factors such as pressure.
Therefore, it is necessary to improve not only the adhesive force of the pressure-sensitive adhesive sheet but also these factors comprehensively and efficiently to prevent separation of the optical fiber.

Therefore, an object of the present invention is to provide an adhesive sheet for optical fiber wiring, which makes it difficult for the optical fiber to peel from the adhesive sheet during the manufacturing process.

[0007]

DISCLOSURE OF THE INVENTION The inventors of the present invention have come up with a method for evaluating the adhesive force of an optical fiber in a state close to an actual use condition, and after intensive studies, as a result, a standard optical fiber was adhered. It was found that the above object can be achieved by setting the minimum radius of curvature that does not peel off when the pressure-sensitive adhesive sheet is bent to 20 mm or less, and the present invention has been completed.

That is, the pressure-sensitive adhesive sheet for optical fiber wiring of the present invention is an adhesive sheet for optical fiber wiring in which a pressure-sensitive adhesive layer is formed on a substrate sheet, and the pressure-sensitive adhesive layer has a diameter of 12 mm.
An optical fiber element wire made of glass and having an acrylic resin coating layer of 5 μm is pressed and adhered in a state where ¼ of the peripheral surface is in contact with the end portion of the optical fiber element wire in this state. When the columnar body is inscribed perpendicularly to the optical fiber element wire and bent together with the adhesive sheet so that the end portion of the optical fiber element wire does not separate from the adhesive layer, the minimum radius of curvature is 20 mm or less. It is characterized by

In the above, it is preferable that the pressure-sensitive adhesive layer is formed of a silicone-based pressure-sensitive adhesive.

[Operation and Effect] According to the adhesive sheet for optical fiber wiring of the present invention, the adhesive force of the optical fiber is evaluated in a state close to the actual use condition, and the value is adjusted within an appropriate range. As shown by the results of the examples, it is possible to prevent the optical fiber from peeling off from the adhesive sheet during the manufacturing process.

When the pressure-sensitive adhesive layer is formed of a silicone-based pressure-sensitive adhesive, it is easy to adjust the properties of the pressure-sensitive adhesive sheet within the above-mentioned radius of curvature, and the pressure-sensitive adhesive layer has good heat resistance and transparency. Can be formed.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a cross-sectional view showing an example of a usage state of the pressure-sensitive adhesive sheet for optical fiber wiring of the present invention.

The adhesive sheet for optical fiber wiring of the present invention is
As shown in FIG. 1, the pressure-sensitive adhesive layer 2 is formed on the base material sheet 1. In use, the optical fiber 3 is fixed to the adhesive surface of the adhesive sheet S1 of the present invention by wiring, and the cover material 4 or another adhesive sheet is attached to the adhesive surface side to form an optical fiber wiring sheet. In the illustrated example, the cover material 4 is attached to the adhesive surface side.

In such an optical fiber wiring sheet, after fixing the optical fiber 3 to the adhesive sheet S1, the cover material 4 is formed.
During the process of attaching the adhesive sheet S1 to the optical fiber 3 due to flexural deformation and vibration of the adhesive sheet S1, external force, residual stress during optical fiber wiring, and the like.
It may come off and float up, and it may come apart or become entangled.

Therefore, in the present invention, as shown in FIG.
The optical fiber element wire 3 made of glass having a diameter of 125 μm and having a coating layer of acrylic resin is pressed against the adhesive layer 2 to press the optical fiber element wire 3 on the peripheral surface 1
/ 4 are in contact with each other, and the cylindrical body R is made so that the end 3a of the optical fiber element wire 3 becomes the bending start point in that state.
The minimum radius of curvature at which the end portion 3a of the optical fiber element wire 3 does not separate from the adhesive agent layer 2 when inscribed perpendicularly to the optical fiber element wire 3 and bent together with the adhesive sheet S1 is 20 mm or less. The minimum radius of curvature is preferably 15 mm
It is the following.

In adjusting the radius of curvature, the pressure-sensitive adhesive layer 2 may vary depending on the type of pressure-sensitive adhesive.
Adhesive power of 6N / 20mm or more, and further 8N / 20m
It is preferably m or more. The method for evaluating the adhesive strength is as shown in the examples.

The pressure-sensitive adhesive sheet S1 has a structure in which the pressure-sensitive adhesive layer 2 is formed on the base material sheet 1. However, in order to enhance the anchoring force of the pressure-sensitive adhesive layer 2, the pressure-sensitive adhesive sheet S1 has a surface on the pressure-sensitive adhesive side. You may give a process. Also, release processing (peeling processing) on the back side
Etc. may be given.

A material having high heat resistance is used for the base sheet 1, and for example, polytetrafluoroethylene (PT) is used.
FE), a copolymer of tetrafluoroethylene and perfluoroalkyl vinyl ether (PFA), a copolymer of tetrafluoroethylene and hexafluoropropylene (F
EP), polychlorotrifluoroethylene (PCTF
E), a copolymer of tetrafluoroethylene and ethylene (ETFE), polyvinylidene fluoride (PVd
Fluorine resin film such as F) or polyimide film,
Examples thereof include PET film and silicone rubber sheet. Of these, a fluororesin film is preferable.

The thickness of the base material sheet 1 is 0.02 to 1.00.
mm is preferred. It is more preferable to use one having a thickness of 0.10 to 0.50 mm while having flexibility, while having flexibility.

As the surface treatment for increasing the anchoring force,
Surface treatments such as corona discharge treatment, sputtering treatment, low-pressure UV treatment, plasma treatment, and alkali metal etching treatment can be mentioned. Among these surface treatment methods, it has good heat resistance,
A sputtering process that can physically roughen the surface and increase the surface area for forming the adhesive layer is preferable.

When the sputtering process is adopted as the surface treatment method, for example, argon gas is used as the atmosphere gas and the atmospheric pressure is 0.667 to 6.666P.
a, it is preferable to treat with a discharge power of 5 to 50 W · sec / cm ² .

As the pressure-sensitive adhesive layer 2, any material can be used as long as it can obtain the above-mentioned characteristics.
Silicone-based pressure-sensitive adhesives are used, and silicone-based pressure-sensitive adhesives are desirable for the reasons described above. The silicone-based pressure-sensitive adhesive contains, for example, silicone rubber or silicone resin containing organopolysiloxane as a main component, and a pressure-sensitive adhesive layer can be formed by adding a crosslinking agent to the silicone rubber and curing it. As described above, the pressure-sensitive adhesive is usually added with a crosslinking agent to form a three-dimensional structure to increase cohesive force. In addition, a tackifier, an antioxidant, other additives, and the like can be added to the pressure-sensitive adhesive, if necessary.

As the silicone rubber, various ones used in silicone pressure-sensitive adhesives can be used without particular limitation. For example, organopolysiloxane containing dimethylsiloxane as a main constituent unit can be preferably used. A vinyl group and other functional groups may be introduced into the organopolysiloxane as needed. The weight average molecular weight of the organopolysiloxane is usually 180,000 or more, preferably 280,000 to 1,000,000, particularly preferably 500,000 to 900,000.

As the silicone resin, various resins used in silicone pressure-sensitive adhesives can be used without particular limitation. For example, M unit (R ₃ SiO _1/2 ),
Q unit (SiO ₂ ), T unit (RSiO _3/2 ) and D
At least one selected from the units (R ₂ SiO)
An organopolysiloxane composed of a copolymer having a unit of a kind (in the unit, R represents a monovalent hydrocarbon group or a hydroxyl group) can be preferably used. In addition to having an OH group, the organopolysiloxane made of the above-mentioned copolymer may have various functional groups such as a vinyl group introduced if necessary. The functional group to be introduced may be one that causes a crosslinking reaction. The copolymer may be M composed of M units and Q units.
Q resin is preferred. The ratio (molar ratio) of M unit to Q unit, T unit or D unit is not particularly limited, but former: latter = about 0.3: 1 to 1.5: 1, preferably 0.5:
It is preferable to use one having a ratio of 1 to 1.3: 1.

The compounding ratio (weight ratio) of the silicone rubber and the silicone resin is as follows: former: latter = 100: 100 to 10
About 0: 220 is preferable, and 100: 120 to 100 :.
It is more preferable to use the one having about 180. The silicone rubber and the silicone resin may be used by simply blending them, or may be a partial condensate thereof.

The above-mentioned composition usually contains a cross-linking agent in order to make it a cross-linked structure. As a cross-linking agent, SiH
Examples thereof include a siloxane-based crosslinking agent having a group and a peroxide-based crosslinking agent. As the peroxide cross-linking agent, various ones conventionally used in silicone pressure-sensitive adhesives can be used without particular limitation. For example, benzoyl peroxide, t
-Butylperoxybenzoate, dicumyl peroxide, t-butylcumyl peroxide, t-butyl oxide, 2,5-dimethyl-2,5-di-t-butylperoxyhexane, 2,4-dichloro-benzoylper Oxide, di-t-butylperoxy-di-isopropylbenzene, 1,1-bis (t-butylperoxy) -3,3,5-trimethyl-cyclohexane, 2,
Examples thereof include 5-dimethyl-2,5-di-t-butylperoxyhexyne-3.

As the siloxane-based cross-linking agent, for example, polyorganohydrogensiloxane having at least two hydrogen atoms bonded to silicon atoms in the molecule on average is used. Examples of the organic group bonded to the silicon atom include an alkyl group, a phenyl group, a halogenated alkyl group and the like, but a methyl group is preferable because it is easy to synthesize and handle. The siloxane skeleton structure may be linear, branched, or cyclic, but linear is often used.

The thickness of the pressure-sensitive adhesive layer 2 is an important factor in obtaining the above characteristics. When the thickness of the pressure-sensitive adhesive layer 2 is increased, the floating and peeling characteristics and the adhesive strength can be improved. In order to obtain the above characteristics, the thickness of the pressure-sensitive adhesive layer 2 varies depending on the type of pressure-sensitive adhesive, but is preferably 20 μm or more, more preferably 30 μm or more. The thicker the pressure-sensitive adhesive layer 2 is, the more the above characteristics are improved, but it is preferably 60 μm or less in view of easiness of bending, space saving, and the like.

As the method for forming the pressure-sensitive adhesive layer 2, a pressure-sensitive adhesive is applied to the substrate sheet 1 by a reverse coating method, a fan-ten coating method, a dipping method or the like, and the respective crosslinking methods (heating, UV irradiation) are applied. Etc.) for curing.

As the optical fiber 3, various commercially available glass optical fibers and plastic optical fibers can be used. Optical fiber 3 in which the present invention is considered to be particularly effective
The diameter may be 50 to 500 μm.

As a method for wiring and fixing the optical fiber 3 to the adhesive sheet S1, there are a method of using a numerically controlled wiring machine and a method of adding vibration such as ultrasonic waves at that time. It is also possible to stick it to the adhesive surface of the adhesive sheet S1 with a roller or the like.

As with the base sheet 1, a film made of a material having high heat resistance is usually used as the cover material 4. In order to cover the raised portion of the optical fiber 3, the adhesive sheet S
It is better that it is more flexible than 1 and has a thickness of 0.
02-0.20 mm is preferable, 0.02-0.10 m
m is more preferred.

The cover material 4 and the pressure sensitive adhesive sheet S1 can be adhered by various laminating methods, and it is preferable to use a vacuum laminating method. In addition, in order to improve the adhesiveness with the adhesive sheet S1 and the optical fiber 3, another adhesive sheet may be used instead of the cover material 4. In that case, the same thing as the adhesive sheet S1 can be used.

[0034]

EXAMPLES Examples and the like specifically showing the constitution and effects of the present invention will be described below. In addition, evaluation of physical properties and the like in Examples and the like was performed as follows.

(Measurement Method of Optical Fiber Peeling Test) One optical fiber element having a diameter of 125 μm and having a coating layer of acrylic resin is made of glass and has a diameter of 125 μm is placed on a flat table on which a rubber mat having weak adhesiveness with an adhesive sheet is placed. Place the book and place the pressure-sensitive adhesive sheet from above with the pressure-sensitive adhesive layer facing down so that the end of the book is in the center 1
It is stuck by pressing with a roller of 00g. By this, 1/4 of the peripheral surface of the optical fiber is adhered in a contact state. On the other hand, prepare cylindrical jigs with different radii in 1 mm increments, peel off the adhesive sheet to which the optical fiber is attached from the rubber mat, and make the optical fiber side outside so that the end of the optical fiber becomes the bending start point. A cylindrical body is inscribed perpendicularly to the optical fiber and wound (see FIG. 2). At that time, the presence or absence of peeling from the adhesive sheet at the end of the optical fiber is observed. The diameter of the columnar body was gradually decreased, and the minimum radius of the columnar body where the ends did not peel off was taken as the minimum radius of curvature at which the ends did not peel off.

(Measurement Method of Adhesive Strength) Sputtering treatment (discharging power 30 W · sec / cm ² , processing gas Ar, atmospheric pressure 3.333) on the pressure-sensitive adhesive layer side of the pressure-sensitive adhesive sheet and on one side as a cover material.
Pa)) FEP film (Neoflon FEP: manufactured by Daikin Industries, Ltd.) with a treatment surface side having a thickness of 0.05 mm is 2 kg.
Stick the rubber roller back and forth once. The test piece is cut into a width of 20 mm. After bonding at room temperature for 30 minutes, the test piece was peeled off with a tensile tester under conditions of a tensile speed of 300 mm / min and 180 ° peel while being attached to an SUS plate, and the adhesive strength was measured.

(Evaluation of peeling during process) The obtained pressure-sensitive adhesive sheet cut into a size of 10 × 30 cm was placed on a flat table, and 100 g of a roller (diameter 3
0 mm) is used to wire and temporarily fix one optical fiber element having a diameter of 125 μm and having a coating layer of acrylic resin in parallel at intervals of 10 mm. At this time,
Vibration and external force by the roller are applied to the optical fiber and the adhesive sheet, and the adhesive sheet is liable to be deformed before and after the rolling. After temporarily fixing a total of five to the adhesive sheet, a cover material of the same size was pasted on it with a laminator at a pressure of 196 KPa and a speed of 1 m / min, and the deviation of the optical fiber wiring from the initial position after pasting. By observing, the presence or absence of peeling during the process was evaluated. As the cover material, PTFE dispersion (Polyflon D-2: manufactured by Daikin Industries, Ltd.) was applied to an aluminum foil by a dipping method, dried, and baked at 360 ° C. for 2 minutes,
The process was repeated and a sheet having a thickness of 0.05 mm was used.

(Example 1) A PTFE sheet was cut on the base sheet.
Thickness of cutting sheet (NO.900UL: Nitto Denko Corporation)
Only 0.1 mm was used. Discharge power on one side of this sheet
30 W / sec / cm ² , Processing gas Ar, atmospheric pressure 3.333P
The sputtering process was performed under the condition of a. The adhesive is silicone
Adhesive (SH4280: Toray Dow Corning Siri
Corn) 100 parts by weight, benzoic peroxide as a crosslinking agent
Ill (Nyper BO: made by NOF Corporation) 1.5 parts by weight
And dilute with toluene to a solid content of 40% by weight.
I was there. Reapply the compounded adhesive to the surface-treated surface of the base sheet.
The thickness is 0.030 mm (dry) by the verse coat method.
Coating at 80 ℃ and dry for 3 minutes, then at 200 ℃
It was cured under the condition of 3 minutes.

Example 2 A PET film (Lumirror S-10: manufactured by Toray) having a thickness of 0.10 mm is used as a base material sheet, and a silicone adhesive (X-40-3103: manufactured by Shin-Etsu Chemical) 1
A catalyst (PL-50T: manufactured by Shin-Etsu Chemical Co., Ltd.) was added to 100 parts by weight of 1.
0 parts by weight was added, diluted to 40% by weight with toluene, and applied by a reverse coating method so as to have a thickness of 0.020 mm (Dry), and cured at 150 ° C. for 3 minutes.

Comparative Example 1 A pressure-sensitive adhesive sheet was produced in the same manner as in Example 1 except that the thickness of the pressure-sensitive adhesive was 0.015 mm (Dry).

Comparative Example 2 An adhesive sheet was produced in the same manner as in Example 2 except that the thickness of the adhesive was 0.010 mm (Dry).

Table 1 shows the results of the above evaluations using the above-mentioned pressure-sensitive adhesive sheets.

[0043]

[Table 1] As is clear from Table 1, by setting the minimum radius of curvature at which the end portion does not peel from the pressure-sensitive adhesive layer to 20 mm or less, the optical fiber can be made difficult to peel from the pressure-sensitive adhesive sheet during the manufacturing process.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing an example of a usage state of an adhesive sheet for optical fiber wiring of the present invention.

FIG. 2 is a perspective view for explaining a method for evaluating an adhesive sheet for optical fiber wiring according to the present invention.

[Explanation of symbols]

1 Base sheet 2 Adhesive layer 3 Optical fiber (strand) 4 Cover material S1 adhesive sheet R cylinder

Claims (2)

[Claims] 1. A pressure-sensitive adhesive sheet for optical fiber wiring in which a pressure-sensitive adhesive layer is formed on a substrate sheet, wherein the pressure-sensitive adhesive layer presses an optical fiber element wire having a 125 μm diameter glass-made acrylic resin coating layer. Adhesion is made with 1/4 of the peripheral surface in contact, and in such a state, the columnar body is inscribed perpendicularly to the optical fiber element wire so that the end of the optical fiber element becomes the bending start point and adheres. An adhesive sheet for optical fiber wiring, which has a minimum radius of curvature of 20 mm or less at which an end portion of the optical fiber element wire does not separate from the adhesive layer when bent together with the sheet. 2. The pressure-sensitive adhesive sheet for optical fiber wiring according to claim 1, wherein the pressure-sensitive adhesive layer is formed of a silicone-based pressure-sensitive adhesive.