JP2004113101A - Weedproofing sheet - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a weedproofing sheet high in mechanical strength and durability, low in light transmittance, therefore high in herbicidal effect, and environmentally friendly and also emitting no noise due to raindrops' splash. <P>SOLUTION: The weedproofing sheet is obtained by applying a thermoplastic synthetic resin onto a ground fabric 3 which is formed by crossing drawn yarns 2a and 2b of thermoplastic synthetic resin longitudinally and transversely followed by laminating a nonwoven fabric 4 50-300 g/m<SP>2</SP>in basis weight thereon so as to join the ground fabric 3 and the nonwoven fabric 4 each other via the thermoplastic synthetic resin. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a grass sheet, and more particularly, to a grass sheet which is excellent in strength and durability, has a high grass weeding effect, does not impair the environment, and has little noise generated due to splashing of raindrops and the like.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, on a bank of a river, a levee of a field, or a slope of an embankment such as a railroad or a road, there is a great deal of erosion of sediment, and prevention of the slope has been an important issue. In addition, if weeds grow on slopes or the like, there is a possibility that pests may occur on plants, so frequent cutting or weed prevention measures are required. However, cutting grass requires a great deal of effort, and the application of herbicides is not preferable from the viewpoint of environmental destruction.
[0003]
As a method for solving such a problem, it has been proposed to lay a nonwoven fabric made of synthetic long fibers (Patent Document 1).
[0004]
However, various performances are required for a weed control sheet for laying such a sheet to prevent the growth of weeds. For example, in order to walk on it, mechanical strength is required, and it is necessary to have excellent corrosion resistance and good durability. Further, in order to prevent weeds, it is required that the light transmittance is low, and it is also necessary that reflection of sunlight does not adversely affect the environment.
[0005]
Furthermore, in order to provide a light-shielding property, when a sheet woven with drawn yarn densely, or a grass-proof sheet in which a sheet made of a thermoplastic synthetic resin is laid, the grass-proof sheet is hit by water such as rain. There is also the problem of popping and noise. For this reason, it is also important to prevent noise caused by the splash of water droplets.
[0006]
To the inventor's knowledge, conventional weed control sheets have been insufficient to satisfy all of these requirements.
[0007]
[Patent Document 1] Japanese Patent Publication No. 4-52727
[Problems to be solved by the invention]
The present invention provides a herbicidal sheet which is excellent in mechanical strength and durability, has a low light transmittance, and thus has an excellent weed control effect, is environmentally friendly, and does not generate noise caused by splashing of raindrops. Is what you do.
[0009]
[Means for Solving the Problems]
The present invention has been made as a result of intensive studies to achieve such an object.Specifically, a thermoplastic synthetic resin drawn yarn is formed on a base cloth formed by crossing the fibers vertically and horizontally to form a thermoplastic synthetic resin. The present invention provides a herbicidal sheet comprising a resin, a nonwoven fabric having a basis weight of 50 to 300 g / m ² , and a base fabric and a nonwoven fabric joined via a joining thermoplastic synthetic resin. is there.
[0010]
Further, the present invention provides the above-mentioned grass-proof sheet wherein a thermoplastic synthetic resin flat yarn is used for at least a part of the drawn yarn, and a thermoplastic resin in which at least a part of the drawn yarn is formed with a large number of small cuts in a longitudinal direction. The above-mentioned weed-proof sheet comprising a synthetic resin split yarn, the above-mentioned weed-proof sheet wherein a base fabric and a nonwoven fabric are partially bonded so as to form a gap therebetween, and one of the base fabric and the nonwoven fabric Alternatively, the present invention provides the above herbicidal sheet, in which both are colored.
[0011]
Furthermore, the present invention provides the above-mentioned grass-proof sheet in which a thermoplastic resin sheet is laminated on at least one surface of a base cloth, and the above-mentioned fraying prevention in which longitudinal and horizontal stretched yarns of the base cloth are thermally fused to each other. Weed prevention sheet, the above-mentioned weed prevention sheet in which uniaxially drawn yarns of different colors are woven at predetermined intervals in a nonwoven fabric, and the above-mentioned in which line marks are printed at predetermined intervals on the surface of the weed prevention sheet. The present invention provides a weed control sheet.
[0012]
BEST MODE FOR CARRYING OUT THE INVENTION
As shown in FIG. 1, the grass sheet 1 of the present invention comprises a nonwoven fabric formed of a thermoplastic synthetic resin on a base cloth 3 formed of a drawn yarn 2 formed by uniaxially stretching a thermoplastic synthetic resin. 4 are superimposed and joined.
[0013]
As the drawn yarn 2 forming the base fabric 3, a thermoplastic synthetic resin having an excellent drawing effect is used. Generally, high-density polyethylene, linear low-density polyethylene, ethylene-propylene copolymer, polypropylene, polyester, polyamide , An acrylonitrile resin or the like is used alone or in an appropriate combination.
[0014]
In the present invention, the drawn yarn 2 constituting the base fabric 3 includes a filament such as a multifilament, a tape-like material, a string-like material, a belt-like material, a monofilament, a spun yarn, and these are twisted. It may be one having no twist or one having no twist.
[0015]
The structure of the drawn yarn 2 may be any, but is preferably in the form of a tape. For example, as shown in FIG. 3A, a thermoplastic synthetic resin film is slit into a predetermined width and uniaxially drawn. Alternatively, as shown in FIG. 3B, a split yarn in which a large number of cuts 5, 5 are formed in a uniaxially stretched tape-like body can be used. Further, as shown in FIG. 3 (C), the tape-shaped body may be provided with an extremely fine vertical rib 6.
[0016]
In addition, a round shape, an oval shape, a square shape, a polygonal shape, and other irregular shapes can be formed.Furthermore, a mixture of different types of resins is extruded into a filament, and a fibril-formed Dunline is formed by dividing the resins. It is also possible to give flexibility by using. Further, one drawn yarn 2 can be used alone, or several drawn yarns can be bundled and used.
[0017]
The drawn yarn 2 may be a single layer of the base layer 7 as shown in FIG. 4 (A), or one side or both sides of the base layer 7 as shown in FIGS. 4 (B) and 4 (C). The surface layer 8 can be formed on the surface, and the surface layer 8 can function as a bonding layer. Further, the surface layer 8 may have a sea core structure as shown in FIG. 4D and a side-by-side structure as shown in FIG. 4E.
[0018]
When the surface layer 8 is provided on the drawn yarn 2, after the drawn yarn 2 is formed into a cloth, the drawn yarn 2 can function as a layer for joining the drawn yarns 2 together. Examples of the thermoplastic synthetic resin used as the surface layer 8 functioning as a bonding layer include polyolefins such as low-density polyethylene, high-density polyethylene, linear low-density polypropylene, ethylene-propylene copolymer, ethylene-vinyl acetate copolymer, Examples thereof include polyesters such as polyethylene terephthalate and polybutylene terephthalate, polyamides such as nylon 6 and nylon 66, and a thermoplastic synthetic resin having a lower melting point than the base layer 7 is selected in relation to the thermoplastic synthetic resin of the base layer 7.
[0019]
Furthermore, an inorganic filler can be added to the drawn yarn 2, and by adding the inorganic filler, the light-shielding property can be enhanced, and the weed control effect can be enhanced. As the inorganic filler, talc, carbon black, graphite, titanium dioxide, silica, mica, calcium carbonate, calcium sulfate, barium carbonate, magnesium carbonate, magnesium sulfate, barium sulfate, alumina, kaolin, silicon carbide, metal powder, and the like are used. be able to. The inorganic filler may be added to the entire drawn yarn 2 or may be added only to the surface layer 8 forming the surface.
[0020]
Further, various additives can be added to the thermoplastic synthetic resin forming the base layer 7 or the surface layer 8 used as the drawn yarn 2 according to the purpose.
[0021]
Specifically, phenol-based, organic phosphite-based organic phosphorus-based, thioether-based antioxidants; hindered amine-based light stabilizers; benzophenone-based, benzotriazole-based, benzoate-based ultraviolet absorbers, etc .; Antioxidants such as amide, wax, and organic metal salts; lubricants such as amide, wax, organic metal salts, and esters; organic compounds containing bromine; Flame retardants such as phosphoric acid, antimony trioxide, magnesium hydroxide, red phosphorus and the like can be mentioned.
[0022]
These additives are appropriately combined and blended in any step of producing the material composition of the base layer 7 or the surface layer 8. The compounding of the additives may be prepared by mixing at a predetermined ratio using a kneading device such as a conventionally known twin-screw extruder, a Banbury mixer, a kneader, a mixing roll, and melt-kneading the mixture. A high-concentration so-called masterbatch may be prepared and used after dilution.
[0023]
When a laminate is used as the drawn yarn 2, as a means for molding a laminated flat yarn, or a laminated film to be a molding material of the laminated split yarn, a method known per se can be employed, and the base layer 7 and the Means for forming a film to be used as a surface layer 8 and a film to be used as a surface layer 8 to form a multilayer by using a dry laminating method or a heat laminating method. The method may be appropriately selected from known methods such as a method of extruding and laminating the surface layer 8 on a film to be a base layer 7 formed in advance, or a method of extrusion molding as a laminated film by a multilayer coextrusion method. In terms of easiness and cost, as well as the adhesiveness between the layers of the product, the laminate of the base layer 7 and the surface layer 8 can be integrated by multilayer coextrusion. The method of obtaining at desirable. A co-extrusion method is generally used for the sea core structure or the side-by-side structure.
[0024]
As means for stretching, after stretching the film to be the base layer 7 in a uniaxial direction, a thermoplastic synthetic resin to be the surface layer 8 may be laminated and slit into a tape shape. It can also be obtained by stretching in a uniaxial direction before or after slitting the laminated film on which the surface layer 8 is laminated.
[0025]
As the stretching operation, for example, using a hot-air circulation oven, a hot roll, a hot plate, or the like, in one stage or in two or more stages, stretch in the take-off direction by 2.5 to 12.0 times, and Relaxation heat treatment of 0 to 30% is performed at a temperature of 60 to 160 ° C using a circulation oven, a hot roll, a hot plate, or the like. The stretching ratio is usually about 3 to 10 times.
[0026]
The thickness of the drawn yarn 2 is not particularly limited and can be arbitrarily set according to the purpose. In general, the drawn yarn 2 has a thickness of 500 to 10,000 decitex, preferably 1,000 to 5,000 decitex. In this case, the yarn width is in the range of 0.3 to 200 mm, preferably 1.0 to 100 mm, and the yarn thickness is 5 to 500 μm.
[0027]
As shown in FIG. 1, the drawn yarn 2 can be woven and used as a woven fabric. As shown in FIG. 2, the drawn yarn 2a is arranged in one direction, and the drawn yarn 2a is drawn in a direction intersecting the drawn yarn 2a. 2b can be used as a cross-bonding cloth (soft) by arranging the intersections in parallel. Further, it is also possible to make the drawn yarn 2 intersect with the length, width, and slug and join the intersection.
[0028]
The base fabric 3 is desirably light-shielding to obtain a herbicidal effect. As a method for imparting light-shielding properties to the base cloth 3, a light-reflective powder such as aluminum powder or a light-absorbing powder such as carbon black or pigment is added to the drawn yarn 2 constituting the base cloth 3. Can do it.
[0029]
Further, in the present invention, it is desirable that the stretched yarn 2 is formed in a dense state in the base fabric 3 in order to obtain mechanical strength and light shielding properties. The state in which the drawn yarns 2 are dense means a state in which the drawn yarns 2 constituting the warp and the weft have no gaps therebetween, or a state in which the drawn yarns 2 are formed into a cloth in a very small state.
[0030]
In the grass sheet 1 of the present invention, the nonwoven fabric 4 is superimposed on the base fabric 3 and joined by the joining thermoplastic resin 11.
[0031]
As the nonwoven fabric 4, a thermoplastic synthetic resin is used, and specifically, low-density polyethylene, high-density polyethylene, linear low-density polypropylene, polyolefin such as ethylene-propylene copolymer, polyethylene terephthalate, polybutylene terephthalate, and the like. Polyester such as polyester, nylon 6, and nylon 66, and acrylonitrile resin can be used.
[0032]
It is possible to add an inorganic filler to these thermoplastic resins, and by adding the inorganic filler, it is possible to enhance the light-shielding property and enhance the herbicidal effect. As the inorganic filler, talc, carbon black, graphite, titanium dioxide, silica, mica, calcium carbonate, calcium sulfate, barium carbonate, magnesium carbonate, magnesium sulfate, barium sulfate, alumina, kaolin, silicon carbide, metal powder, and the like are used. be able to.
[0033]
Furthermore, various additives can be added to the thermoplastic synthetic resin constituting the nonwoven fabric 4 according to the purpose.
[0034]
Specifically, phenol-based, organic phosphite-based organic phosphorus-based, thioether-based antioxidants; hindered amine-based light stabilizers; benzophenone-based, benzotriazole-based, benzoate-based ultraviolet absorbers; Antioxidants such as amide, wax, and organic metal salts; lubricants such as amide, wax, organic metal salts, and esters; organic compounds containing bromine; Flame retardants such as phosphoric acid type, antimony trioxide, magnesium hydroxide, and red phosphorus, pigments, and the like.
[0035]
The non-woven fabric 4 is formed as a non-woven fabric by stacking thermoplastic resins as ultrafine fibers. As a means for forming the nonwoven fabric, a needle punch method, a spun bond method, a melt blow method, a tow opening method, a burst fiber method, or the like can be employed.
[0036]
Nonwoven 4 having a basis weight, 50 to 300 g / ^{m 2,} and preferably from 100 to 200 g / ^{m 2.} If the basis weight is less than 50 g / m ² , the mechanical strength is insufficient, and the sound-absorbing effect of raindrops is low. If the basis weight is more than 300 g / m ² , cost effectiveness is low and the weight is heavy and the handling is difficult.
[0037]
As a method of bonding the base fabric 3 and the nonwoven fabric 4, the base fabric 3 and the nonwoven fabric 4 can be bonded using a bonding thermoplastic resin 11 such as low-density polyethylene or ethylene / vinyl acetate copolymer. At this time, the base fabric 3 and the nonwoven fabric 4 may be joined on the entire surface of the base fabric 3 and the nonwoven fabric 4 as shown in FIG. 2, but as shown in FIG. Is desirably formed so as to form a gap between the base fabric 3 and the nonwoven fabric 4. By forming the gap, it is possible to increase the noise reduction effect of raindrops.
[0038]
When joining the base fabric 3 and the nonwoven fabric 4 so as to have a gap, the joining thermoplastic resin 11 is set to have a height of 0.5 to 10 mm, preferably 2 to 6 mm.
[0039]
It is desirable that the nonwoven fabric 4 be colored by adding a pigment. Although the coloring color does not limit the present invention, it is preferable to have a calm color so as not to impair the environment, and it is desirable to use black, green, brown or the like.
[0040]
As shown in FIGS. 1 and 2, a thermoplastic resin sheet 10 can be laminated on one or both sides of the base fabric 3, and preferably on the lower surface. Since it is possible to prevent infiltration of rainwater or the like on the laying surface of the sheet 1 and block the laying surface, the weeding effect can be improved. In addition, by coloring the thermoplastic resin sheet 10, the light-shielding property can be improved. As the thermoplastic resin sheet 10, a thermoplastic resin, preferably a polyolefin, as described above for the surface layer 8 of the drawn yarn 2 can be used. Powder or a powder to which a light absorbing powder is added can be used.
[0041]
As the sheet 10 made of a thermoplastic resin, a film or a nonwoven fabric can be used.
[0042]
In addition, other compounds can be added to the thermoplastic resin constituting the thermoplastic resin sheet 10 according to the purpose, and an antioxidant, a light stabilizer, an ultraviolet absorber, a plasticizer, an antistatic agent can be added. Dispersants, chlorine supplements, lubricants, flame retardants, pigments and the like can also be added.
[0043]
In the present invention, it is desirable that the weed prevention sheet 1 is a sheet having a light transmittance of less than 10% and a mass of 70 to 700 g / m ² . When the light transmittance is 10% or more, it is difficult to obtain a herbicidal effect, and when the mass is less than 50 g / m ^2, it is difficult to secure light-shielding properties, and when the mass exceeds 700 g / m ² , economic efficiency is deteriorated.
[0044]
In order to prevent the fraying sheet 1 from fraying at the end, it is preferable to heat-weld the end by heat cutting using a hot blade, and it is also desirable to prevent fraying by tuck-in. It is.
[0045]
Furthermore, it is possible to prevent fraying by applying a molten thermoplastic resin or a hot-melt agent to the base fabric, or by applying an aqueous adhesive, and the application and application for preventing fraying are usually performed at a predetermined interval. Is performed linearly. When a laminate is used as the drawn yarn 2, fraying can be prevented by heat welding.
[0046]
In addition, as shown in FIG. 5, it is preferable that thread 12 of a different color is sewn into the grass sheet 1 at a predetermined interval. By sewing the thread 12 of a different color, positioning becomes easy when laying a sheet or engaging with a pin or a pile. The positioning mark can also be provided by printing a line mark on the surface using a printing ink.
[0047]
The weed control sheet 1 of the present invention can perform a weed control function by laying on a ridge of a field, a bank of a river, a slope of a railway line embankment, a slope of a road embankment, a road median strip, a lower part of a steel tower, or the like. .
[0048]
As shown in FIG. 6, the herbicidal sheet 1 of the present invention can be fixed by laying it at a place where the weeding treatment is to be performed, with a margin, and engaging with a pile 14 or the like. As the pile 14, a nail or a U-shaped body such as a metal or a thermoplastic synthetic resin can be used.
[0049]
In addition, the herbicidal sheet 1 of the present invention is generally laid on the surface of a place where weeding treatment is to be performed. However, it can be laid as an underlay material on a laying place such as chestnut stone.
[0050]
【The invention's effect】
According to the present invention having such a configuration, a herbicidal sheet having high mechanical strength, excellent durability, excellent light-shielding properties, excellent herbicidal properties, and free of noise due to splashing of rain drops can be obtained.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view showing the weed-proof sheet of the present invention. FIG. 2 is a longitudinal sectional view showing another example of the weed-proof sheet of the present invention. FIG. FIG. 4 is a longitudinal sectional view showing an example of a drawn yarn used in the herbicidal sheet of the present invention. FIG. 5 is a perspective view showing an example of a herbicidal sheet of the present invention. FIG. Perspective view showing an example of laying
1: Weed prevention sheet 2: Stretched yarn 3: Base cloth 4: Non-woven fabric 5: Cut 6: Rib 7: Base layer 8: Surface layer 10: Thermoplastic resin sheet 11: Hot melt agent 12: Yarn 14 of different colors 14: Pile

Claims (9)

A nonwoven fabric made of a thermoplastic synthetic resin and having a basis weight of 50 to 300 g / m ² is overlaid on a base fabric formed by intersecting drawn yarns made of a thermoplastic synthetic resin in a matrix, and the base fabric and the nonwoven fabric are joined. A herbicidal sheet characterized by being bonded via a thermoplastic synthetic resin. The grass sheet according to claim 1, wherein a flat yarn made of a thermoplastic synthetic resin is used for at least a part of the drawn yarn. The weed prevention sheet according to claim 1, wherein a split yarn made of a thermoplastic synthetic resin having a large number of small cuts formed in a longitudinal direction is used in at least a part of the drawn yarn. The grass sheet according to any one of claims 1 to 3, wherein the base fabric and the nonwoven fabric are partially bonded so as to form a gap therebetween. The grass sheet according to any one of claims 1 to 4, wherein one or both of the base fabric and the nonwoven fabric are colored. The grass sheet according to any one of claims 1 to 5, wherein a sheet made of a thermoplastic resin is laminated on at least one surface of the base fabric. The grass sheet according to any one of claims 1 to 6, wherein the vertical and horizontal drawn yarns of the base fabric are prevented from fraying by heat fusion. The grass sheet according to any one of claims 1 to 7, wherein uniaxially drawn yarns having different colors are sewn at predetermined intervals in the nonwoven fabric. The grass sheet according to any one of claims 1 to 7, wherein line marks are printed on the grass sheet surface at predetermined intervals.

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