JPH06286062A - Self-restorable water barrier composite sheet - Google Patents

Abstract

PURPOSE:To impart a hole extension preventing function and a self-restoring function to a sheet and to improve fitness by laminating water-barrier sheets on front and rear surfaces of water crosslinking rubber sheet having specific values of saturated crosslinkability at the time of dipping in water, volume expansion coefficient after a specific time and expansion pressure, and reinforcing a fiber sheet to set a cut elongation, tearing strength to specific values or more. CONSTITUTION:A self-restorable water-barrier composite sheet 10 comprises water- barrier outer sheets 11 made of normal rubber or resin laminated on both front and rear surfaces of a water crosslinking rubber sheet 12 having 0.5X10<-4>-3.8X10<-4>mol/ml of saturated crosslinkability at the time of dipping in water, 50 10000% of a volume expansion coefficient after 10 hours of dipping and 1-50kg/cm<2> of an expansion pressure, reinforced with a fiber sheet 13, an entire cut elongation is 50% or more, and a tearing strength is 10kg/cm<2> or more. Since the sheet 12 is provided as an intermediate layer, if a hole is opened due to an uneven surface of a soft laying surface, the sheet 12 is brought into contact with water to be invaded from the hole, and hence the sheet 12 is expanded to block the hole, thereby preventing invasion of the water. That is, water is stopped by self-restoration force of the sheet 12 itself.

Description

Detailed Description of the Invention

[0001]

This invention relates to a waste treatment plant, an artificial reservoir, a river embankment, a roof of a reinforced concrete building,
A water barrier sheet for civil engineering construction that is laid to prevent water leakage in subway station buildings and underground buried objects, etc., and prevents the expansion of holes caused by contact with sharp objects during construction or use. The present invention relates to a self-healing composite sheet for water shielding that can automatically close holes.

[0002]

2. Description of the Related Art As a water-blocking sheet for civil engineering construction laid on the roof of a waste treatment plant or a reinforced concrete building to prevent water leakage, vinyl chloride type, polyethylene type,
Sheets made of synthetic polymer materials such as synthetic rubber and asphalt are often used. The water-blocking sheets made of these synthetic polymer materials are all 100 to 600
% Elongation, it is easier to fit irregularities on the laying surface than metal-based water impermeable sheets, and damage due to external force can be reduced, but on the laying surface such as rocks and crushed stones When contacted, it was easy to cause laceration.

In order to prevent this laceration, a composite sheet in which the above synthetic polymer material sheet is reinforced with a fiber sheet such as a woven fabric or a non-woven fabric has been developed, but this composite sheet has a tensile elongation of 20% or less. Therefore, it is more difficult to fit the unevenness of the laying surface as compared with the water blocking sheet made of a synthetic polymer material, and tearing is likely to occur particularly when hitting an acute-angled object under a state where a tensile force is applied.

Therefore, a composite sheet based on a knitted fabric having a higher elongation than a woven fabric or a non-woven fabric has been developed. In this case, too, an acute angle portion of the laying surface or nails, glass, blades, etc. are developed. When you contact a sharp object, stress concentrates on the contact area and a hole is made, and the pollutant in the waste flows out with the water from this hole, causing pollution of groundwater and rivers, which has a great adverse effect on the surrounding environment. There was a problem.

In order to solve these problems, it has been attempted to laminate water-permeable outer rubber sheets made of normal rubber on both the front and back sides of a water-absorbent rubber sheet made of rubber mixed with a water-absorbent resin. When the water-absorbent rubber sheet of the layer is vulcanized, it takes a long time to completely stop the water when a hole is opened in the sheet and water begins to leak, while the water-absorbent rubber sheet of the intermediate layer is In the case of unvulcanized, there was a problem that the water-stopping effect did not last because the physical properties of rubber were low.

[0006]

DISCLOSURE OF THE INVENTION The present invention is an improvement of the water-impermeable sheet for civil engineering and construction, which is made of the synthetic polymer material as described above, and prevents expansion of holes formed in the sheet during construction and use. And the function of self-repairing due to the water-absorptive property of the sheet itself by contacting the hole with water leakage, and the water-stopping effect of this self-repairing is completed in a short time and is maintained for a long time, In addition, the fitting property to the unevenness of the laying surface is good, and thus the reliability as the water impermeable sheet is enhanced.

[0007]

[Means for Solving the Problems] That is, the self-healing water-impermeable composite sheet according to the present invention has a degree of saturation crosslinking of 0.5 × 10 ^{−4 to} 3.8 × 10 ⁻⁴ mol when immersed in water. / ml, volume expansion coefficient 50-10,000% after 10 hours immersion in water,
A water-blocking outer sheet made of ordinary rubber or resin is laminated on both front and back surfaces of a water-crosslinkable rubber sheet having an expansion pressure of 1 to 50 kg / cm ² after 10 hours of immersion in water, and is reinforced with a fiber sheet, The breaking elongation of the whole is 50% or more, and the tear strength is 10 kg / cm or more.

The water-crosslinkable rubber sheet of the present invention has both water-crosslinkability and high water absorption obtained by mixing a rubber with a water-crosslinking agent and a water-absorbing material. The above-mentioned rubber is CSM. , Chlorinated polyethylene, halogenated II
Various synthetic rubbers grafted with reactive groups such as R, halogenated EPDM and maleic acid can be used alone or as a mixture, and especially brominated IIR and chlorinated IIR are It is preferable because it is excellent in strength, that is, green strength.

On the other hand, examples of the water-absorbing material include natural materials such as pulp, bentonite, starches and celluloses having excellent water-absorbing ability, polyacrylic acid salts, starch
Acrylic acid, vinyl acetate / acrylic acid copolymer, polyethylene oxide, isobutylene / maleic anhydride copolymer, PVA / maleic anhydride copolymer, acrylate /
Super absorbent polymers such as acrylamide copolymer and CMC type are used alone or in combination.

In the present invention, a water-crosslinking agent such as the above water-absorbing material, for example, a silane coupling agent such as vinyl silane, methacryloxy silane, epoxy silane, amino silane, mercapto silane and chloropropyl silane is used. Is added to the above rubber. In other words, a thermal vulcanizing agent such as sulfur is not added, but it is used in an unvulcanized state and crosslinked by contacting with water. The water-absorbing water-crosslinkable rubber is formed into a sheet, and the thickness thereof is preferably 0.5 to 20 mm.

The outer sheets laminated on both the front and back sides of the water-crosslinkable rubber sheet have water-blocking properties and protect the water-crosslinkable rubber sheet of the intermediate layer, and have an elastic modulus of 1
The thickness is preferably 0 to 500 kg / cm ² , and the thickness is preferably 0.5 to 20 mm. In addition to the rubber used for the above water-crosslinkable rubber sheet, this outer sheet includes PVC, high density polyethylene, low density polyethylene, crosslinked polyethylene,
It can be molded from chlorinated polyethylene, EVA or other olefin resin.

The above-mentioned water-crosslinkable rubber sheet and outer sheet are individually molded into a sheet shape, then stacked in an unvulcanized state, and then thermocompression bonded to vulcanize only the outer sheet to form an integral body. Can be converted. Note that it is not necessary to use the same rubber for the water-crosslinkable rubber sheet and the outer surface sheet.
IR can be used, NBR or EPDM can be used for the outer sheet, and ordinary resin can be used.

According to the present invention, a laminated sheet comprising the above water-crosslinkable rubber sheet and outer and outer sheets thereof is reinforced with a fibrous sheet so that the breaking elongation of the whole is 50% or more and the tear strength is 10 kg / cm. As mentioned above,
The fibrous sheet is preferably a knitted fabric from the viewpoint of elongation, a weft knitted fabric is preferable to the warp knitted fabric, and a circular knitted fabric is preferable among the weft knitted fabrics from the viewpoint of productivity. The fibers constituting this knitted fabric may be any of natural fibers, semi-synthetic fibers and synthetic fibers, but nylon crimped yarns are particularly preferable. The above fiber sheet can be laminated on the surface of the outer sheet, can be embedded in the outer sheet, and can be interposed at the boundary surface between the outer sheet and the water-crosslinkable rubber sheet. Alternatively, it can be embedded in a water-crosslinkable rubber sheet.

[0014]

The self-healing water-impermeable composite sheet of the present invention comprises a water-crosslinkable rubber sheet, a water-impervious outer sheet laminated on both front and back surfaces, and a fiber sheet reinforced,
Like the conventional water-blocking sheet, it is laid at the waste treatment plant and other desired places to prevent water leakage, and at that time, it is spliced with an adhesive or the like in the length direction and the width direction according to the size of the construction site. The area can be used. In that case, since the composite sheet is reinforced with a fiber sheet and has a breaking elongation of 50% or more and a tear strength of 10 kg / cm or more, it easily fits the unevenness of the laying surface and is damaged by an operation during construction. In addition, it is difficult to break when it comes into contact with an acute-angled object such as rock or crushed stone on the laying surface, and further expansion of the damaged part is prevented.

However, since water-impervious outer sheets made of ordinary rubber or resin are laminated on both front and back surfaces of the water-crosslinkable rubber sheet, under normal conditions until the composite sheet is damaged, The water-crosslinkable rubber sheet is protected by this outer sheet, and the water impermeability of the entire composite sheet is maintained. Since the intermediate layer has a water-crosslinkable rubber sheet, if a hole is tentatively opened due to the unevenness of the laying surface or an acute-angled object in the waste, the water-crosslinkable rubber sheet comes into contact with the water entering through this hole. As a result, the water-crosslinkable rubber sheet expands to close the hole and prevent water from entering. That is, water is stopped by the self-repairing force of the water-crosslinkable rubber sheet itself. Moreover, since this water-crosslinkable rubber sheet has water-crosslinking properties, crosslinking proceeds while closing the above-mentioned holes by expansion, so that water-stopping can be completed in a short time, and it will not dissolve in water after completion of water-stopping. No, keep the water-stop effect.

However, when the breaking elongation of the composite sheet is less than 50%, the composite sheet is likely to be damaged due to the unevenness of the laying surface or the unevenness of the waste at the waste disposal site. The tear strength is 10
If it is less than kg / cm, the damaged part or hole will expand. Then, by using a knitted fabric as a fiber sheet, particularly a flat knitted fabric, the above-mentioned breaking elongation and tear strength can be easily obtained, and when a circular knitted fabric is used, it is advantageous in terms of productivity. . Further, by using the knitted fabric made of the crimped yarn of nylon, the elongation can be further improved, and the adhesiveness to the water-crosslinkable rubber sheet or the outer sheet is improved. When the above knitted fabric is embedded in the middle of the water-crosslinkable rubber sheet, the composite sheet is easy to process because warpage and front and back are not distinguished, and the water-crosslinkable rubber sheet and the outer sheet are also available. When it is provided on the boundary surface of, the number of steps is reduced, which is advantageous in terms of productivity.

However, when the saturated cross-linking degree (mesh chain strength) of the water-crosslinkable rubber sheet is less than 0.5 × 10 ⁻⁴ mol / ml, the tenacity after closing the hole is insufficient and the water-stopping property is reduced. Is reduced,
On the other hand, when it exceeds 3.8 × 10 ⁻⁴ mol / ml, the water crosslinking agent reacts during the production process, and the production becomes difficult. When the volume expansion coefficient of the water-crosslinkable rubber sheet after immersion in water for 10 hours is less than 50%, the desired water-stopping effect cannot be obtained, and when it exceeds 10,000%, the production is At the time of or after installation, it is easily affected by moisture, making it difficult to provide a stable repair function. Also, the infiltration of water from the scratches becomes excessive,
It is easy to cause new cuts. Also, if the inflation pressure is less than 1 kg / cm ^2, can not be maintained tension when the shielding holes, easily leak a small water pressure resistance after repairing a hole, a 50 kg / cm ² on the opposite If it exceeds, the expansion pressure of the water-expandable sheet itself may cause damage or deformation of the composite sheet when absorbing water.

[0018]

EXAMPLE As shown in FIG. 1, a water-blocking outer sheet 1
1. Intermediate rubber sheet 12 with various characteristics, fiber sheet 13
Then, a water-impervious composite sheet 10 in which outer sheets 11 similar to the above are laminated in order from the top is manufactured. Upper and lower outer sheets 11 have a thickness of 0.7 mm and an elastic modulus of 30 kg according to EPDM.
The sheet was molded into a sheet having a size of / cm ² . Also, the intermediate rubber sheet 1
Sample Nos. 1 to 2 each having a composition of Table 1 below kneaded with a Banbury mixer, air-cooled, and then molded into a sheet having a thickness of 2 mm using a sheet extruder, and differing only in the amount of the water-crosslinking agent. 5 was used as the intermediate rubber sheet 12.

Table 1 JSR chlorinated butyl rubber 1066 100 parts Carbon HAF 50 parts Process oil 30 parts Paraffin 2 parts Super absorbent resin 100 parts Water cross-linking agent 0-20 parts However, the super absorbent resin in Table 1 is Japan Co., Ltd. Made of catalyst,
The product name is "Aquaric CS-7S", and the water-crosslinking agent is γ-mercaptoproprtrimethoxysilane (manufactured by Nippon Unica Co., Ltd., product name "silane coupling A-189").

As the fiber sheet 13, a circular knitted fabric having a plain weave structure (crimped amount 270 g / m ² , break elongation 180%) made of nylon crimped yarn (140 denier) was used. Then, the unvulcanized outer surface sheet 11, the unvulcanized water-crosslinkable rubber sheet 12, the fiber sheet 13 and the unvulcanized outer surface sheet 11 are stacked to apply a surface pressure of 10 kg / cm ² to 1
The outer sheet 11 was vulcanized by heating at 80 ° C. for 15 minutes.

On the other hand, an intermediate rubber sheet 12 having thermal vulcanizability instead of the above water-crosslinking property was formed into a sheet having a thickness of 2 mm by the composition shown in Table 2 below. The sheet 13 was stacked, a surface pressure of 10 kg / cm ² was applied, and the sheet was heated at 180 ° C. for 15 minutes to vulcanize the intermediate rubber sheet and the outer sheet 11 to obtain a composite sheet 10 of sample number 6.

Table 2 JSR chlorinated butyl rubber 1066 100 parts Carbon HAF 50 parts Process oil 30 parts Paraffin 2 parts Zinc white 5 parts Stearic acid 1 part TMTM 1.5 parts MBTS 2 parts Sulfur 1 part Super absorbent resin 100 parts However, The super absorbent polymer in Table 2 is manufactured by Nippon Shokubai Co., Ltd.
The trade name is "Aqualic CS-7S", TMTM is tetramethyl tilarammoxy sulfide, and MBTS is 2 mercaptobenzothiazole.

As described above, the physical properties of six types of water-permeable composite sheets 10 having different compositions of the intermediate rubber sheet 12 were tested. The results are shown in Table 3 below. However, the breaking elongation and the tear strength in the table are the composite sheet 10
Is the measured value of. Further, the volume expansion coefficient was calculated from the measured value after immersing the test piece (thickness: 2 mm, diameter: 50 mm) of the intermediate rubber sheet 12 in tap water at room temperature for 10 hours. The expansion pressure was determined by immersing the test piece of the intermediate rubber sheet 12 in tap water, recording the time-dependent change in the pressure applied to the load cell via the pressing plate, and measuring the value after 10 hours as the expansion pressure. However, the volume expansion coefficient and expansion pressure of Sample No. 1 could not be measured due to dissolution. Further, the saturated cross-linking degree (mesh chain concentration) of the intermediate rubber sheet 12 is obtained by immersing the test piece in water at 70 ° C., taking out after 24 hours, drying at 100 ° C., and after 24 hours according to JIS K6301 tensile test ( A pulling speed of 20 mm / min) was performed, and the obtained tensile stress was used for measurement according to a conventional method.

Table 3 Sample No. 1 2 3 4 5 6 Amount of water crosslinking agent added (part) 0 5 10 15 20 S vulcanization Elongation at break (%) 128 126 125 124 126 125 Tear strength (kg / cm) 34 35 37 33 36 35 Volume expansion rate (%) − 1030 810 590 470 480 Expansion pressure (kg / cm ² ) − 8 13 15 16 16 Network chain concentration (× 10 ⁻⁴ ) − 0.5 2.0 3.6 4.0 −

Next, a disc having a diameter of 260 mm was cut out from each of the above-mentioned various composite sheets 10 to obtain a test piece, and six bolt holes (diameter: 1) were formed along a circle having a diameter of 220 mm inside the peripheral edge thereof.
8.6 mm) at equal intervals, a 14-mesh wire net 15 is superposed on the test piece 10a (see FIG. 2) and fixed on the test stand 16 with a pressing ring 17, bolts 18 and nuts 19. The water supply pipe 20 was connected to the hole provided in the center. Then, a nail (diameter 2.5 mm, length 14.4 mm) 21 is pierced on the test piece 10a from above the wire net 15, and in that state, a pressure of 3 kg / cm is applied from the water supply pipe 20.
The high pressure water of ² was supplied to the space between the test piece 10a and the test stand 16 and 15 minutes later, the nail 21 was pulled out, and
Each water leak condition was tested after 5 minutes, 3 hours and 1 month. The water leakage state 15 minutes, 3 hours, and 1 month after the nail was pulled out is shown in Table 4 below. However, ◯ indicates that the water was completely stopped, Δ indicates that the water oozes out, and x indicates that the water did not stop at all.

Table 4 Sample No. 1 2 3 4 5 6 Water leak state after 15 minutes △ △ △ △ − × Water leak state after 3 hours 〇 〇 〇 〇 − 〇 Water leak state after 1 month × 〇 〇 〇 − 〇

As is clear from Tables 3 and 4 above, in Sample Nos. 2 to 4 which are examples of the present invention, 15 minutes after pulling out the nails, the water was stopped to such an extent that the water oozes out. The water was completely stopped even after a month.
On the other hand, Sample No. 1 to which the water-crosslinking agent was not added had a low water-stopping property and did not stop at all after 1 month. Further, in Sample No. 5 in which the amount of the water-crosslinking agent added was too large, the water-crosslinking started during the processing and the processing was impossible. Also,
Sample No. 6 in which the intermediate rubber sheet was S-vulcanized had a poor water-stopping property immediately after the nail was pulled out.

[0028]

As described above, the self-healing composite sheet for water blocking according to the present invention has a saturation crosslinking degree of 0.5 × 10 ^{−4 to} 3.8 × 10 ⁻⁴ mol / when immersed in water. ml, soaked in water 1
Water-blocking property of ordinary rubber or resin on both front and back surfaces of a water-crosslinkable rubber sheet having a volume expansion coefficient of 50 to 10,000% after 0 hours and an expansion pressure of 1 to 50 kg / cm ² after immersion in water for 1 hour. The outer sheets are laminated and reinforced with fibrous sheets, and the total breaking elongation is 50% or more and the tear strength is 1
Since it is 0 kg / cm or more, it can be used as a waterproof sheet for civil engineering and construction to prevent water leakage in waste treatment plants, etc., and at that time it has a good fit to the unevenness of the laying surface, and It is possible to prevent the holes from expanding during construction and use, and when the holes do occur, the above-mentioned holes can be self-repaired by the water-swelling expansion of the sheet itself due to contact with water leakage, and the intermediate layer is water-repellent. Since it is a crosslinkable rubber sheet, the time required to completely stop the water is short, and the water stopping effect is sustained, so that the reliability of the water blocking sheet is improved.

[Brief description of drawings]

FIG. 1 is a sectional view of an example.

FIG. 2 is a cross-sectional view of a water leak test device.

[Explanation of symbols]

 10: Self-healing water-proof composite sheet 10a: Test piece 11: External sheet 12: Intermediate rubber sheet (water-crosslinkable rubber sheet) 13: Fiber sheet 15: Wire mesh 16: Test stand 17: Pressing ring 20: Water supply pipe 21 :nail

(72) Inventor Tetsuo Miyake 255 Kannonji-cho, Tsu City, Mie Prefecture Kureha Rubber Industry Co., Ltd.Tsu factory (72) Inventor Akio Yokawa 255 Kanonji-cho, Tsu City, Mie Prefecture Kureha Rubber Industry Co., Ltd.

Claims (1)

[Claims] 1. The degree of saturation crosslinking when immersed in water is 0.5.
× 10 ^{−4 to} 3.8 × 10 ⁻⁴ mol / ml, the volume expansion coefficient after 10 hours immersion in water is 50 to 10,000%, and the expansion pressure after 10 hours immersion in water is 1 to 50 kg / cm ^2. A water-blocking outer sheet made of ordinary rubber or resin is laminated on both the front and back sides of the water-crosslinkable rubber sheet and is reinforced with a fiber sheet, and the total elongation at break is 50% or more and the tear strength is 10 kg /
A self-healing composite sheet for water shielding, which is characterized by being cm or more.