JPH11320728A - Water barrier sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve chemical resistance, weather resistance, mechanical physical properties and further executability by covering at least one side surface of a cloth sheet formed of synthetic resin fibers with a polyethylene resin. SOLUTION: The water barrier sheet comprises a cloth sheet formed of synthetic fibers having a strength of 6 g/d or more, and a resin film sheet made of a polyethylene sheet covered on at least one side surface of the cloth sheet. The film sheet has a tensile strength of 100 kgf/3 cm or more, an elongation at the time of a maximum load of 45% or less, a thickness of 1 mm or more, and a tensile strength holding rate after it is treated by illuminating by an exposure unit for 250 hrs at 63 deg.C or lower of 60% or more, thereby providing excellent chemical resistance, weather resistance, and mechanical characteristics, and low repairing work cost.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a seepage control sheet used for a final waste disposal site (general waste disposal site, industrial waste disposal site, etc.) or a roofing material.

[0002]

2. Description of the Related Art In a landfill for waste, the rain that falls on the pit penetrates and passes through the waste and becomes leachate.
Conventionally, it has been stipulated that a seepage control sheet be laid in the pit in order to prevent seepage water from leaking into the ground.

[0003] Incidentally, the leachate must be quickly discharged from the pit without being permeated into the ground by the impermeable sheet, and must be guided to a water treatment facility for treatment. For this reason, in recent years, measures have been taken to develop a material for the water-impervious sheet and to make it a double structure.

[0004] However, if heavy equipment comes and goes or falls during the construction of the final disposal site pit, or if the impermeable sheet is damaged due to the impact of dumping waste, etc., leachate will be generated from the damaged portion. It is conceivable that it may flow out.

[0005] Incidentally, a rubber-based, vinyl chloride-based or polyethylene-based film is used as a conventional water-impervious sheet, but this film sheet has low mechanical strength.
It does not have sufficient resistance to the above-mentioned factors which are considered to be the causes of breakage of the impermeable sheet.

In general, the roof of a high-rise house such as a condominium is waterproofed in order to prevent leaching of rainwater or the like. However, in recent years, rain containing harmful substances such as acid rain has fallen in urban areas, and it is necessary to process the waterproofing itself so that it does not have chemical resistance, high weather resistance, or damage by traffic. . For this processing, a method of directly coating concrete with polyurethane, synthetic rubber, or the like is employed.

[0007]

However, coatings such as polyurethane and synthetic rubber are concerned with chemical resistance, high weather resistance and mechanical properties, and also require a large amount of cost for repair work. .

Therefore, an object of the present invention is to provide a water-blocking sheet that can solve the above-mentioned problems.

[0009]

The object of the present invention is to provide a cloth sheet composed of synthetic fibers having a strength of 6 g / d or more, and a resin coating made of a polyethylene resin coated on at least one surface of the cloth sheet. This resin-coated sheet has a tensile strength of 100 kgf /
3cm or more, elongation under maximum load of 45% or less, thickness 1mm
As described above, the tensile strength retention after irradiation for 250 hours at 63 ° C. by the SW type accelerated exposure apparatus is set to 60% or more.

As described above, a cloth sheet composed of synthetic fibers having a strength of 6 g / d or more is coated on at least one side with a polyethylene resin, and the tensile force of the polyethylene resin is 100 kgf / 3 cm or more, and the maximum load is When the elongation is 4
A water-blocking sheet having a tensile strength retention of 5% or less, a thickness of 1 mm or more, and a tensile strength retention of 60% or more after irradiation at 63 ° C. for 250 hours with a WS-type accelerated exposure apparatus is 60% or more. Excellent physical properties, and excellent workability.

[0011]

Embodiments of the present invention will be described below. The impermeable sheet according to the embodiment of the present invention is to be laid in a pit for waste input in a general waste disposal site or an industrial waste disposal site, and a cloth sheet and a coating resin covering the cloth sheet. It is composed of

The cloth sheet is made of synthetic fibers having a strength of 6 to 20 g / d or more. If the strength is less than 6 g / d, the mechanical properties required for the application are insufficient, and the yarns adhere to each other when forming the fabric sheet, and the sufficient adhesive force with the coating resin cannot be obtained. Because. More preferably, the single yarn fiber is 1d or more, and if it is less than 1d, the surface area of the fiber itself becomes large, so that the durability such as the chemical resistance as a final disposal site or a roofing material and the high weather resistance are inferior. is there.

The synthetic fibers can be appropriately selected according to the application, and examples thereof include polyvinyl alcohol fibers, polyamide fibers, polyester fibers, polyvinyl chloride fibers, acrylic fibers, and polyolefin fibers. . Since it is assumed that the leachate generated by passing the wastewater into the waste input pit will contain alkaline components, it is more preferable to use alkali-resistant when used in the final disposal site. Polyamide fibers are preferable, and polyester fibers are preferable as the roofing material in consideration of dimensional stability and the like.

The coating resin must be a polyethylene resin in consideration of chemical resistance, weather resistance and mechanical properties. As the polyethylene resin, any of high density, medium density, low density and ultra-low density may be used, and in consideration of workability and the like, it is desirable to use a low-density resin from the viewpoint of flexibility and mechanical properties.

In order to impart rubber elasticity, an unsaturated hydrocarbon rubber material may be added as a third component.
In consideration of weather resistance and mechanical properties, a pigment such as an ultraviolet absorber or carbon black may be added to the resin.

In consideration of the water shielding, it is necessary that the coating resin is coated on at least one surface of the synthetic fiber. Examples of the coating method include lamination in which films are laminated, calendar coating in which the film is extruded and coated, and knife coating in which a liquid material is applied using a knife or the like.

In consideration of quality and processing cost, extrusion coating using a calender is preferable. The tensile strength of the coating resin is 100-300kgf / 3cm
As described above, the elongation at the maximum load is 45 to 8% or less, and the thickness is 1 to
5 mm, 25 at 63 ° C. with a WS type accelerated exposure device
The tensile strength retention after irradiation for 0 hours is 60% or more. If the tensile strength of the coating resin is less than 100 kgf / 3 cm, the mechanical properties required for the final disposal site and roofing material cannot be obtained. When laying is laid, elongation occurs and workability deteriorates. If the thickness is less than 1 mm, there is no cushioning property, mechanical properties for use are inferior, and it is easy to break, so preferably 1.5 mm or more It is.

Further, 63 ° by a WS type accelerated exposure device
If the tensile strength retention after irradiation for 250 hours under C is less than 60%, the durability required for these applications exposed outdoors cannot be sufficiently obtained, and therefore it is preferably 70% or more. In order to further improve the weather resistance, a spun bond or the like may be laminated on the resin-coated sheet.

As described above, a cloth sheet composed of synthetic fibers having a strength of 6 g / d or more is coated on at least one side with a polyethylene resin, and the tensile force of the polyethylene resin is 100 kgf / 3 cm or more, and the maximum load is When the elongation is 4
According to the water-shielding sheet having a tensile strength retention of 5% or less, a thickness of 1 mm or more, and a tensile strength retention of 60% or more after irradiation for 250 hours at 63 ° C. by a WS-type accelerated exposure apparatus, chemical resistance, weather resistance and It is a water-impervious sheet with excellent mechanical properties and excellent workability.

Next, an embodiment of the present invention will be described. In addition,
Evaluation of the obtained impermeable sheet was performed by the following method. (1) Thickness: The thickness of each impermeable sheet was measured according to JIS-L-1096. (2) Denier and number of filaments: JIS-L-1
It was measured in accordance with No. 013. (3) Strength (yarn): Measured according to JIS-L-1013. (4) Elongation at break (yarn): Measured according to JIS-L-1013. (5) Fabric density: Measured according to JIS-L-1096. (6) Tensile strength: Measured according to JIS-L-1096. (7) Elongation at maximum load: Elongation at maximum load when tensile strength was measured according to JIS-L-1096. (8) 250 at 63 ° C. by a WS type accelerated exposure device
Tensile strength retention after time irradiation: 63 ° C. × 2 in a WS-type accelerated exposure device (using a sunshine weather meter)
After irradiation under the condition of 50 hours, the tensile strength was measured by the method of (6), and the retention was measured. (9) Tensile strength retention after alkali treatment: After immersion in a saturated aqueous solution of calcium hydroxide (PH12) at 70 ° C. for 250 hours, the tensile strength was measured by the method of (6) to measure the retention. (10) Workability: A sheet of 2 m width was spread on a site of 20 mx 20 m (site laid with about 5 kg / piece of rock), and the sheets were bonded with a puff to confirm workability. (11) Test by heavy equipment: Cover the sheet placed in (10) with about 30 cm of soil, and use a 10 t dump truck (6 cm)
In ³ of sediment loading) and 15t class bulldozer at 5kg / h 1
After reciprocating 0 times, the covering soil was removed, and the change in appearance was visually confirmed.

The following Table 1 shows the conditions and the measurement results of physical properties of the examples and comparative examples.

[0022]

[Table 1]

Example 1 to Comparative Example 4 After melt-spinning various fibers under the conditions of (Table 1), weaving was performed in a water jet loom with a flat structure and a predetermined weaving density, followed by extrusion calendering. Then, LDPE (eg, Sumikasen, trade name, manufactured by Sumitomo Chemical Co., Ltd.) was coated to produce water-blocking sheets of Examples 1 to 5 shown in (Table 1).

Comparative Example 5: A case in which LDPE was extruded onto release paper without using a fabric sheet to form a 0.8 mm film to be used as a water-blocking sheet. As is clear from the above (Table 1), it was confirmed that Examples 1 and 2 all had good physical property results and had excellent performance as a water-blocking sheet. Compared with each of these examples, in Comparative Examples 1 and 2, the strength of the impermeable sheet was weak, and several damages were confirmed from the test results by heavy equipment. In Comparative Example 3, the elongation was large, and Since elongation sometimes occurs and the workability is poor, and Comparative Example 4 is thin,
Several damaged parts were confirmed in the test with the heavy equipment, and Comparative Example 5 was poor in both the workability and the test with the heavy equipment because Comparative Example 5 had low strength and large elongation.

[0025]

As apparent from the above description, the present invention relates to a fabric sheet composed of synthetic fibers having a strength of 6 g / d or more, and a resin comprising a polyethylene resin coated on at least one surface of the fabric sheet. The resin-coated sheet has a tensile strength of not less than 100 kgf / 3 cm, an elongation at the maximum load of not more than 45%, a thickness of not less than 1 mm and a SW type exposure device at 63 ° C. under 250 ° C. Since the tensile strength retention after time irradiation is set to 60% or more, it is excellent in chemical resistance, weather resistance and mechanical physical properties, and further excellent in workability.

────────────────────────────────────────────────── ─── Continued on the front page (51) Int.Cl. ⁶ Identification code FI E02B 3/18 E02B 7/02 A 7/02 D06M 17/00 K (72) Inventor Yoshifumi Moriguchi 23 Uji Kozakura, Uji City, Kyoto Prefecture Unitika's Central Research Laboratory (72) Inventor Yoshihisa Karatari 23 Uji Kozakura, Uji City, Kyoto Prefecture Unitika's Central Research Laboratory

Claims (1)

[Claims] 1. A cloth sheet comprising a synthetic fiber having a strength of 6 g / d or more, and a resin-coated sheet made of a polyethylene-based resin coated on at least one surface of the cloth sheet. 100 tensile strength
kgf / 3cm or more, elongation at maximum load is 45% or less, thickness is 1mm or more, and 63 ° C by SW-type accelerated exposure equipment
A water-impervious sheet having a tensile strength retention of 60% or more after irradiation for 250 hours.