JPH05174636A - Thin cut-off tape for cable - Google Patents

Abstract

PURPOSE:To reduce the used quantity of a polyethylene outer sheath as well as its weight and diameter by providing a water absorption resin layer of a predetermined apparent density on polyester nonwoven fabrics of a predetermined apparent density followed by cladding a cover material thereon by means of a wet-lamination method. CONSTITUTION:A water permeability preventing layer 2 is provided at least on one side of high density nonwoven fabrics 1 subjected to a high temperature pressing treatment to the extent that its apparent density becomes 0.5g/cm<3> or more, and subsequently compression-processed water absorption resin layer 3 consisting of a water absorption resin powder 4 and a synthesized resin binder 5, the apparent density of which ranges from 0.50 to 1.25g/cm<2>, are provided thereon. At least one of the layers 3 is covered with a cover material 6. The thickness of the thin cut-off tape for a cable ranges from 0.18 to 0.23mm. A synthesized polymer which is insoluble in water and has a water absorbing function ten to some hundred times its tare weight as well as decomposition-resistance to a microorganism, such as an acrylc acidic crosslinked product, is used as the water absorption resin powder 4. The compound ratio of the powder 4 to the binder 5 is preferably in a range from 300 to 600 weight parts for the powder 4 relative to 100 weight parts for the binder.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thin waterproof tape used for optical fiber cables, electric power cables and the like.

[0002]

2. Description of the Related Art Conventionally, it has been known to use a water-stop tape to prevent water running from the outside into a communication cable such as an optical fiber waterproof cable or a power cable.

For example, FIG. 2 is a sectional view showing an example of the structure of a relay system optical fiber waterproof cable. Groove 8a of slotted polyethylene slot rod 8 having FRP tensile strength body 7 in the center and spiral groove provided on the outer periphery
A plurality of optical fiber tape core wires 9 are housed inside, and a water blocking tape 10 and a polyethylene jacket 11 are further provided. When the jacket of a cable with such a structure deteriorates or is damaged due to some accident, and water enters the cable, the waterproof tape placed under the jacket absorbs water and expands, causing Water is stopped only near the infiltration part of the cable to prevent water from running in the longitudinal or inward direction of the cable, and it has an excellent water-stop function that prevents accidents due to water in the cable.

The following water blocking tapes have been proposed for these cables.

(1) A sandwich type waterproof tape in which a water-absorbent resin layer obtained by mixing a water-absorbent resin powder and a low-melting-point heat-adhesive resin powder is sprinkled between two non-woven fabric substrates (Japanese Patent Application Laid-Open No. Sho-SHO). 63-301418).

(2) A coating type water-stop tape in which a water-absorbent resin powder and a water-absorbent resin composition of a resin binder are applied to one or both sides of a polyester filament non-woven fabric (JP-A-61-1).
29228).

(3) A water-absorbent resin powder having a specific particle diameter and a water-absorbent resin composition of a rubber binder are applied to one surface of a non-woven fabric substrate and compressed together with a cover material by a high-pressure calender. 3-31390).

[0008]

However, these water blocking tapes are generally thick.

In the sandwich type water-stop tape of (1), powders of a water-absorbent resin and a low-melting point heat-adhesive resin are sprinkled on a non-woven fabric substrate and heated from above to melt the heat-adhesive resin, Since it is manufactured by lightly crimping and bonding between heating rolls together with a thin non-woven fabric as a cover material, the thickness is relatively large, for example, 0.5 mm or more. Although the thickness will become thinner if it is pressed firmly, the water-absorbent resin powder will be covered with the heat-adhesive resin, and the water-stopping function will deteriorate.

Since the water-absorbent resin powder of (2) is simply coated with the water-absorbent resin powder and the water-absorbent resin composition of the resin binder dissolved in the organic solvent, and dried.
The water absorbent resin layer contains innumerable voids and has a large thickness, for example, 0.4 mm or more.

In the compression type water-stop tape (3), since the particle diameter of the water-absorbent resin powder is as large as 50 μm or more because of the water-stopping function, the water-absorbent resin composition of the water-absorbent resin and the rubber binder is Even if it is applied on a non-woven fabric substrate and dried, and then compressed with a high-pressure calender, the thickness does not become so thin and 0.30 m
The m type is practically used.

[0012] The waterproof tape for optical fiber waterproof cables currently in practical use is used as a non-woven fabric substrate from the viewpoint of mechanical strength and antibacterial property, and has a basis weight of 40 to 60 g / m ^2.
Spunbond long-fiber polyester non-woven fabric is used. The above thickness figures are for the case where this non-woven fabric is used.

On the other hand, along with the expansion of the application area of optical fibers in the future, studies for increasing the number of cores and increasing the density of optical fiber cables are in progress. In this study, a thin and lightweight optical fiber cable that takes advantage of the characteristics of the optical fiber is desired. Particularly, regarding the outer diameter of the optical cable, since the diameter of the cable conduit is 75 mm, the outer diameter needs to be less than this. Regarding the weight of the optical cable, the lighter the weight of the optical cable, the lesser the number of installation operations and the easier the installation. As described above, in increasing the number of cores and increasing the density of optical cables, making the optical cables thinner and lighter is the most important consideration item. In order to reduce the diameter and weight of the optical cable, it is advantageous to use a waterproof tape with a small thickness while maintaining waterproof properties, and development of a thin waterproof tape is desired.

Further, since the taping machine for winding the waterproof tape around the cable has a limited volume for mounting the tape, if the thickness of the tape is large, the length per one pad becomes short, and the tape pad is used. It must be replaced every time, and the longer the length of one pad of the tape is, the more effective the productivity of the cable is.

Under the above circumstances, there has been a strong demand for the development of a thin waterproof tape capable of reducing the diameter of the cable, increasing the length of the tape per roll of the pad, and reducing the amount of the polyethylene jacket used.

An object of the present invention is to provide a seawater stopping function which is the same as that of a conventional one.
A thin waterproof tape with antibacterial properties and mechanical strength, a cable that can be made thin, the length per roll of the pad can be made long, and the amount of polyethylene outer coating used can be reduced to make it lightweight and thin. Is to provide.

[0017]

The thin waterproof tape for cables according to the present invention comprises a polyester non-woven fabric having an apparent density of 0.5 g / cm ³ or more, which has been subjected to a high temperature press treatment, on at least one side thereof.
It has a compressed water-absorbent resin layer having an apparent density of 0.50 to 1.25 g / cm ^{3 comprising} a water-absorbent resin powder and a synthetic resin binder, and at least one of the water-absorbent resin layers is optionally covered with a cover material. It has a thickness of 0.18
It is characterized by being about 0.23 mm.

The thin waterproof tape for a cable may have a structure in which the cover material is attached by a wet laminating method.

Further, the thin waterproof tape for a cable may be obtained by subjecting the polyester nonwoven fabric to a water permeation preventive treatment.

The apparent density here is calculated by the following equation.

Apparent density (g / cm ³ ) = Nonwoven fabric basis weight (g
/ M ² ) ÷ Nonwoven fabric thickness (cm) ÷ 10000 Apparent density (g / cm ³ ) = Water absorbent resin layer weight% (g / m
² ) ÷ water-absorbent resin thickness (cm) ÷ 10,000 The polyester nonwoven fabric substrate used for the thin waterproof tape for cables of the present invention is coated with a water-absorbent resin composition comprising a water-absorbent resin powder, a synthetic resin binder and an organic solvent. -It has the strength to withstand the tension when it is dried and when the tape is wrapped around the cable, it is not decomposed by microorganisms, it has flexibility, and the thickness hardly changes with the solvent. 25 g /
It was a high-temperature press treatment of ³ cm ³ or more.

As a concrete example, for example, areal weights 35 to 6
0 g / m ² spunbond long-fiber polyester non-woven fabric (for example, ES-5040 manufactured by Asahi Kasei Kogyo Co., Ltd .: apparent density 0.32 g / cm ³ or ES-5060: apparent density 0.3
2 g / cm ³ ) subjected to high temperature press treatment under a linear pressure of 35 to 40 kg / cm between metal rolls having a surface temperature of 220 to 230 ° C., and polyester short fibers having a basis weight of 35 to 35 by a wet method.
There is a wet non-woven fabric which is paper-made at 60 kg / m ² and is subjected to a high temperature press treatment under a linear pressure of 40 to 45 kg / cm between metal rolls having a surface temperature of 220 to 230 ° C.

Since the density of these non-woven fabric base materials is increased to 0.5 g / cm ³ or more by the high temperature press treatment,
It has a characteristic that the thickness is thin and the thickness does not change even when the water absorbent resin composition is applied. Moreover, since it does not contain impurities, it is not decomposed by microorganisms.

Here, the basis weight of the non-woven fabric substrate is 35 to 60 g.
/ M ² and are you doing, the strength is too weak is less than current technology on 35 g / m ^2, is too thick thickness is 60 g / m ^2, greater than also because the price disadvantageous.

In the case of the present invention, the non-woven fabric base material can be used as long as at least a tensile strength in the machine direction of at least 5 kg / 25 mm can be secured, but from the viewpoint of thinning the present invention, the unit weight is as low as possible. desirable. The surface temperature of the press roll is preferably 200 ° C. or higher. Two
This is because if the temperature is less than 00 ° C., the density of the nonwoven fabric decreases and the thickness increases when the water-absorbent resin composition containing an organic solvent is applied. When the temperature is 240 ° C. or higher, the nonwoven fabric shrinks and the strength also decreases. It is desirable that the linear pressure of the press is as high as possible from the viewpoint of thinning of the present invention.

As in the case of the compression type waterproof tape of (3), the water absorbent resin composition is applied and dried on the surface of an ordinary spunbond polyester non-woven fabric base material, and then subjected to high temperature and high pressure calender treatment to stop. A method of reducing the thickness of the water tape is also conceivable, but in this case, if the surface temperature of the roll is set to a high temperature, the water-absorbent resin layer will stick to the surface of the roll, so the high temperature cannot be used and the temperature will not stick Even if the water absorbent resin layer can be thinned at the roll surface temperature, the thickness of the non-woven fabric substrate can hardly be made thin, and as a result, the thickness of the water blocking tape does not become so thin.

The water-absorbent resin powder that can be used in the water-absorbent resin composition of the thin waterproof tape for cables of the present invention does not melt when it comes into contact with water, and has 10 to several tens of its own weight.
A synthetic polymer that has a 0-fold water absorption function and is not decomposed by microorganisms, and includes, for example, acrylate-based crosslinked products, vinyl acetate, saponified vinyl acrylate copolymers, polyvinyl alcohol / maleic anhydride reaction products, isobutylene /
There are cross-linked maleic acid copolymers, acrylate / acrylamide copolymers, polyethylene oxide modified products, and the like, and one kind or a mixture of two or more kinds may be used. From the viewpoint of water absorption capacity of seawater, a cross-linked product of isobutylene / maleic anhydride copolymer (KI gel manufactured by Kuraray Co., Ltd.), JP-A-61-
Sulfoalkyl acrylate described in Japanese Patent No. 36309
Acrylic acid copolymer cross-linked product (Aqualic CS type manufactured by Nippon Shokubai Co., Ltd.), JP-A-63-307613, JP-A-1-167306, JP-A-1-249808, and JP-A-2-155953. , JP 2-15
Various salt-resistant water-absorbent resin powders disclosed in JP-A-5954, JP-A-2-242809, etc. are desirable.

The synthetic resin binder that can be used in the water-absorbent resin composition of the thin waterproof tape for cables of the present invention is one in which the water-absorbent resin powder is adhered to the non-woven fabric substrate and is not decomposed by microorganisms. For example, acrylic copolymer resin,
Polyurethane resin, unsaturated polyester resin, ethylene copolymer resin, silicone resin, polyisobutylene, butyl rubber, acrylic rubber, ethylene / propylene rubber, SIS rubber, SBS rubber, etc. desirable.

The mixing ratio of the water-absorbent resin powder and the synthetic resin binder is 3 parts by weight of powder to 100 parts by weight of the binder.
Suitable is from 0 to 600 parts by weight. If it is less than 300 parts by weight, the water-stopping function cannot be exhibited, and if it exceeds 600 parts by weight, sufficient adhesion with the non-woven fabric material cannot be obtained, and the water-absorbent resin powder falls off from the side surface of the tape during cutting and during use and the surrounding area Because it contaminates.

It is desirable to add a surfactant to the water-absorbent resin composition of the thin waterproof tape for cables of the present invention. This is because the surfactant improves the water blocking function.
In addition, anti-aging agents, rust preventives, crosslinking agents, processing aids, etc. can be added.

The cover material optionally used in the thin waterproof tape for a cable of the present invention prevents blocking between tapes when the waterproof tape is left in a high humidity environment such as the rainy season to absorb moisture. When the molten polyethylene cover of the cable is extruded, it prevents the tape from sticking to the polyethylene slot rod due to heat, and there is an appropriate eye gap so as not to impede the water blocking function of the water blocking tape. It is not decomposed by microorganisms and must withstand the strength during processing. As the cover material, a low-density fabric made of synthetic fibers can be used. Polypropylene, nylon and polyester can be used as synthetic fibers, especially for the price,
From the viewpoint of strength, a long fiber nonwoven fabric having a basis weight of 5 to 20 g / m ² produced by the spunbond method or the melt blow method is advantageous. If it is less than 5 g / m ² , the strength during processing cannot be obtained, and 2
If it exceeds 0 g / m ^{2, the} gap between the eyes is too small and when water enters the cable, the water-absorbent resin powder absorbs and swells and falls into the groove of the slot rod to prevent the water-stopping function from being exerted. Is.

The water-absorbent resin composition composed of the water-absorbent resin powder and the synthetic resin binder used in the production of the thin waterproof tape for cables of the present invention is dissolved in an organic solvent because it is applied on a non-woven fabric substrate. It is prepared by dispersing. As the organic solvent, any solvent that does not dissolve the water-absorbent resin powder but can dissolve the synthetic resin binder can be used. For example, toluene, xylene, benzene, methyl ethyl ketone, acetone, methyl isobutylene, ethyl acetate, dioxane, tetrahydrofuran, cyclohexane, There is alcohol etc.

A water-absorbent resin composition comprising these water-absorbent resin powder, synthetic resin binder, organic solvent and various auxiliaries is adjusted to a paint by sufficiently stirring, dissolving and mixing them in a well-known dissolving and mixing machine. It The obtained coating material is applied and dried on a non-woven fabric substrate by a known coating method and then compressed between heating and pressure rolls, or in some cases, after the application, the coating material is stuck in a wet state and then dried ( It is wet-laminated) and then compressed between heating / pressurizing rolls, or after coating and drying, it is compressed between heating / pressurizing rolls together with the cover material (dry laminating).

When the cover material is adhered to the water-absorbent resin layer by heat at the time of compression, the dry laminating method is sufficient, but when the cover material is not adhered, the wet laminating method is advantageous. This is because, in the case of the wet laminating method, the cover material is attached to the water absorbent resin composition when the water absorbent resin composition is in a wet state, so that the cover material enters the synthetic resin binder of the water absorbent resin layer to enable adhesion.

The non-woven fabric substrate having the water absorbent resin layer is compressed by being passed between the heating and pressing rolls as described above. The surface temperature of the roll may be a temperature at which the water absorbent resin layer does not stick to the surface of the roll, but is generally 100 ° C. or lower.

The compression linear pressure between the heating and pressurizing rolls determines the thickness of the water-absorbent resin layer, but if it is too high, the initial water-absorption rate of the water-absorbent resin layer decreases and the water-stopping function is impaired. Must be moderate. The relationship between the degree of compression and the initial water absorption rate will be explained by the apparent density.

For example, the apparent density of the water absorbent resin layer applied and dried on the non-woven fabric substrate having the formulation shown in Example 1 is 0.
It is 36 g / m ² , and the time required to reach the water absorption height of 0.7 mm is 55 seconds. When this composite is compressed between heating and pressing rolls, the apparent density of the water absorbent resin layer increases.
On the other hand, the time required to reach the water absorption height of 0.7 mm becomes longer as the apparent density of the water absorbent resin layer increases. The relationship is as follows.

Apparent density (g / m ² ) of water-absorbent resin layer Time to 0.7 mm (second) 0.36 55 0.80 63 0.92 75 1.03 80 1.25 90 1.30 110 When the waterproof tape is wrapped around the optical fiber prevention cable, it must be able to stop the water within 10 m in a simulated L-type waterproof test in which seawater is run from the cable cross section described in the examples. In general, when five optical fiber ribbons are stored in the groove of a polyethylene slot rod, there is a gap of 0.5 mm between the groove and the tape, so the water-stop tape has a water absorption height of 0 even if there is a margin. The time to reach 0.7 mm must be within 90 seconds.
Note that 90 seconds is the time required for water to run 10 m through the gap of 0.5 mm. Due to this, the apparent density of the water absorbent resin layer must be 1.25 g / cm ³ or less.

The time required for the water absorption height to reach 0.7 mm is measured by the apparatus whose front sectional view is shown in FIG. In FIG. 3, 12 is a dial gauge (U-30J digital indicator manufactured by Sony Corporation), 13 is a polyamide circular top cover (weight 97 g) in which 60 small holes with a diameter of 1.5 mm are regularly distributed over the whole, 14 is a circular lower cup made of polyamide, 15 is tissue paper, 10
Is a water blocking tape sample. The measuring method is as follows.

A sample 10 having a diameter of 80 mm is taken from a water blocking tape and sandwiched between two pieces of tissue paper 15 having a diameter of 79 mm. This is put in the bottom of the circular lower cup 14 and the circular upper lid 13 is put on it. The dial cage 12 is set on the protruding portion at the center of the circular upper lid. Dial gauge 12
Zero adjustment is performed, and 50 ml of artificial seawater (Aquamarine manufactured by Yasu Chemical Co., Ltd.) having a water temperature of 20 ± 5 ° C. is poured all at once from the top of the circular top lid 13. Read the water absorption height as time passes after water injection. Examine the time when the water absorption height reaches 0.7 mm.

In the thin waterproof tape for a cable of the present invention, when water penetrates from the cross section of the cable while being wound around the cable, first, the water-absorbent resin layer of the tape absorbs the water and swells. , Filling the gap in the groove of the slot rod, and then the water-absorbent resin powder of the water-absorbent resin layer falls into the groove,
The running water is thickened and stopped within 10 m.

In that sense, if the amount of the water-absorbent resin powder in the water-absorbent resin layer is much larger than the amount of the synthetic resin binder, the water-absorbent resin layer is more likely to fall off, which is advantageous for the water-stopping function. However, in that case, when water invades from the jacket of the cable as in the T-type water stop test to be described later, the water-absorbent resin powder immediately enters the groove of the slot rod from the water-absorbent resin layer of the water-stop tape. It may fall into the same state as in the L-type water stoppage test, and water stoppage may not be possible within 1.5 m.

Such a problem can be solved by applying a water permeation preventive treatment to the polyester nonwoven fabric. The water permeation prevention treatment means impregnating or applying a water permeation preventive agent onto a non-woven fabric and drying it to prevent water from passing through in the thickness direction of the non-woven fabric.

As the water permeation preventive agent, an organic solvent solution of the above-mentioned synthetic resin binder or a mixture of two or more kinds thereof can be used, and a mixture of the above-mentioned water-absorbent resin powder can also be used. In order to improve the adhesion between the water absorbent resin layer and the water permeation preventive agent, it is advantageous to use a mixture of a synthetic resin binder and a water absorbent resin powder. In that case, 100 parts by weight of the synthetic resin binder is used for the water absorbent resin powder 0
~ 300 parts by weight are preferred. If it exceeds 300 parts by weight, the adhesiveness between the water permeation preventive agent and the non-woven fabric substrate will be poor, and the water-absorbent resin layer will peel off from the tape substrate when taping to the cable, causing serious trouble. Further, it is desirable to add isocyanates as an adhesion promoter to the water permeation preventive agent.

[0045]

Since the water-stop tape of the present invention uses the water-absorbent resin powder having the ability to absorb seawater, not only pure water and low ion water but also seawater can be stopped, and all materials are microbial. Since it is not decomposed, it does not generate harmful hydrogen gas in the optical fiber, and the polyester non-woven fabric base material with sufficient mechanical strength is used, and each layer is well adhered, and it is suitable for tension during processing and taping. Withstands and does not cause trouble. Further, since the non-woven fabric substrate and the water absorbent resin layer are compressed to a high apparent density, the thickness of the water blocking tape is about 1/3 thinner than that of the conventional tape. As a result, the waterproof tape of the present invention can have a longer length per pad winding than the conventional tape, improving the productivity of the cable, and
It reduces the amount of polyester jacket used, and further contributes to reducing the diameter and weight of the cable.

[0046]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The thin waterproof tape of the present invention will be described in detail below with reference to the drawings.

Example 1 FIG. 1 is a sectional view showing an example of the structure of the thin waterproof tape of the present invention. In the figure, 1 is a high-density polyester non-woven fabric that has been subjected to high-temperature press treatment to an apparent density of 0.5 g / cm ³ or more, 2 is a water permeation preventive layer, and 3 is a water-absorbent resin that has been compressed to an apparent density of 1.25 g / cm ³ or less. Layers 4, a water-absorbent resin powder, 5 a synthetic resin binder, and 6 a cover material.

A spunbonded polyester non-woven fabric having a basis weight of 40 g / m ² (ES-5040 manufactured by Asahi Kasei Kogyo Co., Ltd .: apparent density 0.25 g / cm ³ : thickness 0.16 mm) was placed between metal rolls having a roll surface temperature of 225 ° C. High-temperature press treatment with a linear pressure of 37 kg / cm was performed to obtain a high-density nonwoven fabric 1 shown in FIG. 1 having an apparent density of 0.57 g / cm ^{3 and a} thickness of 0.07 mm.

Next, 100 parts by weight of an acrylic copolymer resin (Chriscoat P1018A manufactured by Dainippon Ink and Chemicals, Inc.), 200 parts by weight of seawater absorbent resin powder (Aqualic CS type manufactured by Nippon Shokubai Co., Ltd.), and isocyanates 2 By weight, 100 parts by weight of toluene and 500 parts by weight of toluene were sufficiently mixed, dissolved and dispersed with a stirrer to obtain a water permeation preventive agent.

100 parts by weight of ethylene / propylene rubber, seawater water-absorbent resin powder (Nippon Catalyst Aqualic CS
Type) 500 parts by weight, antioxidant 3 parts by weight, surfactant 1 part by weight and toluene 800 parts by weight were sufficiently mixed, dissolved and dispersed by a stirrer to obtain a water absorbent resin composition liquid.

Next, a water permeation preventive agent liquid was dried on one surface of the high-density nonwoven fabric 1 by a floating method in an amount of 20 g / dry adhesion.
The coating was applied so as to have a surface area of m ² and dried in a drying oven at a temperature of 100 ° C. to obtain a water permeation preventive layer 2. Next, a seawater-absorbent resin composition liquid is dried and attached onto the water-permeable prevention layer 2 of the high-density nonwoven fabric subjected to the water-permeable prevention treatment by using a comma doctor.
Immediately after coating so as to have g / m ² , the cover material 6 (Syntex PK102 manufactured by Sunlex Industrial Co., Ltd .: basis weight 12 g /
m ² melt-blown polypropylene non-woven fabric) were stuck together and dried in a drying oven at 120 ° C. Furthermore, a linear pressure of 8 is applied between the metal roll with the surface temperature of 80 ℃ and the paper roll.
The composite was compressed at 0 kg / cm to obtain the thin waterproof tape for cables of the present invention. Tape weight is 155g / m
² , the thickness was 0.20 mm, and the apparent density of the water absorbent resin layer was 0.80 g / cm.

Comparative Example 1 Instead of the high density nonwoven fabric of Example 1, a conventional spunbond polyester nonwoven fabric having the same basis weight (E manufactured by Asahi Kasei Kogyo Co., Ltd.
S-5040) and subjected to the processing of Example 1,
A conventional waterproof tape for cables was obtained. The tape thickness was 0.28 mm.

Example 2 Example 1 was repeated. However, the cover material was not attached immediately after the application of the water-absorbent resin composition liquid, but was attached during the compression treatment after application and drying.

Example 3 Example 1 was repeated. However, the high-density nonwoven fabric was not subjected to transparent waterproofing treatment. The dry adhesion amount of the water absorbent resin composition liquid was 100 g / m ² . The weight of the tape was 155 g / m ² , the thickness was 0.21 mm, and the apparent density of the water absorbent resin layer was 0.85 g / cm ³ .

Example 4 Example 1 was repeated. However, the cover material was not used.

Example 5 Example 1 was repeated. However, the high density nonwoven fabric was not subjected to water permeation prevention treatment. Further, the water-absorbent resin composition liquid,
The water-absorbent resin powder was 350 parts by weight, and the others were unchanged. Furthermore, the dry adhesion amount of the water absorbent resin composition is 110.
It was set to g / m ² . The weight of the tape is 165 g / m ² , the thickness is 0.22 mm, and the apparent density of the water absorbent resin layer is 0.75 g.
/ Cm ³ .

The water blocking tapes for cables obtained in the above Examples 1 to 5 and Comparative Example 1 were subjected to the following tests.

1. Antibacterial test 4g of test piece, 4g of ammonium dihydrogen phosphate as a nutrient and 200g of the following soil extract in a 300cc Erlenmeyer flask.
Add cc, mix and seal tightly with a silicone stopper, store in the shade at 30 ° C, extract air in the Erlenmeyer flask by 1 cc periodically until 30 days later, analyze the generated gas with a gas chromatograph, and visually. Check the color and condition of the aqueous solution. As a blank test, a tissue paper which is decomposed by microorganisms is simultaneously tested as a test piece.

The soil extract is prepared as follows.

(1) Soil is collected from the waterside where there are leaves and the grass is growing.

(2) 500 g of soil is mixed with 2000 cc of pure water and stirred.

(3) After being left for 12 hours, the supernatant liquid is filtered, and 150 cc of pure water is added to 50 cc of the filtrate to obtain a soil extract.

2. Simulated L-type water stop test A simulated water stop test is conducted assuming that water will enter from the cross section of the cable.

An optical fiber ribbon (core width 1.1 mm) is inserted in the 5 grooves of a slot rod for a 100-core IF cable having a length of 11 m (number of grooves: 5 grooves / dimension of groove: width 1.6 mm: depth 2.5 mm). / Thickness 0.4mm) 5 pieces each, and a 35mm width waterproof tape is applied 5m with the coated surface facing inward.
Wrap with m wrap. Further, a polyester single-sided adhesive tape is double wound on the water blocking tape as a substitute for the polyethylene jacket to obtain a simulated optical fiber cable.

Next, a vinyl chloride tube is connected to one end of the simulated optical fiber cable and sealed at the connecting portion so that there is no water leakage. Place the simulated cable on a horizontal table and run artificial seawater from a height of 1 m through the tube. After maintaining the state for 24 hours, the simulated cable is disassembled and the running distance of the artificial seawater in each groove is measured. Report the longest running distance.

3. Simulated T-type water stop test A simulated water stop test is conducted assuming that water will infiltrate from the cable jacket.

5 fibers of the same optical fiber tape as in 2 are stored in 5 grooves of the slot rod for the 100-fiber IF cable having the length of 3 m, which is the same as 2 in the above, and the surface coated with the water blocking tape having a width of 35 mm is inward. Wrap with a 5mm wrap toward. Next, a polyester single-sided adhesive tape is doubly wound on the left and right, leaving about 30 mm of the central portion of the slot rod around which the water blocking tape is wound. Insert a 50 mm long transparent acrylic pipe into the central portion of the slot rod where the waterproof tape is exposed, and seal both ends of the pipe to prevent water leakage. Place this on a horizontal table, make a hole in the center of the upper part of the pipe, and connect it to a vinyl chloride tube hanging from a height of 1 m. The connection is sealed to prevent water leakage, and a simulated cable is obtained.

Next, artificial seawater is flowed through the tube from a height of 1 m. After maintaining that state for 24 hours, the simulated cable is disassembled and the running distance of the artificial seawater in each groove is measured. Measure the left and right sides of the center of the slot rod and report the longest running distance.

4. Adhesive force of cover material The adhesive force between the water absorbent resin layer of the water blocking tape and the cover material is measured.

30 mm wide and 300 m long from the waterproof tape
Take m test pieces. The test piece is attached using a double-sided adhesive tape of a metal plate having a width of 50 mm and a length of 320 mm with the non-coated surface facing the metal plate side. About 2 pieces of cover material from the test piece
Peel 00 mm and use a tensile tester to pull at a speed of 300
The cover material is pulled at mm / min and the 180 ° peel force is measured.

5. Transferability of Water-Absorbent Resin Layer It is examined whether the water-absorbent resin layer of the water blocking tape is transferred to the slot rod by the heat during extrusion of the polyethylene jacket.

A high density polyethylene sheet having a thickness of 1.5 mm is prepared and cut into a width of 60 mm and a length of 60 mm.

Width 60 mm, length 60 mm from water blocking tape
Collect the test piece of. Laminate the test piece with the coated surface facing the polyethylene sheet. This is 1 mm thick and 1 width
A glass plate having a length of 00 mm and a length of 100 mm is used as a test sample.

The test sample was placed in a hot air circulation type oven, the temperature of which was adjusted to 130 ± 3 ° C., and immediately placed on a glass plate.
A load of kg is placed and left for 10 minutes, the load is immediately removed, a test sample is taken out, a load of 500 g is placed, and the sample is allowed to cool to room temperature. After allowing to cool, the glass plate is removed, the test piece is slowly peeled from the polyethylene sheet, and the degree of migration of the water absorbent resin layer is visually inspected.

6. Tape length per roll of the pad Cut the waterproof tape with a slitter and wind it around a paper tube with an inner diameter of 52 mm: wall thickness of 7 mm (outer diameter of 66 mm). Find the length.

The above-mentioned test results of each water-stop tape are shown in Table 1.

[0077]

[Table 1]

[0078]

As described above, the thin waterproof tape for a cable of the present invention comprises a water-absorbent resin powder on at least one side of a high-pressure-pressed polyester nonwoven fabric having an apparent density of 0.5 g / cm ³ or more. It has a compressed water absorbent resin layer having an apparent density of 0.50 to 1.25 g / cm ^{3 made} of a synthetic resin binder, and at least one of the water absorbent resin layers is optionally covered with a cover material. The material is laminated by the wet laminating method in some cases, and the non-woven fabric is optionally subjected to water permeation treatment. Since it has strength and is 1/3 thin, the length per roll of the pad is long, and the amount of polyethylene jacket used can be reduced. As a result,
It contributes to the reduction in diameter and weight of cables, and its practical value is extremely large.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of an example of a thin waterproof tape for cables of the present invention.

FIG. 2 is a cross-sectional view showing an example of an optical fiber waterproof cable to which the thin waterproof tape for cables of the present invention is applied.

FIG. 3 is a front sectional view of a device for measuring the water absorption height of a water blocking tape.

[Explanation of symbols]

1 High Density Nonwoven Fabric 2 Water Permeation Prevention Layer 3 Water Absorbent Resin Layer 4 Water Absorbent Resin Powder 5 Synthetic Resin Binder 6 Cover Material 7 Tensile Body 8 Grooved Polyethylene Slot Rod 8a Groove 9 Optical Fiber Tape Core Wire 10 Water-Proof Tape 11 Polyethylene Jacket 12 Dial gauge 13 Circular polyamide upper lid 14 Circular polyamide lower cup 15 Tissue paper

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Shinji Koyanagi 1820 Harakami, Shingu-machi, Kasuya-gun, Fukuoka Prefecture Fukuoka Cross Industrial Co., Ltd. Shingu Factory

Claims (4)

[Claims] 1. A polyester non-woven fabric having an apparent density of 0.5 g / cm ³ or more, which has been subjected to a high temperature press treatment, on at least one surface thereof,
A compressed water-absorbent resin layer having an apparent density of 0.50 to 1.25 g / cm ^{3 comprising} a water-absorbent resin powder and a synthetic resin binder is provided, and a total thickness of 0.18 to 0.23 mm for cables is thin. Water tape. 2. A polyester non-woven fabric having an apparent density of 0.5 g / cm ³ or more, which has been subjected to a high temperature press treatment, on at least one surface thereof,
A compressed water-absorbent resin layer having an apparent density of 0.50 to 1.25 g / cm ^{3 comprising} a water-absorbent resin powder and a synthetic resin binder is provided, and at least one of the water-absorbent resin layers is covered with a cover material, And the total thickness is 0.18 to 0.23
Thin waterproof tape for mm cable. 3. A thin waterproof tape for a cable according to claim 1 or 2, wherein the polyester nonwoven fabric is subjected to a water permeation preventive treatment. 4. The thin waterproof tape for a cable according to claim 2, wherein the cover material is attached by a wet laminating method.