JPH085162B2 - Water-stopping material - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to a protective material for preventing leakage of water from a water pipe, a material for preventing leakage of water from civil engineering and construction work, or a material for preventing ingress of water such as power transmission pipes and submarine cables. The present invention relates to a water blocking taping material used as.

(Conventional technology) Conventionally, as a water stop material for water pipes, power transmission pipes, etc., rubber,
Waterproof materials such as bitumen and plastic were used. Such waterproof materials deteriorated over a long period of use, resulting in reduced elasticity and cracking. Therefore, in recent years, a water-stopping material that uses a water-swelling substance having a water-absorbing ability in place of these materials has been disclosed in, for example, JP-A-53-99.
It is proposed in Japanese Patent No. 611, Japanese Utility Model Laid-Open No. 61-67120, and the like. The water-swelling substance has a function of forming a water-blocking film by the progress of gelation when absorbing water and preventing further passage of water. The water-swellable substance can be used as it is in the form of a plate or a block, but in order to prevent water leakage of the water pipe or the like, a particulate water-swellable substance is supported on a nonwoven fabric and wound on the water pipe or the like. It is used as a tape so that it can be turned. However, in such tape-shaped waterproofing material, since the non-woven fabric has a low basis weight (200 g / m ² ), the particulate water-swelling substance is not reliably supported on the non-woven fabric, and the particulate water-swelling material does not swell when absorbing water. There is a problem that a continuous impermeable layer is not formed by the organic substance.

Japanese Utility Model Laid-Open No. 61-67120 discloses a waterproof sheet that utilizes the adhesive force of a particulate thermoplastic resin when a particulate water-swellable substance is carried on a substrate such as a nonwoven fabric. However, in the waterproof sheet, it is difficult to uniformly mix the particulate water-swellable substance and the particulate thermoplastic resin. If the particulate water-swellable substance and the thermoplastic resin are not uniformly mixed, a continuous water-impervious layer may not be formed during water absorption.

(Problems to be Solved by the Invention) The present invention is to solve the above-mentioned conventional problems, and an object thereof is to be able to reliably form a continuous water-impervious layer during water absorption,
It is to provide a water blocking taping material having an excellent water blocking effect.

(Means for Solving Problems) A water-stopping taping material of the present invention comprises a water-absorbent core material having a water-swellable fiber entangled in a particulate water-swellable polymer substance and a non-woven fabric, and a water-repellent fiber. It is coated with a flexible substrate, which achieves the above objectives.

(Example) As shown in FIG. 1 (a), the water blocking taping material of the present invention has a water absorbent core material 10 sandwiched between fibrous base layers 20 and 20.

The water-absorbent core material 10 is a water-swellable fiber entwined with a non-woven fabric.
Between the particles 12, the particulate water-swellable polymer substance 11 adheres in layers. The particulate water-swellable polymer substance 11 undergoes gelation due to water absorption. On the other hand, the water-swellable fiber 12 expands in volume by absorbing water. Water absorbent core material in which these are intertwined with each other
The reference numeral 10 indicates that the water-swellable fibers 12 are volume-expanded by absorbing water, so that the particulate water-swellable polymer substances 11 attached to the water-swellable fibers 12 come close to each other, and the particulate water The swelling polymer substance 11 itself absorbs water and progresses gelation to form a continuous water-impervious layer.

The fiber base 20 holds the water absorbent core material 10 and imparts strength as a taping material.

The water blocking taping material having such a configuration is, for example, the first
As shown in the figure (b), the particulate water-swellable polymer substance 11 is arranged in layers on both sides of the layered water-swellable fiber 12, and each layer of the particulate water-swellable polymer substance 11 is Each of the layers of the fiber base 20 is provided on the surface, and is heated and pressure-bonded to form a sheet.

As the particulate water-swellable polymer substance 11, a substance having a large water absorption capacity and a high water supply rate is preferable in order to obtain a quick water-stopping effect. As the water absorption capacity, the water absorption capacity in fresh water is 50 times or more, preferably 200 times or more, the water absorption capacity in seawater is 5 times or more, preferably 10 times or more, and the water absorption time of 1/2 of the equilibrium water absorption is It is preferable that the water absorption rate is 30 seconds or less. The particle size of the particulate water-swellable polymer substance is usually 20 to 800 µ, and particularly preferably 500 µ or less from the viewpoint of water absorption capacity.

Examples of the particulate water-swellable polymer substance 11 include crosslinked polyvinyl alcohol, crosslinked acrylic acid or methacrylic acid hydroxyalkyl ester polymer, crosslinked polyvinylpyrrolidone, high sodium bentonite, and formalized polyvinyl alcohol. Among them, a crosslinked acrylic acid or methacrylic acid hydroxyalkyl ester polymer is particularly preferable.

The water-swellable fiber 12 may have a high water-absorption property capable of forming a continuous water-impervious layer together with the particulate water-swellable polymer substance by volume expansion when absorbing water. Is 5 times or more, preferably 10 times or more per fiber diameter. The water-swellable fiber 12 is not limited in its fineness, cross-sectional shape, fiber length and the like.

In the above-mentioned embodiment, the water-absorbent core material 10 is manufactured by pressing the particulate water-swellable polymer substance 11 and the water-swellable fiber 12 together with the fibrous base material 20 while heating them. The water absorbent core material 10 may be manufactured by previously impregnating the web of the functional fibers 12 with the particulate water-swellable polymer substance. In this case, the water-swellable fiber 12 is made sure so that the particulate water-swellable polymer substance 11 can be securely retained.
It is preferable to attach a binder resin to. Also,
For the same purpose, a heat-welding type fiber, so-called hot-melt type fiber, may be appropriately mixed in the water-swellable fiber 12.

The fiber base 20 holding the water-absorbent core 10 is made of a material having a small water-absorbing ability. If a material having a large water absorption capacity is used as the fiber base 20, moisture will flow through the fiber base 20, and a sufficient water blocking effect cannot be obtained as a water blocking taping material. As the fiber base 20, a polyester fiber, a polypropylene fiber, a polyamide fiber, or the like in a web shape, or a web shape obtained by subjecting these fibers to a waterproof treatment or a water repellent treatment is used. In this case, the fineness, sectional shape, and fiber length of each fiber are not limited at all.
In order to improve the adhesiveness between the fibrous base material 20 and the water absorbent core material 10, a fibrous base material 20 in which a hot-melt type fiber (hot melt fiber) is appropriately mixed with the above fiber may be used.

In order to prevent the water absorbing ability of the water absorbent core material 10 from decreasing when not in use and to ensure the water stopping effect in such a water stopping taping material, as shown in FIG. The waterproof layer 30 may be provided on the surface of the base body 20.
As the waterproof layer 30, a plastic film having excellent water resistance such as vinyl chloride resin, polyethylene resin, polypropylene resin, polyester resin is used. The waterproof layer 30 made of such a plastic film is bonded to the fiber base 20 with a water resistant adhesive 40 such as a hot melt resin or a water resistant binder.

Water-stopping taping material with such a configuration may be wound around power transmission pipes, seabed tables, water pipes that may leak due to aging, or leaks during civil engineering and construction work. It is used by being attached to a place with. Then, when water infiltration or leakage occurs, water reaches the water absorbent core material 10 through the fiber base material 20. Moisture that has reached the water absorbent core material 10 is
Is absorbed by the particulate water-swellable polymer substance 11 and the water-swellable fiber. The particulate water-swellable polymer substance 11 is gelated by water absorption, and the water-swellable fiber 12 is expanded in volume by water absorption. And a gelled particulate water-swellable polymeric substance
A continuous water-impervious layer is formed by 11 and the volume-expanded water-swellable fiber 12. When the impermeable layer is formed, water does not pass through the impermeable layer and is stopped by the impermeable layer.

Experimental Example 1 Particulate water-swellable polymeric material: Aquakeep 10SH
(Particle size, 200μ, manufactured by Steel Manufacturing Co., Ltd.), basis weight 30g / m ² water-swellable fiber ・ ・ ・ Lanseal F (2.8 ^d × 38 ^mm , manufactured by Nippon Exlan Industrial Co., Ltd.), basis weight 30g / m ² , web-shaped fiber Substrate: Water repellent polyester fiber (2 ^d ×
51 ^mm ) 65%, hot melt fiber (3 ^d × 51 ^mm , Unitika Melty) 35%, basis weight 20 g / m ² , web shape These are arranged as shown in Fig. 1 (b). , 135 ℃
While being heated at 30 ° C., pressure bonding was carried out for 30 seconds to obtain a water blocking taping material of the present invention shown in FIG. From the waterproof taping material
Ten 5 cm square test pieces were sampled, the thickness was measured with a peacock dial thickness gauge, and the average value was obtained. Next, the water repellency and hydrophilicity of the fibrous substrate surface were evaluated. The water repellency was evaluated by taking a 10 cm square test piece from the water blocking taping material obtained as described above, and applying a solution of 50% isopropyl alcohol and 50% water to the surface of the test piece with a height of 1 cm. Then, after dropping, the water-repellent property was evaluated if the surface did not leak for 5 minutes or more after dropping. The hydrophilicity evaluation method is
Water was dropped onto the surface of the test piece from a height of 1 cm and the surface was wet within 30 seconds was evaluated as hydrophilic.

Also, 10 test pieces with a width of 1 cm and a length of 10 cm were sampled from the water taping material, and the tensile strength in the longitudinal direction of each test piece was measured with a Tensilon type tester, and the average value was obtained.

Furthermore, the water stopping property was measured by the test apparatus shown in FIG. The test apparatus is a tank 51 in which fresh water (ion-exchanged water) or artificial seawater is stored, and a flow pipe 52 is attached to the bottom surface of the tank 51. The flow pipe 52 and the bottom surface of the tank 51 extend downward substantially vertically and then are bent at a substantially right angle. The flow pipe 52
Has an inner diameter of 1 cm, one end communicates with the inside of the tank 51, and the other end is open. Then, a water blocking taping material is attached to this open end. An on-off valve 53 is arranged near the bent portion of the flow pipe 52. The bent portion of the flow pipe 52 has a length of 10 cm from the surface of the fresh water or seawater stored in the tank 51 to the bent portion of the flow pipe 52.
Located below.

The open end of the flow pipe 52 is, as shown in FIG.
A flange portion 52a is formed, and the flange portion 52a has
Test pieces 1, 1, 1 having a width of 5 cm, which are sandwiched between packings 54 and 54 made of silicon, are stacked in three layers and arranged so as to cover the open end surface of the flow pipe 52.

The test piece arranged in this way was placed in the fresh water (ion-exchanged water) and artificial seawater (sodium chloride 3.4
% Solution) was added dropwise, and the water-stopping property of the test piece was evaluated in 5 grades for fresh water and seawater according to the number of days during which the middle layer of the test piece, which was layered in 3 layers, leaked. The evaluation criteria were 1, 3 days or more, 2 or 7 days or more, 3 or 20 days or more, 4 or 1 month or more, 5 when the number of days that the middle class did not leak was within 1 day.

The water stop rating of fresh water was 5, and the water stop rating of seawater was 4. The respective results are shown in Table 1.

Experimental Example 2 A polyethylene film (100 μm thick) as a waterproof layer was attached to one surface of the fiber substrate of the water blocking taping material obtained in Experimental Example 1 with a water resistant adhesive to form a water blocking taping material. Obtained. The waterproof taping material was subjected to the same test as in Experimental Example 1. The water-stopping evaluations of fresh water and seawater were both 5. The test results are also shown in Table 1.

Comparative Example 1 Only the water-swellable fiber used in Experimental Example 1 was formed into a tape to prepare a water blocking taping material. The waterproof taping material was subjected to the same test as in Experimental Example 1. The water-stopping evaluations of fresh water and seawater were both 1. The test results are also shown in Table 1. The test results in Comparative Examples 2 to 5 below are also shown in Table 1.

Comparative Example 2 A particulate thermoplastic resin (low melting point polyethylene powder, MP120) was added to the particulate water-swellable polymer substance used in Experimental Example 1.
℃, 15 g / m ^{2 of} basis weight is uniformly dispersed, and this dispersion layer is used for polyester fiber web (2 ^d × 51 ^mm , basis weight 2
It was clamped at 0 g / m ² ) to obtain a waterproof taping material. The waterproof taping material was subjected to the same test as in Experimental Example 1. The water-stopping evaluation was 3 for fresh water and 2 for seawater.

Comparative Example 3 Water absorbent polyester fiber web (2 ^d x 51 ^mm ,
A polyethylene film (thickness 10) with a basis weight of 20 g / m ² )
0 μ) was attached with a water-resistant adhesive to make a waterproof taping material. This was subjected to the same test as in Experimental Example 1. The water-stopping evaluation was 3 for fresh water and 4 for seawater.

Comparative Example 4 Water absorbing core material of the water blocking taping material used in Experimental Example 2
No. 10 did not use the particulate water-swellable polymer substance but used only the water-swellable fiber. Others were the same as the waterproof taping material of Experimental Example 2, and the same test as in Experimental Example 1 was performed. The waterproofness was 4 for fresh water and 3 for seawater.

Comparative Example 5 In the water-proof taping material used in Experimental Example 2, a fibrous substrate was prepared from a mixture of water-repellent polyester fiber and hot melt fiber, and a hydrophilic rayon fiber web (1 ^d x 51 ^mm , basis weight 20 g / weight). m ² ). Others were the same as the water blocking taping material of Experimental Example 2, and the same experiment as in Experimental Example 1 was performed. The waterproofness was 4 for fresh water and 3 for seawater.

(Effects of the Invention) Since the water-stopping taping material of the present invention uses the particulate water-swellable polymer substance and the water-swellable fiber as the water-absorbent core material as described above, A layer is formed and a thin-walled taping material with excellent water-stopping effect is obtained.
The water-stopping taping material is
If the power transmission pipe is flooded, it can be dealt with promptly. In a submarine cable or the like used under high water pressure, a desired water blocking effect can be obtained by winding the water blocking taping material in multiple layers.

[Brief description of drawings]

FIG. 1 (a) is a cross-sectional view showing an example of the water blocking taping material of the present invention, (b) is a cross-sectional view for explaining the manufacturing method thereof, and FIG.
FIG. 3 is a sectional view of a water blocking taping material according to another embodiment of the present invention, FIG. 3 is a schematic view of an apparatus used for a water blocking test of the water blocking taping material, and FIG. Is. 10 …… Water-absorbent core material, 11 …… Particulate water-swellable polymer, 12
…… Water-swellable fiber, 20 …… Fiber substrate, 30 …… Waterproof layer.

Claims (4)

[Claims] 1. A water-stopping taping material obtained by coating a water-absorbent core material having a water-swellable fiber entangled in a particulate water-swellable polymer substance and a non-woven fabric with a fibrous substrate having water repellency. 2. The water blocking taping material according to claim 1, wherein a waterproof layer is provided on one surface of the fibrous substrate. 3. The water-stop taping according to claim 1, wherein the particulate water-swellable polymer substance has a water absorption capacity of 50 times or more in fresh water and a water absorption capacity of 5 times or more in seawater. Material. 4. The water-stopping taping material according to claim 1, wherein the water-swellable fiber is capable of expanding in volume five times or more per fiber diameter when absorbing water.