JPH08215657A - Impermeable sheet and detection method - Google Patents

Abstract

(57) [Summary] [Object] An object of the present invention is a water-shielding sheet and a detection method capable of easily detecting breakage and leakage of the sheet during storage, construction, use, etc. of the sheet. To provide. [Structure] Resin is coated on both sides of a reinforcing fiber cloth in which a conductive fibrous material having an electrical resistivity of 2 × 10 ⁻⁷ Ω / m or less is woven.
A water-shielding sheet that has been attached, characterized in that a terminal for checking the continuity of the conductive fiber is provided, and the water-shielding sheet is checked by checking the continuity of the conductive fiber. Method of detecting breakage or water leakage.

Description

Detailed Description of the Invention

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water shield sheet and a method for detecting breakage or water leakage of the water shield sheet. In particular, the present invention relates to a water impervious sheet used for preventing groundwater contamination by contaminated water mixed with harmful liquid, rainwater, etc. leached from industrial waste and industrial waste such as waste disposal sites.

[0002]

2. Description of the Related Art Conventionally, when waste (general waste, industrial waste) is landfilled in a waste disposal site, it is necessary to prevent pollutants from leaching from the waste and contaminating underground soil and groundwater. The water barrier is applied. As the water impermeable sheet, a resin sheet made of a high polymer such as soft polyvinyl chloride, super soft polyvinyl chloride, butyl rubber, epichlorohydrin rubber, ethylene propylene diene monomer rubber, neoprene, high density polyethylene and chlorinated polyethylene is used. -G is mainly used. However,
Since the water-blocking sheet made of a resin sheet has a problem that it is likely to leak due to tears, a water-blocking sheet reinforced with a fiber cloth is proposed in JP-A-6-294075. Has been done. The water-impervious sheet reinforced with a fiber cloth can obtain an excellent tensile strength without increasing the thickness so much, so that water leakage can be effectively prevented.

However, even in a water-impervious sheet reinforced with a cloth, accidents (tears, breakages, etc.) due to overload may still occur, so it is necessary to be careful in management construction and efficient. Construction management could not be performed. From the above,
Japanese Unexamined Patent Publication No. 1-127715 proposes a method in which a conductive fiber having an electric resistance of 1 Ω to 1000 kΩ / m is arranged in a sheet and the electric resistance value is observed to detect breakage of the sheet. This method measures the load weight by utilizing the fact that when the load weight increases, the conductive fibers are stretched, the fiber cross-sectional area decreases, and the electrical resistance value increases.

[0004]

According to the above method, although the construction controllability can be improved to some extent, it is necessary to examine the relationship between electric resistance and stress in advance.
Further, if the use condition is different, an error is likely to occur in the detected stress, and there is a problem that it is difficult to detect the breakage of the waterproof sheet during use. In view of the above, the present invention provides a water shield sheet and a detection method capable of easily detecting breakage and water leakage of the seat during storage, construction, use, etc. of the water shield sheet. is there.

[0005]

The present invention has an electrical resistivity of 2
A terminal for checking the continuity of a conductive fibrous material, which is a waterproof sheet with resin coated on both sides of a reinforcing fiber cloth woven with a conductive fibrous material of × 10 ^-7 Ω · m or less. The present invention provides a method for detecting breakage or water leakage of a waterproof sheet by checking the continuity of the waterproof sheet and the conductive fibrous material.

The electrically conductive fibrous material used in the present invention has an electric resistivity of 2 × 10 ⁻⁷ Ω · m or less, preferably an electric resistivity of 2 or less.
× 10 ⁻⁸ Ω · m or less. If the electrical resistivity is high,
It is difficult for electricity to flow and it is difficult to confirm continuity. The electrical resistivity referred to in the present invention refers to the electrical resistivity at 20 ° C. As a preferable substance constituting the conductive fibrous material, gold, silver, copper, aluminum, nickel, iron, brass,
Metals such as tungsten, zinc, tin or copper and silver (3-5
Alloys such as copper and chromium (0.8 wt%), copper and zirconium (0.1 to 0.2 wt%).
Since the conductivity decreases due to impurities in the metal, it is preferable that the content of impurities be as low as possible. Examples of the conductive fibrous material include a continuous fibrous material composed of a single wire or a double wire of a metal or the like, a metal foil obtained by laminating a synthetic polymer and the metal, or a metal-deposited film in a fibrous shape. Such a fibrous material has a thickness of 5 μm or more (JIS-C-
3012), and 0.1 mmG or more.

Even if the reinforcing fibers are cut by some stress, the breaking elongation of the resin sheet is as high as 100 to 1000%, so that the water-impervious effect is not impaired. Therefore, for the purpose of detecting water leakage, it is necessary to detect an abnormality of the water-blocking sheet when the resin sheet is broken, not when the reinforcing fiber is broken. From the above, it is preferable that the breaking elongation of the conductive fiber is larger than that of the reinforcing fibers other than the conductive fiber and smaller than the breaking elongation of the resin sheet constituting the waterproof sheet. Also,
When the resin sheet is damaged or cracked, water penetrates into the fabric layer and the conductive fibers corrode and break the wire, losing electrical continuity and detecting an abnormality in the water-blocking sheet. can do.
The proportion of the conductive fibers mixed with the reinforcing fibers is preferably 30% or less (total reduced cross-sectional area) from the viewpoint that the weaving and knitting properties are not deteriorated and the conductivity is not mistakenly detected.

Further, the conductive fibers are preferably arranged in the cloth at intervals of 0.5 to 4 m, and when the cloth is a woven fabric, it is preferable to mix them as warp yarns. Although the conductivity can be checked by providing terminals at both ends of the conductive fiber, it is preferable to provide a plurality of terminals as shown in FIG. That is, if a plurality of terminals are formed, the damaged portion can be limited, so that the sheet can be easily repaired.

As reinforcing fibers other than the conductive fibrous material,
Although any fibers such as synthetic fibers and natural fibers can be used, synthetic fibers are preferable from the viewpoint of strength. Specifically, nylon 6, nylon 66, polyamide fibers such as aromatic aramid fibers, polyethylene terephthalate,
Polybutylene terephthalate, polyester fibers such as molten liquid crystalline polyester, polyvinyl alcohol fibers, polyvinylidene chloride fibers, polyvinyl chloride fibers, polyacrylonitrile fibers, polyolefin fibers, polypropylene fibers. However, rayon, polynosic fiber and the like can also be used.

Either spun yarn or filament yarn may be used, but from the viewpoint of strength, it is preferable to use filament yarn, particularly multifilament having single fiber 1 to 30 dr and yarn denier 120 to 2400 dr. Strength 5
Those having a rupture elongation of 25% or less and -30 g / dr are particularly preferable.

As the reinforcing fiber cloth used in the present invention, any cloth such as a woven fabric, a warp insertion Russell, a knitted fabric, a long fiber non-woven fabric, a short fiber non-woven fabric, and a multiaxial scrim can be used. Preferably JIS-L-1096 (3 cm width)
Tensile strength is measured according to
A cloth having a tensile strength of 0 m or more is used. JIS-L
Even in the case of conforming to -1908 (5 cm width), those having such tensile strength are more preferable. The tensile strength can be set according to the type, form, number of fibers, density, etc. of the fiber. The fabric used in the present invention is required to have a high strength because it needs to bear the stress due to the top load and the subsidence, but from the economical point of view, if the safety is satisfied, the strength is more than necessary. No need to raise. For example, on the slope of a general disposal site, 150kg / 3cm
As described above, it is estimated that the bottom surface portion may be 50 kg / 3 cm or more.

The tensile elongation at break is preferably 30% or less. If the elongation exceeds 30%, the elongation becomes large, and the stress load is small due to the relationship between the overburden load and the elongation due to ground subsidence, which is not preferable in terms of reinforcement. The thickness of the cloth is preferably 0.5 mm or less from the viewpoint of resin coatability. If it exceeds 0.5 mm, the resin impregnating property is deteriorated, and the resin and the fabric are easily peeled off, which is not preferable.

The polymer used for the resin sheet is not particularly limited. For example, soft polyvinyl chloride, ultra soft vinyl chloride, butyl rubber, epichlorohydrin rubber, ethylene propylene diene monomer rubber, neoprene, high density polyethylene, low density polyethylene, chlorinated polyethylene, chlorosulfonated polyethylene, ethylene vinyl acetate copolymer, Polyurethane or the like can be used. Further, these polymers may contain compounding agents such as an antioxidant, an ultraviolet absorber and a pigment (carbon black etc.). The coating method of these resins and the cloth is not particularly limited as long as the cloth is impregnated with the resin and the waterproof resin layer is formed on the surface of the cloth. A water-dispersed emulsion, a solvent-soluble polymer, a heat-fusible polymer or the like may be appropriately selected and applied.

For example, an aqueous dispersion emulsion in which intramolecular crosslinking does not occur or a solvent-soluble polymer (polyvinyl chloride, chlorinated polyethylene, chlorosulfonated polyethylene,
(Ethylene-vinyl acetate copolymer, polyurethane, etc.) is a general knife coater, knife over coater, or rotor.
It is possible to employ a method of coating while controlling the coating thickness using a lucotor, a dip coater or the like. In addition, heat-fusible polymers (polyvinyl chloride, butyl rubber, epicrylhydrin rubber, ethylene propylene diene monomer rubber, neoprene, high density polyethylene, low density polyethylene, chlorinated polyethylene, chlorosulfonated polyethylene, ethylene vinyl acetate copolymer In the case of united, polyurethane, high bra, etc., extrusion coating
A so-called topping process for wrapping a laminate or a calendar film can be performed. Alternatively, a film sheet made of a heat-fusible polymer prepared in advance may be applied to both sides or one side of the cloth to impregnate and bond it to the cloth with hot air, a heat roll, an adhesive or embossing.

The thickness of the resin layer is about 0.2 to 1.0 mm in total from the viewpoint of water impermeability, and the total thickness of the water impervious sheet is
It is preferably about 0.3 to 5 mm. Further, if the fibers are exposed on both end faces of the sheet, water permeates and the conductive fibers are deteriorated. Therefore, it is preferable to coat both end faces with a resin. The surface of the sheet on the side that is in direct contact with wastes is preferably smooth so that the coefficient of friction is small.
The waterproof sheet of the present invention may be used as a single sheet, or may be used by laminating a plurality of sheets. In the case of stacking, it is preferable to completely shut out the leakage of water from the bonded portions of the water-blocking sheets, and it is preferable to heat-bond the overlapping portions in a double or triple bond with an adhesive or the like. .

The water permeability of the water impervious sheet of the present invention is described in J.
P. Estimated several decades later by WORKMAN et al., 1 × 10
^-7 cm / sec. The following is preferable. As a preferred method for detecting water leakage, conductive fibers are woven as warp threads as shown in FIG.
Provide terminals for checking conductors at both ends of other terminals. Then, weaving of cloth, polymer coating, etc., carrying in a water-impervious sheet, laying, adhering sheets such as welding, adhering to a connecting portion with a gas vent pipe, ceiling end During the construction such as fixing to a small or small stage, carrying in and out of the garbage truck,
If the items to be disposed of such as dust are full and the top is covered with earth and sand, the ground is stable and waiting for the next use -It is possible to easily detect abnormalities (breakage etc.) and water leakage.

Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited thereto.

【Example】

[Thickness of cloth] It was measured according to JIS-L-1096.

[Example 1] Conductive fiber (copper wire, thickness 50)
μ x 7, single wire tensile strength 25 kg / mm ² , breaking elongation 3
8%, 20 ° C. electrical resistivity 1.7 × 10 ⁻⁸ Ω · m fiber made of polyester filament (Kuraray KS-233)
1200d / 192f, tensile strength 8.1g / d, elongation at break 17%, 120T / m twisted according to 120T / m are arranged at intervals of 0.5m. For other warp and weft Using the above polyester yarn, width 1.
Woven cloth of 8 m x 50 cm in length was woven (weaving density was 7 /
m). The fabric has a thickness of 0.3 mm, a tensile strength of 3 cm and a breaking elongation of 210 kg and 200 in the warp and weft directions, respectively.
kg, 18% and 19%. The dry heat shrinkage ratio (test length 15 cm) in the longitudinal direction after 10 minutes at 200 ° C. was as low as 0.1%, and polymer coating at about 230 ° C. had no particular problem.

Next, a high density polyethylene chip containing 2% of carbon black was placed in an extruder and discharged at 230 ° C. from a die attached to the tip in order to enhance the absorption of ultraviolet rays. After cooling, it was wound up. Next, one side was extruded while heating to 230 ° C., laminating, and then passed through a roll calender to produce a fiber-reinforced water impervious sheet (thickness 1.55 mm, water permeability 0.9+).
10 ^-12 cm / s, tensile strength history 190 kg / s
3 cm, 180 kg / 3 cm). A terminal was attached to the end of the conductive fiber, and the conductivity of the fiber-reinforced water impervious sheet was confirmed by a tester check, but there was no problem. When conducting a tensile test of the sample contained in the conductive fiber, the broken state of the reinforcing fiber was observed while checking the continuity of the Tsumago and copper wires. Polyester fiber cut at an elongation of 21-28%, copper wire has an elongation of 3
It breaks at 2-40% and finally the polymer sheet part is 400
It was torn off at ~ 700%.

Example 2 The conductive fiber used in Example 1 was a vinylon fiber (T-5501 manufactured by Kuraray Co., Ltd.).
1800d / 1000f, tensile strength 13.5g / d, breaking elongation 6%, 120T / m twisted according to 120T / m are arranged at intervals of 0.5m, and for other warp and weft Using the above polyester yarn, width 1.
Woven cloth of 8 m x 50 cm in length was woven (weaving density was 7 /
m). The fabric has a thickness of 0.5 mm and a tensile strength of 3 cm and a breaking elongation of 350 kg and 320 in the warp and weft directions, respectively.
kg, 8% and 9%. The cloth was polymer-coated in the same manner as in Example 1 to give a thickness of 1.50 m.
m, water permeability of 0.9 + 10 ⁻¹² cm / s, tensile strength and history of 330 kg / 3 cm and 300 kg / 3 cm, respectively. A terminal was attached to the end of the conductive fiber and the conductivity was confirmed by a tester check, but there was no problem. As in Example 1, the breakage of the water-proof sheet was observed. As for the breaking, the vinylon fiber was cut at an elongation of 8 to 11%, the copper wire was cut at an elongation of 32 to 40%, and finally the polymer portion was torn off at an elongation of 400 to 700%.

[0021]

According to the present invention, during storage of the water-blocking sheet,
It is possible to provide a water-shielding sheet and a detection method capable of easily detecting breakage and water leakage of a sheet during construction, use, and the like.

[Brief description of drawings]

FIG. 1 is a developed view showing an example of a water-blocking sheet according to the present invention.

FIG. 2 is a diagram showing a specific example of the water-blocking sheet and the laying method of the present invention.

Claims (2)

[Claims] 1. A water-impervious sheet comprising a reinforcing fiber cloth mixed with a conductive fibrous material having an electric resistivity of 2 × 10 ⁻⁷ Ω · m or less and coated with resin on both sides, which is electrically conductive. A waterproof sheet having a terminal for checking the continuity of the conductive fiber. 2. A water impervious sheet in which a resin is coated on both sides of a reinforcing fiber cloth mixed with a conductive fibrous material having an electric resistivity of 2 × 10 ⁻⁷ Ω · m or less, the conductive fiber A method of detecting breakage or water leakage of the impermeable sheet by checking the continuity of the. [0001]