JP2006283278A - Water cutoff vegetative base material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a water cutoff vegetative base material which is useful in general civil engineering works such as a slope, a slope top, and a revetment section, in a waste disposal area as a water cutoff sheet forming a bottom surface and a slope of the waste disposal area, and as a water cutoff capping sheet for preventing movement of harmful substance due to rainwater infiltration after completion of landfill, etc. <P>SOLUTION: The water cutoff vegetative base material (12) is formed of a water cutoff sheet (9), and three-dimensional network bodies (3) laminated on and connected to both surfaces of the same in one body. Each network body is made of a thermoplastic resin, and formed by irregularly superposing a plurality of continuous fibers having a diameter of 0.1 to 2 mm, on each other in a longitudinal direction. One of three-dimensional network body layers has a function (cover soil retaining layer 3a) of preventing cover soil from deviating, and the other three-dimensional network body layer has a function (slip preventive layer 3b) of preventing the water cutoff sheet from slipping down. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention prevents civilian civil engineering such as slopes, slopes, revetments, water shielding sheets that form the bottom and slope of waste disposal sites, and movement of harmful substances due to infiltration of rainwater after landfill completion. The present invention relates to a water-impervious vegetation base material useful for a waste disposal site such as a water-impervious capping sheet.

  Conventionally, in order to prevent landslides caused by precipitation on the shoulders and slopes of roads and railways in soft ground areas such as embankments and Shirasu Plateau, water-impervious sheets that prevent the infiltration of rainwater have been used. Water shielding work is being carried out on the surface. Since these water-impervious works are all carried out on slopes, even if the water-impervious sheet is simply stretched, the sheet itself tends to slip off due to the weight of the water-impervious sheet. The sheet tended to break easily. For this reason, when the thickness of the sheet is increased, its own weight is increased, the shear stress is further increased, and it is difficult to follow the slope because it is thick.

  In addition, many of the above-mentioned water-blocking works are also carried out as important works at the bottom of the (industrial) waste disposal site. The bottom water-impervious construction of this waste disposal site was not done at all in the time when there was no awareness of pollution, but as the awareness of pollution increases, there is a concern about groundwater contamination, and gradually from the reclamation of severely contaminated things It was expanded to be performed. Initially it was made of concrete, but due to the increase in landfill amount and the spread of plastics, the demand for the use of inexpensive polyolefin sheets became stronger, and new construction methods such as double construction were devised. Recently, polyolefin sheets Water-blocking work by is becoming common.

  Furthermore, the water shielding work at the waste disposal site is not limited to the bottom surface water shielding work, but recently, it prevents the infiltration of rainwater that falls on the waste disposal site and reduces the amount of sewage flowing out of the waste disposal site. In order to reduce maintenance costs after the waste disposal site is full, a capping method has been proposed that covers the surface with a water-impervious sheet that shields the upper surface of the full waste disposal site. Since the water shielding work at these waste disposal sites includes not only the flat part but also the water shielding work on the slope, There was a problem that breakage easily occurred. In order to solve the above problem, for example, JP 2001-314830 A (Patent Document 1) proposes a protective mat with a non-slip function for protecting a water shielding sheet.

On the other hand, in general, the water-proof sheet is colored with carbon black to ensure weather resistance. Because carbon black is black, waste disposal sites that are often constructed in mountainous valleys are conspicuous, and there is a demand for greening the surface of water-impervious sheets even in newly constructed waste disposal sites. Many. In addition, the water-impervious sheet constructed on the slope is often blown by the wind, so you want to drive a large number of anchors for fixing. Due to technical factors, when constructing a water-impervious sheet, the water-impervious sheet is lightweight for convenience of construction work, and there is a need for a water-impervious construction method that can be heavy when used. Has been. For this reason, by covering the water-impervious sheet with the spraying greening method that can easily cover the mud containing the seeds that are currently popular in slope planting at high pressure, the sheet is made heavy by the wind Contractors have devised measures to prevent peeling. Since the soil covered with soil to give weight to the sheet easily flows out with rainwater as it is, the surface of the water-impervious sheet must be greened, which is the same as the above-mentioned request for greening for landscape preservation. It was. In addition, the slope at the bottom of the industrial waste disposal site is large, and it is necessary to pile up to the angle of repose of the earth and sand to cover the conventional water-impervious sheet and to replant it. The need for soil caused a significant reduction in landfill volume. In order to solve such a problem, JP-A-10-227033 (Patent Document 2) proposes a water-impervious vegetation base material in which a three-dimensional network is joined to one surface of an impermeable sheet.
JP 2001-314830 A Japanese Patent Laid-Open No. 10-227033

  However, the conventional water-impervious sheet has the following problems. It is necessary to avoid the water-impervious sheet as much as possible from perforating the sheet itself for the purpose of use. Moreover, in order to prevent water leakage between sheets, the water-impervious sheet is bonded and sealed one by one to form a sheet with a large area. For this reason, if there is water leakage from a part, it is a difficult task to repair, and if a part of the water leaks, there is a high possibility that it will spread to the surroundings. Moreover, unlike the case of construction on a flat place, in the construction on an inclined surface such as a slope, it is necessary to hit an anchor in order to fix the sheet, so that water may leak.

  Moreover, in the protective mat with a non-slip function for protecting the water shielding sheet of Patent Document 1, although it has a function of preventing the nonwoven fabric from sliding off for protecting the water shielding sheet, it cannot suppress the sliding of the water shielding sheet itself, As a result, it was necessary to hit the anchor. In addition, since the nonwoven fabric cannot sufficiently hold the covering soil, it cannot be said to be sufficient for vegetation such as plants.

  Furthermore, although the water-impervious vegetation base material of Patent Document 2 can be greened for improving the landscape, it is difficult to suppress sliding of the water-impervious sheet itself.

  Therefore, in construction on slopes such as slopes, the water-impervious sheet that does not leak or drown, the sheet itself does not slide down, and prevents the cover from slipping and can be greened for landscape improvement. The fact is that was not obtained.

  The present inventors have been made in view of such a situation, and a network layer having a function of preventing slipping and a network layer having a function of holding a cover soil are bonded to both surfaces of a water shielding sheet. As a result, it has been found out that the above problems can be solved, and the present invention has been achieved. That is, in the water-impervious vegetation base material of the present invention, a plurality of continuous yarns having a diameter of 0.1 to 2 mm made of a thermoplastic resin are irregularly overlapped on both surfaces of the water-impervious sheet and the water-impervious sheet. A solid network having a parallel light transmittance of 50 to 90%, which is continuous in the length direction, is laminated, joined and integrated.

  Even if the water-impervious vegetation base material of the present invention is attached to a sloped slope, a three-dimensional network will bite into the sloped soil by its own weight and exert a slip-preventing function. The amount of the anchor can be remarkably reduced, and as a result, the decrease in the water barrier due to hitting the anchor can be remarkably reduced. Furthermore, since the three-dimensional network is joined to the other surface of the water-impervious sheet, even in the operation of welding and sealing the margin of the water-impervious sheet, compared to the case where the three-dimensional network is not on the surface of the water-impervious sheet. , The degree of freedom of work activities is increased, and the safety of work is significantly increased. Moreover, when the soil is covered and the surface is greened, the possibility of the wind rising due to the weight of the soil can be reduced, the direct sunlight exposure is eliminated, and the deterioration life of the water shielding sheet can be remarkably improved. Furthermore, since the upper surface of the water-impervious sheet can be greened, the landscape can be improved.

  In addition, it is possible to cover the soil and extend the life of the water-impervious sheet, so there is no need to use a thick sheet to secure the life as in the past, and a thinner sheet can be used. The convenience can be improved. As a result, in addition to the water-impervious construction at the bottom of an industrial waste disposal site where absolute water leakage prevention is required, it can be easily applied to prevent landslides and rainwater infiltration on embankments such as roads. Compared to conventional water-blocking construction, construction with high economic efficiency can be performed.

  The inventors first examined the prevention of slipping of the water-impervious sheet by using a water-impervious sheet having a three-dimensional network bonded on one side, and the thermoplasticity depends on the soil quality of the other slope and the state of excavation. A three-dimensional net-like body in which a plurality of continuous yarns made of resin having a diameter of 0.1 to 2 mm are irregularly overlapped and continuous in the length direction holds the ground on an inclined ground and prevents the sheet itself from slipping down. I learned that it functions as an anti-skid layer.

  Further, in order to cover the surface of the water-impervious sheet and make it green, a three-dimensional network body in which a plurality of continuous yarns made of a thermoplastic resin having a diameter of 0.1 to 2 mm are irregularly overlapped and continuous in the length direction. However, it was found that it functions as a soil cover retaining layer that prevents slippage of the soil cover on slopes. And it knew that the water-impervious vegetation base material provided with the slipperiness prevention property of the water-impervious sheet and the soil slippage-preventing property was obtained by joining and integrating them to both surfaces of the water-impervious sheet.

  The water-impervious vegetation base material of the present invention has a length in which a plurality of continuous yarns having a diameter of 0.1 to 2 mm made of a thermoplastic resin are irregularly overlapped on both surfaces of the water-impervious sheet and the water-impervious sheet. The three-dimensional network continuous in the direction is laminated, joined and integrated. Furthermore, it is preferable that one three-dimensional network body forms a slip-preventing layer and the other three-dimensional network body forms a covering soil retaining layer. Specifically, a water-impervious sheet whose both surfaces are covered with a three-dimensional network, a three-dimensional network is 5 to 25 mm thick and thermally bonded to both surfaces of a flexible plastic sheet having a thickness of 0.5 to 5 mm. The flexible plastic sheet has a water shielding function, the thick three-dimensional network layer has a function of preventing the slippage of the cover, and the three-dimensional three-dimensional network layer has a composite structure. It is preferable to provide a water-impervious vegetation base material having a function of preventing slippage of the sheet itself and preventing slippage of the water-impermeable sheet itself and an ability to prevent the soil from slipping on slopes.

  The three-dimensional network used in the present invention has a fiber diameter of 0.1 to 2 mm. More preferably, it is 0.5-1.5 mm, More preferably, it is 0.6-1.2 mm. When these are melted and discharged downward from the nozzle, a plurality of continuous yarns are irregularly overlapped and continuously deposited in the length direction on the mold.

  The three-dimensional network used in the present invention, for example, allows a plurality of continuous yarns made of a thermoplastic resin having a fiber diameter of 0.1 to 2 mm to flow down into a metal mold formed into irregularities with a depth of about 20 mm. The three-dimensional shape is formed in a three-dimensional network by forming a three-dimensional shape and making an irregular loop for each continuous yarn using the circumferential phenomenon, and then fusing and bonding the two yarns at the point where the yarns overlap. In the three-dimensional network, the cross-section in the thickness direction is a pleated shape, and the plane plate of continuous yarn that is bonded in a plane and heat bonded is pleated, and the height of the pleat is measured as the thickness of the three-dimensional network. Preferably there is. That is, the three-dimensional network is a thick yarn similar to a dried instant noodle product, and a large number of continuous yarns of a thermoplastic resin having a diameter of 0.1 to 2 mm form irregular loops and have a thickness. It is a bulky three-dimensional network that is continuous in the length direction at 5 to 25 mm, has a parallel light transmittance of 50 to 90% and a large porosity. The parallel light transmittance refers to the ratio of the area where the parallel light beam directly reaches the opposite surface (water-impervious sheet surface) without being interrupted by the continuous filament when the solid network is irradiated with the parallel light beam. .

  The conventional water-impervious sheet having a three-dimensional network bonded to one side has not been studied at all for the thermoplastic resin constituting each, and the melting point of the resin constituting the water-impervious sheet is high, and the three-dimensional network is By lowering the melting point of the constituent resin, the trouble of opening holes in the sheet at the time of thermal bonding to the sheet of the three-dimensional network was avoided, so the compatibility between the thermoplastic resins used for each was It was not particularly a problem. However, since it is desired to perform thermal bonding with a small pressing pressure, in consideration of the compatibility of the resins used for each, it has been found that one method is to use the same type (system) for the resins constituting both. Therefore, the present inventors are a water-proof sheet having a soft and high physical strength made of a thermoplastic resin having a melting point of 100 to 150 ° C., which is a continuous yarn having a diameter of 0.1 to 2 mm. Are formed in irregular loops, have a thickness of 5 to 25 mm and are continuous in the length direction, and can form a bulky three-dimensional network having a parallel light transmittance of 50 to 90% and a large porosity, and As a result of studying a thermoplastic resin and a water-impervious sheet comprising the thermoplastic resin, which has a rigid three-dimensional network body and sufficiently functions as an anchor, a linear low-density polyethylene resin is the most preferred example. As for this resin, it was found that there are various varieties for which a three-dimensional network can be made and a water-proof sheet can be obtained.

  As an example of the present invention, a resin having a high melting point of more than 100 ° C. to withstand direct sunlight in summer and not brittle even in winter cold, and having a brittle temperature of less than −50 ° C. and excellent chemical resistance. In addition, as a resin that does not require labor such as drying in production and can be obtained at low cost, a resin using a linear low-density polyethylene resin, which is a polyolefin resin, for a three-dimensional network and a water-proof sheet is mentioned. It is done. The resin was further selected from resins having a melting point lower than 150 ° C., more preferably lower than 140 ° C., in order to facilitate thermal bonding even in winter.

  One example of the present invention is a resin in which the three-dimensional network and the thermoplastic resin constituting the water-proof sheet are both resins containing at least 70 mass% of a similar resin, and the melting point of the similar resin is 100 to 150 ° C. It is an aqueous vegetation base material, more preferably, a similar resin is a low-density polyethylene resin, a propylene-based (propylene component is 50 mass% or more) ethylene-propylene copolymer, and a polyolefin resin such as an ethylene-vinyl acetate copolymer. Water-proof vegetation base material, which is one or a plurality of selected types of flexible resin, and the thermoplastic resin mixed as necessary is composed of a similar resin and a compatible thermoplastic resin It is. More preferably, the thermoplastic resin contains 100 to 70 mass% of a linear low density polyethylene resin having a melting point of 110 to 140 ° C. as a similar resin, and includes 0 to 30 mass% of a low density polyethylene resin or a propylene copolymer resin. It is preferable that it is a water-impervious vegetation base material which is resin contained in the range.

  Of course, the other thermoplastic resin mixed with the similar resin is preferably a material that is familiar with the similar resin, and the other thermoplastic resin may be used when one of the three-dimensional network or the sheet requires rigidity. It is preferable to use it when more flexibility is required, and when the required properties described above are far from each other, it is also convenient to add separate thermoplastic resins. In addition, the same resin refers to a resin selected in each resin system in types such as polyolefin resin, polyester resin, polyamide resin, plasticizer-added vinyl chloride resin and urethane resin.

  The other is the idea of a conventional method for producing a water-proof sheet that has a three-dimensional network on one side. The water-proof sheet material has a higher melting point than the three-dimensional network material, and the three-dimensional network is A linear low density polyethylene resin having a melting point of 110 to 140 ° C., a water shielding sheet having a melting point of 130 to 150 ° C., and the melting point being not less than the linear low density polyethylene resin. It is preferable that both the three-dimensional network and the water-proof sheet, which are propylene-based copolymer resins such as a copolymer resin or a propylene-based ethylene-butene-propylene copolymer resin, are made of a polyolefin resin.

  The other is that the three-dimensional network and the water-impervious sheet are non-polyolefin-based resins, and both polyester-type or polyamide-type thermoplastic elastomer resins having the same type of flexibility are compatible with 100 to 70 mass%. The polyester-based or polyamide-based thermoplastic elastomer resin is preferably a water-impervious vegetation base material having a melting point Tm ° C. of 130 <Tm <180. Even if the resin constituting the three-dimensional network and the water-impervious sheet is a non-polyolefin resin, the slip-preventing property of the sheet itself on the sloped surface of the water-impervious sheet and the anti-slipping effect of the covering soil are not changed at all.

  Hereinafter, the contents of the present invention will be described in more detail. In the present invention, when all the polyolefin resin having good chemical resistance is used, depending on the thickness and feeding speed of the water-proof sheet, the workability is better as the melting point is lower for the convenience of heating the water-proof sheet. . Therefore, for practical use in outdoor construction, the melting point is preferably 100 ° C. or higher, more preferably 110 ° C. or higher, and 150 ° C. or lower, more preferably 140 ° C. or lower, for work and facilities. If the melting point is too high, uneven heating tends to occur during production in winter.

  Within the above melting point range, the sheet is flexible, and the three-dimensional network fiber is a low-density polyethylene resin, a low-density polyethylene resin, a propylene-based ethylene-propylene copolymer, and ethylene-vinyl acetate. There are polyolefin resins such as copolymers, which can be preferably used in the present invention. More preferably, a linear low density polyethylene resin having high strength and flexibility is preferable. A non-polyolefin resin can also be used, and although the melting point of the material is a little high, a polyester or polyamide thermoplastic elastomer resin having a melting point Tm ° C. of 130 <Tm <180 is preferably used depending on the application. it can.

  Further, a water-proof sheet in which the above-mentioned similar resin is used in 100 mass% and the three-dimensional network of the present invention is thermally bonded to both sides is also preferable, but the masterbatch used for coloring these is not necessarily based on the desired resin. In many situations, such as when it is desired to increase the waist of a three-dimensional network, even if a thermoplastic resin different from the same resin is mixed within the range of 30 mass% or less, production is possible. It does not cause any problems in terms of quality and quality, so it can be used. The other thermoplastic resin to be mixed is preferably compatible with the main thermoplastic resin. Of course, the sheet and the solid network resin may have different melt flowability (melt flow rate (MFR); g / 10 minutes), and the sheet is generally a combination of lower flowability.

  The water-impervious sheet, which is a flexible plastic sheet in which a three-dimensional network is thermally bonded to both surfaces of the present invention, is a thermoplastic resin (hereinafter, referred to as “thermoplastic” Resin A ”) is a resin containing at least 70 mass% of the same kind of flexible thermoplastic resin (similar resin), and the similar resin preferably has a melting point Tm ° C. of 100 ≦ Tm ≦ 150, Of course, other thermoplastic resins that are mixed with the similar resin as needed are preferably those that are compatible with the similar resin. The other thermoplastic resin is preferably used when one of the three-dimensional network or sheet requires rigidity or when more flexibility is required, and when the required properties described above are far apart, respectively. It is also convenient to add a separate thermoplastic resin.

  More specifically, the similar resin may be one or more selected from polyolefin resins such as low density polyethylene resin, propylene-based ethylene-propylene copolymer resin, and ethylene-vinyl acetate copolymer resin. Other types of flexible resins that are used in combination with similar resins are preferably thermoplastic resins that are compatible to some extent with these resins. More preferable thermoplastic resin A includes 100 to 70 mass% of a linear low density polyethylene resin having a melting point of 110 to 140 ° C., and includes 0 to 30 mass% of a low density polyethylene resin or a propylene-based ethylene-propylene copolymer resin. It is made of a resin, and the most preferable example is a water-proof sheet in which a three-dimensional network is thermally bonded to both surfaces composed of only the linear low-density polyethylene resin.

  When the rigidity of the water-impervious sheet is required, the three-dimensional network is a linear low density polyethylene resin having a melting point of 110 to 140 ° C, the water-impervious sheet has a melting point of 130 to 150 ° C, and the melting point is A three-dimensional network is formed on both sides of a combination of only a polyolefin-based resin, which is a propylene-based ethylene-propylene copolymer resin or a propylene-based ethylene-butene-propylene copolymer resin having a melting point higher than that of the linear low-density polyethylene resin. A heat-bonded water-proof sheet is convenient.

  When the same resin is a polyolefin resin, the melt flow rate is indicated as an index of melt flowability (MFR, in the case of polyethylene resin, also referred to as a melt index MI measured at 190 ° C. The unit is g / 10 minutes, weight) 2.169 Kg, according to JIS-K-6760), 0.1 to 10 for the film, 0.5 to 100 for the thick yarn, and IV value of 0.5 to 0.7 for the polyester resin. The polyamide resin preferably has a number average molecular weight of 10,000 to 30,000.

  The soft impervious sheet used for the water-impervious sheet is, for example, a rubber sheet, a soft synthetic resin sheet such as a polyolefin resin or a vinyl chloride resin, and a sheet reinforced with a reinforcing material. Instead of a sheet made of soft vinyl chloride resin, a sheet made of linear low-density polyethylene resin has strong physical strength such as piercing strength and tensile strength and is soft, and it can be used as a plasticizer bleed-out like PVC. It is becoming popular because there is no worry.

  When using the sheet of the present invention as a water-proof sheet for water shielding on the bottom or rainwater penetration at industrial waste disposal sites or acidic waste disposal sites, gases with high chemical reactivity such as hydrogen sulfide and mercaptans are used. Because the sheet of the present invention is exposed to strongly acidic or alkaline wastewater due to infiltration of rainwater or rainwater, polyolefin resin is desirable as its constituent material, but it is simply water shielding and greening in general cases such as prevention of landslide Since there is no chemical problem with the resin used, the thermoplastic resin constituting the three-dimensional network and / or the water-impervious sheet has the same kind of flexibility in addition to the polyolefin resin. Contains 100 to 70 mass% of a certain polyester or polyamide thermoplastic elastomer resin, and 0 to 30 mass% of other thermoplastic resins compatible with these. No is a resin, syngeneic resins may be used conveniently the melting point Tm ° C. as an aqueous vegetation base material shielding to 130 <Tm <180.

  Although it depends on the basis weight and thickness of the three-dimensional network, the three-dimensional network having a parallel light transmittance of 50 to 90% is excellent in anti-sliding property and soil retention, and is convenient for the purpose. Is good. In addition, the thickness of the three-dimensional network is at least 5 mm, more preferably 10 mm or more, and even more preferably 15 mm or more in order to exhibit the slip-preventing property. There is a problem of reducing the thickness of the three-dimensional network in order to wind up orderly and to increase the length per wound roll to further secure the productivity. In the present invention, the thickness is set to 5 to 25 mm. It has been found that the thickness of the solid network for holding the other side covering soil is 10 mm or more, more preferably 15 mm or more, and even more preferably 25 mm or more. There is a strong demand for increasing the length of the product, and a thickness of 5 mm may be used depending on the application. In the present invention, the thickness is 5 to 25 mm. Accordingly, the most preferable thickness of the three-dimensional network is 15 mm for the slip-preventing surface and 25 mm for the covering soil retaining surface, but in order to prevent construction mistakes during construction, both sides have the same thickness. A thickness of 25 mm is also preferable. Of course, there is no inconvenience even if the soil covering surface has a thickness of 40 mm or more, but it is inevitable to wind tightly in order to secure the length, and it is easy to induce sag of the three-dimensional network, and when it is stored in a roll shape Since the three-dimensional network located at the lower part of the roll tends to sag, the effect of increasing the thickness of the three-dimensional network may be difficult to obtain. In view of strength, the thickness of the water-impervious sheet is preferably 0.5 to 3 mm, and 1 to 1.5 mm is more preferable in terms of the convenience of construction. If it exceeds 3 mm, there are problems in terms of weight and flexibility in use, and water shielding performance such as piercing performance is excessive and expensive, which is not preferable. The thickness was measured by the JIS L-1913-6.1.2A method.

  The water-proof sheet in which both sides are heat-bonded with a three-dimensional network formed of a linear low-density polyethylene resin, which is one form of the present invention, has a melting point of the linear low-density polyethylene resin constituting them of 120 to 120 It is 125 ° C., and the 1 mm thick sheet can be heated enough to be softened by infrared heating regardless of the season and soften the one side surface by preheating, and the whole is softened and cannot maintain the film form. The production conditions that can be continuously softened only on one surface can be easily set. The linear low-density polyethylene resin constituting the sheet can be bonded to each other by thermal bonding if one having a low melt flowability MFR, that is, one having a high molecular weight, is selected from the one constituting the three-dimensional network. In addition, the tolerance of manufacturing conditions can be widened, which is convenient.

In the present invention, the degree of bulky three-dimensional network having a large porosity is indicated by parallel light transmittance, and the parallel light is irradiated from the top of the three-dimensional network, and the bulk and void ratio are determined by the transmittance of the light. Stipulated. Any of the three-dimensional network used in the present invention preferably has a parallel light transmittance in the range of 50 to 90%, and the resin amount of the three-dimensional network is generally in the range of 300 to 2000 g / m ² for each layer. It is preferable. Of course, thickness and basis weight are related, and the greater the thickness, the higher the basis weight.

  In order to increase the rigidity of the thick yarn, the three-dimensional network of the anti-sliding functional layer preferably has a higher weight than the soil covering retaining layer if the thickness is the same. That is, it is preferable to reduce the parallel light transmittance.

  Next, the manufacturing method of the water-impervious vegetation base material of the present invention will be described. The water-impervious vegetation base material of the present invention has a structure in which a three-dimensional network is adhered to both surfaces of a water-impervious sheet, but the water-impervious sheet in which a three-dimensional network is adhered to one side has a convex upper end positioned in a planar shape. The melted yarn is allowed to flow down from the nozzle into the mold and poured into the mold, and when the yarn is not sufficiently solidified, the upper end where the convex portions are aligned in a plane is blocked. By pressing the water-based sheet and pressing the sheet against the tip of the convex portion with a weighting roller, it is made as a sheet with thermocompression bonding of the three-dimensional network at the tip, so the composite with the three-dimensional network adhering to the weighting roller side temporarily In the case of using the water-impervious sheet, there is a basic problem that the three-dimensional network on the weight roller side becomes smooth. In addition, films and sheets are materials that are extremely difficult to bond, and there is a problem that thermal bonding cannot be performed unless the pressure rollers are forcibly pressed against each other. Furthermore, the water-impervious sheet is not as flexible as the nonwoven fabric, and the composite water-impervious sheet in which the solid network is thermally bonded on one side is difficult to wind up with the end faces aligned, and the water-impervious sheet without the end faces is repeated. Even when it is put out, there is a problem that it is very difficult to return to the original because it lacks flexibility when tilted once, and if it can be done without using a weight roller, the solid network is heated on one side. Create a bonded composite water-impervious sheet (hereinafter also referred to as a single-sided composite water-impervious sheet) and roll it up to attach a three-dimensional network to the other side. Therefore, the waterproof sheet that is fed out meanders violently and randomly to the right and left, and unlike a non-woven fabric, the sheet can be slipped and gripped even if you try to adjust the meander by gripping both ears with a nip roller etc. If a three-dimensional network is adhered to both ears, problems such as the roller becoming stuck between the nip rollers frequently occur, making it impossible to control this meandering. close. Actually, it was attempted to control the meandering manually. However, the meandering stress was so great that it was impossible to adjust the meandering manually.

  Therefore, the water-impervious vegetation base material of the present invention can be manufactured as follows, taking as an example a water-impervious sheet that is a combination of linear low-density polyethylene resins. First, the three-dimensional network for the purpose of preventing slipping is applied to the water-impervious sheet by heat pressing, and the height of the unevenness is as low as about 15 mm, but the thickness extends in the width direction of the water-impervious sheet having a thickness of 0.5 to 3 mm. From a multi-row nozzle to a metal mold having an upper surface on the same plane and having a depth of about 20 mm, a large number of continuous yarns of thermoplastic resin having a fiber diameter of 0.1 to 2 mm The three-dimensional shape is formed by flowing down and forming a three-dimensional shape by making irregular loops on each continuous yarn using the circumferential motion phenomenon, and fusing and bonding the two yarns at the point where the yarns overlap. Let it be the body. When the yarn is still in a softened state, the water-impervious sheet is drawn out and placed on the upper surface of the mold, and further pressed by a pressure roll from the upper surface of the water-impervious sheet, and is continuously caught on the convex part of the mold. The yarn is pressed and thermally bonded to make a water-proof sheet with a solid network attached to one side. The three-dimensional network adhering to the sheet has many continuous yarns of a thermoplastic resin having a diameter of 0.1 to 2 mm forming irregular loops and is continuous in the length direction, and transmits parallel rays. It is a bulky three-dimensional network having a ratio of 50 to 90% and a large porosity. Further, the three-dimensional network is bonded and integrated with the water-impervious sheet so that the three-dimensional network is not formed on both ends of the water-impervious sheet at least 5 cm in order to provide a water-impervious thermal adhesive seal. While holding both ends of the water-impervious sheet to which the three-dimensional network is not adhered with a powerful nip roller for adjusting the oblique direction, the inclination is always adjusted, and the water-impervious sheet having the three-dimensional network adhered on one side is obtained. A semi-finished water-impervious sheet in which a three-dimensional network is thermally bonded to one side of which the winding end surfaces are aligned is rolled up.

  Next, a bulky three-dimensional network for holding the cover soil is formed on the other surface by thermal bonding. The equipment for making the three-dimensional network is the same as the equipment for making the three-dimensional network on one side, and the mold is deep. Replaced with a sheet having a thickness of 25 mm or more, instead of the water-impervious sheet, while continuously feeding out the water-impervious sheet of the semi-finished product as a water-impervious sheet in which the solid network is not adhered to the mold side The water-impervious sheet to which the three-dimensional network is not bonded is heated with an infrared heater or the like to forcibly soften the surface of the sheet, and immediately, the three-dimensional network in a state where the yarn on the mold is still softened. The water-proof sheet of the present invention is obtained by pressing the semi-finished water-proof sheet on the body by its own weight and thermally bonding the three-dimensional network to both sides. Of course, when the second three-dimensional network is affixed, it is also possible to apply partial pressure using a spike-shaped roller from the opposite side of the mold to further strengthen the thermal bonding. However, although the shape of the spike is generated on the opposite surface of the three-dimensional network, the appearance is deteriorated, but since it hardly affects the sliding effect, there is no problem in practical use.

  The three-dimensional network, which is the constituent material of the present invention, is produced by flowing a large number of continuous yarns of a thermoplastic resin having a fiber diameter of 0.1 to 2 mm into a metal mold having irregularities as described above. In addition to forming the shape, a continuous network is used to create an irregular loop for each continuous yarn, and the two yarns are fused and bonded at the point where the yarns overlap, The cross section in the thickness direction is a three-dimensional network body in which the flat plate of continuous yarns bonded in a plane and thermally bonded is pleated, and the height of the pleat is measured as the thickness of the three-dimensional network body Is preferred. The digging h (mm) of the mold to be shaped into a pleat is preferably approximately H ≦ h ≦ 1.2H, where the thickness of the three-dimensional network to be made is H (mm). In the case of using a resin having low properties, it is preferable that h is deeper and the digging angle is more obtuse. The digging angle is generally 75 degrees or less with respect to the bottom surface of the mold, and the digging interval on the upper surface of the mold is conveniently 12 mm or more. It may not be able to flow in enough. In addition, the digging angle is not limited to 75 degrees, but when extracting a solid thick yarn from the mold, it is easier to extract it when it is not at right angles, such as when extracting it in a slightly oblique direction, and the mold is made of a casting It is preferable to provide an angle in terms of the case and the strength against the pressing force.

  In addition, in the mold with a digging, on the contrary, the side of the upper surface is extremely narrow, and the die with the sharp trapezoidal weight lying on its side may be pressed by a roll, so the lower surface of the mold and the upper surface are parallel. It is preferable to make the mold in such a structure that the upper end of the most projecting protrusion of at least a certain height in the width direction is continuously in contact with the roll continuously. That is, in the mold, at least a plurality of protrusion vertices at the same height near at least both ends in the roll width direction have the same height at different protrusion vertices even when the protrusion vertices are discontinuous. It is preferable that the mold has a structure that can be maintained. Of course, in order to make a three-dimensional net-like body that exhibits the soil covering holding function, the mold having the above conditions may be a mold having protrusions lower than the protrusions of the protrusion height. In this case, protrusions that are not adhered to the water-impervious sheet are generated, and there is a space between the sheet and the apex of the protrusion, so that the cover soil that has entered the space is surrounded by the sheet and the three-dimensional network and remains against the outflow due to rainwater. However, the protrusion not bonded to the sheet is preferably 50% or less from the viewpoint of the adhesive strength between the sheet and the three-dimensional network. Of course, it is also very preferable that all the protrusions are thermally bonded to the sheet.

  Another example of how to make the water-impervious vegetation base material of the present invention is the same until the production of the single-side composite water-impervious sheet, but in adhering the second three-dimensional network, a pressing roll Instead of this, a method is used in which the semi-molten solid network on the mold is firmly bonded to the sheet by strongly pressing the sheet at the projection portion using a protruding spike roll having a rough interval. At this time, heating of the sheet is more preferable, but non-heating is not impossible. In this method, a part of the three-dimensional network that has been previously bonded is crushed. The crushing ratio is preferably 50% or less. If it exceeds 50%, a problem is likely to occur in the slip-preventing function.

  Another example of a specific method of making the water-impervious vegetation base material of the present invention is a combination in which thermal adhesion is slightly inferior, and a resin that is easily thermally bonded to a three-dimensional network is pre-extruded on one side of the water-impervious sheet in advance. It is made into a two-layer sheet or laminate sheet, or it is applied to one side with a hot melt processing machine, or while semi-molten with an infrared heating machine or the like, and applied along a pressing roll with clearance. The water-proof vegetation base material in which the three-dimensional network is bonded to both surfaces of the present invention is obtained.

  Still another example of the specific method for producing the water-impervious vegetation base material of the present invention is a composite fiber such as a sheath-core composite fiber in which a thick thread of a three-dimensional network is eccentric, and the thermoplastic covering the majority of the fiber surface The resin and the constituent resin of the sheet are made of the same type of thermoplastic resin (similar resin), and a water-impervious vegetation base material with further increased rigidity can be obtained with the resin constituting the inside of the fiber.

  In any of the production methods of the present invention, the single-side composite water-impervious sheet needs to be fed out while adjusting the meander, and the single-side composite water-impervious sheet uses, for example, a nip-type meander adjuster that can easily adjust the meander. In some cases, the thickness is constant, the thinner the thickness, the easier the adjustment, and the three-dimensional network as a state in which the three-dimensional network is not formed at both ends of the water-proof sheet for water-proof and thermal adhesive sealing. It is particularly preferable that the water-shielding sheet is bonded and integrated, and when using a nip-type meandering controller, both ends of the water-shielding sheet to which the three-dimensional network is not bonded are strongly nip-adjusted nip rollers. Conveniently, it is easy to always adjust the tilt while gripping.

  As mentioned above, although the manufacturing method was demonstrated centering on polyolefin resin, it can manufacture similarly also in a polyester-type resin and a polyamide-type resin.

  Next, the water-impervious vegetation base material of the present invention will be described with reference to the drawings. FIG. 1 is an example of a production apparatus that can be used in the method for producing a water-impervious vegetation base material of the present invention. FIG. 2 is an example of a cross-sectional view in which the three-dimensional network of the present invention is shaped on a mold. FIG. 3 is a perspective view showing an example in which a three-dimensional network is disposed on one side of a water-proof sheet. FIG. 4 is a perspective view showing an example of the water-impervious vegetation base material of the present invention in which a three-dimensional network is disposed on both surfaces of the water-impervious sheet. FIG. 5 is an example of a mold used for molding a three-dimensional network.

  FIG. 1 shows a fixed width for receiving a nozzle 2 in which nozzle holes are regularly arranged in 3 to 6 rows connected to a melt extruder, and a thick thread 1 discharged from the nozzle. The divided caterpillar type mold conveyor equipped with the metal mold 4 is arranged at a place including the lower part thereof at a distance of 10 to 50 cm, and above the caterpillar type mold conveyor, This is a three-dimensional network manufacturing facility in which a sheet feeding machine capable of feeding the water-impervious sheet 9 along the pressing roll 6 is disposed most recently, and a winder is disposed below the conveyor.

  First, the single-sided composite water-proof sheet 5 in which the three-dimensional network 3 is thermally bonded to one side of the flexible water-proof sheet 9 shown in FIG. 3 is produced. In general, the three-dimensional network layer (sliding prevention layer) 3b for preventing slipping may be thinner than the three-dimensional network layer (covering layer holding layer) 3a for retaining the soil. The sheet 5 to be produced is a sheet with a slip-preventing layer. Of course, it is unavoidable from the economical aspect that the thinner three-dimensional network body can wind, and the thicker the three-dimensional network body, the more easily the shape of the three-dimensional network body collapses. The reverse is not a problem.

  The rolled up single-sided composite water-impervious sheet 5 is set in a sheet feeding machine to which a meandering regulator 10 is attached so that the surface to which the three-dimensional network is not bonded is on the mold conveyor side. In addition, a treatment is performed to float the sheet on the conveyor by approximately the thickness of the three-dimensional network that adheres the pressing roll 6 to be placed on the mold conveyor along the sheet. Further, in order to heat the surface of the sheet 5 on which the solid network is not bonded, a heating device 11 such as an infrared lamp or an infrared heating plate is installed. Of course, it is also preferable to use the heating device 11 and the meandering adjuster 10 when the single-side composite water-impervious sheet 5 is produced. In the same manner as in the manufacture of the single-side composite water-impervious sheet, a three-dimensional network is adhered to the other side under extremely weak or weak pressing pressure while heating and softening the sheet surface, and a book as shown in FIG. A water-impervious vegetation base material in which a three-dimensional network is bonded to both sides of the invention can be obtained. Naturally, it is more preferable that the latter three-dimensional network is a thick three-dimensional network 3a having a different thickness by exchanging the mold.

  FIG. 4 is a preferred embodiment of a water-impervious vegetation base material in which a solid network is bonded to both surfaces of the present invention. The water-impervious vegetation base material 12 is a water-impervious sheet 9 that is a base material, and a three-dimensional network 3 that is bonded and integrated with the water-impervious sheet 9, and is a three-dimensional network layer that is expected to have a slip-preventing function ( An anti-sliding layer) 3a and a three-dimensional network layer (covering layer) 3b that is expected to have a holding function with a thickness greater than that of the three-dimensional network layer (sliding prevention layer) 3a.

  Next, the effects of the present invention will be specifically described with reference to examples and comparative examples. In addition, it is a water-impervious vegetation base material in which a solid network is bonded to both surfaces of a water-impervious sheet and a solid network using a linear low-density polyethylene resin as a raw material according to an embodiment of the present invention. To do. It goes without saying that water-impervious vegetation base materials of other manufacturing methods and forms can be similarly easily made by referring to the examples.

(Production of a single-sided composite water-proof sheet in which a solid network is thermally bonded to one side of the water-proof sheet)
Using the manufacturing apparatus of FIG. 1, a water-impervious sheet having a three-dimensional network thermally bonded on one side was first prepared. The thermoplastic resins used for these are all linear low density polyethylene resins. The water-proof sheet used was an extruded sheet having a melting point of 124 ° C. and a MI of about 1 g / 10 min melted and extruded with a T-die and having a thickness of 1 mm, 1.5 mm, 3 mm, and 5 mm. It was. Sheets having a thickness of 0.3 and 0.5 mm were obtained by molding the resin used for the three-dimensional network by the inflation method.

  As the thermoplastic resin used for the three-dimensional network, a resin having a melting point of 122 ° C. and MI of about 30 g / 10 min and 20 g / 10 min was used. The molds used were 5 mm, 10 mm and 15 mm solid meshes with a minimum protrusion spacing of 10 mm and 25 mm thick solids with a minimum protrusion spacing of 10 mm and 20 mm. Each type was used.

Using the resin and the sheet, the thread 1 thicker than the nozzle heated to 260 ° C. is discharged and accumulated on the mold, and the fibers are thermally bonded to form the three-dimensional network 3, which is immediately heated by infrared rays. The heated sheet was placed on a mold along a pressing roll while being pressed. At this time, the thick yarn 1 on the mold protrusion was thermally bonded to the sheet while being crushed.
Table 1 shows the results of the obtained single-side composite water-impervious sheet.

  “Excellent” in Table 1 can be used without any problem, “Excellent +” means a particularly excellent quality, “Good” means that it can be used at a practical level, and “Yes” means something that needs to be selected when used. , “×” indicates a problem in use.

  Regarding the quality of a single-sided product, “excellent” indicates an appearance that can be used, and “good” indicates that there is a portion without fiber.

  As for the state of the bonded part, “excellent” has almost no dent in the heat-bonded part, and there is almost no unbonded part in the solid network part that should be bonded to the sheet. “Yes” has a dent, but there is no hole. It is not open and can be used as a water-proof sheet, but the possibility of opening holes is not zero, “×” indicates that a hole in the sheet can be easily found and cannot be used as a water-proof sheet .

  The pressure resistance of a single-sided product was evaluated by whether the sheet was placed on a flat floor surface, and the three-dimensional network did not deform much when stepped on with a dirt foot and returned to its original state when the foot was lifted. . “Excellent” and “Excellent +” hardly deform, and “Good” deforms but returns.

The slip-off prevention property and soil covering retention property were evaluated by placing an ocher-colored mountain soil, forming a 45-degree inclined surface, and placing each 1 m square (1 m ² ) sample thereon.

  The evaluation of the slip-off prevention property was performed based on whether or not a three-dimensional reticulated body surface was touched to the mountain soil, and a person could ride on the rope from the top of the mountain and go to the center of the sample. “Excellent” means that the seat does not slide even if it goes to the center, “Good” means that the seat shifts slightly when starting to walk, but the displacement of the seat stops while going to the center, “Yes” means 20 cm above the seat, etc. If it strikes at intervals, it will be in the same state as good, “X” means that it slides down when the sheet is pulled.

  The soil covering retainability is that the surface of the three-dimensional mesh body is pulled up to the top of the mountain, and the top is anchored and fixed, the 3 cm thick cover is applied from the top, and the embankment slides down in the same manner as the sheet to which the three-dimensional network body is not bonded. The thing was made into x. “Excellent” can cover 3 cm, and “Good” and “OK” can easily cover 2 cm and 1 cm respectively.

  When bonding the solid network, the sample 12 does not heat the sheet, but when the sheet is too thin and the melted tanglet touches, a hole is opened in the sheet by heat at the bonded part. Pulling occurred and heating was not possible. In sample 13, the three-dimensional network is too hard, not flexible, and slips on the soil surface when pulled, and the fiber density is too high in the cover soil, so that the soil does not enter the three-dimensional network and the height of the three-dimensional network is high. As a result, the soil that exceeded the limit was easily slid down. Further, the sample 14 was tried to be bonded to a water-impervious sheet having a thickness of 5 mm, but it was hard and the feeding could not be controlled well, and the three-dimensional network was stuck.

(Preparation of composite water-impervious sheet of the present invention in which a three-dimensional network is thermally bonded on both sides)
Using the manufacturing apparatus of FIG. 1 in which an infrared heater was operated, a water-impervious vegetation base material in which a solid network was thermally bonded to both surfaces of the present invention was produced. The single-sided composite water-impervious sheet (samples 1 to 10) in which the three-dimensional network body is thermally bonded to one side that has been wound up by adjusting the meandering in the width direction as little as possible is illustrated so that the sheet faces the infrared heating device 11. 1 was installed in place of the water-impervious sheet 9, and the meandering adjuster 10 was used to further adjust the meandering, and the water-impervious sheet was fed out in the same manner as that of the water-impervious sheet. While checking the degree of softening of the heated sheet surface, the sheet feeding speed is adjusted by adjusting the voltage adjustment of the infrared heating device 11 to adjust the thickness clearance of the three-dimensional network attached. The sheet was fed out in synchronism with the speed of the mold conveyor while being pressed along the pressure roll 6 onto the mold 4 with a slight pressing pressure. The mold is exchanged in advance according to the specifications of the three-dimensional network attached to the other surface, and simultaneously with the feeding of the sheet, the thread 1 thicker than the nozzle 2 is discharged onto the mold 4 conveyor. The forming operation of the three-dimensional network was performed, and the softened three-dimensional network was pressed against the water-impervious sheet softened by heating, and heat-bonded. After solidifying on a mold conveyor, a double-sided composite water-impervious sheet was wound up and heat-bonded with a solid network on both sides.

[Example 1]
The single-sided composite water-impervious sheet of Sample 1 is fed out, and a 15 mm-thick three-dimensional network is attached to the other surface under the same conditions as Sample 1 using the mold used when Sample 1 was prepared. A double-sided composite water-impervious sheet having a 15 mm solid network firmly adhered thereto was obtained. When this was evaluated in the same manner as Sample 1, the slip-off prevention property and the soil covering retention property were evaluated, and the same numerical results were obtained that satisfied both characteristics of the Sample 1 sheet with one sheet. In addition, the pressure resistance is almost the same as that of Sample 1, and a water-impervious vegetation base material that has no problem in practical use and has the ability to prevent slippage of the impervious sheet itself and the ability to prevent the soil from slipping is obtained. I was able to.

[Example 2]
The single-sided composite water-impervious sheet of sample 1 is fed out, and the mold used at the time of preparing sample 3 is used, and a three-dimensional network having a thickness of 25 mm is attached to the other surface under the same conditions as in sample 3. Thus, a double-sided composite water-impervious sheet having a solid network with a surface of 25 mm on the other side was obtained. Evaluation was made in the same manner as in Example 1 using a 15 mm-thick three-dimensional network as a slip-preventing layer and a 25-mm thick three-dimensional network as a covering soil retaining layer. As a result, a water-impervious vegetation base material having better covering properties than Sample 11 was obtained. I was able to.

[Example 3]
In the same manner as in Example 1, using the single-side composite water-impervious sheet of Sample 2, a double-side composite water-impervious sheet in which a solid network having a thickness of 15 mm was attached to both surfaces was obtained. The evaluation results were the same as in Example 1.

[Example 4]
In the same manner as in Example 1, the single-side composite water-impervious sheet of Sample 7 was fed out under the condition that the feeding speed of the single-side composite water-impervious sheet was increased from Example 1 to lower the degree of softening of the water-impervious sheet. A double-sided composite water-impervious sheet that does not open holes and has a three-dimensional network that is not partly thermally bonded but can be practically used can be produced, and the evaluation result of the obtained sheet is the same as in Example 1. It was.

[Example 5]
The single-sided composite water-impervious sheet of sample 6 is fed out, and the mold used at the time of preparing sample 3 is used, and a three-dimensional network having a thickness of 25 mm is attached to the other surface under the same conditions as sample 3, and one side is 10 mm. Thus, a double-sided composite water-impervious sheet having a solid network with a surface of 25 mm on the other side was obtained. Evaluation was conducted in the same manner as in Example 1 using a 10 mm-thick three-dimensional network as a slip-preventing layer and a 25 mm-thick three-dimensional network as a covering soil retaining layer. When covering with soil was better than Example 1, it was possible to obtain a water-impervious vegetation base material having slippage prevention and covering properties equivalent to those of Example 1.

[Example 6]
Instead of the single-side composite water-impervious sheet of Example 5, a double-side composite water-impervious sheet was prepared in the same manner as in Example 5 using the sheet of Sample 5. When the obtained sheet was covered with soil in the same manner as in Example 5, a water-impervious vegetation base material having a soil covering retention property almost equivalent to that in Example 1 and a soil covering retention property could be obtained.

[Example 7]
In the same manner as in Example 1, a double-sided composite water-impervious sheet was prepared using the sheet of Sample 8. The obtained sheet had a tendency to lack the bending resistance at the time of construction, but the evaluation result was the same as in Example 1.

[Comparative Example 1]
Using the single-side composite water-impervious sheet of Sample 11, a three-dimensional network was attached to the other surface under the same conditions as Sample 11 to produce a double-side composite water-impervious sheet. The obtained sheet had the same result as that of the sample 11. The same applies to samples 13.

[Comparative Example 2]
Using the single-sided composite water-impervious sheet of Sample 11, a three-dimensional network was affixed to the other surface under the same conditions as Sample 1 to produce a double-sided composite water-impervious sheet. The obtained sheet had the same result as that of the sample 11 in the three-dimensional network layer of the sample 11, and was not practical as a water-impervious vegetation base material having anti-sliding property and covering property.

  The water-impervious vegetation base material of the present invention is not only useful as a bottom water-impervious material for industrial waste disposal sites and a capping material for eliminating rainwater infiltration, but is also extremely useful as a water-impervious material for acid waste soil disposal sites. It is useful, and it is also useful as a restoration work material for preventing rainwater penetration and preventing landslides.

It is an example of the manufacturing apparatus in the water-proof vegetation base material of this invention. It is an example of sectional drawing with which the solid network object of the present invention is formed on a metallic mold. It is a perspective view which shows an example of the sheet | seat (single-side compound water-impervious sheet) by which the three-dimensional network body was arrange | positioned on the single side | surface of the water-impervious sheet. It is a perspective view which shows an example of the water-impervious vegetation base material of this invention. It is an example of the metal mold | die used for shaping | molding of a solid network body.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Thread 2 Nozzle 3 Three-dimensional network 3a Three-dimensional network body for covering covering (covering retaining layer)
3b Three-dimensional network for preventing slipping (sliding preventing layer)
4 Mold 5 Single-sided composite water-impervious sheet 6 Pressing roll 7 Guide roll 8 Pickup roll 9 Water-impervious sheet 10 Meander adjuster 11 Heating device 12 Water-impervious vegetation base material

Claims (8)

A water-impervious sheet,
A plurality of continuous yarns having a diameter of 0.1 to 2 mm made of a thermoplastic resin are irregularly overlapped on both surfaces of the water-impervious sheet and are continuous in the length direction. The parallel light transmittance is 50 to 90. Permeable vegetation base material made by stacking, joining, and unifying 3% solid network.   The water-impervious vegetation base material according to claim 1, wherein one three-dimensional network body forms a slip-preventing layer and the other three-dimensional network body forms a cover soil retaining layer.   The water-impervious vegetation base material according to claim 2, wherein the covering soil retaining layer has a thickness of 5 to 25 mm, and the anti-sliding layer has a thickness of 5 to 25 mm.   2. The water-impervious property according to claim 1, wherein both the three-dimensional network and the thermoplastic resin constituting the water-impervious sheet are resins containing at least 70 mass% of a similar resin, and the melting point of the similar resin is 100 to 150 ° C. 3. Vegetation base material.   The water-impervious vegetation base material according to claim 4, wherein the similar resin is at least one resin selected from a low-density polyethylene resin, a propylene-based copolymer resin, and an ethylene-vinyl acetate copolymer resin.   Resin which the said thermoplastic resin contains 100-70 mass% of linear low density polyethylene resin which makes melting | fusing point 110-140 degreeC as a similar resin, and contains in the range of 0-30 mass% of low density polyethylene resin or propylene-type copolymer resin The water-impervious vegetation base material according to claim 4, wherein   The thermoplastic resin constituting the three-dimensional network is a linear low density polyethylene resin having a melting point of 110 to 140 ° C., and the thermoplastic resin constituting the water shielding sheet has a melting point of 130 to 150 ° C., And the water-proof vegetation base material of Claim 1 which is a propylene-type copolymer resin more than melting | fusing point of the said linear low density polyethylene.   The thermoplastic resin constituting the three-dimensional network and the water-impervious sheet is a resin containing at least 70 mass% of a similar resin, and the similar resin has a melting point of 130 to 180 ° C., a polyester-based thermoplastic elastomer resin or a polyamide-based heat The water-impervious vegetation base material according to claim 1, which is a plastic elastomer resin.

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